Effect of porcine chondrocyte-derived extracellular matrix on the pterygium in mouse model

Abstract

To investigate the effect of porcine chondrocyte-derived extracellular matrix (PCDECM) on an experimental mouse model of human pterygial epithelial cells. Cultured human pterygial epithelial cells (hPECs) were stained with pan-cytokeratin (CK), CK3/2p, vimentin, and CK13 antibodies to characterize the cells. A pterygium mouse model was developed by injecting 1X10⁴ hPECs into the nasal subconjunctival space in athymic nude mice. PCDECM (25 mg/mL, 10 μL) was injected into the nasal subconjunctival space in the right eye 7, 10 and 14 days after the epithelial cell injection (PCDECM group). Image analysis was performed using ImageJ® to compare the lesion size. A histopathological analysis of the cornea was conducted to evaluate the state of the epithelium and the expression of pterygial epithelial cell markers. The isolated pterygial cells were positive for pan-CK, CK3/2p and vimentin, and they were negative for CK13 under immunofluorescence microscopy. On day 17 after epithelial cell injection, the size of the lesion compared to the entire cornea was increased to 37.1 % in the control group. However, in the PCDECM group, the lesion covered only 26.3 % of the entire cornea. The corneas of the pterygium mice showed an epithelium of irregular thickness, proliferation of the stroma, extracellular matrix breakdown and overexpression of pterygium-positive markers. However, these changes were significantly suppressed by the application of PCDEDM. Our findings suggest that PCDECM seems to suppress pterygial epithelial cell growth and it could be used as a promising biomaterial for the noninvasive treatment of pterygium.