College of Life Science, Liaoning Normal University, Dalian, 116081, China.
Lamprey Research Center, Liaoning Normal University, Dalian, 116081, China.
Immunogenetics. 2019 May;71(5-6):421-432. doi: 10.1007/s00251-019-01117-w. Epub 2019 May 14.
Cathepsins are key mammalian proteases that play an important role in the immune response. Several studies have revealed the versatile and critical functions of cathepsins. Here, we obtained ten kinds of cathepsin homologs and identified seven homologs with complete coding sequences. Phylogenetic analysis verified their identities and supported the classification of cathepsins into seven families, which is similar to other vertebrates. Tissue-specific expression analysis showed that all lamprey cathepsins (L-cathepsins) are present in the supraneural body (SB), kidney, gill, intestine, brain, heart, and liver, but their relative abundance varied among tissues. Additionally, we focused on the lamprey cathepsin L (L-cathepsin L) and used recombinant L-cathepsin L protein (rL-cathepsin L) to prepare anti rL-cathepsin L polyclonal antibodies, which were used to detect its distribution in lamprey tissues. The L-cathepsin L protein was primarily detected in the SB, kidney, gill, intestine, brain, and liver via western blot and immunohistochemistry assays. Importantly, quantitative real-time PCR (RT-PCR) revealed that the expression level of L-cathepsins mRNA significantly increased after exposure to three different stimuli (poly I:C, Staphylococcus aureus (S.a) and Vibro anguilarum (V.an)). This suggested that L-cathepsins may participate in defense processes. These results revealed that L-cathepsins may play key roles in the immune response to exogenous stimuli. The findings provide important information for future studies aiming to understand the molecular mechanisms underlying the immune response to pathogen invasion in lamprey.
组织蛋白酶是哺乳动物中重要的蛋白酶，在免疫反应中发挥重要作用。多项研究揭示了组织蛋白酶的多功能和关键功能。在此，我们获得了 10 种组织蛋白酶同源物，并鉴定出 7 种具有完整编码序列的同源物。系统发育分析验证了它们的身份，并支持将组织蛋白酶分为 7 个家族，这与其他脊椎动物相似。组织特异性表达分析表明，所有七鳃鳗组织蛋白酶（L-组织蛋白酶）都存在于神经上体（SB）、肾脏、鳃、肠、脑、心脏和肝脏中，但它们在组织中的相对丰度不同。此外，我们重点研究了七鳃鳗组织蛋白酶 L（L-组织蛋白酶 L），并使用重组 L-组织蛋白酶 L 蛋白（rL-组织蛋白酶 L）制备抗 rL-组织蛋白酶 L 多克隆抗体，用于检测其在七鳃鳗组织中的分布。通过 Western blot 和免疫组织化学检测，L-组织蛋白酶 L 蛋白主要在 SB、肾脏、鳃、肠、脑和肝脏中被检测到。重要的是，定量实时 PCR（RT-PCR）显示，在暴露于三种不同刺激物（多聚 I:C、金黄色葡萄球菌（S.a）和鳗弧菌（V.an））后，L-组织蛋白酶 mRNA 的表达水平显著增加。这表明 L-组织蛋白酶可能参与防御过程。这些结果表明，L-组织蛋白酶可能在对外源刺激的免疫反应中发挥关键作用。这些发现为未来研究提供了重要信息，旨在了解七鳃鳗对病原体入侵的免疫反应的分子机制。
