1
|
Emerging mechanisms involving brain Kv7 channel in the pathogenesis of hypertension. Biochem Pharmacol 2022; 206:115318. [PMID: 36283445 DOI: 10.1016/j.bcp.2022.115318] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Revised: 10/15/2022] [Accepted: 10/17/2022] [Indexed: 12/14/2022]
Abstract
Hypertension is a prevalent health problem inducing many organ damages. The pathogenesis of hypertension involves a complex integration of different organ systems including the brain. The elevated sympathetic nerve activity is closely related to the etiology of hypertension. Ion channels are critical regulators of neuronal excitability. Several mechanisms have been proposed to contribute to hypothalamic-driven elevated sympathetic activity, including altered ion channel function. Recent findings indicate one of the voltage-gated potassium channels, Kv7 channels (M channels), plays a vital role in regulating cardiovascular-related neurons activity, and the expression of Kv7 channels is downregulated in hypertension. This review highlights recent findings that the Kv7 channels in the brain, blood vessels, and kidneys are emerging targets involved in the pathogenesis of hypertension, suggesting new therapeutic targets for treating drug-resistant, neurogenic hypertension.
Collapse
|
2
|
Sheng ZF, Zhang H, Zheng P, Chen S, Gu Z, Zhou JJ, Phaup JG, Chang HM, Yeh ETH, Pan HL, Li DP. Impaired Kv7 channel activity in the central amygdala contributes to elevated sympathetic outflow in hypertension. Cardiovasc Res 2022; 118:585-596. [PMID: 33512443 PMCID: PMC8803073 DOI: 10.1093/cvr/cvab031] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 11/11/2020] [Accepted: 01/25/2021] [Indexed: 11/13/2022] Open
Abstract
AIMS Elevated sympathetic outflow is associated with primary hypertension. However, the mechanisms involved in heightened sympathetic outflow in hypertension are unclear. The central amygdala (CeA) regulates autonomic components of emotions through projections to the brainstem. The neuronal Kv7 channel is a non-inactivating voltage-dependent K+ channel encoded by KCNQ2/3 genes involved in stabilizing the neuronal membrane potential and regulating neuronal excitability. In this study, we investigated if altered Kv7 channel activity in the CeA contributes to heightened sympathetic outflow in hypertension. METHODS AND RESULTS The mRNA and protein expression levels of Kv7.2/Kv7.3 in the CeA were significantly reduced in spontaneously hypertensive rats (SHRs) compared with Wistar-Kyoto (WKY) rats. Lowering blood pressure with coeliac ganglionectomy in SHRs did not alter Kv7.2 and Kv7.3 channel expression levels in the CeA. Fluospheres were injected into the rostral ventrolateral medulla (RVLM) to retrogradely label CeA neurons projecting to the RVLM (CeA-RVLM neurons). Kv7 channel currents recorded from CeA-RVLM neurons in brain slices were much smaller in SHRs than in WKY rats. Furthermore, the basal firing activity of CeA-RVLM neurons was significantly greater in SHRs than in WKY rats. Bath application of specific Kv7 channel blocker 10, 10-bis (4-pyridinylmethyl)-9(10H)-anthracnose (XE-991) increased the excitability of CeA-RVLM neurons in WKY rats, but not in SHRs. Microinjection of XE-991 into the CeA increased arterial blood pressure (ABP) and renal sympathetic nerve activity (RSNA), while microinjection of Kv7 channel opener QO-58 decreased ABP and RSNA, in anaesthetized WKY rats but not SHRs. CONCLUSIONS Our findings suggest that diminished Kv7 channel activity in the CeA contributes to elevated sympathetic outflow in primary hypertension. This novel information provides new mechanistic insight into the pathogenesis of neurogenic hypertension.
Collapse
Affiliation(s)
- Zhao-Fu Sheng
- Center for Precision Medicine, Department of Medicine, School of Medicine, University of Missouri, 1 Hospital Drive, Columbia, MO 65212, USA
| | - Hua Zhang
- Center for Precision Medicine, Department of Medicine, School of Medicine, University of Missouri, 1 Hospital Drive, Columbia, MO 65212, USA
| | - PeiRu Zheng
- Center for Precision Medicine, Department of Medicine, School of Medicine, University of Missouri, 1 Hospital Drive, Columbia, MO 65212, USA
| | - Shanyan Chen
- Department of Pathology and Anatomical Sciences, School of Medicine, University of Missouri, 1 Hospital Drive, Columbia, MO 65212, USA
| | - Zezong Gu
- Department of Pathology and Anatomical Sciences, School of Medicine, University of Missouri, 1 Hospital Drive, Columbia, MO 65212, USA
| | - Jing-Jing Zhou
- Department of Anesthesiology and Perioperative Medicine, The University of Texas, MD Anderson Cancer Center, 1515 Holcombe Blvd., Houston, TX 77030, USA
| | - Jeffery G Phaup
- Center for Precision Medicine, Department of Medicine, School of Medicine, University of Missouri, 1 Hospital Drive, Columbia, MO 65212, USA
| | - Hui-Ming Chang
- Departments of Pharmacology and Toxicology and Internal Medicine, The University of Arkansas for Medical Sciences, 4301 West Markham St., Little Rock, AR 72205, USA
| | - Edward T H Yeh
- Departments of Pharmacology and Toxicology and Internal Medicine, The University of Arkansas for Medical Sciences, 4301 West Markham St., Little Rock, AR 72205, USA
| | - Hui-Lin Pan
- Department of Anesthesiology and Perioperative Medicine, The University of Texas, MD Anderson Cancer Center, 1515 Holcombe Blvd., Houston, TX 77030, USA
| | - De-Pei Li
- Center for Precision Medicine, Department of Medicine, School of Medicine, University of Missouri, 1 Hospital Drive, Columbia, MO 65212, USA
| |
Collapse
|
3
|
Activation of KCNQ4 as a Therapeutic Strategy to Treat Hearing Loss. Int J Mol Sci 2021; 22:ijms22052510. [PMID: 33801540 PMCID: PMC7958948 DOI: 10.3390/ijms22052510] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Revised: 02/16/2021] [Accepted: 02/22/2021] [Indexed: 12/14/2022] Open
Abstract
Potassium voltage-gated channel subfamily q member 4 (KCNQ4) is a voltage-gated potassium channel that plays essential roles in maintaining ion homeostasis and regulating hair cell membrane potential. Reduction of the activity of the KCNQ4 channel owing to genetic mutations is responsible for nonsyndromic hearing loss, a typically late-onset, initially high-frequency loss progressing over time. In addition, variants of KCNQ4 have also been associated with noise-induced hearing loss and age-related hearing loss. Therefore, the discovery of small compounds activating or potentiating KCNQ4 is an important strategy for the curative treatment of hearing loss. In this review, we updated the current concept of the physiological role of KCNQ4 in the inner ear and the pathologic mechanism underlying the role of KCNQ4 variants with regard to hearing loss. Finally, we focused on currently developed KCNQ4 activators and their pros and cons, paving the way for the future development of specific KCNQ4 activators as a remedy for hearing loss.
Collapse
|
4
|
Barrese V, Stott JB, Greenwood IA. KCNQ-Encoded Potassium Channels as Therapeutic Targets. Annu Rev Pharmacol Toxicol 2018; 58:625-648. [DOI: 10.1146/annurev-pharmtox-010617-052912] [Citation(s) in RCA: 72] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
| | | | - Iain A. Greenwood
- Vascular Biology Research Centre, Molecular and Clinical Sciences Institute, St George's, University of London, London, SW17 0RE, United Kingdom;, ,
| |
Collapse
|
5
|
Salomonsson M, Brasen JC, Sorensen CM. Role of renal vascular potassium channels in physiology and pathophysiology. Acta Physiol (Oxf) 2017; 221:14-31. [PMID: 28371470 DOI: 10.1111/apha.12882] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Revised: 05/10/2016] [Accepted: 03/22/2017] [Indexed: 12/31/2022]
Abstract
The control of renal vascular tone is important for the regulation of salt and water balance, blood pressure and the protection against damaging elevated glomerular pressure. The K+ conductance is a major factor in the regulation of the membrane potential (Vm ) in vascular smooth muscle (VSMC) and endothelial cells (EC). The vascular tone is controlled by Vm via its effect on the opening probability of voltage-operated Ca2+ channels (VOCC) in VSMC. When K+ conductance increases Vm becomes more negative and vasodilation follows, while deactivation of K+ channels leads to depolarization and vasoconstriction. K+ channels in EC indirectly participate in the control of vascular tone by endothelium-derived vasodilation. Therefore, by regulating the tone of renal resistance vessels, K+ channels have a potential role in the control of fluid homoeostasis and blood pressure as well as in the protection of the renal parenchyma. The main classes of K+ channels (calcium activated (KCa ), inward rectifier (Kir ), voltage activated (Kv ) and ATP sensitive (KATP )) have been found in the renal vessels. In this review, we summarize results available in the literature and our own studies in the field. We compare the ambiguous in vitro and in vivo results. We discuss the role of single types of K+ channels and the integrated function of several classes. We also deal with the possible role of renal vascular K+ channels in the pathophysiology of hypertension, diabetes mellitus and sepsis.
Collapse
Affiliation(s)
| | - J. C. Brasen
- Department of Electrical Engineering; Technical University of Denmark; Kgs. Lyngby Denmark
| | - C. M. Sorensen
- Department of Biomedical Sciences; Division of Renal and Vascular Physiology; University of Copenhagen; Copenhagen Denmark
| |
Collapse
|
6
|
Nassoiy SP, Byron KL, Majetschak M. Kv7 voltage-activated potassium channel inhibitors reduce fluid resuscitation requirements after hemorrhagic shock in rats. J Biomed Sci 2017; 24:8. [PMID: 28095830 PMCID: PMC5240358 DOI: 10.1186/s12929-017-0316-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Accepted: 01/10/2017] [Indexed: 12/24/2022] Open
Abstract
Background Recent evidence suggests that drugs targeting Kv7 channels could be used to modulate vascular function and blood pressure. Here, we studied whether Kv7 channel inhibitors can be utilized to stabilize hemodynamics and reduce resuscitation fluid requirements after hemorrhagic shock. Methods Anesthetized male Sprague-Dawley rats were instrumented with arterial and venous catheters for blood pressure monitoring, hemorrhage and fluid resuscitation. Series 1: Linopirdine (Kv7 channel blocker, 0.1–6 mg/kg) or retigabine (Kv7 channel activator, 0.1–12 mg/kg) were administered to normal animals. Series 2: Animals were hemorrhaged to a MAP of 25 mmHg for 30 min, followed by fluid resuscitation with normal saline (NS) to a MAP of 70 mmHg until t = 75 min. Animals were treated with single bolus injections of vehicle, linopirdine (1–6 mg/kg), XE-991 (structural analogue of linopirdine with higher potency for channel blockade, 1 mg/kg) prior to fluid resuscitation. Series 3: Animals were resuscitated with NS alone or NS supplemented with linopirdine (1.25–200 μg/mL). Data were analyzed with 2-way ANOVA/Bonferroni post-hoc testing. Results Series 1: Linopirdine transiently (10–15 min) and dose-dependently increased MAP by up to 15%. Retigabine dose-dependently reduced MAP by up to 60%, which could be reverted with linopirdine. Series 2: Fluid requirements to maintain MAP at 70 mmHg were 65 ± 34 mL/kg with vehicle, and 57 ± 13 mL/kg, 22 ± 8 mL/kg and 22 ± 11 mL/kg with intravenous bolus injection of 1, 3 and 6 mg/kg linopirdine, respectively. XE-991 (1 mg/kg), reduced resuscitation requirements comparable to 3 mg/kg linopirdine. Series 3: When resuscitation was performed with linopirdine-supplemented normal saline (NS), fluid requirements to stabilize MAP were 73 ± 12 mL/kg with NS alone and 72 ± 24, 61 ± 20, 36 ± 9 and 31 ± 9 mL/kg with NS supplemented with 1.25, 6.25, 12.5 and 200 μg/mL linopirdine, respectively. Conclusions Our data suggest that Kv7 channel blockers could be used to stabilize blood pressure and reduce fluid resuscitation requirements after hemorrhagic shock.
Collapse
Affiliation(s)
- Sean P Nassoiy
- Burn and Shock Trauma Research Institute, Department of Surgery, Loyola University Chicago, Stritch School of Medicine, 2160 S. 1st Avenue, Maywood, IL, 60153, USA
| | - Kenneth L Byron
- Department of Molecular Pharmacology and Therapeutics, Loyola University Chicago, Stritch School of Medicine, 2160 S. 1st Avenue, Maywood, IL, 60153, USA
| | - Matthias Majetschak
- Burn and Shock Trauma Research Institute, Department of Surgery, Loyola University Chicago, Stritch School of Medicine, 2160 S. 1st Avenue, Maywood, IL, 60153, USA. .,Department of Molecular Pharmacology and Therapeutics, Loyola University Chicago, Stritch School of Medicine, 2160 S. 1st Avenue, Maywood, IL, 60153, USA.
| |
Collapse
|
7
|
Carter JJ, Fretwell LV, Woolard J. Effects of 4 multitargeted receptor tyrosine kinase inhibitors on regional hemodynamics in conscious, freely moving rats. FASEB J 2016; 31:1193-1203. [PMID: 27986807 PMCID: PMC5295730 DOI: 10.1096/fj.201600749r] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Accepted: 12/03/2016] [Indexed: 11/17/2022]
Abstract
VEGF inhibitors, including receptor tyrosine kinase inhibitors, are used as adjunct therapies in a number of cancer treatments. An emerging issue with these drugs is that most cause hypertension. To gain insight into the physiological mechanisms involved, we evaluated their regional hemodynamic effects in conscious rats. Male Sprague Dawley rats (350–450 g) were chronically implanted with pulsed Doppler flow probes (renal and mesenteric arteries, and the descending abdominal aorta) and catheters (jugular vein, peritoneal cavity, and distal abdominal aorta). Regional hemodynamics were measured over 4 d, before and after daily administration of cediranib (3 and 6 mg/kg, 3 and 6 mg/kg/h for 1 h, i.v.), sorafenib (10 and 20 mg/kg, 10 and 20 mg kg/h for 1 h, i.v.), pazopanib (30 and100 mg/kg, i.p.), or vandetanib (12.5 and 25 mg/kg, i.p.). All drugs evoked significant increases (P < 0.05; n = 7–8) in mean arterial pressure, which were generally accompanied by significant mesenteric and hindquarters, but not renal, vasoconstrictions. The hypertensive effects of cediranib were unaffected by losartan (10 mg/kg/h), bosentan (20 mg/kg/h), or a combination of phentolamine and propranolol (each 1 mg/kg/h), suggesting a need for new strategies to overcome them.—Carter, J. J., Fretwell, L. V., Woolard, J. Effects of 4 multitargeted receptor tyrosine kinase inhibitors on regional hemodynamics in conscious, freely moving rats.
Collapse
Affiliation(s)
- Joanne J Carter
- Cell Signalling Research Group, School of Life Sciences, Medical School, The University of Nottingham, Queen's Medical Centre, Nottingham, United Kingdom; and
| | - Laurice V Fretwell
- Faculty of Health and Life Sciences, De Montfort University, Leicester, United Kingdom
| | - Jeanette Woolard
- Cell Signalling Research Group, School of Life Sciences, Medical School, The University of Nottingham, Queen's Medical Centre, Nottingham, United Kingdom; and
| |
Collapse
|