miR‑16‑5p Protects RGCs Against Retinal Ischemia-Reperfusion Injury by Modulating Astrocyte-Mediated Neuroinflammation Through the Wip1/NF-κB Signaling Axis.

Astrocyte-mediated neuroinflammation has recently been implicated as a key contributor to neurodegeneration following retinal ischemia-reperfusion (IR) injury. However, the role of miR‑16‑5p in this process remains unclear. This study aimed to investigate the function and mechanism of miR‑16‑5p. TargetScan was used to predict miR-16-5p targets, which were validated by RNA pull-down. miR‑16‑5p expression was assessed by RT‑qPCR in IR retinas and in astrocytes after oxygen-glucose deprivation/reoxygenation (OGD/R). Astrocyte activation, inflammatory cytokine, and Wip1/nuclear factor kappa B (NF‑κB) signaling were examined following miR-16-5p modulation with mimics or inhibitors in vitro and in vivo. Retinal ganglion cell (RGC) apoptosis, retinal function, and morphology were evaluated. miR‑16‑5p was found to potentially target wild-type p53-induced phosphatase 1 (Wip1) and decreased Wip1 expression. In IR-injured mouse retinas and OGD/R-treated astrocytes, miR‑16‑5p expression was significantly downregulated. This decrease was accompanied by astrocyte activation, increased TNF-α and IL-1β levels, and upregulation of Wip1 and phosphorylated NF-κB p65 (p-p65). These retinal changes indicated retinal injury, characterized by increased TUNEL-positive RGCs, elevated cleaved caspase-3 levels, retinal thinning, and reduced electroretinography (ERG) amplitudes. Treatment with miR-16-5p mimics ameliorated these molecular, cellular, structural, and functional alterations, whereas miR‑16‑5p inhibitors exacerbated them. Collectively, miR-16-5p may protect RGCs from IR-induced apoptosis by suppressing astrocyte-mediated inflammation via the Wip1/NF-κB signaling axis.