circMTO1调控Wnt/β-catenin抑制乳腺癌细胞增殖和转移能力的机制研究

目的 研究环状RNA MTO1（circMTO1）对乳腺癌细胞增殖和转移的影响及其可能机制。方法 收集102例浸润性乳腺癌患者的癌组织及癌旁组织,选用乳腺癌细胞系MDA-MB-231、HCC-70、MCF-7和人乳腺正常细胞系MCF-10A,采用荧光定量PCR（qPCR）检测circMTO1在乳腺癌组织和细胞系中的表达水平。分别构建circMTO1过表达和circMTO1敲减质粒转染乳腺癌细胞系,分为NC组、oe-circMTO1组和sh-circMTO1组,qPCR检测转染效果。MTS实验检测各组细胞增殖能力,Transwell实验检测各组细胞转移能力。TOP/FOP荧光素酶实验检测各组细胞Wnt/β-catenin信号通路活性,Western blot检测各组细胞Wnt/β-catenin信号通路相关蛋白Wnt3a、β-catenin、cMyc、Cyclin D1和基质金属蛋白酶7（MMP7）的表达。结果 与癌旁组织和人正常乳腺细胞系相比,circMTO1在乳腺癌组织和乳腺癌细胞系中的相对表达量降低（P<0.05）。有淋巴结转移和TNM分期为Ⅲ期的乳腺癌患者组织中circMTO1的相对表达水平较低（P<0.05）。与NC组相比,oe-circMTO1组circMTO1相对表达量增加,细胞的增殖、转移能力以及Wnt/β-catenin信号通路活性减弱,Wnt3a、β-catenin、cMyc、Cyclin D1和MMP7蛋白表达水平降低（P<0.05）;sh-circMTO1组circMTO1相对表达量降低,细胞的增殖、转移能力以及Wnt/β-catenin信号通路活性增强,Wnt3a、β-catenin、cMyc、Cyclin D1和MMP7蛋白表达水平增加（P<0.05）。结论 circMTO1在乳腺癌细胞中呈低表达,circMTO1通过抑制Wnt/β-catenin信号通路活性,从而抑制乳腺癌细胞的增殖和转移能力。     

白藜芦醇通过BRD4调控Wnt/β-catenin通路逆转胶质瘤细胞替莫唑胺耐药的机制研究

目的 探究白藜芦醇（RES）逆转胶质瘤细胞替莫唑胺（TMZ）耐药的作用是否与通过溴结合域蛋白4（BRD4）调控Wnt/β-链蛋白（β-catenin）通路有关。方法 取人神经胶质瘤TMZ低敏细胞株（U138）、高敏细胞株（U251）、耐药株（T98G）,Western blot法检测3种细胞株中BRD4、Wnt3a、β-catenin、TMZ耐药蛋白（MGMT）蛋白表达。取T98G细胞株分为对照1组（添加100 μmoL/L TMZ）、RES1组（添加50 μmoL/L RES）、RES+TMZ（添加100 μmoL/L TMZ和50 μmoL/L RES）组,用CCK-8法、流式细胞术检测各组细胞增殖、凋亡情况;Western blot法检测各组BRD4、Wnt3a、β-catenin、MGMT蛋白表达。为分析BRD4过表达对TMZ耐药性的影响,在添加100 μmoL/L TMZ的基础上,转染BRD4过表达质粒（pcDNA BRD4）或加入50 μmoL/L RES分别作为pcDNA NC组、pcDNA BRD4组、RES2组、RES+pcDNA BRD4组。为验证BRD4对Wnt3a/β-catenin通路的调控作用,在添加100 μmoL/L TMZ的基础上,加入BRD4抑制剂JQ1和Wnt3a/β-catenin通路激活剂LiCl,分为对照2组、JQ1组、JQ1+LiCl组。将T98G细胞接种于裸鼠左肩胛区,给予RES、TMZ和（或）JQ1治疗,检测瘤体中Ki67,BRD4、MGMT及Wnt3a/β-catenin蛋白表达。结果 与U251细胞相比,U138、T98G中BRD4、Wnt3a、β-catenin及MGMT表达均依次升高（P<0.05）。与对照1组相比,RES干预可抑制T98G细胞BRD4、Wnt3a/β-catenin、MGMT蛋白表达及增殖,促进凋亡,逆转细胞的耐药性（P<0.05）。pcDNA BRD4可逆转RES的抗增殖、促凋亡等上述作用。BRD4抑制剂JQ1可抑制T98G细胞BRD4、Wnt3a/β-catenin、MGMT蛋白表达及增殖,促进凋亡（P<0.05）;LiCl可逆转JQ1的抗增殖、促凋亡作用。RES单独或与JQ1联合治疗,可激活TMZ对瘤体内Wnt3a/β-catenin通路、MGMT表达和细胞增殖的抑制作用（P<0.05）。结论 RES可能通过下调BRD4,进而抑制Wnt3a/β-catenin通路活化,实现对胶质瘤T98G细胞TMZ耐药性的逆转。     

γ-分泌酶抑制剂在肺纤维化上皮间质转化中的作用

目的 检测体外转化生长因子（TGF）-β1诱导肺纤维化上皮间质转化（EMT）的形成情况并检测Notch信号特异性抑制剂γ-分泌酶抑制剂（DAPT）对其影响及可能机制。方法 将A549细胞分成对照组（RPMI 1640完全培养基培养）、TGF-β1组（在含有10 μg/L TGF-β1的RPMI 1640培养基中培养）、TGF-β1+DAPT组（在含有10 μg/L TGF-β1和2 μmol DAPT的RPMI 1640培养基中培养）、DAPT组（在含有2 μmol DAPT的RPMI 1640培养基中培养）。通过倒置显微镜观察细胞形态,实时荧光定量逆转录聚合酶链反应检测肺泡上皮细胞特异性蛋白E-钙黏合素以及间质细胞特异性蛋白α-肌动蛋白（α-SMA）mRNA相对表达水平,Western blot检测E-钙黏合素以及α-SMA蛋白表达水平。结果 倒置显微镜检查示,对照组细胞呈多边形,铺路石样,细胞间连接紧密;TGF-β1组细胞呈梭行,纺锤状,细胞间连接减少;TGF-β1+DAPT组仅有少量细胞呈梭形,多数细胞形态与对照组相似;DAPT组细胞形态大致同对照组。与对照组相比,TGF-β1组α-SMA蛋白及mRNA表达增加,而E-钙黏合素蛋白及mRNA表达减弱（P<0.05）;与TGF-β1组比较,TGF-β1+DAPT组α-SMA蛋白及mRNA表达水平降低,而E-钙黏合素蛋白及mRNA表达水平增加（P<0.05）;DAPT组与对照组2指标的蛋白与mRNA相对表达水平差异无统计学意义（P>0.05）。结论 TGF-β1可诱导肺上皮间质转化,而Notch信号抑制剂DAPT能够阻断、部分或全部逆转这一过程。     

Wnt信号通路转录上调EGFR促进非小细胞肺癌 吉非替尼耐药

目的 探讨Wnt信号通路和表皮生长因子受体（EGFR）在非小细胞肺癌（NSCLC）吉非替尼耐药中的作用 及其机制。方法 运用实时荧光定量PCR（qRT-PCR）和免疫印迹实验（Western blot）检测EGFR在亲代HCC827细 胞与吉非替尼耐药细胞（HCC827/R）中的表达;免疫组化染色检测耐药前后3对NSCLC肿瘤组织中EGFR的表达。 双荧光素酶报告基因实验（Luciferase）检测亲代 HCC827 细胞与耐药 HCC827/R 细胞 Wnt 信号通路活化情况;在 Jaspar数据库中预测EGFR基因启动子区上TCF/LEF转录因子结合位点;染色质免疫共沉淀实验（Chip）和Luciferase 实验检测转录因子对基因表达的调控;功能阻断实验检测Wnt信号通路/EGFR途径介导吉非替尼耐药的作用。结 果 与亲代HCC827细胞相比较,HCC827/R细胞的EGFR在mRNA和蛋白水平表达均明显增高（P＜0.05）。免疫组 化染色结果显示在 3 例吉非替尼耐药前后 NSCLC 配对肿瘤组织样品中有 2 例耐药后 EGFR 表达较耐药前增加。 Luciferase实验结果显示,与亲代细胞比较,Wnt/β-catenin信号通路在耐药HCC827/R细胞中异常活化（P＜0.05）。生 物信息学分析预测到EGFR基因启动子区-1476~-1468区域存在Wnt/β-catenin信号通路下游转录因子TCF3/TCF4 结合位点,Chip和Luciferase实验证实Wnt/β-catenin信号通路可转录上调EGFR表达。功能阻断实验结果显示当利 用Wnt3a刺激亲代HCC827细胞的同时敲低EGFR,吉非替尼对细胞的抑制率较单独利用Wnt3a刺激细胞时的细胞 抑制率得到恢复（P＜0.05）。结论 Wnt/β-catenin信号通路转录上调EGFR促进NSCLC的吉非替尼耐药,其为提高 NSCLC吉非替尼靶向治疗效果提供了新的实验依据。     

1,25-二羟基维生素D3抑制脂肪细胞分化作用的研究

【摘要】目的研究1,25-二羟基维生素D3[1,25(OH)₂D₃]对脂肪细胞分化的影响及其机制。方法以间充质干细胞系C3H10T1/2为研究对象,将其分为6组,分别为对照组、诱导分化组和4个不同剂量的1,25(OH)₂D₃处理组。其中对照组加入溶媒,诱导分化组加入脂肪细胞诱导分化试剂,1,25(OH)₂D₃处理组除了加入脂肪细胞诱导分化试剂外,予以10^-9、10^-8、10^-7、10^-6mol/L 1,25(OH)₂D₃处理。处理后5d进行油红O染色,RT-PCR检测脂肪细胞特异性转录因子和Wnt/β-catenin信号通路相关因子表达水平,Western blot检测β-catenin蛋白水平。结果1,25(OH)₂D₃能够强烈抑制脂肪细胞生成,阻断脂肪细胞特异性转录因子过氧化物酶体增殖物激活受体（PPAR）γ、CCAAT增强子结合蛋白（C/EBP）α及脂肪细胞表征因子aP2mRNA表达,下调Wnt/β-catenin信号通路抑制因子分泌性卷曲相关蛋白1（sFRP1）mRNA,上调β连环素（β-catenin）蛋白水平。结论1,25(OH)₂D₃强烈抑制脂肪细胞分化,该作用可能与其激活Wnt/β-catenin信号通路有关。     

Wnt10b、β-catenin与鼻咽癌放射敏感性的关系

目的 探讨Wnt/β-catenin信号通路与鼻咽癌细胞放射敏感性的关系.方法 收集对数生长期以及经直线加速器6MV X射线0、2、4、6 Gy照后48 h的鼻咽癌CNE2细胞和放射抗拒的CNE-2 (R743)细胞,RT-PCR方法检测Wnt10b基因、β-catenin基因mRNA的表达,Western blot检测Wnt10b、β-catenin蛋白的表达.结果 放射抗拒株CNE-2(R743)细胞的Wnt10b和β-catenin基因mRNA及蛋白的表达均高于放射敏感的CNE 2细胞(P＜0.05).经照射后CNE 2细胞和CNE-2 (R743)细胞的Wnt10b和β-catenin的mRNA及蛋白表达量随着照射剂量的增加而增加;在相同照射剂量下放射抗拒株CNE-2 (R743)细胞Wnt10b和β-catenin的表达量均高于CNE 2细胞(P＜0.05).结论 Wnt/β-catenin信号通路可能与鼻咽癌细胞放射敏感性有关.     

石蒜碱通过TLR4/NF-κB途径抑制LPS诱导的原代小胶质细胞炎症反应

目的 观察石蒜碱（LYC）对脂多糖（LPS）诱导的原代小胶质细胞炎症反应和表型变化的影响,并探讨其作用机制。方法 将培养的原代小胶质细胞分为对照组、LYC组（0.1、0.5、1和5 μmol/L LYC）、LPS组（0.1 mg/L LPS）和LPS（0.1 mg/L LPS）+LYC组（5 μmol/L LYC）。倒置显微镜观察细胞形态变化;流式细胞术检测原代小胶质细胞的纯度及LPS诱导原代小胶质细胞向两种表型转化的情况;CCK-8法检测细胞活性;实时荧光定量PCR（qPCR）检测白细胞介素（IL）-1β、IL-6、肿瘤坏死因子-α（TNF-α）以及不同表型小胶质细胞表面标志物mRNA表达;Griess法检测一氧化氮（NO）含量;免疫印迹法检测细胞TLR4、p-NF-κB p65蛋白表达情况。结果 原代小胶质细胞纯度达95%以上。对照组及各浓度LYC组细胞活性差异无统计学意义。后续实验以5 μmol/L的LYC为药物浓度。与LPS组相比,LPS+LYC组的阿米巴样小胶质细胞数量明显减少,IL-1β、IL-6、TNF-α mRNA表达水平以及NO含量降低,CD86 mRNA表达水平和表型比例降低,CD206 mRNA表达水平和表型比例升高,TLR4和p-NF-κB p65蛋白表达水平降低（P<0.01）。结论 LYC通过TLR4/NF-κB信号通路抑制LPS诱导的原代小胶质细胞炎症反应,并促进其向“抑炎型”极化。     

芹菜素调控Wnt信号通路对卵巢癌细胞侵袭能力的影响

目的　探讨芹菜素对Wnt/β-catenin 信号通路的调控及其对卵巢癌细胞侵袭能力的影响。方法　在经芹菜素处理的人卵巢癌细胞系HO8910 中,通过实时PCR 和Western blot 检测Wnt/β-catenin 通路相关蛋白及下游蛋白的表达;采用Transwell 法检测细胞体外迁移和侵袭能力;利用Luciferase 双荧光素酶报告系统检测Wnt/β-catenin 通路的活化情况。结果　芹菜素作用24 h 能够有效抑制HO8910 细胞的迁移和侵袭能力,降低β-catenin 和E-catenin 的mRNA 相对表达量和蛋白表达水平。芹菜素对Wnt/β-catenin 信号通路中相关蛋白及下游靶蛋白具有调控作用（P<0.0001）。结论　芹菜素可以通过抑制人卵巢癌细胞中Wnt/β-catenin 信号通路,下调促转移靶蛋白的表达,抑制卵巢癌细胞的迁移和侵袭能力。     

多纳非尼抑制胆管癌TFK-1细胞增殖、迁移和侵袭及促进凋亡的机制研究

目的 研究多纳非尼抑制人胆管癌TFK-1细胞增殖、迁移和侵袭及促进凋亡的机制。方法 将人胆管癌TFK-1细胞分为对照组（加入等量的二甲基亚砜处理）,2、5、10 μmol/L多纳非尼组。CCK-8法检测细胞增殖抑制率;平板克隆实验检测细胞增殖情况;流式细胞术检测细胞凋亡;Transwell实验检测细胞迁移和侵袭能力;蛋白质免疫印迹法检测通路蛋白Wnt、β-catenin、细胞周期蛋白-D1（Cyclin D1）、抗凋亡蛋白Bcl-2、促凋亡蛋白Bax的表达;免疫荧光实验检测β-catenin进入细胞核的变化。结果 随着多纳非尼浓度增加,TFK-1细胞增殖抑制率、凋亡率升高,平板克隆形成数、细胞迁移和侵袭数量逐渐减少,Wnt、β-catenin、Cyclin D1、Bcl-2表达均逐渐下降,Bax表达逐渐增高（P<0.05）;免疫荧光显示,与对照组比较,2 μmol/L多纳非尼组能够抑制β-catenin进入细胞核（P<0.05）。结论 多纳非尼可以抑制人胆管癌TFK-1细胞增殖、迁移和侵袭,其机制可能与抑制Wnt/β-catenin通路活化及促进细胞凋亡相关。     

Downregulation of Dickkopf-1 is responsible for high proliferation of breast cancer cells via losing control of Wnt/β-catenin signaling

Aim:

To investigate the role of DKK-1/Wnt/β-catenin signaling in high proliferation of LM-MCF-7 breast cancer cells, a sub-clone of MCF-7 cell line.

Methods:

Two cell lines (MCF-7 and LM-MCF-7) with different proliferation abilities were used. LM-MCF-7 cells were transiently transfected with the pcDNA3-DKK-1 plasmid encoding the DKK-1 gene (or MCF-7 cells were transfected siRNA targeting DKK-1 mRNA). Flow cytometry analysis and 5-bromo-2′-deoxyuridine (BrdU) incorporation assay were applied to detect the cell proliferation. The expression levels of β-catenin, phosphorylated β-catenin, c-Myc, cyclin D1 and Survivin were examined by Western blot analysis. The regulation of Survivin was investigated by Luciferase reporter gene assay.

Results:

Western blot and RT-PCR analysis showed that the expression level of DKK-1 was downregulated in LM-MCF-7 relative to MCF-7 cells. Flow cytometry and BrdU incorporation assay showed DKK-1 could suppress growth of breast cancer cells. Overexpression of DKK-1 was able to accelerate phosphorylation-dependent degradation of β-catenin and downregulate the expression of β-catenin, c-Myc, cyclin D1 and Survivin. Luciferase reporter gene assay demonstrated that Survivin could be regulated by β-catenin/TCF4 pathway.

Conclusion:

We conclude that the downregulation of DKK-1 is responsible for the high proliferation ability of LM-MCF-7 breast cancer cells via losing control of Wnt/β-catenin signaling pathway, in which c-Myc, cyclinD1 and Survivin serve as essential downstream effectors. Our finding provides a new insight into the mechanism of breast cancer cell proliferation.     

Diallyl disulfide inhibits proliferation,epithelial–mesenchymal transition,and invasion through RORα-mediated downregulation of Wnt1/β-catenin pathway in gastric cancer cells

Overactivation of Wnt/β-catenin pathway due to dysfunction of retinoid-related orphan receptor α (RORα) is related to cancer development and progression. Diallyl disulfide (DADS), an active component of garlic, has been reported in our previous study for upregulation of RORα expression in gastric cancer (GC) cells. It remains to be elucidated the role and mechanism of RORα in DADS against GC. This study revealed that DADS treatment resulted in reduced expression levels of Wnt1, β-catenin, TCF-4, intranuclear β-catenin and p-β-catenin in GC cells, concomitant with the compromised expression of β-catenin target genes (Axin, c-Jun, and c-Myc). RORα overexpression augmented DADS-induced downregulation of Wnt1/β-catenin pathway, G2/M phase arrest, and cell growth inhibition in vitro and in vivo. Contrarily, knockdown of RORα attenuated these effects of DADS. Interestingly, DADS induced an increase in the binding of RORα to β-catenin, which may lead to reduction of β-catenin phosphorylation and nuclear translocation. This interplay modulated by DADS may affect β-catenin target gene expression for that the opposite results were observed in DADS-treated RORα knockdown and overexpression cells. DADS caused a decrease in vimentin, snail and MMP-9, as well as an increase in E-cadherin and TIMP3 expression, which restricted epithelial–mesenchymal transition (EMT), migration, and invasion. The aforementioned effects of DADS were weakened simultaneously when the suppression of DADS on the Wnt1/β-catenin pathway was resisted by knockdown of RORα. In contrast, overexpression of RORα enhanced the effects of DADS. Therefore, RORα-mediated downregulation of Wnt1/β-catenin pathway could undertake an important role in anticancer activity of DADS against GC cell proliferation, EMT, migration, and invasion.     

Wnt-C59 inhibits proinflammatory cytokine expression by reducing the interaction between β-catenin and NF-κB in LPS-stimulated epithelial and macrophage cells

Dysregulation of the Wnt pathway causes various diseases including cancer, Parkinson’s disease, Alzheimer’s disease, schizophrenia, osteoporosis, obesity and chronic kidney diseases. The modulation of dysregulated Wnt pathway is absolutely necessary. In the present study, we evaluated the anti-inflammatory effect and the mechanism of action of Wnt-C59, a Wnt signaling inhibitor, in lipopolysaccharide (LPS)-stimulated epithelial cells and macrophage cells. Wnt-C59 showed a dose-dependent anti-inflammatory effect by suppressing the expression of proinflammatory cytokines including IL6, CCL2, IL1A, IL1B, and TNF in LPS-stimulated cells. The dysregulation of the Wnt/β-catenin pathway in LPS stimulated cells was suppressed by Wnt-C59 treatment. The level of β-catenin, the executor protein of Wnt/β-catenin pathway, was elevated by LPS and suppressed by Wnt-C59. Overexpression of β-catenin rescued the suppressive effect of Wnt-C59 on proinflammatory cytokine expression and nuclear factor-kappa B (NF-κB) activity. We found that the interaction between β-catenin and NF-κB, measured by co-immunoprecipitation assay, was elevated by LPS and suppressed by Wnt-C59 treatment. Both NF-κB activity for its target DNA binding and the reporter activity of NF-κB-responsive promoter showed identical patterns with the interaction between β-catenin and NF-κB. Altogether, our findings suggest that the anti-inflammatory effect of Wnt-C59 is mediated by the reduction of the cellular level of β-catenin and the interaction between β-catenin and NF-κB, which results in the suppressions of the NF-κB activity and proinflammatory cytokine expression.     

lncRNA SOX21-AS1的表达对卵巢癌细胞增殖和转移能力的影响及机制研究

目的 探讨长链非编码RNA SRY-box转录因子21反义RNA 1（lncRNA SOX21-AS1）对卵巢癌细胞增殖和转移能力的影响及其作用机制。方法 选取卵巢癌组织和其邻近的癌旁组织各75例,另选取卵巢癌细胞株SKOV3、A2780、OVCR3和人卵巢正常上皮细胞HOSE作为实验对象,实时荧光定量PCR法检测lncRNA SOX21-AS1在组织和细胞中的表达。根据是否干扰lncRNA SOX21-AS1表达将细胞分为si-NC组和si-SOX21-AS1组。MTS实验和平板克隆实验检测细胞增殖能力,Transwell实验检测细胞转移能力,TOP/FOP荧光素酶实验和Western blot实验检测细胞中Wnt/β-catenin信号通路活性和相关蛋白表达水平。结果 与癌旁组织相比,lncRNA SOX21-AS1在卵巢癌组织中的表达上调（P<0.05）。与卵巢正常上皮细胞HOSE相比,lncRNA SOX21-AS1在卵巢癌细胞中的表达上调,SKOV3中最高（P<0.05）。与FIGO分期Ⅰ-Ⅱ期、无淋巴结转移的患者相比,FIGO分期Ⅲ-Ⅳ期、有淋巴结转移患者lncRNA SOX21-AS1相对表达水平升高（P<0.05）。干扰lncRNA SOX21-AS1表达可抑制卵巢癌细胞增殖和转移能力、抑制Wnt/β-catenin信号通路活性并降低Wnt/β-catenin信号通路各蛋白的表达水平（P<0.05）。结论 lncRNA SOX21-AS1在卵巢癌组织和细胞中高表达,干扰lncRNA SOX21-AS1的表达可抑制卵巢癌细胞增殖和转移能力。     

Interferon-α2b and transforming growth factor-β1 treatments on HCC cell lines: Are Wnt/β-catenin pathway and Smads signaling connected in hepatocellular carcinoma?

Wnt/β-catenin pathway is often dysregulated in hepatocellular carcinoma (HCC). Activated β-catenin accumulates in the cytosol and nucleus and forms a nuclear complex with TCF/LEF factors like TCF4. Interferon-α (IFN-α) has recently been recognized to harbor therapeutic potential in prevention and treatment of HCC. Transforming Growth Factor-β1 (TGF-β1) is a mediator of apoptosis, exerting its effects via Smads proteins. One mode of interaction between Wnt/β-catenin and TGF-β1/Smads pathways is the association of Smads with β-catenin/TCF4. In this study we analyzed the effects of IFN-α2b and TGF-β1 treatments on Wnt/β-catenin pathway, Smads proteins levels, β-catenin/TCF4/Smads interaction and proliferation and apoptotic death in HepG2/C3A and Huh7 cell lines. IFN-α2b and TGF-β1 attenuated Wnt/β-catenin signal by decreasing β-catenin and Frizzled7 receptor proteins contents and the interaction of β-catenin with TCF4. Truncated β-catenin form present in C3A cell line also diminished after treatments. Both cytokines declined Smads proteins and their interaction with TCF4. The overall cellular response to cytokines was the decrease in proliferation and increase in apoptotic death. Treatment with Wnt3a, which elevates β-catenin protein levels, also generated the increment of Smads proteins contents when comparing with untreated cells. In conclusion, IFN-α2b and TGF-β1 proved to be effective as modulators of Wnt/β-catenin pathway in HCC cell lines holding both wild-type and truncated β-catenin. Since the inhibition of β-catenin/TCF4/Smads complexes formation may have a critical role in slowing down oncogenesis, IFN-α2b and TGF-β1 could be useful as potential treatments in patients with HCC.     

川续断皂苷Ⅵ对小鼠骨髓基质细胞ST-2 成脂分化的影响及其机制研究

目的观察川续断皂苷Ⅵ（Asperosaponin Ⅵ,ASAⅥ）对脂肪细胞分化的影响及Wnt 通路的调节。方法以小鼠骨髓基质细胞系ST-2 为研究对象,将其分为对照组、成脂分化组以及4 个不同剂量的ASAⅥ组。其中对照组加入溶媒,成脂分化组加入成脂诱导分化试剂,ASAⅥ组除加入成脂诱导分化试剂外,使用不同浓度（10-7、10-6、10-5、 10-4 mol/L）的ASAⅥ干预细胞。各组细胞处理5 d 后,行油红O 染色,观察脂滴形成情况并计算成脂率进行定量分析;荧光定量PCR（FQ-PCR）检测成脂相关基因PPARγ、FABP4 和Wnt/β-连环素（β-catenin）通路蛋白β-catenin 的 mRNA 表达水平;Wnt 通路抑制剂DKK1 干预诱导成脂分化的ST-2 细胞5 d,FQ-PCR 检测ASAⅥ所调节的 PPARγ、FABP4 和β-catenin mRNA 表达水平。结果与成脂分化组相比,10-5 mol/L 和10-4 mol/L ASAⅥ组中分化的脂肪细胞显著减少,10-5、10-4 mol/L ASAⅥ明显抑制PPARγ、FABP4 的mRNA 表达,但上调β-catenin mRNA 表达。 DKK1 能够逆转ASAⅥ对ST-2 细胞成脂分化的抑制作用,促进PPARγ、FABP4 的mRNA 表达,抑制β-catenin 的 mRNA 表达。结论ASAⅥ能显著抑制ST-2 细胞的成脂分化,这一作用可能是通过Wnt/β-catenin 通路的激活所介导的。