Role of connective tissue growth factor in renal tubular epithelial-myofibroblast transdifferentiation and extracellular matrix accumulation in vitro.
Connective tissue growth factor (CTGF) has been reported to play an important role in mediating the profibrotic effects of transforming growth factor-beta (TGF-beta) in the pathogenesis of renal fibrosis. To further elucidate the role of CTGF in renal tubular transdifferentiation and extracellular matrix (ECM) metabolism, we examined the time-course of CTGF, alpha-smooth muscle actin (alpha-SMA), fibronectin and plasminogen activator inhibitor-1(PAI-1) gene expression upon the stimulation of TGF-beta1 (5 microg/L) in cultured human proximal tubular epithelial cell line (HKC), and further investigated the effects of endogenous CTGF blockade. On reverse transcriptional-polymerase chain reaction (RT-PCR) analysis, TGF-beta1 upregulated CTGF gene expression, preceding that of alpha-SMA, fibronectin and PAI-1. The alpha-SMA, fibronectin and PAI-1 mRNA expression induced by TGF-beta1 were significantly inhibited by CTGF antisense oligodeoxynucleotide (ODN) transfection. With prolonged incubation time, CTGF antisense ODN also inhibited intracellular alpha-SMA and PAI-1 protein synthesis, lowered the level of fibronectin and PAI-1 protein secreted into the media, as confirmed by indirect immuno-fluorescence, flow cytometry, enzyme-linked immunosorbent assay (ELISA) and Western blot methods respectively. These results suggested that CTGF may play a crucial role in the renal tubular epithelial-transdifferentiation and the following deposition/degradation process of ECM during tubulointerstitial fibrosis.
Zhang
Chun
C
Department of Nephrology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China. zhangchun1234@hotmail.com
Meng
Xianfang
X
Zhu
Zhonghua
Z
Yang
Xiao
X
Deng
Anguo
A
D000199:Actins / Q000096:biosynthesis / Q000235:genetics; D015153:Blotting, Western; D002454:Cell Differentiation / Q000187:drug effects; D002478:Cells, Cultured; D055513:Connective Tissue Growth Factor; D004797:Enzyme-Linked Immunosorbent Assay; D004847:Epithelial Cells / Q000187:drug effects; D005109:Extracellular Matrix / Q000187:drug effects*; D005347:Fibroblasts / Q000187:drug effects; D005353:Fibronectins / Q000096:biosynthesis / Q000235:genetics; D005434:Flow Cytometry; D019085:Fluorescent Antibody Technique, Direct; D006801:Humans; D017874:Immediate-Early Proteins / Q000235:genetics / Q000494:pharmacology / Q000502:physiology*; D036341:Intercellular Signaling Peptides and Proteins / Q000235:genetics / Q000494:pharmacology / Q000502:physiology*; D007684:Kidney Tubules / Q000187:drug effects* / Q000648:ultrastructure; D008934:Mitogens / Q000494:pharmacology*; D016376:Oligonucleotides, Antisense / Q000494:pharmacology; D012333:RNA, Messenger / Q000032:analysis / Q000096:biosynthesis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016212:Transforming Growth Factor beta / Q000494:pharmacology
D000199:Actins; C526317:CCN2 protein, human; D005353:Fibronectins; D017874:Immediate-Early Proteins; D036341:Intercellular Signaling Peptides and Proteins; D008934:Mitogens; D016376:Oligonucleotides, Antisense; D012333:RNA, Messenger; D016212:Transforming Growth Factor beta; D055513:Connective Tissue Growth Factor