Neuroprotection of SRT2104 in Murine Ischemia/Reperfusion Injury Through the Enhancement of Sirt1-Mediated Deacetylation.

Purpose: Strategies for neuroprotection are the main targets of glaucoma research. The neuroprotective properties of SRT2104 administration have been proven in central nervous system degeneration diseases through the activation of nicotinamide adenine dinucleotide-dependent deacetylase-silence information regulator 1 (Sirt1). Here, we investigated whether SRT2104 could protect the retina from ischemia/reperfusion (I/R) injury and the underlying mechanisms.

Methods: SRT2104 was intravitreally injected immediately after I/R induction. RNA and protein expression were detected by quantitative real-time PCR and Western blot. Protein expression and distribution were examined by immunofluorescence staining. Retinal structure and function were analyzed by hematoxylin and eosin staining, optical coherence tomography, and electroretinogram. Optic nerve axons were quantified using toluidine blue staining. Cellular apoptosis and senescence were evaluated by TUNEL assay and SA-β-gal staining.

Results: The protein expression of Sirt1 decreased dramatically after I/R injury and SRT2104 administration effectively enhanced the stability of Sirt1 protein without significantly influencing Sirt1 mRNA synthesis. SRT2104 administration alone exerted no influence on the structure and function of normal retinas. However, SRT2104 intervention significantly protected the inner retinal structure and neurons; partially restored retinal function after I/R injury. I/R-induced cellular apoptosis and senescence were effectively alleviated by SRT2104 administration. Additionally, SRT2104 intervention markedly reduced neuroinflammation, including reactive gliosis, retinal vascular inflammation, and the overexpression of pro-inflammatory cytokines after I/R injury. Mechanistically, I/R-induced acetylation of p53, NF-κB p65, and STAT3 was significantly reversed by SRT2104 intervention.

Conclusions: We demonstrated that SRT2104 exerted potent protective effects against I/R injury by enhancing Sirt1-mediated deacetylation and suppressing apoptosis, senescence, and neuroinflammation-related pathways.