Dataset Information

Reduced insulin secretion in WFS1-deficient mice may be related to downregulation of Trpm5

ABSTRACT: Wolfram syndrome, an autosomal recessive disorder characterized by juvenile-onset diabetes mellitus and optic atrophy, is caused by mutations in the WFS1 gene. WFS1 encodes an endoplasmic reticulum resident transmembrane protein. The Wfs1-null mice exhibit progressive insulin deficiency and diabetes. The aim of the present study was to describe the insulin secretion and transcriptome of pancreatic islets in WFS1-deficient mice. WFS1-deficient (Wfs1KO) mice had considerably less pancreatic islets than heterozygous (Wfs1HZ) or wild-type (WT) mice. Wfs1KO pancreatic islets secreted less insulin after stimulation with 2 and 10 mM glucose and with tolbutamide solution compared to WT and Wfs1HZ islets, but not after stimulation with 20 mM glucose. Differences in proinsulin amount were not statistically significant although there was a trend that Wfs1KO had an increased level of proinsulin. After stimulation with 2 mM glucose solution the proinsulin/insulin ratio in Wfs1KO was significantly higher than that of WT and Wfs1HZ. RNA-seq from pancreatic islets found melastatin-related transient receptor potential subfamily member 5 protein gene (Trpm5) to be downregulated in WFS1-deficient mice. Functional annotation of RNA sequencing results showed that WFS1 deficiency influenced significantly the pathways related to tissue morphology, endocrine system development and function, molecular transport network. These findings suggest an interactive role of WFS1 and TRPM5 in insulin secretion.

ORGANISM(S): Mus musculus

PROVIDER: GSE65929 | GEO | 2015/02/14

SECONDARY ACCESSION(S): PRJNA275429

REPOSITORIES: GEO

ACCESS DATA

Similar Datasets

Project description:Maternal low-protein diet increases the susceptibility of offspring to type 2 diabetes. An insult to the pancreas during development can have long-term consequences on ?-cell mass and function. Because nutrients and growth factors signaling converge on mTOR, we hypothesized that mTOR plays a central role in ?-cell programming during fetal development. In this study, we revealed that newborns of dams exposed to low-protein diet (LP0.5) throughout pregnancy exhibited decreased insulin levels, ?-cell fraction, and mTOR signaling. Adult LP0.5 offspring demonstrated enhanced insulin sensitivity but remained glucose intolerant due to an insulin secretory defect and not reduced ?-cell mass. The insulin secretory defect was distal to Ca2+ influx, at the level of proinsulin biosynthesis and insulin content. LP0.5 islets exhibited reduced mTOR protein and increased expression of specific microRNAs. The reductions in mTOR protein and insulin secretion in LP0.5 islets were restored to normal by blockade of microRNAs 199a-3p and 342. Finally, transient activation of mTORC1 signaling in ?-cells during the last week of pregnancy rescued the neonatal ?-cell fraction defect and metabolic abnormalities in LP0.5 mice. These findings identify a major role of microRNAs and mTOR in ?-cell programing by maternal low-protein diet. To investigate which microRNAs are altered in islets isolated from 2-3 months old male offspring of dams fed low-protein diet (LP0.5) or control diet throughout pregnancy Pancreatic islets were isolated from 2-3 months old male offspring of dams fed low-protein diet (LP0.5) or control diet throughout pregnancy. Islets were isolated by collagenase digestion. The pancreas was perfused via the common duct with 1 mg/ml collagenase XI (Sigma-Aldrich) in HBSS (Life Technologies). Pancreatic digestion was carried out at 37 °C for 15 min, after which cold HBSS with 2.5% FBS (Life Technologies) was added. The suspension was centrifuged at 1000 rpm for 30s, washed 3 times with HBSS with 2.5% FBS, resuspended in RPMI complete media (RPMI 1640 with 5 mM Glucose, 10% FBS,100 IU/ml penicillin, 100 g/ml streptomycin) and poured onto a 70 µm cell strainer (BD Falcon, BD Biosciences). Islets were rinsed and handpicked. Islets were allowed to recover overnight in RPMI complete media before RNA isolation using MirVana Kit (Life Technologies).

Project description:The NF-κB pathway is a master regulator of inflammatory processes and is implicated in insulin resistance and pancreatic beta cell dysfunction in the metabolic syndrome. While canonical NF-κB signaling is well studied, there is little information on the divergent non-canonical NF-κB pathway in the context of pancreatic islet dysfunction in diabetes. Here, we demonstrate that pharmacological activation of the non-canonical NF-κB inducing kinase (NIK) disrupts glucose homeostasis in zebrafish in vivo. Further, we identify NIK as a critical negative regulator of beta cell function as pharmacological NIK activation results in impaired glucose-stimulated insulin secretion in mouse and human islets. NIK levels are elevated in pancreatic islets isolated from diet-induced obese (DIO) mice, which exhibit increased processing of non-canonical NF-κB components p100 to p52, and accumulation of RelB. Tumor necrosis factor α (TNFα) and receptor activator of NF-κB ligand (RANKL), two ligands associated with diabetes, induce NIK in islets. Mice with constitutive beta cell intrinsic NIK activation present impaired insulin secretion with DIO. NIK activation triggers the non-canonical NF-κB transcriptional network to induce genes identified in human type 2 diabetes genome-wide association studies linked to beta cell failure. These studies reveal that NIK contributes a central mechanism for beta cell failure in diet-induced obesity. We identify a role for Nuclear Factor inducing κB (NIK) in pancreatic beta cell failure. NIK activation disrupts glucose homeostasis in zebrafish in vivo and impairs glucose-stimulated insulin secretion in mouse and human islets in vitro. NIK activation also perturbs beta cell insulin secretion in a diet-induced obesity mouse model. These studies reveal that NIK contributes a central mechanism for beta cell failure in obesity. To uncover the role of NIK in pancreatic beta cells, we performed a gene expression microarray analysis comparing pancreatic islets with constitutive beta cell intrinsicNIK activation from the 16 week old mice (beta cell specific TRAF2 and TRAF2 knockout mice) to their controls (n=3 per group).

Dataset Information

Reduced insulin secretion in WFS1-deficient mice may be related to downregulation of Trpm5

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure