1
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Scheede-Bergdahl C, Bergdahl A. Adaptation of mitochondrial expression and ATP production in dedifferentiating vascular smooth muscle cells. Can J Physiol Pharmacol 2017; 95:1473-1479. [PMID: 28846852 DOI: 10.1139/cjpp-2017-0227] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Atherosclerosis is one of the leading causes of morbidity and mortality in the Western world. Although the clinical manifestations of this disease are well documented, the etiology and progression remain to be fully understood. Recently, the mitochondria have been implicated in important cellular processes involved in development of atherosclerosis. Despite the link between mitochondria and atherosclerosis, early-phase mechanisms of the disease have yet to be elucidated. The aim of this project was to explore the role of mitochondria in vascular smooth muscle (VSMC) dedifferentiation. A murine in vitro model, involving organ culture of aortic tissue in serum-free media, was used. Mitochondrial function was measured by high-resolution respirometry. Proteins associated with the VSMC phenotype switch, as well as mitochondrial density, were assessed by immunoblotting. The findings show that intrinsic mitochondrial Complex I activity is significantly upregulated during VSMC dedifferentiation. Diminished coupling between phosphorylation and oxidation was also found, indicating a greater ADP:ATP ratio. This data suggests increased leak in the electron transport chain and altered mitochondrial function specifically at Complex I. This project provides important information regarding the role of mitochondria in the early atherosclerotic process and that detectable changes in mitochondrial function and expression are related to VSMC dedifferentiation.
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Affiliation(s)
- Celena Scheede-Bergdahl
- a Department of Kinesiology & Physical Education, McGill University, Montreal, QC H2W 1S4, Canada.,b McGill Research Centre for Physical Activity & Health, McGill University, Montreal, QC H2W 1S4, Canada
| | - Andreas Bergdahl
- c Department of Exercise Science, Concordia University, Montreal, QC H4B 1R6, Canada
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2
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Berglund LM, Lyssenko V, Ladenvall C, Kotova O, Edsfeldt A, Pilgaard K, Alkayyali S, Brøns C, Forsblom C, Jonsson A, Zetterqvist AV, Nitulescu M, McDavitt CR, Dunér P, Stancáková A, Kuusisto J, Ahlqvist E, Lajer M, Tarnow L, Madsbad S, Rossing P, Kieffer TJ, Melander O, Orho-Melander M, Nilsson P, Groop PH, Vaag A, Lindblad B, Gottsäter A, Laakso M, Goncalves I, Groop L, Gomez MF. Glucose-Dependent Insulinotropic Polypeptide Stimulates Osteopontin Expression in the Vasculature via Endothelin-1 and CREB. Diabetes 2016; 65:239-54. [PMID: 26395740 DOI: 10.2337/db15-0122] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/26/2015] [Accepted: 09/10/2015] [Indexed: 11/13/2022]
Abstract
Glucose-dependent insulinotropic polypeptide (GIP) is an incretin hormone with extrapancreatic effects beyond glycemic control. Here we demonstrate unexpected effects of GIP signaling in the vasculature. GIP induces the expression of the proatherogenic cytokine osteopontin (OPN) in mouse arteries via local release of endothelin-1 and activation of CREB. Infusion of GIP increases plasma OPN concentrations in healthy individuals. Plasma endothelin-1 and OPN concentrations are positively correlated in patients with critical limb ischemia. Fasting GIP concentrations are higher in individuals with a history of cardiovascular disease (myocardial infarction, stroke) when compared with control subjects. GIP receptor (GIPR) and OPN mRNA levels are higher in carotid endarterectomies from patients with symptoms (stroke, transient ischemic attacks, amaurosis fugax) than in asymptomatic patients, and expression associates with parameters that are characteristic of unstable and inflammatory plaques (increased lipid accumulation, macrophage infiltration, and reduced smooth muscle cell content). While GIPR expression is predominantly endothelial in healthy arteries from humans, mice, rats, and pigs, remarkable upregulation is observed in endothelial and smooth muscle cells upon culture conditions, yielding a "vascular disease-like" phenotype. Moreover, the common variant rs10423928 in the GIPR gene is associated with increased risk of stroke in patients with type 2 diabetes.
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MESH Headings
- Aged
- Aged, 80 and over
- Animals
- Aorta/cytology
- Blotting, Western
- Cardiovascular Diseases/genetics
- Carotid Arteries/cytology
- Case-Control Studies
- Coronary Vessels/cytology
- Cyclic AMP Response Element-Binding Protein/metabolism
- Diabetes Mellitus, Type 2/complications
- Diabetes Mellitus, Type 2/genetics
- Diabetes Mellitus, Type 2/metabolism
- Endothelial Cells/metabolism
- Endothelin-1/genetics
- Endothelin-1/metabolism
- Enzyme-Linked Immunosorbent Assay
- Female
- Fluorescent Antibody Technique
- Gastric Inhibitory Polypeptide/metabolism
- Humans
- Immunohistochemistry
- Male
- Mice
- Mice, Knockout
- Microscopy, Confocal
- Microvessels/cytology
- Middle Aged
- Myocytes, Smooth Muscle/metabolism
- Osteopontin/genetics
- Osteopontin/metabolism
- Peripheral Arterial Disease/metabolism
- Plaque, Atherosclerotic/metabolism
- Polymorphism, Single Nucleotide
- RNA, Messenger/metabolism
- Rats
- Rats, Inbred WKY
- Real-Time Polymerase Chain Reaction
- Receptors, Gastrointestinal Hormone/genetics
- Stroke/complications
- Stroke/genetics
- Stroke/metabolism
- Sus scrofa
- Swine
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Affiliation(s)
- Lisa M Berglund
- Department of Clinical Sciences, Lund University, Malmö, Sweden
| | - Valeriya Lyssenko
- Department of Clinical Sciences, Lund University, Malmö, Sweden Steno Diabetes Center A/S, Gentofte, Denmark
| | - Claes Ladenvall
- Department of Clinical Sciences, Lund University, Malmö, Sweden
| | - Olga Kotova
- Department of Clinical Sciences, Lund University, Malmö, Sweden
| | | | | | - Sami Alkayyali
- Department of Clinical Sciences, Lund University, Malmö, Sweden
| | | | - Carol Forsblom
- Folkhälsan Institute of Genetics, Folkhälsan Research Center, Biomedicum Helsinki, Helsinki, Finland Division of Nephrology, Department of Medicine, Helsinki University Central Hospital, Helsinki, Finland
| | - Anna Jonsson
- Department of Clinical Sciences, Lund University, Malmö, Sweden
| | | | | | | | - Pontus Dunér
- Department of Clinical Sciences, Lund University, Malmö, Sweden
| | - Alena Stancáková
- Department of Medicine, University of Eastern Finland, Kuopio University Hospital, Kuopio, Finland
| | - Johanna Kuusisto
- Department of Medicine, University of Eastern Finland, Kuopio University Hospital, Kuopio, Finland
| | - Emma Ahlqvist
- Department of Clinical Sciences, Lund University, Malmö, Sweden
| | - Maria Lajer
- Steno Diabetes Center A/S, Gentofte, Denmark
| | - Lise Tarnow
- Steno Diabetes Center A/S, Gentofte, Denmark HEALTH University of Aarhus, Aarhus, Denmark
| | - Sten Madsbad
- Department of Endocrinology, Hvidovre Hospital, University of Copenhagen, Copenhagen, Denmark
| | - Peter Rossing
- Steno Diabetes Center A/S, Gentofte, Denmark HEALTH University of Aarhus, Aarhus, Denmark NNF Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
| | - Timothy J Kieffer
- Department of Cellular and Physiological Sciences and Surgery, University of British Columbia, Vancouver, BC, Canada
| | - Olle Melander
- Department of Clinical Sciences, Lund University, Malmö, Sweden
| | | | - Peter Nilsson
- Department of Clinical Sciences, Lund University, Malmö, Sweden
| | - Per-Henrik Groop
- Folkhälsan Institute of Genetics, Folkhälsan Research Center, Biomedicum Helsinki, Helsinki, Finland Division of Nephrology, Department of Medicine, Helsinki University Central Hospital, Helsinki, Finland
| | - Allan Vaag
- Department of Clinical Sciences, Lund University, Malmö, Sweden Steno Diabetes Center A/S, Gentofte, Denmark Department of Endocrinology, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Bengt Lindblad
- Department of Clinical Sciences, Lund University, Malmö, Sweden
| | | | - Markku Laakso
- Department of Medicine, University of Eastern Finland, Kuopio University Hospital, Kuopio, Finland
| | - Isabel Goncalves
- Department of Cardiology, Skåne University Hospital, Malmö, Sweden
| | - Leif Groop
- Department of Clinical Sciences, Lund University, Malmö, Sweden
| | - Maria F Gomez
- Department of Clinical Sciences, Lund University, Malmö, Sweden
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3
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Mesenchymal stromal cells for sphincter regeneration. Adv Drug Deliv Rev 2015; 82-83:123-36. [PMID: 25451135 DOI: 10.1016/j.addr.2014.10.026] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2014] [Revised: 09/29/2014] [Accepted: 10/15/2014] [Indexed: 02/06/2023]
Abstract
Stress urinary incontinence (SUI), defined as the involuntary loss of considerable amounts of urine during increased abdominal pressure (exertion, effort, sneezing, coughing, etc.), is a severe problem to the individuals affected and a significant medical, social and economic challenge. SUI is associated with pelvic floor debility, absence of detrusor contraction, or a loss of control over the sphincter muscle apparatus. The pathology includes an increasing loss of muscle cells, replacement of muscular tissue with fibrous tissue, and general aging associated processes of the sphincter complex. When current therapies fail to cure or improve SUI, application of regeneration-competent cells may be an alternative therapeutic option. Here we discuss different aspects of the biology of mesenchymal stromal cells, which are relevant to their clinical applications and for regenerating the sphincter complex. However, there are reports in favor of and against cell-based therapies. We therefore summarize the potential and the risks of cell-based therapies for the treatment of SUI.
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Garín-Aguilar ME, Benavides-Catalán D, Segura Cobos D, Ramírez Sotelo G, Piña Guzmán AB, Valencia-Del Toro G. Spasmolytic effect of Alternanthera repens on isolated rat ileum. PHARMACEUTICAL BIOLOGY 2013; 52:479-485. [PMID: 24192401 DOI: 10.3109/13880209.2013.844716] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Abstract Context: Alternanthera repens (L.) Kuntze (Amaranthaceae) is widely used in Mexican traditional medicine for the treatment of gastrointestinal disorders that are mainly related to diarrhea. Objective: The aim of the present study was to investigate the spasmolytic effect of hexane (Hx), methanol (Me) and aqueous (Aq) extracts as well as chromatographic Me fractions (F1-F6) of A. repens in rat ileum. Materials and methods: Dried and powdered aerial parts were used to obtain the extracts. The rat ileum preparations were incubated in Tyrode's solution gassed (95% O2-5% CO2) at 37 °C. The effect on the contractile response of isolated ileum was evaluated by obtaining cumulative concentration-response curves to CaCl2, KCl, 5-HT and acetylcholine in the absence and presence of different doses of Aq (0.56-2.09 mg/mL), Me (0.24-0.91 mg/mL) and Hx (0.24-0.91 mg/mL) extracts, as well as six Me fractions of 0.66 mg/mL (F1 to F6). Results: The A. repens Me (0.24 mg/mL) caused an inhibitory response of the Ca2+-induced contractions, with IC50 values of 0.18 ± 0.061 and 0.67 ± 0.061 mM in the presence and absence of the Me, respectively. Me fractions F2 to F4 presented a significant inhibitory effect (F(3,8) = 60.17, p = 0.0001), causing a reduction in the CaCl2-induced contractions and shifting the Ca2+ (0.39 to 1.81 mM) concentration-response curves to the right. With respect to the effect on 5-HT-induced contractions, IC50 values Hx extract (0.24 mg/mL) were 5.44 ± 0.08 × 10-6 M and 3.38 ± 0.07 × 10-6 M in the presence and absence of the Hx, respectively. Discussion and conclusion: The spasmolytic effects induced by Me and Me fractions of A. repens may involve a serotonergic and Ca2+ influx blockade mechanisms, which may justify the use of A. repens extracts as an effective traditional treatment against diarrhea.
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Affiliation(s)
- María E Garín-Aguilar
- Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Los Reyes Iztacala , Tlalnepantla, Estado México , México and
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5
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Wang T, Kendig DM, Chang S, Trappanese DM, Chacko S, Moreland RS. Bladder smooth muscle organ culture preparation maintains the contractile phenotype. Am J Physiol Renal Physiol 2012; 303:F1382-97. [PMID: 22896042 PMCID: PMC3518193 DOI: 10.1152/ajprenal.00261.2011] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2011] [Accepted: 08/13/2012] [Indexed: 01/26/2023] Open
Abstract
Smooth muscle cells, when subjected to culture, modulate from a contractile to a secretory phenotype. This has hampered the use of cell culture for molecular techniques to study the regulation of smooth muscle biology. The goal of this study was to develop a new organ culture model of bladder smooth muscle (BSM) that would maintain the contractile phenotype and aid in the study of BSM biology. Our results showed that strips of BSM subjected to up to 9 days of organ culture maintained their contractile phenotype, including the ability to achieve near-control levels of force with a temporal profile similar to that of noncultured tissues. The technical aspects of our organ culture preparation that were responsible, in part, for the maintenance of the contractile phenotype were a slight longitudinal stretch during culture and subjection of the strips to daily contraction-relaxation. The tissues contained viable cells throughout the cross section of the strips. There was an increase in extracellular collagenous matrix, resulting in a leftward shift in the passive length-tension relationship. There were no significant changes in the content of smooth muscle-specific α-actin, calponin, h-caldesmon, total myosin heavy chain, protein kinase G, Rho kinase-I, or the ratio of SM1 to SM2 myosin isoforms. Moreover the organ cultured tissues maintained functional voltage-gated calcium channels and large-conductance calcium-activated potassium channels. Therefore, we propose that this novel BSM organ culture model maintains the contractile phenotype and will be a valuable tool for the use in cellular/molecular biology studies of bladder myocytes.
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Affiliation(s)
- Tanchun Wang
- Dept. of Pharmacology and Physiology, Drexel Univ. College of Medicine, 245 N 15th St., MS 488, Philadelphia, PA 19102, USA
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6
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Berglund LM, Kotova O, Osmark P, Grufman H, Xing C, Lydrup ML, Goncalves I, Autieri MV, Gomez MF. NFAT regulates the expression of AIF-1 and IRT-1: yin and yang splice variants of neointima formation and atherosclerosis. Cardiovasc Res 2011; 93:414-23. [PMID: 22116621 DOI: 10.1093/cvr/cvr309] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
AIMS Alternative transcription and splicing of the allograft inflammatory factor-1 (AIF-1) gene results in the expression of two different proteins: AIF-1 and interferon responsive transcript-1 (IRT-1). Here, we explore the impact of AIF-1 and IRT-1 on vascular smooth muscle cell (VSMC) activation and neointima formation, the mechanisms underlying their alternative splicing, and associations of AIF-1 and IRT-1 mRNA with parameters defining human atherosclerotic plaque phenotype. METHODS AND RESULTS Translation of AIF-1 and IRT-1 results in different products with contrasting cellular distribution and functions. Overexpression of AIF-1 stimulates migration and proliferation of human VSMCs, whereas IRT-1 exerts opposite effects. Adenoviral infection of angioplasty-injured rat carotid arteries with AdAIF-1 exacerbates intima hyperplasia, whereas infection with AdIRT-1 reduces neointima. Expression of these variants is modulated by changes in nuclear factor of activated T-cells (NFAT) activity. Pharmacological inhibition of NFAT or targeting of NFATc3 with small interfering RNA (siRNA) lowers the AIF-1/IRT-1 ratio and favours an anti-proliferative outcome. NFAT acts as a repressor on the IRT-1 transcriptional start site, which is also sensitive to interferon-γ stimulation. Expression of AIF-1 mRNA in human carotid plaques associates with less extracellular matrix and a more pro-inflammatory plaque and plasma profile, features that may predispose to plaque rupture. In contrast, expression of IRT-1 mRNA associates with a less aggressive phenotype and less VSMCs at the most stenotic region of the plaque. CONCLUSION Inhibition of NFAT signalling, by shifting the AIF-1/IRT-1 ratio, may be an attractive target to regulate the VSMC response to injury and manipulate plaque stability in atherosclerosis.
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Affiliation(s)
- Lisa M Berglund
- Department of Clinical Sciences, Lund University, CRC, Entrance 72, Building 91, Level 12, 205 02 Malmö, Sweden
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7
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Leung FP, Yung LM, Yao X, Laher I, Huang Y. Store-operated calcium entry in vascular smooth muscle. Br J Pharmacol 2007; 153:846-57. [PMID: 17876304 PMCID: PMC2267267 DOI: 10.1038/sj.bjp.0707455] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
In non-excitable cells, activation of G-protein-coupled phospholipase C (PLC)-linked receptors causes the release of Ca(2+) from intracellular stores, which is followed by transmembrane Ca(2+) entry. This Ca(2+) entry underlies a small and sustained phase of the cellular [Ca(2+)](i) increases and is important for several cellular functions including gene expression, secretion and cell proliferation. This form of transmembrane Ca(2+) entry is supported by agonist-activated Ca(2+)-permeable ion channels that are activated by store depletion and is referred to as store-operated Ca(2+) entry (SOCE) and represents a major pathway for agonist-induced Ca(2+) entry. In excitable cells such as smooth muscle cells, Ca(2+) entry mechanisms responsible for sustained cellular activation are normally considered to be mediated via either voltage-operated or receptor-operated Ca(2+) channels. Although SOCE occurs following agonist activation of smooth muscle, this was thought to be more important in replenishing Ca(2+) stores rather than acting as a source of activator Ca(2+) for the contractile process. This review summarizes our current knowledge of SOCE as a regulator of vascular smooth muscle tone and discusses its possible role in the cardiovascular function and disease. We propose a possible hypothesis for its activation and suggest that SOCE may represent a novel target for pharmacological therapeutic intervention.
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Affiliation(s)
- F P Leung
- Li Ka Shing Institute of Health Sciences, Chinese University of Hong Kong Hong Kong, China
- Department of Physiology, Chinese University of Hong Kong Hong Kong, China
| | - L M Yung
- Department of Physiology, Chinese University of Hong Kong Hong Kong, China
| | - X Yao
- Li Ka Shing Institute of Health Sciences, Chinese University of Hong Kong Hong Kong, China
- Department of Physiology, Chinese University of Hong Kong Hong Kong, China
- Institute of Vascular Medicine, Chinese University of Hong Kong Hong Kong, China
| | - I Laher
- Department of Pharmacology and Therapeutics, University of British Columbia Vancouver, Canada
| | - Y Huang
- Li Ka Shing Institute of Health Sciences, Chinese University of Hong Kong Hong Kong, China
- Department of Physiology, Chinese University of Hong Kong Hong Kong, China
- Institute of Vascular Medicine, Chinese University of Hong Kong Hong Kong, China
- Author for correspondence:
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8
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Smolock EM, Wang T, Nolt JK, Moreland RS. siRNA knock down of casein kinase 2 increases force and cross-bridge cycling rates in vascular smooth muscle. Am J Physiol Cell Physiol 2007; 292:C876-85. [PMID: 16987988 DOI: 10.1152/ajpcell.00343.2006] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Contraction of smooth muscle involves myosin light chain (MLC) kinase catalyzed phosphorylation of the regulatory MLC, activation of myosin, and the development of force. However, this cannot account for all aspects of a smooth muscle contraction, suggesting that other regulatory mechanisms exist. One potentially important technique to study alternative sites of contractile regulation is the use of small interfering RNA (siRNA). The goal of this study was to determine whether siRNA technology can decrease the levels of a specific protein and allow for the determination of how that protein affects contractile regulation. To achieve this goal, we tested the hypothesis that casein kinase 2 (CK2) is part of the complex regulatory scheme present in vascular smooth muscle. Using intact strips of swine carotid artery, we determined that siRNA against CK2 produced a tissue that resulted in a ∼60% knockdown after 4 days in organ culture. Intact strips of vascular tissue depleted of CK2 produced greater levels of force and exhibited an increased sensitivity to all stimuli tested. This was accompanied by an increase in cross-bridge cycling rates but not by a change in MLC phosphorylation levels. α-Toxin-permeabilized vascular tissue depleted of CK2 also showed an increased sensitivity to calcium compared with control tissues. Our results demonstrate that siRNA is a viable technique with which to study regulatory pathways in intact smooth muscle tissue. Our results also demonstrate that CK2 plays an important role in the mechanism(s) responsible for the development of force and cross-bridge cycling by a MLC phosphorylation-independent pathway.
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Affiliation(s)
- Elaine M Smolock
- Dept. of Pharmacology and Physiology, 245 N. 15th St., MS 488, Philadelphia, PA 19102, USA
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Gosens R, Zaagsma J, Grootte Bromhaar M, Nelemans A, Meurs H. Acetylcholine: a novel regulator of airway smooth muscle remodelling? Eur J Pharmacol 2005; 500:193-201. [PMID: 15464033 DOI: 10.1016/j.ejphar.2004.07.025] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/01/2004] [Indexed: 11/26/2022]
Abstract
Increased airway smooth muscle mass is a pathological feature that asthma and chronic obstructive pulmonary disease (COPD) have in common. This increase has gained renewed interest in view of recent developments showing that airway smooth muscle, instead of solely being a contractile partner, is capable of interacting dynamically with its environment, especially under inflammatory conditions. Airway smooth muscle cells are able to proliferate, to migrate, and to secrete chemokines, cytokines, extracellular matrix proteins and growth factors, and most importantly, to adapt to these functions by changing its phenotype from contractile to proliferative/synthetic. Conversely, switching to a (hyper)contractile phenotype may also occur. A vast number of inflammatory stimuli regulate these functions and exert their effects via excitatory G(q) or G(i)-coupled receptors. Since acetylcholine activates muscarinic M(2) and M(3) receptors in the airway smooth muscle cell membrane, which are coupled to G(i) and G(q) proteins, respectively, and since acetylcholine release may be enhanced in airway inflammation, a pathophysiological role of acetylcholine related to the above processes and exceeding contraction could be envisaged. In this review, evidence in favour of this hypothesis, based on recent data that show a role for muscarinic receptors in modulating airway smooth muscle proliferation, contractility and contractile protein expression is discussed. Based on these findings, we postulate that endogenous acetylcholine contributes to airway remodeling in asthma and COPD.
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Affiliation(s)
- Reinoud Gosens
- Department of Molecular Pharmacology, University Centre for Pharmacy, University of Groningen, Antonius Deusinglaan 1, Groningen 9713 AV, The Netherlands.
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10
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Bergdahl A, Gomez MF, Wihlborg AK, Erlinge D, Eyjolfson A, Xu SZ, Beech DJ, Dreja K, Hellstrand P. Plasticity of TRPC expression in arterial smooth muscle: correlation with store-operated Ca2+ entry. Am J Physiol Cell Physiol 2004; 288:C872-80. [PMID: 15561760 DOI: 10.1152/ajpcell.00334.2004] [Citation(s) in RCA: 133] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Loss of the smooth muscle contractile phenotype is critical in atherosclerosis and in restenosis after angioplasty, but its early signals are incompletely understood. In this study, we have explored the role of transient receptor potential canonical (TRPC) proteins, which have been suggested to mediate store-operated Ca2+ entry (SOCE). Contractility of rat cerebral arteries in organ culture is preserved for several days, whereas SOCE is increased. In correlation with this increase is that nifedipine-insensitive whole cell current, activated by depletion of intracellular Ca2+ stores, was increased by 50% in cells isolated from arteries cultured for 3 days. TRPC1 and TRPC6 mRNA were more than fivefold increased in cells isolated after organ culture, whereas TRPC3 was decreased. Immunofluorescent staining and/or Western blotting of arteries and isolated cells showed upregulation of TRPC1 and TRPC6 proteins during organ culture. In intact arteries, TRPC4 expression correlated with the amount of endothelium present. Ca2+ addition after store depletion caused a contraction in cultured, but not in freshly dissected, arteries. A polyclonal TRPC1 antibody directed against an extracellular epitope inhibited this contraction by approximately 50%. To investigate the basis of the TRPC upregulation and assess its possible clinical significance, segments of human internal mammary artery were organ cultured for 24 h and then exposed to balloon dilatation in vitro, followed by further culturing for up to 48 h. After dilatation, TRPC1 and TRPC6 mRNA were progressively increased compared with undilated control segments. The results of this study indicate that vascular injury enhances plasticity in TRPC expression, that TRPC expression correlates with cellular Ca2+ handling, and that TRPC1 is a subunit of upregulated store-operated Ca2+ channels.
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Affiliation(s)
- Andreas Bergdahl
- Division of Molecular and Cellular Physiology, Department of Physiological Sciences, Lund University, BMC F12, SE-221 84 Lund, Sweden
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11
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Bachar O, Adner M, Uddman R, Cardell LO. Nerve growth factor enhances cholinergic innervation and contractile response to electric field stimulation in a murine in vitro model of chronic asthma. Clin Exp Allergy 2004; 34:1137-45. [PMID: 15248863 DOI: 10.1111/j.1365-2222.2004.1868.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
BACKGROUND Asthma is a chronic inflammatory disease characterized by airway hyper-responsiveness. Alterations in the neurogenic control are believed to contribute to the pathogenesis. Yet, the long-term interaction between nerves and inflammatory mediators, such as the neurotrophin nerve growth factor (NGF), are not fully understood much due to the absence of appropriate experimental assays. OBJECTIVE To develop an ex vivo mouse organ culture assay and to investigate the effects of NGF on nerve-mediated airway contractions. METHOD Mouse tracheal segments were cultured in periods of up to 16 days. Their contractile responses to electric field stimulation (EFS) were investigated. In addition, the effect of 4 days of NGF treatment was analysed using EFS and immunohistochemistry. RESULTS EFS (0.2-25.6 Hz) induced reproducible and frequency-dependent cholinergic contractions of both fresh and cultured tracheal segments. The main part of the EFS response was blocked by tetrodotoxin or atropine. After 4 days in culture, regional differences appeared, with stronger EFS responses in distal than in proximal segments. More nerve fibres were seen in distal segments than in proximal segments. Treatment with NGF during 4 days of culture increased the innervation of the proximal segments, at the same time as the cholinergic contractile responses to EFS were enhanced dose-dependently. CONCLUSION Culture of tracheal segments appears to be a suitable assay for the examination of long-term effects induced by inflammatory mediators on neurally mediated airway contractions. NGF treatment enhanced the cholinergic, nerve-dependent contractions and increased the amount of nerve fibres seen in the murine tracheal segments, suggesting a role for NGF in the development of airway hyper-responsiveness.
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Affiliation(s)
- O Bachar
- Department of Otorhinolaryngology, Laboratory of Clinical Experimental Allergy Research, Malmö University Hospital, SE-20502, Malmö, Sweden.
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12
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Gosens R, Bromhaar MMG, Tonkes A, Schaafsma D, Zaagsma J, Nelemans SA, Meurs H. Muscarinic M(3) receptor-dependent regulation of airway smooth muscle contractile phenotype. Br J Pharmacol 2004; 141:943-50. [PMID: 14993104 PMCID: PMC1574278 DOI: 10.1038/sj.bjp.0705709] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
1. Airway smooth muscle (ASM) cells are known to switch from a contractile to a proliferative and synthetic phenotype in culture in response to serum and growth factors. Phenotype switching in response to contractile agonists, however, is poorly characterised, despite the possible relationship between ASM phenotype and airway remodelling in asthma. 2. To investigate the effects of muscarinic receptor stimulation on ASM phenotype, we used organ-cultured bovine tracheal smooth muscle (BTSM) strips, in which contractile responsiveness, contractile protein expression and proliferation were measured after pretreatment with methacholine. 3. Long-term methacholine pretreatment (8 days) decreased maximal contraction and sensitivity to methacholine as well as to histamine and KCl. This decrease was dose-dependent (pEC(50)=5.2+/-0.1). Pretreatment with the highest concentration of methacholine applied (100 microm) could suppress maximal histamine-induced contraction to 8+/-1% of control. In addition, contractile protein expression (myosin, actin) was downregulated two-fold. No concomitant increase in proliferative capacity was observed. 4. The M(3)/M(2) muscarinic receptor antagonist DAU 5884 (0.1 microm) completely inhibited the observed decrease in contractility. In contrast, the M(2)/M(3) muscarinic receptor antagonist gallamine (10 microm) was ineffective, demonstrating that M(2) receptors were not involved. 5. Pretreatment (8 days) with 60 mm KCl could mimick the strong decreases in contractility. This was completely prevented by pretreatment with verapamil (1 microm). 6. Regulation of contractility was not affected by protein kinase C inhibition, whereas inhibitors of phosphatidyl inositol 3-kinase and p42/p44 mitogen activated protein kinase were partially effective. 7. These results show that long-term methacholine pretreatment (8 days) induces an M(3) receptor-dependent decrease in BTSM contractility without increased proliferative capacity.
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Affiliation(s)
- Reinoud Gosens
- Department of Molecular Pharmacology, University Centre for Pharmacy, University of Groningen, A. Deusinglaan 1, 9713 AV Groningen, The Netherlands.
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Thorne GD, Paul RJ. Effects of organ culture on arterial gene expression and hypoxic relaxation: role of the ryanodine receptor. Am J Physiol Cell Physiol 2003; 284:C999-C1005. [PMID: 12477664 DOI: 10.1152/ajpcell.00158.2002] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Organ culture specifically inhibits vasorelaxation to acute hypoxia and preferentially decreases specific voltage-dependent K(+) channel expression over other K(+) and Ca(2+) channel subtypes. To isolate further potential oxygen-sensing mechanisms correlated with altered gene expression, we performed differential display analysis on RNA isolated from control and cultured coronary arterial rings. We hypothesize that organ culture results in altered gene expression important for vascular smooth muscle contractility important to the mechanism of hypoxia-induced relaxation. Our results indicate a milieu of changes suggesting both up- and downregulation of several genes. The altered expression pattern of two positive clones was verified by Northern analysis. Subsequent screening of a porcine cDNA library indicated homology to the ryanodine receptor (RyR). RT-PCR using specific primers to the three subtypes of RyR shows an upregulation of RyR2 and RyR3 after organ culture. Additionally, the caffeine- and/or ryanodine-sensitive intracellular Ca(2+) store was significantly more responsive to caffeine activation after organ culture. Our data indicate that organ culture increases expression of specific RyR subtypes and inhibits hypoxic vasorelaxation. Importantly, ryanodine blunted hypoxic relaxation in control coronary arteries, suggesting that upregulated RyR might play a novel role in altered intracellular Ca(2+) handling during hypoxia.
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Affiliation(s)
- George D Thorne
- Department of Molecular and Cellular Physiology, University of Cincinnati, College of Medicine, Cincinnati, Ohio 45267-0576, USA.
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Lindqvist A, Nilsson BO, Ekblad E, Hellstrand P. Platelet-derived growth factor receptors expressed in response to injury of differentiated vascular smooth muscle in vitro: effects on Ca2+ and growth signals. ACTA PHYSIOLOGICA SCANDINAVICA 2001; 173:175-84. [PMID: 11683675 DOI: 10.1046/j.1365-201x.2001.00873.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Vascular smooth muscle cells (VSMCs) in the intact vascular wall are differentiated for contraction, whereas the response to vascular injury involves transition towards a synthetic phenotype, with increased tendency for proliferation. Platelet-derived growth factor (PDGF) is thought to be important for this process. We investigated expression and functional coupling of PDGF receptors (PDGFRs) alpha and beta in rat tail arterial rings kept in organ culture, in order to capture early events in the phenotypic transition. In freshly dissected rings no PDGFR immunoreactivity was found in medial VSMCs, whereas PDGFR alpha was detected in nerve fibres. After organ culture for 1-4 days PDGFR alpha and beta as well as phospholipase Cgamma2 (PLCgamma2), known to couple to PDGFR, were expressed in VSMCs within 100 microm of the cut ends. Calponin, a marker for the contractile phenotype, was decreased near the injured area, suggesting that cells were in transition towards synthetic phenotype. In these cells, which showed functional Ca2+-release from the sarcoplasmic reticulum, PDGF-AB (100 ng x mL(-1)) had no effect on [Ca2+]i, whereas cultured VSMCs obtained from explants of rat tail arterial rings responded to PDGF-AB with an increase in [Ca2+]i. However, PDGFR within the cultured rings coupled to growth signalling pathways, as PDGF-AB caused a tyrphostin AG1295-sensitive activation of extracellular signal-regulated kinases 1 and 2 and of [3H]-thymidine incorporation. Thus, early expression of PDGFR in VSMC adjacent to sites of vascular injury coincides with signs of dedifferentiation. These receptors couple to growth signalling, but do not activate intracellular Ca2+ release.
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Affiliation(s)
- A Lindqvist
- Department of Physiological Sciences, Lund University, Lund, Sweden
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Thorne GD, Shimizu S, Paul RJ. Hypoxic vasodilation in porcine coronary artery is preferentially inhibited by organ culture. Am J Physiol Cell Physiol 2001; 281:C24-32. [PMID: 11401824 DOI: 10.1152/ajpcell.2001.281.1.c24] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Hypoxia (95% N2-5% CO2) elicits an endothelium-independent relaxation (45-80%) in freshly dissected porcine coronary arteries. Paired artery rings cultured at 37 degrees C in sterile DMEM (pH approximately 7.4) for 24 h contracted normally to KCl or 1 microM U-46619. However, relaxation in response to hypoxia was sharply attenuated compared with control (fresh arteries or those stored at 4 degrees C for 24 h). Hypoxic vasorelaxation in organ cultured vessels was reduced at both high and low stimulation, indicating that both Ca2+-independent and Ca2+-dependent components are altered. In contrast, relaxation to G-kinase (sodium nitroprusside) or A-kinase (forskolin and isoproterenol) activation was not significantly affected by organ culture. Additionally, there was no difference in relaxation after washout of the stimulus, indicating that the inhibition is specific to acute hypoxia-induced relaxation. Simultaneous force and intracellular calcium concentration ([Ca2+]i) measurements indicate the reduction in [Ca2+]i concomitant with hypoxia at low stimulus levels in these tissue is abolished by culture. Our results indicate that organ culture at 37 degrees C specifically attenuates hypoxic relaxation in vascular smooth muscle by altering dynamics of [Ca2+]i handling and decreasing a Ca2+-independent component of relaxation. Thus organ culture can be a novel tool for investigating the mechanisms of hypoxia-induced vasodilation.
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Affiliation(s)
- G D Thorne
- Department of Molecular and Cellular Physiology, University of Cincinnati, College of Medicine, Cincinnati, Ohio 45267 - 0576, USA
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Lymn JS, Hughes AD. Phospholipase C Isoforms, Cytoskeletal Organization, and Vascular Smooth Muscle Differentiation. NEWS IN PHYSIOLOGICAL SCIENCES : AN INTERNATIONAL JOURNAL OF PHYSIOLOGY PRODUCED JOINTLY BY THE INTERNATIONAL UNION OF PHYSIOLOGICAL SCIENCES AND THE AMERICAN PHYSIOLOGICAL SOCIETY 2000; 15:41-45. [PMID: 11390874 DOI: 10.1152/physiologyonline.2000.15.1.41] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The function of differentiated vascular smooth muscle cells (VSMC) in vivo is the regulation of contractility. Following injury or disease, however, VSMC lose their contractile function and take on a synthetic, proliferative phenotype. This dedifferentiation is generally accompanied by a change in the expression profile of phospholipase C isoforms.
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Affiliation(s)
- Joanne S. Lymn
- Department of Clinical Pharmacology, National Heart and Lung Institute, Imperial College School of Medicine, QEQM Wing, St. Mary's Hospital, Paddington, London W2 1NY, England
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