ALBERT

Description: 〈p〉Publication date: March 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 98〈/p〉 〈p〉Author(s): Junzhi Zhang, Qiangde Liu, Yuning Pang, Xiang Xu, Kun Cui, Yanjiao Zhang, Kangsen Mai, Qinghui Ai〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Apart from mitigating endoplasmic reticulum (ER) stress, vast studies have demonstrated the crucial role of inositol-requiring transmembrane kinase and endonuclease 1α (IRE1α) - spliced X-box binding protein 1 (XBP1s) signaling pathway in inflammatory response in mammals. In addition, palmitic acid (PA)-induced inflammation has been verified in large yellow croaker (〈em〉Larimichthys crocea〈/em〉). However, whether the IRE1α-XBP1s signaling pathway is involved in inflammatory response caused by PA remains poorly studied in fish. The present study was aimed at elucidating the role of the IRE1α-XBP1s signaling pathway in inflammatory response induced by PA in primary hepatocytes from large yellow croaker. In the present study, the full-length cDNA of 〈em〉ire1α〈/em〉 and 〈em〉xbp1s〈/em〉 were cloned and comprised 3793 bp and 1789 bp with an open reading frame of 3279 bp and 1170 bp, encoding 1093 and 390 amino acids, respectively. IRE1α protein possessed a protein kinase and endoribonuclease domain and XBP1s protein possessed a basic-leucine zipper domain. The IRE1α protein and XBP1s protein located to the ER membrane and nucleus respectively. The 〈em〉ire1α〈/em〉 and 〈em〉xbp1s〈/em〉 were widely transcribed in various tissues with the higher level in intestine, liver, adipose and head kidney. The ER stress-inducing agent tunicamycin (Tm) and PA treatment significantly activated the IRE1α-XBP1s signaling pathway and increased the pro-inflammatory genes expression including tumor necrosis factor α (〈em〉tnfα〈/em〉), interleukin 6 (〈em〉il-6〈/em〉) and interleukin 1β (〈em〉il-1β〈/em〉) (〈em〉P〈/em〉 〈 0.05). When KIRA6, the IRE1α kinase inhibitor, was used to block the IRE1α-XBP1s signaling pathway, the Tm and PA-induced pro-inflammatory genes expression was significantly suppressed (〈em〉P〈/em〉 〈 0.05). These data indicated that the IRE1α-XBP1s signaling pathway was involved in the PA-induced inflammatory response in large yellow croaker.〈/p〉〈/div〉 〈/div〉