Metformin Inhibits Inflammatory Response Of Macrophages With Mycobacterium Bovis Infection Based On PPARγ/p38MAPK Pathway

Objective:In this experiment,the macrophage infected by M.bovis was used to establish an experimental model,and the effect of metformin regulating PPARy/p38MAPK pathway on the inflammatory response of macrophage infected by M.bovis was discussed,so as to provide a new basis for the prevention and treatment of tuberculosis.Methods:M.bovis strain was prepared with BCG for intradermal injection.Human monocyte acute leukemia cells(THP-1)were induced into macrophages with 50 mmol/L phorbol ester,and the infection model was established by bacterial infection cells(MOI=10:1);The experiment consisted of four groups:Control group,M.bovis group,M.bovis+Met group and M.bovis+Met+GW9662(PPARy inhibitor)group;The expression of PPARy,p38MAPK and p-p38MAPK genes was detected by RT-PCR;The expression of PPARy,p38MAPK and p-p38MAPK protein was detected by Western blotting;ELISA was used to detect the levels of TNF-α,IL-6 and IL-10 of macrophages in each group;Person test was used for correlation analysis;The bacterial load of macrophages in each group was detected.Results:Compared with Control group,the expression of PPARy,p-p38MAPK gene and protein and the levels of TNF-α and IL-6 were significantly increased after M.bovis infected macrophages(P<0.05).There was no significant change in the expression of p38MAPK gene and protein(P>0.05).After metformin treatment,the expression of PPARy in macrophages increased further(P<0.05),while the expression of p-p38MAPK and the concentrations of TNF-α and IL-6 were decreased and the expression of IL-10 was increased(P<0.05).The specific PPARy antagonist GW9662 reversed the above effects of metformin.The correlation analysis results show that after treatment with metformin,the PPARy expression was negatively correlated with TNF-α and IL-6,and positively correlated with IL-10(P<0.05),while the expression of p-p38MAPK was positively correlated with TNF-α and IL-6,and negatively correlated with IL-10(P<0.05).Compared with M.bovis group,the bacterial load of M.bovis+Met and M.bovis+Met+GW9662 groups decreased significantly(P<0.05),but it was no significant difference between M.bovis+Met and M.bovis+Gw9662 groups(P>0.05).Conclusion:1.Metformin can up-regulate PPARy expression and further inhibit the activation of p38MAPK,thus inhibiting the inflammatory response of macrophages infected with M.bovis,suggesting that PPARy and p38MAPK,as regulatory factors of inflammatory response,are expected to become candidate targets for tuberculosis prevention and treatment.2.Metformin can enhance immune response and promote bacterial clearance.so it is a candidate drug for adjuvant anti-tuberculosis treatment.