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Sultanian P, Lundgren P, Louca A, Andersson E, Djärv T, Hessulf F, Henningsson A, Martinsson A, Nordberg P, Piasecki A, Gupta V, Mandalenakis Z, Taha A, Redfors B, Herlitz J, Rawshani A. Prediction of survival in out-of-hospital cardiac arrest: the updated Swedish cardiac arrest risk score (SCARS) model. EUROPEAN HEART JOURNAL. DIGITAL HEALTH 2024; 5:270-277. [PMID: 38774371 PMCID: PMC11104459 DOI: 10.1093/ehjdh/ztae016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/28/2023] [Revised: 01/28/2024] [Accepted: 02/08/2024] [Indexed: 05/24/2024]
Abstract
Aims Out-of-hospital cardiac arrest (OHCA) is a major health concern worldwide. Although one-third of all patients achieve a return of spontaneous circulation and may undergo a difficult period in the intensive care unit, only 1 in 10 survive. This study aims to improve our previously developed machine learning model for early prognostication of survival in OHCA. Methods and results We studied all cases registered in the Swedish Cardiopulmonary Resuscitation Registry during 2010 and 2020 (n = 55 615). We compared the predictive performance of extreme gradient boosting (XGB), light gradient boosting machine (LightGBM), logistic regression, CatBoost, random forest, and TabNet. For each framework, we developed models that optimized (i) a weighted F1 score to penalize models that yielded more false negatives and (ii) a precision-recall area under the curve (PR AUC). LightGBM assigned higher importance values to a larger set of variables, while XGB made predictions using fewer predictors. The area under the curve receiver operating characteristic (AUC ROC) scores for LightGBM were 0.958 (optimized for weighted F1) and 0.961 (optimized for a PR AUC), while for XGB, the scores were 0.958 and 0.960, respectively. The calibration plots showed a subtle underestimation of survival for LightGBM, contrasting with a mild overestimation for XGB models. In the crucial range of 0-10% likelihood of survival, the XGB model, optimized with the PR AUC, emerged as a clinically safe model. Conclusion We improved our previous prediction model by creating a parsimonious model with an AUC ROC at 0.96, with excellent calibration and no apparent risk of underestimating survival in the critical probability range (0-10%). The model is available at www.gocares.se.
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Affiliation(s)
- Pedram Sultanian
- Department of Molecular and Clinical Medicine, Institute of Medicine, University of Gothenburg, Wallenberg Laboratory, Blå stråket 5, staircase H, Sahlgrenska University Hospital, 413 45 Gothenburg, Sweden
| | - Peter Lundgren
- Department of Molecular and Clinical Medicine, Institute of Medicine, University of Gothenburg, Wallenberg Laboratory, Blå stråket 5, staircase H, Sahlgrenska University Hospital, 413 45 Gothenburg, Sweden
- Department of Cardiology, Sahlgrenska University Hospital, Blå stråket 5, Västra Götalands län, 413 45 Gothenburg, Sweden
| | - Antros Louca
- Department of Molecular and Clinical Medicine, Institute of Medicine, University of Gothenburg, Wallenberg Laboratory, Blå stråket 5, staircase H, Sahlgrenska University Hospital, 413 45 Gothenburg, Sweden
| | - Erik Andersson
- Department of Molecular and Clinical Medicine, Institute of Medicine, University of Gothenburg, Wallenberg Laboratory, Blå stråket 5, staircase H, Sahlgrenska University Hospital, 413 45 Gothenburg, Sweden
| | - Therese Djärv
- Department of Clinical Medicine, Medicine Solna, Karolinska Institutet, Framstegsgatan, 171 64 Solna, Sweden
| | - Fredrik Hessulf
- Department of Anesthesiology and Intensive Care, Sahlgrenska University Hospital, Blå stråket 5, 413 45 Gothenburg, Sweden
- Department of Anaesthesiology and Intensive Care, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Blå stråket 5, 413 45 Gothenburg, Sweden
| | - Anna Henningsson
- Department of Anesthesiology and Intensive Care, Sahlgrenska University Hospital, Blå stråket 5, 413 45 Gothenburg, Sweden
- Department of Anaesthesiology and Intensive Care, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Blå stråket 5, 413 45 Gothenburg, Sweden
| | - Andreas Martinsson
- Department of Molecular and Clinical Medicine, Institute of Medicine, University of Gothenburg, Wallenberg Laboratory, Blå stråket 5, staircase H, Sahlgrenska University Hospital, 413 45 Gothenburg, Sweden
- Department of Cardiology, Sahlgrenska University Hospital, Blå stråket 5, Västra Götalands län, 413 45 Gothenburg, Sweden
| | - Per Nordberg
- Center for Resuscitation Science, Department of Clinical Science and Education, Karolinska Institutets, Södersjukhuset, Jägargatan 20, staircase 1, 171 77 Stockholm, Sweden
- Function Perioperative Medicine and Intensive Care, Karolinska University Hospital, Tomtebodavägen 18, 171 76 Stockholm, Sweden
| | - Adam Piasecki
- Department of Anesthesiology and Intensive Care, Sahlgrenska University Hospital, Blå stråket 5, 413 45 Gothenburg, Sweden
- Department of Anaesthesiology and Intensive Care, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Blå stråket 5, 413 45 Gothenburg, Sweden
| | - Vibha Gupta
- Department of Molecular and Clinical Medicine, Institute of Medicine, University of Gothenburg, Wallenberg Laboratory, Blå stråket 5, staircase H, Sahlgrenska University Hospital, 413 45 Gothenburg, Sweden
| | - Zacharias Mandalenakis
- Department of Molecular and Clinical Medicine, Institute of Medicine, University of Gothenburg, Wallenberg Laboratory, Blå stråket 5, staircase H, Sahlgrenska University Hospital, 413 45 Gothenburg, Sweden
- Department of Cardiology, Sahlgrenska University Hospital, Blå stråket 5, Västra Götalands län, 413 45 Gothenburg, Sweden
| | - Amar Taha
- Department of Molecular and Clinical Medicine, Institute of Medicine, University of Gothenburg, Wallenberg Laboratory, Blå stråket 5, staircase H, Sahlgrenska University Hospital, 413 45 Gothenburg, Sweden
- Department of Cardiology, Sahlgrenska University Hospital, Blå stråket 5, Västra Götalands län, 413 45 Gothenburg, Sweden
| | - Bengt Redfors
- Department of Molecular and Clinical Medicine, Institute of Medicine, University of Gothenburg, Wallenberg Laboratory, Blå stråket 5, staircase H, Sahlgrenska University Hospital, 413 45 Gothenburg, Sweden
| | - Johan Herlitz
- Department of Molecular and Clinical Medicine, Institute of Medicine, University of Gothenburg, Wallenberg Laboratory, Blå stråket 5, staircase H, Sahlgrenska University Hospital, 413 45 Gothenburg, Sweden
- The Swedish Registry for Cardiopulmonary Resuscitation, Medicinaregatan 18G, 413 90 Gothenburg, Sweden
| | - Araz Rawshani
- Department of Molecular and Clinical Medicine, Institute of Medicine, University of Gothenburg, Wallenberg Laboratory, Blå stråket 5, staircase H, Sahlgrenska University Hospital, 413 45 Gothenburg, Sweden
- Department of Cardiology, Sahlgrenska University Hospital, Blå stråket 5, Västra Götalands län, 413 45 Gothenburg, Sweden
- The Swedish Registry for Cardiopulmonary Resuscitation, Medicinaregatan 18G, 413 90 Gothenburg, Sweden
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Horn-Oudshoorn EJJ, Broekhuizen M, Harhangi MS, Simons SHP, Eggink AJ, Danser AHJ, Reiss IKM, DeKoninck PLJ. Vascular reactivity is altered in the placentas of fetuses with congenital diaphragmatic hernia. Placenta 2024; 145:51-59. [PMID: 38064938 DOI: 10.1016/j.placenta.2023.11.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Revised: 11/06/2023] [Accepted: 11/25/2023] [Indexed: 01/12/2024]
Abstract
INTRODUCTION Infants with congenital diaphragmatic hernia (CDH) often develop pulmonary hypertension but frequently fail to respond to vasodilator therapy, for instance because of an altered pulmonary vasoreactivity. Investigating such alterations in vivo is impossible. We hypothesised that these alterations are also present in fetoplacental vessels, since both vasculatures are exposed to the same circulating factors (e.g. endothelin-1) and respond similarly to certain stimuli (e.g. hypoxia). As proof-of-concept, we compared fetoplacental vasoreactivity between healthy and CDH-affected placentas. METHODS Fetoplacental vascular function of healthy and antenatally diagnosed left-sided CDH fetuses was assessed by wire myography. Placental expression of enzymes and receptors involved in the altered vasoreactive pathways was measured using quantitative PCR. RESULTS CDH arteries (n = 6) constricted more strongly to thromboxane A2 agonist U46619 (p < 0.001) and dilated less to bradykinin (p = 0.01) and nitric oxide (NO)-donor sodium nitroprusside (p = 0.04) than healthy arteries (n = 8). Vasodilation to prostacyclin analogue iloprost and adenylate cyclase stimulator forskolin, and vasoconstriction to endothelin-1 were not different between both groups. Angiotensin II did not induce vasoconstriction. Phosphodiesterase inhibitors sildenafil and milrinone did not affect responses to sodium nitroprusside, forskolin, or U46619. The mRNA expression of guanylate cyclase 1 soluble subunit alpha 1 (p = 0.003) and protein kinase cyclic guanine monophosphate (cGMP)-dependent 1 (p = 0.02) were reduced in CDH versus healthy placentas. DISCUSSION The identified changes in the thromboxane and NO-cGMP pathways in the fetoplacental vasculature correspond with currently described alterations in the pulmonary vasculature in CDH. Therefore, fetoplacental arteries may provide an opportunity to predict pulmonary therapeutic responses in infants with CDH.
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Affiliation(s)
- Emily J J Horn-Oudshoorn
- Department of Neonatal and Pediatric Intensive Care, Division of Neonatology, Rotterdam, the Netherlands
| | - Michelle Broekhuizen
- Department of Neonatal and Pediatric Intensive Care, Division of Neonatology, Rotterdam, the Netherlands; Department of Internal Medicine, Division of Pharmacology and Vascular Medicine, Rotterdam, the Netherlands; Department of Cardiology, Division of Experimental Cardiology, Rotterdam, the Netherlands
| | - Madhavi S Harhangi
- Department of Neonatal and Pediatric Intensive Care, Division of Neonatology, Rotterdam, the Netherlands; Department of Internal Medicine, Division of Pharmacology and Vascular Medicine, Rotterdam, the Netherlands; Department of Obstetrics and Gynaecology, Division of Obstetrics and Fetal Medicine, Erasmus MC University Medical Center, Rotterdam, the Netherlands
| | - Sinno H P Simons
- Department of Neonatal and Pediatric Intensive Care, Division of Neonatology, Rotterdam, the Netherlands
| | - Alex J Eggink
- Department of Obstetrics and Gynaecology, Division of Obstetrics and Fetal Medicine, Erasmus MC University Medical Center, Rotterdam, the Netherlands
| | - A H Jan Danser
- Department of Internal Medicine, Division of Pharmacology and Vascular Medicine, Rotterdam, the Netherlands
| | - Irwin K M Reiss
- Department of Neonatal and Pediatric Intensive Care, Division of Neonatology, Rotterdam, the Netherlands
| | - Philip L J DeKoninck
- Department of Obstetrics and Gynaecology, Division of Obstetrics and Fetal Medicine, Erasmus MC University Medical Center, Rotterdam, the Netherlands.
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Fang Q, Bai Y, Hu S, Ding J, Liu L, Dai M, Qiu J, Wu L, Rao X, Wang Y. Unleashing the Potential of Nrf2: A Novel Therapeutic Target for Pulmonary Vascular Remodeling. Antioxidants (Basel) 2023; 12:1978. [PMID: 38001831 PMCID: PMC10669195 DOI: 10.3390/antiox12111978] [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: 09/28/2023] [Revised: 10/22/2023] [Accepted: 11/05/2023] [Indexed: 11/26/2023] Open
Abstract
Pulmonary vascular remodeling, characterized by the thickening of all three layers of the blood vessel wall, plays a central role in the pathogenesis of pulmonary hypertension (PH). Despite the approval of several drugs for PH treatment, their long-term therapeutic effect remains unsatisfactory, as they mainly focus on vasodilation rather than addressing vascular remodeling. Therefore, there is an urgent need for novel therapeutic targets in the treatment of PH. Nuclear factor erythroid 2-related factor 2 (Nrf2) is a vital transcription factor that regulates endogenous antioxidant defense and emerges as a novel regulator of pulmonary vascular remodeling. Growing evidence has suggested an involvement of Nrf2 and its downstream transcriptional target in the process of pulmonary vascular remodeling. Pharmacologically targeting Nrf2 has demonstrated beneficial effects in various diseases, and several Nrf2 inducers are currently undergoing clinical trials. However, the exact potential and mechanism of Nrf2 as a therapeutic target in PH remain unknown. Thus, this review article aims to comprehensively explore the role and mechanism of Nrf2 in pulmonary vascular remodeling associated with PH. Additionally, we provide a summary of Nrf2 inducers that have shown therapeutic potential in addressing the underlying vascular remodeling processes in PH. Although Nrf2-related therapies hold great promise, further research is necessary before their clinical implementation can be fully realized.
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Affiliation(s)
- Qin Fang
- Division of Cardiology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China; (Q.F.); (Y.B.); (S.H.); (J.D.); (L.L.); (M.D.); (J.Q.); (L.W.)
- Hubei Key Laboratory of Genetics and Molecular Mechanisms of Cardiological Disorders, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Yang Bai
- Division of Cardiology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China; (Q.F.); (Y.B.); (S.H.); (J.D.); (L.L.); (M.D.); (J.Q.); (L.W.)
- Hubei Key Laboratory of Genetics and Molecular Mechanisms of Cardiological Disorders, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Shuiqing Hu
- Division of Cardiology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China; (Q.F.); (Y.B.); (S.H.); (J.D.); (L.L.); (M.D.); (J.Q.); (L.W.)
- Hubei Key Laboratory of Genetics and Molecular Mechanisms of Cardiological Disorders, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Jie Ding
- Division of Cardiology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China; (Q.F.); (Y.B.); (S.H.); (J.D.); (L.L.); (M.D.); (J.Q.); (L.W.)
- Hubei Key Laboratory of Genetics and Molecular Mechanisms of Cardiological Disorders, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Lei Liu
- Division of Cardiology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China; (Q.F.); (Y.B.); (S.H.); (J.D.); (L.L.); (M.D.); (J.Q.); (L.W.)
- Hubei Key Laboratory of Genetics and Molecular Mechanisms of Cardiological Disorders, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Meiyan Dai
- Division of Cardiology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China; (Q.F.); (Y.B.); (S.H.); (J.D.); (L.L.); (M.D.); (J.Q.); (L.W.)
- Hubei Key Laboratory of Genetics and Molecular Mechanisms of Cardiological Disorders, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Jie Qiu
- Division of Cardiology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China; (Q.F.); (Y.B.); (S.H.); (J.D.); (L.L.); (M.D.); (J.Q.); (L.W.)
- Hubei Key Laboratory of Genetics and Molecular Mechanisms of Cardiological Disorders, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Lujin Wu
- Division of Cardiology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China; (Q.F.); (Y.B.); (S.H.); (J.D.); (L.L.); (M.D.); (J.Q.); (L.W.)
- Hubei Key Laboratory of Genetics and Molecular Mechanisms of Cardiological Disorders, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Xiaoquan Rao
- Division of Cardiology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China; (Q.F.); (Y.B.); (S.H.); (J.D.); (L.L.); (M.D.); (J.Q.); (L.W.)
- Hubei Key Laboratory of Genetics and Molecular Mechanisms of Cardiological Disorders, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Yan Wang
- Division of Cardiology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China; (Q.F.); (Y.B.); (S.H.); (J.D.); (L.L.); (M.D.); (J.Q.); (L.W.)
- Hubei Key Laboratory of Genetics and Molecular Mechanisms of Cardiological Disorders, Huazhong University of Science and Technology, Wuhan 430030, China
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Specterman MJ, Aziz Q, Li Y, Anderson NA, Ojake L, Ng KE, Thomas AM, Finlay MC, Schilling RJ, Lambiase PD, Tinker A. Hypoxia Promotes Atrial Tachyarrhythmias via Opening of ATP-Sensitive Potassium Channels. Circ Arrhythm Electrophysiol 2023; 16:e011870. [PMID: 37646176 PMCID: PMC10510820 DOI: 10.1161/circep.123.011870] [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: 10/14/2022] [Accepted: 08/15/2023] [Indexed: 09/01/2023]
Abstract
BACKGROUND Hypoxia-ischemia predisposes to atrial arrhythmia. Atrial ATP-sensitive potassium channel (KATP) modulation during hypoxia has not been explored. We investigated the effects of hypoxia on atrial electrophysiology in mice with global deletion of KATP pore-forming subunits. METHODS Whole heart KATP RNA expression was probed. Whole-cell KATP current and action potentials were recorded in isolated wild-type (WT), Kir6.1 global knockout (6.1-gKO), and Kir6.2 global knockout (6.2-gKO) murine atrial myocytes. Langendorff-perfused hearts were assessed for atrial effective refractory period (ERP), conduction velocity, wavefront path length (WFPL), and arrhymogenicity under normoxia/hypoxia using a microelectrode array and programmed electrical stimulation. Heart histology was assessed. RESULTS Expression patterns were essentially identical for all KATP subunit RNA across human heart, whereas in mouse, Kir6.1 and SUR2 (sulphonylurea receptor subunit) were higher in ventricle than atrium, and Kir6.2 and SUR1 were higher in atrium. Compared with WT, 6.2-gKO atrial myocytes had reduced tolbutamide-sensitive current and action potentials were more depolarized with slower upstroke and reduced peak amplitude. Action potential duration was prolonged in 6.1-gKO atrial myocytes, absent of changes in other ion channel gene expression or atrial myocyte hypertrophy. In Langendorff-perfused hearts, baseline atrial ERP was prolonged and conduction velocity reduced in both KATP knockout mice compared with WT, without histological fibrosis. Compared with baseline, hypoxia led to conduction velocity slowing, stable ERP, and WFPL shortening in WT and 6.1-gKO hearts, whereas WFPL was stable in 6.2-gKO hearts due to ERP prolongation with conduction velocity slowing. Tolbutamide reversed hypoxia-induced WFPL shortening in WT and 6.1-gKO hearts through ERP prolongation. Atrial tachyarrhythmias inducible with programmed electrical stimulation during hypoxia in WT and 6.1-gKO mice correlated with WFPL shortening. Spontaneous arrhythmia was not seen. CONCLUSIONS KATP block/absence leads to cellular and tissue level atrial electrophysiological modification. Kir6.2 global knockout prevents hypoxia-induced atrial WFPL shortening and atrial arrhythmogenicity to programmed electrical stimulation. This mechanism could be explored translationally to treat ischemically driven atrial arrhythmia.
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Affiliation(s)
- Mark J. Specterman
- William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, United Kingdom (M.J.S., Q.A., Y.L., N.A.A., L.O., K.-E.N., A.M.T., M.C.F., R.J.S., A.T.)
| | - Qadeer Aziz
- William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, United Kingdom (M.J.S., Q.A., Y.L., N.A.A., L.O., K.-E.N., A.M.T., M.C.F., R.J.S., A.T.)
| | - Yiwen Li
- William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, United Kingdom (M.J.S., Q.A., Y.L., N.A.A., L.O., K.-E.N., A.M.T., M.C.F., R.J.S., A.T.)
| | - Naomi A. Anderson
- William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, United Kingdom (M.J.S., Q.A., Y.L., N.A.A., L.O., K.-E.N., A.M.T., M.C.F., R.J.S., A.T.)
| | - Leona Ojake
- William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, United Kingdom (M.J.S., Q.A., Y.L., N.A.A., L.O., K.-E.N., A.M.T., M.C.F., R.J.S., A.T.)
| | - Keat-Eng Ng
- William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, United Kingdom (M.J.S., Q.A., Y.L., N.A.A., L.O., K.-E.N., A.M.T., M.C.F., R.J.S., A.T.)
| | - Alison M. Thomas
- William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, United Kingdom (M.J.S., Q.A., Y.L., N.A.A., L.O., K.-E.N., A.M.T., M.C.F., R.J.S., A.T.)
| | - Malcolm C. Finlay
- William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, United Kingdom (M.J.S., Q.A., Y.L., N.A.A., L.O., K.-E.N., A.M.T., M.C.F., R.J.S., A.T.)
| | - Richard J. Schilling
- William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, United Kingdom (M.J.S., Q.A., Y.L., N.A.A., L.O., K.-E.N., A.M.T., M.C.F., R.J.S., A.T.)
| | - Pier D. Lambiase
- Institute of Cardiovascular Science, University College London, United Kingdom (P.D.L.)
| | - Andrew Tinker
- William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, United Kingdom (M.J.S., Q.A., Y.L., N.A.A., L.O., K.-E.N., A.M.T., M.C.F., R.J.S., A.T.)
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Dutta S, Iyer KK, Vanhatalo S, Breakspear M, Roberts JA. Mechanisms underlying pathological cortical bursts during metabolic depletion. Nat Commun 2023; 14:4792. [PMID: 37553358 PMCID: PMC10409751 DOI: 10.1038/s41467-023-40437-0] [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: 03/08/2022] [Accepted: 07/27/2023] [Indexed: 08/10/2023] Open
Abstract
Cortical activity depends upon a continuous supply of oxygen and other metabolic resources. Perinatal disruption of oxygen availability is a common clinical scenario in neonatal intensive care units, and a leading cause of lifelong disability. Pathological patterns of brain activity including burst suppression and seizures are a hallmark of the recovery period, yet the mechanisms by which these patterns arise remain poorly understood. Here, we use computational modeling of coupled metabolic-neuronal activity to explore the mechanisms by which oxygen depletion generates pathological brain activity. We find that restricting oxygen supply drives transitions from normal activity to several pathological activity patterns (isoelectric, burst suppression, and seizures), depending on the potassium supply. Trajectories through parameter space track key features of clinical electrophysiology recordings and reveal how infants with good recovery outcomes track toward normal parameter values, whereas the parameter values for infants with poor outcomes dwell around the pathological values. These findings open avenues for studying and monitoring the metabolically challenged infant brain, and deepen our understanding of the link between neuronal and metabolic activity.
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Affiliation(s)
- Shrey Dutta
- Brain Modelling Group, QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia.
- Faculty of Medicine, University of Queensland, Brisbane, QLD, Australia.
- School of Psychological Sciences, College of Engineering, Science and Environment, University of Newcastle, Callaghan, NSW, Australia.
| | - Kartik K Iyer
- Brain Modelling Group, QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia
| | - Sampsa Vanhatalo
- Pediatric Research Center, Department of Physiology, Helsinki University Hospital, University of Helsinki, Helsinki, Finland
| | - Michael Breakspear
- School of Psychological Sciences, College of Engineering, Science and Environment, University of Newcastle, Callaghan, NSW, Australia
- School of Medicine and Public Health, College of Health and Medicine, University of Newcastle, Callaghan, NSW, Australia
| | - James A Roberts
- Brain Modelling Group, QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia
- Faculty of Medicine, University of Queensland, Brisbane, QLD, Australia
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Dumanska H, Telka M, Veselovsky N. Inhibition of high-voltage-activated calcium currents by acute hypoxia in cultured retinal ganglion cells. Front Cell Neurosci 2023; 17:1202083. [PMID: 37465211 PMCID: PMC10351036 DOI: 10.3389/fncel.2023.1202083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Accepted: 06/08/2023] [Indexed: 07/20/2023] Open
Abstract
Hypoxia is a common factor of numerous ocular diseases that lead to dysfunctions and loss of retinal ganglion cells (RGCs) with subsequent vision loss. High-voltage-activated calcium channels are the main source of calcium entry into neurons. Their activity plays a central role in different signaling processes in health and diseases, such as enzyme activation, gene transcription, synaptic transmission, or the onset of cell death. This study aims to establish and evaluate the initial effect of the early stage of acute hypoxia on somatic HVA calcium currents in cultured RGCs. HVA calcium currents were recorded in RGCs using the whole-cell patch-clamp technique in the voltage-clamp mode. The fast local superfusion was used for a brief (up to 270 s) application of the hypoxic solution (pO2 < 5 mmHg). The switch from normoxic to hypoxic solutions and vice versa was less than 1 s. The HVA calcium channel activity was inhibited by acute hypoxia in 79% of RGCs (30 of 38 RGCs) in a strong voltage-dependent manner. The level of inhibition was independent of the duration of hypoxia or repeated applications. The hypoxia-induced inhibition of calcium currents had a strong correlation with the duration of hypoxia and showed the transition from reversible to irreversible at 75 s of hypoxia and longer. The results obtained are the first demonstration of the phenomena of HVA calcium current inhibition by acute hypoxia in RGCs and provide a conceptual framework for further research.
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Aboouf MA, Thiersch M, Soliz J, Gassmann M, Schneider Gasser EM. The Brain at High Altitude: From Molecular Signaling to Cognitive Performance. Int J Mol Sci 2023; 24:10179. [PMID: 37373327 DOI: 10.3390/ijms241210179] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Revised: 06/13/2023] [Accepted: 06/13/2023] [Indexed: 06/29/2023] Open
Abstract
The brain requires over one-fifth of the total body oxygen demand for normal functioning. At high altitude (HA), the lower atmospheric oxygen pressure inevitably challenges the brain, affecting voluntary spatial attention, cognitive processing, and attention speed after short-term, long-term, or lifespan exposure. Molecular responses to HA are controlled mainly by hypoxia-inducible factors. This review aims to summarize the cellular, metabolic, and functional alterations in the brain at HA with a focus on the role of hypoxia-inducible factors in controlling the hypoxic ventilatory response, neuronal survival, metabolism, neurogenesis, synaptogenesis, and plasticity.
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Affiliation(s)
- Mostafa A Aboouf
- Institute of Veterinary Physiology, Vetsuisse Faculty, University of Zürich, 8057 Zurich, Switzerland
- Department of Biochemistry, Faculty of Pharmacy, Ain Shams University, Cairo 11566, Egypt
- Zurich Center for Integrative Human Physiology (ZIHP), University of Zurich, 8057 Zurich, Switzerland
| | - Markus Thiersch
- Institute of Veterinary Physiology, Vetsuisse Faculty, University of Zürich, 8057 Zurich, Switzerland
- Zurich Center for Integrative Human Physiology (ZIHP), University of Zurich, 8057 Zurich, Switzerland
| | - Jorge Soliz
- Institute Universitaire de Cardiologie et de Pneumologie de Québec (IUCPQ), Faculty of Medicine, Université Laval, Québec, QC G1V 4G5, Canada
| | - Max Gassmann
- Institute of Veterinary Physiology, Vetsuisse Faculty, University of Zürich, 8057 Zurich, Switzerland
- Zurich Center for Integrative Human Physiology (ZIHP), University of Zurich, 8057 Zurich, Switzerland
| | - Edith M Schneider Gasser
- Institute of Veterinary Physiology, Vetsuisse Faculty, University of Zürich, 8057 Zurich, Switzerland
- Institute Universitaire de Cardiologie et de Pneumologie de Québec (IUCPQ), Faculty of Medicine, Université Laval, Québec, QC G1V 4G5, Canada
- Neuroscience Center Zurich, University of Zurich and ETH Zurich, 8057 Zurich, Switzerland
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8
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Ca 2+-Activated K + Channels and the Regulation of the Uteroplacental Circulation. Int J Mol Sci 2023; 24:ijms24021349. [PMID: 36674858 PMCID: PMC9867535 DOI: 10.3390/ijms24021349] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Revised: 01/06/2023] [Accepted: 01/08/2023] [Indexed: 01/13/2023] Open
Abstract
Adequate uteroplacental blood supply is essential for the development and growth of the placenta and fetus during pregnancy. Aberrant uteroplacental perfusion is associated with pregnancy complications such as preeclampsia, fetal growth restriction (FGR), and gestational diabetes. The regulation of uteroplacental blood flow is thus vital to the well-being of the mother and fetus. Ca2+-activated K+ (KCa) channels of small, intermediate, and large conductance participate in setting and regulating the resting membrane potential of vascular smooth muscle cells (VSMCs) and endothelial cells (ECs) and play a critical role in controlling vascular tone and blood pressure. KCa channels are important mediators of estrogen/pregnancy-induced adaptive changes in the uteroplacental circulation. Activation of the channels hyperpolarizes uteroplacental VSMCs/ECs, leading to attenuated vascular tone, blunted vasopressor responses, and increased uteroplacental blood flow. However, the regulation of uteroplacental vascular function by KCa channels is compromised in pregnancy complications. This review intends to provide a comprehensive overview of roles of KCa channels in the regulation of the uteroplacental circulation under physiological and pathophysiological conditions.
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9
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Terefe E, Belay G, Han J, Hanotte O, Tijjani A. Genomic adaptation of Ethiopian indigenous cattle to high altitude. Front Genet 2022; 13:960234. [PMID: 36568400 PMCID: PMC9780680 DOI: 10.3389/fgene.2022.960234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Accepted: 11/22/2022] [Indexed: 12/13/2022] Open
Abstract
The mountainous areas of Ethiopia represent one of the most extreme environmental challenges in Africa faced by humans and other inhabitants. Selection for high-altitude adaptation is expected to have imprinted the genomes of livestock living in these areas. Here we assess the genomic signatures of positive selection for high altitude adaptation in three cattle populations from the Ethiopian mountainous areas (Semien, Choke, and Bale mountains) compared to three Ethiopian lowland cattle populations (Afar, Ogaden, and Boran), using whole-genome resequencing and three genome scan approaches for signature of selection (iHS, XP-CLR, and PBS). We identified several candidate selection signature regions and several high-altitude adaptation genes. These include genes such as ITPR2, MB, and ARNT previously reported in the human population inhabiting the Ethiopian highlands. Furthermore, we present evidence of strong selection and high divergence between Ethiopian high- and low-altitude cattle populations at three new candidate genes (CLCA2, SLC26A2, and CBFA2T3), putatively linked to high-altitude adaptation in cattle. Our findings provide possible examples of convergent selection between cattle and humans as well as unique African cattle signature to the challenges of living in the Ethiopian mountainous regions.
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Affiliation(s)
- Endashaw Terefe
- Department of Microbial Cellular and Molecular Biology (MCMB), College of Natural and Computational Science, Addis Ababa University, Addis Ababa, Ethiopia,International Livestock Research Institute (ILRI), Addis Ababa, Ethiopia,Department of Animal Science, College of Agriculture and Environmental Science, Arsi University, Asella, Ethiopia,*Correspondence: Endashaw Terefe, Abdulfatai Tijjani,
| | - Gurja Belay
- Department of Microbial Cellular and Molecular Biology (MCMB), College of Natural and Computational Science, Addis Ababa University, Addis Ababa, Ethiopia
| | - Jianlin Han
- Livestock Genetics Program, International Livestock Research Institute (ILRI), Nairobi, Kenya,CAAS-ILRI Joint Laboratory on Livestock and Forage Genetic Resources, Institute of Animal Science, Chinese Academy of Agricultural Sciences (CAAS), Beijing, China
| | - Olivier Hanotte
- International Livestock Research Institute (ILRI), Addis Ababa, Ethiopia,Centre for Tropical Livestock Genetics and Health (CTLGH), The Roslin Institute, The University of Edinburgh, Midlothian, United Kingdom,School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Abdulfatai Tijjani
- International Livestock Research Institute (ILRI), Addis Ababa, Ethiopia,Centre for Tropical Livestock Genetics and Health (CTLGH), The Roslin Institute, The University of Edinburgh, Midlothian, United Kingdom,*Correspondence: Endashaw Terefe, Abdulfatai Tijjani,
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10
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Gonon G, de Toledo SM, Perumal V, Jay-Gerin JP, Azzam EI. Impact of the redox environment on propagation of radiation bystander effects: The modulating effect of oxidative metabolism and oxygen partial pressure. MUTATION RESEARCH. GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2022; 883-884:503559. [PMID: 36462795 DOI: 10.1016/j.mrgentox.2022.503559] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Revised: 11/09/2022] [Accepted: 11/11/2022] [Indexed: 11/16/2022]
Abstract
Redox modulated pathways play important roles in out-of-field effects of ionizing radiation. We investigated how the redox environment impacts the magnitude of propagation of stressful effects from irradiated to bystander cells. Normal human fibroblasts that have incorporated [3H]-thymidine were intimately co-cultured with bystander cells in a strategy that allowed isolation of bystander cells with high purity. The antioxidant glutathione peroxidase (GPX) was maintained either at wild-type conditions or overexpressed in the bystanders. Following 24 h of coculture, levels of stress-responsive p21Waf1, p-Hdm2, and connexin43 proteins were increased in bystander cells expressing wild-type GPX relative to respective controls. These levels were significantly attenuated when GPX was ectopically overexpressed, demonstrating by direct approach the involvement of a regulator of intracellular redox homeostasis. Evidence of participation of pro-oxidant compounds was generated by exposing confluent cell cultures to low fluences of 3.7 MeV α particles in presence or absence of t-butyl hydroperoxide. By 3 h post-exposure to fluences wherein only ∼2% of cells are traversed through the nucleus by a particle track, increases in chromosomal damage were greater than expected in absence of the drug (p < 0.001) and further enhanced in its presence (p < 0.05). While maintenance and irradiation of cell cultures at low oxygen pressure (pO2 3.8 mm Hg) to mimic in vivo still supported the participation of bystander cells in responses assessed by chromosomal damage and stress-responsive protein levels (p < 0.001), the effects were attenuated compared to ambient pO2 (155 mm Hg) (p < 0.05). Together, the results show that bystander effects are attenuated at below ambient pO2 and when metabolic oxidative stress is reduced but increased when the basal redox environment tilts towards oxidizing conditions. They are consistent with bystander effects being independent of radiation dose rate.
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Affiliation(s)
- Géraldine Gonon
- Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PSE-SANTE/SERAMED/LRAcc, Fontenay-aux-Roses, France; Department of Radiology, Rutgers New Jersey Medical School, Newark, NJ, USA.
| | - Sonia M de Toledo
- Department of Radiology, Rutgers New Jersey Medical School, Newark, NJ, USA
| | - Venkatachalam Perumal
- Department of Radiology, Rutgers New Jersey Medical School, Newark, NJ, USA; Department of Human Genetics, Sri Ramachandra Institute of Higher Education and Research (Deemed to be University), Chennai, India
| | - Jean-Paul Jay-Gerin
- Département de médecine nucléaire et de radiobiologie, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Sherbrooke, Québec, Canada
| | - Edouard I Azzam
- Department of Radiology, Rutgers New Jersey Medical School, Newark, NJ, USA; Radiobiology and Health Branch, Isotopes, Radiobiology & Environment Directorate (IRED), Canadian Nuclear Laboratories (CNL), Chalk River, Ontario, Canada.
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11
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Audero MM, Prevarskaya N, Fiorio Pla A. Ca 2+ Signalling and Hypoxia/Acidic Tumour Microenvironment Interplay in Tumour Progression. Int J Mol Sci 2022; 23:7377. [PMID: 35806388 PMCID: PMC9266881 DOI: 10.3390/ijms23137377] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 06/26/2022] [Accepted: 06/27/2022] [Indexed: 01/18/2023] Open
Abstract
Solid tumours are characterised by an altered microenvironment (TME) from the physicochemical point of view, displaying a highly hypoxic and acidic interstitial fluid. Hypoxia results from uncontrolled proliferation, aberrant vascularization and altered cancer cell metabolism. Tumour cellular apparatus adapts to hypoxia by altering its metabolism and behaviour, increasing its migratory and metastatic abilities by the acquisition of a mesenchymal phenotype and selection of aggressive tumour cell clones. Extracellular acidosis is considered a cancer hallmark, acting as a driver of cancer aggressiveness by promoting tumour metastasis and chemoresistance via the selection of more aggressive cell phenotypes, although the underlying mechanism is still not clear. In this context, Ca2+ channels represent good target candidates due to their ability to integrate signals from the TME. Ca2+ channels are pH and hypoxia sensors and alterations in Ca2+ homeostasis in cancer progression and vascularization have been extensively reported. In the present review, we present an up-to-date and critical view on Ca2+ permeable ion channels, with a major focus on TRPs, SOCs and PIEZO channels, which are modulated by tumour hypoxia and acidosis, as well as the consequent role of the altered Ca2+ signals on cancer progression hallmarks. We believe that a deeper comprehension of the Ca2+ signalling and acidic pH/hypoxia interplay will break new ground for the discovery of alternative and attractive therapeutic targets.
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Affiliation(s)
- Madelaine Magalì Audero
- U1003—PHYCEL—Laboratoire de Physiologie Cellulaire, Inserm, University of Lille, Villeneuve d’Ascq, 59000 Lille, France; (M.M.A.); (N.P.)
- Laboratory of Cellular and Molecular Angiogenesis, Department of Life Sciences and Systems Biology, University of Turin, 10123 Turin, Italy
| | - Natalia Prevarskaya
- U1003—PHYCEL—Laboratoire de Physiologie Cellulaire, Inserm, University of Lille, Villeneuve d’Ascq, 59000 Lille, France; (M.M.A.); (N.P.)
| | - Alessandra Fiorio Pla
- U1003—PHYCEL—Laboratoire de Physiologie Cellulaire, Inserm, University of Lille, Villeneuve d’Ascq, 59000 Lille, France; (M.M.A.); (N.P.)
- Laboratory of Cellular and Molecular Angiogenesis, Department of Life Sciences and Systems Biology, University of Turin, 10123 Turin, Italy
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12
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Fernández-Morales JC, Morad M. Oxygen Sensor of the Heart. Can J Physiol Pharmacol 2022; 100:848-857. [PMID: 35679617 DOI: 10.1139/cjpp-2022-0072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
How oxygen is sensed by the heart and what mechanisms mediate its sensing remain poorly understood. Since recent reports show that low PO2 levels are detected by the cardiomyocytes in a few seconds, the rapid and short applications of low levels of oxygen (acute hypoxia), that avoid multiple effects of chronic hypoxia may be used to probe the oxygen sensing pathway of the heart. Here we explore the oxygen sensing pathway, focusing primarily on cellular surface membrane proteins that are first exposed to low PO2. Such studies suggest that acute hypoxia primarily targets the cardiac calcium channels, where either the channel itself or moieties closely associated with it, for instance, heme-oxygenase-2 (HO-2) interacting through kinase phosphorylation, signals the α-subunit of the channel as to the altered levels of PO2. Amino acids 1572-1651, the CaMKII phosphorylation sites (S1487 and S1545), CaM-binding site (I1624, Q1625) and Ser1928 of the carboxyl tail of the α-subunit appear to be critical residues that sense oxygen. Future studies in HO-2 knockout mice or CRISPR/Cas9 gene-edited hiPSC-CMs that reduce CaM-binding affinity are likely to provide deeper insights in the O2-sensinsing mechanisms.
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Affiliation(s)
| | - Martin Morad
- USC, MUSC, and Clemson University, Cardiac Signaling Center, Charleston, South Carolina, United States;
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13
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Chen P, Liu Y, Liu W, Wang Y, Liu Z, Rong M. Impact of High-Altitude Hypoxia on Bone Defect Repair: A Review of Molecular Mechanisms and Therapeutic Implications. Front Med (Lausanne) 2022; 9:842800. [PMID: 35620712 PMCID: PMC9127390 DOI: 10.3389/fmed.2022.842800] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2021] [Accepted: 04/15/2022] [Indexed: 11/23/2022] Open
Abstract
Reaching areas at altitudes over 2,500–3,000 m above sea level has become increasingly common due to commerce, military deployment, tourism, and entertainment. The high-altitude environment exerts systemic effects on humans that represent a series of compensatory reactions and affects the activity of bone cells. Cellular structures closely related to oxygen-sensing produce corresponding functional changes, resulting in decreased tissue vascularization, declined repair ability of bone defects, and longer healing time. This review focuses on the impact of high-altitude hypoxia on bone defect repair and discusses the possible mechanisms related to ion channels, reactive oxygen species production, mitochondrial function, autophagy, and epigenetics. Based on the key pathogenic mechanisms, potential therapeutic strategies have also been suggested. This review contributes novel insights into the mechanisms of abnormal bone defect repair in hypoxic environments, along with therapeutic applications. We aim to provide a foundation for future targeted, personalized, and precise bone regeneration therapies according to the adaptation of patients to high altitudes.
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Affiliation(s)
- Pei Chen
- Department of Periodontology and Implantology, Stomatological Hospital, Southern Medical University, Guangzhou, China
| | - Yushan Liu
- Department of Periodontology and Implantology, Stomatological Hospital, Southern Medical University, Guangzhou, China
| | - Wenjing Liu
- Department of Prosthodontics, Stomatological Hospital, Southern Medical University, Guangzhou, China
| | - Yarong Wang
- Department of Periodontology and Implantology, Stomatological Hospital, Southern Medical University, Guangzhou, China
| | - Ziyi Liu
- Department of Periodontology and Implantology, Stomatological Hospital, Southern Medical University, Guangzhou, China
| | - Mingdeng Rong
- Department of Periodontology and Implantology, Stomatological Hospital, Southern Medical University, Guangzhou, China
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14
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The Tp-e/QT ratio as a predictor of nocturnal premature ventricular contraction events in patients with obstructive sleep apnea. Sleep Breath 2022; 27:469-476. [DOI: 10.1007/s11325-022-02626-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 04/05/2022] [Accepted: 04/22/2022] [Indexed: 10/18/2022]
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15
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Nagaraj C, Li Y, Tang B, Bordag N, Guntur D, Enyedi P, Olschewski H, Olschewski A. Potassium Channels in the Transition from Fetal to the Neonatal Pulmonary Circulation. Int J Mol Sci 2022; 23:ijms23094681. [PMID: 35563072 PMCID: PMC9106051 DOI: 10.3390/ijms23094681] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Revised: 04/12/2022] [Accepted: 04/20/2022] [Indexed: 12/10/2022] Open
Abstract
The transition from the fetal to the neonatal circulation includes dilatation of the pulmonary arteries (PA) and closure of the Ductus Arteriosus Botalli (DAB). The resting membrane potential and various potassium channel activities in smooth muscle cells (SMC) from fetal and neonatal PA and DAB obtained from the same species has not been systematically analyzed. The key issue addressed in this paper is how the resting membrane potential and the whole-cell potassium current (IK) change when PASMC or DABSMC are transitioned from hypoxia, reflecting the fetal state, to normoxia, reflecting the post-partal state. Patch-clamp measurements were employed to characterize whole-cell K+ channel activity in fetal and post-partal (newborn) PASMC and DABSMC. The main finding of this paper is that the SMC from both tissues use a similar set of K+ channels (voltage-dependent (Kv), calcium-sensitive (KCa), TASK-1 and probably also TASK-2 channels); however, their activity level depends on the cell type and the oxygen level. Furthermore, we provide the first evidence for pH-sensitive non-inactivating K+ current in newborn DABSMC and PASMC, suggesting physiologically relevant TASK-1 and TASK-2 channel activity, the latter particularly in the Ductus Arteriosus Botalli.
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Affiliation(s)
- Chandran Nagaraj
- Ludwig Boltzmann Institute for Lung Vascular Research, Neue Stiftingtalstraße 6, 8010 Graz, Austria; (C.N.); (N.B.)
| | - Yingji Li
- Experimental Anaesthesiology, Department of Anaesthesiology and Intensive Care Medicine, Medical University of Graz, Auenbruggerplatz 5, 8036 Graz, Austria; (Y.L.); (B.T.); (D.G.)
| | - Bi Tang
- Experimental Anaesthesiology, Department of Anaesthesiology and Intensive Care Medicine, Medical University of Graz, Auenbruggerplatz 5, 8036 Graz, Austria; (Y.L.); (B.T.); (D.G.)
| | - Natalie Bordag
- Ludwig Boltzmann Institute for Lung Vascular Research, Neue Stiftingtalstraße 6, 8010 Graz, Austria; (C.N.); (N.B.)
- Department of Dermatology and Venereology, Medical University of Graz, Auenbruggerplatz 8, 8036 Graz, Austria
| | - Divya Guntur
- Experimental Anaesthesiology, Department of Anaesthesiology and Intensive Care Medicine, Medical University of Graz, Auenbruggerplatz 5, 8036 Graz, Austria; (Y.L.); (B.T.); (D.G.)
| | - Péter Enyedi
- Department of Physiology, Faculty of Medicine, Semmelweis University, Tűzoltó utca 37-47, 1094 Budapest, Hungary;
| | - Horst Olschewski
- Division of Pulmonology, Department of Internal Medicine, Medical University of Graz, Auenbruggerplatz 15, 8036 Graz, Austria;
| | - Andrea Olschewski
- Experimental Anaesthesiology, Department of Anaesthesiology and Intensive Care Medicine, Medical University of Graz, Auenbruggerplatz 5, 8036 Graz, Austria; (Y.L.); (B.T.); (D.G.)
- Correspondence:
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16
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Horváth B, Szentandrássy N, Almássy J, Dienes C, Kovács ZM, Nánási PP, Banyasz T. Late Sodium Current of the Heart: Where Do We Stand and Where Are We Going? Pharmaceuticals (Basel) 2022; 15:ph15020231. [PMID: 35215342 PMCID: PMC8879921 DOI: 10.3390/ph15020231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Revised: 02/07/2022] [Accepted: 02/09/2022] [Indexed: 02/05/2023] Open
Abstract
Late sodium current has long been linked to dysrhythmia and contractile malfunction in the heart. Despite the increasing body of accumulating information on the subject, our understanding of its role in normal or pathologic states is not complete. Even though the role of late sodium current in shaping action potential under physiologic circumstances is debated, it’s unquestioned role in arrhythmogenesis keeps it in the focus of research. Transgenic mouse models and isoform-specific pharmacological tools have proved useful in understanding the mechanism of late sodium current in health and disease. This review will outline the mechanism and function of cardiac late sodium current with special focus on the recent advances of the area.
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Affiliation(s)
- Balázs Horváth
- Department of Physiology, University of Debrecen, 4032 Debrecen, Hungary; (B.H.); (N.S.); (J.A.); (C.D.); (Z.M.K.); (P.P.N.)
| | - Norbert Szentandrássy
- Department of Physiology, University of Debrecen, 4032 Debrecen, Hungary; (B.H.); (N.S.); (J.A.); (C.D.); (Z.M.K.); (P.P.N.)
- Department of Basic Medical Sciences, Faculty of Dentistry, University of Debrecen, 4032 Debrecen, Hungary
| | - János Almássy
- Department of Physiology, University of Debrecen, 4032 Debrecen, Hungary; (B.H.); (N.S.); (J.A.); (C.D.); (Z.M.K.); (P.P.N.)
| | - Csaba Dienes
- Department of Physiology, University of Debrecen, 4032 Debrecen, Hungary; (B.H.); (N.S.); (J.A.); (C.D.); (Z.M.K.); (P.P.N.)
| | - Zsigmond Máté Kovács
- Department of Physiology, University of Debrecen, 4032 Debrecen, Hungary; (B.H.); (N.S.); (J.A.); (C.D.); (Z.M.K.); (P.P.N.)
| | - Péter P. Nánási
- Department of Physiology, University of Debrecen, 4032 Debrecen, Hungary; (B.H.); (N.S.); (J.A.); (C.D.); (Z.M.K.); (P.P.N.)
- Department of Dental Physiology and Pharmacology, University of Debrecen, 4032 Debrecen, Hungary
| | - Tamas Banyasz
- Department of Physiology, University of Debrecen, 4032 Debrecen, Hungary; (B.H.); (N.S.); (J.A.); (C.D.); (Z.M.K.); (P.P.N.)
- Correspondence: ; Tel.: +36-(52)-255-575; Fax: +36-(52)-255-116
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17
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Abstract
The carotid body (CB) is a bilateral arterial chemoreceptor located in the carotid artery bifurcation with an essential role in cardiorespiratory homeostasis. It is composed of highly perfused cell clusters, or glomeruli, innervated by sensory fibers. Glomus cells, the most abundant in each glomerulus, are neuron-like multimodal sensory elements able to detect and integrate changes in several physical and chemical parameters of the blood, in particular O2 tension, CO2 and pH, as well as glucose, lactate, or blood flow. Activation of glomus cells (e.g., during hypoxia or hypercapnia) stimulates the afferent fibers which impinge on brainstem neurons to elicit rapid compensatory responses (hyperventilation and sympathetic activation). This chapter presents an updated view of the structural organization of the CB and the mechanisms underlying the chemosensory responses of glomus cells, with special emphasis on the molecular processes responsible for acute O2 sensing. The properties of the glomus cell-sensory fiber synapse as well as the organization of CB output are discussed. The chapter includes the description of recently discovered CB stem cells and progenitor cells, and their role in CB growth during acclimatization to hypoxemia. Finally, the participation of the CB in the mechanisms of disease is briefly discussed.
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Affiliation(s)
- José López-Barneo
- Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/Consejo Superior de Investigaciones Científicas (CSIC)/Universidad de Sevilla, Seville, Spain; Biomedical Research Center for Neurodegenerative Diseases (CIBERNED), Madrid, Spain.
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18
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Abstract
Oxygen (O2) is essential for life and therefore the supply of sufficient O2 to the tissues is a major physiological challenge. In mammals, a deficit of O2 (hypoxia) triggers rapid cardiorespiratory reflexes (e.g. hyperventilation and increased heart output) that within a few seconds increase the uptake of O2 by the lungs and its distribution throughout the body. The prototypical acute O2-sensing organ is the carotid body (CB), which contains sensory glomus cells expressing O2-regulated ion channels. In response to hypoxia, glomus cells depolarize and release transmitters which activate afferent fibers terminating at the brainstem respiratory and autonomic centers. In this review, we summarize the basic properties of CB chemoreceptor cells and the essential role played by their specialized mitochondria in acute O2 sensing and signaling. We focus on recent data supporting a "mitochondria-to-membrane signaling" model of CB chemosensory transduction. The possibility that the differential expression of specific subunit isoforms and enzymes could allow mitochondria to play a generalized adaptive O2-sensing and signaling role in a wide variety of cells is also discussed.
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Affiliation(s)
- José López-Barneo
- Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Seville, Spain.,Departamento de Fisiología Médica y Biofísica, Facultad de Medicina, Universidad de Sevilla, Seville, Spain.,Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
| | - Patricia Ortega-Sáenz
- Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Seville, Spain.,Departamento de Fisiología Médica y Biofísica, Facultad de Medicina, Universidad de Sevilla, Seville, Spain.,Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
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19
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Kistamás K, Hézső T, Horváth B, Nánási PP. Late sodium current and calcium homeostasis in arrhythmogenesis. Channels (Austin) 2021; 15:1-19. [PMID: 33258400 PMCID: PMC7757849 DOI: 10.1080/19336950.2020.1854986] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 10/26/2020] [Accepted: 11/19/2020] [Indexed: 12/19/2022] Open
Abstract
The cardiac late sodium current (INa,late) is the small sustained component of the sodium current active during the plateau phase of the action potential. Several studies demonstrated that augmentation of the current can lead to cardiac arrhythmias; therefore, INa,late is considered as a promising antiarrhythmic target. Fundamentally, enlarged INa,late increases Na+ influx into the cell, which, in turn, is converted to elevated intracellular Ca2+ concentration through the Na+/Ca2+ exchanger. The excessive Ca2+ load is known to be proarrhythmic. This review describes the behavior of the voltage-gated Na+ channels generating INa,late in health and disease and aims to discuss the physiology and pathophysiology of Na+ and Ca2+ homeostasis in context with the enhanced INa,late demonstrating also the currently accessible antiarrhythmic choices.
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Affiliation(s)
- Kornél Kistamás
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Tamás Hézső
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Balázs Horváth
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Péter P Nánási
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
- Department of Dental Physiology, Faculty of Dentistry, University of Debrecen, Debrecen, Hungary
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20
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Gkasdaris G, Tabatabaei P, Kourtopoulos H, Birbilis T. Vertigo: Could this Symptom Indicate the Existence of an Unruptured Intracranial Aneurysm? MAEDICA 2021; 16:555-562. [PMID: 35261652 PMCID: PMC8897800 DOI: 10.26574/maedica.2021.16.4.555] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Background:Unruptured intracranial aneurysms (UIAs) can be presented with various symptoms, including atypical headaches and cranial nerve deficits. Vertigo is often referred in the literature as a coexisting symptom. Our aim was to investigate the importance of vertigo in the UIA symptomatology and present a possible explanation for its existence. Methods:We conducted a retrospective observational multicenter study concerning patients with surgically treated intracranial aneurysms. During a period of 10 years, 1 085 patients with cerebral aneurysms underwent surgery. There were 812 patients with ruptured intracranial aneurysms (RIA) and 273 with UIA. The medical records for each of the 273 patients were analyzed. Results: After the implementation of exclusion criteria, 89 (32.6%) of UIA patients were selected in the study, from which 71 (79.8%) were females and 18 (20.2%) males. The mean age was 56.9 (± 12.876) years old. Vertigo existed in 72 (80.9%), headache in 41 (46.1%) and visual symptoms in 21 (23.6%) patients. No significant correlation (p >0.05) was demonstrated between gender, age or aneurysm location in correlation with vertigo, headache or visual symptoms, apart from a negative significant correlation between age and vertigo (p=0.031). Conclusion:Vertigo is an alarming symptom that could indicate the existence of an UIA. The pathophysiological mechanism could be explained by the formation of an aneurysmal vortex that projects into the parent artery, leading to disturbances in the laminar flow and formation of an irregular/turbulent flow, which potentially affects the cerebral autoregulation and by consequence, the central processing of movement.
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Affiliation(s)
- Grigorios Gkasdaris
- Department of Neurosurgery, University Hospital of Alexandroupolis, Alexandroupolis, Greece
| | | | | | - Theodossios Birbilis
- Department of Neurosurgery, University Hospital of Alexandroupolis, Alexandroupolis, Greece
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Hocanli I, Tanriverdi Z, Kabak M, Gungoren F, Tascanov MB. The relationship between frontal QRS-T angle and the severity of newly diagnosed chronic obstructive pulmonary disease. Int J Clin Pract 2021; 75:e14500. [PMID: 34117683 DOI: 10.1111/ijcp.14500] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/20/2021] [Revised: 05/17/2021] [Accepted: 06/10/2021] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND Chronic obstructive pulmonary disease (COPD) is characterised by persistent airflow restriction and respiratory symptoms. Studies demonstrated that cardiac arrhythmias and cardiovascular mortality increased in these patients as a result of altered myocardial repolarization. Frontal QRS-T angle is a novel marker of myocardial depolarization and repolarization heterogeneity. In this study, we aimed to investigate the relationship between frontal QRS-T angle and disease severity in patients with newly diagnosed COPD. METHODS A total of 104 newly diagnosed COPD patients were included in this study. Patients were divided into two groups according to GOLD (Global Obstructive Lung Disease) stage as follows: patients with mild and moderate COPD (group I), and severe and very severe COPD (group II). Frontal QRS-T angle was calculated from the automatic report of the electrocardiography device. RESULTS Frontal QRS-T angle was significantly higher in group II patients compared with in group I patients (43.0 [25.5-60.0] vs. 20.0 [12.0-32.0], P < .001). The best cut-off value of frontal QRS-T angle for predicting severe-very severe COPD was ≥34.5°. Correlation analysis showed that frontal QRS-T angle was negatively correlated with FEV1/FVC (r = -.524, P < .001) and MEF25-75 (r = -.453, P < .001). Multivariate logistic regression analysis was showed that frontal QRS-T angle was the only independent predictor of severe-very severe COPD (OR: 1.051, 95% CI: 1.024-1.079, P < .001). CONCLUSIONS Frontal QRS-T angle is an easily obtainable marker form surface electrocardiography. In this study, we have shown for the first time that frontal QRS-T angle was significantly increased in patients with severe and very severe COPD.
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Affiliation(s)
- Iclal Hocanli
- Department of Chest Diseases, Faculty of Medicine, Harran University, Sanliurfa, Turkey
| | - Zulkif Tanriverdi
- Department of Cardiology, Faculty of Medicine, Harran University, Sanliurfa, Turkey
| | - Mehmet Kabak
- Clinic of Chest Diseases, Mardin State Hospital, Mardin, Turkey
| | - Fatih Gungoren
- Department of Cardiology, Faculty of Medicine, Harran University, Sanliurfa, Turkey
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Verratti V, Tonacci A, Bondi D, Chiavaroli A, Ferrante C, Brunetti L, Crisafulli A, Cerretelli P. Ethnic Differences on Cardiac Rhythms and Autonomic Nervous System Responses During a High-Altitude Trek: A Pilot Study Comparing Italian Trekkers to Nepalese Porters. Front Physiol 2021; 12:709451. [PMID: 34497537 PMCID: PMC8419438 DOI: 10.3389/fphys.2021.709451] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Accepted: 07/28/2021] [Indexed: 01/10/2023] Open
Abstract
Altitude hypoxia exposure results in increased sympathetic activity and heart rate due to several mechanisms. Recent studies have contested the validity of heart rate variability (HRV) analysis on sympathetic activity measurement. But the plethora of HRV metrics may provide meaningful insights, particularly if linked with cardiovascular and autonomic nervous system parameters. However, the population-specific nature of HRV and cardiorespiratory response to altitude hypoxia are still missing. Six Italian trekkers and six Nepalese porters completed 300 km of a Himalayan trek. The ECG analysis was conducted at baseline, and before (bBC) and after (aBC) the high-altitude (HA) circuit. Urine was collected before and after the expedition in Italians, for assessing catecholamines. Heart rate increased with altitude significantly (p < 0.001) in the Italian group; systolic (p = 0.030) and diastolic (p = 0.012) blood pressure, and mean arterial pressure (p = 0.004) increased with altitude. Instead, pulse pressure did not change, although the Nepalese group showed lower baseline values than the Italians. As expected, peripheral oxygen saturation decreased with altitude (p < 0.001), independently of the ethnic groups. Nepalese had a higher respiratory rate (p = 0.007), independent of altitude. The cardiac vagal index increased at altitude, from baseline to bBC (p = 0.008). Higuchi fractal dimension (HFD) showed higher basal values in the Nepalese group (p = 0.041), and a tendency for the highest values at bBC. Regarding the urinary catecholamine response, exposure to HA increased urinary levels, particularly of norepinephrine (p = 0.005, d = 1.623). Our findings suggest a better cardiovascular resilience of the Nepalese group when compared with Italians, which might be due to an intrinsic adaptation to HA, resulting from their job.
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Affiliation(s)
- Vittore Verratti
- Department of Psychological, Health and Territorial Sciences, University "G. d'Annunzio" of Chieti-Pescara, Chieti, Italy
| | - Alessandro Tonacci
- Institute of Clinical Physiology, National Research Council of Italy, Pisa, Italy
| | - Danilo Bondi
- Department of Neuroscience, Imaging and Clinical Sciences, University "G. d'Annunzio" of Chieti-Pescara, Chieti, Italy
| | - Annalisa Chiavaroli
- Department of Pharmacy, University "G. d'Annunzio" of Chieti-Pescara, Chieti, Italy
| | - Claudio Ferrante
- Department of Pharmacy, University "G. d'Annunzio" of Chieti-Pescara, Chieti, Italy
| | - Luigi Brunetti
- Department of Pharmacy, University "G. d'Annunzio" of Chieti-Pescara, Chieti, Italy
| | - Antonio Crisafulli
- Department of Medical Science and Public Health, University of Cagliari, Cagliari, Italy
| | - Paolo Cerretelli
- Institute of Bioimaging and Molecular Physiology, National Research Council of Italy, Segrate, Italy
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Ivonina NI, Fokin AA, Roshchevskaya IM. Body Surface Potential Mapping During Heart Ventricular Repolarization in Male Swimmers and Untrained Persons Under Hypoxic and Hypercapnic Hypoxia. High Alt Med Biol 2021; 22:308-316. [PMID: 34314614 DOI: 10.1089/ham.2020.0103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Ivonina, Natalya I., Andrey A. Fokin, and Irina M. Roshchevskaya. Body surface potential mapping during heart ventricular repolarization in male swimmers and untrained persons under hypoxic and hypercapnic hypoxia. High Alt Med Biol. 00:000-000, 2021. Background: In swimmers, as a result of prolonged breath-holding during swimming, first hypoxic hypoxia (HH) and then hypercapnic hypoxia (HCH) occurs, which may influence the electrical activity of the heart (EAH). What type of normobaric hypoxia more strongly affects the EAH-normocapnic HH or HCH? Methods: The electrical activity of swimmers' hearts (n = 7) and untrained persons (n = 10) was studied by using electrocardiography (ECG) and body surface potential mapping (BSPM) during the period of ventricular repolarization at baseline, at normocapnic HH, at HCH, and in the recovery period. Results: HH led to more significant changes in the EAH in all participants in comparison with HCH. There was no change in the amplitude of T waveECG at hypoxic and HCH, but a change in the amplitude of the minimum was noted in BSPM. The minimum in athletes changed by the end of the exposure (from -0.40 ± 0.12 mV to -0.26 ± 0.11 mV, p = 0.001); in the control, it decreased earlier (after 8 minutes of exposure to HH, the amplitude of the minimum was -0.24 ± 0.08 mV, p = 0.026). With HH, the duration of the QT interval in athletes was shortened due to the shortening of the J-Tpeak (from 250 to 188 ms, p = 0.001) and the Tpeak-Tend (from 98 to 86 ms) intervals. In controls, the decrease in the QT interval was due to the J-Tpeak shortening only (from 280 to 200 ms, p = 0.026). Conclusions: In the study of the effect of hypoxia on the EAH during ventricular repolarization, the use of the BSPM has proven to be more informative than the use of traditional ECG. When using potential mapping, more significant changes in ventricular repolarization at HH than at HCH were revealed, whereas the parameters changed less in swimmers compared with the baseline than in controls during both exposures.
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Affiliation(s)
- Natalya I Ivonina
- Department of Comparative Cardiology of the Federal Research Centre "Komi Science Centre of the Ural Branch of the Russian Academy of Sciences," Syktyvkar, Russian Federation
| | - Andrey A Fokin
- Department of Comparative Cardiology of the Federal Research Centre "Komi Science Centre of the Ural Branch of the Russian Academy of Sciences," Syktyvkar, Russian Federation
| | - Irina M Roshchevskaya
- Federal State Budgetary Institution "Research Zakusov Institute of Pharmacology," Moscow, Russian Federation
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Choi SW, Yin MZ, Park NK, Woo JH, Kim SJ. Dual Mechanisms of Cardiac Action Potential Prolongation by 4-Oxo-Nonenal Increasing the Risk of Arrhythmia; Late Na + Current Induction and hERG K + Channel Inhibition. Antioxidants (Basel) 2021; 10:antiox10071139. [PMID: 34356372 PMCID: PMC8301175 DOI: 10.3390/antiox10071139] [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: 06/22/2021] [Revised: 07/13/2021] [Accepted: 07/15/2021] [Indexed: 11/16/2022] Open
Abstract
4-Oxo-nonenal (4-ONE) is an endogenous lipid peroxidation product that is more reactive than 4-hydroxy-nonenal (4-HNE). We previously reported the arrhythmic potential of 4-HNE by suppression of cardiac human Ether-a-go-go Related Gene (hERG) K+ channels with prolonged action potential duration (APD) in cardiomyocytes. Here, we illustrate the higher arrhythmic risk of 4-ONE by modulating the cardiac hNaV1.5 channel currents (INaV). Although the peak amplitude of INaV was not significantly changed by 4-ONE up to 10 μM, the rate of INaV inactivation was slowed, and the late Na+ current (INaL) became larger by 10 μM 4-ONE. The chemical modification of specific residues in hNaV1.5 by 4-ONE was identified using MS-fingerprinting analysis. In addition to the changes in INaV, 4-ONE decreased the delayed rectifier K+ channel currents including the hERG current. The L-type Ca2+ channel current was decreased, whereas its inactivation was slowed by 4-ONE. The APD prolongation by 10 μM of 4-ONE was more prominent than that by 100 μM of 4-HNE. In the computational in silico cardiomyocyte simulation analysis, the changes of INaL by 4-ONE significantly exacerbated the risk of arrhythmia exhibited by the TdP marker, qNet. Our study suggests an arrhythmogenic effect of 4-ONE on cardiac ion channels, especially hNaV1.5.
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Affiliation(s)
- Seong-Woo Choi
- Department of Physiology, Dongguk University College of Medicine, Gyeongju 38066, Korea; (S.-W.C.); (J.-H.W.)
| | - Ming-Zhe Yin
- Department of Physiology, Seoul National University College of Medicine, Seoul 03080, Korea; (M.-Z.Y.); (N.-K.P.)
- Department of Anesthesiology, Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou 310058, China
| | - Na-Kyeong Park
- Department of Physiology, Seoul National University College of Medicine, Seoul 03080, Korea; (M.-Z.Y.); (N.-K.P.)
| | - Joo-Han Woo
- Department of Physiology, Dongguk University College of Medicine, Gyeongju 38066, Korea; (S.-W.C.); (J.-H.W.)
| | - Sung-Joon Kim
- Department of Physiology, Seoul National University College of Medicine, Seoul 03080, Korea; (M.-Z.Y.); (N.-K.P.)
- Correspondence: or ; Tel.: +82-2-740-8230
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Iturriaga R, Alcayaga J, Chapleau MW, Somers VK. Carotid body chemoreceptors: physiology, pathology, and implications for health and disease. Physiol Rev 2021; 101:1177-1235. [PMID: 33570461 PMCID: PMC8526340 DOI: 10.1152/physrev.00039.2019] [Citation(s) in RCA: 81] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The carotid body (CB) is the main peripheral chemoreceptor for arterial respiratory gases O2 and CO2 and pH, eliciting reflex ventilatory, cardiovascular, and humoral responses to maintain homeostasis. This review examines the fundamental biology underlying CB chemoreceptor function, its contribution to integrated physiological responses, and its role in maintaining health and potentiating disease. Emphasis is placed on 1) transduction mechanisms in chemoreceptor (type I) cells, highlighting the role played by the hypoxic inhibition of O2-dependent K+ channels and mitochondrial oxidative metabolism, and their modification by intracellular molecules and other ion channels; 2) synaptic mechanisms linking type I cells and petrosal nerve terminals, focusing on the role played by the main proposed transmitters and modulatory gases, and the participation of glial cells in regulation of the chemosensory process; 3) integrated reflex responses to CB activation, emphasizing that the responses differ dramatically depending on the nature of the physiological, pathological, or environmental challenges, and the interactions of the chemoreceptor reflex with other reflexes in optimizing oxygen delivery to the tissues; and 4) the contribution of enhanced CB chemosensory discharge to autonomic and cardiorespiratory pathophysiology in obstructive sleep apnea, congestive heart failure, resistant hypertension, and metabolic diseases and how modulation of enhanced CB reactivity in disease conditions may attenuate pathophysiology.
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Affiliation(s)
- Rodrigo Iturriaga
- Laboratorio de Neurobiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile, and Centro de Excelencia en Biomedicina de Magallanes, Universidad de Magallanes, Punta Arenas, Chile
| | - Julio Alcayaga
- Laboratorio de Fisiología Celular, Facultad de Ciencias, Universidad de Chile, Santiago, Chile
| | - Mark W Chapleau
- Department of Internal Medicine, University of Iowa and Department of Veterans Affairs Medical Center, Iowa City, Iowa
| | - Virend K Somers
- Department of Cardiovascular Medicine, Mayo Clinic, Rochester, Minnesota
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Hostrup M, Cairns SP, Bangsbo J. Muscle Ionic Shifts During Exercise: Implications for Fatigue and Exercise Performance. Compr Physiol 2021; 11:1895-1959. [PMID: 34190344 DOI: 10.1002/cphy.c190024] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Exercise causes major shifts in multiple ions (e.g., K+ , Na+ , H+ , lactate- , Ca2+ , and Cl- ) during muscle activity that contributes to development of muscle fatigue. Sarcolemmal processes can be impaired by the trans-sarcolemmal rundown of ion gradients for K+ , Na+ , and Ca2+ during fatiguing exercise, while changes in gradients for Cl- and Cl- conductance may exert either protective or detrimental effects on fatigue. Myocellular H+ accumulation may also contribute to fatigue development by lowering glycolytic rate and has been shown to act synergistically with inorganic phosphate (Pi) to compromise cross-bridge function. In addition, sarcoplasmic reticulum Ca2+ release function is severely affected by fatiguing exercise. Skeletal muscle has a multitude of ion transport systems that counter exercise-related ionic shifts of which the Na+ /K+ -ATPase is of major importance. Metabolic perturbations occurring during exercise can exacerbate trans-sarcolemmal ionic shifts, in particular for K+ and Cl- , respectively via metabolic regulation of the ATP-sensitive K+ channel (KATP ) and the chloride channel isoform 1 (ClC-1). Ion transport systems are highly adaptable to exercise training resulting in an enhanced ability to counter ionic disturbances to delay fatigue and improve exercise performance. In this article, we discuss (i) the ionic shifts occurring during exercise, (ii) the role of ion transport systems in skeletal muscle for ionic regulation, (iii) how ionic disturbances affect sarcolemmal processes and muscle fatigue, (iv) how metabolic perturbations exacerbate ionic shifts during exercise, and (v) how pharmacological manipulation and exercise training regulate ion transport systems to influence exercise performance in humans. © 2021 American Physiological Society. Compr Physiol 11:1895-1959, 2021.
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Affiliation(s)
- Morten Hostrup
- Section of Integrative Physiology, Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
| | - Simeon Peter Cairns
- SPRINZ, School of Sport and Recreation, Auckland University of Technology, Auckland, New Zealand.,Health and Rehabilitation Research Institute, Auckland University of Technology, Auckland, New Zealand
| | - Jens Bangsbo
- Section of Integrative Physiology, Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
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Yang M, Dart C, Kamishima T, Quayle JM. Hypoxia and metabolic inhibitors alter the intracellular ATP:ADP ratio and membrane potential in human coronary artery smooth muscle cells. PeerJ 2020; 8:e10344. [PMID: 33240653 PMCID: PMC7664465 DOI: 10.7717/peerj.10344] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Accepted: 10/20/2020] [Indexed: 11/20/2022] Open
Abstract
ATP-sensitive potassium (KATP) channels couple cellular metabolism to excitability, making them ideal candidate sensors for hypoxic vasodilation. However, it is still unknown whether cellular nucleotide levels are affected sufficiently to activate vascular KATP channels during hypoxia. To address this fundamental issue, we measured changes in the intracellular ATP:ADP ratio using the biosensors Perceval/PercevalHR, and membrane potential using the fluorescent probe DiBAC4(3) in human coronary artery smooth muscle cells (HCASMCs). ATP:ADP ratio was significantly reduced by exposure to hypoxia. Application of metabolic inhibitors for oxidative phosphorylation also reduced ATP:ADP ratio. Hyperpolarization caused by inhibiting oxidative phosphorylation was blocked by either 10 µM glibenclamide or 60 mM K+. Hyperpolarization caused by hypoxia was abolished by 60 mM K+ but not by individual K+ channel inhibitors. Taken together, these results suggest hypoxia causes hyperpolarization in part by modulating K+ channels in SMCs.
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Affiliation(s)
- Mingming Yang
- Department of Cardiology, Zhongda Hospital, Medical School of Southeast University, Nanjing, People’s Republic of China
- Department of Cellular and Molecular Physiology, Institute of Translational Medicine, Liverpool, UK
| | - Caroline Dart
- Department of Biochemistry, Institute of Integrative Biology, Liverpool, UK
| | - Tomoko Kamishima
- Department of Cellular and Molecular Physiology, Institute of Translational Medicine, Liverpool, UK
| | - John M. Quayle
- Department of Cellular and Molecular Physiology, Institute of Translational Medicine, Liverpool, UK
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The Role and Regulation of Pulmonary Artery Smooth Muscle Cells in Pulmonary Hypertension. Int J Hypertens 2020; 2020:1478291. [PMID: 32850144 PMCID: PMC7441461 DOI: 10.1155/2020/1478291] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Accepted: 07/20/2020] [Indexed: 02/06/2023] Open
Abstract
Pulmonary hypertension (PH) is one of the most devastating cardiovascular diseases worldwide and it draws much attention from numerous scientists. As an indispensable part of pulmonary artery, smooth muscle cells are worthy of being carefully investigated. To elucidate the pathogenesis of PH, several theories focusing on pulmonary artery smooth muscle cells (PASMC), such as hyperproliferation, resistance to apoptosis, and cancer theory, have been proposed and widely studied. Here, we tried to summarize the studies, concentrating on the role of PASMC in the development of PH, feasible molecular basis to intervene, and potential treatment to PH.
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29
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Lucu Č. Hypoxia attenuate ionic transport in the isolated gill epithelium of Carcinus maenas. J Comp Physiol B 2020; 190:391-401. [PMID: 32333115 DOI: 10.1007/s00360-020-01277-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Revised: 03/31/2020] [Accepted: 04/08/2020] [Indexed: 12/18/2022]
Abstract
The gills are osmorespiratory organs of aquatic organisms and the prime target of environmentally induced hypoxia. We have studied the impact of severe hypoxia (0.5 mg O2/L) on the ionic transport across posterior gills of Carcinus maenas acclimated to 12 ppt seawater (DSW). The short-circuit current (Isc) across hemilamellae from gills i.e. active ion transport was studied in micro Ussing chambers. Hypoxia induced by deoxygenation of the basolateral side, and not the apical side, resulted in time-dependent inhibition of Isc and full recovery of Isc after reoxygenation. Exposure of the crabs to severe 7 h hypoxia decreased the specific activity of Na+,K+-ATPase in the gills by 36%. Full recovery of enzyme activity occurred in fasted crabs after 3 days of reoxygenation. The intensity of Western blotting bands was not different in the gills of oxygenated, hypoxic and reoxygenated crabs. The reversible, nonspecific blocker of K+ channels Cs and hypoxia inhibited over 90% of Isc which is after reoxygenation fully recovered. The specific blocker of Cl- channels NPPB [5-nitro-2-(3-phenylpropylamino)benzoic acid] blocked Isc by 68.5%. Only the rest of not inhibited Isc in aerated saline was blocked by hypoxia and recovered after reoxygenation. The activity of the antioxidant enzyme catalase was not changed during hypoxia and reoxygenation kept the high enzyme activity in the gills at the level of crabs acclimated to DSW. As a response to hypoxia the presence of 2 mM H2O2 induce an initial slight transient decrease of Isc followed by a rise and after reoxygenation fully recovered Isc. Incubation of hemilamellae with the antioxidant derivative Trolox did not affect the inhibition of Isc by hypoxia.
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Affiliation(s)
- Čedomil Lucu
- Center for Marine Research, Institute Ruđer Bošković, Rovinj, Zagreb, Croatia.
- Alfred Wegener-Institute Helmholtz Centre for Polar and Marine Research, Wadden Sea Station List, Sylt, Germany.
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Horváth B, Hézső T, Kiss D, Kistamás K, Magyar J, Nánási PP, Bányász T. Late Sodium Current Inhibitors as Potential Antiarrhythmic Agents. Front Pharmacol 2020; 11:413. [PMID: 32372952 PMCID: PMC7184885 DOI: 10.3389/fphar.2020.00413] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Accepted: 03/18/2020] [Indexed: 12/19/2022] Open
Abstract
Based on recent findings, an increased late sodium current (INa,late) plays an important pathophysiological role in cardiac diseases, including rhythm disorders. The article first describes what is INa,late and how it functions under physiological circumstances. Next, it shows the wide range of cellular mechanisms that can contribute to an increased INa,late in heart diseases, and also discusses how the upregulated INa,late can play a role in the generation of cardiac arrhythmias. The last part of the article is about INa,late inhibiting drugs as potential antiarrhythmic agents, based on experimental and preclinical data as well as in the light of clinical trials.
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Affiliation(s)
- Balázs Horváth
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
- Faculty of Pharmacy, University of Debrecen, Debrecen, Hungary
| | - Tamás Hézső
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Dénes Kiss
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Kornél Kistamás
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - János Magyar
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
- Division of Sport Physiology, University of Debrecen, Debrecen, Hungary
| | - Péter P. Nánási
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
- Department of Dental Physiology and Pharmacology, Faculty of Dentistry, University of Debrecen, Debrecen, Hungary
| | - Tamás Bányász
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
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Pavlacky J, Polak J. Technical Feasibility and Physiological Relevance of Hypoxic Cell Culture Models. Front Endocrinol (Lausanne) 2020; 11:57. [PMID: 32153502 PMCID: PMC7046623 DOI: 10.3389/fendo.2020.00057] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/27/2019] [Accepted: 01/29/2020] [Indexed: 12/13/2022] Open
Abstract
Hypoxia is characterized as insufficient oxygen delivery to tissues and cells in the body and is prevalent in many human physiology processes and diseases. Thus, it is an attractive state to experimentally study to understand its inner mechanisms as well as to develop and test therapies against pathological conditions related to hypoxia. Animal models in vivo fail to recapitulate some of the key hallmarks of human physiology, which leads to human cell cultures; however, they are prone to bias, namely when pericellular oxygen concentration (partial pressure) does not respect oxygen dynamics in vivo. A search of the current literature on the topic revealed this was the case for many original studies pertaining to experimental models of hypoxia in vitro. Therefore, in this review, we present evidence mandating for the close control of oxygen levels in cell culture models of hypoxia. First, we discuss the basic physical laws required for understanding the oxygen dynamics in vitro, most notably the limited diffusion through a liquid medium that hampers the oxygenation of cells in conventional cultures. We then summarize up-to-date knowledge of techniques that help standardize the culture environment in a replicable fashion by increasing oxygen delivery to the cells and measuring pericellular levels. We also discuss how these tools may be applied to model both constant and intermittent hypoxia in a physiologically relevant manner, considering known values of partial pressure of tissue normoxia and hypoxia in vivo, compared to conventional cultures incubated at rigid oxygen pressure. Attention is given to the potential influence of three-dimensional tissue cultures and hypercapnia management on these models. Finally, we discuss the implications of these concepts for cell cultures, which try to emulate tissue normoxia, and conclude that the maintenance of precise oxygen levels is important in any cell culture setting.
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Affiliation(s)
- Jiri Pavlacky
- Department of Pathophysiology, Third Faculty of Medicine, Charles University, Prague, Czechia
- Rare Diseases Research Unit, Department of Pediatrics and Adolescent Medicine, First Faculty of Medicine, Charles University, Prague, Czechia
| | - Jan Polak
- Department of Pathophysiology, Third Faculty of Medicine, Charles University, Prague, Czechia
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Abstract
The carotid body (CB) is an arterial chemoreceptor organ located in the carotid bifurcation and has a well-recognized role in cardiorespiratory regulation. The CB contains neurosecretory sensory cells (glomus cells), which release transmitters in response to hypoxia, hypercapnia, and acidemia to activate afferent sensory fibers terminating in the respiratory and autonomic brainstem centers. Knowledge of the physiology of the CB has progressed enormously in recent years. Herein we review advances concerning the organization and function of the cellular elements of the CB, with emphasis on the molecular mechanisms of acute oxygen sensing by glomus cells. We introduce the modern view of the CB as a multimodal integrated metabolic sensor and describe the properties of the CB stem cell niche, which support CB growth during acclimatization to chronic hypoxia. Finally, we discuss the increasing medical relevance of CB dysfunction and its potential impact on the mechanisms of disease.
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Affiliation(s)
- Patricia Ortega-Sáenz
- Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Sevilla 41013, Spain; , .,Departamento de Fisiología Médica y Biofísica, Universidad de Sevilla, Sevilla 41009, Spain.,Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Sevilla 41013, Spain
| | - José López-Barneo
- Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Sevilla 41013, Spain; , .,Departamento de Fisiología Médica y Biofísica, Universidad de Sevilla, Sevilla 41009, Spain.,Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Sevilla 41013, Spain
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33
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Rosenberry R, Nelson MD. Reactive hyperemia: a review of methods, mechanisms, and considerations. Am J Physiol Regul Integr Comp Physiol 2020; 318:R605-R618. [PMID: 32022580 DOI: 10.1152/ajpregu.00339.2019] [Citation(s) in RCA: 111] [Impact Index Per Article: 27.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Reactive hyperemia is a well-established technique for noninvasive assessment of peripheral microvascular function and a predictor of all-cause and cardiovascular morbidity and mortality. In its simplest form, reactive hyperemia represents the magnitude of limb reperfusion following a brief period of ischemia induced by arterial occlusion. Over the past two decades, investigators have employed a variety of methods, including brachial artery velocity by Doppler ultrasound, tissue reperfusion by near-infrared spectroscopy, limb distension by venous occlusion plethysmography, and peripheral artery tonometry, to measure reactive hyperemia. Regardless of the technique used to measure reactive hyperemia, blunted reactive hyperemia is believed to reflect impaired microvascular function. With the advent of several technological advancements, together with an increased interest in the microcirculation, reactive hyperemia is becoming more common as a research tool and is widely used across multiple disciplines. With this in mind, we sought to review the various methodologies commonly used to assess reactive hyperemia and current mechanistic pathways believed to contribute to reactive hyperemia and reflect on several methodological considerations.
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Affiliation(s)
- Ryan Rosenberry
- Department of Kinesiology, University of Texas at Arlington, Arlington, Texas
| | - Michael D Nelson
- Department of Kinesiology, University of Texas at Arlington, Arlington, Texas.,Department of Bioengineering, University of Texas at Arlington, Arlington, Texas
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34
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Girault A, Ahidouch A, Ouadid-Ahidouch H. Roles for Ca 2+ and K + channels in cancer cells exposed to the hypoxic tumour microenvironment. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2020; 1867:118644. [PMID: 31931022 DOI: 10.1016/j.bbamcr.2020.118644] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Revised: 12/26/2019] [Accepted: 12/31/2019] [Indexed: 02/07/2023]
Abstract
For twenty years, ion channels have been studied in cancer progression. Several information have been collected about their involvement in cancer cellular processes like cell proliferation, motility and their participation in tumour progression using in-vivo models. Tumour microenvironment is currently the focus of many researches and the highlighting of the relationship between cancer cells and surrounding elements, is expanding. One of the major physic-chemical parameter involved in tumour progression is the hypoxia conditions observed in solid cancer. Due to their position on the cell membrane, ion channels are good candidates to transduce or to be modulated by environmental modifications. Until now, few reports have been interested in the modification of ion channel activities or expression in this context, compared to other pathological situations such as ischemia reperfusion. The aim of our review is to summarize the current knowledge about the calcium and potassium channels properties in the context of hypoxia in tumours. This review could pave the way to orientate new studies around this exciting field to obtain new potential therapeutic approaches.
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Affiliation(s)
- Alban Girault
- Université de Picardie Jules Verne, UFR des Sciences, Laboratoire de Physiologie Cellulaire et Moléculaire (EA 4667), Amiens, France
| | - Ahmed Ahidouch
- Université de Picardie Jules Verne, UFR des Sciences, Laboratoire de Physiologie Cellulaire et Moléculaire (EA 4667), Amiens, France; Université Ibn Zohr, Faculté des sciences, Département de Biologie, Agadir, Morocco
| | - Halima Ouadid-Ahidouch
- Université de Picardie Jules Verne, UFR des Sciences, Laboratoire de Physiologie Cellulaire et Moléculaire (EA 4667), Amiens, France.
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35
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Calcium-Permeable Channels in Tumor Vascularization: Peculiar Sensors of Microenvironmental Chemical and Physical Cues. Rev Physiol Biochem Pharmacol 2020; 182:111-137. [DOI: 10.1007/112_2020_32] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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36
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Identifying neuronal correlates of dying and resuscitation in a model of reversible brain anoxia. Prog Neurobiol 2019; 185:101733. [PMID: 31836416 DOI: 10.1016/j.pneurobio.2019.101733] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Revised: 11/29/2019] [Accepted: 12/06/2019] [Indexed: 11/20/2022]
Abstract
We developed a new rodent model of reversible brain anoxia and performed continuous electrocorticographic (ECoG) and intracellular recordings of neocortical neurons to identify in real-time the cellular and network dynamics that successively emerge throughout the dying-to-recovery process. Along with a global decrease in ECoG amplitude, deprivation of oxygen supply resulted in an early surge of beta-gamma activities, accompanied by rhythmic membrane depolarizations and regular firing in pyramidal neurons. ECoG and intracellular signals were then dominated by low-frequency activities which progressively declined towards isoelectric levels. Cortical neurons during the isoelectric state underwent a massive membrane potential depolarizing shift, captured in the ECoG as a large amplitude triphasic wave known as the "wave-of-death" (WoD). This neuronal anoxic depolarization, associated with a block of action potentials and a loss of cell integrative properties, could however be reversed if brain re-oxygenation was rapidly restored (within 2-3.5 min). The subsequent slow repolarization of neocortical neurons resulted in a second identifiable ECoG wave we termed "wave-of-resuscitation" since it inaugurated the progressive regaining of pre-anoxic synaptic and firing activities. These results demonstrate that the WoD is not a biomarker of an irremediable death and unveil the cellular correlates of a novel ECoG wave that may be predictive of a successful recovery. The identification of real-time biomarkers of onset and termination of cell anoxic insult could benefit research on interventional strategies to optimize resuscitation procedures.
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37
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Iorio J, Petroni G, Duranti C, Lastraioli E. Potassium and Sodium Channels and the Warburg Effect: Biophysical Regulation of Cancer Metabolism. Bioelectricity 2019; 1:188-200. [PMID: 34471821 PMCID: PMC8370285 DOI: 10.1089/bioe.2019.0017] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Ion channels are progressively emerging as a novel class of membrane proteins expressed in several types of human cancers and regulating the different aspects of cancer cell behavior. The metabolism of cancer cells, usually composed by a variable proportion of respiration, glycolysis, and glutaminolysis, leads to the excessive production of acidic metabolic products. The presence of these acidic metabolites inside the cells results in intracellular acidosis, and hinders survival and proliferation. For this reason, tumor cells activate mechanisms of pH control that produce a constitutive increase in intracellular pH (pHi) that is more acidic than the extracellular pH (pHe). This condition forms a perfect microenvironment for metastatic progression and may be permissive for some of the acquired characteristics of tumors. Recent analyses have revealed complex interconnections between oncogenic activation, ion channels, hypoxia signaling and metabolic pathways that are dysregulated in cancer. Here, we summarize the molecular mechanisms of the Warburg effect and hypoxia and their association. Moreover, we discuss the recent findings concerning the involvement of ion channels in various aspects of the Warburg effect and hypoxia, focusing on the role of Na+ and K+ channels in hypoxic and metabolic reprogramming in cancer.
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Affiliation(s)
- Jessica Iorio
- Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
| | - Giulia Petroni
- Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
| | - Claudia Duranti
- Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
| | - Elena Lastraioli
- Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
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38
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Trotta MC, Ferraro B, Messina A, Panarese I, Gulotta E, Nicoletti GF, D'Amico M, Pieretti G. Telmisartan cardioprotects from the ischaemic/hypoxic damage through a miR-1-dependent pathway. J Cell Mol Med 2019; 23:6635-6645. [PMID: 31369209 PMCID: PMC6787508 DOI: 10.1111/jcmm.14534] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Revised: 05/27/2019] [Accepted: 06/24/2019] [Indexed: 01/01/2023] Open
Abstract
The aim of this study was to investigate whether telmisartan protects the heart from the ischaemia/reperfusion damage through a local microRNA‐1 modulation. Studies on the myocardial ischaemia/reperfusion injury in vivo and on the cardiomyocyte hypoxia/reoxygenation damage in vitro were done. In vivo, male Sprague‐Dawley rats administered for 3 weeks with telmisartan 12 mg/kg/d by gastric gavage underwent ischaemia/reperfusion of the left descending coronary artery. In these rats, infarct size measurement, ELISA, immunohistochemistry (IHC) and reverse transcriptase real‐time polymerase chain reaction showed that expressions of connexin 43, potassium voltage‐gated channel subfamily Q member 1 and the protein Bcl‐2 were significantly increased by telmisartan in the reperfused myocardium, paralleled by microRNA‐1 down‐regulation. In vitro, the transfection of cardiomyocytes with microRNA‐1 reduced the expressions of connexin 43, potassium voltage‐gated channel subfamily Q member 1 and Bcl‐2 in the cells. Telmisartan (50 µmol/L) 60 minutes before hypoxia/reoxygenation, while not affecting the levels of miR‐1 in transfected cells in normoxic condition, almost abolished the increment of miR‐1 induced by the hypoxia/reoxygenation to transfected cells. All together, telmisartan cardioprotected against the myocardial damage through the microRNA‐1 modulation, and consequent modifications of its downstream target connexin 43, potassium voltage‐gated channel subfamily Q member 1 and Bcl‐2.
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Affiliation(s)
- Maria Consiglia Trotta
- Department of Experimental Medicine, University of Campania 'Luigi Vanvitelli', Naples, Italy
| | - Bartolo Ferraro
- Department of Experimental Medicine, University of Campania 'Luigi Vanvitelli', Naples, Italy
| | - Antonietta Messina
- Department of Experimental Medicine, University of Campania 'Luigi Vanvitelli', Naples, Italy
| | - Iacopo Panarese
- Department of Mental and Physical Health and Preventive Medicine, University of Campania 'Luigi Vanvitelli', Naples, Italy
| | - Eliana Gulotta
- Department of Surgical, Oncological and Stomatological Disciplines, University of Palermo, Palermo, Italy
| | - Giovanni Francesco Nicoletti
- Multidisciplinary Department of Surgical and Dental Specialties, University of Campania 'Luigi Vanvitelli', Naples, Italy
| | - Michele D'Amico
- Department of Experimental Medicine, University of Campania 'Luigi Vanvitelli', Naples, Italy
| | - Gorizio Pieretti
- Multidisciplinary Department of Surgical and Dental Specialties, University of Campania 'Luigi Vanvitelli', Naples, Italy
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39
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Wood CE, Keller-Wood M. Current paradigms and new perspectives on fetal hypoxia: implications for fetal brain development in late gestation. Am J Physiol Regul Integr Comp Physiol 2019; 317:R1-R13. [PMID: 31017808 DOI: 10.1152/ajpregu.00008.2019] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
The availability of oxygen to the fetus is limited by the route taken by oxygen from the atmosphere to fetal tissues, aided or diminished by pregnancy-associated changes in maternal physiology and, ultimately, a function of atmospheric pressure and composition of the mother's inspired gas. Much of our understanding of the fetal physiological response to hypoxia comes from experiments designed to elucidate the cardiovascular and endocrine responses to transient hypoxia. Complementing this work is equally impactful research into the origins of intrauterine growth restriction in which animal models designed to restrict the transfer of oxygen from the maternal to the fetal circulation were used. A common assumption has been that outcomes measured after a period of hypoxia are related to cellular deprivation of oxygen and reoxygenation: an assumption based on a focus on what we can see "under the streetlights." Recent studies demonstrate that availability of oxygen may not tell the whole story. Transient hypoxia in the fetal sheep stimulates transcriptomics responses that mirror inflammation. This response is accompanied by the appearance of bacteria in the fetal brain and other tissues, likely resulting from a hypoxia-stimulated release of bacteria from the placenta. The appearance of bacteria in the fetus after transient hypoxia complements the recent discovery of bacterial DNA in the normal human placenta and in the tissues of fetal sheep. An understanding of the mechanism of the physiological, cellular, and molecular responses to hypoxia requires an appreciation of stimuli other than cellular oxygen deprivation: stimuli that we would have never known about without looking "between the streetlights," illuminating direct responses to the manipulated variables.
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Affiliation(s)
- Charles E Wood
- Department of Physiology and Functional Genomics, University of Florida College of Medicine , Gainesville, Florida
| | - Maureen Keller-Wood
- Department of Pharmacodynamics, University of Florida College of Pharmacy , Gainesville, Florida
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40
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Christiansen D, Eibye KH, Rasmussen V, Voldbye HM, Thomassen M, Nyberg M, Gunnarsson TGP, Skovgaard C, Lindskrog MS, Bishop DJ, Hostrup M, Bangsbo J. Cycling with blood flow restriction improves performance and muscle K + regulation and alters the effect of anti-oxidant infusion in humans. J Physiol 2019; 597:2421-2444. [PMID: 30843602 DOI: 10.1113/jp277657] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2019] [Accepted: 02/27/2019] [Indexed: 12/14/2022] Open
Abstract
KEY POINTS Training with blood flow restriction (BFR) is a well-recognized strategy for promoting muscle hypertrophy and strength. However, its potential to enhance muscle function during sustained, intense exercise remains largely unexplored. In the present study, we report that interval training with BFR augments improvements in performance and reduces net K+ release from contracting muscles during high-intensity exercise in active men. A better K+ regulation after BFR-training is associated with an elevated blood flow to exercising muscles and altered muscle anti-oxidant function, as indicated by a higher reduced to oxidized glutathione (GSH:GSSG) ratio, compared to control, as well as an increased thigh net K+ release during intense exercise with concomitant anti-oxidant infusion. Training with BFR also invoked fibre type-specific adaptations in the abundance of Na+ ,K+ -ATPase isoforms (α1 , β1 , phospholemman/FXYD1). Thus, BFR-training enhances performance and K+ regulation during intense exercise, which may be a result of adaptations in anti-oxidant function, blood flow and Na+ ,K+ -ATPase-isoform abundance at the fibre-type level. ABSTRACT We examined whether blood flow restriction (BFR) augments training-induced improvements in K+ regulation and performance during intense exercise in men, and also whether these adaptations are associated with an altered muscle anti-oxidant function, blood flow and/or with fibre type-dependent changes in Na+ ,K+ -ATPase-isoform abundance. Ten recreationally-active men (25 ± 4 years, 49.7 ± 5.3 mL kg-1 min-1 ) performed 6 weeks of interval cycling, where one leg trained without BFR (control; CON-leg) and the other trained with BFR (BFR-leg, pressure: ∼180 mmHg). Before and after training, femoral arterial and venous K+ concentrations and artery blood flow were measured during single-leg knee-extensor exercise at 25% (Ex1) and 90% of thigh incremental peak power (Ex2) with i.v. infusion of N-acetylcysteine (NAC) or placebo (saline) and a resting muscle biopsy was collected. After training, performance increased more in BFR-leg (23%) than in CON-leg (12%, P < 0.05), whereas K+ release during Ex2 was attenuated only from BFR-leg (P < 0.05). The muscle GSH:GSSG ratio at rest and blood flow during exercise was higher in BFR-leg than in CON-leg after training (P < 0.05). After training, NAC increased resting muscle GSH concentration and thigh net K+ release during Ex2 only in BFR-leg (P < 0.05), whereas the abundance of Na+ ,K+ -ATPase-isoform α1 in type II (51%), β1 in type I (33%), and FXYD1 in type I (108%) and type II (60%) fibres was higher in BFR-leg than in CON-leg (P < 0.05). Thus, training with BFR elicited greater improvements in performance and reduced thigh K+ release during intense exercise, which were associated with adaptations in muscle anti-oxidant function, blood flow and Na+ ,K+ -ATPase-isoform abundance at the fibre-type level.
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Affiliation(s)
- Danny Christiansen
- Section of Integrative Physiology, Department of Nutrition, Exercise and Sports (NEXS), University of Copenhagen, Copenhagen, Denmark.,Institute for Health and Sport (IHES), Victoria University, Melbourne, VIC, Australia
| | - Kasper H Eibye
- Section of Integrative Physiology, Department of Nutrition, Exercise and Sports (NEXS), University of Copenhagen, Copenhagen, Denmark
| | - Villads Rasmussen
- Section of Integrative Physiology, Department of Nutrition, Exercise and Sports (NEXS), University of Copenhagen, Copenhagen, Denmark
| | - Hans M Voldbye
- Section of Integrative Physiology, Department of Nutrition, Exercise and Sports (NEXS), University of Copenhagen, Copenhagen, Denmark
| | - Martin Thomassen
- Section of Integrative Physiology, Department of Nutrition, Exercise and Sports (NEXS), University of Copenhagen, Copenhagen, Denmark
| | - Michael Nyberg
- Section of Integrative Physiology, Department of Nutrition, Exercise and Sports (NEXS), University of Copenhagen, Copenhagen, Denmark
| | - Thomas G P Gunnarsson
- Section of Integrative Physiology, Department of Nutrition, Exercise and Sports (NEXS), University of Copenhagen, Copenhagen, Denmark
| | - Casper Skovgaard
- Section of Integrative Physiology, Department of Nutrition, Exercise and Sports (NEXS), University of Copenhagen, Copenhagen, Denmark
| | - Mads S Lindskrog
- Section of Integrative Physiology, Department of Nutrition, Exercise and Sports (NEXS), University of Copenhagen, Copenhagen, Denmark
| | - David J Bishop
- Institute for Health and Sport (IHES), Victoria University, Melbourne, VIC, Australia.,School of Medical and Health Sciences, Edith Cowan University, Perth, WA, Australia
| | - Morten Hostrup
- Section of Integrative Physiology, Department of Nutrition, Exercise and Sports (NEXS), University of Copenhagen, Copenhagen, Denmark
| | - Jens Bangsbo
- Section of Integrative Physiology, Department of Nutrition, Exercise and Sports (NEXS), University of Copenhagen, Copenhagen, Denmark
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41
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Marinheiro R, Parreira L, Amador P, Mesquita D, Farinha J, Fonseca M, Duarte T, Lopes C, Fernandes A, Caria R. Ventricular Arrhythmias in Patients with Obstructive Sleep Apnea. Curr Cardiol Rev 2019; 15:64-74. [PMID: 30338742 PMCID: PMC6367697 DOI: 10.2174/1573403x14666181012153252] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Revised: 10/05/2018] [Accepted: 10/09/2018] [Indexed: 12/15/2022] Open
Abstract
Obstructive Sleep Apnea (OSA) is a prevalent condition thought to increase in the future. Being mostly undiagnosed, the most serious complications are cardiovascular diseases, among which are arrhythmias. Controversy remains as to whether OSA is a primary etiologic factor for ventricular arrhythmias, because of the high incidence of cardiovascular comorbidities in OSA patients. Howev-er, there is mostly a strong evidence of a relation between OSA and ventricular arrhythmias. A few mechanisms have been proposed to be responsible for this association and some electrocardiographic changes have also been demonstrated to be more frequent in OSA patients. Treatment of OSA with Continuous Positive Airway Pressure (CPAP) has the potential to reduce arrhythmias and confer a mortality benefit.
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Affiliation(s)
- Rita Marinheiro
- Cardiology Department, Centro Hospitalar de Setubal, Setubal, Portugal
| | - Leonor Parreira
- Cardiology Department, Centro Hospitalar de Setubal, Setubal, Portugal
| | - Pedro Amador
- Cardiology Department, Centro Hospitalar de Setubal, Setubal, Portugal
| | - Dinis Mesquita
- Cardiology Department, Centro Hospitalar de Setubal, Setubal, Portugal
| | - José Farinha
- Cardiology Department, Centro Hospitalar de Setubal, Setubal, Portugal
| | - Marta Fonseca
- Cardiology Department, Centro Hospitalar de Setubal, Setubal, Portugal
| | - Tatiana Duarte
- Cardiology Department, Centro Hospitalar de Setubal, Setubal, Portugal
| | - Cláudia Lopes
- Cardiology Department, Centro Hospitalar de Setubal, Setubal, Portugal
| | - Andreia Fernandes
- Cardiology Department, Centro Hospitalar de Setubal, Setubal, Portugal
| | - Rui Caria
- Cardiology Department, Centro Hospitalar de Setubal, Setubal, Portugal
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Taglauer E, Abman SH, Keller RL. Recent advances in antenatal factors predisposing to bronchopulmonary dysplasia. Semin Perinatol 2018; 42:413-424. [PMID: 30389227 PMCID: PMC6286866 DOI: 10.1053/j.semperi.2018.09.002] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Bronchopulmonary dysplasia (BPD) remains a major cause of late morbidities and death after preterm birth. BPD is characterized by an arrest of vascular and alveolar growth and high risk for pulmonary hypertension; yet mechanisms contributing to its pathogenesis and early strategies to prevent BPD are poorly understood. Strong epidemiologic studies have shown that the "new BPD" reflects the long-lasting impact of antenatal factors on lung development, partly due to placental dysfunction, as reflected in recent data from animal models. Improved understanding of mechanisms through which antenatal stress alters placental function and contributes to BPD may lead to preventive therapies.
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Affiliation(s)
| | - Steven H. Abman
- Pediatric Heart Lung Center, Department of Pediatrics, University of Colorado Anschutz School of Medicine, Aurora CO USA
| | - Roberta L. Keller
- Division of Neonatology, Department of Pediatrics, University of California San Francisco, San Francisco, CA USA
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43
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The hypoxia-tolerant vertebrate brain: Arresting synaptic activity. Comp Biochem Physiol B Biochem Mol Biol 2018; 224:61-70. [DOI: 10.1016/j.cbpb.2017.11.015] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Revised: 11/23/2017] [Accepted: 11/30/2017] [Indexed: 01/16/2023]
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44
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Hu XQ, Chen M, Dasgupta C, Xiao D, Huang X, Yang S, Zhang L. Chronic hypoxia upregulates DNA methyltransferase and represses large conductance Ca2+-activated K+ channel function in ovine uterine arteries. Biol Reprod 2018; 96:424-434. [PMID: 28203702 DOI: 10.1095/biolreprod.116.145946] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Revised: 11/23/2016] [Accepted: 12/19/2016] [Indexed: 01/06/2023] Open
Abstract
Chronic hypoxia during gestation suppresses large-conductance Ca2+-activated K+ (BKCa) channel function and impedes uterine arterial adaptation to pregnancy. This study tested the hypothesis that chronic hypoxia has a direct effect in upregulating DNA methyltransferase (DNMT) and epigenetically repressing BKCa channel beta-1 subunit (KCNMB1) expression in uterine arteries. Resistance-sized uterine arteries were isolated from near-term pregnant sheep maintained at ∼300 m above sea level or animals acclimatized to high-altitude (3,801 m) hypoxia for 110 days during gestation. For ex vivo hypoxia treatment, uterine arteries from normoxic animals were treated with 21.0% O2 or 10.5% O2 for 48 h. High-altitude hypoxia significantly upregulated DNMT3b expression and enzyme activity in uterine arteries. Similarly, ex vivo hypoxia treatment upregulated DNMT3b expression and enzyme activity that was blocked by a DNMT inhibitor 5-aza-2'-deoxycytidine (5-Aza). Of importance, 5-Aza inhibited hypoxia-induced hypermethylation of specificity protein (SP) 1 binding site at the KCNMB1 promoter and restored transcription factor binding to the KCNMB1 promoter, resulting in the recovery of KCNMB1 gene expression in uterine arteries. Furthermore, 5-Aza blocked the effect of hypoxia and rescued BKCa channel activity and reversed hypoxia-induced decrease in BKCa channel-mediated relaxations and increase in myogenic tone of uterine arteries. Collectively, these results suggest that chronic hypoxia during gestation upregulates DNMT expression and activity, resulting in hypermethylation and repression of KCNMB1 gene and BKCa channel function, impeding uterine arterial adaptation to pregnancy.
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Affiliation(s)
- Xiang-Qun Hu
- Center for Perinatal Biology, Division of Pharmacology, Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, California, USA
| | - Man Chen
- Center for Perinatal Biology, Division of Pharmacology, Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, California, USA
| | - Chiranjib Dasgupta
- Center for Perinatal Biology, Division of Pharmacology, Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, California, USA
| | - Daliao Xiao
- Center for Perinatal Biology, Division of Pharmacology, Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, California, USA
| | - Xiaohui Huang
- Center for Perinatal Biology, Division of Pharmacology, Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, California, USA
| | - Shumei Yang
- Department of Chemistry and Biochemistry, California State University, San Bernardino, California, USA
| | - Lubo Zhang
- Center for Perinatal Biology, Division of Pharmacology, Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, California, USA
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45
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Lam A, Karekar P, Shah K, Hariharan G, Fleyshman M, Kaur H, Singh H, Gururaja Rao S. Drosophila Voltage-Gated Calcium Channel α1-Subunits Regulate Cardiac Function in the Aging Heart. Sci Rep 2018; 8:6910. [PMID: 29720608 PMCID: PMC5932002 DOI: 10.1038/s41598-018-25195-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Accepted: 04/17/2018] [Indexed: 12/20/2022] Open
Abstract
Ion channels maintain numerous physiological functions and regulate signaling pathways. They are the key targets for cellular reactive oxygen species (ROS), acting as signaling switches between ROS and ionic homeostasis. We have carried out a paraquat (PQ) screen in Drosophila to identify ion channels regulating the ROS handling and survival in Drosophila melanogaster. Our screen has revealed that α1-subunits (D-type, T-type, and cacophony) of voltage-gated calcium channels (VGCCs) handle PQ-mediated ROS stress differentially in a gender-based manner. Since ROS are also involved in determining the lifespan, we discovered that the absence of T-type and cacophony decreased the lifespan while the absence of D-type maintained a similar lifespan to that of the wild-type strain. VGCCs are also responsible for electrical signaling in cardiac cells. The cardiac function of each mutant was evaluated through optical coherence tomography (OCT), which revealed that α1-subunits of VGCCs are essential in maintaining cardiac rhythmicity and cardiac function in an age-dependent manner. Our results establish specific roles of α1-subunits of VGCCs in the functioning of the aging heart.
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Affiliation(s)
- Alexander Lam
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, PA, 19102, USA
| | - Priyanka Karekar
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, PA, 19102, USA
| | - Kajol Shah
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, PA, 19102, USA
| | - Girija Hariharan
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, PA, 19102, USA
| | - Michelle Fleyshman
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, PA, 19102, USA
| | - Harmehak Kaur
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, PA, 19102, USA
| | - Harpreet Singh
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, PA, 19102, USA. .,Division of Cardiology, Department of Medicine, Drexel University College of Medicine, Philadelphia, PA, 19102, USA.
| | - Shubha Gururaja Rao
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, PA, 19102, USA.
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Senavirathna LK, Huang C, Yang X, Munteanu MC, Sathiaseelan R, Xu D, Henke CA, Liu L. Hypoxia induces pulmonary fibroblast proliferation through NFAT signaling. Sci Rep 2018; 8:2709. [PMID: 29426911 PMCID: PMC5807313 DOI: 10.1038/s41598-018-21073-x] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Accepted: 01/23/2018] [Indexed: 11/09/2022] Open
Abstract
Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive and typically fatal lung disease with a very low survival rate. Excess accumulation of fibroblasts, myofibroblasts and extracellular matrix creates hypoxic conditions within the lungs, causing asphyxiation. Hypoxia is, therefore, one of the prominent features of IPF. However, there have been few studies concerning the effects of hypoxia on pulmonary fibroblasts. In this study, we investigated the molecular mechanisms of hypoxia-induced lung fibroblast proliferation. Hypoxia increased the proliferation of normal human pulmonary fibroblasts and IPF fibroblasts after exposure for 3–6 days. Cell cycle analysis demonstrated that hypoxia promoted the G1/S phase transition. Hypoxia downregulated cyclin D1 and A2 levels, while it upregulated cyclin E1 protein levels. However, hypoxia had no effect on the protein expression levels of cyclin-dependent kinase 2, 4, and 6. Chemical inhibition of hypoxia-inducible factor (HIF)-2 reduced hypoxia-induced fibroblast proliferation. Moreover, silencing of Nuclear Factor Activated T cell (NFAT) c2 attenuated the hypoxia-mediated fibroblasts proliferation. Hypoxia also induced the nuclear translocation of NFATc2, as determined by immunofluorescence staining. NFAT reporter assays showed that hypoxia-induced NFAT signaling activation is dependent on HIF-2, but not HIF-1. Furthermore, the inhibition or silencing of HIF-2, but not HIF-1, reduced the hypoxia-mediated NFATc2 nuclear translocation. Our studies suggest that hypoxia induces the proliferation of human pulmonary fibroblasts through NFAT signaling and HIF-2.
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Affiliation(s)
- Lakmini Kumari Senavirathna
- Oklahoma Center for Respiratory and Infectious Diseases, Oklahoma State University, Stillwater, OK, 74078, USA.,Department of Physiological Sciences, Lundberg-Kienlen Lung Biology and Toxicology Laboratory, Oklahoma State University, Stillwater, OK, 74078, USA
| | - Chaoqun Huang
- Oklahoma Center for Respiratory and Infectious Diseases, Oklahoma State University, Stillwater, OK, 74078, USA.,Department of Physiological Sciences, Lundberg-Kienlen Lung Biology and Toxicology Laboratory, Oklahoma State University, Stillwater, OK, 74078, USA
| | - Xiaoyun Yang
- Oklahoma Center for Respiratory and Infectious Diseases, Oklahoma State University, Stillwater, OK, 74078, USA.,Department of Physiological Sciences, Lundberg-Kienlen Lung Biology and Toxicology Laboratory, Oklahoma State University, Stillwater, OK, 74078, USA
| | - Maria Cristina Munteanu
- Oklahoma Center for Respiratory and Infectious Diseases, Oklahoma State University, Stillwater, OK, 74078, USA.,Department of Physiological Sciences, Lundberg-Kienlen Lung Biology and Toxicology Laboratory, Oklahoma State University, Stillwater, OK, 74078, USA
| | - Roshini Sathiaseelan
- Oklahoma Center for Respiratory and Infectious Diseases, Oklahoma State University, Stillwater, OK, 74078, USA.,Department of Physiological Sciences, Lundberg-Kienlen Lung Biology and Toxicology Laboratory, Oklahoma State University, Stillwater, OK, 74078, USA
| | - Dao Xu
- Oklahoma Center for Respiratory and Infectious Diseases, Oklahoma State University, Stillwater, OK, 74078, USA.,Department of Physiological Sciences, Lundberg-Kienlen Lung Biology and Toxicology Laboratory, Oklahoma State University, Stillwater, OK, 74078, USA
| | - Craig A Henke
- Department of Medicine, Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, University of Minnesota, Minneapolis, Minnesota, USA
| | - Lin Liu
- Oklahoma Center for Respiratory and Infectious Diseases, Oklahoma State University, Stillwater, OK, 74078, USA. .,Department of Physiological Sciences, Lundberg-Kienlen Lung Biology and Toxicology Laboratory, Oklahoma State University, Stillwater, OK, 74078, USA.
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47
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Perez-Neut M, Haar L, Rao V, Santha S, Lansu K, Rana B, Jones WK, Gentile S. Activation of hERG3 channel stimulates autophagy and promotes cellular senescence in melanoma. Oncotarget 2017; 7:21991-2004. [PMID: 26942884 PMCID: PMC5008339 DOI: 10.18632/oncotarget.7831] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Accepted: 02/15/2016] [Indexed: 01/07/2023] Open
Abstract
Ion channels play a major factor in maintaining cellular homeostasis but very little is known about the role of these proteins in cancer biology. In this work we have discovered that, the Kv11.3 (hERG3) a plasma-membrane potassium channel plays a critical role in the regulation of autophagy in a cancer cell model. We have found that pharmacologic stimulation of the Kv11.3 channel with a small molecule activator, NS1643 induced autophagy via activation of an AMPK-dependent signaling pathway in melanoma cell line. In addition, we have found that NS1643 produced a strong inhibition of cell proliferation by activating a cellular senescence program. Furthermore, inhibition of autophagy via siRNA targeting AMPK or treatment with hydroxychloroquine an autophagy inhibitor activates apoptosis in NS1643-treated cells. Thus, we propose that, Kv11.3 is a novel mediator of autophagy, autophagy can be a survival mechanism contributing to cellular senescence, and that use of a combinatorial pharmacologic approach of Kv11.3 activator with inhibitors of autophagy represents a novel therapeutic approach against melanoma.
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Affiliation(s)
- Mathew Perez-Neut
- Department of Molecular Pharmacology & Therapeutics, Loyola University, Chicago, IL-60153, USA
| | - Lauren Haar
- Department of Molecular Pharmacology & Therapeutics, Loyola University, Chicago, IL-60153, USA
| | - Vidhya Rao
- Department of Molecular Pharmacology & Therapeutics, Loyola University, Chicago, IL-60153, USA
| | - Sreevidya Santha
- Department of Molecular Pharmacology & Therapeutics, Loyola University, Chicago, IL-60153, USA
| | - Katherine Lansu
- Department of Molecular Pharmacology & Therapeutics, Loyola University, Chicago, IL-60153, USA
| | - Basabi Rana
- Department of Molecular Pharmacology & Therapeutics, Loyola University, Chicago, IL-60153, USA
| | - Walter K Jones
- Department of Molecular Pharmacology & Therapeutics, Loyola University, Chicago, IL-60153, USA
| | - Saverio Gentile
- Department of Molecular Pharmacology & Therapeutics, Loyola University, Chicago, IL-60153, USA
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48
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Zhou T, Matsunami H. Lessons from single-cell transcriptome analysis of oxygen-sensing cells. Cell Tissue Res 2017; 372:403-415. [PMID: 28887696 DOI: 10.1007/s00441-017-2682-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2017] [Accepted: 08/07/2017] [Indexed: 12/15/2022]
Abstract
The advent of single-cell RNA-sequencing (RNA-Seq) technology has enabled transcriptome profiling of individual cells. Comprehensive gene expression analysis at the single-cell level has proven to be effective in characterizing the most fundamental aspects of cellular function and identity. This unbiased approach is revolutionary for small and/or heterogeneous tissues like oxygen-sensing cells in identifying key molecules. Here, we review the major methods of current single-cell RNA-Seq technology. We discuss how this technology has advanced the understanding of oxygen-sensing glomus cells in the carotid body and helped uncover novel oxygen-sensing cells and mechanisms in the mice olfactory system. We conclude by providing our perspective on future single-cell RNA-Seq research directed at oxygen-sensing cells.
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Affiliation(s)
- Ting Zhou
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, 261 CARL Building, Box 3509, Durham, NC, USA.
| | - Hiroaki Matsunami
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, 261 CARL Building, Box 3509, Durham, NC, USA.,Department of Neurobiology and Duke Institute for Brain Sciences, Duke University Medical Center, Durham, NC, USA
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49
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Lamothe SM, Song W, Guo J, Li W, Yang T, Baranchuk A, Graham CH, Zhang S. Hypoxia reduces mature hERG channels through calpain up‐regulation. FASEB J 2017; 31:5068-5077. [DOI: 10.1096/fj.201700255r] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2017] [Accepted: 07/17/2017] [Indexed: 01/07/2023]
Affiliation(s)
- Shawn M. Lamothe
- Department of Biomedical and Molecular SciencesQueen’s UniversityKingstonOntarioCanada
| | - WonJu Song
- Department of Biomedical and Molecular SciencesQueen’s UniversityKingstonOntarioCanada
| | - Jun Guo
- Department of Biomedical and Molecular SciencesQueen’s UniversityKingstonOntarioCanada
| | - Wentao Li
- Department of Biomedical and Molecular SciencesQueen’s UniversityKingstonOntarioCanada
| | - Tonghua Yang
- Department of Biomedical and Molecular SciencesQueen’s UniversityKingstonOntarioCanada
| | - Adrian Baranchuk
- Department of Medicine, Kingston General HospitalQueen’s UniversityKingstonOntarioCanada
| | - Charles H. Graham
- Department of Biomedical and Molecular SciencesQueen’s UniversityKingstonOntarioCanada
| | - Shetuan Zhang
- Department of Biomedical and Molecular SciencesQueen’s UniversityKingstonOntarioCanada
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50
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Wang F, Chen ZH, Shabala S. Hypoxia Sensing in Plants: On a Quest for Ion Channels as Putative Oxygen Sensors. PLANT & CELL PHYSIOLOGY 2017; 58:1126-1142. [PMID: 28838128 DOI: 10.1093/pcp/pcx079] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Accepted: 05/22/2017] [Indexed: 05/18/2023]
Abstract
Over 17 million km2 of land is affected by soil flooding every year, resulting in substantial yield losses and jeopardizing food security across the globe. A key step in resolving this problem and creating stress-tolerant cultivars is an understanding of the mechanisms by which plants sense low-oxygen stress. In this work, we review the current knowledge about the oxygen-sensing and signaling pathway in mammalian and plant systems and postulate the potential role of ion channels as putative oxygen sensors in plant roots. We first discuss the definition and requirements for the oxygen sensor and the difference between sensing and signaling. We then summarize the literature and identify several known candidates for oxygen sensing in the mammalian literature. This includes transient receptor potential (TRP) channels; K+-permeable channels (Kv, BK and TASK); Ca2+ channels (RyR and TPC); and various chemo- and reactive oxygen species (ROS)-dependent oxygen sensors. Identified key oxygen-sensing domains (PAS, GCS, GAF and PHD) in mammalian systems are used to predict the potential plant counterparts in Arabidopsis. Finally, the sequences of known mammalian ion channels with reported roles in oxygen sensing were employed to BLAST the Arabidopsis genome for the candidate genes. Several plasma membrane and tonoplast ion channels (such as TPC, AKT and KCO) and oxygen domain-containing proteins with predicted oxygen-sensing ability were identified and discussed. We propose a testable model for potential roles of ion channels in plant hypoxia sensing.
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Affiliation(s)
- Feifei Wang
- School of Land and Food, University of Tasmania, Hobart, Tasmania 7001, Australia
| | - Zhong-Hua Chen
- School of Science and Health, Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW, 2751, Australia
| | - Sergey Shabala
- School of Land and Food, University of Tasmania, Hobart, Tasmania 7001, Australia
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