A Novel Synthetic Steroid of 2,3,5-Trihydroxy-androst-6-one Alleviates the Loss of Rat Retinal Ganglion Cells Caused by Acute Intraocular Hypertension via Inhibiting the Inflammatory Activation of Microglia

Neuroinflammation has been well recognized as a key pathological event in acute glaucoma. The medical therapy of acute glaucoma mainly focuses on lowering intraocular pressure (IOP), while there are still scarce anti-inflammatory agents in the clinical treatment of acute glaucoma. Here we reported that ,3,5-trihydroxy-androst-6-one (sterone), a novel synthetic polyhydric steroid, blocked neuroinflammation mediated by microglia/macrophages and alleviated the loss of retinal ganglion cells (RGCs) caused by acute intraocular hypertension (AIH). The results showed that sterone significantly inhibited the morphological changes, the up-regulation of inflammatory biomarker ionized calcium-binding adapter molecule 1 (Iba-1), and the mRNA increase of proinflammatory tumor necrosis factor- (TNF-), interleukin-1 (IL-1), and interleukin-6 (IL-6) induced by lipopolysaccharide (LPS) in BV2 microglia and RAW264.7 macrophages. Moreover, immunofluorescence and western blotting analysis revealed that sterone markedly abrogated the nuclear translocation and phosphorylation of nuclear factor-B (NF-B) p65 subunit. Furthermore, sterone significantly suppressed the inflammatory microglial activation and RGCs' reduction caused by retinal ischemia/reperfusion (I/R) injury in a rat AIH model. These results suggest sterone may be a potential candidate in the treatment of acute glaucoma caused by microglial activation-mediated neuroinflammatory injury.