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Nanoscale coupling of junctophilin-2 and ryanodine receptors regulates vascular smooth muscle cell contractility. Proc Natl Acad Sci U S A 2019; 116:21874-21881. [PMID: 31591206 PMCID: PMC6815135 DOI: 10.1073/pnas.1911304116] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Junctophilin proteins maintain close contacts between the endoplasmic/sarcoplasmic reticulum (ER/SR) and the plasma membrane in many types of cells, as typified by junctophilin-2 (JPH2), which is necessary for the formation of the cardiac dyad. Here, we report that JPH2 is the most abundant junctophilin isotype in native smooth muscle cells (SMCs) isolated from cerebral arteries and that acute knockdown diminishes the area of sites of interaction between the SR and plasma membrane. Superresolution microscopy revealed nanometer-scale colocalization of JPH2 clusters with type 2 ryanodine receptor (RyR2) clusters near the cell surface. Knockdown of JPH2 had no effect on the frequency, amplitude, or kinetics of spontaneous Ca2+ sparks generated by transient release of Ca2+ from the SR through RyR2s, but it did nearly abolish Ca2+ spark-activated, large-conductance, Ca2+-activated K+ (BK) channel currents. We also found that JPH2 knockdown was associated with hypercontractility of intact cerebral arteries. We conclude that JPH2 maintains functional coupling between RyR2s and BK channels and is critically important for cerebral arterial function.
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Khan A, Kamran S, Akhtar N, Ponirakis G, Al-Muhannadi H, Petropoulos IN, Al-Fahdawi S, Qahwaji R, Sartaj F, Babu B, Wadiwala MF, Shuaib A, Malik RA. Corneal Confocal Microscopy detects a Reduction in Corneal Endothelial Cells and Nerve Fibres in Patients with Acute Ischemic Stroke. Sci Rep 2018; 8:17333. [PMID: 30478334 PMCID: PMC6255787 DOI: 10.1038/s41598-018-35298-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Accepted: 10/23/2018] [Indexed: 12/25/2022] Open
Abstract
Endothelial dysfunction and damage underlie cerebrovascular disease and ischemic stroke. We undertook corneal confocal microscopy (CCM) to quantify corneal endothelial cell and nerve morphology in 146 patients with an acute ischemic stroke and 18 age-matched healthy control participants. Corneal endothelial cell density was lower (P < 0.001) and endothelial cell area (P < 0.001) and perimeter (P < 0.001) were higher, whilst corneal nerve fibre density (P < 0.001), corneal nerve branch density (P < 0.001) and corneal nerve fibre length (P = 0.001) were lower in patients with acute ischemic stroke compared to controls. Corneal endothelial cell density, cell area and cell perimeter correlated with corneal nerve fiber density (P = 0.033, P = 0.014, P = 0.011) and length (P = 0.017, P = 0.013, P = 0.008), respectively. Multiple linear regression analysis showed a significant independent association between corneal endothelial cell density, area and perimeter with acute ischemic stroke and triglycerides. CCM is a rapid non-invasive ophthalmic imaging technique, which could be used to identify patients at risk of acute ischemic stroke.
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Affiliation(s)
- Adnan Khan
- Department of Medicine, Weill Cornell Medicine-Qatar, Doha, Qatar
| | - Saadat Kamran
- Department of Neurology and Institute of Neurosciences, Hamad Medical Corporation, Doha, Qatar
| | - Naveed Akhtar
- Department of Neurology and Institute of Neurosciences, Hamad Medical Corporation, Doha, Qatar
| | | | | | | | - Shumoos Al-Fahdawi
- School of Electrical Engineering and Computer Science, University of Bradford, Bradford, UK
| | - Rami Qahwaji
- School of Electrical Engineering and Computer Science, University of Bradford, Bradford, UK
| | - Faheem Sartaj
- Department of Neurology and Institute of Neurosciences, Hamad Medical Corporation, Doha, Qatar
| | - Blessy Babu
- Department of Neurology and Institute of Neurosciences, Hamad Medical Corporation, Doha, Qatar
| | | | - Ashfaq Shuaib
- Department of Neurology and Institute of Neurosciences, Hamad Medical Corporation, Doha, Qatar
- Stroke Program, Department of Neurology, University of Alberta, Edmonton, Canada
| | - Rayaz A Malik
- Department of Medicine, Weill Cornell Medicine-Qatar, Doha, Qatar.
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Bokslag A, Franssen C, Alma LJ, Kovacevic I, van Kesteren F, Teunissen PW, Kamp O, Ganzevoort W, Hordijk PL, de Groot CJM, Paulus WJ. Early-onset preeclampsia predisposes to preclinical diastolic left ventricular dysfunction in the fifth decade of life: An observational study. PLoS One 2018; 13:e0198908. [PMID: 29894501 PMCID: PMC5997308 DOI: 10.1371/journal.pone.0198908] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Accepted: 05/29/2018] [Indexed: 12/11/2022] Open
Abstract
Background Systemic inflammation, endothelial dysfunction and deficient vascularization of either uterus or myocardium are mechanistic hallmarks of early-onset preeclampsia and heart failure with preserved ejection fraction (HFpEF). HFpEF is especially prevalent in elderly women and preceded in middle age by preclinical left ventricular (LV) diastolic dysfunction. To detect if preeclampsia predisposes to HFpEF at later age, echocardiographic indices of LV function and of LV structure and biomarkers of systemic inflammation and of endothelial dysfunction were compared in middle-aged women with a history of early-onset preeclampsia or uncomplicated pregnancy. Methods and findings Middle-aged women with a history of early-onset preeclampsia (n = 131) or uncomplicated pregnancy (n = 56) were prospectively recruited 9 to 16 years after pregnancy. Women with a history of preeclampsia had higher body mass index (p = 0.006), blood pressure (p<0.001) and plasma levels of interleukin-6 (p = 0.005) and soluble intercellular adhesion molecule-1 (sICAM-1) (p = 0.014). They had thicker septal (p = 0.001) and posterior (p = 0.003) LV walls and worse diastolic LV function evident from reduced mean mitral annular lengthening velocity (E’mean; p = 0.007) and higher ratio of early diastolic mitral flow velocity (E) over E’mean (E/E’mean; p<0.001). Differences of sICAM-1, E’mean and E/E’mean remained significant after accounting for BMI and blood pressure. Conclusions History of preeclampsia predisposes in middle age to worse LV diastolic function, which could increase the likelihood of later HFpEF development. This predisposition derives not only from persistent cardiovascular risk but may also be caused by persistent endothelial dysfunction hindering adequate vascularization in the uterus during pregnancy and in the myocardium in middle age.
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Affiliation(s)
- Anouk Bokslag
- Department of Obstetrics and Gynaecology, Amsterdam Cardiovascular Sciences, VU University Medical Center, Amsterdam, The Netherlands
| | - Constantijn Franssen
- Department of Physiology, Amsterdam Cardiovascular Sciences, VU University Medical Center, Amsterdam, The Netherlands
- Department of Cardiology, Antwerp University Hospital, Antwerp, Belgium
| | - Lisa J. Alma
- Department of Obstetrics and Gynaecology, Amsterdam Cardiovascular Sciences, VU University Medical Center, Amsterdam, The Netherlands
- Department of Physiology, Amsterdam Cardiovascular Sciences, VU University Medical Center, Amsterdam, The Netherlands
| | - Igor Kovacevic
- Department of Physiology, Amsterdam Cardiovascular Sciences, VU University Medical Center, Amsterdam, The Netherlands
| | - Floortje van Kesteren
- Department of Obstetrics and Gynaecology, Amsterdam Cardiovascular Sciences, VU University Medical Center, Amsterdam, The Netherlands
| | - Pim W. Teunissen
- Department of Obstetrics and Gynaecology, Amsterdam Cardiovascular Sciences, VU University Medical Center, Amsterdam, The Netherlands
- Department of Educational Development and Research, Faculty of Health, Medicine and Life Sciences, Maastricht University, Maastricht, The Netherlands
| | - Otto Kamp
- Department of Cardiology, Amsterdam Cardiovascular Sciences, VU University Medical Center, Amsterdam, The Netherlands
| | - Wessel Ganzevoort
- Department of Obstetrics and Gynaecology, Academic Medical Center, Amsterdam, The Netherlands
| | - Peter L. Hordijk
- Department of Physiology, Amsterdam Cardiovascular Sciences, VU University Medical Center, Amsterdam, The Netherlands
| | - Christianne J. M. de Groot
- Department of Obstetrics and Gynaecology, Amsterdam Cardiovascular Sciences, VU University Medical Center, Amsterdam, The Netherlands
| | - Walter J. Paulus
- Department of Physiology, Amsterdam Cardiovascular Sciences, VU University Medical Center, Amsterdam, The Netherlands
- * E-mail:
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Obert P, Walther G, Dutheil F, Lesourd B, Chapier R, Courteix D, Vinet A. Regional myocardial function abnormalities are associated with macro- and microcirculation dysfunction in the metabolic syndrome: the RESOLVE study. Heart Vessels 2018; 33:688-694. [PMID: 29352759 DOI: 10.1007/s00380-017-1108-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Accepted: 12/15/2017] [Indexed: 12/16/2022]
Abstract
Abnormalities in myocardial and vascular function have been reported in the metabolic syndrome (MetS), but whether these alterations are related remains poorly documented. Our aim was accordingly to investigate interrelationships between macro- and microcirculatory vasoreactivity and left ventricular (LV) myocardial function in MetS patients. Eighty-eight MetS individuals and 44 age- and gender-matched healthy controls were enrolled. LV global longitudinal strain (GLS) was measured using Vector Velocity Imaging. Endothelial-dependent and independent reactivity in macro- and microcirculatory territories was established using flow-mediated dilation and nitrate-mediated dilation of the brachial artery and cutaneous blood flow measured with laser Doppler flowmetry in response to iontophoresis of acetylcholine and sodium nitroprusside, respectively. Carotid intima-media thickness (cIMT) was measured according to the Mannheim consensus. Compared to controls, MetS patients presented with reduced GLS (p < 0.001) increased cIMT and impaired (p < 0.001) endothelial and smooth muscle function of the brachial artery and the forearm skin microcirculation. Highly significant relationships (p < 0.01) were noticed between GLS and vascular outcomes. In addition, cIMT (β = 0.21, p = 0.024) and microcirculatory endothelium-dependent reactivity (β = - 0.20, p = 0.035) were identified as independent predictors of GLS. In MetS, abnormalities in myocardial function and endothelial as well as smooth muscle function of small and large arteries co-exist and are closely associated. This study supports a role for microvascular dysfunction in the pathogenesis of LV myocardial dysfunction.
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Affiliation(s)
- Philippe Obert
- LAPEC EA4278, Faculty of Sciences, University of Avignon, 301 rue Baruch de Spinoza, 84916, Avignon Cedex 9, France.
- School of Exercise Science, Australian Catholic University, Melbourne, Australia.
| | - Guillaume Walther
- LAPEC EA4278, Faculty of Sciences, University of Avignon, 301 rue Baruch de Spinoza, 84916, Avignon Cedex 9, France
| | - Frédéric Dutheil
- School of Exercise Science, Australian Catholic University, Melbourne, Australia
- Laboratory of Metabolic Adaptations to Exercise in Physiological and Pathological Conditions (AME2P), EA3533, Blaise Pascal University, Clermont-Ferrand, France
- University Hospital of Clermont-Ferrand CHU, Clermont-Ferrand, France
| | - Bruno Lesourd
- Laboratory of Metabolic Adaptations to Exercise in Physiological and Pathological Conditions (AME2P), EA3533, Blaise Pascal University, Clermont-Ferrand, France
- University Hospital of Clermont-Ferrand CHU, Clermont-Ferrand, France
| | | | - Daniel Courteix
- School of Exercise Science, Australian Catholic University, Melbourne, Australia
- Laboratory of Metabolic Adaptations to Exercise in Physiological and Pathological Conditions (AME2P), EA3533, Blaise Pascal University, Clermont-Ferrand, France
| | - Agnes Vinet
- LAPEC EA4278, Faculty of Sciences, University of Avignon, 301 rue Baruch de Spinoza, 84916, Avignon Cedex 9, France
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