Reyes-Becerril Martha, Sanchez Veronica, Delgado Karen, Guerra Kevyn, Velazquez Esteban, Ascencio Felipe, Angulo Carlos
Immunology & Vaccinology Group. Centro de Investigaciones Biológicas del Noroeste (CIBNOR), Av. Instituto Politécnico Nacional 195, Playa Palo de Santa Rita Sur, La Paz, B.C.S., 23096, Mexico.
Immunology & Vaccinology Group. Centro de Investigaciones Biológicas del Noroeste (CIBNOR), Av. Instituto Politécnico Nacional 195, Playa Palo de Santa Rita Sur, La Paz, B.C.S., 23096, Mexico.
Immunobiology. 2018 Oct;223(10):562-576. doi: 10.1016/j.imbio.2018.07.002. Epub 2018 Jul 4.
Caspases are a family of proteases involved in many important biological processes including apoptosis and inflammation. In order to get insights into the caspase gene family and antioxidant enzymes in Totoaba macdonaldi during bacterial infection, an in vitro assay was performed involving three different types of caspases (Casp-1, Casp-3 and Casp-8) and antioxidant enzymes (catalase, gluthathione peroxidase 1 and 4) after Vibrio parahaemolyticus and Aeromonas veronii infection, using head-kidney and spleen leukocytes from the teleost fish totoaba at 12 and 24 h post-exposure. Characterization of caspases by bioinformatics analyses showed that TmCas-1, TmCas-3 and TmCas-8 shared overall sequence identities of 82-61%, 85-97% and 77-63%, respectively, with other teleost fish. Caspase-1, -3 and -8 proteins revealed a conserved penta-peptide sequence at the catalytic site and three amino acid residues involved in the catalysis (H, G and C), as well as two conserved domains. The expression levels of the three caspases were detected in a wide range of fish tissues; however, they varied among tissues and caspases, which were highly up-regulated in immune organs, such as head-kidney, liver and/or spleen. The pathogen-induced gene expression pattern revealed two interesting facts; first, that the expression of all the caspase genes and antioxidant enzyme genes evaluated in this study were strongly induced following V. parahaemolyticus infection; second, these up-regulations reached a maximum level at 24 h post-infection in head-kidney whereas in spleen leukocytes, it was observed at 6-h post-infection. In conclusion, based on these observations, the acute toxic effects of V. parahaemolyticus are associated to cell death and release of free radicals. This information provides a better understanding of the effects and nature of early immune response against common bacterial infections in totoaba leukocytes.
半胱天冬酶是一类蛋白酶，参与包括细胞凋亡和炎症在内的许多重要生物学过程。为了深入了解麦氏托头石首鱼在细菌感染期间的半胱天冬酶基因家族和抗氧化酶，在副溶血性弧菌和维氏气单胞菌感染后，使用暴露后12小时和24小时的硬骨鱼麦氏托头石首鱼的头肾和脾脏白细胞，进行了一项涉及三种不同类型半胱天冬酶（Casp-1、Casp-3和Casp-8）和抗氧化酶（过氧化氢酶、谷胱甘肽过氧化物酶1和4）的体外试验。通过生物信息学分析对半胱天冬酶进行表征，结果表明，TmCas-1、TmCas-3和TmCas-8与其他硬骨鱼的总体序列同一性分别为82%-61%、85%-97%和77%-63%。半胱天冬酶-1、-3和-8蛋白在催化位点显示出保守的五肽序列以及参与催化的三个氨基酸残基（H、G和C），还有两个保守结构域。在多种鱼类组织中检测到了这三种半胱天冬酶的表达水平；然而，它们在不同组织和半胱天冬酶之间存在差异，在免疫器官如头肾、肝脏和/或脾脏中高度上调。病原体诱导的基因表达模式揭示了两个有趣的事实：第一，本研究中评估的所有半胱天冬酶基因和抗氧化酶基因的表达在副溶血性弧菌感染后均被强烈诱导；第二，这些上调在头肾中于感染后24小时达到最高水平，而在脾脏白细胞中，在感染后6小时观察到。总之，基于这些观察结果，副溶血性弧菌的急性毒性作用与细胞死亡和自由基释放有关。这些信息有助于更好地理解麦氏托头石首鱼白细胞对常见细菌感染的早期免疫反应的影响和性质。
