Fig. 1.

Histone H2AX depletion elicits pronounced diminution of mitochondrial biogenesis genes and reduced expression of OXPHOS complexes. (A–D) H2AX deletion reduces PGC-1α, a major mitochondrial biogenesis gene. Protein lysates from wild-type and H2AX knockout MEFs, as well as lysates from the striatum, were processed for immunoblot detection of H2AX and PGC-1α. Actin was used as a loading control. (A) Representative image of PGC-1α expression in MEFs and (B) quantification. (C) Representative image of PGC-1α expression in the striatum and (D) quantification. Data are means ± SEM (n = 3). Statistical significance was determined by a two-tailed, unpaired Student’s t test. (E) Analysis of POLRMT, TFB2M, TFAM, and PPARGC1B transcript levels in wild-type and H2AX knockout MEFs by RT-PCR. Expression values are relative fold changes for gene transcripts normalized to GAPDH. Error bars represent SEM (n = 3). (F and G) Western blot analysis of OXPHOS subunits in wild-type and H2AX knockout MEFs. We performed the immunoblot detection using total OXPHOS Human WB Antibody Mixture, enabling concomitant analysis of main proteins of each complex in the electron transport chain, including complex I subunit NDUFB8, complex II subunit 30 kDa, complex III subunit Core 2, complex IV subunit I, and ATP synthase subunit alpha; (F) representative image; (G) quantification. Data are means ± SEM (n = 3). (H and I) Western blot analysis of the OXPHOS subunits in the striatum of 4-mo-old wild-type and H2AX knockout mice; (H) representative image; (I) quantification. Data are means ± SEM (n = 3; *P < 0.05; **P < 0.001; ***P < 0.0001).