ObjectiveTo investigate the inhibitory effect of peroxisome proliferator-activated receptor-?(PPAR?) agonist on mesangial cell(MC) proliferation and extracellular matrix expression induced by angiotensin Ⅱ(Ang Ⅱ).MethodsThe incorporation of 3H-thymidine(3H-TdR) and cell count were used as the measurement of MC proliferation.MC cell-cycle was analyzed by flow cytometry.Mouse primary MC was treated with various concentration of Ang Ⅱ(1,10,100 nmol/L) in the presence or Absence of N-acytosistin(NAC) or rosiglitazone.Transforming growth factor-?1(TGF-?1),plasminogen activator inhibitor-1(PAI-1),and fibronectin(FN) mRNA expression were determined by real time-PCR.Reactive oxygen species(ROS) production was measured by 2,7-dichlorofluorescein diacetate(DCFDA) fluorescence.Results1.One hundred nmol/L Ang Ⅱ increased 3H-TdR incorporation and cell number by 2.14 and 2.32 fold,respectively.Ang Ⅱ-induced MC proliferation was inhibited by PPAR? agonist rosiglitazone with dose-dependent manner in mouse MC.2.One hundred nmol/L Ang Ⅱ stimulation for 24 h induced 48% MC processed to S and G2/M phase.Rosiglitazone significantly blocked Ang Ⅱ increased cell number in S and G2/M phase.3.Rosiglitazone reduced Ang Ⅱ-induced TGF-?1,PAI-1,and FN mRNA expression with dose-dependent manner.4.One hundred nmol/L Ang Ⅱ stimulation for 60 min increased ROS production by 3.85 folds.Rosiglitazone significantly inhibited Ang Ⅱ-induced ROS production.Ten ?mol/L rosiglitazone almost completely blocked Ang Ⅱ-induced ROS production.ConclusionPPAR? agonist rosiglitazone could block Ang Ⅱ-induced MC proliferation and extracellular matrix expression via inhibition of ROS production.

Arsenic ; toxicity ; Arsenic Poisoning ; Ecotoxicology

Objective To investigate the DNA methylation feature and DNA methylation regulation to its transcription and expression of O6-methylguanine-DNA methyltransferase gene (MGMT) in NaAsO2-treated HaCaT cells. Methods HaCaT cells were treated 72 hours at intervals and repeatedly by 3.13, 6.25,12.50, and 25.00 μmol/L NaAsO2, MGMT gene promoter region was amplified in the transcription initiation site - 329 - + 93 region by bisulfate-sequencing polymerase chain reaction (BSP), the mRNA transcription and the protein expression of MGMT was detected by real-time quantitative PCR and Western blotting. NaAsO2-untreated HaCaT cell was set as a blank control, and human epidermal squamous carcinoma cell strain A431 was set as a positive control. Results Among the groups of HaCaT cells treated with 3.13, 6.25, 12.50 and 25.00 μmol/L NaAsO2, the positive rates of the DNA methylation of promoter region in MGMT gene were 0.63%(l/160), 6.25% (10/160), 10.63%( 17/160) and 18.75% (30/160), respectively, and methylated CpG sites were mainly located in - 249--146 region relative to transcription start site. There was no DNA methylation in the blank control. There were significant differences between the blank control and the NaAsO2-treated cells (x2 = 76.687, P< 0.05). Average levels of MGMT mRNA were 1.518 31 ± 0.180 54, 1.425 22 ± 0.180 39, 1.014 54 ± 0.096 79 and 0.887 72 ± 0.020 00, respectively among the groups of HaCaT cells treated with 3.13, 6.25, 12.50 and 25.00 μmol/L NaAsO2, compared with the blank control cells(1.198 29 ± 0.159 97), there were significant differences(F = 37.359, P < 0.05). Average levels of MGMT protein were 1.174 47 ± 0.064 75, 0.848 83 ± 0.057 01, 0.471 63 ± 0.023 34 and 0.240 34 ± 0.014 43, respectively among the groups of HaCaT cells treated with 3.13, 6.25, 12.50 and 25.00 μmol/L NaAsO2, compared with the blank control cells (1.066 19 ± 0.061 24), there were significant differences(F = 20.687, P < 0.05). Conclusions Arsenic can cause CpC island hypermethylation in the promoter region of MGMT gene, which results in inhibited MGMT mRNA transcription and protein expression. It might be one of the important mechanisms of arsenic-induced skin lesion.

Objective To investigate the effect of NaAsO2 on the binding levels of methyl CpG binding protein 2(MeCP2),DNA methyltransferase 1 (DNMT1) and histone deacetylase 1(HDAC1) to the hypermethylation promoter region of MGMT gene in HaCaT cells,in order to provide a basis to deepen the interpretation of the role of arsenic poisoning mechanism.Methods HaCaT cells were treated repeatedly and interval with different concentrations of NaAsO2(3.13,6.25,12.50,25.00 μnol/L,respectively) for 72 h.Untreated HaCaT was used as blank control group and human epidermal squamous carcinoma cell line(A431 cells) as positive control group.The binding levels to the two transcription regulatory regions(ChIP1,ChIP2) and to the coding region(ChIP3) of MGMT 8ene were detected by chromatin immuno-precipitation combined with quantitative PCR.Results The differences of binding levels of MeCP2,DNMT1 and HDAC1 to ChIP1 and ChIP2 in each group were significant (F=7.387,84.634,78.442 and 19.263,69.649,26.546,all P ＜ 0.05).The binding levels of MeCP2,DNMT1 and HDAC1 to ChIP1 and ChIP2 in each NaAsO2 exposed group[3.13 μmol/L NaAsO2 exposed group:(136.00 ±16.97)％,(145.00 ± 2.83)％,(88.50 ± 19.09)％ and (106.50 ± 37.48)％,(112.34 ± 8.73)％,(59.71 ± 8.49)％;6.25 μmol/L NaAsO2 exposed group:(130.00 ± 42.43)％,(154.50 ± 4.95)％,(101.00 ± 1.27)％ and (88.50 ±3.54)％,(134.32 ± 2.82)％,(102.75 ± 19.91)％ ; 12.50 μmol/L NaAsO2 exposed group:(141.50 ± 23.33)％,(161.50 ± 7.78)％,(125.00 ± 11.31)％ and (119.50 ± 24.75)％,(171.59 ± 3.54)％,(167.61 ± 10.61)％; 25.00μmol/L NaAsO2 exposed group:(134.50 ± 43.13)％,(472.50+ 50.20)％,(383.50 ± 30.41)％ and (180.09 ±12.73)％,(348.50 ± 27.58)％,(158.45 ± 12.02)％] were higher than that in the blank control group[(51.50 ±9.19)％,(82.00 ± 12.73)％,(25.03 ± 2.91)％ and (37.02 ± 4.24)％,(91.56 ± 26.16)％,(19.09 ± 2.90)％,all P ＜ 0.05].The differences of binding levels of MeCP2 to ChIP3 in each group were not significant(F =1.670,P ＞0.05),but the differences of binding levels of DNMT1 and HDAC1 to ChIP3 were significant (F =4.404,9.863,all P ＜ 0.05),and only the binding levels in the 25.00 μmol/L NaAsO2 exposed group [(615.85 ± 29.63)％,(306.09 ± 59.40)％] were higher than that in the blank control group[(99.70 ± 12.02)％,(92.45 ± 48.79)％,all P ＜ 0.05].Conclusions MeCP2 can bind to the methylated MGMT gene transcriptional regulatory regions which are induced by arsenic and leads to histone deacetylation by the recruitment of DNMT1 and HDAC1 and,meanwhile,DNMT1 can bind to the coding region of MGMT gene to recruit HDAC1 in a methyl DNA binding protein(MBD) independence manner and media MGMT gene silencing through the chromatin remodeling way,which might be the early molecular events of arsenic poisoning.

AIM:To observe the effects of Dickkopf-3 ( Dkk-3 ) in diabetic retinopathy ( DR ) circulating blood in patients with the expression level, the Dkk - 3 development changes in the diabetic retinopathy of significance in the diagnosis of early DR.
● METHODS: Eighty - five type 2 diabetic patients, included the non - proliferative diabetic retinopathy ( NPDR ) 23 patients, proliferative diabetic retinopathy, proliferative DR ( PDR ) in patients with 30 and non-diabetic retinopathy ( NDR ) with 32 cases. The same period of healthy physical examination was selected as control group ( 80 cases ) . Serum samples were collected, and the relative expression level of Dkk-3 was detected by enzyme - linked immunosorbent assay ( ELlSA) double antibody sandwich assay. The statistical differences were compared between groups.
●RESULTS: The plasma level of Dkk - 3 ( 430. 16 ± 198. 11pg/mL) in DR patients was significantly lower than that in healthy control group (627. 48±294. 45 pg/mL; P<0. 05 ) and NDR patients ( 601. 99 ± 194. 16 pg/mL; P<0. 05). While there was no significant difference in Dkk-3 level between NDR and healthy control group ( P =0. 729). The level of PDR in patients with Dkk-3 (396. 38± 185. 59 pg/mL) was lower than that of NPDR (538. 82 ± 187. 20 pg/mL;P=0. 002).
●CONCLUSION:The decrease of Dkk-3 level may be related to the occurrence and development of diabetic retinopathy, and there is a significant correlation with PDR. Circulating blood Dkk - 3 protein in diabetic retinopathy has a certain differential efficacy, it is likely to become diabetic retinopathy patients peripheral blood test indicators.

Adult ; Humans ; Lipids ; blood ; Male ; Occupational Exposure ; Vanadium ; toxicity

Angiotensin II ; pharmacology ; Blotting, Western ; Cells, Cultured ; Glomerular Mesangium ; cytology ; drug effects ; metabolism ; Humans ; I-kappa B Kinase ; NF-kappa B ; analysis ; Peptide Fragments ; pharmacology ; Protein-Serine-Threonine Kinases ; analysis

Animals ; Cadmium Radioisotopes ; toxicity ; Female ; Fetal Development ; drug effects ; Fetus ; Maternal-Fetal Exchange ; Pregnancy ; Rats ; Rats, Sprague-Dawley

Adolescent ; Adult ; Athletic Injuries ; Clinical Clerkship ; Female ; Humans ; Nurses ; Occupational Injuries ; Young Adult

Objective To investigate the distribution of pathogenic bacteria,drug sensitivity,and the relationship between drug sensitivity and Escherichia coli(E.coli) induced enzymes in childhood diarrhea in the last 2 years in Chongqing area,so as to provide important evidence for pediatric clinical therapy.Methods Thirty-one E.coli induced enzymes,extended spectrum ?-laetamases(ESBLs),cephalosporinase(AmpC)detected in different phenotype methods,and drug sensitivity was measured in paper strip method,and the specimens were collected from children′s hospital affiliated to chongqing university of medical sciences from Jan.2005 to Dec.2006 were determined.Among the total,there were 18 enteropathogeic E.coli(EPEC) strains,8 enterotoxigenic E.coli(ETEC) strains and 5 enteroinvasive E.coli(EIEC) strains.In addition,drug resistance tests by paper strip included chloramphenicol(CHL),amikacin(AMK),gentamicin(GEN),norfloxacin(NOF),ciproflocacin(CIP),cefazolin(CEZ),cefoperazone(CPZ),ceftriaxone(CRO),ceftazidime(CAZ),cefotacime(CTX),cefepime(FEP),imipenem(IPM).SPSS 12.0 software was used to analyze the data.Results Three point two percent of the 31 E.coli were drug resistant to IPM,and 35.5%,38.7% to NOF,CIP individually,but more than 60% to AMK,GEN,even more than 67.7% towards cephalosporin(except ceftazidime and cefepime);the gross enzyme-produced rate was 87.1%,rate of single ESBLs,AmpC,and induction of both enzymes simultaneously presented 64.5%,6.5%,16.1% respectively;and there was marked difference in drug resistance when bacteria that produced single AmpC versus bacteria that produced single ESBLs or that produced both ESBLs and AmpC(Pa﹤0.05).Conclusions The relationships among enzyme′s quantity,sort and bacterial resistance are different.These data show E.coli infected by bacterial diarrhea children in Chongqing due to a high rate of induced enzymes,and their drug resistance vary according to the state of induced enzymes.