Wnt信号通路与人类疾病相关性的研究进展

Wnt信号传导通路是一条广泛存在于多细胞生物体内且具有高度进化保守性的信号通路。该通路对细胞增殖、分化、凋亡、细胞极性及细胞的迁移和侵入产生影响,在多种器官的发育形成过程以及成体状态下病理生理过程中发挥重要作用。目前已有大量研究表明,Wnt信号通路的改变与肿瘤的形成和发生、退行性疾病的发展以及干细胞功能的改变密切相关。有更多新的研究表明,该通路与炎症发生、新生血管形成、免疫功能的维持以及创伤愈合和组织再生也有潜在性的联系。该通路正作为一个关键热点应用于上述各个领域的基础应用及药物开发研究中。本文在检索Pub Med上关于Wnt信号通路与人类疾病文献的基础上,从Wnt信号通路的组成及其与人类纤维化疾病、代谢综合征、眼部疾病、肿瘤和骨相关疾病等方面的相关性,阐明Wnt信号传导通路在细胞的增殖、分化、凋亡等过程中发挥的重要调节作用及对维持诸多器官的正常发育和形成所起的至关重要的作用。     

科学家发现纳米二氧化硅干涉Wnt信号通路的分子机制

正7月18日,中国科学院上海生命科学研究院营养科学研究所宋海云组与中国科学院上海应用物理研究所樊春海组合作的研究论文Silica Nanoparticles Target a Wnt Signal Transducer for Degradation and Impair Embryonic Development in Zebrafish在线发表于Theranostics。该研究发现二氧化硅纳米粒子(SiO 2NPs)在不产生细胞毒性的剂量范围内,会诱导Wnt通路的信号传递分子Dvl的降解,干涉Wnt信号转导和靶基因表达,从而影响Wnt信号通路介导的重要生理和病理过程。     

肝癌组织中Wnt通路上下游因子的表达及其临床意义

目的探讨Wnt通路Wif-1、C-myc、Cycling-D1mRNA及蛋白在正常肝组织、肝硬化及肝癌组织中的表达及其与肝癌临床病理参数的相关性。方法运用免疫组织化学SP法与原位杂交技术检测100份肝癌组织、50份肝硬化组织、50例正常肝组织中Wif-1、C-myc、Cycling-D1蛋白及mRNA的表达,并测定肝癌组织中的Wif-1、C-myc和Cycling-D1的阳性率、敏感性及特异性。结果肝硬化与肝癌组织中Wif-1 mRNA及蛋白的阳性细胞表达率明显低于正常肝组织(P<0.05),C-myc和Cycling-D1mRNA及蛋白的阳性细胞表达率明显高于正常肝组织(P<0.05)。肝癌组织中Wif-1、C-myc和Cycling-D1mRNA及蛋白的阳性表达均与HBV分级、TNM分期及β-catenin异质表达显著相关(P<0.05)。Wif-1、C-myc和Cycling-D1mRNA及蛋白在肝癌组织中的表达呈正相关(rWif-1=0.892,rC-myc=0.354,rCycling-D1=0.378)。肝癌组织中mRNA及蛋白的敏感性:Wif-1:9.09%、11.11%,C-myc:91.38%、89.66%,Cycling-D1:91.67%、82.5%,特异性:Wif-1:97.75%、95.6%,C-myc:82.5%、85.71%,Cycling-D1:92.86%、81.82%。结论肝癌的侵润和β-catenin的异质表达均与Wif-1下降,C-myc及Cycling-D1上调相关。     

基于Wnt/β-catenin信号通路的骨质疏松靶向治疗研究进展

Wnt/β-catenin信号通路在胚胎发育、成人组织稳态以及组织再生等方面发挥着重要作用,同时对骨形成也起着重要的促进作用。随着Wnt/β-catenin信号通路在骨质疏松中作用的阐明,针对Wnt/β-catenin信号通路的靶向治疗已经成功地应用于临床。对基于Wnt/β-catenin信号通路的骨质疏松靶向治疗进行了综述,为抗骨质疏松药物的设计提供了理论依据。     

Wnt2和β-catenin在乳腺癌及其配对癌旁乳腺组织中的表达与临床意义

目的探讨Wnt2和β-catenin在乳腺癌及其配对癌旁乳腺组织中的表达与临床意义。方法采用RT-PCR法检测7份乳腺癌及其配对癌旁乳腺组织中Wnt2和β-catenin基因mRNA的转录水平;免疫组织化学方法检测40份浸润性乳腺导管癌及其配对癌旁乳腺组织中Wnt2和β-catenin蛋白的表达水平;分析Wnt2和β-catenin与乳腺癌临床病理特征的相关性及二者联合检测与乳腺癌恶性程度及淋巴结转移的相关性。结果乳腺癌组织中Wnt2和β-catenin基因mRNA的相对转录水平均显著高于配对癌旁乳腺组织(P0.05)。Wnt2在配对癌旁乳腺组织细胞质中呈弱表达,在浸润性乳腺导管癌组织细胞质中呈高表达,乳腺癌Wnt2阳性表达率(77.5%)显著高于配对癌旁乳腺组织(15.0%)(P0.05);配对癌旁乳腺组织中β-catenin均表达于细胞膜中,在浸润性乳腺导管癌组织细胞质及细胞核中均有表达,异常表达率为67.5%(27/40)。Wnt2和β-catenin的表达与浸润性乳腺导管癌患者年龄无关(P0.05),与乳腺癌临床分期、病理组织学分级及淋巴结转移有关(P0.05)。Wnt2和β-catenin均为阳性表达者的肿瘤恶性程度和淋巴结转移的发生率显著高于两者均为阴性或两者之一为阳性表达者(P0.05)。结论 Wnt2和β-catenin表达在乳腺癌发生和侵袭转移中可能起重要作用,本实验为进一步探讨Wnt2和β-catenin在乳腺癌发病机制中的作用奠定了基础。     

缺氧诱导因子-1α与Wnt/β-catenin信号通路在缺氧胃癌细胞中的相互作用

目的在缺氧环境下,探讨缺氧诱导因子-1α(Hypoxia-inducible factor-1α,HIF-1α)与Wnt/β-catenin信号通路在胃癌细胞SGC-7901中的相互作用。方法将质粒β-catenin-micRNA转染SGC-7091细胞,筛选稳定转染细胞株SGC-7901-β-catenin-micRNA。将SGC-7901细胞分为对照组、脂质体组和阴性对照组,对照组:常氧培养48 h;脂质体组:常氧培养24 h后,加入10μl脂质体,培养24 h;阴性对照组:常氧培养24 h后,转染阴性对照质粒,培养24 h;设稳定转染细胞株为干扰组,常氧培养48 h。采用倍增时间试验、平板克隆形成试验及流式细胞术检测各组细胞倍增时间、平板克隆集落数及细胞周期的变化。另取SGC-7901细胞,分为对照组、缺氧组、双重缺氧组;对照组:常氧培养48 h;缺氧组:常氧培养32 h,物理缺氧培养16 h;双重缺氧组:常氧培养24 h,化学缺氧培养8 h后,再同时物理缺氧培养16 h。同时取稳定转染细胞株,分为对照干扰组、缺氧干扰组和双重缺氧干扰组。对照干扰组:常氧培养48 h;缺氧干扰组:常氧培养32 h,物理缺氧培养16 h;双重缺氧干扰组:常氧培养24 h,化学缺氧培养8 h后,再同时物理缺氧培养16 h。采用RT-PCR和Western blot法检测各组细胞中HIF-1α、β-catenin的mRNA及蛋白的表达水平。结果与对照组、脂质体组、阴性对照组比较,干扰组倍增时间延长,平板克隆集落数减少,细胞阻滞在G1期比例增加,S期减少,差异均有统计学意义(P<0.05)。缺氧组与对照组、双重缺氧组与缺氧组、缺氧干扰组与对照干扰组及双重缺氧干扰组与缺氧干扰组相比,HIF-1α、β-catenin的mRNA及蛋白表达水平均升高,差异有统计学意义(P均<0.05)。缺氧干扰组与缺氧组及双重缺氧干扰组与双重缺氧组比较,β-catenin、HIF-1α的mRNA及蛋白表达水平均降低,差异有统计学意义(P均<0.05)。结论 HIF-1α激活可调控Wnt/β-catenin通路,但也受控于Wnt/β-catenin通路,二者之间相互影响,相互调节。     

Axin2基因对肝癌细胞中Wnt/β-catenin信号通路相关分子表达的调控及机制

目的探讨Axin2基因对肝癌细胞中Wnt/β-catenin信号通路相关分子表达的调控及其机制。方法通过TOPflash试验检测Axin2基因对Wnt/β-catenin信号通路的影响;荧光定量PCR(Quantitative Real-time PCR,QPCR)法检测Axin2基因在正常肝细胞LO2及3种肝癌细胞HepG2、HHCC、HB611中的表达水平;对肝癌细胞HepG2中Axin2的表达进行干扰,并检测Wnt/β-catenin信号通路相关基因(β-catenin、Cyclin A、CDK2、Wnt5a、STAT3、EGFR、APC)mRNA转录水平及相关蛋白(β-catenin、Cyclin A、CDK2、APC)的表达量。结果 Axin2对Wnt/β-catenin信号通路有显著抑制作用,且呈剂量依赖性(P 0. 05);3种肝癌细胞Axin2的表达水平显著低于正常肝细胞LO2(P 0. 05);干扰HepG2细胞中Axin2基因表达后,Axin2基因m RNA转录及蛋白表达水平降低,Wnt信号通路下游基因β-catenin、Cyclin A、CDK2、Wnt5a、STAT3和EGFR基因mRNA转录水平及β-catenin、Cyclin A、CDK2蛋白表达量均上升,而APC基因mRNA转录水平及蛋白表达量降低。结论 Axin2基因通过调控Wnt/β-catenin信号通路相关基因的表达抑制肝癌细胞的生成,本研究为寻找新的肝癌治疗靶点及防治药物提供了实验依据。     

急性脑梗死患者血清Sfrp5、Wnt5a的表达与颈动脉粥样硬化斑块稳定性的关系

目的:探讨急性脑梗死患者血清分泌型卷曲相关蛋5(Sfrp5)、无翅型MMTV整合位点家族成员5a(Wnt5a)水平与颈动脉粥样硬化斑块稳定性的相关性。方法:选取2018-12～2019-11在佳木斯大学附属第一医院神经内科住院治疗的急性脑梗死病人90例为实验组,根据颈动脉彩色多普勒超声检查结果分为无斑块组(20例)、稳定性斑块组(25例)、不稳定性斑块组(45例);预选取同期45例健康体检者为对照组,采用酶联免疫吸附法(ELISA)检测各组血清Sfrp5、Wnt5a水平,并分析Sfrp5、Wnt5a与斑块稳定性的相关性。结果:实验组血清Sfrp5水平(27.06±8.74)ng/mL低于对照组(34.28±9.01)ng/mL,血清Wnt5a水平(4.28±0.98)ng/mL高于对照组(3.31±0.99)ng/mL,差异均有统计学意义。不稳定性斑块组血清Sfrp5(23.70±9.13)ng/mL低于稳定性斑块组(28.72±8.00)ng/mL,血清Wnt5a(4.74±1.02)ng/mL高于稳定性斑块组(4.08±0.69)ng/mL,差异均有统计学意义。结论:血清Sfrp5、Wnt5a的表达程度对提示颈动脉粥样硬化斑块性质有一定的作用,可能参加颈动脉粥样硬化斑块发生发展的过程中。     

Impact of an Altered Wnt1/β-Catenin Expression on Clinicopathology and Prognosis in Clear Cell Renal Cell Carcinoma

In renal cell carcinoma (RCC), single members of the Wnt/β-catenin signaling cascade were recently identified to contribute to cancer progression. However, the role of Wnt1, one of the key ligands in β-catenin regulation, is currently unknown in RCC. Therefore, alterations of the Wnt1/β-catenin axis in clear cell RCC (ccRCC) were examined with regard to clinicopathology, overall survival (OS) and cancer specific survival (CSS). Corresponding ccRCCs and benign renal tissue were analyzed in 278 patients for Wnt1 and β-catenin expression by immunohistochemistry in tissue microarrays. Expression scores, including intensity and percentage of stained cells, were compared between normal kidney and ccRCCs. Data was categorized according to mean expression scores and correlated to tumor and patients’ characteristics. Survival was analyzed according to the Kaplan-Meier and log-rank test. Univariable and multivariable Cox proportional hazard regression models were used to explore the independent prognostic value of Wnt1 and β-catenin. In ccRCCs, high Wnt1 was associated with increased tumor diameter, stage and vascular invasion (p ≤ 0.02). High membranous β-catenin was associated with advanced stage, vascular invasion and tumor necrosis (p ≤ 0.01). Higher diameter, stage, node involvement, grade, vascular invasion and sarcomatoid differentiation (p ≤ 0.01) were found in patients with high cytoplasmic β-catenin. Patients with a high cytoplasmic β-catenin had a significantly reduced OS (hazard ratio (HR) 1.75) and CSS (HR 2.26), which was not independently associated with OS and CSS after adjustment in the multivariable model. Increased ccRCC aggressiveness was reflected by an altered Wnt1/β-catenin signaling. Cytoplasmic β-catenin was identified as the most promising candidate associated with unfavorable clinicopathology and impaired survival. Nevertheless, the shift of membranous β-catenin to the cytoplasm with a subsequently increased nuclear expression, as shown for other malignancies, could not be demonstrated to be present in ccRCC.     

A Caspase-Dependent Pathway Is Involved in Wnt/β-Catenin Signaling Promoted Apoptosis in Bacillus Calmette-Guerin Infected RAW264.7 Macrophages

Apoptosis of alveolar macrophages following Mycobacterium tuberculosis infection have been demonstrated to play a central role in the pathogenesis of tuberculosis. In the present study, we found that Wnt/β-catenin signaling possesses the potential to promote macrophage apoptosis in response to mycobacterial infection. In agreement with other findings, an activation Wnt/β-catenin signaling was observed in murine macrophage RAW264.7 cells upon Mycobacterium bovis Bacillus Calmette-Guerin (BCG) infection at a multiple-of-infection of 10, which was accompanied with up-regulation of pro-inflammatory cytokines TNF-α and IL-6 production. However, the BCG-induced TNF-α and IL-6 secretion could be significantly reduced when the cells were exposed to a canonical Wnt signaling ligand, Wnt3a. Importantly, the activation of Wnt/β-catenin signaling was able to further promote apoptosis in BCG-infected RAW264.7 cells in part by a mitochondria-dependent apoptosis pathway. Immunoblotting analysis further demonstrated that Wnt/β-catenin signaling-induced cell apoptosis partly through a caspase-dependent apoptosis mechanism by down-regulation of anti-apoptotic protein Mcl-1, and up-regulation of pro-apoptotic proteins Bax and cleaved-caspase-3, as well as enhancement of caspase-3 activity in BCG-infected RAW264.7 cells. These data may imply an underlying mechanism of alveolar macrophages in response to mycobacterial infection, by which the pathogen induces Wnt/β-catenin signaling activation, which in turn represses mycobacterium-trigged inflammatory responses and promotes mycobacteria-infected cell apoptosis.     

Wnt16 Signaling Is Required for IL-1β-Induced Matrix Metalloproteinase-13-Regulated Proliferation of Human Stem Cell-Derived Osteoblastic Cells

We established a differentiation method for homogeneous α7 integrin-positive human skeletal muscle stem cell (α7⁺hSMSC)-derived osteoblast-like (α7⁺hSMSC-OB) cells, and found that interleukin (IL)-1β induces matrix metalloproteinase (MMP)-13-regulated proliferation of these cells. These data suggest that MMP-13 plays a potentially unique physiological role in the regeneration of osteoblast-like cells. Here, we examined whether up-regulation of MMP-13 activity by IL-1β was mediated by Wingless/int1 (Wnt) signaling and increased the proliferation of osteoblast-like cells. IL-1β increased the mRNA and protein levels of Wnt16 and the Wnt receptor Lrp5/Fzd2. Exogenous Wnt16 was found to increase MMP-13 mRNA, protein and activity, and interestingly, the proliferation rate of these cells. Treatment with small interfering RNAs against Wnt16 and Lrp5 suppressed the IL-1β-induced increase in cell proliferation. We revealed that a unique signaling cascade IL-1β→Wnt16→Lrp5→MMP-13, was intimately involved in the proliferation of osteoblast-like cells, and suggest that IL-1β-induced MMP-13 expression and changes in cell proliferation are regulated by Wnt16.     

苦参碱对人急性红白血病细胞株TF-1SALL4基因及Wnt/β-catenin信号通路下游靶基因表达的影响

目的探讨苦参碱对人急性红白血病细胞株TF-1 SALL4基因及Wnt/β-catenin信号通路下游靶基因表达的影响。方法用不同浓度的苦参碱(0.5、1.0、2.0 g/L)处理TF-1细胞,另设对照组(不加苦参碱)。苦参碱作用48 h后,采用实时荧光定量PCR法检测各组TF-1细胞中SALL4基因及Wnt/β-catenin信号通路下游靶基因β-catenin、C-myc、Cyclin DI的表达水平,并分析SALL4基因与β-catenin、C-myc及Cyclin DI表达的相关性;Western blot法检测各组TF-1细胞中SALL4蛋白的表达水平。结果经不同浓度苦参碱处理48 h后,TF-1细胞中SALL4、β-catenin、C-myc、Cyclin DI基因的表达水平及SALL4蛋白的表达水平与对照组相比,均明显下降,且呈浓度依赖性(P<0.05);SALL4基因与β-catenin、C-myc、Cyclin DI基因的表达明显相关(r s值分别为0.912、0.818和0.832,P均<0.01)。结论苦参碱对TF-1细胞中SALL4基因和蛋白表达及Wnt/β-catenin信号通路下游靶基因β-catenin、C-myc、Cyclin DI的抑制可能在抑制细胞增殖、诱导细胞凋亡过程中起重要作用。     

仿生控释BMP-2和VEGF的PELA微球支架对骨髓间充质干细胞向成骨细胞分化的Wnt/β-catenin通路的影响

目的制备外黏附复合重组人骨形态发生蛋白(recombinant human bone morphogenetic protein 2,rh BMP-2)内包封血管内皮细胞生长因子(vascular endothelial growth factor,VEGF)的微囊,并研究其对骨髓间充质干细胞(bone mesenchymal stem cells,BMSCs)向成骨细胞分化的Wnt/β-catenin通路的影响。方法以聚乳酸-聚乙二醇-聚乳酸三嵌段共聚物(polylactide-poly-ethylene glycol-polylactide,PELA)作为微囊的囊材,制备其外黏附rh BMP-2、内包封VEGF的微囊,制备微囊支架,实验分为对照组、BMP-2/PELA组、PELA/VEGF组和BMP-2/PELA/VEGF组。ELISA法检测微囊支架在1、2、4、8、12、16、22、28、35、42 d于PBS中缓释的rh BMP-2和VEGF的浓度;MTT法检测微囊支架对BMSCs作用3、7、14 d细胞活性的影响;Western blot法检测微囊支架对BMSCs作用3、7、14 d,BMSCs向成骨细胞分化中Wnt/β-catenin通路及碱性磷酸酶(alkaline phosphatase,ALP)蛋白表达的影响。结果微囊支架在PBS中第2天,BMP-2释放了约60%,而VEGF则释放了约32%;4组微囊支架对BMSCs作用3、7、14 d,细胞活性差异无统计学意义(P0.05)。在第14天,BMP-2/PELA/VEGF组Wnt、β-catenin及ALP的表达量均显著高于第3和7天(P0.05),而第7天的表达量均显著高于第3天(P0.05)。结论成功制备了BMP-2/PELA/VEGF微囊支架,对BMSCs无细胞毒性作用,可使BMSCs向成骨细胞进一步分化。     

绿茶提取物表没食子儿茶素-3-没食子酸酯对人卵巢癌HO-8910细胞增殖及Wnt/β-catenin信号通路相关基因表达的影响

目的研究绿茶提取物表没食子儿茶素-3-没食子酸酯(Epigallocatechin-3 gallste,EGCG)对人卵巢癌HO-8910细胞增殖及细胞内Wnt/β-catenin信号通路相关基因表达的影响,探讨EGCG抑制卵巢癌细胞生长的机制。方法用不同浓度的EGCG(10、20和40μg/ml)处理体外培养的人卵巢癌HO-8910细胞不同时间(24、48和72 h),采用MTT法检测细胞的增殖活力;流式细胞术检测细胞周期的变化;RT-PCR和Western blot分别检测细胞中β-catenin和下游靶基因CyclinD1 mRNA的转录水平和蛋白的表达水平。结果 EGCG可明显抑制HO-8910细胞的增殖活力,且抑制作用呈剂量-时间依赖性(P<0.05);40μg/ml EGCG干预后,HO-8910细胞主要阻滞于G0/G1期,且在48 h阻滞作用最为明显;EGCG可显著降低HO-8910细胞中β-catenin和CyclinD1基因mRNA的转录水平和蛋白的表达水平,且呈剂量-时间依赖性(P<0.01)。结论 EGCG可抑制HO-8910细胞的增殖,其机制可能与其抑制Wnt/β-catenin信号通路的活性有关,提示EGCG可能在卵巢癌的治疗中具有一定的应用前景。