Original Article

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

Long Chen, Bi-cheng Liu, Xiao-liang Zhang, Jian-dong Zhang, Hong Liu, Min-xia Li

Abstract

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 μg/mL) on Ang II-induced (1×10-7 mol/L) CTGF mRNA and 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 α-smooth action (α-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 α-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.
Keywords: