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1.
Oncogenesis ; 6(6): e350, 2017 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-28650445

RESUMO

Here, by combining lipidomics with transcriptome analysis, we demonstrate that Rb depletion in mouse embryonic fibroblastss induces significant alterations in their lipid composition. We discovered that Rb depletion induced increase in lysophosphatidylserine, diacylglycerol (DAG), fatty acid (FA), acylcarnitine, phosphatidylcholine (PC), arachidonoyl ethanolamine, and decrease in phosphatidylglycerol, monoacylglycerol, without change in total lipid per protein levels. Analysis of the acyl chain composition of DAG, PC and phosphatidylserine revealed increase of saturated and mono-unsaturated acyl chains with specific carbon chain length. Consistently, we observed that Rb depletion increased the levels of fatty acids with the corresponding carbon chain length and number of carbon-carbon double bondssuch as myristic acid (14:0), palmitic acid (16:0), stearic acid (18:0) and all forms of FA 18:1. Microarray analysis revealed that Rb depletion induced significant upregulation of enzymes involved in elongation and desaturation of fatty acids. Among these, we found that elongation of long chain fatty acid family member 6 (Elovl6) and stearoyl-CoA desaturase 1 (Scd1) are the most robustly controlled by Rb possibly through E2F and sterol regulatory element-binding protein transcription factors. Depletion of Elovl6 or Scd1 significantly suppressed colony formation, sphere formation and xenograft tumor growth of Rb-deficient tumor cells. Suppression of self-renewal by the SCD1 inhibitor was rescued upon supplementation of the mono-unsaturated fatty acids generated by this enzyme. This study suggests a novel role for Rb in suppressing the malignant progression of tumors by controlling the lipid composition.

2.
Oncogene ; 36(36): 5145-5157, 2017 09 07.
Artigo em Inglês | MEDLINE | ID: mdl-28481867

RESUMO

Retinoblastoma (RB) protein inactivation during tumor progression is often associated with acquisition of immature phenotypes and resistance to therapy. Determination of an RB inactivation signature in a context of gaining undifferentiated phenotype in a p53-null sarcoma system revealed a critical role for interleukin (IL)-6. Using a Gene Set Enrichment Analysis (GSEA), we discovered that poorly differentiated breast cancers are enriched for this RB inactivation signature. Accelerated IL-6 secretion following RB inactivation in an RB-intact luminal-type breast cancer cell line MCF-7 promoted a positive feed forward loop between IL-6 and STAT3 driving tumor growth and endocrine therapy resistance. In addition, some of RB-intact basal-like type breast cancer cell lines exhibited a similar phenotype following RB depletion. The mechanism whereby RB inactivation increases IL-6 production in MCF-7 cells appeared to involve fatty acid oxidation (FAO)-dependent mitochondrial metabolism and c-Jun NH(2)-terminal kinase (JNK). In addition, IL-6, via STAT3-mediated feedback to mitochondria, autonomously adjusts mitochondrial superoxide to levels suitable to maintain stem cell-like activity. The gene expression profile of luminal-type breast cancer patients with low RB expression revealed high enrichment of genes involved in mitochondrial respiration and downstream targets of IL-6. These findings unveiled an unexpected strategy whereby RB suppresses malignant features of cancer cells through metabolic reprogramming and cell-autonomous inflammation.


Assuntos
Neoplasias da Mama/patologia , Autorrenovação Celular/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos , Interleucina-6/metabolismo , Mitocôndrias/patologia , Proteína do Retinoblastoma/metabolismo , Tamoxifeno/farmacologia , Animais , Antineoplásicos Hormonais/farmacologia , Apoptose/efeitos dos fármacos , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/metabolismo , Diferenciação Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Ácidos Graxos/química , Ácidos Graxos/metabolismo , Feminino , Humanos , Interleucina-6/genética , Metaboloma , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Proteína do Retinoblastoma/genética , Fator de Transcrição STAT3/genética , Fator de Transcrição STAT3/metabolismo , Células Tumorais Cultivadas , Proteína Supressora de Tumor p53/fisiologia , Ensaios Antitumorais Modelo de Xenoenxerto
3.
Eur Respir J ; 38(4): 861-9, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21828032

RESUMO

Several mutations in the surfactant protein C (SP-C) gene (SFTPC) have been reported as causing familial pulmonary fibrosis (FPF). However, the genetic background and clinical features of FPF are still not fully understood. We identified one Japanese kindred, in which at least six individuals over three generations were diagnosed with pulmonary fibrosis. We examined the patients radiologically and histopathologically and sequenced their SFTPC and ABCA3 genes. We also established a cell line stably expressing the mutant gene. All the patients had similar radiological and histopathological characteristics. Their histopathological pattern was that of usual interstitial pneumonia, showing numerous fibroblastic foci even in areas without abnormal radiological findings on chest high-resolution computed tomography. No child had respiratory symptoms in the kindred. Sequencing of SFTPC showed a novel heterozygous mutation, c.298G>A (G100S), in the BRICHOS domain of proSP-C, which co-segregated with the disease. However, in the ABCA3 gene, no mutation was found. In vitro expression of the mutant gene revealed that several endoplasmic reticulum stress-related proteins were strongly expressed. The mutation increases endoplasmic reticulum stress and induces apoptotic cell death compared with wild-type SP-C in alveolar type II cells, supporting the significance of this mutation in the pathogenesis of pulmonary fibrosis.


Assuntos
Povo Asiático/genética , Estresse do Retículo Endoplasmático/genética , Mutação Puntual/genética , Fibrose Pulmonar/genética , Proteína C Associada a Surfactante Pulmonar/genética , Transportadores de Cassetes de Ligação de ATP/genética , Adolescente , Substituição de Aminoácidos/genética , Apoptose/genética , Biópsia , Saúde da Família , Feminino , Células HEK293 , Humanos , Masculino , Linhagem , Fibrose Pulmonar/etnologia , Fibrose Pulmonar/patologia
4.
Clin Nephrol ; 75(2): 158-64, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21255546

RESUMO

We report the case of a 31-year-old male with enlarged kidneys and glomerulocystic kidney disease (GCKD). The patient had no family history of renal disease or other diseases. On initial presentation he complained of poor eyesight, and hypertensive retinopathy and elevated serum creatinine (5.0 mg/dl) were found at that time. Renal biopsy showed cystic dilatation of Bowman's capsule and atrophy of the glomerular tuft. Thus, an adult case of sporadic GCKD was diagnosed. Based on previous reports, kidney size in patients with adult type GCKD varies from small to large. Our patient's kidneys are the largest ever reported (right kidney was 22 cm×10 cm, left kidney was 19 cm×10 cm). A review of the literature dealing with sporadic adult GCKD suggested that it is difficult to diagnose this disease early in its course.


Assuntos
Doenças Renais Císticas/diagnóstico , Rim/patologia , Adulto , Biópsia , Cápsula Glomerular/patologia , Humanos , Rim/diagnóstico por imagem , Doenças Renais Císticas/terapia , Glomérulos Renais/patologia , Imageamento por Ressonância Magnética , Masculino , Tamanho do Órgão , Valor Preditivo dos Testes , Diálise Renal , Tomografia Computadorizada por Raios X , Ultrassonografia
5.
Endoscopy ; 41(8): 679-83, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19670135

RESUMO

BACKGROUND AND STUDY AIMS: Endoscopic submucosal dissection (ESD) permits removal of colorectal epithelial neoplasms en bloc, but a substantial risk of procedure-related perforation has been reported. We sought to unravel the clinicopathological factors associated with the clinical outcomes of ESD for colorectal epithelial neoplasms in a large series. PATIENTS AND METHODS: ESD was done in 278 patients with 292 colorectal tumors that fulfilled the inclusion criteria. The criteria for ESD were: lesion greater than 20 mm in size, lesion with fibrotic scarring, locally residual colorectal lesion, or invasive carcinoma with slight submucosal penetration. Resection was assessed as en bloc or piecemeal, complete (en bloc with tumor-free lateral and basal margins) or incomplete. Complications including perforation and bleeding were assessed, and factors related to each were analyzed using logistic regression. Patients underwent multiple follow-up endoscopic examinations (mean 4.6; median 4; range 2 - 9; total number 1010). RESULTS: En bloc resection was achieved in 90.1 % of lesions (263/292) and resection was deemed to be complete in 233 (79.8 %). Right-side colonic location and the finding of fibrosis were the significant contributors to incomplete resection. Perforation was seen in 24 cases (8.2 %), and was associated with large tumor size and the presence of fibrosis. When the contributive factors for each were combined, the risks of incomplete resection and perforation were substantially increased. CONCLUSION: The present study provides useful information for predicting risks for incomplete resection and complication in colorectal ESD.


Assuntos
Neoplasias Colorretais/cirurgia , Esofagoscopia/efeitos adversos , Mucosa/cirurgia , Neoplasias Epiteliais e Glandulares/cirurgia , Adulto , Idoso , Idoso de 80 Anos ou mais , Distribuição de Qui-Quadrado , Neoplasias Colorretais/patologia , Dissecação , Feminino , Fibrose , Hemorragia Gastrointestinal/etiologia , Humanos , Perfuração Intestinal/etiologia , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Mucosa/patologia , Invasividade Neoplásica , Neoplasias Epiteliais e Glandulares/patologia , Fatores de Risco , Estatísticas não Paramétricas , Resultado do Tratamento
7.
Scand J Rheumatol ; 38(4): 263-7, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19444719

RESUMO

OBJECTIVE: To determine the association of distinct clinical subsets with myositis-specific autoantibodies (MSAs) towards anti-155/140-kDa polypeptides [anti-155/140 antibodies (Abs)], anti-140-kDa polypeptides (anti-140 Abs), and anti-aminoacyl tRNA synthetases (ARS Abs) in Japanese patients with dermatomyositis (DM). METHODS: We compared the clinical features and short-term prognoses of 30 DM patients whose serological status included these MSAs. The MSAs were determined by immunoprecipitation. RESULTS: Anti-155/140 Abs (n = 5), anti-140 Abs (n = 8), and anti-ARS Abs (n = 7) did not overlap each other. All of the anti-155/140 Ab-positive patients (n = 5) were complicated by malignancies, as were all of the anti-140 Ab-positive patients (n = 8), who showed rapidly progressive interstitial lung disease (ILD). The survival rate at 6 months from the diagnosis of DM was significantly lower in the anti-140 Ab-positive patients than in the other patients. CONCLUSION: This is the first study to report, in a single cohort of DM patients, that distinct clinical subsets are distributed in an anti-155/140 Ab-positive group, an anti-140 Ab-positive group, or an anti-ARS Ab-positive group. Our data also confirm previous evidence that anti-155/140 Abs are involved in malignancies and that anti-140 Abs are involved in rapidly progressive ILD.


Assuntos
Aminoacil-tRNA Sintetases/imunologia , Autoanticorpos/imunologia , Dermatomiosite/diagnóstico , Dermatomiosite/imunologia , RNA de Transferência/imunologia , Adulto , Idoso , Estudos de Coortes , Estudos Transversais , Feminino , Humanos , Imunoprecipitação , Japão , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Peptídeos/imunologia , Probabilidade , Estatísticas não Paramétricas
8.
Int J Clin Pract ; 63(2): 269-74, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19196365

RESUMO

BACKGROUND: The prevalence of chronic obstructive pulmonary disease (COPD) continues to increase all over the world. Nonetheless, COPD is often misdiagnosed in general clinics because of insufficient use of spirometry. OBJECTIVES: To estimate the prevalence of COPD in general clinics in Japan, we performed spirometry to screen patients who consulted general clinics. METHODS: Patients 40 years of age and older who consulted clinics in Nagasaki Prefecture, Japan, for non-respiratory diseases and who met certain inclusion criteria had their airflow limitation measured by spirometry. We defined COPD as forced expiratory volume in the first second (FEV(1)) over forced vital capacity (FVC) (FEV(1)/FVC) of < 70% in patients without active pulmonary disease, including physician-diagnosed asthma. RESULTS: Of the 1424 patients included in the study, 193 (13.6%) showed airflow limitation. Airflow limitation was significantly related to older age, male gender and cumulative pack-years. FEV(1)/FVC in patients with hypertension and chronic hepatitis were significantly lower than in patients without these diseases when adjusted for age, gender and pack-years. CONCLUSIONS: We showed that there are potentially a number of cases with COPD that are undiagnosed by general physicians in Japan. Measuring airflow limitation by spirometry in smokers with coexisting diseases, such as hypertension and chronic hepatitis, may be very beneficial because COPD is thought to be a systemic disease. The distribution of spirometers to general clinics is definitely needed to detect undiagnosed COPD.


Assuntos
Doença Pulmonar Obstrutiva Crônica/epidemiologia , Adulto , Idoso , Assistência Ambulatorial/estatística & dados numéricos , Volume Expiratório Forçado , Humanos , Japão/epidemiologia , Masculino , Pessoa de Meia-Idade , Prevalência , Doença Pulmonar Obstrutiva Crônica/diagnóstico , Doença Pulmonar Obstrutiva Crônica/fisiopatologia , Fumar/epidemiologia , Fumar/fisiopatologia , Espirometria , Capacidade Vital
9.
Gut ; 58(3): 331-6, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19001058

RESUMO

OBJECTIVE: Endoscopic submucosal dissection (ESD) has the advantage over conventional endoscopic mucosa resection, permitting removal of early gastric cancer (EGC) en bloc, but long-term clinical outcomes remain unknown. A follow-up study on tumour recurrence and survival after ESD was conducted. METHOD: ESD was performed for patients with EGC that fulfilled the expanded criteria: mucosal cancer without ulcer findings irrespective of tumour size; mucosal cancer with ulcer findings

Assuntos
Adenocarcinoma/cirurgia , Endoscopia/métodos , Mucosa Gástrica/cirurgia , Recidiva Local de Neoplasia/cirurgia , Neoplasias Gástricas/cirurgia , Adenocarcinoma/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Dissecação , Detecção Precoce de Câncer , Estudos de Viabilidade , Feminino , Seguimentos , Mucosa Gástrica/patologia , Humanos , Metástase Linfática , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/patologia , Estadiamento de Neoplasias , Neoplasias Gástricas/patologia , Resultado do Tratamento
12.
Cancer Gene Ther ; 14(11): 918-26, 2007 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17693992

RESUMO

Direct viral infection of solid tumors can cause tumor cell death, but these techniques offer the opportunity to express exogenous factors to enhance the antitumor response. We investigated the antitumor effects of a herpes simplex virus (HSV) amplicon expressing mouse granulocyte-macrophage colony-stimulating factor (mGM-CSF) using the replication-competent HSV type 1 mutant HF10 as a helper virus. HF10-packaged mGM-CSF-expressing amplicon (mGM-CSF amplicon) was used to infect subcutaneously inoculated murine colorectal tumor cells (CT26 cells) and the antitumor effects were compared to tumors treated with only HF10. The mGM-CSF amplicon efficiently replicated in CT26 cells with similar oncolytic activity to HF10 in vitro. However, when mice subcutaneously inoculated with CT26 cells were intratumorally injected with HF10 or mGM-CSF amplicon, greater tumor regression was seen in mGM-CSF amplicon-treated animals. Furthermore, mGM-CSF amplicon treatment prolonged mouse survival. Immunohistochemical analysis revealed increased inflammatory cell infiltration in the solid tumor in the mGM-CSF amplicon-treated animals. These results suggest that expression of GM-CSF enhances the antitumor effects of HF10, and HF10-packaged GM-CSF-expressing amplicon is a promising agent for the treatment of subcutaneous tumors.


Assuntos
Neoplasias Colorretais/terapia , Terapia Genética/métodos , Vetores Genéticos , Fator Estimulador de Colônias de Granulócitos e Macrófagos/genética , Vírus Auxiliares/genética , Herpesvirus Humano 1/genética , Terapia Viral Oncolítica , Animais , Neoplasias Colorretais/patologia , Camundongos , Camundongos Endogâmicos BALB C , Replicação Viral , Ensaios Antitumorais Modelo de Xenoenxerto
15.
Clin Exp Immunol ; 147(3): 540-6, 2007 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17302905

RESUMO

Summary The macrolide antibiotics are now well known to have anti-inflammatory effects. Because dendritic cells (DCs) orchestrate immune responses, we examined the in vitro effects of clarithromycin (CAM), azithromycin (AZM) and midecamycin (MDM) on the expression of co-stimulatory molecules and production of cytokines [interleukin (IL)-10, IL-6, interferon (IFN)-gamma, IL-12p40, tumour necrosis factor (TNF)-alpha] of murine bone marrow-derived DCs by lipopolysaccharide (LPS) stimulation. A 15-membered macrolide, AZM, and a 14-membered macrolide, CAM, significantly enhanced the intensity of a co-stimulatory molecule, CD80, on DCs but not CD86 and CD40. AZM significantly increased the production of IL-10 and CAM significantly inhibited the production of IL-6 by DCs. However, a 16-membered macrolide, MDM, did not have any significant effect on these surface markers and cytokine productions. Moreover, AZM increased IL-10 and CAM decreased IL-2 productions significantly, when naive T cells derived from spleen were co-cultured with DCs treated in advance with LPS and these macrolides. These findings suggest that 14-membered and 15-membered, but not 16-membered macrolides play as anti-inflammatory agents, at least in part, through modulating the functions of DCs. However, each macrolide affects them in different ways.


Assuntos
Antibacterianos/farmacologia , Azitromicina/farmacologia , Claritromicina/farmacologia , Citocinas/biossíntese , Células Dendríticas/efeitos dos fármacos , Animais , Antígenos CD/metabolismo , Células da Medula Óssea/imunologia , Células Cultivadas , Técnicas de Cocultura , Células Dendríticas/imunologia , Feminino , Lipopolissacarídeos/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Linfócitos T/imunologia
16.
Eur Respir J ; 29(5): 965-8, 2007 May.
Artigo em Inglês | MEDLINE | ID: mdl-17301098

RESUMO

Pseudomonas aeruginosa is one of the most important pathogens in patients with chronic airway conditions, such as cystic fibrosis and diffuse panbronchiolitis. Type III secretion system-mediated virulence factors contribute to the lung damage in chronic P. aeruginosa infection. The effects of the anti-PcrV immunoglobulin (Ig)G, which blocks the type III secretion system, were evaluated in a mouse model of chronic P. aeruginosa infection. On bacteriological examination, anti-PcrV IgG showed no bactericidal effects. On bronchoalveolar lavage fluid (BALF) analysis, total cell number and neutrophil ratios in the anti-PcrV IgG-treated groups were lower than those in the control group. In addition, macrophage inflammatory protein-2, tumour necrosis factor-alpha, and interleukin-beta concentrations in BALF were lower in the anti-PcrV IgG-treated groups when compared with controls. Plasma anti-PcrV IgG titre was elevated after administration of anti-PcrV IgG. Although plasma titre decreased gradually, a significant concentration was maintained during the experimental period. These data suggest that anti-PcrV immunoglobulin G reduces the inflammatory reaction caused by chronic Pseudomonas aeruginosa respiratory infection and may be useful in treating respiratory diseases.


Assuntos
Anticorpos Antibacterianos/uso terapêutico , Antígenos de Bactérias/imunologia , Toxinas Bacterianas/imunologia , Fragmentos Fab das Imunoglobulinas/uso terapêutico , Infecções por Pseudomonas/terapia , Pseudomonas aeruginosa/patogenicidade , Infecções Respiratórias/terapia , Animais , Anticorpos Antibacterianos/metabolismo , Líquido da Lavagem Broncoalveolar/química , Modelos Animais de Doenças , Ensaio de Imunoadsorção Enzimática , Fragmentos Fab das Imunoglobulinas/metabolismo , Imunoglobulina G/metabolismo , Imunoglobulina G/uso terapêutico , Masculino , Camundongos , Proteínas Citotóxicas Formadoras de Poros , Infecções por Pseudomonas/imunologia , Infecções por Pseudomonas/microbiologia , Pseudomonas aeruginosa/imunologia , Infecções Respiratórias/imunologia , Infecções Respiratórias/microbiologia
17.
Aquat Toxicol ; 81(3): 245-55, 2007 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-17240461

RESUMO

Previous studies of Eastern mosquitofish in contaminated Lake Apopka, Florida, have documented reduced sperm count and sexual behaviour in males but increased fecundity and liver weight in females, compared to nearby reference lakes. Liver weight can be an indicator of vitellogenin (Vtg) synthesis in fish, such as the mosquitofish. It was therefore hypothesized that estrogenic organochlorine pesticides, present at elevated concentrations in animals from Lake Apopka, could cause the reproductive disorders in males, as well as increase female fecundity. We initiated a test of this hypothesis by examining the relationship between 17beta-estradiol (E2) tissue concentrations, hepatic estrogen receptor alpha (ERalpha) and Vtg A, B and C gene expression and fecundity in sexually mature female Eastern mosquitofish from Lake Apopka and two reference lakes, Lake Woodruff and Lake Orange. We observed that female Eastern mosquitofish from one site in contaminated Lake Apopka produced fewer but bigger embryos than females from the other Lake Apopka site and two reference sites. However, female E2 concentrations and hepatic ERalpha and Vtg A, B and C gene expression showed no overall differences among the four sites, and it is therefore unlikely that the differences in fecundity were caused by estrogenic EDCs. In addition, we observed no induction of any of the three Vtg genes in male Eastern mosquitofish at the two Lake Apopka sites. Based on the well-documented high sensitivity of Vtg induction as a biomarker of xenoestrogen exposure, the evidence from the present study does not support the hypothesis that estrogenic EDCs are affecting reproduction in Eastern mosquitofish living in Lake Apopka. Our experimental design tested specifically for effects mediated via the ER, and e.g. antiandrogenic DDT metabolites might still be of importance for mosquitofish reproduction in Lake Apopka.


Assuntos
Ciprinodontiformes/fisiologia , Exposição Ambiental , Estradiol/análise , Fertilidade/efeitos dos fármacos , Expressão Gênica/efeitos dos fármacos , Praguicidas/toxicidade , Animais , Tamanho Corporal/efeitos dos fármacos , Primers do DNA/química , Embrião não Mamífero/efeitos dos fármacos , Feminino , Florida , Água Doce , Fígado/efeitos dos fármacos , Masculino , Receptores de Estrogênio/análise , Receptores de Estrogênio/biossíntese , Receptores de Estrogênio/genética , Vitelogeninas/análise , Vitelogeninas/biossíntese , Vitelogeninas/genética , Poluentes Químicos da Água/toxicidade
18.
J Dent Res ; 86(1): 52-7, 2007 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-17189463

RESUMO

Epidemiological studies have shown that post-menopausal women who do not use an estrogen supplement have fewer teeth than those who do. We hypothesized that changes in the dentition of post-menopausal women might be due to alveolar bone alterations by estrogen deficiency. To clarify this, we analyzed the microstructural alveolar bone changes in ovariectomized monkeys and compared these with their lumbar bone mineral density. The % of baseline bone mineral density showed a significant decrease in the ovariectomized group as compared with the controls. The second-molar interradicular septa in ovariectomized monkeys showed a significantly decreased nodes number, cortices number, and an increased structural model index value. More pores were seen in the ovariectomized group at the top of the septa. This study demonstrated that, in such monkeys, estrogen deficiency led to fragility of the trabecular structure of the molar alveolar bone, and such fragility was inversely correlated with lumbar bone mineral density.


Assuntos
Processo Alveolar/ultraestrutura , Vértebras Lombares/ultraestrutura , Osteoporose/patologia , Absorciometria de Fóton , Perda do Osso Alveolar/diagnóstico por imagem , Perda do Osso Alveolar/patologia , Processo Alveolar/diagnóstico por imagem , Animais , Densidade Óssea/fisiologia , Modelos Animais de Doenças , Estradiol/sangue , Feminino , Processamento de Imagem Assistida por Computador , Vértebras Lombares/diagnóstico por imagem , Macaca fascicularis , Osteoporose/diagnóstico por imagem , Ovariectomia , Distribuição Aleatória , Fatores de Tempo , Tomografia Computadorizada por Raios X , Alvéolo Dental/diagnóstico por imagem , Alvéolo Dental/ultraestrutura
19.
Aquat Toxicol ; 78(3): 272-83, 2006 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-16713641

RESUMO

In this study we describe an alligator hepatic CYP3A gene, CYP3A77, which is inducible by dexamethasone and toxaphene. CYP3A plays a broad role in biotransforming both exogenous compounds and endogenous hormones such as testosterone and estradiol. Alligators collected from sites in Florida that are contaminated with organochlorine compounds exhibit differences in sex steroid concentrations. Many organochlorine compounds induce CYP3A expression in other vertebrates; hence, CYP3A induction by organochlorine contaminants could increase biotransformation and clearance of sex steroids by CYP3A and provide a plausible mechanism for the lowering of endogenous sex steroid concentrations in alligator plasma. We used real time PCR to examine whether known and suspected CYP3A inducers (dexamethasone, metyrapone, rifampicin, and toxaphene) up-regulate steady state levels of hepatic CYP3A77 transcript to determine if induction patterns in female juvenile alligators are similar to those reported in other vertebrates and whether toxaphene, an organochlorine compound found in high concentrations in Lake Apopka alligators, induces this gene. Estrogen receptor alpha (ERalpha), estrogen receptor beta (ERbeta), androgen receptor (AR), glucocorticoid receptor (GR), progesterone receptor (PR), and steroid-xenobiotic receptor (SXR) transcripts were also measured to determine whether any of these nuclear receptors are also regulated by these compounds in alligators. Dexamethasone (4.2-fold) and toxaphene (3.5-fold) significantly induced CYP3A77 gene transcript, whereas rifampicin (2.8-fold) and metyrapone (2.1-fold) up-regulated ERbeta after 24h. None of the compounds significantly up-regulated AR, ERalpha, GR, PR, or SXR over this time period. Plasma testosterone (T) did not change significantly after 24h in alligators from any of the treatment groups. Dexamethasone treated animals exhibited a strong relationship between the 24h plasma T concentrations and CYP3A77 (R(2)=0.9, positive) and SXR (R(2)=0.77, negative) transcripts, which suggests that the expression of these genes is related to plasma T in alligators. In light of our findings, we hypothesized that higher steady state CYP3A77 (and possibly SXR) gene expression would be observed in alligators collected from Lake Apopka, a polluted lake containing organochlorine compounds known to induce CYP3A isoforms in other taxa. Therefore, we measured basal levels of CYP3A77 and SXR gene transcripts in wild juvenile alligators collected from Orange Lake (reference lake), Lake Woodruff (reference lake), and Lake Apopka (contaminated lake). We found that no differences existed in CYP3A77 or SXR gene expression among animals from the lakes sampled suggesting that exposure to organochlorine compounds at concentrations present in Lake Apopka does not lead to variation in the expression of these genes, although capture stress could be interfering with these results since the glucocorticoid dexamethasone induces CYP3A77 transcript in alligators.


Assuntos
Jacarés e Crocodilos/genética , Citocromo P-450 CYP3A/genética , Dexametasona/toxicidade , Testosterona/sangue , Toxafeno/toxicidade , Poluentes Químicos da Água/toxicidade , Jacarés e Crocodilos/sangue , Sequência de Aminoácidos , Animais , Citocromo P-450 CYP3A/química , Citocromo P-450 CYP3A/efeitos dos fármacos , Feminino , Expressão Gênica/efeitos dos fármacos , Glucocorticoides/toxicidade , Inseticidas/toxicidade , Masculino , Metirapona/toxicidade , Dados de Sequência Molecular , Receptor de Pregnano X , Receptores Citoplasmáticos e Nucleares/efeitos dos fármacos , Receptores Citoplasmáticos e Nucleares/genética , Receptores de Esteroides/biossíntese , Receptores de Esteroides/efeitos dos fármacos , Reação em Cadeia da Polimerase Via Transcriptase Reversa/veterinária , Rifampina/toxicidade , Regulação para Cima/efeitos dos fármacos
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