0


组织蛋白酶C对亮氨酸甲酯引发的细胞凋亡中溶酶体释放其他组织蛋白酶至关重要

Cathepsin C is critical for the release of other cathepsins from lysosomes in leucyl-leucine methyl ester-triggered apoptosis
课程网址: http://videolectures.net/ipssc2017_kavcic_cathepsinC/  
主讲教师: Nežka Kavčič
开课单位: 约瑟夫·斯特凡研究所
开课时间: 2017-05-23
课程语种: 英语
中文简介:
溶酶体洗涤剂是亲脂性碱,它们被酸性囊泡捕获,并能诱导溶酶体膜通透性(LMP)。LMP是一个不返回点,随后是细胞死亡,通常由组织蛋白酶介导。L-亮氨酸-亮氨酸甲酯(LLOMe)是一种合成的溶酶体洗涤剂,通过成功清除供体的免疫细胞,在体内预防移植物抗宿主病方面显示出非常好的效果。复合作用的机制取决于组织蛋白酶C的转移酶活性,它导致形成具有膜溶解潜力的LeuLeu寡聚体,导致溶酶体泄漏,组织蛋白酶释放到细胞质中,并触发细胞死亡。然而,不同组织蛋白酶之间的确切作用机制和相互联系从未阐明。 使用几种含有不同水平的组织蛋白酶的不同细胞系,我们已经证明,细胞与LLOMe的孵育会导致溶酶体pH值的早期升高,表明LMP,随后组织蛋白酶释放到胞浆中,并随后导致细胞死亡。组织蛋白酶C选择性抑制剂GlyPheDMK可以防止溶酶体pH值升高和细胞死亡。相比之下,广谱组织蛋白酶抑制剂E64d有效地防止了细胞死亡,但仅部分溶酶体pH值升高。根据这些结果,我们可以推测组织蛋白酶C是溶酶体蛋白质(包括组织蛋白酶)进入胞质溶胶所必需的,而后者在下一步触发细胞死亡。利用组织蛋白酶B和L双缺陷的原代细胞和组织蛋白酶stefin B主要胞质抑制剂缺陷的细胞证实了这一机制。细胞对LLOMe的不同敏感性是不同组织蛋白酶、stefin B以及其他凋亡蛋白(包括Bcl2同源物)水平的组合。
课程简介: Lysosomal detergents are lipophilic bases, which remain captured in acidic vesicles and can induce lysosomal membrane permeabilization (LMP). LMP is a point-of-no-return, followed by cell death, usually mediated by cathepsins. L-Leucyl-leucine methyl ester (LLOMe) is synthetical lysosomotropic detergent, which showed extremely good results in preventing the graft-versus-host disease in vivo by successfully eliminating immune cells of the donor. The mechanism of compound action is dependent on the transferase activity of cathepsin C, which leads to the formation of LeuLeu oligomers with membranolytic potential, leading to lysosomal leakage, release of cathepsins into the cytosol and triggering of cell death. However, the exact mechanism of action and interconnection between different cathepsins were never clarified. Using several different cell lines containing different levels of individual cathepsins we have shown that incubation of cells with LLOMe leads to a very early increase in lysosomal pH, indicative of LMP, followed by release of cathepsins into the cytosol and subsequent cell death. Both the increase in lysosomal pH and cell death could be prevented by the cathepsin C selective inhibitor GlyPheDMK. In contrast, the broad spectrum cathepsin inhibitor E64d, efficiently prevented cell death, but only partially lysosomal pH increase. According to the results we can speculate that cathepsin C is required for the exit of lysosomal proteins, including the cathepsins, into the cytosol, where the latter then trigger cell death in the next step. This mechanism was confirmed using primary cells double deficient for cathepsins B and L, and cells deficient for the major cytosolic inhibitor of cathepsins stefin B. The different sensitivity of cells to LLOMe is a combination of the levels of different cathepsins, stefin B, as well as other apoptotic proteins, including Bcl2 homologs.
关 键 词: 溶酶体洗涤剂; L-亮氨酸-亮氨酸甲酯; 组织蛋白酶
课程来源: 视频讲座网
数据采集: 2022-03-26:zkj
最后编审: 2022-03-26:zkj
阅读次数: 63