Chen Hsiang-Wen, Hsu Chin, Lu Tzong-Shi, Wang Shu-Jung, Yang Rei-Cheng
Department of Microbiology, School of Medicine, Kaohsiung Medical University, Kaohsiung City, Taiwan, Republic of China.
Shock. 2003 Sep;20(3):274-9. doi: 10.1097/00024382-200309000-00013.
The present study was designed to investigate the effect of previous heat shock treatment on the mitochondria function of the heart during a cecal ligation and puncture (CLP)-induced sepsis model. Rats of the heated group were heated by whole-body hyperthermia 24 h before the CLP operation. Cardiac mitochondria were freshly collected 9 and 18 h after CLP, indicating early and late sepsis, respectively. The expressions of heat shock protein 72 (Hsp72), glucose-regulated protein 75 (Grp75), and mitochondrial complexes I, II, III, and IV were evaluated by Western blot and immunochemical analysis. Enzyme activities of NADH cytochrome c reductase (NCCR), succinate cytochrome c reductase (SCCR), and cytochrome c oxidase (CCO) were measured after the reduction or oxidation of cytochrome c using a spectrophotometer. The results showed that the ATP content in the heart significantly declined during late sepsis, whereas heat shock treatment reversed this declination. The enzyme activities of NCCR, SCCR, and CCO were apparently suppressed during late stage of sepsis. The protein expressions of mitochondrial complex II and complex IV and Grp75 were also down-regulated during sepsis. Previously treated by heat shock, late-sepsis rats emerged with a high preservation of mitochondrial respiratory chain enzymes, both the protein amount and enzyme activity. Aspects of morphology were observed by electron microscopy, while heat shock treatment revealed the attenuation of cardiac mitochondrial damage induced by sepsis. In conclusion, structural deformity and the decrease of respiratory chain enzyme activity in mitochondria and its leading to a decline of ATP content are highly correlated with the deterioration of cardiac function during sepsis, and heat shock can reverse adverse effects, thus achieving a protective goal.
本研究旨在探讨在盲肠结扎和穿刺（CLP）诱导的脓毒症模型中，预先热休克处理对心脏线粒体功能的影响。热休克组大鼠在CLP手术前24小时进行全身热疗。分别在CLP术后9小时和18小时新鲜采集心脏线粒体，分别代表早期和晚期脓毒症。通过蛋白质免疫印迹法和免疫化学分析评估热休克蛋白72（Hsp72）、葡萄糖调节蛋白75（Grp75）以及线粒体复合物I、II、III和IV的表达。使用分光光度计在细胞色素c还原或氧化后测量NADH细胞色素c还原酶（NCCR）、琥珀酸细胞色素c还原酶（SCCR）和细胞色素c氧化酶（CCO）的酶活性。结果显示，在晚期脓毒症期间心脏中的ATP含量显著下降，而热休克处理可逆转这种下降。在脓毒症晚期，NCCR、SCCR和CCO的酶活性明显受到抑制。在脓毒症期间，线粒体复合物II和复合物IV以及Grp75的蛋白表达也下调。预先接受热休克处理的晚期脓毒症大鼠，线粒体呼吸链酶在蛋白量和酶活性方面均得到高度保留。通过电子显微镜观察形态学方面，热休克处理显示脓毒症诱导的心脏线粒体损伤减轻。总之，线粒体结构畸形、呼吸链酶活性降低及其导致的ATP含量下降与脓毒症期间心脏功能恶化高度相关，热休克可逆转不良反应，从而实现保护目的。
