Effect of Pax6 gene expression on hydrogen peroxide-induced aging in bone marrow mesenchymal stem cells / 中国组织工程研究

BACKGROUND:The occurrence and development of various ophthalmic diseases are closely related to excessive oxidative stress,and the inhibition of oxidative stress response may produce preventive and therapeutic effects. OBJECTIVE:To explore the role of Pax6 gene expression on hydrogen peroxide-induced aging of mouse bone marrow mesenchymal stem cells(BM-MSCs). METHODS:Resuscitated BM-MSCs,Pax6/BM-MSCs,and shPax6/BM-MSCs were treated with hydrogen peroxide for 24 hours,and then β-galactosidase staining was performed.The proliferation index Ki67 expression and apoptosis were detected by flow cytometry.The expression of senescence-associated molecules(Wnt7a,p21,and p53)was detected by RT-PCR. RESULTS AND CONCLUSION:(1)After hydrogen peroxide treatment,the cells of the three groups showed senescence phenotype and β-galactosidase staining was positive.Compared with BM-MSCs group,the expression of positive cells in Pax6/BM-MSCs group was less and that in the shPax6/BM-MSCs group was more,and the difference was statistically significant(P<0.05).(2)The results of flow cytometry showed that compared with BM-MSCs group,the positive expression of Ki67 in the Pax6/BM-MSCs group increased and the level of apoptosis decreased,while the positive expression of Ki67 decreased and the level of apoptosis increased in the shPax6/BM-MSCs group;the difference was significantly different(P<0.05).(3)RT-PCR showed that compared with the BM-MSCs group,the expression of Wnt7a,p53,and p21 decreased in the Pax6/BM-MSCs group,while the expression of Wnt7a,p53,and p21 increased in the shPax6/BM-MSCs group;the difference was significantly different(P<0.05).(4)These findings indicate that overexpression of Pax6 can antagonize the aging progression of BM-MSCs induced by hydrogen peroxide,which may be related to Wnt signaling pathway.

Multiple idiopathic root resorption: a case report and literature review / 口腔疾病防治

Objective @#To explore the etiology, clinical manifestations, diagnosis and treatment of multiple idiopathic root resorption to provide a reference for clinical diagnosis and treatment. @*Methods@# The clinical data of a case of multiple idiopathic root resorption were analyzed retrospectively, and the related literature was reviewed.@*Results@#The patient had no history of orthodontic correction, occlusal trauma, trauma history or other causes of root resorption. Clinical examination revealed full-mouth gingival congestion, redness, a loose texture, and variable degrees of destruction of the alveolar bone. Imaging examination showed that teeth 13, 16, 26, 36, 46 had idiopathic root resorption. The diagnoses were multiple idiopathic root resorption and periodontitis. The pathology tests showed that a large number of osteoclasts were present in the soft tissue surrounding the teeth. Whole-exome sequencing showed that there was a strong correlation between gene mutations (WNT7a and HSPG2) and the present phenotype. Root resorption of teeth without periodontitis was stopped after periodontal treatment during the 19-month follow-up. Tooth 13 was removed, and extraction socket preservation was performed. The etiology of idiopathic root resorption may be related to gene mutations, but it is not clear. At present, there is no effective treatment. @* Conclusion @#Multiple idiopathic root resorption has an unknown etiology, but it may be related to WNT7A and HSPG2 gene mutations. The rate of root resorption can be slowed by controlling periodontal inflammation.

The research progress of Wnt7a and malignant tumors,and its relationship / 实用肿瘤学杂志

Wnt7a is a secreted glycoprotein in the Wnt signaling family. It is located on chromosome 3p25 and is easy dele-ted. It is mainly expressed in placenta,kidney,testis,uterus,fetal lung and brain,and participates in human embryonic development and cell differentiation. More and more studies have found that Wnt7a is also expressed and plays an important role in many tumor cells. As a new tumor target of therapy or an important factor in the tumor growth pathway,Wnt7a has begun to attract the attention of many scientists.

Function and mechanisms of Wnt7a in bone mesenchymal stem cells osteogenic differentiation / 国际生物医学工程杂志

Objective To explore the function and mechanisms of Wnt7a in bone msenchymal stem cells (BMSCs) osteogenic differentiation.Methods BMSCs were isolated and cultured.After transfection of siRNA-Wnt7a and mock in BMSCs and induction by osteogenic medium for 3 d,Western Blot were employed to detect the silencing effect of siRNA-Wnt7a.Then the effect of silencing Wnt7a on the expression of osteocyte marker osteocalcin and osteogenesis regulator protein Runx2 were detected by Western Blot after culture by osteogenic medium for 10 d.Finally,Alizarin S Red staining was used to detect the effect of silencing siRNA-Wnt7a on osteogenesis after culture by osteogenic medium for 2 weeks.Results The silencing effect of siRNA-Wnt7a was confirmed by Western Blot after transfection of oligocleotides siRNA-Wnt7a and mock into mesechymal stem cells.The silencing Wnt7a decreased the expression of osteocalcin and Runx2 after culture by osteogenic medium for 10 d.Alizarin S red staining results showed that silencing Wnt7a blocked bone differentiation.Conclusions The results demonstrated that Wnt7a could promot osteocyte marker osteocalcin expression by upregulating osteogenesis regulator protein Runx2 expression,which played a key role in BMSCs osteogenic differentiation.

Clinical Significance of Aberrant Wnt7a Promoter Methylation in Human Non-Small Cell Lung Cancer in Koreans

The Wnt signaling pathway has regulatory roles in cell proliferation, differentiation, and polarity. Aberrant Wnt pathway regulation can lead to abnormal cell proliferation and cancer, and loss of Wnt7a expression has been demonstrated in lung cancer cell lines. E-cadherin keeps intercellular integrity and prevents metastasis. Therefore, E-cadherin has been known as a prognostic factor in cancer. In the present study, we investigated the E-cadherin expression status by immunohistochemical stain and the Wnt7a promoter methylation status in human non-small cell lung carcinoma (NSCLC) by methylation-specific PCR. We also analyzed their correlations with clinicopathological factors. Methylation of the Wnt7a gene promoter was detected in the lung tissues of 32 of 121 (26.4%) patients with NSCLC. Wnt7a promoter methylation was correlated with advanced tumor stage (P = 0.036) and distant metastasis (P = 0.037). In addition, Wnt7a promoter methylation showed correlation with loss of E-cadherin expression (P < 0.001). However, Wnt7a promoter methylation was not closely related with gender, age, histological type, or smoking habit. Even though Wnt7a methylation could not show significant correlation with the long term survival of the patients with limited follow up data, these findings suggest that loss of the Wnt7a gene induced by promoter methylation might be another prognostic factor for NSCLC and that restoration of Wnt7a may be a promising treatment for NSCLC.

Clinical Significance of Aberrant Wnt7a Promoter Methylation in Human Non-Small Cell Lung Cancer in Koreans

The Wnt signaling pathway has regulatory roles in cell proliferation, differentiation, and polarity. Aberrant Wnt pathway regulation can lead to abnormal cell proliferation and cancer, and loss of Wnt7a expression has been demonstrated in lung cancer cell lines. E-cadherin keeps intercellular integrity and prevents metastasis. Therefore, E-cadherin has been known as a prognostic factor in cancer. In the present study, we investigated the E-cadherin expression status by immunohistochemical stain and the Wnt7a promoter methylation status in human non-small cell lung carcinoma (NSCLC) by methylation-specific PCR. We also analyzed their correlations with clinicopathological factors. Methylation of the Wnt7a gene promoter was detected in the lung tissues of 32 of 121 (26.4%) patients with NSCLC. Wnt7a promoter methylation was correlated with advanced tumor stage (P = 0.036) and distant metastasis (P = 0.037). In addition, Wnt7a promoter methylation showed correlation with loss of E-cadherin expression (P < 0.001). However, Wnt7a promoter methylation was not closely related with gender, age, histological type, or smoking habit. Even though Wnt7a methylation could not show significant correlation with the long term survival of the patients with limited follow up data, these findings suggest that loss of the Wnt7a gene induced by promoter methylation might be another prognostic factor for NSCLC and that restoration of Wnt7a may be a promising treatment for NSCLC.

The experimental study of murine cytomegalovirus inhibits the differentiation and the differentiation genes expression of neural stem cells in vitro / 中华微生物学和免疫学杂志

Objective To investigate the influence of murine cytomegalovirus(MCMV) infection on differentiation and differentiation gene expression of neural stem cells (NSCs) in vitro for studying the mechanisms of brain abnormalities calmed by congenital cytomegalovirns infection. Methods NSCs were separated from fetal BALB/c mouse and cultured and identified in vitro. The differentiation potency of NSCs was observed by immunnfluorescence. The NSCs infected by MCMV at dosage of multiplicity of infection (MOI) equaled to 5, I and 0. 1, respectively, were cultured in differentiation medium. The morphological changes of the cells were observed by inverted microscope. The ratios of NSCs and its differentiated cells were detected by flow cytometry. The expression changes of nestin, GFAP and NSE, markers of NSCs and its differentiated cells, were studied by immunofluorescence ( MOI = 1 ). The expression of early antigen (EA) of MCMV was detected to observe the infection process. Real-time RT-PCR method was employed to measure the expression levels of the key differentiation genes Wnt-3 and Wnt-7a in Wnt signal pathway of NSCs at early phage of differentiation culture. Results NSCs isolated from embryonic mouse brains could proliferate to form neurnspheres and strongly express Nestin and differentiate into NF-200 positive neurons or GFAP positive astrocytes. The NSCs of the infected groups couldn't adhere to the wall and appear differentia-tion growth, but showed swollen gradually after differentiation culture. The nostin expression of the infected groups downregulated slowly and was higher than that of the control groups ( P < 0.05 ). The GFAP and NSE expression of the infected groups were lower than that of the control groups (P <0.05). The EA of MCMV could be always detected in the cells of the infected groups. The ratios of nestin positive cells of the infected groups were higher than that of the control groups, but the ratios of GFAP and NSE positive cells of the for-mer were lower than that of the latter from 3rd to 9th day after differentiation culture ( P < 0.05 ). The levels of Wnt-3 mRNA and Wnt-7a mRNA of the infected groups were markedly lower than that of the control groups from 1st to 2nd clay and from 12th hour to 2nd day after differentiation culture respectively ( P < 0.05 ) . These changes of the infected groups became more obvious as MCMV MOI increased . Conclusion MCMV could inhibit significantly NSCs differentiate to neurons and astrocytes and lead to the decrease of dif-ferentiated cells. MCMV could inhibit or interfere with the gene expression of Wnt-3 and Wnt-7a in Wnt sig-nal pathway of NSCs. The effect that MCMV inhibited the differentiation and the differentiation gene expres-sion of NSCs showed dose-dependent with MCMV MOI. The inhibitory effect of MCMV on the differentiation of NSCs might be induced by interfering the differentiation gene expression of NSCs, which is possibly the one of primary causes of brain development disorders caused by congenital CMV infection.