经典Wnt信号通路在原发性肝癌发生中的作用

原发性肝癌（HCC）是世界第5大肿瘤,死亡率高,其发病率呈上升趋势。研究表明,多种信号通路参与了HCC的发生发展如p53信号通路、Rb信号通路、经典Wnt信号通路等[2]。Wnt基因家族编码蛋白的异常表达可引起经典Wnt信号通路的激活,进而导致核心因子β-catenin稳态并定位于核内,激活下游靶基因的转录,与肿瘤发生有关。了解该通路在HCC发生发展中的作用有重要意义。     

Wnt/β-catenin信号通路与骨关节炎

近年大量研究证实Wnt/β-catenin信号通路通过调节胚胎期软骨发育及出生后软骨发生、成骨细胞和破骨细胞生成、软骨内成骨、骨重塑、骨折修复等过程,调控骨骼系统相关疾病和骨代谢,对骨关节炎(OA)发生发展、骨软骨组织诱导和修复起着至关重要的作用。基因敲除小鼠模型常用于Wnt/β-catenin信号通路与OA关系研究,全基因组扫描已发现一些与OA密切相关的单核苷酸多态性位点。目前在多个水平进行Wnt/β-catenin信号通路靶向治疗OA研究,重点考虑药物安全性。该文就Wnt/β-catenin与OA关系的研究进展作一综述。     

Wnt5a在甲状腺乳头状癌中的表达及意义

目的：探讨Wnt5a在甲状腺乳头状癌（PTC）组织中的表达及意义。 方法：收集术后病理确诊为PTC的患者石蜡标本47例,包括癌组织及癌旁组织,以及手术切除的PTC新鲜标本及其癌旁组织10例。分别采用免疫组化法及real-time PCR检测Wnt5a在PTC及癌旁组织中的表达。 结果：47例患者的石蜡标本中,PTC及癌旁组织中,Wnt5a在PTC组织的阳性表达率为68.09%（32/47）,在癌旁甲状腺组织为6.38%（3/47）,两者间差异有统计学意义（P<0.01）;统计分析显示,Wnt5a的表达与患者的性别及年龄无关（均P>0.05）,而与肿瘤的TNM分期、淋巴结转移有关（P<0.05或P<0.01）。10例手术标本检测显示,PTC中Wnt5a mRNA的表达明显高于其的癌旁甲状腺组织（6.43±1.38 vs. 1.12±0.59,P<0.01）。 结论：PTC组织中Wnt5a表达水平增高,这可能对PTC的发生和发展有着重要的作用。     

Vps4A对肝癌细胞SMMC-7721的Wnt途径的影响

【摘要】 目的 探讨Vps4A对肝癌细胞SMMC-7721中Wnt途径的影响。方法〓构建过表达Vps4A的SMMC-7721细胞稳定株,通过RT-qPCR的方法检测19个WNT基因的转录水平的变化,进一步通过Western blot及检测相关下游基因Notch2的变化进行确定。结果〓在SMMC-7721中,经典Wnt亚型Wnt10a和Wnt10b的mRNA水平较高,而在过表达Vps4A之后,其蛋白及mRNA水平均显著下降。同时,在过表达Vps4A细胞株中,与经典Wnt通路相关的下游靶基因Notch2在转录及表达水平同样明显下调。结论〓Vps4A选择性抑制肝癌细胞SMMC-7721的经典Wnt/Notch2途径。     

Wnt/连环蛋白信号通路在体表创面愈合中的作用机制研究进展

创面愈合是一个缓慢而复杂的生物学过程, 包括炎症反应、细胞增殖分化和迁移、血管新生、细胞外基质沉积和组织重塑等。Wnt信号通路可分为经典通路和非经典通路, 其中Wnt经典通路又称Wnt/β连环蛋白信号通路, 其在细胞分化、迁移和组织稳态维持过程中发挥重要作用。许多炎症因子、生长因子等都参与该通路的上游调控。Wnt/β连环蛋白信号通路的激活在皮肤创面的发生、发展、再生、修复及相关治疗的过程中, 起到了重要作用。该文综述了Wnt/β连环蛋白信号通路与创面愈合的关系, 并总结了其对炎症反应、细胞增殖、血管新生、毛囊再生和皮肤纤维化等创面愈合重要过程的影响以及Wnt信号通路抑制因子在创面愈合中的作用。     

Wnt信号通路与骨关节炎

Wnt信号通路广泛地存在于各种属生物体中,调节控制着许多生命过程,如细胞形态与功能的分化及维持、免疫、应激、凋亡等。随着对其研究的不断深入,发现Wnt信号通路对早期软骨的化生与形成、体外软骨细胞的增殖与分化具有重要的作用,并已成为骨关节炎(osteoarthritis,OA)发病机制研究的新热点。     

特异性顶部盘状底板反应蛋白在骨关节炎中的研究进展

骨关节炎(OA)是中老年人群常见的慢性退行性关节疾病, 其病理特征主要是关节软骨变性、软骨下骨硬化、骨赘形成、滑膜组织炎症和增生、韧带和半月板变性以及关节囊肥大。特异性顶部盘状底板反应(RSPOs)蛋白是一种分泌型糖蛋白, 主要通过激活Wnt/β-连环蛋白信号通路发挥其生理功能。近年来, 随着RSPOs在OA领域的不断探索, 越来越多的证据揭示了RSPOs在骨关节炎中的作用及影响。本文总结了RSPOs在OA领域的作用机制及研究现状, 并且还讨论了RSPOs在OA多种细胞中的影响, 为OA的发病机制和治疗提供参考。     

Wnt信号通路调节因子在肝门部胆管癌组织中的表达

目的研究肝门部胆管癌组织中Wnt经典通路调节因子Frizzled、LRP5/6、APC、Axin的表达,结合既往的研究明确Wnt经典通路的整体调节。 方法以1998年4月至2007年5月病理确诊为肝门部胆管癌的129例肿瘤标本作为胆管癌组,使用同期的45例先天性胆总管囊肿标本作为对照（囊肿组）,通过组织芯片技术检测所有标本的Wnt经典通路中主要调节因子Frizzled、LRP5/6、APC、Axin的表达。 结果囊肿组中Frizzled阳性率高于胆管癌组（91.1% vs 78.3%,H=9.29,P<0.05）;胆管癌组的LRP5/6及APC阳性率分别为91.5%、84.5%,囊肿组的LRP5/6及APC阳性率分别为95.6%、77.8%,两组差异均无统计学意义（H=0.622、1.800,P=0.733、0.400）;而Axin在胆管癌组的表达阳性率显著高于囊肿组（91.4% vs 88.9%,H=6.23,P<0.05）。 结论以组织芯片技术为手段,本研究反映出肝门部胆管癌Wnt通路中Frizzled及Axin两种蛋白较囊肿组织体现显著差异,有望成为诊断及治疗的靶点。     

Wnt/β-catenin信号通路重要分子及其靶基因在原发性肝癌中的作用机制

肝癌是我国及某些亚非地区常见的恶性肿瘤之一,死亡率较高.近年来我国肝癌的发生率有上升趋势,因此了解肝癌的发生发展机制及其治疗刻不容缓.但目前对其发生机制仍不清楚.其中细胞信号转导对其发生、发展、转移起着至关重要的作用.如Notch信号通路、Wnt信号通路、Ras、Jnk信号通路、mTOR通路等,目前倍受关注的是Wnt/β-catenin转导途径.经典Wnt信号通路研究最多且相关机制解释较为清楚,其激活的重要标志是β-catenin于胞质稳定表达及核内定位.研究表明,Wnt信号通路各蛋白表达水平改变及相关基因突变参与了原发性肝癌(hepatocellular carcinoma,HCC)的发生.     

Notch信号通路在骨肉瘤中的研究进展

骨肉瘤（Osteosarcoma,OS）相关信号转导通路已成为OS基因治疗研究的热点之一,其中经典的抑癌基因p53、Rbl、Wnt/β-catenin,原癌基因C-myc、erbB-2、Survivin、CTRP3等,以及血管内皮生长因子（vascularendothelialgrowthfactor,VEGF）、环氧合酶-2（cyclooxygenase-2,COX-2）等研究较为深入并已尝试应用于基因治疗。Notch作为一条重要的信号通路在OS中的研究相对较少,其作用机制尚不明确,本文就近年来Notch信号通路在OS中的研究进展作一综述。Notch基因发现于1919年,其突变可造成果蝇的残翅。随后研究发现,     

Elevated Dickkopf‐2 levels contribute to the abnormal phenotype of human osteoarthritic osteoblasts

The Wnt signaling pathway is crucial for osteogenesis and regulates terminal osteoblast differentiation. Although osteoarthritic (OA) osteoblasts show an abnormal phenotype and poor in vitro mineralization, the mechanism leading to this situation still remains unknow. Recent evidence indicates that Wnt signaling may be altered in OA osteoblasts. In this study we determined whether an alteration of the Wnt/β‐catenin signaling pathway is responsible for the abnormal phenotype of OA osteoblasts. Expression of the Wnt signaling antagonist Dickkopf‐1 (DKK1) was similar in normal and OA osteoblasts, whereas DKK2 expression was higher in OA osteoblasts than in normal osteoblasts. OA osteoblasts showed a decrease of Wnt3a‐dependent Wnt/β‐catenin signaling, measured by the TOPflash reporter assay and by Western blot analysis, compared with normal osteoblasts. Correcting DKK2 levels in OA osteoblasts by siRNA techniques enhanced Wnt/β‐catenin signaling. Elevated DKK2 levels could be explained by elevated transforming growth factor β1 (TGF‐β1) in OA osteoblasts, and exogenous TGF‐β1 increased DKK2 expression in normal osteoblasts, whereas ablating TGF‐β1 expression in OA osteoblasts reduced DKK2 expression. Inhibiting TGF‐β1 or DKK2 expression corrected the abnormal phenotype of OA osteoblasts. In vitro mineralization of OA osteoblasts also was increased by DKK2 siRNA. We conclude that elevated TGF‐β1 levels in OA osteoblasts can stimulate DKK2 expression, which, in turn, is responsible, at least in part, for their abnormal phenotype. © 2011 American Society for Bone and Mineral Research.     

Low‐density lipoprotein receptor‐related protein 5 (LRP5) expression in human osteoarthritic chondrocytes

The aim of this study was to investigate the activation of the Wnt/β‐catenin pathway in osteoarthritis and the role of low‐density lipoprotein receptor‐related protein 5 (LRP5) in human osteoarthritic chondrocytes. The influence of 1,25(OH)₂D₃ on the expression of the LRP5 gene in human chondrocytes was also assessed. Human cartilage was obtained from 11 patients with primary osteoarthritis (OA) undergoing total knee replacement surgery. Normal cartilage was obtained from five healthy individuals. Beta‐catenin and LRP5 mRNA levels were investigated using real‐time PCR and LRP5 protein expression using Western blot analysis. Furthermore, we evaluated the effect of 1,25(OH)₂D₃ on LRP5 mRNA expression levels in osteoarthritic chondrocytes. Blocking LRP5 expression was performed using small interfering RNA (siRNA) against LRP5, and subsequent MMP‐13 mRNA and protein levels were evaluated by real‐time PCR and Western blot analysis, respectively. We confirmed the activation of the Wnt/β‐catenin pathway in OA, as we observed significant up‐regulation of β‐catenin mRNA expression in osteoarthritic chondrocytes. We also observed that LRP5 mRNA and protein expression were significantly up‐regulated in osteoarthritic cartilage compared to normal cartilage, and LRP5 mRNA expression was further increased by vitamin D. Also, blocking LRP5 expression using siRNA against LRP5 resulted in a significant decrease in MMP‐13 mRNA and protein expressions. Our findings suggest the catabolic role of LRP5 is mediated by the Wnt/β‐catenin pathway in human osteoarthritis. © 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 28:348–353, 2010     

肝细胞肝癌中Wnt5a基因的表达及其临床意义

目的 探讨Wnt5a基因mRNA及其蛋白在肝细胞肝癌(hepatocellular carcinoma, HCC)中的表达规律及其临床意义.方法 应用实时定量RT-PCR方法 检测22例HCC癌和癌旁配对组织中Wnt5a基因mRNA表达,采用免疫组织化学(ABC)法检测76例Wnt5a蛋白的表达情况,结合病人的临床病理资料分析Wnt5a基因在HCC中的表达意义.结果 对比癌旁肝组织,68%(15/22)的肝癌组织Wnt5a基因mRNA呈上调表达(P=0.038);而80.3%(61/76)的HCC癌组织Wnt5a蛋白显示低或阴性表达(P<0.001),Wnt5a蛋白低表达与病人的性别、肿瘤的大小、肿瘤的分化程度、HBsAg、以及有无肝硬化无关(P>0.05),而与高的甲胎蛋白水平(AFP,P=0.020)和差的肿瘤分期有关(P<0.001).结论 Wnt5蛋白缺失表达是HCC进展中的频发事件,Wnt5a在HCC肿瘤发生过程中可能发挥肿瘤抑制基因活性,该蛋白极可能是一个有用的HCC预后不良指标.     

Dog as a Model for Osteoarthritis: The FGF4 Retrogene Insertion May Matter

Osteoarthritis (OA) is a degenerative joint disease associated with chronic pain and disability in humans and companion animals. The canine species can be subdivided into non‐chondrodystrophic (NCD) and chondrodystrophic (CD) dogs, the latter having disproportionally short limbs due to disturbance in endochondral ossification of long bones. This phenotype is associated with retrogene insertions of the fibroblast growth factor 4 (FGF4) gene, resulting in enhanced fibroblast growth factor receptor 3 (FGFR3) signaling. The effect on cartilage is unknown and in experimental studies with dogs, breeds are seemingly employed randomly. The aim of this study was to determine whether CD‐ and NCD‐derived cartilage differs on a structural and biochemical level, and to explore the relationship between FGF4 associated chondrodystrophy and OA. Cartilage explants from CD and NCD dogs were cultured for 21 days. Activation of canonical Wnt signaling was assessed in primary canine chondrocytes. OA and synovitis severity from an experimental OA model were compared between healthy and OA samples from CD and NCD dogs. Release of glycosaminoglycans, DNA content, and cyclooxygenase 2 (COX‐2) expression were higher in NCD cartilage explants. Healthy cartilage from NCD dogs displayed higher cartilage degeneration and synovitis scores, which was aggravated by the induction of OA. Dikkopf‐3 gene expression was higher in NCD cartilage. No differences in other Wnt pathway read outs were found. To conclude, chondrodystrophy associated with the FGF4 retrogene seems to render CD dogs less susceptible to the development of OA when compared with NCD dogs. These differences should be considered when choosing a canine model to study the pathobiology and new treatment strategies of OA. © 2019 The Authors. Journal of Orthopaedic Research^® Published by Wiley Periodicals, Inc. J Orthop Res 37:2550–2560, 2019     

Mice Lacking Wnt9a or Wnt4 Are Prone to Develop Spontaneous Osteoarthritis With Age and Display Alteration in Either the Trabecular or Cortical Bone Compartment

Osteoarthritis (OA) is a common degenerative disease of the joint, with a complex multifactorial not yet fully understood etiology. Over the past years, the Wnt signaling pathway has been implicated in osteoarthritis. In a recent genomewide association study (GWAS), the chromosomal location on chromosome 1, linked to the Wnt3a-Wnt9a gene locus, was identified as the most significant locus associated with a thumb osteoarthritis endophenotype. Previously, it was shown that WNT9a is involved in maintaining synovial cell identity in the elbow joint during embryogenesis. Here, we report that the conditional loss of Wnt9a in the Prx1-Cre expressing limb mesenchyme or Prg4-CreER expressing cells predispositions the mice to develop spontaneous OA-like changes with age. In addition, the trabecular bone volume is altered in these mice. Similarly, mice with a conditional loss of Wnt4 in the limb mesenchyme are also more prone to develop spontaneously OA-like joint alterations with age. These mice display additional alterations in their cortical bone. The combined loss of Wnt9a and Wnt4 increased the likelihood of the mice developing osteoarthritis-like changes and enhanced disease severity in the affected mice. © 2022 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).     

汉族、哈萨克族湿热痹阻证类风湿关节炎患者Wnt信号通路的研究

目的:检测汉族、哈萨克族湿热痹阻证类风湿关节炎患者Wnt信号通路基因,以期发现不同民族类风湿关节炎患者在Wnt信号通路上的表现机制是否存在差异,为进一步研究类风湿关节炎的发病机制及临床治疗提供理论依据。方法:运用PCR Array技术对4例哈萨克族和4例汉族湿热痹阻证类风湿关节炎患者的Wnt基因进行检测,筛选出表达差异有统计学意义且与类风湿关节炎发病相关的基因,再选取哈萨克族(试验组)与汉族(对照组)湿热痹阻证类风湿关节炎患者,每组30例,应用实时荧光定量PCR技术对其外周血进行检测,进一步验证所筛选出的Wnt基因表达差异。结果:试验组与对照组相比,有21个Wnt基因表达差异有统计学意义(差异倍数>2,P<0.05)。从中选出FZD9、MMP7、Wnt8A、Wnt1和Axin2基因,用实时荧光定量PCR技术进一步验证,发现这5个基因在试验组中均呈现高表达,2组间Wnt8A、Axin2和Wnt1比较,差异有统计学意义(P<0.05)。结论:哈萨克族与汉族湿热痹阻证类风湿关节炎患者相比,Wnt8A、Axin2和Wnt1基因存在显著差异,且呈正向倍数变化,这些基因的异常表达可能与哈萨克族类风湿关节炎患者发病特点有关。     

Pulsating fluid flow modulates gene expression of proteins involved in Wnt signaling pathways in osteocytes

Strain‐derived flow of interstitial fluid activates signal transduction pathways in osteocytes that regulate bone mechanical adaptation. Wnts are involved in this process, but whether mechanical loading modulates Wnt signaling in osteocytes is unclear. We assessed whether mechanical stimulation by pulsating fluid flow (PFF) leads to functional Wnt production, and whether nitric oxide (NO) is important for activation of the canonical Wnt signaling pathway in MLO‐Y4 osteocytes. MC3T3‐E1 osteoblasts were studied as a positive control for the MLO‐Y4 osteocyte response to mechanical loading. MLO‐Y4 osteocytes and MC3T3‐E1 osteoblasts were submitted to 1‐h PFF (0.7 ± 0.3 Pa, 5 Hz), and postincubated (PI) without PFF for 0.5–3 h. Gene expression of proteins related to the Wnt canonical and noncanonical pathways were studied using real‐time polymerase chain reaction (PCR). In MLO‐Y4 osteocytes, PFF upregulated gene expression of Wnt3a, c‐jun, connexin 43, and CD44 at 1–3‐h PI. In MC3T3‐E1 osteoblasts, PFF downregulated gene expression of Wnt5a and c‐jun at 0.5–3‐h PI. In MLO‐Y4 osteocytes, gene expression of PFF‐induced Wnt target genes was suppressed by the Wnt antagonist sFRP4, suggesting that loading activates the Wnt canonical pathway through functional Wnt production. The NO inhibitor L‐NAME suppressed the effect of PFF on gene expression of Wnt target genes, suggesting that NO might play a role in PFF‐induced Wnt production. The response to PFF differed in MC3T3‐E1 osteoblasts. Because Wnt signaling is important for bone mass regulation, osteocytes might orchestrate loading‐induced bone remodeling through, among others, Wnts. © 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 27:1280–1287, 2009     

Canonical Wnt signaling in the notochordal cell is upregulated in early intervertebral disk degeneration

The notochordal cell (NC) of the nucleus pulposus (NP) is considered a potential NP progenitor cell, and early intervertebral disk (IVD) degeneration involves replacement of NCs by chondrocyte-like cells (CLCs). Wnt/β-catenin signaling plays a crucial role in maintaining the notochordal fate during embryogenesis, but is also involved in tissue degeneration and regeneration. The canine species, which can be subdivided into non-chondrodystrophic and chondrodystrophic breeds, is characterized by differential maintenance of the NC: in non-chondrodystrophic dogs, the NC remains the predominant cell type during the majority of life, with IVD degeneration only occurring at old age; conversely, in chondrodystrophic dogs the NC is lost early in life, with concurrent degeneration of all IVDs. This study investigated Wnt/β-catenin signaling in the healthy, NC-rich NP and early degenerated, CLC-rich NP of both breed types by immunohistochemistry of β-catenin and relative gene expression of brachyury and cytokeratin 8 (notochordal markers) and Wnt targets axin2, cyclin D1, and c-myc. Both NCs and CLCs showed nuclear and cytoplasmic β-catenin protein expression and axin2 gene expression, but β-catenin signal intensity and Wnt target gene expression were higher in the CLC-rich NP. Primary NCs in monolayer culture (normoxic conditions) showed Wnt/β-catenin signaling comparable to the in vivo situation, with increased cyclin D1 and c-myc gene expression. In conclusion, Wnt/β-catenin signaling activity in the NC within the NC-rich NP and in culture supports the role of this cell as a potential progenitor cell; increased Wnt/β-catenin signaling activity in early IVD degeneration may be a reflection of its dual role.