[Analysis of changes about hsbp1, hsf1, hsf2 AND hsp70's expression levels in rat's regenerating liver]

Heat shock factor binding protein 1 (HSBP1), a recently discovered protein, weakens and blocks transcription of the heat shock protein 70 (HSP70) gene when binding to HSF1, but HSBP1 can promote cell growth, cell development and cell differentiation when binding to HSF2. Partial hepatectomy (PH) in rat creates injury stimulation and induces liver regeneration. How does hsbp1 coordinate two processes sequently is extremely interesting. This paper, based on cloning the full-length cDNA of hsbpl in rat, applied in situ hybridration and Rat Genome 230 2.0 Array to analyze hsbp1, hsf1, hsf2 and hsp70 expression in liver after PH and sham-operation. The results indicated that the hsbp1 expression level was down-regulated meaningfully at 0.5-2h and up-regulated meaningfully at 8-16h after sham-operation, while hsf2 expression level did not meaningfully change at 0-144h after sham-operation. hsbp1 expression level was up-regulated meaningfully at 6h and 66-144h,and hsf1 at 8-16h, hsf2 at 2-16h, hsp70 at 0.5-24h after PH. Our data suggested that up-regulated expression of the hsp70 at 0.5-12h after sham-operation was controlled by intracellular HSF1, and then controlled by hsbp1 down-regulated at 0.5-2h and hsf1 up-regulated at 8-16h. In the early phase of liver regeneration in rats, hsbp1 and hsf2 expression levels were up-regulated, which promoted cell proliferation through HSBP1 and HSF2 up-regulating,upa activating,c-jun enhancing, intracellular matrix (ECM) degradation, activating the hepatocyte-like growth factor (HGF) etc. In the late phase of liver regeneration (66-144h), hsbp1 expression level was up-regulated, which promoted reconstruction of liver structure and recovery of liver function through HSBP1 inhibiting hsp70 expression, up-regulating genes related to growth, development, differentiation. In conclusion, down-regulating of hsbp1 contributed to interaction between HSF1 and HSE,increased hsp70 expression and enhanced anti-injured capacity of liver and rats. HSBP1 and HSF2 activated the genes related to growth, development, differentiation and then promoted liver regeneration in rats.