Figure 5
Chronic HIF-1α stabilization impairs mitochondrial function. (a) MTCO1 protein was significantly different between groups (F(2,9) = 4.814, p = 0.0379). Tukey's multiple comparisons test showed MTCO1 was significantly lower in 4-week Roxa retinas compared to control retinas (p = 0.0316). MTCO1 protein levels were not significantly different between control vs. 2-week Roxa (p = 0.4497) and 2-week vs. 4-week retinas; n = 4 per group. (b) Mitochondrial cytochrome c subunit 1 (MTCO1, green) labels cytochrome c oxidase (COX) and GLAST (magenta) labels Müller glia. Arrow points to an RGC in the GCL with MTCO1 immunolabel. GCL = ganglion cell layer; INL = inner nuclear layer. Scale bar: 20 μm, (c) SDH-A protein was significantly lower (F(2,12) = 26.24, p < 0.0001) in Roxa-treated retinas compared to control. Tukey's multiple comparisons test showed SDH-A decreased in 4-week Roxa retinas (n = 6) compared to control (n = 6, p < 0.0001) and 2-week Roxa (n = 6, p = 0.0005) retinas. There were no differences in SDHA protein levels between control and 2-week Roxa retinas (p = 0.264). (d) Citrate synthase activity was significantly reduced in 4-week Roxa retinas (F(2, 15) = 12.26, p = 0.0007), n = 6 samples per group. Tukey's multiple comparisons test showed citrate synthase activity decreased in 4-week Roxa compared to 2-week Roxa (p = 0.0005). There was no significant difference in citrate synthase activity in control vs. 2-week Roxa (p = 0.05) and control vs. 4-week Roxa (p = 0.0788). (e) The ratio of pAMPK to AMPK was significantly higher (F(2,9) = 76.26, p < 0.0001) in 4-week Roxa retina compared to control and 2-week retinas. Tukey's multiple comparisons test showed pAMPK to AMPK ratio increased in 4-week retinas compared to control (p < 0.0001) and 2-week Roxa (p < 0.0001) retinas; n = 4 samples per group.
