Figure 2. PU-91 regulates mitochondrial function. We used the fluorometric JC-1 assay and MitoSOX assay to measure mitochondrial membrane potential and mitochondrial superoxide production, respectively. Treatment with PU-91 led to elevated mitochondrial membrane potential (p≤0.05, n=3) (A) and reduced mitochondrial superoxide production (p≤0.05, n=3) (B) in AMD cybrids (AMD PU-91) compared to the untreated group (AMD UN). Furthermore, PU-91-treated AMD cybrids showed upregulation of the mitochondrial superoxide dismutase, SOD2 gene (p≤0.05, n=5) (C) and reduced expression of HIF1α gene (p≤0.05, n=3-4) (D). (E) PU-91 upregulates MT-RNR2 gene. Using TaqMan probe for the MT-RNR2 gene, qRT-PCR analysis revealed that PU-91 increases MT-RNR2 gene expression by 104% compared to untreated control (p≤0.05, n=5). Data are presented as mean ± SEM and normalized to untreated (UN) AMD cybrids which were assigned a value of 1. Mann-Whitney test was used to measure statistical differences; *p≤0.05, **p≤0.01.