Inhibition of cAMP/PKA Pathway Protects Optic Nerve Head Astrocytes against Oxidative Stress by Akt/Bax Phosphorylation-Mediated Mfn1/2 Oligomerization

Figure 5

Effects of elevated intracellular cAMP on mitochondrial dynamics in ONH astrocytes exposed to oxidative stress. ONH astrocytes exposed to H₂O₂ (50 μM) were cotreated with dbcAMP (25 or 125 μM) for 1 h. (a) Cell viability/mitochondrial activity analysis using MTT assay in ONH astrocytes. Note that elevated intracellular cAMP accelerated loss of cell viability in ONH astrocytes exposed to H₂O₂ compared with ONH astrocytes exposed to H₂O₂ alone. (b, c) Western blot analyses for the protein expression of Drp1, OPA1, and Mfn1 and Mfn2. Note that elevated intracellular cAMP induced loss of total OPA1 and Mfn1 and Mfn2 protein expression in ONH astrocytes exposed to H₂O₂ compared with ONH astrocytes exposed to H₂O₂ alone. For each determination, the cell viability and protein expression in controls were normalized to a value of 1.0. Data are shown as the (). , , and denote , , and , respectively.

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