Upregulation of Low-Density Lipoprotein Receptor After Exposure to Transforming Growth Factor-β2in Tenon's Capsule Fibroblasts from Patients with Glaucoma

Abstract

The aim of this study was to investigate the dynamic alteration of a low-density lipoprotein receptor (LDLr) and its binding and uptake of LDL after exposure to transforming growth factor-β(2) (TGF-β(2)) in Tenon's capsule fibroblasts from glaucoma patients. Tenon's capsule fibroblasts obtained from patients who had undergone selective glaucoma surgery were cultured and stimulated with different concentrations (0.1-10 ng/mL) of TGF-β(2) for 1, 3, 5, and 7 days. Expression of LDLr mRNA was detected with relative quantification real-time reverse transcription-polymerase chain reaction, and expression of the corresponding protein was demonstrated with western blot. The extent of binding and uptake of 1,1'-dioctadecyl-3,3,3',3'-tetramethyl-indocarbocyanine perchlorate (DiI)-labeled LDL by GTFs was also checked. After exposure to TGF-β(2), LDLr was upregulated at the mRNA and protein levels in a concentration-dependent and/or time-dependent manner with a peak at a concentration of 5 ng/mL TGF-β(2). Binding and uptake of LDL were time dependent, reaching saturation at the first 6 h. This study shows that LDLr has a dose- and/or time-effect relationship with TGF-β(2) in Tenon's capsule fibroblasts from glaucoma patients. The results suggest that LDLr may play an important role in wound healing and scar formation in the activated Tenon's capsule fibroblasts from patients with glaucoma.