Chen Yuhan, Chen Yuanyuan, Jiang Xueze, Shi Mengkun, Yang Zhenwei, Chen Zhiyong, Hua Xuesheng, Chen Jie, Wang Yuepeng
Department of Cardiology, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, 200092, People's Republic of China.
Department of Cardio-Thoracic Surgery, Shanghai Tongji Hospital, Tongji University School of Medicine, Shanghai, 200065, People's Republic of China.
J Inflamm Res. 2021 May 25;14:2207-2223. doi: 10.2147/JIR.S305204. eCollection 2021.
Activation of vascular adventitial fibroblasts (VAFs) upon vascular injury contributes greatly to the medial vascular smooth muscle cells (VSMCs) proliferation, migration and the subsequent neointima formation. A number of factors including fibroblast growth factors (FGFs) have been shown to control VSMC growth, proliferation and phenotypic switching, suggesting that they may function as paracrine signals for VAFs to modulate VSMCs functions. However, little is known about the signaling molecule(s) and its mechanism of action. This study is set to identify which and how FGF family members are involved in VAFs mediated vascular remodeling.
We used qPCR, Western blot and Immunohistochemistry to observe the spatiotemporal expression of FGF10 and FGFR2 in injured vascular tissue. The proliferation and migration assays of VSMCs were performed in a co-culture system. The activation of signaling pathway was detected by Western blot, immunohistochemistry and immunofluorescence. Hematoxylin-eosin and immunofluorescence were used to assess the effects of exogenous FGF10 and siFGF10 on the neointima formation.
The expression of FGF10 and FGFR2 were increased from day 3 through day 14 post injury. FGF10 was significantly upregulated in adventitia, and FGFR2 was detected in both media and neointima after injury. In vitro, FGF10 was most prominently expressed in VAFs and FGFR2 was significantly expressed in VSMCs. Both were regulated by PDGF. Co-culture of VAFs and VSMCs in vitro showed that VAF-derived FGF10 promoted the proliferation and migration of VSMCs. PDGF could synergistically enhance the process. VAF-derived FGF10 can significantly activate the FGFR2 in VSMCs and furthermore significantly activate the downstream MAPK/PI3K-AKT signaling pathways. Delivery of exogenous FGF10 potentiated the neointima formation, while siFGF10 attenuated the neointima formation.
VAFs-derived FGF10 promoted the proliferation and migration of VSMCs and neointima formation, and FGF10-FGFR2 signaling triggered the activation of MAPK/PI3K-AKT pathways in VSMCs and PDGF synergistically amplified FGF10 signaling.
血管损伤时血管外膜成纤维细胞（VAFs）的激活在很大程度上促进了血管中层平滑肌细胞（VSMCs）的增殖、迁移以及随后的新生内膜形成。包括成纤维细胞生长因子（FGFs）在内的多种因子已被证明可控制VSMC的生长、增殖和表型转换，这表明它们可能作为旁分泌信号，使VAFs调节VSMCs的功能。然而，对于信号分子及其作用机制知之甚少。本研究旨在确定哪些FGF家族成员参与以及如何参与VAFs介导的血管重塑。
我们使用qPCR、蛋白质免疫印迹法和免疫组织化学来观察FGF10和FGFR2在损伤血管组织中的时空表达。VSMCs的增殖和迁移实验在共培养系统中进行。通过蛋白质免疫印迹法、免疫组织化学和免疫荧光检测信号通路的激活情况。苏木精-伊红染色和免疫荧光用于评估外源性FGF10和siFGF10对新生内膜形成的影响。
FGF10和FGFR2的表达在损伤后第3天至第14天增加。FGF10在外膜中显著上调，损伤后在内膜和新生内膜中均检测到FGFR2。在体外，FGF10在VAFs中表达最为显著，FGFR2在VSMCs中显著表达。两者均受血小板衍生生长因子（PDGF）调节。VAFs和VSMCs的体外共培养显示，VAFs来源的FGF10促进了VSMCs的增殖和迁移。PDGF可协同增强这一过程。VAFs来源的FGF10可显著激活VSMCs中的FGFR2，并进一步显著激活下游的MAPK/PI3K-AKT信号通路。外源性FGF10的递送增强了新生内膜的形成，而siFGF10则减弱了新生内膜的形成。
VAFs来源的FGF10促进了VSMCs的增殖和迁移以及新生内膜的形成，FGF10-FGFR2信号触发了VSMCs中MAPK/PI3K-AKT通路的激活，并且PDGF协同放大了FGF10信号。
