Notch信号通路对婴幼儿血管瘤周细胞分化的调控作用

目的 研究Notch信号通路在婴幼儿血管瘤(IH)中的动态表达,探讨其对血管瘤周细胞(Her-pericyte)分化的影响.方法 选取增殖期与消退前期IH瘤体组织.采用免疫荧光双染检测Jagged1、Notch3及Hes1在增殖期与消退前期IH组织中的表达状况.应用Real-time PCR检测增殖期与消退前期Hem-pericyte中Jagged1、Notch3及Hes1基因表达水平.使用Notch信号通路的特异性抑制剂DAPT作用于Hem-pericyte,观察其对Hem-pericyte分化的影响.结果 消退前期IH血管网较增殖期IH血管网排列更为成熟规则.Jagged1、Notch3及Hes1在增殖期与消退前期血管瘤中均有表达,其中Jagged1主要分布于HemEC,Notch3与Hes1则主要表达于Hem-pericyte.与增殖期Hem-pericyte相比,消退前期Hem-pericyte中Notch3与Hes1基因表达水平显著升高(3.10±0.32 vs 1.41±0.37,1.89±0.35 vs 0.78±0.41);与周细胞分化/收缩力相关的基因:smMHC与αSMA的表达水平在消退前期Hem-pericyte中也显著升高(4.27±0.28 vs 0.48±0.19,1.43±0.21 vs 0.39±0.20).采用y-分泌酶抑制剂DAPT阻断Notch信号通路后,消退前期Hem-pericyte中smMHC与αSMA基因的表达水平显著下调(4.31±0.34 vs 2.1±0.32,1.40±0.31vs 0.56±0.27).结论 Hem-pericyte中存在活化的Notch信号通路;Notch参与了对体外培养Hem-pericyte分化的调控.

Effect of Notch signaling on differentiation of hemangioma-derived pericytes

Objective To explore the dynamic expression of major Notch components in infantile hemangioma (IH) and determine whether or not Notch pathway is involved in the regulation of hemangioma-derived pericyte (Hem-pericyte) differentiation.Methods Immunofluorescence staining was performed for evaluating the expression of Jagged1,Notch3 and Hes1 in proliferating and involuting IH tissues.The gene expressions of Notch components in Hem-pericytes were assayed by real-time polymerase chain reaction (PCR).The roles of Notch pathway in modulating Hem-pericytes were also examined.Results The lumens of proliferating specimens were less well-formed as compared to involuting counterparts.Both proliferating and involuting IH expressed Jagged1,Notch3 and Hes1.Notch3 and Hes1 co-localized predominantly with pericyte marker α-SMA.In contrast,Jagegd1 colocalized with endothelial cell marker CD31.As compared with proliferating Hem-pericytes,involuting Hem-pericytes showed higher expressions of Notch3 and Hes1 (3.10 ± 0.32 vs 1.41 ± 0.37,1.89 ±0.35 vs 0.78 ± 0.41).Furthermore the expressions of genes associated with differentiated/contractile phenotype,including smooth muscle myosin heavy chain (smMHC) and smooth muscle-specific isoform of actin (αSMA) in involuting Hem-pericytes increased as compared to proliferating Hempericytes (4.27 ± 0.28 vs 0.48 ± 0.19,1.43 ± 0.21 vs 0.39 ± 0.20).An inhibition of Notch signaling restored involuting Hem-pericyte phenotype from differentiated to dedifferentiated states through a negative effect on the expressions of smMHC and αSMA (4.31 ±± 0.34 vs 2.1 ± 0.32,1.40 ± 0.31 vs 0.56 ± 0.27).Cnclusiom Consistent activation of Notch signaling occurs in Hem-pericytes.And Notch may play a role in in vitro differentiation of Hem-pericytes.