Abstract
PURPOSE: To examine the role of aqueous tumor necrosis factor α (TNF-α)-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-α, 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-α and nuclear factor kappa B (NF-κB) 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-α, 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-α was negatively correlated with the number of corneal endothelial cells. In CMV-infected hCECs, upregulation of TNF-α and NF-κB 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-α was upregulated in CMV+/PSS patients, which may have triggered corneal endothelial cell loss. Modulation of TNF-α, including its downstream Rho-ROCK signaling, could serve as a novel treatment modality for corneal endothelial cell loss in CMV+/PSS patients.