Sun Jiejie, Lv Xiaoqian, Leng Jinyuan, Wang Lingling, Song Linsheng
Liaoning Key Laboratory of Marine Animal Immunology, Dalian Ocean University, Dalian, China.
Liaoning Key Laboratory of Marine Animal Immunology & Disease Control, Dalian Ocean University, Dalian, China.
Front Cell Dev Biol. 2022 May 20;10:885478. doi: 10.3389/fcell.2022.885478. eCollection 2022.
Mitochondrial selective autophagy, known as mitophagy, surveils the mitochondrial population by eliminating superfluous and/or impaired organelles to mediate cellular survival and viability in response to injury/trauma and infection. In this study, the components of the mitophagy pathway in the Pacific oyster were screened from NCBI with reference to the protein sequences of the human mitophagy process. A total of 10 mitophagy process-related genes were identified from , including NIX, FUNDC1, PHB2, Cardiolipin, P62, VDAC2, MFN2, PARL, MPP, and OPTN. They shared high similarities with their homologs in the human mitophagy pathway and were expressed in various tissues of . After CCCP exposure, the fluorescence intensity of the mitochondrial probe JC-1 monomers increased significantly in hemocytes, while the fluorescence intensity of JC-1 aggregates decreased significantly. Meanwhile, the fluorescence of lysosomes was found to be co-localized with that of LC3 and mitochondria in CCCP-treated hemocytes. Double- and single-membrane-bound vacuoles resembling autophagic structures were observed in the hemocytes after CCCP exposure. The fluorescence intensity of JC-1 monomers and the abundance of LC3Ⅱ in hemocytes both increased after exposure. At the same time, the green signals of LC3 were co-localized with red signals of the mitochondria, and the fluorescence intensity of autophagy increased significantly in hemocytes after exposure. The results confirmed the existence of a complete mitophagy pathway in mollusks for the first time, which was helpful for further study on the function of mitochondrial autophagy in mollusks.
线粒体选择性自噬，即线粒体自噬，通过清除多余和/或受损的细胞器来监测线粒体群体，以介导细胞在应对损伤/创伤和感染时的存活和活力。在本研究中，参照人类线粒体自噬过程的蛋白质序列，从NCBI中筛选了太平洋牡蛎中线粒体自噬途径的组成成分。共从[具体来源未明确]中鉴定出10个与线粒体自噬过程相关的基因，包括NIX、FUNDC1、PHB2、心磷脂、P62、VDAC2、MFN2、PARL、MPP和OPTN。它们与其在人类线粒体自噬途径中的同源物具有高度相似性，并在[具体物种未明确]的各种组织中表达。用CCCP处理后，血细胞中线粒体探针JC-1单体的荧光强度显著增加，而JC-1聚集体的荧光强度显著降低。同时，在CCCP处理的血细胞中发现溶酶体的荧光与LC3和线粒体的荧光共定位。CCCP处理后，在血细胞中观察到类似自噬结构的双膜和单膜结合液泡。[具体处理未明确]处理后，血细胞中JC-1单体的荧光强度和LC3Ⅱ的丰度均增加。同时，LC3的绿色信号与线粒体的红色信号共定位，[具体处理未明确]处理后血细胞中的自噬荧光强度显著增加。结果首次证实了软体动物中存在完整的线粒体自噬途径，这有助于进一步研究线粒体自噬在软体动物中的功能。
