Functional Characteristics of Connective Tissue Growth Factor on Human Tenon’s Capsule Fibroblast

Abstract

Purpose of the study: To explore the characteristic of connective tissue growth factor (CTGF) on the phenotype transition, extracellular matrix (ECM) synthesis and proliferation of human Tenon’s capsule fibroblasts (HTFs).

Materials and methods: HTFs were obtained from patients during cataract surgery and induced by CTGF (1 to 100 µg/L). Western blot and immunofluorescence were performed to observe the expression of alpha smooth muscle actin (α-SM-actin) protein. The levels of mRNAs were quantified by real-time PCR. Col I and FN expression at both protein and RNA levels were tested after induction by CTGF and transforming growth factor β (TGF-β), respectively. Statistical significance was assumed if p < 0.05.

Results: CTGF upregulated the expression of α-SM-actin in cultured HTFs. Its maximum effect at protein level attained under the optimal concentration of 50 μg/L at the peak time of 48 hours, though still weaker than the effect of TGF-β1 (10 μg/L, p < 0.05). The expression of Col I and FN at both protein and mRNA levels was elevated by the induction of CTGF (50 μg/L) (p < 0.01) and TGF-β1 (10 μg/L) (p < 0.05), while CTGF (50 μg/L) showed a greater effect than the latter (p < 0.05). CTGF (1 to100 μg/L) increased the proliferation of HTFs significantly (p < 0.05).

Conclusions: CTGF induced the phenotype transition of HTFs individually and significantly promoted their proliferation. Moreover, it promoted ECM synthesis, thus demonstrating its role as a crucial factor in fibrosis. Thus, CTGF could potentially be a safer and more efficient target than TGF-β at suppressing scar formation after filtering surgery.

• α-smooth muscle actin
• connective tissue growth factor
• extracellular matrix
• fibrosis
• myofibroblast