Effects Of Insulin-like Growth Factor 2 On The Proliferation And Differentiation Of HemSCs

Objective: Infantile hemangioma(IH)is a unique benign tumor of the blood vessels and has a high incidence in infants and young children,affecting approximately 10%of all ethnic and infant infants worldwide.About the natural outcome of infantile hemangiomas for adipose tissue and drug treatment of hemangiomas tissue specific mechanism of fat has not yet formed a unified conclusion.Among them,hemangioma stem cells(Hem SCs)as the origins of infantile hemangiomas to study the natural process of infantile hemangiomas and the final outcome of the morphology become the new hot spot.Insulin-like growth factor-2(IGF-2),as a small and multifunctional polypeptide,plays an important role in tumor growth and regulation of various biological functions.Previous studies confirmed that IGF-2 is highly expressed in hemangiomas,Whether it is involved in infantile hemangiomas stem cell plasticity,for the future research provides a new idea.Therefore,we boldly speculate that IGF-2is involved in the regulation of proliferation and differentiation of hemangiomas stem cells in order to provide a new direction for further revealing the final transformation of infantile hemangiomas.Method:(1)The immunomagnetic beads(CD133)adsorption and sorting technology was used to select the strawberry infantile hemangiomas in proliferating stage.Hem SCs were isolated after digestion and then cultured and passaged.(2)The effects of different concentrations of IGF-2 on the proliferation of Hem SCs and the time growth curve were studied by CCK-8.(3)Adipogenic differentiation: control group;IGF-2(100ng/ml)group;IGF-2(100ng/ml)+OSI-906(1?M)group;IGF-2(100ng/ml)+LY294002(10?M)group;LY294002(10?M)group.(4)cells were cultured in EGM-2/FBS-10% containing IGF-2(100 ng/ml),IGF-2(100 ng/ml)plus OSI-906(1 ?M),IGF-2(100 ng/ml)plus LY294002(10 ?M),LY294002(10 ?M)or no treatment,the protein expression of C/EBP?,C/EBP?,PPAR?,adiponectin,p-AKT and total AKT were detected.The expression of IGF-2 after different concentration of propranolol treatment Hem SCs was detected.Results:(1)The IGF-2 concentration of 100-200 ng / ml significantly promoted the proliferation of Hem SCs in vitro,with statistical significance(P <0.05).Compared with the control group,the cell growth curve of cells treated with 100 ng / ml IGF-2increased significantly on day 3-7(P <0.05).(2)The results of oil red O staining of adipogenic differentiation of Hem SCs in different treatment groups showed that the size and number of lipid droplets in the cytoplasm of Hem SCs in IGF-2 group were significantly increased compared with the control group;IGF-2 + IGF-1R inhibitor group,IGF-2 + PI3 K inhibitor group and PI3 K inhibitor group Hem SCs in the cytoplasm lipid droplets were significantly reduced compared to the IGF-2 group.(3)Western blot showed that the expression of C/EBP?,C/EBP?,PPAR? and adiponectin increased significantly compared with the control group.IGF-2 plus OSI-906,IGF-2plus LY294002,LY294002.the expression of those significantly decreased compared with IGF-2,the LY294002 expression of those significantly decreased compared control group.(4)AKT phosphorylation was significantly increased treated with IGF-2 for 1 h compared with blank control group;AKT phosphorylation treated with IGF-2 + IGF-1R inhibitor and IGF-2 + PI3 K inhibitor Compared with IGF-2 group,the level of expression was significantly decreased.(5)Western blot showed that propranolol had different effect on the expression of IGF-2 in Hem SCs: 25?M,50?M and 100?M propranolol increased the expression of IGF-2,but did not change in concentration gradient.Conclusions: In vitro,insulin-like growth factor 2 promotes the proliferation of Hem SCs and promotes its differentiation into adipocytes.