Short communicationConnective tissue growth factor induces apoptosis via caspase 3 in cultured human aortic smooth muscle cells
Introduction
Connective tissue growth factor (CTGF) is a novel cysteine-rich, secreted peptide (Oemar and Luscher, 1997). CTGF was originally identified in conditioned medium of human umbilical vein endothelial cells (Bradham et al., 1991) and has been shown to play a role in various human diseases including systemic scleroderma (Igarashi et al., 1995), atherosclerosis (Oemar et al., 1997), and renal diseases (Ito et al., 1998). CTGF family members are the immediate early growth-responsive genes that are thought to regulate cell proliferation, differentiation, embryogenesis, and wound healing. Recombinant CTGF protein stimulates type I collagen and fibronectin production in normal rat kidney (NRK) fibroblasts (Frazier et al., 1996). When injected subcutaneously, recombinant CTGF induces granulation and fibrosis in neonatal NIH Swiss mice (Frazier et al., 1996). In addition, the polypeptide stimulates DNA synthesis in cultured fibroblasts (Oemar and Luscher, 1997).
To clarify the effect of CTGF on smooth muscle cells, we treated cultured human aortic smooth muscle cells with recombinant human CTGF (r-hCTGF) and investigated its effect on cell viability and induction of apoptosis.
Section snippets
Cell and materials
Human aortic vascular smooth muscle cells were purchased from KURABO (Tokyo, Japan). Cells were cultured in smooth muscle basal medium (SmBM) (Hishikawa and Luscher, 1998) and the cells in passages 4–8 were used for experiments. All experiments were performed after a 48-h incubation in serum-free Dulbecco's modified eagle medium (DMEM) (GIBCO, Grand Island, NY) with insulin–transferrin–selenite supplement (Hishikawa et al., 1994) (Sigma, St. Louis, MO). r-hCTGF and antibody to CTGF was
Effects of r-hCTGF on cell viability
After a 48-h incubation in serum-free medium, human aortic vascular smooth muscle cells were treated with r-hCTGF for 24–72 h. At 1 μg/ml, r-hCTGF showed no effect until 72 h (Fig. 1). At 5 and 10 μg/ml, r-hCTGF significantly reduced cell viability in a time-dependent manner (Fig. 1A).
To clarify the specificity of the induction of apoptosis by r-hCTGF, antibody to r-hCTGF was used. Pre-treatment with antibody (20 μg/ml) alone had no effect (Fig. 1B). However, the antibody significantly
Discussion
Our results demonstrate the pro-apoptotic effect of r-hCTGF in HASC. CTGF is expressed at very high levels in atherosclerotic but not in normal human blood vessels (Oemar et al., 1997). CTGF expression is localized predominantly in areas with extracellular matrix accumulation, and specially along the shoulder of fibrous caps (Oemar et al., 1997). Interestingly, in human carotid arteries, CTGF-expressing cells are non-proliferating (staining negative for proliferating cell nuclear antigen)
Conclusion
Recombinant human CTGF induces apoptosis in human aortic vascular smooth muscle cells by activating caspase 3. Our results suggest a new therapeutic approach to cardiovascular diseases by modulation of the stability of atherosclerotic lesions with CTGF.
References (13)
- et al.
Stimulation of fibroblast cell growth, matrix production, and granulation tissue formation by connective tissue growth factor
J. Invest. Dermatol.
(1996) - et al.
Significant correlation between connective tissue growth factor gene expression and skin sclerosis in tissue sections from patients with systemic sclerosis
J. Invest. Dermatol.
(1995) - et al.
Expression of connective tissue growth factor in human renal fibrosis
Kidney Int.
(1998) - et al.
Caspase-3 is required for DNA fragmentation and morphological changes associated with apoptosis
J. Biol. Chem.
(1998) - et al.
Fisp12/mouse connective tissue growth factor mediates endothelial cell adhesion and migration through integrin αvβ3, promotes endothelial cell survival, and induces angiogenesis in vivo
Mol. Cell Biol.
(1999) - et al.
Connective tissue growth factor: a cysteine-rich mitogen secreted by human vascular endothelial cells is related to the SRC-induced immediate early gene product CEF-10
J. Cell Biol.
(1991)
Cited by (80)
The effect of prostaglandin E<inf>2</inf> receptor (PTGER2) activation on growth factor expression and cell proliferation in bovine endometrial explants
2017, Prostaglandins Leukotrienes and Essential Fatty AcidsCitation Excerpt :Various growth factors are responsible for endometrial growth. CTGF is reported to be essential for tissue growth, including chemotaxis, differentiation, extracellular matrix production, angiogenesis, tumour growth, wound healing [30–33]. CTGF expression increases during the menstrual and proliferative phases in glandular epithelia, surface epithelia, and stromal cells compared with the secretory phase in human endometrium, in addition, CTGF mRNA and protein expression is significantly increased in human endometrial epithelial cells after incubation with PGE2 [7].
Phenotypic screen quantifying differential regulation of cardiac myocyte hypertrophy identifies CITED4 regulation of myocyte elongation
2014, Journal of Molecular and Cellular CardiologyOsteocyte function under compressive mechanical force
2014, Japanese Dental Science Review