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1.
Fish Shellfish Immunol Rep ; 2: 100036, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-36420515

RESUMEN

A new cell line was isolated and characterized from the head kidney of Siganus fuscescens (rabbit fish). The new macrophagic-like cell line was named as rabbit fish macrophage (RFM), and which could be sub-cultured for over 50 cycles since the development. RFM cell line was tested for growth in different temperatures and serum concentrations: the best growing condition was optimized at 20% serum under 28 °C. In cultured RFM cells, sequencing of 18S rRNA, as well as immunostaining of cytokeratin and CD 68, confirmed the identity as macrophagic cell of S. fuscescens. Cultured RFM cells were exposed to challenge of inflammation, as triggered by LPS, showing highly sensitive responses to inflammation, including release of nitric oxide, expression of cytokine, and activation of phagocytosis. The water extract of aerial part of Scutellaria baicalensis, named as SBA, has been shown anti-inflammatory property in S. fuscescens fish. In order to extend the application of SBA in aquaculture, the extract and its effective flavonoids, i.e. baicalin and scutellarin, were applied in LPS-treated RFM cells. Application of SBA extract, baicalin or scutellarin, inhibited the expressions of LPS-induced inflammatory cytokines, i.e. IL-1ß, TNF-α, as well as the signaling of transcription factor NF-κB. The results support the established RFM cell line could be an ideal in vitro model in drug screening relating to inflammation. Additionally, the notion of SBA herbal extract in fish aquaculture is supported by its efficacy against inflammation.

2.
J Cosmet Dermatol ; 20(7): 2277-2286, 2021 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-33095946

RESUMEN

BACKGROUND: Wrinkles and extracellular matrix (ECM) loss are common signs of skin aging and are thought to be the result of damage caused by reactive oxygen species (ROS); ROS induces an imbalance between ECM degradation and production. OBJECTIVES: In this study, we evaluate soy peptides (SP) and collagen peptides (CP), alone and in combination, for their ability to inhibit ROS formation and increase ECM gene expression in order to ameliorate the signs of skin aging. METHODS: Using tert-Butyl hydroperoxide (t-BuOOH)-treated dermal fibroblasts, we explored the potential of CP and SP to inhibit ROS formation by flow cytometry, as well as their effect on ECM component genes by real-time quantitative PCR. In addition, we examined the effect of CP and SP on UVA irradiated fibroblasts in a 3D collagen lattice model that measured contractility. RESULTS: The results showed that the combination of CP and SP synergistically reduces ROS formation. This combination also increased expression of collagen I, collagen II, elastin, and fibronectin in t-BuOOH-treated or untreated dermal fibroblasts. In the UVA-treated 3D collagen lattice model, the results show that CP and SP significantly improved fibroblast contractility when compared to UVA control (P < 0.05). CONCLUSIONS: In conclusion, CP and SP attenuate the loss of contractility due to UVA damage, inhibit t-BuOOH-induced ROS formation, and improve expression of ECM component genes.


Asunto(s)
Antioxidantes , Envejecimiento de la Piel , Antioxidantes/farmacología , Células Cultivadas , Colágeno , Fibroblastos , Humanos , Péptidos/farmacología , Piel , Rayos Ultravioleta/efectos adversos
3.
Mol Cancer Ther ; 18(2): 245-256, 2019 02.
Artículo en Inglés | MEDLINE | ID: mdl-30401693

RESUMEN

Pancreatic cancer has an abysmal 5-year survival rate of 8%, making it a deadly disease with a need for novel therapies. Here we describe a multitargeting heparin-based mimetic, necuparanib, and its antitumor activity in both in vitro and in vivo models of pancreatic cancer. Necuparanib reduced tumor cell proliferation and invasion in a three-dimensional (3D) culture model; in vivo, it extended survival and reduced metastasis. Furthermore, proteomic analysis demonstrated that necuparanib altered the expression levels of multiple proteins involved in cancer-driving pathways including organ development, angiogenesis, proliferation, genomic stability, cellular energetics, and invasion and metastasis. One protein family known to be involved in invasion and metastasis and altered by necuparanib treatment was the matrix metalloprotease (MMP) family. Necuparanib reduced metalloproteinase 1 (MMP1) and increased tissue inhibitor of metalloproteinase 3 (TIMP3) protein levels and was found to increase RNA expression of TIMP3. MMP enzymatic activity was also found to be reduced in the 3D model. Finally, we confirmed necuparanib's in vivo activity by analyzing plasma samples of patients enrolled in a phase I/II study in patients with metastatic pancreatic cancer; treatment with necuparanib plus standard of care significantly increased TIMP3 plasma protein levels. Together, these results demonstrate necuparanib acts as a broad multitargeting therapeutic with in vitro and in vivo anti-invasive and antimetastatic activity.


Asunto(s)
Antineoplásicos/administración & dosificación , Heparitina Sulfato/análogos & derivados , Metaloproteinasa 1 de la Matriz/metabolismo , Neoplasias Pancreáticas/tratamiento farmacológico , Inhibidor Tisular de Metaloproteinasa-3/metabolismo , Animales , Antineoplásicos/farmacología , Línea Celular Tumoral , Movimiento Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Ensayos Clínicos Fase I como Asunto , Ensayos Clínicos Fase II como Asunto , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Heparitina Sulfato/administración & dosificación , Heparitina Sulfato/farmacología , Humanos , Ratones , Invasividad Neoplásica , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/metabolismo , Proteómica/métodos , Esferoides Celulares/citología , Esferoides Celulares/efectos de los fármacos , Esferoides Celulares/metabolismo , Células del Estroma/efectos de los fármacos , Inhibidor Tisular de Metaloproteinasa-3/genética , Ensayos Antitumor por Modelo de Xenoinjerto
4.
Ecol Lett ; 21(10): 1477-1485, 2018 10.
Artículo en Inglés | MEDLINE | ID: mdl-30043472

RESUMEN

Conflict is risky, but mechanisms that allow animals to assess dominance status without aggression can reduce such costs. Two different mechanisms of competitor assessment are expected to evolve in different contexts: badges of status are expected in larger, anonymous groups, whereas individual recognition is feasible in small, stable groups. However, both mechanisms may be important when social interactions occur both within and across stable social groups. We manipulated plumage in golden-crowned sparrows (Zonotrichia atricapilla) and found that two known badges of status - gold and black head plumage patch sizes - independently affect dominance among strangers but manipulations had no effect on dominance among familiar flockmates. Moreover, familiar flockmates showed less aggression and increased foraging relative to strangers. Our study provides clear experimental evidence that social recognition affects badge function, and suggests that variation in social contexts maintains coexistence and context-dependent use of these two dominance resolution mechanisms.


Asunto(s)
Agresión , Animales
5.
Anal Chem ; 88(11): 5579-84, 2016 06 07.
Artículo en Inglés | MEDLINE | ID: mdl-27175512

RESUMEN

The concept of ambient desorption-optical emission spectroscopy (AD-OES) is demonstrated using a liquid sampling-atmospheric pressure glow discharge (LS-APGD) microplasma as the desorption/excitation source. The LS-APGD has previously been employed for elemental analysis of solution samples and particulates introduced via laser ablation in both the optical emission and mass spectrometries (OES, MS) modes. In addition, the device has been shown to be effective for the analysis of elemental and molecular species operating in an ambient desorption/ionization mass spectrometry (ADI-MS) mode. Proof-of-concept is presented here in the use of the LS-APGD to volatilize three very diverse sample forms (metallic thin films, dry solution residues, and bulk materials), with the liberated material excited within the microplasma and detected via OES, i.e., AD-OES. While the demonstration is principally qualitative at this point, it is believed that the basic approach may find application across a broad spectrum of analytical challenges requiring elemental analysis, including metals, soils, and volume-limited solutions, analogous to what has been seen in the development of the field of ADI-MS for molecular species determinations.

6.
Analyst ; 141(3): 807-14, 2016 Feb 07.
Artículo en Inglés | MEDLINE | ID: mdl-26646022

RESUMEN

Presented here is a novel implementation of polypropylene capillary-channeled polymer (C-CP) films, functionalized for bioaffinity separations and implemented as a platform for lateral flow (immuno) assays. The parallel ∼80 µm × 80 µm channels pass test solutions down the 30 mm film length via spontaneous wicking action, setting up the possibility for immobilizing different capture agents in the respective channels. The base-film modification process is divided into two steps: ultraviolet light treatment to improve hydrophillicity of the polypropylene substrate and the physical adsorption of a functionalized lipid tethered ligand (LTL) as a selective capture agent. The entire modification procedure is performed under ambient conditions in an aqueous solution without extreme pH conditions. In this demonstration, physical adsorption of a biotinylated-LTL onto the UV-treated PP surface selectively captures Texas Red-labeled streptavidin (SAv-TR) in the presence of enhanced green fluorescence protein (EGFP), which passes without retention in less than 5 s. In addition to the fluorescence imaging of the protein solutes, matrix assisted laser desorption/ionization-mass spectrometry (MALDI-MS) was used to confirm the formation of the LTL-SAv conjugates on the channel surface as well as to demonstrate an alternative means of probing the capture step. The present effort sets the groundwork for further development of C-CP films as a parallel, multi-analyte LFA platform; a format that to-date has not been described.


Asunto(s)
Técnicas de Sonda Molecular/instrumentación , Polipropilenos/química , Estreptavidina/análisis , Adsorción , Biotina/análogos & derivados , Biotina/química , Proteínas Fluorescentes Verdes/química , Ligandos , Oxígeno/química , Espectrometría de Fluorescencia , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción , Estreptavidina/química , Rayos Ultravioleta , Xantenos/química
7.
J AOAC Int ; 98(6): 1483-90, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26651559

RESUMEN

The characterization of marker components in botanical materials is a challenging task, and the increased consumption of botanicals and dietary supplements demands a greater understanding of the associated health benefits and risks. In order to successfully acquire and compare clinical results and correlate health trends, accurate, precise, and validated methods of analysis must be developed. Presented here is the development of a quantitative method for the determination of soy isoflavones (daidzin, glycitin, genistin, daidzein, and genistein) using LC-particle beam/electron ionization-MS (LC-PB/EIMS). An internal standard (IS) approach for quantitation with 7-hydroxy-4- chromone as the IS compound was used, with response factors for each individual isoflavone obtained from calibrant solutions. The results from this method were compared with the certified and reference values for National Institute of Standards and Technology (NIST) SRM 3238 Soy-Containing Solid Oral Dosage Form to demonstrate that the method was in control. Results obtained using LC-PB/EIMS were consistent with the NIST certified or reference values and their uncertainties for all five isoflavones, demonstrating that the LC-PB/EIMS approach is both accurate and precise when used for the determination of the target isoflavones in soy-containing dietary supplement finished products while simultaneously providing structural information.


Asunto(s)
Cromatografía Liquida/métodos , Isoflavonas/análisis , Alimentos de Soja/análisis , Espectrometría de Masa por Ionización de Electrospray/métodos
8.
Anal Chem ; 87(14): 7218-25, 2015 Jul 21.
Artículo en Inglés | MEDLINE | ID: mdl-26134783

RESUMEN

The determination of metals, including the generation of metal-ligand speciation information, is essential across a myriad of biochemical, environmental, and industrial systems. Metal speciation is generally affected by the combination of some form of chromatographic separation (reflective of the metal-ligand chemistry) with element-specific detection for the quantification of the metal composing the chromatographic eluent. Thus, the identity of the metal-ligand is assigned by inference. Presented here, the liquid sampling-atmospheric pressure glow discharge (LS-APGD) is assessed as an ionization source for metal speciation, with the uranyl ion-acetate system used as a test system. Molecular mass spectra can be obtained from the same source by simple modification of the sustaining electrolyte solution. Specifically, chemical information pertaining to the degree of acetate complexation of uranyl ion (UO2(2+)) is assessed as a function of pH in the spectral abundance of three metallic species: inorganic (nonligated) uranyl, UO2Ac(H2O)n(MeOH)m(+), and UO2Ac2(H2O)n(MeOH)(m)H(+) (n = 1, 2, 3, ...; m = 1, 2, 3, ...). The product mass spectra are different from what are obtained from electrospray ionization sources that have been applied to this system. The resulting relationships between the speciation and pH values have been compared to calculated concentrations of the corresponding uranyl species: UO2(2+), UO2Ac(+), UO2Ac2. The capacity for the LS-APGD to affect both atomic mass spectra and structurally significant spectra for organometallic complexes is a unique and potentially powerful combination.

9.
Analyst ; 140(5): 1523-34, 2015 Mar 07.
Artículo en Inglés | MEDLINE | ID: mdl-25619845

RESUMEN

Polypropylene (PP) capillary-channeled polymer (C-CP) fibers have been used in this laboratory as stationary phases for high performance liquid chromatography and solid phase extraction of proteins. Greater selectivity has been realized through the functionalization of the PP fibers through the physical adsorption of commercially available head group-modified poly(ethylene glycol) lipids (PEG-lipids), where the head group is chosen to affect affinity separations. We refer to this general surface modification methodology as lipid tethered ligands (LTLs). In this study, LTLs were synthesized by solid phase synthesis. In comparison to the commercial PEG-lipids, the synthesized LTLs contain no chemically labile phosphate groups. Instead of an ester linkage in the commercial lipids, amide functionality was used in the synthesized LTLs to attach the lipids and ligands. By use of fluorescence imaging of FITC-labeled LTLs, the synthesized LTL was shown to be superior to the commercial LTL in terms of the adsorption efficiency to PP C-CP fibers, the resistance to solvent wash from the PP C-CP fibers, and their chemical stability under acidic, neutral and basic conditions. The PP C-CP fibers functionalized with a synthesized LTL that was biotinylated at the head group are shown to be capable of capturing streptavidin from E. coli cell lysate more efficiently than the PP C-CP fibers functionalized with the commercial biotinylated PEG-lipid. The functionalization of PP C-CP fibers with the synthesized LTLs is a simple, but highly efficient, method to generate novel stationary phases with a variety of functionalities for solid phase extraction and liquid chromatography.


Asunto(s)
Lípidos/química , Polietilenglicoles/química , Polímeros/química , Polipropilenos/química , Extracción en Fase Sólida/métodos , Adsorción , Cromatografía Líquida de Alta Presión/métodos , Escherichia coli/química , Ligandos , Microscopía Fluorescente , Estreptavidina/química , Propiedades de Superficie
10.
Anal Bioanal Chem ; 406(29): 7497-509, 2014 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-25002336

RESUMEN

The liquid sampling-atmospheric pressure glow discharge (LS-APGD) has been assessed as an ionization source for elemental analysis with an interdependent, parametric evaluation regarding sheath/cooling gas flow rate, discharge current, liquid flow rate, and the distance between the plasma and the sampling cone of the mass spectrometer. In order to better understand plasma processes (and different from previous reports), no form of collision/reaction processing was performed to remove molecular interferents. The evaluation was performed employing five test elements: cesium, silver, lead, lanthanum and nickel (10(-4) mol L(-1) in 1 mol L(-1) HNO3). The intensity of the atomic ions, levels of spectral background, the signal-to-background ratios, and the atomic-to-oxide/hydroxide adduct ratios were monitored in order to obtain fundamental understanding with regards to not only how each parameter effects the performance of this LS-APGD source, but also the inter-parametric effects. The results indicate that the discharge current and the liquid sampling flow rates are the key aspects that control the spectral composition. A compromise set of operating conditions was determined: sheath gas flow rate = 0.9 L min(-1), discharge current = 10 mA, solution flow rate = 10 µL min(-1), and sampling distance = 1 cm. Limits of detection (LODs) were calculated using the SBR-RSDB (signal-to-background ratio/relative standard deviation of the background) approach under the optimized condition. The LODs for the test elementals ranged from 15 to 400 ng mL(-1) for 10 µL injections, with absolute mass values from 0.2 to 4 ng.

11.
Anal Bioanal Chem ; 405(25): 8171-84, 2013 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-23877182

RESUMEN

A novel approach to ambient desorption/ionization mass spectrometry (ADI-MS) is described, based on a recently developed liquid sampling-atmospheric pressure glow discharge (LS-APGD) ionization source. The device is essentially unmodified relative to its implementation in elemental mass spectrometry, where the operational space is characterized by low operation power (<10 W) and low solution delivery rates (<50 µL min(-1)). In this implementation, the plasma is produced between a Ni anode and an electrolytic liquid (1 M HNO3) cathode flowing through a glass capillary that is angled towards the sample surface, at a distance of ~2 mm away. Analyte species can be desorbed/ionized from neat solution residues and complex solid samples. The ADI-LS-APGD source is mounted onto the source interface of a Thermo Finnigan LCQ Advantage Max quadrupole ion trap mass spectrometer without modifications to the instrument faceplate or ion optics. Described here is the initial evaluation of the roles of source geometry and working parameters, including electrolytic solution composition and plasma current, on the response of caffeine residues, with preliminary limits of detection based on the relative standard deviation of the spectral background suggested to be on the 10-pg level. Demonstrative spectra are presented for green tea extracts and raw leaves, coffee beans, a dried (raw) tobacco leaf, an analgesic tablet, and paper currency. Versatility is further revealed through the determination of components in common cigarette smoke. In each case, the spectra are characterized by (M + H)(+) species of the expected constituents. The capacity for a single source to perform both in solution and particulate elemental analysis (as shown previously) and ADI of molecular species is unique in the realm of mass spectrometry.


Asunto(s)
Cafeína/análisis , Espectrometría de Masas/instrumentación , Analgésicos no Narcóticos/química , Presión Atmosférica , Café/química , Electrólitos/química , Diseño de Equipo , Ibuprofeno/química , Iones/química , Límite de Detección , Espectrometría de Masas/métodos , Hojas de la Planta/química , Té/química , Nicotiana/química
12.
PLoS One ; 6(3): e17670, 2011 Mar 14.
Artículo en Inglés | MEDLINE | ID: mdl-21423802

RESUMEN

Neuropathic pain resulting from nerve lesions or dysfunction represents one of the most challenging neurological diseases to treat. A better understanding of the molecular mechanisms responsible for causing these maladaptive responses can help develop novel therapeutic strategies and biomarkers for neuropathic pain. We performed a miRNA expression profiling study of dorsal root ganglion (DRG) tissue from rats four weeks post spinal nerve ligation (SNL), a model of neuropathic pain. TaqMan low density arrays identified 63 miRNAs whose level of expression was significantly altered following SNL surgery. Of these, 59 were downregulated and the ipsilateral L4 DRG, not the injured L5 DRG, showed the most significant downregulation suggesting that miRNA changes in the uninjured afferents may underlie the development and maintenance of neuropathic pain. TargetScan was used to predict mRNA targets for these miRNAs and it was found that the transcripts with multiple predicted target sites belong to neurologically important pathways. By employing different bioinformatic approaches we identified neurite remodeling as a significantly regulated biological pathway, and some of these predictions were confirmed by siRNA knockdown for genes that regulate neurite growth in differentiated Neuro2A cells. In vitro validation for predicted target sites in the 3'-UTR of voltage-gated sodium channel Scn11a, alpha 2/delta1 subunit of voltage-dependent Ca-channel, and purinergic receptor P2rx ligand-gated ion channel 4 using luciferase reporter assays showed that identified miRNAs modulated gene expression significantly. Our results suggest the potential for miRNAs to play a direct role in neuropathic pain.


Asunto(s)
Perfilación de la Expresión Génica , Regulación de la Expresión Génica , MicroARNs/genética , Neuralgia/genética , Nervios Espinales/metabolismo , Nervios Espinales/patología , Animales , Minería de Datos , Modelos Animales de Enfermedad , Pruebas de Enzimas , Ganglios Espinales/metabolismo , Ganglios Espinales/patología , Técnicas de Silenciamiento del Gen , Genes Reporteros , Ligadura , Luciferasas/metabolismo , Masculino , Ratones , MicroARNs/metabolismo , MicroARNs/normas , Neuralgia/patología , Control de Calidad , ARN Mensajero/genética , ARN Mensajero/metabolismo , ARN Interferente Pequeño/metabolismo , Ratas , Ratas Sprague-Dawley , Estándares de Referencia , Reproducibilidad de los Resultados
13.
Mol Cell Neurosci ; 42(4): 438-47, 2009 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-19796684

RESUMEN

In rodents, the orphan G protein-coupled receptor, Gpr88, is highly expressed in brain regions implicated in the pathophysiology of and is modulated by treatments for schizophrenia. We compared striatal function of Gpr88 knockout mice (Gpr88KOs) to wild-type mice using molecular, neurochemical and behavioral tests. Gpr88KOs lacked expression of Gpr88 in striatum, nucleus accumbens and layer IV of cortex. Gpr88KOs had normal striatal dopamine D2 receptor density and affinity and DARPP-32 expression but Gpr88KOs had higher basal striatal phosphorylated DARPP-32 Thr-34. In vivo microdialysis detected lower basal dopamine in Gpr88KOs while amphetamine-induced dopamine release was normal. Behaviorally, Gpr88KOs demonstrated disrupted prepulse inhibition of startle (PPI) and increased sensitivity to apomorphine-induced climbing and stereotypy (AICS) and amphetamine-stimulated locomotor activity. Antipsychotic administration to Gpr88KOs normalized the PPI deficit and blocked AICS. The modulatory role of Gpr88 in striatal dopamine function suggests it may be a new target for treatments for psychiatric disorders.


Asunto(s)
Cuerpo Estriado/metabolismo , Dopamina/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Animales , Antipsicóticos/farmacología , Apomorfina , Conducta Animal/efectos de los fármacos , Conducta Animal/fisiología , Encéfalo/anatomía & histología , Encéfalo/metabolismo , Cuerpo Estriado/citología , Agonistas de Dopamina/farmacología , Antagonistas de Dopamina/farmacología , Fosfoproteína 32 Regulada por Dopamina y AMPc/metabolismo , Femenino , Haloperidol/farmacología , Humanos , Masculino , Ratones , Ratones Noqueados , Actividad Motora/efectos de los fármacos , Actividad Motora/fisiología , Pruebas Neuropsicológicas , Receptores de Dopamina D2/metabolismo , Receptores Acoplados a Proteínas G/genética , Reflejo de Sobresalto/efectos de los fármacos , Reflejo de Sobresalto/fisiología , Risperidona/farmacología
14.
Biochim Biophys Acta ; 1770(6): 890-901, 2007 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-17363172

RESUMEN

GPR26 and GPR78 are orphan GPCRs (oGPCRs) that share 51% amino acid sequence identity and are widely expressed in selected tissues of the human brain as well as the developing and adult mouse brain. Investigation of the functional activity of GPR26 and GPR78 via expression in HEK293 cells showed that both proteins are constitutively active and coupled to elevated cAMP production. Accordingly, in yeast, GPR26 demonstrated apparent agonist-independent coupling to a chimeric Gpa1 protein in which the 5 C-terminal amino acids were from Galphas. A comparison of the proteins revealed an atypical glutamine residue in GPR78 in place of the conserved arginine residue (R3.50) in the so-called DRY box. Site-directed mutants R3.50 in GPR26 were constructed and retained their constitutive activity suggesting that these 2 receptors activate G proteins in a manner that is distinct from other group 1 GPCRs.


Asunto(s)
Encéfalo/metabolismo , Receptores Acoplados a Proteínas G/biosíntesis , Animales , Secuencia de Bases , Encéfalo/citología , Línea Celular , AMP Cíclico/biosíntesis , Chaperón BiP del Retículo Endoplásmico , Subunidades alfa de la Proteína de Unión al GTP/biosíntesis , Subunidades alfa de la Proteína de Unión al GTP/genética , Subunidades alfa de la Proteína de Unión al GTP Gq-G11 , Humanos , Masculino , Ratones , Datos de Secuencia Molecular , Mutagénesis Sitio-Dirigida , Mutación Missense , Receptores Acoplados a Proteínas G/genética , Proteínas Recombinantes de Fusión/biosíntesis , Proteínas Recombinantes de Fusión/genética , Proteínas de Saccharomyces cerevisiae/biosíntesis , Proteínas de Saccharomyces cerevisiae/genética , Homología de Secuencia de Aminoácido
15.
Arterioscler Thromb Vasc Biol ; 26(9): 1991-7, 2006 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-16763158

RESUMEN

OBJECTIVE: Vascular endothelial growth factor (VEGF) induces angiogenesis by stimulating reactive oxygen species (ROS) production primarily through the VEGF receptor-2 (VEGFR2). One of the initial responses in established vessels to stimulate angiogenesis is loss of vascular endothelial (VE)-cadherin-based cell-cell adhesions; however, little is known about the underlying mechanisms. IQGAP1 is a novel VEGFR2 binding protein, and it interacts directly with actin, cadherin, and beta-catenin, thereby regulating cell motility and morphogenesis. METHODS AND RESULTS: Confocal microscopy analysis shows that IQGAP1 colocalizes with VE-cadherin at cell-cell contacts in unstimulated human endothelial cells (ECs). VEGF stimulation reduces staining of IQGAP1 and VE-cadherin at the adherens junction without affecting interaction of these proteins. Knockdown of IQGAP1 using siRNA inhibits localization of VE-cadherin at cell-cell contacts, VEGF-stimulated recruitment of VEGFR2 to the VE-cadherin/beta-catenin complex, ROS-dependent tyrosine phosphorylation of VE-cadherin, which is required for loss of cell-cell contacts and capillary tube formation. IQGAP1 expression is increased in a mouse hindlimb ischemia model of angiogenesis. CONCLUSIONS: IQGAP1 is required for establishment of cell-cell contacts in quiescent ECs. To induce angiogenesis, it may function to link VEGFR2 to the VE-cadherin containing adherens junctions, thereby promoting VEGF-stimulated, ROS-dependent tyrosine phosphorylation of VE-cadherin and loss of cell-cell contacts.


Asunto(s)
Uniones Adherentes/fisiología , Cadherinas/fisiología , Comunicación Celular/fisiología , Neovascularización Fisiológica/fisiología , Transducción de Señal/fisiología , Factor A de Crecimiento Endotelial Vascular/metabolismo , Proteínas Activadoras de ras GTPasa/fisiología , Animales , Antígenos CD , Células Cultivadas , Miembro Posterior/irrigación sanguínea , Humanos , Isquemia/metabolismo , Isquemia/fisiopatología , Ratones , Fosforilación , Especies Reactivas de Oxígeno/metabolismo , Fracciones Subcelulares/metabolismo , Distribución Tisular , Tirosina/metabolismo , Factor A de Crecimiento Endotelial Vascular/farmacología , Receptor 2 de Factores de Crecimiento Endotelial Vascular/metabolismo , beta Catenina/metabolismo
16.
Brain Res ; 1087(1): 1-14, 2006 May 04.
Artículo en Inglés | MEDLINE | ID: mdl-16647048

RESUMEN

This report describes the identification and characterization of the murine orphan GPCR, Gpr101. Both human and murine genes were localized to chromosome X. Similar to its human ortholog, murine Gpr101 mRNA was detected predominantly in the brain within discrete nuclei. A knowledge-restricted hidden Markov model-based algorithm, capable of accurately predicting G-protein coupling selectivity, indicated that both human and murine GPR101 were likely coupled to Gs. This prediction was supported by the elevation of cyclic AMP levels and the activation of a cyclic AMP response element-luciferase reporter gene in HEK293 cells over-expressing human GPR101. Consistent with this, over-expression of human GPR101 in a yeast-based system yielded an elevated, agonist-independent reporter gene response in the presence of a yeast chimeric Galphas protein. These results indicate that GPR101 participates in a potentially wide range of activities in the CNS via modulation of cAMP levels.


Asunto(s)
Proteínas de Unión al GTP/fisiología , Expresión Génica/fisiología , Proteínas del Tejido Nervioso/fisiología , Receptores Acoplados a Proteínas G/fisiología , Animales , Northern Blotting/métodos , Encéfalo/metabolismo , Línea Celular , Mapeo Cromosómico/métodos , Clonación Molecular/métodos , AMP Cíclico/metabolismo , Biblioteca de Genes , Genes Reporteros/fisiología , Pruebas Genéticas/métodos , Humanos , Hibridación in Situ/métodos , Ratones , Modelos Biológicos , Datos de Secuencia Molecular , Transfección/métodos , Técnicas del Sistema de Dos Híbridos
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