Expression profiling and functional analysis of Wnt signaling mechanisms in mesenchymal stem cells
Expression profiling and functional analysis of Wnt signaling mechanisms in mesenchymal stem cells
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DOI：
10.1634/stemcells.22-5-849
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发表时间：
2004-01-01
期刊：
影响因子：
5.2
通讯作者：
Genever, PG
中科院分区：
文献类型：
--
作者：
Etheridge, SL;Spencer, GJ;Genever, PG
间充质干细胞 (MSC) 凭借其广泛的分化潜力，成为一系列治疗应用的候选者，但决定其分化命运的精确信号通路尚不完全清楚。越来越多的证据表明，发育信号线索可能对调节干细胞自我更新和分化程序很重要。在这里，我们鉴定了 MSC 中 Wnt 信号分子的一致表达谱，并提供了内源性经典 Wnt 通路在这些细胞中发挥作用的证据。Wnt 与卷曲 (Fz) 受体结合，随后的经典信号传导抑制糖原合酶激酶 - 3beta (GSK-3beta)，导致 β-连环蛋白易位到细胞核中，诱导靶基因表达。在从不同供体的骨髓中分离的人类 MSC 中，我们似乎使用逆转录酶聚合酶链反应 (RT-PCR) 鉴定了共同的 Wnt/Fz 表达谱。相关 Writ 信号成分，包括低密度脂蛋白受体相关蛋白 5 (LRP-5)、kremen-1、dickkopf-1 (Dkk-1)、分泌型卷曲相关肽 (sFRP)-2、sFRP3、sFRP4、Disheveled (Dvl)、GSK-3beta、腺瘤性息肉病大肠杆菌 (APC)、β-连环蛋白、T 细胞因子(TCF)-1 和 TCF-4 也被鉴定出来。在 30%-40% 的 MSC 中观察到核 β-连环蛋白，表明存在内源性 Wnt 信号传导。暴露于 Wnt3a 和 Li+ 离子，可通过抑制 GSK-3beta 促进经典 Wnt 信号传导，减少 MSC 中 β-连环蛋白的磷酸化，并使 β-连环蛋白核转位增加约是对照组的三倍。我们的研究结果表明，自分泌 Wnt 信号传导在原始 MSC 群体中起作用，并支持之前的证据，即 Wnt 信号传导调节间充质谱系规范。 MSC 中假定的常见 Wnt/Fz 分子特征的鉴定将有助于我们了解调节自我更新和谱系特异性分化的分子机制。
Through their broad differentiation potential, mesenchymal stem cells (MSCs) are candidates for a range of therapeutic applications, but the precise signaling pathways that determine their differentiated fate are not fully understood. Evidence is emerging that developmental signaling cues may be important in regulating stem cell self-renewal and differentiation programs. Here we have identified a consistent expression profile of Wnt signaling molecules in MSCs and provide evidence that an endogenous canonical Wnt pathway functions in these cells.Wnts bind to Frizzled (Fz) receptors and subsequent canonical signaling inhibits glycogen synthase kinase-3beta (GSK-3beta), causing beta-catenin translocation into the nucleus to induce target gene expression. In human MSCs isolated from bone marrow of different donors, we appear to have identified a common Wnt/Fz expression profile using reverse transcriptase polymerase chain reaction (RT-PCR). Associated Writ signaling components, including low-density lipoprotein receptor-related protein-5 (LRP-5), kremen-1, dickkopf-1 (Dkk-1), secreted Frizzled-related peptide (sFRP)-2, sFRP3, sFRP4, Disheveled (Dvl), GSK-3beta, adenomatous polyposis coli (APC), beta-catenin, T-cell factor (TCF)-1, and TCF-4, were also identified. Nuclear beta-catenin was observed in 30%-40% of MSCs, indicative of endogenous Wnt signaling. Exposure to both Wnt3a and Li+ ions, which promotes canonical Wnt signaling by inhibiting GSK-3beta, reduced phosphorylation of beta-catenin in MSCs and increased beta-catenin nuclear translocation approximately threefold over that of the controls.Our findings indicate that autocrine Wnt signaling operates in primitive MSC populations and supports previous evidence that Wnt signaling regulates mesenchymal lineage specification. The identification of a putative common Wnt/Fz molecular signature in MSCs will contribute to our understanding of the molecular mechanisms that regulate self-renewal and lineage-specific differentiation.