Suppressed COP9 signalosome 5 promotes hemocyte proliferation through Cyclin E in the early G1 phase to defend against bacterial infection in crab
Suppressed COP9 signalosome 5 promotes hemocyte proliferation through Cyclin E in the early G1 phase to defend against bacterial infection in crab
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DOI：
10.1096/fj.202101710rrrr
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发表时间：
2022-04
期刊：
影响因子：
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通讯作者：
Hui Zhao;Zhe Chen;Hao Li;Yue Zhao;Qun Wang;Weiwei Li
中科院分区：
文献类型：
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作者：
Hui Zhao;Zhe Chen;Hao Li;Yue Zhao;Qun Wang;Weiwei Li
血细胞是无脊椎动物的免疫细胞，类似于脊椎动物的血细胞，在先天免疫中起着至关重要的作用。先前的研究发现，成熟的循环血细胞缺乏增殖能力。然而，最近的无脊椎动物单细胞RNA测序和功能研究对这一观点提出了挑战。在这里，我们报道了细菌诱导中华绒螯蟹（Eriocheir sinensis）血细胞增殖。流式细胞术收集非增殖和增殖血细胞群，增殖血细胞中EsCyclin E表达高，而增殖血细胞中EsCsn5表达明显抑制。随后的研究发现，EsCsn5以holo - complex和单体两种形式分布，而敲除EsCsn5对holo - complex的数量影响不大。EsCsn5在蟹的不同组织中广泛表达，但细菌感染后其表达量明显降低。当基因敲低EsCsn5时，螃蟹血细胞的增殖能力显著增强，提示CSN5在螃蟹血细胞增殖的负调控中起关键作用。此外，EsCSN5而非EsCSN8被证明通过泛素化步骤控制EsCyclin E的降解，而不是影响其转录，从而负向调节细胞周期的早期G1期。此外，在EsCyclin E抑制的螃蟹中，存活率显著降低，血淋巴细菌浓度升高。综上所述，本研究提供的证据表明，无脊椎动物血细胞在细菌攻击时下调EsCsn5的表达，从而以EsCyclin E依赖性的方式促进增殖，以保护螃蟹免受感染。
Hemocytes are invertebrate immune cells that are similar to blood cells in vertebrates and play a crucial role in innate immunity. Previous work has found that mature circulating hemocytes lack the ability to proliferate. However, recent single‐cell RNA sequencing and functional studies in invertebrate have challenged this view. Here, we report that bacteria induced hemocytes proliferation in the Chinese mitten crab, Eriocheir sinensis. Flow cytometry was used to collect non‐proliferating and proliferating hemocytes populations, while the expression of EsCyclin E was highly expressed in proliferating hemocytes, but the expression of EsCsn5 was significantly suppressed in proliferating hemocytes. Subsequent studies have found EsCsn5 distributed in two fractions include holo‐complex and monomeric form, whereas knockdown of EsCsn5 has little impact on the amount of the holo‐complex. EsCsn5 was widely expressed in different crab tissues, while its expression was significantly reduced upon bacterial infection. Crab hemocytes showed significantly enhanced proliferation when EsCsn5 was genetically knocked down, suggesting a critical role for CSN5 in the negative regulation of crab hemocyte proliferation. Moreover, EsCSN5 but not the EsCSN8 was demonstrated to negatively regulate the early G1 phase of the cell cycle by controlling the degradation of EsCyclin E through ubiquitination steps, rather than affecting its transcription. Furthermore, in the EsCyclin E‐suppressed crab there was a significantly reduced survival rate and an up‐regulated hemolymph bacterial concentration. Taken together, this study provides evidence demonstrating that invertebrate hemocytes down‐regulate the expression of EsCsn5 upon bacterial challenge, thus promoting proliferation in an EsCyclin E‐dependent manner in order to protect the crab from infection.