Influence of connective tissue growth factor antisense oligonucleotide on angiotensin II-induced epithelial mesenchymal transition in HK2 cells

Aim: The present study was designed to further investigate the effect of connective tissue growth factor antisense oligonucleotide (CTGF-AS) on angiotensin II (Ang II)-induced tubular cell epithelial mesenchymal transition (EMT) in vitro. Methods: The human proximal tubular cell line (HK2) was grown in Dulbecco's modified Eagle's medium containing 10% heat inactivated fetal calf serum. After being rested in serum-free medium for 24 h, the influence of CTGF-AS (20 mu g/mL) on Ang II-induced (1 x 10(-7) mol/L) CTGF mRNAand the protein expression were examined by using reverse transcription-polymerase chain reaction and indirect-immunofluorescence. The effect of CTGF-AS on Ang II-induced cellular ultra-structure was observed using a transmissive electronic microscope. The expression of alpha-smooth action (alpha-SMA) was assayed by immunocytochemistry. In all experiments, the control group was treated with scrambled oligonucleotide. Results: It was shown that Ang II significantly induced the increasing expression of CTGF mRNA and protein (P < 0.01, respectively), which were significantly abolished by treatment with CTGF-AS. After stimulating cells with Ang II, the cellular ultrastructure showed mesenchymal features. These effects were partially inhibited by CTGF-AS. Ang II significantly resulted in the expression of alpha-SMA in time dependent manner, which was markedly attenuated by the treatment with CTGF-AS (P < 0.01, respectively). In contrast, no similar effects were observed in the control group treated with scrambled oligonucleotide. Conclusion: Ang II-induced EMT in human proximal tubular epithelial cells (PTC) can be attenuated by treatment with CTGF-AS. Our data provides further evidence that CTGF might be involved in Ang II-induced EMT in PTC.