GSK3β Serine 389 Phosphorylation Modulates Cardiomyocyte Hypertrophy and Ischemic Injury

Prior studies show that glycogen synthase kinase 3β (GSK3β) contributes to cardiac ischemic injury and cardiac hypertrophy. GSK3β is constitutionally active and phosphorylation of GSK3β at serine 9 (S9) inactivates the kinase and promotes cellular growth. GSK3β is also phosphorylated at serine 389 (S389), but the significance of this phosphorylation in the heart is not known. We analyzed GSK3β S389 phosphorylation in diseased hearts and utilized overexpression of GSK3β carrying ser→ala mutations at S9 (S9A) and S389 (S389A) to study the biological function of constitutively active GSK3β in primary cardiomyocytes. We found that phosphorylation of GSK3β at S389 was increased in left ventricular samples from patients with dilated cardiomyopathy and ischemic cardiomyopathy, and in hearts of mice subjected to thoracic aortic constriction. Overexpression of either GSK3β S9A or S389A reduced the viability of cardiomyocytes subjected to hypoxia–reoxygenation. Overexpression of double GSK3β mutant (S9A/S389A) further reduced cardiomyocyte viability. Determination of protein synthesis showed that overexpression of GSK3β S389A or GSK3β S9A/S389A increased both basal and agonist-induced cardiomyocyte growth. Mechanistically, GSK3β S389A mutation was associated with activation of mTOR complex 1 signaling. In conclusion, our data suggest that phosphorylation of GSK3β at S389 enhances cardiomyocyte survival and protects from cardiomyocyte hypertrophy.

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PYK2 expression and phosphorylation increases in pressure overload-induced left ventricular hypertrophy

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.00021.2002 ◽

2002 ◽

Vol 283 (2) ◽

pp. H695-H706 ◽

Cited By ~ 36

Author(s):

Allison L. Bayer ◽

Maria C. Heidkamp ◽

Nehu Patel ◽

Michael J. Porter ◽

Steven J. Engman ◽

...

Keyword(s):

Pressure Overload ◽

Left Ventricular ◽

Cellular Growth ◽

Mitogen Activated Protein Kinase ◽

Cardiomyocyte Hypertrophy ◽

Sprague Dawley ◽

Aortic Banding ◽

Tyrosine Kinase 2 ◽

High Degree

Proline-rich tyrosine kinase 2 (PYK2) is a member of the focal adhesion kinase (FAK) family of nonreceptor protein tyrosine kinases. PYK2 has been implicated in linking G protein-coupled receptors to activation of mitogen-activated protein kinase cascades and cellular growth in a variety of cell types. To determine whether PYK2 expression and phosphorylation is altered in left ventricular (LV) myocardium undergoing LV hypertrophy (LVH) and heart failure in vivo, suprarenal abdominal aortic coarctation was performed in 160-g male Sprague-Dawley rats. Immunohistochemistry and Western blotting were performed on LV tissue 1, 8, and 24 wk after aortic banding. Aortic banding produced sustained hypertension and gradually developing LVH. PYK2 levels were increased 1.8 ± 0.2-, 2.7 ± 0.6-, and 2.0 ± 0.2-fold in 1-, 8-, and 24-wk banded animals compared with their respective sham-operated controls. The increase in PYK2 expression was paralleled by an increase in PYK2 phosphorylation, both of which preceded the development of LVH. Immunohistochemistry revealed that enhanced PYK2 expression occurred predominantly in the cardiomyocyte population. Furthermore, there was a high degree of correlation ( R = 0.75; P< 0.001) between the level of PYK2 and the degree of LVH in 24-wk sham and banded animals. In contrast, FAK levels and FAK phosphorylation were not increased before the development of LVH. However, there was a high degree of correlation (R = 0.68; P < 0.001) between the level of FAK and the degree of LVH in 24-wk sham and banded rats. There was also a significant increase in the ratio of phosphospecific anti-FAK to FAK at this time point. These data are consistent with a role for PYK2 in the induction of pressure overload-induced cardiomyocyte hypertrophy, and suggest that PYK2 and FAK have distinctly different roles in LVH progression.

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Modeling heart failure risk in diabetes and kidney disease: limitations and potential applications of transverse aortic constriction in high-fat-fed mice

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.00357.2017 ◽

2018 ◽

Vol 314 (6) ◽

pp. R858-R869 ◽

Cited By ~ 4

Author(s):

Wei Sheng Tan ◽

Thomas P. Mullins ◽

Melanie Flint ◽

Sarah L. Walton ◽

Helle Bielefeldt-Ohmann ◽

...

Keyword(s):

Heart Failure ◽

Kidney Disease ◽

Left Ventricular ◽

Cardiomyocyte Hypertrophy ◽

Transverse Aortic Constriction ◽

High Fat ◽

Aortic Constriction ◽

Failure Risk ◽

Cardiovascular Prognosis ◽

Fat Feeding

There is an increased incidence of heart failure in individuals with diabetes mellitus (DM). The coexistence of kidney disease in DM exacerbates the cardiovascular prognosis. Researchers have attempted to combine the critical features of heart failure, using transverse aortic constriction, with DM in mice, but variable findings have been reported. Furthermore, kidney outcomes have not been assessed in this setting; thus its utility as a model of heart failure in DM and kidney disease is unknown. We generated a mouse model of obesity, hyperglycemia, and mild kidney pathology by feeding male C57BL/6J mice a high-fat diet (HFD). Cardiac pressure overload was surgically induced using transverse aortic constriction (TAC). Normal diet (ND) and sham controls were included. Heart failure risk factors were evident at 8-wk post-TAC, including increased left ventricular mass (+49% in ND and +35% in HFD), cardiomyocyte hypertrophy (+40% in ND and +28% in HFD), and interstitial and perivascular fibrosis (Masson’s trichrome and picrosirius red positivity). High-fat feeding did not exacerbate the TAC-induced cardiac outcomes. At 11 wk post-TAC in a separate mouse cohort, echocardiography revealed reduced left ventricular size and increased left ventricular wall thickness, the latter being evident in ND mice only. Systolic function was preserved in the TAC mice and was similar between ND and HFD. Thus combined high-fat feeding and TAC in mice did not model the increased incidence of heart failure in DM patients. This model, however, may mimic the better cardiovascular prognosis seen in overweight and obese heart failure patients.

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Pressure overload by suprarenal aortic constriction in mice leads to left ventricular hypertrophy without c-Kit expression in cardiomyocytes

Scientific Reports ◽

10.1038/s41598-020-72273-3 ◽

2020 ◽

Vol 10 (1) ◽

Cited By ~ 2

Author(s):

Amy M. Nicks ◽

Scott H. Kesteven ◽

Ming Li ◽

Jianxin Wu ◽

Andrea Y. Chan ◽

...

Keyword(s):

Systolic Dysfunction ◽

Hypertensive Heart Disease ◽

Pressure Overload ◽

Wall Stress ◽

Left Ventricular ◽

Cardiomyocyte Hypertrophy ◽

Wall Thickening ◽

Aortic Constriction ◽

Concentric Hypertrophy ◽

R Ratio

Abstract Animal models of pressure overload are valuable for understanding hypertensive heart disease. We characterised a surgical model of pressure overload-induced hypertrophy in C57BL/6J mice produced by suprarenal aortic constriction (SAC). Compared to sham controls, at one week post-SAC systolic blood pressure was significantly elevated and left ventricular (LV) hypertrophy was evident by a 50% increase in the LV weight-to-tibia length ratio due to cardiomyocyte hypertrophy. As a result, LV end-diastolic wall thickness-to-chamber radius (h/R) ratio increased, consistent with the development of concentric hypertrophy. LV wall thickening was not sufficient to normalise LV wall stress, which also increased, resulting in LV systolic dysfunction with reductions in ejection fraction and fractional shortening, but no evidence of heart failure. Pathological LV remodelling was evident by the re-expression of fetal genes and coronary artery perivascular fibrosis, with ischaemia indicated by enhanced cardiomyocyte Hif1a expression. The expression of stem cell factor receptor, c-Kit, was low basally in cardiomyocytes and did not change following the development of robust hypertrophy, suggesting there is no role for cardiomyocyte c-Kit signalling in pathological LV remodelling following pressure overload.

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Sepiapterin prevents left ventricular hypertrophy and dilatory remodeling induced by pressure overload in rats

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.00417.2015 ◽

2015 ◽

Vol 309 (10) ◽

pp. H1782-H1791 ◽

Cited By ~ 7

Author(s):

Kei Yoshioka ◽

Hajime Otani ◽

Takayuki Shimazu ◽

Masanori Fujita ◽

Toshiji Iwasaka ◽

...

Keyword(s):

Ventricular Hypertrophy ◽

Interstitial Fibrosis ◽

Pressure Overload ◽

Capillary Density ◽

Left Ventricular ◽

Cardiomyocyte Hypertrophy ◽

Salvage Pathway ◽

Aortic Constriction ◽

Beneficial Effects ◽

Lv Remodeling

Uncoupling of nitric oxide (NO) synthase (NOS) has been implicated in left ventricular (LV) hypertrophy (LVH) and dilatory remodeling induced by pressure overload. We investigated whether administration of sepiapterin, a substrate of the salvage pathway of tetrahydrobiopterin synthesis, prevents LVH and dilatory LV remodeling by inhibiting NOS uncoupling and increasing bioavailable NO. Pressure overload was induced in rats by transverse aortic constriction (TAC). Concentric LVH developed during 8 wk after TAC, and dilatory LV remodeling and dysfunction developed between 8 and 16 wk after TAC associated with a decrease in capillary density. Oral administration of sepiapterin or the superoxide/peroxynitrite scavenger N-(2-mercaptopropionyl)-glycine for 8 wk after TAC inhibited oxidative stress, but only sepiapterin increased bioavailable NO and inhibited cardiomyocyte hypertrophy associated with a further increase in capillary density. When sepiapterin was administered between 8 and 16 wk after TAC, cardiomyocyte hypertrophy was regressed and capillary density was restored. This was associated with the inhibition of interstitial fibrosis and dilatory LV remodeling. N-nitro-l-arginine methyl ester abrogated all the beneficial effects of sepiapterin in rats with TAC. These results suggest that sepiapterin prevents concentric LVH and dilatory remodeling after TAC primarily by increasing the bioavailability of NO.

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Sequential alterations in Akt, GSK3β, and calcineurin signalling in the mouse left ventricle after thoracic aortic constriction

Canadian Journal of Physiology and Pharmacology ◽

10.1139/y10-087 ◽

2010 ◽

Vol 88 (11) ◽

pp. 1093-1101 ◽

Cited By ~ 8

Author(s):

Miresta Prévilon ◽

Mylène Pezet ◽

Céline Dachez ◽

Jean-Jacques Mercadier ◽

Patricia Rouet-Benzineb

Keyword(s):

Ventricular Hypertrophy ◽

Glycogen Synthase ◽

Left Ventricular ◽

Glycogen Synthase Kinase 3 ◽

Transverse Aortic Constriction ◽

Aortic Constriction ◽

Biomechanical Stress ◽

Akt Activation ◽

Early Stages ◽

Old Mice

Left ventricular hypertrophy (LVH) is an adaptive response to chronic biomechanical stress that generally progresses to maladaptive hypertrophy and heart failure (HF). We studied the activation of protein kinase B (Akt/PKB), glycogen synthase kinase 3 beta (GSK3β), and calcineurin (Cn) at 3, 7, 15, 30, and 60 days following transverse aortic constriction (TAC) in 4-week-old mice. Following TAC, GSK3β inactivation at day 3 was associated with Akt activation, whereas at days 15 and 30, it appeared to be controlled by other kinases. Moderate nonsignificant Cn activation occurred at the early stages, and peak activation at day 30, concomitant with GSK3β inactivation and overt LVH and HF. At the latest stage (day 60), despite further progression of LVH and HF, Cn activation appeared attenuated. Early stages of LVH were associated with Ca2+-handling protein upregulation, whereas major Cn activation, associated with GSK3β inactivation, appeared to engage maladaptive hypertrophy and progression to HF associated with Ca2+-handling protein downregulation.

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cis-Acting Sequences That Mediate Induction of β-Myosin Heavy Chain Gene Expression During Left Ventricular Hypertrophy due to Aortic Constriction

Circulation ◽

10.1161/01.cir.96.11.3943 ◽

1997 ◽

Vol 96 (11) ◽

pp. 3943-3953 ◽

Cited By ~ 118

Author(s):

Koji Hasegawa ◽

Soo Jin Lee ◽

Shawn M. Jobe ◽

Bruce E. Markham ◽

Richard N. Kitsis

Keyword(s):

Gene Expression ◽

Left Ventricular Hypertrophy ◽

Heavy Chain ◽

Ventricular Hypertrophy ◽

Left Ventricular ◽

Chain Gene ◽

Heavy Chain Gene ◽

Myosin Heavy Chain Gene ◽

Aortic Constriction ◽

Cis Acting

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Hypertrophy-Reduced Autophagy Causes Cardiac Dysfunction by Directly Impacting Cardiomyocyte Contractility

Cells ◽

10.3390/cells10040805 ◽

2021 ◽

Vol 10 (4) ◽

pp. 805

Author(s):

Christiane Ott ◽

Tobias Jung ◽

Sarah Brix ◽

Cathleen John ◽

Iris R. Betz ◽

...

Keyword(s):

Cardiomyocyte Hypertrophy ◽

Aortic Constriction ◽

Cell Contractility ◽

Neonatal Cardiomyocytes ◽

Cardiomyocyte Contractility ◽

Cardioprotective Effects ◽

Modified Proteins ◽

Cardiomyocyte Autophagy

Cardiac remodeling and contractile dysfunction are leading causes in hypertrophy-associated heart failure (HF), increasing with a population’s rising age. A hallmark of aged and diseased hearts is the accumulation of modified proteins caused by an impaired autophagy-lysosomal-pathway. Although, autophagy inducer rapamycin has been described to exert cardioprotective effects, it remains to be shown whether these effects can be attributed to improved cardiomyocyte autophagy and contractility. In vivo hypertrophy was induced by transverse aortic constriction (TAC), with mice receiving daily rapamycin injections beginning six weeks after surgery for four weeks. Echocardiographic analysis demonstrated TAC-induced HF and protein analyses showed abundance of modified proteins in TAC-hearts after 10 weeks, both reduced by rapamycin. In vitro, cardiomyocyte hypertrophy was mimicked by endothelin 1 (ET-1) and autophagy manipulated by silencing Atg5 in neonatal cardiomyocytes. ET-1 and siAtg5 decreased Atg5–Atg12 and LC3-II, increased natriuretic peptides, and decreased amplitude and early phase of contraction in cardiomyocytes, the latter two evaluated using ImageJ macro Myocyter recently developed by us. ET-1 further decreased cell contractility in control but not in siAtg5 cells. In conclusion, ET-1 decreased autophagy and cardiomyocyte contractility, in line with siAtg5-treated cells and the results of TAC-mice demonstrating a crucial role for autophagy in cardiomyocyte contractility and cardiac performance.

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Role of PRAS40 in Akt and mTOR signaling in health and disease

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.00660.2011 ◽

2012 ◽

Vol 302 (12) ◽

pp. E1453-E1460 ◽

Cited By ~ 92

Author(s):

Claudia Wiza ◽

Emmani B. M. Nascimento ◽

D. Margriet Ouwens

Keyword(s):

Mammalian Target Of Rapamycin ◽

Mtor Signaling ◽

Cellular Growth ◽

S6 Kinase ◽

Binding Partners ◽

Health And Disease ◽

Mtor Complex 1 ◽

Mtor Activity

The proline-rich Akt substrate of 40 kDa (PRAS40) acts at the intersection of the Akt- and mammalian target of rapamycin (mTOR)-mediated signaling pathways. The protein kinase mTOR is the catalytic subunit of two distinct signaling complexes, mTOR complex 1 (mTORC1) and mTORC2, that link energy and nutrients to the regulation of cellular growth and energy metabolism. Activation of mTOR in response to nutrients and growth factors results in the phosphorylation of numerous substrates, including the phosphorylations of S6 kinase by mTORC1 and Akt by mTORC2. Alterations in Akt and mTOR activity have been linked to the progression of multiple diseases such as cancer and type 2 diabetes. Although PRAS40 was first reported as substrate for Akt, investigations toward mTOR-binding partners subsequently identified PRAS40 as both component and substrate of mTORC1. Phosphorylation of PRAS40 by Akt and by mTORC1 itself results in dissociation of PRAS40 from mTORC1 and may relieve an inhibitory constraint on mTORC1 activity. Adding to the complexity is that gene silencing studies indicate that PRAS40 is also necessary for the activity of the mTORC1 complex. This review summarizes the regulation and potential function(s) of PRAS40 in the complex Akt- and mTOR-signaling network in health and disease.

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