Identification of a novel transcriptional factor HMGB34367 for activation of ?-smooth muscle actin gene in relation to pulmonary fibrosis / 医学研究生学报

ABSTRACT

Objective: To demonstrate the influence of HMGB34367,a subfamily member of the high-mobility group protein B1(HMGB1),as a transcriptional factor of the ?-SMA gene expression.Methods: We cloned HMGB34367 cDNA from the fibrotic lung tissue of the Balb/C mouse treated with BLM by RT-PCR,sub-cloned it into a eukaryotic expression vector pcDNA 3.0 or pEGF-N2,and constructed a report plasmid,pDsRed-SMA,encoding red fluorescence(RFP) driven by ?-SMA promoter.Following the co-transfection of pDsRed-SMA and HMGB34367-pcDNA3.0/ pEGF-N2-HMGB34367 in the cultured 16HBE cells,we tested the expression of the RFP in the absence and presence of TGF?1 by fluorescence microscopy.After the transfection of HMGB34367-pcDNA3.0,the nucleus extracts from the transfected cells were subjected to electrophoretic mobility shift assay(EMSA) for the detection of the binding activity of HMGB34367 with ?-SMA promoter CarGB motif.RT-PCR was performed for the evaluation of the ?-SMA gene expression in the cells.Results: The over expression of HMGB34367 activated the ?-SMA promoter and enhances the expression of the ?-SMA gene.An increased binding activity of HMGB34367 with CarGB motif was detected by EMSA in the transfected cells.Conclusion:HMGB34367,a member of HMGB1 family,could act as a transcription factor for the transcriptional activation of the ?-SMA gene,which may play an important role in the development of lung fibrosis.