PURPOSE: The matrix metalloproteinase (MMP), gelatinase B, is expressed by both corneal cell types found at the epithelial-stromal tissue interface, the site of basement membrane repair in the healing cornea. This study investigates the relative regulation of gelatinase B compared to other MMPs in response to agents related to those found in the corneal repair environment or in corneal ulcers. METHODS: A culture model of corneal cells isolated from rabbit was used. RESULTS: Gelatinase B is the major MMP expressed by corneal epithelial cells, whereas stromal fibroblasts produce gelatinase B along with three other MMPs: collagenase, stromelysin, and gelatinase A. Phorbol-12-myristate 13-acetate (PMA) stimulates gelatinase B mRNA and protein synthesis by corneal cells, which is similar to its effect on the other MMPs. Stimulation occurs, at least partially, at the transcriptional level. PMA-stimulated MMP expression follows biphasic kinetics, with the major effect on collagenase, stromelysin, and gelatinase A occurring during the late component. In contrast, the major gelatinase B response occurs during the early component. Transforming growth factor-beta (TGF-beta) has no effect on constitutive expression of gelatinase B by fibroblasts; however, expression stimulated by PMA is enhanced. In contrast, constitutive expression of collagenase and stromelysin is inhibited by TGF-beta. However, in the presence of PMA, the initial inhibitory effect of TGF-beta is reversed after treatment. CONCLUSION: Gelatinase B expression is regulated differently from other corneal MMPs. This provides a mechanism for control of basement membrane repair independent of repair processes in the stroma.
PURPOSE: The matrix metalloproteinase (MMP), gelatinase B, is expressed by both corneal cell types found at the epithelial-stromal tissue interface, the site of basement membrane repair in the healing cornea. This study investigates the relative regulation of gelatinase B compared to other MMPs in response to agents related to those found in the corneal repair environment or in corneal ulcers. METHODS: A culture model of corneal cells isolated from rabbit was used. RESULTS:Gelatinase B is the major MMP expressed by corneal epithelial cells, whereas stromal fibroblasts produce gelatinase B along with three other MMPs: collagenase, stromelysin, and gelatinase A. Phorbol-12-myristate 13-acetate (PMA) stimulates gelatinase B mRNA and protein synthesis by corneal cells, which is similar to its effect on the other MMPs. Stimulation occurs, at least partially, at the transcriptional level. PMA-stimulated MMP expression follows biphasic kinetics, with the major effect on collagenase, stromelysin, and gelatinase A occurring during the late component. In contrast, the major gelatinase B response occurs during the early component. Transforming growth factor-beta (TGF-beta) has no effect on constitutive expression of gelatinase B by fibroblasts; however, expression stimulated by PMA is enhanced. In contrast, constitutive expression of collagenase and stromelysin is inhibited by TGF-beta. However, in the presence of PMA, the initial inhibitory effect of TGF-beta is reversed after treatment. CONCLUSION:Gelatinase B expression is regulated differently from other corneal MMPs. This provides a mechanism for control of basement membrane repair independent of repair processes in the stroma.
Authors: Emily Guerriero; Jian Chen; Yoshikazu Sado; Rajiv R Mohan; Steven E Wilson; James L Funderburgh; Nirmala Sundarraj Journal: Invest Ophthalmol Vis Sci Date: 2007-02 Impact factor: 4.799
Authors: Ralph J Hazlewood; Benjamin R Roos; Frances Solivan-Timpe; Robert A Honkanen; Lee M Jampol; Stephen C Gieser; Kacie J Meyer; Robert F Mullins; Markus H Kuehn; Todd E Scheetz; Young H Kwon; Wallace L M Alward; Edwin M Stone; John H Fingert Journal: Hum Mutat Date: 2015-03 Impact factor: 4.878