Posttraumatic Temporal TGF-β mRNA Expression in Lens Epithelial Cells of Paediatric Patients

Abstract

The aim of the study was to determine temporal TGFB1, TGFB2 and TGFB3 gene expression profiles in the anterior lens capsule of paediatric patients with posttraumatic cataract. The patient group comprised 22 children selected with a fragment of anterior lens capsule obtained during elective cataract surgery and sampled for molecular analysis. The levels of TGF-β isoforms in the anterior lens capsule were determined based on the number of mRNA copies per 1 μg total RNA by real-time qRTPCR. Three time-related result clusters were identified based on hierarchical cluster analysis: 2.2, 4.4 and 15.0 months (time span from injury to anterior capsule sampling during surgery) and compared with regard to temporal gene expression profile and quantitative relations of TGF-β1, 2 and 3 mRNAs. TGF-β1, TGF-β2, and TGF-β3 mRNAs were detected in all anterior lens capsule samples. A comparative analysis revealed: TGF-β1>TGF-β2>TGF-β3 during the entire observation period. The TGF-β mRNA levels continued to increase up to four months after injury, then returning close to the base levels after around 15 months. The expression patterns of TGF-β isoforms showed a similar tendency. Differences in the expression levels of TGF-β1 and TGF-β2 between the particular clusters were statistically significant. Posttraumatic transcriptional activities of TGF-β1 and TGF-β2 in the anterior lens capsule of paediatric patients depend on the time elapsing from injury. Our findings indicate that the transcriptional activities of TGFB family genes show a transient period of over-expression during the months after injury. TGF-β1 is a dominant isoform expressed in lens epithelial cells following injury.