Objective: To determine the effect of 2 transforming growth factor beta1 (TGF-beta1) short hairpin RNA (shRNA) expression plasmids (pcDU6-A1-A2 and pcDU6-B1-B2) on proliferation, TGF-beta1, connective tissue growth factor (CTGF), and fibronectin (FN) expression induced by human serum albumin (HSA) in HK2 cells.
Methods: A vector plasmid containing the TGF-beta1 shRNA was generated. An HK2 cell line was used in the study. The 2 TGF-beta1 shRNA expression plasmids were transfected into cultured HK2 cells by lipofectamine 2000. Cellular proliferation was assessed by tetrazolium salt colorimetry. The semi-quantitative reverse transcriptive PCR was performed to detect the expression of TGF-beta1, CTGF, and FN mRNA. Levels of TGF-beta1 and FN protein were measured with a sandwich enzyme-linked immunosorbent assay.
Results: After treating with 5 g/L HSA for 24 hours in HK2 cells, cellular proliferating capacity increased significantly (P<0.05). The expression levels of TGF-beta1, CTGF, and FN mRNA were upregulated in HK2 cells stimulated by 5 g/L HSA, and levels of TGF-beta1 and FN protein in the culture supernatant increased (P<0.05). The introduction of pcDU6-A1-A2 and pcDU6-B1-B2 resulted in significant reduction of cellular proliferation activity, and the expression levels of TGF-beta1, CTGF, and FN mRNA were downregulated (P<0.05). Levels of TGF-beta1 and FN protein in the culture supernatant decreased (P<0.05) after 12 or 24 hours of TGF-beta1 shRNA transfection into HK2 cells There was no significant difference in the expression levels of TGF-beta1, CTGF, and FN mRNA between the 2 pcDU6 vector plasmid mediated TGF-beta1 shRNA groups (P>0.05).
Conclusion: pcDU6 vector plasmid mediated TGF-beta1 shRNAs could obviously inhibit the expression levels of TGF-beta1, CTGF, FN and cellular proliferation stimulated by HSA in HK2 cells, which may be related to the mediation of TGF-beta1.