Hexarelin treatment preserves myocardial function and reduces cardiac fibrosis in mouse model of acute myocardial infarction

Hayley McDonald, Jason Peart, Nyoman Kurniawan, Graham Galloway, Simon Royce, Chrishan S. Samuel, Chen Chen

Research output: Contribution to journalArticleResearchpeer-review

Abstract

Ischemic heart disease (IHD) is a leading cause of morbidity and mortality worldwide. Growth hormone secretagogues (GHS) have been shown to improve cardiac function in models of IHD. This study determined whether hexarelin (HEX), a synthetic GHS, preserves cardiac function and morphology in a mouse model of myocardial infarction (MI). MI was induced by ligation of the left descending coronary artery in C57BL/6J mice followed by vehicle (VEH; n = 10) or HEX (0.3 mg/kg/day; n = 11) administration for 21 days. MI‐injured and sham mice (treated with VEH; n = 6 or HEX; n = 5) underwent magnetic resonance imaging for measurement of left ventricular (LV) function, mass and infarct size at 24 h and 14 days post‐MI. MI‐HEX mice displayed a significant improvement (P < 0.05) in LV function compared with MI‐VEH mice after 14 days treatment. A significant decrease in LV mass, interstitial collagen and collagen concentration was demonstrated with chronic HEX treatment (for 21 days), accompanied by a decrease in TGF‐β1 expression, myofibroblast differentiation and an increase in collagen‐degrading MMP‐13 expression levels. Furthermore, heart rate variability analysis demonstrated that HEX treatment shifted the balance of autonomic nervous activity toward a parasympathetic predominance and sympathetic downregulation. This was combined with a HEX‐dependent decrease in troponin‐I, IL‐1β and TNF‐α levels suggestive of amelioration of cardiomyocyte injury. These results demonstrate that GHS may preserve ventricular function, reduce inflammation and favorably remodel the process of fibrotic healing in a mouse model of MI and hold the potential for translational application to patients suffering from MI.
Original languageEnglish
Article numbere13699
Number of pages14
JournalPhysiological Reports
Volume6
Issue number9
DOIs
Publication statusPublished - 13 May 2018

Keywords

  • fibrosis
  • heart failure
  • ischemia
  • myocardial infarction
  • remodeling

Cite this

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title = "Hexarelin treatment preserves myocardial function and reduces cardiac fibrosis in mouse model of acute myocardial infarction",
abstract = "Ischemic heart disease (IHD) is a leading cause of morbidity and mortality worldwide. Growth hormone secretagogues (GHS) have been shown to improve cardiac function in models of IHD. This study determined whether hexarelin (HEX), a synthetic GHS, preserves cardiac function and morphology in a mouse model of myocardial infarction (MI). MI was induced by ligation of the left descending coronary artery in C57BL/6J mice followed by vehicle (VEH; n = 10) or HEX (0.3 mg/kg/day; n = 11) administration for 21 days. MI‐injured and sham mice (treated with VEH; n = 6 or HEX; n = 5) underwent magnetic resonance imaging for measurement of left ventricular (LV) function, mass and infarct size at 24 h and 14 days post‐MI. MI‐HEX mice displayed a significant improvement (P < 0.05) in LV function compared with MI‐VEH mice after 14 days treatment. A significant decrease in LV mass, interstitial collagen and collagen concentration was demonstrated with chronic HEX treatment (for 21 days), accompanied by a decrease in TGF‐β1 expression, myofibroblast differentiation and an increase in collagen‐degrading MMP‐13 expression levels. Furthermore, heart rate variability analysis demonstrated that HEX treatment shifted the balance of autonomic nervous activity toward a parasympathetic predominance and sympathetic downregulation. This was combined with a HEX‐dependent decrease in troponin‐I, IL‐1β and TNF‐α levels suggestive of amelioration of cardiomyocyte injury. These results demonstrate that GHS may preserve ventricular function, reduce inflammation and favorably remodel the process of fibrotic healing in a mouse model of MI and hold the potential for translational application to patients suffering from MI.",
keywords = "fibrosis, heart failure, ischemia, myocardial infarction, remodeling",
author = "Hayley McDonald and Jason Peart and Nyoman Kurniawan and Graham Galloway and Simon Royce and Samuel, {Chrishan S.} and Chen Chen",
year = "2018",
month = "5",
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language = "English",
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Hexarelin treatment preserves myocardial function and reduces cardiac fibrosis in mouse model of acute myocardial infarction. / McDonald, Hayley; Peart, Jason; Kurniawan, Nyoman; Galloway, Graham ; Royce, Simon; Samuel, Chrishan S.; Chen, Chen.

In: Physiological Reports, Vol. 6, No. 9, e13699, 13.05.2018.

Research output: Contribution to journalArticleResearchpeer-review

TY - JOUR

T1 - Hexarelin treatment preserves myocardial function and reduces cardiac fibrosis in mouse model of acute myocardial infarction

AU - McDonald, Hayley

AU - Peart, Jason

AU - Kurniawan, Nyoman

AU - Galloway, Graham

AU - Royce, Simon

AU - Samuel, Chrishan S.

AU - Chen, Chen

PY - 2018/5/13

Y1 - 2018/5/13

N2 - Ischemic heart disease (IHD) is a leading cause of morbidity and mortality worldwide. Growth hormone secretagogues (GHS) have been shown to improve cardiac function in models of IHD. This study determined whether hexarelin (HEX), a synthetic GHS, preserves cardiac function and morphology in a mouse model of myocardial infarction (MI). MI was induced by ligation of the left descending coronary artery in C57BL/6J mice followed by vehicle (VEH; n = 10) or HEX (0.3 mg/kg/day; n = 11) administration for 21 days. MI‐injured and sham mice (treated with VEH; n = 6 or HEX; n = 5) underwent magnetic resonance imaging for measurement of left ventricular (LV) function, mass and infarct size at 24 h and 14 days post‐MI. MI‐HEX mice displayed a significant improvement (P < 0.05) in LV function compared with MI‐VEH mice after 14 days treatment. A significant decrease in LV mass, interstitial collagen and collagen concentration was demonstrated with chronic HEX treatment (for 21 days), accompanied by a decrease in TGF‐β1 expression, myofibroblast differentiation and an increase in collagen‐degrading MMP‐13 expression levels. Furthermore, heart rate variability analysis demonstrated that HEX treatment shifted the balance of autonomic nervous activity toward a parasympathetic predominance and sympathetic downregulation. This was combined with a HEX‐dependent decrease in troponin‐I, IL‐1β and TNF‐α levels suggestive of amelioration of cardiomyocyte injury. These results demonstrate that GHS may preserve ventricular function, reduce inflammation and favorably remodel the process of fibrotic healing in a mouse model of MI and hold the potential for translational application to patients suffering from MI.

AB - Ischemic heart disease (IHD) is a leading cause of morbidity and mortality worldwide. Growth hormone secretagogues (GHS) have been shown to improve cardiac function in models of IHD. This study determined whether hexarelin (HEX), a synthetic GHS, preserves cardiac function and morphology in a mouse model of myocardial infarction (MI). MI was induced by ligation of the left descending coronary artery in C57BL/6J mice followed by vehicle (VEH; n = 10) or HEX (0.3 mg/kg/day; n = 11) administration for 21 days. MI‐injured and sham mice (treated with VEH; n = 6 or HEX; n = 5) underwent magnetic resonance imaging for measurement of left ventricular (LV) function, mass and infarct size at 24 h and 14 days post‐MI. MI‐HEX mice displayed a significant improvement (P < 0.05) in LV function compared with MI‐VEH mice after 14 days treatment. A significant decrease in LV mass, interstitial collagen and collagen concentration was demonstrated with chronic HEX treatment (for 21 days), accompanied by a decrease in TGF‐β1 expression, myofibroblast differentiation and an increase in collagen‐degrading MMP‐13 expression levels. Furthermore, heart rate variability analysis demonstrated that HEX treatment shifted the balance of autonomic nervous activity toward a parasympathetic predominance and sympathetic downregulation. This was combined with a HEX‐dependent decrease in troponin‐I, IL‐1β and TNF‐α levels suggestive of amelioration of cardiomyocyte injury. These results demonstrate that GHS may preserve ventricular function, reduce inflammation and favorably remodel the process of fibrotic healing in a mouse model of MI and hold the potential for translational application to patients suffering from MI.

KW - fibrosis

KW - heart failure

KW - ischemia

KW - myocardial infarction

KW - remodeling

U2 - 10.14814/phy2.13699

DO - 10.14814/phy2.13699

M3 - Article

VL - 6

JO - Physiological Reports

JF - Physiological Reports

SN - 2051-817X

IS - 9

M1 - e13699

ER -