ABSTRACT
OBJECTIVE@#To observe the effect of heat shock factor 1 (HSF1) on heat stress-induced apoptosis in Raw264.7 macrophages.@*METHODS@#Raw264.7 cells transfected with pcDNA3.1 and pcDNA3.1-HSF1 were exposed to heat stress (42.5 degrees C +/- 0.5 degrees C) for 1 h and recovered at 37 degrees C for 6, 9, 12, and 24 h respectively. Flow cytometry (FCM), Hoechst 33258 staining and DNA ladder assays were performed to assess the apoptosis.@*RESULTS@#After heat stress, FCM showed that apoptotic cells were increased significantly and reached the peak at 9 h in Raw 264.7 cells transfected with pcDNA3.1, and were characterized with classical morphologic changes including apoptotic body and nuclear condensation. Agarose gel electrophoresis showed that "DNA ladder" could be observed clearly at 6, 9, and 12 h after the heat stress. But the overexpression of HSF1 could reduce the number of apoptotic cells and inhibit DNA fragmentation.@*CONCLUSION@#HSF1 can inhibit heat stress-induced apoptosis in Raw264.7 macrophages.
Subject(s)
Animals , Mice , Rats , Apoptosis , Cells, Cultured , DNA-Binding Proteins , Pharmacology , Heat Shock Transcription Factors , Heat-Shock Response , Macrophages , Cell Biology , Transcription Factors , Pharmacology , TransfectionABSTRACT
OBJECTIVE@#To screen the inflammatory mediators genes regulated by HSF1, and explore the mechanism of downstream genes regulated by HSF1.@*METHODS@#HSF-/- and HSF1+/+ mice were injected with 15 mg/kg LPS intraperitoneally (ip), respectively, and were treated as previous after HSR. The total RNA of lung tissues were extracted and filtrated by SuperArray gene Microarry. The promoter of candidate genes were analyzed by transcription element search software to search for heat shock element (HSE). Select the suppressor of cytokine signaling 3 (SOCS3) with HSE. Macrophage cells were stimulated with 400 ng/mL LPS, and were treated as previous after HSR, then the total RNA was extracted respectively. RT-PCR and northern blot assay were performed to detect the expression levels of SOCS3 mRNA.@*RESULTS@#Fifteen genes were repressed by HSF1, including 9 genes with complete HSE. Eleven genes were accelerated by HSF1 possibly, including 8 genes with complete HSE. The promoter of SOCS3 gene contained one complete HSE. LPS stimulation obviously increased the levels of SOCS3 mRNA in macrophages of RAW264.7 mice, which was inhibited by HSR and over-expression of HSF1.@*CONCLUSION@#HSR or HSF1 inhibits LPS induced expression of SOCS3 mRNA; HSF1 might inhibit LPS-induced expression of SOCS3 mRNA by binding to HSE in the promoter of SOCS3 gene.