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1.
Gastroenterology ; 157(1): 193-209.e9, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-30872106

RESUMO

BACKGROUND & AIMS: Mechanical forces contribute to portal hypertension (PHTN) and fibrogenesis. We investigated the mechanisms by which forces are transduced by liver sinusoidal endothelial cells (LSECs) into pressure and matrix changes. METHODS: We isolated primary LSECs from mice and induced mechanical stretch with a Flexcell device, to recapitulate the pulsatile forces induced by congestion, and performed microarray and RNA-sequencing analyses to identify gene expression patterns associated with stretch. We also performed studies with C57BL/6 mice (controls), mice with deletion of neutrophil elastase (NE-/-) or peptidyl arginine deiminase type IV (Pad4-/-) (enzymes that formation of neutrophil extracellular traps [NETs]), and mice with LSEC-specific deletion of Notch1 (Notch1iΔEC). We performed partial ligation of the suprahepatic inferior vena cava (pIVCL) to simulate congestive hepatopathy-induced portal hypertension in mice; some mice were given subcutaneous injections of sivelestat or underwent bile-duct ligation. Portal pressure was measured using a digital blood pressure analyzer and we performed intravital imaging of livers of mice. RESULTS: Expression of the neutrophil chemoattractant CXCL1 was up-regulated in primary LSECs exposed to mechanical stretch, compared with unexposed cells. Intravital imaging of livers in control mice revealed sinusoidal complexes of neutrophils and platelets and formation of NETs after pIVCL. NE-/- and Pad4-/- mice had lower portal pressure and livers had less fibrin compared with control mice after pIVCL and bile-duct ligation; neutrophil recruitment into sinusoidal lumen of liver might increase portal pressure by promoting sinusoid microthrombi. RNA-sequencing of LSECs identified proteins in mechanosensitive signaling pathways that are altered in response to mechanical stretch, including integrins, Notch1, and calcium signaling pathways. Mechanical stretch of LSECs increased expression of CXCL1 via integrin-dependent activation of transcription factors regulated by Notch and its interaction with the mechanosensitive piezo calcium channel. CONCLUSIONS: In studies of LSECs and knockout mice, we identified mechanosensitive angiocrine signals released by LSECs which promote PHTN by recruiting sinusoidal neutrophils and promoting formation of NETs and microthrombi. Strategies to target these pathways might be developed for treatment of PHTN. RNA-sequencing accession number: GSE119547.


Assuntos
Capilares/metabolismo , Quimiocina CXCL1/metabolismo , Células Endoteliais/metabolismo , Hipertensão Portal/metabolismo , Fígado/irrigação sanguínea , Infiltração de Neutrófilos , Estresse Mecânico , Trombose/metabolismo , Animais , Sinalização do Cálcio , Capilares/citologia , Armadilhas Extracelulares , Hidrolases/genética , Técnicas In Vitro , Integrinas/metabolismo , Elastase de Leucócito/genética , Ligadura , Fígado/metabolismo , Mecanotransdução Celular , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Pressão na Veia Porta , Proteína-Arginina Desiminase do Tipo 4 , Receptor Notch1/genética , Veia Cava Inferior/cirurgia
2.
Zhonghua Yi Xue Za Zhi ; 99(24): 1859-1863, 2019 Jun 25.
Artigo em Zh | MEDLINE | ID: mdl-31269580

RESUMO

Objective: To observe the efficacy and feasibility of a new therapy using a combination of different anticholinergic eyedrops in controlling myopia progression and axial prolongation in adolescents. Methods: Between July 2013 and June 2014, a total of 150 myopia adolescents aged 6-12 years were recruited at the clinic of Tongji Hospital in Shanghai. Participants were assigned in a 1∶2∶2 ratio to placebo group (no medication), combined treatment group (0.5% racanisodamine eyedrops were used twice a day during semesters, 1% atropine eyedrops were used before sleep during vacation) and atropine group (1% atropine eyedrops were used before sleep everyday). All subjects wore glasses. Visual acuity, best corrected visual acuity, cycloplegic refraction, corneal curvature, axial length, intraocular pressure, fundus and adverse events were recorded every 6 months during follow-up for 24 months. Results: At baseline, there was no significant difference in age,equivalent spherical mirror number and axial length among the three groups (all P>0.05). At the end of the second year,the mean myopia progression (changes of spherical equivalent) was -2.34 (-2.93,-1.75) D,-0.63 (-1.00,-0.50) D and -0.25 (-0.50,-0.06) D in placebo group, combined treatment group and atropine group, respectively (P<0.001), and there was statistically significant difference between each two groups (all P<0.001). The axial length change of each group were (1.51±0.23) mm, (0.69±0.30) mm and (0.31±0.30) mm, respectively (P<0.001), and there was statistically significant difference between each two groups (all P<0.001). Conclusion: Therapy using a combination of different anticholinergic eyedrops can effectively control the progression of myopia and axial prolongation in adolescents, and increase the compliance of children and the safety of drug use.


Assuntos
Antagonistas Colinérgicos/uso terapêutico , Miopia , Adolescente , Idoso , Atropina , Criança , China , Progressão da Doença , Humanos , Miopia/tratamento farmacológico , Soluções Oftálmicas , Refração Ocular
3.
Development ; 141(5): 1120-8, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24550118

RESUMO

Coordinated arterial-venous differentiation is crucial for vascular development and function. The origin of the cardinal vein (CV) in mammals is unknown, while conflicting theories have been reported in chick and zebrafish. Here, we provide the first molecular characterization of endothelial cells (ECs) expressing venous molecular markers, or venous-fated ECs, within the emergent dorsal aorta (DA). These ECs, expressing the venous molecular markers Coup-TFII and EphB4, cohabited the early DA with ECs expressing the arterial molecular markers ephrin B2, Notch and connexin 40. These mixed ECs in the early DA expressed either the arterial or venous molecular marker, but rarely both. Subsequently, the DA exhibited uniform arterial markers. Real-time imaging of mouse embryos revealed EC movement from the DA to the CV during the stage when venous-fated ECs occupied the DA. We analyzed mutants for EphB4, which encodes a receptor tyrosine kinase for the ephrin B2 ligand, as we hypothesized that ephrin B2/EphB4 signaling may mediate the repulsion of venous-fated ECs from the DA to the CV. Using an EC quantification approach, we discovered that venous-fated ECs increased in the DA and decreased in the CV in the mutants, whereas the rest of the ECs in each vessel were unaffected. This result suggests that the venous-fated ECs were retained in the DA and missing in the CV in the EphB4 mutant, and thus that ephrin B2/EphB4 signaling normally functions to clear venous-fated ECs from the DA to the CV by cell repulsion. Therefore, our cellular and molecular evidence suggests that the DA harbors venous progenitors that move to participate in CV formation, and that ephrin B2/EphB4 signaling regulates this aortic contribution to the mammalian CV.


Assuntos
Aorta/citologia , Células-Tronco/citologia , Veias/citologia , Animais , Células Endoteliais/citologia , Células Endoteliais/metabolismo , Camundongos , Camundongos Transgênicos , Neovascularização Fisiológica/fisiologia , Transdução de Sinais/fisiologia , Células-Tronco/metabolismo
4.
Development ; 141(19): 3782-92, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25209249

RESUMO

Arteriovenous malformations (AVMs) are tortuous vessels characterized by arteriovenous (AV) shunts, which displace capillaries and shunt blood directly from artery to vein. Notch signaling regulates embryonic AV specification by promoting arterial, as opposed to venous, endothelial cell (EC) fate. To understand the essential role of endothelial Notch signaling in postnatal AV organization, we used inducible Cre-loxP recombination to delete Rbpj, a mediator of canonical Notch signaling, from postnatal ECs in mice. Deletion of endothelial Rbpj from birth resulted in features of AVMs by P14, including abnormal AV shunting and tortuous vessels in the brain, intestine and heart. We further analyzed brain AVMs, as they pose particular health risks. Consistent with AVM pathology, we found cerebral hemorrhage, hypoxia and necrosis, and neurological deficits. AV shunts originated from capillaries (and possibly venules), with the earliest detectable morphological abnormalities in AV connections by P8. Prior to AV shunt formation, alterations in EC gene expression were detected, including decreased Efnb2 and increased Pai1, which encodes a downstream effector of TGFß signaling. After AV shunts had formed, whole-mount immunostaining showed decreased Efnb2 and increased Ephb4 expression within AV shunts, suggesting that ECs were reprogrammed from arterial to venous identity. Deletion of Rbpj from adult ECs led to tortuosities in gastrointestinal, uterine and skin vascular beds, but had mild effects in the brain. Our results demonstrate a temporal requirement for Rbpj in postnatal ECs to maintain proper artery, capillary and vein organization and to prevent abnormal AV shunting and AVM pathogenesis.


Assuntos
Malformações Arteriovenosas/genética , Malformações Arteriovenosas/patologia , Endotélio Vascular/metabolismo , Proteína de Ligação a Sequências Sinal de Recombinação J de Imunoglobina/deficiência , Receptores Notch/metabolismo , Transdução de Sinais/fisiologia , Animais , Deleção de Genes , Perfilação da Expressão Gênica , Processamento de Imagem Assistida por Computador , Proteína de Ligação a Sequências Sinal de Recombinação J de Imunoglobina/genética , Camundongos , Microscopia de Fluorescência , Reação em Cadeia da Polimerase em Tempo Real , Receptor EphB4/metabolismo
5.
Hepatology ; 64(4): 1302-1316, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27362333

RESUMO

UNLABELLED: Liver vasculature is crucial for adequate hepatic functions. Global deletion of Notch signaling in mice results in liver vascular pathologies. However, whether Notch in endothelium is essential for hepatic vascular structure and function remains unknown. To uncover the function of endothelial Notch in the liver, we deleted Rbpj, a transcription factor mediating all canonical Notch signaling, or Notch1 from the endothelium of postnatal mice. We investigated the hepatic vascular defects in these mutants. The liver was severely affected within 2 weeks of endothelial deletion of Rbpj from birth. Two-week old mutant mice had enlarged vessels on the liver surface, abnormal vascular architecture, and dilated sinusoids. Vascular casting and fluorosphere passage experiments indicated the presence of porto-systemic shunts. These mutant mice presented with severely necrotic liver parenchyma and significantly larger hypoxic areas, likely resulting from vascular shunts. We also found elevated levels of VEGF receptor 3 together with reduced levels of ephrin-B2, suggesting a possible contribution of these factors to the generation of hepatic vascular abnormalities. Deletion of Rbpj from the adult endothelium also led to dilated sinusoids, vascular shunts, and necrosis, albeit milder than that observed in mice with deletion from birth. Similar to deletion of Rbpj, loss of endothelial Notch1 from birth led to similar hepatic vascular malformations within 2 weeks. CONCLUSIONS: Endothelial Notch signaling is essential for the development and maintenance of proper hepatic vascular architecture and function. These findings may elucidate the molecular pathogenesis of hepatic vascular malformation and the safety of therapeutics inhibiting Notch. (Hepatology 2016;64:1302-1316).


Assuntos
Fígado/irrigação sanguínea , Receptor Notch1/fisiologia , Malformações Vasculares/etiologia , Animais , Endotélio Vascular , Proteína de Ligação a Sequências Sinal de Recombinação J de Imunoglobina/fisiologia , Camundongos , Transdução de Sinais
6.
Proc Natl Acad Sci U S A ; 111(50): 18007-12, 2014 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-25468970

RESUMO

Arteriovenous (AV) malformation (AVM) is a devastating condition characterized by focal lesions of enlarged, tangled vessels that shunt blood from arteries directly to veins. AVMs can form anywhere in the body and can cause debilitating ischemia and life-threatening hemorrhagic stroke. The mechanisms that underlie AVM formation remain poorly understood. Here, we examined the cellular and hemodynamic changes at the earliest stages of brain AVM formation by time-lapse two-photon imaging through cranial windows of mice expressing constitutively active Notch4 (Notch4*). AVMs arose from enlargement of preexisting microvessels with capillary diameter and blood flow and no smooth muscle cell coverage. AV shunting began promptly after Notch4* expression in endothelial cells (ECs), accompanied by increased individual EC areas, rather than increased EC number or proliferation. Alterations in Notch signaling in ECs of all vessels, but not arteries alone, affected AVM formation, suggesting that Notch functions in the microvasculature and/or veins to induce AVM. Increased Notch signaling interfered with the normal biological control of hemodynamics, permitting a positive feedback loop of increasing blood flow and vessel diameter and driving focal AVM growth from AV connections with higher blood velocity at the expense of adjacent AV connections with lower velocity. Endothelial expression of constitutively active Notch1 also led to brain AVMs in mice. Our data shed light on cellular and hemodynamic mechanisms underlying AVM pathogenesis elicited by increased Notch signaling in the endothelium.


Assuntos
Capilares/patologia , Malformações Arteriovenosas Intracranianas/metabolismo , Malformações Arteriovenosas Intracranianas/fisiopatologia , Proteínas Proto-Oncogênicas/metabolismo , Receptores Notch/metabolismo , Animais , Bromodesoxiuridina , Capilares/metabolismo , Células Endoteliais/metabolismo , Citometria de Fluxo , Malformações Arteriovenosas Intracranianas/etiologia , Camundongos , Receptor Notch4 , Fluxo Sanguíneo Regional/fisiologia , Transdução de Sinais/fisiologia , Microtomografia por Raio-X
7.
Genet Mol Res ; 14(3): 7801-10, 2015 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-26214461

RESUMO

We observed the variation in in vivo blood lipid and blood glucose metabolism in rats with atherosclerosis after 5-(3,4-dihydroxy-phenyl)-1-piperidin-1-yl-penta-2,4-dien-1-one (GBOT) administration. Wistar rats aged 10 weeks received a high-fat diet to establish the atherosclerosis model. Metabolic indices related to blood lipid and blood glucose were measured before modeling and at 4 and 8 weeks after modeling. Liver fat levels in rats were measured at 8 weeks to analyze the relationship between liver fat and blood lipid levels. We examined the mechanism of blood lipid reduction. The levels of serum triglycerides, total cholesterol, and very-low-density lipoprotein cholesterol in rats in the control group were significantly decreased (P < 0.05) compared with those in the 4-week control group at 4 weeks and decreased significantly and continuously until the 8th week (P < 0.05). Compared with the 8-week control group, the blood glucose level in rats in the 8-week experimental group decreased significantly (P < 0.05), and the level of insulin sensitivity index decreased significantly (P < 0.05). Compared with the control group, triglyceride and total cholesterol levels per unit mass in rat liver tissue in the 8-week experimental group decreased significantly (P < 0.05). Western blotting indicated that GBOT significantly increased the expression of lecithin-cholesterol acyltransferase, low-density lipoprotein receptor, and cholesterol 7 alpha-hydroxylase proteins. GBOT can significantly decrease the levels of blood lipid and blood glucose in rat models of atherosclerosis, and its mechanism may be associated with the promotion of expression of lecithin-cholesterol acyltransferase, low-density lipoprotein receptor, and cholesterol 7 alpha-hydroxylase proteins.


Assuntos
Aterosclerose/sangue , Aterosclerose/metabolismo , Glicemia/metabolismo , Lipídeos/sangue , Piperidinas/farmacologia , Alcamidas Poli-Insaturadas/farmacologia , Animais , Aorta/efeitos dos fármacos , Aorta/patologia , Hidrocarboneto de Aril Hidroxilases/metabolismo , Western Blotting , Peso Corporal/efeitos dos fármacos , Colesterol/sangue , Insulina/sangue , Masculino , Fosfatidilcolina-Esterol O-Aciltransferase/metabolismo , Piperidinas/química , Alcamidas Poli-Insaturadas/química , Ratos Wistar , Receptores de LDL/metabolismo , Esteroide Hidroxilases/metabolismo , Triglicerídeos/sangue
8.
Microcirculation ; 21(7): 578-86, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24673722

RESUMO

OBJECTIVE: The cell surface protein ephrin-B2 is expressed in arterial and not venous ECs throughout development and adulthood. Endothelial ephrin-B2 is required for vascular development and angiogenesis, but its role in established arteries is currently unknown. We investigated the physiological role of ephrin-B2 signaling in adult endothelium. METHODS: We generated adult conditional knockout mice lacking the Efnb2 gene specifically in ECs and evaluated the vasodilation responses to blood flow increase and ACh in the cremaster muscle preparation by intravital microscope and in carotid artery by in vivo ultrasound. RESULTS: We found that the Efnb2 conditional knockout mice were defective in acute arterial dilation. Vasodilation was impaired in cremaster arterioles in response to either increased flow or ACh, and in the carotid arteries in response to increased flow. Levels of cGMP, an effector of NO, were diminished in mutant arteries following ACh stimulation. GSNO, a donor for the vasodilator NO, alleviated the vasodilatory defects in the mutants. Immunostaining showed that a subset of ephrin-B2 proteins colocalized with caveolin-1, a negative regulator of eNOS. CONCLUSIONS: Our data suggest that endothelial ephrin-B2 is required for endothelial-dependent arterial dilation and NO signaling in adult endothelium.


Assuntos
Artérias/fisiologia , Células Endoteliais/fisiologia , Efrina-B2/fisiologia , Vasodilatação/fisiologia , Acetilcolina/farmacologia , Animais , Arteríolas/efeitos dos fármacos , Arteríolas/fisiologia , Artéria Carótida Primitiva/fisiologia , Caveolina 1/análise , GMP Cíclico/metabolismo , Células Endoteliais/efeitos dos fármacos , Feminino , Genes Reporter , Hemorreologia , Masculino , Camundongos , Camundongos Knockout , Músculo Esquelético/irrigação sanguínea , Óxido Nítrico/fisiologia , Doadores de Óxido Nítrico/farmacologia , Especificidade de Órgãos , S-Nitrosoglutationa/farmacologia , Vasodilatação/efeitos dos fármacos , Vasodilatadores/farmacologia
9.
J Exp Med ; 220(2)2023 02 06.
Artigo em Inglês | MEDLINE | ID: mdl-36441145

RESUMO

Upregulation of Notch signaling is associated with brain arteriovenous malformation (bAVM), a disease that lacks pharmacological treatments. Tetracycline (tet)-regulatable endothelial expression of constitutively active Notch4 (Notch4*tetEC) from birth induced bAVMs in 100% of mice by P16. To test whether targeting downstream signaling, while sustaining the causal Notch4*tetEC expression, induces AVM normalization, we deleted Rbpj, a mediator of Notch signaling, in endothelium from P16, by combining tet-repressible Notch4*tetEC with tamoxifen-inducible Rbpj deletion. Established pathologies, including AV connection diameter, AV shunting, vessel tortuosity, intracerebral hemorrhage, tissue hypoxia, life expectancy, and arterial marker expression were improved, compared with Notch4*tetEC mice without Rbpj deletion. Similarly, Rbpj deletion from P21 induced advanced bAVM regression. After complete AVM normalization induced by repression of Notch4*tetEC, virtually no bAVM relapsed, despite Notch4*tetEC re-expression in adults. Thus, inhibition of endothelial Rbpj halted Notch4*tetEC bAVM progression, normalized bAVM abnormalities, and restored microcirculation, providing proof of concept for targeting a downstream mediator to treat AVM pathologies despite a sustained causal molecular lesion.


Assuntos
Malformações Arteriovenosas , Encefalopatias , Malformações do Sistema Nervoso , Animais , Camundongos , Antibacterianos , Malformações Arteriovenosas/genética , Encéfalo , Endotélio , Proteína de Ligação a Sequências Sinal de Recombinação J de Imunoglobina/genética , Tetraciclina , Receptor Notch4/metabolismo
10.
Sci Adv ; 9(21): eade7280, 2023 05 26.
Artigo em Inglês | MEDLINE | ID: mdl-37235659

RESUMO

Mechanisms underlying arteriovenous malformations (AVMs) are poorly understood. Using mice with endothelial cell (EC) expression of constitutively active Notch4 (Notch4*EC), we show decreased arteriolar tone in vivo during brain AVM initiation. Reduced vascular tone is a primary effect of Notch4*EC, as isolated pial arteries from asymptomatic mice exhibited reduced pressure-induced arterial tone ex vivo. The nitric oxide (NO) synthase (NOS) inhibitor NG-nitro-l-arginine (L-NNA) corrected vascular tone defects in both assays. L-NNA treatment or endothelial NOS (eNOS) gene deletion, either globally or specifically in ECs, attenuated AVM initiation, assessed by decreased AVM diameter and delayed time to moribund. Administering nitroxide antioxidant 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl also attenuated AVM initiation. Increased NOS-dependent production of hydrogen peroxide, but not NO, superoxide, or peroxynitrite was detected in isolated Notch4*EC brain vessels during AVM initiation. Our data suggest that eNOS is involved in Notch4*EC-mediated AVM formation by up-regulating hydrogen peroxide and reducing vascular tone, thereby permitting AVM initiation and progression.


Assuntos
Malformações Arteriovenosas , Peróxido de Hidrogênio , Óxido Nítrico Sintase Tipo III , Animais , Camundongos , Artérias/metabolismo , Peróxido de Hidrogênio/metabolismo , Óxido Nítrico Sintase/genética , Óxido Nítrico Sintase/metabolismo , Nitroarginina/farmacologia
11.
Virus Genes ; 44(3): 403-7, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22395913

RESUMO

In this study, 176 serum specimens were collected from hospitalized cardiovascular diseases patients in Shanghai, China. 140 samples (79.5%) were positive with the primers located in non-coding region, and 30 samples (17.04%) were identified to be positive with group-specific primers. Of the 30 samples, 9 (5.11%) were classified to group 1, 23 (13.07%) were clustered to group 2, and 3 belonged to group 3. Five samples were confirmed to be dual infection with different groups of TTMV, and no sample was found to be infected with groups 4-6.


Assuntos
Doenças Cardiovasculares/virologia , Infecções por Vírus de DNA/virologia , Torque teno virus/genética , Torque teno virus/isolamento & purificação , China , Análise por Conglomerados , Coinfecção/virologia , DNA Viral/química , DNA Viral/genética , Genótipo , Humanos , Dados de Sequência Molecular , Análise de Sequência de DNA
12.
Science ; 378(6623): eabo5503, 2022 12 02.
Artigo em Inglês | MEDLINE | ID: mdl-36454848

RESUMO

Monitoring of cell-cell communication in multicellular organisms is fundamental to understanding diverse biological processes such as embryogenesis and tumorigenesis. To track cell-cell contacts in vivo, we developed an intercellular genetic technology to monitor cell-cell contact and to trace cell contact histories by permanently marking contacts between cells. In mice, we engineered an artificial Notch ligand into one cell (the sender cell) and an artificial receptor into another cell (the receiver cell). Contact between the sender and receiver cells triggered a synthetic Notch signaling that activated downstream transcriptional programs in the receiver cell, thereby transiently or permanently labeling it. In vivo cell-cell contact was observed during development, tissue homeostasis, and tumor growth. This technology may be useful for studying dynamic in vivo cell-cell contacts and cell fate plasticity.


Assuntos
Comunicação Celular , Perfilação da Expressão Gênica , Receptores Notch , Animais , Camundongos , Carcinogênese , Plasticidade Celular , Transdução de Sinais , Receptores Notch/genética , Perfilação da Expressão Gênica/métodos
14.
Proc Natl Acad Sci U S A ; 105(31): 10901-6, 2008 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-18667694

RESUMO

Brain arteriovenous malformations (BAVMs) can cause devastating stroke in young people and contribute to half of all hemorrhagic stroke in children. Unfortunately, the pathogenesis of BAVMs is unknown. In this article we show that activation of Notch signaling in the endothelium during brain development causes BAVM in mice. We turned on constitutively active Notch4 (int3) expression in endothelial cells from birth by using the tetracycline-regulatable system. All mutants developed hallmarks of BAVMs, including cerebral arteriovenous shunting and vessel enlargement, by 3 weeks of age and died by 5 weeks of age. Twenty-five percent of the mutants showed signs of neurological dysfunction, including ataxia and seizure. Affected mice exhibited hemorrhage and neuronal cell death within the cerebral cortex and cerebellum. Strikingly, int3 repression resolved ataxia and reversed the disease progression, demonstrating that int3 is not only sufficient to induce, but also required to sustain the disease. We show that int3 expression results in widespread enlargement of the microvasculature, which coincided with a reduction in capillary density, linking vessel enlargement to Notch's known function of inhibiting vessel sprouting. Our data suggest that the Notch pathway is a molecular regulator of BAVM pathogenesis in mice, and offer hope that their regression might be possible by targeting the causal molecular lesion.


Assuntos
Endotélio Vascular/metabolismo , Malformações Arteriovenosas Intracranianas/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Receptores Notch/metabolismo , Transdução de Sinais/fisiologia , Animais , Imuno-Histoquímica , Malformações Arteriovenosas Intracranianas/etiologia , Malformações Arteriovenosas Intracranianas/patologia , Camundongos , Receptor Notch4
15.
Am J Physiol Cell Physiol ; 298(5): C1087-99, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20181926

RESUMO

The bone morphogenetic protein (BMP) pathway is known to be involved in limb myogenesis during development, but whether it is involved in postnatal muscle regeneration is unclear. We have found that adult inhibitor of differentiation (Id)-mutant (Id1(+/-)Id3(-/-)) mice display delayed and reduced skeletal muscle regeneration after injury compared with either wild-type littermates or Id3-null mice. Immunoblotting of wild-type muscle lysates revealed that, not only were Id1 and Id3 highly upregulated within 24 h after injury, but other upstream components of the BMP pathway were as well, including the BMP receptor type II and phosphorylated Smad1/5/8 (pSmad1/5/8). Inhibition of BMP signaling in injured skeletal muscle by Noggin injection reduced pSmad1/5/8, Id1, and Id3 protein levels. The mouse myoblast-derived cell line C2C12 also expressed Id1, Id3, BMP receptor type II, and pSmad1/5/8 during proliferation, but all were reduced upon differentiation into myotubes. In addition, these cells secreted mature BMP-4, and BMP signaling could be inhibited with exogenous Noggin, causing a reduction in pSmad1/5/8, Id1, and Id3 levels. Confocal immunofluorescence microscopy revealed that activated Pax7(+) myoblasts coexpressed nuclear pSmad1/5/8, Id1, and Id3 in injured mouse skeletal muscle sections. Although we did not observe differences in the numbers of quiescent Pax7(+) satellite cells in adult uninjured hindlimb muscles, we did observe a significant reduction in the number of proliferating Pax7(+) cells in the Id-mutant mice after muscle injury compared with either wild-type or Id3-null mice. These data suggest a model in which BMP signaling regulates Id1 and Id3 in muscle satellite cells, which directs their proper proliferation before terminal myogenic differentiation after skeletal muscle injury in postnatal animals.


Assuntos
Proteínas Morfogenéticas Ósseas/metabolismo , Proteína 1 Inibidora de Diferenciação/genética , Proteína 1 Inibidora de Diferenciação/metabolismo , Proteínas Inibidoras de Diferenciação/genética , Proteínas Inibidoras de Diferenciação/metabolismo , Músculo Esquelético/lesões , Animais , Receptores de Proteínas Morfogenéticas Ósseas/metabolismo , Proliferação de Células , Regulação da Expressão Gênica/fisiologia , Camundongos , Camundongos Knockout , Mutação , Regeneração , Células Satélites de Músculo Esquelético , Transdução de Sinais
16.
Am J Physiol Lung Cell Mol Physiol ; 298(2): L169-77, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19933399

RESUMO

Lung arteriovenous (AV) shunts or malformations cause significant morbidity and mortality in several distinct clinical syndromes. For most patients with lung AV shunts, there is still no optimal treatment. The underlying molecular and cellular etiology for lung AV shunts remains elusive, and currently described animal models have insufficiently addressed this problem. Using a tetracycline-repressible system, we expressed constitutively active Notch4 (Notch4*) specifically in the endothelium of adult mice. More than 90% of mice developed lung hemorrhages and respiratory insufficiency and died by 6-7 wk after gene expression began. Vascular casting and fluorescent microsphere analysis showed evidence of lung AV shunts in affected mice. Cessation of Notch4* expression reversed these pathophysiological effects. Assessment of the vascular morphology revealed enlarged, tortuous vessels in the lungs that resembled arteriovenous malformations. By using whole lung organ culture, we demonstrated the effects of constitutively active Notch4 on the lung vasculature to be a primary lung phenomenon. Together, our results indicate the importance of Notch signaling in maintaining the lung vasculature and offer a new, reliable model with which to study the pathobiology of lung arteriovenous shunts and malformations.


Assuntos
Malformações Arteriovenosas/metabolismo , Endotélio Vascular/metabolismo , Pulmão/irrigação sanguínea , Pulmão/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Receptores Notch/metabolismo , Animais , Malformações Arteriovenosas/patologia , Embrião de Mamíferos/anatomia & histologia , Humanos , Pulmão/embriologia , Pulmão/patologia , Camundongos , Modelos Animais , Mutação , Proteínas Proto-Oncogênicas/genética , Receptor Notch4 , Receptores Notch/genética , Transdução de Sinais/fisiologia , Técnicas de Cultura de Tecidos
17.
Lab Invest ; 89(9): 971-82, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19546852

RESUMO

Brain arteriovenous malformations (BAVMs) can cause lethal hemorrhagic stroke and have no effective treatment. The cellular and molecular basis for this disease is largely unknown. We have previously shown that expression of constitutively-active Notch4 receptor in the endothelium elicits and maintains the hallmarks of BAVM in mice, thus establishing a mouse model of the disease. Our work suggested that Notch pathway could be a critical molecular mediator of BAVM pathogenesis. Here, we investigated the hypothesis that upregulated Notch activation contributes to the pathogenesis of human BAVM. We examined the expression of the canonical Notch downstream target Hes1 in the endothelium of human BAVMs by immunofluorescence, and showed increased levels relative to either autopsy or surgical biopsy controls. We then analyzed receptor activity using an antibody to the activated form of the Notch1 receptor, and found increased levels of activity. These findings suggest that Notch activation may promote the development and even maintenance of BAVM. We also detected increases in Hes1 and activated Notch1 expression in our mouse model of BAVM induced by constitutively active Notch4, demonstrating molecular similarity between the mouse model and the human disease. Our work suggests that activation of Notch signaling is an important molecular candidate in BAVM pathogenesis and further validates that our animal model provides a platform to study the progression as well as the regression of the disease.


Assuntos
Endotélio Vascular/metabolismo , Malformações Arteriovenosas Intracranianas/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Receptor Notch1/biossíntese , Receptores Notch/metabolismo , Transdução de Sinais/fisiologia , Animais , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Modelos Animais de Doenças , Endotélio Vascular/patologia , Proteínas de Homeodomínio/metabolismo , Humanos , Malformações Arteriovenosas Intracranianas/patologia , Camundongos , Camundongos Mutantes , Microscopia de Fluorescência , Neovascularização Patológica , Receptor Notch4 , Fatores de Transcrição HES-1 , Regulação para Cima
18.
Chin Med J (Engl) ; 130(19): 2296-2301, 2017 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-28937034

RESUMO

BACKGROUND: As a traditional Chinese medicine, Cordyceps sinensis (CS) possesses a variety of immunoregulatory properties. This study aimed to explore the therapeutic potential of CS in a mice model of multiple sclerosis (MS)-experimental autoimmune encephalomyelitis (EAE). METHODS: Female C57BL/6 mice were immunized with myelin oligodendrocyte glycoprotein35-55to induce EAE, followed by an instant intragastric feeding with a low dosage of CS (low-CS group, n = 5), high dosage of CS (high-CS group, n = 5), or the same volume of normal saline (control group, n = 5). All the mice were observed for clinical assessment. Over the 30 days of CS treatment, flow cytometry was used to detect the frequency of helper T-cell (Th) subsets, Th1 and Th17, and CD4+ CD25+ regulatory T cells in the spleen and lymph nodes. Meanwhile, pathological changes in brain were determined using both hematoxylin-eosin and luxol fast blue staining. Data were analyzed using the one-way analysis of variance (ANOVA). RESULTS: Over the 15 and 30 days of CS treatment, the clinical assessment for EAE demonstrated that both high-CS group (2.51 ± 0.31 and 2.26 ± 0.39 scores, respectively) and low-CS group (2.99 ± 0.40 and 2.69 ± 0.46, respectively) had lower disease severity scores than those of control group (3.57 ± 0.53 and 3.29 ± 0.53, all P < 0.01, respectively). Meanwhile, after 15 and 30 days, the high-CS group (19.18 ± 1.34 g and 20.41 ± 1.56 g, respectively) and low-CS group (18.07 ± 1.18 g and 19.48 ± 1.69 g, respectively) had a lower body weight, as compared with control group (16.85 ± 1.15 g and 18.22 ± 1.63 g, all P < 0.01, respectively). At 30 days post-CS treatment, there was a lower Th1 frequency in the lymph nodes (2.85 ± 1.54% and 2.77 ± 1.07% vs. 5.35 ± 1.34%, respectively; P < 0.05) and spleens (3.96 ± 1.09% and 3.09 ± 0.84% vs. 5.07 ± 1.50%, respectively; P < 0.05) and less inflammatory infiltration and demyelination in the brain of CS-treated mice than that of control group. CONCLUSIONS: Our preliminary study demonstrated that CS efficiently alleviated EAE severity and EAE-related pathology damage and decreased the number of Th1s in the periphery, indicating its effectiveness in the treatment of murine EAE. Thus, our findings strongly support the therapeutic potential of this agent as a new traditional Chinese medicine approach in MS treatment.


Assuntos
Cordyceps , Encefalomielite Autoimune Experimental/imunologia , Encefalomielite Autoimune Experimental/metabolismo , Medicina Tradicional Chinesa/métodos , Análise de Variância , Animais , Linfócitos T CD4-Positivos/metabolismo , Modelos Animais de Doenças , Encefalomielite Autoimune Experimental/tratamento farmacológico , Feminino , Citometria de Fluxo , Camundongos , Camundongos Endogâmicos C57BL , Projetos Piloto , Células Th1/metabolismo , Células Th17/metabolismo
19.
Sci Rep ; 7(1): 11965, 2017 09 20.
Artigo em Inglês | MEDLINE | ID: mdl-28931948

RESUMO

The functions of blood flow in the morphogenesis of mammalian arteries and veins are not well understood. We examined the development of the dorsal aorta (DA) and the cardinal vein (CV) in Ncx1 -/- mutants, which lack blood flow due to a deficiency in a sodium calcium ion exchanger expressed specifically in the heart. The mutant DA and CV were abnormally connected. The endothelium of the Ncx1 -/- mutant DA lacked normal expression of the arterial markers ephrin-B2 and Connexin-40. Notch1 activation, known to promote arterial specification, was decreased in mutant DA endothelial cells (ECs), which ectopically expressed the venous marker Coup-TFII. These findings suggest that flow has essential functions in the DA by promoting arterial and suppressing venous marker expression. In contrast, flow plays a lesser role in the CV, because expression of arterial-venous markers in CV ECs was not as dramatically affected in Ncx1 -/- mutants. We propose a molecular mechanism by which blood flow mediates DA and CV morphogenesis, by regulating arterial-venous specification of DA ECs to ensure proper separation of the developing DA and CV.


Assuntos
Circulação Sanguínea , Vasos Sanguíneos/embriologia , Morfogênese , Animais , Aorta/patologia , Conexinas/análise , Células Endoteliais/patologia , Efrina-B2/análise , Camundongos , Camundongos Knockout , Receptor Notch1/análise , Trocador de Sódio e Cálcio/genética , Veias/patologia , Proteína alfa-5 de Junções Comunicantes
20.
J Phys Chem B ; 110(30): 14754-60, 2006 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-16869583

RESUMO

Spinel Zn2SnO4 particles with the cubic shape are prepared via a hydrothermal reaction under mild conditions. The hydrothermal conditions, such as alkaline concentration, reaction temperature, and duration time, have an important influence on the product structure and the performance of the electrode prepared with the product. The optimized product is cube-shaped Zn2SnO4 crystalline, which is prepared with 0.4 M of NaOH solution at 200 degrees C for 24 h. These cube-shaped Zn2SnO4 particles with the spinel structure exhibit a large electrochemical capacity of 988 mA h/g and a relatively good capacity retention as anode materials for Li-ion battery. The structures of the as-prepared product and specimens taken from the electrodes after charging-discharging cycles are analyzed by X-ray diffraction, scanning electron microscopy, and transition electron microscopy techniques. In particular, it is found for the first time that the spinel Zn2SnO4 structure exists to a great extent after the first cycle and contributes to the extremely high reversible capacity during the following cycles.

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