1
|
Bonyanian Z, Walker M, Du Toit E, Rose'Meyer RB. Multiple adenosine receptor subtypes stimulate wound healing in human EA.hy926 endothelial cells. Purinergic Signal 2019; 15:357-366. [PMID: 31254200 DOI: 10.1007/s11302-019-09668-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Accepted: 06/20/2019] [Indexed: 10/26/2022] Open
Abstract
Wound healing is an important outcome of tissue damage and can be stimulated by adenosine released from cells during events such as tissue injury, ischaemia or tumour growth. The aim of this research was to determine the potency and efficacy of adenosine A1, A2A and A2B receptor agonists on the rate of wound healing and cell proliferation in human EA.hy926 endothelial cells. Real-time PCR data showed that only adenosine A1, A2A and A2B receptor mRNA were expressed in this cell line. All three adenosine receptor agonists, CPA, CGS21680 and NECA, significantly increased the rate of wound healing in human EAhy926 endothelial cells with the following order of potency CGS21680>CPA>NECA and efficacy CPA>NECA>CGS21680. The selective adenosine A1, A2A and A2B receptor antagonists, DPCPX, ZM241385 and MRS1754 (all at 10 nM), reversed the effects of their respective agonists. EAhy926 endothelial cell proliferation was also significantly increased with the adenosine A1 and A2B receptor agonists, CPA and NECA. Western blot analysis demonstrated that adenosine A2A and A1 receptor protein levels were highly expressed compared with the adenosine A2B receptors in the EAhy926 endothelial cell lines. While all three adenosine A1, A2A and A2B receptor subtypes contribute to cell proliferation and wound healing in human EAhy926 endothelial cells, treatments selectively targeting receptor subtypes may further enhance wound healing.
Collapse
Affiliation(s)
- Zeinab Bonyanian
- School of Medical Sciences, Griffith University, Gold Coast Campus Southport, Queensland, 4122, Australia
| | - Matthew Walker
- School of Medical Sciences, Griffith University, Gold Coast Campus Southport, Queensland, 4122, Australia
| | - Eugene Du Toit
- School of Medical Sciences, Griffith University, Gold Coast Campus Southport, Queensland, 4122, Australia
| | - Roselyn B Rose'Meyer
- School of Medical Sciences, Griffith University, Gold Coast Campus Southport, Queensland, 4122, Australia.
| |
Collapse
|
2
|
Knock-down of AHCY and depletion of adenosine induces DNA damage and cell cycle arrest. Sci Rep 2018; 8:14012. [PMID: 30228286 PMCID: PMC6143609 DOI: 10.1038/s41598-018-32356-8] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Accepted: 09/03/2018] [Indexed: 01/09/2023] Open
Abstract
Recently, functional connections between S-adenosylhomocysteine hydrolase (AHCY) activity and cancer have been reported. As the properties of AHCY include the hydrolysis of S-adenosylhomocysteine and maintenance of the cellular methylation potential, the connection between AHCY and cancer is not obvious. The mechanisms by which AHCY influences the cell cycle or cell proliferation have not yet been confirmed. To elucidate AHCY-driven cancer-specific mechanisms, we pursued a multi-omics approach to investigate the effect of AHCY-knockdown on hepatocellular carcinoma cells. Here, we show that reduced AHCY activity causes adenosine depletion with activation of the DNA damage response (DDR), leading to cell cycle arrest, a decreased proliferation rate and DNA damage. The underlying mechanism behind these effects might be applicable to cancer types that have either significant levels of endogenous AHCY and/or are dependent on high concentrations of adenosine in their microenvironments. Thus, adenosine monitoring might be used as a preventive measure in liver disease, whereas induced adenosine depletion might be the desired approach for provoking the DDR in diagnosed cancer, thus opening new avenues for targeted therapy. Additionally, including AHCY in mutational screens as a potential risk factor may be a beneficial preventive measure.
Collapse
|
3
|
Xu Y, Wang Y, Yan S, Zhou Y, Yang Q, Pan Y, Zeng X, An X, Liu Z, Wang L, Xu J, Cao Y, Fulton DJ, Weintraub NL, Bagi Z, Hoda MN, Wang X, Li Q, Hong M, Jiang X, Boison D, Weber C, Wu C, Huo Y. Intracellular adenosine regulates epigenetic programming in endothelial cells to promote angiogenesis. EMBO Mol Med 2018; 9:1263-1278. [PMID: 28751580 PMCID: PMC5582416 DOI: 10.15252/emmm.201607066] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
The nucleoside adenosine is a potent regulator of vascular homeostasis, but it remains unclear how expression or function of the adenosine‐metabolizing enzyme adenosine kinase (ADK) and the intracellular adenosine levels influence angiogenesis. We show here that hypoxia lowered the expression of ADK and increased the levels of intracellular adenosine in human endothelial cells. Knockdown (KD) of ADK elevated intracellular adenosine, promoted proliferation, migration, and angiogenic sprouting in human endothelial cells. Additionally, mice deficient in endothelial ADK displayed increased angiogenesis as evidenced by the rapid development of the retinal and hindbrain vasculature, increased healing of skin wounds, and prompt recovery of arterial blood flow in the ischemic hindlimb. Mechanistically, hypomethylation of the promoters of a series of pro‐angiogenic genes, especially for VEGFR2 in ADK KD cells, was demonstrated by the Infinium methylation assay. Methylation‐specific PCR, bisulfite sequencing, and methylated DNA immunoprecipitation further confirmed hypomethylation in the promoter region of VEGFR2 in ADK‐deficient endothelial cells. Accordingly, loss or inactivation of ADK increased VEGFR2 expression and signaling in endothelial cells. Based on these findings, we propose that ADK downregulation‐induced elevation of intracellular adenosine levels in endothelial cells in the setting of hypoxia is one of the crucial intrinsic mechanisms that promote angiogenesis.
Collapse
Affiliation(s)
- Yiming Xu
- Vascular Biology Center, Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA, USA .,School of Basic Medical Sciences, Guangzhou Medical University, Guangzhou, China
| | - Yong Wang
- Vascular Biology Center, Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA, USA.,College of Basic Medicine, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Siyuan Yan
- Vascular Biology Center, Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA, USA.,State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Science, Beijing, China
| | - Yaqi Zhou
- Vascular Biology Center, Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA, USA.,Drug Discovery Center, Key Laboratory of Chemical Genomics, Peking University Shenzhen Graduate School, Shenzhen, China
| | - Qiuhua Yang
- Vascular Biology Center, Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA, USA.,Drug Discovery Center, Key Laboratory of Chemical Genomics, Peking University Shenzhen Graduate School, Shenzhen, China
| | - Yue Pan
- Georgia Prevention Institute, Augusta University, Augusta, GA, USA
| | - Xianqiu Zeng
- Vascular Biology Center, Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA, USA.,Drug Discovery Center, Key Laboratory of Chemical Genomics, Peking University Shenzhen Graduate School, Shenzhen, China
| | - Xiaofei An
- Vascular Biology Center, Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA, USA
| | - Zhiping Liu
- Vascular Biology Center, Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA, USA
| | - Lina Wang
- Vascular Biology Center, Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA, USA.,Drug Discovery Center, Key Laboratory of Chemical Genomics, Peking University Shenzhen Graduate School, Shenzhen, China
| | - Jiean Xu
- Vascular Biology Center, Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA, USA.,Drug Discovery Center, Key Laboratory of Chemical Genomics, Peking University Shenzhen Graduate School, Shenzhen, China
| | - Yapeng Cao
- Vascular Biology Center, Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA, USA.,Drug Discovery Center, Key Laboratory of Chemical Genomics, Peking University Shenzhen Graduate School, Shenzhen, China
| | - David J Fulton
- Vascular Biology Center, Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA, USA
| | - Neal L Weintraub
- Vascular Biology Center, Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA, USA
| | - Zsolt Bagi
- Vascular Biology Center, Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA, USA
| | - Md Nasrul Hoda
- Departments of Medical Laboratory, Imaging & Radiologic Sciences, and Neurology, Augusta University, Augusta, GA, USA
| | - Xiaoling Wang
- Georgia Prevention Institute, Augusta University, Augusta, GA, USA
| | - Qinkai Li
- Drug Discovery Center, Key Laboratory of Chemical Genomics, Peking University Shenzhen Graduate School, Shenzhen, China
| | - Mei Hong
- Drug Discovery Center, Key Laboratory of Chemical Genomics, Peking University Shenzhen Graduate School, Shenzhen, China
| | - Xuejun Jiang
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Science, Beijing, China
| | - Detlev Boison
- Robert S. Dow Neurobiology Laboratories, Legacy Research Institute, Portland, OR, USA
| | - Christian Weber
- Institute for Cardiovascular Prevention, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Chaodong Wu
- Department of Nutrition and Food Science, Texas A&M University, College Station, TX, USA
| | - Yuqing Huo
- Vascular Biology Center, Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA, USA
| |
Collapse
|
4
|
Kiese K, Jablonski J, Boison D, Kobow K. Dynamic Regulation of the Adenosine Kinase Gene during Early Postnatal Brain Development and Maturation. Front Mol Neurosci 2016; 9:99. [PMID: 27812320 PMCID: PMC5071315 DOI: 10.3389/fnmol.2016.00099] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2016] [Accepted: 09/26/2016] [Indexed: 12/02/2022] Open
Abstract
The ubiquitous metabolic intermediary and nucleoside adenosine is a “master regulator” in all living systems. Under baseline conditions adenosine kinase (ADK) is the primary enzyme for the metabolic clearance of adenosine. By regulating the availability of adenosine, ADK is a critical upstream regulator of complex homeostatic and metabolic networks. Not surprisingly, ADK dysfunction is involved in several pathologies, including diabetes, epilepsy, and cancer. ADK protein exists in the two isoforms nuclear ADK-L, and cytoplasmic ADK-S, which are subject to dynamic expression changes during brain development and in response to brain injury; however, gene expression changes of the Adk gene as well as regulatory mechanisms that direct the cell-type and isoform specific expression of ADK have never been investigated. Here we analyzed potential gene regulatory mechanisms that may influence Adk expression including DNA promoter methylation, histone modifications and transcription factor binding. Our data suggest binding of transcription factor SP1 to the Adk promoter influences the regulation of Adk expression.
Collapse
Affiliation(s)
- Katharina Kiese
- Department of Neuropathology, University Hospital Erlangen Erlangen, Germany
| | - Janos Jablonski
- Department of Neuropathology, University Hospital Erlangen Erlangen, Germany
| | - Detlev Boison
- Robert Stone Dow Neurobiology Laboratories, Legacy Research Institute Portland, OR, USA
| | - Katja Kobow
- Department of Neuropathology, University Hospital Erlangen Erlangen, Germany
| |
Collapse
|
5
|
Li S, Li X, Guo H, Liu S, Huang H, Liu N, Yang C, Tang P, Liu J. Intracellular ATP concentration contributes to the cytotoxic and cytoprotective effects of adenosine. PLoS One 2013; 8:e76731. [PMID: 24098558 PMCID: PMC3789704 DOI: 10.1371/journal.pone.0076731] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2013] [Accepted: 08/24/2013] [Indexed: 02/04/2023] Open
Abstract
Extracellular adenosine (Ade) interacts with cells by two pathways: by activating cell surface receptors at nanomolar/micromolar concentrations; and by interfering with the homeostasis of the intracellular nucleotide pool at millimolar concentrations. Ade shows both cytotoxic and cytoprotective effects; however, the underlying mechanisms remain unclear. In the present study, the effects of adenosine-mediated ATP on cell viability were investigated. Adenosine treatment was found to be cytoprotective in the low intracellular ATP state, but cytotoxic under the normal ATP state. Adenosine-mediated cytotoxicity and cytoprotection rely on adenosine-derived ATP formation, but not via the adenosine receptor pathway. Ade enhanced proteasome inhibition-induced cell death mediated by ATP generation. These data provide a new pathway by which adenosine exerts dual biological effects on cell viability, suggesting an important role for adenosine as an ATP precursor besides the adenosine receptor pathway.
Collapse
Affiliation(s)
- Shujue Li
- Protein Modification and Degradation Lab, Department of Pathophysiology, Guangzhou Medical University, Guangzhou, Guangdong, People's Republic of China
- Department of Urology, the First Affiliated Hospital, Guangzhou Medical University, Guangzhou, Guangdong, People's Republic of China
| | - Xiaofen Li
- Protein Modification and Degradation Lab, Department of Pathophysiology, Guangzhou Medical University, Guangzhou, Guangdong, People's Republic of China
| | - Haiping Guo
- Protein Modification and Degradation Lab, Department of Pathophysiology, Guangzhou Medical University, Guangzhou, Guangdong, People's Republic of China
| | - Shouting Liu
- Protein Modification and Degradation Lab, Department of Pathophysiology, Guangzhou Medical University, Guangzhou, Guangdong, People's Republic of China
| | - Hongbiao Huang
- Protein Modification and Degradation Lab, Department of Pathophysiology, Guangzhou Medical University, Guangzhou, Guangdong, People's Republic of China
| | - Ningning Liu
- Protein Modification and Degradation Lab, Department of Pathophysiology, Guangzhou Medical University, Guangzhou, Guangdong, People's Republic of China
- Guangzhou Research Institute of Cardiovascular Disease, the Second Affiliated Hospital, Guangzhou Medical University, Guangzhou, Guangdong, People's Republic of China
| | - Changshan Yang
- Protein Modification and Degradation Lab, Department of Pathophysiology, Guangzhou Medical University, Guangzhou, Guangdong, People's Republic of China
| | - Ping Tang
- Protein Modification and Degradation Lab, Department of Pathophysiology, Guangzhou Medical University, Guangzhou, Guangdong, People's Republic of China
| | - Jinbao Liu
- Protein Modification and Degradation Lab, Department of Pathophysiology, Guangzhou Medical University, Guangzhou, Guangdong, People's Republic of China
- * E-mail:
| |
Collapse
|
6
|
Ahmad A, Schaack JB, White CW, Ahmad S. Adenosine A2A receptor-dependent proliferation of pulmonary endothelial cells is mediated through calcium mobilization, PI3-kinase and ERK1/2 pathways. Biochem Biophys Res Commun 2013; 434:566-71. [PMID: 23583199 DOI: 10.1016/j.bbrc.2013.03.115] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2013] [Accepted: 03/26/2013] [Indexed: 12/13/2022]
Abstract
Hypoxia and HIF-2α-dependent A2A receptor expression and activation increase proliferation of human lung microvascular endothelial cells (HLMVECs). This study was undertaken to investigate the signaling mechanisms that mediate the proliferative effects of A2A receptor. A2A receptor-mediated proliferation of HLMVECs was inhibited by intracellular calcium chelation, and by specific inhibitors of ERK1/2 and PI3-kinase (PI3K). The adenosine A2A receptor agonist CGS21680 caused intracellular calcium mobilization in controls and, to a greater extent, in A2A receptor-overexpressing HLMVECs. Adenoviral-mediated A2A receptor overexpression as well as receptor activation by CGS21680 caused increased PI3K activity and Akt phosphorylation. Cells overexpressing A2A receptor also manifested enhanced ERK1/2 phosphorylation upon CGS21680 treatment. A2A receptor activation also caused enhanced cAMP production. Likewise, treatment with 8Br-cAMP increased PI3K activity. Hence A2A receptor-mediated cAMP production and PI3K and Akt phosphorylation are potential mediators of the A2A-mediated proliferative response of HLMVECs. Cytosolic calcium mobilization and ERK1/2 phosphorylation are other critical effectors of HLMVEC proliferation and growth. These studies underscore the importance of adenosine A2A receptor in activation of survival and proliferative pathways in pulmonary endothelial cells that are mediated through PI3K/Akt and ERK1/2 pathways.
Collapse
Affiliation(s)
- Aftab Ahmad
- Pediatric Airway Research Center, Department of Pediatrics, Aurora, CO 80045, USA.
| | | | | | | |
Collapse
|
7
|
Feoktistov I, Biaggioni I, Cronstein BN. Adenosine receptors in wound healing, fibrosis and angiogenesis. Handb Exp Pharmacol 2009:383-97. [PMID: 19639289 DOI: 10.1007/978-3-540-89615-9_13] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Wound healing and tissue repair are critical processes, and adenosine, released from injured or ischemic tissues, plays an important role in promoting wound healing and tissue repair. Recent studies in genetically manipulated mice demonstrate that adenosine receptors are required for appropriate granulation tissue formation and in adequate wound healing. A(2A) and A(2B) adenosine receptors stimulate both of the critical functions in granulation tissue formation (i.e., new matrix production and angiogenesis), and the A(1) adenosine receptor (AR) may also contribute to new vessel formation. The effects of adenosine acting on these receptors is both direct and indirect, as AR activation suppresses antiangiogenic factor production by endothelial cells, promotes endothelial cell proliferation, and stimulates angiogenic factor production by endothelial cells and other cells present in the wound. Similarly, adenosine, acting at its receptors, stimulates collagen matrix formation directly. Like many other biological processes, AR-mediated promotion of tissue repair is critical for appropriate wound healing but may also contribute to pathogenic processes. Excessive tissue repair can lead to problems such as scarring and organ fibrosis and adenosine, and its receptors play a role in pathologic fibrosis as well. Here we review the evidence for the involvement of adenosine and its receptors in wound healing, tissue repair and fibrosis.
Collapse
Affiliation(s)
- Igor Feoktistov
- Division of Cardiovascular Medicine, Vanderbilt University, Nashville, TN 37232-6300, USA.
| | | | | |
Collapse
|
8
|
Chunn JL, Mohsenin A, Young HWJ, Lee CG, Elias JA, Kellems RE, Blackburn MR. Partially adenosine deaminase-deficient mice develop pulmonary fibrosis in association with adenosine elevations. Am J Physiol Lung Cell Mol Physiol 2005; 290:L579-87. [PMID: 16258000 DOI: 10.1152/ajplung.00258.2005] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Adenosine, a signaling nucleoside, exhibits tissue-protective and tissue-destructive effects. Adenosine levels in tissues are controlled in part by the enzyme adenosine deaminase (ADA). ADA-deficient mice accumulate adenosine levels in multiple tissues, including the lung, where adenosine contributes to the development of pulmonary inflammation and chronic airway remodeling. The present study describes the development of pulmonary fibrosis in mice that have been genetically engineered to possess partial ADA enzyme activity and, thus, accumulate adenosine over a prolonged period of time. These partially ADA-deficient mice live for up to 5 mo and die from apparent respiratory distress. Detailed investigations of the lung histopathology of partially ADA-deficient mice revealed progressive pulmonary fibrosis marked by an increase in the number of pulmonary myofibroblasts and an increase in collagen deposition. In addition, in regions of the distal airways that did not exhibit fibrosis, an increase in the number of large foamy macrophages and a substantial enlargement of the alveolar air spaces suggest emphysemic changes. Furthermore, important proinflammatory and profibrotic signaling pathways, including IL-13 and transforming growth factor-beta1, were activated. Increases in tissue fibrosis were also seen in the liver and kidneys of these mice. These changes occurred in association with pronounced elevations of lung adenosine concentrations and alterations in lung adenosine receptor levels, supporting the hypothesis that elevation of endogenous adenosine is a proinflammatory and profibrotic signal in this model.
Collapse
Affiliation(s)
- Janci L Chunn
- Dept. of Biochemistry and Molecular Biology, Univ. of Texas-Houston Medical School, 6431 Fannin, Houston, TX 77030, USA
| | | | | | | | | | | | | |
Collapse
|
9
|
Adair TH. Growth regulation of the vascular system: an emerging role for adenosine. Am J Physiol Regul Integr Comp Physiol 2005; 289:R283-R296. [PMID: 16014444 DOI: 10.1152/ajpregu.00840.2004] [Citation(s) in RCA: 141] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The importance of metabolic factors in the regulation of angiogenesis is well understood. An increase in metabolic activity leads to a decrease in tissue oxygenation causing tissues to become hypoxic. The hypoxia initiates a variety of signals that stimulate angiogenesis, and the increase in vascularity that follows promotes oxygen delivery to the tissues. When the tissues receive adequate amounts of oxygen, the intermediate effectors return to normal levels, and angiogenesis ceases. An emerging concept is that adenosine released from hypoxic tissues has an important role in driving the angiogenesis. The following feedback control hypothesis is proposed: AMP is dephosphorylated by ecto-5′-nucleotidase, producing adenosine under hypoxic conditions in the extracellular space adjacent to a parenchymal cell (e.g., cardiomyocyte, skeletal muscle fiber, hepatocyte, etc.). Extracellular adenosine activates A2receptors, which stimulates the release of vascular endothelial growth factor (VEGF) from the parenchymal cell. VEGF binds to its receptor (VEGF receptor 2) on endothelial cells, stimulating their proliferation and migration. Adenosine can also stimulate endothelial cell proliferation independently of VEGF, which probably involves modulation of other proangiogenic and antiangiogenic growth factors and perhaps an intracellular mechanism. In addition, hemodynamic factors associated with adenosine-induced vasodilation may have a role in the development and remodeling of the vasculature. Once a new capillary network has been established, and the diffusion/perfusion capabilities of the vasculature are sufficient to supply the parenchymal cells with adequate amounts of oxygen, adenosine and VEGF as well as other proangiogenic and antiangiogenic growth factors return to near-normal levels, thus closing the negative feedback loop. The available data indicate that adenosine might be an essential mediator for up to 50–70% of the hypoxia-induced angiogenesis in some situations; however, additional studies in intact animals will be required to fully understand the quantitative importance of adenosine.
Collapse
Affiliation(s)
- Thomas H Adair
- Dept. of Physiology and Biophysics, University of Mississippi Medical Center, 2500 N. State Street, Jackson, MS 39216-4505, USA.
| |
Collapse
|
10
|
Adair TH, Cotten R, Gu JW, Pryor JS, Bennett KR, McMullan MR, McDonnell P, Montani JP. Adenosine infusion increases plasma levels of VEGF in humans. BMC PHYSIOLOGY 2005; 5:10. [PMID: 15967042 PMCID: PMC1183224 DOI: 10.1186/1472-6793-5-10] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/09/2005] [Accepted: 06/20/2005] [Indexed: 11/16/2022]
Abstract
Background Many in vitro studies have shown that adenosine (Ado) can induce vascular endothelial growth factor (VEGF) mRNA and protein expression and stimulate endothelial proliferation. In the present study, we seek to determine whether Ado can increase circulating levels of VEGF protein in the intact human. Methods Five outpatients 49.3 ± 6.7 years of age and weighing 88.2 ± 8.5 kg were selected. They were given a 6 min intravenous infusion of Ado (0.14 mg kg-1 min-1) in conjunction with sestamibi myocardial perfusion scans. Mean blood pressure (MBP, calculated from systolic and diastolic values) and heart rate (HR) were determined before Ado infusion and every 2 min for the next 10 min. Plasma VEGF concentrations (ELISA) were determined immediately before Ado infusion and 1 h, 2 h, and 8 h after the infusion. Results Plasma VEGF concentration averaged 20.3 ± 2.0 pg ml-1 prior to Ado infusion, and increased to 62.7 ± 18.1 pg ml-1 at 1 h post- infusion (p < 0.01). VEGF plasma concentration returned to basal levels 2 h after infusion (23.3 ± 3.4 pg ml-1). MBP averaged 116 ± 7 mmHg and heart rate averaged 70 ± 7 prior to Ado infusion. MBP decreased by a maximum of ~22% and HR increased by a maximum of ~17% during the infusion. Conclusion We conclude from these preliminary findings that intravenous infusion of adenosine can increase plasma levels of VEGF in humans.
Collapse
Affiliation(s)
- Thomas H Adair
- Angiogenesis Research LaboratoriesCenter for Excellence in Cardiovascular-Renal Research
- Department of Physiology & Biophysics University of Mississippi Medical Center Jackson, MS 39216, USA
| | - Reid Cotten
- Angiogenesis Research LaboratoriesCenter for Excellence in Cardiovascular-Renal Research
- Department of Medicine University of Mississippi Medical Center Jackson, MS 39216, USA
| | - Jian-Wei Gu
- Angiogenesis Research LaboratoriesCenter for Excellence in Cardiovascular-Renal Research
- Department of Physiology & Biophysics University of Mississippi Medical Center Jackson, MS 39216, USA
| | - Janelle S Pryor
- Angiogenesis Research LaboratoriesCenter for Excellence in Cardiovascular-Renal Research
- Department of Physiology & Biophysics University of Mississippi Medical Center Jackson, MS 39216, USA
| | - Kenneth R Bennett
- Angiogenesis Research LaboratoriesCenter for Excellence in Cardiovascular-Renal Research
- Department of Medicine University of Mississippi Medical Center Jackson, MS 39216, USA
| | - Michael R McMullan
- Angiogenesis Research LaboratoriesCenter for Excellence in Cardiovascular-Renal Research
- Department of Medicine University of Mississippi Medical Center Jackson, MS 39216, USA
| | - Preston McDonnell
- Angiogenesis Research LaboratoriesCenter for Excellence in Cardiovascular-Renal Research
- Department of Physiology & Biophysics University of Mississippi Medical Center Jackson, MS 39216, USA
| | - Jean-Pierre Montani
- Angiogenesis Research LaboratoriesCenter for Excellence in Cardiovascular-Renal Research
- Institute of PhysiologyUniversity of Fribourg, 1700 Fribourg, Switzerland
| |
Collapse
|
11
|
Carey GB, Wotjukiewicz LJ, Goodman JM, Reineck KE, Overman KC. Extracellular cyclic AMP and adenosine appearance in adipose tissue of Sus scrofa: effects of exercise. Exp Biol Med (Maywood) 2004; 229:1026-32. [PMID: 15522838 DOI: 10.1177/153537020422901006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Cyclic AMP (cAMP) appears extracellularly in a variety of tissues including brain, liver, and kidney; whether it appears in adipose tissue and responds to physiological perturbation is unknown. The purpose of this study was to examine adipose tissue extracellular cAMP appearance and metabolism in situ and in vitro in physiologically challenged animals. Littermate swine were either sedentary or exercise trained on a treadmill for 3 months and subjected to acute exercise on experiment day. In situ, microdialysis probes in subcutaneous back fat were perfused before, during, and after animals performed 20 mins of acute exercise, and dialysate was analyzed for cAMP and adenosine. In vitro, isolated adipocytes were hormonally stimulated to provoke cAMP synthesis and efflux, and plasma membrane phosphodiesterase and 5'-nucleotidase activities were measured. Extracellular cAMP and adenosine levels in adipose tissue of sedentary swine averaged 5.2 +/- 1.7 and 863 +/- 278 nM, respectively. Exercise training tended to increase extracellular cAMP (11.3 +/- 1.7 nM) and reduce extracellular adenosine (438 +/- 303 nM), although neither change was statistically significant. Acute exercise caused a significant 3-fold and 16-fold increase in extracellular cAMP and adenosine, respectively, compared to rest. These changes occurred despite a 2- to 3-fold increase in adipose tissue blood flow during acute exercise. In vitro, cAMP efflux from exercise-trained swine was 42% greater than that from adipocytes of sedentary swine, yet adipocyte plasma membranes from exercise-trained and sedentary swine did not differ in maximal phosphodiesterase and 5'-nucleotidase activities. We conclude that cAMP appears extracellularly in swine adipose tissue and that the levels of extracellular cAMP and adenosine in intact swine adipose tissue are influenced by both acute and chronic exercise. The subsequent impact of the changes in these biochemicals on local cellular metabolism and growth remains to be determined.
Collapse
Affiliation(s)
- Gale B Carey
- Department of Animal and Nutritional Sciences, 403 Kendall Hall, University of New Hampshire, Durham, NH 03824, USA.
| | | | | | | | | |
Collapse
|
12
|
Németh ZH, Deitch EA, Lu Q, Szabó C, Haskó G. NHE blockade inhibits chemokine production and NF-kappaB activation in immunostimulated endothelial cells. Am J Physiol Cell Physiol 2002; 283:C396-403. [PMID: 12107048 DOI: 10.1152/ajpcell.00491.2001] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Na(+)/H(+) exchanger (NHE) activation has been documented to contribute to endothelial cell injury caused by inflammatory states. However, the role of NHEs in regulation of the endothelial cell inflammatory response has not been investigated. The present study tested the hypothesis that NHEs contribute to endothelial cell inflammation induced by endotoxin or interleukin (IL)-1beta. NHE inhibition using amiloride, 5-(N-ethyl-N-isopropyl)-amiloride, and 5-(N-methyl-N-isobutyl)amiloride as well as the non-amiloride NHE inhibitors cimetidine, clonidine, and harmaline suppressed endotoxin-induced IL-8 and monocyte chemoattractant protein (MCP)-1 production by human umbilical endothelial vein cells (HUVECs). The suppressive effect of amiloride on endotoxin-induced IL-8 production was associated with a decreased accumulation of IL-8 mRNA. NHE inhibitors suppressed both inhibitory (I)kappaB degradation and nuclear factor (NF)-kappaB DNA binding, suggesting that a decrease in activation of the IkappaB-NF-kappaB system contributed to the suppression of HUVEC inflammatory response by NHE blockade. NHE inhibition decreased also the IL-1beta-induced HUVEC inflammatory response, because amiloride suppressed IL-1beta-induced E-selectin expression on HUVECs. These results demonstrate that maximal activation of the HUVEC inflammatory response requires a functional NHE.
Collapse
Affiliation(s)
- Zoltán H Németh
- Department of Surgery, University of Medicine and Dentistry-New Jersey Medical School, Newark, New Jersey 07103, USA
| | | | | | | | | |
Collapse
|
13
|
Montesinos MC, Desai A, Chen JF, Yee H, Schwarzschild MA, Fink JS, Cronstein BN. Adenosine promotes wound healing and mediates angiogenesis in response to tissue injury via occupancy of A(2A) receptors. THE AMERICAN JOURNAL OF PATHOLOGY 2002; 160:2009-18. [PMID: 12057906 PMCID: PMC1850820 DOI: 10.1016/s0002-9440(10)61151-0] [Citation(s) in RCA: 167] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Recent evidence indicates that topical application of adenosine A(2A) receptor agonists, unlike growth factors, increases the rate at which wounds close in normal animals and promotes wound healing in diabetic animals as well as growth factors, yet neither the specific adenosine receptor involved nor the mechanism(s) by which adenosine receptor occupancy promotes wound healing have been fully established. To determine which adenosine receptor is involved and whether adenosine receptor-mediated stimulation of angiogenesis plays a role in promotion of wound closure we compared the effect of topical application of the adenosine receptor agonist CGS-21680 (2-p-[2-carboxyethyl]phenethyl-amino-5'-N-ethylcarboxamido-adenosine) on wound closure and angiogenesis in adenosine A(2A) receptor knockout mice and their wild-type littermates. There was no change in the rate of wound closure in the A(2A) receptor knockout mice compared to their wild-type littermates although granulation tissue formation was nonhomogeneous and there seemed to be greater inflammation at the base of the wound. Topical application of CGS-21680 increased the rate of wound closure and increased the number of microvessels in the wounds of wild-type mice but did not affect the rate of wound closure in A(2A) receptor knockout mice. Similarly, in a model of internal trauma and repair (murine air pouch model), endogenously produced adenosine released into areas of internal tissue injury stimulates angiogenesis because there was a marked reduction in blood vessels in the walls of healing air pouches of A(2A) receptor knockout mice compared to their wild-type controls. Inflammatory vascular leakage and leukocyte accumulation in the inflamed air pouch were similarly reduced in the A(2A) receptor knockout mice reflecting the reduced vascularity. Thus, targeting the adenosine A(2A) receptor is a novel approach to promoting wound healing and angiogenesis in normal individuals and those suffering from chronic wounds.
Collapse
Affiliation(s)
- M Carmen Montesinos
- Department of Medicine, New York University School of Medicine, New York, New York, USA
| | | | | | | | | | | | | |
Collapse
|
14
|
Sakumura T, Fujii Z, Umemoto S, & TM, Kawata Y, Fujii K, Minami M, Sasaki K, Matsuzaki M. Dilazep, a nucleoside transporter inhibitor, modulates cell cycle progression and DNA synthesis in rat mesangial cells in vitro. Cell Prolif 2001; 33:19-28. [PMID: 10741641 PMCID: PMC6622404 DOI: 10.1046/j.1365-2184.2000.00145.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The direct effects of the nucleoside transporter inhibitor dilazep on the cell cycle of mesangial cells have not before been investigated. The purpose of this study was to elucidate whether dilazep can inhibit the proliferation of mesangial cells and how it interferes with the cell cycle of these cells. DNA histograms were used and BrdUrd uptake rate was measured by flow cytometry. There was no significant difference in the cell numbers among the untreated group and the 10(-5) M, 10(-6) M or 10(-7) M dilazep-treated groups at 24 h of incubation. However, at 48 and 72 h, the cell numbers in the dilazep-treated groups were significantly lower compared with that of the untreated group (P < 0.005). The DNA histograms of cultured rat mesangial cells at 12, 24, and 48 h of incubation with 10(-5) M dilazep showed that the ratio of the S phase population in the dilazep-treated group decreased by 2.2% at 12 h, by 9.6% at 24 h, and by 18.9% at 48 h compared with the untreated group. The ratio of the G0/G1 phase population in the dilazep-treated group significantly increased: 6.8% at 12h (P < 0.05), 13.9% at 24 h (P < 0.001), and 76.5% at 48 h (P < 0.001) compared with the untreated group. A flow cytometric measurement of bivariate DNA/BrdUrd distribution demonstrated that the DNA synthesis rate in the S phase decreased after 6 h (P < 0.005) and 12 h (P < 0.05) of incubation compared with the untreated group. These results suggest that dilazep inhibits the proliferation of cultured rat mesangial cells by suppressing the G1/S transition by prolonging G2/M and through decreasing the DNA synthesis rate.
Collapse
Affiliation(s)
- T. Sakumura
- The Second Department of Internal Medicine and
| | - Z. Fujii
- The Second Department of Internal Medicine and
| | - S. Umemoto
- The Second Department of Internal Medicine and
| | | | - Dagger
- The Second Department of Internal Medicine and
| | - Y. Kawata
- The Second Department of Internal Medicine and
| | - K. Fujii
- The Second Department of Internal Medicine and
| | - M. Minami
- The Second Department of Internal Medicine and
| | - K. Sasaki
- The Department of Pathophysiology, Yamaguchi University School of Medicine, Ube, Yamaguchi, Japan; and ‡The Department of Clinical Research, National Sanyo Hospital, Ube, Yamaguchi, Japan
| | | |
Collapse
|
15
|
Merighi S, Varani K, Gessi S, Cattabriga E, Iannotta V, Ulouglu C, Leung E, Borea PA. Pharmacological and biochemical characterization of adenosine receptors in the human malignant melanoma A375 cell line. Br J Pharmacol 2001; 134:1215-26. [PMID: 11704641 PMCID: PMC1573044 DOI: 10.1038/sj.bjp.0704352] [Citation(s) in RCA: 94] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
1. The present work characterizes, from a pharmacological and biochemical point of view, adenosine receptors in the human malignant melanoma A375 cell line. 2. Adenosine receptors were detected by RT - PCR experiments. A1 receptors were characterized using [3H]-DPCPX binding with a KD of 1.9+/-0.2 nM and Bmax of 23+/-7 fmol x mg(-1) of protein. A2A receptors were studied with [3H]-SCH 58261 binding and revealed a KD of 5.1+/-0.2 nM and a Bmax of 220+/-7 fmol x mg(-1) of protein. A3 receptors were studied with the new A3 adenosine receptor antagonist [3H]-MRE 3008F20, the only A3 selective radioligand currently available. Saturation experiments revealed a single high affinity binding site with KD of 3.3+/-0.7 nM and Bmax of 291+/-50 fmol x mg(-1) of protein. 3. The pharmacological profile of radioligand binding on A375 cells was established using typical adenosine ligands which displayed a rank order of potency typical of the different adenosine receptor subtype. 4. Thermodynamic data indicated that radioligand binding to adenosine receptor subtypes in A375 cells was entropy- and enthalpy-driven. 5. In functional assays the high affinity A2A agonists HE-NECA, CGS 21680 and A2A - A2B agonist NECA were able to increase cyclic AMP accumulation in A375 cells whereas A3 agonists Cl-IB-MECA, IB-MECA and NECA were able to stimulate Ca2+ mobilization. In conclusion, all these data indicate, for the first time, that adenosine receptors with a pharmacological and biochemical profile typical of the A1, A2A, A2B and A3 receptor subtype are present on A375 melanoma cell line.
Collapse
Affiliation(s)
- Stefania Merighi
- Department of Clinical and Experimental Medicine, Pharmacology Unit, University of Ferrara, Centro Nazionale Di Eccellenza Per Lo Sviluppo Di Metodologie Innovative Per Lo Studio Ed Il Trattamento Delle Patologie Infiammatorie, Italy
| | - Katia Varani
- Department of Clinical and Experimental Medicine, Pharmacology Unit, University of Ferrara, Centro Nazionale Di Eccellenza Per Lo Sviluppo Di Metodologie Innovative Per Lo Studio Ed Il Trattamento Delle Patologie Infiammatorie, Italy
| | - Stefania Gessi
- Department of Clinical and Experimental Medicine, Pharmacology Unit, University of Ferrara, Centro Nazionale Di Eccellenza Per Lo Sviluppo Di Metodologie Innovative Per Lo Studio Ed Il Trattamento Delle Patologie Infiammatorie, Italy
| | - Elena Cattabriga
- Department of Clinical and Experimental Medicine, Pharmacology Unit, University of Ferrara, Centro Nazionale Di Eccellenza Per Lo Sviluppo Di Metodologie Innovative Per Lo Studio Ed Il Trattamento Delle Patologie Infiammatorie, Italy
| | - Valeria Iannotta
- Department of Clinical and Experimental Medicine, Pharmacology Unit, University of Ferrara, Centro Nazionale Di Eccellenza Per Lo Sviluppo Di Metodologie Innovative Per Lo Studio Ed Il Trattamento Delle Patologie Infiammatorie, Italy
| | - Canan Ulouglu
- Department of Pharmacology, Gazi University, Medical Faculty, Ankara, Turkey
| | - Edward Leung
- King Pharmaceuticals, Cary, North Carolina, U.S.A
| | - Pier Andrea Borea
- Department of Clinical and Experimental Medicine, Pharmacology Unit, University of Ferrara, Centro Nazionale Di Eccellenza Per Lo Sviluppo Di Metodologie Innovative Per Lo Studio Ed Il Trattamento Delle Patologie Infiammatorie, Italy
- Author for correspondence:
| |
Collapse
|
16
|
Gu JW, Ito BR, Sartin A, Frascogna N, Moore M, Adair TH. Inhibition of adenosine kinase induces expression of VEGF mRNA and protein in myocardial myoblasts. Am J Physiol Heart Circ Physiol 2000; 279:H2116-23. [PMID: 11045944 DOI: 10.1152/ajpheart.2000.279.5.h2116] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We tested whether increased endogenous adenosine produced by the adenosine kinase inhibitor GP-515 (Metabasis Therapeutics) can induce vascular endothelial growth factor (VEGF) expression in cultured rat myocardial myoblasts (RMMs). RMMs were cultured for 18 h in the absence (control) and presence of GP-515, adenosine (Ado), adenosine deaminase (ADA), or GP-515 + ADA. GP-515 (0.2-200 microM) caused a dose-related increase in VEGF protein expression (1.99-2.84 ng/mg total cell protein); control VEGF was 1.84 +/- 0.05 ng/mg. GP-515 at 2 and 20 microM also increased VEGF mRNA by 1.67- and 1. 82-fold, respectively. ADA (10 U/ml) decreased baseline VEGF protein levels by 60% and completely blocked GP-515 induction of VEGF. Ado (20 microM) and GP-515 (20 microM) caused a 59 and 39% increase in VEGF protein expression and a 98 and 33% increase in human umbilical vein endothelial cell proliferation, respectively, after 24 h of exposure. GP-515 (20 microM) had no effect on VEGF protein expression during severe hypoxia (1% O(2)) but increased VEGF by an additional 27% during mild hypoxia (10% O(2)). These results indicate that raising endogenous levels of Ado through inhibition of adenosine kinase can increase the expression of VEGF and stimulate endothelial cell proliferation during normoxic and hypoxic conditions.
Collapse
Affiliation(s)
- J W Gu
- Angiogenesis Research Laboratories, Department of Physiology and Biophysics, Center for Excellence in Cardiovascular-Renal Research, University of Mississippi Medical Center, Jackson, Mississippi 39216, USA
| | | | | | | | | | | |
Collapse
|
17
|
Picano E, Abbracchio MP. Adenosine, the imperfect endogenous anti-ischemic cardio-neuroprotector. Brain Res Bull 2000; 52:75-82. [PMID: 10808076 DOI: 10.1016/s0361-9230(00)00249-5] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Affiliation(s)
- E Picano
- Italian National Research Council, Institute of Clinical Physiology, Pisa, Italy
| | | |
Collapse
|