Effects of CCN3 on fibroblast proliferation, apoptosis and extracellular matrix production

Abstract

Abstract. CCN2 and CCN3 belong to the CCN family of proteins, which show a high level of structural similarity. Previous studies have shown that CCN2 mediates the ability of transforming growth factor (TGF)-β to stimulate collagen synthesis, leading to keloid formation. CCN2 and CCN3 are opposing factors in regulating the promoter activity and secretion of this extracellular matrix (ECM) protein. Thus, we hypothesize that CCN3 possesses an anti-scarring effect. However, the exact mechanism of CCN3 in this anti-scarring effect remains unclear. The aim of this study was to investigate the mechanism of CCN3 in reducing scar formation. Palatal fibroblasts were obtained from the explants of the oral palatal mucosa of 8-week-old male Sprague-Dawley rats. CCN3 overexpression vector was constructed and then transfected into cells. The inhibitory effects of CCN3 on cell growth were detected via the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Apoptosis was measured using an Annexin V-fluorescein isothiocyanate (FITC)/propidium iodide (PI) apoptosis detection kit and flow cytometry. The expression levels of collagen I, collagen III and α-smooth muscle actin (α-SMA) were determined by western blot analysis and RT-PCR. Following treatment with TGF-β1, we detected the expression of CCN3 and Smad1 in the fibroblasts. CCN3 significantly inhibited the growth and induction of apoptosis of fibroblasts. The expression of collagen I, collagen III and α-SMA was lower in the CCN3-transfected group as compared to the control and vector groups. TGF-β1 stimulation efficiently suppressed the expression of CCN3 at the mRNA and protein levels, and CCN3 was required for TGF-β1-induced Smad1 phosphorylation. Results of this study demonstrated that CCN3 is involved in the proliferation and apoptosis of fibroblasts and the synthesis of ECM proteins. Therefore, CCN3 may play an important role in the development of scar tissue, and may represent a novel therapeutic target for reducing scar formation.

NOV inhibits proliferation while promoting apoptosis and migration in osteosarcoma cell lines through p38/MAPK and JNK/MAPK pathways

“…NOV was originally described as antiproliferative (8) and its expression was associated with differentiation and growth arrest in Wilm's tumor (9), rhabdomyosarcomas (10), cartilaginous tumors (11), renal cell carcinoma (12) and Ewing sarcoma (13), while more recent data associate NOV expression with increased proliferative index of 3T3 fibroblast (14,15) and tissue samples of prostate. Furthermore, although NOV reduced the growth rate of renal cell carcinoma and Ewing sarcoma transfectants in vitro, NOV expression was associated with poor prognosis and shown to increase cell motility, resulting in enhanced metastatic potential in these tumors (12,13).…”

A Missense Variant (R239Q) in CCN3 Induces Aberrant Apoptosis in the Developing Mouse Brain

“…CCN3 is a member of the CCN family with four functional domains and is known to play an important role in various diseases such as injury repair, fibrotic disease, and cancer; as well as cardiovascular development, skeletal development, and neural development (Holbourn et al, 2008;Heath et al, 2008;Chen et al, 2009;Ouellet et al, 2011;Jun and Lau, 2011;Ren et al, 2014;Park et al, 2015;Malik et al, 2015;Fong et al, 2017;Kim et al, 2018). In particular, CCN1, 2, and 3 induce apoptotic cell death in fibroblasts, but prevent apoptosis in endothelial cells (Chen et al, 2009;Jun and Lau, 2011).…”

“…In fibroblasts, CCN1, CCN2, and CCN3 can induce apoptosis as cell adhesion substrates. In particular, CCN1 binds to α6β1 and syndecan-4, and induces activation of Bax through p53, leading to apoptosis (Chen et al, 2009;Ren et al, 2014). On the other hand, binding of CCNs to endothelial cells protects against apoptosis (Ren et al, 2014;Jun and Lau, 2011).…”

Effects of CCN3 on rat cartilage endplate chondrocytes cultured under serum deprivation in vitro

“…A previous study reported that CCN3 expression was markedly upregulated in CCN2 deletion mice, which was associated with impaired development of IVDs and markedly accelerated age-associated IVD degeneration ( 13 ). The antiproliferative activities of CCN3 have also been documented in embryonic fibroblasts, chondrocytes, vascular smooth muscle cells, osteogenic mesenchymal cells and NP cells ( 12 , 14 , 15 ). Furthermore, CCN proteins are able to interact with tumor necrosis factor (TNF) family cytokines to promote cell apoptosis ( 16 – 18 ).…”

“…CCN3 can unmask the cytotoxic potential of TNFα and lymphotoxin-α (LTα), and promote the apoptotic activity of Fas ligand (FasL) and TNF-related apoptosis-inducing ligand (TRAIL) in normal fibroblasts ( 18 ). In addition, CCN2 can increase the expression of ECM proteins ( 12 ), whereas CCN3 appears to be expressed reciprocally and to act antagonistically to CCN2 ( 13 , 14 , 19 ). The most prominent phenotype of CCN3 knockout mice involves enhanced chondrogenesis and osteogenesis ( 20 ), whereas CCN2 mutant mice exhibit severe chondrodysplasia ( 21 ).…”