Connective tissue growth factor (CTGF) acts as a downstream mediator of TGF-β1 to induce mesenchymal cell condensation

2006 ◽  
Vol 210 (2) ◽  
pp. 398-410 ◽  
Author(s):  
Jason J. Song ◽  
Rulla Aswad ◽  
Reem A. Kanaan ◽  
Mario C. Rico ◽  
Thomas A. Owen ◽  
...  
2011 ◽  
Vol 441 (1) ◽  
pp. 499-510 ◽  
Author(s):  
Helen C. O'Donovan ◽  
Fionnuala Hickey ◽  
Derek P. Brazil ◽  
David H. Kavanagh ◽  
Noelynn Oliver ◽  
...  

The critical involvement of TGF-β1 (transforming growth factor-β1) in DN (diabetic nephropathy) is well established. However, the role of CTGF (connective tissue growth factor) in regulating the complex interplay of TGF-β1 signalling networks is poorly understood. The purpose of the present study was to investigate co-operative signalling between CTGF and TGF-β1 and its physiological significance. CTGF was determined to bind directly to the TβRIII (TGF-β type III receptor) and antagonize TGF-β1-induced Smad phosphorylation and transcriptional responses via its N-terminal half. Furthermore, TGF-β1 binding to its receptor was inhibited by CTGF. A consequent shift towards non-canonical TGF-β1 signalling and expression of a unique profile of differentially regulated genes was observed in CTGF/TGF-β1-treated mesangial cells. Decreased levels of Smad2/3 phosphorylation were evident in STZ (streptozotocin)-induced diabetic mice, concomitant with increased levels of CTGF. Knockdown of TβRIII restored TGF-β1-mediated Smad signalling and cell contractility, suggesting that TβRIII is key for CTGF-mediated regulation of TGF-β1. Comparison of gene expression profiles from CTGF/TGF-β1-treated mesangial cells and human renal biopsy material with histological diagnosis of DN revealed significant correlation among gene clusters. In summary, mesangial cell responses to TGF-β1 are regulated by cross-talk with CTGF, emphasizing the potential utility of targeting CTGF in DN.


2020 ◽  
Author(s):  
Toyoshi Yanagihara ◽  
Sy Giin Chong ◽  
Mahsa Gholiof ◽  
Kenneth E. Lipson ◽  
Quan Zhou ◽  
...  

AbstractIdiopathic pulmonary fibrosis (IPF) is a fatal lung disease characterized by progressive and excessive accumulation of myofibroblasts and extracellular matrix in the lung. Connective-tissue growth factor (CTGF) is known to exacerbate pulmonary fibrosis in radiation-induced lung fibrosis, and in this study, we show the upregulation of CTGF from a rat lung fibrosis model induced by adenovirus vector encoding active TGF-β1 (AdTGF-β1), and also in patients with IPF. The expression of CTGF was upregulated in vascular smooth muscle cells cultured from fibrotic lungs on days 7 or 14 as well as endothelial cells sorted from fibrotic lungs on day 14 or 28 respectively. These findings suggest the role of different cells in maintaining the fibrotic phenotype during fibrogenesis. Treatment of fibroblasts with recombinant CTGF along with TGF-β increases pro-fibrotic markers in fibroblasts, confirming the synergistic effect of recombinant CTGF with TGF-β in inducing pulmonary fibrosis. Also, fibrotic extracellular matrix upregulated the expression of CTGF, as compared to normal extracellular matrix, suggesting that not only profibrotic mediators but also a profibrotic environment contributes to fibrogenesis. We also showed that pamrevlumab, a CTGF inhibitory antibody, partially attenuates fibrosis in the model. These results suggest that pamrevlumab could be an option for the treatment of pulmonary fibrosis.


2013 ◽  
Vol 456 (1) ◽  
pp. 109-118 ◽  
Author(s):  
Su Jin Lee ◽  
Jeong Han Kang ◽  
Soo Young Choi ◽  
Oh-Shin Kwon

In the present study, we demonstrated that PKCδ-stimulated RhoA/ROCK activation resulted in a reduction in PPM1A, thereby up-regulating Smad-dependent gene induction for extended periods. These findings indicated that PKCδ plays a critical role in TGF-β1-induced CTGF production in HepG2 cells.


2006 ◽  
Vol 290 (3) ◽  
pp. F703-F709 ◽  
Author(s):  
Weier Qi ◽  
Xinming Chen ◽  
Tania S. Polhill ◽  
Siska Sumual ◽  
Stephen Twigg ◽  
...  

Transforming growth factor-β1 (TGF-β1) functions as an important immunomodulatory cytokine in human kidney. Evidence suggests that connective tissue growth factor (CTGF) is an important downstream mediator of the profibrotic effects of TGF-β1. However, the role of CTGF in TGF-β1-induced chemokine production remains unknown. This study was undertaken to determine whether CTGF is involved in mediating TGF-β1-induced chemokine production in renal proximal tubular (HK-2) cells. Interleukin-8 (IL-8) and macrophage chemoattractant protein-1 (MCP-1) were measured. TGF-β1 induced an increase in IL-8 and MCP-1 (both P < 0.05) compared with control levels. CTGF was effectively silenced using small interference RNA (siRNA) in HK-2 cells. RT-PCR and real-time PCR confirmed a 94% reduction in CTGF mRNA. In the CTGF-silenced cells, TGF-β1-stimulated IL-8 and MCP-1 secretion was not altered compared with control cells. Similarly, basal secretion of IL-8 and MCP-1 was not changed in CTGF-silenced cells. The direct effect of CTGF (20, 200, and 400 ng/ml) on IL-8 and MCP-1 was assessed at 24-, 48-, and 72-h time points and no stimulation was observed. Our studies further demonstrate that in the CTGF gene-silenced cells, CTGF partially mediates TGF-β1-induced fibronectin and collagen IV secretion. These data suggest that TGF-β1 induced IL-8 and MCP-1 via CTGF-independent pathway. TGF-β mediates both fibrosis and chemokine production in the proximal tubule of the kidney. However, CTGF plays a more specific role as a downstream mediator of TGF-β1-induced fibrosis.


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