Study On Activation Of NF-κB Pathway And The Expression Of Inflammatory Cytokines Of Macrophage By MtDNA

Objective The systemic inflammatory response syndrome（SIRS） is seriouscomplications after trauma and severe burns.Patients with it have high mortality.The pathogenesis and prevention of aseptic SIRS have not yet fully beenunderstood. Now it is known that the body after trauma can produce a largenumber of mtDNA that can activate P38protein kinase pathways and produceinflammatory factors. But whether mtDNA can activative NF-κB pathway throughTLR-9and produce inflammation factors is still unknown. The paper furtherexplores the mechanism of aseptic SIRS through the study into the stimulation ofmacrophage NF-κB pathway by mtDNA.Methods In the first part the rat peritoneal macrophages can be divided intomedium control group, nDNA (10ug/ml) group, mtDNA (5ug/ml) group andmtDNA (10ug/ml) group. In the second part mtDNA (10ug/ml) group will beinhibited by1umol/ml,5umol/ml,10umol/mlPDTC,respectively. In two parts,the expression of NF-κB subunit p65mRNA, I-κB mRNA and TLR-9mRNA canbe analyzed by Real-time PCR, the concentration of TNF-α, IL-1and IL-6canbe analyzed by ELISA, and the concentration changes of I-κB protein、TLR-9protein and NF-kB subunit P65protein can be detected by Western blotting atdifferent times, respectively.Results The mtDNA (5ug/ml) group and mtDNA (10ug/ml) group can increasethe expression of TLR-9mRNA and TLR-9protein in the macrophage and theexpression of p65mRNA and p65protein in NF-kB subunit, decrease theexpression of I-κBmRNA and I-κB protein, and produce IL-1and IL-6; PDTC,regardless its concentration, can inhibit the effect produced by mtDNA on macrophages.Conclusions MtDNA can activate NF-κB pathway through TLR-9macrophageand stimulate macrophages to produce cytokines IL-1and IL-6. PDTC caninhibit the effect produced by mtDNA on macrophages.