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1.
Life Sci ; 243: 117257, 2020 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-31917992

RESUMO

Electrical field stimulation (EFS) has been used for decades in classical pharmacological preparations in order to characterize the mediators released by neural endings involved in smooth muscle contraction or relaxation. Since most of the human umbilical cord has no innervation, EFS has never been used in this preparation. This study aimed to investigate the effect of EFS on vascular responsiveness from human umbilical cord. Segments of the human umbilical cord were obtained from normotensive parturients and the human umbilical artery (HUA) and the human umbilical vein (HUV) were isolated and mounted in organ bath chambers. Electrical field stimulation-induced contractions in both HUA (2.35 ±â€¯1.31 mN and 3.77 ±â€¯2.31 mN for 8 Hz and 16 Hz respectively, n = 24) and HUV (3.81 ±â€¯2.54 mN and 6.26 ±â€¯4.51 mN for 8 Hz and 16 Hz respectively, n = 25). The addition of tetrodotoxin (1 µM) did not alter the EFS-induced contractions in both tissues (n = 5). Pre-incubation with atropine (10 and 100 µM), glibenclamide (10 µM) and indomethacin (10 µM) did not affect the EFS-induced contractions in both tissues. The contractions of both vessels were significantly reduced by pre-incubation of the tissues with phentolamine (10 and 100 µM). The endothelium removal almost abolished the EFS- induced contractions in both vessels (n = 5). In sandwich preparation, donor tissue (with endothelium) released a factor (s) that promoted contraction of the recipient tissue (endothelium removal) in both HUA and HUV (n = 5, respectively). Our findings indicate a potential role of endothelium-derived catecholamines in modulating HUA and HUV reactivities.


Assuntos
Vasos Sanguíneos/fisiologia , Estimulação Elétrica , Cordão Umbilical/irrigação sanguínea , Adulto , Atropina/farmacologia , Vasos Sanguíneos/efeitos dos fármacos , Glibureto/farmacologia , Humanos , Indometacina/farmacologia , Contração Muscular/efeitos dos fármacos , Tetrodotoxina/farmacologia , Adulto Jovem
2.
Mater Sci Eng C Mater Biol Appl ; 105: 110035, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31546369

RESUMO

Aiming to perfuse porous tubular scaffolds for vascular tissue engineering (VTE) with controlled flow rate, prevention of leakage through the scaffold lumen is required. A gel coating made of 8% w/v alginate and 6% w/v gelatin functionalized with fibronectin was produced using a custom-made bioreactor-based method. Different volumetric proportions of alginate and gelatin were tested (50/50, 70/30, and 90/10). Gel swelling and stability, and rheological, and uniaxial tensile tests reveal superior resistance to the aggressive biochemical microenvironment, and their ability to withstand physiological deformations (~10%) and wall shear stresses (5-20 dyne/cm2). These are prerequisites to maintain the physiologic phenotypes of vascular smooth muscle cells and endothelial cells (ECs), mimicking blood vessels microenvironment. Gels can induce ECs proliferation and colonization, especially in the presence of fibronectin and higher percentages of gelatin. The custom-designed bioreactor enables the development of reproducible and homogeneous tubular gel coating. The permeability tests show the effectiveness of tubular scaffolds coated with 70/30 alginate/gelatin gel to occlude wadding pores, and therefore prevent leakages. The synthesized double-layered tubular scaffolds coated with alginate/gelatin gel and fibronectin represent both promising substrate for ECs and effective leakproof scaffolds, when subjected to pulsatile perfusion, for VTE applications.


Assuntos
Vasos Sanguíneos/fisiologia , Hidrogéis/farmacologia , Resistência ao Cisalhamento , Engenharia Tecidual/métodos , Tecidos Suporte/química , Reatores Biológicos , Vasos Sanguíneos/efeitos dos fármacos , Linhagem Celular , Humanos , Permeabilidade , Porosidade , Resistência à Tração
3.
Adv Exp Med Biol ; 1161: 65-75, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31562622

RESUMO

Inflammation is a fundamentally protective process that guards the host from invading pathogens and is central in the repair and regeneration of damaged tissue. However, when uncontrolled, the overzealous response leads to tissue damage and malaise. Indeed, this process is now appreciated to be at the center of many chronic inflammatory diseases including vascular disease and arthritis. Studies investigating the mechanisms through which acute inflammation is actively turned off allowing tissues to regain function demonstrated that the essential fatty acids, arachidonic acid (AA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are enzymatically converted to bioactive mediators. These autacoids carry distinct structures and biological actions, actively reprogramming the inflammatory reaction to promote its termination by counter-regulating the production of pro-inflammatory mediators and regulate leukocyte trafficking as well as phenotype. Recently we found that n-3 docosapentaenoic acid (DPA), which was until then only regarded as a biosynthetic intermediate in the formation of DHA from EPA, is also converted to structurally distinct bioactive mediators that reprogram the host immune response. In the present review we will discuss the evidence underpinning the biological actions of these novel n-3 DPA-derived autacoids in particular as they pertain to the vascular system.


Assuntos
Vasos Sanguíneos , Inibidores de Hidroximetilglutaril-CoA Redutases , Mediadores da Inflamação , Inflamação , Vasos Sanguíneos/efeitos dos fármacos , Vasos Sanguíneos/fisiologia , Ácidos Docosa-Hexaenoicos/química , Humanos , Inibidores de Hidroximetilglutaril-CoA Redutases/química , Inibidores de Hidroximetilglutaril-CoA Redutases/farmacologia , Inflamação/tratamento farmacológico , Inflamação/fisiopatologia , Mediadores da Inflamação/química , Mediadores da Inflamação/metabolismo , Leucócitos/efeitos dos fármacos
4.
Adv Gerontol ; 32(3): 357-363, 2019.
Artigo em Russo | MEDLINE | ID: mdl-31512421

RESUMO

The aim of this work was to examine the content of Piezo1 in fibroblasts and blood vessels of human dermis from the development until deep aging (from 20 weeks of pregnancy until 85 years old), and defining of a role of Piezo1 in age-dependent changes in the number of fibroblasts and blood vessels in the dermis. Piezo1, proliferating cells nuclear antigen (PCNA), endothelial cells marker CD31 were detected with indirect immunohistochemical technique. Results showed that a portion of fibroblasts with positive staining for Piezo1 in the dermis is decreased from 20 weeks of pregnancy to 40 years old. Percent of Piezo1 positive fibroblasts in dermis is increased sufficiently since 41 years old until 60-85 years old group. The content of Piezo1 in blood vessels in the human dermis is decreased sufficiently from 20 weeks of pregnancy until 40 years old. Age-related changes in the content of Piezo1 in fibroblasts and blood vessels is not associated with an age-related decrease in total number and percent of PCNA positive fibroblasts, the number of blood vessels in the dermis.


Assuntos
Vasos Sanguíneos , Derme , Fibroblastos , Canais Iônicos , Envelhecimento da Pele , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Vasos Sanguíneos/fisiologia , Criança , Pré-Escolar , Derme/irrigação sanguínea , Derme/citologia , Derme/embriologia , Derme/crescimento & desenvolvimento , Feminino , Fibroblastos/citologia , Fibroblastos/metabolismo , Humanos , Lactente , Canais Iônicos/metabolismo , Masculino , Pessoa de Meia-Idade , Molécula-1 de Adesão Celular Endotelial a Plaquetas/metabolismo , Gravidez , Antígeno Nuclear de Célula em Proliferação/metabolismo , Envelhecimento da Pele/fisiologia
5.
Mol Carcinog ; 58(12): 2286-2296, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31545000

RESUMO

Differentiation antagonizing non-protein coding RNA (DANCR) is a newly identified oncogenic long noncoding RNA found in various cancers. However, the functional role of DANCR in tumor angiogenesis and the underlying mechanisms are still unclear. The expression of DANCR was determined in ovarian malignant tissues and cell lines. The functional role of DANCR in tumor angiogenesis was revealed by the following methods: CD31 staining of ovarian tumor tissues, matrigel-plug assay tissues, HUVEC-related tube formation assay, and invasion assay. Enzyme-linked immunosorbent assay, Western blotting, luciferase assay, and rescue experiments were used to investigate the underlying mechanisms of DANCR-regulating angiogenesis. DANCR was upregulated in ovarian malignant tissues and ovarian cancer cells. Knockdown of DANCR efficiently impaired ovarian tumor growth through inhibition of tumor angiogenesis. Furthermore, the conditional culture medium from DANCR-knockdown ovarian cells significantly inhibited tube formation and invasion of HUVEC in vitro. Mechanistic investigation indicated that vascular endothelial growth factor A (VEGF-A, VEGF) plays a crucial role during DANCR inhibition of tumor angiogenesis in ovarian cancer. Further results demonstrated that miR-145 is the direct binding target of DANCR during regulation of VEGF expression and tumor angiogenesis in ovarian cancer cells. Collectively, DANCR plays a promotional role in tumor angiogenesis in ovarian cancer through regulation of miR-145/VEGF axis. Therefore, DANCR may be a novel therapy target for ovarian cancer.


Assuntos
Regulação Neoplásica da Expressão Gênica , MicroRNAs/genética , Neovascularização Patológica/genética , Neoplasias Ovarianas/genética , RNA Longo não Codificante/genética , Fator A de Crescimento do Endotélio Vascular/metabolismo , Animais , Vasos Sanguíneos/metabolismo , Vasos Sanguíneos/fisiologia , Linhagem Celular Tumoral , Progressão da Doença , Feminino , Células Endoteliais da Veia Umbilical Humana/metabolismo , Células Endoteliais da Veia Umbilical Humana/fisiologia , Humanos , Camundongos , Neovascularização Patológica/metabolismo , Neoplasias Ovarianas/irrigação sanguínea , Neoplasias Ovarianas/terapia , Interferência de RNA , Terapêutica com RNAi/métodos , Carga Tumoral/genética , Ensaios Antitumorais Modelo de Xenoenxerto/métodos
6.
Exp Eye Res ; 188: 107796, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31521629

RESUMO

Mineralocorticoid receptor activation in endothelial and smooth muscle cells can promote vascular disease by increasing oxidative stress, promoting inflammation, accelerating vascular stiffness, remodeling, and calcification, altering vessel responsiveness to various vasoactive factors, thus altering vascular tone and blood pressure, and by altering angiogenesis. Here, we review the recent evidence highlighting the impact of vascular mineralocorticoid receptor activation in pathological situations, including kidney injury, vascular injury associated with metabolic diseases, atherosclerosis, cerebral vascular injury during hypertension, vascular stiffening and aging, pulmonary hypertension, vascular calcification, cardiac remodeling, wound healing, inflammation, thrombosis, and disorders related to angiogenic defects in the eye. The possible mechanisms implicating mineralocorticoid receptor activation in various vascular disorders are discussed. Altogether, recent evidence points towards pharmacological mineralocorticoid receptor inhibition as a strategy to treat diseases in which overactivation of the mineralocorticoid receptor in endothelial and/or smooth muscle cells may play a pivotal role.


Assuntos
Vasos Sanguíneos/fisiologia , Receptores de Mineralocorticoides/metabolismo , Doenças Vasculares/metabolismo , Animais , Pressão Sanguínea , Células Endoteliais/metabolismo , Humanos , Hipertensão/metabolismo , Inflamação/metabolismo , Músculo Liso Vascular/fisiologia , Rigidez Vascular
7.
Mater Sci Eng C Mater Biol Appl ; 104: 109936, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31500055

RESUMO

Fabricating biomimetic vasculatures is considered one of the greatest challenges in tissue regeneration due to their complex structures across various length scales. Many strategies have been investigated on how to fabricate tissue-engineering vasculatures (TEVs), including vascular-like and vascularized structures that can replace their native counterparts. The advancement of additive manufacturing (AM) technologies has enabled a wide range of fabrication techniques that can directly-write TEVs with complex and delicate structures. Meanwhile, sacrifice-based techniques, which rely on the removal of encapsulated sacrificial templates to form desired cavity-like structures, have also been widely studied. This review will specifically focus on the two most promising methods in these recently developed technologies, which are the direct-write method and the sacrifice-based method. The performance, advantages, and shortcomings of each technique are analyzed and compared. In the discussion, we list current challenges in this field and present our vision of next-generation TEVs technologies. Perspectives on future research in this field are given at the end.


Assuntos
Vasos Sanguíneos/fisiologia , Engenharia Tecidual/métodos , Animais , Materiais Biocompatíveis/farmacologia , Vasos Sanguíneos/efeitos dos fármacos , Humanos , Neovascularização Fisiológica/efeitos dos fármacos , Polímeros/farmacologia , Impressão Tridimensional
8.
Invest Ophthalmol Vis Sci ; 60(10): 3563-3569, 2019 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-31419299

RESUMO

Purpose: To obtain a choroidal vascularity index (CVI) map of macular area on an Early Treatment Diabetic Retinopathy Study (ETDRS) grid. Methods: The study was a cross-sectional study involving 30 eyes of 30 healthy individuals. In brief, a shadow-compensated automated algorithm was used to segment and binarize the individual optical coherence tomography (OCT) B-scans. This was followed by three-dimensional reconstruction of these processed B-scans to obtain the overall thickness and vascularity maps. ETDRS grid was overlaid on both the extrapolated thickness and vascularity maps to obtain the corresponding sector-wise CVI. The main outcome measure was to evaluate the topographical variation of CVI in the macular area. Results: The mean age of the study participants was 44.33 ± 16.29 years (range, 18-70 years). CVI showed no significant difference in different rings, subfields, or quadrants of the ETDRS map. CVI had a negative correlation with age (r = -0.384, P = 0.03). There were no statistically significant differences between CVI of both eyes in either rings or the full ETDRS grid (P = 0.30) among normal subjects. Conclusions: The variation in CVI does not follow similar patterns as seen in choroidal thickness (CT) in various locations. The novel choroidal vascularity mapping in the macular area may expand understanding on regional differences of choroidal vasculature in healthy eyes.


Assuntos
Vasos Sanguíneos/fisiologia , Corioide/irrigação sanguínea , Adolescente , Adulto , Idoso , Algoritmos , Corioide/diagnóstico por imagem , Estudos Transversais , Feminino , Voluntários Saudáveis , Humanos , Processamento de Imagem Assistida por Computador , Imageamento Tridimensional , Masculino , Pessoa de Meia-Idade , Tomografia de Coerência Óptica/métodos , Adulto Jovem
9.
J Therm Biol ; 84: 323-330, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31466770

RESUMO

Local heat can accelerate the blood circulation and induce the vasodilatation. Investigators reported that local heat causes an increase in skin blood flow consisting of two phases. The first is solely sensory neural, and the second is nitric oxide mediated. However, the mechanism underlying the skin blood flow response to local heating are complex and poorly understood. The mechanisms behind these two phases are deduced to be linked by flow-mediated dilation. In this study, the variation of the blood flow and the blood vessel diameter are monitored during local heating. According to the dynamic blood flow, the theoretical model of flow mediated dilation involving the key agents production and transportation was first used to study vasodilatation process during heating, and the variations of blood vessel was obtained. Finally, accurate distributions of the nitric oxide, calcium and myosin concentrations in the arterial wall were found during autoregulation. We evaluated the time course of the blood vessel changing and verified the fact that the second increase in blood flow is the result of flow dilation mediation. The effects of dilation of blood vessel were also analyzed.


Assuntos
Temperatura Alta , Modelos Biológicos , Fenômenos Fisiológicos da Pele , Pele/irrigação sanguínea , Vasodilatação , Animais , Vasos Sanguíneos/fisiologia , Simulação por Computador , Camundongos , Camundongos Nus , Fluxo Sanguíneo Regional
10.
Cardiol Young ; 29(8): 1016-1019, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31221238

RESUMO

Splanchnic circulation constitutes a major portion of the vasculature capacitance and plays an important role in maintaining blood perfusion. Because patients with asplenia syndrome lack this vascular bed as a blood reservoir, they may have a unique blood volume and distribution, which may be related to their vulnerability to the haemodynamic changes often observed in clinical practice. During cardiac catheterisation, the mean circulatory filling pressure was calculated with the Valsalva manoeuvre in 19 patients with Fontan circulation, including 5 patients with asplenia syndrome. We also measured the cardiac output index and circulatory blood volume by using a dye dilution technique. The blood volume and the mean circulatory filling pressure and the venous capacitance in patients with asplenia syndrome were similar to those in the remaining patients with Fontan circulation (85 ± 14 versus 77 ± 18 ml/kg, p = 0.43, 31 ± 8 versus 27 ± 5 mmHg, p = 0.19, 2.8 ± 0.6 versus 2.9 ± 0.9 ml/kg/mmHg, p = 0.86). Unexpectedly, our data indicated that patients with asplenia syndrome, who lack splanchnic capacitance circulation, have blood volume and venous capacitance comparable to those in patients with splanchnic circulation. These data suggest that (1) there is a blood reservoir other than the spleen even in patients with asplenia; (2) considering the large blood pool of the spleen, the presence of a symmetrical liver may represent the possible organ functioning as a blood reservoir in asplenia syndrome; and (3) if this is indeed the case, there may be a higher risk of hepatic congestion in patients with Fontan circulation with asplenia syndrome than in those without.


Assuntos
Vasos Sanguíneos/fisiologia , Técnica de Fontan , Síndrome de Heterotaxia/cirurgia , Circulação Esplâncnica , Adaptação Fisiológica , Volume Sanguíneo , Cateterismo Cardíaco , Débito Cardíaco , Criança , Pré-Escolar , Hemodinâmica , Humanos
11.
Analyst ; 144(15): 4461-4471, 2019 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-31162494

RESUMO

Microfluidic technology has been extensively employed in biology and medicine since the field emerged in the 1990s. By utilizing microfluidic approaches, a variety of vascular system-related structures and functions have been mimicked on in vitro platforms. Herein, we begin by introducing microfluidic circulatory devices for the study of two-dimensional (2D) endothelial cells culture. Next, we focus on recent progress on on-chip mimicry of native vasculature, specifically generation of complex three-dimensional (3D) structures within cell-laden hydrogels using microfluidics and self-assembly-based methods. The utilization of microfluidic technology will facilitate the construction of progressively biomimetic in vitro models that have great potential in complementing existing animal models. We envision such platforms to be utilized in a wide range of applications involving vascular systems, including microphysiological studies, drug screening, and disease modeling.


Assuntos
Biomimética/métodos , Vasos Sanguíneos/fisiologia , Hidrogéis/química , Dispositivos Lab-On-A-Chip , Biomimética/instrumentação , Técnicas de Cultura de Células , Linhagem Celular , Células Endoteliais/fisiologia , Humanos , Microfluídica/instrumentação , Engenharia Tecidual/instrumentação , Engenharia Tecidual/métodos
12.
Yale J Biol Med ; 92(2): 283-290, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31249489

RESUMO

The cardiovascular (CV) system has been established to be significantly influenced by the molecular components of circadian rhythm. Oscillations of circadian rhythm occur within the circulation to affect thrombosis and blood pressure and within CV tissues including arteries, heart, and kidney to control function. Physiologic and molecular oscillations of circadian rhythm have been well connected via global, tissue-specific, and transgenic reporter mouse models of key core clock signals such as Bmal1, Period, and Clock, which can produce both pathology and protection with their mutation. With different nuances of CV clock action continuing to emerge in studies of the cardiovascular system, new questions are raised in both new and old mouse model system observations that underscore the importance, complexity, and continued study of the circadian clock mechanism in cardiovascular disease.


Assuntos
Fenômenos Fisiológicos Cardiovasculares , Relógios Circadianos/fisiologia , Peptídeos e Proteínas de Sinalização do Ritmo Circadiano/fisiologia , Ritmo Circadiano/fisiologia , Animais , Pressão Sanguínea/genética , Pressão Sanguínea/fisiologia , Vasos Sanguíneos/metabolismo , Vasos Sanguíneos/fisiologia , Relógios Circadianos/genética , Ritmo Circadiano/genética , Peptídeos e Proteínas de Sinalização do Ritmo Circadiano/genética , Peptídeos e Proteínas de Sinalização do Ritmo Circadiano/metabolismo , Regulação da Expressão Gênica , Humanos
13.
Biomech Model Mechanobiol ; 18(5): 1529-1548, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31076923

RESUMO

A profound analysis of pressure and flow wave propagation in cardiovascular systems is the key in noninvasive assessment of hemodynamic parameters. Pulse transit time (PTT), which closely relates to the physical properties of the cardiovascular system, can be linked to variations of blood pressure and stroke volume to provide information for patient-specific clinical diagnostics. In this work, we present mathematical and numerical tools, capable of accurately predicting the PTT, local pulse wave velocity, vessel compliance, and pressure/flow waveforms, in a viscous hyperelastic cardiovascular network. A new one-dimensional framework, entitled cardiovascular flow analysis (CardioFAN), is presented to describe the pulsatile fluid-structure interaction in the hyperelastic arteries, where pertaining hyperbolic equations are solved using a high-resolution total variation diminishing Lax-Wendroff method. The computational algorithm is validated against well-known numerical, in vitro and in vivo data for networks of main human arteries with 55, 37 and 26 segments, respectively. PTT prediction is improved by accounting for hyperelastic nonlinear waves between two arbitrary sections of the arterial tree. Consequently, arterial compliance assignments at each segment are improved in a personalized model of the human aorta and supra-aortic branches with 26 segments, where prior in vivo data were available for comparison. This resulted in a 1.5% improvement in overall predictions of the waveforms, or average relative errors of 5.5% in predicting flow, luminal area and pressure waveforms compared to prior in vivo measurements. The open source software, CardioFAN, can be calibrated for arbitrary patient-specific vascular networks to conduct noninvasive diagnostics.


Assuntos
Algoritmos , Vasos Sanguíneos/fisiologia , Elasticidade , Fluxo Pulsátil/fisiologia , Análise de Onda de Pulso , Artérias/fisiologia , Análise de Elementos Finitos , Humanos , Análise Numérica Assistida por Computador , Pressão , Reprodutibilidade dos Testes , Stents
14.
Ter Arkh ; 91(4): 130-135, 2019 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-31094487

RESUMO

Obesity is closely associated with metabolic and cardiovascular diseases, including dyslipidemia, coronary artery disease, hypertension, and heart failure. Adipose tissue (AT) is identified as a complex endocrine organ, with a wide range of regulatory functions at the cellular, tissue and systemic levels. Various terms, including paracardiac, epicardial and pericardial, are used to describe the fatty deposits surrounding the heart. Among all the fat depots, perivascular AT (PVAT) is of great biological significance for the cardiovascular system due to its anatomical proximity to the vessels. Recent studies have shown the presence of a complex, bidirectional paracrine and vasocardial signaling system between the vascular wall and PVAT. In the review, we will discuss the biological role of PVAT in both the physiological state and cardiovascular pathology, emphasizing its dual proatherogenic and antiatherogenic role. Let us consider PVAT as a target for various therapeutic agents in cardiovascular diseases. We will also analyze data on the role of non-invasive techniques as a diagnostic tool for assessing coronary artery inflammation.


Assuntos
Tecido Adiposo , Vasos Sanguíneos/metabolismo , Doenças Cardiovasculares/diagnóstico , Doença da Artéria Coronariana , Tecido Adiposo/metabolismo , Tecido Adiposo/patologia , Tecido Adiposo/fisiologia , Vasos Sanguíneos/fisiologia , Doenças Cardiovasculares/metabolismo , Doenças Cardiovasculares/patologia , Doença da Artéria Coronariana/diagnóstico , Doença da Artéria Coronariana/metabolismo , Insuficiência Cardíaca , Humanos , Obesidade/patologia , Pericárdio
15.
Biofabrication ; 11(3): 035020, 2019 05 17.
Artigo em Inglês | MEDLINE | ID: mdl-30943452

RESUMO

At the present time, there is no successful synthetic, off-the-shelf small-caliber vascular graft (<6 mm) for the repair or bypass of the coronary or carotid arteries. This stimulates on-going investigations to fabricate an artificial vascular graft that has both sufficient mechanical properties as well as superior biological performance. Collagen has long been considered as a viable material to encourage cell recruitment, tissue regeneration, and revascularization, but its use has been limited by its inferior mechanical properties. In this study, novel electrochemically aligned collagen filaments were used to engineer a bilayer small-caliber vascular graft, by circular knitting the collagen filaments and electrospinning collagen nanofibers. The collagen prototype grafts showed significantly greater bursting strength under dry and hydrated conditions to that of autografts such as the human internal mammary artery and the saphenous vein (SV). The suture retention strength was sufficient under dry condition, but that under hydrated condition needs to be further improved. The radial dynamic compliance of the collagen grafts was similar to that of the human SV. During in vitro cell culture assays with human umbilical vein endothelial cells, the prototype collagen grafts also encouraged cell adhesion and promoted cell proliferation compared to the synthetic poly(lactic acid) grafts. In conclusion, this study demonstrated the feasibility of the use of novel collagen filaments for fabricating small caliber tissue-engineered vascular grafts that provide both sufficient mechanical properties and superior biological performance.


Assuntos
Prótese Vascular , Vasos Sanguíneos/fisiologia , Colágeno/farmacologia , Nanofibras/química , Engenharia Tecidual/métodos , Animais , Fenômenos Biomecânicos , Adesão Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Camundongos , Poliésteres/química , Ratos , Suturas , Tecidos Suporte/química
16.
Skin Res Technol ; 25(5): 618-624, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30942508

RESUMO

BACKGROUND: Vascular changes, that is, functional and cellular endothelial changes, are of essential importance in healing. Alongside these vascular changes, inflammatory factors and hypoxia may play an important role in recovery. OBJECTIVES: To investigate the dynamics of functional and cellular endothelial changes and hypoxia in vivo following standardized skin damage caused by tape stripping. METHODS: Vascular changes (endothelial cell proliferation, vascular network size, vessel diameter) and hypoxia-inducible factor-1α were examined immunohistochemically using a CD31/Ki67 double staining and HIF-1α single staining. Cutaneous perfusion was evaluated using the Twente Optical Perfusion Camera (TOPCam). RESULTS: The initial phase is seen to be dominated by endothelial cell proliferation, HIF-1α expression, and vasodilatation. Cutaneous perfusion intensity is particularly increased in the first 16 hours. The late phase of recovery (after 72 hours) is characterized by a peak of expansion of the vascular network and a second peak of endothelial cell proliferation and HIF-1α expression. CONCLUSION: Endothelial cell proliferation and HIF-1α expression appear to be (strongly) related, having maximum levels at 16 hours and 72 hours. Angiogenesis and HIF-1α expression are not continuous processes, but rather occur intermittently.


Assuntos
Eritema/patologia , Pele/lesões , Adolescente , Adulto , Biomarcadores/metabolismo , Biópsia , Vasos Sanguíneos/fisiologia , Hipóxia Celular/fisiologia , Proliferação de Células/fisiologia , Células Endoteliais/citologia , Endotélio Vascular/citologia , Feminino , Voluntários Saudáveis , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Imuno-Histoquímica , Antígeno Ki-67/metabolismo , Masculino , Pessoa de Meia-Idade , Fotografação , Pele/irrigação sanguínea , Pele/citologia , Adulto Jovem
17.
Clin Physiol Funct Imaging ; 39(4): 261-275, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30920132

RESUMO

Exercise capacity as well as many resting central and peripheral haemodynamic features declines by age. We aimed to investigate which haemodynamic features change the most during life and which change in parallel to exercise capacity. We performed a maximal bicycle exercise test with gas exchange in 103 healthy subjects (24 young, 55 middle-aged and 24 elderly). Endothelial function, arterial compliance/stiffness and heart rate variability (HRV) were evaluated, and the myocardium and carotid arteries were investigated by ultrasound. Exercise capacity declined by almost 50% over the lifespan. Several markers reflecting arterial compliance/stiffness and HRV, as well as carotid intima-media thickness (IMT), showed lifetime impairments by >100%, while markers of LV systolic function, diastolic blood pressure and carotid artery blood flow showed only minor changes with age. The decline in exercise capacity clusters closely with many other variables measured during the exercise test, but also to resting vital capacity, left ventricular end-diastolic diameter and resting gas exchange (VO2 , VCO2 ) to a lesser degree. Resting vital capacity was closely related to exercise capacity in the middle-aged group. We conclude that many of the resting markers of central and peripheral haemodynamics declined during life, in parallel to the decline in exercise capacity. However, some haemodynamic features, such as LF/HF ratio at HRV, stiffness index beta of the carotid artery, and heart rate reserve at the exercise test, showed a more exaggerated decline, indicating that those are not closely linked to exercise capacity.


Assuntos
Envelhecimento/fisiologia , Vasos Sanguíneos/fisiologia , Tolerância ao Exercício , Coração/fisiologia , Hemodinâmica , Fatores Etários , Idoso , Ciclismo , Vasos Sanguíneos/diagnóstico por imagem , Estudos Transversais , Feminino , Coração/diagnóstico por imagem , Humanos , Masculino , Pessoa de Meia-Idade , Consumo de Oxigênio , Fluxo Sanguíneo Regional , Adulto Jovem
18.
Neurochem Int ; 126: 69-73, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30851365

RESUMO

Neurogenesis and angiogenesis share regulatory factors that contribute to the formation of vascular networks and neuronal circuits in the brain. While crosstalk mechanisms between neural stem cells (NSCs) and the vasculature have been extensively investigated, recent studies have provided evidence that blood vessels also play an essential role in neuronal migration in the brain during development and regeneration. The mechanisms of the neuronal migration along blood vessels, referred to as "vascular-guided migration," are now being elucidated. The vascular endothelial cells secrete soluble factors that attract and promote neuronal migration in collaboration with astrocytes that enwrap the blood vessels. In addition, especially in the adult brain, the blood vessels serve as a migration scaffold for adult-born immature neurons generated in the ventricular-subventricular zone (V-SVZ), a germinal zone surrounding the lateral ventricles. The V-SVZ-derived immature neurons use the vascular scaffold to assist their migration toward an injured area after ischemic stroke, and contribute to neuronal regeneration. Here we review the current knowledge about the role of vasculature in neuronal migration and the molecular mechanisms controlling this process. While most of this research has been done in rodents, a comprehensive understanding of vasculature-guided neuronal migration could contribute to new therapeutic approaches for increasing new neurons in the brain after injury.


Assuntos
Vasos Sanguíneos/fisiologia , Encéfalo/fisiologia , Movimento Celular/fisiologia , Células-Tronco Neurais/fisiologia , Neurônios/fisiologia , Tecidos Suporte/tendências , Animais , Astrócitos/fisiologia , Vasos Sanguíneos/citologia , Barreira Hematoencefálica/citologia , Barreira Hematoencefálica/fisiologia , Encéfalo/irrigação sanguínea , Encéfalo/citologia , Humanos , Neurogênese/fisiologia , Acidente Vascular Cerebral/patologia , Acidente Vascular Cerebral/terapia
19.
Int J Mol Sci ; 20(6)2019 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-30901816

RESUMO

Nitric oxide (NO) produced in the wall of blood vessels is necessary for the regulation of vascular tone to ensure an adequate blood supply of organs and tissues. In this review, we present evidence that the functioning of endothelial NO-synthase (eNOS) changes considerably during postnatal maturation. Alterations in NO-ergic vasoregulation in early ontogeny vary between vascular beds and correlate with the functional reorganization of a particular organ. Importantly, the anticontractile effect of NO can be an important mechanism responsible for the protectively low blood pressure in the immature circulatory system. The activity of eNOS is regulated by a number of hormones, including thyroid hormones which are key regulators of the perinatal developmental processes. Maternal thyroid hormone deficiency suppresses the anticontractile effect of NO at perinatal age. Such alterations disturb perinatal cardiovascular homeostasis and lead to delayed occurring cardiovascular pathologies in adulthood. The newly discovered role of thyroid hormones may have broad implications in cardiovascular medicine, considering the extremely high prevalence of maternal hypothyroidism in human society.


Assuntos
Vasos Sanguíneos/fisiologia , Endotélio Vascular/fisiologia , Neovascularização Fisiológica , Óxido Nítrico/biossíntese , Animais , Biomarcadores , Circulação Sanguínea , Humanos , Óxido Nítrico Sintase Tipo III/genética , Óxido Nítrico Sintase Tipo III/metabolismo , Hormônios Tireóideos/metabolismo
20.
Int J Sports Med ; 40(4): 245-252, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30836390

RESUMO

The early vascular adaptation to indoor cycling, a popular activity at many fitness centres, is incompletely evaluated. Forty two healthy women (21-45 years) underwent measurements of arterial wall properties and geometry as well as a maximal bicycle exercise test before and after a 3 months period during which 21 of the women joined indoor cycling classes at a gym 2-3 times per week, while 21 women served as time controls. Peak work load increased by in average 16% (p<0.001) and ascending aortic diameter by 4% (p<0.01) in the exercise group, while unchanged in control group. The exercise intervention had no significant influence on the local intima-media thickness, blood pressure or the pulse pressure wave configuration while the carotid artery distensibility (p<0.05) was higher after the intervention. There was a positive correlation between change in (Δ) peak work load and Δ-diameter of tubular ascending aorta (r=0.42, p<0.01) in the exercise group. In conclusion, after only 3 months of bicycle exercise training, signs of central arterial remodelling were seen in premenopausal women, which was associated to improvement in exercise capacity.


Assuntos
Adaptação Fisiológica , Ciclismo/fisiologia , Vasos Sanguíneos/fisiologia , Pré-Menopausa/fisiologia , Adulto , Aorta/anatomia & histologia , Aorta/fisiologia , Pressão Sanguínea , Artéria Braquial/fisiologia , Artéria Carótida Primitiva/fisiologia , Espessura Intima-Media Carotídea , Teste de Esforço , Feminino , Frequência Cardíaca , Humanos , Pessoa de Meia-Idade , Pulso Arterial , Remodelação Vascular , Adulto Jovem
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