TIMP-1 production by human scleral fibroblast decreases in response to cyclic mechanical stretching

Purpose: The effect of mechanical stretching was examined on cultured scler al fibroblasts of the human eye in order to observe changes in their produc tion of TIMP (tissue inhibitor of metalloproteinase)-1, MMP (matrix metallo proteinase)-1 and -2 in response to physiological strain. Methods: Human sc leral fibroblasts were cultured from scleral tissue resected during foveal translocation surgery. The fibroblasts in near confluency were exposed to m echanical stretching of the bottom of a 6-cm Petri dish at the maximum magn itude of 4500 microstrain and at a cycle of 30 s for 72 h, TIMP-1, MMP-1 an d MMP-2 levels in the medium following 24, 48 and 72 h of cyclic stretching were measured by enzyme immunoassay. Results: The growth of scleral fibrob lasts during the 72-hour period of stretching did not show a significant di fference from that of non-stretched control fibroblasts, Scleral fibroblast s in the stretched group produced a significantly smaller amount of TIMP-1 at 72 h after stretching, compared with nonstretched control (p = 0.0353, S tudent t-test). The levels of MMP-1 and MMP-2 produced by scleral fibroblas ts were not significantly different between the stretched group and nonstre tched group. Conclusion: The production of TIMP-1 by human scleral fibrobla sts was suppressed by cyclic mechanical stretching. Mechanical strain would be one factor to regulate the homeostasis of extracellular matrix in the s clera, Copyright (C) 2001 S. Karger AG, Basel.