Suberoylanilide hydroxamic acid suppresses inflammation-induced neovascularization

Inflammatory corneal neovascularization remains a poorly understood process. Prior research has shown that histone deacetylases influence gene expression patterns. These enzymes modify histone and nonhistone proteins to regulate transcription. Deregulated HDAC activity has been linked to tumor development and abnormal blood vessel growth. However, the precise role of HDACs in corneal inflammation is unclear. No prior work had resolved how HDAC inhibition might affect inflammatory angiogenesis. This gap motivated researchers to explore the impact of HDAC inhibitors on corneal neovascularization. The study aimed to clarify whether HDAC inhibition could suppress abnormal blood vessel formation in inflamed corneas.

The research aimed to assess the anti-angiogenic potential of SAHA in corneal inflammation. Inflammatory corneal neovascularization is a major clinical concern. The study focused on whether SAHA could reduce blood vessel growth in injured corneas. Researchers used an alkali-induced corneal injury model in mice. They hypothesized that HDAC inhibition might downregulate pro-angiogenic signals. The motivation stemmed from prior evidence linking HDACs to tumor and angiogenic processes. By testing SAHA, the team sought to identify a possible therapeutic strategy. The study's goal was to provide experimental evidence for HDAC inhibition as a treatment option.

The researchers used an alkali-burn model to induce corneal neovascularization in mice. SAHA was applied topically to the injured corneas for the duration of the experiment. Corneal tissues were analyzed for changes in blood vessel density. Expression levels of pro- and anti-angiogenic factors were measured using qPCR and immunohistochemistry. Human microvascular endothelial cells were cultured in vitro for additional testing. SAHA's effects on cell migration and proliferation were assessed using migration assays. Tube formation was evaluated in Matrigel cultures to simulate angiogenesis. The study combined in vivo and in vitro approaches to validate the findings.

Topical SAHA application reduced corneal neovascularization in the mouse model. SAHA downregulated VEGF, bFGF, TGFβ1, and EGF in the injured corneas. The anti-angiogenic factors TSP-1, TSP-2, and ADAMTS-1 were upregulated by SAHA. In vitro, SAHA inhibited the expression of pro-angiogenic proteins in HEMC-1 cells. The drug also suppressed cell migration and proliferation in these endothelial cells. SAHA-treated cells showed reduced tube formation on Matrigel. The effects were consistent across both in vivo and in vitro models. These findings suggest that SAHA may suppress angiogenesis by modulating key signaling pathways.

The study suggests that SAHA may suppress inflammatory corneal neovascularization. The drug appears to reduce pro-angiogenic signals and enhance anti-angiogenic responses. These effects were observed in both corneal tissues and cultured endothelial cells. The findings support the hypothesis that HDAC inhibition could be a viable treatment strategy. The researchers propose that SAHA may interfere with multiple angiogenic pathways. The results align with prior evidence of HDACs in tumor and angiogenesis regulation. The study does not claim that SAHA is the only effective HDAC inhibitor. The authors suggest further research to explore the clinical potential of SAHA in corneal diseases.