Short-Term TGF ß2 Exposure Mediates Long-Term Changes In The Human Lens Capsular Bag

Abstract

Abstract: : Purpose: To determine whether a brief exposure to human TGFß2 can induce long-term enhanced transdifferentiation and matrix wrinkling in an in vitro model for posterior capsule opacification (PCO). Methods: Human lens capsular bag preparations were maintained in 1.5ml of EMEM (5% CO₂) and were exposed to 10ng/ml TGFß2 for the initial 1hr or 2 days of culture. Control paired bags were untreated. In some cases, CAT-152 (lerdelimumab; human anti-TGFß2 monoclonal antibody) was added to the medium (10µg/ml) following 2 days exposure to TGFß2. Control bags were exposed to TGFß2 alone. End-point analyses at 28 days for F-actin and alpha smooth muscle actin (αSMA; a transdifferentiation marker) were performed using immunocytochemistry and wrinkling was assessed by phase contrast microscopy. Quantification was achieved using image analysis and the data (Table 1) expressed in terms of arbitrary intensity units. Results: Exposure of capsular bags to TGFß2 for 1hr or 2 days significantly increased capsular wrinkling, altered F-actin organisation and significantly enhanced αSMA expression at day 28 in an exposure-dependent manner (Table 1). When treated with CAT-152 following the initial 2 days TGFß2 exposure, wrinkling and αSMA expression were significantly reduced compared with TGFß2 controls (Table 1). Table 1. Wrinkling and αSMA expression in matched capsular bags.  

*Student’s t-test: p<0.05 vs. matched-paired control. N=4 in all cases. Conclusions: Only a short exposure to TGFß2 is required to induce long-term capsular bag changes, such as sustained expression of transdifferentiation markers and matrix wrinkling. Treatment with CAT-152 following exposure to TGFß2 can significantly inhibit wrinkling and transdifferentiation. This indicates that an autocrine production of TGFß2 is involved in long-term changes arising from short exposures to exogenous TGFß2. Treatment with CAT-152 may therefore prevent development of PCO.

Keywords: 522 posterior capsular opacification (PCO) • 423 growth factors/growth factor receptors • 631 wound healing