■阿尔茨海默病(AD)大脑中存在线粒体功能障碍,受损的线粒体需要通过线粒体自噬去除。小GTP酶Rab7调节线粒体和溶酶体的融合,而TBC1D5抑制Rab7激活。然而,目前尚不清楚TBC1D5对Rab7活性的调节是否可以改善线粒体自噬和抑制AD进展。
■探讨TBC1D5在线粒体自噬中的作用及其对Rab7的调控机制,以及激活线粒体自噬能否抑制AD的进展。
■通过蛋白质印迹和免疫荧光测定线粒体自噬。通过TEM跟踪线粒体的形态和数量。pCMV-Mito-AT1.03用于检测细胞ATP。通过ELISA检测AD细胞分泌的淀粉样β。免疫共沉淀用于研究靶蛋白的结合配偶体。应用高尔基-cox染色观察小鼠神经元形态。进行Morris水迷宫测试和Y迷宫以评估空间学习和记忆。并测量开放场测试以评估实验动物的运动功能和焦虑样表型。
■AD模型中线粒体形态受损,TBC1D5高表达。敲低TBC1D5可增加活性Rab7的表达,促进溶酶体与自噬体的融合,从而改善线粒体自噬,并改善了AD小鼠海马神经元的形态和行为受损。
■敲除TBC1D5可增加Rab7活性,促进自噬体和溶酶体融合。我们的研究为针对线粒体自噬的AD治疗带来新可能性的机制提供了见解。
UNASSIGNED: Mitochondrial dysfunction exists in Alzheimer\'s disease (AD) brain, and damaged mitochondria need to be removed by mitophagy. Small GTPase
Rab7 regulates the fusion of mitochondria and lysosome, while TBC1D5 inhibits
Rab7 activation. However, it is not clear whether the regulation of
Rab7 activity by TBC1D5 can improve mitophagy and inhibit AD progression.
UNASSIGNED: To investigate the role of TBC1D5 in mitophagy and its regulatory mechanism for
Rab7, and whether activation of mitophagy can inhibit the progression of AD.
UNASSIGNED: Mitophagy was determined by western blot and immunofluorescence. The morphology and quantity of mitochondria were tracked by TEM. pCMV-Mito-AT1.03 was employed to detect the cellular ATP. Amyloid-β secreted by AD cells was detected by ELISA. Co-immunoprecipitation was used to investigate the binding partner of the target protein. Golgi-cox staining was applied to observe neuronal morphology of mice. The Morris water maze test and Y-maze were performed to assess spatial learning and memory, and the open field test was measured to evaluate motor function and anxiety-like phenotype of experimental animals.
UNASSIGNED: Mitochondrial morphology was impaired in AD models, and TBC1D5 was highly expressed. Knocking down TBC1D5 increased the expression of active
Rab7, promoted the fusion of lysosome and autophagosome, thus improving mitophagy, and improved the morphology of hippocampal neurons and the impaired behavior in AD mice.
UNASSIGNED: Knocking down TBC1D5 increased
Rab7 activity and promoted the fusion of autophagosome and lysosome. Our study provided insights into the mechanisms that bring new possibilities for AD therapy targeting mitophagy.