线粒体自噬在低剂量镉暴露对鸡肝脏抗损伤中的作用

Mitophagy is an important way of regulating the injury and repair of cells. It clears the damaged mitochondria selectively in an active way and ensures the cell survival and mitochondrial homeostasis in the stress environment. Liver is main target organ of cadmium initial accumulation and toxicity in organism. When we studied on cadmium-induced hepatic cytotoxicity, investigations by our lab have found that mitochondria injury in the chicken hepatocyte was induced by low concentrations cadmium exposure, but change of cell activity was no significant in this condition. However, it is unclear how the mitophagy function in the resistence to the chicken liver damage induced by cadmium. In order to elucidate the role of Mitophagy in anti-injury mechanism, in this project, chicken liver and primary cultured chicken hepatocytes were used in the experiment. Some methods including fluorescent protein labeling and monitoring technology, siRNA, laser scanning confocal microscopy and flow cytometry etc were applied in this project. Double fluorescent tracer models of mitophagy and Parkin gene silence in hepatocytes were established. We detected the biological function of chicken liver and hepatocytes, mitochondrial injury, autophagy and the expression level of autophagy related proteins, antioxidant function and free radical content. These results will elucidate the molecular mechanism of mitophagy regulated by low concentrations Cd exposure from four levels of the organ-cell-organelle-molecular. These results will elucidate the molecular mechanism of regulation between mitophagy and the anti-injury effect of chicken hepatocyte induced by low concentrations Cd exposure. This project will elucidate the molecular mechanism of the anti-injury effect of chicken liver against Cd toxicity from a new perspective and reveal the cleaning mechanism of Cd toxicity in organism. It will also provide a new target of preventing the Cd toxicity and the reference for the comparative medicine.

线粒体自噬能够主动选择性清除受损伤的线粒体，确保应激环境中细胞存活和线粒体功能稳定。肝脏是重金属镉在动物体内最初蓄积和损害的靶器官，本课题组在研究镉致肝细胞毒性过程中，发现低剂量镉能够诱导鸡肝细胞线粒体损伤，而细胞活性变化不显著，其机制仍不清楚。为了探明线粒体自噬在细胞抗镉损伤中作用，本项目以鸡肝脏和原代肝细胞为研究对象，应用荧光蛋白标记示踪技术、siRNA技术、激光共聚焦显微技术、流式细胞术等技术，建立线粒体自噬双荧光示踪模型和Parkin基因沉默模型，检测肝脏与肝细胞功能、线粒体损伤、自噬及自噬相关蛋白含量及mRNA表达水平、抗氧化功能与自由基水平等，从器官-细胞-细胞器-分子四个层次，阐明镉调控肝脏线粒体自噬的分子机制。本课题将从新的视觉阐明肝脏抵抗低剂量镉毒性损伤的分子机制，揭示机体对低剂量镉毒性清除机理，为镉毒性的防治提供新靶点，并为比较医学提供借鉴。

镉是一种重要的工业和环境重金属污染物，肝脏是重金属镉在动物体内最初蓄积和损害的靶器官。然而低剂量镉能够诱导鸡肝细胞线粒体损伤，细胞活性变化不显著，其机制仍不清楚。本项目应用荧光蛋白标记示踪技术、siRNA技术、激光共聚焦显微技术、流式细胞术等方法进行了低剂量镉暴露对鸡肝脏抗损伤中的作用探究，结果表明（1）低浓度染镉致鸡肝细胞线粒体肿胀、嵴断裂、溶解、消失、空泡化等，未见显著影响肝细胞活性，证实鸡肝细胞存在抵抗低浓度染镉的损伤的自我保护机制；（2）线粒体自噬能够主动选择性清除受损伤的线粒体，确保应低浓度染镉致鸡肝细胞存活和线粒体功能稳定；（3）阐明线粒体健康调控与线粒体自噬是参与鸡肝细胞抵抗低剂量镉暴露损伤的分子机制。本课题组表SCI收录学术论文30篇，其中ESI高被引学术论文3篇，中科院大类一区期刊8篇，二区期刊21篇，累积影响因子为136；应邀参加国际学术会议3次，进行大会学术报告9次，参加全国性学术会议并进行特邀学术报告4次。培养中青年学术带头人1人，黑龙江省杰出青年1人次，龙江学者特聘教授1人次，获得博士学位1名，硕士学位5名。本课题将从新的视角阐明肝脏抵抗低剂量镉毒性损伤的分子机制，揭示机体对低剂量镉毒性清除机理，为镉毒性的防治提供新靶点，并为比较医学提供借鉴。