Activation of NADPH oxidase 4 in the endoplasmic reticulum promotes cardiomyocyte autophagy and survival during energy stress through the protein kinase RNA-activated-like endoplasmic reticulum kinase/eukaryotic initiation factor 2α/activating transcription factor 4 pathway

Sebastiano Sciarretta, Peiyong Zhai, Dan Shao, Daniela Zablocki, Narayani Nagarajan, Lance S. Terada, Massimo Volpe, Junichi Sadoshima

Research output: Contribution to journalArticle

81 Citations (Scopus)

Abstract

RATIONALE: Autophagy is an essential survival mechanism during energy stress in the heart. Oxidative stress is activated by energy stress, but its role in mediating autophagy is poorly understood. NADPH oxidase (Nox) 4 is an enzyme that generates reactive oxygen species (ROS) at intracellular membranes. Whether Nox4 acts as a sensor of energy stress to mediate activation of autophagy is unknown. OBJECTIVE: We investigated whether Nox4 is involved in the regulation of autophagy and cell survival during energy stress in cardiomyocytes. METHODS AND RESULTS: Production of ROS in cardiomyocytes was increased during glucose deprivation (GD) in a Nox4-dependent manner. Protein levels and the ROS-producing activity of Nox4 were increased in the endoplasmic reticulum (ER), but not in mitochondria, in response to GD. Selective knockdown of Nox4, but not Nox2, or selective reduction of ROS in the ER with ER-targeted catalase, but not mitochondria-targeted perioxiredoxin 3, abrogated GD-induced autophagy. Nox4 promoted autophagy during GD through activation of the protein kinase RNA-activated-like ER kinase pathway by suppression of prolyl hydroxylase 4. The decrease in cell survival during GD in the presence of Nox4 knockdown was rescued by reactivation of autophagy by Atg7 overexpression, indicating that the effect of Nox4 on cell survival is critically mediated through regulation of autophagy. Nox4 was activated during fasting and prolonged ischemia in the mouse heart, where Nox4 is also required for autophagy activation and cardioprotection. CONCLUSIONS: Nox4 critically mediates autophagy in response to energy stress in cardiomyocytes by eliciting ROS in the ER and stimulating the protein kinase RNA-activated-like ER kinase signaling pathway.

Original languageEnglish (US)
Pages (from-to)1253-1264
Number of pages12
JournalCirculation Research
Volume113
Issue number11
DOIs
StatePublished - Nov 8 2013

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Activating Transcription Factor 4
Eukaryotic Initiation Factor-2
NADPH Oxidase
Autophagy
Heat-Shock Proteins
Cardiac Myocytes
Endoplasmic Reticulum
Protein Kinases
Phosphotransferases
RNA
Reactive Oxygen Species
Glucose
eIF-2 Kinase
Cell Survival
Mitochondria
Prolyl Hydroxylases
Intracellular Membranes
Catalase
Fasting
Oxidative Stress

Keywords

  • autophagy
  • endoplasmic reticulum
  • fasting
  • myocardial ischemia
  • NOX4 protein
  • reactive oxygen species

ASJC Scopus subject areas

  • Physiology
  • Cardiology and Cardiovascular Medicine

Cite this

Activation of NADPH oxidase 4 in the endoplasmic reticulum promotes cardiomyocyte autophagy and survival during energy stress through the protein kinase RNA-activated-like endoplasmic reticulum kinase/eukaryotic initiation factor 2α/activating transcription factor 4 pathway. / Sciarretta, Sebastiano; Zhai, Peiyong; Shao, Dan; Zablocki, Daniela; Nagarajan, Narayani; Terada, Lance S.; Volpe, Massimo; Sadoshima, Junichi.

In: Circulation Research, Vol. 113, No. 11, 08.11.2013, p. 1253-1264.

Research output: Contribution to journalArticle

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abstract = "RATIONALE: Autophagy is an essential survival mechanism during energy stress in the heart. Oxidative stress is activated by energy stress, but its role in mediating autophagy is poorly understood. NADPH oxidase (Nox) 4 is an enzyme that generates reactive oxygen species (ROS) at intracellular membranes. Whether Nox4 acts as a sensor of energy stress to mediate activation of autophagy is unknown. OBJECTIVE: We investigated whether Nox4 is involved in the regulation of autophagy and cell survival during energy stress in cardiomyocytes. METHODS AND RESULTS: Production of ROS in cardiomyocytes was increased during glucose deprivation (GD) in a Nox4-dependent manner. Protein levels and the ROS-producing activity of Nox4 were increased in the endoplasmic reticulum (ER), but not in mitochondria, in response to GD. Selective knockdown of Nox4, but not Nox2, or selective reduction of ROS in the ER with ER-targeted catalase, but not mitochondria-targeted perioxiredoxin 3, abrogated GD-induced autophagy. Nox4 promoted autophagy during GD through activation of the protein kinase RNA-activated-like ER kinase pathway by suppression of prolyl hydroxylase 4. The decrease in cell survival during GD in the presence of Nox4 knockdown was rescued by reactivation of autophagy by Atg7 overexpression, indicating that the effect of Nox4 on cell survival is critically mediated through regulation of autophagy. Nox4 was activated during fasting and prolonged ischemia in the mouse heart, where Nox4 is also required for autophagy activation and cardioprotection. CONCLUSIONS: Nox4 critically mediates autophagy in response to energy stress in cardiomyocytes by eliciting ROS in the ER and stimulating the protein kinase RNA-activated-like ER kinase signaling pathway.",
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author = "Sebastiano Sciarretta and Peiyong Zhai and Dan Shao and Daniela Zablocki and Narayani Nagarajan and Terada, {Lance S.} and Massimo Volpe and Junichi Sadoshima",
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T1 - Activation of NADPH oxidase 4 in the endoplasmic reticulum promotes cardiomyocyte autophagy and survival during energy stress through the protein kinase RNA-activated-like endoplasmic reticulum kinase/eukaryotic initiation factor 2α/activating transcription factor 4 pathway

AU - Sciarretta, Sebastiano

AU - Zhai, Peiyong

AU - Shao, Dan

AU - Zablocki, Daniela

AU - Nagarajan, Narayani

AU - Terada, Lance S.

AU - Volpe, Massimo

AU - Sadoshima, Junichi

PY - 2013/11/8

Y1 - 2013/11/8

N2 - RATIONALE: Autophagy is an essential survival mechanism during energy stress in the heart. Oxidative stress is activated by energy stress, but its role in mediating autophagy is poorly understood. NADPH oxidase (Nox) 4 is an enzyme that generates reactive oxygen species (ROS) at intracellular membranes. Whether Nox4 acts as a sensor of energy stress to mediate activation of autophagy is unknown. OBJECTIVE: We investigated whether Nox4 is involved in the regulation of autophagy and cell survival during energy stress in cardiomyocytes. METHODS AND RESULTS: Production of ROS in cardiomyocytes was increased during glucose deprivation (GD) in a Nox4-dependent manner. Protein levels and the ROS-producing activity of Nox4 were increased in the endoplasmic reticulum (ER), but not in mitochondria, in response to GD. Selective knockdown of Nox4, but not Nox2, or selective reduction of ROS in the ER with ER-targeted catalase, but not mitochondria-targeted perioxiredoxin 3, abrogated GD-induced autophagy. Nox4 promoted autophagy during GD through activation of the protein kinase RNA-activated-like ER kinase pathway by suppression of prolyl hydroxylase 4. The decrease in cell survival during GD in the presence of Nox4 knockdown was rescued by reactivation of autophagy by Atg7 overexpression, indicating that the effect of Nox4 on cell survival is critically mediated through regulation of autophagy. Nox4 was activated during fasting and prolonged ischemia in the mouse heart, where Nox4 is also required for autophagy activation and cardioprotection. CONCLUSIONS: Nox4 critically mediates autophagy in response to energy stress in cardiomyocytes by eliciting ROS in the ER and stimulating the protein kinase RNA-activated-like ER kinase signaling pathway.

AB - RATIONALE: Autophagy is an essential survival mechanism during energy stress in the heart. Oxidative stress is activated by energy stress, but its role in mediating autophagy is poorly understood. NADPH oxidase (Nox) 4 is an enzyme that generates reactive oxygen species (ROS) at intracellular membranes. Whether Nox4 acts as a sensor of energy stress to mediate activation of autophagy is unknown. OBJECTIVE: We investigated whether Nox4 is involved in the regulation of autophagy and cell survival during energy stress in cardiomyocytes. METHODS AND RESULTS: Production of ROS in cardiomyocytes was increased during glucose deprivation (GD) in a Nox4-dependent manner. Protein levels and the ROS-producing activity of Nox4 were increased in the endoplasmic reticulum (ER), but not in mitochondria, in response to GD. Selective knockdown of Nox4, but not Nox2, or selective reduction of ROS in the ER with ER-targeted catalase, but not mitochondria-targeted perioxiredoxin 3, abrogated GD-induced autophagy. Nox4 promoted autophagy during GD through activation of the protein kinase RNA-activated-like ER kinase pathway by suppression of prolyl hydroxylase 4. The decrease in cell survival during GD in the presence of Nox4 knockdown was rescued by reactivation of autophagy by Atg7 overexpression, indicating that the effect of Nox4 on cell survival is critically mediated through regulation of autophagy. Nox4 was activated during fasting and prolonged ischemia in the mouse heart, where Nox4 is also required for autophagy activation and cardioprotection. CONCLUSIONS: Nox4 critically mediates autophagy in response to energy stress in cardiomyocytes by eliciting ROS in the ER and stimulating the protein kinase RNA-activated-like ER kinase signaling pathway.

KW - autophagy

KW - endoplasmic reticulum

KW - fasting

KW - myocardial ischemia

KW - NOX4 protein

KW - reactive oxygen species

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DO - 10.1161/CIRCRESAHA.113.301787

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EP - 1264

JO - Circulation Research

JF - Circulation Research

SN - 0009-7330

IS - 11

ER -