FGFR2-IIIb D3胞外段抑制角质形成细胞的脂质合成  

FGFR2-IIIb D3 extracellular domain inhibits lipid synthesis in keratinocytes

作　　者：谢盈 刘鸽 汪炬[1] XIE Ying;LIU Ge;WANG Ju(Institute of Biomedicine, Jinan University, Guangzhou 510632, China)

机构地区：[1]暨南大学生物医药研究院

出　　处：《中国病理生理杂志》2019年第8期1501-1507,共7页Chinese Journal of Pathophysiology

基　　金：国家自然科学基金资助项目(No.81773330)

摘　　要：目的:探讨成纤维细胞生长因子受体2(FGFR2)-IIIb D3胞外段对角质形成细胞中脂质合成的抑制作用。方法:利用等温滴定量热(ITC)法和CCK-8法检测FGFR2-IIIb D3胞外段的生物特性,并利用real-time PCR、Western blot、流式细胞术和油红O染色法分析其对角质形成细胞HaCaT脂质合成的抑制作用。结果:(1)ITC、real-time PCR和CCK-8结果显示FGFR2-IIIb在HaCaT细胞中高表达,FGFR2-IIIb D3胞外段可与FGF7特异性结合,抑制HaCaT细胞活力;(2)Western blot结果显示在HaCaT细胞中FGF7可显著上调固醇调节元件结合蛋白1c(SREBP-1c)、脂肪酸合成酶(FAS)、乙酰辅酶A合成酶(ACS)、硬脂酰辅酶A脱饱和酶(SCD)和羟甲基戊二酰辅酶A还原酶(HMGCR) mRNA的表达及p-FGFR、p-AKT和SREBP-1蛋白的表达(P<0.01),用FGFR2-IIIb D3胞外段和AKT抑制剂处理后可抑制它们的上调,且与FGF7组相比差异显著;(3)油红O染色法和流式细胞术结果显示,FGF7诱导后HaCaT细胞的脂质含量明显上调,用FGFR2-IIIb D3胞外段和AKT抑制剂处理后,脂质含量下调(P<0.01)。结论:FGFR2-IIIb D3胞外段竞争性地与FGF7结合,抑制FGFR2-IIIb的自体磷酸化,抑制下游PI3K-AKT信号通路,抑制SREBP-1c和下游脂质合成酶的表达,进而抑制角质形成细胞中脂质的合成。AIM: To investigate the inhibitory effect of extracellular domain of fibroblast growth factor receptor 2(FGFR2)-IIIb D3 on lipid synthesis in HaCaT keratinocyteas. METHODS: The bioactivity of FGFR2-IIIb D3 extracellular domain was detected by isothermal titration calorimetry(ITC) and CCK-8 assay. The inhibitory effect of FGFR2-IIIb D3 extracellular domain on lipid synthesis in HaCaT cells was analyzed by real-time PCR, Western blot, flow cytometry and oil red O staining. RESULTS: The results of ITC, real-time PCR and CCK-8 assay showed that FGFR2-IIIb was highly expressed in HaCaT cells, and FGFR2-IIIb D3 extracellular domain specifically bound to FGF7 to inhibit HaCaT cell viability. The results of real-time PCR and Western blot showed that FGF7 significantly up-regulated the mRNA expression of sterol regulatory element binding protein-1 c(SREBP-1 c), fatty acid synthase(FAS), acetyl-CoA synthase(ACS), stearoyl-CoA desaturase(SCD) and 3-hydroxy-3-methylglutaryl-CoA reductase(HMGCR), and the protein levels of p-FGFR, p-AKT and SREBP-1 in HaCaT cells, and these effects were inhibited after the treatment with FGFR2-IIIb D3 extracellular domain and AKT inhibitor, which was significantly different from the FGF7 group. and The results of oil red O staining and flow cytometry showed that the lipid content of HaCaT cells was increased after FGF7 induction. After treatment with FGFR2-IIIb D3 extracellular domain and AKT inhibitor, the lipid content was decreased(P<0.01). CONCLUSION: FGFR2-IIIb D3 extracellular domain inhibits the autophosphorylation of FGFR2-IIIb by its competitive binding to FGF7, and then blocks downstream PI3 K-AKT signaling pathway, thus resulting in the down-regulation of SREBP-1 c and downstream lipid synthases, and inhibiting lipid synthesis in keratinocytes.

关 键 词：FGFR2-IIIb D3胞外段 成纤维细胞生长因子7 固醇调节元件结合蛋白1C 脂质合成 角质形成细胞 

分 类 号：R392.23[医药卫生—免疫学] R363.2[医药卫生—基础医学]