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1.
Science ; 364(6436)2019 04 12.
Artigo em Inglês | MEDLINE | ID: mdl-30975860

RESUMO

To understand the health impact of long-duration spaceflight, one identical twin astronaut was monitored before, during, and after a 1-year mission onboard the International Space Station; his twin served as a genetically matched ground control. Longitudinal assessments identified spaceflight-specific changes, including decreased body mass, telomere elongation, genome instability, carotid artery distension and increased intima-media thickness, altered ocular structure, transcriptional and metabolic changes, DNA methylation changes in immune and oxidative stress-related pathways, gastrointestinal microbiota alterations, and some cognitive decline postflight. Although average telomere length, global gene expression, and microbiome changes returned to near preflight levels within 6 months after return to Earth, increased numbers of short telomeres were observed and expression of some genes was still disrupted. These multiomic, molecular, physiological, and behavioral datasets provide a valuable roadmap of the putative health risks for future human spaceflight.


Assuntos
Adaptação Fisiológica , Astronautas , Voo Espacial , Imunidade Adaptativa , Peso Corporal , Artérias Carótidas/diagnóstico por imagem , Espessura Intima-Media Carotídea , Dano ao DNA , Metilação de DNA , Microbioma Gastrointestinal , Instabilidade Genômica , Humanos , Masculino , Homeostase do Telômero , Fatores de Tempo , Estados Unidos , United States National Aeronautics and Space Administration
2.
Int J Mol Sci ; 20(5)2019 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-30866404

RESUMO

Nitric oxide (NO) produced by endothelial nitric oxide synthase (eNOS) plays crucial roles in cardiac homeostasis. Adult cardiomyocyte specific overexpression of eNOS confers protection against myocardial-reperfusion injury. However, the global effects of NO overexpression in developing cardiovascular system is still unclear. We hypothesized that nitric oxide overexpression affects the early migration of cardiac progenitor cells, vasculogenesis and function in a chick embryo. Vehicle or nitric oxide donor DEAN (500 mM) were loaded exogenously through a small window on the broad side of freshly laid egg and embryonic development tracked by live video-microscopy. At Hamburg Hamilton (HH) stage 8, the cardiac progenitor cells (CPC) were isolated and cell migration analysed by Boyden Chamber. The vascular bed structure and heart beats were compared between vehicle and DEAN treated embryos. Finally, expression of developmental markers such as BMP4, Shh, Pitx2, Noggin were measured using reverse transcriptase PCR and in-situ hybridization. The results unexpectedly showed that exogenous addition of pharmacological NO between HH stage 7⁻8 resulted in embryos with situs inversus in 28 out of 100 embryos tested. Embryos treated with NO inhibitor cPTIO did not have situs inversus, however 10 embryos treated with L-arginine showed a situs inversus phenotype. N-acetyl cysteine addition in the presence of NO failed to rescue situs inversus phenotype. The heart beat is normal (120 beats/min) although the vascular bed pattern is altered. Migration of CPCs in DEAN treated embryos is reduced by 60% compared to vehicle. BMP4 protein expression increases on the left side of the embryo compared to vehicle control. The data suggests that the NO levels in the yolk are important in turning of the heart during embryonic development. High levels of NO may lead to situs inversus condition in avian embryo by impairing cardiac progenitor cell migration through the NO-BMP4-cGMP axis.


Assuntos
Proteína Morfogenética Óssea 4/genética , Coração/fisiologia , Miócitos Cardíacos/citologia , Óxido Nítrico/farmacologia , Situs Inversus/induzido quimicamente , Animais , Movimento Celular/efeitos dos fármacos , Células Cultivadas , Embrião de Galinha , Desenvolvimento Embrionário , Coração/efeitos dos fármacos , Testes de Função Cardíaca/efeitos dos fármacos , Microscopia de Vídeo , Miócitos Cardíacos/efeitos dos fármacos , Situs Inversus/genética , Regulação para Cima
3.
Aerosp Med Hum Perform ; 89(4): 357-364, 2018 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-29562965

RESUMO

BACKGROUND: We compared microvascular and macrovascular blood flows of the tibia and anterior tibial artery during graded whole-body tilt. We hypothesized equal responses for bone microvascular and macrovascular blood flows during varying angles of tilt. METHODS: There were 18 volunteers who were randomly positioned in the following postures: supine, 15° head-up tilt, 6° head-up tilt, 6° head-down tilt, and 15° head-down tilt using an inversion table with reference to seated posture (baseline control). Ultrasonography quantified anterior tibial arterial diameter and peak systolic velocity, enabling calculation of macrovascular blood flow to the tibia. Tibial bone microvascular blood flow was measured noninvasively using photoplethysmography in the same leg. RESULTS: Transitioning from a seated position to a supine position, macrovascular blood flow did not change significantly (1.81 ± 1.18 to 2.80 ± 1.74cm 3 · s-1). However, bone microvascular flow increased significantly (0.36 ± 0.23 to 1.11 ± 0.79 V) from the seated to the supine position. Transitioning from a seated posture to 15° head-down tilt, both arterial macrovascular and bone microvascular flows increased significantly (1.81 ± 1.18 to 3.32 ± 2.08 cm3 · s-1 and 0.36 ± 0.23 V to 2.99 ± 2.71 V, respectively). The normalized flow for microvascular blood flow as a function of body tilt was significantly greater than that for macrovascular blood flow at 6° and 15° head-down tilt. DISCUSSION: These data do not support our hypothesis that bone microvascular flow and arterial macrovascular flow share equal responses to altered body tilt. Therefore, for a given decrease in local blood pressure in the leg with head-down body tilt, the magnitude of increase in blood flow is greater in the microcirculation as compared to the feeding artery.Becker RL, Siamwala JH, Macias BR, Hargens AR. Tibia bone microvascular flow dynamics as compared to anterior tibial artery flow during body tilt. Aerosp Med Hum Perform. 2018; 89(4):357-364.


Assuntos
Velocidade do Fluxo Sanguíneo/fisiologia , Decúbito Inclinado com Rebaixamento da Cabeça/fisiologia , Microcirculação/fisiologia , Tíbia/irrigação sanguínea , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Voo Espacial , Tíbia/diagnóstico por imagem , Ultrassonografia , Ausência de Peso , Simulação de Ausência de Peso
4.
Front Physiol ; 9: 72, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29491839

RESUMO

Hands may show early signs of aging with altered skin texture, skin permeability and vascular properties. In clinics, a hand volumeter is used to measure swelling of hands due to edema, carpal tunnel syndrome or drug interventions. The hand volume measurements are generally taken without taking age into consideration. We hypothesized that age affects hand volumeter measurements and that the younger age group (≤40 years) records a greater change in hand volume as compared to the older group (>40 years). Four volumetric measurements were taken at 5 min intervals during 20 min of water immersion using a clinically-approved hand volumeter. After 20 min of immersion, the hand volume changes of the younger age group were significantly higher than the older age group (p < 0.001). Specifically, the right-hand volume of the younger age group (≤40 years, n = 30) increased by 4.3 ± 2%, and the left hand increased by 3.4 ± 2.1%. Conversely, the right-hand volume of the older age group (>40 years, n = 10) increased by 2.2 ± 2.0%, and the left hand decreased by 0.6 ± 2.4% after 20 min of water immersion. The data are presented as Mean ± SD. Hand volume changes were not correlated with body mass index (BMI) or gender, and furthermore, neither of these two variables affected the relationship between age and hand volume changes with water immersion. We conclude that the younger age group has a higher increase in hand volume with water immersion as compared to the older age group.

5.
Bone Rep ; 7: 57-62, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28875158

RESUMO

Previously our laboratory documented increases in calvaria bone volume and thickness in mice exposed to 15 days of spaceflight aboard the NASA Shuttle mission STS-131. However, the tissues were not processed for gene expression studies to determine what bone formation pathways might contribute to these structural adaptations. Therefore, this study was designed to investigate both the structural and molecular changes in mice calvariae after a longer duration of spaceflight. The primary purpose was to determine the calvaria bone volume and thickness of mice exposed to 30 days of spaceflight using micro-computed tomography for comparison with our previous findings. Because sclerostin, the secreted glycoprotein of the Sost gene, is a potent inhibitor of bone formation, our second aim was to quantify Sost mRNA expression using quantitative PCR. Calvariae were obtained from six mice aboard the Russian 30-day Bion-M1 biosatellite and seven ground controls. In mice exposed to 30 days of spaceflight, calvaria bone structure was not significantly different from that of their controls (bone volume was about 5% lower in spaceflight mice, p = 0.534). However, Sost mRNA expression was 16-fold (16.4 ± 0.4, p < 0.001) greater in the spaceflight group than that in the ground control group. Therefore, bone formation may have been suppressed in mice exposed to 30 days of spaceflight. Genetic responsiveness (e.g. sex or strain of animals) or in-flight environmental conditions other than microgravity (e.g. pCO2 levels) may have elicited different bone adaptations in STS-131 and Bion-M1 mice. Although structural results were not significant, this study provides biochemical evidence that calvaria mechanotransduction pathways may be altered during spaceflight, which could reflect vascular and interstitial fluid adaptations in non-weight bearing bones. Future studies are warranted to elucidate the processes that mediate these effects and the factors responsible for discordant calvaria bone adaptations between STS-131 and Bion-M1 mice.

6.
J Appl Physiol (1985) ; 123(4): 860-866, 2017 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-28663380

RESUMO

Loss of hydrostatic pressures in microgravity may alter skin and bone microvascular flows in the lower extremities and potentially reduce wound healing and bone fracture repair. The purpose of this study was to determine the rate at which skin and bone microvascular flows respond to head-down tilt (HDT). We hypothesized that microvascular flows in tibial bone and overlying skin would increase at different rates during HDT. Tibial bone and skin microvascular flows were measured simultaneously using photoplethysmography (PPG) in a total of 17 subjects during sitting (control posture), supine, 6° HDT, 15° HDT, and 30° HDT postures in random order. With greater angles of HDT, bone microvascular flow increased significantly, but skin microvascular flow did not change. Tibial bone microvascular flow increased from the sitting control posture (0.77 ± 0.41 V) to supine (1.95 ± 1.01 V, P = 0.001) and from supine posture to 15° HDT (3.74 ± 2.43 V, P = 0.004) and 30° HDT (3.91 ± 2.68 V, P = 0.006). Skin microvascular flow increased from sitting (0.703 ± 0.75 V) to supine (2.19 ± 1.72 V, P = 0.02) but did not change from supine posture to HDT (P = 1.0). We show for the first time that microcirculatory flows in skin and bone of the leg respond to simulated microgravity at different rates. These altered levels of blood perfusion may affect rates of wound and bone fracture healing in spaceflight.NEW & NOTEWORTHY Our data show that bone microvascular flow increases more than cutaneous blood flow with greater degrees of head-down tilt. A higher level of perfusion in bone may give insight into the bone mineral density loss in lower extremities of astronauts and why similar tissue degradation is not observed in the skin of the same areas.


Assuntos
Decúbito Inclinado com Rebaixamento da Cabeça , Microcirculação/fisiologia , Pele/irrigação sanguínea , Tíbia/irrigação sanguínea , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fotopletismografia , Postura , Simulação de Ausência de Peso , Adulto Jovem
7.
Physiol Rep ; 5(4)2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28242824

RESUMO

The purpose of the investigation was to study lower body negative pressure recovery in response to head down tilt position in men and women. The study examined the primary hypothesis that tibial bone microvascular flow responses to HDT and lower body negative pressure (LBNP) differ in women and men. Nine women and nine men between 20 to 30 years of age participated in the study. Tibial microvascular flow, head and tibial oxygenation and calf circumference were measured using photoplethysmography (PPG), near-infrared spectroscopy (NIRS) and strain gauge plethysmography (SGP), respectively, during sitting (control baseline), supine, 15° HDT, and 15° HDT with 25 mmHg LBNP Tibial microvascular flow with HDT increased by 57% from supine position (from 1.4V ± 0.7 to 2.2V ± 1.0 HDT; ANOVA P < 0.05) in men but there is no significant difference between supine and HDT in women. Ten minutes of LBNP during 15o HDT restored tibial bone microvascular flows to supine levels, (from 2.2V±1.0 HDT to 1.1V ± 0.7 supine; ANOVA P < 0.05) in men but not in women. These data support the concept that there are gender specific microvascular responses to a fluid-shift countermeasure such as LBNP Thus, gender differences should be considered while developing future countermeasure strategies to headward fluid shifts in microgravity.


Assuntos
Decúbito Inclinado com Rebaixamento da Cabeça , Pressão Negativa da Região Corporal Inferior , Microvasos/fisiologia , Fluxo Sanguíneo Regional/fisiologia , Caracteres Sexuais , Tíbia/irrigação sanguínea , Adulto , Pressão Sanguínea/fisiologia , Feminino , Frequência Cardíaca/fisiologia , Humanos , Masculino , Fotopletismografia , Espectroscopia de Luz Próxima ao Infravermelho , Adulto Jovem
8.
Invest Ophthalmol Vis Sci ; 56(11): 6714-23, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26567782

RESUMO

PURPOSE: To test the retinal differentiation potential and to establish an optimized protocol for enriching retinal cells from an Indian origin, human embryonic stem cell (hESC) line, BJNhem20. METHODS: The BJNhem20 cells were cultured and expanded under feeder-free culture conditions. Differentiation was initiated by embryoid body (EB) formation and were cultured on Matrigel in neural induction medium (NIM) for 1 week and further maintained in retinal differentiation medium (RDM). After 1 month, the neuro-retinal progenitor clusters located at the center of pigmented retinal patches were picked and cultured as suspended neurospheres in RDM for 3 days and subsequently on Matrigel in neuro-retinal medium. The mildly pigmented, immature retinal pigmented epithelial (RPE) cells were picked separately and cultured on Matrigel in RPE medium (RPEM). After 1 week, the confluent neuro-retinal and RPE cultures were maintained in RDM for 2 to 3 months and characterized by immunofluorescence and RT-PCR. RESULTS: The BJNhem20 cells efficiently differentiated into both neuro-retinal and RPE cells. The early retinal progenitors expressed Nestin, GFAP, Pax6, Rx, MitfA, Chx10, and Otx2. Neuro-retinal cells expressed the neural markers, Map2, ß-III tubulin, acetylated tubulin and photoreceptor-specific markers, Crx, rhodopsin, recoverin, calbindin, PKC, NeuroD1, RLBP1, rhodopsin kinase, PDE6A, and PDE6C. Mature RPE cells developed intense pigmentation within 3 months and showed ZO-1 and Phalloidin staining at cell-cell junctions and expressed RPE65, tyrosinase, bestrophin1, Mertk, and displayed phagocytic activity. CONCLUSIONS: This study confirms the retinal differentiation potential of BJNhem20 cells and describes an optimized protocol to generate enriched populations of neuro-retinal and RPE cells.


Assuntos
Técnicas de Cultura de Células/métodos , Diferenciação Celular , Células-Tronco Embrionárias Humanas/citologia , Neurônios Retinianos/citologia , Epitélio Pigmentado da Retina/citologia , Biomarcadores/metabolismo , Linhagem Celular , Colágeno , Combinação de Medicamentos , Humanos , Laminina , Proteoglicanas , Neurônios Retinianos/metabolismo
9.
Vitam Horm ; 99: 249-72, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26279379

RESUMO

Bone structure and function is shaped by gravity. Prolonged exposure to microgravity leads to 1-2% bone loss per month in crew members compared to 1% bone loss per year in postmenopausal women. Exercise countermeasures developed to date are ineffective in combating bone loss in microgravity. The search is on for alternate therapies to prevent bone loss in space. Microgravity is an ideal stimulus to understand bone interactions at different levels of organizations. Spaceflight experiments are limited by high costs and lack of opportunity. Ground-based microgravity analogs have proven to simulate biological responses in space. Mice experiments have given important signaling clues in microgravity-associated bone loss, but are restricted by numbers and human application. Cell-based systems provide initial clues to signaling changes; however, the information is simplistic and limited to the cell type. There is a need to integrate information at different levels and provide a complete picture which will help develop a unique strategy to prevent bone weakening. Limited exposure to simulated microgravity using random positioning machine induces proliferation and differentiation of bipotential murine oval liver stem cells. Bone morphogenetic proteins (BMPs) are the prototypal osteogenic signaling molecule with multitude of bone protective functions. In this chapter, we discuss the basic BMP structure, its significance in bone repair, and stem cell differentiation in microgravity. Based on the current information, we propose a model for BMP signaling in space. Development of new technologies may help osteoporosis patients, bedridden people, spinal injuries, or paralytic patients.


Assuntos
Proteínas Morfogenéticas Ósseas/química , Proteínas Morfogenéticas Ósseas/metabolismo , Osso e Ossos/metabolismo , Transdução de Sinais/fisiologia , Ausência de Peso , Animais , Densidade Óssea/fisiologia , Diferenciação Celular/fisiologia , Humanos , Camundongos , Células-Tronco/citologia , Células-Tronco/metabolismo
10.
J Appl Physiol (1985) ; 119(2): 101-9, 2015 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-25930022

RESUMO

Skeletal unloading and cephalic fluid shifts in microgravity may alter the bone microvascular flow and may be associated with the 1-2% bone loss per month during spaceflight. The purpose of this study was to determine if lower-body negative pressure (LBNP) can prevent microgravity-induced alterations of tibial microvascular flow. Head-down tilt (HDT) simulates the cephalad fluid shift and microvascular flow responses that may occur in microgravity. We hypothesized that LBNP prevents HDT-induced increases in tibial microvascular flow. Tibial bone microvascular flow, oxygenation, and calf circumference were measured during 5 min sitting, 5 min supine, 5 min 15° HDT, and 10 min 15° HDT with 25 mmHg LBNP using photoplethysmography (PPG), near-infrared spectroscopy (NIRS), and strain-gauge plethysmography (SGP). Measurements were made simultaneously. Tibial microvascular flow increased by 36% with 5 min 15° HDT [2.2 ± 1.1 V; repeated-measures ANOVA (RMANOVA) P < 0.0001] from supine (1.4 ± 0.8 V). After 10 min of LBNP in the 15° HDT position, tibial microvascular flow returned to supine levels (1.1 ± 0.5 V; RMANOVA P < 0.001). Tibial oxygenation did not change significantly during sitting, supine, HDT, or HDT with LBNP. However, calf circumference decreased with 5 min 15° HDT (-0.7 ± 0.4 V; RMANOVA P < 0.0001) from supine (-0.5 ± 0.4 V). However, with LBNP calf circumference returned to supine levels (-0.4 ± 0.1 V; RMANOVA P = 0.002). These data establish that simulated microgravity increases tibial microvascular flow and LBNP prevents these increases. The results suggest that LBNP may provide a suitable countermeasure to normalize the bone microvascular flow during spaceflight.


Assuntos
Decúbito Inclinado com Rebaixamento da Cabeça/fisiologia , Perna (Membro)/fisiologia , Microvasos/fisiologia , Fluxo Sanguíneo Regional/fisiologia , Tíbia/fisiologia , Adulto , Feminino , Humanos , Pressão Negativa da Região Corporal Inferior/métodos , Masculino , Pletismografia/métodos , Voo Espacial/métodos , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Decúbito Dorsal/fisiologia , Simulação de Ausência de Peso/métodos , Adulto Jovem
11.
Nitric Oxide ; 36: 76-86, 2014 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-24333563

RESUMO

Nitric oxide (NO) is a known modulator of angiogenesis. The NONOate subfamily of NO donors has long been used in experimental and clinical studies to promote angiogenesis. However, no studies have been conducted yet to compare the angiogenesis potential of these NO donors in respect to their pattern of NO release. We hypothesize that having different pattern of NO release, each of the NO donors in NONOate subfamily can promote key stages of angiogenesis in differential manner. To verify our hypothesis, NO donors with half life ranging from seconds to several hours and having very different pattern of NO release were selected to evaluate their efficacy in modulating angiogenesis. Endothelial tube formation using EAhy926 cells was maximally increased by Spermine NONOate (SP) treatment. SP treatment maximally induced both ex vivo and in vivo angiogenesis using egg yolk and cotton plug angiogenesis models respectively. Experiment using chick embryo partial ischemia model revealed SP as the best suited NO donor to recover ischemia driven hampered angiogenesis. The present study elaborated that differential release pattern of NO by different NO donors can modulate angiogenesis differentially and also suggested that SP have a unique pattern of NO release that best fits for angiogenesis.


Assuntos
Indutores da Angiogênese/química , Neovascularização Fisiológica , Doadores de Óxido Nítrico/química , Espermina/análogos & derivados , Animais , Aorta/metabolismo , Bovinos , Células Cultivadas , Embrião de Galinha , Gema de Ovo , Endotélio Vascular/metabolismo , Perfilação da Expressão Gênica , Isquemia/metabolismo , Masculino , Óxido Nítrico/química , Ratos , Ratos Wistar , Transdução de Sinais , Espermina/química , Cicatrização
12.
Cell Biol Int ; 37(5): 495-506, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23404577

RESUMO

Cadmium targets the vascular endothelium causing endothelial dysfunction and leakiness of endothelial barrier. Nitric oxide plays a major role in mediating endothelial functions including angiogenesis, migration and permeability. The present study investigates the nitric oxide effects on cadmium induced endothelial leakiness. Results of ex vivo and in vitro permeability assays showed that even a sub-lethal dose of cadmium chloride (1 µM) was sufficient to induce leakiness of endothelial cells. Cadmium drastically altered the actin polymerisation pattern and membrane tension of these cells compared to controls. Addition of nitric oxide donor Spermine NONOate (SP) significantly blunted cadmium-mediated effects and recover endothelial cells integrity. Cadmium-induced cytoskeletal rearrangements and membrane leakiness are associated with the low nitric oxide availability and high reactive oxygen species generation. In brief, we show the protective role of nitric oxide against cadmium-mediated endothelial leakiness.


Assuntos
Cádmio/toxicidade , Permeabilidade da Membrana Celular/efeitos dos fármacos , Espermina/análogos & derivados , Actinas/metabolismo , Linhagem Celular , Movimento Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , GMP Cíclico/metabolismo , Células Endoteliais/citologia , Células Endoteliais/efeitos dos fármacos , Células Endoteliais/metabolismo , Endotélio Vascular/citologia , Endotélio Vascular/patologia , Humanos , Óxido Nítrico Sintase Tipo III/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Espermina/farmacologia
13.
J Nutr Biochem ; 24(3): 595-605, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22819553

RESUMO

Consumption of tea (Camellia sinensis) improves vascular function and is linked to lowering the risk of cardiovascular disease. Endothelial nitric oxide is the key regulator of vascular functions in endothelium. In this study, we establish that l-theanine, a non-protein amino-acid found in tea, promotes nitric oxide (NO) production in endothelial cells. l-theanine potentiated NO production in endothelial cells was evaluated using Griess reaction, NO sensitive electrode and a NO specific fluorescent probe (4-amino-5-methylamino-2',7'-difluororescein diacetate). l-Theanine induced NO production was partially attenuated in presence of l-NAME or l-NIO and completely abolished using eNOS siRNA. eNOS activation was Ca(2+) and Akt independent, as assessed by fluo-4AM and immunoblotting experiments, respectively and was associated with phosphorylation of eNOS Ser 1177. eNOS phosphorylation was inhibited in the presence of ERK1/2 inhibitor, PD-98059 and partially inhibited by PI3K inhibitor, LY-294002 and Wortmanin suggesting PI3K-ERK1/2 dependent pathway. Increased NO production was associated with vasodilation in ex ovo (chorioallantoic membrane) model. These results demonstrated that l-theanine administration in vitro activated ERK/eNOS resulting in enhanced NO production and thereby vasodilation in the artery. The results of our experiments are suggestive of l-theanine mediated vascular health benefits of tea.


Assuntos
Células Endoteliais/efeitos dos fármacos , Glutamatos/farmacologia , Óxido Nítrico Sintase Tipo III/genética , Óxido Nítrico/biossíntese , Extratos Vegetais/farmacologia , Apoptose/efeitos dos fármacos , Cálcio/análise , Cálcio/metabolismo , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Cromonas/farmacologia , Células Endoteliais/metabolismo , Endotélio Vascular/citologia , Endotélio Vascular/efeitos dos fármacos , Flavonoides/farmacologia , Humanos , Proteína Quinase 1 Ativada por Mitógeno/antagonistas & inibidores , Proteína Quinase 1 Ativada por Mitógeno/genética , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/antagonistas & inibidores , Proteína Quinase 3 Ativada por Mitógeno/genética , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Morfolinas/farmacologia , NG-Nitroarginina Metil Éster/metabolismo , Óxido Nítrico Sintase Tipo III/metabolismo , Ornitina/análogos & derivados , Ornitina/metabolismo , Fosfatidilinositol 3-Quinases/genética , Fosfatidilinositol 3-Quinases/metabolismo , Fosforilação , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais , Chá/química , Vasodilatação/efeitos dos fármacos
14.
J Food Sci ; 77(12): H273-9, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23240972

RESUMO

Recent evidence has demonstrated that nitrites play an important role in the cardiovascular system. Fennel (Foneiculum vulgare) seeds are often used as mouth fresheners after a meal in both the Indian sub-continent and around the world. The present study aims to quantify the nitrite and nitrates in fennel seeds as well as elucidating the effect of fennel derived-nitrites on vascular functions. Results from our study show that fennel seeds contain significantly higher amount of nitrites when compared to other commonly used post-meal seeds. Furthermore our study confirmed the functional effects of fennel derived-nitrites using in vitro and ex vivo models that describe the promotion of angiogenesis, cell migration, and vasorelaxation. We also showed that chewing fennel seeds enhanced nitrite content of saliva. Thus our study indicates the potential role of fennel derived-nitrites on the vascular system.


Assuntos
Foeniculum/química , Nitritos/farmacologia , Extratos Vegetais/farmacologia , Sementes/química , Vasodilatação/efeitos dos fármacos , Indutores da Angiogênese/farmacologia , Linhagem Celular , Citoproteção/efeitos dos fármacos , Humanos , Nitratos/análise , Especiarias/análise
15.
Sci Rep ; 2: 679, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22997553

RESUMO

Thalidomide, a sedative drug given to pregnant women, unfortunately caused limb deformities in thousands of babies. Recently the drug was revived because of its therapeutic potential; however the search is still ongoing for an antidote against thalidomide induced limb deformities. In the current study we found that nitric oxide (NO) rescues thalidomide affected chick (Gallus gallus) and zebrafish (Danio rerio) embryos. This study confirms that NO reduced the number of thalidomide mediated limb deformities by 94% and 80% in chick and zebrafish embryos respectively. NO prevents limb deformities by promoting angiogenesis, reducing oxidative stress and inactivating caspase-3 dependent apoptosis. We conclude that NO secures angiogenesis in the thalidomide treated embryos to protect them from deformities.


Assuntos
Indutores da Angiogênese/farmacologia , Anormalidades Musculoesqueléticas/induzido quimicamente , Doadores de Óxido Nítrico/farmacologia , Espermina/análogos & derivados , Teratogênios/toxicidade , Talidomida/toxicidade , Indutores da Angiogênese/uso terapêutico , Animais , Aorta/efeitos dos fármacos , Aorta/patologia , Apoptose/efeitos dos fármacos , Caspase 3/metabolismo , Catalase/fisiologia , Embrião de Galinha , Avaliação Pré-Clínica de Medicamentos , Desenvolvimento Embrionário/efeitos dos fármacos , Células Endoteliais/efeitos dos fármacos , Células Endoteliais/fisiologia , Feminino , Técnicas In Vitro , Masculino , Anormalidades Musculoesqueléticas/prevenção & controle , Neovascularização Fisiológica/efeitos dos fármacos , Doadores de Óxido Nítrico/uso terapêutico , Óxido Nítrico Sintase Tipo III/biossíntese , Espécies Reativas de Oxigênio/metabolismo , Espermina/farmacologia , Espermina/uso terapêutico , Peixe-Zebra , Proteínas de Peixe-Zebra/metabolismo
16.
J Cell Biochem ; 112(7): 1898-908, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21433062

RESUMO

Faster growth and differentiation of liver stem cells to hepatocyte is one of the key factors during liver regeneration. In recent years, simulated microgravity, a physical force has shown to differentially regulate the differentiation and proliferation of stem cells. In the present work, we studied the effect of simulated microgravity on differentiation and proliferation of liver stem cells. The cells were subjected to microgravity, which was simulated using indigenously fabricated 3D clinostat. Proliferation, apoptosis, immunofluorescence assays and Western blot analysis were carried out to study the effects of simulated microgravity on liver stem cells. Microgravity treatment for 2 h enhanced proliferation of stem cells by twofold without inducing apoptosis and compromising cell viability. Analysis of hepatocyte nuclear factor 4-α (HNF4-α) expression after 2 h of microgravity treatment revealed that microgravity alone can induce the differentiation of stem cells within 2-3 days. Probing bone morphogenic protein 4 (BMP4) and Notch1 in microgravity treated stem cells elaborated downregulation of Notch1 and upregulation of BMP4 after 2 days of incubation. Further, blocking BMP4 using dorsomorphin and chordin conditioned media from chordin plasmid transfected cells attenuated microgravity mediated differentiation of liver stem cells. In conclusion, microgravity interplays with BMP4/Notch1 signaling in stem cells thus inducing differentiation of stem cells to hepatocytes. Present findings can be implicated in clinical studies where microgravity activated stem cells can regenerate the liver efficiently after liver injury.


Assuntos
Proteína Morfogenética Óssea 4/metabolismo , Diferenciação Celular , Fígado/citologia , Receptor Notch1/metabolismo , Células-Tronco/citologia , Simulação de Ausência de Peso , Animais , Antígenos de Diferenciação/metabolismo , Apoptose , Proteína Morfogenética Óssea 4/antagonistas & inibidores , Proliferação de Células , Células Cultivadas , Meios de Cultivo Condicionados , Ensaios Enzimáticos , Glicoproteínas/farmacologia , Fator 4 Nuclear de Hepatócito/metabolismo , Peptídeos e Proteínas de Sinalização Intercelular/farmacologia , L-Lactato Desidrogenase/química , L-Lactato Desidrogenase/metabolismo , Camundongos , Pirazóis/farmacologia , Pirimidinas/farmacologia , Transdução de Sinais , Células-Tronco/metabolismo
17.
FEBS Lett ; 584(15): 3415-23, 2010 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-20600009

RESUMO

Angiogenesis is a physiological process involving the growth of blood vessel in response to specific stimuli. The present study shows that limited microgravity treatments induce angiogenesis by activating macrovascular endothelial cells. Inhibition of nitric oxide production using pharmacological inhibitors and inducible nitric oxide synthase (iNOS) small interfering ribo nucleic acid (siRNA) abrogated microgravity induced nitric oxide production in macrovascular cells. The study further delineates that iNOS acts as a molecular switch for the heterogeneous effects of microgravity on macrovascular, endocardial and microvascular endothelial cells. Further dissection of nitric oxide downstream signaling confirms that simulated microgravity induces angiogenesis via the cyclic guanosine monophosphate (cGMP)-PKG dependent pathway.


Assuntos
Proteínas Quinases Dependentes de GMP Cíclico/metabolismo , GMP Cíclico/metabolismo , Células Endoteliais/enzimologia , Neovascularização Fisiológica , Óxido Nítrico Sintase Tipo II/metabolismo , Óxido Nítrico/metabolismo , Simulação de Ausência de Peso , Animais , Bovinos , Movimento Celular , Proliferação de Células , Galinhas , Células Endoteliais/citologia , Humanos , Óxido Nítrico Sintase Tipo III/metabolismo , Transdução de Sinais , Sus scrofa , Ausência de Peso , Cicatrização
18.
PLoS One ; 5(5): e10524, 2010 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-20479865

RESUMO

BACKGROUND: Ischemia is a pathophysiological condition due to blockade in blood supply to a specific tissue thus damaging the physiological activity of the tissue. Different in vivo models are presently available to study ischemia in heart and other tissues. However, no ex vivo ischemia model has been available to date for routine ischemia research and for faster screening of anti-ischemia drugs. In the present study, we took the opportunity to develop an ex vivo model of partial ischemia using the vascular bed of 4(th) day incubated chick embryo. METHODOLOGY/PRINCIPAL FINDINGS: Ischemia was created in chick embryo by ligating the right vitelline artery using sterile surgical suture. Hypoxia inducible factor- 1 alpha (HIF-1alpha), creatine phospho kinase-MB and reactive oxygen species in animal tissues and cells were measured to confirm ischemia in chick embryo. Additionally, ranolazine, N-acetyl cysteine and trimetazidine were administered as an anti-ischemic drug to validate the present model. Results from the present study depicted that blocking blood flow elevates HIF-1alpha, lipid peroxidation, peroxynitrite level in ischemic vessels while ranolazine administration partially attenuates ischemia driven HIF-1alpha expression. Endothelial cell incubated on ischemic blood vessels elucidated a higher level of HIF-1alpha expression with time while ranolazine treatment reduced HIF-1alpha in ischemic cells. Incubation of caprine heart strip on chick embryo ischemia model depicted an elevated creatine phospho kinase-MB activity under ischemic condition while histology of the treated heart sections evoked edema and disruption of myofibril structures. CONCLUSIONS/SIGNIFICANCE: The present study concluded that chick embryo partial ischemia model can be used as a novel ex vivo model of ischemia. Therefore, the present model can be used parallel with the known in vivo ischemia models in understanding the mechanistic insight of ischemia development and in evaluating the activity of anti-ischemic drug.


Assuntos
Modelos Animais de Doenças , Isquemia/patologia , Procedimentos Cirúrgicos Vasculares/métodos , Acetanilidas/farmacologia , Animais , Apoptose/efeitos dos fármacos , Vasos Sanguíneos/efeitos dos fármacos , Vasos Sanguíneos/metabolismo , Vasos Sanguíneos/patologia , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Embrião de Galinha , Creatina Quinase Forma MB/metabolismo , Edema/complicações , Edema/patologia , Células Endoteliais/efeitos dos fármacos , Células Endoteliais/metabolismo , Células Endoteliais/patologia , Glutationa/metabolismo , Cabras , Saúde , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Miocárdio/enzimologia , Miocárdio/patologia , Neovascularização Patológica/metabolismo , Especificidade de Órgãos/efeitos dos fármacos , Piperazinas/farmacologia , Ranolazina , Espécies Reativas de Oxigênio/metabolismo , Fatores de Tempo
19.
Biochimie ; 92(9): 1186-98, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20363286

RESUMO

Endothelium plays a fundamental role in maintaining the vascular tone by releasing various biochemical factors that modulate the contractile and relaxatory behavior of the underlying vascular smooth muscle, regulation of inflammation, immunomodulation, platelet aggregation, and thrombosis. Endothelium regulates these cellular processes by activating endothelial nitric oxide synthase (eNOS) responsible for nitric oxide (NO) production. eNOS is constitutively expressed in ECs in response to humoral, mechanical or pharmacological stimulus. eNOS activity is regulated mainly by protein-protein interactions and multisite phosphorylations. The phosphorylation state of specific serine, threonine and tyrosine residues of the enzyme plays a pivotal role in regulation of eNOS activity. Perturbations of eNOS phosphorylation have been reported in a number of diseases thereby emphasizing the importance of regulation of eNOS activity. This review summarizes the mechanism of eNOS regulation through multi-site phosphorylation in different pathologies. Attempts have been made to highlight phosphorylation of eNOS at various residues, regulation of the enzyme activity via posttranslational modifications and its implications on health and disease.


Assuntos
Óxido Nítrico Sintase Tipo III/metabolismo , Animais , Humanos , Modelos Biológicos , Óxido Nítrico/metabolismo , Fosforilação , Serina/metabolismo
20.
Cell Biol Int ; 34(7): 755-61, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20397975

RESUMO

Hypoxia induces barrier dysfunctions in endothelial cells. Nitric oxide is an autacoid signalling molecule that confers protection against hypoxia-mediated barrier dysfunctions. Dyn-2 (dynamin-2), a large GTPase and a positive modulator of eNOS (endothelial nitric oxide synthase), plays an important role in maintaining vascular homeostasis. The present study aims to elucidate the role of dyn-2 in hypoxia-mediated leakiness of the endothelial monolayer in relation to redox milieu. Inhibition of dyn-2 by transfecting the cells with K44A, a dominant negative construct of dyn-2, elevated leakiness of the endothelial monolayer under hypoxia. Sodium nitroprusside (nitric oxide donor) and uric acid (peroxynitrite quencher) were used to evaluate the role of nitric oxide and peroxynitrite in maintaining endothelial barrier functions under hypoxia. Administration of nitric oxide and uric acid recovered hypoxia-mediated leakiness of K44A-overexpressed endothelial monolayer. Our study confirms that inhibition of dyn-2 induces leakiness in the endothelial monolayer by increasing the load of peroxynitrite under hypoxia.


Assuntos
Permeabilidade Capilar/fisiologia , Dinamina II/antagonistas & inibidores , Endotélio Vascular/metabolismo , Óxido Nítrico/biossíntese , Antioxidantes/metabolismo , Linhagem Celular , Dinamina II/metabolismo , Células Endoteliais/citologia , Células Endoteliais/metabolismo , Endotélio Vascular/citologia , Humanos , Hipóxia/metabolismo , Doadores de Óxido Nítrico/metabolismo , Óxido Nítrico Sintase Tipo III/metabolismo , Nitroprussiato/metabolismo , Ácido Peroxinitroso/metabolismo , Ácido Úrico/metabolismo
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