Guangdong Provincial Key Laboratory of Marine Biology, Shantou University, Shantou 515063, China; STU-UMT Joint Shellfish Research Laboratory, Shantou University, Shantou 515063, China.
Key Laboratory of Cultivation and High-value Utilization of Marine Organisms, Fisheries Research Institute of Fujian, Xiamen 361021, China.
Dev Comp Immunol. 2019 Jun;95:38-49. doi: 10.1016/j.dci.2019.02.003. Epub 2019 Feb 6.
The p38 mitogen-activated protein kinases (MAPKs) are evolutionally conserved from yeasts to mammals, and are involved in the regulation of cells response to various extracellular stimuli. In this study, the p38 MAPK gene (designated as Spp38) of mud crab (Scylla paramamosain) was identified and studied. Spp38 contained the conserved Thr-Gly-Tyr (TGY) motif and a Ala-Thr-Arg-Trp (ATRW) substrate-binding site. Spp38 transcript was ubiquitously expressed in all tissues examined, with the highest expression found in muscle and hepatopancras. Quantitative real-time PCR revealed that Spp38 was upregulated in hemocytes and hepatopancras after infection with Vibrio parahemolyticus and Lipopolysaccharides (LPS). Reporter gene assays indicated that Spp38 activated the expression of anti-lipopolysaccharides (SpALF1 - SpALF6) in S. paramamosian. RNA interference (RNAi)-mediated knockdown of Spp38 or inhibition of Spp38 by SB203580 decreased the expression levels of SpALF1-6 and dual oxidase (SpDuox1 and SpDuox2) in S. paramamosian, which consequently reduced reactive oxygen species (ROS) production thereby significantly increasing the bacterial count in the hemolymph of mud crabs. Similarly, there was a significant reduction in bacterial clearance ability of hemolymph after Spp38 knockdown followed by V. parahemolyticus infection. Taken together, the current data indicated that Spp38 could play a vital role in maintaining the homeostasis of hemolymph microbiota in S. paramamosain.
p38 丝裂原活化蛋白激酶（MAPKs）从酵母到哺乳动物在进化上是保守的，参与调节细胞对各种细胞外刺激的反应。本研究鉴定并研究了泥蟹（Scylla paramamosain）的 p38 MAPK 基因（命名为 Spp38）。Spp38 含有保守的 Thr-Gly-Tyr（TGY）基序和 Ala-Thr-Arg-Trp（ATRW）底物结合位点。Spp38 转录本在所有检测组织中广泛表达，在肌肉和肝胰腺中表达量最高。定量实时 PCR 显示，在感染副溶血弧菌和脂多糖（LPS）后，血细胞和肝胰腺中 Spp38 上调。报告基因检测表明，Spp38 激活了 S. paramamosain 中抗脂多糖（SpALF1-SpalF6）的表达。Spp38 的 RNA 干扰（RNAi）介导的敲低或 Spp38 被 SB203580 抑制降低了 SpALF1-6 和双氧化酶（SpDuox1 和 SpDuox2）在 S. paramamosain 中的表达水平，从而导致活性氧（ROS）产生减少，进而显著增加泥蟹血细胞中的细菌数量。同样，在 Spp38 敲低后再感染副溶血弧菌，血细胞的清除能力显著降低。总之，这些数据表明 Spp38 在维持泥蟹 S. paramamosain 血细胞微生物群的内环境平衡中可能发挥重要作用。
