CAS Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, China.
CAS Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, China; College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing, China.
Fish Shellfish Immunol. 2023 Mar;134:108594. doi: 10.1016/j.fsi.2023.108594. Epub 2023 Feb 6.
Cathepsin H and Cathepsin B are two lysosomal cysteine proteases participating in various physiological processes including immune responses. In fish, the functional roles of Cathepsin H and Cathepsin B during bacterial infection are less understood. In a previous work, we characterized a Cathepsin B homologue (CsCatB) of half-smooth tongue sole (Cynoglossus semilaevis), an economically valuable fish species in China. In this report, we identified a Cathepsin H homologue (CsCatH) from C. semilaevis. In healthy tongue sole, the transcriptional expression of CsCatH was detected in nine different tissues. Laser scanning confocal microscopic analysis showed that ectopically expressed CsCatH and CsCatB were co-localized with the lysosome. Upon infection by Edwardsiella tarda, a significant fish pathogen which caused a severe fish disease termed edwardsiellosis, the expressions of CsCatH and CsCatB were remarkedly upregulated. The knockdown of CsCatH and CsCatB significantly increased the replication of E. tarda and mitigated E. tarda-induced apoptosis in tongue sole tissues. These findings revealed the importance of CsCatH and CsCatB in anti-bacterial immunity of tongue sole.
组织蛋白酶 H 和组织蛋白酶 B 是两种参与包括免疫反应在内的各种生理过程的溶酶体半胱氨酸蛋白酶。在鱼类中，组织蛋白酶 H 和组织蛋白酶 B 在细菌感染过程中的功能作用还不太清楚。在之前的工作中，我们对中国经济价值很高的鱼类半滑舌鳎的组织蛋白酶 B 同源物（CsCatB）进行了特征描述。在本报告中，我们从半滑舌鳎中鉴定出了一种组织蛋白酶 H 同源物（CsCatH）。在健康的舌鳎中，检测到 CsCatH 在 9 种不同组织中的转录表达。激光共聚焦显微镜分析表明，异位表达的 CsCatH 和 CsCatB 与溶酶体共定位。在感染一种重要的鱼类病原体爱德华氏菌后，这种病原体引起了一种严重的鱼类疾病——爱德华氏菌病，CsCatH 和 CsCatB 的表达显著上调。CsCatH 和 CsCatB 的敲低显著增加了爱德华氏菌的复制，并减轻了爱德华氏菌诱导的舌鳎组织细胞凋亡。这些发现揭示了 CsCatH 和 CsCatB 在舌鳎抗菌免疫中的重要性。
