AIM　In order to improve the biological activity and reduce the side effects and toxicity, a series of novel estrogen receptor antagonists were designed. METHODS　The key triphenylethylene intermediates were obtained by the McMurry reaction. The target compounds were prepared by etherification. The binding affinities of the target compounds for the estrogen receptor in rat uterine cytosol were measured by a competitive binding assay and their estrogen agonistic/antagonistic properties were investigated in the 3-day uterine weight assay in the immature rats. RESULTS　Thirty-five new compounds have been synthesized and their geometric configuration were determined by X-ray crystallography and 1HNMR spectral data. CONCLUSION　All of the test compounds showed affinity for the estrogen receptor (IC50<10-6 mol.L-1), especially compound 35 with IC50 1.07×10-8 mol.L-1. Some compounds are antagonists, inhibiting uterus growth; others are agonists, promoting uterus growth. Compounds 14 and 27 are superior antagonists to tamoxifen.

Objective: To explore if conventional protein kinase C (cPKC: PKCα and PKCβ) contributes to paraquat (PQ) -induced abnormal permeability of mouse brain microvascular endothelial cells (BMECs) via the regulation of tight junction (TJ) proteins. Methods: The immortalized mouse brain endothelial cell line (bEnd.3) was used to establish a monolayer blood-brain barrier (BBB) model. In order to evaluate the function of the in vitro BBB model, the transendothelial electrical resistance (TEER) and permeability were measured by a Millicell-ERS volt-ohmmeter and sodium fluorescent (Na-FLU) , respectively. MTT assay was used to determine the relative survival rate of cells. The dose-response relationship was determined by treating cells with 0, 50, 100, 200, and 300 μmol/L PQ for 24 hours. The time-response relationship was determined by treating cells with 200 μmol/L PQ for 6, 12, 24, 48, and 72 hours. After the treatment of cells with 0, 100, 200, and 300 μmol/L PQ for 24 hours, the protein and mRNA expression levels of ZO-1, Occludin, and Claudin-5 were measured by immunofluorescence (IF) and quantitative real-time RT-PCR (qRT-PCR) , respectively; the expression of PKCα, PKCβ, phosphorylated (p) -PKCα, and p-PKCβ was determined by Western blot. After the treatment of cells with 200? mol/L PQ for 24 hours following the pretreatment with a classical PKC inhibitor (Go 6983, 1 μmol/L) for 1 hour, the protein expression of ZO-1, Occludin, Claudin-5, p-PKCα, and p-PKCβ was measured by Western blot. Results: The TEER of the bEnd. 3 cells increased gradually with the cell culture time, and reached a peak value of 114.3±6.9 Ω·cm² on day 6. According to the permeability analysis by Na-FLU, cell permeability gradually decreased with the cell culture time, and reached 1.7±0.2 cm/min on day 6, suggesting a well-behaved barrier function of cells. Compared with the control group, the survival rates of the bEnd.3 cells were significantly reduced after exposure to 100, 200, or 300 μmol/L PQ for 24 hours (P<0.05) , or after exposure to 200 μmol/L PQ for 6, 12, 24, 48, or 72 hours (P <0.05) , indicating a dose-and time-dependent relationship. The IF and qRT-PCR results showed that the protein and mRNA expression levels of ZO-1, Occludin, and Claudin-5 were significantly reduced with the increase in the concentration of PQ (P<0.05) . The Western blot analysis showed that compared with the control group, cells exposed to PQ had significantly higher protein expression of p-PKCα and p-PKCβ and significantly lower protein expression of ZO-1, Occludin, and Claudin-5 (P<0.05) . Compared with the PQ treatment group, the Go 6983 intervention group had significantly higher protein expression of ZO-1, Occludin, and Claudin-5 and significantly lower protein expression of p-PKCα and p-PKCβ (P<0.05) . Conclusion By activation of cPKC (PKCα and PKCβ) , PQ reduces the protein and mRNA expression of TJ proteins and enhances the permeability of murine BMECs.

Objective: To investigate the effects of Paraquat on neural stem cell proliferation in vitro and explore the its mechanism based on DNA methylation pathway. Methods: Nestin, β-tubulin III, and glial fibrillary acidic protein (GFAP) were detected by indirect immunofluorescence assay to evaluate self renewal and differentiation potentia of ReNcell CX human neural stem. The cells were treated with terminal concentrations of 0, 5, 25, 50, and 100μmol/L PQ for 24 hours, and the cells were induced by 50 μmol/L PQ for different time (6, 12, 24, 48 h). Cell viability was determined by MTT assay. The proliferation of neural stem cells was evaluated using Sox2/Brdu and Nestin/Brdu double immunofluorescence staining. The global DNA methylation level was assayed by MethyflashTM methylated DNA Quantification kit. The expression levels of Dnmts mRNA and protein were analyzed by quantitative reverse transcription polymerase chain reaction(qRT-PCR) and Western blot, respectively. Results: Immunofluorescence showed that nestin was primarily expressed in proliferative neural stem cell and peotein biomarkers (β-tubulin III, GFAP) for neuron and astrocyte were expressed in differentiated cells. MTT assay showed PQ induced cell survival rate decrease in a time and dose dependent manner. Double immunfluorescence staining of cells showed colocalization of Sox2 and Brdu. The percentage of Brdu/Sox2 positive cells was significantly lower in the PQ-exposed (25, 50, 100μmol/L PQ treatment) groups compared to control (P<0.05); Meanwhile, The percentage of Brdu/Nestin positive cells was also significantly lower in the PQ-exposed(50,100μmol/L PQ treatment) groups compared to control (P<0.05). The results of global DNA methylation revealed a significant decrease in PQ-exposed groups (P<0.05). Western blot showed that compared with control group, the protein and mRNA levels of Dnmt1, Dnmt3a in PQ-exposed group were significantly decreased (P<0.05), but there was a significant increase in expression level of Dnmt3b in 50, 100 μmol/L PQ-treated group(P<0.05). Conclusion Paraquat could inhibite the proliferation of human neural stem cells through reducing the level of DNA methylation reaction by suppressing the protein expression and transcription of DNA methylated transferase(Dnmts).

Objective: To investigate the roles of p38 mitogen-activated protein kinases (p38 MAPK) , extracellular regulated protein kinases (ERK) and c-Jun N-tenninal kinases (JNK) of MAPK signaling pathway in Paraquat-induced epithelial to mesenchymal transition (EMT) of type II alveolarepithelial cells. Methods: RLE-6NT cells were incubated with different concentrations of PQ (0, 25, 50, 100μmol/L) for 6, 12 and 24 h. Cell morphology alteration was observed under phase-contrast microscopy. Cell viability was determined using an MTT assay. Cell migration ability was detected using scratch wound assay. Protein expression of P-p38 MAP, P-Erk1/2, P-JNK, E-cad, ZO-1, Vimentin and а-SMA were detected by western blot. The level of genes related to fibrosis (COL-I, COL-III, FN and FSP-1) were analyzed via quantitative real-time RT-PCR. Results: Cell morphology started to undergo EMT changes with a phenotype characteristic of mesenchymal cells, including an elongated shape and a lack of tight cell-cell adhesions induced by 100μmol/L PQ treatment in a time-dependent manner. MTT showed that cell viability decreased with increasing PQ concentration (50、100、200、300 μmol/L PQ treatment for 24 h) and increasing treatment time (200 μmol/L PQ treatment for 6, 12, 24, 36, 48 h) . Compared to control group, the expressions of the epithelial phenotype marker E-cad and ZO-1 significantly decreased with PQ treatment (50, 100μmol/L) in a time-dependent manner (P<0.05) . Additionally, the level of the mesenchymal marker (a-SMA, vimentin) dramatically increased with PQ treatment in the same concentration-and time-dependent manner (P<0.05) . Cell migration ability was markedly increased after 24 h of 100 μmol/L PQ treatment compared to control (P<0.05) . The phosphorylated forms of p38 MAPK, Erk1/2, and JNK were increased at 24 h after stimulation with PQ (P<0.05) . This PQ induced (100 μmol/L) phosphorylation was markedly attenuated in the presence of the p38 MAPK, ERK and JNK inhibitors (SB-203580, SP-600125 and PD98059) respectively. Furthermore, RT-PCR showed that PQ significantly induced the upregulation expression of COL I and III mRNA, Fn, and FSP-1 mRNA (P<0.05) . Conclusion PQ-induced pulmonary fibrosis occurs via EMT, which is mediated by the MAPK pathway.