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1.
Zhonghua Er Bi Yan Hou Tou Jing Wai Ke Za Zhi ; 58(10): 966-973, 2023 Oct 07.
Artigo em Chinês | MEDLINE | ID: mdl-37840161

RESUMO

Objective: To evaluate the associations between the renalase single-nucleotide polymorphisms rs2576178 and rs10887800 and the risk of hypertension in OSA patients. Methods: A total of 3, 570 male OSA subjects diagnosed via standard polysomnography were included in this retrospective study. We recorded anthropometric, genomic, and polysomnographic parameters and blood pressure levels. All subjects were divided into four groups based on quartiles of the apnea-hypopnea index (AHI). The relationships between rs2576178 and rs10887800 and the risk of hypertension were evaluated using the binary logistic regression, and haplotype analysis. Results: In the bottom AHI quartile, rs10887800 was significantly associated with the risk of hypertension according to the dominant model [odds ratio(OR)=0.691, 95% confidence interval (CI)=0.483-0.990, P=0.044] even after adjustment for age, sex, and the body mass index. The G-A haplotype was associated with a co-effect of the two SNPs, namely, the risk of hypertension decreased (OR=0.879, 95%CI=0.784-0.986, P=0.028). Conclusions: We find no association between single rs2576178 or rs10887800 variants with the risk of hypertension in our OSA population. But, the synergistic effect of the two polymorphisms is associated with the risk of hypertension in OSA patients.


Assuntos
Hipertensão , Apneia Obstrutiva do Sono , Humanos , Masculino , Polimorfismo de Nucleotídeo Único , Estudos Retrospectivos , Hipertensão/complicações , Hipertensão/genética , Apneia Obstrutiva do Sono/genética , Apneia Obstrutiva do Sono/complicações , Fatores de Risco
2.
Zhonghua Yi Xue Za Zhi ; 103(20): 1538-1545, 2023 May 30.
Artigo em Chinês | MEDLINE | ID: mdl-37246003

RESUMO

Objective: To analyze high-risk factors affecting BK polyomavirus (BKPyV) infection and to construct a prediction model for BKPyV infection in children after renal transplantation. Methods: The clinical data of 332 children who received allogeneic kidney transplantation in the First Affiliated Hospital of Zhengzhou University from January 2014 to March 2022 were retrospectively collected. According to the BKPyV load level, the dynamic change process of lymphocytes at different time points were analyzed. The factors that have potential influence on BKPyV infection were screened by Cox regression analysis, and the receiver operating characteristic curve (ROC) was used to evaluate the sensitivity and specificity of the predictive model of infection. Results: Among the 332 children, there were 215 males and 117 females; the age of transplantation was (12.2±3.9) years old; 37 cases were preschool (1-5 years old), and 295 cases were post-school age (6-18 years old). BKPyV load in 224 urine samples and 30 blood samples of children were detected. There were 9 cases of BKPyV-associated viruria and 3 cases of BKPyV associated viremia in pre-school children, 76 cases BKPyV associated viruria and 14 cases of BKPyV associated viremia in post-school children. Multivariate Cox regression analysis showed that higher body mass index (BMI) (HR=1.105, 95%CI: 1.020-1.197), antithyroglobulin (ATG) application (HR=2.196, 95%CI: 1.335-3.613), and higher tacrolimus concentration (HR=2.484, 95%CI: 1.298-4.753), higher natural killer (NK) lymphocyte count (HR=1.193, 95%CI: 1.009-1.411), higher CD14++CD16-cell count (HR=1.096, 95%CI: 1.024-1.173) were independent risk factors for BKPyV associated viruria in post-school children. Delayed graft function (DGF) (HR=4.993, 95%CI: 1.555-16.038), Acute rejection (AR) (HR=6.021, 95%CI: 1.930-18.787), higher CD14++CD16-cell count (HR=1.227, 95%CI: 1.081-1.392) were independent risk factors for BKPyV associated viremia in post-school children. The results of ROC curve analysis showed that combined BMI, immune induction drugs, tacrolimus concentration, NK cell count, and CD14++CD16-cell count predicted the occurrence of BKPyV associated viruria in post-school children after kidney transplantation at 0.5, 1, 2, and 5 years with area under curve (AUC) of 0.712 (95%CI: 0.626-0.798), 0.708 (95%CI: 0.612-0.804), 0.754 (95%CI: 0.668-0.840) and 0.767 (95%CI: 0.685-0.849). The sensitivity and specificity of the model were 64.9%, 61.4%, 61.6%, 55.8% and 70.9%, 72.4%, 76.0%, 84.0%, respectively. Combined with DGF, AR, and CD14++CD16-cell counts predicted the occurrence of BKPyV-associated viremia at 0.5, 1, 2, and 5 years after renal transplantation in post-school children with AUC of 0.791 (95%CI: 0.631-0.951), 0.744 (95%CI: 0.547-0.936), 0.786 (95%CI: 0.629-0.946) and 0.812 (95%CI: 0.672-0.948). The sensitivity and specificity of the model were 76.1%, 67.1%, 75.0%, 77.9% and 88.9%, 89.0%, 89.9%, 88.0%, respectively. Conclusions: The postoperative CD14++CD16-cell level can be used as an independent predictor of BKPyV infection in post-school children after renal transplantation. Combined BMI, immune induction drugs, tacrolimus concentration, NK cell count, CD14++CD16-cell count and combined DGF, AR, CD14++CD16-cell count show good fitting effect in predicting the occurrence of BKPyV-associated viruria and viremia after transplantation in post-school children respectively.


Assuntos
Vírus BK , Nefropatias , Transplante de Rim , Infecções por Polyomavirus , Infecções Tumorais por Vírus , Masculino , Feminino , Humanos , Pré-Escolar , Criança , Adolescente , Lactente , Transplante de Rim/efeitos adversos , Estudos Retrospectivos , Tacrolimo , Viremia/etiologia , Infecções por Polyomavirus/epidemiologia , Infecções Tumorais por Vírus/epidemiologia
3.
Zhonghua Er Bi Yan Hou Tou Jing Wai Ke Za Zhi ; 58(12): 1243-1247, 2023 Dec 07.
Artigo em Chinês | MEDLINE | ID: mdl-38186100

RESUMO

Objective: To investigate clinical and imaging parameters to predict blood loss and cranial nerve injury (CNI) following carotid body paraganglioma (CBP) resection. Methods: A retrospective examination of clinical and imaging data was conducted on 63 patients who underwent CBP resection at Xiangya Hospital of Central South University from January 2016 to December 2022, including 23 males and 40 females, aged 26-87 years old. Three imaging parameters including tumor volume, the angle of contact with the internal carotid artery (ICA), and the distance to the base of skull (DTBOS) were gauged using the IMEDPACS software on CTA and MR imaging. The predictive efficacies of age, gender, Shamblin classification, and three imaging parameters for blood loss and CNI following surgery were analysed. Logistic composite parameter models were constructed and their predictive validity was assessed. Results: Multivariate logistic regression analysis underscored that only tumor volume (OR=1.381,95%CI:1.167-1.507,P=0.001) showed significant statistical correlations with blood loss following surgery. Area under curve (AUC) values of 0.910 for receiver operating characteristic (ROC) curves showed a sensitivity of 1.000 and a specificity of 0.694. Tumor volume (OR=1.126,95%CI:1.030-1.231, P=0.002) and DTBOS (OR=0.225,95%CI:0.081-0.630,P=0.005) were significantly associated with postoperative CNI. The analysis of logistic composite model showed AUC values for tumor volume, DTBOS and combination of the two parameters were 0.858, 0.788, and 0.872, respectively. The model for combination of tumor volume and DTBOS also proved superior in predicting postoperative CNI (Z=3.106, P<0.001), with a sensitivity of 0.833 and a specificity of 0.769. Conclusions: Tumor volume and DTBOS emerged as effective predictors for blood loss and/or CNI in patients with CBP resection. Moreover, the logistic composite parameter model outclassed single-parameter models in terms of their predictive clinical value.


Assuntos
Tumor do Corpo Carotídeo , Traumatismos dos Nervos Cranianos , Feminino , Masculino , Humanos , Adulto , Pessoa de Meia-Idade , Idoso , Idoso de 80 Anos ou mais , Tumor do Corpo Carotídeo/cirurgia , Estudos Retrospectivos , Hemorragia , Artéria Carótida Interna
4.
Malays J Pathol ; 42(2): 237-243, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32860376

RESUMO

INTRODUCTION: Follicular lymphoma (FL) is usually a nodal lymphoma expressing CD10, rarely with leukaemic presentation (FL-LP). MATERIALS AND METHODS: We searched for FL-LP in our institution from 2000 to 2018 and characterised the neoplastic cells by flow cytometry, immunohistochemistry and fluorescence in situ hybridization. Thirteen (6.1%) of 212 FL cases were FL-LP, all de novo neoplasms. The leukaemic cells were small in 12 cases and large in one. All had concurrent FL, mostly (92%; 12/13) low-grade. The single case with large leukaemic cells had a concurrent primary splenic low-grade FL and a double-hit large B-cell lymphoma in the marrow. RESULTS: CD10 was expressed in the leukaemic cells in 38% (5/13) cases by flow cytometry and in 77% (10/13) cases in tumours (p= 0.0471). IGH/BCL2 reciprocal translocation was identified in 85% (11/13) cases. Most patients were treated with chemotherapy. In a median follow-up time of 36 months, nine patients were in complete remission. The 2- and 5-year survival rates were at 100% and 83%, respectively. In this study, we characterised a series of de novo FL-LP in Taiwan. All patients had concurrent nodal and/or tissue tumours, which might suggest that these patients seek medical help too late. CONCLUSION: The lower CD10 expression rate by flow cytometry than by immunohistochemistry might be due to different epitopes for these assays. Alternatively, loss of CD10 expression might play a role in the pathogenesis of leukaemic change. The clinical course of FL-LP could be aggressive, but a significant proportion of the patients obtained complete remission with chemotherapy.


Assuntos
Leucemia de Células B , Linfoma Folicular , Neprilisina/metabolismo , Adulto , Idoso , Feminino , Citometria de Fluxo , Humanos , Imuno-Histoquímica , Hibridização in Situ Fluorescente , Leucemia de Células B/metabolismo , Leucemia de Células B/patologia , Leucemia Linfocítica Crônica de Células B/metabolismo , Linfoma Folicular/metabolismo , Linfoma Folicular/patologia , Masculino , Pessoa de Meia-Idade , Prognóstico , Taxa de Sobrevida
5.
Zhonghua Liu Xing Bing Xue Za Zhi ; 41(5): 711-715, 2020 May 10.
Artigo em Chinês | MEDLINE | ID: mdl-32447912

RESUMO

Objective: To investigate sleep quality in pregnant women during their first and second trimester and to identify risk factors. Methods: Data was from the Chinese Pregnant Women Cohort Study. A total of 3 618 pregnant women were included, with the exclusion 346 women who had missing information. Sociodemographic, health-related behavior, depression and sleep quality information were collected and analyzed. Logistic regression analysis were used to explore the influencing factors of sleep quality in pregnant women. Results: Among the 3 618 pregnant woman 28.2% had poor sleep quality in their first trimester and 28.7% in the second trimester. 15.2% pregnant women had progressively worse sleep and 13.0% had persistently poor sleep had pregnant women were generally suffered from poor sleep quality, difficulty falling asleep, sleep disorders and daily fatigue. Regular diet (OR=0.75, 95%CI: 0.62-0.92) and work (OR=0.84,95%CI: 0.71-0.99) in the first trimester were protective factors of sleep quality in pregnant women. Age ≥30 year old (OR=1.19, 95%CI: 1.03-1.37), passive smoking (OR=1.18, 95%CI: 1.02-1.36) and depression (OR=2.25, 95%CI: 1.95-2.61) in the first trimester were risk factors. Conclusions: The rate of poor sleep quality are high among Chinese pregnant woman during their first and second trimester. The risk factors of sleep quality are multiple. Regular diet and work, reduction of tobacco exposure, alleviation of depression symptom may help improve sleep quality among pregnant women.


Assuntos
Gestantes , Sono , Estudos de Coortes , Estudos Transversais , Feminino , Humanos , Gravidez , Segundo Trimestre da Gravidez
6.
Zhonghua Liu Xing Bing Xue Za Zhi ; 40(9): 1125-1129, 2019 Sep 10.
Artigo em Chinês | MEDLINE | ID: mdl-31594158

RESUMO

Objective: To study the relationship between exposure factors in early pregnancy and preterm birth (PB), low birth weight (LBW) and small for gestational age (SGA) of neonates. Methods: A total of 3 172 pregnant women who were enrolled in the project of Chinese Pregnant Women Cohort Study-Peking Union Medical College (CPWCS-PUMC) from July 25, 2017 to July 24, 2018 and delivered before December 31, 2018 were selected as subjects in this study. The relationship between exposure factors in early pregnancy and adverse outcomes of neonatal delivery was analyzed by using binary logistic regression analysis. Results: The incidence rates of PB, LBW and SGA were 4.76%, 3.53% and 5.74%, respectively. In terms of PB, the analysis results showed that the gestational weight gain (GWG) and living in northern China were protective factors, while premature rupture of membranes, gestational hypertension, dental examination or treatment within 1-3 years and family with 3-4 members were risk factors. In the respect of LBW, GWG and daily consumption of milk and dairy products were the protective factors, while premature rupture of membranes, gestational hypertension, sedentary working time more than 6 hours, dental examination or treatment within 1-3 years and passive smoking were risk factors. For SGA, baby girl, passive smoking, peanut oil consumption and unsalted taste were risk factors, while folic acid supplementation was protective factor. Conclusion: The risk factors for PB, LBW and SGA were multifactorial, and relevant specific measures should be taken to reduce the occurrence of adverse neonatal outcomes.


Assuntos
Complicações do Trabalho de Parto/epidemiologia , Peso ao Nascer , China , Estudos de Coortes , Feminino , Idade Gestacional , Humanos , Recém-Nascido de Baixo Peso , Recém-Nascido , Recém-Nascido Pequeno para a Idade Gestacional , Gravidez , Nascimento Prematuro/epidemiologia , Estudos Prospectivos , Fatores de Risco
7.
Zhonghua Shao Shang Za Zhi ; 34(4): 214-218, 2018 Apr 20.
Artigo em Chinês | MEDLINE | ID: mdl-29690739

RESUMO

Objective: To investigate the effects of short chain fatty acid (SCFA) on barrier disruption of human intestinal epithelial cell induced by endotoxin/lipopolysaccharide (LPS) and the related mechanism. Methods: The human intestinal epithelial cell line Caco-2 was used to reproduce monolayer-cells. Cells were divided into control group, LPS group, and SCFA+ LPS group according to the random number table. Cells in control group were only routinely cultured with DMEM medium. Cells in LPS group were cultured with DMEM medium and LPS with final mass concentration of 10 µg/mL. Cells in SCFA+ LPS group were cultured with DMEM medium, LPS and SCFA (consisting of 0.5 mmol/L acetate, 0.01 mmol/L propionate, and 0.01 mmol/L butyrate) with final mass concentration of 10 µg/mL. At post culture hour (PCH) 0, 1, 2, 6, 12, and 24, transepithelial electrical resistance (TER) of cells was determined with an ohmmeter, with sample number of 72. Another portion of cells were divided and treated as above, and then Western blotting was employed to detect the protein expressions of zonula occludens 1 (ZO-1), occludin, and claudin-1 at PCH 24, with sample number of 6. Another portion of cells were divided and treated as above and then immunofluorescence was used to observe cellular morphology and distribution of ZO-1. Data were processed with analysis of variance of factorial design, one-way analysis of variance, least-significant difference test, and Bonferroni correction. Results: (1) Compared with that in control group, TER of cells in LPS group was significantly reduced from PCH 1 to 24 (P<0.01), while TER of cells in SCFA+ LPS group showed no obvious change (P>0.05). TER of cells in SCFA+ LPS group was significantly higher than that in LPS group from PCH 1 to 24 (P<0.01). (2) Compared with the protein expressions of ZO-1, occludin, and claudin-1 of cells in control group (1.25±0.10, 1.17±0.04, and 1.24±0.20), those of cells in LPS group (0.74±0.23, 0.76±0.11, and 0.77±0.11) at PCH 24 were significantly decreased (P<0.05), while those of cells in SCFA+ LPS group (1.23±0.46, 1.05±0.09, and 1.01±0.13) showed no significant differences (P>0.05). Protein expressions of occludin and claudin-1 of cells in SCFA+ LPS group were significantly higher than those in LPS group at PCH 24 (P<0.05). Protein expression of ZO-1 of cells in SCFA+ LPS group was higher than that in LPS group at PCH 24 with no significant difference (P>0.05). (3) At PCH 24, cells in control group were compact in arrangement with pebble-like appearance, and ZO-1 was distributed smoothly and continuously along the cell membrane. In LPS group, cells were sparse in arrangement with change in appearance, and ZO-1 was distributed uncontinuously along the cell membrane with curls and breaks. In SCFA+ LPS group, the appearance of cells and distribution of ZO-1 were remarkably ameliorated compared with those in LPS group. Conclusions: SCFA can alleviate the barrier disruption of human intestinal epithelial cell induced by LPS through interdicting the abnormal distribution of ZO-1 and decrease of TER and tight junction proteins' expressions.


Assuntos
Células CACO-2/fisiologia , Células Epiteliais/citologia , Ácidos Graxos Voláteis , Mucosa Intestinal/efeitos dos fármacos , Lipopolissacarídeos/farmacologia , Junções Íntimas/efeitos dos fármacos , Proteína da Zônula de Oclusão-1/metabolismo , Western Blotting , Células CACO-2/efeitos dos fármacos , Claudina-1 , Células Epiteliais/efeitos dos fármacos , Humanos , Mucosa Intestinal/metabolismo , Mucosa Intestinal/patologia , Intestinos , Ocludina , Distribuição Aleatória , Junções Íntimas/metabolismo
8.
Ann Oncol ; 29(6): 1402-1408, 2018 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-29659672

RESUMO

Background: Arginine depletion is a putative target in hepatocellular carcinoma (HCC). HCC often lacks argininosuccinate synthetase, a citrulline to arginine-repleting enzyme. ADI-PEG 20 is a cloned arginine degrading enzyme-arginine deiminase-conjugated with polyethylene glycol. The goal of this study was to evaluate this agent as a potential novel therapeutic for HCC after first line systemic therapy. Methods and patients: Patients with histologically proven advanced HCC and Child-Pugh up to B7 with prior systemic therapy, were randomized 2 : 1 to ADI-PEG 20 18 mg/m2 versus placebo intramuscular injection weekly. The primary end point was overall survival (OS), with 93% power to detect a 4-5.6 months increase in median OS (one-sided α = 0.025). Secondary end points included progression-free survival, safety, and arginine correlatives. Results: A total of 635 patients were enrolled: median age 61, 82% male, 60% Asian, 52% hepatitis B, 26% hepatitis C, 76% stage IV, 91% Child-Pugh A, 70% progressed on sorafenib and 16% were intolerant. Median OS was 7.8 months for ADI-PEG 20 versus 7.4 for placebo (P = 0.88, HR = 1.02) and median progression-free survival 2.6 months versus 2.6 (P = 0.07, HR = 1.17). Grade 3 fatigue and decreased appetite occurred in <5% of patients. Two patients on ADI-PEG 20 had ≥grade 3 anaphylactic reaction. Death rate within 30 days of end of treatment was 15.2% on ADI-PEG 20 versus 10.4% on placebo, none related to therapy. Post hoc analyses of arginine assessment at 4, 8, 12 and 16 weeks, demonstrated a trend of improved OS for those with more prolonged arginine depletion. Conclusion: ADI-PEG 20 monotherapy did not demonstrate an OS benefit in second line setting for HCC. It was well tolerated. Strategies to enhance prolonged arginine depletion and synergize the effect of ADI-PEG 20 are underway. Clinical Trial number: www.clinicaltrials.gov (NCT 01287585).


Assuntos
Carcinoma Hepatocelular/terapia , Hidrolases/uso terapêutico , Neoplasias Hepáticas/terapia , Cuidados Paliativos , Polietilenoglicóis/uso terapêutico , Carcinoma Hepatocelular/patologia , Terapia Combinada , Feminino , Seguimentos , Humanos , Neoplasias Hepáticas/patologia , Masculino , Pessoa de Meia-Idade , Prognóstico , Taxa de Sobrevida
10.
Eur J Med Chem ; 124: 537-543, 2016 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-27598239

RESUMO

Two complexes dichloro(9,9-dihexyl-4,5-diazafluorene)platinum(II) (Pt-DHF) and dichloro(9,9-dihexyl-4,5-diazafluorene)palladium(II) (Pd-DHF) were synthesized and their in vivo antitumour activity was investigated using an athymic nude mice model xenografted with human Hep3B carcinoma cells. Pt-DHF- and Pd-DHF-treated groups showed significant tumour growth inhibition (with about 9-fold and 3-fold tumour growth retardation) when compared with the vehicle control group. The liver toxicology effects on the animals of the two compounds were investigated. Pt-DHF and Pd-DHF-treated groups had a lower alanine transaminase and aspartate transaminase values than those of the vehicle treated group as the animals from the vehicle control group had very heavy hepatoma burden. We assume that both complexes could be further investigated as effective antitumour agents and it is worthwhile to study their underlying working mechanism.


Assuntos
Complexos de Coordenação/síntese química , Compostos Organoplatínicos/síntese química , Compostos Organoplatínicos/farmacologia , Paládio/química , Platina/química , Animais , Antineoplásicos/síntese química , Antineoplásicos/química , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Carcinoma Hepatocelular/tratamento farmacológico , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Complexos de Coordenação/química , Complexos de Coordenação/farmacologia , Modelos Animais de Doenças , Ativação Enzimática/efeitos dos fármacos , Xenoenxertos , Humanos , Fígado/efeitos dos fármacos , Neoplasias Hepáticas/tratamento farmacológico , Camundongos , Compostos Organoplatínicos/química , Compostos Organoplatínicos/uso terapêutico , Paládio/farmacologia , Paládio/uso terapêutico , Platina/farmacologia , Platina/uso terapêutico
11.
Genet Mol Res ; 12(3): 3806-12, 2013 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-24085442

RESUMO

Prostate cancer is one of the most common malignancies in men. The multidrug resistance 1 gene (MDR1) is an important candidate gene for prostate cancer. The aim of this study was to evaluate the association between MDR1 gene polymorphisms and the risk of prostate cancer. MDR1 gene polymorphism and its association with the risk of prostate cancer were investigated in 357 Chinese men. A novel c.1465C>T polymorphism was detected with created restriction site-polymerase chain reaction and DNA sequencing. We found a significantly increased risk of prostate cancer in the homozygote comparison [TT vs CC: odds ratio (OR) = 2.300, 95% confidence interval (95%CI) = 1.261-4.196, chi-square = 7.53, P = 0.007], heterozygote comparison (TC vs CC: OR = 1.667, 95%CI = 1.049-2.648, chi-square = 4.71, P = 0.030), dominant model (TT/TC vs CC: OR = 1.835, 95%CI = 1.197-2.815, chi-square = 7.81, P = 0.005), recessive model (TT vs TC/CC: OR = 1.776, 95%CI = 1.023- 3.085, chi-square = 4.23, P = 0.041), and allele contrast (T vs C: OR = 1.625, 95%CI = 1.199-2.202, chi-square = 9.87, P = 0.002). These findings suggested that the c.1465C>T polymorphism of MDR1 may be risk factors for prostate cancer in Chinese men.


Assuntos
Membro 1 da Subfamília B de Cassetes de Ligação de ATP/genética , Povo Asiático/genética , Polimorfismo de Nucleotídeo Único , Neoplasias da Próstata/genética , Subfamília B de Transportador de Cassetes de Ligação de ATP , Idoso , Idoso de 80 Anos ou mais , Alelos , Estudos de Casos e Controles , Frequência do Gene , Predisposição Genética para Doença , Genótipo , Humanos , Masculino , Razão de Chances , Fatores de Risco , Análise de Sequência de DNA
12.
Nucleosides Nucleotides Nucleic Acids ; 25(9-11): 1271-6, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-17065105

RESUMO

A truncated naturally occurring variant of the human purinergic receptor P2X7 (P2X7-R) was found in human cancer cervical cells. The novel protein consists of 258 amino acids, and compared to the wild-type P2X7-R it lacks the entire intracellular carboxy terminus, the second transmembrane domain, and the distal third of the extracellular loop. The truncated P2X7-R failed to form pores and mediate apoptosis, and it interacted with the wild-type P2X7-R in a manner suggesting auto-hetero-oligomerization. In contrast to cancer cells the novel truncated P2X7-R was expressed relatively little in normal cervical cells. These data raise the possibility that coexpression of the truncated form could block P2X7 mediated apoptosis and promote uncontrolled growth of cells.


Assuntos
Apoptose , Células Epiteliais/metabolismo , Regulação Neoplásica da Expressão Gênica , Receptores Purinérgicos P2/biossíntese , Neoplasias Cutâneas/metabolismo , Regulação para Cima , Animais , Linhagem Celular , Cães , Feminino , Células HeLa , Humanos , Estrutura Secundária de Proteína , Estrutura Terciária de Proteína , Receptores Purinérgicos P2/química , Receptores Purinérgicos P2X7 , Neoplasias do Colo do Útero/metabolismo
13.
FEBS Lett ; 484(2): 133-8, 2000 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-11068047

RESUMO

Dithiothreitol (DTT) treatment of angiotensin II (Ang II) type 2 (AT(2)) receptor potentiates ligand binding, but the underlying mechanism is not known. Two disulfide bonds proposed in the extracellular domain were examined in this report. Based on the analysis of ligand affinity of cysteine (Cys, C) to alanine (Ala, A) substitution mutants, we provide evidence that Cys(35)-Cys(290) and Cys(117)-Cys(195) disulfide bonds are formed in the wild-type AT(2) receptor. Disruption of the highly conserved Cys(117)-Cys(195) disulfide bond linking the second and third extracellular segments leads to inactivation of the receptor. The Cys(35)-Cys(290) bond is highly sensitive to DTT. Its breakage results in an increased binding affinity for both Ang II and the AT(2) receptor-specific antagonist PD123319. Surprisingly, in the single Cys mutants, C35A and C290A, a labile population of receptors is produced which can be re-folded to high-affinity state by DTT treatment. These results suggest that the free -SH group of Cys(35) or Cys(290) competes with the disulfide bond formation between Cys(117) and Cys(195). This Cys-disulfide bond exchange results in production of the inactive population of the mutant receptors through formation of a non-native disulfide bond.


Assuntos
Cisteína/metabolismo , Dissulfetos/metabolismo , Receptores de Angiotensina/metabolismo , Alanina/genética , Sequência de Aminoácidos , Substituição de Aminoácidos , Animais , Ligação Competitiva , Células COS , Ditiotreitol/farmacologia , Dados de Sequência Molecular , Mutação , Conformação Proteica , Ratos , Ratos Endogâmicos SHR , Receptor Tipo 1 de Angiotensina , Receptor Tipo 2 de Angiotensina , Receptores de Angiotensina/química , Receptores de Angiotensina/genética , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo
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