The HIF-1 alpha subunit (HIF-1α) is a master regulator of oxygen sensitivity. This study investigated the role of HIF-1α in the energy metabolism and immune responses of hypoxic Scylla paramamosain. After hypoxia treatment for 12 h, the expression levels of HIF-1α in the hemocytes, gills and hepatopancreas were significantly upregulated. After hypoxia and dsHIF-1α treatment for 12 h, the expression level of HIF-1α in hemocytes was successfully inhibited by specific double-strand RNAs for HIF-1α (dsHIF-1α). After inhibition of HIF-1α expression, the expression levels of prophenol oxidase, ATP synthase subunit beta, and Astakine were significantly upregulated, and those of C-type-lectin and lactate dehydrogenase (LDH) were significantly downregulated; the activities of catalase, pyruvate kinase and LDH as well as the contents of pyruvic acid and lactic acid and the levels of apoptosis and phagocytosis in hypoxic S. paramamosain were all significantly decreased. After challenge by Vibrio alginolyticus, the survival rate was significantly lower in hypoxia and dsHIF-1α treated S. paramamosain. Since cell proliferation is an energy-dependent process, the impaired glycolysis after inhibition of HIF-1α expression might be the main reason for the significant decrease of V. alginolyticus burden in hypoxic S. paramamosain. These results indicated that activated HIF-1α enhanced the resistance of S. paramamosain to V. alginolyticus under hypoxic conditions, and the enhanced resistance may be related to the changes in important immune- and metabolism-related gene expression, CAT and PO activities, total hemocyte count, apoptosis, phagocytosis, and anaerobic glycolysis.

HIF-1 α 亚基 (HIF-1α) 是氧气敏感性的主要调节器。本研究调查了HIF-1α在缺氧青蟹的能量代谢和免疫反应中的作用。缺氧处理12 h后，HIF-1α在血细胞、鳃和肝胰腺中的表达水平显着上调。缺氧和dsHIF-1α处理12小时后，HIF-1α的特异性双链RNA（dsHIF-1α）成功抑制了血细胞中HIF-1α的表达水平。抑制HIF-1α表达后，前酚氧化酶、ATP 合酶亚基 β和Astakine的表达水平显着上调，C型凝集素和乳酸脱氢酶（LDH）显着下调；过氧化氢酶、丙酮酸激酶和LDH的活性以及丙酮酸和乳酸的含量以及低氧S. paramamosain的凋亡和吞噬水平均显着降低。经溶藻弧菌攻击后，在缺氧和dsHIF-1α处理的S. paramamosain条件下存活率显着降低。由于细胞增殖是一个能量依赖的过程，抑制HIF-1α表达后糖酵解受损可能是V.低氧S. paramamosain 中的溶藻菌负担。这些结果表明活化的HIF-1α增强了S. paramamosain在低氧条件下对V. alginolyticus的抗性，增强的抗性可能与重要的免疫和代谢相关基因表达、CAT 和 PO 活性的变化有关。血细胞计数、细胞凋亡、吞噬作用和无氧糖酵解。