Matrix metalloproteinase and cytokine expression in Tenon fibroblasts during scar formation after glaucoma filtration or implant surgery in rats

Abstract

Failure of surgery for glaucoma is usually due to post-surgical scarring (fibrosis), a process in which fibroblasts play a prominent role. We investigated the molecular mechanisms of such scarring by examining the expression of matrix metalloproteinases and cytokines in Tenon fibroblasts isolated from rats after glaucoma surgery. Filtration surgery was performed in one eye and implant surgery in the other; and Tenon fibroblasts were isolated from the tissue surrounding the bleb after surgery. The cells were cultured and examined for the expression of matrix metalloproteinases (MMPs) by reverse transcription-polymerase chain reaction, immunoblot and gelatin zymographic analyses. Culture supernatants were also assayed for cytokines with a multiplex array. The amounts of MMP-1 and MMP-3 mRNAs and proteins were greater in cells isolated after implant surgery than in those isolated after filtration surgery, with the progression of scar formation being more complete after the former surgery. The secretion of interleukin-6 (IL-6) by cells isolated after filtration surgery was greater than that for cells isolated after implant surgery. Depletion of IL-6 by RNA interference in cells isolated after filtration surgery increased the expression of MMP-1 and MMP-3 in these cells. These results thus suggest that the expression of MMP-1 and MMP-3 in Tenon fibroblasts is regulated by IL-6 during, and may play an important role in, scar formation after glaucoma surgery.

The fibrolytic potentials of vitamin D and thymoquinone remedial therapies: insights from liver fibrosis established by CCl4 in rats

“…The latter bind reversibly to the active site of MMPs in a 1:1 molar ratio and, pathological imbalances in this system have been linked to the pathogenesis of hepatic fibrosis [ 17 , 18 ]. It has also been shown that the levels of TIMPs increase significantly by TGF-β, IL-6 and IL-22 in several in vitro and in vivo studies [ 16 , 50 , 51 ]. Alternately, treatment with IL-10 has been demonstrated to significantly increase the production of MMPs, including MMP-9, as well as significantly decrease TIMPs during liver fibrosis [ 7 , 37 , 38 ].…”

All-trans-retinoic acid inhibition of transforming growth factor-β-induced collagen gel contraction mediated by human Tenon fibroblasts: role of matrix metalloproteinases

“…Cell-mediated tissue contraction is a complex process that involves various cellular activities, including cell migration and reorganisation of the extracellular matrix, and MMPs have been implicated in wound contraction and matrix reorganisation 17. MMPs play a central role in collagen contraction and their overexpression is associated with excessive scarring at the ocular surface 18. Inhibition of MMPs was shown to limit subconjunctival scarring after experimental glaucoma filtration surgery in rabbits 19.…”

A simple and effective protocol for fast isolation of human Tenon’s fibroblasts from a single trabeculectomy biopsy – a comparison of cell behaviour in different culture media

“…According to the available literature, there are some protocols for primary Tenon’s fibroblast isolation [4, 5, 14]. Most papers present effective isolation of Tenon’s fibroblasts or trabecular meshwork cells using a complicated collagenase digestion method [1, 5] with basal culture media such as MEM [15], DMEM [1, 4, 14, 16] or RPMI-1640 [4, 17].…”

“…Most papers present effective isolation of Tenon’s fibroblasts or trabecular meshwork cells using a complicated collagenase digestion method [1, 5] with basal culture media such as MEM [15], DMEM [1, 4, 14, 16] or RPMI-1640 [4, 17]. According to these protocols, successful HTF isolation requires long-term culture of the tissue explants: approx.…”

“…Human Tenon’s fibroblasts (HTFs) are the main cells responsible for initiation and mediation of wound healing and scarring after a trabeculectomy [5]. During wound healing, activated HTFs adhere to the surgical site and start excessive proliferation and accumulation of extracellular matrix (ECM) components, leading to fibrotic scar formation [4–6].…”