Project description:Maturity onset diabetes of the young (MODY) is caused by a mutation in a single gene and leads to diabetes under the age of 25. The mutations in HNF1A gene (leading to HNF1A-MODY) cause about 70% of all MODY cases. It was shown that patients with HNF1A-MODY often develop diabetic microvascular complications, related to endothelial dysfunction, however, it is not clear whether these complications are the result of hyperglycemia or due to the genetic mutation in HNF1A gene. For analysis, monoallelic (MAC) and biallelic (BAC) mutants in the HNF1A gene were used for comparative proteomics to the isogenic control (hiPSCs-EC).
Project description:Introduction: Maturity-onset Diabetes of the Young (MODY) is a rare form of diabetes and arises from mutations in key regulatory genes of the pancreatic beta-cell, leading to their functional impairment and early-onset diabetes. Research into PDX1-MODY, a form of MODY caused by mutations in the PDX1 gene, enhances understanding of gene-specific mechanisms underlying glucose dysregulation and provides insights into possible approaches to restore normal metabolic function. However, no currently published mouse model accurately depicts the genetic cause of PDX1-MODY in human patients. Methods: Using CRISPR-Cas9 technology, we generated the first mouse model carrying one of the most prevalent pathological PDX1 point mutation found in human patients, P33T, and conducted an 18-week in vivo phenotyping experiment assessing homozygous PDX1P33T and wild type littermates on both chow and high fat diet (HFD). Additionally, transcriptomic and proteomic analyses were performed on isolated pancreatic islets. Islet architecture was investigated via fluorescent microscopy. Result: Contrary to expectations, our comprehensive phenotypic analysis of the mouse model carrying the homozygous PDX1P33T point mutation revealed no significant differences in metabolic parameters compared to wild-type controls, and no pathological outcomes were observed as seen in human patients. Notably, male PDX1P33T mice exhibited an increase in islet size and number on chow diet but failed to adapt respectively on HFD. Discussion: Our work indicates substantial differences between mouse and human PDX1 function in the pancreas. Further refinement of animal models is necessary to better elucidate the pathophysiology of PDX1-MODY. Ultimately, this study emphasizes the complexities involved in translating human pathologies to animal models, serving as a reminder that findings generated in mice may not always be easily translated to humans.
Project description:Maturity-onset Diabetes of the young (MODY) is an early-onset, autosomal dominant form of non-insulin dependent diabetes. Genetic diagnosis of MODY can transform patient management. Earlier data on the genetic predisposition to MODY have come primarily from familial studies in populations of European origin. Using next generation sequencing, we carried out a comprehensive genomic analysis of 289 individuals from India that included 152 clinically diagnosed MODY cases to identify variants in known MODY genes. Our findings report that HNF1A and ABCC8 are among the most frequently mutated MODY genes in south India.
Project description:Pancreatic b-cell failure in type 2 diabetes is associated with functional abnormalities of insulin secretion and deficits of b-cell mass. It’s unclear how one begets the other. We have shown that loss of b-cell mass can be ascribed to impaired FoxO1 function in different models of diabetes. Here we show that ablation of the three FoxO genes (1, 3a, and 4) in mature b-cells results in early-onset, maturity onset diabetes of the young (MODY)-like diabetes, with signature abnormalities of the MODY networks of Hnf4a, Hnf1a, and Pdx1. Transcriptome and functional analyses reveal that FoxO-deficient b-cells are metabolically inflexible, i.e., they preferentially utilize lipids rather than carbohydrates as source of acetyl-CoA for mitochondrial oxidative phosphorylation. This results in impaired ATP generation, and reduced Ca2+-dependent insulin secretion. When viewed in the context of prior data illustrating a role of FoxO1 in b-cell dedifferentiation, the present findings define a seamless FoxO-dependent mechanism linking the twin abnormalities of b-cell function in diabetes. We used microarrays to detail the change of gene expression in pancreatic beta cells after knocking out FoxO1,3 and 4. Primary islets were isolated from pancretic beta cell- specific triple FoxO(1,3, and 4) KO and their littermates control (WT) mice. Gene expression was analyzed by microarray.
Project description:This project investigates the impact of the hotspot mutation P291fsinsC in HNF1A-MODY (Maturity-Onset Diabetes of the Young) on stem cell-derived islets. RNA sequencing (RNA-seq) was performed on islets differentiated from mutant and control HNF1A-MODY stem cells to study the mutation's effect on gene expression. By comparing the transcriptomic profiles of these islets, the study aims to uncover molecular mechanisms underlying the dysfunction caused by the P291fsinsC mutation during islet development and maturation.
Project description:This project investigates the impact of the hotspot mutation P291fsinsC in HNF1A-MODY (Maturity-Onset Diabetes of the Young) on stem cell-derived islets. RNA sequencing (RNA-seq) was performed on islets differentiated from mutant and control HNF1A-MODY stem cells to study the mutation's effect on gene expression. By comparing the transcriptomic profiles of these islets, the study aims to uncover molecular mechanisms underlying the dysfunction caused by the P291fsinsC mutation during islet development and maturation.
Project description:This project investigates the impact of the hotspot mutation P291fsinsC in HNF1A-MODY (Maturity-Onset Diabetes of the Young) on stem cell-derived islets. RNA sequencing (RNA-seq) was performed on islets differentiated from mutant and control HNF1A-MODY stem cells to study the mutation's effect on gene expression. By comparing the transcriptomic profiles of these islets, the study aims to uncover molecular mechanisms underlying the dysfunction caused by the P291fsinsC mutation during islet development and maturation.
Project description:This project investigates the impact of the hotspot mutation P291fsinsC in HNF1A-MODY (Maturity-Onset Diabetes of the Young) on stem cell-derived islets. RNA sequencing (RNA-seq) was performed on islets differentiated from mutant and control HNF1A-MODY stem cells to study the mutation's effect on gene expression. By comparing the transcriptomic profiles of these islets, the study aims to uncover molecular mechanisms underlying the dysfunction caused by the P291fsinsC mutation during islet development and maturation.
Project description:This project investigates the impact of the hotspot mutation P291fsinsC in HNF1A-MODY (Maturity-Onset Diabetes of the Young) on stem cell-derived islets. RNA sequencing (RNA-seq) was performed on islets differentiated from mutant and control HNF1A-MODY stem cells to study the mutation's effect on gene expression. By comparing the transcriptomic profiles of these islets, the study aims to uncover molecular mechanisms underlying the dysfunction caused by the P291fsinsC mutation during islet development and maturation.
Project description:Introduction: Maturity-onset Diabetes of the Young (MODY) is a rare form of diabetes and arises from mutations in key regulatory genes of the pancreatic beta-cell, leading to their functional impairment and early-onset diabetes. Research into PDX1-MODY, a form of MODY caused by mutations in the PDX1 gene, enhances understanding of gene-specific mechanisms underlying glucose dysregulation and provides insights into possible approaches to restore normal metabolic function. However, no currently published mouse model accurately depicts the genetic cause of PDX1-MODY in human patients. Methods: Using CRISPR-Cas9 technology, we generated the first mouse model carrying one of the most prevalent pathological PDX1 point mutation found in human patients, P33T, and conducted an 18-week in vivo phenotyping experiment assessing homozygous PDX1P33T and wild-type littermates on both chow and high fat diet (HFD). Additionally, transcriptomic and proteomic analyses were performed on isolated pancreatic islets. Islet architecture was investigated via fluorescent microscopy. Result: Contrary to expectations, our comprehensive phenotypic analysis of the mouse model carrying the homozygous PDX1P33T point mutation revealed no significant differences in metabolic parameters compared to wild-type controls, and no pathological outcomes were observed as seen in human patients. Notably, male PDX1P33T mice exhibited an increase in islet size and number on chow diet but failed to adapt respectively on HFD. Discussion: Our work indicates substantial differences between mouse and human PDX1 function in the pancreas. Further refinement of animal models is necessary to better elucidate the pathophysiology of PDX1-MODY. Ultimately, this study emphasizes the complexities involved in translating human pathologies to animal models, serving as a reminder that findings generated in mice may not always be easily translated to humans.