Sugiyama Akira, Shimizu Yurie, Okada Muneyoshi, Otani Kosuke, Yamawaki Hideyuki
Laboratory of Veterinary Pharmacology, School of Veterinary Medicine, Kitasato University, Higashi 23 Bancho 35-1, Towada City, Aomori 034-8628, Japan.
Int J Mol Sci. 2021 Jan 20;22(3):1004. doi: 10.3390/ijms22031004.
Ventricular arrhythmia induced by ischemia/reperfusion (I/R) injury is a clinical problem in reperfusion therapies for acute myocardial infarction. Ca overload through reactive oxygen species (ROS) production is a major cause for I/R-induced arrhythmia. We previously demonstrated that canstatin, a C-terminal fragment of type IV collagen α2 chain, regulated Ca handling in rat heart. In this study, we aimed to clarify the effects of canstatin on I/R-induced ventricular arrhythmia in rats. Male Wistar rats were subjected to I/R injury by ligating the left anterior descending artery followed by reperfusion. Ventricular arrhythmia (ventricular tachycardia and ventricular fibrillation) was recorded by electrocardiogram. Nicotinamide adenine dinucleotide phosphate oxidase (NOX) activity and ROS production in neonatal rat cardiomyocytes (NRCMs) stimulated with oxygen glucose deprivation/reperfusion (OGD/R) were measured by lucigenin assay and 2',7'-dichlorodihydrofluorescein diacetate staining, respectively. The HO-induced intracellular Ca ([Ca]) rise in NRCMs was measured by a fluorescent Ca indicator. Canstatin (20 µg/kg) inhibited I/R-induced ventricular arrhythmia in rats. Canstatin (250 ng/mL) inhibited OGD/R-induced NOX activation and ROS production and suppressed the HO-induced [Ca] rise in NRCMs. We for the first time demonstrated that canstatin exerts a preventive effect against I/R-induced ventricular arrhythmia, perhaps in part through the suppression of ROS production and the subsequent [Ca] rise.
缺血/再灌注（I/R）损伤诱发的室性心律失常是急性心肌梗死再灌注治疗中的一个临床问题。通过活性氧（ROS）生成导致的钙超载是I/R诱发心律失常的主要原因。我们之前证明，IV型胶原α2链的C末端片段canstatin可调节大鼠心脏中的钙处理。在本研究中，我们旨在阐明canstatin对大鼠I/R诱发的室性心律失常的影响。雄性Wistar大鼠通过结扎左前降支动脉然后再灌注来进行I/R损伤。通过心电图记录室性心律失常（室性心动过速和室颤）。分别通过光泽精测定法和2',7'-二氯二氢荧光素二乙酸酯染色来测量用氧糖剥夺/再灌注（OGD/R）刺激的新生大鼠心肌细胞（NRCMs）中的烟酰胺腺嘌呤二核苷酸磷酸氧化酶（NOX）活性和ROS生成。通过荧光钙指示剂测量HO诱导的NRCMs细胞内钙（[Ca]）升高。Canstatin（20μg/kg）可抑制大鼠I/R诱发的室性心律失常。Canstatin（250ng/mL）可抑制OGD/R诱导的NOX激活和ROS生成，并抑制HO诱导的NRCMs中[Ca]升高。我们首次证明，canstatin对I/R诱发的室性心律失常具有预防作用，可能部分是通过抑制ROS生成以及随后的[Ca]升高来实现的。
