Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2011 Jun 7;108(23):9572-7.
doi: 10.1073/pnas.1106291108. Epub 2011 May 23.

PTEN-inducible kinase 1 (PINK1)/Park6 is indispensable for normal heart function

Filio Billia  1 , Ludger Hauck, Filip Konecny, Vivek Rao, Jie Shen, Tak Wah Mak
Affiliations

PTEN-inducible kinase 1 (PINK1)/Park6 is indispensable for normal heart function

Filio Billia et al. Proc Natl Acad Sci U S A. .

Abstract

Oxidative stress is caused by an imbalance between reactive oxygen species (ROS) production and the ability of an organism to eliminate these toxic intermediates. Mutations in PTEN-inducible kinase 1 (PINK1) link mitochondrial dysfunction, increased sensitivity to ROS, and apoptosis in Parkinson's disease. Whereas PINK1 has been linked to the regulation of oxidative stress, the exact mechanism by which this occurs has remained elusive. Oxidative stress with associated mitochondrial dysfunction leads to cardiac dysfunction and heart failure (HF). We hypothesized that loss of PINK1 in the heart would have deleterious consequences on mitochondrial function. Here, we observed that PINK1 protein levels are markedly reduced in end-stage human HF. We also report that PINK1 localizes exclusively to the mitochondria. PINK1(-/-) mice develop left ventricular dysfunction and evidence of pathological cardiac hypertrophy as early as 2 mo of age. Of note, PINK1(-/-) mice have greater levels of oxidative stress and impaired mitochondrial function. There were also higher degrees of fibrosis, cardiomyocyte apoptosis, and a reciprocal reduction in capillary density associated with this baseline cardiac phenotype. Collectively, our in vivo data demonstrate that PINK1 activity is crucial for postnatal myocardial development, through its role in maintaining mitochondrial function, and redox homeostasis in cardiomyocytes. In conclusion, PINK1 possesses a distinct, nonredundant function in the surveillance and maintenance of cardiac tissue homeostasis.

PubMed Disclaimer

Conflict of interest statement

The authors declare no conflict of interest.

Figures

Fig. 1.
Fig. 1.
Down-regulation of PINK1 protein expression in human end-stage HF. (A) Representative Western blot of PINK1 in total human LV extracts (Lower) with densitometric quantification (Upper). Lane 1 was set at 100%. MW, relative molecular weight. kDa, kilodalton. One result of two independent experiments. (B) Quantitative real-time PCR (qRT-PCR) analysis of PINK1 mRNA levels in LV tissues from human patients described in A. Lane 1 was set at onefold. Mean ± SEM. (C) Subcellular localization of PINK1 protein in adult mouse LV tissue. M, mitochondria; C, cytoplasm; N, nucleus; CoxIV, cytochrome c oxidase subunit IV; Npm1, nucleophosmin1. (D) Isolated neonatal mouse LV cardiomyocytes were fixed and costained with specific antibodies to PINK1 and mitochondrial CoxIV for indirect immunofluorescence confocal microscopic analysis. (E) PINK1 protein levels are susceptible to acute pressure overload (TAB) and ischemia (MI) for 24 h. (F) PINK1 is not redistributed to the cytoplasm or nucleus in response to increased hemodynamic load and hypoxic stress. Mice (10–12 wk) were subjected to TAB (Left) or MI (Right).
Fig. 2.
Fig. 2.
(A and B) PINK1 overexpression does not affect hypertrophic growth in response to Ang II. (A) Isolated neonatal rat LV cardiomyocytes were transduced with the indicated lentiviruses and incubated with Ang II (100 nM) for 48 h. Fixed cells were stained with antibodies to α-actinin. Mean ± SEM *P < 0.01 versus vehicle. (B) Analysis of hypertrophic marker gene expression (ANF, atrial natriuretic factor; Sk-actin, skeletal α-actin) by qRT-PCR. Mean ± SEM. *P < 0.01 versus mock vehicle. (C) Isolated neonatal mouse LV cardiomyocytes transduced with WT or KD PINK1 lentiviruses and incubated with antimycin (50 μM) for 6 h. Analysis of apoptosis of fixed cells by TUNEL immunofluorescence. Mean ± SEM. *P < 0.01 versus vehicle. (D) The mitochondrial membrane potential (ΔΨm) of PINK1−/− cardiomyocytes is susceptible to ROS-induced depolarization. Ectopic WT PINK1 rescues antimycin-induced decreases of ΔΨm in PINK1−/− cardiomyocytes. Cells, incubated with JC-1 (5 μg/mL), were treated with antimycin (50 μM). JC-1 emission at 535/595 nm was recorded at 1 reading/min for 30 min using a fluorescence spectrophotometer. The rate between two time points (Δemission at 595 nm/min) was calculated in the most linear range of decline for JC-1 fluorescence intensity. Mean ± SEM. *P < 0.01 versus vehicle.
Fig. 3.
Fig. 3.
PINK1−/− mice develop age-dependent cardiac hypertrophy and LV dysfunction. (A) Heart/body-weight ratio (Left) and Masson stain (Right) of myocardial longitudinal sections. (Scale bar, 2 mm.) Mean ± SEM. *P < 0.05. Sample size is indicated inside respective bar. (B) Fractional shortening (FS) determined by echocardiography. Mean ± SEM. *P < 0.05. **P < 0.05 versus PINK1−/− 2 mo. (C) Cardiomyocyte size (Left) and representative immunofluorescence micrographs of wheat germ agglutinin–Alexa Fluor 488 conjugate (WGA) stained myocardial cross-sections (Right). Mean ± SEM. #P < 0.05. *P < 0.05 versus PINK1+/+ 2 mo. (D) Quantitative RT-PCR analysis of mRNA levels of hypertrophic marker genes normalized to GAPDH mRNA. The ratio of hypertrophic markers to GAPDH in PINK1+/+ hearts at 2 mo was arbitrarily set to 1. *P < 0.05 versus PINK1+/+ 2 mo. Mean ± SEM. #P < 0.05 versus PINK1+/+ 6 mo.
Fig. 4.
Fig. 4.
Enhanced cardiac oxidative stress in PINK1−/− mice. (A) 4-hydroxyalkenals (4-HAE; Upper) and 8-hydroxy-2���-deoxyguanosine (8-OhdG; Lower), (B) oxidized glutathione (GSSG; Upper) and reduced glutathione (GSH; Lower) levels, (C) superoxide dismutase (SOD), and (D) aconitase activities, in total LV extracts from 2-mo-old PINK1 littermates. Mean ± SEM. *P < 0.05. n = 4.
Fig. 5.
Fig. 5.
Impaired cardiac mitochondrial biogenesis and bioenergetics in PINK1−/− mice. (A) Impaired mitochondrial (mt) biogenesis in 2-mo-old PINK1−/− mice (Lower). mtDNA copy number of mt-gene cytochrome b (Cytb) normalized to levels of nuclear encoded single-copy gene β-actin. We used mt-gene transcription as a surrogate for mt-capacity (Upper). mRNA expression levels of the mtCytb gene were measured by qRT-PCR and corrected for transcript expression of nuclear β-actin. Mean ± SEM. *P < 0.05. (B) PINK1 deficiency induces global down-regulation of mitochondrial protein expression in cardiac ventricles of 2-mo-old mice. (C) Impaired ATP production (Upper) and reduced complex I (NADH dehydrogenase) activity in total LV extracts from 2-mo-old PINK1−/− mice (Lower). Mean ± SEM. *P < 0.05.
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

References

    1. Braunwald E, Bristow MR. Congestive heart failure: Fifty years of progress. Circulation. 2000;102(20, Suppl 4):IV14–IV23. - PubMed
    1. Sadoshima J, Izumo S. The cellular and molecular response of cardiac myocytes to mechanical stress. Annu Rev Physiol. 1997;59:551–571. - PubMed
    1. Valente EM, et al. Hereditary early-onset Parkinson's disease caused by mutations in PINK1. Science. 2004;304:1158–1160. - PubMed
    1. Schapira AH. Mitochondria in the aetiology and pathogenesis of Parkinson's disease. Lancet Neurol. 2008;7:97–109. - PubMed
    1. Poole AC, et al. The PINK1/Parkin pathway regulates mitochondrial morphology. Proc Natl Acad Sci USA. 2008;105:1638–1643. - PMC - PubMed

Publication types

MeSH terms

Substances