Effect of knockdown the α2 isoform of AMPK on the viability of MPT cells from α1
KO and WT mice subjected to metabolic stress. A: MPT cells from α1-/- mice, or their WT control, were infected with control shRNA (solid lines) or anti-α2 shRNA designed to knock down the expression of the α2 isoform of AMPK (dashed lines). Cells were then subjected to graded ATP depletion by incubation for 16–18 hrs in the presence of antimycin (2 μM) and varying concentrations of dextrose. The percentage of viable cells remaining was determined by flow cytometry (n = 5). * p < 0.01, anti-α2 shRNA vs. control shRNA, for MPT cells from α1-/- or WT mice (ANOVA for repeated measures). B: Representative flow cytometric analysis of metabolically stressed MPT cells from α2-/- mice infected with anti-α2 shRNA (right panels) or control shRNA (left panels). Cell viability was quantified by staining cells with calcein AM (x-axis) and ethidium homodimer-1 (Eth-H1) (y-axis). For each condition, 10,000 cells were analyzed, and the percentage of viable cells was calculated by dividing the number of calcein-positive and Eth-H1-negative cells by the total number of cells counted.