Objective:To investigate the effect of mitogen-activated protein kinase interaction serine kinase 1(Mnk1)gene deletion on lipopolysaccharide(LPS)-induced inflammatory response in mouse macrophages(Mφ)and the possible...Objective:To investigate the effect of mitogen-activated protein kinase interaction serine kinase 1(Mnk1)gene deletion on lipopolysaccharide(LPS)-induced inflammatory response in mouse macrophages(Mφ)and the possible mechanism.Methods:Healthy male wildtype C57BL/6J(WT)and Mnk1 knockout(KO)mice were selected at 8-10 weeks of age and divided into WT+PBS,KO+PBS,WT+LPS and KO+LPS groups,and the serum levels of IL-1βwere measured by ELISA after 24 h intraperitoneal injection of PBS or LPS.The mRNA expression levels of IL-1βand Sprouty2(Spry2)in the spleen Mφwere measured by qRTPCR.Mφwas also extracted from the peritoneal cavity of two strains of mice for in vitro experiments to detect macrophage adhesion function and stimulated with equal volumes of LPS or PBS solution for 24 h,divided into WT+PBS group,KO+PBS group,WT+LPS group and KO+LPS group,and transfected with adenovirus expressing Spry2.qRT-PCR was used to detect the mRNA expression levels of LFA-1α,IL-1β,iNOS,CD206,Arg1 and Spry2 in Mφ.Mnk1,ERK1/2,P-ERK1/2,P-p38,P-JNK and Spry2 protein levels in Mφwere detected by western blot.Results:In the in vivo experiments,the concentration of IL-1βin the serum of the KO+LPS group was more significantly elevated than that of the WT+LPS group in mice injected intraperitoneally with LPS.The expression level of splenic MφIL-1βwas higher and the mRNA expression level of Spry2 was decreased in the KO+LPS group compared to the WT+LPS group.In the in vitro experiments,the mRNA expression levels of IL-1βand iNOS were elevated and those of CD206,Arg1 and Spry2 were decreased in the KO+LPS group compared with the WT+LPS group;the expression of LFA-1αwas not significantly different in the WT+PBS and WT+LPS groups,while the expression level of LFA-1αwas significantly increased in the KO+LPS group compared with the WT+LPS group.The results of the macrophage adhesion function assay showed that the adhesion rate of Mφin the KO group was increased at several time points compared to the WT group.After LPS stimulation,the expression of MφSpry2 decreased in Mnk1 KO group compared to WT group,while the expression of P-ERK1/2 increased compared to WT group.After Mφwas transfected with adenovirus overexpressing Spry2 and stimulated with LPS,MφSpry2 expression increased in the KO+AdSpry2 group and P-ERK1/2 expression decreased significantly compared to KO+AdGFP.Conclusion:Mnk1 knockdown enhances LPS-induced inflammatory responses in macrophages,and the mechanism may be related to the involvement of Spry2,a substrate of Mnk1,in regulating macrophage function.展开更多
基金The National Key R&D Program(2018YFC1311300)Scientific Research Project of Hubei Health Commission(WJ2021Q035)。
文摘Objective:To investigate the effect of mitogen-activated protein kinase interaction serine kinase 1(Mnk1)gene deletion on lipopolysaccharide(LPS)-induced inflammatory response in mouse macrophages(Mφ)and the possible mechanism.Methods:Healthy male wildtype C57BL/6J(WT)and Mnk1 knockout(KO)mice were selected at 8-10 weeks of age and divided into WT+PBS,KO+PBS,WT+LPS and KO+LPS groups,and the serum levels of IL-1βwere measured by ELISA after 24 h intraperitoneal injection of PBS or LPS.The mRNA expression levels of IL-1βand Sprouty2(Spry2)in the spleen Mφwere measured by qRTPCR.Mφwas also extracted from the peritoneal cavity of two strains of mice for in vitro experiments to detect macrophage adhesion function and stimulated with equal volumes of LPS or PBS solution for 24 h,divided into WT+PBS group,KO+PBS group,WT+LPS group and KO+LPS group,and transfected with adenovirus expressing Spry2.qRT-PCR was used to detect the mRNA expression levels of LFA-1α,IL-1β,iNOS,CD206,Arg1 and Spry2 in Mφ.Mnk1,ERK1/2,P-ERK1/2,P-p38,P-JNK and Spry2 protein levels in Mφwere detected by western blot.Results:In the in vivo experiments,the concentration of IL-1βin the serum of the KO+LPS group was more significantly elevated than that of the WT+LPS group in mice injected intraperitoneally with LPS.The expression level of splenic MφIL-1βwas higher and the mRNA expression level of Spry2 was decreased in the KO+LPS group compared to the WT+LPS group.In the in vitro experiments,the mRNA expression levels of IL-1βand iNOS were elevated and those of CD206,Arg1 and Spry2 were decreased in the KO+LPS group compared with the WT+LPS group;the expression of LFA-1αwas not significantly different in the WT+PBS and WT+LPS groups,while the expression level of LFA-1αwas significantly increased in the KO+LPS group compared with the WT+LPS group.The results of the macrophage adhesion function assay showed that the adhesion rate of Mφin the KO group was increased at several time points compared to the WT group.After LPS stimulation,the expression of MφSpry2 decreased in Mnk1 KO group compared to WT group,while the expression of P-ERK1/2 increased compared to WT group.After Mφwas transfected with adenovirus overexpressing Spry2 and stimulated with LPS,MφSpry2 expression increased in the KO+AdSpry2 group and P-ERK1/2 expression decreased significantly compared to KO+AdGFP.Conclusion:Mnk1 knockdown enhances LPS-induced inflammatory responses in macrophages,and the mechanism may be related to the involvement of Spry2,a substrate of Mnk1,in regulating macrophage function.
