Dental stem cells for dental pulp regeneration have become a new strategy for pulpitis treatment. Angiogenesis and neurogenesis play a vital role in the pulp-dentin complex regeneration, and appropriate growth factors will promote the process of angiogenesis and neurogenesis. Insulin-like growth factor-binding protein 5 (IGFBP5) is involved in the regulation of tooth growth and development. A previous study showed that IGFBP5 enhanced osteo/odontogenic differentiation of dental stem cells. Our research intends to reveal the function of IGFBP5 in the angiogenic and neurogenic differentiation of human dental stem cells. Human dental pulp stem cells (DPSCs) were used in the present study. Lentiviral IGFBP5 shRNA was used to silence the IGFBP5. Retroviruses expressing Wild-type IGFBP5 were used to over-express IGFBP5. Angiogenic and neurogenic differentiation were carried out by in vitro study. Real-time RT-PCR and western blot results showed that over-expression of IGFBP5 upregulated the expressions of angiogenic markers, including VEGF, PDGFA and ANG-1, and neurogenic markers, including NCAM, TH, Nestin, βIII-tubulin, and TH, in DPSCs. Moreover, microscope observation confirmed that over-expression of IGFBP5 enhanced neurosphere formation in DPSCs in size and amount. Immunofluorescence staining results showed that over-expression of IGFBP5 also prompted the percentage of Nestin and βIII-tubulin positive neurospheres in DPSCs. While depletion of IGFBP5 downregulated the expressions of VEGF, PDGFA, ANG-1, NCAM, TH, Nestin, βIII-tubulin, and TH, it decreased the neurosphere formation and percentage of Nestin and βIII-tubulin positive neurospheres in DPSCs. In conclusion, our results revealed that IGFBP5 promoted angiogenic and neurogenic differentiation potential of DPSCs in vitro and provided the possible potential target for enhancing directed differentiation of dental stem cells and dental pulp-dentin functional regeneration.

中文翻译：

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IGFBP5促进牙髓干细胞的血管生成和神经生成分化潜能。

用于牙髓再生的牙科干细胞已成为治疗牙髓炎的新策略。血管生成和神经发生在牙髓-牙本质复合物的再生中起着至关重要的作用，适当的生长因子将促进血管生成和神经发生的过程。胰岛素样生长因子结合蛋白5（IGFBP5）参与牙齿生长发育的调控。先前的研究表明，IGFBP5增强了牙齿干细胞的骨/牙源性分化。我们的研究旨在揭示IGFBP5在人类牙齿干细胞的血管生成和神经生成分化中的功能。人类牙髓干细胞（DPSCs）用于本研究。慢病毒IGFBP5 shRNA用于沉默IGFBP5。表达野生型IGFBP5的逆转录病毒用于过表达IGFBP5。通过体外研究进行血管生成和神经源性分化。实时RT-PCR和Western印迹结果表明，IGFBP5的过表达上调了血管生成标记物（包括VEGF，PDGFA和ANG-1）以及神经源标记物（包括NCAM，TH，Nestin，βIII-微管蛋白和TH）的表达，在DPSC中。此外，显微镜观察证实IGFBP5的过表达增强了DPSCs中神经球形成的大小和数量。免疫荧光染色结果表明，IGFBP5的过表达也促进了DPSC中Nestin和βIII-微管蛋白阳性神经球的百分比。IGFBP5的消耗虽然下调了VEGF，PDGFA，ANG-1，NCAM，TH，巢蛋白，βIII-微管蛋白和TH的表达，但它却减少了DPSCs中神经球的形成以及Nestin和βIII-微管蛋白阳性神经球的百分比。