Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 36
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
3.
J Biol Regul Homeost Agents ; 35(2): 605-615, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33928771

RESUMO

Osteogenic differentiation of human bone marrow-derived mesenchymal stem cells (hBMSCs) is vital for bone formation, and its dysfunction is linked to osteoporosis (OP). In this work, we explored the function of long non-coding RNA (lncRNA) small nucleolar RNA host gene 14 (SNHG14) in regulating osteogenic differentiation of hBMSCs. In the present study, the expression of SNHG14 in hBMSCs obtained from OP patients was measured by quantitative real-time polymerase chain reaction (qRT-PCR). SNHG14 was over-expressed or knocked down in hBMSCs, and the expression levels of OP-related genes (ALP, OCN, and OPN) in hBMSCs were detected by qRT-PCR and Western blot. StarBase database and miRanda database were used to predict the binding sites between SNHG14 and miR-185-5p, and between miR-185-5p and 3'UTR of WNT1 inducible signaling pathway protein 2 (WISP2), respectively. Luciferase reporter gene assay was used to validate the binding relationship between SNHG14 and miR-185-5p, and miR-185-5p and 3'UTR of WISP2, respectively. Here, we report that SNHG14 was significantly down-regulated in hBMSCs obtained from patients with OP. Overexpression of SNHG14 promoted osteogenic differentiation, while knockdown of SNHG14 worked oppositely. Mechanistically, miR-185-5p was demonstrated to be a target of SNHG14, and could reverse the function of SNHG14. Additionally, WISP2 was identified as a target gene of miR-185-5p in hBMSCs and could be indirectly regulated by SNHG14. Taken together, down-regulation of SNHG14 in hBMSCs accelerated the progression of OP via regulating miR-185-5p/WISP2 axis.


Assuntos
Células-Tronco Mesenquimais , MicroRNAs , RNA Longo não Codificante , Medula Óssea , Diferenciação Celular , Células Cultivadas , Humanos , MicroRNAs/genética , Osteogênese/genética , RNA Longo não Codificante/genética
4.
J Appl Microbiol ; 130(6): 2008-2017, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32358825

RESUMO

AIMS: To identify a lambda promoter pL mutant that could extend the thermal stability of the thermo-inducible λcI857-pR/pL system and to evaluate the effects of the modified system for the controlled expression of lysis gene E during the production of bacterial ghosts (BGs). METHODS AND RESULTS: The promoter pL mutant was identified by random mutagenesis and site-directed mutagenesis. The results showed that a T â†’ 35C mutation in the pL promoter was responsible for the phenotype alteration. Under the same induction conditions, the lysis rates of the modified lytic system on Escherichia coli and Salmonella enteritidis were significantly lower than that of the control, while the lysis rates of Escherichia coli with the thermo-inducible lytic system were significantly higher than that of S. enteritidis with the corresponding plasmid (P < 0·05). CONCLUSIONS: Increasing the heat stability of the thermo-inducible lytic systems decreased lysis efficiency during the production of BGs. There exist differences in the lysis efficiency of thermo-inducible lytic systems between different bacterial strains. SIGNIFICANCE AND IMPACT OF THE STUDY: These findings enrich current knowledge about modifications to thermo-inducible systems and provide a reference for the application of these modified systems for the production of BGs and controlled gene expression in bacteria.


Assuntos
Bacteriófago lambda/fisiologia , Regulação Viral da Expressão Gênica , Regiões Promotoras Genéticas/genética , Proteínas Virais/genética , Bacteriólise , Bacteriófago lambda/genética , Escherichia coli/fisiologia , Escherichia coli/virologia , Mutação , Plasmídeos/genética , Plasmídeos/fisiologia , Salmonella enteritidis/fisiologia , Salmonella enteritidis/virologia , Temperatura
5.
J Biol Regul Homeost Agents ; 34(5): 1679-1688, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33164477

RESUMO

Acute lung injury (ALI)/Acute respiratory distress syndrome (ARDS) is a very dangerous disease. The purpose of this study was to investigate the effects of fibrogrowth factor-2 (FGF-2) on lipopolysaccharide (LPS)-induced lung injury and its mechanisms. C57/BL6 mice were used in the study and LPS was used to construct the ALI/ARDS model. In addition, human normal lung epithelial cell line BEAS-2B was cultured to investigate the effect of FGF-2 on the lung and its mechanism of action in vitro. FGF-2 significantly reduced wet/dry weight ratio of mice, the number of cells and inflammatory factors in BALF, and MPO activity in lung tissue. In addition, FGF-2 also reduced the level of oxidative stress in mouse lung tissue. In vitro, FGF-2 effectively reduced LPS-induced inflammatory and apoptotic levels of BEAS-2B cells and increased the activity of the PI3K/Akt signaling pathway. However, LY294002, an inhibitor of the PI3K/Akt signaling pathway, alleviated the protective effect of FGF-2 on lung tissue. Therefore, FGF-2 attenuated inflammation, oxidative stress and apoptosis in alveolar epithelial cells by activating the PI3K/Akt signaling pathway.


Assuntos
Lesão Pulmonar Aguda , Fator 2 de Crescimento de Fibroblastos/farmacologia , Fosfatidilinositol 3-Quinases , Proteínas Proto-Oncogênicas c-akt , Transdução de Sinais , Lesão Pulmonar Aguda/induzido quimicamente , Lesão Pulmonar Aguda/tratamento farmacológico , Lesão Pulmonar Aguda/prevenção & controle , Animais , Apoptose , Linhagem Celular , Cromonas , Células Epiteliais , Humanos , Inflamação , Lipopolissacarídeos/toxicidade , Pulmão/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Morfolinas , Estresse Oxidativo , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo
6.
Artigo em Chinês | MEDLINE | ID: mdl-30032496

RESUMO

Objective: To investigate the effect of ubiquitous mitochondrial creatine kinase 1(CKMT1) on the sensitivity of human nasopharyngeal carcinoma cell line CNE-1 to DDP. Methods: CNE-1 cells were transiently transfected with CKMT1 overexpression (CKMT1) or empty vector (EV). The growth curve and DDP IC50 were developed by MTT assay, plate clone formation assay was performed by gradient concentration of DDP treatment, cell cycle and apoptosis were detected by flow cytometry, levels of apoptosis related protein Bax/Bcl-2/C-PARP and the transcription factor p-STAT3-Tyr705 were detected by Western Blot. Results: The transfection efficiencies of CKMT1 and EV were more than 90% with a higher proliferation rate in the CKMT1-transfected cells. However, the CKMT1-transfected cells had a DDP IC50 of 2.76 µmol/L, which was significantly lower than that of 4.60 µmol/L in the EV-transfected cells (P<0.01). With the treatment of certain concentration of DDP, the CKMT1-transfected cells had a lower clone formation rate, the cell cycle arrested more obviously in G2/M phase, and the apoptosis rate was higher (P<0.01), with higher levels of Bax/C-PARP (P<0.05 or P<0.01), but lower levels of Bcl-2 (P<0.01) and p-STAT3-Tyr705 (P<0.01), compare with the EV-transfected cells. Conclusions: CKMT1 may inhibit the activation of STAT3, increasing the sensitivity of CNE-1 to chemotherapeutic drug DDP.


Assuntos
Antineoplásicos/farmacologia , Carcinoma/tratamento farmacológico , Cisplatino/farmacologia , Creatina Quinase Mitocondrial/metabolismo , Neoplasias Nasofaríngeas/tratamento farmacológico , Fator de Transcrição STAT3/metabolismo , Apoptose , Carcinoma/patologia , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células , Vetores Genéticos , Humanos , Carcinoma Nasofaríngeo , Neoplasias Nasofaríngeas/patologia , Transfecção/métodos
7.
Clin Exp Dermatol ; 42(8): 849-856, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28597992

RESUMO

BACKGROUND: Psoriasis is one of the most common immune-mediated chronic inflammatory skin disorders. In spite of significant advances in the treatment of psoriasis, more effective and safer therapeutic strategies are still needed. Photodynamic therapy (PDT) is a method of light treatment that is being used increasingly in the treatment of dermatological diseases. AIM: To evaluate the therapeutic effects of systemic 5-aminolaevulinic acid (ALA)-PDT on psoriasis and to explore its potential mechanism of action. METHODS: We investigated the therapeutic effects of systemic ALA-PDT in K14-vascular endothelial growth factor (VEGF) transgenic homozygous mice, an animal model of psoriasis, which has many clinical and histopathological characteristics similar to those of human psoriasis. Using haematoxylin and eosin staining, immunohistochemistry and real-time quantitative PCR respectively, we assessed the changes in psoriasis-like lesions, cellular infiltration of T cells, dendritic cells (DCs) and neutrophils, and the mRNA expression of the inflammatory cytokines interleukin (IL)-17 and interferon (IFN)-γ in the lesions. RESULTS: Systemic ALA-PDT blocked the development of psoriasis-like lesions and moderately attenuated the histopathological changes in K14-VEGF transgenic mice. Furthermore, systemic ALA-PDT produced an obvious reduction in infiltration of T cells, CD11c+ DCs and neutrophils in psoriasis-like lesions. In addition, systemic ALA-PDT also significantly decreased the mRNA expression of IL-17 and IFN-γ. CONCLUSIONS: We suggest that the mechanism of systemic ALA-PDT in this psoriasis-like model might be associated with selective damage to abnormal T helper (Th)1 and Th17 cells, and reduction of the inflammatory cytokines IL-17 and IFN-γ. These observations partly explain the potential mechanism of systemic ALA-PDT in psoriasis and other inflammatory skin diseases.


Assuntos
Ácido Aminolevulínico/uso terapêutico , Fotoquimioterapia , Psoríase/tratamento farmacológico , Linfócitos T Auxiliares-Indutores/efeitos dos fármacos , Ácido Aminolevulínico/farmacologia , Animais , Modelos Animais de Doenças , Imuno-Histoquímica , Interferons/genética , Interferons/metabolismo , Interleucina-17/genética , Interleucina-17/metabolismo , Masculino , Camundongos , Camundongos Transgênicos , Psoríase/imunologia , Psoríase/prevenção & controle , RNA Mensageiro/metabolismo , Distribuição Aleatória , Reação em Cadeia da Polimerase em Tempo Real , Linfócitos T Auxiliares-Indutores/fisiologia , Fator A de Crescimento do Endotélio Vascular/genética
8.
J Biol Regul Homeost Agents ; 31(1): 51-58, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28337870

RESUMO

The Janus kinase-signal transducers and activators of transcription signaling pathway (JAK/STAT pathway) have displayed a critical role in tumor development and progression in multiple malignancies. Previous studies showed that inhibition of JAK/STAT signaling blocked cell growth and metastasis in cancer cells, however, the antitumor effects of JAK inhibitor AG490 on gallbladder cancer (GBC) have not been reported. Our present study aimed to investigate the effects and associated mechanisms of JAK inhibitor AG490 on cell growth, invasive potential and apoptosis in GBC cells (GBC-SD and SGC-996) indicated by MTT, cell colony formation, Transwell and flow cytometry. As a consequence, we found that JAK2 inhibitor AG490 inhibited cell growth and invasion, and induced cell apoptosis and cycle arrest in GBC-SD and SGC-996 cells. Furthermore, the expression levels of p-JAK2, p-STAT3, VEGFC-/-D and cyclinD1 were downregulated, while p53 expression was upregulated in AG490-treated GBC cells indicated by Western blot assay. Therefore, our findings demonstrate that JAK inhibitor AG490 inhibits growth and invasion of GBC cells via blockade of JAK2/STAT3 signaling and provides the potential therapeutic strategy for the treatment of GBC patients.


Assuntos
Antineoplásicos/farmacologia , Células Epiteliais/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica , Janus Quinase 2/antagonistas & inibidores , Inibidores de Proteínas Quinases/farmacologia , Fator de Transcrição STAT3/antagonistas & inibidores , Tirfostinas/farmacologia , Apoptose/efeitos dos fármacos , Apoptose/genética , Ciclo Celular/efeitos dos fármacos , Ciclo Celular/genética , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Ciclina D1/antagonistas & inibidores , Ciclina D1/genética , Ciclina D1/metabolismo , Células Epiteliais/metabolismo , Células Epiteliais/patologia , Vesícula Biliar/efeitos dos fármacos , Vesícula Biliar/metabolismo , Vesícula Biliar/patologia , Humanos , Janus Quinase 2/genética , Janus Quinase 2/metabolismo , Fator de Transcrição STAT3/genética , Fator de Transcrição STAT3/metabolismo , Transdução de Sinais , Proteína Supressora de Tumor p53/agonistas , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo , Fator C de Crescimento do Endotélio Vascular/antagonistas & inibidores , Fator C de Crescimento do Endotélio Vascular/genética , Fator C de Crescimento do Endotélio Vascular/metabolismo , Fator D de Crescimento do Endotélio Vascular/antagonistas & inibidores , Fator D de Crescimento do Endotélio Vascular/genética , Fator D de Crescimento do Endotélio Vascular/metabolismo
9.
Clin Exp Dermatol ; 41(8): 871-877, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27753135

RESUMO

BACKGROUND: Tumour necrosis factor (TNF)-like weak inducer of apoptosis (TWEAK) is a pro-inflammatory cytokine, which is closely associated with the pathogenesis of various types of cutaneous vasculitis (CV). AIM: To investigate the therapeutic effects of an anti-TWEAK monoclonal antibody (mAb) in a mouse model of cutaneous reverse passive Arthus (RPA) reaction. METHODS: Cutaneous RPA reaction was induced in BALB/c mice by intradermal injection of anti-ovalbumin IgG into the left ear followed immediately by intravenous injection of chicken ovalbumin. After treatment, haemorrhagic lesions in the mouse skin were scored semiquantitatively. The amount of extravasated fluorescein isothiocyanate (FITC)-labelled bovine serum albumin (BSA) in the ears was detected spectrophotometrically. Expression of myeloperoxidase (MPO) was detected by immunohistochemical staining, while mRNA expression of TNF-α and interleukin (IL)-6 in lesional skin was detected by real-time quantitative (q)PCR. RESULTS: Our results indicated that anti-TWEAK mAb significantly attenuated the clinical and histopathological changes in immune complex (IC)-induced mice, and also reduced the semiquantitative haemorrhage score, FITC-labelled BSA extravasation and MPO activity. Real-time qPCR showed that anti-TWEAK mAb significantly inhibited mRNA expression of TNF-α and IL-6 in lesional skin from IC-induced mice. CONCLUSION: These data suggest that anti-TWEAK mAb can block vascular damage and leucocyte infiltration in IC-induced mice. TWEAK might be a candidate immunotherapeutic medicine for suppression of IC-induced CV.


Assuntos
Anticorpos Monoclonais/uso terapêutico , Reação de Arthus/tratamento farmacológico , Citocina TWEAK/antagonistas & inibidores , Dermatopatias/tratamento farmacológico , Animais , Reação de Arthus/metabolismo , Reação de Arthus/patologia , Citocina TWEAK/sangue , Citocinas/metabolismo , Modelos Animais de Doenças , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Peroxidase/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Dermatopatias/metabolismo , Dermatopatias/patologia
10.
J Vet Pharmacol Ther ; 31(3): 240-5, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18471145

RESUMO

This study was performed in 105 ill cows to determine the best practical individualized dose of enrofloxacin after i.m. (2.5 mg/kg) single-dose administration. Samples were collected from each cow at random time to ensure the percentage of samples distributed equally in the absorption phase, distribution phase, and elimination phase of the drug. Drug concentrations were determined by high-performance liquid chromatography with fluorometric detector, analyzed by population pharmacokinetic (PPK) modeling with NONMEM. The concentration-time data for enrofloxacin in plasma and ciprofloxacin were fitted to the one-compartment model with first-order absorption and elimination. The final covariate model indicated that body weight and daily milk productions have significant influence on clearance (CL) of enrofloxacin and ciprofloxacin, and the volume (V) of distribution of enrofloxacin. The typical PPK parameters were K(a) = 3.33 h(-1), CL = 1.25 L/h/kg, and V = 2.98 L/kg of enrofloxacin, and the interindividual variability for CL and V were 20.2% and 24.3%, respectively, the population mean estimates of K(a), CL, and V for ciprofloxacin were 1.12 h(-1), 2.36 L/h/kg, 8.20 L/kg, respectively, and their interindividual variability was 36.9%, 15.8% and 14.1%, respectively.


Assuntos
Anti-Infecciosos/farmacocinética , Doenças dos Bovinos/metabolismo , Ciprofloxacina/farmacocinética , Fluoroquinolonas/farmacocinética , Absorção , Animais , Anti-Infecciosos/metabolismo , Anti-Infecciosos/uso terapêutico , Área Sob a Curva , Bovinos , Doenças dos Bovinos/tratamento farmacológico , Ciprofloxacina/metabolismo , Ciprofloxacina/uso terapêutico , Enrofloxacina , Feminino , Fluoroquinolonas/metabolismo , Fluoroquinolonas/uso terapêutico , Taxa de Depuração Metabólica , Modelos Biológicos
11.
Int J Cardiol ; 115(1): 24-8, 2007 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-16762434

RESUMO

UNLABELLED: There is increasing evidence showing that inflammation is involved in heart failure. However, heart failure may differ greatly due to different aetiologies. The role of inflammation in hypertensive heart failure, particularly in the early stage of cardiac dysfunction, has not been studied completely. This study aims at finding out whether inflammation is involved in the early stage of heart dysfunction due to hypertension. METHODS: Ten spontaneously hypertensive rats (SHR) and ten age-matched Wistar rats were used. Cardiac morphology and function, as well as coronary flow reserve, were examined by echocardiography. mRNAs for cytokines and brain natriuretic peptide were determined by RT-PCR. RESULTS: The results demonstrate cardiac hypertrophy with increased heart/body weight ratio in SHR. Echocardiographic examination has shown that SHR developed diastolic heart dysfunction as determined by tissue Doppler without decrease in systolic function. In heart biopsies, there were increased mRNA levels for interleukin-6 and brain natriuretic peptide whereas decreased mRNA for interleukin-2, beta adrenergic receptor, interferon and NFkb in SHR as compared to WKY group. Coronary flow remained unchanged in both groups. CONCLUSION: SHR developed cardiac hypertrophy complicated with diastolic heart dysfunction with increased expression of brain natriuretic peptide, down-regulation of beta adrenergic receptors and simultaneous up-regulation of IL-6, which indicates active proinflammatory process as, at least partly, underlying mechanism during the early stage when cardiac hypertrophy associated with diastolic dysfunction occurs.


Assuntos
Cardiomegalia/genética , Insuficiência Cardíaca/genética , Hipertensão/complicações , Interleucina-6/genética , Peptídeo Natriurético Encefálico/genética , Animais , Cardiomegalia/diagnóstico por imagem , Cardiomegalia/etiologia , Cardiomegalia/fisiopatologia , Diástole , Modelos Animais de Doenças , Ecocardiografia , Regulação da Expressão Gênica , Insuficiência Cardíaca/etiologia , Hipertrofia , Miocárdio/patologia , Ratos , Ratos Wistar , Receptores Adrenérgicos beta/genética
12.
Chin Med J (Engl) ; 113(10): 867-71, 2000 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11775829

RESUMO

OBJECTIVE: To study the activity of anti-peptide antibodies against the second extracellular loop of human M2 muscarinic receptors on cAMP production and inward calcium currents (Ica) in guinea pig ventricular myocytes. A comparison was also made with those of a muscarinic receptor agonist. METHODS: cAMP content was determined by radioimmunoassay and the Ica in guinea pig single ventricular cells were recorded by the whole-cell patch clamp technique. RESULTS: Both the muscarinic receptor agonist, carbachol (Carb 10 mumol/L), and anti-peptide antibodies (Abs 100 nmol/L) could decrease basal cAMP levels (by 46.9% +/- 4.2% and 60.2% +/- 4.6%, respectively) and basal Ica. Both Carb (10 mumol/L) and Abs (100 nmol/L) could also inhibit the isoprenaline-induced (Iso 0.8 mumol/L) increases in cAMP production (from 108.2 +/- 7.0 to 88.4 +/- 7.2 pmol/mg.protein/min for Carb and 88.6 +/- 5.1 pmol/mg.protein/min for Abs, respectively) and the increases in Ica. The muscarinic receptor antagonist atropine (Atr) was able to prevent these effects of Carb and Abs. CONCLUSIONS: Anti-peptide antibodies against an epitope located in the second extracellular loop of human M2 muscarinic receptors, similar to muscarinic receptor agonist, could decrease the basal Ica and beta-receptor agonist stimulated increase of Ica by decreasing the basal and beta-receptor agonist stimulated increase of cAMP production, and therefore could have an effect on their target receptor. These results further suggest that autoimmunity may participate in the pathogenesis of human cardiomyopathy and the second extracellular loop of human M2 muscarinic receptor could be the main immunodominant region.


Assuntos
Anticorpos/imunologia , Cálcio/metabolismo , AMP Cíclico/biossíntese , Fragmentos de Peptídeos/imunologia , Receptores Muscarínicos/imunologia , Sequência de Aminoácidos , Animais , Atropina/farmacologia , Carbacol/farmacologia , Feminino , Cobaias , Humanos , Masculino , Dados de Sequência Molecular , Receptor Muscarínico M2
13.
Eur J Biochem ; 251(3): 659-66, 1998 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-9490038

RESUMO

Monoclonal antibodies were raised against a peptide corresponding to the second extracellular loop of the M2 acetylcholine receptor. One of the monoclonal antibodies, B8E5, was selected for further characterization on the basis of its high yield, its isotype (IgG2a), its dissociation kinetics and its agonist-like activity. The epitope recognized by B8E5 corresponded to the N-terminal part of the second extracellular loop of the receptor (V-R-T-V-E-) as determined by competition immunoassays and epitope scanning. The KA of B8E5 for the target peptide was assessed by surface plasmon resonance (SPR) to be 6.5x10(7) M(-1) by equilibrium and 3.7x10(7) M(-1) by kinetic analysis. B8E5 recognized the M2 acetylcholine receptor on rat cardiac tissue. It only recognized the non-reduced receptor in immunoblots. The antibody had no effect on antagonist binding but decreased the affinity for the agonist carbachol. B8E5 decreased the beating frequency of neonatal rat cardiomyocytes. The effect was specific since it was blocked by the target peptide and the antagonist atropine. The EC50 of the antibody corresponded to the KA measured by surface plasmon resonance. The physiological effect of the antibody did not lead to desensitization. The Fab fragments had no physiological effect; subsequent addition of anti-mouse IgG however restored the physiological effect. These results confirm that the N-terminus of the second extracellular loop is a functional target for antibodies against the M2 acetylcholine receptor. They suggest that the functional epitope is only accessible in the non-reduced receptor. The antibodies act through a functional dimerization of the receptor.


Assuntos
Anticorpos Monoclonais/farmacologia , Contração Miocárdica/fisiologia , Miocárdio/metabolismo , Receptores Muscarínicos/metabolismo , Sequência de Aminoácidos , Animais , Animais Recém-Nascidos , Anticorpos Monoclonais/isolamento & purificação , Atropina/farmacologia , Epitopos/análise , Epitopos/metabolismo , Ventrículos do Coração , Humanos , Immunoblotting , Imuno-Histoquímica , Cinética , Dados de Sequência Molecular , Contração Miocárdica/efeitos dos fármacos , Miocárdio/citologia , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/imunologia , Fragmentos de Peptídeos/metabolismo , Ratos , Receptor Muscarínico M2 , Receptores Muscarínicos/análise , Receptores Muscarínicos/imunologia
14.
Life Sci ; 62(5): 461-8, 1998.
Artigo em Inglês | MEDLINE | ID: mdl-9449237

RESUMO

Previous studies have suggested that epididymal and sperm functions are subject to control by a local renin-angiotensin II system (RAS) in the rat epididymis. Type-1 angiotensin II receptor, AT1 and type-2 receptor, AT2 were localized in epididymal epithelium, indicating that RAS may act in a paracrine or autocrine fashion to regulate fluid secretion, probably through the basally placed membrane-bound AT1 protein as revealed by immunocytochemical and electrophysiological studies. In the present work, the expression of the angiotensin II receptor subtypes in the rat epididymis was showed by western blot analysis and reverse-transcription polymerase chain reaction (RT-PCR) using specific primers for the angiotensin II receptor subtypes. Western blot analysis showed the expression of AT1 receptor in the rat epididymis. Results from RT-PCR, using specific primers based on the corresponding angiotensin II receptor subtype genes for AT1a, AT1b and AT2 , demonstrated the differential expression of mRNAs from these receptor subtypes in the epididymides of mature and immature rats. Both the genes for AT1a and AT1b, but not that for AT2, are predominantly expressed in the epididymides of mature rat. In contrast, only AT1a and AT2 were highly expressed in the epididymides of immature rat. These results suggest that the expression of type-1 and type-2 angiotensin II receptor subtypes are developmentally regulated. Type-1 subtype may play a role in regulation of electrolyte and fluid transport in mature rat whereas type-2 subtype may be important in growth and development in the immature rat.


Assuntos
Epididimo/metabolismo , Receptores de Angiotensina/metabolismo , Glândulas Suprarrenais/metabolismo , Fatores Etários , Animais , Western Blotting , Rim/metabolismo , Fígado/metabolismo , Masculino , Peso Molecular , Reação em Cadeia da Polimerase , Ratos , Ratos Sprague-Dawley , Receptor Tipo 1 de Angiotensina , Receptor Tipo 2 de Angiotensina , Receptores de Angiotensina/genética , Maturidade Sexual
15.
Biochim Biophys Acta ; 1357(1): 65-72, 1997 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-9202176

RESUMO

Previous work from our laboratory has provided evidence for the presence of a tissue renin-angiotensin system in the rat epididymis. In the current investigation, the regional localization of angiotensin II receptors, type I (AT1) and type II (AT2) was studied immunocytochemically using specific anti-peptide antibodies against the second extracellular loops of AT1 and AT2 receptors, and pharmacologically using specific receptor antagonists in conjunction with the short-circuit current technique. The immunocytochemical results showed that AT1 and AT2 immunoreactivities were predominantly localized in the basal region of the epididymal epithelium. Electrophysiological studies using the short-circuit current technique demonstrated a stimulatory effect of basolaterally applied angiotensin II on the epididymal electrogenic ion transport. This effect was inhibitable by the addition of AT1 antagonist, losartan but not by AT2 antagonist, PD123177, indicating a functional role of AT1 in epididymal electrolyte transport. The present finding suggests that angiotensin II receptors may play an important role in the regulation of epididymal function.


Assuntos
Epididimo/metabolismo , Receptores de Angiotensina/análise , Antagonistas de Receptores de Angiotensina , Animais , Ânions/metabolismo , Eletrofisiologia , Imunofluorescência , Transporte de Íons , Masculino , Ratos , Receptor Tipo 1 de Angiotensina , Receptor Tipo 2 de Angiotensina , Receptores de Angiotensina/metabolismo
16.
J Endocrinol ; 153(2): 269-74, 1997 May.
Artigo em Inglês | MEDLINE | ID: mdl-9166116

RESUMO

Previous studies have demonstrated the existence of several key components of the renin-angiotensin system in the pancreas. In the present study, the localization of angiotensin II receptor subtypes, type I (AT1) and type II (AT2), in the mouse and the rat pancreas was studied by immunocytochemistry using specific antipeptide antibodies against the second extracellular loops of AT1 and AT2 receptors in conjunction with confocal laser scanning microscopy. In the mouse, immunoreactivity for AT1 and AT2 was observed predominantly in the endothelia of the blood vessels and the epithelia of the pancreatic ductal system. Similar distribution of immunoreactivity for AT1 and AT2 was also observed. However, the intensity of immunoreactivity for AT1 and AT2 was stronger in the rat than that found in the mouse pancreas. Much weaker immunostaining for both AT1 and AT2, as compared with that found in ductal regions, was also found in the acini of the rodent pancreas. Together with the previous findings, the present results suggest that AT1 and/or AT2 receptors may play a role in regulating pancreatic functions in the rodent.


Assuntos
Angiotensina II , Pâncreas/química , Receptores de Angiotensina/análise , Animais , Técnica Indireta de Fluorescência para Anticorpo , Masculino , Camundongos , Camundongos Endogâmicos ICR , Microscopia Confocal , Ratos , Ratos Sprague-Dawley
17.
J Membr Biol ; 157(1): 97-103, 1997 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-9141362

RESUMO

Previous studies from our laboratory have provided evidence for the existence of a local renin-angiotensin system in the rat epididymis. Evidence has also accumulated, indicating that locally formed angiotensin II from the rat epididymis may play a paracrine and/or autocrine role in regulating epididymal electrolyte and fluid transport. In the present study, specific anti-peptide antibodies against the second extracellular loops of angiotensin II type I (AT1) and type II (AT2) receptors were used to localize immunocytochemically these receptors in the rat cauda epididymides of three developmental stages, namely, immature (2-week), early mature (6-week) and fully mature (10-week). The immunostaining intensity for AT1 receptors was found to be stronger than that for AT2 receptors throughout rat epididymides of all stages. However, the immunostaining for both AT1 and AT2 receptors observed in the fully mature rat epididymis was much more intense than that observed in the epididymides of the two younger stages. While the immunostaining for both AT1 and AT2 receptors in the younger rat epididymides appeared to be distributed in both basal and apical regions, the immunostaining in the fully mature epididymis was predominantly localized in the basal region. The present finding of the differential patterns of angiotensin II receptor immunoreactivity in three different stages of the rat epididymis may reflect the fine tuning of rat epididymal function by angiotensin II, acting as a paracrine or autocrine agent, during the course of development.


Assuntos
Epididimo/metabolismo , Receptores de Angiotensina/metabolismo , Sequência de Aminoácidos , Animais , Diferenciação Celular , Epididimo/citologia , Técnica Indireta de Fluorescência para Anticorpo , Humanos , Masculino , Dados de Sequência Molecular , Ratos , Ratos Sprague-Dawley
18.
J Membr Biol ; 156(3): 241-9, 1997 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-9096065

RESUMO

The beta-adrenergic (cAMP-dependent) regulation of Cl- conductance is defective in cystic fibrosis (CF). The present study explored alternative regulation of anion secretion in CF pancreatic ductal cells (CFPAC-1) by angiotensin II (AII) using the short-circuit current (ISC) technique. An increase in ISC could be induced in CFPAC-1 cells by basolateral or apical application of AII in a concentration-dependent manner (EC50 at 3 microm and 100 nm, respectively). Angiotensin receptor subtypes were identified using specific antagonists, losartan and PD123177, for AT1 and AT2 receptors, respectively. It was found that losartan (1 microm) could completely inhibit the AII-induced ISC, whereas, PD123177 exerted insignificant effect on the ISC, indicating predominant involvement of AT1 receptors. The presence of AT1 receptors in CFPAC-1 cells was also demonstrated by immunohistochemical studies using specific antibodies against AT1 receptors. Confocal microscopic study demonstrated a rise in intracellular Ca2+ upon stimulation by AII indicating a role of intracellular Ca2+ in mediating the AII response. Depletion of intracellular but not extracellular pool of Ca2+ diminished the AII-induced ISC. Treatment of the monolayers with a Cl- channel blocker, DIDS, markedly reduced the ISC, indicating that a large portion of the AII-activated ISC was Cl--dependent. AII-induced ISC was also observed in monolayers whose basolateral membranes had been permeabilized by nystatin, suggesting that the ISC was mediated by apical Cl- channels. Our study indicates an AT1-mediated Ca2+-dependent regulatory mechanism for anion secretion in CF pancreatic duct cells which may be important for the physiology and pathophysiology of the pancreas.


Assuntos
Antiporters/metabolismo , Bicarbonatos/metabolismo , Cloretos/metabolismo , Regulador de Condutância Transmembrana em Fibrose Cística/deficiência , Fibrose Cística/metabolismo , Ductos Pancreáticos/metabolismo , Receptores de Angiotensina/fisiologia , Ácido 4,4'-Di-Isotiocianoestilbeno-2,2'-Dissulfônico/farmacologia , Angiotensina II/farmacologia , Antagonistas de Receptores de Angiotensina , Transporte Biológico Ativo/efeitos dos fármacos , Compostos de Bifenilo/farmacologia , Cálcio/fisiologia , Polaridade Celular , Células Cultivadas , Antiportadores de Cloreto-Bicarbonato , Fibrose Cística/patologia , Humanos , Imidazóis/farmacologia , Líquido Intracelular/metabolismo , Transporte de Íons/efeitos dos fármacos , Losartan , Microscopia Confocal , Nistatina/farmacologia , Ductos Pancreáticos/efeitos dos fármacos , Ductos Pancreáticos/patologia , Piridinas/farmacologia , Receptor Tipo 1 de Angiotensina , Receptor Tipo 2 de Angiotensina , Receptores de Angiotensina/agonistas , Taxa Secretória/efeitos dos fármacos , Tetrazóis/farmacologia
19.
Biol Pharm Bull ; 18(10): 1430-4, 1995 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-8593450

RESUMO

beta 1 and beta 2 adrenoceptor ligand activity has been shown to be down-regulated in failing myocardium. It is the aim of this study to test the hypothesis that also mRNA levels are down-regulated in dilated cardiomyopathy. beta 1 and beta 2 adrenoceptor ligand activities and mRNA expressions were analyzed in left ventricular biopsies from six organ donor hearts, in papillary muscles from seven patients operated on for mitral regurgitation, and in six explanted hearts as the result of dilated cardiomyophathy. mRNA levels were determined by solution hybridization. beta 1 ligand activity was decreased in the cases of mitral regurgitation (p < 0.01) and dilated cardiomyopathy (p < 0.001). beta 2 ligand activity did not differ between the three groups. mRNA expression was depressed in mitral regurgitation regarding both beta 1 (p < 0.001) and beta 2 (p < 0.01), while no differences were observed in dilated cardiomyopathy as compared to the donor hearts. The regulation of beta 1 and beta 2 adrenoceptor ligand activity and mRNA expression appears to follow a specific pattern in dilated cardiomyopathy. The specific down-regulation of beta 1 ligand activity seems to occur at a posttranslational level.


Assuntos
Cardiomiopatia Dilatada/metabolismo , Miocárdio/metabolismo , Receptores Adrenérgicos beta 1/metabolismo , Receptores Adrenérgicos beta 2/metabolismo , Tecido Adiposo/metabolismo , Adolescente , Antagonistas Adrenérgicos beta/farmacologia , Adulto , Idoso , Sequência de Bases , Regulação para Baixo/fisiologia , Humanos , Hibridização In Situ , Técnicas In Vitro , Ligantes , Fígado/metabolismo , Pessoa de Meia-Idade , Prolapso da Valva Mitral/metabolismo , Dados de Sequência Molecular , Músculos Papilares/metabolismo , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , Receptores Adrenérgicos beta 1/biossíntese , Receptores Adrenérgicos beta 2/biossíntese
20.
Zhonghua Yu Fang Yi Xue Za Zhi ; 28(6): 330-2, 1994 Nov.
Artigo em Chinês | MEDLINE | ID: mdl-7867448

RESUMO

Intelligence in children without iodine supplement during their fetal and infant periods, and in those born three to four years after the implementation of stable supply of iodized salt in the areas with endemic cretinism and goiter was tested with Standord-Binet method. Results indicated there existed a lot of mental retarded children in the iodine-deficiency areas, with most of them born before the implementation of iodine supplement. In order to study the changes of intelligence development in children probably induced by stable supply with iodine, the tested children living in the areas with endemic cretinism were followed-up for two years, and no improvement in children's intelligence could been seen. It suggested that impairment to children's intelligence development caused by iodine deficiency during their fetal and infant periods was irreversible.


Assuntos
Hipotireoidismo Congênito/epidemiologia , Deficiência Intelectual/etiologia , Iodo/deficiência , Criança , China/epidemiologia , Feminino , Bócio Endêmico/epidemiologia , Humanos , Lactente , Iodo/uso terapêutico , Masculino , Gravidez , Complicações na Gravidez , Prevalência , Teste de Stanford-Binet
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...