1
|
Li HH, Hsu HH, Chang GJ, Chen IC, Ho WJ, Hsu PC, Chen WJ, Pang JHS, Huang CC, Lai YJ. Prostanoid EP 4 agonist L-902,688 activates PPARγ and attenuates pulmonary arterial hypertension. Am J Physiol Lung Cell Mol Physiol 2017; 314:L349-L359. [PMID: 29146573 DOI: 10.1152/ajplung.00245.2017] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Prostacyclin agonists that bind the prostacyclin receptor (IP) to stimulate cAMP synthesis are effective vasodilators for the treatment of idiopathic pulmonary arterial hypertension (IPAH), but this signaling may occur through nuclear peroxisome proliferator-activated receptor-γ (PPARγ). There is evidence of scant IP and PPARγ expression but stable prostanoid EP4 receptor (EP4) expression in IPAH patients. Both IP and EP4 functionally couple with stimulatory G protein (Gs), which activates signal transduction. We investigated the effect of an EP4-specific agonist on pulmonary arterial remodeling and its regulatory mechanisms in pulmonary arterial smooth muscle cells (PASMCs). Immunoblotting evealed IP, EP4, and PPARγ expression in human pulmonary arterial hypertension (PAH) and monocrotaline (MCT)-induced PAH rat lung tissue. Isolated PASMCs from MCT-induced PAH rats (MCT-PASMCs) were treated with L-902,688, a selective EP4 agonist, to investigate the anti-vascular remodeling effect. Scant expression of IP and PPARγ but stable expression of EP4 was observed in IPAH patient lung tissues and MCT-PASMCs. L-902,688 inhibited IP-insufficient MCT-PASMC proliferation and migration by activating PPARγ in a time- and dose-dependent manner, but these effects were reversed by AH-23848 (an EP4 antagonist) and H-89 [a protein kinase A (PKA) inhibitor], highlighting the crucial role of PPARγ in the activity of this EP4 agonist. L-902,688 attenuated pulmonary arterial remodeling in hypoxic PAH mice and MCT-induced PAH rats; therefore, we conclude that the selective EP4 agonist L-902,688 reverses vascular remodeling by activating PPARγ. This study identified a novel EP4-PKA-PPARγ pathway, and we propose EP4 as a potential therapeutic target for PAH.
Collapse
Affiliation(s)
- Hsin-Hsien Li
- Department of Respiratory Therapy, Chang-Gung University College of Medicine , Tao-Yuan , Taiwan
| | - Hsao-Hsun Hsu
- Division of Thoracic Surgery, Department of Surgery, National Taiwan University Hospital and National Taiwan University College of Medicine , Taipei , Taiwan
| | - Gwo-Jyh Chang
- Graduate Institute of Clinical Medical Sciences, Chang Gung University , Tao-Yuan , Taiwan
| | - I-Chen Chen
- Graduate Institute of Clinical Medical Sciences, Chang Gung University , Tao-Yuan , Taiwan
| | - Wan-Jing Ho
- Cardiovascular Division, Chang Gung Memorial Hospital , Tao-Yuan , Taiwan
| | - Pei-Chen Hsu
- Division of Thoracic Surgery, Department of Surgery, National Taiwan University Hospital and National Taiwan University College of Medicine , Taipei , Taiwan
| | - Wei-Jan Chen
- Cardiovascular Division, Chang Gung Memorial Hospital , Tao-Yuan , Taiwan
| | - Jong-Hwei S Pang
- Graduate Institute of Clinical Medical Sciences, Chang Gung University , Tao-Yuan , Taiwan
| | - Chung-Chi Huang
- Department of Respiratory Therapy, Chang-Gung University College of Medicine , Tao-Yuan , Taiwan.,Division of Thoracic Medicine, Chang Gung Memorial Hospital , Tao-Yuan , Taiwan
| | - Ying-Ju Lai
- Department of Respiratory Therapy, Chang-Gung University College of Medicine , Tao-Yuan , Taiwan.,Cardiovascular Division, Chang Gung Memorial Hospital , Tao-Yuan , Taiwan.,Department of Respiratory Care, Chang-Gung University of Science and Technology, Chia-Yi, Taiwan
| |
Collapse
|
2
|
Chang Y, Zhang N, Yang Y, Du J, Fan X, Tao C. Time-periodic oscillation reaction in an organic-solvent dominated electrolyte. Phys Chem Chem Phys 2017; 19:27643-27650. [PMID: 28983548 DOI: 10.1039/c7cp05414a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Time-periodic phenomena widely exist in natural life sustaining systems but are rarely reported in highly efficient artificial electrochemical energy-harvesting systems. Herein, we observed for the first time the periodic oscillation reaction in organic-solvent dominated electrolytes that could be also derived from some electrochemical energy harvesting cells. Owing to different reaction activity and acidity in the organic solvent, the oscillation reaction could occur under milder pH conditions and exhibit better durability. Its influence on electric output and related differences from an aqueous B-Z reaction are discussed from a mechanism point of view. Our findings may contribute to smart self-oscillation materials and new strategies for highly efficient long-term energy harvesting.
Collapse
Affiliation(s)
- Yu Chang
- College of Chemistry and Chemical Engineering, Chongqing University, Chongqing, 400044, P. R. China.
| | | | | | | | | | | |
Collapse
|
3
|
Effects of Hyperglycemia on Vascular Smooth Muscle Ca 2+ Signaling. BIOMED RESEARCH INTERNATIONAL 2017; 2017:3691349. [PMID: 28713824 PMCID: PMC5497615 DOI: 10.1155/2017/3691349] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/04/2016] [Accepted: 05/24/2017] [Indexed: 12/25/2022]
Abstract
Diabetes is a complex disease that is characterized with hyperglycemia, dyslipidemia, and insulin resistance. These pathologies are associated with significant cardiovascular implications that affect both the macro- and microvasculature. It is therefore important to understand the effects of various pathologies associated with diabetes on the vasculature. Here we directly test the effects of hyperglycemia on vascular smooth muscle (VSM) Ca2+ signaling in an isolated in vitro system using the A7r5 rat aortic cell line as a model. We find that prolonged exposure of A7r5 cells to hyperglycemia (weeks) is associated with changes to Ca2+ signaling, including most prominently an inhibition of the passive ER Ca2+ leak and the sarcoplasmic reticulum Ca2+-ATPase (SERCA). To translate these findings to the in vivo condition, we used primary VSM cells from normal and diabetic subjects and find that only the inhibition of the ER Ca2+ leaks replicates in cells from diabetic donors. These results show that prolonged hyperglycemia in isolation alters the Ca2+ signaling machinery in VSM cells. However, these alterations are not readily translatable to the whole organism situation where alterations to the Ca2+ signaling machinery are different.
Collapse
|
4
|
Martins TV, Evans MJ, Wysham DB, Morris RJ. Nuclear pores enable sustained perinuclear calcium oscillations. BMC SYSTEMS BIOLOGY 2016; 10:55. [PMID: 27449670 PMCID: PMC4957432 DOI: 10.1186/s12918-016-0289-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/23/2015] [Accepted: 06/14/2016] [Indexed: 11/16/2022]
Abstract
Background Calcium signalling relies on the flux of calcium ions across membranes yet how signals in different compartments are related remains unclear. In particular, similar calcium signals on both sides of the nuclear envelope have been reported and attributed to passive diffusion through nuclear pores. However, observed differing cytosolic and nucleosolic calcium signatures suggest that the signalling machinery in these compartments can act independently. Results We adapt the fire-diffuse-fire model to investigate the generation of perinuclear calcium oscillations. We demonstrate that autonomous spatio-temporal calcium patterns are still possible in the presence of nuclear and cytosolic coupling via nuclear pores. The presence or absence of this autonomy is dependent upon the strength of the coupling and the maximum firing rate of an individual calcium channel. In all cases, coupling through the nuclear pores enables robust signalling with respect to changes in the diffusion constant. Conclusions We show that contradictory interpretations of experimental data with respect to the autonomy of nuclear calcium oscillations can be reconciled within one model, with different observations being a consequence of varying nuclear pore permeabilities for calcium and refractory conditions of channels. Furthermore, our results provide an explanation for why calcium oscillations on both sides of the nuclear envelope may be beneficial for sustained perinuclear signaling. Electronic supplementary material The online version of this article (doi:10.1186/s12918-016-0289-9) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Teresa Vaz Martins
- Computational & Systems Biology and Crop Genetics, John Innes Centre, Norwich Research Park, Norwich, UK.
| | - Matthew J Evans
- Computational & Systems Biology and Crop Genetics, John Innes Centre, Norwich Research Park, Norwich, UK
| | - Derin B Wysham
- Mathematics Department, Wenatchee Valley College, Wenatchee, USA
| | - Richard J Morris
- Computational & Systems Biology and Crop Genetics, John Innes Centre, Norwich Research Park, Norwich, UK
| |
Collapse
|
5
|
Cook DP, Rector MV, Bouzek DC, Michalski AS, Gansemer ND, Reznikov LR, Li X, Stroik MR, Ostedgaard LS, Abou Alaiwa MH, Thompson MA, Prakash YS, Krishnan R, Meyerholz DK, Seow CY, Stoltz DA. Cystic Fibrosis Transmembrane Conductance Regulator in Sarcoplasmic Reticulum of Airway Smooth Muscle. Implications for Airway Contractility. Am J Respir Crit Care Med 2016; 193:417-26. [PMID: 26488271 DOI: 10.1164/rccm.201508-1562oc] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
RATIONALE An asthma-like airway phenotype has been described in people with cystic fibrosis (CF). Whether these findings are directly caused by loss of CF transmembrane conductance regulator (CFTR) function or secondary to chronic airway infection and/or inflammation has been difficult to determine. OBJECTIVES Airway contractility is primarily determined by airway smooth muscle. We tested the hypothesis that CFTR is expressed in airway smooth muscle and directly affects airway smooth muscle contractility. METHODS Newborn pigs, both wild type and with CF (before the onset of airway infection and inflammation), were used in this study. High-resolution immunofluorescence was used to identify the subcellular localization of CFTR in airway smooth muscle. Airway smooth muscle function was determined with tissue myography, intracellular calcium measurements, and regulatory myosin light chain phosphorylation status. Precision-cut lung slices were used to investigate the therapeutic potential of CFTR modulation on airway reactivity. MEASUREMENTS AND MAIN RESULTS We found that CFTR localizes to the sarcoplasmic reticulum compartment of airway smooth muscle and regulates airway smooth muscle tone. Loss of CFTR function led to delayed calcium reuptake following cholinergic stimulation and increased myosin light chain phosphorylation. CFTR potentiation with ivacaftor decreased airway reactivity in precision-cut lung slices following cholinergic stimulation. CONCLUSIONS Loss of CFTR alters porcine airway smooth muscle function and may contribute to the airflow obstruction phenotype observed in human CF. Airway smooth muscle CFTR may represent a therapeutic target in CF and other diseases of airway narrowing.
Collapse
Affiliation(s)
- Daniel P Cook
- 1 Department of Internal Medicine.,2 Department of Molecular Physiology and Biophysics
| | | | | | | | | | | | | | | | | | | | - Michael A Thompson
- 3 Department of Anesthesiology and.,4 Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota
| | - Y S Prakash
- 3 Department of Anesthesiology and.,4 Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota
| | - Ramaswamy Krishnan
- 5 Department of Emergency Medicine, Center for Vascular Biology Research, Beth Israel Deaconess Medical Center, Boston, Massachusetts; and
| | | | - Chun Y Seow
- 7 Department of Pathology and Laboratory Medicine, James Hogg Research Centre/St. Paul's Hospital, University of British Columbia, Vancouver, British Columbia, Canada
| | - David A Stoltz
- 1 Department of Internal Medicine.,2 Department of Molecular Physiology and Biophysics.,8 Department of Biomedical Engineering, and.,9 Pappajohn Biomedical Institute, University of Iowa, Iowa City, Iowa
| |
Collapse
|
6
|
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
|
7
|
Searls YM, Loganathan R, Smirnova IV, Stehno-Bittel L. Intracellular Ca2+ regulating proteins in vascular smooth muscle cells are altered with type 1 diabetes due to the direct effects of hyperglycemia. Cardiovasc Diabetol 2010; 9:8. [PMID: 20122173 PMCID: PMC2829469 DOI: 10.1186/1475-2840-9-8] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/26/2009] [Accepted: 02/01/2010] [Indexed: 02/01/2023] Open
Abstract
Background Diminished calcium (Ca2+) transients in response to physiological agonists have been reported in vascular smooth muscle cells (VSMCs) from diabetic animals. However, the mechanism responsible was unclear. Methodology/Principal Findings VSMCs from autoimmune type 1 Diabetes Resistant Bio-Breeding (DR-BB) rats and streptozotocin-induced rats were examined for levels and distribution of inositol trisphosphate receptors (IP3R) and the SR Ca2+ pumps (SERCA 2 and 3). Generally, a decrease in IP3R levels and dramatic increase in ryanodine receptor (RyR) levels were noted in the aortic samples from diabetic animals. Redistribution of the specific IP3R subtypes was dependent on the rat model. SERCA 2 was redistributed to a peri-nuclear pattern that was more prominent in the DR-BB diabetic rat aorta than the STZ diabetic rat. The free intracellular Ca2+ in freshly dispersed VSMCs from control and diabetic animals was monitored using ratiometric Ca2+ sensitive fluorophores viewed by confocal microscopy. In control VSMCs, basal fluorescence levels were significantly higher in the nucleus relative to the cytoplasm, while in diabetic VSMCs they were essentially the same. Vasopressin induced a predictable increase in free intracellular Ca2+ in the VSMCs from control rats with a prolonged and significantly blunted response in the diabetic VSMCs. A slow rise in free intracellular Ca2+ in response to thapsigargin, a specific blocker of SERCA was seen in the control VSMCs but was significantly delayed and prolonged in cells from diabetic rats. To determine whether the changes were due to the direct effects of hyperglycemica, experiments were repeated using cultured rat aortic smooth muscle cells (A7r5) grown in hyperglycemic and control conditions. In general, they demonstrated the same changes in protein levels and distribution as well as the blunted Ca2+ responses to vasopressin and thapsigargin as noted in the cells from diabetic animals. Conclusions/Significance This work demonstrates that the previously-reported reduced Ca2+ signaling in VSMCs from diabetic animals is related to decreases and/or redistribution in the IP3R Ca2+ channels and SERCA proteins. These changes can be duplicated in culture with high glucose levels.
Collapse
Affiliation(s)
- Yvonne M Searls
- Department of Physical Therapy and Rehabilitation Science, University of Kansas Medical Center, Kansas City, KS 66160, USA
| | | | | | | |
Collapse
|
8
|
Bootman MD, Fearnley C, Smyrnias I, MacDonald F, Roderick HL. An update on nuclear calcium signalling. J Cell Sci 2009; 122:2337-50. [PMID: 19571113 DOI: 10.1242/jcs.028100] [Citation(s) in RCA: 149] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Over the past 15 years or so, numerous studies have sought to characterise how nuclear calcium (Ca2+) signals are generated and reversed, and to understand how events that occur in the nucleoplasm influence cellular Ca2+ activity, and vice versa. In this Commentary, we describe mechanisms of nuclear Ca2+ signalling and discuss what is known about the origin and physiological significance of nuclear Ca2+ transients. In particular, we focus on the idea that the nucleus has an autonomous Ca2+ signalling system that can generate its own Ca2+ transients that modulate processes such as gene transcription. We also discuss the role of nuclear pores and the nuclear envelope in controlling ion flux into the nucleoplasm.
Collapse
Affiliation(s)
- Martin D Bootman
- Laboratory of Molecular Signalling, The Babraham Institute, Babraham, Cambridge CB22 3AT, UK.
| | | | | | | | | |
Collapse
|
9
|
Meng F, To W, Kirkman-Brown J, Kumar P, Gu Y. Calcium oscillations induced by ATP in human umbilical cord smooth muscle cells. J Cell Physiol 2007; 213:79-87. [PMID: 17477379 DOI: 10.1002/jcp.21092] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Arterial smooth muscle cells exhibit vasomotion, related to oscillations in intracellular Ca(2+) concentration, but the origin and function of these has not yet been fully determined. We measured intracellular Ca(2+) using conventional fluorescent methods in primary cultured, human umbilical cord artery smooth muscle cells (HUCASMC). Spontaneous oscillations in Ca(2+) was found in only 1% of all cells but exogenous, micromolar concentrations of ATP could induce Ca(2+) oscillations in 70% of cells with the most common pattern being one of regular amplitude and frequency with a return to basal levels between each peak. The P2Y agonist, UTP, but not the P2X agonist alphabeta-methylene ATP, could also induce Ca(2+) oscillations. Once induced, these oscillations could not be blocked by G-protein, PLC, VGCC or TRP channel antagonists applied individually, but could be prevented when antagonists were applied together. In the presence of EGTA, micromolar concentrations of ATP induced an elevation in intracellular Ca(2+) but did not induce Ca(2+) oscillations. The oscillation frequency induced by ATP was affected by bath Ca(2+) concentration. Taken together, these data suggest that external Ca(2+) entry maintains the Ca(2+) oscillation induced by activation of P2Y receptors. Once induced, multiple mechanisms are involved to maintain the oscillation and the oscillation frequency is determined by the speed of Ca(2+) refilling. Chronic hypoxia enhanced the Ca(2+) response and altered the oscillation frequency. We suggest that these oscillations may play a role in the maintenance of umbilical blood flow during situations in which GPCR are activated.
Collapse
MESH Headings
- Adenosine Triphosphate/analogs & derivatives
- Adenosine Triphosphate/pharmacology
- Arachidonic Acid/pharmacology
- Calcium/pharmacology
- Calcium Channels/drug effects
- Calcium Channels/metabolism
- Calcium Signaling/drug effects
- Cell Hypoxia/drug effects
- Cell Hypoxia/physiology
- Cells, Cultured
- Humans
- Muscle, Smooth, Vascular/cytology
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/metabolism
- Myocytes, Smooth Muscle/drug effects
- Myocytes, Smooth Muscle/metabolism
- Purinergic P2 Receptor Agonists
- Receptors, Purinergic P2/classification
- Receptors, Purinergic P2/metabolism
- Uridine Triphosphate/pharmacology
Collapse
Affiliation(s)
- Fei Meng
- Department of Physiology, School of Medicine, University of Birmingham, Edgbaston, UK
| | | | | | | | | |
Collapse
|