Mice Model Of Hemangioma Built By Hemangioma Derived Stem Cell Combined With Estrogen Injection And Study Of Underlying Molecular Mechanism

Objective: The aim of the study was to establish mice model with hemangioma derivedstem cell (HemSC) and human umbilical vein endothelial cell(HUVEC),combined withestrogen（E2） injection. And investigate the mechanism of E2on proliferatinghemangioma.Methods: HemSCs were selected from proliferating hemangioma tissue by CD133taggedmagnetic-activated cell sorting technique. Their ability of multilineage differentiation wasverified by multiplex differentiation induction experiment. HemSCs were cultured with10-9M,10-8M,10-7M,10-6M and10-5M E2for48to72h respectively; then the impact onproliferation, mRNA and protein expression of FGF2, VEGF-A, ERα, Notch1andJagged1were investigated by MTT, RT-PCR, real-time PCR, Elisa and Western blotting,respectively. Finally, HemSC and HUVEC were mixed，then injected subcutaneously into20flank of BALB/c-nu mice that were randomly divided into5groups，group1(n=4) withgroup1(n=4) with0.01mg E2, group2(n=5) with0.1mg E2, group3(n=5) with1mg E2，group4(n=5) with0.1mg DMSO as control, group3(n=5) with0mg E2administeredintramuscularly every week. Two and4weeks later, the subcutaneous implants wereharvested and made into tissue spices for micro vessel density assay (MVD) andimmunohistochemistry.Results: Few HemSCs were isolated from IH tissue by MACS. HemSCs possessed theability of multilineage differentiation into adipocyte, osteoblast and endothelial cell. E2could increase the expression of FGF2, VEGF-A, ERα, Notch1and Jagged1in HemSCwith the optimal concentration from10-9M to10-5M. Two weeks after injection into BALB/c-nu mice with E2, HemSC and HUVEC formed micro vessels，the quantity ofblood vessel was greatly increased。Glucose transporter-1(Glut-1) which was a specificmarker of IH was positively stained. E2in normal concentration could increase theviability and proliferation of HemSC, and stimulation of angiogenesis.Conclusions: HemSCs possess the unique ability of robust proliferation and multilineagedifferentiation. HemSCs and HUVEC were co-injected into immunodeficient miceresuspended in Matrigel administered intramuscularly. E2modulation of Notch pathway ismediated by estrogen receptors. E2affects several Notch pathway components in HemSC,leading to an activation of the Notch pathway and to a modulation of VEGF-A whenNotch signalling is inhibited. These results contribute to our understanding of themolecular mechanisms of hemangioma by uncovering a novel role of E2in the Notchsignalling-mediated modulation of HemSC.