A comparative immunohistochemical study of human corneotrabecular tissue

Abstract

Using in situ immunohistochemical techniques and a broad panel of antibodies directed against intermediate filament proteins, vascular endothelial markers, neuroectodermal/neuroendocrine markers, and monoclonal antibodies raised against human corneal endothelial cells (HCECs), a comparative phenotypical analysis was performed on HCECs, keratocytes, trabecular cells, and cells lining the canal of Schlemm. The coexpression of cytokeratins and neurofilaments by HCECs argues in favor of a neuroectodermal origin, which is further supported by the fact that they stain positive for neuron-specific enolase (NSE) and that they express neural cell adhesion molecules (N-CAM) at their surface. The expression of NSE and N-CAM also applies to the trabecular cells. The cells lining the canal of Schlemm were found to share many immunophenotypical features with vascular endothelial cells (i.e., factor-VIII-related antigen and BMA-120), rather than with HCECs. This was further supported by the reactivity of two monoclonal antibodies (i.e., 9.3 E and 5.52 H) that were raised against HCECs, and which labelled vascular endothelium and cells lining Schlemm's canal.

Expression of factor VIII‐related antigen in human aqueous drainage channels

“…As Tripathi & Tripathi (1989) have demonstrated a neuroectodermal origin of the human trabecular meshwork, this finding was expected and in agreement with previous immunohistochemical studies of the angular region (Pandolfi 1976;Rodrigues et al 1980;Foets et al 1992).…”

“…A negative immunostaining was demonstrated both by Pandolfi (1976) and Rodrigues et al (1980), while Foets et al (1992) found the endothelium of the canal to be positive. A positive reaction to FVIII-rAg was also shown by Hamanaka et al (1992), but the intensity of the staining reaction was very weak, particularly in the inner wall of the canal, where some parts were completely negative.…”

Immortalization of human corneal endothelial cells using electroporation protocol optimized for human corneal endothelial and human retinal pigment epithelial cells

“…5). This antibody reacts only with corneal endothelial cells of human origin (Foets et al 1992). It does not bind to other corneal cell types or corneal endothelial cells from other species.…”

“…On the one hand this could be demonstrated by means of an antibody raised against HCEC which recognize a 130 kDa protein (Foets et al 1992). Furthermore, the immortalized cell culture developed a cobblestone-like morphology characteristic of corneal endothelial cells in vivo.…”

“…After another three washing steps with PBS containing 1% FCS first antibody was added and chamber slides were incubated for 30 min at RT. As primary antibody, mouse anti-SV40 large T antigen (dianova, Hamburg, Germany) or mouse anti-HCEC (Foets et al 1992) were used. All primary and secondary antibodies were diluted 1:100 in PBS containing 10% FCS.…”