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Zhou K, Yuan M, Sun J, Zhang F, Zong X, Li Z, Tang D, Zhou L, Zheng J, Xiao X, Wu X. Sildenafil increases AAV9 transduction after a systemic administration and enhances AAV9-dystrophin therapeutic effect in mdx mice. Gene Ther 2024; 31:19-30. [PMID: 37500816 DOI: 10.1038/s41434-023-00411-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 07/07/2023] [Accepted: 07/17/2023] [Indexed: 07/29/2023]
Abstract
Adeno-associated virus (AAV) vectors have been successfully used to deliver genes for treating rare diseases. However, the systemic administration of high AAV vector doses triggers several adverse effects, including immune response, the asymptomatic elevation of liver transaminase levels, and complement activation. Thus, improving AAV transduction and reducing AAV dosage for treatment is necessary. Recently, we found that a phosphodiesterase-5 inhibitor significantly promoted AAV9 transduction in vitro by regulating the caveolae and macropinocytosis pathways. When AAV9-Gaussian luciferase (AAV9-Gluc) and AAV9-green fluorescent protein (AAV9-GFP) were injected intravenously into mice pre-treated with sildenafil, the expressions of Gluc in the plasma and GFP in muscle tissues significantly increased (P < 0.05). Sildenafil also improved Evans blue permeation in tissues. Additionally, we found that sildenafil promoted Treg proliferation, inhibited B-cell activation, and decreased anti-AAV9 IgG levels (P < 0.05). Furthermore, sildenafil significantly promoted Duchenne muscular dystrophy gene therapy efficacy using AAV9 in mdx mice; it increased micro-dystrophin gene expression, forelimb grip strength, and time spent on the rotarod test, decreased serum creatine kinase levels, and ameliorated histopathology by improving muscle cell morphology and reducing fibrosis (P < 0.05). These results show that sildenafil significantly improved AAV transduction, suppressed the levels of anti-AAV9 IgG, and enhanced the efficacy of gene therapy.
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Affiliation(s)
- Kaiyi Zhou
- School of Pharmacy, East China University of Science and Technology, Shanghai, China
| | - Meng Yuan
- School of Pharmacy, East China University of Science and Technology, Shanghai, China
| | - Jiabao Sun
- School of Pharmacy, East China University of Science and Technology, Shanghai, China
| | - Feixu Zhang
- State Key Laboratory of Bioreactor Engineering, School of Biotechnology, East China University of Science and Technology, Shanghai, China
| | - Xiaoying Zong
- School of Pharmacy, East China University of Science and Technology, Shanghai, China
| | - Zhanao Li
- School of Pharmacy, East China University of Science and Technology, Shanghai, China
| | - Dingyue Tang
- State Key Laboratory of Bioreactor Engineering, School of Biotechnology, East China University of Science and Technology, Shanghai, China
| | - Lichen Zhou
- The General Hospital of Western Theater Command PLA, Sichuan Province, China
| | - Jing Zheng
- Belief BioMed, Xuhui District, Shanghai, China
| | - Xiao Xiao
- School of Pharmacy, East China University of Science and Technology, Shanghai, China.
- Division of Pharmacoengineering and Molecular Pharmaceutics, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC, 27517, USA.
| | - Xia Wu
- School of Pharmacy, East China University of Science and Technology, Shanghai, China.
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Blood-Brain Barrier Modulation to Improve Glioma Drug Delivery. Pharmaceutics 2020; 12:pharmaceutics12111085. [PMID: 33198244 PMCID: PMC7697580 DOI: 10.3390/pharmaceutics12111085] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 11/09/2020] [Accepted: 11/10/2020] [Indexed: 02/07/2023] Open
Abstract
The blood-brain barrier (BBB) is formed by brain microvascular endothelial cells that are sealed by tight junctions, making it a significant obstacle for most brain therapeutics. The poor BBB penetration of newly developed therapeutics has therefore played a major role in limiting their clinical success. A particularly challenging therapeutic target is glioma, which is the most frequently occurring malignant brain tumor. Thus, to enhance therapeutic uptake in tumors, researchers have been developing strategies to modulate BBB permeability. However, most conventional BBB opening strategies are difficult to apply in the clinical setting due to their broad, non-specific modulation of the BBB, which can result in damage to normal brain tissue. In this review, we have summarized strategies that could potentially be used to selectively and efficiently modulate the tumor BBB for more effective glioma treatment.
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Xie H, Lu WC. Inhibition of transient receptor potential vanilloid 4 decreases the expressions of caveolin-1 and caveolin-2 after focal cerebral ischemia and reperfusion in rats. Neuropathology 2018; 38:337-346. [PMID: 29665111 DOI: 10.1111/neup.12469] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Revised: 02/20/2018] [Accepted: 03/18/2018] [Indexed: 01/26/2023]
Abstract
This study aimed to investigate the effects of transient receptor potential vanilloid 4 (TRPV4) inhibition on blood-brain barrier (BBB) integrity and the expressions of caveolae structural proteins caveolin-1 and caveolin-2 in rats with focal cerebral ischemia and reperfusion. BBB permeability was assessed by Evans blue extravasation. The mRNA and protein expressions of caveolin-1 and caveolin-2 were determined by RT-PCR, Western blot and immunohistochemistry assays. We found that BBB permeability significantly increased and reaches its peak at 72 h of reperfusion in cerebral ischemia-reperfusion rats and is able to be ameliorated by administration of HC-067047, an antagonist of TRPV4. Additionally, it shows a significant upregulation of caveolin-1 and caveolin-2 expression in cerebral microvessels of ischemic tissue. However, treatment with HC-067047 was shown to downregulate caveolin-1 and caveolin-2 expression during cerebral ischemia-reperfusion. This study demonstrates that inhibition of TRPV4 ameliorates BBB leakage induced by ischemia-reperfusion injury through the downregulation of caveolin-1 and caveolin-2.
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Affiliation(s)
- Hui Xie
- Department of Histology and Embryology, College of Basic Medicine, Shenyang Medical College, Shenyang, China
| | - Wei-Cheng Lu
- Department of Neurosurgery, First Affiliated Hospital of China Medical University, Shenyang, China
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Hudson C, Kimura TE, Duggirala A, Sala-Newby GB, Newby AC, Bond M. Dual Role of CREB in The Regulation of VSMC Proliferation: Mode of Activation Determines Pro- or Anti-Mitogenic Function. Sci Rep 2018; 8:4904. [PMID: 29559698 PMCID: PMC5861041 DOI: 10.1038/s41598-018-23199-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Accepted: 03/06/2018] [Indexed: 11/15/2022] Open
Abstract
Vascular smooth muscle cell (VSMC) proliferation has been implicated in the development of restenosis after angioplasty, vein graft intimal thickening and atherogenesis. We investigated the mechanisms underlying positive and negative regulation of VSMC proliferation by the transcription factor cyclic AMP response element binding protein (CREB). Incubation with the cAMP elevating stimuli, adenosine, prostacyclin mimetics or low levels of forksolin activated CREB without changing CREB phosphorylation on serine-133 but induced nuclear translocation of the CREB co-factors CRTC-2 and CRTC-3. Overexpression of CRTC-2 or -3 significantly increased CREB activity and inhibited VSMC proliferation, whereas CRTC-2/3 silencing inhibited CREB activity and reversed the anti-mitogenic effects of adenosine A2B receptor agonists. By contrast, stimulation with serum or PDGFBB significantly increased CREB activity, dependent on increased CREB phosphorylation at serine-133 but not on CRTC-2/3 activation. CREB silencing significantly inhibited basal and PDGF induced proliferation. These data demonstrate that cAMP activation of CREB, which is CRTC2/3 dependent and serine-133 independent, is anti-mitogenic. Growth factor activation of CREB, which is serine-133-dependent and CRTC2/3 independent, is pro-mitogenic. Hence, CREB plays a dual role in the regulation of VSMC proliferation with the mode of activation determining its pro- or anti-mitogenic function.
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Affiliation(s)
- Claire Hudson
- Translational Health Sciences, University of Bristol, Research Floor Level 7, Bristol Royal Infirmary, Bristol, BS2 8HW, UK
| | - Tomomi E Kimura
- Translational Health Sciences, University of Bristol, Research Floor Level 7, Bristol Royal Infirmary, Bristol, BS2 8HW, UK.,School of Life Sciences, University of Warwick, Coventry, CV4 7AL, UK
| | - Aparna Duggirala
- Translational Health Sciences, University of Bristol, Research Floor Level 7, Bristol Royal Infirmary, Bristol, BS2 8HW, UK
| | - Graciela B Sala-Newby
- Translational Health Sciences, University of Bristol, Research Floor Level 7, Bristol Royal Infirmary, Bristol, BS2 8HW, UK
| | - Andrew C Newby
- Translational Health Sciences, University of Bristol, Research Floor Level 7, Bristol Royal Infirmary, Bristol, BS2 8HW, UK
| | - Mark Bond
- Translational Health Sciences, University of Bristol, Research Floor Level 7, Bristol Royal Infirmary, Bristol, BS2 8HW, UK.
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Cheung CY. Vascular Endothelial Growth Factor Activation of Intramembranous Absorption: A Critical Pathway for Amniotic Fluid Volume Regulation. ACTA ACUST UNITED AC 2016; 11:63-74. [PMID: 14980307 DOI: 10.1016/j.jsgi.2003.09.002] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
OBJECTIVE The purpose of this review is to propose a critical role for vascular endothelial growth factor (VEGF) in mediating the transfer of amniotic fluid from the amniotic compartment through the fetal membranes and fetal surface of the placenta into fetal blood. METHODS Experimental findings in humans and animal models on the action of VEGF in mediating fluid transfer are reviewed and interpreted in order to postulate a proposed mechanism for VEGF regulation of amniotic fluid absorption through the fetal membranes and placenta. RESULTS Recent scientific advances suggest that up-regulation of VEGF gene expression in the amnion and chorion is associated with increased transfer of amniotic fluid into fetal blood. The possible mechanisms of action for VEGF appear to involve regulation of intramembranous blood vessel proliferation and membrane transport via passive permeation as well as nonpassive transcytotic vesicular movement of fluid. CONCLUSION Currently evolving concepts suggest that amniotic fluid volume is regulated through modulation of the rate of intramembranous absorption of amniotic fluid by both passive and nonpassive mechanisms. The permeability factor VEGF appears to be a critical regulator of amniotic fluid transport in the fetal membranes.
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Affiliation(s)
- Cecilia Y Cheung
- Division of Perinatal Medicine, Department of Reproductive Medicine, University of California at San Diego, La Jolla, California 92093-0802, USA.
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Ohno S, Saitoh Y, Ohno N, Terada N. Renaissance of morphological studies: the examination of functional structures in living animal organs using the in vivo cryotechnique. Anat Sci Int 2016; 92:55-78. [DOI: 10.1007/s12565-016-0355-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Accepted: 06/27/2016] [Indexed: 11/28/2022]
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Interplay of hypoxia and A2B adenosine receptors in tissue protection. ADVANCES IN PHARMACOLOGY 2011; 61:145-86. [PMID: 21586359 DOI: 10.1016/b978-0-12-385526-8.00006-0] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
That adenosine signaling can elicit adaptive tissue responses during conditions of limited oxygen availability (hypoxia) is a long-suspected notion that recently gained general acceptance from genetic and pharmacologic studies of the adenosine signaling pathway. As hypoxia and inflammation share an interdependent relationship, these studies have demonstrated that adenosine signaling events can be targeted to dampen hypoxia-induced inflammation. Here, we build on the hypothesis that particularly the A(2B) adenosine receptor (ADORA(2B)) plays a central role in tissue adaptation to hypoxia. In fact, the ADORA(2B) requires higher adenosine concentrations than any of the other adenosine receptors. However, during conditions of hypoxia or ischemia, the hypoxia-elicited rise in extracellular adenosine is sufficient to activate the ADORA(2B). Moreover, several studies have demonstrated very robust induction of the ADORA(2B) elicited by transcriptional mechanisms involving hypoxia-dependent signaling pathways and the transcription factor "hypoxia-induced factor" 1. In the present chapter, genetic and pharmacologic evidence is presented to support our hypothesis of a tissue protective role of ADORA(2B) signaling during hypoxic conditions, including hypoxia-elicited vascular leakage, organ ischemia, or acute lung injury. All these disease models are characterized by hypoxia-elicited tissue inflammation. As such, the ADORA(2B) has emerged as a therapeutic target for dampening hypoxia-induced inflammation and tissue adaptation to limited oxygen availability.
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8
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Hu J, Ljubimova JY, Inoue S, Konda B, Patil R, Ding H, Espinoza A, Wawrowsky KA, Patil C, Ljubimov AV, Black KL. Phosphodiesterase type 5 inhibitors increase Herceptin transport and treatment efficacy in mouse metastatic brain tumor models. PLoS One 2010; 5:e10108. [PMID: 20419092 PMCID: PMC2856671 DOI: 10.1371/journal.pone.0010108] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2010] [Accepted: 03/18/2010] [Indexed: 11/20/2022] Open
Abstract
Background Chemotherapeutic drugs and newly developed therapeutic monoclonal antibodies are adequately delivered to most solid and systemic tumors. However, drug delivery into primary brain tumors and metastases is impeded by the blood-brain tumor barrier (BTB), significantly limiting drug use in brain cancer treatment. Methodology/Principal Findings We examined the effect of phosphodiesterase 5 (PDE5) inhibitors in nude mice on drug delivery to intracranially implanted human lung and breast tumors as the most common primary tumors forming brain metastases, and studied underlying mechanisms of drug transport. In vitro assays demonstrated that PDE5 inhibitors enhanced the uptake of [14C]dextran and trastuzumab (Herceptin®, a humanized monoclonal antibody against HER2/neu) by cultured mouse brain endothelial cells (MBEC). The mechanism of drug delivery was examined using inhibitors for caveolae-mediated endocytosis, macropinocytosis and coated pit/clathrin endocytosis. Inhibitor analysis strongly implicated caveolae and macropinocytosis endocytic pathways involvement in the PDE5 inhibitor-enhanced Herceptin uptake by MBEC. Oral administration of PDE5 inhibitor, vardenafil, to mice with HER2-positive intracranial lung tumors led to an increased tumor permeability to high molecular weight [14C]dextran (2.6-fold increase) and to Herceptin (2-fold increase). Survival time of intracranial lung cancer-bearing mice treated with Herceptin in combination with vardenafil was significantly increased as compared to the untreated, vardenafil- or Herceptin-treated mice (p<0.01). Log-rank survival analysis of mice bearing HER2-positive intracranial breast tumor also showed a significant survival increase (p<0.02) in the group treated with Herceptin plus vardenafil as compared to other groups. However, vardenafil did not exert any beneficial effect on survival of mice bearing intracranial breast tumor with low HER2 expression and co-treated with Herceptin (p>0.05). Conclusions/Significance These findings suggest that PDE5 inhibitors may effectively modulate BTB permeability, and enhance delivery and therapeutic efficacy of monoclonal antibodies in hard-to-treat brain metastases from different primary tumors that had metastasized to the brain.
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Affiliation(s)
- Jinwei Hu
- Department of Neurosurgery, Maxine Dunitz Neurosurgical Institute, Cedars-Sinai Medical Center, Los Angeles, California, United States of America
| | - Julia Y. Ljubimova
- Department of Neurosurgery, Maxine Dunitz Neurosurgical Institute, Cedars-Sinai Medical Center, Los Angeles, California, United States of America
- * E-mail:
| | - Satoshi Inoue
- Department of Neurosurgery, Maxine Dunitz Neurosurgical Institute, Cedars-Sinai Medical Center, Los Angeles, California, United States of America
| | - Bindu Konda
- Department of Neurosurgery, Maxine Dunitz Neurosurgical Institute, Cedars-Sinai Medical Center, Los Angeles, California, United States of America
| | - Rameshwar Patil
- Department of Neurosurgery, Maxine Dunitz Neurosurgical Institute, Cedars-Sinai Medical Center, Los Angeles, California, United States of America
| | - Hui Ding
- Department of Neurosurgery, Maxine Dunitz Neurosurgical Institute, Cedars-Sinai Medical Center, Los Angeles, California, United States of America
| | - Andres Espinoza
- Department of Neurosurgery, Maxine Dunitz Neurosurgical Institute, Cedars-Sinai Medical Center, Los Angeles, California, United States of America
| | - Kolja A. Wawrowsky
- Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California, United States of America
| | - Chirag Patil
- Department of Neurosurgery, Maxine Dunitz Neurosurgical Institute, Cedars-Sinai Medical Center, Los Angeles, California, United States of America
| | - Alexander V. Ljubimov
- Department of Surgery, Cedars-Sinai Medical Center, Los Angeles, California, United States of America
- David Geffen School of Medicine at University of California Los Angeles, Los Angeles, California, United States of America
| | - Keith L. Black
- Department of Neurosurgery, Maxine Dunitz Neurosurgical Institute, Cedars-Sinai Medical Center, Los Angeles, California, United States of America
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Veldhuijzen van Zanten JJCS, Ring C, Carroll D, McIntyre D, Brown MD. Hemoconcentration during a prolonged stress task: associations with hemodynamic reactivity and microvascular permeability. Biol Psychol 2009; 82:260-6. [PMID: 19699776 DOI: 10.1016/j.biopsycho.2009.08.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2008] [Revised: 08/13/2009] [Accepted: 08/16/2009] [Indexed: 11/30/2022]
Abstract
This study explored the association between stress-induced hemoconcentration and plasma colloid osmotic pressure, hemodynamic reactivity, and microvascular permeability during a protracted stress task in 26 healthy, young participants. Microvascular permeability was measured during rest using venous congestion plethysmography in a subsample of 13 participants. The task increased hematocrit, colloid osmotic pressure, blood pressure, and heart rate and decreased R-wave to pulse interval. Resting microvascular permeability was not correlated with hemoconcentration. Colloid osmotic pressure and diastolic blood pressure were associated with stress-induced hemoconcentration throughout the task. The association with systolic blood pressure as well as heart rate, however, was more evident during the initial 8min of the task than throughout the total task duration. These findings suggest that factors associated with hemoconcentration vary with task duration.
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Xia CY, Zhang Z, Xue YX, Wang P, Liu YH. Mechanisms of the increase in the permeability of the blood-tumor barrier obtained by combining low-frequency ultrasound irradiation with small-dose bradykinin. J Neurooncol 2009; 94:41-50. [PMID: 19234812 DOI: 10.1007/s11060-009-9812-9] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2008] [Accepted: 02/02/2009] [Indexed: 12/15/2022]
Abstract
The research was conducted to study the characteristics of the noninvasive, reversible, targeted opening of the blood-brain barrier (BBB) by use of low-frequency ultrasound (LFU) irradiation and the selective opening of the blood-tumor barrier (BTB) by intracarotid infusion of bradykinin (BK) in small-dose, with the objective of exploring maximum opening of the BTB by combining LFU irradiation with BK infusion. Thus, it provides new therapeutic strategies for targeted transport of macromolecular or granular drugs to the brain. By using the rat C6 glioma model it was shown that extravasation of Evans blue (EB) through the BTB was significantly increased by combining LFU irradiation (frequency = 1.0 MHz, power = 12 mW, duration = 20 s) with intracarotid small-dose BK infusion, compared with utilizing the two methods separately. By transmission electron microscopy (TEM) we observed that this combination significantly increased the number of pinocytotic vesicles of brain microvascular endothelial cells (BMECs) in the BTB. An even more significant increase was observed by using RT-PCR, western blot, immunohistochemistry, and immunofluorescence to detect mRNA and changes of expression of the caveolae structure proteins caveolin-1 and caveolin-2 of BMECs. In summary, this research concludes that LFU irradiation and small-dose BK together selectively enhance the permeability of the BTB and increase the number of pinocytic vesicles of BMECs to a maximum. Significant up-regulation of the level of expression of caveolae structure proteins caveolin-1 and caveolin-2 might be the molecular mechanism of the co-enhanced endocytotic transport by BMECs. Thus, this research provides new therapeutic strategies for targeted transport of macromolecular drugs and the design of drugs.
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Affiliation(s)
- Chun-yi Xia
- Department of Neurosurgery, Shengjing Hospital of China Medical University, Shenyang 110004, People's Republic of China
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11
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Abstract
Cyclic guanosine 3', 5'-monophosphate (cGMP) plays an integral role in the control of vascular function. Generated from guanylate cyclases in response to the endogenous ligands, nitric oxide (NO) and natriuretic peptides (NPs), cGMP influences a number of vascular cell types and regulates vasomotor tone, endothelial permeability, cell growth and differentiation, as well as platelet and blood cell interactions. Reciprocal regulation of the NO-cGMP and NP-cGMP pathways is evident in the vasculature such that one cGMP generating system may compensate for the dysfunction of the other. Indeed, aberrant cGMP production and/or signalling accompanies many vascular disorders such as hypertension, atherosclerosis, coronary artery disease and diabetic complications. This chapter highlights the main vascular functions of cGMP, its role in disease and the resulting current and potential therapeutic applications. With respect to pulmonary hypertension, heart failure and erectile dysfunction, as well as cGMP signal transduction, the reader is specifically referred to other dedicated chapters.
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Affiliation(s)
- Barbara Kemp-Harper
- Department of Pharmacology, Monash University, Melbourne (Clayton), VIC, 3800, Australia.
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12
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Abstract
Extracellular adenosine has been implicated in adaptation to hypoxia and previous studies demonstrated a central role in vascular responses. Here, we examined the contribution of individual adenosine receptors (ARs: A1AR/A2AAR/A2BAR/A3AR) to vascular leak induced by hypoxia. Initial profiling studies revealed that siRNA-mediated repression of the A2BAR selectively increased endothelial leak in response to hypoxia in vitro. In parallel, vascular permeability was significantly increased in vascular organs of A2BAR(-/-)-mice subjected to ambient hypoxia (8% oxygen, 4 hours; eg, lung: 2.1 +/- 0.12-fold increase). By contrast, hypoxia-induced vascular leak was not accentuated in A1AR(-/-)-, A2AAR(-/-)-, or A3AR(-/-)-deficient mice, suggesting a degree of specificity for the A2BAR. Further studies in wild type mice revealed that the selective A2BAR antagonist PSB1115 resulted in profound increases in hypoxia-associated vascular leakage while A2BAR agonist (BAY60-6583 [2-[6-amino-3,5-dicyano-4-[4-(cyclopropylmethoxy)-. phenyl]pyridin-2-ylsulfanyl]acetamide]) treatment was associated with almost complete reversal of hypoxia-induced vascular leakage (eg, lung: 2.0 +/- 0.21-fold reduction). Studies in bone marrow chimeric A2BAR mice suggested a predominant role of vascular A2BARs in this response, while hypoxia-associated increases in tissue neutrophils were, at least in part, mediated by A2BAR expressing hematopoietic cells. Taken together, these studies provide pharmacologic and genetic evidence for vascular A2BAR signaling as central control point of hypoxia-associated vascular leak.
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Morris CE, Skalak TC. Acute exposure to a moderate strength static magnetic field reduces edema formation in rats. Am J Physiol Heart Circ Physiol 2007; 294:H50-7. [PMID: 17982018 DOI: 10.1152/ajpheart.00529.2007] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
External application of static magnetic fields (SMF), used specifically for the treatment of inflammatory conditions such as soft tissue injuries, has recently become popular as a complementary and/or alternative therapy with minimal investigation into efficacy or mechanism. Localized inflammation was induced via injection of inflammatory agents lambda-carrageenan (CA) or histamine into rat hindpaws, alone or in conjunction with pharmacological agents, resulting in a spatially and temporally defined inflammatory reaction. Application of a 10- or 70-mT, but not a 400-mT, SMF for 15 or 30 min immediately following histamine-induced edema resulted in a significant, 20-50% reduction in edema formation. In addition, a 2-h, 70-mT field application to CA-induced edema also resulted in significant (33-37%) edema reduction. Field application before injection or at the time of maximal edema did not influence edema formation or resolution, respectively. Together, these results suggest the existence of a therapeutic threshold of SMF strength (below 400 mT) and a temporal dependence of efficacy. Administration of pharmacological agents directed at nitric oxide signaling and L-type Ca(2+) channel dynamics in conjunction with SMF treatment and histamine-induced edema revealed that the potential mechanism of SMF action may be via modulation of vascular tone through effects on L-type Ca(2+) channels in vascular smooth muscle cells.
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Affiliation(s)
- Cassandra E Morris
- Department of Biomedical Engineering, University of Virginia Health Sciences Center, Health System, Charlottesville, VA 22908, USA
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Dieterich HJ, Weissmüller T, Rosenberger P, Eltzschig HK. Effect of hydroxyethyl starch on vascular leak syndrome and neutrophil accumulation during hypoxia. Crit Care Med 2006; 34:1775-82. [PMID: 16625120 DOI: 10.1097/01.ccm.0000218814.77568.bc] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
OBJECTIVE Several studies have suggested that intravenous hydroxyethyl starch treatment may dampen acute inflammatory responses. It is well documented that limited oxygen delivery to tissues (hypoxia) is common in acute inflammation, and numerous parallels exist between acute responses to hypoxia and to inflammation, including the observation that both are associated with increased vascular leakage and neutrophil infiltration of tissues. Therefore, we compared functional influences of hydroxyethyl starch on normoxic or posthypoxic endothelia. DESIGN Laboratory study. SETTING University hospital. SUBJECTS Cultured human microvascular endothelial cells and mice (C57BL/6/129 svj). INTERVENTIONS We measured functional influences of hydroxyethyl starch on normoxic or posthypoxic endothelia. MEASUREMENTS AND MAIN RESULTS Studies to assess endothelial barrier function in vitro indicated that the addition of hydroxyethyl starch promotes endothelial barrier in a dose-dependent fashion and hydroxyethyl starch-barrier effects are increased following endothelial hypoxia exposure (human microvascular endothelial cells, 48 hrs, 2% oxygen). Treatment of human microvascular endothelial cells with hydroxyethyl starch resulted in a dose-dependent increase in 157-phosphorylated vasodilator-stimulated phosphoprotein, a protein responsible for controlling the geometry of actin-filaments. Neutrophil adhesion was decreased in the presence of physiologically relevant concentrations of hydroxyethyl starch in vitro, particularly after endothelial hypoxia exposure. Using a murine model of normobaric hypoxia, increases in vascular leakage and pulmonary edema associated with hypoxia exposure (4 hrs at 8% oxygen) were decreased in animals treated with intravenous hydroxyethyl starch. Increases of tissue neutrophil accumulation following hypoxia exposure were dampened in hydroxyethyl starch-treated mice. CONCLUSIONS Taken together, these results indicate that hypoxia-induced increases in vascular leakage and acute inflammation are attenuated by hydroxyethyl starch treatment.
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Affiliation(s)
- Hans-Jürgen Dieterich
- Department of Anesthesiology and Intensive Care Medicine, Tübingen University Hospital, Tübingen, Germany
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15
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Dynamic purine signaling and metabolism during neutrophil-endothelial interactions. Purinergic Signal 2005; 1:229-39. [PMID: 18404508 PMCID: PMC2096542 DOI: 10.1007/s11302-005-6323-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2004] [Revised: 03/07/2005] [Accepted: 03/23/2005] [Indexed: 01/09/2023] Open
Abstract
During episodes of hypoxia and inflammation, polymorphonuclear leukocytes (PMN) move into underlying tissues by initially passing between endothelial cells that line the inner surface of blood vessels (transendothelial migration, TEM). TEM creates the potential for disturbances in vascular barrier and concomitant loss of extravascular fluid and resultant edema. Recent studies have demonstrated a crucial role for nucleotide metabolism and nucleoside signaling during inflammation. These studies have implicated multiple adenine nucleotides as endogenous tissue protective mechanisms invivo. Here, we review the functional components of vascular barrier, identify strategies for increasing nucleotide generation and nucleoside signaling, and discuss potential therapeutic targets to regulate the vascular barrier during inflammation.
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Thompson LF, Eltzschig HK, Ibla JC, Van De Wiele CJ, Resta R, Morote-Garcia JC, Colgan SP. Crucial role for ecto-5'-nucleotidase (CD73) in vascular leakage during hypoxia. ACTA ACUST UNITED AC 2005; 200:1395-405. [PMID: 15583013 PMCID: PMC1237012 DOI: 10.1084/jem.20040915] [Citation(s) in RCA: 432] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Extracellular adenosine has been widely implicated in adaptive responses to hypoxia. The generation of extracellular adenosine involves phosphohydrolysis of adenine nucleotide intermediates, and is regulated by the terminal enzymatic step catalyzed by ecto-5′-nucleotidase (CD73). Guided by previous work indicating that hypoxia-induced vascular leakage is, at least in part, controlled by adenosine, we generated mice with a targeted disruption of the third coding exon of Cd73 to test the hypothesis that CD73-generated extracellular adenosine functions in an innate protective pathway for hypoxia-induced vascular leakage. Cd73−/− mice bred and gained weight normally, and appeared to have an intact immune system. However, vascular leakage was significantly increased in multiple organs, and after subjection to normobaric hypoxia (8% O2), Cd73−/− mice manifested fulminant vascular leakage, particularly prevalent in the lung. Histological examination of lungs from hypoxic Cd73−/− mice revealed perivascular interstitial edema associated with inflammatory infiltrates surrounding larger pulmonary vessels. Vascular leakage secondary to hypoxia was reversed in part by adenosine receptor agonists or reconstitution with soluble 5′-nucleotidase. Together, our studies identify CD73 as a critical mediator of vascular leakage in vivo.
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Affiliation(s)
- Linda F Thompson
- Immunobiology and Cancer Program, Oklahoma Medical Research Foundation, 825 NE 13th St., Oklahoma City, OK 73104, USA.
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Zhu B, Kelly J, Vemavarapu L, Thompson WJ, Strada SJ. Activation and induction of cyclic AMP phosphodiesterase (PDE4) in rat pulmonary microvascular endothelial cells. Biochem Pharmacol 2004; 68:479-91. [PMID: 15242814 DOI: 10.1016/j.bcp.2004.03.039] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2004] [Accepted: 03/30/2004] [Indexed: 11/28/2022]
Abstract
Regulation of the rolipram-sensitive cAMP-specific phosphodiesterase 4 (PDE4) gene family was studied in rat pulmonary microvascular endothelial cells (RPMVECs). Total PDE4 hydrolysis was increased within 10 min after addition of forskolin (10 microM), reached a maximum at 20-40 min, and then gradually declined in the cells. A similar activation of PDE4 activity was observed using a protein kinase A (PKA) activator, N(6)-monobutyryl cAMP. Both the forskolin and the N(6)-monobutyryl cAMP activated PDE4 activities were blocked by the PKA-specific inhibitor, H89. This forskolin-stimulated and PKA-mediated short-term activation of PDE4 activity was further confirmed by in vitro phosphorylation of 87kDa PDE4A6 and 83kDa PDE4B3 polypeptides using exogenous PKA Calpha. Increased immunoreactivity of phosphorylated PDE4A6 in situ was detected in Western blots by a PDE4A-phospho antibody specific to the putative PKA phosphorylation sites. Following long-term treatment of RPMVECs with rolipram and forskolin medium (RFM) for more than 60 days, PDE4 activity reached ten-fold higher values than control RPMVECS with twenty-fold increases detected in intracellular cAMP content. The RFM cells showed increased immunoreactivities of the constitutive 4A6 and 4B3 isoforms plus two novel splice variants at 101kDa (4B1) and 71kDa (4B2). Treatment with H89 did not inhibit the PDE4 elevation in RFM cells. In addition to the increased levels of PDE4 in RFM cells, immunofluorescence showed a translocation of PDE4A and 4B to a nuclear region, which was normally not observed in RPMVECs. The PDE4 activity in RFM cells decayed rapidly with an even faster decline of intracellular cAMP content when forskolin/rolipram were removed from the medium. These results suggest that both the activation (short-term) and induction (long-term) of PDE4A/4B isoforms in RPMVECs are closely modulated by the intracellular cAMP content via both post-translational and synthetic mechanisms.
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Affiliation(s)
- Bing Zhu
- Department of Pharmacology, University of South Alabama College of Medicine, Mobile, AL 36688, USA
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Veldhuijzen van Zanten JJCS, Ring C, Burns VE, Edwards KM, Drayson M, Carroll D. Mental stress-induced hemoconcentration: Sex differences and mechanisms. Psychophysiology 2004; 41:541-51. [PMID: 15189477 DOI: 10.1111/j.1469-8986.2004.00190.x] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Given the possible role of hemoconcentration in myocardial infarction and apparent sex differences in susceptibility, three studies examined sex differences in mental stress-induced hemoconcentration, and explored possible underlying mechanisms. Blood pressure, heart rate, and hematocrit were monitored at rest and in response to a mental stress task that was contrived to be increasingly provocative across the three studies. This was confirmed by self-report, performance, and cardiovascular reactivity data. The most convincing evidence for hemoconcentration effects and sex differences in hemoconcentration emerged from exposure to the more provocative of the stress tasks, with men also showing greater hemoconcentration than women. Blood pressure reactivity was a strong and consistent predictor of stress-induced hemoconcentration. These findings may help to explain sex differences in susceptibility to myocardial infarction.
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Jacobs M, Levin M. An improved endothelial barrier model to investigate dengue haemorrhagic fever. J Virol Methods 2002; 104:173-85. [PMID: 12088827 DOI: 10.1016/s0166-0934(02)00065-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
A cell culture model suitable for studies of dengue haemorrhagic fever was developed, based on culture of primary human umbilical vein endothelial cells (HUVECs) on a permeable membrane. By electron microscopy, cultured HUVECs at day 11 resembled morphologically microvascular endothelium. Endothelial barrier function was assessed by measuring transendothelial flux of albumin. Instead of using a labelled tracer molecule, an enzyme-linked immunosorbent assay (ELISA) was developed to measure concentrations of native human albumin. The permeability characteristics of the HUVEC monolayer were found to be improved significantly (approximately 1 log reduction in permeability coefficient for albumin) by culturing HUVECs in human serum rather than fetal calf serum. Permeability coefficients for albumin in the range 1-4 x 10(-7) cm/s were achieved, which is an improvement on previous in vitro models of the endothelial barrier. Comparison of transendothelial flux of albumin and urea provided evidence of molecular sieving by the HUVEC monolayer. Moreover, tumour necrosis factor-alpha induced a dose-dependent, reversible increase in permeability of the HUVEC monolayer. This endothelial barrier model thus has many important characteristics that resembled human microvascular endothelium and is an improvement on the previous model proposed for studies of dengue haemorrhagic fever.
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Affiliation(s)
- Michael Jacobs
- Department of Medicine, Imperial College of Science, Technology and Medicine, 10th Floor, QEQM Wing, Norfolk Place, London W2 1PG, UK.
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Abstract
Caveolae are spherical invaginations of the plasma membrane and associated vesicles that are found at high surface densities in most cells, endothelia included. Their structural framework has been shown to consist of oligomerized caveolin molecules interacting with cholesterol and sphingolipids. Caveolae have been involved in many cellular functions such as endocytosis, signal transduction, mechano-transduction, potocytosis, and cholesterol trafficking. Some confusion still persists in the field with respect to the relationship between caveolae and the lipid rafts, which have been involved in many of the above functions. In addition to all these, endothelial caveolae have been involved in capillary permeability by their participation in the process of transcytosis. This short review will focus on their structure and components, methods used to determine these components, and the role of caveolae in the transendothelial exchanges between blood plasma and the interstitial fluid.
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Affiliation(s)
- Radu-Virgil Stan
- Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, California 92093-0651, USA.
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Zeneberg A, Roulo A, Grobe J, Zhao P, Lelkes PI, Clare P, Barney C. Expression of VACM-1 protein in cultured rat adrenal endothelial cells is linked to the cell cycle. ENDOTHELIUM : JOURNAL OF ENDOTHELIAL CELL RESEARCH 2002; 8:49-63. [PMID: 11409851 DOI: 10.3109/10623320109063157] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The vasopressin-activated calcium-mobilizing (VACM-1) protein is a unique arginine vasopressin (AVP) receptor which shares sequence homology with the cullins, genes involved in the regulation of cell cycle transitions. Unlike either cullins or AVP receptors, however, VACM-1 is expressed exclusively in the vascular endothelial cells and in the renal collecting tubule cells. In order to test the hypothesis that the expression of VACM-1 might be correlated with the cell cycle, and to establish an endothelial cell model for the VACM-1 receptor, we examined VACM-1 expression in rat adrenal medulla endothelial cells (RAMEC). Northern and Western blot analyses of mRNA and protein from RAMEC identified presence of 6.4 kb mRNA and a Mr 81 kDa protein, respectively. Immunostaining of RAMEC with anti-VACM-1 antibodies and Western blot analyses indicated that in RAMEC, VACM-1 protein expression is dependent on the cell cycle. VACM-1 protein virtually disappears during the S phase and localizes to the cytosol during cell division and to the cell membrane at the completion of cytokinesis. Furthermore, pretreatment of RAMEC with anti-VACM-1 specific antibodies increased basal levels of Ca2+and attenuated the AVP-dependent increase in cytosolic Ca2+. In summary, these results indicate that VACM-1 protein expression in RAMEC membrane is linked to the cell cycle, and consequently, VACM-1 may be involved in the regulation of cell division.
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