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猕猴胚胎干细胞(rhesus monkey embryonic stem(rES))与人胚胎干细胞有相似的生物学特性,因此是理想的临床前研究的替代模型。Notch信号通路在胆管及胆管上皮细胞的形成中有重要的作用,然而,有关Notch信号通路在ES细胞的胆向分化中的作用了解甚少。该实验以rES为模型,对Notch信号通路对ES细胞的胆向分化过程中的作用进行了较为系统的研究。rES在细胞因子ActivinA诱导作用下产生约80%的限定性内胚层细胞。以Matrigel作为细胞外基质,在含BMP4和FGF1的无血清培养体系中继续诱导5～7d,rES细胞来源的限定性内胚层细胞分化产生约胆管样细胞。分化的细胞表达胆管细胞的特异性蛋白((CK7、CK18、CK19、CK20和OV-6)及基因(GSTPi、IB4和HNF1β)。在胆管样细胞的分化过程中检测到了Notch1和Notch2基因及下游信号分子hes1和hes5的表达。用Notch抑制剂L-685458处理分化过程中的细胞可导致Notch1和Notch2基因及下游信号分子hes1和hes5的表达下降,同时CK19阳性的胆管样细胞分化比率也从90%下降至约20%。这一研究提示Notch信号通路可能在ES细胞的胆管样分化过程中扮演重要的角色。
Rhesus monkey embryonic stem (rES) cells share similar biological characteristics to human embryonic stem cells and are therefore ideal surrogate models for preclinical studies. Notch signaling pathway plays an important role in the formation of bile ducts and biliary epithelial cells. However, little is known about the role of Notch signaling in the biliary differentiation of ES cells. In this experiment, we used rES as a model to study the role of Notch signaling pathway in ES cell differentiation. The rES produces about 80% of the definitive endoderm cells under the induction of the cytokine ActivinA. With Matrigel as the extracellular matrix, the differentiated endoderm cells derived from rES cells were induced to differentiate into bile duct-like cells in the serum-free culture system containing BMP4 and FGF1 for 5-7 days. Differentiated cells expressed cholangiocyte specific proteins (CK7, CK18, CK19, CK20 and OV-6) and genes (GSTPi, IB4 and HNF1β). Notch1 and Notch2 genes were detected downstream of bile duct- The expression of hes1 and hes5 signaling molecules.Cell differentiation of cells treated with Notch inhibitor L-685458 resulted in decreased expression of Notch1 and Notch2 genes and downstream signaling molecules hes1 and hes5, and CK19-positive bile duct-like cell differentiation ratio from 90 % Down to about 20% .This study suggests that Notch signaling pathway may play an important role in the bile duct-like differentiation of ES cells.