Jiang Dongli, Yang Chuanyan, Gu Wenfei, Ma Xiaoxue, Tong Ziling, Wang Lingling, Song Linsheng
Liaoning Key Laboratory of Marine Animal Immunology & Disease Control, Dalian Ocean University, Dalian, 116023, China; Laboratory of Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266235, China; Dalian Key Laboratory of Aquatic Animal Disease Prevention and Control, Dalian Ocean, China.
Liaoning Key Laboratory of Marine Animal Immunology & Disease Control, Dalian Ocean University, Dalian, 116023, China; Laboratory of Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266235, China; Dalian Key Laboratory of Aquatic Animal Disease Prevention and Control, Dalian Ocean, China.
Dev Comp Immunol. 2024 Apr;153:105128. doi: 10.1016/j.dci.2023.105128. Epub 2023 Dec 30.
Liver kinase B1 (LKB1) is a classical serine/threonine protein kinase and plays an important role in maintaining energy homeostasis through phosphorylate AMP-activated protein kinase α subunit (AMPKα). In this study, a homologous molecule of LKB1 with a typical serine/threonine kinase domain and two nuclear localization sequences (NLSs) was identified in Yesso Scallop Patinopecten yessoensis (PyLKB1). The mRNA transcripts of PyLKB1 were found to be expressed in haemocytes and all the examined tissues, including gill, mantle, gonad, adductor muscle and hepatopancreas, with the highest expression level in hepatopancreas. PyLKB1 was mainly located in cytoplasm and nucleus of scallop haemocytes. At 3 h after high temperature stress treatment (25 °C), the mRNA transcripts of PyLKB1, PyAMPKα, and PyGLUT1 in hepatopancreas, the phosphorylation level of PyAMPKα at Thr170 in hepatopancreas, the positive fluorescence signals of PyLKB1 in haemocytes, glucose analogue 2-NBDG content in haemocytes, and glucose content in hepatopancreas, haemocytes and serum all increased significantly (p < 0.05) compared to blank group (15 °C). However, there was no significant difference at the protein level of PyLKB1 and PyAMPKα. After PyLKB1 was knockdown by siRNA, the mRNA expression level of PyGLUT1, and the glucose content in hepatopancreas and serum were significantly down-regulated (p < 0.05) compared with the negative control group receiving an injection of siRNA-NC. However, there were no significant difference in PyGLUT1 expression, glucose content and glucose analogue 2-NBDG content in haemocytes. These results collectively suggested that PyLKB1-PyAMPKα pathway was activated to promote glucose transport by regulating PyGLUT1 in response to high temperature stress. These results would be helpful for understanding the function of PyLKB1-PyAMPKα pathway in regulating glucose metabolism and maintaining energy homeostasis under high temperature stress in scallops.
肝脏激酶B1（LKB1）是一种经典的丝氨酸/苏氨酸蛋白激酶，通过磷酸化AMP激活的蛋白激酶α亚基（AMPKα）在维持能量稳态中发挥重要作用。在本研究中，在虾夷扇贝（Patinopecten yessoensis）中鉴定出一种LKB1的同源分子（PyLKB1），其具有典型的丝氨酸/苏氨酸激酶结构域和两个核定位序列（NLSs）。发现PyLKB1的mRNA转录本在血细胞以及所有检测的组织中表达，包括鳃、外套膜、性腺、闭壳肌和肝胰腺，其中在肝胰腺中的表达水平最高。PyLKB1主要位于扇贝血细胞的细胞质和细胞核中。在高温应激处理（25°C）3小时后，与空白组（15°C）相比，肝胰腺中PyLKB1、PyAMPKα和PyGLUT1的mRNA转录本、肝胰腺中Thr170位点PyAMPKα的磷酸化水平、血细胞中PyLKB1的阳性荧光信号、血细胞中葡萄糖类似物2-NBDG含量以及肝胰腺、血细胞和血清中的葡萄糖含量均显著增加（p<0.05）。然而，PyLKB1和PyAMPKα的蛋白质水平没有显著差异。在用siRNA敲低PyLKB1后，与注射siRNA-NC的阴性对照组相比，PyGLUT1的mRNA表达水平以及肝胰腺和血清中的葡萄糖含量显著下调（p<0.05）。然而，血细胞中PyGLUT1表达、葡萄糖含量和葡萄糖类似物2-NBDG含量没有显著差异。这些结果共同表明，在高温应激下，PyLKB1-PyAMPKα途径被激活，通过调节PyGLUT1促进葡萄糖转运。这些结果将有助于理解PyLKB1-PyAMPKα途径在扇贝高温应激下调节葡萄糖代谢和维持能量稳态中的作用。
