scholarly journals The Mutation Spectrum of Maturity Onset Diabetes of the Young (MODY)-Associated Genes among Western Siberia Patients

2021 ◽  
Vol 11 (1) ◽  
pp. 57
Author(s):  
Dinara E. Ivanoshchuk ◽  
Elena V. Shakhtshneider ◽  
Oksana D. Rymar ◽  
Alla K. Ovsyannikova ◽  
Svetlana V. Mikhailova ◽  
...  
Keyword(s):  
Western Siberia ◽  
Cell Function ◽  
Specific Gene ◽  
Maturity Onset Diabetes ◽  
Β Cell ◽  
Primary Defect ◽  
Onset Diabetes ◽  
Β Cell Function ◽  
Large Rearrangements ◽  
Dependent Probe

Maturity onset diabetes of the young (MODY) is a congenital form of diabetes characterized by onset at a young age and a primary defect in pancreatic-β-cell function. Currently, 14 subtypes of MODY are known, and each is associated with mutations in a specific gene: HNF4A, GCK, HNF1A, PDX1, HNF1B, NEUROD1, KLF11, CEL, PAX4, INS, BLK, KCNJ11, ABCC8, and APPL1. The most common subtypes of MODY are associated with mutations in the genes GCK, HNF1A, HNF4A, and HNF1B. Among them, up to 70% of cases are caused by mutations in GCK and HNF1A. Here, an analysis of 14 MODY genes was performed in 178 patients with a MODY phenotype in Western Siberia. Multiplex ligation-dependent probe amplification analysis of DNA samples from 50 randomly selected patients without detectable mutations did not reveal large rearrangements in the MODY genes. In 38 patients (37% males) among the 178 subjects, mutations were identified in HNF4A, GCK, HNF1A, and ABCC8. We identified novel potentially causative mutations p.Lys142*, Leu146Val, Ala173Glnfs*30, Val181Asp, Gly261Ala, IVS7 c.864 −1G>T, Cys371*, and Glu443Lys in GCK and Ser6Arg, IVS 2 c.526 +1 G>T, IVS3 c.713 +2 T>A, and Arg238Lys in HNF1A.

scholarly journals Characteristic phenotype of Chinese patients with adult-onset diabetes who are autoantibody positive by 3-Screen ICA™ ELISA

2021 ◽  
Author(s):  
Zhida Wang ◽  
Liang Guo ◽  
Shu Chen ◽  
Jun Guan ◽  
Michael Powell ◽  
...  
Keyword(s):  
Cell Function ◽  
Chinese Patients ◽  
Model Assessment ◽  
Adult Onset ◽  
Β Cell ◽  
Serum Samples ◽  
Thyroid Autoantibody ◽  
Onset Diabetes ◽  
Β Cell Function ◽  
Adult Onset Diabetes

Abstract Aims To assess the prevalence of diabetes-associated autoantibodies in Chinese patients recently diagnosed with adult-onset diabetes and to evaluate the potential role of the autoantibody markers for characterization of disease phenotype in the patient population. Methods The study included 1273 recent-onset adult patients with phenotypic type 2 diabetes mellitus (T2DM). Serum samples were tested using the 3-Screen ICA™ ELISA (3-Screen) designed for combined measurement of GADAb and/or IA-2Ab and/or ZnT8Ab. 3-Screen positive samples were then tested for individual diabetes-associated and other organ-specific autoantibodies. Clinical characteristics of patients positive and negative in 3-Screen were analysed. Results Forty-four (3.5%) of the T2DM patients were positive in 3-Screen, and 38 (86%) of these were also positive for at least one of GADAb, IA-2Ab and ZnT8Ab in assays for the individual autoantibodies. 3-Screen positive patients had lower BMI, higher HbA1c, lower fasting insulin levels and lower fasting C-peptide levels compared to 3-Screen negative patients. Analysis using a homeostatic model assessment (HOMA2) indicated that HOMA2-β-cell function was significantly lower for the forty-four 3-Screen positive patients compared to 3-Screen negative patients. Twenty (45%) 3-Screen positive patients were also positive for at least one thyroid autoantibody. Conclusions The 3-Screen ELISA has been used successfully for the first time in China to detect diabetes autoantibodies in patients with phenotypic T2DM. 3-Screen positive patients presented with poorer β cell function.

scholarly journals Maturity-Onset Diabetes of the Young Type 1 (MODY1)-Associated Mutations R154X and E276Q in Hepatocyte Nuclear Factor 4α (HNF4α) Gene Impair Recruitment of p300, a Key Transcriptional Coactivator

2001 ◽  
Vol 15 (7) ◽  
pp. 1200-1210 ◽  
Author(s):  
Jérôme Eeckhoute ◽  
Pierre Formstecher ◽  
Bernard Laine
Keyword(s):  
Transcription Factor ◽  
Transcriptional Activity ◽  
Cell Function ◽  
Nuclear Factor ◽  
Maturity Onset Diabetes ◽  
Hepatocyte Nuclear Factor ◽  
Β Cell ◽  
Β Cell Function ◽  
Hepatocyte Nuclear Factor 4Α

Abstract Hepatocyte nuclear factor 4α (HNF4α) is a nuclear receptor involved in glucose homeostasis and is required for normal β-cell function. Mutations in the HNF4α gene are associated with maturity-onset diabetes of the young type 1. E276Q and R154X mutations were previously shown to impair intrinsic transcriptional activity (without exogenously supplied coactivators) of HNF4α. Given that transcriptional partners of HNF4α modulate its intrinsic transcriptional activity and play crucial roles in HNF4α function, we investigated the effects of these mutations on potentiation of HNF4α activity by p300, a key coactivator for HNF4α. We show here that loss of HNF4α function by both mutations is increased through impaired physical interaction and functional cooperation between HNF4α and p300. Impairment of p300-mediated potentiation of HNF4α transcriptional activity is of particular importance for the E276Q mutant since its intrinsic transcriptional activity is moderately affected. Together with previous results obtained with chicken ovalbumin upstream promoter-transcription factor II, our results highlight that impairment of recruitment of transcriptional partners represents an important mechanism leading to abnormal HNF4α function resulting from the MODY1 E276Q mutation. The impaired potentiations of HNF4α activity were observed on the promoter of HNF1α, a transcription factor involved in a transcriptional network and required for β-cell function. Given its involvement in a regulatory signaling cascade, loss of HNF4α function may cause reduced β-cell function secondary to defective HNF1α expression. Our results also shed light on a better structure-function relationship of HNF4α and on p300 sequences involved in the interaction with HNF4α.

Why expression of some genes is disallowed in β-cells

2008 ◽  
Vol 36 (3) ◽  
pp. 300-305 ◽  
Author(s):  
Roel Quintens ◽  
Nico Hendrickx ◽  
Katleen Lemaire ◽  
Frans Schuit
Keyword(s):  
Insulin Release ◽  
Cell Function ◽  
Ex Vivo ◽  
Housekeeping Genes ◽  
Cell Phenotype ◽  
Specific Gene ◽  
Β Cells ◽  
Β Cell ◽  
Atp Production ◽  
Β Cell Function

A differentiated β-cell results not only from cell-specific gene expression, but also from cell-selective repression of certain housekeeping genes. Indeed, to prevent insulin toxicity, β-cells should handle insulin stores carefully, preventing exocytosis under conditions when circulating insulin is unwanted. Some ubiquitously expressed proteins would significantly jeopardize this safeguard, when allowed to function in β-cells. This is illustrated by two studied examples. First, low-Km hexokinases are disallowed as their high affinity for glucose would, when expressed, significantly lower the threshold for glucose-induced β-cell function and cause hypoglycaemia, as happens in patients with β-cell tumours. Thus the β-cell phenotype means not only expression of glucokinase but also absence of low-Km hexokinases. Secondly, the absence of MCTs (monocarboxylic acid transporters) in β-cells explains the pyruvate paradox (pyruvate being an excellent substrate for mitochondrial ATP production, yet not stimulating insulin release when added to β-cells). The relevance of this disallowance is underlined in patients with exercise-induced inappropriate insulin release: these have gain-of-function MCT1 promoter mutations and loss of the pyruvate paradox. By genome-wide ex vivo mRNA expression studies using mouse islets and an extensive panel of other tissues, we have started to identify in a systematic manner other specifically disallowed genes. For each of those, the future challenge is to explore the physiological/pathological relevance and study conditions under which the phenotypically disallowed state in the β-cell is breached.

scholarly journals Role of Pancreatic Stellate Cell-Derived Exosomes in Pancreatic Cancer-Related Diabetes: A Novel Hypothesis

Cancers ◽  
2021 ◽  
Vol 13 (20) ◽  
pp. 5224
Author(s):  
Chamini J. Perera ◽  
Marco Falasca ◽  
Suresh T. Chari ◽  
Jerry R. Greenfield ◽  
Zhihong Xu ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Pancreatic Cancer ◽  
Cancer Cells ◽  
Cell Function ◽  
Pancreatic Stellate Cells ◽  
Β Cell ◽  
Onset Diabetes ◽  
Β Cell Function ◽  
New Onset

Pancreatic ductal adenocarcinoma (PDAC) is a devastating condition characterised by vague symptomatology and delayed diagnosis. About 30% of PDAC patients report a history of new onset diabetes, usually diagnosed within 3 years prior to the diagnosis of cancer. Thus, new onset diabetes, which is also known as pancreatic cancer-related diabetes (PCRD), could be a harbinger of PDAC. Diabetes is driven by progressive β cell loss/dysfunction and insulin resistance, two key features that are also found in PCRD. Experimental studies suggest that PDAC cell-derived exosomes carry factors that are detrimental to β cell function and insulin sensitivity. However, the role of stromal cells, particularly pancreatic stellate cells (PSCs), in the pathogenesis of PCRD is not known. PSCs are present around the earliest neoplastic lesions and around islets. Given that PSCs interact closely with cancer cells to drive cancer progression, it is possible that exosomal cargo from both cancer cells and PSCs plays a role in modulating β cell function and peripheral insulin resistance. Identification of such mediators may help elucidate the mechanisms of PCRD and aid early detection of PDAC. This paper discusses the concept of a novel role of PSCs in the pathogenesis of PCRD.

scholarly journals Cell Type-Selective Expression of Circular RNAs in Human Pancreatic Islets

2018 ◽  
Vol 4 (4) ◽  
pp. 38 ◽  
Author(s):  
Simranjeet Kaur ◽  
Aashiq Mirza ◽  
Flemming Pociot
Keyword(s):  
Pancreatic Islets ◽  
Cell Function ◽  
Cell Types ◽  
Circular Rnas ◽  
Specific Gene ◽  
Cell Type ◽  
Β Cell ◽  
Human Pancreatic Islets ◽  
Exocrine Cells ◽  
Β Cell Function

Understanding distinct cell-type specific gene expression in human pancreatic islets is important for developing islet regeneration strategies and therapies to improve β-cell function in type 1 diabetes (T1D). While numerous transcriptome-wide studies on human islet cell-types have focused on protein-coding genes, the non-coding repertoire, such as long non-coding RNA, including circular RNAs, remains mostly unexplored. Here, we explored transcriptional landscape of human α-, β-, and exocrine cells from published total RNA sequencing (RNA-seq) datasets to identify circular RNAs (circRNAs). Our analysis revealed that circRNAs are highly abundant in both α- and β-cells. We identified 10,830 high-confidence circRNAs expressed in human α-, β-, and exocrine cells. The most highly expressed candidates were MAN1A2, RMST, and HIPK3 across the three cell-types. Alternate circular isoforms were observed for circRNAs in the three cell-types, indicative of potential distinct functions. Highly selective α- and β-cell circRNAs were identified, which is suggestive of their potential role in regulating β-cell function.

Maturity-Onset Diabetes of the Young: Recent Findings Indicate Insulin Resistance/Obesity Are Not Factors

1998 ◽  
Vol 24 (4) ◽  
pp. 477-480
Author(s):  
E. Ann Cabanas
Keyword(s):  
Insulin Resistance ◽  
Type 2 Diabetes ◽  
Cell Function ◽  
Age Of Onset ◽  
Pancreatic Beta Cell ◽  
Maturity Onset Diabetes ◽  
Primary Defect ◽  
Onset Diabetes ◽  
Pancreatic Beta Cell Function

Maturity-onset diabetes of the young (MODY) is a relatively rare subtype of type 2 diabetes characterized by an early age of onset and autosomal dominant inheritance. Unlike type 2 diabetes, which is often associated with insulin resistance, MODY is caused by a primary defect in pancreatic beta-cell function resulting in a decrease in insulin secretion. Obesity is not a feature of MODY. However, environmental stressors that increase the demand for insulin, such as illness or puberty, may unmask the genetically limited insulin secretory reserve of the undiagnosed MODY patient. Euglycemia is the primary goal of therapy, and diet is the cornerstone of glycemic control. Sulfonylureas and/or exogenous insulin may also be required depending on the degree of dysfunction of the beta cells.

scholarly journals Maturity-onset diabetes of the young (MODY): Recognition is the need of the hour.

JMS SKIMS ◽  
2019 ◽  
Vol 22 (2) ◽  
Author(s):  
Javaid Bhat ◽  
Shariq Rashid Masoodi ◽  
Moomin Hussain Bhat
Keyword(s):  
Type 2 Diabetes ◽  
Cell Function ◽  
Early Adulthood ◽  
Genetic Diagnosis ◽  
Dominant Mode ◽  
Maturity Onset Diabetes ◽  
Primary Defect ◽  
Onset Diabetes

Maturity-onset diabetes of the young (MODY) is a monogenic form of diabetes that is characterized by autosomal dominant mode of inheritance, an early onset diabetes, mostly mild hyperglycemia as a result of a primary defect in pancreatic β-cell function. MODY represents less than 2% of all diabetes cases and is commonly misdiagnosed as type 1 or type 2 diabetes mellitus.  It is a genetically heterogeneous form of monogenic diabetes that is caused by mutations occurring in a number of different genes thus tends to cause a slightly different variant of diabetes. At least 14 MODY subtypes with distinct genetic etiologies have been identified to date. MODY is typically diagnosed during late childhood, adolescence, or early adulthood and is usually observed to develop in adults during their late 50's. One of the main drawbacks in its diagnosis is that many people with MODY are misdiagnosed as having type 1 or type 2 diabetes owing to low index of suspicion and lack of availability of genetic testing at affordable cost. However, a molecular and genetic diagnosis results in a better treatment and could also help in identifying other family members with MODY. A high index of suspicion is required to diagnose cases of MODY as misdiagnosis and inappropriate treatment may have a significant impact on quality of life (QOL) with increased cost and unnecessary treatment with insulin.

scholarly journals CRTC2 Is Required for β-Cell Function and Proliferation

Endocrinology ◽  
2013 ◽  
Vol 154 (7) ◽  
pp. 2308-2317 ◽  
Author(s):  
Chandra E. Eberhard ◽  
Accalia Fu ◽  
Courtney Reeks ◽  
Robert A. Screaton
Keyword(s):  
Insulin Secretion ◽  
Cell Function ◽  
Critical Role ◽  
Gene Activation ◽  
Β Cell ◽  
Glucose Levels ◽  
Insulinoma Cell ◽  
Onset Diabetes ◽  
Β Cell Function ◽  
New Onset

Abstract Previous work in insulinoma cell lines has established that calcineurin plays a critical role in the activation of cAMP-responsive element binding protein (Creb), a key transcription factor required for β-cell function and survival, by dephosphorylating the Creb coactivator Creb-regulated transcription coactivator (Crtc)2 at 2 regulatory sites, Ser171 and Ser275. Here, we report that Crtc2 is essential both for glucose-stimulated insulin secretion and cell survival in the β-cell. Endogenous Crtc2 activation is achieved via increasing glucose levels to the physiological feeding range, indicating that Crtc2 is a sensor that couples ambient glucose concentrations to Creb activity in the β-cell. Immunosuppressant drugs such as cyclosporin A and tacrolimus that target the protein phosphatase calcineurin are commonly administered after organ transplantation. Chronic use is associated with reduced insulin secretion and new onset diabetes, suggestive of pancreatic β-cell dysfunction. Importantly, we show that overexpression of a Crtc2 mutant rendered constitutively active by introduction of nonphosphorylatable alanine residues at Ser171 and Ser275 permits Creb target gene activation under conditions when calcineurin is inhibited. Taken together, these data suggest that promoting Crtc2-Creb activity is required for β-cell function and proliferation and promoting this pathway could ameliorate symptoms of new onset diabetes after transplantation.

Adipokines as key players in β cell function and failure

2019 ◽  
Vol 133 (22) ◽  
pp. 2317-2327 ◽  
Author(s):  
Nicolás Gómez-Banoy ◽  
James C. Lo
Keyword(s):  
Metabolic Diseases ◽  
Cell Function ◽  
Whole Body ◽  
Pancreatic Β Cell ◽  
Β Cell ◽  
Cell Axis ◽  
Β Cell Function ◽  
Prevalence Of Obesity ◽  
Specific Factors ◽  
Whole Body Metabolism

Abstract The growing prevalence of obesity and its related metabolic diseases, mainly Type 2 diabetes (T2D), has increased the interest in adipose tissue (AT) and its role as a principal metabolic orchestrator. Two decades of research have now shown that ATs act as an endocrine organ, secreting soluble factors termed adipocytokines or adipokines. These adipokines play crucial roles in whole-body metabolism with different mechanisms of action largely dependent on the tissue or cell type they are acting on. The pancreatic β cell, a key regulator of glucose metabolism due to its ability to produce and secrete insulin, has been identified as a target for several adipokines. This review will focus on how adipokines affect pancreatic β cell function and their impact on pancreatic β cell survival in disease contexts such as diabetes. Initially, the “classic” adipokines will be discussed, followed by novel secreted adipocyte-specific factors that show therapeutic promise in regulating the adipose–pancreatic β cell axis.

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