scholarly journals Melatonin Attenuates Diabetic Myocardial Microvascular Injury through Activating the AMPK/SIRT1 Signaling Pathway

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Bin Wang ◽  
Jinyu Li ◽  
Mi Bao ◽  
Runji Chen ◽  
Haiyan Li ◽  
...  

Cardiac microvascular endothelial cell (CMEC) dysfunction is considered as a major contributor to the cardiovascular complications in diabetes mellitus, with oxidative stress caused by hyperglycemia playing a critical role in the progression of CMEC dysfunction. Melatonin is a kind of hormone well known for its antioxidant properties, which has potential protective effects against diabetes mellitus and its complications. However, the role of melatonin on CMEC dysfunction caused by hyperglycemia and its molecular mechanisms underlying these effects has not been clarified. Herein, we investigate the protective effects of melatonin on high glucose- (HG-) evoked oxidative stress and apoptosis in CMECs and underlying mechanisms. Our results revealed that melatonin ameliorated the injury caused by HG in primary cultured rat CMECs. Injury can be accompanied by reduced reactive oxygen species (ROS) and malondialdehyde (MDA) production, and enhanced superoxide dismutase (SOD) activity. Meanwhile, melatonin treatment significantly inhibited HG-induced CMEC apoptosis. Moreover, melatonin increased the activity of the AMPK/SIRT1 signaling axis in CMECs under HG condition, whereas administration of the AMPK inhibitor compound C or SIRT1 silencing partially abrogated the beneficial effects of melatonin. In streptozotocin- (STZ-) evoked diabetic mice, melatonin notably ameliorated cardiac dysfunction and activated the AMPK/SIRT1 signaling. In conclusion, our findings revealed that melatonin attenuates HG-induced CMEC oxidant stress, apoptosis injury, and STZ-induced cardiac dysfunction through regulating the AMPK/SIRT1 signaling pathway.

2016 ◽  
Vol 2016 ◽  
pp. 1-16 ◽  
Author(s):  
Jia-Qing Zhang ◽  
Bin-Wen Gao ◽  
Jing Wang ◽  
Qiao-Ling Ren ◽  
Jun-Feng Chen ◽  
...  

Reactive oxygen species (ROS) are closely related to the follicular granulosa cell apoptosis. Grape seed procyanidin B2 (GSPB2) has been reported to possess potent antioxidant activity. However, the GSPB2-mediated protective effects and the underlying molecular mechanisms in granulosa cell apoptosis process remain unknown. In this study, we showed for the first time that GSPB2 treatment decreased FoxO1 protein level, improved granulosa cell viability, upregulated LC3-II protein level, and reduced granulosa cell apoptosis rate. Under a condition of oxidative stress, GSPB2 reversed FoxO1 nuclear localization and increased its level in cytoplasm. In addition, FoxO1 knockdown inhibited the protective effects of GSPB2 induced. Our findings suggest that FoxO1 plays a pivotal role in regulating autophagy in granulosa cells, GSPB2 exerts a potent and beneficial role in reducing granulosa cell apoptosis and inducing autophagy process, and targeting FoxO1 could be significant in fighting against oxidative stress-reduced female reproductive system diseases.


Cells ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1850
Author(s):  
Qing Guo ◽  
Bing Wang ◽  
Xiaobo Wang ◽  
Wanli W. Smith ◽  
Yi Zhu ◽  
...  

The oxidative-stress-induced impairment of autophagy plays a critical role in the pathogenesis of Parkinson’s disease (PD). In this study, we investigated whether the alteration of Nrf2 in astrocytes protected against 6-OHDA (6-hydroxydopamine)- and rotenone-induced PD-like phenotypes, using 6-OHDA-induced rat PD and rotenone-induced Drosophila PD models. In the PD rat model, we found that Nrf2 expression was significantly higher in astrocytes than in neurons. CDDO-Me (CDDO methyl ester, an Nrf2 inducer) administration attenuated PD-like neurodegeneration mainly through Nrf2 activation in astrocytes by activating the antioxidant signaling pathway and enhancing autophagy in the substantia nigra and striatum. In the PD Drosophila model, the overexpression of Nrf2 in glial cells displayed more protective effects than such overexpression in neurons. Increased Nrf2 expression in glial cells significantly reduced oxidative stress and enhanced autophagy in the brain tissue. The administration of the Nrf2 inhibitor ML385 reduced the neuroprotective effect of Nrf2 through the inhibition of the antioxidant signaling pathway and autophagy pathway. The autophagy inhibitor 3-MA partially reduced the neuroprotective effect of Nrf2 through the inhibition of the autophagy pathway, but not the antioxidant signaling pathway. Moreover, Nrf2 knockdown caused neurodegeneration in flies. Treatment with CDDO-Me attenuated the Nrf2-knockdown-induced degeneration in the flies through the activation of the antioxidant signaling pathway and increased autophagy. An autophagy inducer, rapamycin, partially rescued the neurodegeneration in Nrf2-knockdown Drosophila by enhancing autophagy. Our results indicate that the activation of the Nrf2-linked signaling pathways in glial cells plays an important neuroprotective role in PD models. Our findings not only provide a novel insight into the mechanisms of Nrf2–antioxidant–autophagy signaling, but also provide potential targets for PD interventions.


2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Sang Mi Park ◽  
Sung Woo Kim ◽  
Eun Hye Jung ◽  
Hae Li Ko ◽  
Chae Kwang Im ◽  
...  

Sipjeondaebo-tang (SDT) is used frequently as a herbal prescription to treat deficiency syndromes in traditional Korean medicine. We investigated the hepatoprotective effects of SDT against oxidative stress and attempted to clarify the underlying molecular mechanisms. SDT pretreatment reduced arachidonic acid (AA) plus iron-mediated cytotoxicity in a concentration-dependent manner and prevented changes in apoptosis-related protein expression. In addition, SDT pretreatment significantly reduced glutathione depletion, hydrogen peroxide production, and mitochondrial dysfunction via treatment with AA plus iron. SDT increased the phosphorylation of AMP-activated protein kinase (AMPK) in accordance with the phosphorylation of Ca2+/calmodulin-dependent protein kinase kinase 2 (CaMKK2). Experiments using an AMPK chemical inhibitor (Compound C) or CaMKK2 chemical inhibitor (STO-609) suggested that the CaMKK2-AMPK signaling pathway contributes to SDT-mediated protection of mitochondria and cells. Moreover, administration of SDT for 4 consecutive days to mice significantly reduced the alanine aminotransferase and aspartate aminotransferase activities induced by carbon tetrachloride, and the numbers of degenerated hepatocytes, infiltrated inflammatory cells, nitrotyrosine-positive cells, and 4-hydroxynonenal-positive cells in liver tissue. Therefore, SDT protects hepatocytes from oxidative stress via CaMKK2-dependent AMPK activation and has the therapeutic potential to prevent or treat oxidative stress-related liver injury.


2020 ◽  
Vol 17 (4) ◽  
pp. 394-401
Author(s):  
Yuanhua Wu ◽  
Yuan Huang ◽  
Jing Cai ◽  
Donglan Zhang ◽  
Shixi Liu ◽  
...  

Background: Ischemia/reperfusion (I/R) injury involves complex biological processes and molecular mechanisms such as autophagy. Oxidative stress plays a critical role in the pathogenesis of I/R injury. LncRNAs are the regulatory factor of cerebral I/R injury. Methods: This study constructs cerebral I/R model to investigate role of autophagy and oxidative stress in cerebral I/R injury and the underline regulatory mechanism of SIRT1/ FOXO3a pathway. In this study, lncRNA SNHG12 and FOXO3a expression was up-regulated and SIRT1 expression was down-regulated in HT22 cells of I/R model. Results: Overexpression of lncRNA SNHG12 significantly increased the cell viability and inhibited cerebral ischemicreperfusion injury induced by I/Rthrough inhibition of autophagy. In addition, the transfected p-SIRT1 significantly suppressed the release of LDH and SOD compared with cells co-transfected with SIRT1 and FOXO3a group and cells induced by I/R and transfected with p-SNHG12 group and overexpression of cells co-transfected with SIRT1 and FOXO3 further decreased the I/R induced release of ROS and MDA. Conclusion: In conclusion, lncRNA SNHG12 increased cell activity and inhibited oxidative stress through inhibition of SIRT1/FOXO3a signaling-mediated autophagy in HT22 cells of I/R model. This study might provide new potential therapeutic targets for further investigating the mechanisms in cerebral I/R injury and provide.


Cells ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 629
Author(s):  
Jorge Gutiérrez-Cuevas ◽  
Ana Sandoval-Rodriguez ◽  
Alejandra Meza-Rios ◽  
Hugo Christian Monroy-Ramírez ◽  
Marina Galicia-Moreno ◽  
...  

Obesity is defined as excessive body fat accumulation, and worldwide obesity has nearly tripled since 1975. Excess of free fatty acids (FFAs) and triglycerides in obese individuals promote ectopic lipid accumulation in the liver, skeletal muscle tissue, and heart, among others, inducing insulin resistance, hypertension, metabolic syndrome, type 2 diabetes (T2D), atherosclerosis, and cardiovascular disease (CVD). These diseases are promoted by visceral white adipocyte tissue (WAT) dysfunction through an increase in pro-inflammatory adipokines, oxidative stress, activation of the renin-angiotensin-aldosterone system (RAAS), and adverse changes in the gut microbiome. In the heart, obesity and T2D induce changes in substrate utilization, tissue metabolism, oxidative stress, and inflammation, leading to myocardial fibrosis and ultimately cardiac dysfunction. Peroxisome proliferator-activated receptors (PPARs) are involved in the regulation of carbohydrate and lipid metabolism, also improve insulin sensitivity, triglyceride levels, inflammation, and oxidative stress. The purpose of this review is to provide an update on the molecular mechanisms involved in obesity-linked CVD pathophysiology, considering pro-inflammatory cytokines, adipokines, and hormones, as well as the role of oxidative stress, inflammation, and PPARs. In addition, cell lines and animal models, biomarkers, gut microbiota dysbiosis, epigenetic modifications, and current therapeutic treatments in CVD associated with obesity are outlined in this paper.


Antioxidants ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 931
Author(s):  
Anureet K. Shah ◽  
Sukhwinder K. Bhullar ◽  
Vijayan Elimban ◽  
Naranjan S. Dhalla

Although heart failure due to a wide variety of pathological stimuli including myocardial infarction, pressure overload and volume overload is associated with cardiac hypertrophy, the exact reasons for the transition of cardiac hypertrophy to heart failure are not well defined. Since circulating levels of several vasoactive hormones including catecholamines, angiotensin II, and endothelins are elevated under pathological conditions, it has been suggested that these vasoactive hormones may be involved in the development of both cardiac hypertrophy and heart failure. At initial stages of pathological stimuli, these hormones induce an increase in ventricular wall tension by acting through their respective receptor-mediated signal transduction systems and result in the development of cardiac hypertrophy. Some oxyradicals formed at initial stages are also involved in the redox-dependent activation of the hypertrophic process but these are rapidly removed by increased content of antioxidants in hypertrophied heart. In fact, cardiac hypertrophy is considered to be an adaptive process as it exhibits either normal or augmented cardiac function for maintaining cardiovascular homeostasis. However, exposure of a hypertrophied heart to elevated levels of circulating hormones due to pathological stimuli over a prolonged period results in cardiac dysfunction and development of heart failure involving a complex set of mechanisms. It has been demonstrated that different cardiovascular abnormalities such as functional hypoxia, metabolic derangements, uncoupling of mitochondrial electron transport, and inflammation produce oxidative stress in the hypertrophied failing hearts. In addition, oxidation of catecholamines by monoamine oxidase as well as NADPH oxidase activation by angiotensin II and endothelin promote the generation of oxidative stress during the prolonged period by these pathological stimuli. It is noteworthy that oxidative stress is known to activate metallomatrix proteases and degrade the extracellular matrix proteins for the induction of cardiac remodeling and heart dysfunction. Furthermore, oxidative stress has been shown to induce subcellular remodeling and Ca2+-handling abnormalities as well as loss of cardiomyocytes due to the development of apoptosis, necrosis, and fibrosis. These observations support the view that a low amount of oxyradical formation for a brief period may activate redox-sensitive mechanisms, which are associated with the development of cardiac hypertrophy. On the other hand, high levels of oxyradicals over a prolonged period may induce oxidative stress and cause Ca2+-handling defects as well as protease activation and thus play a critical role in the development of adverse cardiac remodeling and cardiac dysfunction as well as progression of heart failure.


2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Yan-Fang Xian ◽  
Zhi-Xiu Lin ◽  
Qing-Qiu Mao ◽  
Jian-Nan Chen ◽  
Zi-Ren Su ◽  
...  

The neurotoxicity of amyloid-β(Aβ) has been implicated as a critical cause of Alzheimer’s disease. Isorhynchophylline (IRN), an oxindole alkaloid isolated fromUncaria rhynchophylla,exerts neuroprotective effect againstAβ25–35-induced neurotoxicityin vitro. However, the exact mechanism for its neuroprotective effect is not well understood. The present study aimed to investigate the molecular mechanisms underlying the protective action of IRN againstAβ25–35-induced neurotoxicity in cultured rat pheochromocytoma (PC12) cells. Pretreatment with IRN significantly increased the cell viability, inhibited the release of lactate dehydrogenase and the extent of DNA fragmentation inAβ25–35-treated cells. IRN treatment was able to enhance the protein levels of phosphorylated Akt (p-Akt) and glycogen synthase kinase-3β(p-GSK-3β). Lithium chloride blockedAβ25–35-induced cellular apoptosis in a similar manner as IRN, suggesting that GSK-3βinhibition was involved in neuroprotective action of IRN. Pretreatment with LY294002 completely abolished the protective effects of IRN. Furthermore, IRN reversedAβ25–35-induced attenuation in the level of phosphorylated cyclic AMP response element binding protein (p-CREB) and the effect of IRN could be blocked by the PI3K inhibitor. These experimental findings unambiguously suggested that the protective effect of IRN againstAβ25–35-induced apoptosis in PC12 cells was associated with the enhancement of p-CREB expression via PI3K/Akt/GSK-3βsignaling pathway.


2021 ◽  
Vol 22 (13) ◽  
pp. 6946
Author(s):  
Weishun Tian ◽  
Suyoung Heo ◽  
Dae-Woon Kim ◽  
In-Shik Kim ◽  
Dongchoon Ahn ◽  
...  

Free radical generation and oxidative stress push forward an immense influence on the pathogenesis of neurodegenerative diseases such as Alzheimer’s disease and Parkinson’s disease. Maclura tricuspidata fruit (MT) contains many biologically active substances, including compounds with antioxidant properties. The current study aimed to investigate the neuroprotective effects of MT fruit on hydrogen peroxide (H2O2)-induced neurotoxicity in SH-SY5Y cells. SH-SY5Y cells were pretreated with MT, and cell damage was induced by H2O2. First, the chemical composition and free radical scavenging properties of MT were analyzed. MT attenuated oxidative stress-induced damage in cells based on the assessment of cell viability. The H2O2-induced toxicity caused by ROS production and lactate dehydrogenase (LDH) release was ameliorated by MT pretreatment. MT also promoted an increase in the expression of genes encoding the antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT). MT pretreatment was associated with an increase in the expression of neuronal genes downregulated by H2O2. Mechanistically, MT dramatically suppressed H2O2-induced Bcl-2 downregulation, Bax upregulation, apoptotic factor caspase-3 activation, Mitogen-activated protein kinase (MAPK) (JNK, ERK, and p38), and Nuclear factor-κB (NF-κB) activation, thereby preventing H2O2-induced neurotoxicity. These results indicate that MT has protective effects against H2O2-induced oxidative damage in SH-SY5Y cells and can be used to prevent and protect against neurodegeneration.


Hypertension ◽  
2021 ◽  
Vol 78 (Suppl_1) ◽  
Author(s):  
Yves Wang ◽  
Nhu Nguyen ◽  
Keith Nehrke ◽  
Paul S Brookes ◽  
Thu H Le

The glutathione S-transferase ( Gst ) gene family encodes antioxidant enzymes. In humans, a common null allele deletion variant of GST μ-1 ( GSTM1 ) is highly prevalent across populations and is associated with increased risk and progression of various diseases. Using a Gstm1 knockout (KO) mouse model, we previously showed that KO mice with angiotensin II-induced hypertension (HTN) have increased kidney injury compared to wild-type (WT) controls, mediated by elevated oxidative stress. In the same mouse model, we have recently reported that in a Langendorff-perfused cardiac ischemia-reperfusion injury (IRI) model, where damage is also mediated by oxidative stress, male KO hearts are protected while females are not. Here, we investigated the molecular mechanisms for this difference in male hearts. WT and KO mice of both sexes were studied at 12-20 weeks of age. Hearts were snap frozen at baseline and after 25 min of global ischemia, and kidneys were collected at baseline and 4 weeks following HTN induction. A panel of 18 Gst genes were probed by qPCR from baseline hearts and kidneys of both sexes. Global metabolites were assayed using Metabolon, Inc. from hearts of both sexes and kidneys of males, at both baseline and diseased states. Analysis by qPCR (n = 3/group) showed that male, but not female, KO hearts had upregulation of other Gst s. In contrast, no significant differences between were found in male kidneys. Metabolomics (n = 6/group) detected 695 metabolites in hearts and 926 in kidneys. There were increases in several metabolites in KO vs. WT hearts including those with antioxidant properties. Notably, increases in carnosine and anserine were observed in KO male hearts but not in female hearts, while that of other antioxidant-related metabolites were observed in hearts of both sexes, but not in kidneys. HTN induced significant increases in metabolites in KO vs. WT kidneys in the pathways related to and linking methionine, cysteine, and glutathione, which were not observed in hearts. In this study, gene expression and metabolites suggest that the mechanisms compensating for the loss of GSTM1 are both tissue and sex specific. The resulting differences in antioxidant enzymes and metabolites may explain the unexpected protection for male Gstm1 KO hearts in IRI.


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