Inhibition of Fibrotic Contraction by C-Phycocyanin through Modulation of Connective Tissue Growth Factor and α-Smooth Muscle Actin Expression

ABSTRACT

The effects of C-phycocyanin (C-pc), a phycobiliprotein, on the expression of pro-fibrotic mediators in hyper-tropic scarring such as connective tissue growth factor (CTGF) and α-smooth muscle actins (α-SMA) were investigated in relation to trans-differentiation of fibroblast to myo-fibroblast, an icon of scar formation. C-pc was isolated from Spirulina Platensis extract using sonication method and C-pc concentration was determined by Bennet and Bogorad equation. α-SMA and CTGF levels in wounded primary human dermal fibroblasts were determined by western blot analysis and immuno-fluorescence confocal microscope was employed. Fibroblast contractility was examined by three-dimensional collagen lattice contraction assay. There was an elevation of α-SMA (121%) and CTGF (143%) levels in wound cells as compared with non-wound cells. The does-response profiles of down regulation demonstrated that the maximum inhibitions of α-SMA by 63% (p<0.05) and CTGF by 50% (p<0.1) were achieved by C-pc (6 nM) treated cells. In confocal assay, non-wound fibroblasts exhibited basal level of α-SMA staining, while wounded cells without C-pc treatment showed strong up-regulation of α-SMA by 147% (p<0.05). C-pc (6 nM) inhibited α-SMA expression by 70% (p<0.05) and reduced collagen contraction by 29% (p<0.05). C-pc seemed to lessen the over expression of CTGF, α-SMA, subsequently alleviating the fibrotic contracture. This study suggests the potential application of C-pc to regulation of the expression of pro-fibrotic mediators in scarring process and its potential usage as an efficient means for anti-fibrosis therapy.