Chen Hao, Xin Lusheng, Song Xiaorui, Wang Lin, Wang Weilin, Liu Zhaoqun, Zhang Huan, Wang Lingling, Zhou Zhi, Qiu Limei, Song Linsheng
Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; University of Chinese Academy of Sciences, Beijing 100049, China.
Liaoning Key Laboratory of Marine Animal Immunology and Disease Control, Dalian Ocean University, Dalian 116023, China.
Fish Shellfish Immunol. 2017 May;64:297-307. doi: 10.1016/j.fsi.2017.03.020. Epub 2017 Mar 9.
Oyster Crassostrea gigas is one model mollusc inhabiting in the intertidal zone and is frequently stressed by desiccation. The adaptation mechanism of oyster to environmental stress involves multiple levels, and miRNA is one of the most important regulators in post-transcriptional level. In the present study, an oyster norepinephrine-responsive miRNA cgi-miR-365 was proved to contribute to the host adaptation against desiccation by directly promoting the expression of CgHSP90AA1. Briefly, a significant increase of cgi-miR-365 was observed from the first day after aerial exposure and the up-regulation was vigorously repressed when oysters were injected with adrenoceptors antagonists. A total of 15 genes involved in biological regulation, metabolic process and response to stimulus were predicted to be modulated by cgi-miR-365. Among these genes, CgHSP90AA1 was up-regulated significantly during desiccation and could be down-regulated after simultaneous injection of adrenoceptors antagonists. The interaction between cgi-miR-365 and CgHSP90AA1 was subsequently verified in vitro, and a significant promotion of CgHSP90AA1 transcripts was observed after overexpressing cgi-miR-365 in either in vitro luciferase reporter assay or primarily cultured haemocytes. Meanwhile, CgHSP90AA1 transcripts decreased in vivo when cgi-miR-365 was repressed by its inhibitor during desiccation. Collectively, it was suggested that cgi-miR-365 could be induced by norepinephrine during desiccation and promote CgHSP90AA1 expression directly after binding to its 3'-UTR, which would provide new evidence in miRNA-mediated adaptation mechanism in oysters against intertidal stress.
太平洋牡蛎是一种栖息在潮间带的典型软体动物，经常受到干燥胁迫。牡蛎对环境胁迫的适应机制涉及多个层面，而微小RNA（miRNA）是转录后水平最重要的调控因子之一。在本研究中，一种牡蛎去甲肾上腺素响应性miRNA cgi-miR-365被证明通过直接促进CgHSP90AA1的表达，有助于宿主适应干燥环境。简而言之，在暴露于空气中的第一天就观察到cgi-miR-365显著增加，而当给牡蛎注射肾上腺素能受体拮抗剂时，这种上调被强烈抑制。共有15个参与生物调控、代谢过程和刺激响应的基因被预测受cgi-miR-365调控。在这些基因中，CgHSP90AA1在干燥过程中显著上调，在同时注射肾上腺素能受体拮抗剂后可下调。随后在体外验证了cgi-miR-365与CgHSP90AA1之间的相互作用，在体外荧光素酶报告基因检测或原代培养的血细胞中过表达cgi-miR-365后，观察到CgHSP90AA1转录本显著增加。同时，在干燥过程中，当cgi-miR-365被其抑制剂抑制时，CgHSP90AA1转录本在体内减少。总体而言，表明cgi-miR-365在干燥过程中可被去甲肾上腺素诱导，并在与CgHSP90AA1的3'-UTR结合后直接促进其表达，这将为miRNA介导的牡蛎适应潮间带胁迫机制提供新的证据。
