Research ArticleMOLECULAR BIOLOGY

Mitochondrial PE potentiates respiratory enzymes to amplify skeletal muscle aerobic capacity

See allHide authors and affiliations

Science Advances  11 Sep 2019:
Vol. 5, no. 9, eaax8352
DOI: 10.1126/sciadv.aax8352
  • Fig. 1 Skeletal muscle mitochondrial PE promotes oxidative capacity.

    (A to C) Untrained (UT, n = 6) or trained (T, n = 7 or 8) C57BL6/J mice. (A) Skeletal muscle mitochondrial phospholipidome. LPC, lyso-PC; PG, phosphatidylglycerol; n.s., not significant. (B) Mitochondrial phospholipids quantified by thin-layer chromatography (TLC). (C) Skeletal muscle PSD mRNA. (D to L) Studies on PSD-MKI mice (n = 3 to 9). (D) Generation of mice with conditional knock-in of PSD. 5′UTR, 5′ untranslated region. (E) Skeletal muscle PSD mRNA. (F) Muscle mitochondrial PE. (G and H) Rates for oxygen consumption or ATP production in permeabilized muscle fibers with Krebs cycle substrates. DQ, duroquinol; AA, antimycin A. (I) Protein abundance of respiratory complexes II to V. (J) Myosin heavy chain (MHC) fiber-type distribution. (K) Endurance running test. (L) Ex vivo twitch endurance test. Means ± SEM.

  • Fig. 2 Deficiency of mitochondrial PE promotes atrophy and respiratory failure.

    (A to C) Control (Ctrl; n = 6 or 7) and hindlimb-unloaded (HU; n = 7) C57BL6/J mice. (A) Gastrocnemius weight. (B) Skeletal muscle mitochondrial phospholipidome. (C) Skeletal muscle PSD mRNA. (D to P) Studies on PSD-MKO mice. (D) Generation of PSD-MKO mice. (E) PSD mRNA levels in multiple tissues (n = 5 to 6). (F) TLC analysis of mitochondrial phospholipids. (G) Muscle mitochondrial PE (n = 3 to 4). (H) Body weights after tamoxifen injection (n = 9 to 22). (I) Kyphosis in PSD-MKO mice. (J) Kaplan-Meier survival curve. (K and L) Breathing rate and peripheral capillary oxygen saturation (SpO2) 6 weeks after tamoxifen injection (n = 3). bpm, breaths per minute. (M to P) Diaphragm 4 weeks after tamoxifen injection. (M) Diaphragm weight (n = 4 to 6). (N) Distribution of fiber cross-sectional area (n = 9). (O) Fibrosis and fiber type. (P) Force-frequency curve (n = 4 to 6). Means ± SEM.

  • Fig. 3 PE deficiency in skeletal muscle mitochondria.

    (A) Electron micrograph of subsarcolemmal (SS) and intermyofibrillar (IMF) mitochondria. (B and C) Rates of oxygen consumption and ATP production in permeabilized fibers with Krebs cycle substrates (n = 3 to 5). (D) Protein abundance of respiratory complexes I to V. (E) Activities of respiratory enzymes (n = 4 to 6). (F) Blue native gel of isolated mitochondria revealing supercomplexes (n = 4). High–molecular weight supercomplexes (HMW SCs). (G) Mitochondrial H2O2 production and emission with pyruvate normalized to O2 consumption (n = 3). (H) 4-HNE. (I) MDA (n = 5). (J) Reduced glutathione (GSH) and oxidized glutathione (GSSG) (n = 3 to 5). Means ± SEM.

  • Fig. 4 Overexpression of mitochondrial catalase does not rescue PSD deficiency.

    (A) PSD-MKO mice were crossed with mCAT transgenic mice to generate mCAT × PSD-MKO mice. (B) Mitochondrial H2O2 production and emission with pyruvate normalized to O2 consumption (n = 5 to 7). (C) Kaplan-Meier survival curve. (D) Body weights after tamoxifen injection (n = 6 to 9). (E) Force-frequency curve of diaphragm muscles (n = 4 to 11). (F) Rates of oxygen consumption in permeabilized fibers with Krebs cycle substrates (n = 4 to 10). (G and H) Pathway analyses for differentially expressed genes between control, PSD-MKO, and mCAT × PSD-MKO diaphragms (n = 3 to 4). (G) Area-proportional Venn diagram of differentially activated pathways. (H) Normalized enrichment scores (NES) of differentially activated pathways. ECM, extracellular matrix. (I) Schematic illustration of the consequences of mitochondrial PE deficiency. ROS, reactive oxygen species. Means ± SEM.

Supplementary Materials

  • Supplementary material for this article is available at http://advances.sciencemag.org/cgi/content/full/5/9/eaax8352/DC1

    Fig. S1. Skeletal muscle mitochondrial PE and oxidative capacity.

    Fig. S2. Deficiency of muscle mitochondrial PE in vitro.

    Fig. S3. Deficiency of skeletal muscle mitochondrial PE in vivo.

    Fig. S4. PE deficiency in skeletal muscle mitochondria.

    Fig. S5. Overexpression of mitochondrial catalase does not rescue muscle-specific PSD deficiency.

  • Supplementary Materials

    This PDF file includes:

    • Fig. S1. Skeletal muscle mitochondrial PE and oxidative capacity.
    • Fig. S2. Deficiency of muscle mitochondrial PE in vitro.
    • Fig. S3. Deficiency of skeletal muscle mitochondrial PE in vivo.
    • Fig. S4. PE deficiency in skeletal muscle mitochondria.
    • Fig. S5. Overexpression of mitochondrial catalase does not rescue muscle-specific PSD deficiency.

    Download PDF

    Files in this Data Supplement:

Stay Connected to Science Advances

Navigate This Article