Background: Hypoxic injury to retinal ganglionic cells and adjoining glia is implicated in glaucomatous optic neuropathy. The present study evaluates the effect of IL-6 on R28 retinal precursor cell line exposed to hypoxic injury.
Methods and results: Apoptotic cell death induced by hypoxia mimetic CoCl2 in R28 cells with or without IL-6 treatment was measured using cell viability assays and apoptotic markers. Oxidative stress was also measured. Hypoxia induced by mimetic CoCl2 led to a time and concentration dependent apoptosis of cells mediated by disruption of mitochondrial membrane potential and activation of caspase 3. Cells pre-treated with IL-6 demonstrated significantly higher viability and mitochondrial integrity under hypoxic conditions. A critical role of STAT3 was observed in mediating the cytoprotective effects of IL-6. Treatment of cells with IL-6 led to STAT3-mediated expression of the Bcl-2 family proteins and MnSOD.
Conclusions: The data from the present study indicate cytoprotective role of IL-6 and suggest a previously unreported mechanism of neuroprotection via STAT3 mediated signaling.
Keywords: Glaucoma; Hypoxia; IL-6; Neuroprotection; Retinal ganglion cells; STAT3.
© 2021. The Author(s), under exclusive licence to Springer Nature B.V.