Collagens XII and XIV (FACITs) in capsular opacification and in cultured lens epithelial cells

Abstract

Purpose. We previously reported that extracellular matrix (ECM) accumulation in human capsular opacification included collagen types I, III, IV, V, and VI. To further characterize the ECM in capsular opacification we performed immunohistochemistry to localize collagen types XII and XIV (fibril-associated collagens with interrupted triple helices, or FACITs) in specimens of human capsular opacification and in cultures of bovine lens epithelial cells (LECs). Methods. Cryosections and paraffin sections of human capsular opacification specimens or uninjured lens capsules, as well as cultured bovine LECs, were processed for immunohistochemistry using antibodies against collagen types I to VI, XII, and XIV. A rat crystalline lens was punctured through the central cornea and the eye was processed for immunohistochemistry for FACITs after healing intervals. Results. In the absence of injury human LECs were unstained for FACITs, but as early as 10 days after operation, LECs in healing capsules were immunoreactive. Collagen types I, III, IV, V, and VI were also detected. ECM deposited in confluent LEC cultures stained for FACITs. Normal rat LECs were not stained for FACITs, but ECM accumulated in injured lens stained for them. Conclusions. LECs up-regulate FACITs during post-opera-tive healing. FACITs, as well as other collagen types, are deposited in ECM in healing injured rat lens, in human capsular opacification and in LEC cultures. ECM components may regulate LEC behavior during postoperative healing.