scholarly journals TRPM2 Non-Selective Cation Channels in Liver Injury Mediated by Reactive Oxygen Species

Antioxidants ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1243
Author(s):  
Eunus S. Ali ◽  
Grigori Y. Rychkov ◽  
Greg J. Barritt

TRPM2 channels admit Ca2+ and Na+ across the plasma membrane and release Ca2+ and Zn2+ from lysosomes. Channel activation is initiated by reactive oxygen species (ROS), leading to a subsequent increase in ADP-ribose and the binding of ADP-ribose to an allosteric site in the cytosolic NUDT9 homology domain. In many animal cell types, Ca2+ entry via TRPM2 channels mediates ROS-initiated cell injury and death. The aim of this review is to summarise the current knowledge of the roles of TRPM2 and Ca2+ in the initiation and progression of chronic liver diseases and acute liver injury. Studies to date provide evidence that TRPM2-mediated Ca2+ entry contributes to drug-induced liver toxicity, ischemia–reperfusion injury, and the progression of non-alcoholic fatty liver disease to cirrhosis, fibrosis, and hepatocellular carcinoma. Of particular current interest are the steps involved in the activation of TRPM2 in hepatocytes following an increase in ROS, the downstream pathways activated by the resultant increase in intracellular Ca2+, and the chronology of these events. An apparent contradiction exists between these roles of TRPM2 and the role identified for ROS-activated TRPM2 in heart muscle and in some other cell types in promoting Ca2+-activated mitochondrial ATP synthesis and cell survival. Inhibition of TRPM2 by curcumin and other “natural” compounds offers an attractive strategy for inhibiting ROS-induced liver cell injury. In conclusion, while it has been established that ROS-initiated activation of TRPM2 contributes to both acute and chronic liver injury, considerable further research is needed to elucidate the mechanisms involved, and the conditions under which pharmacological inhibition of TRPM2 can be an effective clinical strategy to reduce ROS-initiated liver injury.

2009 ◽  
Vol 174 (5) ◽  
pp. 1776-1785 ◽  
Author(s):  
Laura Llacuna ◽  
Montserrat Marí ◽  
Josep M. Lluis ◽  
Carmen García-Ruiz ◽  
José C. Fernández-Checa ◽  
...  

2020 ◽  
Vol 16 ◽  
Author(s):  
Andrey Krylatov ◽  
Leonid Maslov ◽  
Sergey Y. Tsibulnikov ◽  
Nikita Voronkov ◽  
Alla Boshchenko ◽  
...  

: There is considerable evidence in the heart that autophagy in cardiomyocytes is activated by hypoxia/reoxygenation (H/R) or in hearts by ischemia/reperfusion (I/R). Depending upon the experimental model and duration of ischemia, increases in autophagy in this setting maybe beneficial (cardioprotective) or deleterious (exacerbate I/R injury). Aside from the conundrum as to whether or not autophagy is an adaptive process, it is clearly regulated by a number of diverse molecules including reactive oxygen species (ROS), various kinases, hydrogen sulfide (H2S) and nitric oxide (NO). The purpose this review is to address briefly the controversy regarding the role of autophagy in this setting and to examine a variety of disparate molecules that are involved in its regulation.


2010 ◽  
Vol 63 (11-12) ◽  
pp. 827-832 ◽  
Author(s):  
Tatjana Radosavljevic ◽  
Dusan Mladenovic ◽  
Danijela Vucevic ◽  
Rada Jesic-Vukicevic

Introduction. Paracetamol is an effective analgesic/antipyretic drug when used at therapeutic doses. However, the overdose of paracetamol can cause severe liver injury and liver necrosis. The mechanism of paracetamol-induced liver injury is still not completely understood. Reactive metabolite formation, depletion of glutathione and alkylation of proteins are the triggers of inhibition of mitochondrial respiration, adenosine triphosphate depletion and mitochondrial oxidant stress leading to hepatocellular necrosis. Role of oxidative stress in paracetamol-induced liver injury. The importance of oxidative stress in paracetamol hepatotoxicity is controversial. Paracetamol induced liver injury cause the formation of reactive oxygen species. The potent sources of reactive oxygen are mitochondria, neutrophils, Kupffer cells and the enzyme xatnine oxidase. Free radicals lead to lipid peroxidation, enzymatic inactivation and protein oxidation. Role of mitochondria in paracetamol-induced oxidative stress. The production of mitochondrial reactive oxygen species is increased, and the glutathione content is decreased in paracetamol overdose. Oxidative stress in mitochondria leads to mito?chondrial dysfunction with adenosine triphosphate depletion, increase mitochondrial permeability transition, deoxyribonu?cleic acid fragmentation which contribute to the development of hepatocellular necrosis in the liver after paracetamol overdose. Role of Kupffer cells in paracetamol-induced liver injury. Paracetamol activates Kupffer cells, which then release numerous cytokines and signalling molecules, including nitric oxide and superoxide. Kupffer cells are important in peroxynitrite formation. On the other hand, the activated Kupffer cells release anti-inflammatory cytokines. Role of neutrophils in paracetamol-induced liver injury. Paracetamol-induced liver injury leads to the accumulation of neutrophils, which release lysosomal enzymes and generate superoxide anion radicals through the enzyme nicotinamide adenine dinucleotide phosphate oxidase. Hydrogen peroxide, which is influenced by the neutrophil-derived enzyme myeloperoxidase, generates hypochlorus acid as a potent oxidant. Role of peroxynitrite in paracetamol-induced oxidative stress. Superoxide can react with nitric oxide to form peroxynitrite, as a potent oxidant. Nitrotyrosine is formed by the reaction of tyrosine with peroxynitrite in paracetamol hepatotoxicity. Conclusion. Overdose of paracetamol may produce severe liver injury with hepatocellular necrosis. The most important mechanisms of cell injury are metabolic activation of paracetamol, glutathione depletion, alkylation of proteins, especially mitochondrial proteins, and formation of reactive oxygen/nitrogen species.


2021 ◽  
Vol 22 (3) ◽  
pp. 1106
Author(s):  
Rayan Bou-Fakhredin ◽  
Batoul Dia ◽  
Hilda E. Ghadieh ◽  
Stefano Rivella ◽  
Maria Domenica Cappellini ◽  
...  

Oxidative damage by reactive oxygen species (ROS) is one of the main contributors to cell injury and tissue damage in thalassemia patients. Recent studies suggest that ROS generation in non-transfusion-dependent (NTDT) patients occurs as a result of iron overload. Among the different sources of ROS, the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase family of enzymes and cytochrome P450 (CYP450) have been proposed to be major contributors for oxidative stress in several diseases. However, the sources of ROS in patients with NTDT remain poorly understood. In this study, Hbbth3/+ mice, a mouse model for β-thalassemia, were used. These mice exhibit an unchanged or decreased expression of the major NOX isoforms, NOX1, NOX2 and NOX4, when compared to their C57BL/6 control littermates. However, a significant increase in the protein synthesis of CYP4A and CYP4F was observed in the Hbbth3/+ mice when compared to the C57BL/6 control mice. These changes were paralleled by an increased production of 20-hydroxyeicosatetraenoic acid (20-HETE), a CYP4A and CYP4F metabolite. Furthermore, these changes corroborate with onset of ROS production concomitant with liver injury. To our knowledge, this is the first report indicating that CYP450 4A and 4F-induced 20-HETE production mediates reactive oxygen species overgeneration in Hbbth3/+ mice through an NADPH-dependent pathway.


2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Tingyang Zhou ◽  
Chia-Chen Chuang ◽  
Li Zuo

Myocardial ischemia-reperfusion (I/R) injury is experienced by individuals suffering from cardiovascular diseases such as coronary heart diseases and subsequently undergoing reperfusion treatments in order to manage the conditions. The occlusion of blood flow to the tissue, termed ischemia, can be especially detrimental to the heart due to its high energy demand. Several cellular alterations have been observed upon the onset of ischemia. The danger created by cardiac ischemia is somewhat paradoxical in that a return of blood to the tissue can result in further damage. Reactive oxygen species (ROS) have been studied intensively to reveal their role in myocardial I/R injury. Under normal conditions, ROS function as a mediator in many cell signaling pathways. However, stressful environments significantly induce the generation of ROS which causes the level to exceed body’s antioxidant defense system. Such altered redox homeostasis is implicated in myocardial I/R injury. Despite the detrimental effects from ROS, low levels of ROS have been shown to exert a protective effect in the ischemic preconditioning. In this review, we will summarize the detrimental role of ROS in myocardial I/R injury, the protective mechanism induced by ROS, and potential treatments for ROS-related myocardial injury.


Nanomedicine ◽  
2021 ◽  
Author(s):  
Muktashree Saha ◽  
Anil P  Bidkar ◽  
Siddhartha S  Ghosh

Aim: The primary aim of this study was to develop biomimetic nanocarriers for specific homologous targeting of the anticancer drugs ammonium pyrrolidine dithiocarbamate (PDTC) and doxorubicin. Methods: Membranous nanovesicles were synthesized from a breast cancer cell line (MCF7) by syringe extrusion process and were loaded with PDTC and doxorubicin. Besides their abilities for self-homing, the drug loaded nanovesicles showed anti-cell proliferative effects via the generation of reactive oxygen species. Results: The nanovesicles demonstrated efficient internalization via homologous targeting. Delivery of PDTC showed a higher killing effect for homologous cell targeting than other cell types. Experimental results demonstrated increased antiproliferative potency of PDTC, which induced apoptosis via reactive oxygen species generation. Conclusion: The developed membrane-derived nanocarrier is an attractive biocompatible system for ex vivo targeted drug delivery.


2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Mingyan Hu ◽  
Ping Ye ◽  
Hua Liao ◽  
Manhua Chen ◽  
Feiyan Yang

Metformin is a first-line drug for the management of type 2 diabetes. Recent studies suggested cardioprotective effects of metformin against ischemia/reperfusion injury. However, it remains elusive whether metformin provides direct protection against hypoxia/reoxygenation (H/R) injury in cardiomyocytes under normal or hyperglycemic conditions. This study in H9C2 rat cardiomyoblasts was designed to determine cell viability under H/R and high-glucose (HG, 33 mM) conditions and the effects of cotreatment with various concentrations of metformin (0, 1, 5, and 10 mM). We further elucidated molecular mechanisms underlying metformin-induced cytoprotection, especially the possible involvement of AMP-activated protein kinase (AMPK) and Jun NH(2)-terminal kinase (JNK). Results indicated that 5 mM metformin improved cell viability, mitochondrial integrity, and respiratory chain activity under HG and/or H/R (P<0.05). The beneficial effects were associated with reduced levels of reactive oxygen species generation and proinflammatory cytokines (TNF-α, IL-1α, and IL-6) (P<0.05). Metformin enhanced phosphorylation level of AMPK and suppressed HG + H/R induced JNK activation. Inhibitor of AMPK (compound C) or activator of JNK (anisomycin) abolished the cytoprotective effects of metformin. In conclusion, our study demonstrated for the first time that metformin possessed direct cytoprotective effects against HG and H/R injury in cardiac cells via signaling mechanisms involving activation of AMPK and concomitant inhibition of JNK.


2021 ◽  
Vol 20 (2) ◽  
pp. 87-91
Author(s):  
A. S. Sementsov ◽  
N. V. Naryzhnaya ◽  
M. A. Sirotina ◽  
L. N. Maslov

Introduction. Increased resistance of the heart to ischemia/reperfusion (I/R) is an urgent aim of physiology, pharmacology, and cardiac surgery, since I/R injury of the heart is often the cause of cardiogenic shock and subsequent death of patients in the postoperative period. Materials and methods. The study was carried out in male rats which were subjected to coronary artery occlusion (45 min) and reperfusion (2 h). Before coronary occlusion, early hypoxic preconditioning (HP) was modeled. The rats were subjected to six sessions of hypoxia (8 % O2, 10 min) and reoxygenation (21 % O2, 10 min) 30 min before coronary artery occlusion. The rats were injected with the following drugs: 1,3-dimethylthiourea (DMTM), 2-mercaptopropionyl glycine (2-MPG), deferoxamine. Results. It was found that HP contributes to infarct size reduction by 30 %. Preliminary administration of DMTM, 2-MPG, deferoxamine eliminated the infarct-reducing effect of HP. Conclisuon. The obtained data indicate that reactive oxygen species are involved in the cardioprotective effect of HP.


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