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Ge C, Wang X, Wang Y, Lei L, Song G, Qian M, Wang S. PKCε inhibition prevents ischemia‑induced dendritic spine impairment in cultured primary neurons. Exp Ther Med 2023; 25:152. [PMID: 36911376 PMCID: PMC9995843 DOI: 10.3892/etm.2023.11851] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Accepted: 01/31/2023] [Indexed: 02/18/2023] Open
Abstract
Brain ischemia is an independent risk factor for Alzheimer's disease (AD); however, the mechanisms underlining ischemic stroke and AD remain unclear. The present study aimed to investigate the function of the ε isoform of protein kinase C (PKCε) in brain ischemia-induced dendritic spine dysfunction to elucidate how brain ischemia causes AD. In the present study, primary hippocampus and cortical neurons were cultured while an oxygen-glucose deprivation (OGD) model was used to simulate brain ischemia. In the OGD cell model, in vitro kinase activity assay was performed to investigate whether the PKCε kinase activity changed after OGD treatment. Confocal microscopy was performed to investigate whether inhibiting PKCε kinase activity protects dendritic spine morphology and function. G-LISA was used to investigate whether small GTPases worked downstream of PKCε. The results showed that PKCε kinase activity was significantly increased following OGD treatment in primary neurons, leading to dendritic spine dysfunction. Pre-treatment with PKCε-inhibiting peptide, which blocks PKCε activity, significantly rescued dendritic spine function following OGD treatment. Furthermore, PKCε could activate Ras homolog gene family member A (RhoA) as a downstream molecule, which mediated OGD-induced dendritic spine morphology changes and caused dendritic spine dysfunction. In conclusion, the present study demonstrated that the PKCε/RhoA signalling pathway is a novel mechanism mediating brain ischemia-induced dendritic spine dysfunction. Developing therapeutic targets for this pathway may protect against and prevent brain ischemia-induced cognitive impairment and AD.
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Affiliation(s)
- Chenjie Ge
- Department of Psychiatry, Huzhou Third Municipal Hospital, The Affiliated Hospital of Huzhou University, Huzhou, Zhejiang 313000, P.R. China
| | - Xuefeng Wang
- WuXi AppTec Co., Ltd., Shanghai 200131, P.R. China
| | - Yunhong Wang
- WuXi AppTec Co., Ltd., Shanghai 200131, P.R. China
| | - Lilei Lei
- Department of Psychiatry, Huzhou Third Municipal Hospital, The Affiliated Hospital of Huzhou University, Huzhou, Zhejiang 313000, P.R. China
| | - Guohua Song
- Department of Psychiatry, Huzhou Third Municipal Hospital, The Affiliated Hospital of Huzhou University, Huzhou, Zhejiang 313000, P.R. China
| | - Mincai Qian
- Department of Psychiatry, Huzhou Third Municipal Hospital, The Affiliated Hospital of Huzhou University, Huzhou, Zhejiang 313000, P.R. China
| | - Shiliang Wang
- Department of Psychiatry, Huzhou Third Municipal Hospital, The Affiliated Hospital of Huzhou University, Huzhou, Zhejiang 313000, P.R. China
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Naryzhnaya NV, Maslov LN, Derkachev IA, Fu F. The Significance of NO-Synthase, Reactive Oxygen Species, Kinases and KATP-Channels in the Development of the Infarct-Limiting Effect of Adaptation to Hypoxia. J EVOL BIOCHEM PHYS+ 2022. [DOI: 10.1134/s0022093022020211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Naryzhnaya NV, Maslov LN, Derkachev IA, Ma H, Zhang Y, Prasad NR, Singh N, Fu F, Pei JM, Sarybaev A, Sydykov A. The effect of adaptation to hypoxia on cardiac tolerance to ischemia/reperfusion. J Biomed Res 2022:1-25. [PMID: 37183617 PMCID: PMC10387748 DOI: 10.7555/jbr.36.20220125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
The acute myocardial infarction (AMI) and sudden cardiac death (SCD), both associated with acute cardiac ischemia, are one of the leading causes of adult death in economically developed countries. The development of new approaches for the treatment and prevention of AMI and SCD remains the highest priority for medicine. A study on the cardiovascular effects of chronic hypoxia (CH) may contribute to the development of these methods. Chronic hypoxia exerts both positive and adverse effects. The positive effects are the infarct-reducing, vasoprotective, and antiarrhythmic effects, which can lead to the improvement of cardiac contractility in reperfusion. The adverse effects are pulmonary hypertension and right ventricular hypertrophy. This review presents a comprehensive overview of how CH enhances cardiac tolerance to ischemia/reperfusion. It is an in-depth analysis of the published data on the underlying mechanisms, which can lead to future development of the cardioprotective effect of CH. A better understanding of the CH-activated protective signaling pathways may contribute to new therapeutic approaches in an increase of cardiac tolerance to ischemia/reperfusion.
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Su Z, Liu Y, Zhang H. Adaptive Cardiac Metabolism Under Chronic Hypoxia: Mechanism and Clinical Implications. Front Cell Dev Biol 2021; 9:625524. [PMID: 33604337 PMCID: PMC7884626 DOI: 10.3389/fcell.2021.625524] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Accepted: 01/11/2021] [Indexed: 11/29/2022] Open
Abstract
Chronic hypoxia is an essential component in many cardiac diseases. The heart consumes a substantial amount of energy and it is important to maintain the balance of energy supply and demand when oxygen is limited. Previous studies showed that the heart switches from fatty acid to glucose to maintain metabolic efficiency in the adaptation to chronic hypoxia. However, the underlying mechanism of this adaptive cardiac metabolism remains to be fully characterized. Moreover, how the altered cardiac metabolism affects the heart function in patients with chronic hypoxia has not been discussed in the current literature. In this review, we summarized new findings from animal and human studies to illustrate the mechanism underlying the adaptive cardiac metabolism under chronic hypoxia. Clinical focus is given to certain patients that are subject to the impact of chronic hypoxia, and potential treatment strategies that modulate cardiac metabolism and may improve the heart function in these patients are also summarized.
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Affiliation(s)
- Zhanhao Su
- State Key Laboratory of Cardiovascular Disease, National Center for Cardiovascular Diseases, Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Yiwei Liu
- Heart center and Shanghai Institute of Pediatric Congenital Heart Disease, Shanghai Children's Medical Center, National Children's Medical Center, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Hao Zhang
- Heart center and Shanghai Institute of Pediatric Congenital Heart Disease, Shanghai Children's Medical Center, National Children's Medical Center, Shanghai Jiaotong University School of Medicine, Shanghai, China
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Naryzhnaya NV, Ma HJ, Maslov LN. The involvement of protein kinases in the cardioprotective effect of chronic hypoxia. Physiol Res 2020; 69:933-945. [PMID: 33129243 DOI: 10.33549/physiolres.934439] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
The purpose of this review is to analyze the involvement of protein kinases in the cardioprotective mechanism induced by chronic hypoxia. It has been reported that chronic intermittent hypoxia contributes to increased expression of the following kinases in the myocardium: PKCdelta, PKCalpha, p-PKCepsilon, p-PKCalpha, AMPK, p-AMPK, CaMKII, p-ERK1/2, p-Akt, PI3-kinase, p-p38, HK-1, and HK-2; whereas, chronic normobaric hypoxia promotes increased expression of the following kinases in the myocardium: PKCepsilon, PKCbetaII, PKCeta, CaMKII, p-ERK1/2, p-Akt, p-p38, HK-1, and HK-2. However, CNH does not promote enhanced expression of the AMPK and JNK kinases. Adaptation to hypoxia enhances HK-2 association with mitochondria and causes translocation of PKCdelta, PKCbetaII, and PKCeta to the mitochondria. It has been shown that PKCdelta, PKCepsilon, ERK1/2, and MEK1/2 are involved in the cardioprotective effect of chronic hypoxia. The role of other kinases in the cardioprotective effect of adaptation to hypoxia requires further research.
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Affiliation(s)
- N V Naryzhnaya
- Cardiology Research Institute, Tomsk National Research Medical Center, Russian Academy of Sciences, Tomsk, Russia.
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Nox2 Upregulation and p38α MAPK Activation in Right Ventricular Hypertrophy of Rats Exposed to Long-Term Chronic Intermittent Hypobaric Hypoxia. Int J Mol Sci 2020; 21:ijms21228576. [PMID: 33202984 PMCID: PMC7698046 DOI: 10.3390/ijms21228576] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Revised: 10/07/2020] [Accepted: 10/09/2020] [Indexed: 12/12/2022] Open
Abstract
One of the consequences of high altitude (hypobaric hypoxia) exposure is the development of right ventricular hypertrophy (RVH). One particular type of exposure is long-term chronic intermittent hypobaric hypoxia (CIH); the molecular alterations in RVH in this particular condition are less known. Studies show an important role of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase complex-induced oxidative stress and protein kinase activation in different models of cardiac hypertrophy. The aim was to determine the oxidative level, NADPH oxidase expression and MAPK activation in rats with RVH induced by CIH. Male Wistar rats were randomly subjected to CIH (2 days hypoxia/2 days normoxia; n = 10) and normoxia (NX; n = 10) for 30 days. Hypoxia was simulated with a hypobaric chamber. Measurements in the RV included the following: hypertrophy, Nox2, Nox4, p22phox, LOX-1 and HIF-1α expression, lipid peroxidation and H2O2 concentration, and p38α and Akt activation. All CIH rats developed RVH and showed an upregulation of LOX-1, Nox2 and p22phox and an increase in lipid peroxidation, HIF-1α stabilization and p38α activation. Rats with long-term CIH-induced RVH clearly showed Nox2, p22phox and LOX-1 upregulation and increased lipid peroxidation, HIF-1α stabilization and p38α activation. Therefore, these molecules may be considered new targets in CIH-induced RVH.
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Oxidative Stress, Kinase Activity and Inflammatory Implications in Right Ventricular Hypertrophy and Heart Failure under Hypobaric Hypoxia. Int J Mol Sci 2020; 21:ijms21176421. [PMID: 32899304 PMCID: PMC7503689 DOI: 10.3390/ijms21176421] [Citation(s) in RCA: 58] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Revised: 08/22/2020] [Accepted: 08/24/2020] [Indexed: 02/06/2023] Open
Abstract
High altitude (hypobaric hypoxia) triggers several mechanisms to compensate for the decrease in oxygen bioavailability. One of them is pulmonary artery vasoconstriction and its subsequent pulmonary arterial remodeling. These changes can lead to pulmonary hypertension and the development of right ventricular hypertrophy (RVH), right heart failure (RHF) and, ultimately to death. The aim of this review is to describe the most recent molecular pathways involved in the above conditions under this type of hypobaric hypoxia, including oxidative stress, inflammation, protein kinases activation and fibrosis, and the current therapeutic approaches for these conditions. This review also includes the current knowledge of long-term chronic intermittent hypobaric hypoxia. Furthermore, this review highlights the signaling pathways related to oxidative stress (Nox-derived O2.- and H2O2), protein kinase (ERK5, p38α and PKCα) activation, inflammatory molecules (IL-1β, IL-6, TNF-α and NF-kB) and hypoxia condition (HIF-1α). On the other hand, recent therapeutic approaches have focused on abolishing hypoxia-induced RVH and RHF via attenuation of oxidative stress and inflammatory (IL-1β, MCP-1, SDF-1 and CXCR-4) pathways through phytotherapy and pharmacological trials. Nevertheless, further studies are necessary.
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Ren J, Liu W, Li GC, Jin M, You ZX, Liu HG, Hu Y. Atorvastatin Attenuates Myocardial Hypertrophy Induced by Chronic Intermittent Hypoxia In Vitro Partly through miR-31/PKCε Pathway. Curr Med Sci 2018; 38:405-412. [PMID: 30074205 DOI: 10.1007/s11596-018-1893-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Revised: 01/03/2018] [Indexed: 02/07/2023]
Abstract
Atorvastatin is proven to ameliorate cardiac hypertrophy induced by chronic intermittent hypoxia (CIH). However, little is known about the mechanism by which atorvastatin modulates CIH-induced cardiac hypertrophy, and whether specific hypertrophyrelated microRNAs are involved in the modulation. MiR-31 plays key roles in the development of cardiac hypertrophy induced by ischemia/hypoxia. This study examined whether miR-31 was involved in the protective role of atorvastatin against CIH-induced myocardial hypertrophy. H9c2 cells were subjected to 8-h intermittent hypoxia per day in the presence or absence of atorvastatin for 5 days. The size of cardiomyocytes, and the expression of caspase 3 and miR-31 were determined by Western blotting and RT-PCR, respectively. MiR-31 mimic or Ro 31-8220, a specific inhibitor of protein kinase C epsilon (PKCε), was used to determine the role of miR-31 in the anti-hypertrophic effect of atorvastatin on cardiomyocytes. PKCε in the cardiomyocytes with miR-31 upregulation or downregulation was detected using RT-PCR and Western blotting. The results showed that CIH induced obvious enlargement of cardiomyocytes, which was paralleled with increased atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), and slow/beta cardiac myosin heavy-chain (MYH7) mRNA levels. All these changes were reversed by the treatment with atorvastatin. Meanwhile, miR-31 was increased by CIH in vitro. Of note, the atorvastatin pretreatment significantly increased the mRNA and protein expression of PKCe and decreased that of miR-31. Moreover, overexpression of miR-31 abolished the anti-hypertrophic effect of atorvastatin on cardiomyocytes. Upregulation and downregulation of miR-31 respectively decreased and increased the mRNA and protein expression of PKCε. These results suggest that atorvastatin provides the cardioprotective effects against CIH probably via up-regulating PKCε and down-regulating miR-31.
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Affiliation(s)
- Jie Ren
- Department of Respiratory and Critical Care Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Wei Liu
- Department of Respiratory and Critical Care Medicine, The Central Hospital of Wuhan, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430010, China
| | - Guang-Cai Li
- Department of Respiratory and Critical Care Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Meng Jin
- Department of Respiratory and Critical Care Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Zhen-Xi You
- Department of Respiratory and Critical Care Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Hui-Guo Liu
- Department of Respiratory and Critical Care Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.
| | - Yi Hu
- Department of Respiratory and Critical Care Medicine, The Central Hospital of Wuhan, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430010, China.
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Mallet RT, Manukhina EB, Ruelas SS, Caffrey JL, Downey HF. Cardioprotection by intermittent hypoxia conditioning: evidence, mechanisms, and therapeutic potential. Am J Physiol Heart Circ Physiol 2018; 315:H216-H232. [PMID: 29652543 DOI: 10.1152/ajpheart.00060.2018] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The calibrated application of limited-duration, cyclic, moderately intense hypoxia-reoxygenation increases cardiac resistance to ischemia-reperfusion stress. These intermittent hypoxic conditioning (IHC) programs consistently produce striking reductions in myocardial infarction and ventricular tachyarrhythmias after coronary artery occlusion and reperfusion and, in many cases, improve contractile function and coronary blood flow. These IHC protocols are fundamentally different from those used to simulate sleep apnea, a recognized cardiovascular risk factor. In clinical studies, IHC improved exercise capacity and decreased arrhythmias in patients with coronary artery or pulmonary disease and produced robust, persistent, antihypertensive effects in patients with essential hypertension. The protection afforded by IHC develops gradually and depends on β-adrenergic, δ-opioidergic, and reactive oxygen-nitrogen signaling pathways that use protein kinases and adaptive transcription factors. In summary, adaptation to intermittent hypoxia offers a practical, largely unrecognized means of protecting myocardium from impending ischemia. The myocardial and perhaps broader systemic protection provided by IHC clearly merits further evaluation as a discrete intervention and as a potential complement to conventional pharmaceutical and surgical interventions.
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Affiliation(s)
- Robert T Mallet
- Department of Integrative Physiology and Anatomy, University of North Texas Health Science Center , Fort Worth, Texas
| | - Eugenia B Manukhina
- Department of Integrative Physiology and Anatomy, University of North Texas Health Science Center , Fort Worth, Texas.,Institute of General Pathology and Pathophysiology, Russian Academy of Medical Sciences , Moscow , Russian Federation.,School of Medical Biology South Ural State University , Chelyabinsk , Russian Federation
| | - Steven Shea Ruelas
- Department of Integrative Physiology and Anatomy, University of North Texas Health Science Center , Fort Worth, Texas
| | - James L Caffrey
- Department of Integrative Physiology and Anatomy, University of North Texas Health Science Center , Fort Worth, Texas
| | - H Fred Downey
- Department of Integrative Physiology and Anatomy, University of North Texas Health Science Center , Fort Worth, Texas.,School of Medical Biology South Ural State University , Chelyabinsk , Russian Federation
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Cole MA, Abd Jamil AH, Heather LC, Murray AJ, Sutton ER, Slingo M, Sebag-Montefiore L, Tan SC, Aksentijević D, Gildea OS, Stuckey DJ, Yeoh KK, Carr CA, Evans RD, Aasum E, Schofield CJ, Ratcliffe PJ, Neubauer S, Robbins PA, Clarke K. On the pivotal role of PPARα in adaptation of the heart to hypoxia and why fat in the diet increases hypoxic injury. FASEB J 2016; 30:2684-97. [PMID: 27103577 PMCID: PMC5072355 DOI: 10.1096/fj.201500094r] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Accepted: 04/05/2016] [Indexed: 12/21/2022]
Abstract
The role of peroxisome proliferator-activated receptor α (PPARα)-mediated metabolic remodeling in cardiac adaptation to hypoxia has yet to be defined. Here, mice were housed in hypoxia for 3 wk before in vivo contractile function was measured using cine MRI. In isolated, perfused hearts, energetics were measured using (31)P magnetic resonance spectroscopy (MRS), and glycolysis and fatty acid oxidation were measured using [(3)H] labeling. Compared with a normoxic, chow-fed control mouse heart, hypoxia decreased PPARα expression, fatty acid oxidation, and mitochondrial uncoupling protein 3 (UCP3) levels, while increasing glycolysis, all of which served to maintain normal ATP concentrations ([ATP]) and thereby, ejection fractions. A high-fat diet increased cardiac PPARα expression, fatty acid oxidation, and UCP3 levels with decreased glycolysis. Hypoxia was unable to alter the high PPARα expression or reverse the metabolic changes caused by the high-fat diet, with the result that [ATP] and contractile function decreased significantly. The adaptive metabolic changes caused by hypoxia in control mouse hearts were found to have occurred already in PPARα-deficient (PPARα(-/-)) mouse hearts and sustained function in hypoxia despite an inability for further metabolic remodeling. We conclude that decreased cardiac PPARα expression is essential for adaptive metabolic remodeling in hypoxia, but is prevented by dietary fat.-Cole, M. A., Abd Jamil, A. H., Heather, L. C., Murray, A. J., Sutton, E. R., Slingo, M., Sebag-Montefiore, L., Tan, S. C., Aksentijević, D., Gildea, O. S., Stuckey, D. J., Yeoh, K. K., Carr, C. A., Evans, R. D., Aasum, E., Schofield, C. J., Ratcliffe, P. J., Neubauer, S., Robbins, P. A., Clarke, K. On the pivotal role of PPARα in adaptation of the heart to hypoxia and why fat in the diet increases hypoxic injury.
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Affiliation(s)
- Mark A Cole
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - Amira H Abd Jamil
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - Lisa C Heather
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - Andrew J Murray
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - Elizabeth R Sutton
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - Mary Slingo
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - Liam Sebag-Montefiore
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, United Kingdom
| | - Suat Cheng Tan
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - Dunja Aksentijević
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, United Kingdom
| | - Ottilie S Gildea
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - Daniel J Stuckey
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - Kar Kheng Yeoh
- Chemistry Research Laboratory, University of Oxford, Oxford, United Kingdom; and
| | - Carolyn A Carr
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - Rhys D Evans
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - Ellen Aasum
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | | | - Peter J Ratcliffe
- Nuffield Department of Clinical Medicine, University of Oxford, Oxford, United Kingdom
| | - Stefan Neubauer
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, United Kingdom
| | - Peter A Robbins
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - Kieran Clarke
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom;
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Cunningham KF, Beeson GC, Beeson CC, McDermott PJ. Increased expression of estrogen-related receptor β during adaptation of adult cardiomyocytes to sustained hypoxia. AMERICAN JOURNAL OF CARDIOVASCULAR DISEASE 2016; 6:46-54. [PMID: 27335690 PMCID: PMC4913214] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Received: 03/29/2016] [Accepted: 05/03/2016] [Indexed: 06/06/2023]
Abstract
UNLABELLED Estrogen-related Receptors (ERR) are members of the steroid hormone receptor superfamily of transcription factors that regulate expression of genes required for energy metabolism including mitochondrial biogenesis, fatty acid oxidation and oxidative phosphorylation. While ERRα and EPPγ isoforms are known to share a wide array of target genes in the adult myocardium, the function of ERRβ has not been characterized in cardiomyocytes. The purpose of this study was to determine the role of ERRβ in regulating energy metabolism in adult cardiomyocytes in primary culture. Adult feline cardiomyocytes were electrically stimulated to contract in either hypoxia (0.5% O2) or normoxia (21% O2). As compared to baseline values measured in normoxia, ERRβ mRNA levels increased significantly after 8 hours of hypoxia and remained elevated over 24 h. Conversely, ERRβ mRNA decreased to normoxic levels after 4 hours of reoxygenation. Hypoxia increased expression of the α and β isoforms of Peroxisome Proliferator-Activated Receptor γ Coactivator-1 (PGC-1) mRNA by 6-fold and 3-fold, respectively. Knockdown of ERRβ expression via adenoviral-mediated delivery of ERRβ shRNA blocked hypoxia-induced increases in PGC-1β mRNA, but not PGC-1α mRNA. Loss of ERRβ had no effect on mtDNA content as measured after 24 h of hypoxia. To determine whether loss of ERRβ affected mitochondrial function, oxygen consumption rates (OCR) were measured in contracting versus quiescent cardiomyocytes in normoxia. OCR was significantly lower in contracting cardiomyocytes expressing ERRβ shRNA than scrambled shRNA controls. Maximal OCR also was reduced by ERRβ knockdown. IN CONCLUSION 1) hypoxia increases in ERRβ mRNA expression in contracting cardiomyocytes; 2) ERRβ is required for induction of the PGC-1β isoform in response to hypoxia; 3) ERRβ expression is required to sustain OCR in normoxic conditions.
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Affiliation(s)
- Kathryn F Cunningham
- Gazes Cardiac Research Institute, Department of Medicine, Medical University of South CarolinaCharleston, South Carolina, USA
| | - Gyda C Beeson
- Department of Drug Discovery and Biomedical Sciences, Medical University of South CarolinaCharleston, South Carolina, USA
| | - Craig C Beeson
- Department of Drug Discovery and Biomedical Sciences, Medical University of South CarolinaCharleston, South Carolina, USA
| | - Paul J McDermott
- Gazes Cardiac Research Institute, Department of Medicine, Medical University of South CarolinaCharleston, South Carolina, USA
- Ralph H. Johnson Department of Veterans Affairs Medical CenterCharleston, South Carolina, USA
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Effect of regional muscle location but not adiposity on mitochondrial biogenesis-regulating proteins. Eur J Appl Physiol 2015; 116:11-8. [DOI: 10.1007/s00421-015-3232-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2015] [Accepted: 07/31/2015] [Indexed: 01/06/2023]
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13
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HOLZEROVÁ K, HLAVÁČKOVÁ M, ŽURMANOVÁ J, BORCHERT G, NECKÁŘ J, KOLÁŘ F, NOVÁK F, NOVÁKOVÁ O. Involvement of PKCε in Cardioprotection Induced by Adaptation to Chronic Continuous Hypoxia. Physiol Res 2015; 64:191-201. [DOI: 10.33549/physiolres.932860] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Continuous normobaric hypoxia (CNH) renders the heart more tolerant to acute ischemia/reperfusion injury. Protein kinase C (PKC) is an important component of the protective signaling pathway, but the contribution of individual PKC isoforms under different hypoxic conditions is poorly understood. The aim of this study was to analyze the expression of PKCε after the adaptation to CNH and to clarify its role in increased cardiac ischemic tolerance with the use of PKCε inhibitory peptide KP-1633. Adult male Wistar rats were exposed to CNH (10 % O2, 3 weeks) or kept under normoxic conditions. The protein level of PKCε and its phosphorylated form was analyzed by Western blot in homogenate, cytosolic and particulate fractions; the expression of PKCε mRNA was measured by RT-PCR. The effect of KP-1633 on cell viability and lactate dehydrogenase (LDH) release was analyzed after 25-min metabolic inhibition followed by 30-min re-energization in freshly isolated left ventricular myocytes. Adaptation to CNH increased myocardial PKCε at protein and mRNA levels. The application of KP-1633 blunted the hypoxia-induced salutary effects on cell viability and LDH release, while control peptide KP-1723 had no effect. This study indicates that PKCε is involved in the cardioprotective mechanism induced by CNH.
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Affiliation(s)
| | - M. HLAVÁČKOVÁ
- Department of Developmental Cardiology, Institute of Physiology, Czech Academy of Sciences, Prague, Czech Republic
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Srisakuldee W, Makazan Z, Nickel BE, Zhang F, Thliveris JA, Pasumarthi KB, Kardami E. The FGF-2-triggered protection of cardiac subsarcolemmal mitochondria from calcium overload is mitochondrial connexin 43-dependent. Cardiovasc Res 2014; 103:72-80. [DOI: 10.1093/cvr/cvu066] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
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15
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The "memory kinases": roles of PKC isoforms in signal processing and memory formation. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2014; 122:31-59. [PMID: 24484697 DOI: 10.1016/b978-0-12-420170-5.00002-7] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The protein kinase C (PKC) isoforms, which play an essential role in transmembrane signal conduction, can be viewed as a family of "memory kinases." Evidence is emerging that they are critically involved in memory acquisition and maintenance, in addition to their involvement in other functions of cells. Deficits in PKC signal cascades in neurons are one of the earliest abnormalities in the brains of patients suffering from Alzheimer's disease. Their dysfunction is also involved in several other types of memory impairments, including those related to emotion, mental retardation, brain injury, and vascular dementia/ischemic stroke. Inhibition of PKC activity leads to a reduced capacity of many types of learning and memory, but may have therapeutic values in treating substance abuse or aversive memories. PKC activators, on the other hand, have been shown to possess memory-enhancing and antidementia actions. PKC pharmacology may, therefore, represent an attractive area for developing effective cognitive drugs for the treatment of many types of memory disorders and dementias.
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Lassaletta AD, Chu LM, Elmadhun NY, Robich MP, Hoffman ZG, Kim DJ, Sellke FW. Mechanism for reduced pericardial adhesion formation in hypercholesterolemic swine supplemented with alcohol. Eur J Cardiothorac Surg 2012; 43:1058-64. [PMID: 22991457 DOI: 10.1093/ejcts/ezs488] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
OBJECTIVE Previous experiments in Yorkshire swine demonstrated significantly fewer pericardial adhesions and intramyocardial collagen deposition at reoperative sternotomy in animals supplemented with vodka but not with red wine. The purpose of this experiment was to determine a mechanism for adhesion reduction. METHODS Twenty-seven male Yorkshire swine were fed a high-cholesterol diet to simulate conditions of coronary artery disease followed by the surgical placement of an ameroid constrictor to the left circumflex coronary artery to induce chronic ischaemia. Postoperatively, control pigs continued their high-fat/cholesterol diet alone, whereas the two experimental groups had diets supplemented with either red wine or vodka for 7 weeks followed by reoperative sternotomy and cardiac harvest. RESULTS The expression of related adhesion focal tyrosine kinase (RAFTK) and caspase 3 in the sodium dodecyl sulphate (SDS)-soluble myocardial fraction was significantly higher only in the vodka-supplemented group. In the more soluble fraction, the expression of caspase 3, cleaved caspase 3 and caspase 9 was lower in both the vodka and red wine treatment groups. CONCLUSIONS In the SDS-soluble lysate fraction, likely representing the transmembrane/cell-extracellular matrix (ECM), a significant increase in RAFTK and caspase 3 expression was seen only in the vodka-treated animals, which may explain why this group demonstrated significantly fewer pericardial adhesions. Caspase expression/signalling was not increased in the more soluble myocardial lysate, suggesting that the increased apoptotic signalling was specific to the epicardial-ECM.
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Affiliation(s)
- Antonio D Lassaletta
- Division of Cardiothoracic Surgery, Cardiovascular Research Center, Warren Alpert Medical School, Brown University, Providence, RI 02905, USA
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Jacobs RA, Siebenmann C, Hug M, Toigo M, Meinild AK, Lundby C. Twenty-eight days at 3454-m altitude diminishes respiratory capacity but enhances efficiency in human skeletal muscle mitochondria. FASEB J 2012; 26:5192-200. [PMID: 22968913 DOI: 10.1096/fj.12-218206] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Modifications of skeletal muscle mitochondria following exposure to high altitude (HA) are generally studied by morphological examinations and biochemical analysis of expression. The aim of this study was to examine tangible measures of mitochondrial function following a prolonged exposure to HA. For this purpose, skeletal muscle biopsies were obtained from 8 lowland natives at sea level (SL) prior to exposure and again after 28 d of exposure to HA at 3454 m. High-resolution respirometry was performed on the muscle samples comparing respiratory capacity and efficiency. Exercise capacity was assessed at SL and HA. Respirometric analysis revealed that mitochondrial respiratory capacity diminished in complex I- and complex II-specific respiration in addition to a loss of maximal state-3 oxidative phosphorylation capacity from SL to HA, all independent from alterations in mitochondrial content. Leak control coupling, respiratory control ratio, and oligomycin-induced leak respiration, all measures of mitochondrial efficiency, improved in response to HA exposure. SL respiratory capacities correlated with measures of exercise capacity near SL, whereas mitochondrial efficiency correlated best with exercise capacity following HA. This data demonstrate that 1 mo of exposure to HA reduces respiratory capacity in human skeletal muscle; however, the efficiency of electron transport improves.
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Affiliation(s)
- Robert A Jacobs
- Zurich Center for Integrative Human Physiology (ZIHP), University of Zurich, Zurich, Switzerland
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Lin HB, Cadete VJJ, Sawicka J, Wozniak M, Sawicki G. Effect of the myosin light chain kinase inhibitor ML-7 on the proteome of hearts subjected to ischemia-reperfusion injury. J Proteomics 2012; 75:5386-95. [PMID: 22749930 DOI: 10.1016/j.jprot.2012.06.016] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2012] [Revised: 06/11/2012] [Accepted: 06/18/2012] [Indexed: 01/05/2023]
Abstract
In the development of ischemia/reperfusion (I/R) injury, the role of the myosin light chain (MLC) phosphorylation has been given increased consideration. ML-7, a MLC kinase inhibitor, has been shown to protect cardiac function from I/R, however the exact mechanism remains unclear. Isolated rat hearts were perfused under aerobic conditions (controls) or subjected to I/R in the presence or absence of ML-7. Continuous administration of ML-7 (5 μM) from 10 min before onset of ischemia to the first 10 min of reperfusion resulted in significant recovery of heart contractility. Analysis of gels from two-dimensional electrophoresis revealed eight proteins with decreased levels in I/R hearts. Six proteins are involved in energy metabolism:ATP synthase beta subunit, cytochrome b-c1 complex subunit 1, 24-kDa mitochondrial NADH dehydrogenase, NADH dehydrogenase [ubiquinone] iron-sulfur protein 8, cytochrome c oxidase subunit, and succinyl-CoA ligase subunit. The other two proteins with decreased levels in I/R hearts are: peroxiredoxin-2 and tubulin. Administration of ML-7 increased level of succinyl-CoA ligase, key enzyme involved in the citric acid cycle. The increased level of succinyl-CoA ligase in I/R hearts perfused with ML-7 suggests that the cardioprotective effect of ML-7, at least partially, also may involve increase of energy production.
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Affiliation(s)
- Han-bin Lin
- Department of Pharmacology, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
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Levett DZ, Radford EJ, Menassa DA, Graber EF, Morash AJ, Hoppeler H, Clarke K, Martin DS, Ferguson-Smith AC, Montgomery HE, Grocott MPW, Murray AJ. Acclimatization of skeletal muscle mitochondria to high-altitude hypoxia during an ascent of Everest. FASEB J 2011; 26:1431-41. [PMID: 22186874 DOI: 10.1096/fj.11-197772] [Citation(s) in RCA: 112] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Ascent to high altitude is associated with a fall in the partial pressure of inspired oxygen (hypobaric hypoxia). For oxidative tissues such as skeletal muscle, resultant cellular hypoxia necessitates acclimatization to optimize energy metabolism and restrict oxidative stress, with changes in gene and protein expression that alter mitochondrial function. It is known that lowlanders returning from high altitude have decreased muscle mitochondrial densities, yet the underlying transcriptional mechanisms and time course are poorly understood. To explore these, we measured gene and protein expression plus ultrastructure in muscle biopsies of lowlanders at sea level and following exposure to hypobaric hypoxia. Subacute exposure (19 d after initiating ascent to Everest base camp, 5300 m) was not associated with mitochondrial loss. After 66 d at altitude and ascent beyond 6400 m, mitochondrial densities fell by 21%, with loss of 73% of subsarcolemmal mitochondria. Correspondingly, levels of the transcriptional coactivator PGC-1α fell by 35%, suggesting down-regulation of mitochondrial biogenesis. Sustained hypoxia also decreased expression of electron transport chain complexes I and IV and UCP3 levels. We suggest that during subacute hypoxia, mitochondria might be protected from oxidative stress. However, following sustained exposure, mitochondrial biogenesis is deactivated and uncoupling down-regulated, perhaps to improve the efficiency of ATP production.
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Affiliation(s)
- Denny Z Levett
- Centre for Altitude, Space, and Extreme Environment Medicine, University College London (UCL) Institute of Child Health, University College London, London, UK
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Ravingerová T, Bernátová I, Matejíková J, Ledvényiová V, Nemčeková M, Pecháňová O, Tribulová N, Slezák J. Impaired cardiac ischemic tolerance in spontaneously hypertensive rats is attenuated by adaptation to chronic and acute stress. Exp Clin Cardiol 2011; 16:e23-e29. [PMID: 22065943 PMCID: PMC3209549] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2011] [Accepted: 08/08/2011] [Indexed: 05/31/2023]
Abstract
Chronic hypertension may have a negative impact on the myocardial response to ischemia. On the other hand, intrinsic ischemic tolerance may persist even in the pathologically altered hearts of hypertensive animals, and may be modified by short- or long-term adaptation to different stressful conditions. The effects of long-term limitation of living space (ie, crowding stress [CS]) and brief ischemia-induced stress on cardiac response to ischemia/reperfusion (I/R) injury are not yet fully characterized in hypertensive subjects. The present study was designed to test the influence of chronic and acute stress on the myocardial response to I/R in spontaneously hypertensive rats (SHR) compared with their effects in normotensive counterparts. In both groups, chronic, eight-week CS was induced by caging five rats per cage in cages designed for two rats (200 cm(2)/rat), while controls (C) were housed four to a cage in cages designed for six animals (480 cm(2)/rat). Acute stress was evoked by one cycle of I/R (5 min each, ischemic preconditioning) before sustained I/R in isolated Langendorff-perfused hearts of normotensive and SHR rats. At baseline conditions, the effects of CS were manifested only as a further increase in blood pressure in SHR, and by marked limitation of coronary perfusion in normotensive animals, while no changes in heart mechanical function were observed in any of the groups. Postischemic recovery of contractile function, severity of ventricular arrhythmias and lethal injury (infarction size) were worsened in the hypertrophied hearts of C-SHR compared with normotensive C. However, myo-cardial stunning and reperfusion-induced ventricular arrhythmias were attenuated by CS in SHR, which was different from deterioration of I/R injury in the hearts of normotensive animals. In contrast, ischemic preconditioning conferred an effective protection against I/R in both groups, although the extent of anti-infarct and anti-arrhythmic effects was lower in SHR. Both forms of stress may improve the altered response to ischemia in hypertensive subjects. In contrast to short-term preconditioning stress, chronic psychosocial stress was associated with a higher risk of lethal arrhythmias and contractile failure in normotensive animals exposed to an acute ischemic challenge.
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Affiliation(s)
| | - I Bernátová
- Institute of Normal and Pathological Physiology, Slovak Academy of Sciences and Centre of Excellence of SAS NOREG, Bratislava, Slovak Republic
| | | | | | | | - O Pecháňová
- Institute of Normal and Pathological Physiology, Slovak Academy of Sciences and Centre of Excellence of SAS NOREG, Bratislava, Slovak Republic
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