scholarly journals Pancreatic islet chromatin accessibility and conformation defines distal enhancer networks of type 2 diabetes risk

2018 ◽  
Author(s):  
William W Greenwald ◽  
Joshua Chiou ◽  
Jian Yan ◽  
Yunjiang Qiu ◽  
Ning Dai ◽  
...  
Keyword(s):  
Type 2 Diabetes ◽  
Pancreatic Islets ◽  
Regulatory Networks ◽  
Complex Disease ◽  
Protein Transport ◽  
Target Genes ◽  
Regulatory Elements ◽  
Distal Enhancer ◽  
Enhancer Activity

AbstractThe gene targets of enhancer activity in pancreatic islets are largely unknown, impeding discovery of islet regulatory networks involved in type 2 diabetes (T2D) risk. We mapped chromatin state, accessibility and conformation using ChIP-seq, ATAC-seq and Hi-C in human pancreatic islets, which we integrated with T2D genetic fine-mapping and islet expression QTL data. Active islet regulatory elements preferentially interacted with other active elements, often at distances over 1MB, and we identified target genes for thousands of distal islet enhancers. A third of T2D risk signals mapped in islet enhancers, and target genes regulated by these signals were specifically involved in processes related to protein transport and secretion. Among implicated target genes of T2D islet enhancer signals with no prior known role in islet function, we demonstrated that reduced IGF2BP2 activity in mouse islets leads to impaired glucose-stimulated insulin secretion. These results link distal islet enhancer regulation of protein secretion and transport to genetic risk of T2D, and highlight the utility of high-throughput chromatin conformation maps to uncover the gene regulatory networks of complex disease.

scholarly journals High-Throughput Approaches onto Uncover (Epi)Genomic Architecture of Type 2 Diabetes

Genes ◽  
2018 ◽  
Vol 9 (8) ◽  
pp. 374 ◽  
Author(s):  
Anna Dziewulska ◽  
Aneta Dobosz ◽  
Agnieszka Dobrzyn
Keyword(s):  
Type 2 Diabetes ◽  
Pancreatic Islets ◽  
High Throughput ◽  
Target Genes ◽  
Association Studies ◽  
Genome Wide Association Studies ◽  
Genomic Landscape ◽  
A Genome ◽  
Next Generation Sequencing Ngs

Type 2 diabetes (T2D) is a complex disorder that is caused by a combination of genetic, epigenetic, and environmental factors. High-throughput approaches have opened a new avenue toward a better understanding of the molecular bases of T2D. A genome-wide association studies (GWASs) identified a group of the most common susceptibility genes for T2D (i.e., TCF7L2, PPARG, KCNJ1, HNF1A, PTPN1, and CDKAL1) and illuminated novel disease-causing pathways. Next-generation sequencing (NGS)-based techniques have shed light on rare-coding genetic variants that account for an appreciable fraction of T2D heritability (KCNQ1 and ADRA2A) and population risk of T2D (SLC16A11, TPCN2, PAM, and CCND2). Moreover, single-cell sequencing of human pancreatic islets identified gene signatures that are exclusive to α-cells (GCG, IRX2, and IGFBP2) and β-cells (INS, ADCYAP1, INS-IGF2, and MAFA). Ongoing epigenome-wide association studies (EWASs) have progressively defined links between epigenetic markers and the transcriptional activity of T2D target genes. Differentially methylated regions were found in TCF7L2, THADA, KCNQ1, TXNIP, SOCS3, SREBF1, and KLF14 loci that are related to T2D. Additionally, chromatin state maps in pancreatic islets were provided and several non-coding RNAs (ncRNA) that are key to T2D pathogenesis were identified (i.e., miR-375). The present review summarizes major progress that has been made in mapping the (epi)genomic landscape of T2D within the last few years.

Alpha-1-Antichymotrypsin: a Common Player for Type 2 Diabetes and Alzheimer's Disease

2020 ◽  
Vol 16 ◽  
Author(s):  
Nataly Guzmán-Herrera ◽  
Viridiana C. Pérez-Nájera ◽  
Luis A. Salazar-Olivo
Keyword(s):  
Oxidative Stress ◽  
Alzheimer’S Disease ◽  
Type 2 Diabetes ◽  
Alzheimer's Disease ◽  
Regulatory Networks ◽  
Therapeutic Strategies ◽  
Oxidative Stresses ◽  
Bibliographic Search ◽  
And Oxidative Stress

Background: Numerous studies have shown a significant association between type 2 diabetes mellitus (T2D) and Alzheimer's disease (AD), two pathologies affecting millions of people worldwide. Chronic inflammation and oxidative stress are two conditions common to these diseases also affecting the activity of the serpin alpha-1-antichymotrypsin (ACT), but a possible common role for this serpin in T2D and AD remains unclear. Objective: To explore the possible regulatory networks linking ACT to T2D and AD. Materials and Methods: A bibliographic search was carried out in PubMed, Med-line, Open-i, ScienceDirect, Scopus and SpringerLink for data indicating or suggesting association among T2D, AD, and ACT. Searched terms like “alpha-1-antichymotrypsin”, “type 2 diabetes”, “Alzheimer's disease”, “oxidative stress”, “pro-inflammatory mediators” among others were used. Moreover, common therapeutic strategies between T2D and AD as well as the use of ACT as a therapeutic target for both diseases were included. Results: ACT has been linked with development and maintenance of T2D and AD and studies suggest their participation through activation of inflammatory pathways and oxidative stress, mechanisms also associated with both diseases. Likewise, evidences indicate that diverse therapeutic approaches are common to both diseases. Conclusion: Inflammatory and oxidative stresses constitute a crossroad for T2D and AD where ACT could play an important role. In-depth research on ACT involvement in these two dysfunctions could generate new therapeutic strategies for T2D and AD.

scholarly journals High Energy Intake Induced Overexpression of Transcription Factors and Its Regulatory Genes Involved in Acceleration of Hepatic Lipogenesis: A Rat Model for Type 2 Diabetes

Biomedicines ◽  
2019 ◽  
Vol 7 (4) ◽  
pp. 76 ◽  
Author(s):  
Suresh P. Khadke ◽  
Aniket A. Kuvalekar ◽  
Abhay M. Harsulkar ◽  
Nitin Mantri
Keyword(s):  
Type 2 Diabetes ◽  
Transcription Factors ◽  
Glucose Tolerance ◽  
Molecular Mechanisms ◽  
Target Genes ◽  
High Energy ◽  
Tolerance Test ◽  
Diabetic Control ◽  
Ppar Γ

Type 2 diabetes mellitus (T2DM) is a metabolic disorder characterized by impaired insulin action and its secretion. The objectives of the present study were to establish an economical and efficient animal model, mimicking pathophysiology of human T2DM to understand probable molecular mechanisms in context with lipid metabolism. In the present study, male Wistar rats were randomly divided into three groups. Animals were fed with high fat diet (HFD) except healthy control (HC) for 12 weeks. After eight weeks, intra peritoneal glucose tolerance test was performed. After confirmation of glucose intolerance, diabetic control (DC) group was injected with streptozotocin (STZ) (35 mg/kg b.w., i.p.). HFD fed rats showed increase (p ≤ 0.001) in glucose tolerance and HOMA-IR as compared to HC. Diabetes rats showed abnormal (p ≤ 0.001) lipid profile as compared to HC. The hepatocyte expression of transcription factors SREBP-1c and NFκβ, and their target genes were found to be upregulated, while PPAR-γ, CPT1A and FABP expressions were downregulated as compared to the HC. A number of animal models have been raised for studying T2DM, but the study has been restricted to only the biochemical level. The model is validated at biochemical, molecular and histopathological levels, which can be used for screening new therapeutics for the effective management of T2DM.

scholarly journals Kidney Disease and Youth Onset Type 2 Diabetes: Considerations for the General Practitioner

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Allison B. Dart ◽  
Elizabeth A. Sellers ◽  
Heather J. Dean
Keyword(s):  
Type 2 Diabetes ◽  
High Risk ◽  
Kidney Disease ◽  
Complex Disease ◽  
Early Adulthood ◽  
Primary Care Providers ◽  
High Risk Group ◽  
Care Providers ◽  
Onset Type

Youth onset type 2 diabetes (T2DM) continues to increase worldwide, concomitant with the rising obesity epidemic. There is evidence to suggest that youth with T2DM are affected by the same comorbidities and complications as adults diagnosed with T2DM. This review highlights specifically the kidney disease associated with youth onset T2DM, which is highly prevalent and associated with a high risk of end-stage kidney disease in early adulthood. A general understanding of this complex disease by primary care providers is critical, so that at-risk individuals are identified and managed early in the course of their disease, such that progression can be modified in this high-risk group of children and adolescents. A review of the pediatric literature will include a focus on the epidemiology, risk factors, pathology, screening, and treatment of kidney disease in youth onset T2DM.

scholarly journals Functional coupling of human pancreatic islets and liver spheroids on-a-chip: Towards a novel human ex vivo type 2 diabetes model

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Sophie Bauer ◽  
Charlotte Wennberg Huldt ◽  
Kajsa P. Kanebratt ◽  
Isabell Durieux ◽  
Daniela Gunne ◽  
...  
Keyword(s):  
Type 2 Diabetes ◽  
Pancreatic Islets ◽  
Ex Vivo ◽  
Functional Coupling ◽  
Human Pancreatic Islets ◽  
Diabetes Model

scholarly journals γ-Aminobutyric acid (GABA) signalling in human pancreatic islets is altered in type 2 diabetes

Diabetologia ◽  
2012 ◽  
Vol 55 (7) ◽  
pp. 1985-1994 ◽  
Author(s):  
J. Taneera ◽  
Z. Jin ◽  
Y. Jin ◽  
S. J. Muhammed ◽  
E. Zhang ◽  
...  
Keyword(s):  
Type 2 Diabetes ◽  
Pancreatic Islets ◽  
Aminobutyric Acid ◽  
Human Pancreatic Islets

scholarly journals Evaluating the contribution of rare variants to type 2 diabetes and related traits using pedigrees

2017 ◽  
Vol 115 (2) ◽  
pp. 379-384 ◽  
Author(s):  
Goo Jun ◽  
Alisa Manning ◽  
Marcio Almeida ◽  
Matthew Zawistowski ◽  
Andrew R. Wood ◽  
...  
Keyword(s):  
Type 2 Diabetes ◽  
Mexican American ◽  
Complex Disease ◽  
Rare Variants ◽  
Whole Genome Analysis ◽  
Mexican American Families ◽  
Extended Pedigrees ◽  
High Prevalence ◽  
Study Designs

A major challenge in evaluating the contribution of rare variants to complex disease is identifying enough copies of the rare alleles to permit informative statistical analysis. To investigate the contribution of rare variants to the risk of type 2 diabetes (T2D) and related traits, we performed deep whole-genome analysis of 1,034 members of 20 large Mexican-American families with high prevalence of T2D. If rare variants of large effect accounted for much of the diabetes risk in these families, our experiment was powered to detect association. Using gene expression data on 21,677 transcripts for 643 pedigree members, we identified evidence for large-effect rare-variant cis-expression quantitative trait loci that could not be detected in population studies, validating our approach. However, we did not identify any rare variants of large effect associated with T2D, or the related traits of fasting glucose and insulin, suggesting that large-effect rare variants account for only a modest fraction of the genetic risk of these traits in this sample of families. Reliable identification of large-effect rare variants will require larger samples of extended pedigrees or different study designs that further enrich for such variants.

scholarly journals Decreased Expression of Cilia Genes in Pancreatic Islets as a Risk Factor for Type 2 Diabetes in Mice and Humans

Cell Reports ◽  
2019 ◽  
Vol 26 (11) ◽  
pp. 3027-3036.e3 ◽  
Author(s):  
Oliver Kluth ◽  
Mandy Stadion ◽  
Pascal Gottmann ◽  
Heja Aga ◽  
Markus Jähnert ◽  
...  
Keyword(s):  
Type 2 Diabetes ◽  
Risk Factor ◽  
Pancreatic Islets ◽  
Diabetes In Mice

scholarly journals An integrative transcriptional logic model of hepatic insulin resistance

2021 ◽  
Author(s):  
TAKUMI KITAMOTO ◽  
Taiyi Kuo ◽  
Atsushi Okabe ◽  
Atsushi Kaneda ◽  
Domenico Accili
Keyword(s):  
Insulin Resistance ◽  
Type 2 Diabetes ◽  
Regulatory Elements ◽  
Hepatic Insulin Resistance ◽  
Dependent Manner ◽  
Metabolic Genes ◽  
Target Sites ◽  
Common Pathogenesis ◽  
Glucose Abnormalities

Abnormalities of lipid/lipoprotein and glucose metabolism are hallmarks of hepatic insulin resistance in type 2 diabetes. The former antedate the latter, but the latter become progressively refractory to treatment and contribute to therapeutic failures. It's unclear whether the two processes share a common pathogenesis and what underlies their progressive nature. In this study, we investigated the hypothesis that genes in the lipid/lipoprotein pathway and those in the glucose metabolic pathway are governed by different transcriptional logics that affect their response to physiologic (fasting/refeeding) as well as pathophysiologic cues (insulin resistance and hyperglycemia). To this end, we obtained genomic and transcriptomic maps of the key insulin-regulated transcription factor, FoxO1, and integrated them with those of CREB, PPARα, and glucocorticoid receptor. We found an enrichment of glucose metabolic genes among those regulated by intergenic and promoter enhancers in a fasting-dependent manner, while lipid genes were enriched among fasting-dependent intron enhancers and fasting-independent enhancer-less introns. Glucose genes also showed a remarkable transcriptional resiliency, i.e., an enrichment of active marks at shared PPARα/FoxO1 regulatory elements when FoxO1 was inactivated. Surprisingly, the main features associated with insulin resistance and hyperglycemia were a ″spreading″ of FoxO1 binding to enhancers, and the emergence of target sites unique to this condition. We surmise that this unusual pattern correlates with the progressively intractable nature of hepatic insulin resistance. This transcriptional logic provides an integrated model to interpret the combined lipid and glucose abnormalities of type 2 diabetes.

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