Department of Pharmacology (the State-Province Key Laboratories of Biomedicine-Pharmaceutics of China, Key Laboratory of Cardiovascular Research, Ministry of Education), College of Pharmacy, Harbin Medical University, Baojian Road 157, Harbin 150086, Heilongjiang Province, PR China; Translational Medicine Research and Cooperation Center of Northern China, Heilongjiang Academy of Medical Sciences, Harbin Medical University, PR China.
Department of Pharmacology (the State-Province Key Laboratories of Biomedicine-Pharmaceutics of China, Key Laboratory of Cardiovascular Research, Ministry of Education), College of Pharmacy, Harbin Medical University, Baojian Road 157, Harbin 150086, Heilongjiang Province, PR China; Translational Medicine Research and Cooperation Center of Northern China, Heilongjiang Academy of Medical Sciences, Harbin Medical University, PR China.
Free Radic Biol Med. 2018 Aug 20;124:288-298. doi: 10.1016/j.freeradbiomed.2018.06.020. Epub 2018 Jun 20.
Induction of mild mitochondrial uncoupling is protective in a variety of disorders; however, it is unclear how to recognize the mild mitochondrial uncoupling induced by chemical mitochondrial uncouplers. The aim of the present study is to identify the pharmacological properties of mitochondrial uncoupling induced by mitochondrial uncouplers in cardiomyocytes. Neonatal rat cardiomyocytes were cultured. Protein levels were measured by using western blot technique. The whole cell respiratory function was determined by using high-resolution respirometry. The typical types of chemical mitochondrial uncouplers, carbonyl cyanide 4-(trifluoromethoxy)phenylhydrazone (FCCP), niclosamide, and BAM15, induced biphasic change of STAT3 activity in cardiomyocytes, activating STAT3 at low dose and inhibiting STAT3 at high dose, though the dose range of these drugs was distinct. Low-dose uncouplers induced STAT3 activation through the mild increase of mitochondrial ROS (mitoROS) generation and the subsequent JAK/STAT3 activation in cardiomyocytes. However, high-dose uncouplers induced inhibition of STAT3, decrease of ATP production, and cardiomyocyte death. High-dose uncouplers induced STAT3 inhibition through the excessive mitoROS generation and the decreased ATP -induced AMPK activation. Low-dose mitochondrial uncouplers attenuated doxorubicin (DOX)-induced STAT3 inhibition and cardiomyocyte death, and activated STAT3 contributed to the cardioprotection of low-dose mitochondrial uncouplers. Uncoupler-induced mild mitochondrial uncoupling in cardiomyocytes is characterized by STAT3 activation and ATP increase whereas excessive mitochondrial uncoupling is characterized by STAT3 inhibition, ATP decrease and cell injury. Development of mitochondrial uncoupler with optimal dose window of inducing mild uncoupling is a promising strategy for heart protection.
诱导轻度线粒体解偶联在多种疾病中具有保护作用；然而，目前尚不清楚如何识别化学线粒体解偶联剂诱导的轻度线粒体解偶联。本研究旨在鉴定化学线粒体解偶联剂诱导的心肌细胞中线粒体解偶联的药理学特性。培养新生大鼠心肌细胞。使用 Western blot 技术测量蛋白质水平。使用高分辨率呼吸测定法测定整个细胞呼吸功能。典型的化学线粒体解偶联剂，羰基氰化物 4-(三氟甲氧基)苯腙（FCCP）、尼克罗酰胺和 BAM15，在心肌细胞中诱导 STAT3 活性的双相变化，低剂量激活 STAT3，高剂量抑制 STAT3，尽管这些药物的剂量范围不同。低剂量解偶联剂通过轻度增加线粒体 ROS（mitoROS）生成并随后在心肌细胞中激活 JAK/STAT3 来诱导 STAT3 激活。然而，高剂量解偶联剂诱导 STAT3 抑制、ATP 产生减少和心肌细胞死亡。高剂量解偶联剂通过过度的 mitoROS 生成和减少 ATP 诱导的 AMPK 激活来诱导 STAT3 抑制。低剂量线粒体解偶联剂减轻多柔比星（DOX）诱导的 STAT3 抑制和心肌细胞死亡，激活 STAT3 有助于低剂量线粒体解偶联剂的心脏保护作用。心肌细胞中解偶联剂诱导的轻度线粒体解偶联的特征是 STAT3 激活和 ATP 增加，而过度的线粒体解偶联的特征是 STAT3 抑制、ATP 减少和细胞损伤。开发具有诱导轻度解偶联最佳剂量窗的线粒体解偶联剂是心脏保护的一种有前途的策略。
