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Objective To investigate the release of enterogenic and hepatogenic high mobility group protein B1(HMGB1)through exosomes and its regulatory pathway.Methods We used wild-type(WT)and ASC-/-mice for this study.We randomly selected five mice per group from each strain and fed them either a normal diet(ND)or a high-fat diet(HFD)for eight weeks.The control group consisted of WT mice fed with the normal diet;the HFD group were WT mice with the HFD;the microflora disturbance(MD)group were ASC-/-mice fed with the normal diet;the high-lipid microflora disturbance(HLMD)group were ASC-/-mice with HFD.We used confocal microscopy to detect the co-localization of liver and intestinal exosome markers with HMGB1.We then measured the expression level of HMGB1 content in exosomes by Western blotting and PCR.The AML12 cells were treated with palmitic acid(PA)and lipopolysaccharide(LPS)for 24 h to build an in vitro model.We also detected HMGB1/CD63 levels using Western blotting.To understand the regulatory mechanism of exosome release,we employed siRNA intervention.Results The secretion of exosomes increased significantly in HFD group compared with control group[(3.5±0.2)ng/ml vs.(1.1±0.3)ng/ml,P<0.05],HLMD group compared with those in MD group[(3.2±0.2)ng/ml vs.(1.9±0.4)ng/ml,P<0.05].Using immunofluorescence detection,we observed increased co-localization of exosome markers(ALP or VPS16)with HMGB1 in HFD group compared with control group.We also observed this in AML12 cells treated with PA and LPS compared with blank control.The PCR data showed that HMGB1 in hepatocyte exosomes was higher in HFD group compared with control group(41.5±10.2 vs.1.3±0.3,P<0.05),HLMD group was significantly higher than that in MD group(48.6±7.2 vs.1.5±0.5,P<0.05).TLR4 expression was higher in HFD group compared with control group(13.8±6.2 vs.2.8±0.9,P<0.05),HLMD group compared with MD group(22.6±4.1 vs.2.5±1.5,P<0.05).In intestinal mucosal cells,the co-location of HMGB1 and exosome marker CD63 was significantly higher in HFD group compared with control group(0.6±0.2 vs.0.4±0.1,P<0.05),and HLMD group compared with MD group(0.9±0.2 vs.0.5±0.1,P<0.05).In vitro,the HMGB1 of exosomes was increased in endotoxin group(5.1±0.8)and high lipid endotoxin group(5.5±0.7)compared with control group(3.8±0.6,P<0.05).On the other hand,the HMGB1 of exosomes in the cell siRNA intervention group was not increased compared with control group(3.7±0.6 vs.3.8±0.6,P>0.05).Conclusion HMGB1 is released by exosomes in hepatocytes and intestinal cells,and regulated by Toll-like receptor 4(TLR4)under a high-fat diet and intestinal flora disorder,which may be one of the contributing factors in promoting the development of steatohepatitis.
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Thrombospondin 4 (THBS4), a member of the THBS family, is a protein secreted by the extracellular matrix and is involved in regulating various physiological processes, such as cell proliferation, adhesion and angiogenesis. Recent studies have shown that the inflammation stimulates THBS4 production and induces the adhesion and accumulation of macrophages. Our previous study confirmed that THBS4 acts as an oncogene in hepatocellular carcinoma (HCC), the effect of THBS4 on the immune microenvironment of HCC remains unclear. This study aims to analyze the role of THBS4 in promoting the metastasis of HCC cells by inducing M2-type polarization of tumor-associated macrophages. We simulate the tumor microenvironment through HCC conditioned medium (HCM) and found that the expression of THBS4 in macrophages increased in a time-dependent manner under the action of HCM (P<0.05); THBS4 knockdown promotes the expression of M1 macrophages markers IL-1β and CD86 (P<0.01), while the expression of M2-type markers IL-10 and CD206 were decreased (P<0.01). Transwell co-culture assay was used to further detect the effect of THBS4-induced M2-type macrophages on HCC metastasis. Results from co-culture of THBS4-downregulated M2 macrophages with HepG2 cells showed that THBS4-downregulated M2-TAMs significantly inhibited the invasion and migration ability of HepG2 cells (all P < 0.01). In conclusion, the tumor microenvironment promotes the expression of THBS4 in macrophages, and THBS4 may promote the invasion and metastasis of HCC cells by inducing M2-type polarization of macrophages. This study provides some new experimental basis for exploring the establishment of THBS4-induced HCC immune microenvironment.
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Objective: To study the expression and effect of small nuclear ribonucleoprotein-associated protein B (SNRPB) on proliferation and metastasis of liver cancer tissues and cells. Methods: The bioinformatics database starBase v3.0 and GEPIA were used to analyze the expression of SNRPB in liver cancer tissue and normal liver tissue, as well as the survival and prognosis of liver cancer patients. The expression of SNRPB mRNA and protein in liver cancer cell lines were analyzed by qRT-PCR and Western blot. RNA interference technique (siRNA) was used to determine SNRPB protein expression down-regulation. The proliferation effect on hepatocellular carcinoma cells was observed by MTT assay. Transwell invasion and migration assay was used to detect the changes in the metastatic ability of liver cancer cells after SNRPB down-regulation. Western blot was used to detect the changes of epithelial mesenchymal transition (EMT) markers in liver cancer cells after down-regulation of SNRPB expression. Data were compared between two groups and multiple groups using t-test and analysis of variance. Results: The expression of SNRPB was significantly higher in liver cancer tissue than normal liver tissue, and its expression level was correlated with the prognosis of liver cancer patients. Compared with the immortalized hepatocyte LO(2), the expression of SNRPB was significantly increased in the liver cancer cells (P < 0.01). siRNA-SNRPB had significantly inhibited the expression of SNRPB mRNA and protein in liver cancer cells. MTT results showed that the absorbance value was lower in SNRPB knockdown group than negative control group, and the difference at 96 h after transfection was most significant (P < 0.01). Transwell assay results showed that compared with the negative control group, the SNRPB knockdown group (MHCC-97H: 121.27 ± 8.12 vs. 46.38 ± 7.54; Huh7: 126.50 ± 6.98 vs. 41.10 ± 8.01) invasion and migration (MHCC-97H: 125.20 ± 4.77 vs. 43.18 ± 7.32; Huh7: 132.22 ± 8.21 vs. 38.00 ± 6.78) ability was significantly reduced (P < 0.01) in liver cancer cells. Western blot showed that the expression level of epithelial phenotype marker E-cadherin was decreased after down-regulation of SNRPB, while the expression levels of mesenchymal phenotype markers N-cadherin and vimentin was increased, suggesting that down-regulation of SNRPB inhibited EMT in liver cancer cells. Conclusion: SNRPB expression is significantly increased in liver cancer tissues and cells, and it is involved in regulating the proliferation, metastasis and EMT of liver cancer cells.
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Humanos , Carcinoma Hepatocelular/genética , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Transição Epitelial-Mesenquimal , Regulação Neoplásica da Expressão Gênica , Neoplasias Hepáticas/genética , Proteínas Centrais de snRNPRESUMO
Objective To investigate the induction of microRNA (microRNA-106a,miR-106a)on the peritoneal metastasis of human gastric cancer cell BGC-823 by regulating matrix metalloproteinase inhibitor 2 (tissue inhibitor of metalloproteinases 2,TIMP2).Methods Human gastric cancer cell line BGC-823 was cultured to the logarithmic growth phase. The cells were divided into three groups: BGC-823, BGC-823/anti-miR-106a (antagomir)and BGC-823/negative control.Real-time PCR was used to identify the effect of antagomir.Transwell assay was used to detect the cell migratory and invasive abilities of these three groups in vitro .With small incision, the cells were injected into the abdominal cavity of nude mice to prepare a xenograft model.The animals were divided into two groups:miR-antagomir and miR-NC.The tumor growth in the nude mice was generally observed and estimated.Immunohistochemistry and Western blot methods were used to detect the expression of metastasis-associated protein TIMP2 on the several abdominal organs.Results The expression level of miR-106a was down- regulated in BGC-823/anti-miR-106a group,with the fold change of 0.05±0.01,which was significantly different from that in NC group (t=-18.001,P<0.001).In vitro exogenously silencing of miR-106a gene,the numbers of invasive and migratory cells in BGC-823/anti-miR-106a group were both significantly lower than those in BGC-823 and BGC-823/negative control groups (P<0.001).In vivo xenograft model showed that the down-regulation of miR-106a weakened the peritoneal metastasis ability of BGC-823 cells in nude mice abdominal cavity,which was reflected by the decrease of tumor number and tumor size.With the inhibition of miR-106a,the expression of TIMP2 in miR-antagomir group was significantly higher than that in miR-NC group (P<0.05).Conclusion BGC-823 cell has the tumorigenicity in nude mice.Silencing of miR-106a inhibits gastric cancer cell metastasis, which suggests that it has the oncogenic function.MiR-106a may induce the strengthened peritoneal metastasis ability of BGC-823 cell through acting on TIMP2.
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<p><b>OBJECTIVE</b>To elucidate whether the polymorphism of asthma immune regulator gene TIM-4 is associated with the risk of childhood allergic asthma in the southwest region of China.</p><p><b>METHODS</b>TIM-4 gene promoter region RS6882076 and intron RS4704727 were studied. PCR-RFLP was used to test the genotypes of two polymorphism loci among 579 cases (average 7.2 years old) of asthma and 524 controls (average 7.6 years old) in a case-control study.</p><p><b>RESULTS</b>There were significant differences in the frequency of gene types at RS4704727 site between the asthma and the control groups (P<0.01). The results of PCR-RFLP showed that the polyporphisms of RS6882076 and RS4704727 in TIM-4 gene were present in this study population. The frequency of T allele at the RS4704727 site in the asthma group was significantly lower than that in the control group (OR=1.603; 95%CI 1.304-1.971; P<0.01). There were no significant differences in the frequencies of gene types and allele at RS6882076 site between the two groups (P>0.05).</p><p><b>CONCLUSIONS</b>RS4704727 polymorphism of TIM-4 gene may be associated with childhood asthma, providing a better understanding of the pathogenesis of childhood asthma in the Southwest region of China.</p>
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Criança , Feminino , Humanos , Masculino , Asma , Genética , Proteínas de Membrana , Genética , Polimorfismo de Nucleotídeo Único , Regiões Promotoras GenéticasRESUMO
<p><b>OBJECTIVE</b>To observe the effect of Tanshinone II A on the expression of epidermal growth facter (EGF) and epidermal growth facter recepter (EGFR) in human hepatocellular carcinoma cell line SMMC-7721.</p><p><b>METHODS</b>The human hepatocellular carcinoma SMMC-7721 cells cultured in vitro was treated with different concentrations of Tanshinone II A. The proliferation of the cells was measured by MTT assay, and the apoptosis of the cells was investigated by flow cytometry and cytochemical staining with Hoechst 33342. The expression of EGF and EGFR was detected by immunocytochemistry method. The levels of EGF in medium were measured by radioimmunoassay.</p><p><b>RESULT</b>Tanshinone II A inhibited the growth of SMMC-7721 cells remarkably in a dose-dependent manner. The inhibitory rate reached the peak (72.5%) after 0.5 microg/ml Tanshinone II A was used for 48 h, which was significantly higher than that in the controls (P<0.05). FCM analysis showed that when SMMC-7721 cells were treated with 0.5 microg/ml Tanshinone II A, the apoptosis rates for 24 h, 48 h and 72 h were (4.06+/-0.27)%, (7.58+/-0.56)% and (5.23+/-0.13)%, respectively which were markedly higher than those in the controls (all P<0.01). SMMC-7721 cell apoptosis with cell shrinkage, nuclear chromatin concentration and fragmentation as well as the formation of apoptotic bodies were observed by cytochemical staining when treated with Tanshinone II A. The immunocytochemistry showed that the expressions of EGF and EGFR were down regulated while the concentration of Tanshinone II A was increasing. The high expression rates for EGF and EGFR were 10%, 20%, respectively, and the gray scale was 181.52+/-1.63, 179.37+/-1.59, which were markedly higher than those in the controls (all P<0.05). The levels of EGF in medium measured by radioimmunoassay were decreased significantly after Tanshinone II A treatment.</p><p><b>CONCLUSION</b>Tanshinone II A can inhibit cell proliferation and induce apoptosis in hepatocellular carcinoma cell line SMMC-7721, which may be related to the down-regulation of EGF and EGFR protein expression.</p>