【Abstract】Objective To investigate the apoptosis induced by TGF-β1 in human hepatic carcinoma cell lines and its relationship with p53 gene and Smad. Methods Three human hepatic carcinoma cell lines which involving in various status of the p53 gene were used in this study. TGF-β1-induced apoptosis in hepatic carcinoma cell lines was measured by the terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay. To study the mechanism of TGF-β1-induced apoptosis, these cell lines were transfected with a TGF-β1-inducible luciferase reporter plasmid containing Smad 4 binding elements (SBE) and luciferase gene using Lipofectamine 2000, then treated with TGF-β1, relative luciferase activity was assayed. Results Of three cell lines studied with TUNEL assay, TGF-β1 induced apoptosis was observed in HepG2 cells (wild type p53). Huh-7 (mutant p53) and Hep3B (deleted p53) cell lines showed less apoptosis. Luciferase activity assay indicated that the response to TGF-β1 induction in HepG2 cells was increased dramatically but was not significant in Huh-7 and Hep3B cell lines. Conclusion HepG2 cells seem to be highly susceptible to TGF-β1-induced apoptosis compared with Hep3B and Huh7 cell lines. Smad 4 is a central mediator of the TGF-β1 signal transduction pathway.
Objective To construct AWP1 (associated with protein kinase C related kinase 1) recombinant adenovirus as the tool of transferring the gene and investigate its expression and localization in human vascular endothelial cell ECV304. Methods Cloned AWP1 cDNA was inserted into the multiply clone sites (MCS) of plasmid pcDNA3 for adding flag tag, and the flag-AWP1 gene was subcloned into shuttle vector pAdTrack-CMV. After identified with restrictional enzymes, plasmid pAdTrack-flag-AWP1 was linearized by digestion with restriction endonuclease PmeⅠ, and subsequently cotransformed into E.coli BJ5183 cells with adenoviral backbone plasmid pAdEasy-1 to make homologous recombination. After linearized by PacⅠ, the homologous recombinant adenovirus plasmid transfected into 293 cells with Lipofectamine to pack recombinant adenovirus. After PCR assay of recombinant adenovirus granules, recombinant adenoviruses infected 293 cells repeatedly for obtaining the high-level adenoviruses solution. And then, the recombinant adenoviruses infected human ECV304 cells for observing the expression and localization of AWP1 under laser scanning confocal microscope (LSCM). Results PCR assay showed that recombinant adenovirus Ad-flag-AWP1 was obtained successfully; and ECV304 cells were infected high-efficiently by the homologous recombinant virus. Then, it was observed that flag-AWP1 protein expressed in ECV304 cells and distributed in the leading edges of the cell membrane. Conclusion The vectors of flag-AWP1 recombinant adenovirus are constructed, and the localization of AWP1 protein in ECV304 cells might show that AWP1 may be a potential role on the cell signal transduction.
ObjectiveTo investigate the expressions of Patched-1 (Ptch1) and glioma-associated oncogene homologl (Gli1) protein of sonic hedgehog signaling pathway in cholangiocarcinoma tissues, and explore their correlations to the occurrence and development of cholangiocarcinoma. MethodsThe expressions of Ptch1 and Gli1 protein in 62 specimens of cholangiocarcinoma and its bile duct tissues adjacent to cancer were detected by immunohistochemistry, and their positive rate correlated with patients, age, tumor size, differentiation grade, tumor location, lymph node metastasis, TNM stage, operation mode, and postoperative survival time were investigated by statistical analysis. ResultsThe positive rates of Ptch1 and Gli1 protein were significantly higher in cholangiocarcinoma than in tissues adjacent to cancer (74.2% vs. 14.5%, 88.7% vs. 9.7%, P < 0.05). The expressions of Ptch1 and Gli1 protein in cholangiocarcinoma had no correlation to patients age, tumor size, and tumor location (P > 0.05), but were correlated to the operation mode, differentiation grade, lymph node metastasis, TNM stage, and postoperative survival time of patients (P < 0.05). ConclusionsThe elevated expressions of Ptch1 and Gli1 protein of Hh signaling pathway participated in the occurrence and development of cholangiocarcinoma. They may be ideal targets for therapy against cholangiocarcinoma.
Objective To probe into the roles of inositol 1, 4, 5-trisphosphate (IP3) and bcl-2 gene expression in inhabiting hepatocellular carcinoma of nude mice by quercetin. Methods Animals with hepatocellular carcinoma in quercetin group were treated with injection peritoneum of quercetin 50 mg/（kg·d ） for 3 weeks, while which in control group were treated with 0.4% DMSO of RPMI 1640 0.05 ml/（g·d）. Then the volume and the weight of tumors were measured, IP3, bcl-2 mRNA and bcl-2 protein were assayed by IP3-［3H］ Birtrak Assay, RT-PCR and Western blot respectively. Results The volume and weight of tumors in quercetin group were lower than those in control group 〔（15.8±10.1） mm3 vs. （52.3±26.5） mm3 in volume, （44.8±10.4） mg vs.（91.3±31.4） mg in weight， P＜0.01〕. Content of IP3 in quercetin group was lower than that in control group 〔（13.4±1.4） pmol/mg prot vs. （35.3±6.6） pmol/mg prot， P＜0.01〕. There was no significant difference in bcl-2 mRNA expression between quercetin group and control group 〔RI （the gray degree multiply area of bcl-2 /the gray degree multiply area of β-actin）： 0.55±0.05 vs. 0.79±0.19， P＞0.05〕， but the expression of bcl-2 protein in quercetin group was lower than that in control group (RI: 1.07±0.12 vs. 6.69±1.80, P＜0.01). Conclusion Quercetin can inhabit the growth of hepatocellular carcinoma tansplanted into liver of nude mice by reducing IP3 production and down-regulating bcl-2 gene expression.
Objective To evaluate the effect of left atrial enlargement on atrial myocardial fibrosis degree and levels of the angiotensinⅡ (AngⅡ)/Rac GTPase activating protein 1 (Rac1)/signal transducersand activators of transcription 3 (STAT3) signaling pathways expressing in patients with persistent atrial fibrillation and rheumatic heart disease (RHD). Methods From March to December 2011, 30 patients with RHD who underwent prosthetic valve replacement in our hospital were enrolled, including 16 males and 14 females, aged 42-70 (56.9±6.8) years. Twenty RHD patients with persistent atrial fibrillation as a research group and ten RHD patients with sinus rhythm as a control group (group A) underwent transthoracic echocardiography and right atrial appendage (RAA) tissue samples were obtained from these patients during mitral/aortic valve replacement operation. The research group according to left atrial diameter (LAD) was divided into two groups, ten patients in each group: a group B with LAD of 50–65 mm and a group C with LAD of LAD>65 mm. For each sample, histological examination was performed by hematoxylin-eosin and Masson’s trichrome staining. Light-microscopic pictures of atrial tissues samples were stained and tissue fibrosis degree in each group was analyzed. AngⅡ concentration was measured by enzyme linked immunosorbent assay. Rac1 and STAT3 were measured by western blotting. Results LAD was significantly greater in AF patients with RHD than in the control group. Hematoxylin-eosin staining demonstrated highly organized arrangement of atrial muscles in the control group and significant derangement in both group B and group C with reduced cell density and increased cell size. Moreover, Masson’s trichrome staining showed that atrial myocytes were surrounded by large trunks of collagen fibers in both group B and group C, but not in the group A. There was a positive correlation between atrial tissue fibrosis and LAD. AngⅡ content was positively correlated with LAD. Similarly, Rac1 and STAT3 protein levels were found considerably higher in the group C and group B than in the group A with excellent correlation to LAD. Conclusion In patients with RHD complicated with persistent atrial fibrillation, the degree of atrial fibrosis and the expression level of AngⅡ/Rac1/STAT3 signaling pathways significantly increase with the left atrialenlargement.
To summarize Notch, basic hel ix-loop-hel ix (bHLH) and Wnt gene signal transduction pathways in the process of differentiation and development of neural stem cells. Methods The l iterature on the gene signal transduction pathway in the process of differentiation and development of neural stem cells was searched and then summarized and analyzed. Results The formation of Nervous System resulted from common actions of multi-signal transduction pathways. There may exist a fixed threshold in the compl icated selective system among Notch, bHLH and Wnt gene signal transduction pathways. Conclusion At present, the specific gene signal transduction pathway of multi pl ication and differentiation of neural stem cells is still unclear.
ObjectiveTo observe whether interleukin-27 (IL-27) intervention could diminish allergic airway inflammation of mouse asthma induced by ovalbumin (OVA) and to investigate the related molecular mechanisms. MethodsSixty female C57/6J mice were randomly divided into six groups, a control group, an asthma group, two IL-27 prevention groups and two IL-27 treatment groups. Based on being sensitized and challenged with OVA in the asthma model, two kinds of IL-27 intervention asthma models were set up, one of which was low-dose multiple prevention model, the other was high-dose few times treatment model. HE stain and inflammation score were done for the lungs. CD4+ T cells were purified from mice spleen and cultured under Th2 medium with/without IL-27. Interleukin-4 (IL-4) was measured by ELISA. CD4+ T cells were cultured under different stringent Th2 medium and stimulated by IL-27. The level of total signal transducer and activator of transcription-1 (STAT1) protein and phos-STAT1 were tested by Western blot. ResultsIn low-dose multiple prevention group, IL-27 inhibited inflammation around bronchial and vascular obviously, the inflammation score was lower than the asthma group (P < 0.05), while the treatment group had no obvious statistical significance (P > 0.05). IL-27 repressed Th2 differentiation of naïve CD4+ T cells which was independent of interferon-γand IL-10. This effect was via STAT1 signaling pathway. CD4+ T cells from asthma mice or cultured under high-IL-4 inducing medium were found impairment of STAT1 phosphorylation. ConclusionsIL-27 could inhibit Th2 differentiation of naïve CD4+ T cells, but not in already committed Th2-CD4+ T cells. The inhibition effect of IL-27 for airway inflammation is obvious in prevention group, while the treatment group shows obviously resistance to inhibitory effect of IL-27. Already committed Th2-CD4+ T cells existed in asthma airway might be the reason for IL-27 resistance.
目的 研究活动期多发性肌炎患者外周血白细胞细胞因子信号转导蛋白抑制因子（SOCS）1、SOCS2、SOCS3和细胞因子诱导的含SH2区域蛋白1（CIS）与正常人表达的差异，探讨SOCS在多发性肌炎发病中可能的作用。 方法 2011年6月－12月，采用实时荧光定量聚合酶链反应法检测了14例活动期多发性肌炎患者和14例正常人外周血白细胞中SOCS1、SOCS2、SOCS3和CIS1基因的相对表达量。 结果 与对照组相比，多发性肌炎症患者外周血白细胞基因SOCS 1～3表达明显降低（P值均＜0.05），CIS1基因的表达较对照组明显升高（P＜0.05），差异有统计学意义。 结论 SOCS基因家族可能参与了多发性肌炎的发病，该蛋白分子家族的成员可能会成为多发性肌炎治疗的一种新的候选基因。
ObjectiveTo investigate the associations of signal transducers and activators of transcription 6 (STAT6) gene polymorphisms with susceptibility to tuberculosis in western Chinese Han population.MethodsA total of 900 tuberculosis patients and 1 534 healthy controls of West China Hospital of Sichuan University were enrolled from January 2014 to February 2016. Improved multiplex ligation detection reaction method was used to detect four polymorphisms (rs1059513, rs73118432, rs841718, and rs10783813) of STAT6 gene. The allelic frequencies, genetic types, and different genetic models were analyzed using the chi-square test and unconditional logistic regression models to evaluate the associations of STAT6 gene with tuberculosis risk.ResultsEventually, a total of 856 cases and 1 511 health controls were recruited in our study. No significant differences were observed in allele frequencies, genotype distributions, or genetic models (additive model, dominant model and recessive model) at rs1059513, rs73118432, rs841718, and rs10783813 in STAT6 gene (P>0.05). We found a strong linkage disequilibrium among rs73118432, rs841718, and rs10783813, but there was no statistical difference in haplotype frequencies between the two groups (P>0.05).ConclusionsSTAT6 gene rs73118432, rs841718, rs10783813, and rs1059513 polymorphisms might have no associations with tuberculosis susceptibility in western Chinese Han population. Further studies with larger sample sizes are needed to comfirm these results.
Objective To review the latest development of the research on the selfrenwal signaling pathway and culture system in vitro of the embryonic stem cells(ESCs). Methods The recent articlesabout the selfrenewal signaling pathway and culture system in vitro of the ESCs were extensively reviewed. Results Understanding of the molecular mechanism of the selfrenewalin vitro and pluripotency of the ESCs was considered important for developing improved methods of deriving, culturing and differentiating these cells into the cells that could be successfully used in the clinical practice. Conclusion A further research is needed to elucidate the selfrenewal signaling pathway and the pluripotency of the ESCs and the culture systemin vitro forthe human ESCs remains to be further improved and developed.