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Proteomics has revealed that the ~20,000 human genes engender a far greater number of proteins, or proteoforms, that are diversified in large part by post-translational modifications (PTMs). How such PTMs affect protein structure and function is an active area of research but remains technically challenging to assess on a proteome-wide scale. Here, we describe a chemical proteomic method to quantitatively relate serine/threonine phosphorylation to changes in the reactivity of cysteine residues, a parameter that can affect the potential for cysteines to be post-translationally modified or engaged by covalent drugs. Leveraging the extensive high-stoichiometry phosphorylation occurring in mitotic cells, we discover numerous cysteines that exhibit phosphorylation-dependent changes in reactivity on diverse proteins enriched in cell cycle regulatory pathways. The discovery of bidirectional changes in cysteine reactivity often occurring in proximity to serine/threonine phosphorylation events points to the broad impact of phosphorylation on the chemical reactivity of proteins and the future potential to create small-molecule probes that differentially target proteoforms with PTMs.
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Cisteína , Proteômica , Cisteína/química , Humanos , Fosforilação , Processamento de Proteína Pós-Traducional , Proteoma/metabolismo , Proteômica/métodos , Serina , Treonina/metabolismoRESUMO
INTRODUCTION: Interrupted time series (ITS) design is a commonly used method for evaluating large-scale interventions in clinical practice or public health. However, improperly using this method can lead to biased results. OBJECTIVE: To investigate design and statistical analysis characteristics of drug utilization studies using ITS design, and give recommendations for improvements. METHODS: A literature search was conducted based on PubMed from January 2021 to December 2021. We included original articles that used ITS design to investigate drug utilization without restriction on study population or outcome types. A structured, pilot-tested questionnaire was developed to extract information regarding study characteristics and details about design and statistical analysis. RESULTS: We included 153 eligible studies. Among those, 28.1% (43/153) clearly explained the rationale for using the ITS design and 13.7% (21/153) clarified the rationale of using the specified ITS model structure. One hundred and forty-nine studies used aggregated data to do ITS analysis, and 20.8% (31/149) clarified the rationale for the number of time points. The consideration of autocorrelation, non-stationary and seasonality was often lacking among those studies, and only 14 studies mentioned all of three methodological issues. Missing data was mentioned in 31 studies. Only 39.22% (60/153) reported the regression models, while 15 studies gave the incorrect interpretation of level change due to time parameterization. Time-varying participant characteristics were considered in 24 studies. In 97 studies containing hierarchical data, 23 studies clarified the heterogeneity among clusters and used statistical methods to address this issue. CONCLUSION: The quality of design and statistical analyses in ITS studies for drug utilization remains unsatisfactory. Three emerging methodological issues warranted particular attention, including incorrect interpretation of level change due to time parameterization, time-varying participant characteristics and hierarchical data analysis. We offered specific recommendations about the design, analysis and reporting of the ITS study.
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Saúde Pública , Projetos de Pesquisa , Humanos , Análise de Séries Temporais Interrompida , Estudos Transversais , Uso de MedicamentosRESUMO
PURPOSE: The oncogenic factor ZNF217 promotes aggressive estrogen receptor (ER)+breast cancer disease suggesting that its inhibition may be useful in the clinic. Unfortunately, no direct pharmacological inhibitor is available. Dimethyl fumarate (DMF) exhibits anti-breast cancer activities, in vitro and in pre-clinical in vivo models. Its therapeutic benefits stem from covalent modification of cellular thiols such as protein cysteines, but the full profile of molecular targets mediating its anti-breast cancer effects remains to be determined. METHODS: ER+breast cancer cells were treated with DMF followed by cysteine-directed proteomics. Cells with modulated ZNF217 levels were used to probe the efficacy of DMF. RESULTS: Covalent modification of ZNF217 by DMF identified by proteomics was confirmed by using a DMF-chemical probe. Inhibition of ZNF217's transcriptional activity by DMF was evident on reported ZNF217-target genes. ZNF217 as an oncogene has been shown to enhance stem-like properties, survival, proliferation, and invasion. Consistent with ZNF217 inhibition, DMF was more effective at blocking these ZNF217-driven phenotypes in cells with elevated ZNF217 expression. Furthermore, partial knockdown of ZNF217 led to a reduction in DMF's efficacy. DMF's in vivo activity was evaluated in a xenograft model of MCF-7 HER2 cells that have elevated expression of ZNF217 and DMF treatment resulted in significant inhibition of tumor growth. CONCLUSION: These data indicate that DMF's anti-breast cancer activities in the ER+HER2+models, at least in part, are due to inhibition of ZNF217. DMF is identified as a new covalent inhibitor of ZNF217.
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Neoplasias da Mama , Humanos , Feminino , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Fumarato de Dimetilo/farmacologia , Fumarato de Dimetilo/uso terapêutico , Receptores de Estrogênio , Transativadores/genética , Transativadores/metabolismo , Transativadores/uso terapêutico , Células MCF-7RESUMO
Cytochrome P450 family 1 subfamily A member 2 (CYP1A2), performs an indispensable role in metabolism of both exogenous and endogenous substances. What is more, CYP1A2 functions in human diseases by regulating homeostasis of cholesterol. Despite the emergence of gene-editing animal models, genetically humanized animals that overcome species differences for further exploring the role of CYP1A2 in drug metabolism and human diseases have not yet been constructed. In this study, we inserted human CYP1A2 cDNA into the rat Cyp1a2 gene by using CRISPR/Cas9 technology. Results showed that human CYP1A2 was successfully expressed in humanized rat liver and there were no statistically significant differences of physiological symptoms compared with wild-type (WT) rats. In vitro incubation results indicated the different inhibition of furafylline on CYP1A2 activity in human liver microsomes, humanized CYP1A2 (hCYP1A2) rat liver microsomes, and WT rat liver microsomes, with IC50 values of 7.1 µM, 36.5 µM, and 285.8 µM, respectively. Meanwhile, pharmacokinetic characteristics of clozapine were conducted, and the results suggested that in hCYP1A2 rats, clozapine tended to be metabolized into norclozapine. Both the in vitro and in vivo results demonstrated the different metabolic functions of CYP1A2 in humanized and WT rats. We successfully constructed a novel humanized CYP1A2 rat model using the CRISPR/Cas9 system, providing a powerful tool for better predicting CYP1A2-mediated drug metabolism and pharmacokinetics. Significance Statement Human CYP1A2 takes active part both in the biotransformation of exogenous substances and endogenous substances. Meanwhile, it plays a regulatory role in human diseases, including hypercholesterolemia, hypertension as well as various malignant tumors. This study successfully constructed humanized CYP1A2 rat model by CRISPR/Cas9 technology, providing a powerful model for promoting drug development and safety evaluation, as well as further exploring the role of CYP1A2 in human diseases.
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Cytochrome P450 2J2 (CYP2J2) enzyme is widely expressed in aortic endothelial cells and cardiac myocytes and affects cardiac function, but the underlying mechanism is still unclear. Based on CYP2J knockout (KO) rats, we have directly studied the metabolic regulation of CYP2J on cardiac function during aging. The results showed that CYP2J deficiency significantly reduced the content of epoxyeicosatrienoic acids (EETs) in plasma, aggravated myocarditis, myocardial hypertrophy, as well as fibrosis, and inhibited the mitochondrial energy metabolism signal network Pgc-1α/Ampk/Sirt1. With the increase of age, the levels of 11,12-EET and 14,15-EET in plasma of KO rats decreased significantly, and the heart injury was more serious. Interestingly, we found that after CYP2J deletion, the heart initiated a self-protection mechanism by upregulating cardiac mechanism factors Myh7, Dsp, Tnni3, Tnni2, and Scn5a, as well as mitochondrial fusion factors Mfn2 and Opa1. However, this protective effect disappeared with aging. In conclusion, CYP2J deficiency not only reduces the amount of EETs, but also plays a dual regulatory role in cardiac function.
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Citocromo P-450 CYP2J2 , Traumatismos Cardíacos , Ratos , Animais , Ácido 8,11,14-Eicosatrienoico/metabolismo , Ácido 8,11,14-Eicosatrienoico/farmacologia , Células Endoteliais/metabolismo , Sistema Enzimático do Citocromo P-450/genética , Sistema Enzimático do Citocromo P-450/metabolismo , Miócitos Cardíacos , Traumatismos Cardíacos/metabolismoRESUMO
BACKGROUND: To investigate the sensitivity and specificity of corneal confocal microscopy (CCM) in the diagnosis of immune-related motor neuron disease syndrome and evaluation of the response to immunosuppressive therapy. METHODS: Seventy-two patients with clinical manifestations of motor neuron disease (MND) were analysed. According to whether they had concomitant rheumatic immune disease or rheumatic immune antibody abnormalities, they were divided into an MND group (33 patients) and an immune-related MND syndrome group (39 patients). Another 10 healthy adults were selected as the control group. All individuals were examined by CCM. RESULTS: For Langerhans cell(LC) density, the area under the receiver operating characteristic(ROC)curve was 0.8, the best cut-off was 67.7 cells/mm2, the sensitivity was 79.5%, and the specificity was 72.7%. For inferior whorl length (IWL), the area under the ROC curve was 0.674, the best cut-off was 17.41 mm/mm2, the sensitivity was 69.2%, and the specificity was 66.7%. After immunosuppressive therapy in 5 patients with immune-related MND syndrome, the LCD was significantly reduced (P < 0.05), and there was no statistically significant change in the IWL (P > 0.05). CONCLUSION: The LC density and IWL are ideal for distinguishing MND from immune-related MND syndrome. The LC density reflects the immunotherapy response sensitively.
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Neuropatias Diabéticas , Doença dos Neurônios Motores , Adulto , Córnea , Neuropatias Diabéticas/diagnóstico , Humanos , Microscopia Confocal , Doença dos Neurônios Motores/diagnóstico por imagem , Curva ROC , SíndromeRESUMO
Deoxyshikonin, a natural naphthoquinone compound extracted from Lithospermum erythrorhizon Sieb. et Zucc (Boraginaceae), has a wide range of pharmacological activities, including anti-tumor, anti-bacterial and wound healing effects. However, the inhibitory effect of deoxyshikonin on cytochrome P450 (CYP) remains unclear. This study investigated the potential inhibitory effects of deoxyshikonin on CYP1A2, 2B1/6, 2C9/11, 2D1/6, 2E1 and 3A2/4 enzymes in human and rat liver microsomes (HLMs and RLMs) by the cocktail approach in vitro. The single-point inactivation experiment showed that deoxyshikonin presented no time-dependent inhibition on CYP activities in HLMs and RLMs. Enzyme inhibition kinetics indicated that in HLMs, deoxyshikonin was not only a competitive inhibitor of CYP1A2 and 2E1, but also a mixed inhibitor of CYP2B6, 2C9, 2D6 and 3A4, with Ki of 2.21, 1.78, 1.68, 0.20, 4.08 and 0.44 µM, respectively. In RLMs, deoxyshikonin not only competitively inhibited CYP2B1 and 2E1, but also exhibited mixed inhibition on CYP1A2, 2C11, 2D1 and 3A2, with Ki values of no more than 18.66 µM. In conclusion, due to the low Ki values of deoxythiokonin on CYP enzymes in HLMs, this may lead to drug-drug interactions (DDI) and potential toxicity.
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Carboxylesterase (CES) 2, an important metabolic enzyme, plays a critical role in drug biotransformation and lipid metabolism. Although CES2 is very important, few animal models have been generated to study its properties and functions. Rat Ces2 is similar to human CES2A-CES3A-CES4A gene cluster, with highly similar gene structure, function, and substrate. In this report, CRISPR-associated protein-9 (CRISPR/Cas9) technology was first used to knock out rat Ces2a, which is a main subtype of Ces2 mostly distributed in the liver and intestine. This model showed the absence of CES2A protein expression in the liver. Further pharmacokinetic studies of diltiazem, a typical substrate of CES2A, confirmed the loss of function of CES2A both in vivo and in vitro. At the same time, the expression of CES2C and CES2J protein in the liver decreased significantly. The body and liver weight of Ces2a knockout rats also increased, but the food intake did not change. Moreover, the deficiency of Ces2a led to obesity, insulin resistance, and liver fat accumulation, which are consistent with the symptoms of nonalcoholic fatty liver disease (NAFLD). Therefore, this rat model is not only a powerful tool to study drug metabolism mediated by CES2 but also a good disease model to study NAFLD. SIGNIFICANCE STATEMENT: Human carboxylesterase (CES) 2 plays a key role in the first-pass hydrolysis metabolism of most oral prodrugs as well as lipid metabolism. In this study, CRISPR/Cas9 technology was used to knock out Ces2a gene in rats for the first time. This model can be used not only in the study of drug metabolism and pharmacokinetics but also as a disease model of nonalcoholic fatty liver disease (NAFLD) and other metabolic disorders.
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Proteína 9 Associada à CRISPR/genética , Sistemas CRISPR-Cas/genética , Carboxilesterase/deficiência , Carboxilesterase/genética , Técnicas de Silenciamento de Genes/métodos , Animais , Anti-Hipertensivos/farmacologia , Sequência de Bases , Diltiazem/farmacologia , Relação Dose-Resposta a Droga , Feminino , Resistência à Insulina/fisiologia , Masculino , Microssomos Hepáticos/efeitos dos fármacos , Microssomos Hepáticos/enzimologia , Ratos , Ratos Sprague-DawleyRESUMO
CYP1A2, as one of the most important cytochrome P450 isoforms, is involved in the biotransformation of many important endogenous and exogenous substances. CYP1A2 also plays an important role in the development of many diseases because it is involved in the biotransformation of precancerous substances and poisons. Although the generation of Cyp1a2 knockout (KO) mouse model has been reported, there are still no relevant rat models for the study of CYP1A2-mediated pharmacokinetics and diseases. In this report, CYP1A2 KO rat model was established successfully by CRISPR/Cas9 without any detectable off-target effect. Compared with wild-type rats, this model showed a loss of CYP1A2 protein expression in the liver. The results of pharmacokinetics in vivo and incubation in vitro of specific substrates of CYP1A2 confirmed the lack of function of CYP1A2 in KO rats. In further studies of potential compensatory effects, we found that CYP1A1 was significantly upregulated, and CYP2E1, CYP3A2, and liver X receptor ß were downregulated in KO rats. In addition, CYP1A2 KO rats exhibited a significant increase in serum cholesterol and free testosterone accompanied by mild liver damage and lipid deposition, suggesting that CYP1A2 deficiency affects lipid metabolism and liver function to a certain extent. In summary, we successfully constructed the CYP1A2 KO rat model, which provides a useful tool for studying the metabolic function and physiologic function of CYP1A2. SIGNIFICANCE STATEMENT: Human CYP1A2 not only metabolizes clinical drugs and pollutants but also mediates the biotransformation of endogenous substances and plays an important role in the development of many diseases. However, there are no relevant CYP1A2 rat models for the research of pharmacokinetics and diseases. This study successfully established CYP1A2 knockout rat model by using CRISPR/Cas9. This rat model provides a powerful tool to study the function of CYP1A2 in drug metabolism and diseases.
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Animais Geneticamente Modificados , Proteína 9 Associada à CRISPR/metabolismo , Sistemas CRISPR-Cas , Citocromo P-450 CYP1A2/genética , Técnicas de Inativação de Genes/métodos , Animais , Animais Geneticamente Modificados/genética , Animais Geneticamente Modificados/metabolismo , Biotransformação , Sistema Enzimático do Citocromo P-450/genética , Isoenzimas/genética , Modelos Animais , Farmacocinética , RatosRESUMO
Cytochrome P450 3A (CYP3A) as an important enzyme metabolizes many drugs and a variety of endogenous substances. Bile acids (BA) regulate physiological function by activating BA receptors. In this study, CYP3A1/2 gene knockout (KO) and wild-type (WT) rats were used to investigate the regulatory effects of CYP3A on BA homeostasis and liver function. Compared with WT rats, BA concentrations in serum, liver and small intestine of CYP3A1/2 KO rats increased significantly, which was due to the decrease of catabolism and the increase of synthesis. In particular, the composition of serum BA (overall hydrophobicity) presented an age- and CYP3A-dependent manner. With the aging of WT rats, the serum BA became more hydrophobic, while this trend was delayed in CYP3A1/2 KO rats. Moreover, the level of serum total cholesterol, the precursor of BA synthesis, decreased by about 20% in CYP3A1/2 KO rats, which is due to the low synthesis but high biotransformation rate. The increase of BA pool further led to the change of transcription level of BA receptor in liver (pregnane X receptor) and small intestine (Takeda G-protein receptor 5), and affected the function and morphology of CYP3A1/2 KO rat liver. In conclusion, CYP3A is a key regulator of BA homeostasis in rats, especially in regulating BA pool size, composition and balance of anabolism, and prevents susceptibility to hepatotoxicity under BA overload.
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Ácidos e Sais Biliares/sangue , Citocromo P-450 CYP3A/deficiência , Intestino Delgado/enzimologia , Fígado/enzimologia , Animais , Colesterol/sangue , Citocromo P-450 CYP3A/genética , Feminino , Genótipo , Homeostase , Interações Hidrofóbicas e Hidrofílicas , Fenótipo , Receptor de Pregnano X/genética , Receptor de Pregnano X/metabolismo , Ratos Sprague-Dawley , Ratos Transgênicos , Receptores Acoplados a Proteínas G/genética , Receptores Acoplados a Proteínas G/metabolismoRESUMO
Clinical trials of olanzapine combined with fluoxetine (Olanzapine/Fluoxetine Combination, OFC) in the treatment of refractory depression have shown significant efficacy, but the drug-drug interaction (DDI) between them remains unclear. In this report, the pharmacokinetic interaction between olanzapine and fluoxetine was studied in wild-type (WT) and Mdr1a/b gene knockout (KO) rats. By analyzing the pharmacokinetics and tissue distribution of olanzapine in single dose and combination, the potential DDI mediated by P-gp was explored. The results showed that in WT rats, the combination of fluoxetine increased the peak concentration (Cmax, 44.1 ± 5.1 ng/mL in the combination group vs 9.0 ± 1.5 ng/mL in the monotherapy group) and the exposure (AUC0-t, 235.8 ± 22.7 h × ng/mL in the combination group vs 47.5 ± 8.4 h × ng/mL in monotherapy group) of olanzapine, and decreased the clearance (CL, 8119.0 ± 677.9 mL/h/kg in the combination group vs 49,469.0 ± 10,306.0 mL/h/kg in monotherapy group). At the same time, fluoxetine significantly increased the in vivo exposure of olanzapine in brain, liver, kidney and ileum of WT rats, indicating the occurrence of DDI. The same phenomenon was observed in Caco-2 cells in vitro as well. However, in KO rats, there was no significant difference in pharmacokinetic parameters between the monotherapy group and the combination group. In conclusion, P-gp plays an important role in the pharmacokinetic interaction between olanzapine and fluoxetine in rats. This study may provide a reference for the clinical safety of olanzapine combined with fluoxetine.
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Subfamília B de Transportador de Cassetes de Ligação de ATP/metabolismo , Antidepressivos de Segunda Geração/farmacocinética , Antipsicóticos/farmacocinética , Fluoxetina/farmacocinética , Olanzapina/farmacocinética , Subfamília B de Transportador de Cassetes de Ligação de ATP/genética , Administração Oral , Animais , Antidepressivos de Segunda Geração/administração & dosagem , Antipsicóticos/administração & dosagem , Células CACO-2 , Interações Medicamentosas , Fluoxetina/administração & dosagem , Humanos , Masculino , Olanzapina/administração & dosagem , Ratos Sprague-Dawley , Ratos Transgênicos , Distribuição Tecidual , Membro 4 da Subfamília B de Transportadores de Cassetes de Ligação de ATPRESUMO
Cytochrome P450 2J2 (CYP2J2) enzyme attracts more attention because it not only metabolizes clinical drugs but also mediates the biotransformation of important endogenous substances and the regulation of physiologic function. Although CYP2J2 is very important, few animal models are available to study its function in vivo In particular, a CYP2J gene knockout (KO) rat model for drug metabolism and pharmacokinetics is not available. In this report, the CRISPR/Cas9 technology was used to delete rat CYP2J3/10, the orthologous genes of CYP2J2 in humans. The CYP2J3/10 KO rats were viable and fertile and showed no off-target effect. Compared with wild-type (WT) rats, the mRNA and protein expression of CYP2J3/10 in liver, small intestine, and heart of KO rats were completely absent. At the same time, CYP2J4 mRNA expression and protein expression were significantly decreased in these tissues. Further in vitro and in vivo metabolic studies of astemizole, a typical substrate of CYP2J, indicated that CYP2J was functionally inactive in KO rats. The heart function indexes of WT and KO rats were also measured and compared. The myocardial enzymes, including creatine kinase-muscle brain type (CK-MB), creatine kinase (CK), and CK-MB/CK ratio, of KO rats increased by nearly 140%, 80%, and 60%, respectively. In conclusion, this study successfully developed a new CYP2J3/10 KO rat model, which is a useful tool to study the function of CYP2J in drug metabolism and cardiovascular disease. SIGNIFICANCE STATEMENT: Human CYP2J2 is involved not only in clinical drug metabolism but also in the biotransformation of important endogenous substances. Therefore, it is very important to construct new animal models to study its function in vivo. This study successfully developed a new CYP2J knockout rat model by using CRISPR/Cas9 technology. This rat model provides a useful tool to study the role of CYP2J in drug metabolism and diseases.
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Sistema Enzimático do Citocromo P-450/metabolismo , Animais , Astemizol/farmacocinética , Biotransformação , Sistemas CRISPR-Cas/genética , Citocromo P-450 CYP2J2 , Sistema Enzimático do Citocromo P-450/genética , Avaliação Pré-Clínica de Medicamentos/métodos , Estudos de Viabilidade , Feminino , Técnicas de Silenciamento de Genes , Masculino , Modelos Animais , Ratos , Ratos TransgênicosRESUMO
BACKGROUND: Epidermal biophysical properties can be affected by many factors, including body site, age, gender, ethnicity, disease, temperature, humidity, and ultraviolet (UV) radiation. Information about variation of epidermal biophysical properties with seasons is still limited. In the present study, we determined seasonal variation of epidermal biophysical properties of women in Kunming, China. MATERIALS AND METHODS: A total of 72 women, aged 22.96 ± 2.11 years, were enrolled in this study. Transepidermal water loss rates (TEWL), stratum corneum (SC) hydration, sebum content, melanin index (MI), erythema index (EI), and L*a* values were measured on the right cheek and the right forearm, using a non-invasive skin physiological instrument in the spring, summer, autumn, and winter in Kunming, China. RESULTS: On the cheek, TEWL, SC hydration, sebum, MI, and L*a* values varied greatly with seasons (P < .05). SC hydration, sebum, MI, and a*value peaked in the summer, but went lowest in winter. In contrast, TEWL and L*value went lowest in summer but peaked in winter. Similarly, SC hydration, MI, and L*value also varied with seasons on the forearm (P < .05). In addition, SC hydration, sebum, MI, EI, and a*value of the cheek were higher than that of the forearm (P < .001), but L*values of the cheek were lower than that of the forearm (P < .001). There were no correlations among TEWL and MI, EI, and L*a*values in any season (P > .05). CONCLUSIONS: Both epidermal permeability barrier function, sebum, and skin pigment in healthy women vary seasons in Kunming, China.
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Epiderme/fisiologia , Estações do Ano , Fenômenos Fisiológicos da Pele , Perda Insensível de Água , Adulto , China/epidemiologia , Estudos de Coortes , Feminino , Humanos , Concentração de Íons de Hidrogênio , Adulto JovemRESUMO
Paris saponins, also known as polyphyllins, are natural compounds extracted from Paris polyphylla, which have many pharmacological activities, such as anti-inflammation and anti-cancer. In particular, paris saponin I, II, VII and polyphyllin VI are the components of the quality standard for Paris polyphylla. However, the inhibition risk of polyphyllins on cytochrome P450 (CYP) and UDP-glucuronosyltransferases (UGT) remains unclear. Therefore, this report investigated the potential inhibitory effects of paris saponin I, II, VII and polyphyllin VI on the activities of CYP (CYP1A2, CYP2B1, CYP2C11, CYP2D1, CYP2E1 and CYP3A2) and UGT (UGT1A1, UGT1A3, UGT1A6, PROG and AZTG) through cocktail inhibition assays in vitro. In the study of CYP, polyphyllin VI exhibited weak inhibition on CYP2D1 activity in rat liver microsomes with IC50 value at 45.2 µM, while paris saponin VII weakly inhibited CYP2C11 and CYP2E1 activities with IC50 value at 42.0 and 67.7 µM, respectively. In the study of UGT, none of the four steroidal saponins showed significant inhibition risk. In conclusion, paris saponin I, II, VII and polyphyllin VI have very low potential to cause the possible toxicity and drug interactions involving CYP and UGT enzymes, indicating that they are safe enough to take with drugs.
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Sistema Enzimático do Citocromo P-450/metabolismo , Inibidores Enzimáticos/farmacologia , Glucuronosiltransferase/antagonistas & inibidores , Microssomos Hepáticos/efeitos dos fármacos , Saponinas/farmacologia , Animais , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/química , Glucuronosiltransferase/metabolismo , Humanos , Masculino , Microssomos Hepáticos/enzimologia , Conformação Molecular , Ratos , Ratos Sprague-Dawley , Medição de Risco , Saponinas/química , Estereoisomerismo , Relação Estrutura-AtividadeRESUMO
With the trend of high integration and high power of insulated gate bipolar transistor (IGBT) components, strict requirements have been placed on the heat dissipation capabilities of the IGBT devices. On the basis of traditional rectangular fins, this paper developed two new types of heat-dissipating fins to meet the high requirements of heat dissipation for the IGBT devices. One is the rectangular radiator with a groove length of 2.5 mm and a width of 0.85 mm, the other is the arc radiator with the angle of 125 arc angle, 0.8 mm arc height, and 1.4 mm circle radius. After theoretically calculating the IGBT junction temperature, numerical simulations have been implemented to verify the theoretical result. The commercial CFD software, STAR-CCM+, was employed to simulate the heat dissipation characteristics of the IGBT module under different wind speeds, power, and fin structures. By analyzing the temperature field and vector field of the IGBT module, the analysis results demonstrate that the error between the simulation result and the theoretical calculation is within 5%, which proves the feasibility of the newly designed heat-dissipating fins. When the wind speed is 12.5 m/s, the power is 110 W, the fin height is 31.2 mm, and the fin thickness is 2.3 mm, the rectangular radiator can achieve the best heat dissipation performance.
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Clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein-9 nuclease (Cas9) technology is widely used as a tool for gene editing in rat genome site-specific engineering. Multidrug resistance 1 [MDR1 (also known as P-glycoprotein)] is a key efflux transporter that plays an important role not only in the transport of endogenous and exogenous substances, but also in tumor MDR. In this report, a novel MDR1 (Mdr1a/b) double-knockout (KO) rat model was generated by the CRISPR/Cas9 system without any off-target effect detected. Western blot results showed that MDR1 was completely absent in the liver, small intestine, brain, and kidney of KO rats. Further pharmacokinetic studies of digoxin, a typical substrate of MDR1, confirmed the deficiency of MDR1 in vivo. To determine the possible compensatory mechanism of Mdr1a/b (-/-) rats, the mRNA levels of the CYP3A subfamily and transporter-related genes were compared in the brain, liver, kidney, and small intestine of KO and wild-type rats. In general, a new Mdr1a/b (-/-) rat model has been successfully generated and characterized. This rat model is a useful tool for studying the function of MDR1 in drug absorption, tumor MDR, and drug target validation.
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Subfamília B de Transportador de Cassetes de Ligação de ATP/genética , Digoxina/farmacocinética , Subfamília B de Transportador de Cassetes de Ligação de ATP/metabolismo , Administração Oral , Animais , Encéfalo/metabolismo , Sistemas CRISPR-Cas/genética , Citocromo P-450 CYP3A/análise , Citocromo P-450 CYP3A/genética , Citocromo P-450 CYP3A/metabolismo , Digoxina/administração & dosagem , Feminino , Técnicas de Inativação de Genes/métodos , Intestino Delgado/metabolismo , Rim/metabolismo , Fígado/metabolismo , Masculino , Modelos Animais , RNA Mensageiro/análise , RNA Mensageiro/metabolismo , Ratos , Ratos Sprague-Dawley , Ratos TransgênicosRESUMO
Structural damage is inevitable due to the structural aging and disastrous external excitation. The auto-regressive (AR) based method is one of the most widely used methods for structural damage identification. In this regard, the classical least-squares algorithm is often utilized to solve the AR model. However, this algorithm generally could not take all the observed noises into account. In this study, a partial errors-in-variables (EIV) model is used so that both the current and prior observation errors are considered. Accordingly, a total least-squares (TLSE) solution is introduced to solve the partial EIV model. The solution estimates and accounts for the correlations between the current observed data and the design matrix. An effective damage indicator is chosen to count for damage levels of the structures. Both mathematical and finite element simulation results show that the proposed TLSE method yields better accuracy than the classical LS method and the AR model. Finally, the response data of a high-rise building shaking table test is used for demonstrating the effectiveness of the proposed method in identifying the location and damage degree of a model structure.
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Osteosarcoma is the most commonly diagnosed primary malignant bone tumor, with similar global incidence rate across childhood and adolescence. Patients with localized disease have a 5-year survival period of 80 %; however, the prognosis is poor in those with metastatic osteosarcoma. The origin of the primary tumor is most frequently the metaphyseal (actively growing) regions of the distal femur, proximal tibia, and proximal humerus, although the tumor can develop in any bone, and the most likely sites for metastasis are the lungs and bone. Ezrin is a member of the ezrin-radixin-moesin (ERM) family of proteins that functions as a cross-linker between the actin cytoskeleton and the plasma membrane, and ezrin also plays a positive role in maintaining cell shape and polarity and facilitates membrane-trafficking pathways, cell migration, cell signaling, growth regulation, and differentiation. There is strong evidence to suggest that ezrin is necessary for osteosarcoma metastasis. The objective of the current review is to summarize the know-how about metastatic progression in osteosarcoma, with a focus on ezrin. Despite the promise that preliminary studies on ezrin have shown, there is a great need to further analyze the role of ezrin in osteosarcoma metastasis and to determine its usefulness as a biomarker for the disease.
Assuntos
Neoplasias Ósseas/patologia , Proteínas do Citoesqueleto/fisiologia , Osteossarcoma/secundário , Animais , Humanos , Receptores de Hialuronatos/fisiologia , Sistema de Sinalização das MAP Quinases/fisiologia , Proteínas Proto-Oncogênicas c-akt/fisiologiaRESUMO
OBJECTIVE: To investigate relationships between serum asymmetric dimethylarginine (ADMA) and transient ischemic attack (TIA). METHODS: Forty healthy controls and 40 patients with TIA were enrolled in the present study. ABCD2 score was used to evaluate risk for future stroke. Serum ADMA levels were measured with ELISA analysis. RESULTS: Serum level of ADMA was higher in TIA group than that in control group [(0.52 ± 0.06) mmol/L vs (0.23 ± 0.04) mmol/L, P < 0.05]. In TIA subgroup, 19 cases (47.5%) developed cerebral infarction and 23 cases (57.5%) had no stroke history. There is positive correlation between serum ADMA levels and ABCD2 score in both cerebral infarction subjects (r = 0.560, P = 0.013), and no stroke history cases(r = 0.602, P = 0.002). TIA subjects were, then, divided in to two groups based on ABCD2 score as 0-3 group and ≥ 4 group. In general linear model analysis, ADMA level was associated with ABCD2 score (F = 4.39, P = 0.043) after adjusted for age and gender. This situation hold true for subjects within cerebral infarction group (F = 7.327, P = 0.017) or non-previous stroke group(F = 12.300, P = 0.002) . No association could be found between ADMA level and ABCD2 score grouping in subjects with non-infarct (F = 0.523, P = 0.675) or stroke history (F = 0.274, P = 0.609). CONCLUSIONS: Elevated ADMA is associated with occurrence of TIA. Endothelial dysfunction may play an important role in the pathogenesis of TIA.