Elsevier

International Journal of Cardiology

Volume 272, 1 December 2018, Pages 281-287
International Journal of Cardiology

Inhibition of prolyl hydroxylases alters cell metabolism and reverses pre-existing diastolic dysfunction in mice

https://doi.org/10.1016/j.ijcard.2018.08.065Get rights and content

Highlights

  • SIRT3 deletion shifts ECs from glycolytic metabolism to mitochondrial respiration.

  • Loss of SIRT3 impairs PHD/HIF signaling pathway and glycolytic function.

  • Treatment with PHD inhibitor DMOG improves endothelial metabolic homeostasis and rescues diastolic dysfunction.

Abstract

Background

Diastolic dysfunction is emerging as a leading cause of heart failure in aging population. Induction of hypoxia tolerance and reprogrammed cell metabolism have emerged as novel therapeutic strategies for the treatment of cardiovascular diseases.

Methods and results

In the present study, we showed that deletion of sirtuin 3 (SIRT3) resulted in a diastolic dysfunction together with a significant increase in the expression of prolyl hydroxylases (PHD) 1 and 2. We further investigated the involvement of PHD in the development of diastolic dysfunction by treating the 12–14 months old mice with a PHD inhibitor, dimethyloxalylglycine (DMOG) for 2 weeks. DMOG treatment increased the expression of hypoxia-inducible factor (HIF)-1α in the endothelium of coronary arteries. This was accompanied by a significant improvement of coronary flow reserve and diastolic function. Inhibition of PHD altered endothelial metabolism by increasing glycolysis and reducing oxygen consumption. Most importantly, treatment with DMOG completely reversed the pre-existing diastolic dysfunction in the endothelial-specific SIRT3 deficient mice.

Conclusions

Our findings demonstrate that inhibition of PHD and reprogrammed cell metabolism can reverse the pre-existed diastolic dysfunction in SIRT3 deficient mice. Our study provides a potential therapeutic strategy of induction of hypoxia tolerance for patients with diastolic dysfunction associated with coronary microvascular dysfunction, especially in the aging population with reduced SIRT3.

Introduction

Diastolic dysfunction is one of the major characteristics of heart failure with preserved ejection fraction (HFpEF), as well as in some population of asymptomatic patients and patients with reduced EF (HFrEF) [1]. More than half of the HF patients are diagnosed with diastolic dysfunction [[2], [3], [4], [5]]. Diastolic dysfunction is commonly associated with cardiovascular, metabolic, and inflammatory comorbidities [6]. For instance, age, hypertension, diabetes mellitus, obesity, chronic renal failure, and LV hypertrophy are the major risk factors for diastolic dysfunction [7,8]. Recent studies demonstrate that persistent or progression of diastolic dysfunction, especially with co-existing comorbidities, promotes the development of heart failure in aging population [9,10]. However, currently available and effective treatment for HFrEF have failed to show promising results in patients with diastolic dysfunction [11]. Clinical studies reveal that patients with HFpEF have coronary microvascular rarefaction and more cardiac hypertrophy than age-matched patients without clinical diagnosis of coronary artery disease and heart failure [6]. Despite the clinical importance of HFpEF, our understanding of its pathophysiology and molecular mechanism is incomplete.

Sirtuins are a family of Class III histone deacetylases (HDACs) that require NAD+ for their lysine residue deacetylase activity [12,13]. Sirtuins regulate cellular homeostasis, including energy metabolism and reactive oxygen species (ROS) [14,15]. Of the Sirtuin family, SIRT3 is primarily localized to the mitochondria in metabolic active organs, including liver, adipose tissue, and heart, where it regulates mitochondrial function and cellular metabolism [[15], [16], [17], [18]]. Increased SIRT3 expression protects cardiomyocytes, pancreatic cells, and neurons from inflammation and apoptosis by reducing oxidative stress [[19], [20], [21], [22]]. SIRT3 levels have been shown to decrease in human cardiac fibroblasts isolated from controls and patients with HF [23]. Hirschey and colleagues report that ablation of SIRT3 in mice impairs glucose tolerance and develops hepatic steatosis and metabolic syndrome [24,25]. In our previous study, we found that ablation of SIRT3 causes coronary microvascular dysfunction and increases ischemic injury in the heart [26]. Moreover, specific deletion of endothelial Sirt3 impairs glycolysis and causes a diastolic dysfunction in mice [27]. Koentges and colleagues report that SIRT3 deficiency causes mitochondrial and contractile dysfunction in the heart [28]. These studies indicate a critical role of SIRT3 in the development of cardiac dysfunction.

Hypoxia triggers the activation of hypoxia-inducible factors (HIFs) and the expression of many genes involving in glucose uptake, glycolysis, erythropoiesis, and angiogenesis [[29], [30], [31]]. Prolyl hydroxylases (PHDs) play an important role in the regulation of HIFs [32,33]. Deactivation of PHD1 reduces oxygen consumption and mitochondrial oxidative stress and protects against muscle ischemic necrosis [34]. However, the consequence of administering PHD inhibitor on the diastolic dysfunction is unclear. In the present study, we hypothesized that inhibition of PHDs that mimics induction of hypoxia tolerance is protective against the diastolic dysfunction in the SIRT3 deficient mice. Our study reveals that the expression of PHD1 and PHD2 is significantly upregulated in the SIRT3 deficient mice. Moreover, treatment with PHD inhibitor DMOG reprograms endothelial metabolism, improves coronary microvascular function and diastolic function in global SIRT3 knock-out (KO) mice and endothelial-specific SIRT3 KO mice.

Section snippets

Methods

See Online Data Supplement for detailed methods and materials.

SIRT3 KO mice develops diastolic dysfunction

We examined whether SIRT3 KO mice developed a diastolic dysfunction in the presence of impaired CFR. Pulse-wave (PW) Doppler measurements indicated that the isovolumic relaxation time (IVRT) was significantly increased in SIRT3 KO mice (Fig. 1A and B). In addition, the calculated myocardial performance index was significantly elevated (Fig. 1B). The mitral valve inflow velocity during early diastolic (E) phase was similar between WT and SIRT3 KO mice, but it was associated with a significant

Discussion

This study demonstrates that SIRT3 deletion results in diastolic dysfunction that is associated with upregulation of PHD1 and PHD2 and alterations in endothelial cell metabolism. These abnormalities lead to coronary microvascular dysfunction manifested as reduced CFR and subsequent diastolic dysfunction in mice. Pharmacological inhibition of PHDs by DMOG improves endothelial glycolytic metabolism and angiogenesis, reverses coronary dysfunction and pre-existed diastolic dysfunction. These

Conclusion

Our study provides the first insight into the potential role of PHD on SIRT3 deficiency-induced diastolic dysfunction. Our results suggest that loss of SIRT3 impairs PHD/HIF signaling pathway and alters cell metabolism. Inhibition of PHD can improve endothelial metabolic homeostasis and reverse pre-existed diastolic dysfunction. This study provides a potential therapeutic strategy that clinically relevant PHD inhibition by DMOG for patients with diastolic dysfunction associated with coronary

Author contributions

X. He, H. Zeng, R. J. Roman, and JX Chen designed the research; X. He and H. Zeng performed the research and analyzed the data; X. He and JX Chen wrote the paper.

Funding

This study was supported by grants from NIH grant 2R01HL102042-05 and University of Mississippi Medical Center Intramural Research Support Program to J.X. Chen.

Acknowledgments

The authors thank Dr. Eric Verdin at Gladstone Institute of California for providing the original SIRT3flox/flox mice.

Conflicts of interest

The authors have no conflicts of interest associated with this manuscript.

References (57)

  • A.J. Majmundar et al.

    Hypoxia-inducible factors and the response to hypoxic stress

    Mol. Cell

    (2010)
  • P. Hegedus et al.

    Dimethyloxalylglycine treatment of brain-dead donor rats improves both donor and graft left ventricular function after heart transplantation

    J Heart Lung Transplant

    (2016)
  • J. Aragones et al.

    Oxygen sensors at the crossroad of metabolism

    Cell Metab.

    (2009)
  • J.I. Blomster et al.

    Coronary flow reserve as a link between exercise capacity, cardiac systolic and diastolic function

    Int. J. Cardiol.

    (2016)
  • J. Wei et al.

    Diastolic dysfunction measured by cardiac magnetic resonance imaging in women with signs and symptoms of ischemia but no obstructive coronary artery disease

    Int. J. Cardiol.

    (2016)
  • A.V. Zhdanov et al.

    A novel effect of DMOG on cell metabolism: direct inhibition of mitochondrial function precedes HIF target gene expression

    Biochim. Biophys. Acta

    (2015)
  • M.M. Lewinter et al.

    Mechanisms of diastolic dysfunction in heart failure with a preserved ejection fraction: if it's not one thing it's another

    Circ. Heart Fail.

    (2013)
  • A. Dhingra et al.

    Epidemiology of heart failure with preserved ejection fraction

    Curr. Heart Fail. Rep.

    (2014)
  • T.E. Owan et al.

    Trends in prevalence and outcome of heart failure with preserved ejection fraction

    N. Engl. J. Med.

    (2006)
  • S.F. Mohammed et al.

    Coronary microvascular rarefaction and myocardial fibrosis in heart failure with preserved ejection fraction

    Circulation

    (2015)
  • M.M. Redfield et al.

    Burden of systolic and diastolic ventricular dysfunction in the community: appreciating the scope of the heart failure epidemic

    JAMA

    (2003)
  • L. Mandinov et al.

    Diastolic heart failure

    Cardiovasc. Res.

    (2000)
  • G.C. Kane et al.

    Progression of left ventricular diastolic dysfunction and risk of heart failure

    JAMA

    (2011)
  • M.J. Andersen et al.

    Heart failure with preserved ejection fraction: current understandings and challenges

    Curr. Cardiol. Rep.

    (2014)
  • V.B. Pillai et al.

    Mitochondrial SIRT3 and heart disease

    Cardiovasc. Res.

    (2010)
  • S. Winnik et al.

    Protective effects of sirtuins in cardiovascular diseases: from bench to bedside

    Eur. Heart J.

    (2015)
  • F.P. Brouwers et al.

    Incidence and epidemiology of new onset heart failure with preserved vs. reduced ejection fraction in a community-based cohort: 11-year follow-up of PREVEND

    Eur. Heart J.

    (2013)
  • M. Tanno et al.

    Emerging beneficial roles of sirtuins in heart failure

    Basic Res. Cardiol.

    (2012)
  • Cited by (14)

    • Role of sirtuins in cardiovascular diseases

      2021, Sirtuin Biology in Medicine: Targeting New Avenues of Care in Development, Aging, and Disease
    • Altered glucose metabolism and cell function in keloid fibroblasts under hypoxia

      2021, Redox Biology
      Citation Excerpt :

      Accumulating studies have demonstrated hypoxia could significantly affect metabolic phenotype in cancer cells [20,21]. The association of hypoxia or HIF-α with altered metabolism in cardiovascular [22,23] and fibrotic disorders [24] was also reported. Many studies demonstrated that chronic hypoxia triggers signaling pathways that regulate cardiac metabolic remodeling, particularly at the transcriptional level, to maintain energy production.

    View all citing articles on Scopus
    View full text