Effects of ROCK Inhibitors on Apoptosis of Corneal Endothelial Cells in CMV-Positive Posner-Schlossman Syndrome Patients

PURPOSE. To examine the role of aqueous tumor necrosis factor alpha (TNF-alpha)-RhoA-Rho kinase (ROCK) signaling in cytomegalovirus (CMV)-induced apoptosis and the barrier function of cultured human corneal endothelial cells (hCECs) in CMV-positive Posner-Schlossman syndrome (CMV+/PSS) patients. METHODS. Aqueous levels of TNF-alpha, IL-8, IL-10, and several other cytokines in 19 CMV+/PSS patients and 20 healthy control subjects were quantitated using a multiplex assay. The expression of active RhoA in hCECs post-CMV infection was determined using western blotting (WB). The expression levels of TNF-alpha and nuclear factor kappa B (NF-kappa B) in CMV-infected hCECs were examined by immunocytochemistry (ICC) and WB with and without ROCK inhibitors. The apoptotic rate and barrier integrity in CMV-infected hCECs were also examined. RESULTS. The expression levels of TNF-alpha, monocyte chemoattractant protein-1 (MCP-1), IL-8, and IL-10 were upregulated in the aqueous humor of CMV+/PSS patients, and among these upregulated cytokines aqueous TNF-alpha was negatively correlated with the number of corneal endothelial cells. In CMV-infected hCECs, upregulation of TNF-alpha and NF-kappa B was determined by WB and ICC. In hCECs, CMV infection induced apoptosis and significantly impaired cell-cell contacts, effects that were attenuated by treatment with a ROCK inhibitor. CONCLUSIONS. Aqueous TNF-alpha was upregulated in CMV+/PSS patients, which may have triggered corneal endothelial cell loss. Modulation of TNF-alpha, including its downstream Rho-ROCK signaling, could serve as a novel treatment modality for corneal endothelial cell loss in CMV+/PSS patients.