POU4F1 and diabetes mellitus: Moreover, long-term PGZ treatment in HFD-fed mice with STZ-induced diabetes showed reduced apoptosis in RGCs, the decreased recruitment of Iba-1+-activated microglial cells, preserved retinal thickness on OCT measurement, and less loss of Brn3A+ RGC counts after AION, and these effects might have occurred through PPAR-γ activation in the retina, as demonstrated via immunofluorescence staining.