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Myocarditis is an inflammatory heart disease that leads to loss of cardiomyocytes and frequently precipitates fibrotic remodeling of the myocardium, culminating in heart failure. However, the molecular mechanisms underlying immune cell control and maintenance of tissue integrity in the inflamed cardiac microenvironment remain elusive. In this study, we found that bone morphogenic protein-4 (BMP4) gradients maintain cardiac tissue homeostasis by single-cell transcriptomics analyses of inflamed murine and human myocardial tissues. Cardiac BMP pathway dysregulation was reflected by reduced BMP4 serum concentration in patients with myocarditis. Restoration of BMP signaling by antibody-mediated neutralization of the BMP inhibitors gremlin-1 and gremlin-2 ameliorated T cell-induced myocardial inflammation in mice. Moreover, progression to inflammatory cardiomyopathy was blocked through the reduction of fibrotic remodeling and preservation of cardiomyocyte integrity. These results unveil the BMP4-gremlin axis as a druggable pathway for the treatment of myocardial inflammation, limiting the severe sequelae of cardiac fibrosis and heart failure.
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Doenças Autoimunes , Proteína Morfogenética Óssea 4 , Modelos Animais de Doenças , Fibrose , Miocardite , Miocardite/metabolismo , Miocardite/patologia , Miocardite/imunologia , Animais , Fibrose/patologia , Fibrose/metabolismo , Proteína Morfogenética Óssea 4/metabolismo , Proteína Morfogenética Óssea 4/genética , Humanos , Doenças Autoimunes/patologia , Doenças Autoimunes/metabolismo , Doenças Autoimunes/imunologia , Masculino , Transdução de Sinais , Camundongos , Microambiente Celular , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Peptídeos e Proteínas de Sinalização Intercelular/genética , Feminino , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/patologia , Camundongos Endogâmicos C57BL , Miocárdio/metabolismo , Miocárdio/patologia , Miocárdio/imunologiaAssuntos
Cardiomiopatias , Sarcoidose , Taquicardia Ventricular , Humanos , Fluordesoxiglucose F18 , Taquicardia Ventricular/diagnóstico por imagem , Taquicardia Ventricular/etiologia , Sarcoidose/diagnóstico , Sarcoidose/diagnóstico por imagem , Tomografia por Emissão de Pósitrons , Compostos RadiofarmacêuticosRESUMO
Background: Postural tachycardia syndrome (POTS) is characterized by orthostatic intolerance and heart rate increase in an upright position without orthostatic hypotension. It has been described after coronavirus disease-19 (COVID-19) as well as after COVID-19 vaccination. Case summary: A 54-year-old female patient presented with a 9-months history of severe orthostatic intolerance since COVID-19 vaccination with messenger RNA (mRNA)-1273 (Spikevax, Moderna). Except for diet-controlled coeliac disease, the patient was healthy, had no allergies, and did not take regular medication. Tilt table testing revealed a significant heart rate increase to 168 bpm without orthostatic hypotension accompanied by light-headedness, nausea, and syncope, findings consistent with POTS. Potential underlying causes including anaemia, thyroid dysfunction, adrenal insufficiency, pheochromocytoma, (auto)-immune disease, chronic inflammation as well as neurological causes were ruled out. Echocardiography and cardiac stress magnetic resonance imaging (MRI) did not detect structural or functional heart disease or myocardial ischaemia. Forty-eight-hour-electrocardiogram (ECG) showed no tachycardias other than sinus tachycardia. Finally, genomic analysis did not detect an inherited arrhythmia syndrome. Serologic analysis revealed adequate immune response to mRNA-1273 vaccination without signs of previous severe acute respiratory syndrome-coronavirus-2 infection. While ivabradine was not tolerated and metoprolol extended release only slightly improved symptoms, physical exercise reduced orthostatic intolerance moderately. At a 5-months follow-up, the patient remained dependant on assistance for activities of daily living. Discussion: The temporal association of POTS with the COVID-19 vaccination in a previously healthy patient and the lack of evidence of an alternative aetiology suggests COVID-19 vaccination is the potential cause of POTS in this patient. To our knowledge, this is the first case reporting severe, long-term, and treatment-refractory POTS following COVID-19 vaccination with mRNA1273.
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(1) Background: Ongoing symptoms after mild or moderate acute coronavirus disease 19 (COVID-19) substantially affect health-related quality of life (HRQoL). However, follow-up data on HRQoL are scarce. We characterized the change in HRQoL over time in post-COVID-19 patients who initially suffered from mild or moderate acute COVID-19 without hospitalization. (2) Methods: Outpatients who visited an interdisciplinary post-COVID-19 consultation at the University Hospital Zurich and suffered from ongoing symptoms after acute COVID-19 were included in this observational study. HRQoL was assessed using established questionnaires. Six months after baseline, the same questionnaires and a self-constructed questionnaire about the COVID-19 vaccination were distributed. (3) Results: In total, 69 patients completed the follow-up, of whom 55 (80%) were female. The mean (SD) age was 44 (12) years and the median (IQR) time from symptom onset to completing the follow-up was 326 (300, 391) days. The majority of patients significantly improved in EQ-5D-5L health dimensions of mobility, usual activities, pain and anxiety. Furthermore, according to the SF-36, patients showed clinically relevant improvements in physical health, whereas no significant change was found regarding mental health. (4) Conclusions: Physical aspects of HRQoL in post-COVID-19 patients relevantly improved over 6 months. Future studies are needed to focus on potential predictors that allow for establishing individual care and early interventions.
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A growing number of patients with SARS-CoV-2 infections experience long-lasting symptoms. Even patients who suffered from a mild acute infection show a variety of persisting and debilitating neurocognitive, respiratory, or cardiac symptoms (Long-Covid syndrome), consequently leading to limitations in everyday life. Because data on health-related quality of life (HRQoL) is scarce, we aimed to characterize the impact of Long-Covid symptoms after a mild or moderate acute infection on HRQoL. In this observational study, outpatients seeking counseling in the interdisciplinary Post-Covid consultation of the University Hospital Zurich with symptoms persisting for more than 4 weeks were included. Patients who received an alternative diagnosis or suffered from a severe acute Covid-19 infection were excluded. St. George's Respiratory Questionnaire (SGRQ), Euroquol-5D-5L (EQ-5D-5L), and the Short form 36 (SF-36) were distributed to assess HRQoL. 112 patients were included, 86 (76.8%) were female, median (IQR) age was 43 (32.0, 52.5) years with 126 (91, 180) days of symptoms. Patients suffered frequently from fatigue (81%), concentration difficulties (60%), and dyspnea (60%). Patients mostly stated impairment in performing usual activities and having pain/discomfort or anxiety out of the EQ-5D-5L. EQ index value and SGRQ activity score component were significantly lower in females. SF-36 scores showed remarkably lower scores in the physical health domain compared to the Swiss general population before and during the COVID-19 pandemic. Long-Covid syndrome has a substantial impact on HRQoL. Long-term surveillance of patients must provide clarity on the duration of impairments in physical and mental health.Trial registration: The study is registered on www.ClinicalTrials.gov , NCT04793269.
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COVID-19 , Qualidade de Vida , Humanos , Feminino , Masculino , Qualidade de Vida/psicologia , Síndrome de COVID-19 Pós-Aguda , Pandemias , SARS-CoV-2 , Inquéritos e QuestionáriosRESUMO
(1) Background: Lung tissue involvement is frequently observed in acute COVID-19. However, it is unclear whether CT findings at follow-up are associated with persisting respiratory symptoms after initial mild or moderate infection. (2) Methods: Chest CTs of patients with persisting respiratory symptoms referred to the post-COVID-19 outpatient clinic were reassessed for parenchymal changes, and their potential association was evaluated. (3) Results: A total of 53 patients (31 female) with a mean (SD) age of 46 (13) years were included, of whom 89% had mild COVID-19. Median (quartiles) time from infection to CT was 139 (86, 189) days. Respiratory symptoms were dyspnea (79%), cough (42%), and thoracic pain (64%). Furthermore, 30 of 53 CTs showed very discrete and two CTs showed medium parenchymal abnormalities. No severe findings were observed. Mosaic attenuation (40%), ground glass opacity (2%), and fibrotic-like changes (25%) were recorded. No evidence for an association between persisting respiratory symptoms and chest CT findings was found. (4) Conclusions: More than half of the patients with initially mild or moderate infection showed findings on chest CT at follow-up. Respiratory symptoms, however, were not related to any chest CT finding. We, therefore, do not suggest routine chest CT follow-up in this patient group if no other indications are given.
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An Uncommon Cause of Arterial Hypertension Abstract. A 54-year-old patient was suffering from arterial hypertension, which was not treated sufficiently despite an antihypertensive therapy with three different types of drugs. In addition, the patient complained an increase in weight of ten kilos during the last year and a new onset of diabetes mellitus type 2. Investigations as to secondary forms of hypertension by MRI revealed an adrenal tumor with a diameter of approx. 6 cm suspect for an adrenal carcinoma. An ACTH-independent cushing syndrome was diagnosed by 24-hour urines collection, 1-mg dexamethasone supression test, and midnight-cortisol measurement. After a laparoscopic tumor excision, histopathological analyses confirmed an adrenal carcinoma.
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Neoplasias das Glândulas Suprarrenais , Síndrome de Cushing , Hipertensão , Neoplasias das Glândulas Suprarrenais/complicações , Síndrome de Cushing/complicações , Humanos , Hidrocortisona , Hipertensão/etiologia , Pessoa de Meia-IdadeRESUMO
CME: Familial Hypercholesterolemia - Statin Treatment during Pregnancy and Breastfeeding Abstract. Patients with familial hypercholesterolemia have a permanent increased cardiovascular risk. Thus, early detection and intensive treatment with statins is vital. However, treatment during pregnancy using statins remains unclear and limited. According to the NICE guidelines, women should stop statins three months before conception in order to avoid teratogenicity. In addition, contraception during statin treatment is recommended. Moreover, women should not take lipid-lowering drugs until the end of lactation. In the event of an unplanned pregnancy, a woman with familial hypercholesterolemia should discontinue the statins and consult her doctor.
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Aleitamento Materno , Inibidores de Hidroximetilglutaril-CoA Redutases , Hiperlipoproteinemia Tipo II , LDL-Colesterol , Feminino , Humanos , Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico , Hiperlipoproteinemia Tipo II/tratamento farmacológico , GravidezAssuntos
Anticoagulantes/efeitos adversos , Anticoagulantes/uso terapêutico , Pré-Medicação , Medição de Risco , Tromboembolia/sangue , Tromboembolia/prevenção & controle , Administração Oral , Idoso , Anticorpos Monoclonais Humanizados/efeitos adversos , Anticorpos Monoclonais Humanizados/uso terapêutico , Anticoagulantes/farmacocinética , Fibrilação Atrial/sangue , Fibrilação Atrial/tratamento farmacológico , Fatores de Coagulação Sanguínea/efeitos adversos , Fatores de Coagulação Sanguínea/uso terapêutico , Testes de Coagulação Sanguínea , Colonoscopia , Dabigatrana/efeitos adversos , Dabigatrana/farmacocinética , Dabigatrana/uso terapêutico , Inibidores do Fator Xa/efeitos adversos , Inibidores do Fator Xa/uso terapêutico , Hemorragia/sangue , Hemorragia/induzido quimicamente , Hemorragia/tratamento farmacológico , Humanos , Masculino , Pirazóis/efeitos adversos , Pirazóis/farmacocinética , Pirazóis/uso terapêutico , Piridinas/efeitos adversos , Piridinas/farmacocinética , Piridinas/uso terapêutico , Piridonas/efeitos adversos , Piridonas/farmacocinética , Piridonas/uso terapêutico , Rivaroxabana/efeitos adversos , Rivaroxabana/farmacocinética , Rivaroxabana/uso terapêutico , Tiazóis/efeitos adversos , Tiazóis/farmacocinética , Tiazóis/uso terapêuticoRESUMO
The pathogenesis of atherosclerosis involves dysfunctions of vascular endothelial cells and smooth muscle cells as well as blood borne inflammatory cells such as monocyte-derived macrophages. In vitro experiments towards a better understanding of these dysfunctions are typically performed in two-dimensional cell culture systems. However, these models lack both the three-dimensional structure and the physiological pulsatile flow conditions of native arteries. We here describe the development and initial characterization of a tissue engineered artery equivalent, which is composed of human primary endothelial and smooth muscle cells and is exposed to flow in vitro. Histological analyses showed formation of a dense tissue composed of a tight monolayer of endothelial cells supported by a basement membrane and multiple smooth muscle cell layers. Both low (LDL) and high density lipoproteins (HDL) perfused through the artery equivalent were recovered both within endothelial cells and in the sub-endothelial intima. After activation of the endothelium with either tumour necrosis factor alpha (TNFα) or LDL, monocytes circulated through the model were found to adhere to the activated endothelium and to transmigrate into the intima. In conclusion, the described tissue engineered human artery equivalent model represents a significant step towards a relevant in vitro platform for the systematic assessment of pathogenic processes in atherosclerosis independently of any systemic factors.
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Artérias/fisiologia , Modelos Anatômicos , Engenharia Tecidual , Artérias/anatomia & histologia , Artérias/citologia , Artérias/efeitos dos fármacos , Transporte Biológico , Movimento Celular/efeitos dos fármacos , Células Endoteliais/citologia , Células Endoteliais/fisiologia , Endotélio Vascular/citologia , Endotélio Vascular/fisiologia , Humanos , Lipoproteínas HDL/metabolismo , Lipoproteínas LDL/metabolismo , Lipoproteínas LDL/farmacologia , Monócitos/citologia , Monócitos/fisiologia , Músculo Liso Vascular/citologia , Músculo Liso Vascular/efeitos dos fármacos , Músculo Liso Vascular/fisiologia , Cultura Primária de Células , Alicerces Teciduais , Fator de Necrose Tumoral alfa/farmacologia , Túnica Íntima/citologia , Túnica Íntima/efeitos dos fármacos , Túnica Íntima/fisiologiaRESUMO
Due to impressive improvements in surgical repair options, even patients with complex congenital heart disease (CHD) may survive into adulthood and have a high risk of end-stage heart failure. Thus, the number of patients with CHD needing heart transplantation (HTx) has been increasing in the last decades. This paper summarizes the changing etiology of causes of death in heart failure in CHD. The main reasons, contraindications, and risks of heart transplantation in CHD are discussed and underlined with three case vignettes. Compared to HTx in acquired heart disease, HTx in CHD has an increased risk of perioperative death and rejection. However, outcome of HTx for complex CHD has improved over the past 20 years. Additionally, mechanical support options might decrease the waiting list mortality in the future. The number of patients needing heart-lung transplantation (especially for Eisenmenger's syndrome) has decreased in the last years. Lung transplantation with intracardiac repair of a cardiac defect is another possibility especially for patients with interatrial shunts. Overall, HTx will remain an important treatment option for CHD in the near future.
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Living autologous tissue engineered vascular-grafts (TEVGs) with growth-capacity may overcome the limitations of contemporary artificial-prostheses. However, the multi-step in vitro production of TEVGs requires extensive ex vivo cell-manipulations with unknown effects on functionality and quality of TEVGs due to an accelerated biological age of the cells. Here, the impact of biological cell-age and tissue-remodeling capacity of TEVGs in relation to their clinical long-term functionality are investigated. TEVGs were implanted as pulmonary-artery (PA) replacements in juvenile sheep and followed for up to 240 weeks (â¼4.5years). Telomere length and telomerase activity were compared amongst TEVGs and adjacent native tissue. Telomerase-activity of in vitro expanded autologous vascular-cells prior to seeding was <5% as compared to a leukemic cell line, indicating biological-aging associated with decreasing telomere-length with each cellular-doubling. Up to 100 weeks, the cells in the TEVGs had consistently shorter telomeres compared to the native counterpart, whereas no significant differences were detectable at 240 weeks. Computed tomography (CT) analysis demonstrated physiological wall-pressures, shear-stresses, and flow-pattern comparable to the native PA. There were no signs of degeneration detectable and continuous native-analogous growth was confirmed by vessel-volumetry. TEVGs exhibit a higher biological age compared to their native counterparts. However, despite of this tissue engineering technology related accelerated biological-aging, growth-capacity and long-term functionality was not compromised. To the contrary, extensive in-vivo remodeling processes with substantial endogenous cellular turnover appears to result in "TEVG rejuvenation" and excellent clinical performance. As these large-animal results can be extrapolated to approximately 20 human years, this study suggests long-term clinical-safety of cardiovascular in vitro tissue engineering and may contribute to safety-criteria as to first-in-man clinical-trials.
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Envelhecimento/fisiologia , Células Endoteliais/citologia , Engenharia Tecidual/métodos , Animais , Células Cultivadas , Células Endoteliais/metabolismo , Citometria de Fluxo , Imuno-Histoquímica , Artéria Pulmonar/citologia , Ovinos , Telomerase/metabolismo , Telômero/metabolismoRESUMO
OBJECT: Cerebral cavernous malformations (CCMs) are among the most prevalent cerebrovascular malformations, and endothelial cells seem to play a major role in the disease. However, the underlying mechanisms, including endothelial intercellular communication, have not yet been fully elucidated. In this article, the authors focus on the endothelial junction proteins CD31, VE-cadherin, and occludin as important factors for functional cell-cell contacts known as vascular adhesion molecules and adherence and tight junctions. METHODS: Thirteen human CCM specimens and 6 control tissue specimens were cryopreserved and examined for the presence of VE-cadherin, occludin, and CD31 by immunofluorescence staining. Protein quantification was performed by triplicate measurements using western blot analysis. RESULTS: Immunofluorescent analyses of the CCM sections revealed a discontinuous pattern of dilated microvessels and capillaries as well as increased expression of occludin, VE-cadherin, and CD31 in the intima and in the enclosed parenchymal tissue compared with controls. Protein quantification confirmed these findings by showing upregulation of the levels of these proteins up to 2-6 times. CONCLUSIONS: A protocol enabling the molecular and morphological examination of the intercellular contact proteins in human CCM was validated. The abnormal and discontinuous pattern in these endothelial cell-contact proteins compared with control tissue explains the loose intercellular junctions that are considered to be one of the causes of CCM-associated bleeding or transendothelial oozing of erythrocytes. Despite the small number of specimens, this study demonstrates for the first time a quantitative analysis of endothelial junction proteins in human CCM.
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Antígenos CD/metabolismo , Caderinas/metabolismo , Endotélio Vascular/metabolismo , Hemangioma Cavernoso do Sistema Nervoso Central/metabolismo , Junções Intercelulares/metabolismo , Malformações Arteriovenosas Intracranianas/metabolismo , Proteínas de Membrana/metabolismo , Junções Íntimas/metabolismo , Adolescente , Adulto , Western Blotting , Moléculas de Adesão Celular/genética , Moléculas de Adesão Celular/metabolismo , Comunicação Celular/genética , Comunicação Celular/fisiologia , Células Cultivadas , Células Endoteliais/metabolismo , Endotélio , Endotélio Vascular/citologia , Feminino , Hemangioma Cavernoso do Sistema Nervoso Central/genética , Humanos , Junções Intercelulares/genética , Malformações Arteriovenosas Intracranianas/genética , Masculino , Proteínas de Membrana/genética , Pessoa de Meia-Idade , Óxido Nítrico Sintase Tipo III , Ocludina , Molécula-1 de Adesão Celular Endotelial a Plaquetas/genética , Molécula-1 de Adesão Celular Endotelial a Plaquetas/metabolismo , Junções Íntimas/genética , Regulação para Cima/genética , Regulação para Cima/fisiologiaRESUMO
Using a custom-built, implantable pulse generator, we studied the effects of small pulsed currents on the viability on rat aortic-derived cells (RAOC) in vitro. The pulsed currents (0.37A/m(2)) underwent apoptosis within 24h as shown by the positive staining for cleaved caspase-3 and classically apoptotic morphology. Based on these findings, we examined the effects of nanocurrents in vivo. The pulse generator was implanted subcutaneously in the rat model. The electrode|tissue interface histology revealed no difference between the active platinum surface and the neighboring control surface, however we found a large difference between electrodes that were functional during the entire experiment and non-active electrodes. These non-active electrodes showed an increase in impedance at higher frequencies 21 days post-implantation, whereas working electrodes retained their impedance value for the entire experiment. These results indicate that applied currents can reduce the impedance of implanted electrodes.
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Tecnologia Biomédica/instrumentação , Eletricidade , Nanoestruturas/química , Animais , Morte Celular , Sobrevivência Celular , Impedância Elétrica , Eletrodos , Implantação de Prótese , Ratos , Ratos Sprague-DawleyRESUMO
OBJECTIVES: The aim of this study was to demonstrate the feasibility of combining the novel heart valve replacement technologies of: 1) tissue engineering; and 2) minimally-invasive implantation based on autologous cells and composite self-expandable biodegradable biomaterials. BACKGROUND: Minimally-invasive valve replacement procedures are rapidly evolving as alternative treatment option for patients with valvular heart disease. However, currently used valve substitutes are bioprosthetic and as such have limited durability. To overcome this limitation, tissue engineering technologies provide living autologous valve replacements with regeneration and growth potential. METHODS: Trileaflet heart valves fabricated from biodegradable synthetic scaffolds, integrated in self-expanding stents and seeded with autologous vascular or stem cells (bone marrow and peripheral blood), were generated in vitro using dynamic bioreactors. Subsequently, the tissue engineered heart valves (TEHV) were minimally-invasively implanted as pulmonary valve replacements in sheep. In vivo functionality was assessed by echocardiography and angiography up to 8 weeks. The tissue composition of explanted TEHV and corresponding control valves was analyzed. RESULTS: The transapical implantations were successful in all animals. The TEHV demonstrated in vivo functionality with mobile but thickened leaflets. Histology revealed layered neotissues with endothelialized surfaces. Quantitative extracellular matrix analysis at 8 weeks showed higher values for deoxyribonucleic acid, collagen, and glycosaminoglycans compared to native valves. Mechanical profiles demonstrated sufficient tissue strength, but less pliability independent of the cell source. CONCLUSIONS: This study demonstrates the principal feasibility of merging tissue engineering and minimally-invasive valve replacement technologies. Using adult stem cells is successful, enabling minimally-invasive cell harvest. Thus, this new technology may enable a valid alternative to current bioprosthetic devices.
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Endotélio Vascular/transplante , Próteses Valvulares Cardíacas , Valvas Cardíacas , Procedimentos Cirúrgicos Minimamente Invasivos/métodos , Músculo Liso Vascular/transplante , Transplante de Células-Tronco/métodos , Engenharia Tecidual/métodos , Animais , Modelos Animais de Doenças , Endotélio Vascular/citologia , Seguimentos , Músculo Liso Vascular/citologia , Ovinos , Alicerces Teciduais , Transplante AutólogoRESUMO
Current scientific attempts to generate in vitro tissue-engineered living blood vessels (TEBVs) show substantial limitations, thereby preventing routine clinical use. In the present report, we describe a novel biotechnology concept to create living small diameter TEBV based exclusively on microtissue self-assembly (living cellular re-aggregates). A novel bioreactor was designed to assemble microtissues in a vascular shape and apply pulsatile flow and circumferential mechanical stimulation. Microtissues composed of human artery-derived fibroblasts (HAFs) and endothelial cells (HUVECs) were accumulated and cultured for 7 and 14 days under pulsatile flow/mechanical stimulation or static culture conditions with a diameter of 3mm and a wall thickness of 1mm. The resulting vessels were analyzed by immunohistochemistry for extracellular matrix (ECM) and cell phenotype (von Willebrand factor, alpha-SMA, Ki67, VEGF). Self-assembled microtissues composed of fibroblasts displayed significantly accelerated ECM formation compared to monolayer cell sheets. Accumulation of vessel-like tissue occurred within 14 days under both, static and flow/mechanical stimulation conditions. A layered tissue formation was observed only in the dynamic group, as indicated by luminal aligned alpha-SMA positive fibroblasts. We could demonstrate that self-assembled cell-based microtissues can be used to generate small diameter TEBV. The significant enhancement of ECM expression and maturation, together with the pre-vascularization capacity makes this approach highly attractive in terms of generating functional small diameter TEBV devoid of any foreign material.
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Artérias/citologia , Reatores Biológicos , Prótese Vascular , Técnicas de Cultura de Tecidos , Engenharia Tecidual , Actinas/metabolismo , Fenômenos Biomecânicos , Colágeno Tipo IV/metabolismo , Células Endoteliais/citologia , Fibroblastos/citologia , Perfilação da Expressão Gênica , Humanos , Imuno-Histoquímica , Modelos Cardiovasculares , Técnicas de Cultura de Tecidos/instrumentação , Técnicas de Cultura de Tecidos/métodos , Engenharia Tecidual/instrumentação , Engenharia Tecidual/métodos , Fator A de Crescimento do Endotélio Vascular/metabolismo , Fator de von Willebrand/metabolismoRESUMO
Human amniotic membranes and amniotic fluid have attracted increasing attention in recent years as a possible reserve of stem cells that may be useful for clinical application in regenerative medicine. Many studies have been conducted to date in terms of the differentiation potential of these cells, with several reports demonstrating that cells from both the amniotic fluid and membrane display high plasticity. In addition, cells from the amniotic membrane have also been shown to display immunomodulatory characteristics both in vivo and in vitro, which could make them useful in an allotransplantation setting. Here, we provide an overview comparing the latest findings regarding the stem characteristics of cells from both the amniotic membrane and amniotic fluid, as well as on the potential utility of these cells for future clinical application in regenerative medicine.
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Âmnio/citologia , Líquido Amniótico/citologia , Medicina Regenerativa/métodos , Animais , Humanos , Transplante de Células-Tronco , Células-TroncoRESUMO
BACKGROUND AND AIM OF THE STUDY: Fetal stem cells represent a promising cell source for heart valve tissue engineering. In particular, amniotic fluid-derived cells (AFDC) have been shown to lead to autologous fetal-like heart valve tissues in vitro for pediatric application. In order to expand the versatility of these cells also for adult application, cryopreserved AFDC were investigated as a potential life-long available cell source for heart valve tissue engineering. METHODS: Human AFDC were isolated using CD133 magnetic beads, and then differentiated and analyzed. After expansion of CD133- as well as CD133+ cells up to passage 7, a part of the cells was cryopreserved. After four months, the cells were re-cultured and phenotyped by flow cytometry and immunohistochemistry, including expression of CD44, CD105, CD90, CD34, CD31, CD141, eNOS and vWF, and compared to their non-cryopreserved counterparts. The stem cell potential was investigated in differentiation assays. The viability of cryopreserved AFDC for heart valve tissue engineering was assessed by creating heart valve leaflets in vitro. RESULTS: After cryopreservation, amniotic fluid-derived CD133- and CD133+ cells retained their stem cell-like phenotype, expressing mainly CD44, CD90 and CD105. This staining pattern was comparable to that of their non-cryopreserved counterparts. Moreover, CD133- cells demonstrated differentiation potential into osteoblast-like and adipocyte-like cells. CD133+ cells showed characteristics of endothelial-like cells by eNOS, CD141 and beginning vWF expression. When used for the fabrication of heart valve leaflets, cryopreserved CD133- cells produced extracellular matrix elements comparable to their non-cryopreserved counterparts. Moreover, the resulting tissues showed a cellular layered tissue formation covered by functional endothelia. The mechanical properties were similar to those of tissues fabricated from non-cryopreserved cells. CONCLUSION: The study results suggest that the use of cell bank technology fetal amniotic fluid-derived stem cells might represent a life-long available autologous cell source for heart valve tissue engineering, and also for adult application.