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Khater SI, El-Emam MMA, Abdellatif H, Mostafa M, Khamis T, Soliman RHM, Ahmed HS, Ali SK, Selim HMRM, Alqahtani LS, Habib D, Metwally MMM, Alnakhli AM, Saleh A, Abdelfattah AM, Abdelnour HM, Dowidar MF. Lipid nanoparticles of quercetin (QU-Lip) alleviated pancreatic microenvironment in diabetic male rats: The interplay between oxidative stress - unfolded protein response (UPR) - autophagy, and their regulatory miRNA. Life Sci 2024; 344:122546. [PMID: 38462227 DOI: 10.1016/j.lfs.2024.122546] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2023] [Revised: 02/20/2024] [Accepted: 03/04/2024] [Indexed: 03/12/2024]
Abstract
BACKGROUND Autophagy is a well-preserved mechanism essential in minimizing endoplasmic reticulum stress (ER)-related cell death. Defects in β-cell autophagy have been linked to type 1 diabetes, particularly deficits in the secretion of insulin, boosting ER stress sensitivity and possibly promoting pancreatic β-cell death. Quercetin (QU) is a potent antioxidant and anti-diabetic flavonoid with low bioavailability, and the precise mechanism of its anti-diabetic activity is still unknown. Aim This study aimed to design an improved bioavailable form of QU (liposomes) and examine the impact of its treatment on the alleviation of type 1 diabetes induced by STZ in rats. METHODS Seventy SD rats were allocated into seven equal groups 10 rats of each: control, STZ, STZ + 3-MA, STZ + QU-Lip, and STZ + 3-MA + QU-Lip. Fasting blood glucose, insulin, c-peptide, serum IL-6, TNF-α, pancreatic oxidative stress, TRAF-6, autophagy, endoplasmic reticulum stress (ER stress) markers expression and their regulatory microRNA (miRNA) were performed. As well as, docking analysis for the quercetin, ER stress, and autophagy were done. Finally, the histopathological and immunohistochemical analysis were conducted. SIGNIFICANCE QU-Lip significantly decreased glucose levels, oxidative, and inflammatory markers in the pancreas. It also significantly downregulated the expression of ER stress and upregulated autophagic-related markers. Furthermore, QU-Lip significantly ameliorated the expression of several MicroRNAs, which both control autophagy and ER stress signaling pathways. However, the improvement of STZ-diabetic rats was abolished upon combination with an autophagy inhibitor (3-MA). The findings suggest that QU-Lip has therapeutic promise in treating type 1 diabetes by modulating ER stress and autophagy via an epigenetic mechanism.
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Affiliation(s)
- Safaa I Khater
- Department of Biochemistry and Molecular Biology, Zagazig University, Zagazig 44511, Egypt.
| | | | - Hussein Abdellatif
- Department of Human and Clinical Anatomy, College of Medicine and Health Sciences, Sultan Qaboos University, Muscat, Sultanate of Oman; Human Anatomy and Embryology Department, Faculty of Medicine, Mansoura University, Egypt
| | - Mahmoud Mostafa
- Department of Pharmaceutics, Faculty of Pharmacy, Minia University, Minia 61519, Egypt
| | - Tarek Khamis
- Department of Pharmacology, Faculty of Veterinary Medicine, Zagazig University, Zagazig 44519, Egypt; Laboratory of Biotechnology, Faculty of Veterinary Medicine, Zagazig University, Zagazig 44519, Egypt.
| | | | - Heba S Ahmed
- Department of Clinical Pharmacology, Faculty of Medicine, Zagazig University, Zagazig 44519, Egypt
| | - Sahar K Ali
- Department of Clinical Pharmacology, Faculty of Medicine, Zagazig University, Zagazig 44519, Egypt
| | - Heba Mohammed Refat M Selim
- Department of Pharmaceutical Sciences, Faculty of Pharmacy, AlMaarefa University, Diriyah 13713, Riyadh, Saudi Arabia; Microbiology and Immunology Department, Faculty of Pharmacy (Girls), Al-Azhar University, Cairo 35527, Egypt
| | - Leena S Alqahtani
- Department of Biochemistry, College of Science, University of Jeddah, Jeddah 23445, Saudi Arabia
| | - Doaa Habib
- Department of Biochemistry and Molecular Biology, Zagazig University, Zagazig 44511, Egypt
| | - Mohamed M M Metwally
- Department of Pathology, Faculty of Veterinary Medicine, Zagazig University, Zagazig 44511, Egypt; Department of pathology and clinical pathology, faculty of veterinary medicine, King Salman international University, Ras sidr, Egypt
| | - Anwar M Alnakhli
- Department of Pharmaceutical Sciences, College of Pharmacy, Princess Nourah bint Abdulrahman University, 84428, Riyadh 11671, Saudi Arabia
| | - Asmaa Saleh
- Department of Pharmaceutical Sciences, College of Pharmacy, Princess Nourah bint Abdulrahman University, 84428, Riyadh 11671, Saudi Arabia
| | | | - Hanim M Abdelnour
- Department of Medical Biochemistry and Molecular Biology, Faculty of Medicine, Zagazig University, Zagazig 44519, Egypt
| | - Mohamed F Dowidar
- Department of Biochemistry and Molecular Biology, Zagazig University, Zagazig 44511, Egypt
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Visanji M, Venegas-Pino DE, Werstuck GH. Understanding One Half of the Sex Difference Equation: The Modulatory Effects of Testosterone on Diabetic Cardiomyopathy. THE AMERICAN JOURNAL OF PATHOLOGY 2024; 194:551-561. [PMID: 38061627 DOI: 10.1016/j.ajpath.2023.11.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Revised: 10/31/2023] [Accepted: 11/20/2023] [Indexed: 12/20/2023]
Abstract
Diabetes is a prevalent disease, primarily characterized by high blood sugar (hyperglycemia). Significantly higher rates of myocardial dysfunction have been noted in individuals with diabetes, even in those without coronary artery disease or high blood pressure (hypertension). Numerous molecular mechanisms have been identified through which diabetes contributes to the pathology of diabetic cardiomyopathy, which presents as cardiac hypertrophy and fibrosis. At the cellular level, oxidative stress and inflammation in cardiomyocytes are triggered by hyperglycemia. Although males are generally more likely to develop cardiovascular disease than females, diabetic males are less likely to develop diabetic cardiomyopathy than are diabetic females. One reason for these differences may be the higher levels of serum testosterone in males compared with females. Although testosterone appears to protect against cardiomyocyte oxidative stress and exacerbate hypertrophy, its role in inflammation and fibrosis is much less clear. Additional preclinical and clinical studies will be required to delineate testosterone's effect on the diabetic heart.
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Affiliation(s)
- Mika'il Visanji
- Faculty of Health Sciences, McMaster University, Hamilton, Ontario, Canada
| | | | - Geoff H Werstuck
- Thrombosis and Atherosclerosis Research Institute, Hamilton, Ontario, Canada; Department of Medicine, McMaster University, Hamilton, Ontario, Canada.
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Li X, Yang JY, Hu WZ, Ruan Y, Chen HY, Zhang Q, Zhang Z, Ding ZS. Mitochondria-associated membranes contribution to exercise-mediated alleviation of hepatic insulin resistance: Contrasting high-intensity interval training with moderate-intensity continuous training in a high-fat diet mouse model. J Diabetes 2024; 16:e13540. [PMID: 38599845 PMCID: PMC11006604 DOI: 10.1111/1753-0407.13540] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Revised: 12/18/2023] [Accepted: 02/03/2024] [Indexed: 04/12/2024] Open
Abstract
OBJECTIVE Mitochondria-associated membranes (MAMs) serve pivotal functions in hepatic insulin resistance (IR). Our aim was to explore the potential role of MAMs in mitigating hepatic IR through exercise and to compare the effects of different intensities of exercise on hepatic MAMs formation in high-fat diet (HFD) mice. METHODS Male C57BL/6J mice were fed an HFD and randomly assigned to undergo supervised high-intensity interval training (HIIT) or moderate-intensity continuous training (MICT). IR was evaluated using the serum triglyceride/high-density lipoprotein cholesterol ratio (TG/HDL-C), glucose tolerance test (GTT), and insulin tolerance test (ITT). Hepatic steatosis was observed using hematoxylin-eosin (H&E) and oil red O staining. The phosphatidylinositol 3-kinase/protein kinase B/glycogen synthase kinase 3 beta (PI3K-AKT-GSK3β) signaling pathway was assessed to determine hepatic IR. MAMs were evaluated through immunofluorescence (colocalization of voltage-dependent anion-selective channel 1 [VDAC1] and inositol 1,4,5-triphosphate receptor [IP3R]). RESULTS After 8 weeks on an HFD, there was notable inhibition of the hepatic PI3K/Akt/GSK3β signaling pathway, accompanied by a marked reduction in hepatic IP3R-VDAC1 colocalization levels. Both 8-week HIIT and MICT significantly enhanced the hepatic PI3K/Akt/GSK3β signaling and colocalization levels of IP3R-VDAC1 in HFD mice, with MICT exhibiting a stronger effect on hepatic MAMs formation. Furthermore, the colocalization of hepatic IP3R-VDAC1 positively correlated with the expression levels of phosphorylation of protein kinase B (p-AKT) and phosphorylation of glycogen synthase kinase 3 beta (p-GSK3β), while displaying a negative correlation with serum triglyceride/high-density lipoprotein cholesterol levels. CONCLUSION The reduction in hepatic MAMs formation induced by HFD correlates with the development of hepatic IR. Both HIIT and MICT effectively bolster hepatic MAMs formation in HFD mice, with MICT demonstrating superior efficacy. Thus, MAMs might wield a pivotal role in exercise-induced alleviation of hepatic IR.
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Affiliation(s)
- Xi Li
- Key Laboratory of Adolescent Health Assessment and Exercise Intervention of Ministry of EducationEast China Normal UniversityShanghaiChina
- College of Physical Education & HealthEast China Normal UniversityShanghaiChina
| | - Jun Yang Yang
- Key Laboratory of Adolescent Health Assessment and Exercise Intervention of Ministry of EducationEast China Normal UniversityShanghaiChina
- College of Physical Education & HealthEast China Normal UniversityShanghaiChina
| | - Wen Zhi Hu
- Key Laboratory of Adolescent Health Assessment and Exercise Intervention of Ministry of EducationEast China Normal UniversityShanghaiChina
- College of Physical Education & HealthEast China Normal UniversityShanghaiChina
| | - YuXin Ruan
- Key Laboratory of Adolescent Health Assessment and Exercise Intervention of Ministry of EducationEast China Normal UniversityShanghaiChina
- College of Physical Education & HealthEast China Normal UniversityShanghaiChina
| | - Hong Ying Chen
- Key Laboratory of Adolescent Health Assessment and Exercise Intervention of Ministry of EducationEast China Normal UniversityShanghaiChina
- College of Physical Education & HealthEast China Normal UniversityShanghaiChina
| | - Qiang Zhang
- Key Laboratory of Adolescent Health Assessment and Exercise Intervention of Ministry of EducationEast China Normal UniversityShanghaiChina
- College of Physical Education & HealthEast China Normal UniversityShanghaiChina
| | - Zhe Zhang
- Key Laboratory of Adolescent Health Assessment and Exercise Intervention of Ministry of EducationEast China Normal UniversityShanghaiChina
- College of Physical Education & HealthEast China Normal UniversityShanghaiChina
| | - Zhe Shu Ding
- Key Laboratory of Adolescent Health Assessment and Exercise Intervention of Ministry of EducationEast China Normal UniversityShanghaiChina
- College of Physical Education & HealthEast China Normal UniversityShanghaiChina
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Saha S, Fang X, Green CD, Das A. mTORC1 and SGLT2 Inhibitors-A Therapeutic Perspective for Diabetic Cardiomyopathy. Int J Mol Sci 2023; 24:15078. [PMID: 37894760 PMCID: PMC10606418 DOI: 10.3390/ijms242015078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Revised: 09/27/2023] [Accepted: 10/04/2023] [Indexed: 10/29/2023] Open
Abstract
Diabetic cardiomyopathy is a critical diabetes-mediated co-morbidity characterized by cardiac dysfunction and heart failure, without predisposing hypertensive or atherosclerotic conditions. Metabolic insulin resistance, promoting hyperglycemia and hyperlipidemia, is the primary cause of diabetes-related disorders, but ambiguous tissue-specific insulin sensitivity has shed light on the importance of identifying a unified target paradigm for both the glycemic and non-glycemic context of type 2 diabetes (T2D). Several studies have indicated hyperactivation of the mammalian target of rapamycin (mTOR), specifically complex 1 (mTORC1), as a critical mediator of T2D pathophysiology by promoting insulin resistance, hyperlipidemia, inflammation, vasoconstriction, and stress. Moreover, mTORC1 inhibitors like rapamycin and their analogs have shown significant benefits in diabetes and related cardiac dysfunction. Recently, FDA-approved anti-hyperglycemic sodium-glucose co-transporter 2 inhibitors (SGLT2is) have gained therapeutic popularity for T2D and diabetic cardiomyopathy, even acknowledging the absence of SGLT2 channels in the heart. Recent studies have proposed SGLT2-independent drug mechanisms to ascertain their cardioprotective benefits by regulating sodium homeostasis and mimicking energy deprivation. In this review, we systematically discuss the role of mTORC1 as a unified, eminent target to treat T2D-mediated cardiac dysfunction and scrutinize whether SGLT2is can target mTORC1 signaling to benefit patients with diabetic cardiomyopathy. Further studies are warranted to establish the underlying cardioprotective mechanisms of SGLT2is under diabetic conditions, with selective inhibition of cardiac mTORC1 but the concomitant activation of mTORC2 (mTOR complex 2) signaling.
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Affiliation(s)
- Sumit Saha
- Department of Biochemistry and Molecular Biology, Virginia Commonwealth University, Richmond, VA 23298, USA; (S.S.); (X.F.); (C.D.G.)
| | - Xianjun Fang
- Department of Biochemistry and Molecular Biology, Virginia Commonwealth University, Richmond, VA 23298, USA; (S.S.); (X.F.); (C.D.G.)
| | - Christopher D. Green
- Department of Biochemistry and Molecular Biology, Virginia Commonwealth University, Richmond, VA 23298, USA; (S.S.); (X.F.); (C.D.G.)
| | - Anindita Das
- Division of Cardiology, Pauley Heart Center, Department of Internal Medicine, Virginia Commonwealth University, Richmond, VA 23298, USA
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Hang T, Lumpuy-Castillo J, Goikoetxea-Usandizaga N, Azkargorta M, Aldámiz G, Martínez-Milla J, Forteza A, Cortina JM, Egido J, Elortza F, Martínez-Chantar M, Tuñón J, Lorenzo Ó. Potential Role of the mTORC1-PGC1α-PPARα Axis under Type-II Diabetes and Hypertension in the Human Heart. Int J Mol Sci 2023; 24:ijms24108629. [PMID: 37239977 DOI: 10.3390/ijms24108629] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 05/04/2023] [Accepted: 05/09/2023] [Indexed: 05/28/2023] Open
Abstract
Type-2 diabetes (T2DM) and arterial hypertension (HTN) are major risk factors for heart failure. Importantly, these pathologies could induce synergetic alterations in the heart, and the discovery of key common molecular signaling may suggest new targets for therapy. Intraoperative cardiac biopsies were obtained from patients with coronary heart disease and preserved systolic function, with or without HTN and/or T2DM, who underwent coronary artery bypass grafting (CABG). Control (n = 5), HTN (n = 7), and HTN + T2DM (n = 7) samples were analysed by proteomics and bioinformatics. Additionally, cultured rat cardiomyocytes were used for the analysis (protein level and activation, mRNA expression, and bioenergetic performance) of key molecular mediators under stimulation of main components of HTN and T2DM (high glucose and/or fatty acids and angiotensin-II). As results, in cardiac biopsies, we found significant alterations of 677 proteins and after filtering for non-cardiac factors, 529 and 41 were changed in HTN-T2DM and in HTN subjects, respectively, against the control. Interestingly, 81% of proteins in HTN-T2DM were distinct from HTN, while 95% from HTN were common with HTN-T2DM. In addition, 78 factors were differentially expressed in HTN-T2DM against HTN, predominantly downregulated proteins of mitochondrial respiration and lipid oxidation. Bioinformatic analyses suggested the implication of mTOR signaling and reduction of AMPK and PPARα activation, and regulation of PGC1α, fatty acid oxidation, and oxidative phosphorylation. In cultured cardiomyocytes, an excess of the palmitate activated mTORC1 complex and subsequent attenuation of PGC1α-PPARα transcription of β-oxidation and mitochondrial electron chain factors affect mitochondrial/glycolytic ATP synthesis. Silencing of PGC1α further reduced total ATP and both mitochondrial and glycolytic ATP. Thus, the coexistence of HTN and T2DM induced higher alterations in cardiac proteins than HTN. HTN-T2DM subjects exhibited a marked downregulation of mitochondrial respiration and lipid metabolism and the mTORC1-PGC1α-PPARα axis might account as a target for therapeutical strategies.
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Affiliation(s)
- Tianyu Hang
- Laboratory of Diabetes and Vascular Pathology, IIS-Fundación Jiménez Díaz, Universidad Autónoma, 28040 Madrid, Spain
- Biomedical Research Network on Diabetes and Associated Metabolic Disorders (CIBERDEM), Carlos III National Health Institute, 28029 Madrid, Spain
| | - Jairo Lumpuy-Castillo
- Laboratory of Diabetes and Vascular Pathology, IIS-Fundación Jiménez Díaz, Universidad Autónoma, 28040 Madrid, Spain
- Biomedical Research Network on Diabetes and Associated Metabolic Disorders (CIBERDEM), Carlos III National Health Institute, 28029 Madrid, Spain
| | - Naroa Goikoetxea-Usandizaga
- Liver Disease Lab, Center for Cooperative Research in Biosciences (CIC bioGUNE), Basque Research and Technology Alliance (BRTA), 48160 Derio, Spain
- Biomedical Research Network on Liver and Digestive Diseases (CIBERehd), Carlos III National Health Institute, 28029 Madrid, Spain
| | - Mikel Azkargorta
- Proteomics Platform, Center for Cooperative Research in Biosciences (CIC bioGUNE), Basque Research and Technology Alliance (BRTA), 48160 Derio, Spain
| | - Gonzalo Aldámiz
- Cardiovascular Surgery Department, Fundación Jiménez Díaz Hospital, 28040 Madrid, Spain
| | | | - Alberto Forteza
- Cardiovascular Surgery Department, Doce de Octubre Hospital, 28041 Madrid, Spain
| | - José M Cortina
- Cardiovascular Surgery Department, Doce de Octubre Hospital, 28041 Madrid, Spain
| | - Jesús Egido
- Laboratory of Diabetes and Vascular Pathology, IIS-Fundación Jiménez Díaz, Universidad Autónoma, 28040 Madrid, Spain
- Biomedical Research Network on Diabetes and Associated Metabolic Disorders (CIBERDEM), Carlos III National Health Institute, 28029 Madrid, Spain
| | - Félix Elortza
- Liver Disease Lab, Center for Cooperative Research in Biosciences (CIC bioGUNE), Basque Research and Technology Alliance (BRTA), 48160 Derio, Spain
| | - Malu Martínez-Chantar
- Liver Disease Lab, Center for Cooperative Research in Biosciences (CIC bioGUNE), Basque Research and Technology Alliance (BRTA), 48160 Derio, Spain
- Biomedical Research Network on Liver and Digestive Diseases (CIBERehd), Carlos III National Health Institute, 28029 Madrid, Spain
| | - José Tuñón
- Cardiology Department, Fundación Jiménez Díaz Hospital, 28040 Madrid, Spain
- Medicine Department, Universidad Autónoma, 28029 Madrid, Spain
- Biomedical Research Network on Cardiovascular Diseases (CIBERCV), Carlos III National Health Institute, 28029 Madrid, Spain
| | - Óscar Lorenzo
- Laboratory of Diabetes and Vascular Pathology, IIS-Fundación Jiménez Díaz, Universidad Autónoma, 28040 Madrid, Spain
- Biomedical Research Network on Diabetes and Associated Metabolic Disorders (CIBERDEM), Carlos III National Health Institute, 28029 Madrid, Spain
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Emerging Therapy for Diabetic Cardiomyopathy: From Molecular Mechanism to Clinical Practice. Biomedicines 2023; 11:biomedicines11030662. [PMID: 36979641 PMCID: PMC10045486 DOI: 10.3390/biomedicines11030662] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 02/08/2023] [Accepted: 02/11/2023] [Indexed: 02/24/2023] Open
Abstract
Diabetic cardiomyopathy is characterized by abnormal myocardial structure or performance in the absence of coronary artery disease or significant valvular heart disease in patients with diabetes mellitus. The spectrum of diabetic cardiomyopathy ranges from subtle myocardial changes to myocardial fibrosis and diastolic function and finally to symptomatic heart failure. Except for sodium–glucose transport protein 2 inhibitors and possibly bariatric and metabolic surgery, there is currently no specific treatment for this distinct disease entity in patients with diabetes. The molecular mechanism of diabetic cardiomyopathy includes impaired nutrient-sensing signaling, dysregulated autophagy, impaired mitochondrial energetics, altered fuel utilization, oxidative stress and lipid peroxidation, advanced glycation end-products, inflammation, impaired calcium homeostasis, abnormal endothelial function and nitric oxide production, aberrant epidermal growth factor receptor signaling, the activation of the renin–angiotensin–aldosterone system and sympathetic hyperactivity, and extracellular matrix accumulation and fibrosis. Here, we summarize several important emerging treatments for diabetic cardiomyopathy targeting specific molecular mechanisms, with evidence from preclinical studies and clinical trials.
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7
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Role of puerarin in pathological cardiac remodeling: A review. Pharmacol Res 2022; 178:106152. [DOI: 10.1016/j.phrs.2022.106152] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/24/2021] [Revised: 02/28/2022] [Accepted: 03/01/2022] [Indexed: 12/22/2022]
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8
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Gomes KP, Jadli AS, de Almeida LGN, Ballasy NN, Edalat P, Shandilya R, Young D, Belke D, Shearer J, Dufour A, Patel VB. Proteomic Analysis Suggests Altered Mitochondrial Metabolic Profile Associated With Diabetic Cardiomyopathy. Front Cardiovasc Med 2022; 9:791700. [PMID: 35310970 PMCID: PMC8924072 DOI: 10.3389/fcvm.2022.791700] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Accepted: 01/24/2022] [Indexed: 01/04/2023] Open
Abstract
Diabetic cardiomyopathy (DbCM) occurs independently of cardiovascular diseases or hypertension, leading to heart failure and increased risk for death in diabetic patients. To investigate the molecular mechanisms involved in DbCM, we performed a quantitative proteomic profiling analysis in the left ventricle (LV) of type 2 diabetic mice. Six-month-old C57BL/6J-lepr/lepr (db/db) mice exhibited DbCM associated with diastolic dysfunction and cardiac hypertrophy. Using quantitative shotgun proteomic analysis, we identified 53 differentially expressed proteins in the LVs of db/db mice, majorly associated with the regulation of energy metabolism. The subunits of ATP synthase that form the F1 domain, and Cytochrome c1, a catalytic core subunit of the complex III primarily responsible for electron transfer to Cytochrome c, were upregulated in diabetic LVs. Upregulation of these key proteins may represent an adaptive mechanism by diabetic heart, resulting in increased electron transfer and thereby enhancement of mitochondrial ATP production. Conversely, diabetic LVs also showed a decrease in peptide levels of NADH dehydrogenase 1β subcomplex subunit 11, a subunit of complex I that catalyzes the transfer of electrons to ubiquinone. Moreover, the atypical kinase COQ8A, an essential lipid-soluble electron transporter involved in the biosynthesis of ubiquinone, was also downregulated in diabetic LVs. Our study indicates that despite attempts by hearts from diabetic mice to augment mitochondrial ATP energetics, decreased levels of key components of the electron transport chain may contribute to impaired mitochondrial ATP production. Preserved basal mitochondrial respiration along with the markedly reduced maximal respiratory capacity in the LVs of db/db mice corroborate the association between altered mitochondrial metabolic profile and cardiac dysfunction in DbCM.
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Affiliation(s)
- Karina P. Gomes
- Department of Physiology and Pharmacology, Cumming School of Medicine, Calgary, AB, Canada
- Libin Cardiovascular Institute, Calgary, AB, Canada
| | - Anshul S. Jadli
- Department of Physiology and Pharmacology, Cumming School of Medicine, Calgary, AB, Canada
- Libin Cardiovascular Institute, Calgary, AB, Canada
| | - Luiz G. N. de Almeida
- Department of Physiology and Pharmacology, Cumming School of Medicine, Calgary, AB, Canada
- McCaig Institute for Bone and Joint Health, Calgary, AB, Canada
| | - Noura N. Ballasy
- Department of Physiology and Pharmacology, Cumming School of Medicine, Calgary, AB, Canada
- Libin Cardiovascular Institute, Calgary, AB, Canada
| | - Pariya Edalat
- Department of Physiology and Pharmacology, Cumming School of Medicine, Calgary, AB, Canada
- Libin Cardiovascular Institute, Calgary, AB, Canada
| | - Ruchita Shandilya
- Department of Physiology and Pharmacology, Cumming School of Medicine, Calgary, AB, Canada
- Libin Cardiovascular Institute, Calgary, AB, Canada
| | - Daniel Young
- Department of Physiology and Pharmacology, Cumming School of Medicine, Calgary, AB, Canada
- McCaig Institute for Bone and Joint Health, Calgary, AB, Canada
| | - Darrell Belke
- Libin Cardiovascular Institute, Calgary, AB, Canada
- Department of Cardiac Sciences, Cumming School of Medicine, Calgary, AB, Canada
| | - Jane Shearer
- Faculty of Kinesiology, University of Calgary, Calgary, AB, Canada
- Department of Biochemistry and Molecular Biology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Antoine Dufour
- Department of Physiology and Pharmacology, Cumming School of Medicine, Calgary, AB, Canada
- McCaig Institute for Bone and Joint Health, Calgary, AB, Canada
- Faculty of Kinesiology, University of Calgary, Calgary, AB, Canada
- Department of Biochemistry and Molecular Biology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Vaibhav B. Patel
- Department of Physiology and Pharmacology, Cumming School of Medicine, Calgary, AB, Canada
- Libin Cardiovascular Institute, Calgary, AB, Canada
- *Correspondence: Vaibhav B. Patel ;
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Association study between relative expression levels of eight genes and growth rate in Hungarian common carp ( Cyprinus carpio). Saudi J Biol Sci 2022; 29:630-639. [PMID: 35002460 PMCID: PMC8716967 DOI: 10.1016/j.sjbs.2021.09.036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Revised: 09/11/2021] [Accepted: 09/12/2021] [Indexed: 11/20/2022] Open
Abstract
One of the most important issues in improving the competitiveness of the fish production sector is to improve the growth rate of fish. The genetic background to this trait is at present poorly understood. In this study, we compared the relative gene expression levels of the Akt1s1, FGF, GH, IGF1, MSTN, TLR2, TLR4 and TLR5 genes in blood in groups of common carps (Cyprinus carpio), which belonged to different growth types and phenotypes. Fish were divided into groups based on growth rate (normal group: n = 6; slow group: n = 6) and phenotype (scaled group: n = 6; mirror group: n = 6). In the first 18 weeks, we measured significant differences (p < 0.05) between groups in terms of body weight and body length. Over the next 18 weeks, the fish in the slow group showed more intense development. In the same period, the slow group was characterized by lower expression levels for most genes, whereas GH and IGF1 mRNA levels were higher compared to the normal group. We found that phenotype was not a determining factor in differences of relative expression levels of the genes studied.
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Chen H, Sun Y, Zhao H, Qi X, Cui H, Li Q, Ma Y. α-Lactalbumin peptide Asp-Gln-Trp alleviates hepatic insulin resistance and modulates gut microbiota dysbiosis in high-fat diet-induced NAFLD mice. Food Funct 2022; 13:9878-9892. [DOI: 10.1039/d2fo01343f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
α-Lactalbumin peptide Asp-Gln-Trp (DQW) alleviates hepatic insulin resistance via activating the IRS1/PI3K/AKT pathway and modulates gut microbiota dysbiosis in high-fat diet-induced NAFLD mice.
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Affiliation(s)
- Haoran Chen
- School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin, 150001, Heilongjiang, China
| | - Yue Sun
- School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin, 150001, Heilongjiang, China
| | - Haiding Zhao
- School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin, 150001, Heilongjiang, China
| | - Xiaofen Qi
- School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin, 150001, Heilongjiang, China
| | - Hui Cui
- School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin, 150001, Heilongjiang, China
| | - Qiming Li
- New Hope Dairy Co, Ltd, Chengdu, 610063, Sichuan, China
- Dairy Nutrition and Function, Key Laboratory of Sichuan Province, Chengdu, 610000, Sichuan, China
| | - Ying Ma
- School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin, 150001, Heilongjiang, China
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Energy metabolism homeostasis in cardiovascular diseases. JOURNAL OF GERIATRIC CARDIOLOGY : JGC 2021; 18:1044-1057. [PMID: 35136399 PMCID: PMC8782763 DOI: 10.11909/j.issn.1671-5411.2021.12.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Cardiovascular disease (CVD) is the leading cause of morbidity and mortality in the general population. Energy metabolism disturbance is one of the early abnormalities in CVDs, such as coronary heart disease, diabetic cardiomyopathy, and heart failure. To explore the role of myocardial energy homeostasis disturbance in CVDs, it is important to understand myocardial metabolism in the normal heart and their function in the complex pathophysiology of CVDs. In this article, we summarized lipid metabolism/lipotoxicity and glucose metabolism/insulin resistance in the heart, focused on the metabolic regulation during neonatal and ageing heart, proposed potential metabolic mechanisms for cardiac regeneration and degeneration. We provided an overview of emerging molecular network among cardiac proliferation, regeneration, and metabolic disturbance. These novel targets promise a new era for the treatment of CVDs.
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12
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Mao S, Chen P, Pan W, Gao L, Zhang M. Exacerbated post-infarct pathological myocardial remodelling in diabetes is associated with impaired autophagy and aggravated NLRP3 inflammasome activation. ESC Heart Fail 2021; 9:303-317. [PMID: 34964299 PMCID: PMC8787965 DOI: 10.1002/ehf2.13754] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 10/28/2021] [Accepted: 11/24/2021] [Indexed: 01/14/2023] Open
Abstract
Background Diabetes mellitus (DM) patients surviving myocardial infarction (MI) have substantially higher mortality due to the more frequent development of subsequent pathological myocardial remodelling and concomitant functional deterioration. This study investigates the molecular pathways underlying accelerated cardiac remodelling in a well‐established mouse model of diabetes exposed to MI. Methods and results Myocardial infarction in DM mice was established by ligating the left anterior descending coronary artery. Cardiac function was assessed by echocardiography. Myocardial hypertrophy and cardiac fibrosis were determined histologically 6 weeks post‐MI or sham operation. Autophagy, the NLRP3 inflammasome, and caspase‐1 were evaluated by western blotting or immunofluorescence. Echocardiographic imaging revealed significantly increased left ventricular dilation in parallel with increased mortality after MI in DM mice (53.33%) compared with control mice (26.67%, P < 0.05). Immunoblotting, electron microscopy, and immunofluorescence staining for LC3 and p62 indicated impaired autophagy in DM + MI mice compared with control mice (P < 0.05). Furthermore, defective autophagy was associated with increased NLRP3 inflammasome and caspase‐1 hyperactivation in DM + MI mouse cardiomyocytes (P < 0.05). Consistent with NLRP3 inflammasome and caspase‐I hyperactivation, cardiomyocyte death and IL‐1β and IL‐18 secretion were increased in DM + MI mice (P < 0.05). Importantly, the autophagy inducer and the NLRP3 inhibitor attenuated the cardiac remodelling of DM mice after MI. Conclusion In summary, our results indicate that DM aggravates cardiac remodelling after MI through defective autophagy and associated exaggerated NLRP3 inflammasome activation, proinflammatory cytokine secretion, suggesting that restoring autophagy and inhibiting NLRP3 inflammasome activation may serve as novel targets for the prevention and treatment of post‐infarct remodelling in DM.
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Affiliation(s)
- Shuai Mao
- Second Clinical College, Guangzhou University of Chinese Medicine, Guangzhou, China.,Department of Critical Care Medicine, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou, 510120, China.,Guangdong Provincial Branch of National Clinical Research Centre for Chinese Medicine Cardiology, Guangzhou, China
| | - Peipei Chen
- Second Clinical College, Guangzhou University of Chinese Medicine, Guangzhou, China.,Department of Critical Care Medicine, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou, 510120, China
| | - Wenjun Pan
- Second Clinical College, Guangzhou University of Chinese Medicine, Guangzhou, China.,Department of Critical Care Medicine, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou, 510120, China
| | - Lei Gao
- Department of Medicine, University of California San Diego, La Jolla, CA, USA
| | - Minzhou Zhang
- Second Clinical College, Guangzhou University of Chinese Medicine, Guangzhou, China.,Department of Critical Care Medicine, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou, 510120, China.,Guangdong Provincial Branch of National Clinical Research Centre for Chinese Medicine Cardiology, Guangzhou, China
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13
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Górska AA, Sandmann C, Riechert E, Hofmann C, Malovrh E, Varma E, Kmietczyk V, Ölschläger J, Jürgensen L, Kamuf-Schenk V, Stroh C, Furkel J, Konstandin MH, Sticht C, Boileau E, Dieterich C, Frey N, Katus HA, Doroudgar S, Völkers M. Muscle-specific Cand2 is translationally upregulated by mTORC1 and promotes adverse cardiac remodeling. EMBO Rep 2021; 22:e52170. [PMID: 34605609 PMCID: PMC8647021 DOI: 10.15252/embr.202052170] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2020] [Revised: 08/26/2021] [Accepted: 09/10/2021] [Indexed: 12/13/2022] Open
Abstract
The mechanistic target of rapamycin (mTOR) promotes pathological remodeling in the heart by activating ribosomal biogenesis and mRNA translation. Inhibition of mTOR in cardiomyocytes is protective; however, a detailed role of mTOR in translational regulation of specific mRNA networks in the diseased heart is unknown. We performed cardiomyocyte genome-wide sequencing to define mTOR-dependent gene expression control at the level of mRNA translation. We identify the muscle-specific protein Cullin-associated NEDD8-dissociated protein 2 (Cand2) as a translationally upregulated gene, dependent on the activity of mTOR. Deletion of Cand2 protects the myocardium against pathological remodeling. Mechanistically, we show that Cand2 links mTOR signaling to pathological cell growth by increasing Grk5 protein expression. Our data suggest that cell-type-specific targeting of mTOR might have therapeutic value against pathological cardiac remodeling.
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Affiliation(s)
- Agnieszka A Górska
- Department of Cardiology, Angiology and Pneumology, University Hospital Heidelberg, Heidelberg, Germany.,DZHK (German Centre for Cardiovascular Research), partner site, Heidelberg/Mannheim, Germany
| | - Clara Sandmann
- Department of Cardiology, Angiology and Pneumology, University Hospital Heidelberg, Heidelberg, Germany.,DZHK (German Centre for Cardiovascular Research), partner site, Heidelberg/Mannheim, Germany
| | - Eva Riechert
- Department of Cardiology, Angiology and Pneumology, University Hospital Heidelberg, Heidelberg, Germany.,DZHK (German Centre for Cardiovascular Research), partner site, Heidelberg/Mannheim, Germany
| | - Christoph Hofmann
- Department of Cardiology, Angiology and Pneumology, University Hospital Heidelberg, Heidelberg, Germany.,DZHK (German Centre for Cardiovascular Research), partner site, Heidelberg/Mannheim, Germany
| | - Ellen Malovrh
- Department of Cardiology, Angiology and Pneumology, University Hospital Heidelberg, Heidelberg, Germany.,DZHK (German Centre for Cardiovascular Research), partner site, Heidelberg/Mannheim, Germany
| | - Eshita Varma
- Department of Cardiology, Angiology and Pneumology, University Hospital Heidelberg, Heidelberg, Germany.,DZHK (German Centre for Cardiovascular Research), partner site, Heidelberg/Mannheim, Germany
| | - Vivien Kmietczyk
- Department of Cardiology, Angiology and Pneumology, University Hospital Heidelberg, Heidelberg, Germany.,DZHK (German Centre for Cardiovascular Research), partner site, Heidelberg/Mannheim, Germany
| | - Julie Ölschläger
- Department of Cardiology, Angiology and Pneumology, University Hospital Heidelberg, Heidelberg, Germany.,DZHK (German Centre for Cardiovascular Research), partner site, Heidelberg/Mannheim, Germany
| | - Lonny Jürgensen
- Department of Cardiology, Angiology and Pneumology, University Hospital Heidelberg, Heidelberg, Germany.,DZHK (German Centre for Cardiovascular Research), partner site, Heidelberg/Mannheim, Germany
| | - Verena Kamuf-Schenk
- Department of Cardiology, Angiology and Pneumology, University Hospital Heidelberg, Heidelberg, Germany.,DZHK (German Centre for Cardiovascular Research), partner site, Heidelberg/Mannheim, Germany
| | - Claudia Stroh
- Department of Cardiology, Angiology and Pneumology, University Hospital Heidelberg, Heidelberg, Germany.,DZHK (German Centre for Cardiovascular Research), partner site, Heidelberg/Mannheim, Germany
| | - Jennifer Furkel
- Department of Cardiology, Angiology and Pneumology, University Hospital Heidelberg, Heidelberg, Germany.,DZHK (German Centre for Cardiovascular Research), partner site, Heidelberg/Mannheim, Germany
| | - Mathias H Konstandin
- Department of Cardiology, Angiology and Pneumology, University Hospital Heidelberg, Heidelberg, Germany.,DZHK (German Centre for Cardiovascular Research), partner site, Heidelberg/Mannheim, Germany
| | - Carsten Sticht
- Medical Research Center, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Etienne Boileau
- Department of Cardiology, Angiology and Pneumology, University Hospital Heidelberg, Heidelberg, Germany.,DZHK (German Centre for Cardiovascular Research), partner site, Heidelberg/Mannheim, Germany.,Section of Bioinformatics and Systems Cardiology, Department of Cardiology, Angiology, and Pneumology and Klaus Tschira Institute for Integrative Computational Cardiology, University of Heidelberg, Heidelberg, Germany
| | - Christoph Dieterich
- Department of Cardiology, Angiology and Pneumology, University Hospital Heidelberg, Heidelberg, Germany.,DZHK (German Centre for Cardiovascular Research), partner site, Heidelberg/Mannheim, Germany.,Section of Bioinformatics and Systems Cardiology, Department of Cardiology, Angiology, and Pneumology and Klaus Tschira Institute for Integrative Computational Cardiology, University of Heidelberg, Heidelberg, Germany
| | - Norbert Frey
- Department of Cardiology, Angiology and Pneumology, University Hospital Heidelberg, Heidelberg, Germany.,DZHK (German Centre for Cardiovascular Research), partner site, Heidelberg/Mannheim, Germany
| | - Hugo A Katus
- Department of Cardiology, Angiology and Pneumology, University Hospital Heidelberg, Heidelberg, Germany.,DZHK (German Centre for Cardiovascular Research), partner site, Heidelberg/Mannheim, Germany
| | - Shirin Doroudgar
- Department of Cardiology, Angiology and Pneumology, University Hospital Heidelberg, Heidelberg, Germany.,DZHK (German Centre for Cardiovascular Research), partner site, Heidelberg/Mannheim, Germany
| | - Mirko Völkers
- Department of Cardiology, Angiology and Pneumology, University Hospital Heidelberg, Heidelberg, Germany.,DZHK (German Centre for Cardiovascular Research), partner site, Heidelberg/Mannheim, Germany
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14
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Bharath LP, Rockhold JD, Conway R. Selective Autophagy in Hyperglycemia-Induced Microvascular and Macrovascular Diseases. Cells 2021; 10:cells10082114. [PMID: 34440882 PMCID: PMC8392047 DOI: 10.3390/cells10082114] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 08/07/2021] [Accepted: 08/13/2021] [Indexed: 02/06/2023] Open
Abstract
Dysregulation of autophagy is an important underlying cause in the onset and progression of many metabolic diseases, including diabetes. Studies in animal models and humans show that impairment in the removal and the recycling of organelles, in particular, contributes to cellular damage, functional failure, and the onset of metabolic diseases. Interestingly, in certain contexts, inhibition of autophagy can be protective. While the inability to upregulate autophagy can play a critical role in the development of diseases, excessive autophagy can also be detrimental, making autophagy an intricately regulated process, the altering of which can adversely affect organismal health. Autophagy is indispensable for maintaining normal cardiac and vascular structure and function. Patients with diabetes are at a higher risk of developing and dying from vascular complications. Autophagy dysregulation is associated with the development of heart failure, many forms of cardiomyopathy, atherosclerosis, myocardial infarction, and microvascular complications in diabetic patients. Here, we review the recent findings on selective autophagy in hyperglycemia and diabetes-associated microvascular and macrovascular complications.
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15
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Zhou Q, Tang S, Zhang X, Chen L. Targeting PRAS40: a novel therapeutic strategy for human diseases. J Drug Target 2021; 29:703-715. [PMID: 33504218 DOI: 10.1080/1061186x.2021.1882470] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Proline-rich Akt substrate of 40 kD (PRAS40) is not only the substrate of protein kinase B (PKB/Akt), but also the binding protein of 14-3-3 protein. PRAS40 is expressed in a variety of tissues in vivo and has multiple phosphorylation sites, which its activity is closely related to phosphorylation. Studies have shown that PRAS40 is involved in regulating cell growth, cell apoptosis, oxidative stress, autophagy and angiogenesis, as well as various of signalling pathways such as mammalian target of mammalian target rapamycin (mTOR), protein kinase B (PKB/Akt), nuclear factor kappa-B(NF-κB), proto-oncogene serine/threonine-protein kinase PIM-1(PIM1) and pyruvate kinase M2 (PKM2). The interactive roles between PRAS40 and these signal proteins were analysed by bioinformatics in this paper. Moreover, it is of great necessity for analyse the important roles of PRAS40 in some human diseases including cardiovascular disease, ischaemia-reperfusion injury, neurodegenerative disease, cancer, diabetes and other metabolic diseases. Finally, the effects of miRNA on the regulation of PRAS40 function and the occurrence and development of PRAS40-related diseases are also discussed. Overall, PRAS40 is expected to be a drug target and provide a new treatment strategy for human diseases.
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Affiliation(s)
- Qun Zhou
- Hunan Province Key Laboratory for Antibody- Based Drug and Intelligent Delivery System, School of Pharmaceutical Sciences, Hunan University of Medicine, Huaihua, China
| | - Shengsong Tang
- Hunan Province Key Laboratory for Antibody- Based Drug and Intelligent Delivery System, School of Pharmaceutical Sciences, Hunan University of Medicine, Huaihua, China
| | - Xianhui Zhang
- Orthopedics Department, Dongkou People's Hospital, Dongkou, China
| | - Linxi Chen
- Hunan Provincial Key Laboratory of Tumor Microenvironment Responsive Drug Research, Hunan Province Cooperative Innovation Center for Molecular Target, New Drug Study, Institute of Pharmacy and Pharmacology, University of South China, Hengyang, China
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16
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Davogustto GE, Salazar RL, Vasquez HG, Karlstaedt A, Dillon WP, Guthrie PH, Martin JR, Vitrac H, De La Guardia G, Vela D, Ribas-Latre A, Baumgartner C, Eckel-Mahan K, Taegtmeyer H. Metabolic remodeling precedes mTORC1-mediated cardiac hypertrophy. J Mol Cell Cardiol 2021; 158:115-127. [PMID: 34081952 DOI: 10.1016/j.yjmcc.2021.05.016] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 05/21/2021] [Accepted: 05/26/2021] [Indexed: 11/17/2022]
Abstract
RATIONALE The nutrient sensing mechanistic target of rapamycin complex 1 (mTORC1) and its primary inhibitor, tuberin (TSC2), are cues for the development of cardiac hypertrophy. The phenotype of mTORC1 induced hypertrophy is unknown. OBJECTIVE To examine the impact of sustained mTORC1 activation on metabolism, function, and structure of the adult heart. METHODS AND RESULTS We developed a mouse model of inducible, cardiac-specific sustained mTORC1 activation (mTORC1iSA) through deletion of Tsc2. Prior to hypertrophy, rates of glucose uptake and oxidation, as well as protein and enzymatic activity of glucose 6-phosphate isomerase (GPI) were decreased, while intracellular levels of glucose 6-phosphate (G6P) were increased. Subsequently, hypertrophy developed. Transcript levels of the fetal gene program and pathways of exercise-induced hypertrophy increased, while hypertrophy did not progress to heart failure. We therefore examined the hearts of wild-type mice subjected to voluntary physical activity and observed early changes in GPI, followed by hypertrophy. Rapamycin prevented these changes in both models. CONCLUSION Activation of mTORC1 in the adult heart triggers the development of a non-specific form of hypertrophy which is preceded by changes in cardiac glucose metabolism.
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Affiliation(s)
- Giovanni E Davogustto
- Division of Cardiology, Department of Internal Medicine, McGovern Medical School at The University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Rebecca L Salazar
- Division of Cardiology, Department of Internal Medicine, McGovern Medical School at The University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Hernan G Vasquez
- Division of Cardiology, Department of Internal Medicine, McGovern Medical School at The University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Anja Karlstaedt
- Division of Cardiology, Department of Internal Medicine, McGovern Medical School at The University of Texas Health Science Center at Houston, Houston, TX, USA
| | - William P Dillon
- Division of Cardiology, Department of Internal Medicine, McGovern Medical School at The University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Patrick H Guthrie
- Division of Cardiology, Department of Internal Medicine, McGovern Medical School at The University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Joseph R Martin
- Division of Cardiology, Department of Internal Medicine, McGovern Medical School at The University of Texas Health Science Center at Houston, Houston, TX, USA
| | | | - Gina De La Guardia
- Division of Cardiology, Department of Internal Medicine, McGovern Medical School at The University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Deborah Vela
- Cardiovascular Pathology Research Laboratory, Texas Heart Institute at CHI St. Luke's Health, and the Department of Pathology and Laboratory Medicine, The University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Aleix Ribas-Latre
- Center for Metabolic and Degenerative Diseases, Institute of Molecular Medicine, The University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Corrine Baumgartner
- Center for Metabolic and Degenerative Diseases, Institute of Molecular Medicine, The University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Kristin Eckel-Mahan
- Center for Metabolic and Degenerative Diseases, Institute of Molecular Medicine, The University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Heinrich Taegtmeyer
- Division of Cardiology, Department of Internal Medicine, McGovern Medical School at The University of Texas Health Science Center at Houston, Houston, TX, USA.
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17
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Packer M. Longevity genes, cardiac ageing, and the pathogenesis of cardiomyopathy: implications for understanding the effects of current and future treatments for heart failure. Eur Heart J 2021; 41:3856-3861. [PMID: 32460327 PMCID: PMC7599035 DOI: 10.1093/eurheartj/ehaa360] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2020] [Revised: 03/26/2020] [Accepted: 04/17/2020] [Indexed: 12/11/2022] Open
Abstract
The two primary molecular regulators of lifespan are sirtuin-1 (SIRT1) and mammalian target of rapamycin complex 1 (mTORC1). Each plays a central role in two highly interconnected pathways that modulate the balance between cellular growth and survival. The activation of SIRT1 [along with peroxisome proliferator-activated receptor-gamma coactivator (PGC-1α) and adenosine monophosphate-activated protein kinase (AMPK)] and the suppression of mTORC1 (along with its upstream regulator, Akt) act to prolong organismal longevity and retard cardiac ageing. Both activation of SIRT1/PGC-1α and inhibition of mTORC1 shifts the balance of cellular priorities so as to promote cardiomyocyte survival over growth, leading to cardioprotective effects in experimental models. These benefits may be related to direct actions to modulate oxidative stress, organellar function, proinflammatory pathways, and maladaptive hypertrophy. In addition, a primary shared benefit of both SIRT1/PGC-1α/AMPK activation and Akt/mTORC1 inhibition is the enhancement of autophagy, a lysosome-dependent degradative pathway, which clears the cytosol of dysfunctional organelles and misfolded proteins that drive the ageing process by increasing oxidative and endoplasmic reticulum stress. Autophagy underlies the ability of SIRT1/PGC-1α/AMPK activation and Akt/mTORC1 suppression to extend lifespan, mitigate cardiac ageing, alleviate cellular stress, and ameliorate the development and progression of cardiomyopathy; silencing of autophagy genes abolishes these benefits. Loss of SIRT1/PGC-1α/AMPK function or hyperactivation of Akt/mTORC1 is a consistent feature of experimental cardiomyopathy, and reversal of these abnormalities mitigates the development of heart failure. Interestingly, most treatments that have been shown to be clinically effective in the treatment of chronic heart failure with a reduced ejection fraction have been reported experimentally to exert favourable effects to activate SIRT1/PGC-1α/AMPK and/or suppress Akt/mTORC1, and thereby, to promote autophagic flux. Therefore, the impairment of autophagy resulting from derangements in longevity gene signalling is likely to represent a seminal event in the evolution and progression of cardiomyopathy. ![]()
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Affiliation(s)
- Milton Packer
- Baylor Heart and Vascular Institute, Baylor University Medical Center, 621 N. Hall Street, Dallas, TX 75226, USA.,Imperial College, London, UK
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18
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Sciarretta S, Forte M, Frati G, Sadoshima J. The complex network of mTOR signaling in the heart. Cardiovasc Res 2021; 118:424-439. [PMID: 33512477 DOI: 10.1093/cvr/cvab033] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Revised: 12/13/2020] [Accepted: 01/26/2021] [Indexed: 12/13/2022] Open
Abstract
The mechanistic target of rapamycin (mTOR) integrates several intracellular and extracellular signals involved in the regulation of anabolic and catabolic processes. mTOR assembles into two macromolecular complexes, named mTORC1 and mTORC2, which have different regulators, substrates and functions. Studies of gain- and loss-of-function animal models of mTOR signaling revealed that mTORC1/2 elicit both adaptive and maladaptive functions in the cardiovascular system. Both mTORC1 and mTORC2 are indispensable for driving cardiac development and cardiac adaption to stress, such as pressure overload. However, persistent and deregulated mTORC1 activation in the heart is detrimental during stress and contributes to the development and progression of cardiac remodeling and genetic and metabolic cardiomyopathies. In this review, we discuss the latest findings regarding the role of mTOR in the cardiovascular system, both under basal conditions and during stress, such as pressure overload, ischemia and metabolic stress. Current data suggest that mTOR modulation may represent a potential therapeutic strategy for the treatment of cardiac diseases.
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Affiliation(s)
- Sebastiano Sciarretta
- Department of Medical and Surgical Sciences and Biotechnologies, Sapienza University of Rome, Latina, Italy.,IRCCS Neuromed, Pozzilli (IS), Italy
| | | | - Giacomo Frati
- Department of Medical and Surgical Sciences and Biotechnologies, Sapienza University of Rome, Latina, Italy.,IRCCS Neuromed, Pozzilli (IS), Italy
| | - Junichi Sadoshima
- Department of Cell Biology and Molecular Medicine, Cardiovascular Research Institute, Rutgers New Jersey Medical School, Newark, NJ, USA
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19
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Samidurai A, Ockaili R, Cain C, Roh SK, Filippone SM, Kraskauskas D, Kukreja RC, Das A. Differential Regulation of mTOR Complexes with miR-302a Attenuates Myocardial Reperfusion Injury in Diabetes. iScience 2020; 23:101863. [PMID: 33319180 PMCID: PMC7725936 DOI: 10.1016/j.isci.2020.101863] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 09/07/2020] [Accepted: 11/20/2020] [Indexed: 01/11/2023] Open
Abstract
Persistent activation of mTOR (mammalian target of rapamycin) in diabetes increases the vulnerability of the heart to ischemia/reperfusion (I/R) injury. We show here that infusion of rapamycin (mTOR inhibitor) at reperfusion following ischemia reduced myocardial infarct size and apoptosis with restoration of cardiac function in type 1 diabetic rabbits. Likewise, treatment with rapamycin protected hyperglycemic human-pluripotent-stem-cells-derived cardiomyocytes (HG-hiPSC-CMs) following simulated ischemia (SI) and reoxygenation (RO). Phosphorylation of S6 (mTORC1 marker) was increased, whereas AKT phosphorylation (mTORC2 marker) and microRNA-302a were reduced with concomitant increase of its target, PTEN, following I/R injury in diabetic heart and HG-hiPSC-CMs. Rapamycin inhibited mTORC1 and PTEN, but augmented mTORC2 with restoration of miRNA-302a under diabetic conditions. Inhibition of miRNA-302a blocked mTORC2 and abolished rapamycin-induced protection against SI/RO injury in HG-hiPSC-CMs. We conclude that rapamycin attenuates reperfusion injury in diabetic heart through inhibition of PTEN and mTORC1 with restoration of miR-302a-mTORC2 signaling. miR-302a and AKT phosphorylation are suppressed in post-ischemic diabetic heart Negative regulator of insulin signaling, PTEN, is induced after ischemia reperfusion miRNA-302a-mimic abolishes ischemic injury in hyperglycemic human iPS cardiocytes Rapamycin treatment restores miR-302a-mTORC2 cardioprotective signaling in diabetes
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Affiliation(s)
- Arun Samidurai
- Division of Cardiology, Pauley Heart Center, Box 980204, Virginia Commonwealth University Medical Center, 1101 East Marshall Street, Sanger Hall, Room 7020d & 7020b, Richmond, VA 23298-0204, USA
| | - Ramzi Ockaili
- Division of Cardiology, Pauley Heart Center, Box 980204, Virginia Commonwealth University Medical Center, 1101 East Marshall Street, Sanger Hall, Room 7020d & 7020b, Richmond, VA 23298-0204, USA
| | - Chad Cain
- Division of Cardiology, Pauley Heart Center, Box 980204, Virginia Commonwealth University Medical Center, 1101 East Marshall Street, Sanger Hall, Room 7020d & 7020b, Richmond, VA 23298-0204, USA
| | - Sean K Roh
- Division of Cardiology, Pauley Heart Center, Box 980204, Virginia Commonwealth University Medical Center, 1101 East Marshall Street, Sanger Hall, Room 7020d & 7020b, Richmond, VA 23298-0204, USA
| | - Scott M Filippone
- Division of Cardiology, Pauley Heart Center, Box 980204, Virginia Commonwealth University Medical Center, 1101 East Marshall Street, Sanger Hall, Room 7020d & 7020b, Richmond, VA 23298-0204, USA
| | - Donatas Kraskauskas
- Division of Cardiology, Pauley Heart Center, Box 980204, Virginia Commonwealth University Medical Center, 1101 East Marshall Street, Sanger Hall, Room 7020d & 7020b, Richmond, VA 23298-0204, USA
| | - Rakesh C Kukreja
- Division of Cardiology, Pauley Heart Center, Box 980204, Virginia Commonwealth University Medical Center, 1101 East Marshall Street, Sanger Hall, Room 7020d & 7020b, Richmond, VA 23298-0204, USA
| | - Anindita Das
- Division of Cardiology, Pauley Heart Center, Box 980204, Virginia Commonwealth University Medical Center, 1101 East Marshall Street, Sanger Hall, Room 7020d & 7020b, Richmond, VA 23298-0204, USA
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20
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Samidurai A, Roh SK, Prakash M, Durrant D, Salloum FN, Kukreja RC, Das A. STAT3-miR-17/20 signalling axis plays a critical role in attenuating myocardial infarction following rapamycin treatment in diabetic mice. Cardiovasc Res 2020; 116:2103-2115. [PMID: 31738412 PMCID: PMC8463091 DOI: 10.1093/cvr/cvz315] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Revised: 10/30/2019] [Accepted: 11/15/2019] [Indexed: 12/12/2022] Open
Abstract
AIMS Deregulation of mTOR (mammalian target of rapamycin) signalling occurs in diabetes, which exacerbates injury following myocardial infarction (MI). We therefore investigated the infarct-limiting effect of chronic treatment with rapamycin (RAPA, mTOR inhibitor) in diabetic mice following myocardial ischaemia/reperfusion (I/R) injury and delineated the potential protective mechanism. METHODS AND RESULTS Adult male diabetic (db/db) or wild-type (WT) (C57) mice were treated with RAPA (0.25 mg/kg/day, intraperitoneal) or vehicle (5% DMSO) for 28 days. The hearts from treated mice were subjected to global I/R in Langendorff mode. Cardiomyocytes, isolated from treated mice, were subjected to simulated ischaemia/reoxygenation (SI/RO) to assess necrosis and apoptosis. Myocardial infarct size was increased in diabetic heart following I/R as compared to WT. Likewise, enhanced necrosis and apoptosis were observed in isolated cardiomyocytes of diabetic mice following SI/RO. Treatment with RAPA reduced infarct size as well as cardiomyocyte necrosis and apoptosis of diabetes and WT mice. RAPA increased STAT3 phosphorylation and miRNA-17/20a expression in diabetic hearts. In addition, RAPA restored AKT phosphorylation (target of mTORC2) but suppressed S6 phosphorylation (target of mTORC1) following I/R injury. RAPA-induced cardioprotection against I/R injury as well as the induction of miR-17/20a and AKT phosphorylation were abolished in cardiac-specific STAT3-deficient diabetic mice, without alteration of S6 phosphorylation. The infarct-limiting effect of RAPA was obliterated in cardiac-specific miRNA-17-92-deficient diabetic mice. The post-I/R restoration of phosphorylation of STAT3 and AKT with RAPA were also abolished in miRNA-17-92-deficient diabetic mice. Additionally, RAPA suppressed the pro-apoptotic prolyl hydroxylase (Egln3/PHD3), a target of miRNA-17/20a in diabetic hearts, which was abrogated in miRNA-17-92-deficient diabetic mice. CONCLUSION Induction of STAT3-miRNA-17-92 signalling axis plays a critical role in attenuating MI in RAPA-treated diabetic mice. Our study indicates that chronic treatment with RAPA might be a promising pharmacological intervention for attenuating MI and improving prognosis in diabetic patients.
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Affiliation(s)
- Arun Samidurai
- Division of Cardiology, Pauley Heart Center, Department of Internal Medicine, Virginia Commonwealth University, 1101 East Marshall Street, Room 7020B, Richmond, VA 23298-0204, USA
| | - Sean K Roh
- Division of Cardiology, Pauley Heart Center, Department of Internal Medicine, Virginia Commonwealth University, 1101 East Marshall Street, Room 7020B, Richmond, VA 23298-0204, USA
| | - Meeta Prakash
- Division of Cardiology, Pauley Heart Center, Department of Internal Medicine, Virginia Commonwealth University, 1101 East Marshall Street, Room 7020B, Richmond, VA 23298-0204, USA
| | - David Durrant
- Division of Cardiology, Pauley Heart Center, Department of Internal Medicine, Virginia Commonwealth University, 1101 East Marshall Street, Room 7020B, Richmond, VA 23298-0204, USA
| | - Fadi N Salloum
- Division of Cardiology, Pauley Heart Center, Department of Internal Medicine, Virginia Commonwealth University, 1101 East Marshall Street, Room 7020B, Richmond, VA 23298-0204, USA
| | - Rakesh C Kukreja
- Division of Cardiology, Pauley Heart Center, Department of Internal Medicine, Virginia Commonwealth University, 1101 East Marshall Street, Room 7020B, Richmond, VA 23298-0204, USA
| | - Anindita Das
- Division of Cardiology, Pauley Heart Center, Department of Internal Medicine, Virginia Commonwealth University, 1101 East Marshall Street, Room 7020B, Richmond, VA 23298-0204, USA
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21
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Aescin Protects Neuron from Ischemia-Reperfusion Injury via Regulating the PRAS40/mTOR Signaling Pathway. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2020; 2020:7815325. [PMID: 33062146 PMCID: PMC7547341 DOI: 10.1155/2020/7815325] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Revised: 08/26/2020] [Accepted: 09/17/2020] [Indexed: 01/18/2023]
Abstract
Ischemic stroke is one of the major causes of disability; widely use of endovascular thrombectomy or intravenous thrombolysis leads to more attention on ischemia-reperfusion injury (I/R injury). Aescin, a natural compound isolated from the seed of the horse chestnut, has been demonstrated anti-inflammatory and antiedematous effects previously. This study was aimed at determining whether aescin could induce protective effects against ischemia-reperfusion injury and exploring the underlying mechanisms in vitro. Primary cultured neurons were subjected to 2 hours of oxygen-glucose deprivation (OGD) followed by 24 hours of simulated reperfusion. Aescin, which worked in a dose-dependent manner, could significantly attenuate neuronal death and reduce lactate dehydrogenase (LDH) release after OGD and simulated reperfusion. Aescin treatment at a concentration of 50 μg/ml provided protection with fewer side effects. Results showed that aescin upregulated the phosphorylation level of PRAS40 and proteins in the mTOR signaling pathway, including S6K and 4E-BP1. However, PRAS40 knockdown or rapamycin treatment was able to undermine and even abolish the protective effects of aescin; meanwhile, the levels of phosphorylation PRAS40 and proteins in the mTOR signaling pathway were obviously decreased. Hence, our study demonstrated that aescin provided neuronal protective effects against I/R injury through the PRAS40/mTOR signaling pathway in vitro. These results might contribute to the potential clinical application of aescin and provide a therapeutic target on subsequent cerebral I/R injury.
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22
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Yang J, Suo H, Song J. Protective role of mitoquinone against impaired mitochondrial homeostasis in metabolic syndrome. Crit Rev Food Sci Nutr 2020; 61:3857-3875. [PMID: 32815398 DOI: 10.1080/10408398.2020.1809344] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Mitochondria control various processes in cellular metabolic homeostasis, such as adenosine triphosphate production, generation and clearance of reactive oxygen species, control of intracellular Ca2+ and apoptosis, and are thus a critical therapeutic target for metabolic syndrome (MetS). The mitochondrial targeted antioxidant mitoquinone (MitoQ) reduces mitochondrial oxidative stress, prevents impaired mitochondrial dynamics, and increases mitochondrial turnover by promoting autophagy (mitophagy) and mitochondrial biogenesis, which ultimately contribute to the attenuation of MetS conditions, including obesity, insulin resistance, hypertension and cardiovascular disease. The regulatory effect of MitoQ on mitochondrial homeostasis is mediated through AMPK and its downstream signaling pathways, including MTOR, SIRT1, Nrf2 and NF-κB. However, there are few reviews focusing on the critical role of MitoQ as a therapeutic agent in the treatment of MetS. The purpose of this review is to summarize the mitochondrial role in the pathogenesis of MetS, especially in obesity and type 2 diabetes, and discuss the effect and underlying mechanism of MitoQ on mitochondrial homeostasis in MetS.
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Affiliation(s)
- Jing Yang
- Chongqing Engineering Research Center for Processing & Storage of Distinct Agricultural Products, Chongqing Technology and Business University, Chongqing, China.,Graduate School, Chongqing Technology and Business University, Chongqing, China
| | - Huayi Suo
- College of Food Science, Southwest University, Chongqing, China
| | - Jiajia Song
- College of Food Science, Southwest University, Chongqing, China
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23
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Packer M. Molecular, Cellular, and Clinical Evidence That Sodium-Glucose Cotransporter 2 Inhibitors Act as Neurohormonal Antagonists When Used for the Treatment of Chronic Heart Failure. J Am Heart Assoc 2020; 9:e016270. [PMID: 32791029 PMCID: PMC7660825 DOI: 10.1161/jaha.120.016270] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Sodium-glucose cotransporter 2 (SGLT2) inhibitors reduce the risk of cardiovascular death and hospitalization for heart failure in patients with chronic heart failure. Initially, these drugs were believed to have a profile similar to diuretics or hemodynamically active drugs, but they do not rapidly reduce natriuretic peptides or cardiac filling pressures, and they exert little early benefit on symptoms, exercise tolerance, quality of life, or signs of congestion. Clinically, the profile of SGLT2 inhibitors resembles that of neurohormonal antagonists, whose benefits emerge gradually during sustained therapy. In experimental models, SGLT2 inhibitors produce a characteristic pattern of cellular effects, which includes amelioration of oxidative stress, mitigation of mitochondrial dysfunction, attenuation of proinflammatory pathways, and a reduction in myocardial fibrosis. These cellular effects are similar to those produced by angiotensin converting enzyme inhibitors, β-blockers, mineralocorticoid receptor antagonists, and neprilysin inhibitors. At a molecular level, SGLT2 inhibitors induce transcriptional reprogramming of cardiomyocytes that closely mimics that seen during nutrient deprivation. This shift in signaling activates the housekeeping pathway of autophagy, which clears the cytosol of dangerous cytosolic constituents that are responsible for cellular stress, thereby ameliorating the development of cardiomyopathy. Interestingly, similar changes in cellular signaling and autophagic flux have been seen with inhibitors of the renin-angiotensin system, β-blockers, mineralocorticoid receptor antagonists, and neprilysin inhibitors. The striking parallelism of these molecular, cellular, and clinical profiles supports the premise that SGLT2 inhibitors should be regarded as neurohormonal antagonists when prescribed for the treatment of heart failure with a reduced ejection fraction.
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Affiliation(s)
- Milton Packer
- Baylor Heart and Vascular InstituteBaylor University Medical CenterDallasTX
- Imperial CollegeLondonUnited Kingdom
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24
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Maity S, Das F, Kasinath BS, Ghosh-Choudhury N, Ghosh Choudhury G. TGFβ acts through PDGFRβ to activate mTORC1 via the Akt/PRAS40 axis and causes glomerular mesangial cell hypertrophy and matrix protein expression. J Biol Chem 2020; 295:14262-14278. [PMID: 32732288 DOI: 10.1074/jbc.ra120.014994] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 07/27/2020] [Indexed: 12/21/2022] Open
Abstract
Interaction of transforming growth factor-β (TGFβ)-induced canonical signaling with the noncanonical kinase cascades regulates glomerular hypertrophy and matrix protein deposition, which are early features of glomerulosclerosis. However, the specific target downstream of the TGFβ receptor involved in the noncanonical signaling is unknown. Here, we show that TGFβ increased the catalytic loop phosphorylation of platelet-derived growth factor receptor β (PDGFRβ), a receptor tyrosine kinase expressed abundantly in glomerular mesangial cells. TGFβ increased phosphorylation of the PI 3-kinase-interacting Tyr-751 residue of PDGFRβ, thus activating Akt. Inhibition of PDGFRβ using a pharmacological inhibitor and siRNAs blocked TGFβ-stimulated phosphorylation of proline-rich Akt substrate of 40 kDa (PRAS40), an intrinsic inhibitory component of mTORC1, and prevented activation of mTORC1 in the absence of any effect on Smad 2/3 phosphorylation. Expression of constitutively active myristoylated Akt reversed the siPDGFRβ-mediated inhibition of mTORC1 activity; however, co-expression of the phospho-deficient mutant of PRAS40 inhibited the effect of myristoylated Akt, suggesting a definitive role of PRAS40 phosphorylation in mTORC1 activation downstream of PDGFRβ in mesangial cells. Additionally, we demonstrate that PDGFRβ-initiated phosphorylation of PRAS40 is required for TGFβ-induced mesangial cell hypertrophy and fibronectin and collagen I (α2) production. Increased activating phosphorylation of PDGFRβ is also associated with enhanced TGFβ expression and mTORC1 activation in the kidney cortex and glomeruli of diabetic mice and rats, respectively. Thus, pursuing TGFβ noncanonical signaling, we identified how TGFβ receptor I achieves mTORC1 activation through PDGFRβ-mediated Akt/PRAS40 phosphorylation to spur mesangial cell hypertrophy and matrix protein accumulation. These findings provide support for targeting PDGFRβ in TGFβ-driven renal fibrosis.
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Affiliation(s)
- Soumya Maity
- Department of Medicine, University of Texas Health Science Center, San Antonio, Texas, USA
| | - Falguni Das
- Department of Medicine, University of Texas Health Science Center, San Antonio, Texas, USA
| | - Balakuntalam S Kasinath
- Department of Medicine, University of Texas Health Science Center, San Antonio, Texas, USA.,Geriatric Research, Education, and Clinical Center, South Texas Veterans Health Care System, San Antonio, Texas, USA
| | | | - Goutam Ghosh Choudhury
- Department of Medicine, University of Texas Health Science Center, San Antonio, Texas, USA .,Department of Veterans Affairs Research, South Texas Veterans Health Care System, San Antonio, Texas, USA.,Geriatric Research, Education, and Clinical Center, South Texas Veterans Health Care System, San Antonio, Texas, USA
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25
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Tu G, Dai C, Qu H, Wang Y, Liao B. Role of exercise and rapamycin on the expression of energy metabolism genes in liver tissues of rats fed a high‑fat diet. Mol Med Rep 2020; 22:2932-2940. [PMID: 32945385 PMCID: PMC7453655 DOI: 10.3892/mmr.2020.11362] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2019] [Accepted: 06/26/2020] [Indexed: 12/19/2022] Open
Abstract
The mTOR pathway serves an important role in the development of insulin resistance induced by obesity. Exercise improves obesity-associated insulin resistance and hepatic energy metabolism; however, the precise mechanism of this process remains unknown. Therefore, the present study investigated the role of rapamycin, an inhibitor of mTOR, on exercise-induced expression of hepatic energy metabolism genes in rats fed a high-fat diet (HFD). A total of 30 male rats were divided into the following groups: Normal group (n=6) fed chow diets and HFD group (n=24) fed an HFD for 6 weeks. The HFD rats performed exercise adaptation for 1 week and were randomly divided into the four following groups (each containing six rats): i) Group of HFD rats with sedentary (H group); ii) group of HFD rats with exercise (HE group); iii) group of HFD rats with rapamycin (HR group); and iv) group of HFD rats with exercise and rapamycin (HER group). Both HE and HER rats were placed on incremental treadmill training for 4 weeks (from week 8–11). Both HR and HER rats were injected with rapamycin intraperitoneally at the dose of 2 mg/kg once a day for 2 weeks (from week 10–11). All rats were sacrificed following a 12–16 h fasting period at the end of week 11. The levels of mitochondrial and oxidative enzyme activities, as well as of the expression of genes involved in energy metabolism were assessed in liver tissues. Biochemical assays and oil red staining were used to assess the content of hepatic triglycerides (TGs). The results indicated that exercise, but not rapamycin, reduced TG content in the liver of HFD rats. Further analysis indicated that rapamycin reduced the activity of cytochrome c oxidase, but not the activities of succinate dehydrogenase and β-hydroxyacyl-CoA dehydrogenase in the liver of HFD rats. Exercise significantly upregulated the mRNA expression of peroxisome proliferator-activated receptor γ coactivator 1 β, while rapamycin exhibited no effect on the mRNA expression levels of hepatic transcription factors associated with energy metabolism enzymes in the liver of HFD rats. Collectively, the results indicated that exercise reduced TG content and upregulated mitochondrial metabolic gene expression in the liver of HFD rats. Moreover, this mechanism may not involve the mTOR pathway.
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Affiliation(s)
- Genghong Tu
- Department of Sports Medicine, Guangzhou Sport University, Guangzhou, Guangdong 510150, P.R. China
| | - Chunyan Dai
- Department of Sports Medicine, Guangzhou Sport University, Guangzhou, Guangdong 510150, P.R. China
| | - Haofei Qu
- Department of Sports Medicine, Guangzhou Sport University, Guangzhou, Guangdong 510150, P.R. China
| | - Yunzhen Wang
- Department of Sports Medicine, Guangzhou Sport University, Guangzhou, Guangdong 510150, P.R. China
| | - Bagen Liao
- Department of Sports Medicine, Guangzhou Sport University, Guangzhou, Guangdong 510150, P.R. China
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26
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Guo W, Qiu W, Ao X, Li W, He X, Ao L, Hu X, Li Z, Zhu M, Luo D, Xing W, Xu X. Low-concentration DMSO accelerates skin wound healing by Akt/mTOR-mediated cell proliferation and migration in diabetic mice. Br J Pharmacol 2020; 177:3327-3341. [PMID: 32167156 DOI: 10.1111/bph.15052] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Revised: 01/09/2020] [Accepted: 01/09/2020] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND AND PURPOSE DMSO has been found to promote tissue repair. However, the role of DMSO in diabetic skin wound healing and the underlying molecular mechanisms are still unclear. EXPERIMENTAL APPROACH The effects of DMSO on wound healing were evaluated by HE staining, immunohistochemistry and collagen staining using a wound model of full-thickness skin resection on the backs of non-diabetic or diabetic mice. Real-time cell analysis and 5-ethynyl-2'-deoxyuridine incorporation assays were used to study the effect of DMSO on primary fibroblast proliferation. A transwell assay was used to investigate keratinocyte migration. The associated signalling pathway was identified by western blotting and inhibitor blocking. The effect of DMSO on the translation rate of downstream target genes was studied by RT-qPCR of polyribosome mRNA. KEY RESULTS We found that low-concentration DMSO significantly accelerated skin wound closure by promoting fibroblast proliferation in both nondiabetic and diabetic mice. In addition, increased migration of keratinocytes may also contribute to accelerated wound healing, which was stimulated by increased TGF-β1 secretion from fibroblasts. Furthermore, we demonstrated that this effect of DMSO depends on Akt/mTOR-mediated translational control and the promotion of the translation of a set of cell proliferation-related genes. As expected, DMSO-induced wound healing and cell proliferation were impaired by rapamycin, an inhibitor of Akt/mTOR signalling. CONCLUSION AND IMPLICATIONS DMSO can promote skin wound healing in diabetic mice by activating the Akt/mTOR pathway. Low-concentration DMSO presents an alternative medication for chronic cutaneous wounds, especially for diabetic patients.
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Affiliation(s)
- Wei Guo
- Department of Stem Cell & Regenerative Medicine.,Central Laboratory, State Key Laboratory of Trauma, Burn and Combined Injury, Daping Hospital, Army Medical University, Chongqing, P.R., China
| | - Wei Qiu
- Department of Stem Cell & Regenerative Medicine.,Central Laboratory, State Key Laboratory of Trauma, Burn and Combined Injury, Daping Hospital, Army Medical University, Chongqing, P.R., China
| | - Xiang Ao
- Department of Stem Cell & Regenerative Medicine.,Central Laboratory, State Key Laboratory of Trauma, Burn and Combined Injury, Daping Hospital, Army Medical University, Chongqing, P.R., China
| | - Weiqiang Li
- Department of Stem Cell & Regenerative Medicine.,Department of Biochemistry and Molecular Biology, College of Basic Medical Sciences, Army Medical University, Chongqing, P.R. China
| | - Xiao He
- Department of Stem Cell & Regenerative Medicine.,Central Laboratory, State Key Laboratory of Trauma, Burn and Combined Injury, Daping Hospital, Army Medical University, Chongqing, P.R., China
| | - Luoquan Ao
- Department of Stem Cell & Regenerative Medicine.,Central Laboratory, State Key Laboratory of Trauma, Burn and Combined Injury, Daping Hospital, Army Medical University, Chongqing, P.R., China
| | - Xueting Hu
- Department of Stem Cell & Regenerative Medicine.,Central Laboratory, State Key Laboratory of Trauma, Burn and Combined Injury, Daping Hospital, Army Medical University, Chongqing, P.R., China
| | - Zhan Li
- Department of Stem Cell & Regenerative Medicine.,Central Laboratory, State Key Laboratory of Trauma, Burn and Combined Injury, Daping Hospital, Army Medical University, Chongqing, P.R., China
| | - Ming Zhu
- Department of Stem Cell & Regenerative Medicine.,Central Laboratory, State Key Laboratory of Trauma, Burn and Combined Injury, Daping Hospital, Army Medical University, Chongqing, P.R., China
| | - Donglin Luo
- Department of General Surgery, Daping Hospital, Army Medical University, Chongqing, P.R. China
| | - Wei Xing
- Department of Stem Cell & Regenerative Medicine.,Central Laboratory, State Key Laboratory of Trauma, Burn and Combined Injury, Daping Hospital, Army Medical University, Chongqing, P.R., China
| | - Xiang Xu
- Department of Stem Cell & Regenerative Medicine.,Central Laboratory, State Key Laboratory of Trauma, Burn and Combined Injury, Daping Hospital, Army Medical University, Chongqing, P.R., China.,Department of Biochemistry and Molecular Biology, College of Basic Medical Sciences, Army Medical University, Chongqing, P.R. China
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27
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Sanlialp A, Schumacher D, Kiper L, Varma E, Riechert E, Ho TC, Hofmann C, Kmietczyk V, Zimmermann F, Dlugosz S, Wirth A, Gorska AA, Burghaus J, Camacho Londoño JE, Katus HA, Doroudgar S, Freichel M, Völkers M. Saraf-dependent activation of mTORC1 regulates cardiac growth. J Mol Cell Cardiol 2020; 141:30-42. [PMID: 32173353 DOI: 10.1016/j.yjmcc.2020.03.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Revised: 03/03/2020] [Accepted: 03/09/2020] [Indexed: 10/24/2022]
Abstract
Pathological cardiac hypertrophy is an independent risk for heart failure (HF) and sudden death. Deciphering signaling pathways regulating intracellular Ca2+ homeostasis that control adaptive and pathological cardiac growth may enable identification of novel therapeutic targets. The objective of the present study is to determine the role of the store-operated calcium entry-associated regulatory factor (Saraf), encoded by the Tmem66 gene, on cardiac growth control in vitro and in vivo. Saraf is a single-pass membrane protein located at the sarco/endoplasmic reticulum and regulates intracellular calcium homeostasis. We found that Saraf expression was upregulated in the hypertrophied myocardium and was sufficient for cell growth in response to neurohumoral stimulation. Increased Saraf expression caused cell growth, which was associated with dysregulation of calcium-dependent signaling and sarcoplasmic reticulum calcium content. In vivo, Saraf augmented cardiac myocyte growth in response to angiotensin II and resulted in increased cardiac remodeling together with worsened cardiac function. Mechanistically, Saraf activated mTORC1 (mechanistic target of rapamycin complex 1) and increased protein synthesis, while mTORC1 inhibition blunted Saraf-dependent cell growth. In contrast, the hearts of Saraf knockout mice and Saraf-deficient myocytes did not show any morphological or functional alterations after neurohumoral stimulation, but Saraf depletion resulted in worsened cardiac function after acute pressure overload. SARAF knockout blunted transverse aortic constriction cardiac myocyte hypertrophy and impaired cardiac function, demonstrating a role for SARAF in compensatory myocyte growth. Collectively, these results reveal a novel link between sarcoplasmic reticulum calcium homeostasis and mTORC1 activation that is regulated by Saraf.
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Affiliation(s)
- Ayse Sanlialp
- Department of Cardiology, Angiology, and Pneumology, University Hospital Heidelberg, University of Heidelberg, Im Neuenheimer Feld 669, 69120 Heidelberg, Germany; DZHK (German Center for Cardiovascular Research), Partner Site Heidelberg/Mannheim, 69120 Heidelberg, Germany
| | - Dagmar Schumacher
- DZHK (German Center for Cardiovascular Research), Partner Site Heidelberg/Mannheim, 69120 Heidelberg, Germany; Institute of Pharmacology, University Hospital Heidelberg, University of Heidelberg, Im Neuenheimer Feld 366, 69120 Heidelberg, Germany
| | - Leon Kiper
- Department of Cardiology, Angiology, and Pneumology, University Hospital Heidelberg, University of Heidelberg, Im Neuenheimer Feld 669, 69120 Heidelberg, Germany; DZHK (German Center for Cardiovascular Research), Partner Site Heidelberg/Mannheim, 69120 Heidelberg, Germany
| | - Eshita Varma
- Department of Cardiology, Angiology, and Pneumology, University Hospital Heidelberg, University of Heidelberg, Im Neuenheimer Feld 669, 69120 Heidelberg, Germany; DZHK (German Center for Cardiovascular Research), Partner Site Heidelberg/Mannheim, 69120 Heidelberg, Germany
| | - Eva Riechert
- Department of Cardiology, Angiology, and Pneumology, University Hospital Heidelberg, University of Heidelberg, Im Neuenheimer Feld 669, 69120 Heidelberg, Germany; DZHK (German Center for Cardiovascular Research), Partner Site Heidelberg/Mannheim, 69120 Heidelberg, Germany
| | - Thanh Cao Ho
- Department of Cardiology, Angiology, and Pneumology, University Hospital Heidelberg, University of Heidelberg, Im Neuenheimer Feld 669, 69120 Heidelberg, Germany; DZHK (German Center for Cardiovascular Research), Partner Site Heidelberg/Mannheim, 69120 Heidelberg, Germany
| | - Christoph Hofmann
- Department of Cardiology, Angiology, and Pneumology, University Hospital Heidelberg, University of Heidelberg, Im Neuenheimer Feld 669, 69120 Heidelberg, Germany; DZHK (German Center for Cardiovascular Research), Partner Site Heidelberg/Mannheim, 69120 Heidelberg, Germany
| | - Vivien Kmietczyk
- Department of Cardiology, Angiology, and Pneumology, University Hospital Heidelberg, University of Heidelberg, Im Neuenheimer Feld 669, 69120 Heidelberg, Germany; DZHK (German Center for Cardiovascular Research), Partner Site Heidelberg/Mannheim, 69120 Heidelberg, Germany
| | - Frank Zimmermann
- Interfacultary Biomedical Faculty (IBF), University of Heidelberg, Im Neuenheimer Feld 347, 69120 Heidelberg, Germany
| | - Sascha Dlugosz
- Interfacultary Biomedical Faculty (IBF), University of Heidelberg, Im Neuenheimer Feld 347, 69120 Heidelberg, Germany
| | - Angela Wirth
- DZHK (German Center for Cardiovascular Research), Partner Site Heidelberg/Mannheim, 69120 Heidelberg, Germany; Institute of Pharmacology, University Hospital Heidelberg, University of Heidelberg, Im Neuenheimer Feld 366, 69120 Heidelberg, Germany
| | - Agnieszka A Gorska
- Department of Cardiology, Angiology, and Pneumology, University Hospital Heidelberg, University of Heidelberg, Im Neuenheimer Feld 669, 69120 Heidelberg, Germany; DZHK (German Center for Cardiovascular Research), Partner Site Heidelberg/Mannheim, 69120 Heidelberg, Germany
| | - Jana Burghaus
- Department of Cardiology, Angiology, and Pneumology, University Hospital Heidelberg, University of Heidelberg, Im Neuenheimer Feld 669, 69120 Heidelberg, Germany; DZHK (German Center for Cardiovascular Research), Partner Site Heidelberg/Mannheim, 69120 Heidelberg, Germany
| | - Juan E Camacho Londoño
- DZHK (German Center for Cardiovascular Research), Partner Site Heidelberg/Mannheim, 69120 Heidelberg, Germany; Institute of Pharmacology, University Hospital Heidelberg, University of Heidelberg, Im Neuenheimer Feld 366, 69120 Heidelberg, Germany
| | - Hugo A Katus
- Department of Cardiology, Angiology, and Pneumology, University Hospital Heidelberg, University of Heidelberg, Im Neuenheimer Feld 669, 69120 Heidelberg, Germany; DZHK (German Center for Cardiovascular Research), Partner Site Heidelberg/Mannheim, 69120 Heidelberg, Germany
| | - Shirin Doroudgar
- Department of Cardiology, Angiology, and Pneumology, University Hospital Heidelberg, University of Heidelberg, Im Neuenheimer Feld 669, 69120 Heidelberg, Germany; DZHK (German Center for Cardiovascular Research), Partner Site Heidelberg/Mannheim, 69120 Heidelberg, Germany
| | - Marc Freichel
- DZHK (German Center for Cardiovascular Research), Partner Site Heidelberg/Mannheim, 69120 Heidelberg, Germany; Institute of Pharmacology, University Hospital Heidelberg, University of Heidelberg, Im Neuenheimer Feld 366, 69120 Heidelberg, Germany
| | - Mirko Völkers
- Department of Cardiology, Angiology, and Pneumology, University Hospital Heidelberg, University of Heidelberg, Im Neuenheimer Feld 669, 69120 Heidelberg, Germany; DZHK (German Center for Cardiovascular Research), Partner Site Heidelberg/Mannheim, 69120 Heidelberg, Germany.
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28
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Liu R, Chen L, Wang Y, Zhang G, Cheng Y, Feng Z, Bai X, Liu J. High ratio of ω-3/ω-6 polyunsaturated fatty acids targets mTORC1 to prevent high-fat diet-induced metabolic syndrome and mitochondrial dysfunction in mice. J Nutr Biochem 2020; 79:108330. [PMID: 32179408 DOI: 10.1016/j.jnutbio.2019.108330] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Revised: 11/29/2019] [Accepted: 12/19/2019] [Indexed: 12/12/2022]
Abstract
Adjusting ω-3/ω-6 polyunsaturated fatty acids (PUFAs) ratio in high-fat diet is one potential mean to improve metabolic syndrome; however, underlying mechanisms remain unclear. Four groups of mice were fed 60% kcal diets with saturated fatty acids, three different ω-3/ω-6 PUFAs ratios (low, middle and high) for 12 weeks, respectively. Body weight, atherosclerosis marker, insulin signal index and level of lipid accumulation in liver were significantly lowered in High group compared with saturated fatty acids group and Low group at week 12. Expressions of p-mTOR and raptor were inhibited by high ω-3 PUFAs. Importantly, ω-3 PUFAs intake up-regulated mitochondrial electron transport chain and tricarboxylic acid cycle pathway through metabolomics analysis in liver. Mitochondrial complexes activities were raised, fumaric acid was reduced and oxidative stress was alleviated in High group. We conclude that consuming long-term high-fat diet with same calories but high ω-3/ω-6 PUFAs ratio relieves metabolic syndrome by regulating mTORC1 pathway to enhance mitochondrial function.
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Affiliation(s)
- Run Liu
- Center for Mitochondrial Biology and Medicine, The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, 710049, China
| | - Lei Chen
- Center for Mitochondrial Biology and Medicine, The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, 710049, China
| | - Yan Wang
- Center for Mitochondrial Biology and Medicine, The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, 710049, China
| | - Guanfei Zhang
- Center for Mitochondrial Biology and Medicine, The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, 710049, China
| | - Ying Cheng
- Center for Mitochondrial Biology and Medicine, The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, 710049, China
| | - Zhihui Feng
- Center for Mitochondrial Biology and Medicine, The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, 710049, China
| | - Xiaochun Bai
- Department of Cell Biology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China
| | - Jiankang Liu
- Center for Mitochondrial Biology and Medicine, The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, 710049, China.
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29
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PRAS40 suppresses atherogenesis through inhibition of mTORC1-dependent pro-inflammatory signaling in endothelial cells. Sci Rep 2019; 9:16787. [PMID: 31728028 PMCID: PMC6856095 DOI: 10.1038/s41598-019-53098-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Accepted: 10/21/2019] [Indexed: 12/20/2022] Open
Abstract
Endothelial pro-inflammatory activation plays a pivotal role in atherosclerosis, and many pro-inflammatory and atherogenic signals converge upon mechanistic target of rapamycin (mTOR). Inhibitors of mTOR complex 1 (mTORC1) reduced atherosclerosis in preclinical studies, but side effects including insulin resistance and dyslipidemia limit their clinical use in this context. Therefore, we investigated PRAS40, a cell type-specific endogenous modulator of mTORC1, as alternative target. Indeed, we previously found PRAS40 gene therapy to improve metabolic profile; however, its function in endothelial cells and its role in atherosclerosis remain unknown. Here we show that PRAS40 negatively regulates endothelial mTORC1 and pro-inflammatory signaling. Knockdown of PRAS40 in endothelial cells promoted TNFα-induced mTORC1 signaling, proliferation, upregulation of inflammatory markers and monocyte recruitment. In contrast, PRAS40-overexpression blocked mTORC1 and all measures of pro-inflammatory signaling. These effects were mimicked by pharmacological mTORC1-inhibition with torin1. In an in vivo model of atherogenic remodeling, mice with induced endothelium-specific PRAS40 deficiency showed enhanced endothelial pro-inflammatory activation as well as increased neointimal hyperplasia and atherosclerotic lesion formation. These data indicate that PRAS40 suppresses atherosclerosis via inhibition of endothelial mTORC1-mediated pro-inflammatory signaling. In conjunction with its favourable effects on metabolic homeostasis, this renders PRAS40 a potential target for the treatment of atherosclerosis.
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30
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Royce GH, Brown-Borg HM, Deepa SS. The potential role of necroptosis in inflammaging and aging. GeroScience 2019; 41:795-811. [PMID: 31721033 DOI: 10.1007/s11357-019-00131-w] [Citation(s) in RCA: 77] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Accepted: 10/23/2019] [Indexed: 02/06/2023] Open
Abstract
An age-associated increase in chronic, low-grade sterile inflammation termed "inflammaging" is a characteristic feature of mammalian aging that shows a strong association with occurrence of various age-associated diseases. However, the mechanism(s) responsible for inflammaging and its causal role in aging and age-related diseases are not well understood. Age-associated accumulation of damage-associated molecular patterns (DAMPs) is an important trigger in inflammation and has been proposed as a potential driver of inflammaging. DAMPs can initiate an inflammatory response by binding to the cell surface receptors on innate immune cells. Programmed necrosis, termed necroptosis, is one of the pathways that can release DAMPs, and cell death due to necroptosis is known to induce inflammation. Necroptosis-mediated inflammation plays an important role in a variety of age-related diseases such as Alzheimer's disease, Parkinson's disease, and atherosclerosis. Recently, it was reported that markers of necroptosis increase with age in mice and that dietary restriction, which retards aging and increases lifespan, reduces necroptosis and inflammation. Genetic manipulations that increase lifespan (Ames Dwarf mice) and reduce lifespan (Sod1-/- mice) are associated with reduced and increased necroptosis and inflammation, respectively. While necroptosis evolved to protect cells/tissues from invading pathogens, e.g., viruses, we propose that the age-related increase in oxidative stress, mTOR signaling, and cell senescence results in cells/tissues in old animals being more prone to undergo necroptosis thereby releasing DAMPs, which contribute to the chronic inflammation observed with age. Approach to decrease DAMPs release by reducing/blocking necroptosis is a potentially new approach to reduce inflammaging, retard aging, and improve healthspan.
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Affiliation(s)
| | - Holly M Brown-Borg
- Department of Biomedical Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND, USA
| | - Sathyaseelan S Deepa
- Stephenson Cancer Center, Oklahoma City, OK, USA. .,Department of Biochemistry and Molecular Biology, Reynolds Oklahoma Center on Aging, University of Oklahoma Health Sciences Center, 975 NE 10th Street, BRC-1368A, Oklahoma City, OK, 73104, USA.
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Karlstaedt A, Khanna R, Thangam M, Taegtmeyer H. Glucose 6-Phosphate Accumulates via Phosphoglucose Isomerase Inhibition in Heart Muscle. Circ Res 2019; 126:60-74. [PMID: 31698999 DOI: 10.1161/circresaha.119.315180] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
RATIONALE Metabolic and structural remodeling is a hallmark of heart failure. This remodeling involves activation of the mTOR (mammalian target of rapamycin) signaling pathway, but little is known on how intermediary metabolites are integrated as metabolic signals. OBJECTIVE We investigated the metabolic control of cardiac glycolysis and explored the potential of glucose 6-phosphate (G6P) to regulate glycolytic flux and mTOR activation. METHODS AND RESULTS We developed a kinetic model of cardiomyocyte carbohydrate metabolism, CardioGlyco, to study the metabolic control of myocardial glycolysis and G6P levels. Metabolic control analysis revealed that G6P concentration is dependent on phosphoglucose isomerase (PGI) activity. Next, we integrated ex vivo tracer studies with mathematical simulations to test how changes in glucose supply and glycolytic flux affect mTOR activation. Nutrient deprivation promoted a tight coupling between glucose uptake and oxidation, G6P reduction, and increased protein-protein interaction between hexokinase II and mTOR. We validated the in silico modeling in cultured adult mouse ventricular cardiomyocytes by modulating PGI activity using erythrose 4-phosphate. Inhibition of glycolytic flux at the level of PGI caused G6P accumulation, which correlated with increased mTOR activation. Using click chemistry, we labeled newly synthesized proteins and confirmed that inhibition of PGI increases protein synthesis. CONCLUSIONS The reduction of PGI activity directly affects myocyte growth by regulating mTOR activation.
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Affiliation(s)
- Anja Karlstaedt
- From the Division of Cardiology, Department of Internal Medicine, McGovern Medical School at The University of Texas Health Science Center at Houston (A.K., H.T.)
| | | | - Manoj Thangam
- Department of Cardiology, Washington University School of Medicine in St. Louis, MO (M.T.)
| | - Heinrich Taegtmeyer
- From the Division of Cardiology, Department of Internal Medicine, McGovern Medical School at The University of Texas Health Science Center at Houston (A.K., H.T.)
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Abstract
Patients with diabetes mellitus have >2× the risk for developing heart failure (HF; HF with reduced ejection fraction and HF with preserved ejection fraction). Cardiovascular outcomes, hospitalization, and prognosis are worse for patients with diabetes mellitus relative to those without. Beyond the structural and functional changes that characterize diabetic cardiomyopathy, a complex underlying, and interrelated pathophysiology exists. Despite the success of many commonly used antihyperglycemic therapies to lower hyperglycemia in type 2 diabetes mellitus the high prevalence of HF persists. This, therefore, raises the possibility that additional factors beyond glycemia might contribute to the increased HF risk in diabetes mellitus. This review summarizes the state of knowledge about the impact of existing antihyperglycemic therapies on HF and discusses potential mechanisms for beneficial or deleterious effects. Second, we review currently approved pharmacological therapies for HF and review evidence that addresses their efficacy in the context of diabetes mellitus. Dysregulation of many cellular mechanisms in multiple models of diabetic cardiomyopathy and in human hearts have been described. These include oxidative stress, inflammation, endoplasmic reticulum stress, aberrant insulin signaling, accumulation of advanced glycated end-products, altered autophagy, changes in myocardial substrate metabolism and mitochondrial bioenergetics, lipotoxicity, and altered signal transduction such as GRK (g-protein receptor kinase) signaling, renin angiotensin aldosterone signaling and β-2 adrenergic receptor signaling. These pathophysiological pathways might be amenable to pharmacological therapy to reduce the risk of HF in the context of type 2 diabetes mellitus. Successful targeting of these pathways could alter the prognosis and risk of HF beyond what is currently achieved using existing antihyperglycemic and HF therapeutics.
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Affiliation(s)
- Helena C Kenny
- From the Fraternal Order of Eagles Diabetes Research Center, and Division of Endocrinology and Metabolism, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City
| | - E Dale Abel
- From the Fraternal Order of Eagles Diabetes Research Center, and Division of Endocrinology and Metabolism, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City
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Abstract
Cardiac ageing manifests as a decline in function leading to heart failure. At the cellular level, ageing entails decreased replicative capacity and dysregulation of cellular processes in myocardial and nonmyocyte cells. Various extrinsic parameters, such as lifestyle and environment, integrate important signalling pathways, such as those involving inflammation and oxidative stress, with intrinsic molecular mechanisms underlying resistance versus progression to cellular senescence. Mitigation of cardiac functional decline in an ageing organism requires the activation of enhanced maintenance and reparative capacity, thereby overcoming inherent endogenous limitations to retaining a youthful phenotype. Deciphering the molecular mechanisms underlying dysregulation of cellular function and renewal reveals potential interventional targets to attenuate degenerative processes at the cellular and systemic levels to improve quality of life for our ageing population. In this Review, we discuss the roles of extrinsic and intrinsic factors in cardiac ageing. Animal models of cardiac ageing are summarized, followed by an overview of the current and possible future treatments to mitigate the deleterious effects of cardiac ageing.
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Sciarretta S, Forte M, Frati G, Sadoshima J. New Insights Into the Role of mTOR Signaling in the Cardiovascular System. Circ Res 2019; 122:489-505. [PMID: 29420210 DOI: 10.1161/circresaha.117.311147] [Citation(s) in RCA: 287] [Impact Index Per Article: 57.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The mTOR (mechanistic target of rapamycin) is a master regulator of several crucial cellular processes, including protein synthesis, cellular growth, proliferation, autophagy, lysosomal function, and cell metabolism. mTOR interacts with specific adaptor proteins to form 2 multiprotein complexes, called mTORC1 (mTOR complex 1) and mTORC2 (mTOR complex 2). In the cardiovascular system, the mTOR pathway regulates both physiological and pathological processes in the heart. It is needed for embryonic cardiovascular development and for maintaining cardiac homeostasis in postnatal life. Studies involving mTOR loss-of-function models revealed that mTORC1 activation is indispensable for the development of adaptive cardiac hypertrophy in response to mechanical overload. mTORC2 is also required for normal cardiac physiology and ensures cardiomyocyte survival in response to pressure overload. However, partial genetic or pharmacological inhibition of mTORC1 reduces cardiac remodeling and heart failure in response to pressure overload and chronic myocardial infarction. In addition, mTORC1 blockade reduces cardiac derangements induced by genetic and metabolic disorders and has been reported to extend life span in mice. These studies suggest that pharmacological targeting of mTOR may represent a therapeutic strategy to confer cardioprotection, although clinical evidence in support of this notion is still scarce. This review summarizes and discusses the new evidence on the pathophysiological role of mTOR signaling in the cardiovascular system.
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Affiliation(s)
- Sebastiano Sciarretta
- From the Department of Medico-Surgical Sciences and Biotechnologies, Sapienza University of Rome, Latina, Italy (S.S., G.F.); Department of AngioCardioNeurology, IRCCS Neuromed, Pozzilli, Italy (S.S., M.F., G.F.); and Department of Cell Biology and Molecular Medicine, Cardiovascular Research Institute, Rutgers New Jersey Medical School, Newark (J.S.)
| | - Maurizio Forte
- From the Department of Medico-Surgical Sciences and Biotechnologies, Sapienza University of Rome, Latina, Italy (S.S., G.F.); Department of AngioCardioNeurology, IRCCS Neuromed, Pozzilli, Italy (S.S., M.F., G.F.); and Department of Cell Biology and Molecular Medicine, Cardiovascular Research Institute, Rutgers New Jersey Medical School, Newark (J.S.)
| | - Giacomo Frati
- From the Department of Medico-Surgical Sciences and Biotechnologies, Sapienza University of Rome, Latina, Italy (S.S., G.F.); Department of AngioCardioNeurology, IRCCS Neuromed, Pozzilli, Italy (S.S., M.F., G.F.); and Department of Cell Biology and Molecular Medicine, Cardiovascular Research Institute, Rutgers New Jersey Medical School, Newark (J.S.)
| | - Junichi Sadoshima
- From the Department of Medico-Surgical Sciences and Biotechnologies, Sapienza University of Rome, Latina, Italy (S.S., G.F.); Department of AngioCardioNeurology, IRCCS Neuromed, Pozzilli, Italy (S.S., M.F., G.F.); and Department of Cell Biology and Molecular Medicine, Cardiovascular Research Institute, Rutgers New Jersey Medical School, Newark (J.S.).
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Zhang D, Bhatnagar A, Baba SP. Inhibition of aldose reductase activity stimulates starvation induced autophagy and clears aldehyde protein adducts. Chem Biol Interact 2019; 306:104-109. [DOI: 10.1016/j.cbi.2019.04.014] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Revised: 03/14/2019] [Accepted: 04/11/2019] [Indexed: 12/31/2022]
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Kmietczyk V, Riechert E, Kalinski L, Boileau E, Malovrh E, Malone B, Gorska A, Hofmann C, Varma E, Jürgensen L, Kamuf-Schenk V, Altmüller J, Tappu R, Busch M, Most P, Katus HA, Dieterich C, Völkers M. m 6A-mRNA methylation regulates cardiac gene expression and cellular growth. Life Sci Alliance 2019; 2:e201800233. [PMID: 30967445 PMCID: PMC6458851 DOI: 10.26508/lsa.201800233] [Citation(s) in RCA: 83] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Revised: 03/22/2019] [Accepted: 03/22/2019] [Indexed: 01/25/2023] Open
Abstract
Conceptually similar to modifications of DNA, mRNAs undergo chemical modifications, which can affect their activity, localization, and stability. The most prevalent internal modification in mRNA is the methylation of adenosine at the N6-position (m6A). This returns mRNA to a role as a central hub of information within the cell, serving as an information carrier, modifier, and attenuator for many biological processes. Still, the precise role of internal mRNA modifications such as m6A in human and murine-dilated cardiac tissue remains unknown. Transcriptome-wide mapping of m6A in mRNA allowed us to catalog m6A targets in human and murine hearts. Increased m6A methylation was found in human cardiomyopathy. Knockdown and overexpression of the m6A writer enzyme Mettl3 affected cell size and cellular remodeling both in vitro and in vivo. Our data suggest that mRNA methylation is highly dynamic in cardiomyocytes undergoing stress and that changes in the mRNA methylome regulate translational efficiency by affecting transcript stability. Once elucidated, manipulations of methylation of specific m6A sites could be a powerful approach to prevent worsening of cardiac function.
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Affiliation(s)
- Vivien Kmietczyk
- Department of Cardiology, Angiology, and Pneumology, University Hospital Heidelberg, University of Heidelberg, Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, Heidelberg, Germany
| | - Eva Riechert
- Department of Cardiology, Angiology, and Pneumology, University Hospital Heidelberg, University of Heidelberg, Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, Heidelberg, Germany
| | - Laura Kalinski
- Department of Cardiology, Angiology, and Pneumology, University Hospital Heidelberg, University of Heidelberg, Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, Heidelberg, Germany
| | - Etienne Boileau
- Department of Cardiology, Angiology, and Pneumology, University Hospital Heidelberg, University of Heidelberg, Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, Heidelberg, Germany
- Section of Bioinformatics and Systems Cardiology, Department of Cardiology, Angiology, and Pneumology and Klaus Tschira Institute for Integrative Computational Cardiology, University of Heidelberg, Heidelberg, Germany
| | - Ellen Malovrh
- Department of Cardiology, Angiology, and Pneumology, University Hospital Heidelberg, University of Heidelberg, Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, Heidelberg, Germany
| | - Brandon Malone
- Department of Cardiology, Angiology, and Pneumology, University Hospital Heidelberg, University of Heidelberg, Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, Heidelberg, Germany
- Section of Bioinformatics and Systems Cardiology, Department of Cardiology, Angiology, and Pneumology and Klaus Tschira Institute for Integrative Computational Cardiology, University of Heidelberg, Heidelberg, Germany
| | - Agnieszka Gorska
- Department of Cardiology, Angiology, and Pneumology, University Hospital Heidelberg, University of Heidelberg, Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, Heidelberg, Germany
| | - Christoph Hofmann
- Department of Cardiology, Angiology, and Pneumology, University Hospital Heidelberg, University of Heidelberg, Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, Heidelberg, Germany
| | - Eshita Varma
- Department of Cardiology, Angiology, and Pneumology, University Hospital Heidelberg, University of Heidelberg, Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, Heidelberg, Germany
| | - Lonny Jürgensen
- Department of Cardiology, Angiology, and Pneumology, University Hospital Heidelberg, University of Heidelberg, Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, Heidelberg, Germany
| | - Verena Kamuf-Schenk
- Department of Cardiology, Angiology, and Pneumology, University Hospital Heidelberg, University of Heidelberg, Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, Heidelberg, Germany
| | - Janine Altmüller
- Cologne Center for Genomics, University Cologne, Cologne, Germany
- Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
| | - Rewati Tappu
- Department of Cardiology, Angiology, and Pneumology, University Hospital Heidelberg, University of Heidelberg, Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, Heidelberg, Germany
| | - Martin Busch
- Department of Cardiology, Angiology, and Pneumology, University Hospital Heidelberg, University of Heidelberg, Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, Heidelberg, Germany
| | - Patrick Most
- Department of Cardiology, Angiology, and Pneumology, University Hospital Heidelberg, University of Heidelberg, Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, Heidelberg, Germany
| | - Hugo A Katus
- Department of Cardiology, Angiology, and Pneumology, University Hospital Heidelberg, University of Heidelberg, Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, Heidelberg, Germany
| | - Christoph Dieterich
- Department of Cardiology, Angiology, and Pneumology, University Hospital Heidelberg, University of Heidelberg, Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, Heidelberg, Germany
- Section of Bioinformatics and Systems Cardiology, Department of Cardiology, Angiology, and Pneumology and Klaus Tschira Institute for Integrative Computational Cardiology, University of Heidelberg, Heidelberg, Germany
| | - Mirko Völkers
- Department of Cardiology, Angiology, and Pneumology, University Hospital Heidelberg, University of Heidelberg, Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, Heidelberg, Germany
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Li J, Zhang D, Wiersma M, Brundel BJJM. Role of Autophagy in Proteostasis: Friend and Foe in Cardiac Diseases. Cells 2018; 7:cells7120279. [PMID: 30572675 PMCID: PMC6316637 DOI: 10.3390/cells7120279] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Revised: 12/13/2018] [Accepted: 12/18/2018] [Indexed: 12/11/2022] Open
Abstract
Due to ageing of the population, the incidence of cardiovascular diseases will increase in the coming years, constituting a substantial burden on health care systems. In particular, atrial fibrillation (AF) is approaching epidemic proportions. It has been identified that the derailment of proteostasis, which is characterized by the loss of homeostasis in protein biosynthesis, folding, trafficking, and clearance by protein degradation systems such as autophagy, underlies the development of common cardiac diseases. Among various safeguards within the proteostasis system, autophagy is a vital cellular process that modulates clearance of misfolded and proteotoxic proteins from cardiomyocytes. On the other hand, excessive autophagy may result in derailment of proteostasis and therefore cardiac dysfunction. Here, we review the interplay between autophagy and proteostasis in the healthy heart, discuss the imbalance between autophagy and proteostasis during cardiac diseases, including AF, and finally explore new druggable targets which may limit cardiac disease initiation and progression.
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Affiliation(s)
- Jin Li
- Department of Physiology, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam Cardiovascular Sciences, 1081 HV Amsterdam, The Netherlands.
| | - Deli Zhang
- Department of Physiology, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam Cardiovascular Sciences, 1081 HV Amsterdam, The Netherlands.
| | - Marit Wiersma
- Department of Physiology, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam Cardiovascular Sciences, 1081 HV Amsterdam, The Netherlands.
| | - Bianca J J M Brundel
- Department of Physiology, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam Cardiovascular Sciences, 1081 HV Amsterdam, The Netherlands.
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Ali M, Bukhari SA, Ali M, Lee HW. Upstream signalling of mTORC1 and its hyperactivation in type 2 diabetes (T2D). BMB Rep 2018; 50:601-609. [PMID: 29187279 PMCID: PMC5749905 DOI: 10.5483/bmbrep.2017.50.12.206] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Indexed: 12/19/2022] Open
Abstract
Mammalian target of rapamycin complex 1 (mTORC1) plays a major role in cell growth, proliferation, polarity, differentiation, development, and controls transitioning between anabolic and catabolic states of the cell. It collects almost all extracellular and intracellular signals from growth factors, nutrients, and maintains cellular homeostasis, and is involved in several pathological conditions including, neurodegeneration, Type 2 diabetes (T2D), obesity, and cancer. In this review, we summarize current knowledge of upstream signaling of mTORC1 to explain etiology of T2D and hypertriglyceridemia, in which state, the role of telomere attrition is explained. We discuss if chronic inhibition of mTORC1 can reverse adverse effects resulting from hyperactivation. In conclusion, we suggest the regulatory roles of telomerase (TERT) and hexokinase II (HKII) on mTORC1 as possible remedies to treat hyperactivation. The former inhibits mTORC1 under nutrient-rich while the latter under starved condition. We provide an idea of TOS (TOR signaling) motifs that can be used for regulation of mTORC1.
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Affiliation(s)
- Muhammad Ali
- Departments of Biochemistry, Government College University, Faisalabad, 38000 Pakistan
| | - Shazia Anwer Bukhari
- Departments of Biochemistry, Government College University, Faisalabad, 38000 Pakistan
| | - Muhammad Ali
- Departments of Zoology, Government College University, Faisalabad, 38000 Pakistan
| | - Han-Woong Lee
- Department of Biochemistry, College of Life Science and Biotechnology, Yonsei University, Seoul 03722, Republic of Korea
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Bhattacharya D, Mukhopadhyay M, Bhattacharyya M, Karmakar P. Is autophagy associated with diabetes mellitus and its complications? A review. EXCLI JOURNAL 2018; 17:709-720. [PMID: 30190661 PMCID: PMC6123605 DOI: 10.17179/excli2018-1353] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Accepted: 07/11/2018] [Indexed: 02/06/2023]
Abstract
Diabetes mellitus (DM) is an endocrine disorder. In coming decades it will be one of the leading causes of death globally. The key factors in the pathogenesis of diabetes are cellular injuries and disorders of energy metabolism leading to severe diabetic complications. Recent studies have confirmed that autophagy plays a pivotal role in diabetes and its complications. It has been observed that autophagy regulates the normal function of pancreatic β cells and insulin-target tissues, such as skeletal muscle, liver, and adipose tissue. This review will summarize the regulation of autophagy in diabetes and its complications, and explore how this process would emerge as a potential therapeutic target for diabetes treatment.
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Affiliation(s)
- Debalina Bhattacharya
- Department of Biochemistry, University of Calcutta, Kolkata-700019
- Department of Life Science and Biotechnology, Jadavpur University, Kolkata-700032
| | | | | | - Parimal Karmakar
- Department of Life Science and Biotechnology, Jadavpur University, Kolkata-700032
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Maity S, Bera A, Ghosh-Choudhury N, Das F, Kasinath BS, Choudhury GG. microRNA-181a downregulates deptor for TGFβ-induced glomerular mesangial cell hypertrophy and matrix protein expression. Exp Cell Res 2018; 364:5-15. [PMID: 29397070 DOI: 10.1016/j.yexcr.2018.01.021] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Accepted: 01/16/2018] [Indexed: 02/06/2023]
Abstract
TGFβ contributes to mesangial cell hypertrophy and matrix protein increase in various kidney diseases including diabetic nephropathy. Deptor is an mTOR-interacting protein and suppresses mTORC1 and mTORC2 activities. We have recently shown that TGFβ-induced inhibition of deptor increases the mTOR activity. The mechanism by which TGFβ regulates deptor expression is not known. Here we identify deptor as a target of the microRNA-181a. We show that in mesangial cells, TGFβ increases the expression of miR-181a to downregulate deptor. Decrease in deptor augments mTORC2 activity, resulting in phosphorylation/activation of Akt kinase. Akt promotes inactivating phosphorylation of PRAS40 and tuberin, leading to stimulation of mTORC1. miR-181a-mimic increased mTORC1 and C2 activities, while anti-miR-181a inhibited them. mTORC1 controls protein synthesis via phosphorylation of translation initiation and elongation suppressors 4EBP-1 and eEF2 kinase. TGFβ-stimulated miR-181a increased the phosphorylation of 4EBP-1 and eEF2 kinase, resulting in their inactivation. miR-181a-dependent inactivation of eEF2 kinase caused dephosphorylation of eEF2. Consequently, miR-181a-mimic increased protein synthesis and hypertrophy of mesangial cells similar to TGFβ. Anti-miR-181a blocked these events in a deptor-dependent manner. Finally, TGFβ-miR-181a-driven deptor downregulation increased the expression of fibronectin. Our results identify a novel mechanism involving miR-181a-driven deptor downregulation, which contributes to mesangial cell pathologies in renal complications.
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Affiliation(s)
- Soumya Maity
- Department of Medicine, UT Health San Antonio, TX, United States
| | - Amit Bera
- Department of Medicine, UT Health San Antonio, TX, United States
| | - Nandini Ghosh-Choudhury
- VA Biomedical Laboratory Research, South Texas Veterans Health Care System, San Antonio, TX, United States; Department of Pathology, UT Health San Antonio, TX, United States
| | - Falguni Das
- Department of Medicine, UT Health San Antonio, TX, United States; VA Biomedical Laboratory Research, South Texas Veterans Health Care System, San Antonio, TX, United States
| | - Balakuntalam S Kasinath
- Department of Medicine, UT Health San Antonio, TX, United States; VA Biomedical Laboratory Research, South Texas Veterans Health Care System, San Antonio, TX, United States
| | - Goutam Ghosh Choudhury
- Department of Medicine, UT Health San Antonio, TX, United States; VA Biomedical Laboratory Research, South Texas Veterans Health Care System, San Antonio, TX, United States; Geriatric Research, Education and Clinical Research Center, South Texas Veterans Health Care System, San Antonio, TX, United States.
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Reifsnyder PC, Ryzhov S, Flurkey K, Anunciado-Koza RP, Mills I, Harrison DE, Koza RA. Cardioprotective effects of dietary rapamycin on adult female C57BLKS/J-Lepr db mice. Ann N Y Acad Sci 2018; 1418:106-117. [PMID: 29377150 DOI: 10.1111/nyas.13557] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Revised: 10/24/2017] [Accepted: 10/30/2017] [Indexed: 02/06/2023]
Abstract
Rapamycin (RAPA), an inhibitor of mTORC signaling, has been shown to extend life span in mice and other organisms. Recently, animal and human studies have suggested that inhibition of mTORC signaling can alleviate or prevent the development of cardiomyopathy. In view of this, we used a murine model of type 2 diabetes (T2D), BKS-Leprdb , to determine whether RAPA treatment can mitigate the development of T2D-induced cardiomyopathy in adult mice. Female BKS-Leprdb mice fed diet supplemented with RAPA from 11 to 27 weeks of age showed reduced weight gain and significant reductions of fat and lean mass compared with untreated mice. No differences in plasma glucose or insulin levels were observed between groups; however, RAPA-treated mice were more insulin sensitive (P < 0.01) than untreated mice. Urine albumin/creatinine ratio was lower in RAPA-treated mice, suggesting reduced diabetic nephropathy and improved kidney function. Echocardiography showed significantly reduced left ventricular wall thickness in mice treated with RAPA compared with untreated mice (P = 0.02) that was consistent with reduced heart weight/tibia length ratios, reduced myocyte size and cardiac fibrosis measured by histomorphology, and reduced mRNA expression of Col1a1, a marker for cardiomyopathy. Our results suggest that inhibition of mTORC signaling is a plausible strategy for ameliorating complications of obesity and T2D, including cardiomyopathy.
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Affiliation(s)
| | - Sergey Ryzhov
- Center for Molecular Medicine, Maine Medical Center Research Institute, Scarborough, Maine
| | | | - Rea P Anunciado-Koza
- Center for Molecular Medicine, Maine Medical Center Research Institute, Scarborough, Maine
| | - Ian Mills
- Center for Molecular Medicine, Maine Medical Center Research Institute, Scarborough, Maine
| | | | - Robert A Koza
- Center for Molecular Medicine, Maine Medical Center Research Institute, Scarborough, Maine
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Samidurai A, Salloum FN, Durrant D, Chernova OB, Kukreja RC, Das A. Chronic treatment with novel nanoformulated micelles of rapamycin, Rapatar, protects diabetic heart against ischaemia/reperfusion injury. Br J Pharmacol 2017; 174:4771-4784. [PMID: 28967097 DOI: 10.1111/bph.14059] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Revised: 08/17/2017] [Accepted: 09/13/2017] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND AND PURPOSE Enhanced mammalian target of rapamycin (mTOR) signalling contributes to the pathogenesis of diabetes and plays a critical role in myocardial ischaemia/reperfusion (I/R) injury. Rapatar is a novel nanoformulated micellar of rapamycin, a putative inhibitor of mTOR that has been rationally designed to increase water solubility of rapamycin to facilitate p.o. administration and enhance bioavailability. We examined the effect of Rapatar on the metabolic status and protection against myocardial I/R injury in type 2 diabetic mice. EXPERIMENTAL APPROACH Adult male db/db mice were treated daily for 10 weeks with Rapatar (0.75 mg·kg-1 ·day-1 , p.o.) or vehicle. Isolated hearts were connected to a Langendorff perfusion system and subjected to global ischaemia (30 min) and reperfusion (1 h). KEY RESULTS Rapatar reduced fasting plasma glucose and triglyceride levels, prevented the gain in body weight and also improved glucose tolerance and insulin sensitivity in db/db mice compared with control. Cardiac function was improved following Rapatar treatment in db/db mice. Myocardial infarct size was reduced in Rapatar-treated mice with improved post-ischaemic rate-force product. Western blot analyses demonstrated a significant inhibition of phosphorylation of ribosomal protein S6 (downstream target of mTORC1), but not Akt (Ser473 , target of mTORC2) following chronic treatment with Rapatar. Rapatar also induced phosphorylation of AMPK, STAT3, ERK1/2 and glycogen synthase kinase 3β, without interfering with phosphorylation of p38. CONCLUSION AND IMPLICATIONS Our studies indicate that chronic treatment with Rapatar improves metabolic status and cardiac function with a reduction of infarct size following myocardial I/R injury in diabetic mice.
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Affiliation(s)
- Arun Samidurai
- Pauley Heart Center, Division of Cardiology, Virginia Commonwealth University, Richmond, VA, USA
| | - Fadi N Salloum
- Pauley Heart Center, Division of Cardiology, Virginia Commonwealth University, Richmond, VA, USA
| | - David Durrant
- Pauley Heart Center, Division of Cardiology, Virginia Commonwealth University, Richmond, VA, USA
| | | | - Rakesh C Kukreja
- Pauley Heart Center, Division of Cardiology, Virginia Commonwealth University, Richmond, VA, USA
| | - Anindita Das
- Pauley Heart Center, Division of Cardiology, Virginia Commonwealth University, Richmond, VA, USA
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Bera A, Das F, Ghosh-Choudhury N, Mariappan MM, Kasinath BS, Ghosh Choudhury G. Reciprocal regulation of miR-214 and PTEN by high glucose regulates renal glomerular mesangial and proximal tubular epithelial cell hypertrophy and matrix expansion. Am J Physiol Cell Physiol 2017; 313:C430-C447. [PMID: 28701356 PMCID: PMC5668576 DOI: 10.1152/ajpcell.00081.2017] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Revised: 07/06/2017] [Accepted: 07/09/2017] [Indexed: 02/06/2023]
Abstract
Aberrant expression of microRNAs (miRs) contributes to diabetic renal complications, including renal hypertrophy and matrix protein accumulation. Reduced expression of phosphatase and tensin homolog (PTEN) by hyperglycemia contributes to these processes. We considered involvement of miR in the downregulation of PTEN. In the renal cortex of type 1 diabetic mice, we detected increased expression of miR-214 in association with decreased levels of PTEN and enhanced Akt phosphorylation and fibronectin expression. Mesangial and proximal tubular epithelial cells exposed to high glucose showed augmented expression of miR-214. Mutagenesis studies using 3'-UTR of PTEN in a reporter construct revealed PTEN as a direct target of miR-214, which controls its expression in both of these cells. Overexpression of miR-214 decreased the levels of PTEN and increased Akt activity similar to high glucose and lead to phosphorylation of its substrates glycogen synthase kinase-3β, PRAS40, and tuberin. In contrast, quenching of miR-214 inhibited high-glucose-induced Akt activation and its substrate phosphorylation; these changes were reversed by small interfering RNAs against PTEN. Importantly, respective expression of miR-214 or anti-miR-214 increased or decreased the mammalian target of rapamycin complex 1 (mTORC1) activity induced by high glucose. Furthermore, mTORC1 activity was controlled by miR-214-targeted PTEN via Akt activation. In addition, neutralization of high-glucose-stimulated miR-214 expression significantly inhibited cell hypertrophy and expression of the matrix protein fibronectin. Finally, the anti-miR-214-induced inhibition of these processes was reversed by the expression of constitutively active Akt kinase and hyperactive mTORC1. These results uncover a significant role of miR-214 in the activation of mTORC1 that contributes to high-glucose-induced mesangial and proximal tubular cell hypertrophy and fibronectin expression.
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Affiliation(s)
- Amit Bera
- Department of Medicine, UT Health San Antonio, San Antonio, Texas
| | - Falguni Das
- Department of Medicine, UT Health San Antonio, San Antonio, Texas
| | - Nandini Ghosh-Choudhury
- Veterans Affairs Biomedical Laboratory Research, South Texas Veterans Health Care System, San Antonio, Texas
- Department of Pathology, UT Health San Antonio, San Antonio, Texas; and
| | | | - Balakuntalam S Kasinath
- Department of Medicine, UT Health San Antonio, San Antonio, Texas
- Veterans Affairs Biomedical Laboratory Research, South Texas Veterans Health Care System, San Antonio, Texas
| | - Goutam Ghosh Choudhury
- Department of Medicine, UT Health San Antonio, San Antonio, Texas;
- Veterans Affairs Biomedical Laboratory Research, South Texas Veterans Health Care System, San Antonio, Texas
- Geriatric Research, Education and Clinical Research, South Texas Veterans Health Care System, San Antonio, Texas
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Zhu G, Qi Q, Havel JJ, Li Z, Du Y, Zhang X, Fu H. PRAS40 promotes NF-κB transcriptional activity through association with p65. Oncogenesis 2017; 6:e381. [PMID: 28945219 PMCID: PMC5623906 DOI: 10.1038/oncsis.2017.80] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2017] [Revised: 06/19/2017] [Accepted: 07/26/2017] [Indexed: 01/06/2023] Open
Abstract
PRAS40 has been shown to have a crucial role in the repression of mammalian target of rapamycin (mTOR). Nonetheless, PRAS40 appears to have an oncogenic function in cancer cells. Whether PRAS40 mediates signaling independent of mTOR inhibition in cancer cells remains elusive. Here PRAS40 overexpression in lung adenocarcinoma and cutaneous melanoma was significantly correlated to worse prognosis. And we identified an unexpected role for PRAS40 in the regulation of nuclear factor (NF)-κB signaling. P65, a subunit of the NF-κB transcription factor complex, was confirmed to associate with PRAS40 by glutathione S-transferase co-precipitation. Importantly, we found that PRAS40 can enhance NF-κB transcriptional activity in a manner dependent upon PRAS40–P65 association. Furthermore, we found that a small p65-derived peptide can disrupt the PRAS40–P65 association and significantly decrease NF-κB transcriptional activity. These findings may help elucidate the pleiotropic functions of PRAS40 in cells and suggest a novel therapeutic strategy in cancer patients with high expression of PRAS40 and NF-κB.
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Affiliation(s)
- G Zhu
- Department of Otolaryngology Head and Neck Surgery, Xiangya Hospital, Central South University, Changsha, China.,Department of Pharmacology, Emory University School of Medicine, Atlanta, GA, USA.,Department of Otolaryngology Head and Neck Surgery, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Q Qi
- Department of Pharmacology, Emory University School of Medicine, Atlanta, GA, USA
| | - J J Havel
- Department of Pharmacology, Emory University School of Medicine, Atlanta, GA, USA
| | - Z Li
- Department of Pharmacology, Emory University School of Medicine, Atlanta, GA, USA
| | - Y Du
- Department of Pharmacology, Emory University School of Medicine, Atlanta, GA, USA
| | - X Zhang
- Department of Otolaryngology Head and Neck Surgery, Xiangya Hospital, Central South University, Changsha, China
| | - H Fu
- Department of Pharmacology, Emory University School of Medicine, Atlanta, GA, USA
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45
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Cao Y, Song J, Shen S, Fu H, Li X, Xu Y, Wang A, Li X, Zhang M. Trimedazidine alleviates pulmonary artery banding-induced acute right heart dysfunction and activates PRAS40 in rats. Oncotarget 2017; 8:92064-92078. [PMID: 29190898 PMCID: PMC5696164 DOI: 10.18632/oncotarget.20752] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Accepted: 08/08/2017] [Indexed: 02/01/2023] Open
Abstract
The molecular mechanism underlying acute right heart failure (RHF) is poorly understood. We used pulmonary artery banding (PAB) to induce acute RHF characterized by a rapid rise of right ventricular pressure, and then a decrease in right ventricular pressure along with a decrease in blood pressure right after banding. We found higher brain natriuretic peptide (BNP) and beta-myosin heavy chain (βMHC) levels and lower alpha-myosin heavy chain (αMHC) levels in RHF rats than sham-operated rats. Hemodynamic indexes in rats with acute RHF were slightly improved by trimedazidine TMZ, a key inhibitor of fatty acid (FA) oxidation. TMZ also reversed downregulation of peroxisome proliferator-activated receptor gamma coactivator 1-beta (PGC-1β) and peroxisome proliferator-activated receptor alpha (PPARα) by PAB and up-regulates peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α), peroxisome proliferator-activated receptor delta (PPARδ) and pyruvate dehydrogenase kinase isoform 4 (PDK4). In addition, TMZ reversed upregulation of phosphorylated Akt by PAB and increased phosphorylated proline-rich Akt-substrate 40 (PRAS40). Autophagy and apoptosis were not modified by PAB or TMZ. An acute RHF model was established in rats through 70% constriction of the pulmonary artery. TMZ treatment alleviated PAB-induced acute RHF by activating PRAS40 and upregulatingPGC-1α, PGC-1β, PPARα, PPARδ, and PDK4.
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Affiliation(s)
- Yunshan Cao
- Department of Cardiology, Gansu Provincial Hospital, Lanzhou 730000, China.,Department of Heart Failure, Shanghai East Hospital, Tongji University School of Medicine, Research Center for Translational Medicine, Shanghai 200120, China
| | - Jiyang Song
- Department of Cardiology, Gansu Provincial Hospital, Lanzhou 730000, China
| | - Shutong Shen
- Department of Cardiology, The First Affiliated Hospital with Nanjing Medical University, Nanjing 210029, China
| | - Heling Fu
- Animal Core Facility, Nanjing Medical University, Nanjing 210029, China
| | - Xiang Li
- Department of Intensive Care, Minhang Hospital, Fudan University, Shanghai 201100, China
| | - Ying Xu
- Intensive Care Unit, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing 210008, China
| | - Aqian Wang
- Department of Cardiology, Gansu Provincial Hospital, Lanzhou 730000, China
| | - Xinli Li
- Department of Cardiology, The First Affiliated Hospital with Nanjing Medical University, Nanjing 210029, China
| | - Min Zhang
- Department of Pathology, Gansu Provincial Hospital, Lanzhou 730000, China
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Suhara T, Baba Y, Shimada BK, Higa JK, Matsui T. The mTOR Signaling Pathway in Myocardial Dysfunction in Type 2 Diabetes Mellitus. Curr Diab Rep 2017; 17:38. [PMID: 28434143 PMCID: PMC8219468 DOI: 10.1007/s11892-017-0865-4] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
PURPOSE OF REVIEW T2DM (type 2 diabetes mellitus) is a risk factor for heart failure. The mTOR (mechanistic target of rapamycin) is a key mediator of the insulin signaling pathway. We will discuss the role of mTOR in myocardial dysfunction in T2DM. RECENT FINDINGS In T2DM, chronically activated mTOR induces multiple pathological events, including a negative feedback loop that suppresses IRS (insulin receptor substrate)-1. While short-term treatment with rapamycin, an mTOR inhibitor, is a promising strategy for cardiac diseases such as acute myocardial infarction and cardiac hypertrophy in T2DM, there are many concerns about chronic usage of rapamycin. Two mTOR complexes, mTORC1 and mTORC2, affect many molecules and processes via distinct signaling pathways that regulate cardiomyocyte function and survival. Understanding mechanisms underlying mTOR-mediated pathophysiological features in the heart is essential for developing effective therapies for cardiac diseases in the context of T2DM.
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Affiliation(s)
- Tomohiro Suhara
- Department of Anatomy, Biochemistry & Physiology, John A. Burns School of Medicine, University of Hawaii at Manoa, 651 Ilalo St., BSB no. 110, Honolulu, HI, 96813, USA
- Department of Anesthesiology, Keio University School of Medicine, Tokyo, Japan
| | - Yuichi Baba
- Department of Anatomy, Biochemistry & Physiology, John A. Burns School of Medicine, University of Hawaii at Manoa, 651 Ilalo St., BSB no. 110, Honolulu, HI, 96813, USA
- Department of Cardiology and Geriatrics, Kochi Medical School, Kochi University, Kochi, Japan
| | - Briana K Shimada
- Department of Anatomy, Biochemistry & Physiology, John A. Burns School of Medicine, University of Hawaii at Manoa, 651 Ilalo St., BSB no. 110, Honolulu, HI, 96813, USA
| | - Jason K Higa
- Department of Anatomy, Biochemistry & Physiology, John A. Burns School of Medicine, University of Hawaii at Manoa, 651 Ilalo St., BSB no. 110, Honolulu, HI, 96813, USA
| | - Takashi Matsui
- Department of Anatomy, Biochemistry & Physiology, John A. Burns School of Medicine, University of Hawaii at Manoa, 651 Ilalo St., BSB no. 110, Honolulu, HI, 96813, USA.
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Zhang L, Du J, Yano N, Wang H, Zhao YT, Dubielecka PM, Zhuang S, Chin YE, Qin G, Zhao TC. Sodium Butyrate Protects -Against High Fat Diet-Induced Cardiac Dysfunction and Metabolic Disorders in Type II Diabetic Mice. J Cell Biochem 2017; 118:2395-2408. [PMID: 28109123 DOI: 10.1002/jcb.25902] [Citation(s) in RCA: 72] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Accepted: 01/18/2017] [Indexed: 12/31/2022]
Abstract
Histone deacetylases are recently identified to act as key regulators for cardiac pathophysiology and metabolic disorders. However, the function of histone deacetylase (HDAC) in controlling cardiac performance in Type II diabetes and obesity remains unknown. Here, we determine whether HDAC inhibition attenuates high fat diet (HFD)-induced cardiac dysfunction and improves metabolic features. Adult mice were fed with either HFD or standard chow food for 24 weeks. Starting at 12 weeks, mice were divided into four groups randomly, in which sodium butyrate (1%), a potent HDAC inhibitor, was provided to chow and HFD-fed mice in drinking water, respectively. Glucose intolerance, metabolic parameters, cardiac function, and remodeling were assessed. Histological analysis and cellular signaling were examined at 24 weeks following euthanization of mice. HFD-fed mice demonstrated myocardial dysfunction and profound interstitial fibrosis, which were attenuated by HDAC inhibition. HFD-induced metabolic syndrome features insulin resistance, obesity, hyperinsulinemia, hyperglycemia, lipid accumulations, and cardiac hypertrophy, these effects were prevented by HDAC inhibition. Furthermore, HDAC inhibition attenuated myocyte apoptosis, reduced production of reactive oxygen species, and increased angiogenesis in the HFD-fed myocardium. Notably, HFD induced decreases in MKK3, p38, p38 regulated/activated protein kinase (PRAK), and Akt-1, but not p44/42 phosphorylation, which were prevented by HDAC inhibition. These results suggest that HDAC inhibition plays a critical role to preserve cardiac performance and mitigate metabolic disorders in obesity and diabetes, which is associated with MKK3/p38/PRAK pathway. The study holds promise in developing a new therapeutic strategy in the treatment of Type II diabetic-induced heart failure and metabolic disorders. J. Cell. Biochem. 118: 2395-2408, 2017. © 2017 Wiley Periodicals, Inc.
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Affiliation(s)
- Ling Zhang
- Department of Surgery, Roger Williams Medical Center, Boston University School of Medicine, Providence, Rhode Island.,Department of Emergency Medicine, Rhode Island Hospital, Providence, Rhode Island
| | - Jianfeng Du
- Department of Surgery, Roger Williams Medical Center, Boston University School of Medicine, Providence, Rhode Island
| | - Naohiro Yano
- Women and Infants Hospital, Brown University, Providence, Rhode Island
| | - Hao Wang
- Department of Surgery, Roger Williams Medical Center, Boston University School of Medicine, Providence, Rhode Island
| | - Yu Tina Zhao
- Department of Surgery, Roger Williams Medical Center, Boston University School of Medicine, Providence, Rhode Island
| | | | - Shougang Zhuang
- Department of Medicine, Rhode Island Hospital, Providence, Rhode Island
| | - Y Eugene Chin
- Key Laboratory of Stem Cell Biology, Institutes of Health Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Gangjian Qin
- Feinberg Cardiovascular Research Institute, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Ting C Zhao
- Department of Surgery, Roger Williams Medical Center, Boston University School of Medicine, Providence, Rhode Island
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Loss of hepatic DEPTOR alters the metabolic transition to fasting. Mol Metab 2017; 6:447-458. [PMID: 28462079 PMCID: PMC5404102 DOI: 10.1016/j.molmet.2017.02.005] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Revised: 01/30/2017] [Accepted: 02/13/2017] [Indexed: 01/08/2023] Open
Abstract
Objective The mechanistic target of rapamycin (mTOR) is a serine/threonine kinase that functions into distinct protein complexes (mTORC1 and mTORC2) that regulates growth and metabolism. DEP-domain containing mTOR-interacting protein (DEPTOR) is part of these complexes and is known to reduce their activity. Whether DEPTOR loss affects metabolism and organismal growth in vivo has never been tested. Methods We have generated a conditional transgenic mouse allowing the tissue-specific deletion of DEPTOR. This model was crossed with CMV-cre mice or Albumin-cre mice to generate either whole-body or liver-specific DEPTOR knockout (KO) mice. Results Whole-body DEPTOR KO mice are viable, fertile, normal in size, and do not display any gross physical and metabolic abnormalities. To circumvent possible compensatory mechanisms linked to the early and systemic loss of DEPTOR, we have deleted DEPTOR specifically in the liver, a tissue in which DEPTOR protein is expressed and affected in response to mTOR activation. Liver-specific DEPTOR null mice showed a reduction in circulating glucose upon fasting versus control mice. This effect was not associated with change in hepatic gluconeogenesis potential but was linked to a sustained reduction in circulating glucose during insulin tolerance tests. In addition to the reduction in glycemia, liver-specific DEPTOR KO mice had reduced hepatic glycogen content when fasted. We showed that loss of DEPTOR cell-autonomously increased oxidative metabolism in hepatocytes, an effect associated with increased cytochrome c expression but independent of changes in mitochondrial content or in the expression of genes controlling oxidative metabolism. We found that liver-specific DEPTOR KO mice showed sustained mTORC1 activation upon fasting, and that acute treatment with rapamycin was sufficient to normalize glycemia in these mice. Conclusion We propose a model in which hepatic DEPTOR accelerates the inhibition of mTORC1 during the transition to fasting to adjust metabolism to the nutritional status. Whole-body DEPTOR KO mice are viable and do not display abnormalities. Liver-specific DEPTOR KO mice are hypoglycemic when fasted. Loss of DEPTOR promotes mTORC1 and increases oxidative metabolism. Rapamycin corrects hypoglycemia in liver-specific DEPTOR KO mice.
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Wang CY, Li XD, Hao ZH, Xu D. Insulin-like growth factor-1 improves diabetic cardiomyopathy through antioxidative and anti-inflammatory processes along with modulation of Akt/GSK-3β signaling in rats. THE KOREAN JOURNAL OF PHYSIOLOGY & PHARMACOLOGY : OFFICIAL JOURNAL OF THE KOREAN PHYSIOLOGICAL SOCIETY AND THE KOREAN SOCIETY OF PHARMACOLOGY 2016; 20:613-619. [PMID: 27847438 PMCID: PMC5106395 DOI: 10.4196/kjpp.2016.20.6.613] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Revised: 09/09/2016] [Accepted: 09/10/2016] [Indexed: 12/13/2022]
Abstract
Diabetic cardiomyopathy (DCM), a serious complication of diabetes mellitus, is associated with changes in myocardial structure and function. This study sought to explore the ability of insulin-like growth factor-1 (IGF-1) to modulate DCM and its related mechanisms. Twenty-four male Wistar rats were injected with streptozotocin (STZ, 60 mg/kg) to mimic diabetes mellitus. Myocardial fibrosis and apoptosis were evaluated by histopathologic analyses, and relevant proteins were analyzed by Western blotting. Inflammatory factors were assessed by ELISA. Markers of oxidative stress were tested by colorimetric analysis. Rats with DCM displayed decreased body weight, metabolic abnormalities, elevated apoptosis (as assessed by the bcl-2/bax ratio and TUNEL assays), increased fibrosis, increased markers of oxidative stress (MDA and SOD) and inflammatory factors (TNF-α and IL-1β), and decreased phosphorylation of Akt and glycogen synthase kinase (GSK-3β). IGF-1 treatment, however, attenuated the metabolic abnormalities and myocardial apoptosis, interstitial fibrosis, oxidative stress and inflammation seen in diabetic rats, while also increasing the phosphorylation levels of Akt and GSK-3β. These findings suggest that IGF-1 ameliorates the pathophysiological progress of DCM along with an activation of the Akt/GSK-3β signaling pathway. Our findings suggest that IGF-1 could be a potential therapeutic choice for controlling DCM.
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Affiliation(s)
- Cheng Yu Wang
- Center of Morphological Experiment, Medical College of Yanbian University, Yanji 133000, Jilin Province, China
| | - Xiang Dan Li
- Center of Morphological Experiment, Medical College of Yanbian University, Yanji 133000, Jilin Province, China
| | - Zhi Hong Hao
- Center of Morphological Experiment, Medical College of Yanbian University, Yanji 133000, Jilin Province, China
| | - Dongyuan Xu
- Center of Morphological Experiment, Medical College of Yanbian University, Yanji 133000, Jilin Province, China
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Zhao Z, Barcus M, Kim J, Lum KL, Mills C, Lei XG. High Dietary Selenium Intake Alters Lipid Metabolism and Protein Synthesis in Liver and Muscle of Pigs. J Nutr 2016; 146:1625-33. [PMID: 27466604 PMCID: PMC4997278 DOI: 10.3945/jn.116.229955] [Citation(s) in RCA: 82] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Accepted: 06/08/2016] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Prolonged high intakes of dietary selenium have been shown to induce gestational diabetes in rats and hyperinsulinemia in pigs. OBJECTIVE Two experiments were conducted to explore metabolic and molecular mechanisms for the diabetogenic potential of high dietary selenium intakes in pigs. METHODS In Expt. 1, 16 Yorkshire-Landrace-Hampshire crossbred pigs (3 wk old, body weight = 7.5 ± 0.81 kg, 50% males and 50% females) were fed a corn-soybean meal basal diet supplemented with 0.3 or 1.0 mg Se/kg (as selenium-enriched yeast for 6 wk). In Expt. 2, 12 pigs of the same crossbreed (6 wk old, body weight = 16.0 ± 1.8 kg) were fed a similar basal diet supplemented with 0.3 or 3.0 mg Se/kg for 11 wk. Biochemical and gene and protein expression profiles of lipid and protein metabolism and selenoproteins in plasma, liver, muscle, and adipose tissues were analyzed. RESULTS In Expt. 1, the 1-mg-Se/kg diet did not affect body weight or plasma concentrations of glucose and nonesterified fatty acids. In Expt. 2, the 3-mg-Se/kg diet, compared with the 0.3-mg-Se/kg diet, increased (P < 0.05) concentrations of plasma insulin (0.2 compared with 0.4 ng/mL), liver and adipose lipids (41% to 2.4-fold), and liver and muscle protein (10-14%). In liver, the 3-mg-Se/kg diet upregulated (P < 0.05) the expression, activity, or both of key factors related to gluconeogenesis [phosphoenolpyruvate carboxykinase (PEPCK); 13%], lipogenesis [sterol regulatory element binding protein 1 (SREBP1), acetyl-coenzyme A carboxylase (ACC), and fatty acid synthase (FASN); 46-90%], protein synthesis [insulin receptor (INSR), P70 ribosomal protein S6 kinase (P70), and phosphorylated ribosomal protein S6 (P-S6); 88-105%], energy metabolism [AMP-activated protein kinase (AMPK); up to 2.8-fold], and selenoprotein glutathione peroxidase 3 (GPX3; 1.4-fold) and suppressed (P < 0.05) mRNA levels of lipolysis gene cytochrome P450, family 7, subfamily A, polypeptide 1 (CYP7A1; 88%) and selenoprotein gene selenoprotein W1 (SEPW1; 46%). In muscle, the 3-mg-Se/kg diet exerted no effect on the lipid profiles but enhanced (P < 0.05) expression of P-S6 and mammalian target of rapamycin (mTOR; 42-176%; protein synthesis); selenoprotein P (SELP; 40-fold); and tumor suppressor protein 53 (P53) and peroxisome proliferator-activated receptor γ (PPARG; 52-58%; lipogenesis) and suppressed (P < 0.05) expression of INSR (59%; insulin signaling); selenoprotein S (SELS); deiodinases, iodothyronine, type I (DIO1); and thioredoxin reductase 1 (TXNRD1; 50%; selenoproteins); and ACC1 and FASN (35-51%; lipogenesis). CONCLUSION Our research showed novel roles, to our best knowledge, and mechanisms of high selenium intakes in regulating the metabolism of protein, along with that of lipid, in a tissue-specific fashion in pigs.
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Affiliation(s)
| | | | | | | | | | - Xin Gen Lei
- Department of Animal Science, Cornell University, Ithaca, NY
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