Heat shock protein 27 (HSP27) plays an important role in protecting cells from various stress factors. This study aimed to investigate the function of HSP27 gene and its regulatory mechanism as infected by Escherichia coli (E. coli) at the tissue and cellular levels. Real-time PCR was used to detect the differential expression of HSP27 gene in F18 resistant and sensitive Sutai pigs and the differential expression upon E. coli F18ab, F18ac, K88ac bacterial supernatant, thallus infection and LPS induction in IPEC-J2. In addition, the HSP27 gene overexpression vector was constructed to detect the effect of the HSP27 gene overexpression on the adhesion of E. coli F18 to IPEC-J2, secretion of pro-inflammatory factors, and the expression of the upstream key genes in Mitogen-activated protein kinase (MAPK) pathway. Ribosomal S6 kinase (RSK2) is an important protein in the MAPK pathway. Therefore, the RSK2 gene overexpression vector was constructed and the number of colonies was counted after co-transfection of HSP27 and RSK2 gene. Results revealed that the expression level of HSP27 gene in resistant individuals in 11 tissues was higher than sensitive type. At the cellular level, the relative expression levels of HSP27 gene were increased after F18ab, F18ac bacterial supernatant, F18ab thallus infection, and LPS induction for 4 h (P < 0.01). The adhesion ability of E. coli F18ab to IPEC-J2 was significantly reduced after HSP27 gene overexpression (P < 0.01), and the concentration of pro-inflammatory factors in the HSP27 gene overexpression group was significantly reduced compared with the control group after F18ab infection (P < 0.05). Furthermore, the expression of RSK2 was significantly increased in HSP27 overexpression group upon F18ab infection (P < 0.01). The colonies quantitative results also showed that the number of colonies was significantly reduced after co-transfection of HSP27 and RSK2 gene. We indicated that the high expression of HSP27 gene may resist the inflammatory response caused by exogenous stress and enhance the ability of IPEC-J2 to resist E. coli F18 infection. RSK2 gene in the MAPK pathway may cooperate with HSP27 gene to participate in the immune response of the organism, which provides a theoretical basis for the study of the mechanism of anti-E. coli infection in piglets.

热休克蛋白27（HSP27）在保护细胞免受各种应激因素的影响中起着重要作用。这项研究旨在调查在组织和细胞水平上HSP27基因的功能及其在大肠杆菌（E. coli）感染下的调控机制。实时荧光定量PCR检测F18抗性和敏感苏泰猪中HSP27基因的差异表达，以及IPEC-J2中大肠杆菌F18ab，F18ac，K88ac细菌上清液，th体感染和LPS诱导的差异表达。此外，构建了HSP27基因过表达载体，以检测HSP27基因过表达对小鼠粘连的影响。大肠杆菌F18至IPEC-J2，促炎因子的分泌以及丝裂原活化蛋白激酶（MAPK）途径中上游关键基因的表达。核糖体S6激酶（RSK2）是MAPK途径中的重要蛋白质。因此，构建了RSK2基因过表达载体，并在HSP27和RSK2基因共转染后计数了菌落数。结果表明，HSP27基因在11个组织的抗性个体中的表达水平高于敏感型。在细胞水平，F18ab，F18ac细菌上清液，F18ab丘疹感染和LPS诱导4 h后，HSP27基因的相对表达水平增加（P<0.01）。HSP27基因过表达后大肠杆菌F18ab对IPEC-J2的黏附能力明显降低（P <0.01），HSP27基因过表达组感染F18ab后与对照组相比促炎因子浓度明显降低。 （P <0.05）。此外，表达RSK2被显著增加HSP27表达组时F18ab感染（P <0.01）。菌落定量结果还显示，HSP27和RSK2共转染后菌落数量明显减少基因。我们表明，HSP27基因的高表达可能抵抗由外源性压力引起的炎症反应，并增强IPEC-J2抵抗大肠杆菌F18感染的能力。MAPK途径中的RSK2基因可能与HSP27基因协同参与机体的免疫反应，为研究仔猪抗大肠杆菌感染的机理提供了理论依据。