title: Ganoderma atrum polysaccharide protects cardiomyocytes against anoxia/reoxygenation-induced oxidative stress by mitochondrial pathway.
abstract: It is now well established that oxidative stress plays a causative role in the pathogenesis of anoxia/reoxygenation (A/R) injury. Ganoderma atrum polysaccharide (PSG-1), the most abundant component isolated from G. atrum, has been shown to possess potent antioxidant activity. The goals of this study were to investigate the effect of PSG-1 against oxidative stress induced by A/R injury and the possible mechanisms in cardiomyocytes. In this work, primary cultures of neonatal rat cardiomyocytes pretreated with PSG-1 were subjected to A/R and subsequently monitored for cell viability by the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay. The levels of intracellular reactive oxygen species (ROS), apoptosis, and mitochondrial membrane potential (Deltapsi(m)) were determined by flow cytometry. Western blot analysis was used to measure the expression of cytochrome c, Bcl-2 family, and manganese superoxide dismutase (MnSOD) proteins, and the activities of caspase-3 and caspase-9 were determined by a colorimetric method. The results showed that PSG-1 protected against cell death caused by A/R injury in cardiomyocytes. PSG-1 reduced the A/R-induced ROS generation, the loss of mitochondrial membrane potential (Deltapsi(m)), and the release of cytochrome c from the mitochondria into cytosol. PSG-1 inhibited the A/R-stimulated activation of caspase-9 and caspase-3 and alteration of Bcl-2 family proteins. Moreover, PSG-1 significantly increased the protein expression of MnSOD in cardiomyocytes. These findings suggest that PSG-1 significantly attenuates A/R-induced oxidative stress and improves cell survival in cardiomyocytes through mitochondrial pathway.
authors.affiliation: State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, China.
authors.forename: Wen-Juan
authors.initials: WJ
authors.lastname: Li
authors.forename: Shao-Ping
authors.initials: SP
authors.lastname: Nie
authors.forename: Yi
authors.initials: Y
authors.lastname: Chen
authors.forename: Ming-Yong
authors.initials: MY
authors.lastname: Xie
authors.forename: Ming
authors.initials: M
authors.lastname: He
authors.forename: Qiang
authors.initials: Q
authors.lastname: Yu
authors.forename: Yan
authors.initials: Y
authors.lastname: Yan
mesh_terms: D000818:Animals; D053148:Caspase 3 / Q000378:metabolism; D053453:Caspase 9 / Q000378:metabolism; D016923:Cell Death / Q000187:drug effects; D045304:Cytochromes c / Q000378:metabolism; D019610:Cytoprotection / Q000187:drug effects*; D003600:Cytosol / Q000187:drug effects / Q000378:metabolism; D032902:Ganoderma / Q000737:chemistry*; D000860:Hypoxia / Q000201:enzymology / Q000473:pathology / Q000517:prevention & control*; D042541:Intracellular Space / Q000187:drug effects / Q000378:metabolism; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D008928:Mitochondria / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D032383:Myocytes, Cardiac / Q000187:drug effects / Q000201:enzymology / Q000473:pathology*; D018384:Oxidative Stress / Q000187:drug effects*; D010100:Oxygen / Q000494:pharmacology; D011134:Polysaccharides / Q000494:pharmacology*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D017382:Reactive Oxygen Species / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D013482:Superoxide Dismutase / Q000378:metabolism
chemical_list: D011134:Polysaccharides; D019253:Proto-Oncogene Proteins c-bcl-2; D017382:Reactive Oxygen Species; D045304:Cytochromes c; D013482:Superoxide Dismutase; D053148:Caspase 3; D053453:Caspase 9; D010100:Oxygen