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1.
Front Pharmacol ; 8: 429, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28751862

RESUMO

Background: Enterochromaffin cells (EC) synthesize and release 5-HT and ATP to trigger or modulate gut neural reflexes and transmit information about visceral/pain sensation. Alterations in 5-HT signaling mechanisms may contribute to the pathogenesis of IBD or IBS, but the pharmacologic or molecular mechanisms modulating Ca2+-dependent 5-HT release are not understood. Previous studies indicated that purinergic signaling via ATP and ADP is an important mechanism in modulation of 5-HT release. However, EC cells also respond to UTP and UDP suggesting uridine triphosphate receptor and signaling pathways are involved as well. We tested the hypothesis that UTP is a regulator of 5-HT release in human EC cells. Methods: UTP signaling mechanisms were studied in BON cells, a human EC model, using Fluo-4/Ca2+imaging, patch-clamp, pharmacological analysis, immunohistochemistry, western blots and qPCR. 5-HT release was monitored in BON or EC isolated from human gut surgical specimens (hEC). Results: UTP, UTPγS, UDP or ATP induced Ca2+oscillations in BON. UTP evoked a biphasic concentration-dependent Ca2+response. Cells responded in the order of UTP, ATP > UTPγS > UDP >> MRS2768, BzATP, α,ß-MeATP > MRS2365, MRS2690, and NF546. Different proportions of cells activated by UTP and ATP also responded to UTPγS (P2Y4, 50% cells), UDP (P2Y6, 30%), UTPγS and UDP (14%) or MRS2768 (<3%). UTP Ca2+responses were blocked with inhibitors of PLC, IP3R, SERCA Ca2+pump, La3+sensitive Ca2+channels or chelation of intracellular free Ca2+ by BAPTA/AM. Inhibitors of L-type, TRPC, ryanodine-Ca2+pools, PI3-Kinase, PKC or SRC-Kinase had no effect. UTP stimulated voltage-sensitive Ca2+currents (ICa), Vm-depolarization and inhibited IK (not IA) currents. An IKv7.2/7.3 K+ channel blocker XE-991 mimicked UTP-induced Vm-depolarization and blocked UTP-responses. XE-991 blocked IK and UTP caused further reduction. La3+ or PLC inhibitors blocked UTP depolarization; PKC inhibitors, thapsigargin or zero Ca2+buffer did not. UTP stimulated 5-HT release in hEC expressing TPH1, 5-HT, P2Y4/P2Y6R. Zero-Ca2+buffer augmented Ca2+responses and 5-HT release. Conclusion: UTP activates a predominant P2Y4R pathway to trigger Ca2+oscillations via internal Ca2+mobilization through a PLC/IP3/IP3R/SERCA Ca2+signaling pathway to stimulate 5-HT release; Ca2+influx is inhibitory. UTP-induced Vm-depolarization depends on PLC signaling and an unidentified K channel (which appears independent of Ca2+oscillations or Ica/VOCC). UTP-gated signaling pathways triggered by activation of P2Y4R stimulate 5-HT release.

2.
Am J Physiol Heart Circ Physiol ; 304(2): H294-302, 2013 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-23161879

RESUMO

The GTP-binding protein Rac regulates diverse cellular functions including activation of NADPH oxidase, a major source of superoxide production (O(2)(·-)). Rac1-mediated NADPH oxidase activation is increased after myocardial infarction (MI) and heart failure both in animals and humans; however, the impact of increased myocardial Rac on impending ischemia-reperfusion (I/R) is unknown. A novel transgenic mouse model with cardiac-specific overexpression of constitutively active mutant form of Zea maize Rac D (ZmRacD) gene has been reported with increased myocardial Rac-GTPase activity and O(2)(·-) generation. The goal of the present study was to determine signaling pathways related to increased myocardial ZmRacD and to what extent hearts with increased ZmRacD proteins are susceptible to I/R injury. The effect of myocardial I/R was examined in young adult wild-type (WT) and ZmRacD transgenic (TG) mice. In vitro reversible myocardial I/R for postischemic cardiac function and in vivo regional myocardial I/R for MI were performed. Following 20-min global ischemia and 45-min reperfusion, postischemic cardiac contractile function and heart rate were significantly reduced in TG hearts compared with WT hearts. Importantly, acute regional myocardial I/R (30-min ischemia and 24-h reperfusion) caused significantly larger MI in TG mice compared with WT mice. Western blot analysis of cardiac homogenates revealed that increased myocardial ZmRacD gene expression is associated with concomitant increased levels of NADPH oxidase subunit gp91(phox), O(2)(·-), and P(21)-activated kinase. Thus these findings provide direct evidence that increased levels of active myocardial Rac renders the heart susceptible to increased postischemic contractile dysfunction and MI following acute I/R.


Assuntos
Traumatismo por Reperfusão Miocárdica/enzimologia , Miocárdio Atordoado/enzimologia , Miócitos Cardíacos/enzimologia , Proteínas rac de Ligação ao GTP/metabolismo , Animais , Western Blotting , Modelos Animais de Doenças , Genótipo , Frequência Cardíaca , Glicoproteínas de Membrana/metabolismo , Camundongos , Camundongos Transgênicos , Contração Miocárdica , Traumatismo por Reperfusão Miocárdica/genética , Traumatismo por Reperfusão Miocárdica/patologia , Traumatismo por Reperfusão Miocárdica/fisiopatologia , Miocárdio Atordoado/genética , Miocárdio Atordoado/patologia , Miocárdio Atordoado/fisiopatologia , Miócitos Cardíacos/patologia , NADPH Oxidase 2 , NADPH Oxidases/metabolismo , Fenótipo , Transdução de Sinais , Superóxidos/metabolismo , Fatores de Tempo , Regulação para Cima , Quinases Ativadas por p21/metabolismo , Proteínas rac de Ligação ao GTP/genética
3.
PLoS One ; 7(8): e42500, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22936985

RESUMO

The pathways inducing the critical transition from compensated hypertrophy to cardiac dilation and failure remain poorly understood. The goal of our study is to determine the role of Rac-induced signaling in this transition process. Our previous results showed that Thyroxin (T4) treatment resulted in increased myocardial Rac expression in wild-type mice and a higher level of expression in Zea maize RacD (ZmRacD) transgenic mice. Our current results showed that T4 treatment induced physiologic cardiac hypertrophy in wild-type mice, as demonstrated by echocardiography and histopathology analyses. This was associated with significant increases in myocardial Rac-GTP, superoxide and ERK1/2 activities. Conversely, echocardiography and histopathology analyses showed that T4 treatment induced dilated cardiomyopathy along with compensatory cardiac hypertrophy in ZmRacD mice. These were linked with further increases in myocardial Rac-GTP, superoxide and ERK1/2 activities. Additionally, there were significant increases in caspase-8 expression and caspase-3 activity. However, there was a significant decrease in p38-MAPK activity. Interestingly, inhibition of myocardial Rac-GTP activity and superoxide generation with pravastatin and carvedilol, respectively, attenuated all functional, structural, and molecular changes associated with the T4-induced cardiomyopathy in ZmRacD mice except the compensatory cardiac hypertrophy. Taken together, T4-induced ZmRacD is a novel mouse model of dilated cardiomyopathy that shares many characteristics with the human disease phenotype. To our knowledge, this is the first study to show graded Rac-mediated O(2)·(-) results in cardiac phenotype shift in-vivo. Moreover, Rac-mediated O(2)·(-) generation, cardiomyocyte apoptosis, and myocardial fibrosis seem to play a pivotal role in the transition from cardiac hypertrophy to cardiac dilation and failure. Targeting Rac signaling could represent valuable therapeutic strategy not only in saving the failing myocardium but also to prevent this transition process.


Assuntos
Apoptose/efeitos dos fármacos , Cardiomegalia/metabolismo , Cardiomegalia/patologia , Fibrose/metabolismo , Miocárdio/patologia , Miócitos Cardíacos/citologia , Miócitos Cardíacos/efeitos dos fármacos , Tiroxina/toxicidade , Proteínas rac de Ligação ao GTP/metabolismo , Animais , Western Blotting , Carbazóis/uso terapêutico , Cardiomegalia/induzido quimicamente , Cardiomiopatias/induzido quimicamente , Cardiomiopatias/tratamento farmacológico , Cardiomiopatias/metabolismo , Carvedilol , Ecocardiografia , Feminino , Fibrose/induzido quimicamente , Masculino , Camundongos , Camundongos Transgênicos , Pravastatina/uso terapêutico , Propanolaminas/uso terapêutico , Vasodilatadores/uso terapêutico , Proteínas rac de Ligação ao GTP/genética
4.
Inflamm Bowel Dis ; 17(8): 1698-713, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21744424

RESUMO

BACKGROUND: Pharmacological studies suggest that adenosine A3AR influences motility and colitis. Functional A3⁻/⁻AR knockout mice were used to prove whether A3AR activation is involved in modulating either motility or colitis. METHODS: A3AR was probed by polymerase chain reaction (PCR) genotyping, Western blot, and immunochemistry. Motility was assessed in vivo by artificial bead-expulsion, stool-frequency, and FITC-dextran transit. Colitis was induced with dextran sodium sulfate (DSS) in A3⁻/⁻AR or wildtype (WT) age- and sex-matched controls. Progression of colitis was evaluated by histopathology, changes in myeloperoxidase (MPO), colon length, CD4(+) -cells, weight-loss, diarrhea, and the guaiac test. RESULTS: Goat anti-hu-A3 antiserum identified a 66 kDa immunogenic band in colon. A3AR-immunoreactivity is expressed in SYN(+) -nerve varicosities, s-100(+) -glia, and crypt cells, but not 5-HT(+) (EC), CD4(+) (T), tryptase(+) (MC), or muscle cells. A3AR immunoreactivity in myenteric ganglia of distal colon >> proximal colon by a ratio of 2:1. Intestinal transit and bead expulsion were accelerated in A3⁻/⁻AR mice compared to WT; stool retention was lower by 40%-60% and stool frequency by 67%. DSS downregulated A3AR in epithelia. DSS histopathology scores indicated less mucosal damage in AA3⁻/⁻AR mice than WT. A3⁻/⁻AR phenotype protected against DSS-induced weight loss, neutrophil (MPO), or CD4(+) -T cell infiltration, colon shortening, change in splenic weight, diarrhea, or occult-fecal blood. CONCLUSIONS: Functional disruption of A3AR in A3⁻/⁻AR mice alters intestinal motility. We postulate that ongoing release of adenosine and activation of presynaptic-inhibitory A3AR can slow down transit and inhibit the defecation reflex. A3AR may be involved in gliotransmission. In separate studies, A3⁻/⁻AR protects against DSS colitis, consistent with a novel hypothesis that A3AR activation contributes to development of colitis.


Assuntos
Colite/fisiopatologia , Colo/fisiopatologia , Trânsito Gastrointestinal/fisiologia , Receptor A3 de Adenosina/fisiologia , Animais , Contagem de Linfócito CD4 , Colite/induzido quimicamente , Colite/patologia , Colo/inervação , Colo/patologia , Defecação/fisiologia , Sulfato de Dextrana , Diarreia/fisiopatologia , Feminino , Genótipo , Camundongos , Camundongos Knockout , Plexo Mientérico/metabolismo , Sangue Oculto , Tamanho do Órgão , Peroxidase/metabolismo , Receptor A3 de Adenosina/genética , Receptor A3 de Adenosina/metabolismo , Baço/patologia , Fatores de Tempo , Redução de Peso
5.
Am J Physiol Heart Circ Physiol ; 301(3): H868-80, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21622832

RESUMO

Rac1-GTPase activation plays a key role in the development and progression of cardiac remodeling. Therefore, we engineered a transgenic mouse model by overexpressing cDNA of a constitutively active form of Zea maize Rac gene (ZmRacD) specifically in the hearts of FVB/N mice. Echocardiography and MRI analyses showed cardiac hypertrophy in old transgenic mice, as evidenced by increased left ventricular (LV) mass and LV mass-to-body weight ratio, which are associated with relative ventricular chamber dilation and systolic dysfunction. LV hypertrophy in the hearts of old transgenic mice was further confirmed by an increased heart weight-to-body weight ratio and histopathology analysis. The cardiac remodeling in old transgenic mice was coupled with increased myocardial Rac-GTPase activity (372%) and ROS production (462%). There were also increases in α(1)-integrin (224%) and ß(1)-integrin (240%) expression. This led to the activation of hypertrophic signaling pathways, e.g., ERK1/2 (295%) and JNK (223%). Pravastatin treatment led to inhibition of Rac-GTPase activity and integrin signaling. Interestingly, activation of ZmRacD expression with thyroxin led to cardiac dilation and systolic dysfunction in adult transgenic mice within 2 wk. In conclusion, this is the first study to show the conservation of Rho/Rac proteins between plant and animal kingdoms in vivo. Additionally, ZmRacD is a novel transgenic model that gradually develops a cardiac phenotype with aging. Furthermore, the shift from cardiac hypertrophy to dilated hearts via thyroxin treatment will provide us with an excellent system to study the temporal changes in cardiac signaling from adaptive to maladaptive hypertrophy and heart failure.


Assuntos
Hipertrofia Ventricular Esquerda/enzimologia , Miocárdio/enzimologia , Proteínas de Plantas/metabolismo , Disfunção Ventricular Esquerda/enzimologia , Função Ventricular Esquerda , Remodelação Ventricular , Proteínas rac1 de Ligação ao GTP/metabolismo , Envelhecimento , Sequência de Aminoácidos , Análise de Variância , Animais , Ecocardiografia , Genótipo , Hipertrofia Ventricular Esquerda/diagnóstico , Hipertrofia Ventricular Esquerda/genética , Hipertrofia Ventricular Esquerda/fisiopatologia , Integrina alfa1/metabolismo , Integrina beta1/metabolismo , Sistema de Sinalização das MAP Quinases , Imageamento por Ressonância Magnética , Masculino , Camundongos , Camundongos Transgênicos , Dados de Sequência Molecular , Mutação , Miocárdio/patologia , Cadeias Pesadas de Miosina/genética , Fenótipo , Proteínas de Plantas/antagonistas & inibidores , Proteínas de Plantas/genética , Pravastatina/farmacologia , Regiões Promotoras Genéticas , Superóxidos/metabolismo , Tiroxina/farmacologia , Disfunção Ventricular Esquerda/diagnóstico , Disfunção Ventricular Esquerda/genética , Disfunção Ventricular Esquerda/fisiopatologia , Função Ventricular Esquerda/efeitos dos fármacos , Função Ventricular Esquerda/genética , Remodelação Ventricular/efeitos dos fármacos , Remodelação Ventricular/genética , Proteínas rac1 de Ligação ao GTP/antagonistas & inibidores , Proteínas rac1 de Ligação ao GTP/genética
6.
J Cardiovasc Pharmacol ; 57(5): 550-8, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-21326111

RESUMO

Hypertension represents a major risk factor for cardiovascular diseases. We have developed a novel transgenic mouse model by overexpressing the cDNA of human profilin1 in the blood vessels of transgenic mice, which led to vascular hypertrophy and hypertension. We assessed the effects of losartan, amlodipine, or atenolol on vascular hypertrophy-associated hypertension, by treating the profilin1 transgenic mice for 4 weeks. Our myograph results showed improvement in the contraction response toward phenylephrine and in the relaxation response toward acetylcholine and sodium nitrite in losartan- and amlodipine-treated profilin1 mice. Western blot analyses using mesenteric arteries of losartan- and amlodipine-treated profilin1 mice showed significant decreases in their signaling, respectively, as follows: the expression of α1 integrin (104% and 93%) and ß1 integrin (116% and 109%); p-ERK1/2 (149% and 130%) and p-JNK (171% and 137%); the phospho-myosin light chain 20 (117% and 150%); and the ROCKII expression (125% and 180%). Conversely, there were significant increases in the endothelial nitric oxide synthase expression (82% and 80%) and activation (p-endothelial nitric oxide synthase) (78% and 76%). On the other hand, atenolol-treated profilin1 mice showed no significant change in all measured parameters. In conclusion, the profilin1 gene may represent a new therapeutic target in the treatment of vascular hypertrophy-associated hypertension.


Assuntos
Anti-Hipertensivos/uso terapêutico , Endotélio Vascular/efeitos dos fármacos , Hipertensão/tratamento farmacológico , Hipertensão/fisiopatologia , Artérias Mesentéricas/efeitos dos fármacos , Profilinas/genética , Animais , Anti-Hipertensivos/administração & dosagem , Anti-Hipertensivos/farmacologia , Western Blotting , Modelos Animais de Doenças , Endotélio Vascular/metabolismo , Endotélio Vascular/fisiopatologia , Hipertensão/metabolismo , Masculino , Artérias Mesentéricas/metabolismo , Artérias Mesentéricas/fisiopatologia , Camundongos , Camundongos Transgênicos , Cadeias Leves de Miosina/metabolismo , Óxido Nítrico Sintase Tipo III/genética , Óxido Nítrico Sintase Tipo III/metabolismo , Vasodilatação/efeitos dos fármacos , Vasodilatação/fisiologia , Quinases Associadas a rho/metabolismo
7.
Am J Physiol Heart Circ Physiol ; 298(6): H2112-20, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20400688

RESUMO

Increased mechanical stress/hypertension in the vessel wall triggers the hypertrophic signaling pathway, resulting in structural remodeling of vasculature. Vascular hypertrophy of resistance vessels leads to reduced compliance and elevation of blood pressure. We showed before that increased expression of profilin1 protein in the medial layer of the aorta induces stress fiber formation, triggering the hypertrophic signaling resulting in vascular hypertrophy and, ultimately, hypertension in older mice. Our hypothesis is that profilin1 induced vascular hypertrophy in resistance vessels, which led to elevation of blood pressure, both of which contributed to the modulation of vascular function. Our results showed significant increases in the expression of alpha(1)- and beta(1)-integrins (280 + or - 6.3 and 325 + or - 7.4%, respectively) and the activation of the Rho/Rho-associated kinase (ROCK) II pathway (260 and 350%, respectively, P < 0.05) in profilin1 mesenteric arteries. The activation of Rho/ROCK led to the inhibition of endothelial nitric oxide synthase expression (39 + or - 5.4%; P < 0.05) and phosphorylation (35 + or - 4.5%; P < 0.05) but also an increase in myosin light chain 20 phosphorylation (372%, P < 0.05). There were also increases in hypertrophic signaling pathways in the mesenteric arteries of profilin1 mice such as phospho-extracellular signal-regulated kinase 1/2 and phospho-c-Jun NH(2)-terminal kinase (312.15 and 232.5%, respectively, P < 0.05). Functional analyses of mesenteric arteries toward the vasoactive drugs were assessed using wire-myograph and showed significant increases in the vascular responses of profilin1 mesenteric arteries toward phenylephrine, but significant decreases in response toward ROCK inhibitor Y-27632, ACh, sodium nitrite, and cytochalasin D. The changes in vascular responses in the mesenteric arteries of profilin1 mice are due to vascular hypertrophy and the elevation of blood pressure in the profilin1 transgenic mice.


Assuntos
Hipertensão/metabolismo , Hipertensão/fisiopatologia , Artérias Mesentéricas/metabolismo , Artérias Mesentéricas/patologia , Músculo Liso Vascular/fisiopatologia , Profilinas/metabolismo , Animais , Pressão Sanguínea/efeitos dos fármacos , Pressão Sanguínea/fisiologia , Modelos Animais de Doenças , Hipertensão/etiologia , Hipertrofia/complicações , Hipertrofia/metabolismo , Hipertrofia/patologia , Integrina alfa1/metabolismo , Integrina beta1/metabolismo , Masculino , Camundongos , Camundongos Transgênicos , Músculo Liso Vascular/metabolismo , Óxido Nítrico Sintase Tipo III/metabolismo , Fenilefrina/farmacologia , Profilinas/genética , Transdução de Sinais/fisiologia , Vasoconstritores/farmacologia , Quinases Associadas a rho/metabolismo
8.
Am J Physiol Gastrointest Liver Physiol ; 297(6): G1147-62, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19808660

RESUMO

We tested the novel hypothesis that endogenous adenosine (eADO) activates low-affinity A3 receptors in a model of neurogenic diarrhea in the guinea pig colon. Dimaprit activation of H2 receptors was used to trigger a cyclic coordinated response of contraction and Cl(-) secretion. Contraction-relaxation was monitored by sonomicrometry (via intracrystal distance) simultaneously with short-circuit current (I(sc), Cl(-) secretion). The short interplexus reflex coordinated response was attenuated or abolished by antagonists at H2 (cimetidine), 5-hydroxytryptamine 4 receptor (RS39604), neurokinin-1 receptor (GR82334), or nicotinic (mecamylamine) receptors. The A1 agonist 2-chloro-N(6)-cyclopentyladenosine (CCPA) abolished coordinated responses, and A1 antagonists could restore normal responses. A1-selective antagonists alone [8-cyclopentyltheophylline (CPT), 1,3-dipropyl-8-(2-amino-4-chlorophenyl)xanthine (PACPX), or 8-cyclopentyl-N(3)-[3-(4-(fluorosulfonyl)benzoyloxy)propyl]-xanthine (FSCPX)] caused a concentration-dependent augmentation of crypt cell secretion or contraction and acted at nanomolar concentrations. The A3 agonist N(6)-(3-iodobenzyl)-adenosine-5'-N-methyluronamide (IB-MECA) abolished coordinated responses and the A3 antagonist 3-ethyl-5-benzyl-2-methyl-4-phenylethynyl-6-phenyl-1,4-(+/-)-dihydropyridine-3,5-dicarboxylate (MRS1191) could restore and further augment responses. The IB-MECA effect was resistant to knockdown of adenosine A1 receptor with the irreversible antagonist FSCPX; the IC(50) for IB-MECA was 0.8 microM. MRS1191 alone could augment or unmask coordinated responses to dimaprit, and IB-MECA suppressed them. MRS1191 augmented distension-evoked reflex I(sc) responses. Adenosine deaminase mimicked actions of adenosine receptor antagonists. A3 receptor immunoreactivity was differentially expressed in enteric neurons of different parts of colon. After tetrodotoxin, IB-MECA caused circular muscle relaxation. The data support the novel concept that eADO acts at low-affinity A3 receptors in addition to high-affinity A1 receptors to suppress coordinated responses triggered by immune-histamine H2 receptor activation. The short interplexus circuit activated by histamine involves adenosine, acetylcholine, substance P, and serotonin. We postulate that A3 receptor modulation may occur in gut inflammatory diseases or allergic responses involving mast cell and histamine release.


Assuntos
Adenosina/metabolismo , Colo/metabolismo , Sistema Nervoso Entérico/metabolismo , Motilidade Gastrointestinal , Histamina/metabolismo , Músculo Liso/metabolismo , Inibição Neural , Intestino Neurogênico/metabolismo , Receptor A3 de Adenosina/metabolismo , Adenosina/análogos & derivados , Adenosina/farmacologia , Animais , Cloretos/metabolismo , Cimetidina/farmacologia , Colo/efeitos dos fármacos , Colo/imunologia , Colo/inervação , Di-Hidropiridinas/farmacologia , Dimaprit/farmacologia , Relação Dose-Resposta a Droga , Sistema Nervoso Entérico/efeitos dos fármacos , Sistema Nervoso Entérico/fisiopatologia , Motilidade Gastrointestinal/efeitos dos fármacos , Cobaias , Agonistas dos Receptores Histamínicos/farmacologia , Antagonistas dos Receptores H2 da Histamina/farmacologia , Técnicas In Vitro , Secreções Intestinais/metabolismo , Masculino , Mecamilamina/farmacologia , Contração Muscular , Relaxamento Muscular , Músculo Liso/efeitos dos fármacos , Músculo Liso/imunologia , Músculo Liso/inervação , Inibição Neural/efeitos dos fármacos , Intestino Neurogênico/imunologia , Intestino Neurogênico/fisiopatologia , Antagonistas dos Receptores de Neurocinina-1 , Antagonistas Nicotínicos/farmacologia , Piperidinas/farmacologia , Propano/análogos & derivados , Propano/farmacologia , Receptor A1 de Adenosina/efeitos dos fármacos , Receptor A1 de Adenosina/metabolismo , Receptor A3 de Adenosina/efeitos dos fármacos , Receptores Histamínicos H2/efeitos dos fármacos , Receptores Histamínicos H2/metabolismo , Receptores da Neurocinina-1/metabolismo , Reflexo , Teofilina/análogos & derivados , Teofilina/farmacologia , Xantinas/farmacologia
9.
J Biol Chem ; 282(52): 37632-9, 2007 Dec 28.
Artigo em Inglês | MEDLINE | ID: mdl-17942408

RESUMO

We have overexpressed either the cDNA of human profilin 1 or expressed the mutant (88R/L) in the blood vessels of transgenic FVB/N mice. Reverse transcription-PCR indicated selective overexpression of profilin 1 and 88R/L in vascular smooth muscle cells. Polyproline binding showed increased profilin 1 and 88R/L proteins in transgenic mice compared with control (~30%, p < 0.05). Rhodamine-phalloidin staining revealed increase stress fiber formation in vascular smooth muscle cells of profilin 1 compared with 88R/L and control. Hematoxylin and eosin staining showed clear signs of vascular hypertrophy in the aorta of profilin 1 mice versus 88R/L and control. However, there were no differences between 88R/L and control mice. Western blotting confirmed the activation of the hypertrophic signaling cascades in aortas of profilin 1 mice. Phospho-ERK1/2 was significantly higher in profilin 1 than 88R/L and control (512.3 and 361.7%, respectively, p < 0.05). Profilin 1 mice had significant increases in phospho-JNK as compared with 88R/L and control (371.4 and 346%, respectively, p < 0.05). However, there were no differences between 88R/L and control mice in both kinases. There was a significant increase in ROCK II kinase in the aorta of profilin 1 mice compared with controls (>400%, p < 0.05). Tail cuff and circadian monitoring of blood pressure showed significant increases in systolic and mean arterial blood pressures of profilin 1 mice starting at age 6 months compared with controls (~25 mm Hg, p < 0.05). These results suggest that increased actin polymerization in blood vessels triggers activation of the hypertrophic signaling cascades and results in elevation of blood pressure at advanced age.


Assuntos
Regulação da Expressão Gênica , Hipertensão/genética , Hipertrofia/genética , Profilinas/biossíntese , Profilinas/genética , Actinas/química , Animais , Aorta/metabolismo , Valva Aórtica/citologia , Pressão Sanguínea , Sistema de Sinalização das MAP Quinases , Camundongos , Camundongos Transgênicos , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Modelos Biológicos , Miócitos de Músculo Liso/citologia , Transdução de Sinais
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