scholarly journals Melatonin Suppresses Ferroptosis Induced by High Glucose via Activation of the Nrf2/HO-1 Signaling Pathway in Type 2 Diabetic Osteoporosis

2020 ◽  
Vol 2020 ◽  
pp. 1-18
Author(s):  
Hongdong Ma ◽  
Xindong Wang ◽  
Weilin Zhang ◽  
Haitian Li ◽  
Wei Zhao ◽  
...  

Ferroptosis is recently identified, an iron- and reactive oxygen species- (ROS-) dependent form of regulated cell death. This study was designed to determine the existence of ferroptosis in the pathogenesis of type 2 diabetic osteoporosis and confirm that melatonin can inhibit the ferroptosis of osteoblasts through activating Nrf2/HO-1 signaling pathway to improve bone microstructure in vivo and in vitro. We treated MC3T3-E1 cells with different concentrations of melatonin (1, 10, or 100 μM) and exposed them to high glucose (25.5 mM) for 48 h in vitro. Our data showed that high glucose can induce osteoblast cytotoxicity and the accumulation of lipid peroxide, the mitochondria of osteoblast show the same morphology changes as the erastin treatment group, and the expression of ferroptosis-related proteins glutathione peroxidase 4 (GPX4) and cystine-glutamate antiporter (SLC7A11) is downregulated, but these effects were reversed by ferroptosis inhibitor ferrastatin-1 and iron chelator deferoxamine (DFO). Furthermore, western blot and real-time polymerase chain reaction were used to detect the expression levels of nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1); osteogenic capacity was evaluated by alizarin red S staining and the expression of osteoprotegerin, osteocalcin, and alkaline phosphatase; the results showed that the expression levels of these proteins in osteoblasts with 1, 10, or 100 μM melatonins were significantly higher than the high glucose group, but after using Nrf2-SiRNA interference, the therapeutic effect of melatonin was significantly inhibited. We also performed in vivo experiments in a diabetic rat model treated with two concentrations of melatonin (10, 50 mg/kg). Dynamic bone histomorphometry and micro-CT were used to observe the rat bone microstructure, and the expression of GPX4 and Nrf2 was determined by immunohistochemistry. Here, we first report that high glucose induces ferroptosis via increased ROS/lipid peroxidation/glutathione depletion in type 2 diabetic osteoporosis. More importantly, melatonin significantly reduced the level of ferroptosis and improved the osteogenic capacity of MC3T3-E1 through activating the Nrf2/HO-1 pathway in vivo and in vitro.

2021 ◽  
Author(s):  
Hongdong Ma ◽  
yueming Jiang ◽  
Haitian Li ◽  
Maowei Yang

Abstract In recent years, type 2 diabetic osteoporosis has become a research hotspot for the complications of diabetes, but the specific mechanism of its occurrence and development remain unknown. Ferroptosis caused by iron overload is considered to be one of the important cause of type 2 diabetic osteoporosis. Polycytosine RNA-binding protein 1 (PCBP1), an iron ion chaperone, was considered as a protector of ferroptosis. The present study aimed to investigate the existence of ferroptosis and specific role of PCBP1 in the development of type 2 diabetes. Firstly, a Cell Counting Kit-8 assay was used to detect the changes of osteoblast viability under the influence of high glucose (HG) and/or ferroptosis inhibitor given at different concentrations and at different times. In addition, the morphological changes of mitochondria in osteoblasts under high glucose were examined via transmission electron microscopy, and the expression levels of PCBP1, ferritin and the ferroptosis-related protein glutathione peroxidase 4 (GPX4) under the action of high glucose were detected via western blotting. Furthermore, a lentivirus was used to silence and overexpress PCBP1. Western blotting was used to detect the expression of levels of the osteoblast functional proteins osteoprotegerin (OPG) and osteocalcin (OCN), while flow cytometry was used to detect the changes of reactive oxygen species (ROS) levels in each group. Under the action of high glucose, the viability of osteoblasts was significantly decreased and the number of mitochondria undergoing atrophy was significantly increased, PCBP1 and ferritin expression levels were increased and GPX4 expression was decreased. Western blotting results demonstrated that infection of the lentivirus overexpressing PCBP1, increased the expression levels of ferritin, GPX4, OPG and OCN, compared with the high glucose group. The flow cytometry results identified a reduction in ROS, and an opposite result was obtained after silencing PCBP1. In conclusion, it was suggested that PCBP1 may protect osteoblasts and reduce the harm caused by ferroptosis by promoting ferritin expression under a high glucose environment. Moreover, it was indicated that PCBP1 may be a potential therapeutic target for treating type 2 diabetic osteoporosis.


2021 ◽  
Author(s):  
Heera Ram ◽  
Pramod Kumar ◽  
Ashok Purohit ◽  
Priya Kashyap ◽  
Suresh Kumar ◽  
...  

Abstract Context: Withania coagulans (Stocks) Dunal fruits are used in the therapeutics of several ailments due to possessing of potent phytoconstituents which is also used traditionally for curing the diabetes. Objective: The present study was assessing the amelioration potential of the phytochemicals of an ethanol fruit extract of Withania coagulans (Stocks) Dunal in the HOMA (Homeostatic model assessment) indices and pancreatic endocrinal tissues by inhibition of DPP-4 and antioxidants activities.Material and methods: The identification of phytoconstituents of the test extract was performed by LCMS. Further, assessments of in-vitro, in-vivo and in-silico were achieved by following standard methods. In-vivo studies were conducted on type-2 diabetic ratsResults: The chosen extract inhibited DPP-4 activity by 63.2% in an in vitro assay as well as significantly inhibit serum DPP-4 levels. Accordingly, the administration of the ethanol fruit extract resulted in a significant (𝑃≤ 0.001) alterations in the lipid profile, antioxidant levels, and HOMA indices. Moreover, pancreatic endocrinal tissues (islet of Langerhans) appeared to have the restoration of normal histoarchitecture as evidenced by increased cellular mass. Molecular docking (Protein - ligands) of identified phytoconstituents with DPP-4 (target enzyme) shown incredibly low binding energy (Kcal/mol) as required for ideal interactions. ADMET analysis of the pharmacokinetics of the identified phytoconstituents indicated an ideal profile as per Lipinski laws. Conclusion: It can be concluded that the phytoconstituents of an ethanol fruit extract of Withania coagulans have the potential to inhibit DPP-4 which result in improved glucose homeostasis and restoration of pancreatic endocrinal tissues in type-2 diabetic rats.


2020 ◽  
Author(s):  
Heera Ram ◽  
Pramod Kumar ◽  
Ashok Purohit ◽  
Priya Kashyap ◽  
Suresh Kumar ◽  
...  

Abstract Context: Withania coagulans (Stocks) Dunal fruits are used in the therapeutics of several ailments due to possessing of potent phytoconstituents which is also used traditionally for curing the diabetes. Objective: The present study was assessing the amelioration potential of the phytochemicals of an ethanol fruit extract of Withania coagulans (Stocks) Dunal in the HOMA (Homeostatic model assessment) indices and pancreatic endocrinal tissues by inhibition of DPP-4 and antioxidants activities.Material and methods: The identification of phytoconstituents of phytochemicals of the test extract was performed by LCMS. Further, assessments of in-vitro, in-vivo and in-silico were achieved by following standard methods. In-vivo studies were conducted on type-2 diabetic ratsResults: The chosen extract inhibited DPP-4 activity by 63.2% in an in vitro assay. Accordingly, the administration of the ethanol fruit extract resulted in a significant (𝑃≤ 0.001) alterations in the lipid profile, antioxidant levels, and HOMA indices. Moreover, pancreatic endocrinal tissues (islet of Langerhans) appeared to have the restoration of normal histoarchitecture as evidenced by increased cellular mass. Molecular docking (Protein - ligands) of identified phytoconstituents with DPP-4 (target enzyme) shown incredibly low binding energy (Kcal/mol) as required for ideal interactions. ADMET analysis of the pharmacokinetics of the identified phytoconstituents indicated an ideal profile as per Lipinski laws. Conclusion: It can be concluded that the phytoconstituents of an ethanol fruit extract of Withania coagulans have the potential to inhibit DPP-4 which result in improved glucose homeostasis and restoration of pancreatic endocrinal tissues in type-2 diabetic rats.


2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Kaifeng Li ◽  
Mengen Zhai ◽  
Liqing Jiang ◽  
Fan Song ◽  
Bin Zhang ◽  
...  

Hyperglycemia-induced oxidative stress and fibrosis play a crucial role in the development of diabetic cardiomyopathy (DCM). Tetrahydrocurcumin (THC), a major bioactive metabolite of natural antioxidant curcumin, is reported to exert even more effective antioxidative and superior antifibrotic properties as well as anti-inflammatory and antidiabetic abilities. This study was designed to investigate the potential protective effects of THC on experimental DCM and its underlying mechanisms, pointing to the role of high glucose-induced oxidative stress and interrelated fibrosis. In STZ-induced diabetic mice, oral administration of THC (120 mg/kg/d) for 12 weeks significantly improved the cardiac function and ameliorated myocardial fibrosis and cardiac hypertrophy, accompanied by reduced reactive oxygen species (ROS) generation. Mechanically, THC administration remarkably increased the expression of the SIRT1 signaling pathway both in vitro and in vivo, further evidenced by decreased downstream molecule Ac-SOD2 and enhanced deacetylated production SOD2, which finally strengthened antioxidative stress capacity proven by repaired activities of SOD and GSH-Px and reduced MDA production. Additionally, THC treatment accomplished its antifibrotic effect by depressing the ROS-induced TGFβ1/Smad3 signaling pathway followed by reduced expression of cardiac fibrotic markers α-SMA, collagen I, and collagen III. Collectively, these finds demonstrated the therapeutic potential of THC treatment to alleviate DCM mainly by attenuating hyperglycemia-induced oxidative stress and fibrosis via activating the SIRT1 pathway.


2019 ◽  
Vol 240 (2) ◽  
pp. 195-214 ◽  
Author(s):  
Te Du ◽  
Liu Yang ◽  
Xu Xu ◽  
Xiaofan Shi ◽  
Xin Xu ◽  
...  

Vincamine, a monoterpenoid indole alkaloid extracted from the Madagascar periwinkle, is clinically used for the treatment of cardio-cerebrovascular diseases, while also treated as a dietary supplement with nootropic function. Given the neuronal protection of vincamine and the potency of β-cell amelioration in treating type 2 diabetes mellitus (T2DM), we investigated the potential of vincamine in protecting β-cells and ameliorating glucose homeostasis in vitro and in vivo. Interestingly, we found that vincamine could protect INS-832/13 cells function by regulating G-protein-coupled receptor 40 (GPR40)/cAMP/Ca2+/IRS2/PI3K/Akt signaling pathway, while increasing glucose-stimulated insulin secretion (GSIS) by modulating GPR40/cAMP/Ca2+/CaMKII pathway, which reveals a novel mechanism underlying GPR40-mediated cell protection and GSIS in INS-832/13 cells. Moreover, administration of vincamine effectively ameliorated glucose homeostasis in either HFD/STZ or db/db type 2 diabetic mice. To our knowledge, our current work might be the first report on vincamine targeting GPR40 and its potential in the treatment of T2DM.


2020 ◽  
Vol 40 (6) ◽  
Author(s):  
MingJun Shi ◽  
PingPing Tian ◽  
ZhongQiang Liu ◽  
Fan Zhang ◽  
YingYing Zhang ◽  
...  

Abstract Diabetic nephropathy (DN) commonly causes end-stage renal disease (ESRD). Increasing evidence indicates that abnormal miRNA expression is tightly associated with chronic kidney disease (CKD). This work aimed to investigate whether miR-27a can promote the occurrence of renal fibrosis in DN by suppressing the expression of secreted frizzled-related protein 1 (Sfrp1) to activate Wnt/β-catenin signalling. Therefore, we assessed the expression levels of miR-27a, Sfrp1, Wnt signalling components, and extracellular matrix (ECM)-related molecules in vitro and in vivo. Sfrp1 was significantly down-regulated in a high-glucose environment, while miR-27a levels were markedly increased. A luciferase reporter assay confirmed that miR-27a down-regulated Sfrp1 by binding to the 3′ untranslated region directly. Further, NRK-52E cells under high-glucose conditions underwent transfection with miR-27a mimic or the corresponding negative control, miR-27a inhibitor or the corresponding negative control, si-Sfrp1, or combined miR-27a inhibitor and si-Sfrp1. Immunoblotting and immunofluorescence were performed to assess the relative expression levels of Wnt/β-catenin signalling and ECM components. The mRNA levels of Sfrp1, miR-27a, and ECM-related molecules were also detected by quantitative real-time PCR (qPCR). We found that miR-27a inhibitor inactivated Wnt/β-catenin signalling and reduced ECM deposition. Conversely, Wnt/β-catenin signalling was activated, while ECM deposition was increased after transfection with si-Sfrp1. Interestingly, miR-27a inhibitor attenuated the effects of si-Sfrp1. We concluded that miR-27a down-regulated Sfrp1 and activated Wnt/β-catenin signalling to promote renal fibrosis.


2014 ◽  
Vol 127 (2) ◽  
pp. 91-100 ◽  
Author(s):  
Qian Wang ◽  
Ning Wang ◽  
Mei Dong ◽  
Fang Chen ◽  
Zhong Li ◽  
...  

In the present study, we demonstrate that GdCl3 reduces hyperglycaemia via the Akt/FoxO1-induced suppression of hepatic gluconeogenesis, both in Type 2 diabetic mice (in vivo) and in hepatocarcinoma cells (in vitro), suggesting that GdCl3 may be a potential therapeutic target for diabetes.


2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Heera Ram ◽  
Pramod Kumar ◽  
Ashok Purohit ◽  
Priya Kashyap ◽  
Suresh Kumar ◽  
...  

Abstract Context Withania coagulans (Stocks) Dunal fruits are used in the therapeutics of several ailments due to possessing of potent phytoconstituents which is also used traditionally for curing the diabetes. Objective The present study was assessing the amelioration potential of the phytochemicals of an ethanol fruit extract of W. coagulans (Stocks) Dunal in the HOMA (Homeostatic model assessment) indices and pancreatic endocrinal tissues by inhibition of DPP-4 and antioxidants activities. Material and methods The identification of phytoconstituents of the test extract was performed by LCMS. Further, assessments of in-vitro, in-vivo and in-silico were achieved by following standard methods. In-vivo studies were conducted on type-2 diabetic rats. Results The chosen extract inhibited DPP-4 activity by 63.2% in an in vitro assay as well as significantly inhibit serum DPP-4 levels. Accordingly, the administration of the ethanol fruit extract resulted in a significant (P ≤ 0.001) alterations in the lipid profile, antioxidant levels, and HOMA indices. Moreover, pancreatic endocrinal tissues (islet of Langerhans) appeared to have the restoration of normal histoarchitecture as evidenced by increased cellular mass. Molecular docking (Protein-ligands) of identified phytoconstituents with DPP-4 (target enzyme) shown incredibly low binding energy (Kcal/mol) as required for ideal interactions. ADMET analysis of the pharmacokinetics of the identified phytoconstituents indicated an ideal profile as per Lipinski laws. Conclusion It can be concluded that the phytoconstituents of an ethanol fruit extract of W. coagulans have the potential to inhibit DPP-4 which result in improved glucose homeostasis and restoration of pancreatic endocrinal tissues in type-2 diabetic rats.


2021 ◽  
Vol 12 ◽  
Author(s):  
Yu Liu ◽  
Da-Wei Wang ◽  
Dan Wang ◽  
Bin-Hong Duan ◽  
Hong-Yu Kuang

Background/AimsExenatide is a glucagon-like polypeptide-1 analog, whose main clinical use is to treat type 2 diabetes. However, the mechanism of exenatide in mitigating non-alcoholic steatohepatitis (NASH) remains unclear. This study aimed to investigate the in vitro and in vivo effect of exenatide on NASH.MethodsLeptin receptor-deficient C57BL/KsJ- db/db male mice were fed with methionine-choline-deficient (MCD) diet for 4 weeks to induce NASH, while oleic acid/LPS-treated HepG2 cells were used as an in vitro cell model. Exenatide (20 µg/kg/day, subcutaneous) and specific exenatide inhibitors (20 µg/kg/day, intraperitoneal) were used to determine the effects of exenatide on NASH.ResultsExenatide treatment inhibited the pyroptosis signaling pathway to attenuate NASH.ConclusionTo the best of our knowledge, this report provides the first evidence showing that exenatide attenuated NASH by inhibiting the pyroptosis signaling pathway. Exenatide thus has important pathophysiological functions in NASH and may represent a useful new therapeutic target.


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