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1.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 31(6): 1706-1713, 2023 Dec.
Artigo em Chinês | MEDLINE | ID: mdl-38071049

RESUMO

OBJECTIVE: To investigate the effect of Baicalin on the proliferation and pyroptosis of diffuse large B-cell lymphoma cell line DB and its mechanism. METHODS: DB cells were treated with baicalin at different concentrations (0, 5, 10, 20, 40 µmol/L). Cell proliferation was detected by CCK-8 assay and half maximal inhibitory concentration (IC50) was calculated. The morphology of pyroptosis was observed under an inverted microscope, the integrity of the cell membrane was verified by LDH content release assay, and the expressions of pyroptosis-related mRNA and protein (NLRP3, GSDMD, GSDME, N-GSDMD, N-GSDME) were detected by real-time fluorescence quantitative PCR and Western blot. In order to further clarify the relationship between baicalin-induced pyroptosis and ROS production in DB cells, DB cells were divided into control group, baicalin group, NAC group and NAC combined with baicalin group. DB cells in the NAC group were pretreated with ROS inhibitor N-acetylcysteine (NAC) 2 mmol/L for 2 h. Baicalin was added to the combined treatment group after pretreatment, and the content of reactive oxygen species (ROS) in the cells was detected by DCFH-DA method after 48 hours of culture. RESULTS: Baicalin inhibited the proliferation of DB cells in a dose-dependent manner (r=-0.99), and the IC50 was 20.56 µmol/L at 48 h. The morphological changes of pyroptosis in DB cells were observed under inverted microscope. Compared with the control group, the release of LDH in the baicalin group was significantly increased (P<0.01), indicating the loss of cell membrane integrity. Baicalin dose-dependently increased the expression levels of NLRP3, N-GSDMD, and N-GSDME mRNA and protein in the pyroptosis pathway (P<0.05). Compared with the control group, the level of ROS in the baicalin group was significantly increased (P<0.05), and the content of ROS in the NAC group was significantly decreased (P<0.05). Compared with the NAC group, the content of ROS in the NAC + baicalin group was increased. Baicalin significantly attenuated the inhibitory effect of NAC on ROS production (P<0.05). Similarly, Western blot results showed that compared with the control group, the expression levels of pyroptosis-related proteins was increased in the baicalin group (P<0.05). NAC inhibited the expression of NLRP3 and reduced the cleavage of N-GSDMD and N-GSDME (P<0.05). Compared with the NAC group, the NAC + baicalin group had significantly increased expression of pyroptosis-related proteins. These results indicate that baicalin can effectively induce pyroptosis in DB cells and reverse the inhibitory effect of NAC on ROS production. CONCLUSION: Baicalin can inhibit the proliferation of DLBCL cell line DB, and its mechanism may be through regulating ROS production to affect the pyroptosis pathway.


Assuntos
Linfoma Difuso de Grandes Células B , Proteína 3 que Contém Domínio de Pirina da Família NLR , Humanos , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Espécies Reativas de Oxigênio/farmacologia , Piroptose , Linhagem Celular , RNA Mensageiro
2.
Ear Nose Throat J ; : 1455613231185074, 2023 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-37515527

RESUMO

BACKGROUND: Otorhinolaryngology diseases are well suited for artificial intelligence (AI)-based interpretation. The use of AI, particularly AI based on deep learning (DL), in the treatment of human diseases is becoming more and more popular. However, there are few bibliometric analyses that have systematically studied this field. OBJECTIVE: The objective of this study was to visualize the research hot spots and trends of AI and DL in ENT diseases through bibliometric analysis to help researchers understand the future development of basic and clinical research. METHODS: In all, 232 articles and reviews were retrieved from The Web of Science Core Collection. Using CiteSpace and VOSviewer software, countries, institutions, authors, references, and keywords in the field were visualized and examined. RESULTS: The majority of these papers came from 44 nations and 498 institutions, with China and the United States leading the way. Common diseases used by AI in ENT include otosclerosis, otitis media, nasal polyps, sinusitis, and so on. In the early years, research focused on the analysis of hearing and articulation disorders, and in recent years mainly on the diagnosis, localization, and grading of diseases. CONCLUSIONS: The analysis shows the periodical hot spots and development direction of AI and DL application in ENT diseases from the time dimension. The diagnosis and prognosis of otolaryngology diseases and the analysis of otolaryngology endoscopic images have been the focus of current research and the development trend of future.

3.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 31(3): 730-738, 2023 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-37356933

RESUMO

OBJECTIVE: To investigate the effect of baicalin on the growth of extranodal NK/T cell lymphoma (ENKTCL) cells and its related mechanism. METHODS: Normal NK cells and human ENKTCL cells lines SNK-6 and YTS were cultured, then SNK-6 and YTS cells were treated with 5, 10, 20 µmol/L baicalin and set control. Cell proliferation and apoptosis was detected by Edu method and FCM method, respectively, and expressions of BCL-2, Bax, FOXO3 and CCL22 proteins were detected by Western blot. Interference plasmids were designed and synthesized. FOXO3 siRNA interference plasmids and CCL22 pcDNA overexpression plasmids were transfected with PEI transfection reagent. Furthermore, animal models were established for validation. RESULTS: In control group and 5, 10, 20 µmol/L baicalin group, the proliferation rate of SNK-6 cells was (56.17±2.96)%, (51.92±4.63)%, (36.42±1.58)%, and (14.60±2.81)%, respectively, while that of YTS cells was (58.85±2.98)%, (51.38±1.32)%, (34.75±1.09)%, and (15.45±1.10)%, respectively. In control group and 5, 10, 20 µmol/L baicalin group, the apoptosis rate of SNK-6 cells was (5.93±0.74)%, (11.78±0.34)%, (28.46±0.44)%, and (32.40±0.37)%, respectively, while that of YTS cells was (7.93±0.69)%, (16.29±1.35)%, (33.91±1.56)%, and (36.27±1.06)%, respectively. Compared with control group, the expression of BCL-2 protein both in SNK-6 and YTS cells decreased significantly (P<0.001), and the expression of Bax protein increased in SNK-6 cells only when the concentration of baicalin was 20 µmol/L (P<0.001), while that in YTS cells increased in all three concentrations(5, 10, 20 µmol/L) of baicalin (P<0.001). The expression of FOXO3 protein decreased while CCL22 protein increased in ENKTCL cell lines compared with human NK cells (P<0.001), but the expression of FOXO3 protein increased (P<0.01) and CCL22 protein decreased after baicalin treatment (P<0.001). Animal experiments showed that baicalin treatment could inhibit tumor growth. The expression of CCL22 protein in ENKTCL tissue of nude mice treated with baicalin decreased compared with control group (P<0.01), while the FOXO3 protein increased (P<0.05). In addition, FOXO3 silencing resulted in the decrease of FOXO3 protein expression and increase of CCL22 protein expression (P<0.01, P<0.001). CONCLUSION: Baicalin can inhibit proliferation and promote apoptosis of ENKTCL cell lines SNK-6 and YTS, up-regulate the expression of Bax protein, down-regulate the expression of BCL-2 protein, and down-regulate the expression of CCL22 protein mediated by FOXO3. Animal experiment shown that the baicalin can inhibit tumor growth. Baicalin can inhibit the growth and induce apoptosis of ENKTCL cells through FOXO3/CCL22 signaling pathway.


Assuntos
Linfoma Extranodal de Células T-NK , Animais , Camundongos , Humanos , Linfoma Extranodal de Células T-NK/patologia , Proteína Forkhead Box O3/metabolismo , Proteína X Associada a bcl-2/farmacologia , Camundongos Nus , Transdução de Sinais , Apoptose , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Quimiocina CCL22/farmacologia
4.
Front Oncol ; 13: 1104425, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37056341

RESUMO

Background: Primary central nervous system lymphoma (PCNSL) is a type of extranodal non-Hodgkin lymphoma. Although there are widely used prognostic scores, their accuracy and practicality are insufficient. Thus, a novel prognostic prediction model was developed for risk stratification of PCNSL patients in our research. Methods: We retrospectively collected 122 patients with PCNSL from two medical centers in China from January 2010 to June 2022. Among them, 72 patients were used as the development cohort to construct a new model, and 50 patients were used for the validation. Then, by using univariate and multivariate Cox regression analsis and Lasso analysis, the Xijing model was developed and composed of four variables, including lesion number, ß2-microglobulin (ß2-MG), systemic inflammation response index (SIRI) and Karnofsky performance status (KPS). Finally, we evaluated the Xijing model through internal and external validation. Results: Compared with the original prognostic scores, the Xijing model has an overall improvement in predicting the prognosis of PCNSL according to the time-dependent area under the curve (AUC), Harrell's concordance index (C-index), decision curve analysis (DCA), integrated discrimination improvement (IDI) and continuous net reclassification index (NRI). For overall survival (OS) and progression-free survival (PFS), the Xijing model can divide PCNSL patients into three groups, and shows more accurate stratification ability. In addition, the Xijing model can still stratify and predict prognosis similarly better in the elderly with PCNSL and subgroups received high-dose methotrexate (HD-MTX) or Bruton's tyrosine kinase inhibitors (BTKi). Finally, external validation confirmed the above results. Conclusions: Integrating four prognostic factors, including imaging findings, tumor burden, systemic inflammation response index, and comprehensive physical condition, we provided a novel prognostic model for PCNSL based on real-world data and evaluated its predictive capacity.

5.
Front Surg ; 9: 957674, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36386547

RESUMO

Objectives: In this study, the objectives were to investigate the clinical efficacy of orthopedic therapeutic surgery (OTS) in patients with bone metastasis of liver cancer and explore the prognostic factors. Methods: The electronic medical records of patients with bone metastasis of liver cancer in the Third Affiliated Hospital of Naval Medical University from September 2016 to August 2021 were retrospectively collected. A total of 53 patients were included. Patients were assigned to the OTS (n = 35) or the control group (n = 18) based on receiving orthopedic therapeutic surgery or conservative treatment. The pre/posttreatment Karnofsky Performance Status scale (KPS) and numeric rating scale (NRS) scores were compared. Univariate and multivariate Cox regression analyses were used to explore the prognostic factors affecting survival after bone metastasis. Logistic regression analyses were adopted to discover potential factors that contributed to greater KPS score improvement. Results: The axial bone accounted for 69.8% of all bone metastases. The proportion of multiple bone metastases was 52.8%. After surgery, the median KPS score of the OTS group increased from 60 to 80 (p < 0.001), and the median increase in the OTS group was higher than that of the control group (p = 0.033). The median NRS score of the OTS group declined from 6 to 2 after surgery (p < 0.001), and the median decline in the OTS group was higher (p = 0.001). The median survival was 10 months in the OTS group vs. 6 months in the control group (p < 0.001). Higher pretreatment KPS scores, undergoing liver primary lesion surgery, and undergoing orthopedic therapeutic surgery were protective factors of survival. Undergoing orthopedic therapeutic surgery greatly improved the KPS score. Conclusions: Orthopedic therapeutic surgery for bone metastasis of liver cancer provides benefits to the quality of life. Patients who have their primary liver lesions removed, undergo orthopedic therapeutic surgery, and have a better physical condition before treatment tend to have longer survival.

6.
Cell Death Discov ; 8(1): 434, 2022 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-36309489

RESUMO

Ferroptosis is a form of programmed cell death characterized by intracellular iron accumulation and lipid peroxidation, and earlier studies identified glutathione peroxidase 4 (GPX4) as an essential regulator of this process. Ferroptosis plays an essential role in tumors, degenerative diseases, and ischemia-reperfusion injury. However, researchers have found that inhibition of GPX4 does not entirely suppress ferroptosis in certain diseases, or cells express resistance to ferroptosis agonists that inhibit GPX4. As research progresses, it has been discovered that there are multiple regulatory pathways for ferroptosis that are independent of GPX4. The study of GPX4-independent ferroptosis pathways can better target ferroptosis to prevent and treat various diseases. Here, the currently inhibited pulmonary GPX4-dependent ferroptosis pathways will be reviewed.

7.
Sheng Wu Gong Cheng Xue Bao ; 36(2): 189-200, 2020 Feb 25.
Artigo em Chinês | MEDLINE | ID: mdl-32147992

RESUMO

Gibberellin is one of the most important plant growth regulators, and widely used in agricultural production. However, the high cost of gibberellins production is restricting its efficient application. In recent years, biotechnological innovations have improved the synthesis of gibberellin. Gibberellin biosynthesis requires various enzymes. Current research focuses on the biosynthetic mechanisms of gibberellin and the metabolic engineering techniques to improve the production of gibberellin. This paper reviews the current research on gibberellin biosynthesis pathway, the key and enzymes environmental factors involved, and the metabolic regulation of gibberellin in Gibberella fujikuroi, summarizes the application of metabolic regulation in gibberellin biosynthesis, to provide the basis for achieving stable gibberellins production.


Assuntos
Gibberella , Fusarium , Giberelinas
8.
Toxicol Lett ; 320: 103-108, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31816332

RESUMO

Acrylamide is included on the State of California's Proposition 65 list as a carcinogen. Acrylamide is found in cigarette smoke and in many types of foods, including breads, cereals, coffee, cookies, French fries, and potato chips. In 1990, California's Office of Environmental Health Hazard Assessment (OEHHA) established a no significant risk level (NSRL) of 0.2 µg/day for acrylamide. Since then, multiple cancer studies have been published. In this report, we developed an updated NSRL for acrylamide. Using benchmark dose modeling and a weight-of-evidence, non-threshold approach to identify the most sensitive species, cancer slope factors (CSFs) were derived based on combined incidences of statistically significant neoplastic lesions in the Harderian gland, lung, and stomach in male mice. We then used a toxicokinetic (TK)-based scaling approach to convert the animal CSF to a human equivalent CSF, which served as the basis for the NSRL of 1.1 µg/day at the cancer risk level of 1 in 100,000. This NSRL can be used in quantitative exposure assessments to assess compliance with Proposition 65 to ascertain either the need for or exemption from the Proposition 65 labeling requirement and drinking water discharge prohibition.


Assuntos
Acrilamida/toxicidade , Carcinógenos/toxicidade , Modelos Teóricos , Neoplasias/induzido quimicamente , Acrilamida/farmacocinética , Animais , Testes de Carcinogenicidade , Carcinógenos/farmacocinética , Relação Dose-Resposta a Droga , Feminino , Humanos , Masculino , Camundongos , Ratos Endogâmicos F344 , Medição de Risco , Toxicocinética
9.
Toxicol Sci ; 150(1): 15-26, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26660635

RESUMO

PCB126 (3,3',4,4',5-pentachlorobiphenyl) is a potent aryl hydrocarbon receptor agonist and induces oxidative stress. Because liver manganese (Mn) levels decrease in response to PCB126, a Mn dietary study was designed to investigate the role of Mn in PCB126 toxicity. Male Sprague Dawley rats received diets containing 0, 10, or 150 ppm added Mn for 3 weeks, followed by a single ip injection of corn oil or PCB126 (5 µmol/kg body weight). After 2 weeks, Mn, Cu, Zn, and Fe levels in the heart, liver, and liver mitochondria, and Mn-containing superoxide dismutase (MnSOD) and metallothionein mRNA, MnSOD protein, and MnSOD activity were determined. Mn levels in liver, heart, and liver mitochondria were strongly decreased by the Mn-deficient diet. Small effects on Fe levels and a stepwise increase in MnSOD activity with dietary Mn were also visible. PCB126 caused profound changes in Cu (up), Zn, Fe, and Mn (down) in liver, but not in heart, and differing effects (Cu, Zn, and Fe up, Mn down) in liver mitochondria. Liver MnSOD and metallothionein mRNA levels and MnSOD protein were increased but MnSOD activity was decreased by PCB126. PCB126-induced liver enlargement was dose-dependently reduced with increasing dietary Mn. These changes in metals homeostasis and MnSOD activity in liver but not heart may be a/the mechanism of PCB126 liver-specific toxicity. Specifically, transport of Fenton metals (Cu, Fe) into and Mn out of the mitochondria, a probable mechanism for lower MnSOD activity, may be a/the cause of PCB126-induced oxidative stress. The role of metallothioneins needs further evaluation. Dietary Mn slightly alleviated PCB126-induced toxicities.


Assuntos
Carbonatos/farmacologia , Poluentes Ambientais/toxicidade , Fígado/efeitos dos fármacos , Manganês/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Bifenilos Policlorados/toxicidade , Superóxido Dismutase/metabolismo , Administração Oral , Animais , Peso Corporal/efeitos dos fármacos , Carbonatos/metabolismo , Relação Dose-Resposta a Droga , Expressão Gênica/efeitos dos fármacos , Fígado/enzimologia , Fígado/patologia , Masculino , Manganês/metabolismo , Mitocôndrias Hepáticas/efeitos dos fármacos , Mitocôndrias Hepáticas/metabolismo , Mitocôndrias Hepáticas/patologia , Tamanho do Órgão/efeitos dos fármacos , Ratos Sprague-Dawley , Superóxido Dismutase/genética
10.
Curr Diabetes Rev ; 10(2): 131-45, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24809394

RESUMO

Among the most widely used animal models in obesity-induced type 2 diabetes mellitus (T2DM) research are the congenital leptin- and leptin receptor-deficient rodent models. These include the leptin-deficient ob/ob mice and the leptin receptor-deficient db/db mice, Zucker fatty rats, Zucker diabetic fatty rats, SHR/N-cp rats, and JCR:LA-cp rats. After decades of mechanistic and therapeutic research schemes with these animal models, many species differences have been uncovered, but researchers continue to overlook these differences, leading to untranslatable research. The purpose of this review is to analyze and comprehensively recapitulate the most common leptin/leptin receptor-based animal models with respect to their relevance and translatability to human T2DM. Our analysis revealed that, although these rodents develop obesity due to hyperphagia caused by abnormal leptin/leptin receptor signaling with the subsequent appearance of T2DM-like manifestations, these are in fact secondary to genetic mutations that do not reflect disease etiology in humans, for whom leptin or leptin receptor deficiency is not an important contributor to T2DM. A detailed comparison of the roles of genetic susceptibility, obesity, hyperglycemia, hyperinsulinemia, insulin resistance, and diabetic complications as well as leptin expression, signaling, and other factors that confound translation are presented here. There are substantial differences between these animal models and human T2DM that limit reliable, reproducible, and translatable insight into human T2DM. Therefore, it is imperative that researchers recognize and acknowledge the limitations of the leptin/leptin receptor- based rodent models and invest in research methods that would be directly and reliably applicable to humans in order to advance T2DM management.


Assuntos
Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Leptina/metabolismo , Obesidade/metabolismo , Receptores para Leptina/metabolismo , Animais , Glicemia/metabolismo , Complicações do Diabetes/metabolismo , Humanos , Hiperglicemia/metabolismo , Hiperinsulinismo/metabolismo , Resistência à Insulina , Camundongos , Camundongos Endogâmicos , Camundongos Obesos , Ratos , Ratos Endogâmicos , Ratos Zucker
11.
Environ Sci Pollut Res Int ; 21(10): 6384-99, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-23644946

RESUMO

Environmental pollutants polychlorinated biphenyls (PCBs), especially dioxin-like PCBs, cause oxidative stress and associated toxic effects, including cancer and possibly atherosclerosis. We previously reported that PCB 126, the most potent dioxin-like PCB congener, not only decreases antioxidants such as hepatic selenium (Se), Se-dependent glutathione peroxidase, and glutathione (GSH) but also increases levels of the antiatherosclerosis enzyme paraoxonase 1 (PON1) in liver and serum. To probe the interconnection of these three antioxidant systems, Se, GSH, and PON1, we examined the influence of varying levels of dietary Se and N-acetylcysteine (NAC), a scavenger of reactive oxygen species (ROS) and precursor for GSH synthesis, on PON1 in the absence and presence of PCB 126 exposure. Male Sprague-Dawley rats, fed diets with differing Se levels (0.02, 0.2, or 2 ppm) or NAC (1%), were treated with a single intraperitoneal injection of corn oil or various doses of PCB 126 and euthanized 2 weeks later. PCB 126 significantly increased liver PON1 mRNA, protein level and activity, and serum PON1 activity in all dietary groups but did not consistently increase thiobarbituric acid levels (thiobarbituric acid reactive substances, TBARS), an indicator of lipid oxidation and oxidative stress, in liver or serum. Inadequate (high or low) dietary Se decreased baseline and PCB 126-induced aryl hydrocarbon receptor (AhR) expression but further increased PCB 126-induced cytochrome P450 1A1 (CYP1A1) expression, the enzyme believed to be the cause for PCB 126-induced oxidative stress. In addition, a significant inverse relationship was observed not only between dietary Se levels and PON1 mRNA and PON1 activity but also with TBARS levels in the liver, suggesting significant antioxidant protection from dietary Se. NAC lowered serum baseline TBARS levels in controls and increased serum PON1 activity but lowered liver PON1 activities in animals treated with 1 µmol/kg PCB 126, suggesting antioxidant activity by NAC primarily in serum. These results also show an unexpected predominantly inverse relationship between Se or NAC and PON1 during control and PCB 126 exposure conditions. These interactions should be further explored in the development of dietary protection regimens.


Assuntos
Acetilcisteína/metabolismo , Arildialquilfosfatase/metabolismo , Poluentes Ambientais/toxicidade , Bifenilos Policlorados/toxicidade , Selênio/metabolismo , Animais , Antioxidantes/metabolismo , Citocromo P-450 CYP1A1/metabolismo , Dieta/estatística & dados numéricos , Glutationa/metabolismo , Fígado/metabolismo , Masculino , Oxirredução , Estresse Oxidativo , Ratos , Ratos Sprague-Dawley , Receptores de Hidrocarboneto Arílico/metabolismo , Substâncias Reativas com Ácido Tiobarbitúrico/metabolismo
12.
Regul Toxicol Pharmacol ; 68(1): 76-84, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24275050

RESUMO

Diethanolamine (DEA) has been listed on the State of California's Proposition 65 List. This listing is based in part on tumors reported in a National Toxicology Program (NTP) 2-year dermal carcinogenicity study in mice which found clear evidence of carcinogenic activity in B6C3F1 mice based on increased incidences of liver neoplasms in both sexes, and increased incidences of renal tubule neoplasms in males. Although considerable controversy exists on the relevance of the NTP study to humans, industries are obligated to comply with the Proposition 65 labeling requirement and drinking water discharge prohibition, unless they are able to demonstrate that DEA levels in their products are below a specific No Significant Risk Level (NSRL). The State of California has not published an NSRL for DEA. In this article, a NSRL of 5.6 µg/day and a life-stage-adjusted NSRL(adj) of 1.4 µg/day are derived from the NTP carcinogenicity study using a benchmark dose modeling method based on the incidence of hepatocellular carcinomas in female mice, in accordance with the guidelines of California EPA.


Assuntos
Carcinógenos/normas , Etanolaminas/normas , Animais , California , Carcinógenos/farmacocinética , Carcinógenos/toxicidade , Etanolaminas/farmacocinética , Etanolaminas/toxicidade , Feminino , Regulamentação Governamental , Humanos , Neoplasias Hepáticas/induzido quimicamente , Neoplasias Hepáticas/prevenção & controle , Masculino , Camundongos , Testes de Mutagenicidade , Ratos , Ratos Endogâmicos F344 , Medição de Risco/normas , Pele/metabolismo , Absorção Cutânea , Governo Estadual
13.
Xenobiotica ; 41(12): 1031-43, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21970748

RESUMO

CYP2S1 is an evolutionarily conserved, mainly extra-hepatic member of the CYP2 family and proposed to be regulated by the aryl hydrocarbon receptor (AhR). The present study explores AhR's regulation of CYP2S1 in male Sprague Dawley rats using PCB126 (3,3',4,4',5-pentachlorobiphenyl), the most potent AhR agonist among the PCBs. Additionally, CYP2S1 expression was examined after treatments with the classic CYP-inducers ß-naphthoflavone (ß-NF, AhR activator), phenobarbital (PB, CAR activator) and dexamethasone (Dex, PXR activator). CYP2S1 and CYP1A1/2, CYP1B1, CYP2B and CYP3A mRNAs were measured in liver, lung, spleen, stomach, kidney, and thymus at different time points. Constitutive CYP2S1 was expressed at comparable levels to other CYPs with the highest expression levels in stomach, kidney and lung. CYP2S1 mRNA was only non-significantly elevated by ß-NF in liver tissues. PCB126 did not increase CYP2S1 mRNA in any organ and at any time point examined despite a significant induction of CYP1 genes. PCB126 reduced CYP2S1 mRNA by 40% (not significant) from the 7th post-exposure day in thymus. PB and Dex had no effect on CYP2S1 mRNA levels. These observations show that in this model CYP2S1 is not, or only weakly, regulated by AhR and not induced by CAR or PXR activators.


Assuntos
Sistema Enzimático do Citocromo P-450/biossíntese , Sistema Enzimático do Citocromo P-450/genética , Bifenilos Policlorados/farmacologia , Receptores de Hidrocarboneto Arílico/agonistas , Animais , Peso Corporal/efeitos dos fármacos , Indução Enzimática/efeitos dos fármacos , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Fígado/efeitos dos fármacos , Fígado/enzimologia , Pulmão/efeitos dos fármacos , Pulmão/enzimologia , Masculino , Tamanho do Órgão/efeitos dos fármacos , Especificidade de Órgãos/efeitos dos fármacos , Especificidade de Órgãos/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos , Ratos Sprague-Dawley , Receptores de Hidrocarboneto Arílico/metabolismo , Especificidade da Espécie , Timo/efeitos dos fármacos , Timo/metabolismo , Fatores de Tempo
14.
Toxicol Sci ; 124(1): 202-14, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21865291

RESUMO

Homeostasis of selenium (Se), a critical antioxidant incorporated into amino acids and enzymes, is disrupted by exposure to aryl hydrocarbon receptor (AhR) agonists. Here we examined the importance of dietary Se in preventing the toxicity of the most toxic polychlorinated biphenyl congener, 3,3',4,4',5-pentachlorobiphenyl (PCB 126), a potent AhR agonist. Male Sprague-Dawley rats were fed a modified AIN-93 diet with differing dietary Se levels (0.02, 0.2, and 2 ppm). Following 3 weeks of acclimatization, rats from each dietary group were given a single ip injection of corn oil (vehicle), 0.2, 1, or 5 µmol/kg body weight PCB 126, followed 2 weeks later by euthanasia. PCB exposure caused dose-dependent increases in liver weight and at the highest PCB 126 dose decreases in whole body weight gains. Hepatic cytochrome P-450 (CYP1A1) activity was significantly increased even at the lowest dose of PCB 126, indicating potent AhR activation. PCB exposure diminished hepatic Se levels in a dose-dependent manner, and this was accompanied by diminished Se-dependent glutathione peroxidase activity. Both these effects were partially mitigated by Se supplementation. Conversely, thioredoxin (Trx) reductase activity and Trx oxidation state, although significantly diminished in the lowest dietary Se groups, were not affected by PCB exposure. In addition, PCB 126-induced changes in hepatic copper, iron, manganese, and zinc were observed. These results demonstrate that supplemental dietary Se was not able to completely prevent the toxicity caused by PCB 126 but was able to increase moderately the levels of several key antioxidants, thereby maintaining them roughly at normal levels.


Assuntos
Antioxidantes/uso terapêutico , Doença Hepática Induzida por Substâncias e Drogas/prevenção & controle , Fígado/efeitos dos fármacos , Bifenilos Policlorados/toxicidade , Compostos de Selênio/uso terapêutico , Administração Oral , Animais , Antioxidantes/administração & dosagem , Doença Hepática Induzida por Substâncias e Drogas/enzimologia , Doença Hepática Induzida por Substâncias e Drogas/etiologia , Doença Hepática Induzida por Substâncias e Drogas/patologia , Citocromo P-450 CYP1A1/metabolismo , Relação Dose-Resposta a Droga , Interações Medicamentosas , Fígado/enzimologia , Fígado/patologia , Masculino , Tamanho do Órgão/efeitos dos fármacos , Especificidade de Órgãos , Oxirredução , Ratos , Ratos Sprague-Dawley , Receptores de Hidrocarboneto Arílico/agonistas , Ácido Selênico , Compostos de Selênio/administração & dosagem , Compostos de Selênio/farmacocinética
15.
Environ Toxicol Pharmacol ; 25(2): 260-6, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18438460

RESUMO

Recent findings of high levels of predominantly lower chlorinated biphenyls in indoor and outdoor air open the question of possible health consequences. Lower chlorinated biphenyls are more readily metabolized to reactive and potentially harmful intermediates, acting as mutagens and cancer initiators. The goal of this study was to assess the mutagenicity of PCB3 in the lungs of rats. Male BigBlue® 334 Fisher transgenic rats, which carry the bacterial lacI gene as a target of mutagenicity, were given intraperitoneal injections of corn oil, 3-methylcholanthrene (3-MC, positive control), 4-monochlorobiphenyl (PCB3) or its metabolite 4-hydroxy-PCB3 (4-OH-PCB3) weekly for 4 weeks. Lungs tissue was harvested to determine mutant frequencies, mutation spectra, and pathological changes. 3-MC caused a 15-fold increase in mutant frequency and an increase in transversion type mutations; a very early occurrence of this type of mutation in lung tissue was previously identified in Ki-ras oncogenes of lung tumors from 3-MC exposed mice. The 2-fold increase in the mutant frequency after treatment with PCB3 and 4-OH-PCB3 was not statistically significant, but a shift in the mutation spectra, especially with PCB3, and an increase in mutations outside of the hotspot region for spontaneous mutations (bp 1-400), suggest that PCB3 and possibly 4-OH-PCB3 are mutagenic in the rat lung.

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