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1.
Acta Endocrinol (Buchar) ; 19(2): 178-186, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37908890

RESUMO

Background: Valepotriate is an active ingredient of valerian (Valeriana officinalis) with strong antioxidant activity that is effective for numerous cardiovascular diseases. Objective: The aim of this study was to investigate the effect of an active ingredient of V. officinalis extract on ischemia-reperfusion-induced cardiac injuries in male rats. Methods: Thirty-two male rats were subjected to ischemia for 40 minutes and reperfusion for five days. The rats were divided into 4 groups of 8 each; group 1 (control) was given normal saline, and groups 2-4 were gavaged with 0.2, 0.1, 0.05 mg/kg of valepotriate extract, respectively, and received extract (0.2 mg/kg ip) two weeks before ischemia induction. Results: Dichloromethane V. officinalis (valepotriate) extract exerted a protective effect against ischemia-reperfusion-induced injuries. So that infarct size and number of ventricular arrhythmia and ventricular escape beats decreased compared to the control group. Moreover, ST segment amplitude, QTC interval, and heart rate decreased in the injured hearts and serum levels of antioxidant enzymes glutathione peroxidase, catalase, and superoxide dismutase increased. Biochemical markers malondialdehyde and lactate dehydrogenase also decreased on day 5 after the onset of reperfusion. Conclusion: V. officinalis extract may have a protective effect against myocardial ischemia-reperfusion by producing antioxidant effects.

2.
J Biomech ; 112: 110043, 2020 11 09.
Artigo em Inglês | MEDLINE | ID: mdl-32950760

RESUMO

Evaluation of workers' body posture in workstations is a prerequisite to estimate spinal loads and assess risk of injury for the subsequent design of preventive interventions. The Microsoft Kinect™ sensor is, in this regard, advantageous over the traditional skin-marker-based optical motion capture systems for being marker-less, portable, cost-effective, and easy-to-use in real workplaces. While several studies have demonstrated the validity/reliability of the Kinect for posture measurements especially during gait trials, its capability to adequately drive a detailed spine musculoskeletal model for injury risk assessments remains to be investigated. Lumbosacral (L5-S1) load predictions of a Kinect-driven and a gold-standard marker-based Vicon-driven musculoskeletal model were compared for various standing static load-handling activities at different heights/asymmetry angles/distances. Full body kinematics of eight individuals each performing eighteen activities were simultaneously recorded by a single-front-placed Kinect and a 10-camera Vicon motion capture system and input to AnyBody Modeling System. The predicted spinal loads by the two models were in average different by 17.8 and 25.9% for the L5-S1 disc compressive and shear forces, respectively, with smaller errors for the activities at higher load heights. Some activities performed near the floor could, however, not be recorded by a single-front-placed Kinect sensor due to the joint occlusion. The capability of the Kinect to adequately drive a spine musculoskeletal model depended on the complexity of the activity. While a single front-placed Kinect camera can be used to evaluate spinal loads in a wide range of static/quasi-static activities, cautious should be exercised when evaluating tasks performed near the floor.


Assuntos
Vértebras Lombares , Postura , Fenômenos Biomecânicos , Marcha , Humanos , Reprodutibilidade dos Testes , Suporte de Carga
3.
J Biomed Phys Eng ; 7(1): 59-68, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28462208

RESUMO

BACKGROUND: Since psychological tests such as questionnaire or drawing tests are almost qualitative, their results carry a degree of uncertainty and sometimes subjectivity. The deficiency of all drawing tests is that the assessment is carried out after drawing the objects and lots of information such as pen angle, speed, curvature and pressure are missed through the test. In other words, the psychologists cannot assess their patients while running the tests. One of the famous drawing tests to measure the degree of Obsession Compulsion Disorder (OCD) is the Bender Gestalt, though its reliability is not promising. OBJECTIVE: The main objective of this study is to make the Bender Gestalt test quantitative; therefore, an optical pen along with a digital tablet is utilized to preserve the key drawing features of OCD patients during the test. MATERIALS AND METHODS: Among a large population of patients who referred to a special clinic of OCD, 50 under therapy subjects voluntarily took part in this study. In contrast, 50 subjects with no sign of OCD performed the test as a control group. This test contains 9 shapes and the participants were not constraint to draw the shapes in a certain interval of time; consequently, to classify the stream of feature vectors (samples through drawing) Hidden Markov Model (HMM) is employed and its flexibility increased by incorporating the fuzzy technique into its learning scheme. RESULTS: Applying fuzzy HMM classifier to the data stream of subjects could classify two groups up to 95.2% accuracy, whereas the results by applying the standard HMM resulted in 94.5%. In addition, multi-layer perceptron (MLP), as a strong static classifier, is applied to the features and resulted in 86.6% accuracy. CONCLUSION: Applying the pair of T-test to the results implies a significant supremacy of the fuzzy HMM to the standard HMM and MLP classifiers.

4.
J Mycol Med ; 22(2): 149-59, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23518017

RESUMO

OBJECTIVE: To compare the specific intracellular proteinase A activity in clinical isolates of Candida species isolated from Iranian and Malaysian patients, the blood and kidneys of mice infected by Candida cells isolated from these human patients. PATIENTS AND METHODS: The intracellular proteinase A was extracted using glass beads and ultracentrifugation from yeasts cells and purified by ion-exchange chromatography (DEAE-cellulose), followed by affinity chromatography (ConA-agarose). Purity of proteinase A was controlled by SDS-PAGE and its identification was realized by western blot. Enzyme activity was performed using azocasein as substrate. RESULTS: Intracellular proteinase A enzyme activity was higher in Candida albicans (C. albicans) than in non-albicans Candida isolates from Malaysian and Iranian patients, mice blood and mice kidneys (P<0.05). In clinical Candida spp. from human patients, proteinase A activity was significantly higher in Malaysian samples than in their Iranian counterparts (P<0.05). However, Candida spp. isolates obtained from blood and kidneys of mice infected by human clinical strains of Candida spp. showed no significant differences in proteinase A activity between Malaysian and Iranian samples (P>0.05). On the other hand, in both clinical and control yeast isolates obtained from Malaysian and Iranian patients, significant differences were found between systemic and non-systemic samples (P<0.05) but this difference was not observed in mice blood and kidneys. CONCLUSION: In the present study, a strong proteinase A activity was observed for C. albicans and higher expression of this enzyme in clinical isolates from Malaysian and Iranian patients with systemic candidiasis indicated higher virulent nature of this yeast species when compared with non-albicans Candida strains.


Assuntos
Ácido Aspártico Endopeptidases/isolamento & purificação , Candida/enzimologia , Candidíase/microbiologia , Proteínas Fúngicas/isolamento & purificação , Animais , Ácido Aspártico Endopeptidases/metabolismo , Western Blotting , Candida/isolamento & purificação , Candidemia/microbiologia , Candidíase/epidemiologia , Caseínas/metabolismo , Cromatografia de Afinidade , Cromatografia por Troca Iônica , Eletroforese em Gel de Poliacrilamida , Feminino , Proteínas Fúngicas/metabolismo , Humanos , Irã (Geográfico)/epidemiologia , Rim/microbiologia , Malásia/epidemiologia , Camundongos , Camundongos Endogâmicos BALB C , Distribuição Aleatória , Especificidade da Espécie , Organismos Livres de Patógenos Específicos , Ultracentrifugação
5.
J Mycol Med ; 22(4): 329-34, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23518167

RESUMO

OBJECTIVE: This study was aimed at evaluating the immunostimulatory effect of Spirulina platensis in prophylaxis of Balb/C mice with systemic candidiasis. MATERIALS AND METHODS: In first experiment, 40 mice were divided into four groups, ten mice per each group, for cytokines assay. Animals received a dose of 800mg/kg of S. platensis for 4days and then were intravenously inoculated with 1×10(6) Candida albicans. Control groups received 0.2mL and 0.1mL normal saline for prophylaxis and inoculation, respectively. Five mice from each group were euthanized after 24hours and 72hours and the serum levels of IFN-γ and TNF-α were measured by Enzyme-linked immunosorbent assay (ELISA) method. In second experiment, two mice groups with systemic candidiasis, 11 mice per each group, were included to evaluate the survival rate. Animals were monitored for 30days and the kidneys, liver, lungs and spleen were analyzed for fungal invasion. RESULTS: The results indicated that the Spirulina-treated mice produced more IFN-g and TNF-α level than their control groups. This infected group showed that the mean survival time (28.86±2.7) was significantly (P<0.05) higher than control group (13.9±3.34). They also exhibited that fungal clearance in selected organs at death time represents significant differences between spleen and liver (P<0.05). CONCLUSION: Prophylaxis with S. platensis had synergistic effect through producing cytokines such as TNF-α and IFN-γ. Our results provide important information for the potential application of S. platensis in the treatment and resistance of Balb/C mice with systemic candidiasis.


Assuntos
Adjuvantes Imunológicos/uso terapêutico , Candidemia/prevenção & controle , Suplementos Nutricionais , Spirulina , Animais , Candida albicans/isolamento & purificação , Candidemia/sangue , Candidemia/tratamento farmacológico , Avaliação Pré-Clínica de Medicamentos , Interferon gama/sangue , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Fator de Necrose Tumoral alfa/sangue , Vísceras/microbiologia
6.
Rev Sci Tech ; 30(3): 955-60, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22435206

RESUMO

Patterns of serum biochemical parameters vary among horse breeds. The objective of the present study was to compare serum lipoproteins of Iranian Caspian ponies with those of other horses (Arabs and Thoroughbreds) in the Iranian region. Serum lipoprotein values were determined by agar-agarose gel electrophoresis and measured by scan densitometry. Moreover, serum triglyceride and cholesterol concentrations were determined and the results were analysed by one-way analysis of variance. Serum triglyceride and cholesterol values were 1.13 +/- 0.23 and 2.38 +/- 0.18 mmol/l in Caspian ponies, 1.96 +/- 0.49 and 1.92 +/- 0.25 mmol/l in Arab horses and 1.38 +/- 0.26 and 2.17 +/- 0.53 mmol/l in Thoroughbred horses. The relative percentages of alpha- (72.63 +/- 17.76%) and beta-lipoproteins (29.10 +/- 5.49%) in serum electrophoretic tracings from Caspian ponies were not significantly different from those of other horses (p > 0.05). The lipoprotein phenotype in Caspian ponies may be useful for evaluating metabolic diseases.


Assuntos
Cavalos/sangue , Lipídeos/sangue , Lipoproteínas/sangue , Animais , Cruzamento , Colesterol/sangue , Eletroforese em Gel de Ágar/veterinária , Feminino , Cavalos/classificação , Irã (Geográfico) , Masculino , Triglicerídeos/sangue
7.
Fish Physiol Biochem ; 32(1): 43-7, 2006 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-20035477

RESUMO

Serum biochemical parameters are important aspects in the management of endangered species, such as Acipenser persicus. The values of these parameters can be used for confirming the maturity and for monitoring any changes in the quality of waters and related soils. Serum samples of 44 A. persicus fishes were analyzed and their serum parameter values were determined as Mean+/-SD in four groups: mature males and females and immature males and females, respectively. We compared the levels of calcium (Ca; 1.97 +/- 0.31-2.38 +/- 0.28 mmol/l), blood urea nitrogen (BUN; 4.4 +/- 0.54-6.16 +/- 0.63 mmol/l), cholesterol (CHO; 2.55 +/- 0.42-13.51 +/- 0.65 mmol/l), creatinine (CREA; 27.23 +/- 3.5-83.98 +/- 7.5 mmol/l), magnesium (Mg; 2.74 +/- 0.18-3.05 +/- 0.46 mmol/l), bilirubin (Bilirubin; 2.05 +/- 0.42-13.93 +/- 4.39 mumol/l), aspatate transaminase (AST; 18.25 +/- 1.5-167 +/- 38 Iu/l), alanine transaminase (ALT; 11 +/- 1-25.33 +/- 9.24 Iu/l), alkaline phosphatase (ALP; 183.5 +/- 17.68-523 +/- 66.23 Iu/l) and creatine kinase (CK; 157.5 +/- 27.58-2132.2 +/- 250.92 Iu/l). We have shown that there were no differences in the Ca and Mg levels among the different groups. However, mature females have higher CREA, AST, CHO and lower BUN, ALP and ALT than the immature females. In the mature males, the values of ALP and bilirubin were higher yet the values of CREA and ALT were lower than in the immature males.

8.
Int Urol Nephrol ; 33(3): 417-22, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-12230264

RESUMO

OBJECTIVES: Parathyroid hormone related protein (PTHrP) has been identified as the major hormone responsible for the syndrome of humoral hypercalcemia of malignancy (HHM). Recent studies have shown that a large number of prostate tumors demonstrate the presence of PTHrP despite the fact that prostate cancer is rarely associated with the HHM syndrome. Other studies have indicated that PTHrP behaves as an early response gene, which stimulates ornithine decarboxylase (ODC) enzyme activity, an enzyme, involved in the biosynthesis of polyamines. It is therefore possible that PTHrP regulates prostate tumor cell proliferation via ODC gene expression. METHODS: In the present study, we evaluated the effects of PTHrP and/or dihydrotestosterone (DHT) treatment on DNA synthesis by thymidine incorporation in androgen-dependent (LnCaP) and androgen-independent (PC3) human prostate adenocarcinoma cell lines. In addition, we utilized Northern blot analysis to investigate the effect of PTHrP [1-34] alone or in combination with DHT on ODC mRNA. RESULTS: PTHrP [1-34] treatment resulted in an increase in thymidine uptake in PC3 cells by 50%, whereas no such increase was seen in LnCaP cells. However, in the LnCaP cells, in the presence of DHT, PTHrP stimulated DNA synthesis to a level greater than that seen with DHT alone. DHT (10 nM) treatment resulted in an induction of PTHrP as well as ODC mRNAs in the androgen-dependent (LnCaP) but not in androgen-independent (PC3) cell line. PTHrP [1-34] treatment resulted in induction of ODC mRNA in the LnCaP cells. Addition of DHT resulted in a further increase in the ODC mRNA expression. CONCLUSIONS: These data suggest that PTHrP may play a role in prostate cancer cell proliferation and the increased ODC gene expression may be one possible mechanisms responsible for this phenomenon.


Assuntos
Adenocarcinoma/metabolismo , DNA/efeitos dos fármacos , Di-Hidrotestosterona/farmacologia , Ornitina Descarboxilase/metabolismo , Hormônios Peptídicos/farmacologia , Neoplasias da Próstata/metabolismo , Adenocarcinoma/genética , Northern Blotting , DNA/biossíntese , Expressão Gênica , Humanos , Masculino , Proteína Relacionada ao Hormônio Paratireóideo , Neoplasias da Próstata/genética , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , Células Tumorais Cultivadas
9.
AIDS Res Hum Retroviruses ; 16(5): 435-40, 2000 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-10772529

RESUMO

Mycobacterium avium complex (MAC) can induce upregulation of HIV. To investigate the underlying mechanisms, the effect of MAC-induced cytokines on HIV replication was first studied. Semiquantitative RT-PCR, followed by Northern blot analysis, revealed that mRNA encoding IL-6 and TNF-alpha was induced by MAC. However, production of these cytokines was undetectable and the addition of anti-cytokine antibodies to coinfected cells could only minimally block the MAC effect on HIV. Infection of U38 cells with MAC resulted in enhancement of HIV-1 LTR-CAT transcription. In addition, transient transfection of U937 cells with full-length wild-type as well as NF-kappaB-binding site-deleted mutant HIV-1 LTR-CAT constructs revealed that MAC-induced HIV-LTR CAT is NF-kappaB dependent. These findings, together with our previous work, indicate that MAC-induced cytokine expression increases the formation of NF-kappaB, which in turn enhances HIV-1 LTR-CAT transcription. However, additional factor(s) yet to be elucidated may play a more significant role in MAC-mediated HIV-upregulation.


Assuntos
HIV/fisiologia , Mycobacterium avium/fisiologia , Northern Blotting , Linhagem Celular , Citocinas/imunologia , Citocinas/metabolismo , HIV/genética , Humanos , Interleucina-6/genética , Mutação , Mycobacterium avium/metabolismo , NF-kappa B/genética , NF-kappa B/metabolismo , RNA/genética , RNA Mensageiro/análise , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fatores de Tempo , Transcrição Gênica , Fator de Necrose Tumoral alfa/genética , Células U937 , Regulação para Cima , Replicação Viral
10.
Hum Pathol ; 27(12): 1319-23, 1996 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-8958305

RESUMO

Parathyroid hormone-related protein (PTHrP) has been shown to be the primary factor responsible for humoral hypercalcemia of malignancy. Recently PTHrP has been shown to be an early-response gene that may be involved in cellular proliferation or differentiation. In addition, PTHrP has been implicated in the pathogenesis of bone metastases. Bone metastases are a significant complication in patients with prostate cancer. We compared the expression of PTHrP by immunohistochemical staining using a monoclonal antibody directed against epitope between amino acids [53-64] in benign prostatic hyperplasia (BPH) with that in various stages of prostate cancer. Tissue sections were obtained on formalin-fixed paraffin-embedded blocks from BPH, well-differentiated prostate cancer, poorly differentiated prostate cancer, lymph node metastases (n = 15 each), and normal prostate (n = 2). In the normal prostate tissue there was no staining observed. In BPH, 13 of 15 tissue samples were positive for PTHrP immunoreactivity. An average of 33% of the cells stained positive with 1+ intensity. All samples from prostate cancer stained positive for PTHrP. In the samples from well-differentiated prostate cancer, an average of 87% of cells stained positive for PTHrP, whereas 100% of cells were positive in poorly differentiated and metastatic tumors. The intensity of staining was 3+ in well-differentiated tumors and 4+ in poorly differentiated tumors. Therefore, the expression of PTHrP is enhanced in prostate cancer as compared with BPH and is greater in poorly differentiated carcinoma as compared with the well-differentiated tumors. The role of PTHrP in the pathogenesis of prostate cancer deserves further study.


Assuntos
Hiperplasia Prostática/metabolismo , Neoplasias da Próstata/química , Biossíntese de Proteínas , Adulto , Anticorpos Monoclonais , Epitopos/imunologia , Humanos , Imuno-Histoquímica , Metástase Linfática , Masculino , Pessoa de Meia-Idade , Proteína Relacionada ao Hormônio Paratireóideo , Neoplasias da Próstata/imunologia , Neoplasias da Próstata/patologia , Coloração e Rotulagem
11.
Am Surg ; 62(7): 540-4; discussion 544-5, 1996 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-8651548

RESUMO

Parathyroid hormone-related protein (PTHrP) has been shown to be the primary factor responsible for humoral hypercalcemia of malignancy. In addition to its hypercalcemic action, PTHrP has been implicated as an autocrine modulator of growth and differentiation, as well as an early response gene in some tissues. Several different types of tumors have been evaluated for the presence of PTHrP immunoreactivity. In the present study, we evaluated the expression of PTHrP by immunohistochemical staining in tissue samples from normal colorectal mucosa, polyps, and colorectal carcinoma removed from the same patients (n = 10 each). We have used a commercially available monoclonal antibody directed against epitopes between amino acids [53-64] which share no homology to parathyroid hormone (PTH). In normal colon, 94.3 per cent of the tissue samples were negative for PTHrP immunoreactivity. In polyps of the colon, only 22.6 per cent of the cells showed positive immunostaining, whereas 91.5 per cent of the samples from colon cancer stained positive for PTHrP. In the case of polyps, the intensity of staining was 1-3+; however, all of the samples from adenocarcinoma stained with 4+ intensity. In the positive samples, the immunoreactivity was present throughout the cytoplasm of the glandular epithelium. Omission of primary antibody, as well as substitution of the primary antibody by a negative control monoclonal antibody or non-immune rabbit serum, resulted in a negative reaction. All analyses were performed in duplicate, and the data have been presented as mean +/- SEM. Differences in normal polyps, carcinoma of the colon, and PTHrP expression were tested for statistical significance by student's t test. Our results show the expression of PTHrP is enhanced in colon cancer tissue as compared to normal colorectal mucosa and polyps. In addition, the expression appears to be greater in polyp than in normal colon. The role of PTHrP in the pathogenesis of colon cancer deserves further study.


Assuntos
Colo/metabolismo , Neoplasias do Colo/metabolismo , Mucosa Intestinal/metabolismo , Proteínas de Neoplasias/metabolismo , Hormônio Paratireóideo/metabolismo , Proteínas/metabolismo , Adenocarcinoma/metabolismo , Anticorpos Monoclonais , Pólipos do Colo/metabolismo , Corantes , Humanos , Técnicas Imunoenzimáticas , Proteína Relacionada ao Hormônio Paratireóideo
12.
Dis Colon Rectum ; 39(4): 406-9, 1996 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-8878500

RESUMO

UNLABELLED: Carcinoma of the colon is the second most common cancer among men and women combined in the United States. PURPOSE: Ornithine decarboxylase (ODC) is the first and key regulatory enzyme in the polyamine biosynthesis pathway and is regulated by various factors. Polyamines are believed to participate in cellular proliferation and differentiation. High levels of polyamines and ODC activity are associated with rapid cell growth, particularly in tumor tissues. Regulation of this enzyme in vivo has important clinical implications. In the present study, we used Northern analysis and mobility shift assay to investigate whether ODC gene expression is regulated by androgens in the three human colonic cell lines, SW620, HT-29, and Caco-2. METHODS: Cell lines were maintained in Dulbecco's Modified Eagle's medium/F12 supplemented with 5 percent fetal bovine serum. At 60 percent confluency, medium was replaced with steroid-depleted medium, and incubation continued for 24 hours. Following this period, medium was replaced with fresh steroid-free medium containing 1 nM dihydrotestosterone. RESULTS: Dihydrotestosterone stimulated ODC messenger ribonucleic acid expression only in HT-29 colonic cell line. Studies using electrophoretic mobility shift assays of nuclear extracts also showed a binding pattern with SP1 and NF-kappaB regulatory sequences only in testosterone-treated HT-29 cells. CONCLUSION: These results suggest that androgens may play an important role in the growth of HT-29 colonic cell lines.


Assuntos
Androgênios/fisiologia , Regulação Neoplásica da Expressão Gênica , Ornitina Descarboxilase/genética , Northern Blotting , Células CACO-2/enzimologia , Neoplasias do Colo/genética , Meios de Cultura , Di-Hidrotestosterona/farmacologia , Feminino , Células HT29/enzimologia , Humanos , Masculino , RNA Mensageiro/genética
13.
Int Urol Nephrol ; 27(1): 67-80, 1995.
Artigo em Inglês | MEDLINE | ID: mdl-7615373

RESUMO

The prostate gland is dependent on androgens for the maintenance of its normal growth and functional integrity. Initially, growth of the majority of prostate tumours can be manipulated by endocrine therapy. In the present study, we evaluated the effects of sex steroids on the cell growth and expression of the C-myc oncogene in two human prostatic adenocarcinoma cell lines. We found that dihydrotestosterone increases the proliferation rate of prostatic cells, and amplification of C-myc oncogene is hormone-dependent. We also demonstrated a positive correlation between the number of cells positive for C-myc oncogene and oncoprotein in hormone-treated prostate cell lines.


Assuntos
Adenocarcinoma/genética , Di-Hidrotestosterona/farmacologia , Estradiol/farmacologia , Regulação Neoplásica da Expressão Gênica , Genes myc , Neoplasias da Próstata/genética , Proteínas Proto-Oncogênicas c-myc/genética , Southern Blotting , Divisão Celular/efeitos dos fármacos , Humanos , Hibridização In Situ , Técnicas In Vitro , Masculino , Células Tumorais Cultivadas/efeitos dos fármacos
14.
Endocrinology ; 134(3): 1179-87, 1994 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-8119157

RESUMO

In proximal tubule cells of the mouse kidney, transcription of a number of genes is induced by androgens. Although a great deal of molecular and genetic information on the induction process has accumulated, the lack of an appropriate cell culture system for DNA transfection studies has hampered efforts to identify and characterize in detail the molecular factors that mediate the response. In the present paper, we have examined a primary renal epithelial cell culture system. We show that in response to androgens, these cells undergo induction of five messenger RNAs that are induced in the intact kidney; thus, the effects of androgens on renal gene expression derive from a direct action of the hormone on proximal tubule cells. The response does not occur in cells from Tfm animals, indicating that androgen receptor is required. Differences in patterns of androgen-inducible messenger RNA expression between mouse species are reflected by similar differences in the cultured cells. Interestingly, the kinetics of induction in culture seem to be distinct from those in the intact kidney, suggesting that a factor or factors differing between the whole animal and tissue culture environments influence the response. Transient transfection experiments with the primary cells showed that the 5'-flanking region of the androgen-regulated RP2 gene, which includes nucleotides -1500 to +42 and contains a glucocorticoid response element that binds the androgen receptor, does not mediate androgen-responsive transcription; thus, this region, and the glucocorticoid response element within it, are either insufficient for, or are not involved in, the gene's response to hormone.


Assuntos
Androgênios/farmacologia , Proteínas do Olho , Regulação da Expressão Gênica/efeitos dos fármacos , Rim/metabolismo , Animais , Sequência de Bases , Células Cultivadas , Proteínas de Ligação a DNA/análise , Epitélio/metabolismo , Feminino , Proteínas de Ligação ao GTP , Peptídeos e Proteínas de Sinalização Intracelular , Proteínas de Membrana , Camundongos , Camundongos Endogâmicos C57BL , Dados de Sequência Molecular , Regiões Promotoras Genéticas , Proteínas/genética , RNA Mensageiro/análise
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