scholarly journals The adaptor protein NumbL is involved in the control of glucolipotoxicity-induced pancreatic beta cell apoptosis

2020 ◽  
Author(s):  
Halesha D. Basavarajappa ◽  
Jose M. Irimia ◽  
Patrick T. Fueger
Keyword(s):  
Cell Death ◽  
Beta Cell ◽  
Beta Cells ◽  
Cell Apoptosis ◽  
Molecular Mechanisms ◽  
Pancreatic Beta Cell ◽  
Adaptor Protein ◽  
Beta Cell Apoptosis ◽  
Beta Cell Death ◽  
Egf Signaling

AbstractAvoiding loss of functional beta cell mass is critical for preventing or treating diabetes. Currently, the molecular mechanisms underlying beta cell death are partially understood, and there is a need to identify new targets for developing novel therapeutics to treat diabetes. Previously, our group established that Mig6, an inhibitor of EGF signaling, mediates beta cell death under diabetogenic conditions. The objective of this study was to clarify the mechanisms linking diabetogenic stimuli to beta cell death by investigating Mig6-interacting proteins. Using co-immunoprecipitation and mass spectrometry, we evaluated the binding partners of Mig6 under both normal glucose (NG) and glucolipotoxic (GLT) conditions in beta cells. We identified that Mig6 interacts dynamically with NumbL; whereas Mig6 associates with NumbL under NG, this interaction is disrupted under GLT conditions. Further, we demonstrate that siRNA-mediated suppression of NumbL expression in beta cells prevented apoptosis under GLT conditions by blocking activation of NF-κB signaling. Using co-immunoprecipitation experiments we observed that NumbL’s interactions with TRAF6, a key component of NFκB signaling, are increased under GLT conditions. The interactions among Mig6, NumbL, and TRAF6 are dynamic and context-dependent. We propose a model wherein these interactions activate pro-apoptotic NF-κB signaling while blocking pro-survival EGF signaling under diabetogenic conditions, leading to beta cell apoptosis. These findings indicate that NumbL should be further investigated as a candidate anti-diabetic therapeutic target.

scholarly journals The Class I Histone Deacetylase Inhibitor MS-275 Prevents Pancreatic Beta Cell Death Induced by Palmitate

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Valérie Plaisance ◽  
Laure Rolland ◽  
Valéry Gmyr ◽  
Jean-Sébastien Annicotte ◽  
Julie Kerr-Conte ◽  
...  
Keyword(s):  
Cell Death ◽  
Beta Cell ◽  
Er Stress ◽  
Beta Cells ◽  
Pancreatic Beta Cell ◽  
Cell Mass ◽  
Beta Cell Mass ◽  
Activating Transcription Factor 3 ◽  
Beta Cell Death ◽  
Stress Markers

Elevation of the dietary saturated fatty acid palmitate contributes to the reduction of functional beta cell mass in the pathogenesis of type 2 diabetes. The diabetogenic effect of palmitate is achieved by increasing beta cell death through induction of the endoplasmic reticulum (ER) stress markers including activating transcription factor 3 (Atf3) and CAAT/enhancer-binding protein homologous protein-10 (Chop). In this study, we investigated whether treatment of beta cells with the MS-275, a HDAC1 and HDAC3 activity inhibitor which prevents beta cell death elicited by cytokines, is beneficial for combating beta cell dysfunction caused by palmitate. We show that culture of isolated human islets and MIN6 cells with MS-275 reduced apoptosis evoked by palmitate. The protective effect of MS-275 was associated with the attenuation of the expression of Atf3 and Chop. Silencing of HDAC3, but not of HDAC1, mimicked the effects of MS-275 on the expression of the two ER stress markers and apoptosis. These data point to HDAC3 as a potential drug target for preserving beta cells against lipotoxicity in diabetes.

scholarly journals Mechanisms of Beta-Cell Apoptosis in Type 2 Diabetes-Prone Situations and Potential Protection by GLP-1-Based Therapies

2021 ◽  
Vol 22 (10) ◽  
pp. 5303
Author(s):  
Safia Costes ◽  
Gyslaine Bertrand ◽  
Magalie A. Ravier
Keyword(s):  
Type 2 Diabetes ◽  
Beta Cell ◽  
Beta Cells ◽  
Cell Apoptosis ◽  
Molecular Mechanisms ◽  
Cell Mass ◽  
Beta Cell Mass ◽  
Beta Cell Apoptosis ◽  
Chronic Hyperglycemia

Type 2 diabetes (T2D) is characterized by chronic hyperglycemia secondary to the decline of functional beta-cells and is usually accompanied by a reduced sensitivity to insulin. Whereas altered beta-cell function plays a key role in T2D onset, a decreased beta-cell mass was also reported to contribute to the pathophysiology of this metabolic disease. The decreased beta-cell mass in T2D is, at least in part, attributed to beta-cell apoptosis that is triggered by diabetogenic situations such as amyloid deposits, lipotoxicity and glucotoxicity. In this review, we discussed the molecular mechanisms involved in pancreatic beta-cell apoptosis under such diabetes-prone situations. Finally, we considered the molecular signaling pathways recruited by glucagon-like peptide-1-based therapies to potentially protect beta-cells from death under diabetogenic situations.

scholarly journals Pancreatic Beta Cell Death: Novel Potential Mechanisms in Diabetes Therapy

2018 ◽  
Vol 2018 ◽  
pp. 1-19 ◽  
Author(s):  
Joselyn Rojas ◽  
Valmore Bermudez ◽  
Jim Palmar ◽  
María Sofía Martínez ◽  
Luis Carlos Olivar ◽  
...  
Keyword(s):  
Diabetes Mellitus ◽  
Cell Death ◽  
Beta Cell ◽  
Molecular Mechanisms ◽  
Pancreatic Beta Cell ◽  
Diabetic Patients ◽  
Pathophysiological Mechanism ◽  
Islet Amyloid ◽  
Beta Cell Death

Purpose of Review. Describing the diverse molecular mechanisms (particularly immunological) involved in the death of the pancreatic beta cell in type 1 and type 2 diabetes mellitus. Recent Findings. Beta cell death is the final event in a series of mechanisms that, up to date, have not been entirely clarified; it represents the pathophysiological mechanism in the natural history of diabetes mellitus. These mechanisms are not limited to an apoptotic process only, which is characteristic of the immune-mediated insulitis in type 1 diabetes mellitus. They also include the action of proinflammatory cytokines, the production of reactive oxygen species, DNA fragmentation (typical of necroptosis in type 1 diabetic patients), excessive production of islet amyloid polypeptide with the consequent endoplasmic reticulum stress, disruption in autophagy mechanisms, and protein complex formation, such as the inflammasome, capable of increasing oxidative stress produced by mitochondrial damage. Summary. Necroptosis, autophagy, and pyroptosis are molecular mechanisms that modulate the survival of the pancreatic beta cell, demonstrating the importance of the immune system in glucolipotoxicity processes and the potential role for immunometabolism as another component of what once known as the “ominous octet.”

scholarly journals The miRNAs miR-211-5p and miR-204-5p modulate ER stress in human beta cells

2019 ◽  
Vol 63 (2) ◽  
pp. 139-149 ◽  
Author(s):  
Fabio Arturo Grieco ◽  
Andrea Alex Schiavo ◽  
Flora Brozzi ◽  
Jonas Juan-Mateu ◽  
Marco Bugliani ◽  
...  
Keyword(s):  
Type 1 Diabetes ◽  
Beta Cell ◽  
Er Stress ◽  
Beta Cells ◽  
Cell Apoptosis ◽  
Interleukin 1 ◽  
Pancreatic Beta Cell ◽  
Beta Cell Apoptosis ◽  
Human Beta Cells

miRNAs are a class of small non-coding RNAs that regulate gene expression. Type 1 diabetes is an autoimmune disease characterized by insulitis (islets inflammation) and pancreatic beta cell destruction. The pro-inflammatory cytokines interleukin 1 beta (IL1B) and interferon gamma (IFNG) are released during insulitis and trigger endoplasmic reticulum (ER) stress and expression of pro-apoptotic members of the BCL2 protein family in beta cells, thus contributing to their death. The nature of miRNAs that regulate ER stress and beta cell apoptosis remains to be elucidated. We have performed a global miRNA expression profile on cytokine-treated human islets and observed a marked downregulation of miR-211-5p. By real-time PCR and Western blot analysis, we confirmed cytokine-induced changes in the expression of miR-211-5p and the closely related miR-204-5p and downstream ER stress related genes in human beta cells. Blocking of endogenous miRNA-211-5p and miR-204-5p by the same inhibitor (it is not possible to block separately these two miRs) increased human beta cell apoptosis, as measured by Hoechst/propidium Iodide staining and by determination of cleaved caspase-3 activation. Interestingly, miRs-211-5p and 204-5p regulate the expression of several ER stress markers downstream of PERK, particularly the pro-apoptotic protein DDIT3 (also known as CHOP). Blocking CHOP expression by a specific siRNA partially prevented the increased apoptosis observed following miR-211-5p/miR-204-5p inhibition. These observations identify a novel crosstalk between miRNAs, ER stress and beta cell apoptosis in early type 1 diabetes.

Perinatal exposure to silver nanoparticles reprograms immunometabolism and promotes pancreatic beta-cell death and kidney damage in mice

2021 ◽  
pp. 1-25
Author(s):  
Ratnakar Tiwari ◽  
Radha Dutt Singh ◽  
Monika Binwal ◽  
Anurag Kumar Srivastav ◽  
Neha Singh ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Cell Death ◽  
Beta Cell ◽  
Pancreatic Beta Cell ◽  
Kidney Damage ◽  
Perinatal Exposure ◽  
Beta Cell Death

scholarly journals Bergenin protects pancreatic beta cells against cytokine-induced apoptosis in INS-1E cells

PLoS ONE ◽  
2020 ◽  
Vol 15 (12) ◽  
pp. e0241349
Author(s):  
Sajid Ali Rajput ◽  
Munazza Raza Mirza ◽  
M. Iqbal Choudhary
Keyword(s):  
Insulin Secretion ◽  
Beta Cell ◽  
Beta Cells ◽  
Proinflammatory Cytokines ◽  
Cell Apoptosis ◽  
Pancreatic Beta Cells ◽  
Cell Function ◽  
Beta Cell Apoptosis ◽  
Atp Levels ◽  
Induced Apoptosis

Beta cell apoptosis induced by proinflammatory cytokines is one of the hallmarks of diabetes. Small molecules which can inhibit the cytokine-induced apoptosis could lead to new drug candidates that can be used in combination with existing therapeutic interventions against diabetes. The current study evaluated several effects of bergenin, an isocoumarin derivative, in beta cells in the presence of cytokines. These included (i) increase in beta cell viability (by measuring cellular ATP levels) (ii) suppression of beta cell apoptosis (by measuring caspase activity), (iii) improvement in beta cell function (by measuring glucose-stimulated insulin secretion), and (iv) improvement of beta cells mitochondrial physiological functions. The experiments were carried out using rat beta INS-1E cell line in the presence or absence of bergenin and a cocktail of proinflammatory cytokines (interleukin-1beta, tumor necrosis factor-alpha, and interferon- gamma) for 48 hr. Bergenin significantly inhibited beta cell apoptosis, as inferred from the reduction in the caspase-3 activity (IC50 = 7.29 ± 2.45 μM), and concurrently increased cellular ATP Levels (EC50 = 1.97 ± 0.47 μM). Bergenin also significantly enhanced insulin secretion (EC50 = 6.73 ± 2.15 μM) in INS-1E cells, presumably because of the decreased nitric oxide production (IC50 = 6.82 ± 2.83 μM). Bergenin restored mitochondrial membrane potential (EC50 = 2.27 ± 0.83 μM), decreased ROS production (IC50 = 14.63 ± 3.18 μM), and improved mitochondrial dehydrogenase activity (EC50 = 1.39 ± 0.62 μM). This study shows for the first time that bergenin protected beta cells from cytokine-induced apoptosis and restored insulin secretory function by virtue of its anti-inflammatory, antioxidant and anti-apoptotic properties. To sum up, the above mentioned data highlight bergenin as a promising anti-apoptotic agent in the context of diabetes.

scholarly journals THE ROLE OF SURVIVIN AND RAF-1 KINASE AGAINST ENHANCEMENT OF PANCREATIC BETA-CELL APOPTOSIS IN PATIENTS WITH TYPE 2 DIABETES MELLITUS

2018 ◽  
Vol 11 (11) ◽  
pp. 344
Author(s):  
Eva Decroli ◽  
Asman Manaf ◽  
Syafril Syahbuddin ◽  
Sarwono Waspadji ◽  
Dwisari Dillasamola
Keyword(s):  
Diabetes Mellitus ◽  
Type 2 Diabetes ◽  
Type 2 Diabetes Mellitus ◽  
Beta Cell ◽  
Cell Apoptosis ◽  
Pancreatic Beta Cell ◽  
Enzyme Linked Immunosorbent Assay ◽  
Beta Cell Apoptosis

Objective: This study aimed to reveal differences in levels of survivin and Raf-1 kinase in prediabetes, controlled Type 2 diabetes mellitus (T2DM), uncontrolled T2DM, and their relationship with hemoglobin A1c (HbA1c) levels and serum triglyceride levels.Methods: This study was an observational study with a cross-sectional design. The study involved 60 people with T2DM who visited the endocrine and metabolic clinic and 30 prediabetes patients. The variables were survivin levels and Raf-1 kinase enzymes that examined using enzyme-linked immunosorbent assay techniques. HbA1c values are measured by high-performance liquid chromatography and triglyceride levels measured by enzymatic method.Results: Average levels of Raf-1 kinase were significantly higher in the prediabetes group, controlled T2DM, and uncontrolled T2DM (11.6±1.4 pg mL, 9.9±1.1 pg/mL, and 9.1±1.5 pg/mL). Survivin was significantly higher in the prediabetes group, controlled T2DM, and uncontrolled T2DM (5.4±0.4 pg mL, 5.0±0.2 pg/mL, and 4.7±0.1 pg/mL). There was no correlation between HbA1c with Raf-1 kinase levels (R=−0.215, p=0.250), but there was a correlation between HbA1c with serum survivin levels (R=−0.6, *p<0.05). There was a correlation between the levels of triglycerides with survivin but not with Raf-1 kinase (R=−0.267, *p=0.039).Conclusion: Survivin and Raf-1 kinase levels are lower in uncontrolled T2DM. This explained the role of survivin and Raf-1 kinase against enhancement of pancreatic beta-cell apoptosis in patients with T2DM.

scholarly journals Adiponectin-induced ERK and Akt Phosphorylation Protects against Pancreatic Beta Cell Apoptosis and Increases Insulin Gene Expression and Secretion

2010 ◽  
Vol 285 (44) ◽  
pp. 33623-33631 ◽  
Author(s):  
Nadeeja Wijesekara ◽  
Mansa Krishnamurthy ◽  
Alpana Bhattacharjee ◽  
Aamir Suhail ◽  
Gary Sweeney ◽  
...  
Keyword(s):  
Gene Expression ◽  
Beta Cell ◽  
Cell Apoptosis ◽  
Pancreatic Beta Cell ◽  
Insulin Gene ◽  
Beta Cell Apoptosis ◽  
Akt Phosphorylation ◽  
Insulin Gene Expression
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