scholarly journals How AMPK and PKA Interplay to Regulate Mitochondrial Function and Survival in Models of Ischemia and Diabetes

2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Jingdian Zhang ◽  
Yumeng Wang ◽  
Xiaofeng Liu ◽  
Ruben K. Dagda ◽  
Ying Zhang

Adenosine monophosphate-activated protein kinase (AMPK) is a conserved, redox-activated master regulator of cell metabolism. In the presence of oxidative stress, AMPK promotes cytoprotection by enhancing the conservation of energy by suppressing protein translation and by stimulating autophagy. AMPK interplays with protein kinase A (PKA) to regulate oxidative stress, mitochondrial function, and cell survival. AMPK and dual-specificity A-kinase anchoring protein 1 (D-AKAP1), a mitochondrial-directed scaffold of PKA, interact to regulate mitochondrial function and oxidative stress in cardiac and endothelial cells. Ischemia and diabetes, a chronic disease that increases the onset of cardiovascular diseases, suppress the cardioprotective effects of AMPK and PKA. Here, we review the molecular mechanisms by which AMPK and D-AKAP1/PKA interplay to regulate mitochondrial function, oxidative stress, and signaling pathways that prime endothelial cells, cardiac cells, and neurons for cytoprotection against oxidative stress. We discuss recent literature showing how temporal dynamics and localization of activated AMPK and PKA holoenzymes play a crucial role in governing cellular bioenergetics and cell survival in models of ischemia, cardiovascular diseases, and diabetes. Finally, we propose therapeutic strategies that tout localized PKA and AMPK signaling to reverse mitochondrial dysfunction, oxidative stress, and death of neurons and cardiac and endothelial cells during ischemia and diabetes.

2016 ◽  
Vol 130 (23) ◽  
pp. 2181-2198 ◽  
Author(s):  
Yujia Yuan ◽  
Meimei Shi ◽  
Lan Li ◽  
Jingping Liu ◽  
Bo Chen ◽  
...  

Vasculopathy is a major complication of diabetes. Impaired mitochondrial bioenergetics and biogenesis due to oxidative stress are a critical causal factor for diabetic endothelial dysfunction. Sirt1, an NAD+-dependent enzyme, is known to play an important protective role through deacetylation of many substrates involved in oxidative phosphorylation and reactive oxygen species generation. Mesenchymal stem cell-conditioned medium (MSC-CM) has emerged as a promising cell-free therapy due to the trophic actions of mesenchymal stem cell (MSC)-secreted molecules. In the present study, we investigated the therapeutic potential of MSC-CMs in diabetic endothelial dysfunction, focusing on the Sirt1 signalling pathway and the relevance to mitochondrial function. We found that high glucose-stimulated MSC-CM attenuated several glucotoxicity-induced processes, oxidative stress and apoptosis of endothelial cells of the human umbilical vein. MSC-CM perfusion in diabetic rats ameliorated compromised aortic vasodilatation and alleviated oxidative stress in aortas. We further demonstrated that these effects were dependent on improved mitochondrial function and up-regulation of Sirt1 expression. MSC-CMs activated the phosphorylation of phosphoinositide 3-kinase (PI3K) and protein kinase B (Akt), leading to direct interaction between Akt and Sirt1, and subsequently enhanced Sirt1 expression. In addition, both MSC-CM and Sirt1 activation could increase the expression of peroxisome proliferator-activated receptor γ co-activator-1α (PGC-1α), as well as increase the mRNA expression of its downstream, mitochondrial, biogenesis-related genes. This indirect regulation was mediated by activation of AMP-activated protein kinase (AMPK). Overall our findings indicated that MSC-CM had protective effects on endothelial cells, with respect to glucotoxicity, by ameliorating mitochondrial dysfunction via the PI3K/Akt/Sirt1 pathway, and Sirt1 potentiated mitochondrial biogenesis, through the Sirt1/AMPK/PGC-1α pathway.


2015 ◽  
Vol 36 (6) ◽  
pp. 2108-2120 ◽  
Author(s):  
Daniela Surico ◽  
Serena Farruggio ◽  
Patrizia Marotta ◽  
Giulia Raina ◽  
David Mary ◽  
...  

Background/Aim: Previous reports have made it hypothetically possible that human chorionic gonadotropin (hCG) could protect against the onset of pregnancy-related pathological conditions by acting as an antioxidant. In the present study we planned to examine the effects of hCG against oxidative stress in human umbilical vein endothelial cells (HUVEC). Methods: HUVEC were subjected to peroxidation by hydrogen peroxide. The modulation of nitric oxide (NO) release by hCG and its effects on cell viability, glutathione (GSH) levels, mitochondrial membrane potential and mitochondrial transition pore opening (MPTP) were examined by specific dyes. Endothelial and inducible NO synthase (eNOS and iNOS), Akt and extracellular -signal-regulated kinases 1/2 (ERK1/2) activation and markers of apoptosis were analyzed by Western Blot. Results: In HUVEC, hCG reduced NO release by modulating eNOS and iNOS. Moreover, hCG protected HUVEC against oxidative stress by preventing GSH reduction and apoptosis, by maintaining Akt and ERK1/2 activation and by keeping mitochondrial function. Conclusion: The present results have for the first time shown protective effects exerted by hCG on vascular endothelial function, which would be achieved by modulation of NO release, antioxidant and antiapoptotic actions and activation of cell survival signalling. These findings could have clinical implications in the management of pregnancy-related disorders.


Marine Drugs ◽  
2021 ◽  
Vol 19 (2) ◽  
pp. 86
Author(s):  
Yunok Oh ◽  
Chang-Bum Ahn ◽  
Jae-Young Je

Oxidative stress-induced endothelial dysfunction is strongly linked to the pathogenesis of cardiovascular diseases. A previous study revealed that seahorse hydrolysates ameliorated oxidative stress-mediated human umbilical vein endothelial cells (HUVECs) injury. However, the responsible compounds have not yet been identified. This study aimed to identify cytoprotective peptides and to investigate the molecular mechanism underlying the cytoprotective role in H2O2-induced HUVECs injury. After purification by gel filtration and HPLC, two peptides were sequenced by liquid chromatography-tandem mass spectrometry as HGSH (436.43 Da) and KGPSW (573.65 Da). The synthesized peptides and their combination (1:1 ratio) showed significant HUVECs protection effect at 100 μg/mL against H2O2-induced oxidative damage via significantly reducing intracellular reactive oxygen species (ROS). Two peptides and their combination treatment resulted in the increased heme oxygenase-1 (HO-1), a phase II detoxifying enzyme, through the activation of nuclear transcription factor-erythroid 2-related factor (Nrf2). Additionally, cell cycle and nuclear staining analysis revealed that two peptides and their combination significantly protected H2O2-induced cell death through antiapoptotic action. Two peptides and their combination treatment led to inhibit the expression of proapoptotic Bax, the release of cytochrome C into the cytosol, the activation of caspase 3 by H2O2 treatment in HUVECs, whereas antiapoptotic Bcl-2 expression was increased with concomitant downregulation of Bax/Bcl-2 ratio. Taken together, these results suggest that seahorse-derived peptides may be a promising agent for oxidative stress-related cardiovascular diseases.


2020 ◽  
Vol 98 (4) ◽  
pp. 243-251
Author(s):  
Mutlu Sarikaya ◽  
Nuray Yazihan ◽  
Net Daş Evcimen

Protein kinase C (PKC) and aldose reductase (AR) enzyme activities are increased in diabetes and complications are include retinopathy, nephropathy, and neuropathy. However, the relationship between PKC and AR and the underlying molecular mechanisms is still unclear. We aimed to evaluate the relationship between these two enzymes and clarify the underlying molecular mechanisms by the related signaling molecules. The effects of hyperglycemia and oxidative stress on AR and PKC enzymes and the signaling molecules such as nuclear factor-kappa B (NF-κB), inhibitor kappa B-alpha (IkB-α), total c-Jun, phospho c-Jun, and stress-activated protein kinases (SAPK)/Jun amino-terminal kinases (JNK) were evaluated in human retinal pigment epithelial cells (ARPE-19). AR, PKC protein levels, and related signaling molecules increased with hyperglycemia and oxidative stress. The AR inhibitor sorbinil decreased PKC expression and activity and all signaling molecule protein levels. Increased AR expression during hyperglycemia and oxidative stress was found to be correlated with the increase in PKC expression and activity in both conditions. Decreased expression and activity of PKC and the protein levels of related signaling molecules with the AR inhibitor sorbinil showed that AR enzyme may play a key role in the expression of PKC enzyme and oxidative stress during diabetes.


2010 ◽  
Vol 88 (3) ◽  
pp. 241-248 ◽  
Author(s):  
Garry X. Shen

Cardiovascular diseases are the predominant cause of death in patients with diabetes mellitus. Underlying mechanism for the susceptibility of diabetic patients to cardiovascular diseases remains unclear. Elevated oxidative stress was detected in diabetic patients and in animal models of diabetes. Hyperglycemia, oxidatively modified atherogenic lipoproteins, and advanced glycation end products are linked to oxidative stress in diabetes. Mitochondria are one of major sources of reactive oxygen species (ROS) in cells. Mitochondrial dysfunction increases electron leak and the generation of ROS from the mitochondrial respiratory chain (MRC). High levels of glucose and lipids impair the activities of MRC complex enzymes. NADPH oxidase (NOX) generates superoxide from NADPH in cells. Increased NOX activity was detected in diabetic patients. Hyperglycemia and hyperlipidemia increased the expression of NOX in vascular endothelial cells. Accumulated lines of evidence indicate that oxidative stress induced by excessive ROS production is linked to many processes associated with diabetic cardiovascular complications. Overproduction of ROS resulting from mitochondrial dysfunction or NOX activation is associated with uncoupling of endothelial nitric oxide synthase, which leads to reduced production of nitric oxide and endothelial-dependent vasodilation. Gene silence or inhibitor of NOX reduced oxidized or glycated LDL-induced expression of plasminogen activator inhibitor-1 in endothelial cells. Statins, hypoglycemic agents, and exercise may reduce oxidative stress in diabetic patients through the reduction of NOX activity or the improvement of mitochondrial function, which may prevent or postpone the development of cardiovascular complications.


2019 ◽  
Vol 2019 ◽  
pp. 1-14 ◽  
Author(s):  
Dehai Xian ◽  
Jing Song ◽  
Lingyu Yang ◽  
Xia Xiong ◽  
Rui Lai ◽  
...  

Angiogenesis is the process of new vessel formation, which sprouts from preexisting vessels. This process is highly complex and primarily involves several key steps, including stimulation of endothelial cells by growth factors, degradation of the extracellular matrix by proteolytic enzymes, migration and proliferation of endothelial cells, and capillary tube formation. Currently, it is considered that multiple cytokines play a vital role in this process, which consist of proangiogenic factors (e.g., vascular endothelial growth factor, fibroblast growth factors, and angiopoietins) and antiangiogenic factors (e.g., endostatin, thrombospondin, and angiostatin). Angiogenesis is essential for most physiological events, such as body growth and development, tissue repair, and wound healing. However, uncontrolled neovascularization may contribute to angiogenic disorders. In physiological conditions, the above promoters and inhibitors function in a coordinated way to induce and sustain angiogenesis within a limited period of time. Conversely, the imbalance between proangiogenic and antiangiogenic factors could cause pathological angiogenesis and trigger several diseases. With insights into the molecular mechanisms of angiogenesis, increasing reports have shown that a close relationship exists between angiogenesis and oxidative stress (OS) in both physiological and pathological conditions. OS, an imbalance between prooxidant and antioxidant systems, is a cause and consequence of many vascular complains and serves as one of the biomarkers for these diseases. Furthermore, emerging evidence supports that OS and angiogenesis play vital roles in many dermatoses, such as psoriasis, atopic dermatitis, and skin tumor. This review summarizes recent findings on the role of OS as a trigger of angiogenesis in skin disorders, highlights newly identified mechanisms, and introduces the antiangiogenic and antioxidant therapeutic strategies.


2013 ◽  
Vol 91 (3) ◽  
pp. 213-220 ◽  
Author(s):  
Biao Feng ◽  
Michael Anthony Ruiz ◽  
Subrata Chakrabarti

Oxidative stress plays an important role in the development and progression of chronic diabetic complications. Diabetes causes mitochondrial superoxide overproduction in the endothelial cells of both large and small vessels. This increased superoxide production causes the activation of several signal pathways involved in the pathogenesis of chronic complications. In particular, endothelial cells are major targets of glucose-induced oxidative damage in the target organs. Oxidative stress activates cellular signaling pathways and transcription factors in endothelial cells including protein kinase C (PKC), c-Jun-N-terminal kinase (JNK), p38 mitogen-activated protein kinase (MAPK), forkhead box O (FOXO), and nuclear factor kappa-B (NF-κB). Oxidative stress also causes DNA damage and activates DNA nucleotide excision repair enzymes including the excision repair cross complimenting 1(ERCC1), ERCC4, and poly(ADP-ribose) polymerase (PARP). Augmented production of histone acetyltransferase p300, and alterations of histone deacetylases, including class III deacetylases sirtuins, are also involved in this process. Recent research has found that small noncoding RNAs, like microRNA, are a new kind of regulator associated with chronic diabetic complications. There are extensive and complicated interactions and among these molecules. The purpose of this review is to demonstrate the role of oxidative stress in the development of diabetic complications in relation to epigenetic changes such as acetylation and microRNA alterations.


2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Yi Chen ◽  
Chen Liu ◽  
Peng Zhou ◽  
Jiannan Li ◽  
Xiaoxiao Zhao ◽  
...  

Coronary artery no-reflow is a complex problem in the area of reperfusion therapy, and the molecular mechanisms underlying coronary artery no-reflow injury have not been fully elucidated. In the present study, we explored whether oxidative stress caused damage to coronary endothelial cells by inducing mitochondrial fission and activating the JNK pathway. The hypoxia/reoxygenation (H/R) model was induced in vitro to mimic coronary endothelial no-reflow injury, and mitochondrial fission, mitochondrial function, and endothelial cell viability were analyzed using western blotting, quantitative polymerase chain reaction (qPCR), enzyme-linked immunosorbent assay (ELISA), and immunofluorescence. Our data indicated that reactive oxygen species (ROS) were significantly induced upon H/R injury, and this was followed by decreased endothelial cell viability. Mitochondrial fission was induced and mitochondrial bioenergetics were impaired in cardiac endothelial cells after H/R injury. Neutralization of ROS reduced mitochondrial fission and protected mitochondrial function against H/R injury. Our results also demonstrated that ROS stimulated mitochondrial fission via JNK-mediated Drp1 phosphorylation. These findings indicate that the ROS-JNK-Drp1 signaling pathway may be one of the molecular mechanisms underlying endothelial cell damage during H/R injury. Novel treatments for coronary no-reflow injury may involve targeting mitochondrial fission and the JNK-Drp1 signaling pathway.


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