Matrix metalloproteinase-2 and -9 activities in the human lens epithelial cells and serum of steroid induced posterior subcapsular cataracts

Iladevi Cataract & IOL Research Center, Raghudeep Eye Clinic, Memnagar, Ahmedabad, India.
Molecular vision (Impact Factor: 1.99). 01/2012; 18:64-73.
Source: PubMed


To evaluate the level of matrix metalloproteinase (MMP)-2 and MMP-9 activities in patients with steroid induced posterior subcapsular cataract (PSC).
This prospective, observational study comprised of 156 patients having either steroid induced PSC (n=50) or non-steroidal PSC (n=106) were performed to evaluate the level of MMP-2 and MMP-9 activities in the lens epithelial cells (LECs) and the serum. Anterior lens capsules harboring LECs were obtained during phacoemulsification and peripheral blood was collected from patients before administration of anesthesia. Serum was separated by centrifugation at 10,000× g for 15 min at 4 °C. The LECs and serum samples were processed to analyze MMP-2 and MMP-9 activities using succinylated gelatin assay. Quantitative real time-PCR (qRT-PCR) was performed to determine the mRNA levels of MMP-2 and MMP-9 in LECs. The mRNA levels were expressed as a ratio, using the delta-delta method for comparing the relative expression results between cases with steroid induced PSC and cases with non-steroidal PSC. MMP-2 and MMP-9 levels were also compared in the two groups using immunolocalization.
The level of MMP-2 and MMP-9 activity was found to be high in LECs and serum of cases with steroid induced PSC. Further in all steroid induced cases, a 1.4 fold increase was observed in MMP-2 activity in LECs and a 1.4 fold increase in MMP-9 activity in the serum. Both qRT-PCR and immunolocalization showed increased expression of MMP-2 and MMP-9 activity.
MMP-2 and MMP-9 activity in both LECs and serum was significantly higher in cases with steroid induced PSC. The possible use of MMP-9 as a non-invasive biomarker in ascertaining the presence of steroid induced PSC should be evaluated using a larger sample size.

Download full-text


Available from: Bhagwat Alapure, Jan 16, 2014
  • Source
    • "The anterior capsule specimens were placed on silane-coated (amino-propyl-triethoxy silane) slides such that the LECs were facing the slide and cell specimens were prepared as described earlier (Alapure et al. 2012). These cells were used for immunolocalization of Cx43, ZO-1, alpha-catenin and beta-catenin. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Specimens of the anterior lens capsule with an attached monolayer of lens epithelial cells (LECs) were obtained from patients (n052) undergoing cataract surgery. Specimens were divided into three groups based on the type of cataract: nuclear cataract, cortical cataract and posterior subcapsular cataract (PSC). Clear lenses (n011) obtained from donor eyes were used as controls. Expression was studied by immunofluorescence, real-time PCR and Western blot. Statistical analysis was done using the student's t-test. Immunofluorescence results showed punctate localization of Cx43 at the cell boundaries in controls, nuclear cataract and PSC groups. In the cortical cataract group, cytoplasmic pools of Cx43 without any localization at the cell boundaries were observed. Real-time PCR results showed significant up-regulation of Cx43 in nuclear and cortical cataract groups. Western blot results revealed significant increase in protein levels of Cx43 and significant decrease of ZO-1 in all three cataract groups. Protein levels of alpha-catenin were decreased significantly in nuclear and cortical cataract group. There was no significant change in expression of beta-catenin in the cataractous groups. Our findings suggest that ZO-1 and alpha-catenin are important for gap junctions containing Cx43 in the LECs. Alterations in cell junction proteins may play a role during formation of different types of cataract.
    Journal of Biosciences 12/2012; 37(6):979-987. DOI:10.1007/s12038-012-9264-9 · 2.06 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Posterior capsule opacification (PCO) is a debilitating and relatively common complication of cataract surgery despite modern medical and surgical advances. The pathophysiology of this condition has largely been attributed to peptide mediators, such as transforming growth factor-beta (TGFβ), epidermal growth factor (EGF) and matrix metalloproteinases (MMPs), with the inhibition of these and other related molecules showing promising results. Studies have also shown that the levels of interleukin-6 are elevated in the eyes following cataract surgery and in various ocular inflammatory disorders that predispose to PCO development. This review proposes, utilizing ocular and extra-ocular disease models, several potential pathways through which IL-6 may modulate the activity of TGFβ, EGF, MMP-2/-9 and immune cells to promote PCO. Among the IL-6-mediated pathways discussed are the transactivation of EGF receptor, the up-regulation of TGFβ and MMP-2/-9, and the loss of ocular immune privilege through trans-signaling, down-regulation of T-regulatory cells (Tregs) and up-regulation of Th17 cells. After establishing both the potential role of ocular IL-6 in the development of PCO and the apparent upstream activity of IL-6 in relation to the known mediators of PCO, the author hypothesizes that intraoperative anti-IL-6 therapy may be of great benefit in reducing all parameters of PCO pathogenesis. This review also provides a strong basis for carrying out multiple experimental studies with IL-6 inhibitors to further elucidate the specific pathways by which IL-6 may promote PCO as well as to better determine what role inflammation may play in this disease process.
    Medical Hypotheses 01/2013; 80(4). DOI:10.1016/j.mehy.2012.12.042 · 1.07 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Epithelial-mesenchymal transition (EMT) is associated with fibrotic diseases in the lens, such as anterior subcapsular cataract (ASC) formation. Often mediated by transforming growth factor (TGF)-β, EMT in the lens involves the transformation of lens epithelial cells into a multilayering of myofibroblasts, which manifest as plaques beneath the lens capsule. TGF-β-induced EMT and ASC have been associated with the up-regulation of two matrix metalloproteinases (MMPs): MMP-2 and MMP-9. The current study used MMP-2 and MMP-9 knockout (KO) mice to further determine their unique roles in TGF-β-induced ASC formation. Adenoviral injection of active TGF-β1 into the anterior chamber of all wild-type and MMP-2 KO mice led to the formation of distinct ASC plaques that were positive for α-smooth muscle actin, a marker of EMT. In contrast, only a small proportion of the MMP-9 KO eyes injected with adenovirus-expressing TGF-β1 exhibited ASC plaques. Isolated lens epithelial explants from wild-type and MMP-2 KO mice that were treated with TGF-β exhibited features indicative of EMT, whereas those from MMP-9 KO mice did not acquire a mesenchymal phenotype. MMP-9 KO mice were further bred onto a TGF-β1 transgenic mouse line that exhibits severe ASC formation and resistance to ASC formation in this model. These findings suggest that MMP-9 expression is more critical than MMP-2 in mediating TGF-β-induced ASC formation.
    American Journal Of Pathology 05/2014; 184(7). DOI:10.1016/j.ajpath.2014.03.013 · 4.59 Impact Factor