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Kervella D, Le Bas-Bernardet S, Bruneau S, Blancho G. Protection of transplants against antibody-mediated injuries: from xenotransplantation to allogeneic transplantation, mechanisms and therapeutic insights. Front Immunol 2022; 13:932242. [PMID: 35990687 PMCID: PMC9389360 DOI: 10.3389/fimmu.2022.932242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Accepted: 07/07/2022] [Indexed: 11/17/2022] Open
Abstract
Long-term allograft survival in allotransplantation, especially in kidney and heart transplantation, is mainly limited by the occurrence of antibody-mediated rejection due to anti-Human Leukocyte Antigen antibodies. These types of rejection are difficult to handle and chronic endothelial damages are often irreversible. In the settings of ABO-incompatible transplantation and xenotransplantation, the presence of antibodies targeting graft antigens is not always associated with rejection. This resistance to antibodies toxicity seems to associate changes in endothelial cells phenotype and modification of the immune response. We describe here these mechanisms with a special focus on endothelial cells resistance to antibodies. Endothelial protection against anti-HLA antibodies has been described in vitro and in animal models, but do not seem to be a common feature in immunized allograft recipients. Complement regulation and anti-apoptotic molecules expression appear to be common features in all these settings. Lastly, pharmacological interventions that may promote endothelial cell protection against donor specific antibodies will be described.
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Affiliation(s)
- Delphine Kervella
- CHU Nantes, Nantes Université, Néphrologie et Immunologie Clinique, Institut Transplantation Urologie Néphrologie (ITUN), Nantes, France
- Nantes Université, CHU Nantes, INSERM, Center for Research in Transplantation and Translational Immunology, UMR 1064, ITUN, Nantes, France
| | - Stéphanie Le Bas-Bernardet
- Nantes Université, CHU Nantes, INSERM, Center for Research in Transplantation and Translational Immunology, UMR 1064, ITUN, Nantes, France
| | - Sarah Bruneau
- Nantes Université, CHU Nantes, INSERM, Center for Research in Transplantation and Translational Immunology, UMR 1064, ITUN, Nantes, France
| | - Gilles Blancho
- CHU Nantes, Nantes Université, Néphrologie et Immunologie Clinique, Institut Transplantation Urologie Néphrologie (ITUN), Nantes, France
- Nantes Université, CHU Nantes, INSERM, Center for Research in Transplantation and Translational Immunology, UMR 1064, ITUN, Nantes, France
- *Correspondence: Gilles Blancho,
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Acadesine suppresses TNF-α induced complement component 3 (C3), in retinal pigment epithelial (RPE) cells. PLoS One 2020; 15:e0244307. [PMID: 33362238 PMCID: PMC7757886 DOI: 10.1371/journal.pone.0244307] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Accepted: 12/07/2020] [Indexed: 01/02/2023] Open
Abstract
Rationale Age-related macular degeneration (AMD) is the most prevalent form of irreversible blindness in the developed world. Aging, inflammation and complement dysregulation affecting the retinal pigment epithelium (RPE), are considered significant contributors in its pathogenesis and several evidences have linked tumor necrosis factor alpha (TNF-α) and complement component 3 (C3) with AMD. Acadesine, an analog of AMP and an AMP-activated protein kinase (AMPK) activator, has been shown to have cytoprotective effects in human clinical trials as well as having anti-inflammatory and anti-vascular exudative effects in animals. The purpose of this study was to evaluate if acadesine is able to suppress TNF-α induced C3 in RPE cells. Methods ARPE-19 and human primary RPE cells were cultured and allowed to grow to confluence. TNF-α was used for C3 induction in the presence or absence of acadesine. Small molecule inhibitors and siRNA were used to determine if acadesine exerts its effect via the extracellular or intracellular pathway and to evaluate the importance of AMPK for these effects. The expression level of C3 was determined by immunoblot analysis. Results Acadesine suppresses TNF-α induced C3 in a dose dependent manner. When we utilized the adenosine receptor inhibitor dipyridamole (DPY) along with acadesine, acadesine’s effects were abolished, indicating the necessity of acadesine to enter the cell in order to exert it’s action. However, pretreatment with 5-iodotubericidin (5-Iodo), an adenosine kinase (AK) inhibitor, didn’t prevent acadesine from decreasing TNF-α induced C3 expression suggesting that acadesine does not exert its effect through AMP conversion and subsequent activation of AMPK. Consistent with this, knockdown of AMPK α catalytic subunit did not affect the inhibitory effect of acadesine on TNF-α upregulation of C3. Conclusions Our results suggest that acadesine suppresses TNF-α induced C3, likely through an AMPK-independent pathway, and could have potential use in complement over activation diseases.
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3
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Kim H, Conway EM. Platelets and Complement Cross-Talk in Early Atherogenesis. Front Cardiovasc Med 2019; 6:131. [PMID: 31555668 PMCID: PMC6742699 DOI: 10.3389/fcvm.2019.00131] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2019] [Accepted: 08/22/2019] [Indexed: 12/16/2022] Open
Abstract
Atherosclerosis remains a ubiquitous and serious threat to human health. The initial formation of the atherosclerotic lesion (atheroma) is driven by pro-inflammatory signaling involving monocytes and vascular endothelial cells; later stages of the disease involve rupture of well-established atherosclerotic plaques, thrombosis, and blood vessel occlusion. While the central role of platelets in thrombosis is undisputed, platelets exhibit pro-inflammatory activities, and contribute to early-stage atheroma formation. Platelets also engage components of the complement system, an essential element of innate immunity that contributes to vascular inflammation. Here we provide an overview of the complex interplay between platelets and the complement system, with a focus on how the crosstalk between them may impact on the initiation of atheroma formation.
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Affiliation(s)
- Hugh Kim
- Centre for Blood Research, Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada.,Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, BC, Canada.,Faculty of Dentistry, University of British Columbia, Vancouver, BC, Canada
| | - Edward M Conway
- Centre for Blood Research, Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada.,Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada
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Zhou H, Hara H, Cooper DK. The complex functioning of the complement system in xenotransplantation. Xenotransplantation 2019; 26:e12517. [PMID: 31033064 PMCID: PMC6717021 DOI: 10.1111/xen.12517] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Revised: 03/15/2019] [Accepted: 03/22/2019] [Indexed: 12/25/2022]
Abstract
The role of complement in xenotransplantation is well-known and is a topic that has been reviewed previously. However, our understanding of the immense complexity of its interaction with other constituents of the innate immune response and of the coagulation, adaptive immune, and inflammatory responses to a xenograft is steadily increasing. In addition, the complement system plays a function in metabolism and homeostasis. New reviews at intervals are therefore clearly warranted. The pathways of complement activation, the function of the complement system, and the interaction between complement and coagulation, inflammation, and the adaptive immune system in relation to xenotransplantation are reviewed. Through several different mechanisms, complement activation is a major factor in contributing to xenograft failure. In the organ-source pig, the detrimental influence of the complement system is seen during organ harvest and preservation, for example, in ischemia-reperfusion injury. In the recipient, the effect of complement can be seen through its interaction with the immune, coagulation, and inflammatory responses. Genetic-engineering and other therapeutic methods by which the xenograft can be protected from the effects of complement activation are discussed. The review provides an updated source of reference to this increasingly complex subject.
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Affiliation(s)
- Hongmin Zhou
- Department of Cardiothoracic Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
- Xenotransplantation Program, Department of Surgery, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Hidetaka Hara
- Xenotransplantation Program, Department of Surgery, University of Alabama at Birmingham, Birmingham, AL, USA
| | - David K.C. Cooper
- Xenotransplantation Program, Department of Surgery, University of Alabama at Birmingham, Birmingham, AL, USA
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5
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Detsika MG, Myrtsi ED, Koulocheri SD, Haroutounian SA, Lianos EA, Roussos C. Induction of decay accelerating factor and membrane cofactor protein by resveratrol attenuates complement deposition in human coronary artery endothelial cells. Biochem Biophys Rep 2019; 19:100652. [PMID: 31193778 PMCID: PMC6541742 DOI: 10.1016/j.bbrep.2019.100652] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Revised: 04/01/2019] [Accepted: 05/13/2019] [Indexed: 11/27/2022] Open
Abstract
The involvement of complement activation in various forms of cardiovascular disease renders it an important factor for disease progression and therapeutic intervention. The protective effect of resveratrol against cardiovascular disease via moderate red wine consumption has been established but the exact mechanisms are still under investigation. The current study utilised human coronary artery endothelial cells (HCAECs) in order to assess the extent to which the protective effect of resveratrol, at concentrations present in red wine, can be attributed to the upregulation of complement regulatory proteins through heme-oxygenase (HO)-1 induction. Resveratrol at concentrations as low as 0.001 μΜ increased HO-1 expression as well as membrane cofactor protein (MCP, CD46) and decay-accelerating factor (DAF, CD55) expression with no-effect on CD59. Silencing of HO-1 expression by HO-1 siRNAs abrogated both DAF and MCP protein expression with no effect on CD59. Resveratrol-mediated induction of DAF and MCP reduced C3b deposition following incubation of HCAECs with 10% normal human serum or normal rat serum as a source of complement. Incubation of HCAECs, with either a DAF blocking antibody or following transfection with HO-1 siRNAs, in the presence of 10% normal rat serum increased C3b deposition, indicating that both DAF and HO-1 are required for C3b reduction. These observations support a novel mechanism for the protective effect of resveratrol against cardiovascular disease and confirm the important role of HO-1 in the regulation of the complement cascade.
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Affiliation(s)
- Maria G Detsika
- First Department of Critical Care Medicine and Pulmonary Services, Thorax Foundation, Research Center of Intensive Care and Emergency Thoracic Medicine, Evangelismos Hospital, School of Medicine, National and Kapodistrian University of Athens, Athens, Greece
| | - Eleni D Myrtsi
- Department of Nutritional Physiology and Feeding, Agricultural University of Athens, Iera Odos 75, 11855, Athens, Greece
| | - Sofia D Koulocheri
- Department of Nutritional Physiology and Feeding, Agricultural University of Athens, Iera Odos 75, 11855, Athens, Greece
| | - Serkos A Haroutounian
- Department of Nutritional Physiology and Feeding, Agricultural University of Athens, Iera Odos 75, 11855, Athens, Greece
| | - Elias A Lianos
- First Department of Critical Care Medicine and Pulmonary Services, Thorax Foundation, Research Center of Intensive Care and Emergency Thoracic Medicine, Evangelismos Hospital, School of Medicine, National and Kapodistrian University of Athens, Athens, Greece
| | - Charis Roussos
- First Department of Critical Care Medicine and Pulmonary Services, Thorax Foundation, Research Center of Intensive Care and Emergency Thoracic Medicine, Evangelismos Hospital, School of Medicine, National and Kapodistrian University of Athens, Athens, Greece
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6
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Celecoxib exerts protective effects in the vascular endothelium via COX-2-independent activation of AMPK-CREB-Nrf2 signalling. Sci Rep 2018; 8:6271. [PMID: 29674687 PMCID: PMC5908847 DOI: 10.1038/s41598-018-24548-z] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Accepted: 04/05/2018] [Indexed: 01/13/2023] Open
Abstract
Although concern remains about the athero-thrombotic risk posed by cyclo-oxygenase (COX)-2-selective inhibitors, recent data implicates rofecoxib, while celecoxib appears equivalent to NSAIDs naproxen and ibuprofen. We investigated the hypothesis that celecoxib activates AMP kinase (AMPK) signalling to enhance vascular endothelial protection. In human arterial and venous endothelial cells (EC), and in contrast to ibuprofen and naproxen, celecoxib induced the protective protein heme oxygenase-1 (HO-1). Celecoxib derivative 2,5-dimethyl-celecoxib (DMC) which lacks COX-2 inhibition also upregulated HO-1, implicating a COX-2-independent mechanism. Celecoxib activated AMPKα(Thr172) and CREB-1(Ser133) phosphorylation leading to Nrf2 nuclear translocation. Importantly, these responses were not reproduced by ibuprofen or naproxen, while AMPKα silencing abrogated celecoxib-mediated CREB and Nrf2 activation. Moreover, celecoxib induced H-ferritin via the same pathway, and increased HO-1 and H-ferritin in the aortic endothelium of mice fed celecoxib (1000 ppm) or control chow. Functionally, celecoxib inhibited TNF-α-induced NF-κB p65(Ser536) phosphorylation by activating AMPK. This attenuated VCAM-1 upregulation via induction of HO-1, a response reproduced by DMC but not ibuprofen or naproxen. Similarly, celecoxib prevented IL-1β-mediated induction of IL-6. Celecoxib enhances vascular protection via AMPK-CREB-Nrf2 signalling, a mechanism which may mitigate cardiovascular risk in patients prescribed celecoxib. Understanding NSAID heterogeneity and COX-2-independent signalling will ultimately lead to safer anti-inflammatory drugs.
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Keir LS, Firth R, Aponik L, Feitelberg D, Sakimoto S, Aguilar E, Welsh GI, Richards A, Usui Y, Satchell SC, Kuzmuk V, Coward RJ, Goult J, Bull KR, Sharma R, Bharti K, Westenskow PD, Michael IP, Saleem MA, Friedlander M. VEGF regulates local inhibitory complement proteins in the eye and kidney. J Clin Invest 2016; 127:199-214. [PMID: 27918307 PMCID: PMC5199702 DOI: 10.1172/jci86418] [Citation(s) in RCA: 91] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Accepted: 10/28/2016] [Indexed: 12/15/2022] Open
Abstract
Outer retinal and renal glomerular functions rely on specialized vasculature maintained by VEGF that is produced by neighboring epithelial cells, the retinal pigment epithelium (RPE) and podocytes, respectively. Dysregulation of RPE- and podocyte-derived VEGF is associated with neovascularization in wet age-related macular degeneration (ARMD), choriocapillaris degeneration, and glomerular thrombotic microangiopathy (TMA). Since complement activation and genetic variants in inhibitory complement factor H (CFH) are also features of both ARMD and TMA, we hypothesized that VEGF and CFH interact. Here, we demonstrated that VEGF inhibition decreases local CFH and other complement regulators in the eye and kidney through reduced VEGFR2/PKC-α/CREB signaling. Patient podocytes and RPE cells carrying disease-associated CFH genetic variants had more alternative complement pathway deposits than controls. These deposits were increased by VEGF antagonism, a common wet ARMD treatment, suggesting that VEGF inhibition could reduce cellular complement regulatory capacity. VEGF antagonism also increased markers of endothelial cell activation, which was partially reduced by genetic complement inhibition. Together, these results suggest that VEGF protects the retinal and glomerular microvasculature, not only through VEGFR2-mediated vasculotrophism, but also through modulation of local complement proteins that could protect against complement-mediated damage. Though further study is warranted, these findings could be relevant for patients receiving VEGF antagonists.
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Affiliation(s)
- Lindsay S. Keir
- Department of Cell and Molecular Biology, The Scripps Research Institute, La Jolla, California, USA
- Academic Renal Unit, School of Clinical Sciences, University of Bristol, Bristol, United Kingdom
| | - Rachel Firth
- Academic Renal Unit, School of Clinical Sciences, University of Bristol, Bristol, United Kingdom
| | - Lyndsey Aponik
- Department of Cell and Molecular Biology, The Scripps Research Institute, La Jolla, California, USA
| | - Daniel Feitelberg
- Department of Cell and Molecular Biology, The Scripps Research Institute, La Jolla, California, USA
| | - Susumu Sakimoto
- Department of Cell and Molecular Biology, The Scripps Research Institute, La Jolla, California, USA
| | - Edith Aguilar
- Department of Cell and Molecular Biology, The Scripps Research Institute, La Jolla, California, USA
| | - Gavin I. Welsh
- Academic Renal Unit, School of Clinical Sciences, University of Bristol, Bristol, United Kingdom
| | - Anna Richards
- Queens Medical Research Institute, University of Edinburgh, Edinburgh, United Kingdom
| | - Yoshihiko Usui
- Department of Cell and Molecular Biology, The Scripps Research Institute, La Jolla, California, USA
- Tokyo Medical University Hospital, Tokyo, Japan
| | - Simon C. Satchell
- Academic Renal Unit, School of Clinical Sciences, University of Bristol, Bristol, United Kingdom
| | - Valeryia Kuzmuk
- Academic Renal Unit, School of Clinical Sciences, University of Bristol, Bristol, United Kingdom
| | - Richard J. Coward
- Academic Renal Unit, School of Clinical Sciences, University of Bristol, Bristol, United Kingdom
| | - Jonathan Goult
- Centre for Cellular and Molecular Physiology, University of Oxford, United Kingdom
| | - Katherine R. Bull
- Centre for Cellular and Molecular Physiology, University of Oxford, United Kingdom
| | - Ruchi Sharma
- National Eye Institute, NIH, Bethesda, Maryland, USA
| | - Kapil Bharti
- National Eye Institute, NIH, Bethesda, Maryland, USA
| | - Peter D. Westenskow
- Department of Cell and Molecular Biology, The Scripps Research Institute, La Jolla, California, USA
- The Lowy Medical Research Institute, La Jolla, California, USA
| | | | - Moin A. Saleem
- Academic Renal Unit, School of Clinical Sciences, University of Bristol, Bristol, United Kingdom
| | - Martin Friedlander
- Department of Cell and Molecular Biology, The Scripps Research Institute, La Jolla, California, USA
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8
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Gerster M, Peker E, Nagel E, Puntmann VO. Deciphering cardiac involvement in systemic inflammatory diseases: noninvasive tissue characterisation using cardiac magnetic resonance is key to improved patients’ care. Expert Rev Cardiovasc Ther 2016; 14:1283-1295. [DOI: 10.1080/14779072.2016.1226130] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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9
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Chiang MC, Cheng YC, Chen SJ, Yen CH, Huang RN. Metformin activation of AMPK-dependent pathways is neuroprotective in human neural stem cells against Amyloid-beta-induced mitochondrial dysfunction. Exp Cell Res 2016; 347:322-31. [PMID: 27554603 DOI: 10.1016/j.yexcr.2016.08.013] [Citation(s) in RCA: 75] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Revised: 08/15/2016] [Accepted: 08/17/2016] [Indexed: 12/17/2022]
Abstract
Alzheimer's disease (AD) is the general consequence of dementia and is diagnostic neuropathology by the cumulation of amyloid-beta (Aβ) protein aggregates, which are thought to promote mitochondrial dysfunction processes leading to neurodegeneration. AMP-activated protein kinase (AMPK), a critical regulator of energy homeostasis and a major player in lipid and glucose metabolism, is potentially implied in the mitochondrial deficiency of AD. Metformin, one of the widespread used anti- metabolic disease drugs, use its actions in part by stimulation of AMPK. While the mechanisms of AD are well established, the neuronal roles for AMPK in AD are still not well understood. In the present study, human neural stem cells (hNSCs) exposed to Aβ had significantly reduced cell viability, which correlated with decreased AMPK, neuroprotective genes (Bcl-2 and CREB) and mitochondria associated genes (PGC1α, NRF-1 and Tfam) expressions, as well as increased activation of caspase 3/9 activity and cytosolic cytochrome c. Co-treatment with metformin distinct abolished the Aβ-caused actions in hNSCs. Metformin also significantly rescued hNSCs from Aβ-mediated mitochondrial deficiency (lower D-loop level, mitochondrial mass, maximal respiratory function, COX activity, and mitochondrial membrane potential). Importantly, co-treatment with metformin significantly restored fragmented mitochondria to almost normal morphology in the hNSCs with Aβ. These findings extend our understanding of the central role of AMPK in Aβ-related neuronal impairment. Thus, a better understanding of AMPK might assist in both the recognition of its critical effects and the implementation of new therapeutic strategies in the treatment of AD.
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Affiliation(s)
- Ming-Chang Chiang
- Department of Life Science, College of Science and Engineering, Fu Jen Catholic University, New Taipei City 242, Taiwan.
| | - Yi-Chuan Cheng
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Shiang-Jiuun Chen
- Department of Life Science and Institute of Ecology and Evolutionary Biology, College of Life Science, National Taiwan University, Taipei 106, Taiwan
| | - Chia-Hui Yen
- Department of International Business, Ming Chuan University, Taipei 111, Taiwan
| | - Rong-Nan Huang
- Department of Entomology and Research Center for Plant-Medicine, National Taiwan University, Taipei 106, Taiwan
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10
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Mason JC. Cytoprotective pathways in the vascular endothelium. Do they represent a viable therapeutic target? Vascul Pharmacol 2016; 86:41-52. [PMID: 27520362 DOI: 10.1016/j.vph.2016.08.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Accepted: 08/08/2016] [Indexed: 12/28/2022]
Abstract
The vascular endothelium is a critical interface, which separates the organs from the blood and its contents. The endothelium has a wide variety of functions and maintenance of endothelial homeostasis is a multi-dimensional active process, disruption of which has potentially deleterious consequences if not reversed. Vascular injury predisposes to endothelial apoptosis, dysfunction and development of atherosclerosis. Endothelial dysfunction is an end-point, a central feature of which is increased ROS generation, a reduction in endothelial nitric oxide synthase and increased nitric oxide consumption. A dysfunctional endothelium is a common feature of diseases including rheumatoid arthritis, systemic lupus erythematosus, diabetes mellitus and chronic renal impairment. The endothelium is endowed with a variety of constitutive and inducible mechanisms that act to minimise injury and facilitate repair. Endothelial cytoprotection can be enhanced by exogenous factors such as vascular endothelial growth factor, prostacyclin and laminar shear stress. Target genes include endothelial nitric oxide synthase, heme oxygenase-1, A20 and anti-apoptotic members of the B cell lymphoma protein-2 family. In light of the importance of endothelial function, and the link between its disruption and the risk of atherothrombosis, interest has focused on therapeutic conditioning and reversal of endothelial dysfunction. A detailed understanding of cytoprotective signalling pathways, their regulation and target genes is now required to identify novel therapeutic targets. The ultimate aim is to add vasculoprotection to current therapeutic strategies for systemic inflammatory diseases, in an attempt to reduce vascular injury and prevent or retard atherogenesis.
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Affiliation(s)
- Justin C Mason
- Vascular Science, Imperial Centre for Translational and Experimental Medicine, National Heart and Lung Institute, Imperial College London, Hammersmith Hospital, London, UK.
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11
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Nadig SN, Dixit SK, Levey N, Esckilsen S, Miller K, Dennis W, Atkinson C, Broome AM. Immunosuppressive nano-therapeutic micelles downregulate endothelial cell inflammation and immunogenicity. RSC Adv 2015; 5:43552-43562. [PMID: 26167278 PMCID: PMC4494678 DOI: 10.1039/c5ra04057d] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
In this study, we developed a stable, nontoxic novel micelle nanoparticle to attenuate responses of endothelial cell (EC) inflammation when subjected to oxidative stress, such as observed in organ transplantation. Targeted Rapamycin Micelles (TRaM) were synthesized using PEG-PE-amine and N-palmitoyl homocysteine (PHC) with further tailoring of the micelle using targeting peptides (cRGD) and labeling with far-red fluorescent dye for tracking during cellular uptake studies. Our results revealed that the TRaM was approximately 10 nm in diameter and underwent successful internalization in Human Umbilical Vein EC (HUVEC) lines. Uptake efficiency of TRaM nanoparticles was improved with the addition of a targeting moiety. In addition, our TRaM therapy was able to downregulate both mouse cardiac endothelial cell (MCEC) and HUVEC production and release of the pro-inflammatory cytokines, IL-6 and IL-8 in normal oxygen tension and hypoxic conditions. We were also able to demonstrate a dose-dependent uptake of TRaM therapy into biologic tissues ex vivo. Taken together, these data demonstrate the feasibility of targeted drug delivery in transplantation, which has the potential for conferring local immunosuppressive effects without systemic consequences while also dampening endothelial cell injury responses.
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Affiliation(s)
- Satish N Nadig
- Department of Surgery, Division of Transplant, Medical University of South Carolina, 96 Jonathan Lucas Street, Charleston, SC 29425, USA. ; Tel: 01 843 792 8596;
- Department of Microbiology and Immunology, Medical University of South Carolina, 173 Ashley Avenue, Charleston, SC 29425, USA. ; Tel: 01 843 792 1716;
- South Carolina Investigators in Transplantation (SCIT), Medical University of South Carolina, 96 Jonathan Lucas Street, Charleston, SC 29425, USA. ; Tel: 01 843 792 3553;
| | - Suraj K Dixit
- Department of Radiology & Radiological Science, Medical University of South Carolina, 68 President Street MSC 120, Charleston, SC 29425, USA. ; Tel: 01 843 876 2481;
- Center for Biomedical Imaging (CBI), Medical University of South Carolina, 68 President Street MSC 120, Charleston, SC 29425, USA. ; Tel: 01 843 876 2481;
| | - Natalie Levey
- Department of Surgery, Division of Transplant, Medical University of South Carolina, 96 Jonathan Lucas Street, Charleston, SC 29425, USA. ; Tel: 01 843 792 8596;
| | - Scott Esckilsen
- Department of Surgery, Division of Transplant, Medical University of South Carolina, 96 Jonathan Lucas Street, Charleston, SC 29425, USA. ; Tel: 01 843 792 8596;
| | - Kayla Miller
- Department of Radiology & Radiological Science, Medical University of South Carolina, 68 President Street MSC 120, Charleston, SC 29425, USA. ; Tel: 01 843 876 2481;
- Center for Biomedical Imaging (CBI), Medical University of South Carolina, 68 President Street MSC 120, Charleston, SC 29425, USA. ; Tel: 01 843 876 2481;
| | - William Dennis
- Department of Surgery, Division of Transplant, Medical University of South Carolina, 96 Jonathan Lucas Street, Charleston, SC 29425, USA. ; Tel: 01 843 792 8596;
| | - Carl Atkinson
- Department of Microbiology and Immunology, Medical University of South Carolina, 173 Ashley Avenue, Charleston, SC 29425, USA. ; Tel: 01 843 792 1716;
- South Carolina Investigators in Transplantation (SCIT), Medical University of South Carolina, 96 Jonathan Lucas Street, Charleston, SC 29425, USA. ; Tel: 01 843 792 3553;
| | - Ann-Marie Broome
- Department of Radiology & Radiological Science, Medical University of South Carolina, 68 President Street MSC 120, Charleston, SC 29425, USA. ; Tel: 01 843 876 2481;
- Center for Biomedical Imaging (CBI), Medical University of South Carolina, 68 President Street MSC 120, Charleston, SC 29425, USA. ; Tel: 01 843 876 2481;
- South Carolina Investigators in Transplantation (SCIT), Medical University of South Carolina, 96 Jonathan Lucas Street, Charleston, SC 29425, USA. ; Tel: 01 843 792 3553;
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12
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The neuroprotective role of metformin in advanced glycation end product treated human neural stem cells is AMPK-dependent. Biochim Biophys Acta Mol Basis Dis 2015; 1852:720-31. [PMID: 25595658 DOI: 10.1016/j.bbadis.2015.01.006] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2014] [Revised: 01/05/2015] [Accepted: 01/08/2015] [Indexed: 12/17/2022]
Abstract
Diabetic neuronal damage results from hyperglycemia followed by increased formation of advanced glycosylation end products (AGEs), which leads to neurodegeneration, although the molecular mechanisms are still not well understood. Metformin, one of the most widely used anti-diabetic drugs, exerts its effects in part by activation of AMP-activated protein kinase (AMPK). AMPK is a critical evolutionarily conserved enzyme expressed in the liver, skeletal muscle and brain, and promotes cellular energy homeostasis and biogenesis by regulating several metabolic processes. While the mechanisms of AMPK as a metabolic regulator are well established, the neuronal role for AMPK is still unknown. In the present study, human neural stem cells (hNSCs) exposed to AGEs had significantly reduced cell viability, which correlated with decreased AMPK and mitochondria associated gene/protein (PGC1α, NRF-1 and Tfam) expressions, as well as increased activation of caspase 3 and 9 activities. Metformin prevented AGEs induced cytochrome c release from mitochondria into cytosol in the hNSCs. Co-treatment with metformin significantly abrogated the AGE-mediated effects in hNSCs. Metformin also significantly rescued hNSCs from AGE-mediated mitochondrial deficiency (lower ATP, D-loop level, mitochondrial mass, maximal respiratory function, COX activity, and mitochondrial membrane potential). Furthermore, co-treatment of hNSCs with metformin significantly blocked AGE-mediated reductions in the expression levels of several neuroprotective genes (PPARγ, Bcl-2 and CREB). These findings extend our understanding of the molecular mechanisms of both AGE-induced neuronal toxicity, and AMPK-dependent neuroprotection by metformin. This study further suggests that AMPK may be a potential therapeutic target for treating diabetic neurodegeneration.
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