The Effect of CHIR 99021, a Glycogen Synthase Kinase-3ß Inhibitor, on Transforming Growth Factor ß-Induced Tenon Fibrosis.

Purpose: This study investigated the effect of glycogen synthase kinase-3ß (GSK-3ß) inhibition on the fibrosis of human Tenon's fibroblasts (HTFs) induced by transforming growth factor-ß (TGF-ß). Methods: Quantitative real-time PCR and Western blot analyses were performed to determine the expression levels of molecules associated with the fibrosis of HTFs by TGF-ß (fibronectin, collagen Iα, and α-smooth muscle actin) and GSK-3ß. The levels of phosphorylated Smad2 and Smad3 were also analyzed in the presence of the GSK-3ß inhibitor CHIR 99021. The wound healing assay was performed to determine the effect of CHIR 99021 on the migration of HTFs. All experiments were conducted using primary cultured HTFs or human tenon tissues obtained from normal subjects and patients with glaucoma. Results: Treatment with TGF-ß resulted in an increase in the levels of molecules associated with the fibrosis of HTFs. The expression levels of these molecules were higher in the tenon tissues obtained from patients with glaucoma than those from normal subjects. When the HTFs were treated with TGF-ß, a significant increase in the active form of GSK-3ß (Y216) was observed. A significant decrease in the active form of GSK-3ß and molecules associated with fibrosis by TGF-ß was noted in HTFs treated with CHIR 99021. CHIR 99021 treatment reduced the phosphorylated Smad2/Smad2 and phosphorylated Smad3/Smad3 ratios in HTFs and attenuated HTF migration. Conclusions: Our results demonstrated the effect of GSK-3ß inhibition on the regulation of TGF-ß-mediated fibrosis of HTFs, suggesting GSK-3ß to be a potential target for maintaining bleb function after glaucoma filtration surgery.

Functional Activity of Matrix Metalloproteinases 2 and 9 in Tears of Patients With Glaucoma.

Purpose: To evaluate the differential expression of tear matrix metalloproteinases (MMP) 2 and 9 in of patients with various forms of glaucoma. Methods: Tear samples were collected with a Schirmer's strip from 148 eyes of 113 patients (medically naïve patients with primary open-angle [POAG] or angle closure glaucoma [PACG] and those with pseudoexfoliation syndrome [PXF] or glaucoma [PXG]). These were compared to patients undergoing cataract surgery (controls) for this cross-sectional study. Functional activities of tear MMP-9 and MMP-2 were analyzed by gelatin zymography. Tenon's capsules (n = 15) were harvested from the inferior quadrant in those undergoing cataract surgery and protein expression of MMP-9 was analyzed by immunohistochemistry (IHC). Hydrogen peroxide (H2O2) stress-induced effects on in vitro activities of MMP-9 in human trabecular meshwork (HTM) cells were analyzed. Results: The MMP-9 activity in tears was increased significantly in POAG, (n = 27), PACG (n = 24), and PXF (n = 40) eyes compared to controls (n = 35), and was increased significantly in eyes with glaucoma compared to moderate/severe glaucoma (P < 0.001). The MMP-9 expression was significantly lower in PXG (n = 22) eyes. Immunohistochemistry of Tenon's capsule revealed increased expression of MMP-9 in primary glaucoma eyes. Increased MMP-9 activity was seen in in vitro by gelatin zymography and was confirmed by Western and immunofluorescent assay on HTM upon 800 and 1000 µM H2O2-induced stress for 2 to 3 hours with approximately 80% cell death. Conclusions: Increased tear MMP-9 activity in early glaucoma and pseudoexfoliation syndrome suggesting activation of extracellular matrix (ECM) degradation can be used as a tear-based predictive biomarker. Decreased expression in advanced stages suggests exhaustion of the degradation response.

Lysyl oxidase-like 2 level and glaucoma surgical outcomes.

PURPOSE: To evaluate the levels of TGF-ß and lysyl oxidases in both the aqueous humor and in Tenon's tissue in patients with POAG, and to assess their association with bleb morphological features and outcomes of glaucoma surgery. METHODS: Eighteen POAG patients scheduled to undergo glaucoma surgery and 17 healthy controls were enrolled. At the time of surgery, approximately 0.1 mL aqueous humor through an anterior chamber paracentesis and a 4 × 4-mm sample of Tenon's tissue were obtained. Concentrations of TGF-ß and lysyl oxidases (types 1 and 2) were analyzed by ELISA. The bleb morphologic features based on the Moorfields Bleb Grading System were evaluated by bleb photographs. RESULTS: The TGF-ß in Tenon's tissue and lysyl oxidase-like 2 in aqueous humor and in Tenon's tissue were significantly elevated in POAG patients. When POAG patients were divided by outcome 1 year after surgery, lysyl oxidase-like 2 protein was significantly higher in both aqueous humor and Tenon's tissue of the failure group. The level of lysyl oxidase-like 2 protein was significantly correlated with that of TGF-ß in the Tenon's tissue. Lysyl oxidase-like 2 level in the aqueous humor (r = 0.563, P < 0.001) and Tenon's tissue (r = 0.760, P < 0.001) had significantly negative correlation with bleb area. CONCLUSIONS: The TGF-ß and lysyl oxidase-like 2 levels at the time of surgery were significantly correlated with 1-year outcomes of glaucoma surgery. The level of lysyl oxidase-like 2 was significantly correlated with that of TGF-ß, suggesting induction by TGF-ß. Modulation of lysyl oxidase-like 2 levels may have important applications in glaucoma surgery.

PTX3 controls activation of matrix metalloproteinase 1 and apoptosis in conjunctivochalasis fibroblasts.

PURPOSE: Conjunctivochalasis (CCh) is an age-related inflammatory ocular surface disease manifesting redundant, loose conjunctiva folds. The pathogenic role of Pentraxin 3 (PTX3) in controlling upregulation of matrix metalloproteinase 1 (MMP-1) and MMP-3 in CCh remains undefined. METHODS: Cytolocation of PTX3 and apoptosis were compared by immunostaining and terminal deoxyribonucleotidyl transferase-mediated FITC-linked dUTP nick-end DNA labeling (TUNEL) assay between normal and CCh specimens containing the conjunctiva and the Tenon. Second to third cultures of normal and CCh fibroblasts were treated with or without Aprotinin, Batimastat, or N-isobutyl-N-(4-methoxyphenylsulfonyl)-glycylhydroxamic acid (NNGH), followed by transfection with or without PTX3 siRNA, and TNF-α or IL-1ß. Cell lysates and culture media were collected to assess apoptosis measured by the Cell Death Detection ELISA and expression of PTX3, MMP-1, and MMP-3 transcripts and proteins by quantitative RT-PCR and Western blot, respectively. RESULTS: PTX3 immunostaining was negative in normal specimens, but strongly positive in the subconjunctival stroma of CCh specimens. More apoptotic cells were found in CCh samples than in normal specimens. Expression of PTX3 transcripts and protein was not constitutive in resting normal fibroblasts but was in resting CCh fibroblasts and was upregulated by IL-1ß in both cell lysates and culture media of both fibroblasts. PTX3 siRNA further upregulated MMP-1 and MMP-3 transcripts in resting normal fibroblasts, but synergistically with IL-1ß upregulated the expression of MMP-1 and MMP-3 transcripts only in CCh fibroblasts, with activation of MMP-1 more so than MMP-3. PTX3 siRNA knockdown also promoted cell death characterized by apoptosis and necrosis, and such cell death could be rescued by inhibitors against serine proteinase, MMP1, or MMP3. CONCLUSIONS: Perturbation of PTX3 expression might partake in apoptosis and pathogenesis of CCh by upregulating expression of MMP-1 and MMP-3, and activation of MMP-1 and MMP-3.