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Kambis TN, Tofilau HMN, Gawargi FI, Chandra S, Mishra PK. Regulating Polyamine Metabolism by miRNAs in Diabetic Cardiomyopathy. Curr Diab Rep 2021; 21:52. [PMID: 34902085 PMCID: PMC8668854 DOI: 10.1007/s11892-021-01429-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 09/22/2021] [Indexed: 11/08/2022]
Abstract
PURPOSE OF REVIEW Insulin is at the heart of diabetes mellitus (DM). DM alters cardiac metabolism causing cardiomyopathy, ultimately leading to heart failure. Polyamines, organic compounds synthesized by cardiomyocytes, have an insulin-like activity and effect on glucose metabolism, making them metabolites of interest in the DM heart. This review sheds light on the disrupted microRNA network in the DM heart in relation to developing novel therapeutics targeting polyamine biosynthesis to prevent/mitigate diabetic cardiomyopathy. RECENT FINDINGS Polyamines prevent DM-induced upregulation of glucose and ketone body levels similar to insulin. Polyamines also enhance mitochondrial respiration and thereby regulate all major metabolic pathways. Non-coding microRNAs regulate a majority of the biological pathways in our body by modulating gene expression via mRNA degradation or translational repression. However, the role of miRNA in polyamine biosynthesis in the DM heart remains unclear. This review discusses the regulation of polyamine synthesis and metabolism, and its impact on cardiac metabolism and circulating levels of glucose, insulin, and ketone bodies. We provide insights on potential roles of polyamines in diabetic cardiomyopathy and putative miRNAs that could regulate polyamine biosynthesis in the DM heart. Future studies will unravel the regulatory roles these miRNAs play in polyamine biosynthesis and will open new doors in the prevention/treatment of adverse cardiac remodeling in diabetic cardiomyopathy.
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Affiliation(s)
- Tyler N Kambis
- Department of Cellular and Integrative Physiology, University of Nebraska Medical Center, Omaha, NE, 68198, USA
| | | | - Flobater I Gawargi
- Department of Cellular and Integrative Physiology, University of Nebraska Medical Center, Omaha, NE, 68198, USA
| | - Surabhi Chandra
- Department of Biology, University of Nebraska-Kearney, Kearney, NE, 68845, USA
| | - Paras K Mishra
- Department of Cellular and Integrative Physiology, University of Nebraska Medical Center, Omaha, NE, 68198, USA.
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Gavini MP, Mahmood A, Belenchia AM, Beauparlant P, Kumar SA, Ardhanari S, DeMarco VG, Pulakat L. Suppression of Inflammatory Cardiac Cytokine Network in Rats with Untreated Obesity and Pre-Diabetes by AT2 Receptor Agonist NP-6A4. Front Pharmacol 2021; 12:693167. [PMID: 34220518 PMCID: PMC8253363 DOI: 10.3389/fphar.2021.693167] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Accepted: 05/31/2021] [Indexed: 12/13/2022] Open
Abstract
Obesity affects over 42% of the United States population and exacerbates heart disease, the leading cause of death in men and women. Obesity also increases pro-inflammatory cytokines that cause chronic tissue damage to vital organs. The standard-of-care does not sufficiently attenuate these inflammatory sequelae. Angiotensin II receptor AT2R is an anti-inflammatory and cardiovascular protective molecule; however, AT2R agonists are not used in the clinic to treat heart disease. NP-6A4 is a new AT2R peptide agonist with an FDA orphan drug designation for pediatric cardiomyopathy. NP-6A4 increases AT2R expression (mRNA and protein) and nitric oxide generation in human cardiovascular cells. AT2R-antagonist PD123319 and AT2RSiRNA suppress NP-6A4-effects indicating that NP-6A4 acts through AT2R. To determine whether NP-6A4 would mitigate cardiac damage from chronic inflammation induced by untreated obesity, we investigated the effects of 2-weeks NP-6A4 treatment (1.8 mg/kg delivered subcutaneously) on cardiac pathology of male Zucker obese (ZO) rats that display obesity, pre-diabetes and cardiac dysfunction. NP-6A4 attenuated cardiac diastolic and systolic dysfunction, cardiac fibrosis and cardiomyocyte hypertrophy, but increased myocardial capillary density. NP-6A4 treatment suppressed tubulointerstitial injury marker urinary β-NAG, and liver injury marker alkaline phosphatase in serum. These protective effects of NP-6A4 occurred in the presence of obesity, hyperinsulinemia, hyperglycemia, and hyperlipidemia, and without modulating blood pressure. NP-6A4 increased expression of AT2R (consistent with human cells) and cardioprotective erythropoietin (EPO) and Notch1 in ZO rat heart, but suppressed nineteen inflammatory cytokines. Cardiac miRNA profiling and in silico analysis showed that NP-6A4 activated a unique miRNA network that may regulate expression of AT2R, EPO, Notch1 and inflammatory cytokines, and mitigate cardiac pathology. Seventeen pro-inflammatory and pro-fibrotic cytokines that increase during lethal cytokine storms caused by infections such as COVID-19 were among the cytokines suppressed by NP-6A4 treatment in ZO rat heart. Thus, NP-6A4 activates a novel anti-inflammatory network comprised of 21 proteins in the heart that was not reported previously. Since NP-6A4's unique mode of action suppresses pro-inflammatory cytokine network and attenuates myocardial damage, it can be an ideal adjuvant drug with other anti-glycemic, anti-hypertensive, standard-of-care drugs to protect the heart tissues from pro-inflammatory and pro-fibrotic cytokine attack induced by obesity.
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Affiliation(s)
| | - Abuzar Mahmood
- Dalton Cardiovascular Research Center, Columbia, MO, United States.,Department of Medicine, Boston, MA, United States.,Harry S. Truman Memorial VA Hospital, Columbia, MO, United States
| | - Anthony M Belenchia
- Dalton Cardiovascular Research Center, Columbia, MO, United States.,Department of Nutrition and Exercise Physiology, University of Missouri, Columbia, MO, United States
| | - Paige Beauparlant
- Dalton Cardiovascular Research Center, Columbia, MO, United States.,Department of Medicine, Boston, MA, United States.,Department of Nutrition and Exercise Physiology, University of Missouri, Columbia, MO, United States
| | | | | | - Vincent G DeMarco
- Dalton Cardiovascular Research Center, Columbia, MO, United States.,Department of Medicine, Boston, MA, United States.,Harry S. Truman Memorial VA Hospital, Columbia, MO, United States
| | - Lakshmi Pulakat
- Dalton Cardiovascular Research Center, Columbia, MO, United States.,Department of Medicine, Boston, MA, United States.,Harry S. Truman Memorial VA Hospital, Columbia, MO, United States.,Department of Nutrition and Exercise Physiology, University of Missouri, Columbia, MO, United States.,Tufts Medical Center and Department of Medicine, Molecular Cardiology Research Institute, Tufts University School of Medicine, Boston, MA, United States
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3
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Aroor AR, Mummidi S, Lopez-Alvarenga JC, Das N, Habibi J, Jia G, Lastra G, Chandrasekar B, DeMarco VG. Sacubitril/valsartan inhibits obesity-associated diastolic dysfunction through suppression of ventricular-vascular stiffness. Cardiovasc Diabetol 2021; 20:80. [PMID: 33882908 PMCID: PMC8061206 DOI: 10.1186/s12933-021-01270-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Accepted: 04/15/2021] [Indexed: 12/12/2022] Open
Abstract
OBJECTIVE Cardiac diastolic dysfunction (DD) and arterial stiffness are early manifestations of obesity-associated prediabetes, and both serve as risk factors for the development of heart failure with preserved ejection fraction (HFpEF). Since the incidence of DD and arterial stiffness are increasing worldwide due to exponential growth in obesity, an effective treatment is urgently needed to blunt their development and progression. Here we investigated whether the combination of an inhibitor of neprilysin (sacubitril), a natriuretic peptide-degrading enzyme, and an angiotensin II type 1 receptor blocker (valsartan), suppresses DD and arterial stiffness in an animal model of prediabetes more effectively than valsartan monotherapy. METHODS Sixteen-week-old male Zucker Obese rats (ZO; n = 64) were assigned randomly to 4 different groups: Group 1: saline control (ZOC); Group 2: sacubitril/valsartan (sac/val; 68 mg•kg-1•day-1; ZOSV); Group 3: valsartan (31 mg•kg-1•day-1; ZOV) and Group 4: hydralazine, an anti-hypertensive drug (30 mg•kg-1•day-1; ZOH). Six Zucker Lean (ZL) rats that received saline only (Group 5) served as lean controls (ZLC). Drugs were administered daily for 10 weeks by oral gavage. RESULTS Sac/val improved echocardiographic parameters of impaired left ventricular (LV) stiffness in untreated ZO rats, without altering the amount of food consumed or body weight gained. In addition to improving DD, sac/val decreased aortic stiffness and reversed impairment in nitric oxide-induced vascular relaxation in ZO rats. However, sac/val had no impact on LV hypertrophy. Notably, sac/val was more effective than val in ameliorating DD. Although, hydralazine was as effective as sac/val in improving these parameters, it adversely affected LV mass index. Further, cytokine array revealed distinct effects of sac/val, including marked suppression of Notch-1 by both valsartan and sac/val, suggesting that cardiovascular protection afforded by both share some common mechanisms; however, sac/val, but not val, increased IL-4, which is increasingly recognized for its cardiovascular protection, possibly contributing, in part, to more favorable effects of sac/val over val alone in improving obesity-associated DD. CONCLUSIONS These studies suggest that sac/val is superior to val in reversing obesity-associated DD. It is an effective drug combination to blunt progression of asymptomatic DD and vascular stiffness to HFpEF development in a preclinical model of obesity-associated prediabetes.
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Affiliation(s)
- Annayya R Aroor
- Diabetes and Cardiovascular Center, University of Missouri School of Medicine, Columbia, MO, USA
- Division of Endocrinology and Metabolism, Department of Medicine, University of Missouri-Columbia School of Medicine, D110, DC043.0 One Hospital Dr, Columbia, MO, 65212, USA
- Research Service, Harry S. Truman Memorial Veterans Hospital, Columbia, MO, USA
| | - Srinivas Mummidi
- South Texas Diabetes and Obesity Institute, Department of Human Genetics, School of Medicine, University of Texas Rio Grande Valley, Edinburg, TX, USA
| | - Juan Carlos Lopez-Alvarenga
- South Texas Diabetes and Obesity Institute, Department of Human Genetics, School of Medicine, University of Texas Rio Grande Valley, Edinburg, TX, USA
| | - Nitin Das
- Department of Cardiothoracic Surgery, University of Texas Health Science Center, San Antonio, TX, USA
| | - Javad Habibi
- Diabetes and Cardiovascular Center, University of Missouri School of Medicine, Columbia, MO, USA
- Division of Endocrinology and Metabolism, Department of Medicine, University of Missouri-Columbia School of Medicine, D110, DC043.0 One Hospital Dr, Columbia, MO, 65212, USA
- Research Service, Harry S. Truman Memorial Veterans Hospital, Columbia, MO, USA
| | - Guanghong Jia
- Diabetes and Cardiovascular Center, University of Missouri School of Medicine, Columbia, MO, USA
- Division of Endocrinology and Metabolism, Department of Medicine, University of Missouri-Columbia School of Medicine, D110, DC043.0 One Hospital Dr, Columbia, MO, 65212, USA
- Research Service, Harry S. Truman Memorial Veterans Hospital, Columbia, MO, USA
| | - Guido Lastra
- Diabetes and Cardiovascular Center, University of Missouri School of Medicine, Columbia, MO, USA
- Division of Endocrinology and Metabolism, Department of Medicine, University of Missouri-Columbia School of Medicine, D110, DC043.0 One Hospital Dr, Columbia, MO, 65212, USA
- Research Service, Harry S. Truman Memorial Veterans Hospital, Columbia, MO, USA
| | - Bysani Chandrasekar
- Research Service, Harry S. Truman Memorial Veterans Hospital, Columbia, MO, USA.
- Division of Cardiovascular Medicine, Department of Medicine, University of Missouri-Columbia School of Medicine, One Hospital Dr, Columbia, MO, 65212, USA.
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, MO, USA.
- Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, MO, USA.
| | - Vincent G DeMarco
- Diabetes and Cardiovascular Center, University of Missouri School of Medicine, Columbia, MO, USA.
- Division of Endocrinology and Metabolism, Department of Medicine, University of Missouri-Columbia School of Medicine, D110, DC043.0 One Hospital Dr, Columbia, MO, 65212, USA.
- Research Service, Harry S. Truman Memorial Veterans Hospital, Columbia, MO, USA.
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, MO, USA.
- Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, MO, USA.
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Yan LN, Zhang X, Xu F, Fan YY, Ge B, Guo H, Li ZL. Four-microRNA signature for detection of type 2 diabetes. World J Clin Cases 2020; 8:1923-1931. [PMID: 32518782 PMCID: PMC7262691 DOI: 10.12998/wjcc.v8.i10.1923] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 04/02/2020] [Accepted: 04/14/2020] [Indexed: 02/05/2023] Open
Abstract
BACKGROUND Sensitive, novel, and accurate biomarkers for the detection of physiological changes in type 2 diabetes (T2DM) at an early stage are urgently needed.
AIM To build a multi-parameter diagnostic model for the early detection of T2DM.
METHODS MiR-148b, miR-223, miR-130a, and miR-19a levels were detected by real-time polymerase chain reaction in serum of healthy controls, individuals with impaired glucose regulation, and T2DM patients. The diagnostic value of miR-148b, miR-223, miR-130a, and miR-19a, alone or in combination, was analyzed.
RESULTS The area under the curve (AUC) of miR-223, which had the best diagnostic value for discriminating the impaired glucose regulation and T2DM groups, was 0.84, and the sensitivity and specificity were 73.37% and 81.37%, respectively. The AUC of the four-miRNA signature was 0.90, and the sensitivity and specificity were 78.82% and 88.23%, respectively. In the validation set, the AUC was 0.88, and the sensitivity and specificity were 78.36% and 87.63%, respectively.
CONCLUSION In summary, we have built a multi-parameter diagnostic model consisting of miR-148b, miR-223, miR-130a, and miR-19a for the detection of T2DM. It may be a potential tool for the early detection of T2DM.
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Affiliation(s)
- Li-Na Yan
- Department of Endocrinology, Inner Mongolia Baogang Hospital, Baotou 014010, Inner Mongolia Autonomous Region, China
| | - Xin Zhang
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Interventional Therapy Department, Peking University Cancer Hospital and Institute, Beijing 100142, China
| | - Fang Xu
- Department of Endocrinology, Inner Mongolia Baogang Hospital, Baotou 014010, Inner Mongolia Autonomous Region, China
| | - Yuan-Yuan Fan
- Department of Endocrinology, Inner Mongolia Baogang Hospital, Baotou 014010, Inner Mongolia Autonomous Region, China
| | - Biao Ge
- Department of Endocrinology, Inner Mongolia Baogang Hospital, Baotou 014010, Inner Mongolia Autonomous Region, China
| | - Hui Guo
- Department of Endocrinology, Inner Mongolia Baogang Hospital, Baotou 014010, Inner Mongolia Autonomous Region, China
| | - Zi-Ling Li
- Department of Endocrinology, Inner Mongolia Baogang Hospital, Baotou 014010, Inner Mongolia Autonomous Region, China
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Pulakat L, Chen HH. Pro-Senescence and Anti-Senescence Mechanisms of Cardiovascular Aging: Cardiac MicroRNA Regulation of Longevity Drug-Induced Autophagy. Front Pharmacol 2020; 11:774. [PMID: 32528294 PMCID: PMC7264109 DOI: 10.3389/fphar.2020.00774] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Accepted: 05/11/2020] [Indexed: 12/15/2022] Open
Abstract
Chronological aging as well as biological aging accelerated by various pathologies such as diabetes and obesity contribute to cardiovascular aging, and structural and functional tissue damage of the heart and vasculature. Cardiovascular aging in humans is characterized by structural pathologic remodeling including cardiac and vascular fibrosis, hypertrophy, stiffness, micro- and macro-circulatory impairment, left ventricular diastolic dysfunction precipitating heart failure with either reduced or preserved ejection fraction, and cardiovascular cell death. Cellular senescence, an important hallmark of aging, is a critical factor that impairs repair and regeneration of damaged cells in cardiovascular tissues whereas autophagy, an intracellular catabolic process is an essential inherent mechanism that removes senescent cells throughout life time in all tissues. Several recent reviews have highlighted the fact that all longevity treatment paradigms to mitigate progression of aging-related pathologies converge in induction of autophagy, activation of AMP kinase (AMPK) and Sirtuin pathway, and inhibition of mechanistic target of rapamycin (mTOR). These longevity treatments include health style changes such as caloric restriction, and drug treatments using rapamycin, the first FDA-approved longevity drug, as well as other experimental longevity drugs such as metformin, rapamycin, aspirin, and resveratrol. However, in the heart tissue, autophagy induction has to be tightly regulated since evidence show excessive autophagy results in cardiomyopathy and heart failure. Here we discuss emerging evidence for microRNA-mediated tight regulation of autophagy in the heart in response to treatment with rapamycin, and novel approaches to monitor autophagy progression in a temporal manner to diagnose and regulate autophagy induction by longevity treatments.
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Affiliation(s)
- Lakshmi Pulakat
- Molecular Cardiology Research Institute, Tufts Medical Center, Boston, MA, United States.,Department of Medicine, Tufts University School of Medicine, Boston, MA, United States
| | - Howard H Chen
- Molecular Cardiology Research Institute, Tufts Medical Center, Boston, MA, United States.,Department of Medicine, Tufts University School of Medicine, Boston, MA, United States
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Wang X, Wang Q, Li W, Zhang Q, Jiang Y, Guo D, Sun X, Lu W, Li C, Wang Y. TFEB-NF-κB inflammatory signaling axis: a novel therapeutic pathway of Dihydrotanshinone I in doxorubicin-induced cardiotoxicity. JOURNAL OF EXPERIMENTAL & CLINICAL CANCER RESEARCH : CR 2020; 39:93. [PMID: 32448281 PMCID: PMC7245789 DOI: 10.1186/s13046-020-01595-x] [Citation(s) in RCA: 58] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Accepted: 05/11/2020] [Indexed: 02/06/2023]
Abstract
BACKGROUND Doxorubicin is effective in a variety of solid and hematological malignancies. Unfortunately, clinical application of doxorubicin is limited due to a cumulative dose-dependent cardiotoxicity. Dihydrotanshinone I (DHT) is a natural product from Salvia miltiorrhiza Bunge with multiple anti-tumor activity and anti-inflammation effects. However, its anti-doxorubicin-induced cardiotoxicity (DIC) effect, either in vivo or in vitro, has not been elucidated yet. This study aims to explore the anti-inflammation effects of DHT against DIC, and to elucidate the potential regulatory mechanism. METHODS Effects of DHT on DIC were assessed in zebrafish, C57BL/6 mice and H9C2 cardiomyocytes. Echocardiography, histological examination, flow cytometry, immunochemistry and immunofluorescence were utilized to evaluate cardio-protective effects and anti-inflammation effects. mTOR agonist and lentivirus vector carrying GFP-TFEB were applied to explore the regulatory signaling pathway. RESULTS DHT improved cardiac function via inhibiting the activation of M1 macrophages and the excessive release of pro-inflammatory cytokines both in vivo and in vitro. The activation and nuclear localization of NF-κB were suppressed by DHT, and the effect was abolished by mTOR agonist with concomitant reduced expression of nuclear TFEB. Furthermore, reduced expression of nuclear TFEB is accompanied by up-regulated phosphorylation of IKKα/β and NF-κB, while TFEB overexpression reversed these changes. Intriguingly, DHT could upregulate nuclear expression of TFEB and reduce expressions of p-IKKα/β and p-NF-κB. CONCLUSIONS Our results demonstrated that DHT can be applied as a novel cardioprotective compound in the anti-inflammation management of DIC via mTOR-TFEB-NF-κB signaling pathway. The current study implicates TFEB-IKK-NF-κB signaling axis as a previously undescribed, druggable pathway for DIC.
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Affiliation(s)
- Xiaoping Wang
- grid.24695.3c0000 0001 1431 9176School of Life Science, Beijing University of Chinese Medicine, Beijing, 100029 China
| | - Qiyan Wang
- grid.24695.3c0000 0001 1431 9176School of Life Science, Beijing University of Chinese Medicine, Beijing, 100029 China
| | - Weili Li
- grid.24695.3c0000 0001 1431 9176School of Life Science, Beijing University of Chinese Medicine, Beijing, 100029 China
| | - Qian Zhang
- grid.24695.3c0000 0001 1431 9176School of Traditional Chinese Medicine, Beijing University of Chinese Medicine, Beijing, 100029 China
| | - Yanyan Jiang
- grid.24695.3c0000 0001 1431 9176School of Life Science, Beijing University of Chinese Medicine, Beijing, 100029 China
| | - Dongqing Guo
- grid.24695.3c0000 0001 1431 9176School of Life Science, Beijing University of Chinese Medicine, Beijing, 100029 China
| | - Xiaoqian Sun
- grid.24695.3c0000 0001 1431 9176School of Traditional Chinese Medicine, Beijing University of Chinese Medicine, Beijing, 100029 China
| | - Wenji Lu
- grid.24695.3c0000 0001 1431 9176School of Traditional Chinese Medicine, Beijing University of Chinese Medicine, Beijing, 100029 China
| | - Chun Li
- grid.24695.3c0000 0001 1431 9176Modern Research Center for Traditional Chinese Medicine, Beijing University of Chinese Medicine, Beijing, 100029 China
| | - Yong Wang
- grid.24695.3c0000 0001 1431 9176School of Life Science, Beijing University of Chinese Medicine, Beijing, 100029 China ,grid.24695.3c0000 0001 1431 9176School of Traditional Chinese Medicine, Beijing University of Chinese Medicine, Beijing, 100029 China
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Xu X, Kobayashi S, Timm D, Huang Y, Zhao F, Shou W, Liang Q. Enhanced mTOR complex 1 signaling attenuates diabetic cardiac injury in OVE26 mice. FASEB J 2019; 33:12800-12811. [PMID: 31469601 DOI: 10.1096/fj.201901206r] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The protein kinase mechanistic target of rapamycin (mTOR) performs diverse cellular functions through 2 distinct multiprotein complexes, mTOR complex (mTORC)1 and 2. Numerous studies using rapamycin, an mTORC1 inhibitor, have implicated a role for mTORC1 in several types of heart disease. People with diabetes are more susceptible to heart failure. mTORC1 activity is increased in the diabetic heart, but its functional significance remains controversial. To investigate the role of mTORC1 in the diabetic heart, we crossed OVE26 type 1 diabetic mice with transgenic mice expressing a constitutively active mTOR (mTORca) or kinase-dead mTOR (mTORkd) in the heart. The expression of mTORca or mTORkd affected only mTORC1 but not mTORC2 activities, with corresponding changes in the activities of autophagy, a cellular degradation pathway negatively regulated by mTORC1. Diabetic cardiac damage in OVE26 mice was dramatically reduced by mTORca but exacerbated by mTORkd expression as assessed by changes in cardiac function, oxidative stress, and myocyte apoptosis. These findings demonstrated that the enhanced mTORC1 signaling in the OVE26 diabetic heart was an adaptive response that limited cardiac dysfunction, suggesting that manipulations that enhance mTORC1 activity may reduce diabetic cardiac injury, in sharp contrast to the results previously obtained with rapamycin.-Xu, X., Kobayashi, S., Timm, D., Huang, Y., Zhao, F., Shou, W., Liang, Q. Enhanced mTOR complex 1 signaling attenuates diabetic cardiac injury in OVE26 mice.
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Affiliation(s)
- Xianmin Xu
- Sanford Research, Sioux Falls, South Dakota, USA
| | - Satoru Kobayashi
- Department of Biomedical Sciences, New York Institute of Technology College of Osteopathic Medicine, Old Westbury, New York, USA
| | - Derek Timm
- Sanford Research, Sioux Falls, South Dakota, USA
| | - Yuan Huang
- Department of Biomedical Sciences, New York Institute of Technology College of Osteopathic Medicine, Old Westbury, New York, USA
| | - Fengyi Zhao
- Department of Endocrinology, The First Affiliated Hospital of Xi'an Jiaotong University Health Science Center, Xi'an, China
| | - Weinian Shou
- Department of Pediatrics, Riley Heart Center, Herman B. Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Qiangrong Liang
- Department of Biomedical Sciences, New York Institute of Technology College of Osteopathic Medicine, Old Westbury, New York, USA
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