1
|
Coccarelli A, Pant S. On the Ca 2+ elevation in vascular endothelial cells due to inositol trisphosphate-sensitive store receptors activation: A data-driven modeling approach. Comput Biol Med 2023; 164:107111. [PMID: 37540925 DOI: 10.1016/j.compbiomed.2023.107111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Revised: 05/18/2023] [Accepted: 05/30/2023] [Indexed: 08/06/2023]
Abstract
Agonist-induced Ca2+ signaling is essential for the regulation of many vital functions in endothelial cells (ECs). A broad range of stimuli elevate the cytosolic Ca2+ concentration by promoting a pathway mediated by inositol 1,4,5 trisphosphate (IP3) which causes Ca2+ release from intracellular stores. Despite its importance, there are very few studies focusing on the quantification of such dynamics in the vascular endothelium. Here, by using data from isolated ECs, we established a minimalistic modeling framework able to quantitatively capture the main features (averaged over a cell population) of the cytosolic Ca2+ response to different IP3 stimulation levels. A suitable description of Ca2+-regulatory function of inositol 1,4,5 trisphosphate receptors (IP3Rs) and corresponding parameter space are identified by comparing the different model variants against experimental mean population data. The same approach is used to numerically assess the relevance of cytosolic Ca2+ buffering, as well as Ca2+ store IP3-sensitivity in the overall cell dynamics. The variability in the dynamics' features observed across the population can be explained (at least in part) through variation of certain model parameters (such as buffering capacity or Ca2+ store sensitivity to IP3). The results, in terms of experimental fitting and validation, support the proposed minimalistic model as a reference framework for the quantification of the EC Ca2+ dynamics induced by IP3Rs activation.
Collapse
Affiliation(s)
- Alberto Coccarelli
- Zienkiewicz Centre for Computational Engineering, Faculty of Science and Engineering, Swansea University, UK.
| | - Sanjay Pant
- Zienkiewicz Centre for Computational Engineering, Faculty of Science and Engineering, Swansea University, UK
| |
Collapse
|
2
|
Chen K, Man Q, Miao J, Xu W, Zheng Y, Zhou X, Gao Z. Kir2.1 channel regulates macrophage polarization via Ca2+/CaMK II/ERK/NF-κB signaling pathway. J Cell Sci 2022; 135:275689. [PMID: 35694964 DOI: 10.1242/jcs.259544] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Accepted: 06/06/2022] [Indexed: 11/20/2022] Open
Abstract
Macrophage polarization plays a key role in inflammatory response. Various ion channels expressed in macrophages has been documented, but very little is known about their roles in macrophage polarization. We find that knockdown or blockade of Kir2.1 channel significantly inhibits M1 polarization, but promotes M2 polarization. LPS induced M1 polarization is also remarkably suppressed in high extracellular K+ solutions (70 mM K+), and this inhibition is partially abolished by adding Ca2+ in the culture medium. Calcium imaging shows that Ca2+ influx is dependent on the hyperpolarized membrane potential generated by Kir2.1 channel. The upregulation of p-CaMK II, p-ERK1/2, and p-NF-κB proteins in RAW264.7 macrophages stimulated with LPS are significantly reversed by blocking Kir2.1 channel or culturing the cells with 70 mM K+ medium. Furthermore, in vivo study shows that mice treated with Kir2.1 channel blocker are protected from LPS-induced peritonitis. In summary, our data reveal the essential role of Kir2.1 channel in regulating macrophage polarization via Ca2+ / CaMK II / ERK1/2 / NF-κB pathway.
Collapse
Affiliation(s)
- Kuihao Chen
- Department of Cardiology, The Affiliated Hospital of Medical School of Ningbo University, 247 Renmin Rd, Ningbo, China.,Department of Pharmacology, Ningbo University School of Medicine, 818 Fenghua Rd, Ningbo, China
| | - Qiaoyan Man
- Department of Pharmacology, Ningbo University School of Medicine, 818 Fenghua Rd, Ningbo, China
| | - Jiaen Miao
- Department of Pharmacology, Ningbo University School of Medicine, 818 Fenghua Rd, Ningbo, China
| | - Wenjing Xu
- Department of Pharmacology, Ningbo University School of Medicine, 818 Fenghua Rd, Ningbo, China
| | - Yangchen Zheng
- Department of Pharmacology, Ningbo University School of Medicine, 818 Fenghua Rd, Ningbo, China
| | - Xiuli Zhou
- Department of Pharmacology, Ningbo University School of Medicine, 818 Fenghua Rd, Ningbo, China
| | - Zhe Gao
- Department of Cardiology, The Affiliated Hospital of Medical School of Ningbo University, 247 Renmin Rd, Ningbo, China.,Ningbo Institute of Medical Sciences, 42 Yangshan Rd, Ningbo, China
| |
Collapse
|
3
|
Jackson WF. Calcium-Dependent Ion Channels and the Regulation of Arteriolar Myogenic Tone. Front Physiol 2021; 12:770450. [PMID: 34819877 PMCID: PMC8607693 DOI: 10.3389/fphys.2021.770450] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Accepted: 10/11/2021] [Indexed: 11/25/2022] Open
Abstract
Arterioles in the peripheral microcirculation regulate blood flow to and within tissues and organs, control capillary blood pressure and microvascular fluid exchange, govern peripheral vascular resistance, and contribute to the regulation of blood pressure. These important microvessels display pressure-dependent myogenic tone, the steady state level of contractile activity of vascular smooth muscle cells (VSMCs) that sets resting arteriolar internal diameter such that arterioles can both dilate and constrict to meet the blood flow and pressure needs of the tissues and organs that they perfuse. This perspective will focus on the Ca2+-dependent ion channels in the plasma and endoplasmic reticulum membranes of arteriolar VSMCs and endothelial cells (ECs) that regulate arteriolar tone. In VSMCs, Ca2+-dependent negative feedback regulation of myogenic tone is mediated by Ca2+-activated K+ (BKCa) channels and also Ca2+-dependent inactivation of voltage-gated Ca2+ channels (VGCC). Transient receptor potential subfamily M, member 4 channels (TRPM4); Ca2+-activated Cl− channels (CaCCs; TMEM16A/ANO1), Ca2+-dependent inhibition of voltage-gated K+ (KV) and ATP-sensitive K+ (KATP) channels; and Ca2+-induced-Ca2+ release through inositol 1,4,5-trisphosphate receptors (IP3Rs) participate in Ca2+-dependent positive-feedback regulation of myogenic tone. Calcium release from VSMC ryanodine receptors (RyRs) provide negative-feedback through Ca2+-spark-mediated control of BKCa channel activity, or positive-feedback regulation in cooperation with IP3Rs or CaCCs. In some arterioles, VSMC RyRs are silent. In ECs, transient receptor potential vanilloid subfamily, member 4 (TRPV4) channels produce Ca2+ sparklets that activate IP3Rs and intermediate and small conductance Ca2+ activated K+ (IKCa and sKCa) channels causing membrane hyperpolarization that is conducted to overlying VSMCs producing endothelium-dependent hyperpolarization and vasodilation. Endothelial IP3Rs produce Ca2+ pulsars, Ca2+ wavelets, Ca2+ waves and increased global Ca2+ levels activating EC sKCa and IKCa channels and causing Ca2+-dependent production of endothelial vasodilator autacoids such as NO, prostaglandin I2 and epoxides of arachidonic acid that mediate negative-feedback regulation of myogenic tone. Thus, Ca2+-dependent ion channels importantly contribute to many aspects of the regulation of myogenic tone in arterioles in the microcirculation.
Collapse
Affiliation(s)
- William F Jackson
- Department of Pharmacology and Toxicology, College of Osteopathic Medicine, Michigan State University, East Lansing, MI, United States
| |
Collapse
|
4
|
Abstract
Of the 21 members of the connexin family, 4 (Cx37, Cx40, Cx43, and Cx45) are expressed in the endothelium and/or smooth muscle of intact blood vessels to a variable and dynamically regulated degree. Full-length connexins oligomerize and form channel structures connecting the cytosol of adjacent cells (gap junctions) or the cytosol with the extracellular space (hemichannels). The different connexins vary mainly with regard to length and sequence of their cytosolic COOH-terminal tails. These COOH-terminal parts, which in the case of Cx43 are also translated as independent short isoforms, are involved in various cellular signaling cascades and regulate cell functions. This review focuses on channel-dependent and -independent effects of connexins in vascular cells. Channels play an essential role in coordinating and synchronizing endothelial and smooth muscle activity and in their interplay, in the control of vasomotor actions of blood vessels including endothelial cell reactivity to agonist stimulation, nitric oxide-dependent dilation, and endothelial-derived hyperpolarizing factor-type responses. Further channel-dependent and -independent roles of connexins in blood vessel function range from basic processes of vascular remodeling and angiogenesis to vascular permeability and interactions with leukocytes with the vessel wall. Together, these connexin functions constitute an often underestimated basis for the enormous plasticity of vascular morphology and function enabling the required dynamic adaptation of the vascular system to varying tissue demands.
Collapse
Affiliation(s)
- Ulrich Pohl
- Walter-Brendel-Centre of Experimental Medicine, University Hospital, LMU Munich, Planegg-Martinsried, Germany; Biomedical Centre, Cardiovascular Physiology, LMU Munich, Planegg-Martinsried, Germany; German Centre for Cardiovascular Research, Partner Site Munich Heart Alliance, Munich, Germany; and Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| |
Collapse
|
5
|
Wilson C, Zhang X, Buckley C, Heathcote HR, Lee MD, McCarron JG. Increased Vascular Contractility in Hypertension Results From Impaired Endothelial Calcium Signaling. Hypertension 2019; 74:1200-1214. [PMID: 31542964 PMCID: PMC6791503 DOI: 10.1161/hypertensionaha.119.13791] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Supplemental Digital Content is available in the text. Endothelial cells line all blood vessels and are critical regulators of vascular tone. In hypertension, disruption of endothelial function alters the release of endothelial-derived vasoactive factors and results in increased vascular tone. Although the release of endothelial-derived vasodilators occurs in a Ca2+-dependent manner, little is known on how Ca2+ signaling is altered in hypertension. A key element to endothelial control of vascular tone is Ca2+ signals at specialized regions (myoendothelial projections) that connect endothelial cells and smooth muscle cells. This work describes disruption in the operation of this key Ca2+ signaling pathway in hypertension. We show that vascular reactivity to phenylephrine is increased in hypertensive (spontaneously hypertensive rat) when compared with normotensive (Wistar Kyoto) rats. Basal endothelial Ca2+ activity limits vascular contraction, but that Ca2+-dependent control is impaired in hypertension. When changes in endothelial Ca2+ levels are buffered, vascular contraction to phenylephrine increased, resulting in similar responses in normotension and hypertension. Local endothelial IP3(inositol trisphosphate)-mediated Ca2+ signals are smaller in amplitude, shorter in duration, occur less frequently, and arise from fewer sites in hypertension. Spatial control of endothelial Ca2+ signaling is also disrupted in hypertension: local Ca2+ signals occur further from myoendothelial projections in hypertension. The results demonstrate that the organization of local Ca2+ signaling circuits occurring at myoendothelial projections is disrupted in hypertension, giving rise to increased contractile responses.
Collapse
Affiliation(s)
- Calum Wilson
- From the Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, United Kingdom
| | - Xun Zhang
- From the Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, United Kingdom
| | - Charlotte Buckley
- From the Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, United Kingdom
| | - Helen R Heathcote
- From the Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, United Kingdom
| | - Matthew D Lee
- From the Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, United Kingdom
| | - John G McCarron
- From the Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, United Kingdom
| |
Collapse
|
6
|
Jackson WF. Boosting the signal: Endothelial inward rectifier K + channels. Microcirculation 2018; 24. [PMID: 27652592 DOI: 10.1111/micc.12319] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Accepted: 09/12/2016] [Indexed: 12/19/2022]
Abstract
Endothelial cells express a diverse array of ion channels including members of the strong inward rectifier family composed of KIR 2 subunits. These two-membrane spanning domain channels are modulated by their lipid environment, and exist in macromolecular signaling complexes with receptors, protein kinases and other ion channels. Inward rectifier K+ channel (KIR ) currents display a region of negative slope conductance at membrane potentials positive to the K+ equilibrium potential that allows outward current through the channels to be activated by membrane hyperpolarization, permitting KIR to amplify hyperpolarization induced by other K+ channels and ion transporters. Increases in extracellular K+ concentration activate KIR allowing them to sense extracellular K+ concentration and transduce this change into membrane hyperpolarization. These properties position KIR to participate in the mechanism of action of hyperpolarizing vasodilators and contribute to cell-cell conduction of hyperpolarization along the wall of microvessels. The expression of KIR in capillaries in electrically active tissues may allow KIR to sense extracellular K+ , contributing to functional hyperemia. Understanding the regulation of expression and function of microvascular endothelial KIR will improve our understanding of the control of blood flow in the microcirculation in health and disease and may provide new targets for the development of therapeutics in the future.
Collapse
Affiliation(s)
- William F Jackson
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI, USA
| |
Collapse
|
7
|
Behringer EJ. Calcium and electrical signaling in arterial endothelial tubes: New insights into cellular physiology and cardiovascular function. Microcirculation 2018; 24. [PMID: 27801542 DOI: 10.1111/micc.12328] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2016] [Accepted: 10/25/2016] [Indexed: 12/23/2022]
Abstract
The integral role of the endothelium during the coordination of blood flow throughout vascular resistance networks has been recognized for several decades now. Early examination of the distinct anatomy and physiology of the endothelium as a signaling conduit along the vascular wall has prompted development and application of an intact endothelial "tube" study model isolated from rodent skeletal muscle resistance arteries. Vasodilatory signals such as increased endothelial cell (EC) Ca2+ ([Ca2+ ]i ) and hyperpolarization take place in single ECs while shared between electrically coupled ECs through gap junctions up to distances of millimeters (≥2 mm). The small- and intermediate-conductance Ca2+ activated K+ (SKCa /IKCa or KCa 2.3/KCa 3.1) channels function at the interface of Ca2+ signaling and hyperpolarization; a bidirectional relationship whereby increases in [Ca2+ ]i activate SKCa /IKCa channels to produce hyperpolarization and vice versa. Further, the spatial domain of hyperpolarization among electrically coupled ECs can be finely tuned via incremental modulation of SKCa /IKCa channels to balance the strength of local and conducted electrical signals underlying vasomotor activity. Multifunctional properties of the voltage-insensitive SKCa /IKCa channels of resistance artery endothelium may be employed for therapy during the aging process and development of vascular disease.
Collapse
Affiliation(s)
- Erik J Behringer
- Department of Basic Sciences, Loma Linda University, Loma Linda, CA, USA
| |
Collapse
|
8
|
Zhang Z, Payne K, Pallone TL. Adaptive responses of rat descending vasa recta to ischemia. Am J Physiol Renal Physiol 2018; 314:F373-F380. [PMID: 28814437 DOI: 10.1152/ajprenal.00062.2017] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
tested whether rat descending vasa recta (DVR) undergo regulatory adaptations after the kidney is exposed to ischemia. Left kidneys (LK) were subjected to 30-min renal artery cross clamp. After 48 h, the postischemic LK and contralateral right kidney (RK) were harvested for study. When compared with DVR isolated from either sham-operated LK or the contralateral RK, postischemic LK DVR markedly increased their NO generation. The selective inducible NOS (iNOS) inhibitor 1400W blocked the NO response. Immunoblots from outer medullary homogenates showed a parallel 2.6-fold increase in iNOS expression ( P = 0.01). Microperfused postischemic LK DVR exposed to angiotensin II (ANG II, 10 nM), constricted less than those from the contralateral RK, and constricted more when exposed to 1400W (10 µM). Resting membrane potentials of pericytes from postischemic LK DVR pericytes were hyperpolarized relative to contralateral RK pericytes (62.0 ± 1.6 vs. 51.8 ± 2.2 mV, respectively, P < 0.05) or those from sham-operated LK (54.9 ± 2.1 mV, P < 0.05). Blockade of NO generation with 1400W did not repolarize postischemic pericytes (62.5 ± 1.4 vs. 61.1 ± 3.4 mV); however, control pericytes were hyperpolarized by exposure to NO donation from S-nitroso- N-acetyl- dl-penicillamine (51.5 ± 2.9 to 62.1 ± 1.4 mV, P < 0.05). We conclude that postischemic adaptations intrinsic to the DVR wall occur after ischemia. A rise in 1400W sensitive NO generation and iNOS expression occurs that is associated with diminished contractile responses to ANG II. Pericyte hyperpolarization occurs that is not explained by the rise in ambient NO generation within the DVR wall.
Collapse
Affiliation(s)
- Zhong Zhang
- Division of Nephrology, Department of Medicine, University of Maryland School of Medicine , Baltimore, Maryland
| | - Kristie Payne
- Division of Nephrology, Department of Medicine, University of Maryland School of Medicine , Baltimore, Maryland
| | - Thomas L Pallone
- Division of Nephrology, Department of Medicine, University of Maryland School of Medicine , Baltimore, Maryland.,Baltimore Veterans Administration Medical Center , Baltimore, Maryland
| |
Collapse
|
9
|
Hill MA, Nourian Z, Ho IL, Clifford PS, Martinez-Lemus L, Meininger GA. Small Artery Elastin Distribution and Architecture-Focus on Three Dimensional Organization. Microcirculation 2018; 23:614-620. [PMID: 27362628 DOI: 10.1111/micc.12294] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2016] [Accepted: 06/28/2016] [Indexed: 12/11/2022]
Abstract
The distribution of ECM proteins within the walls of resistance vessels is complex both in variety of proteins and structural arrangement. In particular, elastin exists as discrete fibers varying in orientation across the adventitia and media as well as often resembling a sheet-like structure in the case of the IEL. Adding to the complexity is the tissue heterogeneity that exists in these structural arrangements. For example, small intracranial cerebral arteries lack adventitial elastin while similar sized arteries from skeletal muscle and intestinal mesentery exhibit a complex adventitial network of elastin fibers. With regard to the IEL, several vascular beds exhibit an elastin sheet with punctate holes/fenestrae while in others the IEL is discontinuous and fibrous in appearance. Importantly, these structural patterns likely sub-serve specific functional properties, including mechanosensing, control of external forces, mechanical properties of the vascular wall, cellular positioning, and communication between cells. Of further significance, these processes are altered in vascular disorders such as hypertension and diabetes mellitus where there is modification of ECM. This brief report focuses on the three-dimensional wall structure of small arteries and considers possible implications with regard to mechanosensing under physiological and pathophysiological conditions.
Collapse
Affiliation(s)
- Michael A Hill
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri, USA.,Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, Missouri, USA
| | - Zahra Nourian
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri, USA
| | - I-Lin Ho
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri, USA.,Department of Physics, National Chung Hsing University, Taichung 402, Taiwan, R.O.C
| | - Philip S Clifford
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri, USA.,College of Applied Health Sciences, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Luis Martinez-Lemus
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri, USA.,Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, Missouri, USA
| | - Gerald A Meininger
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri, USA.,Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, Missouri, USA
| |
Collapse
|
10
|
Pogoda K, Mannell H, Blodow S, Schneider H, Schubert KM, Qiu J, Schmidt A, Imhof A, Beck H, Tanase LI, Pfeifer A, Pohl U, Kameritsch P. NO Augments Endothelial Reactivity by Reducing Myoendothelial Calcium Signal Spreading: A Novel Role for Cx37 (Connexin 37) and the Protein Tyrosine Phosphatase SHP-2. Arterioscler Thromb Vasc Biol 2017; 37:2280-2290. [PMID: 29025706 DOI: 10.1161/atvbaha.117.309913] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Accepted: 09/26/2017] [Indexed: 01/31/2023]
Abstract
OBJECTIVE Because of its strategic position between endothelial and smooth muscle cells in microvessels, Cx37 (Connexin 37) plays an important role in myoendothelial gap junctional intercellular communication. We have shown before that NO inhibits gap junctional intercellular communication through gap junctions containing Cx37. However, the underlying mechanism is not yet identified. APPROACH AND RESULTS Using channel-forming Cx37 mutants exhibiting partial deletions or amino acid exchanges in their C-terminal loops, we now show that the phosphorylation state of a tyrosine residue at position 332 (Y332) in the C-terminus of Cx37 controls the gap junction-dependent spread of calcium signals. Mass spectra revealed that NO protects Cx37 from dephosphorylation at Y332 by inhibition of the protein tyrosine phosphatase SHP-2. Functionally, the inhibition of gap junctional intercellular communication by NO decreased the spread of the calcium signal (induced by mechanical stimulation of individual endothelial cells) from endothelial to smooth muscle cells in intact vessels, while, at the same time, augmenting the calcium signal spreading within the endothelium. Consequently, preincubation of small resistance arteries with exogenous NO enhanced the endothelium-dependent dilator response to acetylcholine in spite of a pharmacological blockade of NO-dependent cGMP formation by the soluable guanylyl cyclase inhibitor ODQ (1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one). CONCLUSIONS Our results identify a novel mechanism by which NO can increase the efficacy of calcium, rising vasoactive agonists in the microvascular endothelium.
Collapse
Affiliation(s)
- Kristin Pogoda
- From the Walter Brendel Centre of Experimental Medicine, University Hospital, Biomedical Center, Munich, Germany (K.P., H.M., S.B., H.S., K.M.S., J.Q., H.B., L.I.T., U.P., P.K.); Protein Analysis Unit, Biomedical Center, Munich, Germany (A.S., A.I.); DZHK (German Center for Cardiovascular Research), partner site Munich Heart Alliance, Germany (K.P., H.M., S.B., H.S., K.M.S., J.Q., H.B., U.P., P.K.); Munich Cluster for Systems Neurology (SyNergY), Germany (A.I., U.P.); and Institute of Pharmacology and Toxicology, Rheinische Friedrich-Wilhelms-Universität Bonn, Germany (A.P.)
| | - Hanna Mannell
- From the Walter Brendel Centre of Experimental Medicine, University Hospital, Biomedical Center, Munich, Germany (K.P., H.M., S.B., H.S., K.M.S., J.Q., H.B., L.I.T., U.P., P.K.); Protein Analysis Unit, Biomedical Center, Munich, Germany (A.S., A.I.); DZHK (German Center for Cardiovascular Research), partner site Munich Heart Alliance, Germany (K.P., H.M., S.B., H.S., K.M.S., J.Q., H.B., U.P., P.K.); Munich Cluster for Systems Neurology (SyNergY), Germany (A.I., U.P.); and Institute of Pharmacology and Toxicology, Rheinische Friedrich-Wilhelms-Universität Bonn, Germany (A.P.)
| | - Stephanie Blodow
- From the Walter Brendel Centre of Experimental Medicine, University Hospital, Biomedical Center, Munich, Germany (K.P., H.M., S.B., H.S., K.M.S., J.Q., H.B., L.I.T., U.P., P.K.); Protein Analysis Unit, Biomedical Center, Munich, Germany (A.S., A.I.); DZHK (German Center for Cardiovascular Research), partner site Munich Heart Alliance, Germany (K.P., H.M., S.B., H.S., K.M.S., J.Q., H.B., U.P., P.K.); Munich Cluster for Systems Neurology (SyNergY), Germany (A.I., U.P.); and Institute of Pharmacology and Toxicology, Rheinische Friedrich-Wilhelms-Universität Bonn, Germany (A.P.)
| | - Holger Schneider
- From the Walter Brendel Centre of Experimental Medicine, University Hospital, Biomedical Center, Munich, Germany (K.P., H.M., S.B., H.S., K.M.S., J.Q., H.B., L.I.T., U.P., P.K.); Protein Analysis Unit, Biomedical Center, Munich, Germany (A.S., A.I.); DZHK (German Center for Cardiovascular Research), partner site Munich Heart Alliance, Germany (K.P., H.M., S.B., H.S., K.M.S., J.Q., H.B., U.P., P.K.); Munich Cluster for Systems Neurology (SyNergY), Germany (A.I., U.P.); and Institute of Pharmacology and Toxicology, Rheinische Friedrich-Wilhelms-Universität Bonn, Germany (A.P.)
| | - Kai Michael Schubert
- From the Walter Brendel Centre of Experimental Medicine, University Hospital, Biomedical Center, Munich, Germany (K.P., H.M., S.B., H.S., K.M.S., J.Q., H.B., L.I.T., U.P., P.K.); Protein Analysis Unit, Biomedical Center, Munich, Germany (A.S., A.I.); DZHK (German Center for Cardiovascular Research), partner site Munich Heart Alliance, Germany (K.P., H.M., S.B., H.S., K.M.S., J.Q., H.B., U.P., P.K.); Munich Cluster for Systems Neurology (SyNergY), Germany (A.I., U.P.); and Institute of Pharmacology and Toxicology, Rheinische Friedrich-Wilhelms-Universität Bonn, Germany (A.P.)
| | - Jiehua Qiu
- From the Walter Brendel Centre of Experimental Medicine, University Hospital, Biomedical Center, Munich, Germany (K.P., H.M., S.B., H.S., K.M.S., J.Q., H.B., L.I.T., U.P., P.K.); Protein Analysis Unit, Biomedical Center, Munich, Germany (A.S., A.I.); DZHK (German Center for Cardiovascular Research), partner site Munich Heart Alliance, Germany (K.P., H.M., S.B., H.S., K.M.S., J.Q., H.B., U.P., P.K.); Munich Cluster for Systems Neurology (SyNergY), Germany (A.I., U.P.); and Institute of Pharmacology and Toxicology, Rheinische Friedrich-Wilhelms-Universität Bonn, Germany (A.P.)
| | - Andreas Schmidt
- From the Walter Brendel Centre of Experimental Medicine, University Hospital, Biomedical Center, Munich, Germany (K.P., H.M., S.B., H.S., K.M.S., J.Q., H.B., L.I.T., U.P., P.K.); Protein Analysis Unit, Biomedical Center, Munich, Germany (A.S., A.I.); DZHK (German Center for Cardiovascular Research), partner site Munich Heart Alliance, Germany (K.P., H.M., S.B., H.S., K.M.S., J.Q., H.B., U.P., P.K.); Munich Cluster for Systems Neurology (SyNergY), Germany (A.I., U.P.); and Institute of Pharmacology and Toxicology, Rheinische Friedrich-Wilhelms-Universität Bonn, Germany (A.P.)
| | - Axel Imhof
- From the Walter Brendel Centre of Experimental Medicine, University Hospital, Biomedical Center, Munich, Germany (K.P., H.M., S.B., H.S., K.M.S., J.Q., H.B., L.I.T., U.P., P.K.); Protein Analysis Unit, Biomedical Center, Munich, Germany (A.S., A.I.); DZHK (German Center for Cardiovascular Research), partner site Munich Heart Alliance, Germany (K.P., H.M., S.B., H.S., K.M.S., J.Q., H.B., U.P., P.K.); Munich Cluster for Systems Neurology (SyNergY), Germany (A.I., U.P.); and Institute of Pharmacology and Toxicology, Rheinische Friedrich-Wilhelms-Universität Bonn, Germany (A.P.)
| | - Heike Beck
- From the Walter Brendel Centre of Experimental Medicine, University Hospital, Biomedical Center, Munich, Germany (K.P., H.M., S.B., H.S., K.M.S., J.Q., H.B., L.I.T., U.P., P.K.); Protein Analysis Unit, Biomedical Center, Munich, Germany (A.S., A.I.); DZHK (German Center for Cardiovascular Research), partner site Munich Heart Alliance, Germany (K.P., H.M., S.B., H.S., K.M.S., J.Q., H.B., U.P., P.K.); Munich Cluster for Systems Neurology (SyNergY), Germany (A.I., U.P.); and Institute of Pharmacology and Toxicology, Rheinische Friedrich-Wilhelms-Universität Bonn, Germany (A.P.)
| | - Laurentia Irina Tanase
- From the Walter Brendel Centre of Experimental Medicine, University Hospital, Biomedical Center, Munich, Germany (K.P., H.M., S.B., H.S., K.M.S., J.Q., H.B., L.I.T., U.P., P.K.); Protein Analysis Unit, Biomedical Center, Munich, Germany (A.S., A.I.); DZHK (German Center for Cardiovascular Research), partner site Munich Heart Alliance, Germany (K.P., H.M., S.B., H.S., K.M.S., J.Q., H.B., U.P., P.K.); Munich Cluster for Systems Neurology (SyNergY), Germany (A.I., U.P.); and Institute of Pharmacology and Toxicology, Rheinische Friedrich-Wilhelms-Universität Bonn, Germany (A.P.)
| | - Alexander Pfeifer
- From the Walter Brendel Centre of Experimental Medicine, University Hospital, Biomedical Center, Munich, Germany (K.P., H.M., S.B., H.S., K.M.S., J.Q., H.B., L.I.T., U.P., P.K.); Protein Analysis Unit, Biomedical Center, Munich, Germany (A.S., A.I.); DZHK (German Center for Cardiovascular Research), partner site Munich Heart Alliance, Germany (K.P., H.M., S.B., H.S., K.M.S., J.Q., H.B., U.P., P.K.); Munich Cluster for Systems Neurology (SyNergY), Germany (A.I., U.P.); and Institute of Pharmacology and Toxicology, Rheinische Friedrich-Wilhelms-Universität Bonn, Germany (A.P.)
| | - Ulrich Pohl
- From the Walter Brendel Centre of Experimental Medicine, University Hospital, Biomedical Center, Munich, Germany (K.P., H.M., S.B., H.S., K.M.S., J.Q., H.B., L.I.T., U.P., P.K.); Protein Analysis Unit, Biomedical Center, Munich, Germany (A.S., A.I.); DZHK (German Center for Cardiovascular Research), partner site Munich Heart Alliance, Germany (K.P., H.M., S.B., H.S., K.M.S., J.Q., H.B., U.P., P.K.); Munich Cluster for Systems Neurology (SyNergY), Germany (A.I., U.P.); and Institute of Pharmacology and Toxicology, Rheinische Friedrich-Wilhelms-Universität Bonn, Germany (A.P.).
| | - Petra Kameritsch
- From the Walter Brendel Centre of Experimental Medicine, University Hospital, Biomedical Center, Munich, Germany (K.P., H.M., S.B., H.S., K.M.S., J.Q., H.B., L.I.T., U.P., P.K.); Protein Analysis Unit, Biomedical Center, Munich, Germany (A.S., A.I.); DZHK (German Center for Cardiovascular Research), partner site Munich Heart Alliance, Germany (K.P., H.M., S.B., H.S., K.M.S., J.Q., H.B., U.P., P.K.); Munich Cluster for Systems Neurology (SyNergY), Germany (A.I., U.P.); and Institute of Pharmacology and Toxicology, Rheinische Friedrich-Wilhelms-Universität Bonn, Germany (A.P.)
| |
Collapse
|
11
|
Taylor MS, Choi CS, Bayazid L, Glosemeyer KE, Baker CCP, Weber DS. Changes in vascular reactivity and endothelial Ca 2+ dynamics with chronic low flow. Microcirculation 2017; 24:10.1111/micc.12354. [PMID: 28106317 PMCID: PMC5404954 DOI: 10.1111/micc.12354] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Accepted: 01/16/2017] [Indexed: 12/29/2022]
Abstract
Disruption of blood flow promotes endothelial dysfunction and predisposes vessels to remodeling and atherosclerosis. Recent findings suggest that spatial and temporal tuning of local Ca2+ signals along the endothelium is vital to vascular function. In this study, we examined whether chronic flow disruption causes alteration of dynamic endothelial Ca2+ signal patterning associated with changes in vascular structure and function. For these studies, we performed surgical PL of the left carotid arteries of mice to establish chronic low flow for 2 weeks; right carotid arteries remained open and served as controls (C). Histological sections showed substantial remodeling of PL compared to C arteries, including formation of neointima. Isometric force measurements revealed increased PE-induced contractions and decreased KCl-induced contractions in PL vs C arteries. Endothelium-dependent vasorelaxation in response to ACh; 10-8 to 10-5 mol/L) was significantly impaired in PL vs C vessels. Evaluation of endothelial Ca2+ using confocal imaging and custom analysis exposed distinct impairment of Ca2+ dynamics in PL arteries, characterized by reduction in active sites and truncation of events, corresponding to attenuated vasorelaxation. Our findings suggest that endothelial dysfunction in developing vascular disease may be characterized by distinct shifts in the spatial and temporal patterns of localized Ca2+ signals.
Collapse
Affiliation(s)
- Mark S Taylor
- Department of Physiology and Cell Biology, University of South Alabama College of Medicine, Mobile, AL, USA
| | - Chung-Sik Choi
- Department of Physiology and Cell Biology, University of South Alabama College of Medicine, Mobile, AL, USA
| | - Leith Bayazid
- Department of Physiology and Cell Biology, University of South Alabama College of Medicine, Mobile, AL, USA
| | - Katherine E Glosemeyer
- Department of Physiology and Cell Biology, University of South Alabama College of Medicine, Mobile, AL, USA
| | - Calvin C P Baker
- Department of Physiology and Cell Biology, University of South Alabama College of Medicine, Mobile, AL, USA
| | - David S Weber
- Department of Physiology and Cell Biology, University of South Alabama College of Medicine, Mobile, AL, USA
| |
Collapse
|
12
|
Garland CJ, Dora KA. EDH: endothelium-dependent hyperpolarization and microvascular signalling. Acta Physiol (Oxf) 2017; 219:152-161. [PMID: 26752699 DOI: 10.1111/apha.12649] [Citation(s) in RCA: 134] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Revised: 11/04/2015] [Accepted: 01/06/2016] [Indexed: 12/31/2022]
Abstract
Endothelium-dependent hyperpolarizing factor (EDHF) is a powerful vasodilator influence in small resistance arteries and thus an important modulator of blood pressure and flow. As the name suggests, EDHF was thought to describe a diffusible factor stimulating smooth muscle hyperpolarization (and thus vasodilatation). However, this idea has evolved with the recognition that a factor can operate alongside the spread of hyperpolarizing current from the endothelium to the vascular smooth muscle (VSM). As such, the pathway is now termed endothelium-dependent hyperpolarization (EDH). EDH is activated by an increase in endothelial [Ca2+ ]i , which stimulates two Ca2+ -sensitive K channels, SKCa and IKCa . This was discovered because apamin and charybdotoxin applied in combination blocked EDHF responses, but iberiotoxin - a blocker of BKCa - was not able to substitute for charybdotoxin. SKCa and IKCa channels are arranged in endothelial microdomains, particularly within projections towards the adjacent smooth muscle, which are rich in IKCa channels and close to interendothelial gap junctions where SKCa channels, are prevalent. KCa activation hyperpolarizes endothelial cells, and K+ efflux through them can act as a diffusible 'EDHF' by stimulating VSM Na+ ,K+ -ATPase and inwardly rectifying K channels (KIR ). In parallel, hyperpolarizing current spreads from the endothelium to the smooth muscle through myoendothelial gap junctions located on endothelial projections. The resulting radial EDH is complemented by the spread of 'conducted' hyperpolarization along the endothelium of arteries and arterioles to affect conducted vasodilatation (CVD). Retrograde CVD effectively integrates blood flow within the microcirculation, but how the underlying hyperpolarization is sustained is unclear.
Collapse
Affiliation(s)
- C. J. Garland
- Department of Pharmacology; University of Oxford; Oxford UK
| | - K. A. Dora
- Department of Pharmacology; University of Oxford; Oxford UK
| |
Collapse
|
13
|
Wilson C, Lee MD, McCarron JG. Acetylcholine released by endothelial cells facilitates flow-mediated dilatation. J Physiol 2016; 594:7267-7307. [PMID: 27730645 PMCID: PMC5157078 DOI: 10.1113/jp272927] [Citation(s) in RCA: 82] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Accepted: 10/03/2016] [Indexed: 01/24/2023] Open
Abstract
KEY POINTS The endothelium plays a pivotal role in the vascular response to chemical and mechanical stimuli. The endothelium is exquisitely sensitive to ACh, although the physiological significance of ACh-induced activation of the endothelium is unknown. In the present study, we investigated the mechanisms of flow-mediated endothelial calcium signalling. Our data establish that flow-mediated endothelial calcium responses arise from the autocrine action of non-neuronal ACh released by the endothelium. ABSTRACT Circulating blood generates frictional forces (shear stress) on the walls of blood vessels. These frictional forces critically regulate vascular function. The endothelium senses these frictional forces and, in response, releases various vasodilators that relax smooth muscle cells in a process termed flow-mediated dilatation. Although some elements of the signalling mechanisms have been identified, precisely how flow is sensed and transduced to cause the release of relaxing factors is poorly understood. By imaging signalling in large areas of the endothelium of intact arteries, we show that the endothelium responds to flow by releasing ACh. Once liberated, ACh acts to trigger calcium release from the internal store in endothelial cells, nitric oxide production and artery relaxation. Flow-activated release of ACh from the endothelium is non-vesicular and occurs via organic cation transporters. ACh is generated following mitochondrial production of acetylCoA. Thus, we show ACh is an autocrine signalling molecule released from endothelial cells, and identify a new role for the classical neurotransmitter in endothelial mechanotransduction.
Collapse
Affiliation(s)
- Calum Wilson
- Strathclyde Institute of Pharmacy and Biomedical SciencesUniversity of StrathclydeSIPBS BuildingGlasgowUK
| | - Matthew D. Lee
- Strathclyde Institute of Pharmacy and Biomedical SciencesUniversity of StrathclydeSIPBS BuildingGlasgowUK
| | - John G. McCarron
- Strathclyde Institute of Pharmacy and Biomedical SciencesUniversity of StrathclydeSIPBS BuildingGlasgowUK
| |
Collapse
|
14
|
Toussaint F, Charbel C, Allen BG, Ledoux J. Vascular CaMKII: heart and brain in your arteries. Am J Physiol Cell Physiol 2016; 311:C462-78. [PMID: 27306369 DOI: 10.1152/ajpcell.00341.2015] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Accepted: 06/14/2016] [Indexed: 01/02/2023]
Abstract
First characterized in neuronal tissues, the multifunctional calcium/calmodulin-dependent protein kinase II (CaMKII) is a key signaling component in several mammalian biological systems. Its unique capacity to integrate various Ca(2+) signals into different specific outcomes is a precious asset to excitable and nonexcitable cells. Numerous studies have reported roles and mechanisms involving CaMKII in brain and heart tissues. However, corresponding functions in vascular cell types (endothelium and vascular smooth muscle cells) remained largely unexplored until recently. Investigation of the intracellular Ca(2+) dynamics, their impact on vascular cell function, the regulatory processes involved and more recently the spatially restricted oscillatory Ca(2+) signals and microdomains triggered significant interest towards proteins like CaMKII. Heteromultimerization of CaMKII isoforms (four isoforms and several splice variants) expands this kinase's peculiar capacity to decipher Ca(2+) signals and initiate specific signaling processes, and thus controlling cellular functions. The physiological functions that rely on CaMKII are unsurprisingly diverse, ranging from regulating contractile state and cellular proliferation to Ca(2+) homeostasis and cellular permeability. This review will focus on emerging evidence of CaMKII as an essential component of the vascular system, with a focus on the kinase isoform/splice variants and cellular system studied.
Collapse
Affiliation(s)
- Fanny Toussaint
- Research Center, Montreal Heart Institute, Montreal, Quebec, Canada; Department of Molecular and Integrative Physiology, Université de Montréal, Montreal Quebec, Canada
| | - Chimène Charbel
- Research Center, Montreal Heart Institute, Montreal, Quebec, Canada; Department of Pharmacology, Université de Montréal, Montreal Quebec, Canada
| | - Bruce G Allen
- Research Center, Montreal Heart Institute, Montreal, Quebec, Canada; Department of Medicine, Université de Montréal, Montreal Quebec, Canada; and Department of Biochemistry and Molecular Medicine, Université de Montréal, Montreal Quebec, Canada
| | - Jonathan Ledoux
- Research Center, Montreal Heart Institute, Montreal, Quebec, Canada; Department of Medicine, Université de Montréal, Montreal Quebec, Canada; and
| |
Collapse
|
15
|
Zhang Z, Payne K, Pallone TL. Descending Vasa Recta Endothelial Membrane Potential Response Requires Pericyte Communication. PLoS One 2016; 11:e0154948. [PMID: 27171211 PMCID: PMC4865043 DOI: 10.1371/journal.pone.0154948] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Accepted: 04/21/2016] [Indexed: 11/30/2022] Open
Abstract
Using dual-cell electrophysiological recording, we examined the routes for equilibration of membrane potential between the pericytes and endothelia that comprise the descending vasa recta (DVR) wall. We measured equilibration between pericytes in intact vessels, between pericytes and endothelium in intact vessels and between pericytes physically separated from the endothelium. Dual pericyte recording on the abluminal surface of DVR showed that both resting potential and subsequent time-dependent voltage fluctuations after vasoconstrictor stimulation remained closely equilibrated, regardless of the agonist employed (angiotensin II, vasopressin or endothelin 1). When pericytes where removed from the vessel wall but retained physical contact with one another, membrane potential responses were also highly coordinated. In contrast, responses of pericytes varied independently when they were isolated from both the endothelium and from contact with one another. When pericytes and endothelium were in contact, their resting potentials were similar and their temporal responses to stimulation were highly coordinated. After completely isolating pericytes from the endothelium, their mean resting potentials became discordant. Finally, complete endothelial isolation eliminated all membrane potential responses to angiotensin II. We conclude that cell-to-cell transmission through the endothelium is not needed for pericytes to equilibrate their membrane potentials. AngII dependent responses of DVR endothelia may originate from gap junction coupling to pericytes rather than via receptor dependent signaling in the endothelium, per se.
Collapse
Affiliation(s)
- Zhong Zhang
- Division of Nephrology, Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland 21201, United States of America
| | - Kristie Payne
- Division of Nephrology, Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland 21201, United States of America
| | - Thomas L Pallone
- Division of Nephrology, Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland 21201, United States of America
| |
Collapse
|
16
|
Schmidt K, Windler R, de Wit C. Communication Through Gap Junctions in the Endothelium. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 2016; 77:209-40. [PMID: 27451099 DOI: 10.1016/bs.apha.2016.04.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
A swarm of fish displays a collective behavior (swarm behavior) and moves "en masse" despite the huge number of individual animals. In analogy, organ function is supported by a huge number of cells that act in an orchestrated fashion and this applies also to vascular cells along the vessel length. It is obvious that communication is required to achieve this vital goal. Gap junctions with their modular bricks, connexins (Cxs), provide channels that interlink the cytosol of adjacent cells by a pore sealed against the extracellular space. This allows the transfer of ions and charge and thereby the travel of membrane potential changes along the vascular wall. The endothelium provides a low-resistance pathway that depends crucially on connexin40 which is required for long-distance conduction of dilator signals in the microcirculation. The experimental evidence for membrane potential changes synchronizing vascular behavior is manifold but the functional verification of a physiologic role is still open. Other molecules may also be exchanged that possibly contribute to the synchronization (eg, Ca(2+)). Recent data suggest that vascular Cxs have more functions than just facilitating communication. As pharmacological tools to modulate gap junctions are lacking, Cx-deficient mice provide currently the standard to unravel their vascular functions. These include arteriolar dilation during functional hyperemia, hypoxic pulmonary vasoconstriction, vascular collateralization after ischemia, and feedback inhibition on renin secretion in the kidney.
Collapse
Affiliation(s)
- K Schmidt
- Institut für Physiologie, Universität zu Lübeck, Lübeck, Germany; Deutsches Zentrum für Herz-Kreislauf-Forschung (DZHK) e.V. (German Center for Cardiovascular Research), Partner Site Hamburg/Kiel/Lübeck, Lübeck, Germany
| | - R Windler
- Institut für Physiologie, Universität zu Lübeck, Lübeck, Germany; Deutsches Zentrum für Herz-Kreislauf-Forschung (DZHK) e.V. (German Center for Cardiovascular Research), Partner Site Hamburg/Kiel/Lübeck, Lübeck, Germany
| | - C de Wit
- Institut für Physiologie, Universität zu Lübeck, Lübeck, Germany; Deutsches Zentrum für Herz-Kreislauf-Forschung (DZHK) e.V. (German Center for Cardiovascular Research), Partner Site Hamburg/Kiel/Lübeck, Lübeck, Germany.
| |
Collapse
|
17
|
Sarelius IH, Titus PA, Maimon N, Okech W, Wilke-Mounts SJ, Brennan JR, Hocking DC. Extracellular matrix fibronectin initiates endothelium-dependent arteriolar dilatation via the heparin-binding, matricryptic RWRPK sequence of the first type III repeat of fibrillar fibronectin. J Physiol 2016; 594:687-97. [PMID: 26661689 DOI: 10.1113/jp271478] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Accepted: 12/04/2015] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS The local arteriolar dilatation produced by contraction of skeletal muscle is dependent upon multiple signalling mechanisms. In addition to the many metabolic signals that mediate this vasodilatation, we show here that the extracellular matrix protein fibronectin also contributes to the response. This vasodilatory signal requires the heparin-binding matricryptic RWRPK sequence in the first type III repeat of fibrillar fibronectin. The fibronectin-dependent component of the integrated muscle contraction-dependent arteriolar vasodilatation is coupled through an endothelial cell-dependent signalling pathway. Recent studies in contracting skeletal muscle have shown that functional vasodilatation in resistance arterioles has an endothelial cell (EC)-dependent component, and, separately have shown that the extracellular matrix protein fibronectin (FN) contributes to functional dilatation in these arterioles. Here we test the hypotheses that (i) the matricryptic heparin-binding region of the first type III repeat of fibrillar FN (FNIII1H) mediates vasodilatation, and (ii) this response is EC dependent. Engineered FN fragments with differing (defined) heparin- and integrin-binding capacities were applied directly to resistance arterioles in cremaster muscles of anaesthetized (pentobarbital sodium, 65 mg kg(-1)) mice. Both FNIII1H,8-10 and FNIII1H induced dilatations (12.2 ± 1.7 μm, n = 12 and 17.2 ± 2.4 μm, n = 14, respectively) whereas mutation of the active sequence (R(613) WRPK) of the heparin binding region significantly diminished the dilatation (3.2 ± 1.8 μm, n = 10). Contraction of skeletal muscle fibres via electrical field stimulation produced a vasodilatation (19.4 ± 1.2 μm, n = 12) that was significantly decreased (to 7.0 ± 2.7 μm, n = 7, P < 0.05) in the presence of FNIII1Peptide 6, which blocks extracellular matrix (ECM) FN and FNIII1H signalling. Furthermore, FNIII1H,8-10 and FNIII1H applied to EC-denuded arterioles failed to produce any dilatation indicating that endothelium was required for the response. Finally, FNIII1H significantly increased EC Ca(2+) (relative fluorescence 0.98 ± 0.02 in controls versus 1.12 ± 0.05, n = 17, P < 0.05). Thus, we conclude that ECM FN-dependent vasodilatation is mediated by the heparin-binding (RWRPK) sequence of FNIII1 in an EC-dependent manner. Importantly, blocking this signalling sequence decreased the dilatation to skeletal muscle contraction, indicating that there is a physiological role for this FN-dependent mechanism.
Collapse
Affiliation(s)
- Ingrid H Sarelius
- Department of Pharmacology and Physiology, University of Rochester, Rochester, NY, USA.,Department of Biomedical Engineering, University of Rochester, Rochester, NY, USA
| | - Patricia A Titus
- Department of Pharmacology and Physiology, University of Rochester, Rochester, NY, USA
| | - Nir Maimon
- Department of Pharmacology and Physiology, University of Rochester, Rochester, NY, USA
| | - William Okech
- Department of Biomedical Engineering, University of Rochester, Rochester, NY, USA
| | - Susan J Wilke-Mounts
- Department of Pharmacology and Physiology, University of Rochester, Rochester, NY, USA
| | - James R Brennan
- Department of Biomedical Engineering, University of Rochester, Rochester, NY, USA
| | - Denise C Hocking
- Department of Pharmacology and Physiology, University of Rochester, Rochester, NY, USA.,Department of Biomedical Engineering, University of Rochester, Rochester, NY, USA
| |
Collapse
|
18
|
Murrant CL, Sarelius IH. Local control of blood flow during active hyperaemia: what kinds of integration are important? J Physiol 2015; 593:4699-711. [PMID: 26314391 DOI: 10.1113/jp270205] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2015] [Accepted: 08/05/2015] [Indexed: 01/06/2023] Open
Abstract
The focus of this review is on local mechanisms modifying arteriolar resistance to match blood flow to metabolism. In skeletal muscle many local mediators are known, including K(+) , nitric oxide (NO), purines and prostaglandins. Each accounts for about 30% of the response; it is widely held that these act redundantly: this concept awaits systematic testing. Understanding signal integration also requires consideration of microvascular network morphology in relation to local communication pathways between endothelial and smooth muscle cells (which are critical for many local responses, including dilatation to skeletal muscle contraction) and in relation to the spread of vasodilator signals up- and downstream throughout the network. Mechanisms mediating the spread of dilatation from local to remote sites have been well studied using acetylcholine (ACh), but remote dilatations to contraction of skeletal muscle fibres also occur. Importantly, these mechanisms clearly differ from those initiated by ACh, but much remains undefined. Furthermore, capillaries contribute to metabolic dilatation as they dilate arterioles directly upstream in response to vasoactive agents or contraction of adjacent muscle fibres. Given the dispersed arrangement of motor units, precise matching of flow to metabolism is not attainable unless signals are initiated only by 'active' capillaries. As motor units are recruited, signals that direct blood flow towards these active fibres will eventually be supported by local and spreading responses in the arterioles associated with those fibres. Thus, mechanisms of integration of vasodilator signalling across elements of the microvasculature remain an important area of focus for new studies.
Collapse
Affiliation(s)
- Coral L Murrant
- Department of Human Health and Nutritional Science, University of Guelph, Guelph, ON, Canada
| | - Ingrid H Sarelius
- Department of Pharmacology and Physiology, University of Rochester, Rochester, NY, USA
| |
Collapse
|
19
|
Behringer EJ, Segal SS. Membrane potential governs calcium influx into microvascular endothelium: integral role for muscarinic receptor activation. J Physiol 2015; 593:4531-48. [PMID: 26260126 DOI: 10.1113/jp271102] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Accepted: 08/03/2015] [Indexed: 01/12/2023] Open
Abstract
In resistance arteries, coupling a rise of intracellular calcium concentration ([Ca(2+)]i) to endothelial cell hyperpolarization underlies smooth muscle cell relaxation and vasodilatation, thereby increasing tissue blood flow and oxygen delivery. A controversy persists as to whether changes in membrane potential (V(m)) alter endothelial cell [Ca(2+)]i. We tested the hypothesis that V(m) governs [Ca(2+)]i in endothelium of resistance arteries by performing Fura-2 photometry while recording and controlling V(m) of intact endothelial tubes freshly isolated from superior epigastric arteries of C57BL/6 mice. Under resting conditions, [Ca(2+)]i did not change when V(m) shifted from baseline (∼-40 mV) via exposure to 10 μM NS309 (hyperpolarization to ∼-80 mV), via equilibration with 145 mm [K(+)]o (depolarization to ∼-5 mV), or during intracellular current injection (±0.5 to 5 nA, 20 s pulses) while V(m) changed linearly between ∼-80 mV and +10 mV. In contrast, during the plateau (i.e. Ca(2+) influx) phase of the [Ca(2+)]i response to approximately half-maximal stimulation with 100 nm ACh (∼EC50), [Ca(2+)]i increased as V(m) hyperpolarized below -40 mV and decreased as V(m) depolarized above -40 mV. The magnitude of [Ca(2+)]i reduction during depolarizing current injections correlated with the amplitude of the plateau [Ca(2+)]i response to ACh. The effect of hyperpolarization on [Ca(2+)]i was abolished following removal of extracellular Ca(2+), was enhanced subtly by raising extracellular [Ca(2+)] from 2 mm to 10 mm and was reduced by half in endothelium of TRPV4(-/-) mice. Thus, during submaximal activation of muscarinic receptors, V(m) can modulate Ca(2+) entry through the plasma membrane in accord with the electrochemical driving force.
Collapse
Affiliation(s)
- Erik J Behringer
- Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, MO, 65212, USA
| | - Steven S Segal
- Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, MO, 65212, USA.,Dalton Cardiovascular Research Center, Columbia, MO, 65211, USA
| |
Collapse
|
20
|
Al-Brakati AY, Kamishima T, Dart C, Quayle JM. Caveolar disruption causes contraction of rat femoral arteries via reduced basal NO release and subsequent closure of BKCa channels. PeerJ 2015; 3:e966. [PMID: 26038721 PMCID: PMC4451037 DOI: 10.7717/peerj.966] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2015] [Accepted: 04/29/2015] [Indexed: 12/22/2022] Open
Abstract
Background and Purpose. Caveolae act as signalling hubs in endothelial and smooth muscle cells. Caveolar disruption by the membrane cholesterol depleting agent methyl-β-cyclodextrin (M-β-CD) has various functional effects on arteries including (i) impairment of endothelium-dependent relaxation, and (ii) alteration of smooth muscle cell (SMC) contraction independently of the endothelium. The aim of this study was to explore the effects of M-β-CD on rat femoral arteries. Methods. Isometric force was measured in rat femoral arteries stimulated to contract with a solution containing 20 mM K(+) and 200 nM Bay K 8644 (20 K/Bay K) or with one containing 80 mM K(+)(80 K). Results. Incubation of arteries with M-β-CD (5 mM, 60 min) increased force in response to 20 K/Bay K but not that induced by 80 K. Application of cholesterol saturated M-β-CD (Ch-MCD, 5 mM, 50 min) reversed the effects of M-β-CD. After mechanical removal of endothelial cells M-β-CD caused only a small enhancement of contractions to 20 K/Bay K. This result suggests M-β-CD acts via altering release of an endothelial-derived vasodilator or vasoconstrictor. When nitric oxide synthase was blocked by pre-incubation of arteries with L-NAME (250 µM) the contraction of arteries to 20 K/Bay K was enhanced, and this effect was abolished by pre-treatment with M-β-CD. This suggests M-β-CD is inhibiting endothelial NO release. Inhibition of large conductance voltage- and Ca(2+)-activated (BKCa) channels with 2 mM TEA(+) or 100 nM Iberiotoxin (IbTX) enhanced 20 K/Bay K contractions. L-NAME attenuated the contractile effect of IbTX, as did endothelial removal. Conclusions. Our results suggest caveolar disruption results in decreased release of endothelial-derived nitric oxide in rat femoral artery, resulting in a reduced contribution of BKCa channels to the smooth muscle cell membrane potential, causing depolarisation and contraction.
Collapse
Affiliation(s)
- AY Al-Brakati
- Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Liverpool, UK
| | - T Kamishima
- Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Liverpool, UK
| | - C Dart
- Department of Biochemistry and Cell Biology, Institute of Integrative Biology, University of Liverpool, Liverpool, UK
| | - JM Quayle
- Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Liverpool, UK
| |
Collapse
|
21
|
van Unen J, Woolard J, Rinken A, Hoffmann C, Hill SJ, Goedhart J, Bruchas MR, Bouvier M, Adjobo-Hermans MJW. A Perspective on Studying G-Protein-Coupled Receptor Signaling with Resonance Energy Transfer Biosensors in Living Organisms. Mol Pharmacol 2015; 88:589-95. [PMID: 25972446 DOI: 10.1124/mol.115.098897] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Accepted: 05/13/2015] [Indexed: 01/09/2023] Open
Abstract
The last frontier for a complete understanding of G-protein-coupled receptor (GPCR) biology is to be able to assess GPCR activity, interactions, and signaling in vivo, in real time within biologically intact systems. This includes the ability to detect GPCR activity, trafficking, dimerization, protein-protein interactions, second messenger production, and downstream signaling events with high spatial resolution and fast kinetic readouts. Resonance energy transfer (RET)-based biosensors allow for all of these possibilities in vitro and in cell-based assays, but moving RET into intact animals has proven difficult. Here, we provide perspectives on the optimization of biosensor design, of signal detection in living organisms, and the multidisciplinary development of in vitro and cell-based assays that more appropriately reflect the physiologic situation. In short, further development of RET-based probes, optical microscopy techniques, and mouse genome editing hold great potential over the next decade to bring real-time in vivo GPCR imaging to the forefront of pharmacology.
Collapse
Affiliation(s)
- Jakobus van Unen
- Department of Biochemistry, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands (M.J.W.A.-H.); Department of Biochemistry, Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, Quebec, Canada (M.B.); Department of Anesthesiology, Washington University, St. Louis, Missouri (M.R.B.); Swammerdam Institute for Life Sciences, Section of Molecular Cytology, van Leeuwenhoek Centre for Advanced Microscopy, University of Amsterdam, Amsterdam, The Netherlands (J.U., J.G.); Cell Signalling Research Group, School of Biomedical Sciences, Medical School, Queen's Medical Centre, University of Nottingham, Nottingham, United Kingdom (J.W., S.J.H.); Bio-Imaging-Center/Rudolf-Virchow-Zentrum and Institute of Pharmacology and Toxicology, University of Würzburg, Würzburg, Germany (C.H.); and Institute of Chemistry, University of Tartu, Tartu, Estonia (A.R.)
| | - Jeanette Woolard
- Department of Biochemistry, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands (M.J.W.A.-H.); Department of Biochemistry, Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, Quebec, Canada (M.B.); Department of Anesthesiology, Washington University, St. Louis, Missouri (M.R.B.); Swammerdam Institute for Life Sciences, Section of Molecular Cytology, van Leeuwenhoek Centre for Advanced Microscopy, University of Amsterdam, Amsterdam, The Netherlands (J.U., J.G.); Cell Signalling Research Group, School of Biomedical Sciences, Medical School, Queen's Medical Centre, University of Nottingham, Nottingham, United Kingdom (J.W., S.J.H.); Bio-Imaging-Center/Rudolf-Virchow-Zentrum and Institute of Pharmacology and Toxicology, University of Würzburg, Würzburg, Germany (C.H.); and Institute of Chemistry, University of Tartu, Tartu, Estonia (A.R.)
| | - Ago Rinken
- Department of Biochemistry, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands (M.J.W.A.-H.); Department of Biochemistry, Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, Quebec, Canada (M.B.); Department of Anesthesiology, Washington University, St. Louis, Missouri (M.R.B.); Swammerdam Institute for Life Sciences, Section of Molecular Cytology, van Leeuwenhoek Centre for Advanced Microscopy, University of Amsterdam, Amsterdam, The Netherlands (J.U., J.G.); Cell Signalling Research Group, School of Biomedical Sciences, Medical School, Queen's Medical Centre, University of Nottingham, Nottingham, United Kingdom (J.W., S.J.H.); Bio-Imaging-Center/Rudolf-Virchow-Zentrum and Institute of Pharmacology and Toxicology, University of Würzburg, Würzburg, Germany (C.H.); and Institute of Chemistry, University of Tartu, Tartu, Estonia (A.R.)
| | - Carsten Hoffmann
- Department of Biochemistry, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands (M.J.W.A.-H.); Department of Biochemistry, Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, Quebec, Canada (M.B.); Department of Anesthesiology, Washington University, St. Louis, Missouri (M.R.B.); Swammerdam Institute for Life Sciences, Section of Molecular Cytology, van Leeuwenhoek Centre for Advanced Microscopy, University of Amsterdam, Amsterdam, The Netherlands (J.U., J.G.); Cell Signalling Research Group, School of Biomedical Sciences, Medical School, Queen's Medical Centre, University of Nottingham, Nottingham, United Kingdom (J.W., S.J.H.); Bio-Imaging-Center/Rudolf-Virchow-Zentrum and Institute of Pharmacology and Toxicology, University of Würzburg, Würzburg, Germany (C.H.); and Institute of Chemistry, University of Tartu, Tartu, Estonia (A.R.)
| | - Stephen J Hill
- Department of Biochemistry, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands (M.J.W.A.-H.); Department of Biochemistry, Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, Quebec, Canada (M.B.); Department of Anesthesiology, Washington University, St. Louis, Missouri (M.R.B.); Swammerdam Institute for Life Sciences, Section of Molecular Cytology, van Leeuwenhoek Centre for Advanced Microscopy, University of Amsterdam, Amsterdam, The Netherlands (J.U., J.G.); Cell Signalling Research Group, School of Biomedical Sciences, Medical School, Queen's Medical Centre, University of Nottingham, Nottingham, United Kingdom (J.W., S.J.H.); Bio-Imaging-Center/Rudolf-Virchow-Zentrum and Institute of Pharmacology and Toxicology, University of Würzburg, Würzburg, Germany (C.H.); and Institute of Chemistry, University of Tartu, Tartu, Estonia (A.R.)
| | - Joachim Goedhart
- Department of Biochemistry, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands (M.J.W.A.-H.); Department of Biochemistry, Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, Quebec, Canada (M.B.); Department of Anesthesiology, Washington University, St. Louis, Missouri (M.R.B.); Swammerdam Institute for Life Sciences, Section of Molecular Cytology, van Leeuwenhoek Centre for Advanced Microscopy, University of Amsterdam, Amsterdam, The Netherlands (J.U., J.G.); Cell Signalling Research Group, School of Biomedical Sciences, Medical School, Queen's Medical Centre, University of Nottingham, Nottingham, United Kingdom (J.W., S.J.H.); Bio-Imaging-Center/Rudolf-Virchow-Zentrum and Institute of Pharmacology and Toxicology, University of Würzburg, Würzburg, Germany (C.H.); and Institute of Chemistry, University of Tartu, Tartu, Estonia (A.R.)
| | - Michael R Bruchas
- Department of Biochemistry, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands (M.J.W.A.-H.); Department of Biochemistry, Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, Quebec, Canada (M.B.); Department of Anesthesiology, Washington University, St. Louis, Missouri (M.R.B.); Swammerdam Institute for Life Sciences, Section of Molecular Cytology, van Leeuwenhoek Centre for Advanced Microscopy, University of Amsterdam, Amsterdam, The Netherlands (J.U., J.G.); Cell Signalling Research Group, School of Biomedical Sciences, Medical School, Queen's Medical Centre, University of Nottingham, Nottingham, United Kingdom (J.W., S.J.H.); Bio-Imaging-Center/Rudolf-Virchow-Zentrum and Institute of Pharmacology and Toxicology, University of Würzburg, Würzburg, Germany (C.H.); and Institute of Chemistry, University of Tartu, Tartu, Estonia (A.R.)
| | - Michel Bouvier
- Department of Biochemistry, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands (M.J.W.A.-H.); Department of Biochemistry, Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, Quebec, Canada (M.B.); Department of Anesthesiology, Washington University, St. Louis, Missouri (M.R.B.); Swammerdam Institute for Life Sciences, Section of Molecular Cytology, van Leeuwenhoek Centre for Advanced Microscopy, University of Amsterdam, Amsterdam, The Netherlands (J.U., J.G.); Cell Signalling Research Group, School of Biomedical Sciences, Medical School, Queen's Medical Centre, University of Nottingham, Nottingham, United Kingdom (J.W., S.J.H.); Bio-Imaging-Center/Rudolf-Virchow-Zentrum and Institute of Pharmacology and Toxicology, University of Würzburg, Würzburg, Germany (C.H.); and Institute of Chemistry, University of Tartu, Tartu, Estonia (A.R.)
| | - Merel J W Adjobo-Hermans
- Department of Biochemistry, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands (M.J.W.A.-H.); Department of Biochemistry, Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, Quebec, Canada (M.B.); Department of Anesthesiology, Washington University, St. Louis, Missouri (M.R.B.); Swammerdam Institute for Life Sciences, Section of Molecular Cytology, van Leeuwenhoek Centre for Advanced Microscopy, University of Amsterdam, Amsterdam, The Netherlands (J.U., J.G.); Cell Signalling Research Group, School of Biomedical Sciences, Medical School, Queen's Medical Centre, University of Nottingham, Nottingham, United Kingdom (J.W., S.J.H.); Bio-Imaging-Center/Rudolf-Virchow-Zentrum and Institute of Pharmacology and Toxicology, University of Würzburg, Würzburg, Germany (C.H.); and Institute of Chemistry, University of Tartu, Tartu, Estonia (A.R.)
| |
Collapse
|
22
|
Qi XY, Huang H, Ordog B, Luo X, Naud P, Sun Y, Wu CT, Dawson K, Tadevosyan A, Chen Y, Harada M, Dobrev D, Nattel S. Fibroblast Inward-Rectifier Potassium Current Upregulation in Profibrillatory Atrial Remodeling. Circ Res 2015; 116:836-45. [DOI: 10.1161/circresaha.116.305326] [Citation(s) in RCA: 69] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Rationale:
Fibroblasts are involved in cardiac arrhythmogenesis and contribute to the atrial fibrillation substrate in congestive heart failure (CHF) by generating tissue fibrosis. Fibroblasts display robust ion currents, but their functional importance is poorly understood.
Objective:
To characterize atrial fibroblast inward-rectifier K
+
current (
I
K1
) remodeling in CHF and its effects on fibroblast properties.
Methods and Results:
Freshly isolated left atrial fibroblasts were obtained from controls and dogs with CHF (ventricular tachypacing). Patch clamp was used to record resting membrane potential (RMP) and
I
K1
. RMP was significantly increased by CHF (from −43.2±0.8 mV, control, to −55.5±0.9 mV). CHF upregulated
I
K1
(eg, at −90 mV from −1.1±0.2 to −2.7±0.5 pA/pF) and increased the expression of KCNJ2 mRNA (by 52%) and protein (by 80%). Ba
2+
(300 μmol/L) decreased the RMP and suppressed the RMP difference between controls and dogs with CHF. Store-operated Ca
2+
entry (Fura-2-acetoxymethyl ester) and fibroblast proliferation (flow cytometry) were enhanced by CHF. Lentivirus-mediated overexpression of KCNJ2 enhanced
I
K1
and hyperpolarized fibroblasts. Functional KCNJ2 suppression by lentivirus-mediated expression of a dominant negative KCNJ2 construct suppressed
I
K1
and depolarized RMP. Overexpression of KCNJ2 increased Ca
2+
entry and fibroblast proliferation, whereas the dominant negative KCNJ2 construct had opposite effects. Fibroblast hyperpolarization to mimic CHF effects on RMP enhanced the Ca
2+
entry. MicroRNA-26a, which targets KCNJ2, was downregulated in CHF fibroblasts. Knockdown of endogenous microRNA-26 to mimic CHF effects unregulated
I
K1
.
Conclusions:
CHF upregulates fibroblast KCNJ2 expression and currents, thereby hyperpolarizing RMP, increasing Ca
2+
entry, and enhancing atrial fibroblast proliferation. These effects are likely mediated by microRNA-26a downregulation. Remodeling-induced fibroblast KCNJ2 expression changes may play a role in atrial fibrillation promoting fibroblast remodeling and structural/arrhythmic consequences.
Collapse
Affiliation(s)
- Xiao-Yan Qi
- From the Research Center and Department of Medicine, Montreal Heart Institute, Université de Montréal, Montreal, Quebec, Canada (X.-Y.Q., H.H., B.O., X.L., P.N., Y.S., C.-T.W., K.D., A.T., Y.C., M.H., S.N.); Department of Pharmacology and Therapeutics, McGill University, Montreal, Quebec, Canada (K.D., Y.C.); Department of Cardiology, Chang-Gung Memorial Hospital and University, Taoyuan, Taiwan, Republic of China (C.T.W., S.N.); Department of Cardiology, Fujita Health University School of Medicine,
| | - Hai Huang
- From the Research Center and Department of Medicine, Montreal Heart Institute, Université de Montréal, Montreal, Quebec, Canada (X.-Y.Q., H.H., B.O., X.L., P.N., Y.S., C.-T.W., K.D., A.T., Y.C., M.H., S.N.); Department of Pharmacology and Therapeutics, McGill University, Montreal, Quebec, Canada (K.D., Y.C.); Department of Cardiology, Chang-Gung Memorial Hospital and University, Taoyuan, Taiwan, Republic of China (C.T.W., S.N.); Department of Cardiology, Fujita Health University School of Medicine,
| | - Balazs Ordog
- From the Research Center and Department of Medicine, Montreal Heart Institute, Université de Montréal, Montreal, Quebec, Canada (X.-Y.Q., H.H., B.O., X.L., P.N., Y.S., C.-T.W., K.D., A.T., Y.C., M.H., S.N.); Department of Pharmacology and Therapeutics, McGill University, Montreal, Quebec, Canada (K.D., Y.C.); Department of Cardiology, Chang-Gung Memorial Hospital and University, Taoyuan, Taiwan, Republic of China (C.T.W., S.N.); Department of Cardiology, Fujita Health University School of Medicine,
| | - Xiaobin Luo
- From the Research Center and Department of Medicine, Montreal Heart Institute, Université de Montréal, Montreal, Quebec, Canada (X.-Y.Q., H.H., B.O., X.L., P.N., Y.S., C.-T.W., K.D., A.T., Y.C., M.H., S.N.); Department of Pharmacology and Therapeutics, McGill University, Montreal, Quebec, Canada (K.D., Y.C.); Department of Cardiology, Chang-Gung Memorial Hospital and University, Taoyuan, Taiwan, Republic of China (C.T.W., S.N.); Department of Cardiology, Fujita Health University School of Medicine,
| | - Patrice Naud
- From the Research Center and Department of Medicine, Montreal Heart Institute, Université de Montréal, Montreal, Quebec, Canada (X.-Y.Q., H.H., B.O., X.L., P.N., Y.S., C.-T.W., K.D., A.T., Y.C., M.H., S.N.); Department of Pharmacology and Therapeutics, McGill University, Montreal, Quebec, Canada (K.D., Y.C.); Department of Cardiology, Chang-Gung Memorial Hospital and University, Taoyuan, Taiwan, Republic of China (C.T.W., S.N.); Department of Cardiology, Fujita Health University School of Medicine,
| | - Yiguo Sun
- From the Research Center and Department of Medicine, Montreal Heart Institute, Université de Montréal, Montreal, Quebec, Canada (X.-Y.Q., H.H., B.O., X.L., P.N., Y.S., C.-T.W., K.D., A.T., Y.C., M.H., S.N.); Department of Pharmacology and Therapeutics, McGill University, Montreal, Quebec, Canada (K.D., Y.C.); Department of Cardiology, Chang-Gung Memorial Hospital and University, Taoyuan, Taiwan, Republic of China (C.T.W., S.N.); Department of Cardiology, Fujita Health University School of Medicine,
| | - Chia-Tung Wu
- From the Research Center and Department of Medicine, Montreal Heart Institute, Université de Montréal, Montreal, Quebec, Canada (X.-Y.Q., H.H., B.O., X.L., P.N., Y.S., C.-T.W., K.D., A.T., Y.C., M.H., S.N.); Department of Pharmacology and Therapeutics, McGill University, Montreal, Quebec, Canada (K.D., Y.C.); Department of Cardiology, Chang-Gung Memorial Hospital and University, Taoyuan, Taiwan, Republic of China (C.T.W., S.N.); Department of Cardiology, Fujita Health University School of Medicine,
| | - Kristin Dawson
- From the Research Center and Department of Medicine, Montreal Heart Institute, Université de Montréal, Montreal, Quebec, Canada (X.-Y.Q., H.H., B.O., X.L., P.N., Y.S., C.-T.W., K.D., A.T., Y.C., M.H., S.N.); Department of Pharmacology and Therapeutics, McGill University, Montreal, Quebec, Canada (K.D., Y.C.); Department of Cardiology, Chang-Gung Memorial Hospital and University, Taoyuan, Taiwan, Republic of China (C.T.W., S.N.); Department of Cardiology, Fujita Health University School of Medicine,
| | - Artavazd Tadevosyan
- From the Research Center and Department of Medicine, Montreal Heart Institute, Université de Montréal, Montreal, Quebec, Canada (X.-Y.Q., H.H., B.O., X.L., P.N., Y.S., C.-T.W., K.D., A.T., Y.C., M.H., S.N.); Department of Pharmacology and Therapeutics, McGill University, Montreal, Quebec, Canada (K.D., Y.C.); Department of Cardiology, Chang-Gung Memorial Hospital and University, Taoyuan, Taiwan, Republic of China (C.T.W., S.N.); Department of Cardiology, Fujita Health University School of Medicine,
| | - Yu Chen
- From the Research Center and Department of Medicine, Montreal Heart Institute, Université de Montréal, Montreal, Quebec, Canada (X.-Y.Q., H.H., B.O., X.L., P.N., Y.S., C.-T.W., K.D., A.T., Y.C., M.H., S.N.); Department of Pharmacology and Therapeutics, McGill University, Montreal, Quebec, Canada (K.D., Y.C.); Department of Cardiology, Chang-Gung Memorial Hospital and University, Taoyuan, Taiwan, Republic of China (C.T.W., S.N.); Department of Cardiology, Fujita Health University School of Medicine,
| | - Masahide Harada
- From the Research Center and Department of Medicine, Montreal Heart Institute, Université de Montréal, Montreal, Quebec, Canada (X.-Y.Q., H.H., B.O., X.L., P.N., Y.S., C.-T.W., K.D., A.T., Y.C., M.H., S.N.); Department of Pharmacology and Therapeutics, McGill University, Montreal, Quebec, Canada (K.D., Y.C.); Department of Cardiology, Chang-Gung Memorial Hospital and University, Taoyuan, Taiwan, Republic of China (C.T.W., S.N.); Department of Cardiology, Fujita Health University School of Medicine,
| | - Dobromir Dobrev
- From the Research Center and Department of Medicine, Montreal Heart Institute, Université de Montréal, Montreal, Quebec, Canada (X.-Y.Q., H.H., B.O., X.L., P.N., Y.S., C.-T.W., K.D., A.T., Y.C., M.H., S.N.); Department of Pharmacology and Therapeutics, McGill University, Montreal, Quebec, Canada (K.D., Y.C.); Department of Cardiology, Chang-Gung Memorial Hospital and University, Taoyuan, Taiwan, Republic of China (C.T.W., S.N.); Department of Cardiology, Fujita Health University School of Medicine,
| | - Stanley Nattel
- From the Research Center and Department of Medicine, Montreal Heart Institute, Université de Montréal, Montreal, Quebec, Canada (X.-Y.Q., H.H., B.O., X.L., P.N., Y.S., C.-T.W., K.D., A.T., Y.C., M.H., S.N.); Department of Pharmacology and Therapeutics, McGill University, Montreal, Quebec, Canada (K.D., Y.C.); Department of Cardiology, Chang-Gung Memorial Hospital and University, Taoyuan, Taiwan, Republic of China (C.T.W., S.N.); Department of Cardiology, Fujita Health University School of Medicine,
| |
Collapse
|