scholarly journals miR‑192 is upregulated in T1DM, regulates pancreatic β‑cell development and inhibits insulin secretion through suppressing GLP‑1 expression

Author(s):  
Wen Pan ◽  
Yanan Zhang ◽  
Chun Zeng ◽  
Fen Xu ◽  
Jinhua Yan ◽  
...  
2001 ◽  
Vol 21 (16) ◽  
pp. 5624-5630 ◽  
Author(s):  
Tadahiro Kitamura ◽  
Yoshiaki Kido ◽  
Serge Nef ◽  
Jussi Merenmies ◽  
Luis F. Parada ◽  
...  

ABSTRACT Receptors of the insulin/insulinlike growth factor (IGF) family have been implicated in the regulation of pancreatic β-cell growth and insulin secretion. The insulin receptor-related receptor (IRR) is an orphan receptor of the insulin receptor gene (Ir) subfamily. It is expressed at considerably higher levels in β cells than either insulin or IGF-1 receptors, and it has been shown to engage in heterodimer formation with insulin or IGF-1 receptors. To address whether IRR plays a physiologic role in β-cell development and regulation of insulin secretion, we have characterized mice lacking IRR and generated a combined knockout of Irand Irr. We report that islet morphology, β-cell mass, and secretory function are not affected in IRR-deficient mice. Moreover, lack of IRR does not impair compensatory β-cell hyperplasia in insulin-resistant Ir +/− mice, nor does it affect β-cell development and function inIr −/− mice. We conclude that glucose-stimulated insulin secretion and embryonic β-cell development occur normally in mice lacking Irr.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Brenda Strutt ◽  
Sandra Szlapinski ◽  
Thineesha Gnaneswaran ◽  
Sarah Donegan ◽  
Jessica Hill ◽  
...  

AbstractThe apelin receptor (Aplnr) and its ligands, Apelin and Apela, contribute to metabolic control. The insulin resistance associated with pregnancy is accommodated by an expansion of pancreatic β-cell mass (BCM) and increased insulin secretion, involving the proliferation of insulin-expressing, glucose transporter 2-low (Ins+Glut2LO) progenitor cells. We examined changes in the apelinergic system during normal mouse pregnancy and in pregnancies complicated by glucose intolerance with reduced BCM. Expression of Aplnr, Apelin and Apela was quantified in Ins+Glut2LO cells isolated from mouse pancreata and found to be significantly higher than in mature β-cells by DNA microarray and qPCR. Apelin was localized to most β-cells by immunohistochemistry although Aplnr was predominantly associated with Ins+Glut2LO cells. Aplnr-staining cells increased three- to four-fold during pregnancy being maximal at gestational days (GD) 9–12 but were significantly reduced in glucose intolerant mice. Apelin-13 increased β-cell proliferation in isolated mouse islets and INS1E cells, but not glucose-stimulated insulin secretion. Glucose intolerant pregnant mice had significantly elevated serum Apelin levels at GD 9 associated with an increased presence of placental IL-6. Placental expression of the apelinergic axis remained unaltered, however. Results show that the apelinergic system is highly expressed in pancreatic β-cell progenitors and may contribute to β-cell proliferation in pregnancy.


Author(s):  
Natanya Kerper ◽  
Sudipta Ashe ◽  
Matthias Hebrok

2010 ◽  
Vol 30 (6) ◽  
pp. 445-453 ◽  
Author(s):  
Marta Michalska ◽  
Gabriele Wolf ◽  
Reinhard Walther ◽  
Philip Newsholme

Various pancreatic β-cell stressors including cytokines and saturated fatty acids are known to induce oxidative stress, which results in metabolic disturbances and a reduction in insulin secretion. However, the key mechanisms underlying dysfunction are unknown. We investigated the effects of prolonged exposure (24 h) to pro-inflammatory cytokines, H2O2 or PA (palmitic acid) on β-cell insulin secretion, ATP, the NADPH oxidase (nicotinamide adenine dinucleotide phosphate oxidase) component p47phox and iNOS (inducible nitric oxide synthase) levels using primary mouse islets or clonal rat BRIN-BD11 β-cells. Addition of a pro-inflammatory cytokine mixture [IL-1β (interleukin-1β), TNF-α (tumour necrosis factor-α) and IFN-γ (interferon-γ)] or H2O2 (at sub-lethal concentrations) inhibited chronic (24 h) levels of insulin release by at least 50% (from islets and BRIN-BD11 cells), while addition of the saturated fatty acid palmitate inhibited acute (20 min) stimulated levels of insulin release from mouse islets. H2O2 decreased ATP levels in the cell line, but elevated p47phox and iNOS levels as did cytokine addition. Similar effects were observed in mouse islets with respect to elevation of p47phox and iNOS levels. Addition of antioxidants SOD (superoxide dismutase), Cat (catalase) and NAC (N-acetylcysteine) attenuated H2O2 or the saturated fatty acid palmitate-dependent effects, but not cytokine-induced dysfunction. However, specific chemical inhibitors of NADPH oxidase and/or iNOS appear to significantly attenuate the effects of cytokines, H2O2 or fatty acids in islets. While pro-inflammatory cytokines are known to increase p47phox and iNOS levels in β-cells, we now report that H2O2 can increase levels of the latter two proteins, suggesting a key role for positive-feedback redox sensitive regulation of β-cell dysfunction.


2018 ◽  
Vol 45 (3) ◽  
pp. 347-361.e5 ◽  
Author(s):  
Chen Huang ◽  
Emily M. Walker ◽  
Prasanna K. Dadi ◽  
Ruiying Hu ◽  
Yanwen Xu ◽  
...  

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Idil I. Aigha ◽  
Essam M. Abdelalim

Abstract Understanding the biology underlying the mechanisms and pathways regulating pancreatic β cell development is necessary to understand the pathology of diabetes mellitus (DM), which is characterized by the progressive reduction in insulin-producing β cell mass. Pluripotent stem cells (PSCs) can potentially offer an unlimited supply of functional β cells for cellular therapy and disease modeling of DM. Homeobox protein NKX6.1 is a transcription factor (TF) that plays a critical role in pancreatic β cell function and proliferation. In human pancreatic islet, NKX6.1 expression is exclusive to β cells and is undetectable in other islet cells. Several reports showed that activation of NKX6.1 in PSC-derived pancreatic progenitors (MPCs), expressing PDX1 (PDX1+/NKX6.1+), warrants their future commitment to monohormonal β cells. However, further differentiation of MPCs lacking NKX6.1 expression (PDX1+/NKX6.1−) results in an undesirable generation of non-functional polyhormonal β cells. The importance of NKX6.1 as a crucial regulator in MPC specification into functional β cells directs attentions to further investigating its mechanism and enhancing NKX6.1 expression as a means to increase β cell function and mass. Here, we shed light on the role of NKX6.1 during pancreatic β cell development and in directing the MPCs to functional monohormonal lineage. Furthermore, we address the transcriptional mechanisms and targets of NKX6.1 as well as its association with diabetes.


Sign in / Sign up

Export Citation Format

Share Document