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. 2015 Dec 4;350(6265):aad2459.
doi: 10.1126/science.aad2459. Epub 2015 Dec 3.

Parkin-mediated mitophagy directs perinatal cardiac metabolic maturation in mice

Guohua Gong  1 , Moshi Song  1 , Gyorgy Csordas  2 , Daniel P Kelly  3 , Scot J Matkovich  1 , Gerald W Dorn 2nd  4
Affiliations

Parkin-mediated mitophagy directs perinatal cardiac metabolic maturation in mice

Guohua Gong et al. Science. .

Abstract

In developing hearts, changes in the cardiac metabolic milieu during the perinatal period redirect mitochondrial substrate preference from carbohydrates to fatty acids. Mechanisms responsible for this mitochondrial plasticity are unknown. Here, we found that PINK1-Mfn2-Parkin-mediated mitophagy directs this metabolic transformation in mouse hearts. A mitofusin (Mfn) 2 mutant lacking PINK1 phosphorylation sites necessary for Parkin binding (Mfn2 AA) inhibited mitochondrial Parkin translocation, suppressing mitophagy without impairing mitochondrial fusion. Cardiac Parkin deletion or expression of Mfn2 AA from birth, but not after weaning, prevented postnatal mitochondrial maturation essential to survival. Five-week-old Mfn2 AA hearts retained a fetal mitochondrial transcriptional signature without normal increases in fatty acid metabolism and mitochondrial biogenesis genes. Myocardial fatty acylcarnitine levels and cardiomyocyte respiration induced by palmitoylcarnitine were concordantly depressed. Thus, instead of transcriptional reprogramming, fetal cardiomyocyte mitochondria undergo perinatal Parkin-mediated mitophagy and replacement by mature adult mitochondria. Mitophagic mitochondrial removal underlies developmental cardiomyocyte mitochondrial plasticity and metabolic transitioning of perinatal hearts.

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Conflict of interest statement

The authors declare no conflicts.

Figures

Fig. 1
Fig. 1. Early lethality of perinatal cardiomyocyte-specific Parkin-deficient mice
(A) Transmission electron microscopy (TEM) showing normal cardiomyocyte mitochondria on the first (P1) and 21st (P21) day of life. Enlargement shows structural details at P1. (B) PCR genotyping of floxed Park2 gene (top) and tamoxifen-inducible cardiac Cre (bottom) of surviving mice from a representative litter at P21; 3 mice died before weaning. KO indicates Cre recombined Park2 fl/fl allele. T is tail DNA; H is heart DNA. (C and D) Representative (of 3) hearts, histological sections, and TEMs from P21 cardiac Parkin deficient (top) and control (bottom) mice. Scale bars for hearts is 2 mm.
Fig. 2
Fig. 2. Mitochondrial Parkin mobilization directed by pseudo-PINK1 phosphorylated Mfn2
(A) Phosphorylation of Mfn2 by recombinant PINK1 in a cell-free system. First three panels show enrichment of FLAG-Mfn2 by anti-FLAG immunoprecipitation (IP); left is Coomassie blue stained gel, middle is anti-Mfn2 immunoblot, right is anti-FLAG immunoblot. Fourth panel shows anti-Mfn2 Phos-Tag immunoblot of in vitro PINK1 phosphorylation reactants; KD is kinase dead PINK1, CIP is calf intestinal phosphatase. Arrowheads show FLAG-Mfn2; bold arrow indicates phospho-Mfn2. (B) Spontaneous mcParkin translocation in MEFs provoked by adeno-Mfn2 EE, and FCCP-mediated Parkin translocation suppressed by adeno-Mfn2 AA. To the left is immunoblot of Mfn2. (C) Lysosomal-mitochondrial interactions (white squares) provoked by adeno-Mfn2 EE and suppressed by adeno-Mfn2 AA. (D) Mitochondrial elongation (aspect ratio) inhibited by adeno-Mfn2 EE and stimulated by adeno-Mfn2 AA. WT is wild type adeno-Mfn2. In B and C grey bars are basal; black bars are after FCCP or antimycin A. In D grey bars are 24h and black bars are 48h after adeno-Mfn virus infection. * is p<0.05 vs adeno β-gal control (Ctrl); # is p<0.05 vs same condition WT adeno-Mfn2.
Fig. 3
Fig. 3. Perinatal cardiomyopathy evoked by non-phosphorylated Mfn2 AA
(A) Immunoblot analysis of Mfn2 expression (top) and mitochondrial Parkin localization (bottom) in transgenic mouse hearts. Upper panel - top pair is cardiac homogenate; bottom pair is mitochondrial-enriched 10,000g pellet (cytochrome oxidase IV; COX IV) and post-mitochondrial supernatant (GAPDH). Lower panel - Immunoblot analysis of mitochondrial-associated Parkin and downstream mitophagy events and their modulation by cardiac-expressed Mfn2 EE and Mfn2 AA. (B) Representative hearts of 6 week old mice. (C) Survival. (D) Serial echocardiographic data of 4-6 week old mice; white bars are Ctrl, grey is WT Mfn2, and black is Mfn2 AA. (E) Heart (top) and lung (bottom) weights of 6 week old mice indexed to body weight (BW). (F) Histological studies of cardiomyocyte cross sectional area (top) and myocardial fibrosis (bottom); quantitative data are on the right. *is p<0.05 vs WT Mfn2 and NTG control.
Fig. 4
Fig. 4. Abnormalities in mitophagy and mitochondria induced by perinatal cardiac Mfn2 AA
(A) Immunoreactive Parkin and p62/SQSTM1 in 2-3 week old mitochondrial-enriched mouse heart fractions (mito-) of fed mice (top) and food-deprived mice (bottom). Cyto-p62 is p62/SQSTM1 in the cytosolic fraction. (B) Substrate-stimulated (left) and maximum uncoupled (right) respiration of isolated cardiac mitochondria. (C) Isolated mitochondrial O2− (MitoSOX; left) and H2O2 (Amplex red; right) production studies. (D) Cardiac mitochondrial protein content. (E) Flow cytometric mitochondrial forward scatter. (F) Ultrastructural studies of cardiomyocyte mitochondria; mitochondrial content is % area occupied by mitochondria, mitochondrial area is mean area of individual organelles, mitochondrial aspect ratio is long axis/short axis. (G) Immunoblot analysis of respiratory complex proteins. Quantitative data to right are n=4. * is p<0.05 vs Ctrl; # is p<0.05 vs WT Mfn2.
Fig. 5
Fig. 5. Fetal mitochondria persist in young adult Mfn2 AA mouse hearts
(A) Representative 4-chamber heart sections and transmission electron micrographs of cardiomyocyte mitochondria from P1, P21, and 5 week old mouse hearts. NTG controls are top row, WT Mfn2 middle row, Mfn2 AA bottom row. Quantitative data for heart weights are in (B) and for mitochondrial ultrastructure in (C); * = p<0.05 vs P1, # = p<0.05 vs WT Mfn2 at same stage.
Fig. 6
Fig. 6. Failure of metabolic gene reprogramming after perinatal Mfn2 AA expression
(A) Heat map of mitochondrial gene expression in P1, P21, and 5 week mouse hearts; functional annotation of Mfn2 AA gene clusters is to the right. (B) Postnatal reprogramming of mitochondrial genes by metabolic function. Bars are mean values from results in Fig 4B; log(2) gene expression at 5 weeks vs P1 for Ctrl (top), WT Mfn2 (middle) and Mfn2 AA (lower) hearts. Blue and red bars are significantly down and upregulated, respectively (1.25 fold, FDR <0.02); black bars are not significantly regulated. (C) Regulated expression of mitochondrial biogenesis and replication genes during the perinatal-adult transition. * = FDR<0.02 vs littermate control mice (TO). # is p<0.0001 vs WT Mfn2 (2-way ANOVA).
Fig. 7
Fig. 7. Adult Mfn2 AA hearts retain a fetal-like glycolytic metabolism
(A) Palmitoylcarnitine-stimulated (top) and pyruvate-stimulated (bottom) respiration of isolated permeabilized cardiomyocytes. (B and C) Standardized heat map showing unsupervised clustering of myocardial acylcarnitine (B) and organic acid (C) metabolite content in P1 NTG and 5 week old NTG, WT Mfn2, and Mfn2 AA mouse hearts. Vertical lines to the right of (B) indicate significantly dysregulated metabolites in 5 week Mfn2 AA hearts vs contemporaneous controls. (D) Quantitative data for absolute myocardial content of dysregulated metabolites in (B). –DC and -OH designate monohydroxylated and dicarboxylic acid acylcarnitine species, respectively. Common names for parent species are in parentheses. *=p<0.05 vs WT Mfn2 (ANOVA).
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References

    1. Porter GA, Jr, et al. Bioenergetics, mitochondria, and cardiac myocyte differentiation. Prog. Pediatr. Cardiol. 2011;31:75–81. - PMC - PubMed
    1. Bartelds B, et al. Perinatal changes in myocardial metabolism in lambs. Circulation. 2000;102:926–931. - PubMed
    1. Kim HD, et al. Human fetal heart development after mid-term: morphometry and ultrastructural study. J. Mol. Cell. Cardiol. 1992;24:949–965. - PubMed
    1. Stanley WC, Recchia FA, Lopaschuk GD. Myocardial substrate metabolism in the normal and failing heart. Physiol. Rev. 2005;85:1093–1129. - PubMed
    1. Taegtmeyer H, Sen S, Vela D. Return to the fetal gene program: a suggested metabolic link to gene expression in the heart. Ann. N. Y. Acad. Sci. 2010;1188:191–198. - PMC - PubMed

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