TGF-ß elicits fibronectin secretion and proliferation in cultured chick lens epithelial cells

Abstract

These results indicate that TGF-beta may have a normal function in the lens regulating capsular protein production. The potent stimulation of lens cell growth by TGF-beta may be due to mis-regulated production of lens capsular proteins not normally found in great abundance.

Effects of interferon-γ on human subconjunctival fibroblasts in the presence of TGFβ1: reversal of TGFβ-stimulated collagen production

“…Fibroblasts in the wounded tissues are thought to be activated by various growth factors and cytokines [3,4,5,6,9,29,30,34,36]. Among these, TGFβ1 is one of the most important factors involving tissue scarring, which is caused by excessive ECM accumulation and fibroblast proliferation, although aqueous humor contains abundant TGFβ2 [18,35].…”

Type I Collagen Accelerates the Spreading of Lens Epithelial Cells through the Expression and Activation of Matrix Metalloproteinases

“…The 66 kDa and 72 kDa gelatinolytic bands were identical to that of the active form and pro-form of chicken MMP-2, respectively. 24 The 92 kDa band was identical to that of pro-MMP-9. 24 As shown in Figure 4(B), when LECs were cultured on type I collagen, pro-MMP-9 expression increased significantly, and active MMP-2 production also showed an increasing trend.…”

“…13,23 With respect to LECs, TGF-b stimulates MMP-2 and MMP-9 expression in the human LEC line, HLE B-3 [1] and in chicken LECs. 24 Furthermore, Wormstone et al demonstrated that TGF-b accelerates transdifferentiation and contraction of sham cataract operated capsular bags and induced the release of MMP-2 and MMP-9. 25 However, at present, the mechanisms regulating MMP expression in the lens are not fully understood.…”

“…32 The ECM has been shown to influence the adhesion, migration, proliferation and differentiation of various types of cells, including LECs. 9,24,[33][34][35] For example, type IV collagen, type I collagen and fibronectin-stimulated cell proliferation in porcine LECs, whereas laminin had no significant effect. 9 In addition, the ECM also affects MMP-9 expression.…”

Downregulated Expression of Integrin α6 by Transforming Growth Factor-β1 on Lens Epithelial Cells in Vitro

“…Whereas passaged cells become mitotically inhibited when exposed to TGF-␤, the accumulation of large plaques of cells beneath the capsule of TGF-␤ exposed organ cultured lenses indicates that some limited form of cell proliferation occurs (29). In primary cultures of chick LECs, Richiert and Ireland showed that TGF-␤ promotes cell proliferation concomitant with the increased secretion and deposition of ECM proteins, particularly fibronectin (32). We hypothesize that TGF-␤-mediated actions in the lens must be tightly regulated in order to avoid proliferative responses due to the inappropriate production of both normal and abnormal lens capsule ECM components.…”