title: RNAi targeting ryanodine receptor 2 protects rat cardiomyocytes from injury caused by simulated ischemia-reperfusion.
abstract: The effects of a small interfering RNA targeting ryanodine receptor 2 (si-Ryr2) on cardiomyocytes injury following a simulated ischemia-reperfusion (I/R) were investigated. Pretreated with si-Ryr2 or ryanodine, primary cultures of neonatal rat cardiomyocytes were subjected to a protocol of simulated I/R. Compared with control, the cytosolic Ca(2+) concentration ([Ca(2+)](i)) and the generation of reactive oxygen species (ROS) was significantly augmented after I/R. Concomitant with these, cell injury assessed by Annexin V/PI staing, mitochondria membrane potential (DeltaPsim) and the leakage of lactic dehydrogenase (LDH) and creatine phosphokinase (CPK) were aggravated. Si-Ryr2 treatment reduced [Ca(2+)](i) and ROS generation and protected the cardiomyocytes from subsequent I/R injury, as evidenced by stable DeltaPsim and decreased Annexin V(+) PI(-) staing and enzymes release. Moreover, si-Ryr2 exerted more effective protection on I/R injury compared to ryanodine. The present study demonstrated for the first time that in neonatal cardiomyocytes, si-Ryr2 reduces cell death associated with attenuating [Ca(2+)](i) and ROS production. Furthermore, we attempt to speculate that si-Ryr2 excel ryanodine in Ryr2 function research of cardioprotection.
authors.affiliation: Experimental Center, No. 3 People's Hospital affiliated to Shanghai Jiao Tong University School of Medicine, No. 280 Mohe Road, Baoshan District, Shanghai, China. zyguoo@126.com
authors.forename: Zhuying
authors.initials: Z
authors.lastname: Guo
authors.forename: Shiting
authors.initials: S
authors.lastname: Wang
authors.forename: Qiang
authors.initials: Q
authors.lastname: Jiao
authors.forename: Manghua
authors.initials: M
authors.lastname: Xu
authors.forename: Fenghou
authors.initials: F
authors.lastname: Gao
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D020013:Calcium Signaling / Q000187:drug effects* / Q000502:physiology; D002245:Carbon Dioxide / Q000494:pharmacology; D002478:Cells, Cultured / Q000187:drug effects; D066298:In Vitro Techniques; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D008929:Mitochondria, Heart / Q000187:drug effects; D015428:Myocardial Reperfusion Injury / Q000517:prevention & control*; D032383:Myocytes, Cardiac / Q000187:drug effects*; D009584:Nitrogen / Q000494:pharmacology; D010100:Oxygen / Q000494:pharmacology; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D017382:Reactive Oxygen Species / Q000378:metabolism; D012433:Ryanodine / Q000494:pharmacology; D019837:Ryanodine Receptor Calcium Release Channel / Q000096:biosynthesis / Q000187:drug effects* / Q000235:genetics / Q000502:physiology
chemical_list: D034741:RNA, Small Interfering; D017382:Reactive Oxygen Species; D019837:Ryanodine Receptor Calcium Release Channel; D002245:Carbon Dioxide; D012433:Ryanodine; D009584:Nitrogen; D010100:Oxygen