Abstract
Abstract: :
Purpose: SPARC (secreted protein which is acidic and rich in cysteine) is thought to play a certain role in corneal stromal wound healing. We previously reported that SPARC-derived peptide, corresponding to domain IV of SPARC, inhibited the collagen gel contraction by corneal fibroblasts. In this study, to understand the active site of SPARC in detail, we investigated the effects of tetrapeptide (TCDL) on the interaction between corneal fibroblasts and collagen matrix. Methods: We synthesized peptides that consist of four to eight amino acids from 254th amino acid of SPARC (TCDL, TCDLDN, TCDLDNDK). Rabbit corneal fibroblasts were cultured in a collagen gel with the peptides. The diameter of the gel was measured for 5 days. The shape of the cells in collagen matrix was observed under a light microscope. The cells were seeded on the collagen matrix and cultured with TCDL. The cells were fixated by 4% paraformaldehyde and were observed under a scanning electron microscope (SEM). Results: When corneal fibroblasts were cultured with peptides (0.3 mM), the diameter of the gel was greater than that of control. The gel diameter increased in proportion to the concentration of tetrapeptide, TCDL, added. When corneal fibroblasts were cultured without peptide in a collagen gel, they became to be spindle shape. On the other hand, the cells cultured with TCDL remained round in shape. Under a SEM, spreading of fibroblasts on the collagen matrix was deterred by the addition of TCDL. Conclusions: These findings indicate that TCDL regulates the interaction between corneal fibroblasts and collagen matrix. It is possible that TCDL will be an agent that modulates the corneal stromal wound healing.
Keywords: cell adhesions/cell junctions • extracellular matrix • cornea: stroma and keratocytes