Liang Qianqian, Wang Baoyu, Pang Lingxia, Wang Youpei, Zheng Meiqin, Wang Qing, Yan Jingbin, Xu Jinzhong
Department of Emergency, Zhengzhou Central Hospital Affiliated to Zhengzhou University, Zhengzhou, 450007 China.
Function Experiment Teaching Center, Wenzhou Medical University, Wenzhou, 325305 China.
Iran J Basic Med Sci. 2016 Jan;19(1):43-8.
Higher cellular reactive oxygen species (ROS) levels is important in reducing cellular energy charge (EC) by increasing the levels of key metabolic protein, and nitrosative modifications, and have been shown to damage the cardiac tissue of diabetic mice. However, the relation between energy production and heart function is unclear.
Streptozotocin (STZ, 150 mg/kg body weight) was injected intraperitoneally once to mice that had been fasted overnight for induction of diabetes. After diabetic induction, mice received citrate (5 µg/kg) through intraperitoneal injection every other day for 5 weeks. The caspase-3, plasminogen activator inhibitor 1 (PAI1), protein kinase B (PKB), commonly known as AKT and phosphorylated-AKT (p-AKT) proteins were examined to elucidate inflammation and apoptosis in the heart. For histological analysis, heart samples were fixed with 10% formalin and stained with hematoxylin-eosin (HE) and Sirius red to assess pathological changes and fibrosis. The expression levels[AGA1] of marker proteins, tyrosine nitration, activity of ATP synthase and succinyl-CoA3-ketoacid coenzyme A transferase-1 (SCOT), and EC were measured.
Intraperitoneal injection of citrate significantly reduced caspase-3 and PAI-1 protein levels and increased p-AKT level on the 5(th) week; EC in the heart was found to be increased as well. Further, the expression level, activity, and tyrosine nitration of ATP synthase and SCOT were not affected after induction of diabetes.
Results indicate that application of citrate, a tricarboxylic acid (TCA) cycle intermediate, might alleviate cardiac dysfunction by reducing cardiac inflammation, apoptosis, and increasing cardiac EC.
较高的细胞活性氧（ROS）水平对于通过提高关键代谢蛋白水平和亚硝化修饰来降低细胞能量电荷（EC）很重要，并且已被证明会损害糖尿病小鼠的心脏组织。然而，能量产生与心脏功能之间的关系尚不清楚。
对禁食过夜的小鼠腹腔注射一次链脲佐菌素（STZ，150 mg/kg体重）以诱导糖尿病。糖尿病诱导后，小鼠每隔一天腹腔注射柠檬酸盐（5 μg/kg），持续5周。检测半胱天冬酶-3、纤溶酶原激活物抑制剂1（PAI1）、蛋白激酶B（PKB，通常称为AKT）和磷酸化-AKT（p-AKT）蛋白，以阐明心脏中的炎症和细胞凋亡。为进行组织学分析，将心脏样本用10%福尔马林固定，并用苏木精-伊红（HE）和天狼星红染色，以评估病理变化和纤维化。测量标记蛋白的表达水平、酪氨酸硝化、ATP合酶和琥珀酰辅酶A-3-酮酸辅酶A转移酶-1（SCOT）的活性以及EC。
腹腔注射柠檬酸盐在第5周时显著降低了半胱天冬酶-3和PAI-1蛋白水平，并提高了p-AKT水平；还发现心脏中的EC增加。此外，糖尿病诱导后，ATP合酶和SCOT的表达水平、活性和酪氨酸硝化不受影响。
结果表明，应用三羧酸（TCA）循环中间体柠檬酸盐可能通过减轻心脏炎症、细胞凋亡和增加心脏EC来缓解心脏功能障碍。
