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Moloi H, Tulloch NL, Watkins D, Perkins S, Engel M, Abdullahi L, Daniels K, Zühlke L. Understanding the local and international stakeholders in rheumatic heart disease field in Tanzania and Uganda: A systematic stakeholder mapping. Int J Cardiol 2022; 353:119-126. [PMID: 35090984 DOI: 10.1016/j.ijcard.2022.01.030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Revised: 01/12/2022] [Accepted: 01/14/2022] [Indexed: 11/05/2022]
Abstract
BACKGROUND Our study aimed to systematically identify RHD stakeholders and categories of stakeholders to consider when developing a scorecard that reflects a broad stakeholder input. METHOD We used the Schiller et al.(2013) framework to identify RHD stakeholders and stakeholder categories in Tanzania and Uganda. The process involved identifying stakeholders by searching literature related to incidence, prevalence, morbidity, mortality, health services, or health outcomes of Group A streptococcus, acute rheumatic fever, or rheumatic heart disease in these countries. The strategy was completed for two electronic databases in 2016 and in 2020 to update the results. We also engaged known stakeholders to obtain practice-based insight. We then categorised and visually represented the identified stakeholders. RESULTS We identified 139 stakeholders in Uganda, with 68% being from 15 different countries across 31 locations. In comparison, local Ugandan stakeholders were dispersed in six locations across the country. In Tanzania, we identified 128 stakeholders, with 66% being locally based and dispersed in seven locations across the country and stakeholders from different countries were situated in 18 countries across 28 locations. We categorised all identified stakeholders into one or more of five categories 1) Civil Society and General Public, 2) Education Sector, 3) Research, Training and Capacity Building, 4) Healthcare service delivery, and 5) Health Policy and Administration. CONCLUSION The stakeholder categories identified include multiple sectors and stakeholders from multiple countries, this reflects the complexities of RHD. This also highlights the need for collaboration and partnership as a critical action for preventing and controlling RHD.
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Affiliation(s)
- Hlengiwe Moloi
- Health Systems Research Unit, The South African Medical Research Council, South Africa.
| | - Nathaniel L Tulloch
- Division of General Internal Medicine, Department of Medicine, School of Medicine, University of Washington, Seattle, USA
| | - David Watkins
- Division of General Internal Medicine, Department of Medicine, School of Medicine, University of Washington, Seattle, USA; Department of Global Health, University of Washington, Seattle, USA
| | - Susan Perkins
- Division of Paediatric Cardiology, Department of Paediatrics, Red Cross War Memorial Children's Hospital, University of Cape Town, South Africa
| | - Mark Engel
- Department of Medicine, Groote Schuur Hospital and Faculty of Health Sciences, University of Cape Town, South Africa
| | - Leila Abdullahi
- African Institute for Development Policy (AFIDEP), Nairobi, Kenya
| | - Karen Daniels
- Health Policy and Systems Division, School of Public Health and Family Medicine, University of Cape Town, Cape Town, South Africa
| | - Liesl Zühlke
- Division of Paediatric Cardiology, Department of Paediatrics, Red Cross War Memorial Children's Hospital, University of Cape Town, South Africa; Division of Cardiology, Department of Medicine, Groote Schuur Hospital and Faculty of Health Sciences, University of Cape Town, South Africa
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Ruan JL, Tulloch NL, Razumova MV, Saiget M, Muskheli V, Pabon L, Reinecke H, Regnier M, Murry CE. Mechanical Stress Conditioning and Electrical Stimulation Promote Contractility and Force Maturation of Induced Pluripotent Stem Cell-Derived Human Cardiac Tissue. Circulation 2016; 134:1557-1567. [PMID: 27737958 DOI: 10.1161/circulationaha.114.014998] [Citation(s) in RCA: 283] [Impact Index Per Article: 35.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/20/2012] [Accepted: 09/20/2016] [Indexed: 12/11/2022]
Abstract
BACKGROUND Tissue engineering enables the generation of functional human cardiac tissue with cells derived in vitro in combination with biocompatible materials. Human-induced pluripotent stem cell-derived cardiomyocytes provide a cell source for cardiac tissue engineering; however, their immaturity limits their potential applications. Here we sought to study the effect of mechanical conditioning and electric pacing on the maturation of human-induced pluripotent stem cell-derived cardiac tissues. METHODS Cardiomyocytes derived from human-induced pluripotent stem cells were used to generate collagen-based bioengineered human cardiac tissue. Engineered tissue constructs were subjected to different mechanical stress and electric pacing conditions. RESULTS The engineered human myocardium exhibits Frank-Starling-type force-length relationships. After 2 weeks of static stress conditioning, the engineered myocardium demonstrated increases in contractility (0.63±0.10 mN/mm2 vs 0.055±0.009 mN/mm2 for no stress), tensile stiffness, construct alignment, and cell size. Stress conditioning also increased SERCA2 (Sarco/Endoplasmic Reticulum Calcium ATPase 2) expression, which correlated with a less negative force-frequency relationship. When electric pacing was combined with static stress conditioning, the tissues showed an additional increase in force production (1.34±0.19 mN/mm2), with no change in construct alignment or cell size, suggesting maturation of excitation-contraction coupling. Supporting this notion, we found expression of RYR2 (Ryanodine Receptor 2) and SERCA2 further increased by combined static stress and electric stimulation. CONCLUSIONS These studies demonstrate that electric pacing and mechanical stimulation promote maturation of the structural, mechanical, and force generation properties of human-induced pluripotent stem cell-derived cardiac tissues.
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Affiliation(s)
- Jia-Ling Ruan
- From Department of Bioengineering (J.-L.R, M.V.R., M.R., C.E.M.), Program in Molecular and Cellular Biology (N.L.T.), Department of Pathology (N.L.T., M.R., V.M., L.P., H.R., C.E.M.), and Department of Medicine/Cardiology (C.E.M.), Center for Cardiovascular Biology, Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle
| | - Nathaniel L Tulloch
- From Department of Bioengineering (J.-L.R, M.V.R., M.R., C.E.M.), Program in Molecular and Cellular Biology (N.L.T.), Department of Pathology (N.L.T., M.R., V.M., L.P., H.R., C.E.M.), and Department of Medicine/Cardiology (C.E.M.), Center for Cardiovascular Biology, Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle
| | - Maria V Razumova
- From Department of Bioengineering (J.-L.R, M.V.R., M.R., C.E.M.), Program in Molecular and Cellular Biology (N.L.T.), Department of Pathology (N.L.T., M.R., V.M., L.P., H.R., C.E.M.), and Department of Medicine/Cardiology (C.E.M.), Center for Cardiovascular Biology, Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle
| | - Mark Saiget
- From Department of Bioengineering (J.-L.R, M.V.R., M.R., C.E.M.), Program in Molecular and Cellular Biology (N.L.T.), Department of Pathology (N.L.T., M.R., V.M., L.P., H.R., C.E.M.), and Department of Medicine/Cardiology (C.E.M.), Center for Cardiovascular Biology, Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle
| | - Veronica Muskheli
- From Department of Bioengineering (J.-L.R, M.V.R., M.R., C.E.M.), Program in Molecular and Cellular Biology (N.L.T.), Department of Pathology (N.L.T., M.R., V.M., L.P., H.R., C.E.M.), and Department of Medicine/Cardiology (C.E.M.), Center for Cardiovascular Biology, Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle
| | - Lil Pabon
- From Department of Bioengineering (J.-L.R, M.V.R., M.R., C.E.M.), Program in Molecular and Cellular Biology (N.L.T.), Department of Pathology (N.L.T., M.R., V.M., L.P., H.R., C.E.M.), and Department of Medicine/Cardiology (C.E.M.), Center for Cardiovascular Biology, Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle
| | - Hans Reinecke
- From Department of Bioengineering (J.-L.R, M.V.R., M.R., C.E.M.), Program in Molecular and Cellular Biology (N.L.T.), Department of Pathology (N.L.T., M.R., V.M., L.P., H.R., C.E.M.), and Department of Medicine/Cardiology (C.E.M.), Center for Cardiovascular Biology, Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle
| | - Michael Regnier
- From Department of Bioengineering (J.-L.R, M.V.R., M.R., C.E.M.), Program in Molecular and Cellular Biology (N.L.T.), Department of Pathology (N.L.T., M.R., V.M., L.P., H.R., C.E.M.), and Department of Medicine/Cardiology (C.E.M.), Center for Cardiovascular Biology, Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle.
| | - Charles E Murry
- From Department of Bioengineering (J.-L.R, M.V.R., M.R., C.E.M.), Program in Molecular and Cellular Biology (N.L.T.), Department of Pathology (N.L.T., M.R., V.M., L.P., H.R., C.E.M.), and Department of Medicine/Cardiology (C.E.M.), Center for Cardiovascular Biology, Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle.
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Watkins DA, Tulloch NL, Anderson ME, Barnhart S, Steyn K, Levitt NS. Delivery of health care for cardiovascular and metabolic diseases among people living with HIV/AIDS in African countries: a systematic review protocol. Syst Rev 2016; 5:63. [PMID: 27084509 PMCID: PMC4833923 DOI: 10.1186/s13643-016-0241-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Accepted: 04/07/2016] [Indexed: 01/30/2023] Open
Abstract
BACKGROUND People living with HIV (PLHIV) in African countries are living longer due to the rollout of antiretroviral drug therapy programs, but they are at increasing risk of non-communicable diseases (NCDs). However, there remain many gaps in detecting and treating NCDs in African health systems, and little is known about how NCDs are being managed among PLHIV. Developing integrated chronic care models that effectively prevent and treat NCDs among PLHIV requires an understanding of the current patterns of care delivery and the major barriers and facilitators to health care. We present a systematic review protocol to synthesize studies of healthcare delivery for an important subset of NCDs, cardiovascular and metabolic diseases (CMDs), among African PLHIV. METHODS/DESIGN We plan to search electronic databases and reference lists of relevant studies published in African settings from January 2003 to the present. Studies will be considered if they address one or both of our major objectives and focus on health care for one or more of six interrelated CMDs (ischemic heart disease, stroke, heart failure, hypertension, diabetes, and hyperlipidemia) in PLHIV. Our first objective will be to estimate proportions of CMD patients along the "cascade of care"-i.e., screened, diagnosed, aware of the diagnosis, initiated on treatment, adherent to treatment, and with controlled disease. Our second objective will be to identify unique barriers and facilitators to health care faced by PLHIV in African countries. For studies deemed eligible for inclusion, we will assess study quality and risk of bias using previously published criteria. We will extract study data using standardized instruments. We will meta-analyze quantitative data at each level of the cascade of care for each CMD (first objective). We will use meta-synthesis techniques to understand and integrate qualitative data on health-related behaviors (second objective). DISCUSSION CMDs and other NCDs are becoming major health concerns for African PLHIV. The results of our review will inform the development of research into chronic care models that integrate care for HIV/AIDS and CMDs among PLHIV. Our findings will be highly relevant to health policymakers, administrators, and practitioners in African settings. SYSTEMATIC REVIEW REGISTRATION PROSPERO CRD42015029375.
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Affiliation(s)
- David A Watkins
- Department of Medicine, University of Washington, 325 9th Ave, Box 359780, Seattle, WA, 98104, USA. .,Chronic Disease Initiative for Africa, Department of Medicine, University of Cape Town, Cape Town, South Africa.
| | - Nathaniel L Tulloch
- Department of Medicine, University of Washington, 325 9th Ave, Box 359780, Seattle, WA, 98104, USA
| | - Molly E Anderson
- Department of Medicine, University of Washington, 325 9th Ave, Box 359780, Seattle, WA, 98104, USA
| | - Scott Barnhart
- Department of Medicine, University of Washington, 325 9th Ave, Box 359780, Seattle, WA, 98104, USA.,Department of Global Health, University of Washington, Seattle, WA, USA
| | - Krisela Steyn
- Chronic Disease Initiative for Africa, Department of Medicine, University of Cape Town, Cape Town, South Africa
| | - Naomi S Levitt
- Chronic Disease Initiative for Africa, Department of Medicine, University of Cape Town, Cape Town, South Africa
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Ruan JL, Tulloch NL, Saiget M, Paige SL, Razumova MV, Regnier M, Tung KC, Keller G, Pabon L, Reinecke H, Murry CE. Mechanical Stress Promotes Maturation of Human Myocardium From Pluripotent Stem Cell-Derived Progenitors. Stem Cells 2015; 33:2148-57. [PMID: 25865043 DOI: 10.1002/stem.2036] [Citation(s) in RCA: 91] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2012] [Accepted: 04/02/2015] [Indexed: 12/22/2022]
Abstract
Recent advances in pluripotent stem cell biology and directed differentiation have identified a population of human cardiovascular progenitors that give rise to cardiomyocytes, smooth muscle, and endothelial cells. Because the heart develops from progenitors in 3D under constant mechanical load, we sought to test the effects of a 3D microenvironment and mechanical stress on differentiation and maturation of human cardiovascular progenitors into myocardial tissue. Progenitors were derived from embryonic stem cells, cast into collagen hydrogels, and left unstressed or subjected to static or cyclic mechanical stress. Compared to 2D culture, the unstressed 3D environment increased cardiomyocyte numbers and decreased smooth muscle numbers. Additionally, 3D culture suppressed smooth muscle α-actin content, suggesting diminished cell maturation. Cyclic stress-conditioning increased expression of several cardiac markers, including β-myosin heavy chain and cardiac troponin T, and the tissue showed enhanced calcium dynamics and force production. There was no effect of mechanical loading on cardiomyocyte or smooth muscle specification. Thus, 3D growth conditions favor cardiac differentiation from cardiovascular progenitors, whereas 2D conditions promote smooth muscle differentiation. Mechanical loading promotes cardiomyocyte structural and functional maturation. Culture in 3-D facilitates understanding how cues such as mechanical stress affect the differentiation and morphogenesis of distinct cardiovascular cell populations into organized, functional human cardiovascular tissue. Stem Cells 2015;33:2148-2157.
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Affiliation(s)
- Jia-Ling Ruan
- Department of Bioengineering, University of Washington, Seattle, Washington, USA.,Center for Cardiovascular Biology, University of Washington, Seattle, Washington, USA.,Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, Washington, USA
| | - Nathaniel L Tulloch
- Center for Cardiovascular Biology, University of Washington, Seattle, Washington, USA.,Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, Washington, USA.,Department of Pathology, University of Washington, Seattle, Washington, USA.,Molecular and Cellular Biology Program, University of Washington, Seattle, Washington, USA.,Medical Scientist Training Program, University of Washington, Seattle, Washington, USA
| | - Mark Saiget
- Center for Cardiovascular Biology, University of Washington, Seattle, Washington, USA.,Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, Washington, USA.,Department of Pathology, University of Washington, Seattle, Washington, USA
| | - Sharon L Paige
- Center for Cardiovascular Biology, University of Washington, Seattle, Washington, USA.,Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, Washington, USA.,Department of Pathology, University of Washington, Seattle, Washington, USA
| | - Maria V Razumova
- Department of Bioengineering, University of Washington, Seattle, Washington, USA.,Center for Cardiovascular Biology, University of Washington, Seattle, Washington, USA.,Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, Washington, USA
| | - Michael Regnier
- Department of Bioengineering, University of Washington, Seattle, Washington, USA.,Center for Cardiovascular Biology, University of Washington, Seattle, Washington, USA.,Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, Washington, USA
| | - Kelvin Chan Tung
- McEwen Central for Regenerative Medicine, University Health Network, Toronto, Ontario, Canada
| | - Gordon Keller
- McEwen Central for Regenerative Medicine, University Health Network, Toronto, Ontario, Canada
| | - Lil Pabon
- Center for Cardiovascular Biology, University of Washington, Seattle, Washington, USA.,Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, Washington, USA.,Department of Pathology, University of Washington, Seattle, Washington, USA
| | - Hans Reinecke
- Center for Cardiovascular Biology, University of Washington, Seattle, Washington, USA.,Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, Washington, USA.,Department of Pathology, University of Washington, Seattle, Washington, USA
| | - Charles E Murry
- Department of Bioengineering, University of Washington, Seattle, Washington, USA.,Center for Cardiovascular Biology, University of Washington, Seattle, Washington, USA.,Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, Washington, USA.,Department of Pathology, University of Washington, Seattle, Washington, USA.,Department of Medicine, Division of Cardiology, University of Washington, Seattle, Washington, USA
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Ruan JL, Tulloch NL, Muskheli V, Genova EE, Mariner PD, Anseth KS, Murry CE. An improved cryosection method for polyethylene glycol hydrogels used in tissue engineering. Tissue Eng Part C Methods 2013; 19:794-801. [PMID: 23448137 DOI: 10.1089/ten.tec.2012.0460] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
The high water content of hydrogels allows these materials to closely mimic the native biological extracellular conditions, but it also makes difficult the histological preparation of hydrogel-based bioengineered tissue. Paraffin-embedding techniques require dehydration of hydrogels, resulting in substantial collapse and deformation, whereas cryosectioning is hampered by the formation of ice crystals within the hydrogel material. Here, we sought to develop a method to obtain good-quality cryosections for the microscopic evaluation of hydrogel-based tissue-engineered constructs, using polyethylene glycol (PEG) as a test hydrogel. Conventional sucrose solutions, which dehydrate cells while leaving extracellular water in place, produce a hydrogel block that is brittle and difficult to section. We therefore replaced sucrose with multiple protein-based and nonprotein-based solutions as cryoprotectants. Our analysis demonstrated that overnight incubation in bovine serum albumin (BSA), fetal bovine serum (FBS), polyvinyl alcohol (PVA), optimum cutting temperature (OCT) compound, and Fisher HistoPrep frozen tissue-embedding media work well to improve the cryosectioning of hydrogels. The protein-based solutions give background staining with routine hematoxylin and eosin, but the use of nonprotein-based solutions PVA and OCT reduces this background by 50%. These methods preserve the tissue architecture and cellular details with both in vitro PEG constructs and in constructs that have been implanted in vivo. This simple hydrogel cryosectioning technique improves the methodology for creation of good-quality histological sections from hydrogels in multiple applications.
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Affiliation(s)
- Jia-Ling Ruan
- Department of Bioengineering, University of Washington, Seattle, Washington 98109, USA
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Tulloch NL, Muskheli V, Razumova MV, Korte FS, Regnier M, Hauch KD, Pabon L, Reinecke H, Murry CE. Growth of engineered human myocardium with mechanical loading and vascular coculture. Circ Res 2011; 109:47-59. [PMID: 21597009 DOI: 10.1161/circresaha.110.237206] [Citation(s) in RCA: 474] [Impact Index Per Article: 36.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
RATIONALE The developing heart requires both mechanical load and vascularization to reach its proper size, yet the regulation of human heart growth by these processes is poorly understood. OBJECTIVE We seek to elucidate the responses of immature human myocardium to mechanical load and vascularization using tissue engineering approaches. METHODS AND RESULTS Using human embryonic stem cell and human induced pluripotent stem cell-derived cardiomyocytes in a 3-dimensional collagen matrix, we show that uniaxial mechanical stress conditioning promotes 2-fold increases in cardiomyocyte and matrix fiber alignment and enhances myofibrillogenesis and sarcomeric banding. Furthermore, cyclic stress conditioning markedly increases cardiomyocyte hypertrophy (2.2-fold) and proliferation rates (21%) versus unconditioned constructs. Addition of endothelial cells enhances cardiomyocyte proliferation under all stress conditions (14% to 19%), and addition of stromal supporting cells enhances formation of vessel-like structures by ≈10-fold. Furthermore, these optimized human cardiac tissue constructs generate Starling curves, increasing their active force in response to increased resting length. When transplanted onto hearts of athymic rats, the human myocardium survives and forms grafts closely apposed to host myocardium. The grafts contain human microvessels that are perfused by the host coronary circulation. CONCLUSIONS Our results indicate that both mechanical load and vascular cell coculture control cardiomyocyte proliferation, and that mechanical load further controls the hypertrophy and architecture of engineered human myocardium. Such constructs may be useful for studying human cardiac development as well as for regenerative therapy.
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Affiliation(s)
- Nathaniel L Tulloch
- Molecular and Cellular Biology Program, Center for Cardiovascular Biology, Institute for Stem Cell and Regenerative Medicine, University of Washington, 815 Mercer St., Seattle, WA 98109, USA
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Nourse MB, Halpin DE, Scatena M, Mortisen DJ, Tulloch NL, Hauch KD, Torok-Storb B, Ratner BD, Pabon L, Murry CE. VEGF induces differentiation of functional endothelium from human embryonic stem cells: implications for tissue engineering. Arterioscler Thromb Vasc Biol 2009; 30:80-9. [PMID: 19875721 DOI: 10.1161/atvbaha.109.194233] [Citation(s) in RCA: 124] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVE Human embryonic stem cells (hESCs) offer a sustainable source of endothelial cells for therapeutic vascularization and tissue engineering, but current techniques for generating these cells remain inefficient. We endeavored to induce and isolate functional endothelial cells from differentiating hESCs. METHODS AND RESULTS To enhance endothelial cell differentiation above a baseline of approximately 2% in embryoid body (EB) spontaneous differentiation, 3 alternate culture conditions were compared. Vascular endothelial growth factor (VEGF) treatment of EBs showed the best induction, with markedly increased expression of endothelial cell proteins CD31, VE-Cadherin, and von Willebrand Factor, but not the hematopoietic cell marker CD45. CD31 expression peaked around days 10 to 14. Continuous VEGF treatment resulted in a 4- to 5-fold enrichment of CD31(+) cells but did not increase endothelial proliferation rates, suggesting a primary effect on differentiation. CD31(+) cells purified from differentiating EBs upregulated ICAM-1 and VCAM-1 in response to TNFalpha, confirming their ability to function as endothelial cells. These cells also expressed multiple endothelial genes and formed lumenized vessels when seeded onto porous poly(2-hydroxyethyl methacrylate) scaffolds and implanted in vivo subcutaneously in athymic rats. Collagen gel constructs containing hESC-derived endothelial cells and implanted into infarcted nude rat hearts formed robust networks of patent vessels filled with host blood cells. CONCLUSIONS VEGF induces functional endothelial cells from hESCs independent of endothelial cell proliferation. This enrichment method increases endothelial cell yield, enabling applications for revascularization as well as basic studies of human endothelial biology. We demonstrate the ability of hESC-derived endothelial cells to facilitate vascularization of tissue-engineered implants.
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Affiliation(s)
- Marilyn B Nourse
- Arra and Eva Woods Professor of Pathology and Bioengineering, Director, Center for Cardiovascular Biology, Codirector, Institute for Stem Cell and Regenerative Medicine, University of Washington, 815 Mercer Street, Room 453 Brotman Building, Seattle, WA 98109, USA
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Lee JG, Dahi S, Mahimkar R, Tulloch NL, Alfonso-Jaume MA, Lovett DH, Sarkar R. Intronic regulation of matrix metalloproteinase-2 revealed by in vivo transcriptional analysis in ischemia. Proc Natl Acad Sci U S A 2005; 102:16345-50. [PMID: 16258061 PMCID: PMC1283457 DOI: 10.1073/pnas.0508085102] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Matrix metalloproteinase-2 (MMP-2) plays an essential role in angiogenesis and arteriogenesis, two processes critical to restoration of tissue perfusion after ischemia. MMP-2 expression is increased in tissue ischemia, but the responsible mechanisms remain unknown. We studied the transcriptional activation of the MMP-2 gene in a model of hindlimb ischemia by using various MMP-2-lacZ reporter mice and chromatin immunoprecipitation. MMP-2 activity and mRNA were increased after hindlimb ischemia. Mice with targeted deletion of MMP-2 had impaired restoration of perfusion and a high incidence of limb gangrene, indicating that MMP-2 plays a critical role in ischemia-induced revascularization. Ischemia induced the expression and binding of c-Fos, c-Jun, JunB, FosB, and Fra2 to a noncanonical activating protein-1 (AP-1) site present in the MMP-2 promoter and decreased binding of the transcriptional repressor JunD. Ischemia also activated the expression and binding of p53 to an adjacent enhancer site (RE-1) and increased expression and binding of nuclear factor of activated T-cells-c2 to consensus sequences within the first intron. Deletion of either the 5' AP-1/RE-1 region of the promoter or substitution of the first intron abolished ischemia-induced MMP-2 transcription in vivo. Thus, AP-1 transcription factors and intronic activation by nuclear factor of activated T-cells-c2 act in concert to drive ischemia-induced MMP-2 transcription. These findings define a critical role for MMP-2 in ischemia-induced revascularization and identify both previously uncharacterized regulatory elements within the MMP-2 gene and the cognate transcription factors required for MMP-2 activation in vivo after tissue ischemia.
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Affiliation(s)
- Jackie G Lee
- Division of Vascular Surgery, San Francisco Veterans Affairs Medical Center, and Pacific Vascular Research Laboratory, University of California, San Francisco, CA 94121, USA
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