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
. 2003 Feb 18;100(4):1711-6.
doi: 10.1073/pnas.0337639100. Epub 2003 Feb 10.

Regulation of peroxisome proliferator-activated receptor gamma coactivator 1 alpha (PGC-1 alpha ) and mitochondrial function by MEF2 and HDAC5

Michael P Czubryt  1 , John McAnally, Glenn I Fishman, Eric N Olson
Affiliations

Regulation of peroxisome proliferator-activated receptor gamma coactivator 1 alpha (PGC-1 alpha ) and mitochondrial function by MEF2 and HDAC5

Michael P Czubryt et al. Proc Natl Acad Sci U S A. .

Abstract

The myocyte enhancer factor-2 (MEF2) transcription factor regulates muscle development and calcium-dependent gene expression. MEF2 activity is repressed by class II histone deacetylases (HDACs), which dissociate from MEF2 when phosphorylated on two serine residues in response to calcium signaling. To explore the potential importance of MEF2/HDAC interactions in the heart, we generated transgenic mice expressing a signal-resistant form of HDAC5 under cardiac-specific and doxycycline-inducible regulation. Transgene expression resulted in sudden death in male mice accompanied by loss and morphologic changes of cardiac mitochondria and down-regulation of mitochondrial enzymes. The transcriptional coactivator PGC-1 alpha, a master regulator of mitochondrial biogenesis and fatty acid oxidation, was also down-regulated in response to HDAC5 expression. Examination of the PGC-1 alpha promoter revealed two MEF2-binding sites that mediate transcriptional activation by MEF2 and repression by HDAC5. These findings identify PGC-1 alpha as a key target of the MEF2/HDAC regulatory pathway and demonstrate this pathway's importance in maintenance of cardiac mitochondrial function.

PubMed Disclaimer

Figures

Figure 1
Figure 1
Characterization of HDAC5S/A expression in DOX-inducible HDAC5S/A mice. (A) Western blotting of equal amounts of total cardiac protein of α-MHC-tTA/tetHDAC5S/A double transgenic mice before or after DOX withdrawal. (B) Immunohistochemical staining for FLAG-HDAC5S/A of cardiac sections from double transgenic mice before or after DOX withdrawal.
Figure 2
Figure 2
Cardiac and mitochondrial abnormalities in HDAC5S/A mice. (A) Survival curve for male and female HDAC5S/A mice before and after withdrawal of DOX on day 0. Transgene activation results in death of 100% of male mice expressing HDAC5S/A within 10 days (n = 6 males or females per group). Squares, males; triangles, females; filled symbols, +DOX; open symbols, −DOX. (B) Hematoxylin/eosin-stained cardiac sections from double-transgenic mice before or after DOX withdrawal. Arrows denote areas of cardiomyocyte death or dropout. The arrowhead indicates inflammatory cell infiltration. Magnification is ×40. (C) Transmission electron micrographs of mitochondria in double transgenic mice before and after DOX withdrawal. (Bar = 500 nm in Upper and 100 nm in Lower.) (D) Transmission electron micrographs of cardiac sections from control mice (Left) or from transgenic mice after 5 days of DOX withdrawal. (Bar = 1 μm.) Arrows denote lipid bodies.
Figure 3
Figure 3
Inhibition of expression of PGC-1α and metabolic enzymes after DOX withdrawal. Total RNA from hearts of HDAC5S/A mice was analyzed by microarray or by semiquantitative RT-PCR. The fold changes in gene expression for a panel of enzymes involved in cardiac energy metabolism pathways are presented in the chart (+DOX mice vs. −DOX), as well as images of bands obtained for each transcript by RT-PCR. NS, no significant change; BD, below detection limit; ND, not determined; M-CPTI, muscle-type carnitine palmitoyltransferase I; CPTII, carnitine palmitoyltransferase II; MCAD, medium chain acyl-CoA dehydrogenase; ACS, acyl-CoA synthetase; OH-AcCoA, OH-long-chain acyl-CoA dehydrogenase; FAT/CD36, fatty acid translocase; AcCoA Ox, acyl-CoA oxidase; Glyc Phosphor, glycogen phosphorylase. Asterisks denote direct targets of PPARα regulation; crosses denote genes regulated by PGC-1α.
Figure 4
Figure 4
Regulation of the PGC-1α promoter by MEF2 and HDAC5. (A) Sequence of putative MEF2 transcription factor-binding sites in the 3.1-kb proximal promoter of the mouse PGC-1α gene, compared with the consensus-binding sequence. Numbers in brackets refer to location in base pairs relative to the ATG start codon for PGC-1α. (B) Electrophoretic mobility-shift assay for binding of MEF2C to the putative MEF2 sites of the 3.1-kb proximal PGC-1α promoter. WT, wild-type oligomer; Mut, mutant oligomer with A/T to C/G conversion. (C) Activation of PGC-1α-promoter–luciferase reporter by MEF2 factors and attenuation by HDAC5S/A in COS cells. Asterisks denote P < 0.05 vs. reporter alone; crosses denote P < 0.05 vs. same sample in absence of HDAC5S/A. Error bars represent standard deviation of the mean for three experiments. (D) Effects of MEF2-binding site mutations in the PGC-1α promoter on transcriptional activation by MEF2C. Asterisks denote P < 0.01 vs. wild-type reporter plus MEF2C. Error bars represent standard deviation of the mean for three experiments. (E) Semiquantitative RT-PCR of PGC-1α expression in noninfected neonatal rat cardiomyocytes compared with cells infected with AdCMV-GFP or AdCMV-HDAC5S/A. (F) Immunoprecipitation of acetylated histone H3/DNA complexes from noninfected neonatal rat cardiomyocytes or cells infected with AdCMV-GFP or AdCMV-HDAC5S/A. Immunoprecipitated DNA was subjected to 32P-PCR under nonsaturating conditions using primers for PGC-1α promoter MEF2-binding sites or GAPDH. An aliquot of nonimmunoprecipitated DNA was used as an input control.
Figure 5
Figure 5
Model for interactions between MEF2/HDAC5 and PGC-1α. PGC-1α and PPARα cooperate to activate genes encoding enzymes involved in cardiac fatty oxidation. PGC-1α and MEF2C have been demonstrated to regulate glucose uptake in muscle by controlling expression of the GLUT4 glucose transporter, the main glucose uptake mechanism in muscle. MEF2 also regulates fetal gene programs during muscle hypertrophy. CnA, calcineurin.
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

References

    1. Eberharter A, Becker P B. EMBO Rep. 2002;3:224–229. - PMC - PubMed
    1. McKinsey T A, Zhang C L, Olson E N. Curr Opin Genet Dev. 2001;11:497–504. - PubMed
    1. Black B L, Olson E N. Annu Rev Cell Dev Biol. 1998;14:167–196. - PubMed
    1. McKinsey T A, Zhang C L, Lu J, Olson E N. Nature. 2000;408:106–111. - PMC - PubMed
    1. Grozinger C M, Schreiber S L. Proc Natl Acad Sci USA. 2000;97:7835–7840. - PMC - PubMed

Publication types

MeSH terms

LinkOut - more resources