Objective: To investigate the influence of heat shock factor1 (HSF1) on gene expression of inflammatory mediators in RAW264.7 murine macrophage cells induced by burn serum.
Methods: Sera were separated from blood of normal rats and rats with severe burns, and the recombinant vector pcDNA3. 1/HSF1 was constructed. RAW264.7 macrophages were divided into non-transfection group, vacant vector group (with burn and normal sera stimulation, respectively after vacant vector transfection) and recombinant vector group (with burn and normal sera stimulation, respectively after recombinant vector transfection). Some recombinant vector transfected macrophages without serum stimulation were prepared for the determination of HSF 1 expression with Western blotting. The mRNA expressions of TNF-alpha, HMGB 1 and IL-10 were determined with RT-PCR.
Results: The cell line attained after recombinant vector transfection was comparatively stable,with partial activation of HSF 1. Burn sera markedly upregulated TNF-alpha, HMGB1 mRNA expression (0.910 +/- 0.100, 0.860 +/- 0.020, respectively), but downregulated IL-10 expression (0.430 +/- 0.010, respectively) in normal macrophages, while these genes maintained in a very low level in normal macrophages with normal serum stimulation . macrophages with recombinant vector transfection and burn serum stimulation could obviously inhibit the expression of TNF-alpha and HMGB 1, but enhance the IL-10 gene expression (0.130 +/- 0.100, 0.450 +/- 0.020 , 0.450 +/- 0.020, respectively )when compared with that with vacant vector transfection and burn serum stimulation (0.800 +/- 0.050, 0.880 +/- 0.030, 0.420 +/- 0.010, respectively).
Conclusion: HSF1 can inhibit the expression of some pro-inflammatory mediators in macrophages after a severe burns, indicating that appropriate upregulation of anti-inflammatory mediators might exert protective effects on the organism.