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Raph SM, Calderin EP, Nong Y, Brittian K, Garrett L, Zhang D, Nystoriak MA. Kv beta complex facilitates exercise-induced augmentation of myocardial perfusion and cardiac growth. Front Cardiovasc Med 2024; 11:1411354. [PMID: 38978788 PMCID: PMC11228310 DOI: 10.3389/fcvm.2024.1411354] [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: 04/02/2024] [Accepted: 05/21/2024] [Indexed: 07/10/2024] Open
Abstract
The oxygen sensitivity of voltage-gated potassium (Kv) channels regulates cardiovascular physiology. Members of the Kv1 family interact with intracellular Kvβ proteins, which exhibit aldo-keto reductase (AKR) activity and confer redox sensitivity to Kv channel gating. The Kvβ proteins contribute to vasoregulation by controlling outward K+ currents in smooth muscle upon changes in tissue oxygen consumption and demand. Considering exercise as a primary physiological stimulus of heightened oxygen demand, the current study tested the role of Kvβ proteins in exercise performance, exercise-induced adaptations in myocardial perfusion, and physiological cardiac growth. Our findings reveal that genetic ablation of Kvβ2 proteins diminishes baseline exercise capacity in mice and attenuates the enhancement in exercise performance observed after long-term training. Moreover, we demonstrate that Kvβ2 proteins are critical for exercise-mediated enhancement in myocardial perfusion during cardiac stress as well as adaptive changes in cardiac structure. Our results underscore the importance of Kvβ proteins in metabolic vasoregulation, highlighting their role in modulating both exercise capacity and cardiovascular benefits associated with training. Furthermore, our study sheds light on a novel molecular target for enhancing exercise performance and improving the health benefits associated with exercise training in patients with limited capacity for physical activity.
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Affiliation(s)
| | | | | | | | | | | | - Matthew A. Nystoriak
- Center for Cardiometabolic Science, Department of Medicine, Division of Environmental Medicine, University of Louisville, Louisville, KY, United States
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2
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Paul A, Chumbale SS, Lakra A, Kumar V, Alhat DS, Singh S. Insights into Leishmania donovani potassium channel family and their biological functions. 3 Biotech 2023; 13:266. [PMID: 37425093 PMCID: PMC10326225 DOI: 10.1007/s13205-023-03692-y] [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: 09/27/2022] [Accepted: 06/26/2023] [Indexed: 07/11/2023] Open
Abstract
Leishmania donovani is the causative organism for visceral leishmaniasis. Although this parasite was discovered over a century ago, nothing is known about role of potassium channels in L. donovani. Potassium channels are known for their crucial roles in cellular functions in other organisms. Recently the presence of a calcium-activated potassium channel in L. donovani was reported which prompted us to look for other proteins which could be potassium channels and to investigate their possible physiological roles. Twenty sequences were identified in L. donovani genome and subjected to estimation of physio-chemical properties, motif analysis, localization prediction and transmembrane domain analysis. Structural predictions were also done. The channels were majorly α-helical and predominantly localized in cell membrane and lysosomes. The signature selectivity filter of potassium channel was present in all the sequences. In addition to the conventional potassium channel activity, they were associated with gene ontology terms for mitotic cell cycle, cell death, modulation by virus of host process, cell motility etc. The entire study indicates the presence of potassium channel families in L. donovani which may have involvement in several cellular pathways. Further investigations on these putative potassium channels are needed to elucidate their roles in Leishmania. Supplementary Information The online version contains supplementary material available at 10.1007/s13205-023-03692-y.
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Affiliation(s)
- Anindita Paul
- Department of Biotechnology, National Institute of Pharmaceutical Education and Research, SAS Nagar, Mohali, 160062 Punjab India
| | - Shubham Sunil Chumbale
- Department of Biotechnology, National Institute of Pharmaceutical Education and Research, SAS Nagar, Mohali, 160062 Punjab India
| | - Anjana Lakra
- Department of Biotechnology, National Institute of Pharmaceutical Education and Research, SAS Nagar, Mohali, 160062 Punjab India
| | - Vijay Kumar
- Department of Biotechnology, National Institute of Pharmaceutical Education and Research, SAS Nagar, Mohali, 160062 Punjab India
| | - Dhanashri Sudam Alhat
- Department of Biotechnology, National Institute of Pharmaceutical Education and Research, SAS Nagar, Mohali, 160062 Punjab India
| | - Sushma Singh
- Department of Biotechnology, National Institute of Pharmaceutical Education and Research, SAS Nagar, Mohali, 160062 Punjab India
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Grandi E, Navedo MF, Saucerman JJ, Bers DM, Chiamvimonvat N, Dixon RE, Dobrev D, Gomez AM, Harraz OF, Hegyi B, Jones DK, Krogh-Madsen T, Murfee WL, Nystoriak MA, Posnack NG, Ripplinger CM, Veeraraghavan R, Weinberg S. Diversity of cells and signals in the cardiovascular system. J Physiol 2023; 601:2547-2592. [PMID: 36744541 PMCID: PMC10313794 DOI: 10.1113/jp284011] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Accepted: 01/19/2023] [Indexed: 02/07/2023] Open
Abstract
This white paper is the outcome of the seventh UC Davis Cardiovascular Research Symposium on Systems Approach to Understanding Cardiovascular Disease and Arrhythmia. This biannual meeting aims to bring together leading experts in subfields of cardiovascular biomedicine to focus on topics of importance to the field. The theme of the 2022 Symposium was 'Cell Diversity in the Cardiovascular System, cell-autonomous and cell-cell signalling'. Experts in the field contributed their experimental and mathematical modelling perspectives and discussed emerging questions, controversies, and challenges in examining cell and signal diversity, co-ordination and interrelationships involved in cardiovascular function. This paper originates from the topics of formal presentations and informal discussions from the Symposium, which aimed to develop a holistic view of how the multiple cell types in the cardiovascular system integrate to influence cardiovascular function, disease progression and therapeutic strategies. The first section describes the major cell types (e.g. cardiomyocytes, vascular smooth muscle and endothelial cells, fibroblasts, neurons, immune cells, etc.) and the signals involved in cardiovascular function. The second section emphasizes the complexity at the subcellular, cellular and system levels in the context of cardiovascular development, ageing and disease. Finally, the third section surveys the technological innovations that allow the interrogation of this diversity and advancing our understanding of the integrated cardiovascular function and dysfunction.
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Affiliation(s)
- Eleonora Grandi
- Department of Pharmacology, University of California Davis, Davis, CA, USA
| | - Manuel F. Navedo
- Department of Pharmacology, University of California Davis, Davis, CA, USA
| | - Jeffrey J. Saucerman
- Department of Biomedical Engineering, University of Virginia, Charlottesville, VA, USA
| | - Donald M. Bers
- Department of Pharmacology, University of California Davis, Davis, CA, USA
| | - Nipavan Chiamvimonvat
- Department of Pharmacology, University of California Davis, Davis, CA, USA
- Department of Internal Medicine, University of California Davis, Davis, CA, USA
| | - Rose E. Dixon
- Department of Physiology and Membrane Biology, University of California Davis, Davis, CA, USA
| | - Dobromir Dobrev
- Institute of Pharmacology, West German Heart and Vascular Center, University Duisburg-Essen, Essen, Germany
- Department of Medicine, Montreal Heart Institute and Université de Montréal, Montréal, Canada
- Department of Molecular Physiology & Biophysics, Baylor College of Medicine, Houston, TX, USA
| | - Ana M. Gomez
- Signaling and Cardiovascular Pathophysiology-UMR-S 1180, INSERM, Université Paris-Saclay, Orsay, France
| | - Osama F. Harraz
- Department of Pharmacology, Larner College of Medicine, and Vermont Center for Cardiovascular and Brain Health, University of Vermont, Burlington, VT, USA
| | - Bence Hegyi
- Department of Pharmacology, University of California Davis, Davis, CA, USA
| | - David K. Jones
- Department of Pharmacology, University of Michigan Medical School, Ann Arbor, MI, USA
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Trine Krogh-Madsen
- Department of Physiology & Biophysics, Weill Cornell Medicine, New York, New York, USA
| | - Walter Lee Murfee
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL, USA
| | - Matthew A. Nystoriak
- Department of Medicine, Division of Environmental Medicine, Center for Cardiometabolic Science, University of Louisville, Louisville, KY, 40202, USA
| | - Nikki G. Posnack
- Department of Pediatrics, Department of Pharmacology and Physiology, The George Washington University, Washington, DC, USA
- Sheikh Zayed Institute for Pediatric and Surgical Innovation, Children’s National Heart Institute, Children’s National Hospital, Washington, DC, USA
| | | | - Rengasayee Veeraraghavan
- Department of Biomedical Engineering, The Ohio State University, Columbus, OH, USA
- Dorothy M. Davis Heart & Lung Research Institute, The Ohio State University – Wexner Medical Center, Columbus, OH, USA
| | - Seth Weinberg
- Department of Biomedical Engineering, The Ohio State University, Columbus, OH, USA
- Dorothy M. Davis Heart & Lung Research Institute, The Ohio State University – Wexner Medical Center, Columbus, OH, USA
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4
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Raph SM, Dwenger MM, Hu X, Nystoriak MA. Basal NAD(H) redox state permits hydrogen peroxide-induced mesenteric artery dilatation. J Physiol 2023; 601:2621-2634. [PMID: 37114864 DOI: 10.1113/jp284195] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Accepted: 04/26/2023] [Indexed: 04/29/2023] Open
Abstract
Smooth muscle voltage-gated K+ (Kv) channels in resistance arteries control vascular tone and contribute to the coupling of blood flow with local metabolic activity. Members of the Kv1 family are expressed in vascular smooth muscle and are modulated upon physiological elevation of local metabolites, including the glycolytic end-product l-lactate and superoxide-derived hydrogen peroxide (H2 O2 ). Here, we show that l-lactate elicits vasodilatation of small-diameter mesenteric arteries in a mechanism that requires lactate dehydrogenase (LDH). Using the inside-out configuration of the patch clamp technique, we show that increases in NADH that reflect LDH-mediated conversion of l-lactate to pyruvate directly stimulate the activity of single Kv1 channels and significantly enhance the sensitivity of Kv1 activity to H2 O2 . Consistent with these findings, H2 O2 -evoked vasodilatation was significantly greater in the presence of 10 mM l-lactate relative to lactate-free conditions, yet was abolished in the presence of 10 mM pyruvate, which shifts the LDH reaction towards the generation of NAD+ . Moreover, the enhancement of H2 O2 -induced vasodilatation was abolished in arteries from double transgenic mice with selective overexpression of the intracellular Kvβ1.1 subunit in smooth muscle cells. Together, our results indicate that the Kvβ complex of native vascular Kv1 channels serves as a nodal effector for multiple redox signals to precisely control channel activity and vascular tone in the face of dynamic tissue-derived metabolic cues. KEY POINTS: Vasodilatation of mesenteric arteries by elevated external l-lactate requires its conversion by lactate dehydrogenase. Application of either NADH or H2 O2 potentiates single Kv channel currents in excised membrane patches from mesenteric artery smooth muscle cells. The binding of NADH enhances the stimulatory effects of H2 O2 on single Kv channel activity. The vasodilatory response to H2 O2 is differentially modified upon elevation of external l-lactate or pyruvate. The presence of l-lactate enhances the vasodilatory response to H2 O2 via the Kvβ subunit complex in smooth muscle.
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Affiliation(s)
- Sean M Raph
- Department of Pharmacology and Toxicology, University of Louisville, Louisville, KY, USA
| | - Marc M Dwenger
- Department of Pharmacology and Toxicology, University of Louisville, Louisville, KY, USA
| | - Xuemei Hu
- Department of Pharmacology and Toxicology, University of Louisville, Louisville, KY, USA
| | - Matthew A Nystoriak
- Department of Medicine, Division of Environmental Medicine, University of Louisville, Louisville, KY, USA
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Dong F, Yin L, Sisakian H, Hakobyan T, Jeong LS, Joshi H, Hoff E, Chandler S, Srivastava G, Jabir AR, Kimball K, Chen YR, Chen CL, Kang PT, Shabani P, Shockling L, Pucci T, Kegecik K, Kolz C, Jia Z, Chilian WM, Ohanyan V. Takotsubo syndrome is a coronary microvascular disease: experimental evidence. Eur Heart J 2023; 44:2244-2253. [PMID: 37170610 PMCID: PMC10290875 DOI: 10.1093/eurheartj/ehad274] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Revised: 02/08/2023] [Accepted: 04/26/2023] [Indexed: 05/13/2023] Open
Abstract
BACKGROUND AND AIMS Takotsubo syndrome (TTS) is a conundrum without consensus about the cause. In a murine model of coronary microvascular dysfunction (CMD), abnormalities in myocardial perfusion played a key role in the development of TTS. METHODS AND RESULTS Vascular Kv1.5 channels connect coronary blood flow to myocardial metabolism and their deletion mimics the phenotype of CMD. To determine if TTS is related to CMD, wild-type (WT), Kv1.5-/-, and TgKv1.5-/- (Kv1.5-/- with smooth muscle-specific expression Kv1.5 channels) mice were studied following transaortic constriction (TAC). Measurements of left ventricular (LV) fractional shortening (FS) in base and apex, and myocardial blood flow (MBF) were completed with standard and contrast echocardiography. Ribonucleic Acid deep sequencing was performed on LV apex and base from WT and Kv1.5-/- (control and TAC). Changes in gene expression were confirmed by real-time-polymerase chain reaction. MBF was increased with chromonar or by smooth muscle expression of Kv1.5 channels in the TgKv1.5-/-. TAC-induced systolic apical ballooning in Kv1.5-/-, shown as negative FS (P < 0.05 vs. base), which was not observed in WT, Kv1.5-/- with chromonar, or TgKv1.5-/-. Following TAC in Kv1.5-/-, MBF was lower in LV apex than in base. Increasing MBF with either chromonar or in TgKv1.5-/- normalized perfusion and function between LV apex and base (P = NS). Some genetic changes during TTS were reversed by chromonar, suggesting these were independent of TAC and more related to TTS. CONCLUSION Abnormalities in flow regulation between the LV apex and base cause TTS. When perfusion is normalized between the two regions, normal ventricular function is restored.
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Affiliation(s)
- Feng Dong
- Department of Integrative Medical Sciences, Northeast Ohio Medical University, 4209 State Route 44, Rootstown, Ohio 44272, USA
| | - Liya Yin
- Department of Integrative Medical Sciences, Northeast Ohio Medical University, 4209 State Route 44, Rootstown, Ohio 44272, USA
| | - Hamayak Sisakian
- Department of Cardiology, Yerevan State Medical University, Yerevan, Kentron, Armenia
| | - Tatevik Hakobyan
- Department of Integrative Medical Sciences, Northeast Ohio Medical University, 4209 State Route 44, Rootstown, Ohio 44272, USA
| | - Lacey S Jeong
- Department of Integrative Medical Sciences, Northeast Ohio Medical University, 4209 State Route 44, Rootstown, Ohio 44272, USA
| | - Hirva Joshi
- Department of Integrative Medical Sciences, Northeast Ohio Medical University, 4209 State Route 44, Rootstown, Ohio 44272, USA
| | - Ellianna Hoff
- Department of Integrative Medical Sciences, Northeast Ohio Medical University, 4209 State Route 44, Rootstown, Ohio 44272, USA
| | - Selena Chandler
- Department of Integrative Medical Sciences, Northeast Ohio Medical University, 4209 State Route 44, Rootstown, Ohio 44272, USA
| | - Geetika Srivastava
- Department of Integrative Medical Sciences, Northeast Ohio Medical University, 4209 State Route 44, Rootstown, Ohio 44272, USA
| | - Abdur Rahman Jabir
- Department of Integrative Medical Sciences, Northeast Ohio Medical University, 4209 State Route 44, Rootstown, Ohio 44272, USA
| | - Kelly Kimball
- Department of Integrative Medical Sciences, Northeast Ohio Medical University, 4209 State Route 44, Rootstown, Ohio 44272, USA
| | - Yeong-Renn Chen
- Department of Integrative Medical Sciences, Northeast Ohio Medical University, 4209 State Route 44, Rootstown, Ohio 44272, USA
| | - Chwen-Lih Chen
- Department of Integrative Medical Sciences, Northeast Ohio Medical University, 4209 State Route 44, Rootstown, Ohio 44272, USA
| | - Patrick T Kang
- Department of Integrative Medical Sciences, Northeast Ohio Medical University, 4209 State Route 44, Rootstown, Ohio 44272, USA
| | - Parisa Shabani
- Department of Integrative Medical Sciences, Northeast Ohio Medical University, 4209 State Route 44, Rootstown, Ohio 44272, USA
| | - Lindsay Shockling
- Department of Integrative Medical Sciences, Northeast Ohio Medical University, 4209 State Route 44, Rootstown, Ohio 44272, USA
| | - Thomas Pucci
- Department of Integrative Medical Sciences, Northeast Ohio Medical University, 4209 State Route 44, Rootstown, Ohio 44272, USA
| | - Karlina Kegecik
- Department of Integrative Medical Sciences, Northeast Ohio Medical University, 4209 State Route 44, Rootstown, Ohio 44272, USA
| | - Christopher Kolz
- Department of Integrative Medical Sciences, Northeast Ohio Medical University, 4209 State Route 44, Rootstown, Ohio 44272, USA
| | - Zhenyu Jia
- Department of Botany and Plant Sciences, University of California, Riverside, CA, USA
| | - William M Chilian
- Department of Integrative Medical Sciences, Northeast Ohio Medical University, 4209 State Route 44, Rootstown, Ohio 44272, USA
| | - Vahagn Ohanyan
- Department of Integrative Medical Sciences, Northeast Ohio Medical University, 4209 State Route 44, Rootstown, Ohio 44272, USA
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6
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Zhou Y, Lin Y, Li W, Liu Q, Gong H, Li Y, Luo D. Expression of AKRs superfamily and prognostic in human gastric cancer. Medicine (Baltimore) 2023; 102:e33041. [PMID: 36827074 DOI: 10.1097/md.0000000000033041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/25/2023] Open
Abstract
The human aldo-keto reductase (AKRs) superfamily is involved in the development of various tumors. However, the different expression patterns of AKRs and their prognostic value in gastric cancer (GC) have not been clarified. In this study, we analyzed the gene expression and gene methylation level of AKRs in GC patients and the survival data and immune infiltration based on AKRs expression, using data from different databases. We found that the expression levels of AKR1B10, AKR1C1, AKR1C2, and AKR7A3 in GC tissues were lower and the expression level of AKR6A5 was higher in GC tissues than in normal tissue. These differentially expressed genes (AKR1B10, AKR1C1, AKR1C2, AKR7A3, and AKR6A5) were significantly correlated with the infiltration level. The expression of SPI1 and AKR6A5 in GC was positively correlated. Survival analysis showed that GC levels of AKR6A5 reduced or increased mRNA levels of AKR7A3, and AKR1B10 was expected to have higher overall survival (OS), first progression (FP) survival, and postprogression survival (PPS) rates and a better prognosis. Moreover, the expression of AKR1B1 was found to be correlated with the staging of GC. The methylation of AKR6A5 (KCNAB2) at cg05307871 and cg01907457 was significantly associated with the classification of GC. Meta-analysis and ROC curve analysis show that the expression level of AKR1B1 and the methylation of cg16156182 (KCNAB1), cg11194299 (KCNAB2), cg16132520 (AKR1B1), and cg13801416 (AKR1B1) had a high hazard ratio and a good prognostic value. These data suggest that the expression and methylation of AKR1B1 and AKR6A5 are significantly related to the prognosis.
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Affiliation(s)
- Yujin Zhou
- NHC Key Laboratory of Metabolic Cardiovascular Diseases Research, Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Ningxia Medical University, Yinchuan, China
- Laboratory Medicine Center of Huazhong University of Science and Technology Union Shenzhen Hospital (Nanshan Hospital), Shenzhen, China
| | - Yi Lin
- Laboratory Medicine Center of Huazhong University of Science and Technology Union Shenzhen Hospital (Nanshan Hospital), Shenzhen, China
| | - Wenjing Li
- Laboratory Medicine Center of Huazhong University of Science and Technology Union Shenzhen Hospital (Nanshan Hospital), Shenzhen, China
| | - Quan Liu
- Laboratory Medicine Center of Huazhong University of Science and Technology Union Shenzhen Hospital (Nanshan Hospital), Shenzhen, China
| | - Hui Gong
- Laboratory Medicine Center of Huazhong University of Science and Technology Union Shenzhen Hospital (Nanshan Hospital), Shenzhen, China
| | - Yifan Li
- NHC Key Laboratory of Metabolic Cardiovascular Diseases Research, Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Ningxia Medical University, Yinchuan, China
- Laboratory Medicine Center of Huazhong University of Science and Technology Union Shenzhen Hospital (Nanshan Hospital), Shenzhen, China
| | - Dixian Luo
- Laboratory Medicine Center of Huazhong University of Science and Technology Union Shenzhen Hospital (Nanshan Hospital), Shenzhen, China
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7
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Sytha SP, Self TS, Heaps CL. K + channels in the coronary microvasculature of the ischemic heart. CURRENT TOPICS IN MEMBRANES 2022; 90:141-166. [PMID: 36368873 PMCID: PMC10494550 DOI: 10.1016/bs.ctm.2022.09.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Ischemic heart disease is the leading cause of death and a major public health and economic burden worldwide with expectations of predicted growth in the foreseeable future. It is now recognized clinically that flow-limiting stenosis of the large coronary conduit arteries as well as microvascular dysfunction in the absence of severe stenosis can each contribute to the etiology of ischemic heart disease. The primary site of coronary vascular resistance, and control of subsequent coronary blood flow, is found in the coronary microvasculature, where small changes in radius can have profound impacts on myocardial perfusion. Basal active tone and responses to vasodilators and vasoconstrictors are paramount in the regulation of coronary blood flow and adaptations in signaling associated with ion channels are a major factor in determining alterations in vascular resistance and thereby myocardial blood flow. K+ channels are of particular importance as contributors to all aspects of the regulation of arteriole resistance and control of perfusion into the myocardium because these channels dictate membrane potential, the resultant activity of voltage-gated calcium channels, and thereby, the contractile state of smooth muscle. Evidence also suggests that K+ channels play a significant role in adaptations with cardiovascular disease states. In this review, we highlight our research examining the role of K+ channels in ischemic heart disease and adaptations with exercise training as treatment, as well as how our findings have contributed to this area of study.
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Affiliation(s)
- Sharanee P Sytha
- Department of Physiology and Pharmacology, School of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, United States
| | - Trevor S Self
- Department of Physiology and Pharmacology, School of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, United States
| | - Cristine L Heaps
- Department of Physiology and Pharmacology, School of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, United States; Michael E. DeBakey Institute for Comparative Cardiovascular Science and Biomedical Devices, School of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, United States.
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8
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Diversification of Potassium Currents in Excitable Cells via Kvβ Proteins. Cells 2022; 11:cells11142230. [PMID: 35883673 PMCID: PMC9317154 DOI: 10.3390/cells11142230] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2022] [Revised: 07/09/2022] [Accepted: 07/12/2022] [Indexed: 12/10/2022] Open
Abstract
Excitable cells of the nervous and cardiovascular systems depend on an assortment of plasmalemmal potassium channels to control diverse cellular functions. Voltage-gated potassium (Kv) channels are central to the feedback control of membrane excitability in these processes due to their activation by depolarized membrane potentials permitting K+ efflux. Accordingly, Kv currents are differentially controlled not only by numerous cellular signaling paradigms that influence channel abundance and shape voltage sensitivity, but also by heteromeric configurations of channel complexes. In this context, we discuss the current knowledge related to how intracellular Kvβ proteins interacting with pore complexes of Shaker-related Kv1 channels may establish a modifiable link between excitability and metabolic state. Past studies in heterologous systems have indicated roles for Kvβ proteins in regulating channel stability, trafficking, subcellular targeting, and gating. More recent works identifying potential in vivo physiologic roles are considered in light of these earlier studies and key gaps in knowledge to be addressed by future research are described.
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9
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Pyridine nucleotide redox potential in coronary smooth muscle couples myocardial blood flow to cardiac metabolism. Nat Commun 2022; 13:2051. [PMID: 35440632 PMCID: PMC9018695 DOI: 10.1038/s41467-022-29745-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Accepted: 03/28/2022] [Indexed: 12/13/2022] Open
Abstract
Adequate oxygen delivery to the heart during stress is essential for sustaining cardiac function. Acute increases in myocardial oxygen demand evoke coronary vasodilation and enhance perfusion via functional upregulation of smooth muscle voltage-gated K+ (Kv) channels. Because this response is controlled by Kv1 accessory subunits (i.e., Kvβ), which are NAD(P)(H)-dependent aldo-keto reductases, we tested the hypothesis that oxygen demand modifies arterial [NAD(H)]i, and that resultant cytosolic pyridine nucleotide redox state influences Kv1 activity. High-resolution imaging mass spectrometry and live-cell imaging reveal cardiac workload-dependent increases in NADH:NAD+ in intramyocardial arterial myocytes. Intracellular NAD(P)(H) redox ratios reflecting elevated oxygen demand potentiate native coronary Kv1 activity in a Kvβ2-dependent manner. Ablation of Kvβ2 catalysis suppresses redox-dependent increases in Kv1 activity, vasodilation, and the relationship between cardiac workload and myocardial blood flow. Collectively, this work suggests that the pyridine nucleotide sensitivity and enzymatic activity of Kvβ2 controls coronary vasoreactivity and myocardial blood flow during metabolic stress. Physiological matching of blood flow to the demand for oxygen by the heart is required for sustained cardiac health, yet the underlying mechanisms are obscure. Here, the authors report a key role for acute modifications to the redox state of intracellular pyridine nucleotides in coronary smooth muscle and their impact on voltage-gated K + channels in metabolic vasodilation
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10
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D'Avanzo N, Miles AJ, Powl AM, Nichols CG, Wallace BA, O'Reilly AO. The T1-tetramerisation domain of Kv1.2 rescues expression and preserves function of a truncated NaChBac sodium channel. FEBS Lett 2022; 596:772-783. [PMID: 35015304 PMCID: PMC9303580 DOI: 10.1002/1873-3468.14279] [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: 11/11/2021] [Revised: 12/27/2021] [Accepted: 12/28/2021] [Indexed: 11/18/2022]
Abstract
Cytoplasmic domains frequently promote functional assembly of multimeric ion channels. To investigate structural determinants of this process, we generated the ‘T1‐chimera’ construct of the NaChBac sodium channel by truncating its C‐terminal domain and splicing the T1‐tetramerisation domain of the Kv1.2 channel to the N terminus. Purified T1‐chimera channels were tetrameric, conducted Na+ when reconstituted into proteoliposomes, and were functionally blocked by the drug mibefradil. Both the T1‐chimera and full‐length NaChBac had comparable expression levels in the membrane, whereas a NaChBac mutant lacking a cytoplasmic domain had greatly reduced membrane expression. Our findings support a model whereby bringing the transmembrane regions into close proximity enables their tetramerisation. This phenomenon is found with other channels, and thus, our findings substantiate this as a common assembly mechanism.
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Affiliation(s)
- Nazzareno D'Avanzo
- Department of Pharmacology and Physiology, Université de Montréal, Canada
| | - Andrew J Miles
- Institute of Structural and Molecular Biology, Birkbeck, University of London, UK
| | - Andrew M Powl
- Institute of Structural and Molecular Biology, Birkbeck, University of London, UK
| | - Colin G Nichols
- Department of Cell Biology and Physiology, Center for the Investigation of Membrane Excitability Diseases, Washington University School of Medicine, USA
| | - B A Wallace
- Institute of Structural and Molecular Biology, Birkbeck, University of London, UK
| | - Andrias O O'Reilly
- School of Biological & Environmental Sciences, Liverpool John Moores University, UK
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11
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Jackson WF. Another Piece of the Puzzle: Voltage-Gated K + Channel β2-Subunits as a Coronary Vascular Smooth Muscle Sensor of Cardiac Work. Circ Res 2021; 128:752-754. [PMID: 33734818 DOI: 10.1161/circresaha.121.318953] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- William F Jackson
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI
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12
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Ohanyan V, Raph SM, Dwenger MM, Hu X, Pucci T, Mack G, Moore JB, Chilian WM, Bhatnagar A, Nystoriak MA. Myocardial Blood Flow Control by Oxygen Sensing Vascular Kvβ Proteins. Circ Res 2021; 128:738-751. [PMID: 33499656 DOI: 10.1161/circresaha.120.317715] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
[Figure: see text].
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Affiliation(s)
- Vahagn Ohanyan
- Department of Integrative Medical Sciences, Northeast Ohio Medical University, Rootstown (V.O., T.P., G.M., W.M.C.)
| | - Sean M Raph
- Division of Environmental Medicine, Department of Medicine, Diabetes and Obesity Center, University of Louisville, KY (S.M.R., M.M.D., X.H., J.B.M., A.B., M.A.N.)
| | - Marc M Dwenger
- Division of Environmental Medicine, Department of Medicine, Diabetes and Obesity Center, University of Louisville, KY (S.M.R., M.M.D., X.H., J.B.M., A.B., M.A.N.)
| | - Xuemei Hu
- Division of Environmental Medicine, Department of Medicine, Diabetes and Obesity Center, University of Louisville, KY (S.M.R., M.M.D., X.H., J.B.M., A.B., M.A.N.)
| | - Thomas Pucci
- Department of Integrative Medical Sciences, Northeast Ohio Medical University, Rootstown (V.O., T.P., G.M., W.M.C.)
| | - Gregory Mack
- Department of Integrative Medical Sciences, Northeast Ohio Medical University, Rootstown (V.O., T.P., G.M., W.M.C.)
| | - Joseph B Moore
- Division of Environmental Medicine, Department of Medicine, Diabetes and Obesity Center, University of Louisville, KY (S.M.R., M.M.D., X.H., J.B.M., A.B., M.A.N.)
| | - William M Chilian
- Department of Integrative Medical Sciences, Northeast Ohio Medical University, Rootstown (V.O., T.P., G.M., W.M.C.)
| | - Aruni Bhatnagar
- Division of Environmental Medicine, Department of Medicine, Diabetes and Obesity Center, University of Louisville, KY (S.M.R., M.M.D., X.H., J.B.M., A.B., M.A.N.)
| | - Matthew A Nystoriak
- Division of Environmental Medicine, Department of Medicine, Diabetes and Obesity Center, University of Louisville, KY (S.M.R., M.M.D., X.H., J.B.M., A.B., M.A.N.)
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13
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Liu Y, Kabakov AY, Xie A, Shi G, Singh AK, Sodha NR, Ehsan A, Usheva A, Agbortoko V, Koren G, Dudley SC, Sellke FW, Feng J. Metabolic regulation of endothelial SK channels and human coronary microvascular function. Int J Cardiol 2020; 312:1-9. [PMID: 32199682 PMCID: PMC7388214 DOI: 10.1016/j.ijcard.2020.03.028] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/29/2019] [Revised: 02/18/2020] [Accepted: 03/10/2020] [Indexed: 12/28/2022]
Abstract
BACKGROUND Diabetic (DM) inactivation of small conductance calcium-activated potassium (SK) channels contributes to coronary endothelial dysfunction. However, the mechanisms responsible for this down-regulation of endothelial SK channels are poorly understood. Thus, we hypothesized that the altered metabolic signaling in diabetes regulates endothelial SK channels and human coronary microvascular function. METHODS Human atrial tissue, coronary arterioles and coronary artery endothelial cells (HCAECs) obtained from DM and non-diabetic (ND) patients (n = 12/group) undergoing cardiac surgery were used to analyze metabolic alterations, endothelial SK channel function, coronary microvascular reactivity and SK gene/protein expression/localization. RESULTS The relaxation response of DM coronary arterioles to the selective SK channel activator SKA-31 and calcium ionophore A23187 was significantly decreased compared to that of ND arterioles (p < 0.05). Diabetes increases the level of NADH and the NADH/NAD+ ratio in human myocardium and HCAECs (p < 0.05). Increase in intracellular NADH (100 μM) in the HCAECs caused a significant decrease in endothelial SK channel currents (p < 0.05), whereas, intracellular application of NAD+ (500 μM) increased the endothelial SK channel currents (p < 0.05). Mitochondrial reactive oxygen species (mROS) of HCAECs and NADPH oxidase (NOX) and PKC protein expression in the human myocardium and coronary microvasculature were increased respectively (p < 0.05). CONCLUSIONS Diabetes is associated with metabolic changes in the human myocardium, coronary microvasculature and HCAECs. Endothelial SK channel function is regulated by the metabolite pyridine nucleotides, NADH and NAD+, suggesting that metabolic regulation of endothelial SK channels may contribute to coronary endothelial dysfunction in the DM patients with diabetes.
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Affiliation(s)
- Yuhong Liu
- Division of Cardiothoracic Surgery, Rhode Island Hospital, Alpert Medical School of Brown University, Providence, RI, United States of America
| | - Anatoli Y Kabakov
- Cardiovascular Research Center, Rhode Island Hospital, Alpert Medical School of Brown University, Providence, RI, United States of America
| | - An Xie
- Department of Medicine, Lillehei Heart Institute, University of Minnesota, Minneapolis, MN, United States of America
| | - Guangbin Shi
- Division of Cardiothoracic Surgery, Rhode Island Hospital, Alpert Medical School of Brown University, Providence, RI, United States of America
| | - Arun K Singh
- Division of Cardiothoracic Surgery, Rhode Island Hospital, Alpert Medical School of Brown University, Providence, RI, United States of America
| | - Neel R Sodha
- Division of Cardiothoracic Surgery, Rhode Island Hospital, Alpert Medical School of Brown University, Providence, RI, United States of America
| | - Afshin Ehsan
- Division of Cardiothoracic Surgery, Rhode Island Hospital, Alpert Medical School of Brown University, Providence, RI, United States of America
| | - Anny Usheva
- Division of Cardiothoracic Surgery, Rhode Island Hospital, Alpert Medical School of Brown University, Providence, RI, United States of America
| | - Vahid Agbortoko
- Division of Cardiothoracic Surgery, Rhode Island Hospital, Alpert Medical School of Brown University, Providence, RI, United States of America
| | - Gideon Koren
- Cardiovascular Research Center, Rhode Island Hospital, Alpert Medical School of Brown University, Providence, RI, United States of America
| | - Samuel C Dudley
- Department of Medicine, Lillehei Heart Institute, University of Minnesota, Minneapolis, MN, United States of America
| | - Frank W Sellke
- Division of Cardiothoracic Surgery, Rhode Island Hospital, Alpert Medical School of Brown University, Providence, RI, United States of America
| | - Jun Feng
- Division of Cardiothoracic Surgery, Rhode Island Hospital, Alpert Medical School of Brown University, Providence, RI, United States of America.
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14
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Snyder J, Zhai R, Lackey AI, Sato PY. Changes in Myocardial Metabolism Preceding Sudden Cardiac Death. Front Physiol 2020; 11:640. [PMID: 32612538 PMCID: PMC7308560 DOI: 10.3389/fphys.2020.00640] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Accepted: 05/20/2020] [Indexed: 12/11/2022] Open
Abstract
Heart disease is widely recognized as a major cause of death worldwide and is the leading cause of mortality in the United States. Centuries of research have focused on defining mechanistic alterations that drive cardiac pathogenesis, yet sudden cardiac death (SCD) remains a common unpredictable event that claims lives in every age group. The heart supplies blood to all tissues while maintaining a constant electrical and hormonal feedback communication with other parts of the body. As such, recent research has focused on understanding how myocardial electrical and structural properties are altered by cardiac metabolism and the various signaling pathways associated with it. The importance of cardiac metabolism in maintaining myocardial function, or lack thereof, is exemplified by shifts in cardiac substrate preference during normal development and various pathological conditions. For instance, a shift from fatty acid (FA) oxidation to oxygen-sparing glycolytic energy production has been reported in many types of cardiac pathologies. Compounded by an uncoupling of glycolysis and glucose oxidation this leads to accumulation of undesirable levels of intermediate metabolites. The resulting accumulation of intermediary metabolites impacts cardiac mitochondrial function and dysregulates metabolic pathways through several mechanisms, which will be reviewed here. Importantly, reversal of metabolic maladaptation has been shown to elicit positive therapeutic effects, limiting cardiac remodeling and at least partially restoring contractile efficiency. Therein, the underlying metabolic adaptations in an array of pathological conditions as well as recently discovered downstream effects of various substrate utilization provide guidance for future therapeutic targeting. Here, we will review recent data on alterations in substrate utilization in the healthy and diseased heart, metabolic pathways governing cardiac pathogenesis, mitochondrial function in the diseased myocardium, and potential metabolism-based therapeutic interventions in disease.
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Affiliation(s)
- J Snyder
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, PA, United States
| | - R Zhai
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, PA, United States
| | - A I Lackey
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, PA, United States
| | - P Y Sato
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, PA, United States
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15
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Severino P, D’Amato A, Pucci M, Infusino F, Birtolo LI, Mariani MV, Lavalle C, Maestrini V, Mancone M, Fedele F. Ischemic Heart Disease and Heart Failure: Role of Coronary Ion Channels. Int J Mol Sci 2020; 21:E3167. [PMID: 32365863 PMCID: PMC7246492 DOI: 10.3390/ijms21093167] [Citation(s) in RCA: 58] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Revised: 04/28/2020] [Accepted: 04/28/2020] [Indexed: 01/09/2023] Open
Abstract
Heart failure is a complex syndrome responsible for high rates of death and hospitalization. Ischemic heart disease is one of the most frequent causes of heart failure and it is normally attributed to coronary artery disease, defined by the presence of one or more obstructive plaques, which determine a reduced coronary blood flow, causing myocardial ischemia and consequent heart failure. However, coronary obstruction is only an element of a complex pathophysiological process that leads to myocardial ischemia. In the literature, attention paid to the role of microcirculation, in the pathophysiology of ischemic heart disease and heart failure, is growing. Coronary microvascular dysfunction determines an inability of coronary circulation to satisfy myocardial metabolic demands, due to the imbalance of coronary blood flow regulatory mechanisms, including ion channels, leading to the development of hypoxia, fibrosis and tissue death, which may determine a loss of myocardial function, even beyond the presence of atherosclerotic epicardial plaques. For this reason, ion channels may represent the link among coronary microvascular dysfunction, ischemic heart disease and consequent heart failure.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | - Francesco Fedele
- Department of Clinical, Internal, Anesthesiology and Cardiovascular Sciences, Sapienza University of Rome, Viale del Policlinico, 155-00161 Rome, Italy; (P.S.); (A.D.); (M.P.); (F.I.); (L.I.B.); (M.V.M.); (C.L.); (V.M.); (M.M.)
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16
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Raph SM, Bhatnagar A, Nystoriak MA. Biochemical and physiological properties of K + channel-associated AKR6A (Kvβ) proteins. Chem Biol Interact 2019; 305:21-27. [PMID: 30926318 DOI: 10.1016/j.cbi.2019.03.023] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Revised: 03/14/2019] [Accepted: 03/25/2019] [Indexed: 11/16/2022]
Abstract
Voltage-gated potassium (Kv) channels play an essential role in the regulation of membrane excitability and thereby control physiological processes such as cardiac excitability, neural communication, muscle contraction, and hormone secretion. Members of the Kv1 and Kv4 families are known to associate with auxiliary intracellular Kvβ subunits, which belong to the aldo-keto reductase superfamily. Electrophysiological studies have shown that these proteins regulate the gating properties of Kv channels. Although the three gene products encoding Kvβ proteins are functional enzymes in that they catalyze the nicotinamide adenine dinucleotide phosphate (NAD[P]H)-dependent reduction of a wide range of aldehyde and ketone substrates, the physiological role for these proteins and how each subtype may perform unique roles in coupling membrane excitability with cellular metabolic processes remains unclear. Here, we discuss current knowledge of the enzymatic properties of Kvβ proteins from biochemical studies with their described and purported physiological and pathophysiological influences.
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Affiliation(s)
- Sean M Raph
- Department of Pharmacology and Toxicology, University of Louisville, Louisville, KY, 40202, USA
| | - Aruni Bhatnagar
- Department of Medicine, Diabetes and Obesity Center, University of Louisville, Louisville, KY, 40202, USA
| | - Matthew A Nystoriak
- Department of Medicine, Diabetes and Obesity Center, University of Louisville, Louisville, KY, 40202, USA.
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17
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Severino P, D'Amato A, Netti L, Pucci M, Infusino F, Maestrini V, Mancone M, Fedele F. Myocardial Ischemia and Diabetes Mellitus: Role of Oxidative Stress in the Connection between Cardiac Metabolism and Coronary Blood Flow. J Diabetes Res 2019; 2019:9489826. [PMID: 31089475 PMCID: PMC6476021 DOI: 10.1155/2019/9489826] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Revised: 02/23/2019] [Accepted: 03/13/2019] [Indexed: 12/27/2022] Open
Abstract
Ischemic heart disease (IHD) has several risk factors, among which diabetes mellitus represents one of the most important. In diabetic patients, the pathophysiology of myocardial ischemia remains unclear yet: some have atherosclerotic plaque which obstructs coronary blood flow, others show myocardial ischemia due to coronary microvascular dysfunction in the absence of plaques in epicardial vessels. In the cross-talk between myocardial metabolism and coronary blood flow (CBF), ion channels have a main role, and, in diabetic patients, they are involved in the pathophysiology of IHD. The exposition to the different cardiovascular risk factors and the ischemic condition determine an imbalance of the redox state, defined as oxidative stress, which shows itself with oxidant accumulation and antioxidant deficiency. In particular, several products of myocardial metabolism, belonging to oxidative stress, may influence ion channel function, altering their capacity to modulate CBF, in response to myocardial metabolism, and predisposing to myocardial ischemia. For this reason, considering the role of oxidative and ion channels in the pathophysiology of myocardial ischemia, it is allowed to consider new therapeutic perspectives in the treatment of IHD.
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Affiliation(s)
- Paolo Severino
- Department of Cardiovascular, Respiratory, Nephrology, Anesthesiology and Geriatric Sciences, Sapienza University of Rome, 00161 Rome, Italy
| | - Andrea D'Amato
- Department of Cardiovascular, Respiratory, Nephrology, Anesthesiology and Geriatric Sciences, Sapienza University of Rome, 00161 Rome, Italy
| | - Lucrezia Netti
- Department of Cardiovascular, Respiratory, Nephrology, Anesthesiology and Geriatric Sciences, Sapienza University of Rome, 00161 Rome, Italy
| | - Mariateresa Pucci
- Department of Cardiovascular, Respiratory, Nephrology, Anesthesiology and Geriatric Sciences, Sapienza University of Rome, 00161 Rome, Italy
| | - Fabio Infusino
- Department of Cardiovascular, Respiratory, Nephrology, Anesthesiology and Geriatric Sciences, Sapienza University of Rome, 00161 Rome, Italy
| | - Viviana Maestrini
- Department of Cardiovascular, Respiratory, Nephrology, Anesthesiology and Geriatric Sciences, Sapienza University of Rome, 00161 Rome, Italy
| | - Massimo Mancone
- Department of Cardiovascular, Respiratory, Nephrology, Anesthesiology and Geriatric Sciences, Sapienza University of Rome, 00161 Rome, Italy
| | - Francesco Fedele
- Department of Cardiovascular, Respiratory, Nephrology, Anesthesiology and Geriatric Sciences, Sapienza University of Rome, 00161 Rome, Italy
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18
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Nystoriak MA, Navedo MF. Regulation of microvascular function by voltage-gated potassium channels: New tricks for an "ancient" dog. Microcirculation 2018; 25:10.1111/micc.12435. [PMID: 29239491 PMCID: PMC5826567 DOI: 10.1111/micc.12435] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Accepted: 12/10/2017] [Indexed: 12/12/2022]
Abstract
Arterial tone is tightly regulated by a variety of potassium (K+ ) permeable ion channels at the sarcolemma of vascular smooth muscle cells. In particular, several types of KV channels provide a significant hyperpolarizing influence and serve to oppose pressure and agonist-induced membrane depolarization to promote smooth muscle relaxation and augmentation of vascular diameter and blood flow. In recent years, a number of studies have underscored previously unknown roles for particular KV subunits, new modes of channel regulation, and distinct cellular functions for these channels during physiological and pathological conditions. In this overview, we highlight articles contained in this Special Topics Issue that focus on the latest, most exciting advancements in the field of KV channels in the microcirculation. The collection of articles aims to highlight important new discoveries and controversies in the field of vascular KV channels as well as to shed light on key questions that require additional investigation.
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Affiliation(s)
- Matthew A. Nystoriak
- Diabetes and Obesity Center, Institute of Molecular Cardiology, Department of Medicine, University of Louisville, Louisville, KY 40202
| | - Manuel F. Navedo
- Department of Pharmacology, University of California, Davis, Davis, CA, 95616
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