RESULTS.Immunocytochemistry showed that QMMuC-1 express known Müller glial markers, including glutamine synthetase, glial fibrillary acidic protein (GFAP), alpha-smooth muscle actin (a-SMA), Aquaporin 4, Kir4.1, interleukin 33 (IL-33), and sex determining region Y (SRY)-box2 (Sox2), but not Cone arrestin, Calbindin 1, CD68, and ionized calcium-binding adapter molecule 1 (Iba1). Compared with PMC, QMMuC-1 express higher levels of chemokine (C-C motif) ligand 2 (Ccl2), VEGFA, and glutamate aspartate transporter (GLAST), but lower levels of interleukin 6 (IL-6), brain-derived neurotrophic factor (BDNF), insulin-like growth factor 1 (IGF1), and neurotrophin 3 (NTF3). Whole-cell patch clamp recordings demonstrated characteristic inward currents in response to L-glutamate and L-trans-pyrrolidine-2,4-dicarboxylic acid (PDC) by QMMuC-1 cells. The L-glutamate-induced current was significantly higher in QMMuC-1 cells compared with PMC. Bioenergetic profiling studies revealed similar levels of glycolysis and basal mitochondrial respiration between QMMuC-1 and PMC. However, mitochondrial spare capacity was significantly lower in QMMuC-1 compared with PMC.
CONCLUSIONS.Our results suggest that the QMMuC-1 Müller glial cell line retains key characteristics of PMC with its unique profiles in cytokine/neurotrophic factor expression and mitochondrial respiration. QMMuC-1 has utility as an invaluable tool for understanding the role of Müller glia in physiological and pathological conditions.