Publications

@article{pmid34241569,

title = {A functional genomic approach to identify reference genes for human pancreatic beta cell real-time quantitative RT-PCR analysis},

author = {Maria Inês Alvelos and Florian Szymczak and Ângela Castela and Sandra Marín-Cañas and Bianca Marmontel de Souza and Ioannis Gkantounas and Maikel Colli and Federica Fantuzzi and Cristina Cosentino and Mariana Igoillo-Esteve and Lorella Marselli and Piero Marchetti and Miriam Cnop and Décio L Eizirik},

doi = {10.1080/19382014.2021.1948282},

issn = {1938-2022},

year  = {2021},

date = {2021-07-01},

journal = {Islets},

volume = {13},

number = {3-4},

pages = {51--65},

abstract = {Exposure of human pancreatic beta cells to pro-inflammatory cytokines or metabolic stressors is used to model events related to type 1 and type 2 diabetes, respectively. Quantitative real-time PCR is commonly used to quantify changes in gene expression. The selection of the most adequate reference gene(s) for gene expression normalization is an important pre-requisite to obtain accurate and reliable results. There are no universally applicable reference genes, and the human beta cell expression of commonly used reference genes can be altered by different stressors. Here we aimed to identify the most stably expressed genes in human beta cells to normalize quantitative real-time PCR gene expression.We used comprehensive RNA-sequencing data from the human pancreatic beta cell line EndoC-βH1, human islets exposed to cytokines or the free fatty acid palmitate in order to identify the most stably expressed genes. Genes were filtered based on their level of significance (adjusted -value >0.05), fold-change (|fold-change| <1.5) and a coefficient of variation <10%. Candidate reference genes were validated by quantitative real-time PCR in independent samples.We identified a total of 264 genes stably expressed in EndoC-βH1 cells and human islets following cytokines - or palmitate-induced stress, displaying a low coefficient of variation. Validation by quantitative real-time PCR of the top five genes  and  corroborated their expression stability under most of the tested conditions. Further validation in independent samples indicated that the geometric mean of  and  expression can be used as a reliable normalizing factor in human beta cells.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid33079780,

title = {Protein misfolding in combination with other risk factors in CEL-HYB1-mediated chronic pancreatitis},

author = {Erling Tjora and Anny Gravdal and Trond Engjom and Miriam Cnop and Bente B Johansson and Georg G Dimcevski and Anders Molven and Karianne Fjeld},

doi = {10.1097/MEG.0000000000001963},

issn = {1473-5687},

year  = {2021},

date = {2021-06-01},

journal = {Eur J Gastroenterol Hepatol},

volume = {33},

number = {6},

pages = {839--843},

abstract = {OBJECTIVES: The hybrid allele of the carboxyl ester lipase gene (CEL-HYB1) is a genetic risk factor for chronic pancreatitis (CP) although the mechanism promoting disease development is largely unknown. Here, we aimed to clinically describe subjects carrying the CEL-HYB1 allele and to elucidate why the protein product is pathogenic by analyzing pancreatic secretions and cellular models.



METHODS: Norwegian cases (n = 154) diagnosed with recurrent acute pancreatitis or CP were subjected to genetic screening by a CEL-HYB1-specific PCR assay followed by Sanger sequencing. For investigation of CEL-HYB1 protein secretion, duodenal juice samples from cases and controls were analyzed by western blotting. HEK293cells were transfected with constructs expressing CEL-HYB1 or the normal CEL protein (CEL-WT) and analyzed by qPCR, cell fractionation and western blotting.



RESULTS: Two CEL-HYB1-positive families were identified. In both pedigrees, CEL-HYB1 did not fully co-segregate with disease. One proband had recurrent acute pancreatitis and was an active smoker. Her mother was a CEL-HYB1 carrier who had suffered from several attacks of acute pancreatitis until she stopped smoking. The other proband was diagnosed with CP and pancreas divisum. Her CEL-HYB1-positive parent was symptom-free but exhibited pancreatic imaging changes. When analyzing the CEL protein in duodenal juice, CEL-WT was readily detectable but no band corresponding to the risk variant was seen. In CEL-HYB1-transfected cells, we observed impaired protein secretion, protein aggregation and endoplasmic reticulum stress.



CONCLUSION: Our data suggest that CEL-HYB1, in combination with well-known pancreatitis risk factors, causes disease through the misfolding-dependent pathway of genetic CP risk.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid33515740,

title = {Prebiotic effect on mood in obese patients is determined by the initial gut microbiota composition: A randomized, controlled trial},

author = {Quentin Leyrolle and Renata Cserjesi and Maria D G H Mulders and Giorgia Zamariola and Sophie Hiel and Marco A Gianfrancesco and Daphné Portheault and Camille Amadieu and Laure B Bindels and Sophie Leclercq and Julie Rodriguez and Audrey M Neyrinck and Patrice D Cani and Nicolas Lanthier and Pierre Trefois and Jérome Bindelle and Nicolas Paquot and Miriam Cnop and Jean-Paul Thissen and Olivier Klein and Olivier Luminet and Nathalie M Delzenne},

doi = {10.1016/j.bbi.2021.01.014},

issn = {1090-2139},

year  = {2021},

date = {2021-05-01},

journal = {Brain Behav Immun},

volume = {94},

pages = {289--298},

abstract = {BACKGROUND AND AIMS: Metabolic and behavioural diseases, which are often related to obesity, have been associated to alterations of the gut microbiota considered as an interesting therapeutic target. We have analyzed in a cohort of obese patients treated with prebiotic inulin versus placebo the potential link between gut microbiota changes occurring upon intervention and their effect on psychological parameters (mood and cognition).



METHODS: A randomized, single-blinded, multicentric, placebo-controlled trial was conducted in 106 obese patients assigned to two groups: prebiotic versus placebo, who received respectively 16 g/d of native inulin or maltodextrin combined with dietary advice to consume inulin-rich or -poor vegetables for 3 months as well as to restrict caloric intake. Anthropometric measurements, food intake, psychological questionnaires, serum measures, and fecal microbiome sequencing were performed before and after the intervention.



RESULTS: Inulin supplementation in obese subjects had moderate beneficial effect on emotional competence and cognitive flexibility. However, an exploratory analysis revealed that some patients exhibiting specific microbial signature -elevated Coprococcus levels at baseline- were more prone to benefit from prebiotic supplementation in terms of mood. Positive responders toward inulin intervention in term of mood also displayed worse metabolic and inflammatory profiles at baseline (increased levels of IL-8, insulin resistance and adiposity).



CONCLUSION: This study shows that inulin intake can be helpful to improve mood in obese subjects exhibiting a specific microbial profile. The present work highlights some microbial, metabolic and inflammatory features (IL-8, insulin resistance) which can predict or mediate the beneficial effects of inulin on behaviour in obesity. Food4gut, clinicaltrial.gov: NCT03852069, https://clinicaltrials.gov/ct2/show/NCT03852069.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid33023763,

title = {Specific gut microbial, biological, and psychiatric profiling related to binge eating disorders: A cross-sectional study in obese patients},

author = {Quentin Leyrolle and Renata Cserjesi and Maria D G H Mulders and Giorgia Zamariola and Sophie Hiel and Marco A Gianfrancesco and Julie Rodriguez and Daphnée Portheault and Camille Amadieu and Sophie Leclercq and Laure B Bindels and Audrey M Neyrinck and Patrice D Cani and Olli Karkkainen and Kati Hanhineva and Nicolas Lanthier and Pierre Trefois and Nicolas Paquot and Miriam Cnop and Jean-Paul Thissen and Olivier Klein and Olivier Luminet and Nathalie M Delzenne},

doi = {10.1016/j.clnu.2020.09.025},

issn = {1532-1983},

year  = {2021},

date = {2021-04-01},

journal = {Clin Nutr},

volume = {40},

number = {4},

pages = {2035--2044},

abstract = {BACKGROUND & AIMS: Binge eating disorder (BED) is a frequent eating disorder associated with obesity and co-morbidities including psychiatric pathologies, which represent a big health burden on the society. The biological processes related to BED remain unknown. Based on psychological testing, anthropometry, clinical biology, gut microbiota analysis and metabolomic assessment, we aimed to examine the complex biological and psychiatric profile of obese patients with and without BED.



METHODS: Psychological and biological characteristics (anthropometry, plasma biology, gut microbiota, blood pressure) of 101 obese subjects from the Food4Gut cohort were analysed to decipher the differences between BED and Non BED patients, classified based on the Questionnaire for Eating Disorder Diagnosis (Q-EDD). Microbial 16S rDNA sequencing and plasma non-targeted metabolomics (liquid chromatography-mass spectrometry) were performed in a subcohort of 91 and 39 patients respectively.



RESULTS: BED subjects exhibited an impaired affect balance, deficits in inhibition and self-regulation together with marked alterations of eating behaviour (increased emotional and external eating). BED subjects displayed a lower blood pressure and hip circumference. A decrease in Akkermansia and Intestimonas as well as an increase in Bifidobacterium and Anaerostipes characterized BED subjects. Interestingly, metabolomics analysis revealed that BED subjects displayed a higher level of one food contaminants, Bisphenol A bis(2,3-dihydroxypropyl) ether (BADGE.2H(2)O) and a food derived-metabolite the Isovalerylcarnitine.



CONCLUSIONS: Non-targeted omics approaches allow to select specific microbial genera and two plasma metabolites that characterize BED obese patients. Further studies are needed to confirm their potential role as drivers or biomarkers of binge eating disorder. Food4gut, clinicaltrial.gov:NCT03852069, https://clinicaltrials.gov/ct2/show/NCT03852069.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid33486469,

title = {DNAJC3 deficiency induces β-cell mitochondrial apoptosis and causes syndromic young-onset diabetes},

author = {Maria Lytrivi and Valérie Senée and Paraskevi Salpea and Federica Fantuzzi and Anne Philippi and Baroj Abdulkarim and Toshiaki Sawatani and Sandra Marín-Cañas and Nathalie Pachera and Anne Degavre and Pratibha Singh and Céline Derbois and Doris Lechner and Laurence Ladrière and Mariana Igoillo-Esteve and Cristina Cosentino and Lorella Marselli and Jean-François Deleuze and Piero Marchetti and Décio L Eizirik and Marc Nicolino and Annabelle Chaussenot and Cécile Julier and Miriam Cnop},

doi = {10.1530/EJE-20-0636},

issn = {1479-683X},

year  = {2021},

date = {2021-03-01},

journal = {Eur J Endocrinol},

volume = {184},

number = {3},

pages = {455--468},

abstract = {OBJECTIVE: DNAJC3, also known as P58IPK, is an Hsp40 family member that interacts with and inhibits PKR-like ER-localized eIF2α kinase (PERK). Dnajc3 deficiency in mice causes pancreatic β-cell loss and diabetes. Loss-of-function mutations in DNAJC3 cause early-onset diabetes and multisystemic neurodegeneration. The aim of our study was to investigate the genetic cause of early-onset syndromic diabetes in two unrelated patients, and elucidate the mechanisms of β-cell failure in this syndrome.



METHODS: Whole exome sequencing was performed and identified variants were confirmed by Sanger sequencing. DNAJC3 was silenced by RNAi in INS-1E cells, primary rat β-cells, human islets, and induced pluripotent stem cell-derived β-cells. β-cell function and apoptosis were assessed, and potential mediators of apoptosis examined.



RESULTS: The two patients presented with juvenile-onset diabetes, short stature, hypothyroidism, neurodegeneration, facial dysmorphism, hypoacusis, microcephaly and skeletal bone deformities. They were heterozygous compound and homozygous for novel loss-of-function mutations in DNAJC3. DNAJC3 silencing did not impair insulin content or secretion. Instead, the knockdown induced rat and human β-cell apoptosis and further sensitized cells to endoplasmic reticulum stress, triggering mitochondrial apoptosis via the pro-apoptototic Bcl-2 proteins BIM and PUMA.



CONCLUSIONS: This report confirms previously described features and expands the clinical spectrum of syndromic DNAJC3 diabetes, one of the five monogenic forms of diabetes pertaining to the PERK pathway of the endoplasmic reticulum stress response. DNAJC3 deficiency may lead to β-cell loss through BIM- and PUMA-dependent activation of the mitochondrial pathway of apoptosis.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid33669901,

title = {Pro-Inflammatory Cytokines Induce Insulin and Glucagon Double Positive Human Islet Cells That Are Resistant to Apoptosis},

author = {Marta Tesi and Marco Bugliani and Gianmarco Ferri and Mara Suleiman and Carmela De Luca and Emanuele Bosi and Matilde Masini and Vincenzo De Tata and Conny Gysemans and Francesco Cardarelli and Miriam Cnop and Decio L Eizirik and Piero Marchetti and Lorella Marselli},

doi = {10.3390/biom11020320},

issn = {2218-273X},

year  = {2021},

date = {2021-02-01},

journal = {Biomolecules},

volume = {11},

number = {2},

abstract = {The presence of islet cells double positive for insulin and glucagon (Ins/Glu) has been described in the pancreas from both type 2 (T2D) and type 1 (T1D) diabetic subjects. We studied the role of pro-inflammatory cytokines on the occurrence, trajectory, and characteristics of Ins/Glu cells in human pancreatic islets. Pancreas samples, isolated islets, and dispersed islet cells from 3 T1D and 11 non-diabetic (ND) multi-organ donors were studied by immunofluorescence, confocal microscopy, and/or electron microscopy. ND islet cells were exposed to interleukin-1β and interferon-γ for up to 120 h. In T1D islets, we confirmed an increased prevalence of Ins/Glu cells. Cytokine-exposed islets showed a progressive increase of Ins/Glu cells that represented around 50% of endocrine cells after 120h. Concomitantly, cells expressing insulin granules only decreased significantly over time, whereas those containing only glucagon granules remained stable. Interestingly, Ins/Glu cells were less prone to cytokine-induced apoptosis than cells containing only insulin. Cytokine-exposed islets showed down-regulation of β-cell identity genes. In conclusion, pro-inflammatory cytokines induce Ins/Glu cells in human islets, possibly due to a switch from a β- to a β-/α-cell phenotype. These Ins/Glu cells appear to be resistant to cytokine-induced apoptosis.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid33433614,

title = {Perioperative Management of Glucose-lowering Drugs: Reply},

author = {Jean-Charles Preiser and Miriam Cnop},

doi = {10.1097/ALN.0000000000003627},

issn = {1528-1175},

year  = {2021},

date = {2021-02-01},

journal = {Anesthesiology},

volume = {134},

number = {2},

pages = {350--351},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid33967960,

title = {Pathological β-Cell Endoplasmic Reticulum Stress in Type 2 Diabetes: Current Evidence},

author = {Neha Shrestha and Elisa De Franco and Peter Arvan and Miriam Cnop},

doi = {10.3389/fendo.2021.650158},

issn = {1664-2392},

year  = {2021},

date = {2021-01-01},

journal = {Front Endocrinol (Lausanne)},

volume = {12},

pages = {650158},

abstract = {The notion that in diabetes pancreatic β-cells express endoplasmic reticulum (ER) stress markers indicative of increased unfolded protein response (UPR) signaling is no longer in doubt. However, what remains controversial is whether this increase in ER stress response actually contributes importantly to the β-cell failure of type 2 diabetes (akin to 'terminal UPR'), or whether it represents a coping mechanism that represents the best attempt of β-cells to adapt to changes in metabolic demands as presented by disease progression. Here an intercontinental group of experts review evidence for the role of ER stress in monogenic and type 2 diabetes in an attempt to reconcile these disparate views. Current evidence implies that pancreatic β-cells require a regulated UPR for their development, function and survival, as well as to maintain cellular homeostasis in response to protein misfolding stress. Prolonged ER stress signaling, however, can be detrimental to β-cells, highlighting the importance of "optimal" UPR for ER homeostasis, β-cell function and survival.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid33862081,

title = {The position of single-base deletions in the VNTR sequence of the carboxyl ester lipase (CEL) gene determines proteotoxicity},

author = {Anny Gravdal and Xunjun Xiao and Miriam Cnop and Khadija El Jellas and Stefan Johansson and Pål R Njølstad and Mark E Lowe and Bente B Johansson and Anders Molven and Karianne Fjeld},

doi = {10.1016/j.jbc.2021.100661},

issn = {1083-351X},

year  = {2021},

date = {2021-01-01},

journal = {J Biol Chem},

volume = {296},

pages = {100661},

abstract = {Variable number of tandem repeat (VNTR) sequences in the genome can have functional consequences that contribute to human disease. This is the case for the CEL gene, which is specifically expressed in pancreatic acinar cells and encodes the digestive enzyme carboxyl ester lipase. Rare single-base deletions (DELs) within the first (DEL1) or fourth (DEL4) VNTR segment of CEL cause maturity-onset diabetes of the young, type 8 (MODY8), an inherited disorder characterized by exocrine pancreatic dysfunction and diabetes. Studies on the DEL1 variant have suggested that MODY8 is initiated by CEL protein misfolding and aggregation. However, it is unclear how the position of single-base deletions within the CEL VNTR affects pathogenic properties of the protein. Here, we investigated four naturally occurring CEL variants, arising from single-base deletions in different VNTR segments (DEL1, DEL4, DEL9, and DEL13). When the four variants were expressed in human embryonic kidney 293 cells, only DEL1 and DEL4 led to significantly reduced secretion, increased intracellular aggregation, and increased endoplasmic reticulum stress compared with normal CEL protein. The level of O-glycosylation was affected in all DEL variants. Moreover, all variants had enzymatic activity comparable with that of normal CEL. We conclude that the longest aberrant protein tails, resulting from single-base deletions in the proximal VNTR segments, have highest pathogenic potential, explaining why DEL1 and DEL4 but not DEL9 and DEL13 have been observed in patients with MODY8. These findings further support the view that CEL mutations cause pancreatic disease through protein misfolding and proteotoxicity, leading to endoplasmic reticulum stress and activation of the unfolded protein response.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid33477961,

title = {Towards a Functional Cure for Diabetes Using Stem Cell-Derived Beta Cells: Are We There Yet?},

author = {Stephanie Bourgeois and Toshiaki Sawatani and Annelore Van Mulders and Nico De Leu and Yves Heremans and Harry Heimberg and Miriam Cnop and Willem Staels},

doi = {10.3390/cells10010191},

issn = {2073-4409},

year  = {2021},

date = {2021-01-01},

journal = {Cells},

volume = {10},

number = {1},

abstract = {Diabetes mellitus is a pandemic metabolic disorder that results from either the autoimmune destruction or the dysfunction of insulin-producing pancreatic beta cells. A promising cure is beta cell replacement through the transplantation of islets of Langerhans. However, donor shortage hinders the widespread implementation of this therapy. Human pluripotent stem cells, including embryonic stem cells and induced pluripotent stem cells, represent an attractive alternative beta cell source for transplantation. Although major advances over the past two decades have led to the generation of stem cell-derived beta-like cells that share many features with genuine beta cells, producing fully mature beta cells remains challenging. Here, we review the current status of beta cell differentiation protocols and highlight specific challenges that are associated with producing mature beta cells. We address the challenges and opportunities that are offered by monogenic forms of diabetes. Finally, we discuss the remaining hurdles for clinical application of stem cell-derived beta cells and the status of ongoing clinical trials.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid33419045,

title = {tRNA Biology in the Pathogenesis of Diabetes: Role of Genetic and Environmental Factors},

author = {Maria Nicol Arroyo and Jonathan Alex Green and Miriam Cnop and Mariana Igoillo-Esteve},

doi = {10.3390/ijms22020496},

issn = {1422-0067},

year  = {2021},

date = {2021-01-01},

journal = {Int J Mol Sci},

volume = {22},

number = {2},

abstract = {The global rise in type 2 diabetes results from a combination of genetic predisposition with environmental assaults that negatively affect insulin action in peripheral tissues and impair pancreatic β-cell function and survival. Nongenetic heritability of metabolic traits may be an important contributor to the diabetes epidemic. Transfer RNAs (tRNAs) are noncoding RNA molecules that play a crucial role in protein synthesis. tRNAs also have noncanonical functions through which they control a variety of biological processes. Genetic and environmental effects on tRNAs have emerged as novel contributors to the pathogenesis of diabetes. Indeed, altered tRNA aminoacylation, modification, and fragmentation are associated with β-cell failure, obesity, and insulin resistance. Moreover, diet-induced tRNA fragments have been linked with intergenerational inheritance of metabolic traits. Here, we provide a comprehensive review of how perturbations in tRNA biology play a role in the pathogenesis of monogenic and type 2 diabetes.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{RN424,

title = {The RNA-binding profile of the splicing factor SRSF6 in immortalized human pancreatic beta-cells},

author = {M. I. Alvelos and M. Bruggemann and F. R. Sutandy and J. Juan-Mateu and M. L. Colli and A. Busch and M. Lopes and A. Castela and A. Aartsma-Rus and J. Konig and K. Zarnack and D. L. Eizirik},

url = {https://www.ncbi.nlm.nih.gov/pubmed/33376132},

doi = {10.26508/lsa.202000825},

issn = {2575-1077 (Electronic) 

2575-1077 (Linking)},

year  = {2021},

date = {2021-01-01},

journal = {Life Sci Alliance},

volume = {4},

number = {3},

abstract = {In pancreatic beta-cells, the expression of the splicing factor SRSF6 is regulated by GLIS3, a transcription factor encoded by a diabetes susceptibility gene. SRSF6 down-regulation promotes beta-cell demise through splicing dysregulation of central genes for beta-cells function and survival, but how RNAs are targeted by SRSF6 remains poorly understood. Here, we define the SRSF6 binding landscape in the human pancreatic beta-cell line EndoC-betaH1 by integrating individual-nucleotide resolution UV cross-linking and immunoprecipitation (iCLIP) under basal conditions with RNA sequencing after SRSF6 knockdown. We detect thousands of SRSF6 bindings sites in coding sequences. Motif analyses suggest that SRSF6 specifically recognizes a purine-rich consensus motif consisting of GAA triplets and that the number of contiguous GAA triplets correlates with increasing binding site strength. The SRSF6 positioning determines the splicing fate. In line with its role in beta-cell function, we identify SRSF6 binding sites on regulated exons in several diabetes susceptibility genes. In a proof-of-principle, the splicing of the susceptibility gene LMO7 is modulated by antisense oligonucleotides. Our present study unveils the splicing regulatory landscape of SRSF6 in immortalized human pancreatic beta-cells.},

note = {Alvelos, Maria Ines 

Bruggemann, Mirko 

Sutandy, Fx Reymond 

Juan-Mateu, Jonas 

Colli, Maikel Luis 

Busch, Anke 

Lopes, Miguel 

Castela, Angela 

Aartsma-Rus, Annemieke 

Konig, Julian 

Zarnack, Kathi 

Eizirik, Decio L 

eng 

Research Support, Non-U.S. Gov't 

Life Sci Alliance. 2020 Dec 29;4(3). pii: 4/3/e202000825. doi: 10.26508/lsa.202000825. Print 2021 Mar.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid33575641,

title = {Integration of single-cell datasets reveals novel transcriptomic signatures of β-cells in human type 2 diabetes},

author = {Emanuele Bosi and Lorella Marselli and Carmela De Luca and Mara Suleiman and Marta Tesi and Mark Ibberson and Decio L Eizirik and Miriam Cnop and Piero Marchetti},

doi = {10.1093/nargab/lqaa097},

issn = {2631-9268},

year  = {2020},

date = {2020-12-01},

journal = {NAR Genom Bioinform},

volume = {2},

number = {4},

pages = {lqaa097},

abstract = {Pancreatic islet β-cell failure is key to the onset and progression of type 2 diabetes (T2D). The advent of single-cell RNA sequencing (scRNA-seq) has opened the possibility to determine transcriptional signatures specifically relevant for T2D at the β-cell level. Yet, applications of this technique have been underwhelming, as three independent studies failed to show shared differentially expressed genes in T2D β-cells. We performed an integrative analysis of the available datasets from these studies to overcome confounding sources of variability and better highlight common T2D β-cell transcriptomic signatures. After removing low-quality transcriptomes, we retained 3046 single cells expressing 27 931 genes. Cells were integrated to attenuate dataset-specific biases, and clustered into cell type groups. In T2D β-cells ( = 801), we found 210 upregulated and 16 downregulated genes, identifying key pathways for T2D pathogenesis, including defective insulin secretion, SREBP signaling and oxidative stress. We also compared these results with previous data of human T2D β-cells from laser capture microdissection and diabetic rat islets, revealing shared β-cell genes. Overall, the present study encourages the pursuit of single β-cell RNA-seq analysis, preventing presently identified sources of variability, to identify transcriptomic changes associated with human T2D and underscores specific traits of dysfunctional β-cells across different models and techniques.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid33264613,

title = {Persistent or Transient Human β Cell Dysfunction Induced by Metabolic Stress: Specific Signatures and Shared Gene Expression with Type 2 Diabetes},

author = {Lorella Marselli and Anthony Piron and Mara Suleiman and Maikel L Colli and Xiaoyan Yi and Amna Khamis and Gaelle R Carrat and Guy A Rutter and Marco Bugliani and Laura Giusti and Maurizio Ronci and Mark Ibberson and Jean-Valery Turatsinze and Ugo Boggi and Paolo De Simone and Vincenzo De Tata and Miguel Lopes and Daniela Nasteska and Carmela De Luca and Marta Tesi and Emanuele Bosi and Pratibha Singh and Daniela Campani and Anke M Schulte and Michele Solimena and Peter Hecht and Brian Rady and Ivona Bakaj and Alessandro Pocai and Lisa Norquay and Bernard Thorens and Mickaël Canouil and Philippe Froguel and Decio L Eizirik and Miriam Cnop and Piero Marchetti},

doi = {10.1016/j.celrep.2020.108466},

issn = {2211-1247},

year  = {2020},

date = {2020-12-01},

journal = {Cell Rep},

volume = {33},

number = {9},

pages = {108466},

abstract = {Pancreatic β cell failure is key to type 2 diabetes (T2D) onset and progression. Here, we assess whether human β cell dysfunction induced by metabolic stress is reversible, evaluate the molecular pathways underlying persistent or transient damage, and explore the relationships with T2D islet traits. Twenty-six islet preparations are exposed to several lipotoxic/glucotoxic conditions, some of which impair insulin release, depending on stressor type, concentration, and combination. The reversal of dysfunction occurs after washout for some, although not all, of the lipoglucotoxic insults. Islet transcriptomes assessed by RNA sequencing and expression quantitative trait loci (eQTL) analysis identify specific pathways underlying β cell failure and recovery. Comparison of a large number of human T2D islet transcriptomes with those of persistent or reversible β cell lipoglucotoxicity show shared gene expression signatures. The identification of mechanisms associated with human β cell dysfunction and recovery and their overlap with T2D islet traits provide insights into T2D pathogenesis, fostering the development of improved β cell-targeted therapeutic strategies.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid33164986,

title = {YIPF5 mutations cause neonatal diabetes and microcephaly through endoplasmic reticulum stress},

author = {Elisa De Franco and Maria Lytrivi and Hazem Ibrahim and Hossam Montaser and Matthew N Wakeling and Federica Fantuzzi and Kashyap Patel and Céline Demarez and Ying Cai and Mariana Igoillo-Esteve and Cristina Cosentino and Väinö Lithovius and Helena Vihinen and Eija Jokitalo and Thomas W Laver and Matthew B Johnson and Toshiaki Sawatani and Hadis Shakeri and Nathalie Pachera and Belma Haliloglu and Mehmet Nuri Ozbek and Edip Unal and Ruken Yıldırım and Tushar Godbole and Melek Yildiz and Banu Aydin and Angeline Bilheu and Ikuo Suzuki and Sarah E Flanagan and Pierre Vanderhaeghen and Valérie Senée and Cécile Julier and Piero Marchetti and Decio L Eizirik and Sian Ellard and Jonna Saarimäki-Vire and Timo Otonkoski and Miriam Cnop and Andrew T Hattersley},

doi = {10.1172/JCI141455},

issn = {1558-8238},

year  = {2020},

date = {2020-12-01},

journal = {J Clin Invest},

volume = {130},

number = {12},

pages = {6338--6353},

abstract = {Neonatal diabetes is caused by single gene mutations reducing pancreatic β cell number or impairing β cell function. Understanding the genetic basis of rare diabetes subtypes highlights fundamental biological processes in β cells. We identified 6 patients from 5 families with homozygous mutations in the YIPF5 gene, which is involved in trafficking between the endoplasmic reticulum (ER) and the Golgi. All patients had neonatal/early-onset diabetes, severe microcephaly, and epilepsy. YIPF5 is expressed during human brain development, in adult brain and pancreatic islets. We used 3 human β cell models (YIPF5 silencing in EndoC-βH1 cells, YIPF5 knockout and mutation knockin in embryonic stem cells, and patient-derived induced pluripotent stem cells) to investigate the mechanism through which YIPF5 loss of function affects β cells. Loss of YIPF5 function in stem cell-derived islet cells resulted in proinsulin retention in the ER, marked ER stress, and β cell failure. Partial YIPF5 silencing in EndoC-βH1 cells and a patient mutation in stem cells increased the β cell sensitivity to ER stress-induced apoptosis. We report recessive YIPF5 mutations as the genetic cause of a congenital syndrome of microcephaly, epilepsy, and neonatal/early-onset diabetes, highlighting a critical role of YIPF5 in β cells and neurons. We believe this is the first report of mutations disrupting the ER-to-Golgi trafficking, resulting in diabetes.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid32994272,

title = {The KINGS   Mouse: A Novel Model of β-Cell Endoplasmic Reticulum Stress and Human Diabetes},

author = {Amazon L F Austin and Lydia F Daniels Gatward and Miriam Cnop and Gabriel Santos and David Andersson and Sally Sharp and Clive Gentry and Stuart Bevan and Peter M Jones and Aileen J F King},

doi = {10.2337/db20-0570},

issn = {1939-327X},

year  = {2020},

date = {2020-12-01},

journal = {Diabetes},

volume = {69},

number = {12},

pages = {2667--2677},

abstract = {Animal models are important tools in diabetes research because ethical and logistical constraints limit access to human tissue. β-Cell dysfunction is a common contributor to the pathogenesis of most types of diabetes. Spontaneous hyperglycemia was developed in a colony of C57BL/6J mice at King's College London (KCL). Sequencing identified a mutation in the  gene, causing a glycine-to-serine substitution at position 32 on the B chain of the preproinsulin 2 molecule. Mice with the   mutation were named KCL Ins2 G32S (KINGS) mice. The same mutation in humans (rs80356664) causes dominantly inherited neonatal diabetes. Mice were characterized, and β-cell function was investigated. Male mice became overtly diabetic at ∼5 weeks of age, whereas female mice had only slightly elevated nonfasting glycemia. Islets showed decreased insulin content and impaired glucose-induced insulin secretion, which was more severe in males. Transmission electron microscopy and studies of gene and protein expression showed β-cell endoplasmic reticulum (ER) stress in both sexes. Despite this, β-cell numbers were only slightly reduced in older animals. In conclusion, the KINGS mouse is a novel model of a human form of diabetes that may be useful to study β-cell responses to ER stress.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid32340903,

title = {Link between gut microbiota and health outcomes in inulin -treated obese patients: Lessons from the Food4Gut multicenter randomized placebo-controlled trial},

author = {Sophie Hiel and Marco A Gianfrancesco and Julie Rodriguez and Daphnée Portheault and Quentin Leyrolle and Laure B Bindels and Carolina Gomes da Silveira Cauduro and Maria D G H Mulders and Giorgia Zamariola and Anne-Sophie Azzi and Gaetan Kalala and Barbara D Pachikian and Camille Amadieu and Audrey M Neyrinck and Audrey Loumaye and Patrice D Cani and Nicolas Lanthier and Pierre Trefois and Olivier Klein and Olivier Luminet and Jérôme Bindelle and Nicolas Paquot and Miriam Cnop and Jean-Paul Thissen and Nathalie M Delzenne},

doi = {10.1016/j.clnu.2020.04.005},

issn = {1532-1983},

year  = {2020},

date = {2020-12-01},

journal = {Clin Nutr},

volume = {39},

number = {12},

pages = {3618--3628},

abstract = {BACKGROUND: The gut microbiota is altered in obesity and is strongly influenced by nutrients and xenobiotics. We have tested the impact of native inulin as prebiotic present in vegetables and added as a supplement on gut microbiota-related outcomes in obese patients. Metformin treatment was analyzed as a potential modulator of the response.



METHODS: A randomized, single-blinded, multicentric, placebo-controlled trial was conducted in 150 obese patients who received 16 g/d native inulin versus maltodextrin, coupled to dietary advice to consume inulin-rich versus -poor vegetables for 3 months, respectively, in addition to dietary caloric restriction. Anthropometry, diagnostic imaging (abdominal CT-scan, fibroscan), food-behavior questionnaires, serum biology and fecal microbiome (primary outcome; 16S rDNA sequencing) were analyzed before and after the intervention.



RESULTS: Both placebo and prebiotic interventions lowered energy intake, BMI, systolic blood pressure, and serum γ-GT. The prebiotic induced greater weight loss and additionally decreased diastolic blood pressure, AST and insulinemia. Metformin treatment compromised most of the gut microbiota changes and metabolic improvements linked to prebiotic intervention. The prebiotic modulated specific bacteria, associated with the improvement of anthropometry (i.e. a decrease in Desulfovibrio and Clostridium sensu stricto). A large increase in Bifidobacterium appears as a signature of inulin intake rather than a driver of prebiotic-linked biological outcomes.



CONCLUSIONS: Inulin-enriched diet is able to promote weight loss in obese patients, the treatment efficiency being related to gut microbiota characteristics. This treatment is more efficacious in patients who did not receive metformin as anti-diabetic drugs prior the intervention, supporting that both drug treatment and microbiota might be taken into account in personalized nutrition interventions. Registered under ClinicalTrials.gov Identifier no NCT03852069.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid32041744,

title = {Discovery of the gut microbial signature driving the efficacy of prebiotic intervention in obese patients},

author = {Julie Rodriguez and Sophie Hiel and Audrey M Neyrinck and Tiphaine Le Roy and Sarah A Pötgens and Quentin Leyrolle and Barbara D Pachikian and Marco A Gianfrancesco and Patrice D Cani and Nicolas Paquot and Miriam Cnop and Nicolas Lanthier and Jean-Paul Thissen and Laure B Bindels and Nathalie M Delzenne},

doi = {10.1136/gutjnl-2019-319726},

issn = {1468-3288},

year  = {2020},

date = {2020-11-01},

journal = {Gut},

volume = {69},

number = {11},

pages = {1975--1987},

abstract = {OBJECTIVE: The gut microbiota has been proposed as an interesting therapeutic target for metabolic disorders. Inulin as a prebiotic has been shown to lessen obesity and related diseases. The aim of the current study was to investigate whether preintervention gut microbiota characteristics determine the physiological response to inulin.



DESIGN: The stools from four obese donors differing by microbial diversity and composition were sampled before the dietary intervention and inoculated to antibiotic-pretreated mice ( mice; humanised obese mice).  mice were fed with a high-fat diet and treated with inulin. Metabolic and microbiota changes on inulin treatment in  mice were compared with those obtained in a cohort of obese individuals supplemented with inulin for 3 months.



RESULTS: We show that  mice colonised with the faecal microbiota from different obese individuals differentially respond to inulin supplementation on a high-fat diet. Among several bacterial genera, a,  and  correlated with the observed metabolic outcomes (decrease in adiposity and hepatic steatosis) in  mice. In addition, in obese individuals, the preintervention levels of  and  drive the decrease of body mass index in response to inulin.



CONCLUSION: These findings support that characterising the gut microbiota prior to nutritional intervention with prebiotics is important to increase the positive outcome in the context of obesity and metabolic disorders.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid32847508,

title = {Combined transcriptome and proteome profiling of the pancreatic β-cell response to palmitate unveils key pathways of β-cell lipotoxicity},

author = {Maria Lytrivi and Kassem Ghaddar and Miguel Lopes and Victoria Rosengren and Anthony Piron and Xiaoyan Yi and Henrik Johansson and Janne Lehtiö and Mariana Igoillo-Esteve and Daniel A Cunha and Lorella Marselli and Piero Marchetti and Henrik Ortsäter and Decio L Eizirik and Miriam Cnop},

doi = {10.1186/s12864-020-07003-0},

issn = {1471-2164},

year  = {2020},

date = {2020-08-01},

journal = {BMC Genomics},

volume = {21},

number = {1},

pages = {590},

abstract = {BACKGROUND: Prolonged exposure to elevated free fatty acids induces β-cell failure (lipotoxicity) and contributes to the pathogenesis of type 2 diabetes. In vitro exposure of β-cells to the saturated free fatty acid palmitate is a valuable model of lipotoxicity, reproducing features of β-cell failure observed in type 2 diabetes. In order to map the β-cell response to lipotoxicity, we combined RNA-sequencing of palmitate-treated human islets with iTRAQ proteomics of insulin-secreting INS-1E cells following a time course exposure to palmitate.



RESULTS: Crossing transcriptome and proteome of palmitate-treated β-cells revealed 85 upregulated and 122 downregulated genes at both transcript and protein level. Pathway analysis identified lipid metabolism, oxidative stress, amino-acid metabolism and cell cycle pathways among the most enriched palmitate-modified pathways. Palmitate induced gene expression changes compatible with increased free fatty acid mitochondrial import and β-oxidation, decreased lipogenesis and modified cholesterol transport. Palmitate modified genes regulating endoplasmic reticulum (ER) function, ER-to-Golgi transport and ER stress pathways. Furthermore, palmitate modulated cAMP/protein kinase A (PKA) signaling, inhibiting expression of PKA anchoring proteins and downregulating the GLP-1 receptor. SLC7 family amino-acid transporters were upregulated in response to palmitate but this induction did not contribute to β-cell demise. To unravel critical mediators of lipotoxicity upstream of the palmitate-modified genes, we identified overrepresented transcription factor binding sites and performed network inference analysis. These identified LXR, PPARα, FOXO1 and BACH1 as key transcription factors orchestrating the metabolic and oxidative stress responses to palmitate.



CONCLUSIONS: This is the first study to combine transcriptomic and sensitive time course proteomic profiling of palmitate-exposed β-cells. Our results provide comprehensive insight into gene and protein expression changes, corroborating and expanding beyond previous findings. The identification of critical drivers and pathways of the β-cell lipotoxic response points to novel therapeutic targets for type 2 diabetes.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid32667156,

title = {Perioperative Management of Oral Glucose-lowering Drugs in the Patient with Type 2 Diabetes},

author = {Jean-Charles Preiser and Bruna Provenzano and Wasineeart Mongkolpun and Katarina Halenarova and Miriam Cnop},

doi = {10.1097/ALN.0000000000003237},

issn = {1528-1175},

year  = {2020},

date = {2020-08-01},

journal = {Anesthesiology},

volume = {133},

number = {2},

pages = {430--438},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid32398822,

title = {Pancreatic β-cells in type 1 and type 2 diabetes mellitus: different pathways to failure},

author = {Décio L Eizirik and Lorenzo Pasquali and Miriam Cnop},

doi = {10.1038/s41574-020-0355-7},

issn = {1759-5037},

year  = {2020},

date = {2020-07-01},

journal = {Nat Rev Endocrinol},

volume = {16},

number = {7},

pages = {349--362},

abstract = {Loss of functional β-cell mass is the key mechanism leading to the two main forms of diabetes mellitus - type 1 diabetes mellitus (T1DM) and type 2 diabetes mellitus (T2DM). Understanding the mechanisms behind β-cell failure is critical to prevent or revert disease. Basic pathogenic differences exist in the two forms of diabetes mellitus; T1DM is immune mediated and T2DM is mediated by metabolic mechanisms. These mechanisms differentially affect early β-cell dysfunction and eventual fate. Over the past decade, major advances have been made in the field, mostly delivered by studies on β-cells in human disease. These advances include studies of islet morphology and human β-cell gene expression in T1DM and T2DM, the identification and characterization of the role of T1DM and T2DM candidate genes at the β-cell level and the endoplasmic reticulum stress signalling that contributes to β-cell failure in T1DM (mostly IRE1 driven) and T2DM (mostly PERK-eIF2α dependent). Here, we review these new findings, focusing on studies performed on human β-cells or on samples obtained from patients with diabetes mellitus.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid32736653,

title = {Circulating unmethylated CHTOP and INS DNA fragments provide evidence of possible islet cell death in youth with obesity and diabetes},

author = {Farooq Syed and Sarah A Tersey and Jean-Valery Turatsinze and Jamie L Felton and Nicole Jiyun Kang and Jennifer B Nelson and Emily K Sims and Mathieu Defrance and Martin Bizet and Francois Fuks and Miriam Cnop and Marco Bugliani and Piero Marchetti and Anette-Gabriele Ziegler and Ezio Bonifacio and Bobbie-Jo Webb-Robertson and Appakalai N Balamurugan and Carmella Evans-Molina and Decio L Eizirik and Kieren J Mather and Silva Arslanian and Raghavendra G Mirmira},

doi = {10.1186/s13148-020-00906-5},

issn = {1868-7083},

year  = {2020},

date = {2020-07-01},

journal = {Clin Epigenetics},

volume = {12},

number = {1},

pages = {116},

abstract = {BACKGROUND: Identification of islet β cell death prior to the onset of type 1 diabetes (T1D) or type 2 diabetes (T2D) might allow for interventions to protect β cells and reduce diabetes risk. Circulating unmethylated DNA fragments arising from the human INS gene have been proposed as biomarkers of β cell death, but this gene alone may not be sufficiently specific to report β cell death.



RESULTS: To identify new candidate genes whose CpG sites may show greater specificity for β cells, we performed unbiased DNA methylation analysis using the Infinium HumanMethylation 450 array on 64 human islet preparations and 27 non-islet human tissues. For verification of array results, bisulfite DNA sequencing of human β cells and 11 non-β cell tissues was performed on 5 of the top 10 CpG sites that were found to be differentially methylated. We identified the CHTOP gene as a candidate whose CpGs show a greater frequency of unmethylation in human islets. A digital PCR strategy was used to determine the methylation pattern of CHTOP and INS CpG sites in primary human tissues. Although both INS and CHTOP contained unmethylated CpG sites in non-islet tissues, they occurred in a non-overlapping pattern. Based on Naïve Bayes classifier analysis, the two genes together report 100% specificity for islet damage. Digital PCR was then performed on cell-free DNA from serum from human subjects. Compared to healthy controls (N = 10), differentially methylated CHTOP and INS levels were higher in youth with new onset T1D (N = 43) and, unexpectedly, in healthy autoantibody-negative youth who have first-degree relatives with T1D (N = 23). When tested in lean (N = 32) and obese (N = 118) youth, increased levels of unmethylated INS and CHTOP were observed in obese individuals.



CONCLUSION: Our data suggest that concurrent measurement of circulating unmethylated INS and CHTOP has the potential to detect islet death in youth at risk for both T1D and T2D. Our data also support the use of multiple parameters to increase the confidence of detecting islet damage in individuals at risk for developing diabetes.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid31896553,

title = {Interindividual Heterogeneity of SGLT2 Expression and Function in Human Pancreatic Islets},

author = {Chiara Saponaro and Markus Mühlemann and Ana Acosta-Montalvo and Anthony Piron and Valery Gmyr and Nathalie Delalleau and Ericka Moerman and Julien Thévenet and Gianni Pasquetti and Anais Coddeville and Miriam Cnop and Julie Kerr-Conte and Bart Staels and François Pattou and Caroline Bonner},

doi = {10.2337/db19-0888},

issn = {1939-327X},

year  = {2020},

date = {2020-05-01},

journal = {Diabetes},

volume = {69},

number = {5},

pages = {902--914},

abstract = {Studies implicating sodium-glucose cotransporter 2 (SGLT2) inhibitors in glucagon secretion by pancreatic α-cells reported controversial results. We hypothesized that interindividual heterogeneity in SGLT2 expression and regulation may affect glucagon secretion by human α-cells in response to SGLT2 inhibitors. An unbiased RNA-sequencing analysis of 207 donors revealed an unprecedented level of heterogeneity of  expression. To determine heterogeneity of SGLT2 expression at the protein level, the anti-SGLT2 antibody was first rigorously evaluated for specificity, followed by Western blot and immunofluorescence analysis on islets from 10 and 12 donors, respectively. The results revealed a high interdonor variability of SGLT2 protein expression. Quantitative analysis of 665 human islets showed a significant SGLT2 protein colocalization with glucagon but not with insulin or somatostatin. Moreover, glucagon secretion by islets from 31 donors at low glucose (1 mmol/L) was also heterogeneous and correlated with dapagliflozin-induced glucagon secretion at 6 mmol/L glucose. Intriguingly, islets from three donors did not secrete glucagon in response to either 1 mmol/L glucose or dapagliflozin, indicating a functional impairment of the islets of these donors to glucose sensing and SGLT2 inhibition. Collectively, these data suggest that heterogeneous expression of SGLT2 protein and variability in glucagon secretory responses contribute to interindividual differences in response to SGLT2 inhibitors.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid31628942,

title = {Recent Insights Into Mechanisms of β-Cell Lipo- and Glucolipotoxicity in Type 2 Diabetes},

author = {Maria Lytrivi and Anne-Laure Castell and Vincent Poitout and Miriam Cnop},

doi = {10.1016/j.jmb.2019.09.016},

issn = {1089-8638},

year  = {2020},

date = {2020-03-01},

journal = {J Mol Biol},

volume = {432},

number = {5},

pages = {1514--1534},

abstract = {The deleterious effects of chronically elevated free fatty acid (FFA) levels on glucose homeostasis are referred to as lipotoxicity, and the concurrent exposure to high glucose may cause synergistic glucolipotoxicity. Lipo- and glucolipotoxicity have been studied for over 25 years. Here, we review the current evidence supporting the role of pancreatic β-cell lipo- and glucolipotoxicity in type 2 diabetes (T2D), including lipid-based interventions in humans, prospective epidemiological studies, and human genetic findings. In addition to total FFA quantity, the quality of FFAs (saturation and chain length) is a key determinant of lipotoxicity. We discuss in vitro and in vivo experimental models to investigate lipo- and glucolipotoxicity in β-cells and describe experimental pitfalls. Lipo- and glucolipotoxicity adversely affect many steps of the insulin production and secretion process. The molecular mechanisms underpinning lipo- and glucolipotoxic β-cell dysfunction and death comprise endoplasmic reticulum stress, oxidative stress and mitochondrial dysfunction, impaired autophagy, and inflammation. Crosstalk between these stress pathways exists at multiple levels and may aggravate β-cell lipo- and glucolipotoxicity. Lipo- and glucolipotoxicity are therapeutic targets as several drugs impact the underlying stress responses in β-cells, potentially contributing to their glucose-lowering effects in T2D.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid31796987,

title = {Stearoyl CoA desaturase is a gatekeeper that protects human beta cells against lipotoxicity and maintains their identity},

author = {Masaya Oshima and Séverine Pechberty and Lara Bellini and Sven O Göpel and Mélanie Campana and Claude Rouch and Julien Dairou and Cristina Cosentino and Federica Fantuzzi and Sanna Toivonen and Piero Marchetti and Christophe Magnan and Miriam Cnop and Hervé Le Stunff and Raphaël Scharfmann},

doi = {10.1007/s00125-019-05046-x},

issn = {1432-0428},

year  = {2020},

date = {2020-02-01},

journal = {Diabetologia},

volume = {63},

number = {2},

pages = {395--409},

abstract = {AIMS/HYPOTHESIS: During the onset of type 2 diabetes, excessive dietary intake of saturated NEFA and fructose lead to impaired insulin production and secretion by insulin-producing pancreatic beta cells. The majority of data on the deleterious effects of lipids on functional beta cell mass were obtained either in vivo in rodent models or in vitro using rodent islets and beta cell lines. Translating data from rodent to human beta cells remains challenging. Here, we used the human beta cell line EndoC-βH1 and analysed its sensitivity to a lipotoxic and glucolipotoxic (high palmitate with or without high glucose) insult, as a way to model human beta cells in a type 2 diabetes environment.



METHODS: EndoC-βH1 cells were exposed to palmitate after knockdown of genes related to saturated NEFA metabolism. We analysed whether and how palmitate induces apoptosis, stress and inflammation and modulates beta cell identity.



RESULTS: EndoC-βH1 cells were insensitive to the deleterious effects of saturated NEFA (palmitate and stearate) unless stearoyl CoA desaturase (SCD) was silenced. SCD was abundantly expressed in EndoC-βH1 cells, as well as in human islets and human induced pluripotent stem cell-derived beta cells. SCD silencing induced markers of inflammation and endoplasmic reticulum stress and also IAPP mRNA. Treatment with the SCD products oleate or palmitoleate reversed inflammation and endoplasmic reticulum stress. Upon SCD knockdown, palmitate induced expression of dedifferentiation markers such as SOX9, MYC and HES1. Interestingly, SCD knockdown by itself disrupted beta cell identity with a decrease in mature beta cell markers INS, MAFA and SLC30A8 and decreased insulin content and glucose-stimulated insulin secretion.



CONCLUSIONS/INTERPRETATION: The present study delineates an important role for SCD in the protection against lipotoxicity and in the maintenance of human beta cell identity.



DATA AVAILABILITY: Microarray data and all experimental details that support the findings of this study have been deposited in in the GEO database with the GSE130208 accession code.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid31900242,

title = {Pro-inflammatory cytokines induce cell death, inflammatory responses, and endoplasmic reticulum stress in human iPSC-derived beta cells},

author = {Stéphane Demine and Andrea Alex Schiavo and Sandra Marín-Cañas and Piero Marchetti and Miriam Cnop and Decio L Eizirik},

doi = {10.1186/s13287-019-1523-3},

issn = {1757-6512},

year  = {2020},

date = {2020-01-01},

journal = {Stem Cell Res Ther},

volume = {11},

number = {1},

pages = {7},

abstract = {BACKGROUND: Adult human pancreatic beta cells are the "gold standard" for studies on diabetes pathogenesis, but their use is limited by insufficient availability and variable quality. An important effort has recently taken place to differentiate beta cells from human induced pluripotent stem cells (iPSCs) and validate their use for diabetes research. We presently used a 7-stage protocol to generate beta cells from human iPSC and evaluated whether these cells are responsive to the pro-inflammatory cytokines (IFNγ, IL-1β, or IFNα) that play a role in type 1 diabetes.



METHODS: The iPSC-derived islet-like cell clusters contained 40-50% beta and 10-15% alpha cells and expressed the receptors for IFNγ, IL-1β, or IFNα. Cells were exposed to either IFNγ (1000 U/mL) + IL-1β (50 U/mL) or IFNα alone (2000 U/mL) for 24/48 h. Apoptosis was quantified using Hoechst/propidium iodide staining or the RealTime Glo Apoptosis Kit (Promega). After treatment, CXCL10 secretion was quantified by ELISA. The expression of multiples genes (Ins, Gcg, Nkx2.2, Nkx6.1, Pdx1, Mafa, BiP, Chop, Atf3, CXCL10, CXCL9, CCL5, and HLA-ABC) was quantified by RT-qPCR. Phosphorylation state and total expression of STAT1/STAT2, as well as expression of PDL1 and of the ER chaperone BiP, were quantified by Western blotting. The co-localization of HLA-ABC or cleaved caspase-3 and Ins/Gcg expression was assessed by immunohistochemistry. The presence of HLA-ABC at the plasma membrane was measured by flow cytometry.



RESULTS: IFNγ + IL-1β and IFNα induced apoptosis of the cells after 48 h of exposure. Cleaved caspase-3 co-localized mostly but not exclusively with Ins+ cells. Exposure to IFNγ + IL-1β induced a pro-inflammatory phenotype, including increased CXCL10, CXCL9, and CCL5 expression; CXCL10 secretion; and HLA-ABC expression. HLA overexpression was confirmed at the protein level by Western blotting and flow cytometry. Exposure to IFNγ + IL-1β (but not IFNα) also induced beta cell dedifferentiation and endoplasmic reticulum stress (increase in BiP, Chop, and Atf3 mRNA expression). Phosphorylation of STAT1 was stimulated already after 1 h by IFNγ + IL-1β and IFNα, while phosphorylation of STAT2 was only activated by IFNα at 1-4 h. PDL1 expression was increased by both IFNγ + IL-1β and IFNα.



CONCLUSIONS: Our data show that human iPSC-derived beta cells respond to pro-inflammatory cytokines IL-1β + IFNγ and IFNα, by activating the same pathogenic processes as adult human primary beta cells. These cells thus represent a valuable tool for future research on the pathogenesis of type 1 diabetes.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid31888393,

title = {Modulation of adiponectin receptors AdipoR1 and AdipoR2 by phage display-derived peptides in  and  models},

author = {Deborah Crombez and Sébastien Delcambre and Denis Nonclercq and Luce Vander Elst and Sophie Laurent and Miriam Cnop and Robert N Muller and Carmen Burtea},

doi = {10.1080/1061186X.2019.1710840},

issn = {1029-2330},

year  = {2020},

date = {2020-01-01},

journal = {J Drug Target},

volume = {28},

number = {7-8},

pages = {831--851},

abstract = {Type 2 diabetes (T2D) is often linked to metabolic syndrome, which assembles various risk factors related to obesity. Plasma levels of adiponectin are decreased in T2D and obese subjects. Aiming to develop a peptide able to bind adiponectin receptors and modulate their signalling pathways, a 12-amino acid sequence homologous in AdipoR1/R2 has been targeted by phage display with a linear 12-mer peptide library. The selected peptide P17 recognises AdipoR1/R2 expressed by skeletal muscle, liver and pancreatic islets. In HepaRG and C2C12 cells, P17 induced the activation of AMPK (AMPKα-pT172) and the expression of succinate dehydrogenase and glucokinase; no cytotoxic effects were observed on HepaRG cells. In db/db mice, P17 promoted body weight and glycaemia stabilisation, decreased plasma triglycerides to the range of healthy mice and increased adiponectin (in high fat-fed mice) and insulin (in chow-fed mice) levels. It restored to the range of healthy mice the tissue levels and subcellular distribution of AdipoR1/R2, AMPKα-pT172 and PPARα-pS12. In liver, P17 reduced steatosis and apoptosis. The docking of P17 to AdipoR is reminiscent of the binding mechanism of adiponectin. To conclude, we have developed an AdipoR1/AdipoR2-targeted peptide that modulates adiponectin signalling pathways and has therapeutic relevance for T2D and obesity associated pathologies.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid31877117,

title = {Exenatide induces frataxin expression and improves mitochondrial function in Friedreich ataxia},

author = {Mariana Igoillo-Esteve and Ana F Oliveira and Cristina Cosentino and Federica Fantuzzi and Céline Demarez and Sanna Toivonen and Amélie Hu and Satyan Chintawar and Miguel Lopes and Nathalie Pachera and Ying Cai and Baroj Abdulkarim and Myriam Rai and Lorella Marselli and Piero Marchetti and Mohammad Tariq and Jean-Christophe Jonas and Marina Boscolo and Massimo Pandolfo and Décio L Eizirik and Miriam Cnop},

doi = {10.1172/jci.insight.134221},

issn = {2379-3708},

year  = {2020},

date = {2020-01-01},

journal = {JCI Insight},

volume = {5},

number = {2},

abstract = {Friedreich ataxia is an autosomal recessive neurodegenerative disease associated with a high diabetes prevalence. No treatment is available to prevent or delay disease progression. Friedreich ataxia is caused by intronic GAA trinucleotide repeat expansions in the frataxin-encoding FXN gene that reduce frataxin expression, impair iron-sulfur cluster biogenesis, cause oxidative stress, and result in mitochondrial dysfunction and apoptosis. Here we examined the metabolic, neuroprotective, and frataxin-inducing effects of glucagon-like peptide-1 (GLP-1) analogs in in vivo and in vitro models and in patients with Friedreich ataxia. The GLP-1 analog exenatide improved glucose homeostasis of frataxin-deficient mice through enhanced insulin content and secretion in pancreatic β cells. Exenatide induced frataxin and iron-sulfur cluster-containing proteins in β cells and brain and was protective to sensory neurons in dorsal root ganglia. GLP-1 analogs also induced frataxin expression, reduced oxidative stress, and improved mitochondrial function in Friedreich ataxia patients' induced pluripotent stem cell-derived β cells and sensory neurons. The frataxin-inducing effect of exenatide was confirmed in a pilot trial in Friedreich ataxia patients, showing modest frataxin induction in platelets over a 5-week treatment course. Taken together, GLP-1 analogs improve mitochondrial function in frataxin-deficient cells and induce frataxin expression. Our findings identify incretin receptors as a therapeutic target in Friedreich ataxia.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid30176740,

title = {Future Perspectives for the Treatment of Diabetes: Importance of a Regulatory Framework},

author = {Katsura Tsukamoto and Miriam Cnop and Daichi Mori and Shoen Kume and Takayuki Anazawa and Masako Doi and Kazuhiko Chikazawa and Naoki Matsumaru},

doi = {10.1177/2168479018795854},

issn = {2168-4804},

year  = {2019},

date = {2019-07-01},

journal = {Ther Innov Regul Sci},

volume = {53},

number = {4},

pages = {535--541},

abstract = {BACKGROUND: The number of diabetes patients is steadily increasing worldwide. Consequently, the social burden of diabetes is huge, requiring urgent countermeasures. We performed an intensive survey of antidiabetic drugs approved in Japan, the United States, and the European Union.



METHODS: Information about approved antidiabetic drugs was obtained by searching databases of regulatory authorities in the 3 regions. Other relevant information was also obtained from publicly available literature and documents.



RESULTS: No difference in the total number and types of approved drugs among the 3 regions was found ( = .173 by log-rank test). However, the numbers of approved dipeptidyl peptidase-4 and sodium-glucose cotransporter 2 inhibitors in Japan were almost double of those in the other regions. The average sample size in clinical trials used for antidiabetic drug approval in Japan (1134 patients) was much smaller than that in the other regions ( < .001 by analysis of variance repeated measures test adjusted by the Holm method). Currently, 6 drugs with known modes of action are being developed for type 1 diabetes in Japan, whereas at the end of 2016, nearly 7-fold more products with novel modes of action were in clinical development in the United States.



CONCLUSION: Antidiabetic drug development in Japan costs less than that in the other regions, although novel development is less active because of regulatory differences. To achieve better pharmacotherapy for diabetes, the regulatory framework requires careful consideration.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid30907926,

title = {The tRNA Epitranscriptome and Diabetes: Emergence of tRNA Hypomodifications as a Cause of Pancreatic β-Cell Failure},

author = {Cristina Cosentino and Miriam Cnop and Mariana Igoillo-Esteve},

doi = {10.1210/en.2019-00098},

issn = {1945-7170},

year  = {2019},

date = {2019-05-01},

journal = {Endocrinology},

volume = {160},

number = {5},

pages = {1262--1274},

abstract = {tRNAs are crucial noncoding RNA molecules that serve as amino acid carriers during protein synthesis. The transcription of tRNA genes is a highly regulated process. The tRNA pool is tissue and cell specific, it varies during development, and it is modulated by the environment. tRNAs are highly posttranscriptionally modified by specific tRNA-modifying enzymes. The tRNA modification signature of a cell determines the tRNA epitranscriptome. Perturbations in the tRNA epitranscriptome, as a consequence of mutations in tRNAs and tRNA-modifying enzymes or environmental exposure, have been associated with human disease, including diabetes. tRNA fragmentation induced by impaired tRNA modifications or dietary factors has been linked to pancreatic β-cell demise and paternal inheritance of metabolic traits. Herein, we review recent findings that associate tRNA epitranscriptome perturbations with diabetes.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid30656194,

title = {OGTT is recommended for glucose homeostasis assessments in Friedreich ataxia},

author = {Anne-Sophie Azzi and Cristina Cosentino and Jésabelle Kibanda and Françoise Féry and Miriam Cnop},

doi = {10.1002/acn3.686},

issn = {2328-9503},

year  = {2019},

date = {2019-01-01},

journal = {Ann Clin Transl Neurol},

volume = {6},

number = {1},

pages = {161--166},

abstract = {Diabetes is a common complication of Friedreich ataxia, requiring sensitive diagnostic methods. Here, we compared the performance of different tests that assess glucose tolerance, insulin sensitivity, and -cell function in Friedreich ataxia patients, heterozygous  mutation carriers and controls. We find that diabetes is underdiagnosed with fasting glucose alone. The oral glucose tolerance test (OGTT) provides 1.2- to 3.5-fold more diagnoses of impaired glucose homeostasis and diabetes, and adequately measures insulin sensitivity, insulin secretion, and -cell function. Clinicians in charge of Friedreich ataxia patients and researchers should incorporate the OGTT as an accurate diagnostic and research tool.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid30284016,

title = {Detection and quantification of beta cells by PET imaging: why clinical implementation has never been closer},

author = {Martin Gotthardt and Decio L Eizirik and Henk-Jan Aanstoot and Olle Korsgren and Dick Mul and Frank Martin and Marti Boss and Tom J P Jansen and Sanne A M van Lith and Mijke Buitinga and Olof Eriksson and Miriam Cnop and Maarten Brom},

doi = {10.1007/s00125-018-4745-5},

issn = {1432-0428},

year  = {2018},

date = {2018-12-01},

journal = {Diabetologia},

volume = {61},

number = {12},

pages = {2516--2519},

abstract = {In this issue of Diabetologia, Alavi and Werner ( https://doi.org/10.1007/s00125-018-4676-1 ) criticise the attempts to use positron emission tomography (PET) for in vivo imaging of pancreatic beta cells, which they consider as 'futile'. In support of this strong statement, they point out the limitations of PET imaging, which they believe render beta cell mass impossible to estimate using this method. In our view, the Alavi and Werner presentation of the technical limitations of PET imaging does not reflect the current state of the art, which leads them to questionable conclusions towards the feasibility of beta cell imaging using this approach. Here, we put forward arguments in favour of continuing the development of innovative technologies enabling in vivo imaging of pancreatic beta cells and concisely present the current state of the art regarding putative technical limitations of PET imaging. Indeed, far from being a 'futile' effort, we demonstrate that beta cell imaging is now closer than ever to becoming a long-awaited clinical reality.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid30142486,

title = {Inflammatory stress in islet β-cells: therapeutic implications for type 2 diabetes?},

author = {Maria Lytrivi and Mariana Igoillo-Esteve and Miriam Cnop},

doi = {10.1016/j.coph.2018.08.002},

issn = {1471-4973},

year  = {2018},

date = {2018-12-01},

journal = {Curr Opin Pharmacol},

volume = {43},

pages = {40--45},

abstract = {Type 2 diabetes is a common complex disease. Relatively little is known about the underlying pathophysiology. Mild islet inflammation has been suggested to play a pathogenic role; here we review the available evidence. Mild islet inflammation is histologically detected in pancreas sections of type 2 diabetic patients. In experimental models, it can be triggered by excess nutrients, amyloid, lipopolysaccharide, and endoplasmic reticulum and oxidative stress. Transcriptome studies do not consistently identify pro-inflammatory gene expression signatures in type 2 diabetic islets, and genetic evidence calls into question the causality of inflammation. Several anti-inflammatory medications confer a modest glucose-lowering effect, supporting the role for inflammation in type 2 diabetes. Whether these anti-inflammatory therapies target inflammation in islets or in other metabolically relevant tissues remains unknown.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid30247717,

title = {Pancreatic β-cell tRNA hypomethylation and fragmentation link TRMT10A deficiency with diabetes},

author = {Cristina Cosentino and Sanna Toivonen and Esteban Diaz Villamil and Mohamed Atta and Jean-Luc Ravanat and Stéphane Demine and Andrea Alex Schiavo and Nathalie Pachera and Jean-Philippe Deglasse and Jean-Christophe Jonas and Diego Balboa and Timo Otonkoski and Ewan R Pearson and Piero Marchetti and Décio L Eizirik and Miriam Cnop and Mariana Igoillo-Esteve},

doi = {10.1093/nar/gky839},

issn = {1362-4962},

year  = {2018},

date = {2018-11-01},

journal = {Nucleic Acids Res},

volume = {46},

number = {19},

pages = {10302--10318},

abstract = {Transfer RNAs (tRNAs) are non-coding RNA molecules essential for protein synthesis. Post-transcriptionally they are heavily modified to improve their function, folding and stability. Intronic polymorphisms in CDKAL1, a tRNA methylthiotransferase, are associated with increased type 2 diabetes risk. Loss-of-function mutations in TRMT10A, a tRNA methyltransferase, are a monogenic cause of early onset diabetes and microcephaly. Here we confirm the role of TRMT10A as a guanosine 9 tRNA methyltransferase, and identify tRNAGln and tRNAiMeth as two of its targets. Using RNA interference and induced pluripotent stem cell-derived pancreatic β-like cells from healthy controls and TRMT10A-deficient patients we demonstrate that TRMT10A deficiency induces oxidative stress and triggers the intrinsic pathway of apoptosis in β-cells. We show that tRNA guanosine 9 hypomethylation leads to tRNAGln fragmentation and that 5'-tRNAGln fragments mediate TRMT10A deficiency-induced β-cell death. This study unmasks tRNA hypomethylation and fragmentation as a hitherto unknown mechanism of pancreatic β-cell demise relevant to monogenic and polygenic forms of diabetes.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid30071851,

title = {Improving glycemic control in critically ill patients: personalized care to mimic the endocrine pancreas},

author = {J Geoffrey Chase and Thomas Desaive and Julien Bohe and Miriam Cnop and Christophe De Block and Jan Gunst and Roman Hovorka and Pierre Kalfon and James Krinsley and Eric Renard and Jean-Charles Preiser},

doi = {10.1186/s13054-018-2110-1},

issn = {1466-609X},

year  = {2018},

date = {2018-08-01},

journal = {Crit Care},

volume = {22},

number = {1},

pages = {182},

abstract = {There is considerable physiological and clinical evidence of harm and increased risk of death associated with dysglycemia in critical care. However, glycemic control (GC) currently leads to increased hypoglycemia, independently associated with a greater risk of death. Indeed, recent evidence suggests GC is difficult to safely and effectively achieve for all patients. In this review, leading experts in the field discuss this evidence and relevant data in diabetology, including the artificial pancreas, and suggest how safe, effective GC can be achieved in critically ill patients in ways seeking to mimic normal islet cell function. The review is structured around the specific clinical hurdles of: understanding the patient's metabolic state; designing GC to fit clinical practice, safety, efficacy, and workload; and the need for standardized metrics. These aspects are addressed by reviewing relevant recent advances in science and technology. Finally, we provide a set of concise recommendations to advance the safety, quality, consistency, and clinical uptake of GC in critical care. This review thus presents a roadmap toward better, more personalized metabolic care and improved patient outcomes.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid29784605,

title = {CoDE-seq, an augmented whole-exome sequencing, enables the accurate detection of CNVs and mutations in Mendelian obesity and intellectual disability},

author = {Louise Montagne and Mehdi Derhourhi and Amélie Piton and Bénédicte Toussaint and Emmanuelle Durand and Emmanuel Vaillant and Dorothée Thuillier and Stefan Gaget and Franck De Graeve and Iandry Rabearivelo and Amélie Lansiaux and Bruno Lenne and Sylvie Sukno and Rachel Desailloud and Miriam Cnop and Ramona Nicolescu and Lior Cohen and Jean-François Zagury and Mélanie Amouyal and Jacques Weill and Jean Muller and Olivier Sand and Bruno Delobel and Philippe Froguel and Amélie Bonnefond},

doi = {10.1016/j.molmet.2018.05.005},

issn = {2212-8778},

year  = {2018},

date = {2018-07-01},

journal = {Mol Metab},

volume = {13},

pages = {1--9},

abstract = {OBJECTIVE: The molecular diagnosis of extreme forms of obesity, in which accurate detection of both copy number variations (CNVs) and point mutations, is crucial for an optimal care of the patients and genetic counseling for their families. Whole-exome sequencing (WES) has benefited considerably this molecular diagnosis, but its poor ability to detect CNVs remains a major limitation. We aimed to develop a method (CoDE-seq) enabling the accurate detection of both CNVs and point mutations in one step.



METHODS: CoDE-seq is based on an augmented WES method, using probes distributed uniformly throughout the genome. CoDE-seq was validated in 40 patients for whom chromosomal DNA microarray was available. CNVs and mutations were assessed in 82 children/young adults with suspected Mendelian obesity and/or intellectual disability and in their parents when available (n = 145).



RESULTS: CoDE-seq not only detected all of the 97 CNVs identified by chromosomal DNA microarrays but also found 84 additional CNVs, due to a better resolution. When compared to CoDE-seq and chromosomal DNA microarrays, WES failed to detect 37% and 14% of CNVs, respectively. In the 82 patients, a likely molecular diagnosis was achieved in >30% of the patients. Half of the genetic diagnoses were explained by CNVs while the other half by mutations.



CONCLUSIONS: CoDE-seq has proven cost-efficient and highly effective as it avoids the sequential genetic screening approaches currently used in clinical practice for the accurate detection of CNVs and point mutations.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid29133342,

title = {Exercise training protects human and rodent β cells against endoplasmic reticulum stress and apoptosis},

author = {Flavia M M Paula and Nayara C Leite and Patricia C Borck and Ricardo Freitas-Dias and Miriam Cnop and Mara P T Chacon-Mikahil and Claudia R Cavaglieri and Piero Marchetti and Antonio C Boschero and Claudio C Zoppi and Decio L Eizirik},

doi = {10.1096/fj.201700710R},

issn = {1530-6860},

year  = {2018},

date = {2018-03-01},

journal = {FASEB J},

volume = {32},

number = {3},

pages = {1524--1536},

abstract = {Prolonged exercise has positive metabolic effects in obese or diabetic individuals. These effects are usually ascribed to improvements in insulin sensitivity. We evaluated whether exercise also generates circulating signals that protect human and rodent β cells against endoplasmic reticulum (ER) stress and apoptosis. For this purpose, we obtained serum from humans or mice before and after an 8 wk training period. Exposure of human islets or mouse or rat β cells to human or rodent sera, respectively, obtained from trained individuals reduced cytokine (IL-1β+IFN-γ)- or chemical ER stressor-induced β-cell ER stress and apoptosis, at least in part via activation of the transcription factor STAT3. These findings indicate that exercise training improves human and rodent β-cell survival under diabetogenic conditions and support lifestyle interventions as a protective approach for both type 1 and 2 diabetes.-Paula, F. M. M., Leite, N. C., Borck, P. C., Freitas-Dias, R., Cnop, M., Chacon-Mikahil, M. P. T., Cavaglieri, C. R., Marchetti, P., Boschero, A. C., Zoppi, C. C., Eizirik, D. L. Exercise training protects human and rodent β cells against endoplasmic reticulum stress and apoptosis.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid28911974,

title = {Molecular genetics of the transcription factor GLIS3 identifies its dual function in beta cells and neurons},

author = {Sophie Calderari and Massimiliano Ria and Christelle Gérard and Tatiane C Nogueira and Olatz Villate and Stephan C Collins and Helen Neil and Nicolas Gervasi and Christophe Hue and Nicolas Suarez-Zamorano and Cécilia Prado and Miriam Cnop and Marie-Thérèse Bihoreau and Pamela J Kaisaki and Jean-Baptiste Cazier and Cécile Julier and Mark Lathrop and Michel Werner and Decio L Eizirik and Dominique Gauguier},

doi = {10.1016/j.ygeno.2017.09.001},

issn = {1089-8646},

year  = {2018},

date = {2018-03-01},

journal = {Genomics},

volume = {110},

number = {2},

pages = {98--111},

abstract = {The GLIS family zinc finger 3 isoform (GLIS3) is a risk gene for Type 1 and Type 2 diabetes, glaucoma and Alzheimer's disease endophenotype. We identified GLIS3 binding sites in insulin secreting cells (INS1) (FDR q<0.05; enrichment range 1.40-9.11 fold) sharing the motif wrGTTCCCArTAGs, which were enriched in genes involved in neuronal function and autophagy and in risk genes for metabolic and neuro-behavioural diseases. We confirmed experimentally Glis3-mediated regulation of the expression of genes involved in autophagy and neuron function in INS1 and neuronal PC12 cells. Naturally-occurring coding polymorphisms in Glis3 in the Goto-Kakizaki rat model of type 2 diabetes were associated with increased insulin production in vitro and in vivo, suggestive alteration of autophagy in PC12 and INS1 and abnormal neurogenesis in hippocampus neurons. Our results support biological pleiotropy of GLIS3 in pathologies affecting β-cells and neurons and underline the existence of trans‑nosology pathways in diabetes and its co-morbidities.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid29044173,

title = {Palmitate-induced lipotoxicity alters acetylation of multiple proteins in clonal β cells and human pancreatic islets},

author = {Federica Ciregia and Marco Bugliani and Maurizio Ronci and Laura Giusti and Claudia Boldrini and Maria R Mazzoni and Sandra Mossuto and Francesca Grano and Miriam Cnop and Lorella Marselli and Gino Giannaccini and Andrea Urbani and Antonio Lucacchini and Piero Marchetti},

doi = {10.1038/s41598-017-13908-w},

issn = {2045-2322},

year  = {2017},

date = {2017-10-01},

journal = {Sci Rep},

volume = {7},

number = {1},

pages = {13445},

abstract = {Type 2 diabetes is characterized by progressive β cell dysfunction, with lipotoxicity playing a possible pathogenetic role. Palmitate is often used to examine the direct effects of lipotoxicity and it may cause mitochondrial alterations by activating protein acetylation. However, it is unknown whether palmitate influences protein acetylation in β cells. We investigated lysine acetylation in mitochondrial proteins from INS-1E β cells (INS-1E) and in proteins from human pancreatic islets (HPI) after 24 h palmitate exposure. First, we confirmed that palmitate damages β cells and demonstrated that chemical inhibition of deacetylation also impairs INS-1E function and survival. Then, by 2-D gel electrophoresis, Western Blot and Liquid Chromatography-Mass Spectrometry we evaluated the effects of palmitate on protein acetylation. In mitochondrial preparations from palmitate-treated INS-1E, 32 acetylated spots were detected, with 13 proteins resulting over-acetylated. In HPI, 136 acetylated proteins were found, of which 11 were over-acetylated upon culture with palmitate. Interestingly, three proteins, glutamate dehydrogenase, mitochondrial superoxide dismutase, and SREBP-1, were over-acetylated in both INS-1E and HPI. Therefore, prolonged exposure to palmitate induces changes in β cell protein lysine acetylation and this modification could play a role in causing β cell damage. Dysregulated acetylation may be a target to counteract palmitate-induced β cell lipotoxicity.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid29026101,

title = {Heterozygous RFX6 protein truncating variants are associated with MODY with reduced penetrance},

author = {Kashyap A Patel and Jarno Kettunen and Markku Laakso and Alena Stančáková and Thomas W Laver and Kevin Colclough and Matthew B Johnson and Marc Abramowicz and Leif Groop and Päivi J Miettinen and Maggie H Shepherd and Sarah E Flanagan and Sian Ellard and Nobuya Inagaki and Andrew T Hattersley and Tiinamaija Tuomi and Miriam Cnop and Michael N Weedon},

doi = {10.1038/s41467-017-00895-9},

issn = {2041-1723},

year  = {2017},

date = {2017-10-01},

journal = {Nat Commun},

volume = {8},

number = {1},

pages = {888},

abstract = {Finding new causes of monogenic diabetes helps understand glycaemic regulation in humans. To find novel genetic causes of maturity-onset diabetes of the young (MODY), we sequenced MODY cases with unknown aetiology and compared variant frequencies to large public databases. From 36 European patients, we identify two probands with novel RFX6 heterozygous nonsense variants. RFX6 protein truncating variants are enriched in the MODY discovery cohort compared to the European control population within ExAC (odds ratio = 131, P = 1 × 10). We find similar results in non-Finnish European (n = 348, odds ratio = 43, P = 5 × 10) and Finnish (n = 80, odds ratio = 22, P = 1 × 10) replication cohorts. RFX6 heterozygotes have reduced penetrance of diabetes compared to common HNF1A and HNF4A-MODY mutations (27, 70 and 55% at 25 years of age, respectively). The hyperglycaemia results from beta-cell dysfunction and is associated with lower fasting and stimulated gastric inhibitory polypeptide (GIP) levels. Our study demonstrates that heterozygous RFX6 protein truncating variants are associated with MODY with reduced penetrance.Maturity-onset diabetes of the young (MODY) is the most common subtype of familial diabetes. Here, Patel et al. use targeted DNA sequencing of MODY patients and large-scale publically available data to show that RFX6 heterozygous protein truncating variants cause reduced penetrance MODY.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid28892713,

title = {Stearic acid at physiologic concentrations induces in vitro lipotoxicity in circulating angiogenic cells},

author = {Valentina Spigoni and Federica Fantuzzi and Alessia Fontana and Monia Cito and Eleonora Derlindati and Ivana Zavaroni and Miriam Cnop and Riccardo C Bonadonna and Alessandra Dei Cas},

doi = {10.1016/j.atherosclerosis.2017.09.004},

issn = {1879-1484},

year  = {2017},

date = {2017-10-01},

journal = {Atherosclerosis},

volume = {265},

pages = {162--171},

abstract = {BACKGROUND AND AIMS: Saturated free fatty acids (SFAs) can induce lipotoxicity in different cells. No studies have investigated the effects of SFA in circulating angiogenic cells (CACs), which play a key role in endothelial repair processes. The aim of the study was to assess the effects of SFAs, specifically stearic acid (SA), on viability and function of CACs and to investigate potential underlying molecular mechanisms.



METHODS: CACs were isolated from healthy subjects by established methods. CACs were incubated with BSA-complexed stearate (100 μM) to assess the time course (from 8 to 24 h exposure) of the effects on viability and apoptosis (activation of caspases 3/7), angiogenic function (tube formation assay), pro-inflammatory cytokine (IL-1β, IL-6, IL-8, MCP-1 and TNFα) gene expression (qPCR) and secretion (ELISA), activation of MAPK (JNK, p38 and Erk1/2) by Western blot and endoplasmic reticulum (ER) stress marker (CHOP, BIP, ATF4, XBP-1 and sXBP-1) gene expression by qPCR.



RESULTS: Stearic acid activates effector caspases in CACs in a dose- and time-dependent manner. SA also impairs CAC function and increases pro-inflammatory molecule (IL-1β, IL-6, IL-8, MCP-1 and TNFα) gene expression and secretion in CACs starting from 3 h of incubation. The activation of JNK by SA mediates pro-inflammatory response, but it may be not necessary for apoptosis. Moreover, SA induces the expression of ER stress markers across the three branches of the ER stress response.



CONCLUSIONS: In humans, both function and viability of CACs are exquisitely vulnerable to physiologic concentrations of stearate; lipotoxic impairment of endothelial repair processes may be implicated in vascular damage caused by SFAs.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid28951826,

title = {Endoplasmic reticulum stress and eIF2α phosphorylation: The Achilles heel of pancreatic β cells},

author = {Miriam Cnop and Sanna Toivonen and Mariana Igoillo-Esteve and Paraskevi Salpea},

doi = {10.1016/j.molmet.2017.06.001},

issn = {2212-8778},

year  = {2017},

date = {2017-09-01},

journal = {Mol Metab},

volume = {6},

number = {9},

pages = {1024--1039},

abstract = {BACKGROUND: Pancreatic β cell dysfunction and death are central in the pathogenesis of most if not all forms of diabetes. Understanding the molecular mechanisms underlying β cell failure is important to develop β cell protective approaches.



SCOPE OF REVIEW: Here we review the role of endoplasmic reticulum stress and dysregulated endoplasmic reticulum stress signaling in β cell failure in monogenic and polygenic forms of diabetes. There is substantial evidence for the presence of endoplasmic reticulum stress in β cells in type 1 and type 2 diabetes. Direct evidence for the importance of this stress response is provided by an increasing number of monogenic forms of diabetes. In particular, mutations in the PERK branch of the unfolded protein response provide insight into its importance for human β cell function and survival. The knowledge gained from different rodent models is reviewed. More disease- and patient-relevant models, using human induced pluripotent stem cells differentiated into β cells, will further advance our understanding of pathogenic mechanisms. Finally, we review the therapeutic modulation of endoplasmic reticulum stress and signaling in β cells.



MAJOR CONCLUSIONS: Pancreatic β cells are sensitive to excessive endoplasmic reticulum stress and dysregulated eIF2α phosphorylation, as indicated by transcriptome data, monogenic forms of diabetes and pharmacological studies. This should be taken into consideration when devising new therapeutic approaches for diabetes.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid28698383,

title = {Pancreatic β-cell protection from inflammatory stress by the endoplasmic reticulum proteins thrombospondin 1 and mesencephalic astrocyte-derived neutrotrophic factor (MANF)},

author = {Daniel A Cunha and Monia Cito and Fabio Arturo Grieco and Cristina Cosentino and Tatiana Danilova and Laurence Ladrière and Maria Lindahl and Andrii Domanskyi and Marco Bugliani and Piero Marchetti and Décio L Eizirik and Miriam Cnop},

doi = {10.1074/jbc.M116.769877},

issn = {1083-351X},

year  = {2017},

date = {2017-09-01},

journal = {J Biol Chem},

volume = {292},

number = {36},

pages = {14977--14988},

abstract = {Cytokine-induced endoplasmic reticulum (ER) stress is one of the molecular mechanisms underlying pancreatic β-cell demise in type 1 diabetes. Thrombospondin 1 (THBS1) was recently shown to promote β-cell survival during lipotoxic stress. Here we show that ER-localized THBS1 is cytoprotective to rat, mouse, and human β-cells exposed to cytokines or thapsigargin-induced ER stress. THBS1 confers cytoprotection by maintaining expression of mesencephalic astrocyte-derived neutrotrophic factor (MANF) in β-cells and thereby prevents the BH3-only protein BIM (BCL2-interacting mediator of cell death)-dependent triggering of the mitochondrial pathway of apoptosis. Prolonged exposure of β-cells to cytokines or thapsigargin leads to THBS1 and MANF degradation and loss of this prosurvival mechanism. Approaches that sustain intracellular THBS1 and MANF expression in β-cells should be explored as a cytoprotective strategy in type 1 diabetes.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid28522407,

title = {High-throughput screening and bioinformatic analysis to ascertain compounds that prevent saturated fatty acid-induced β-cell apoptosis},

author = {Seung-Hee Lee and Daniel Cunha and Carlo Piermarocchi and Giovanni Paternostro and Anthony Pinkerton and Laurence Ladriere and Piero Marchetti and Decio L Eizirik and Miriam Cnop and Fred Levine},

doi = {10.1016/j.bcp.2017.05.007},

issn = {1873-2968},

year  = {2017},

date = {2017-08-01},

journal = {Biochem Pharmacol},

volume = {138},

pages = {140--149},

abstract = {Pancreatic β-cell lipotoxicity is a central feature of the pathogenesis of type 2 diabetes. To study the mechanism by which fatty acids cause β-cell death and develop novel approaches to prevent it, a high-throughput screen on the β-cell line INS1 was carried out. The cells were exposed to palmitate to induce cell death and compounds that reversed palmitate-induced cytotoxicity were ascertained. Hits from the screen were analyzed by an increasingly more stringent testing funnel, ending with studies on primary human islets treated with palmitate. MAP4K4 inhibitors, which were not part of the screening libraries but were ascertained by a bioinformatics analysis, and the endocannabinoid anandamide were effective at inhibiting palmitate-induced apoptosis in INS1 cells as well as primary rat and human islets. These targets could serve as the starting point for the development of therapeutics for type 2 diabetes.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid28323924,

title = {Guanabenz Sensitizes Pancreatic β Cells to Lipotoxic Endoplasmic Reticulum Stress and Apoptosis},

author = {Baroj Abdulkarim and Miriam Hernangomez and Mariana Igoillo-Esteve and Daniel A Cunha and Lorella Marselli and Piero Marchetti and Laurence Ladriere and Miriam Cnop},

doi = {10.1210/en.2016-1773},

issn = {1945-7170},

year  = {2017},

date = {2017-06-01},

journal = {Endocrinology},

volume = {158},

number = {6},

pages = {1659--1670},

abstract = {Deficient as well as excessive/prolonged endoplasmic reticulum (ER) stress signaling can lead to pancreatic β cell failure and the development of diabetes. Saturated free fatty acids (FFAs) such as palmitate induce lipotoxic ER stress in pancreatic β cells. One of the main ER stress response pathways is under the control of the protein kinase R-like endoplasmic reticulum kinase (PERK), leading to phosphorylation of the eukaryotic translation initiation factor 2 (eIF2α). The antihypertensive drug guanabenz has been shown to inhibit eIF2α dephosphorylation and protect cells from ER stress. Here we examined whether guanabenz protects pancreatic β cells from lipotoxicity. Guanabenz induced β cell dysfunction in vitro and in vivo in rodents and led to impaired glucose tolerance. The drug significantly potentiated FFA-induced cell death in clonal rat β cells and in rat and human islets. Guanabenz enhanced FFA-induced eIF2α phosphorylation and expression of the downstream proapoptotic gene C/EBP homologous protein (CHOP), which mediated the sensitization to lipotoxicity. Thus, guanabenz does not protect β cells from ER stress; instead, it potentiates lipotoxic ER stress through PERK/eIF2α/CHOP signaling. These data demonstrate the crucial importance of the tight regulation of eIF2α phosphorylation for the normal function and survival of pancreatic β cells.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}