Human immunodeficiency virus-1 negative factor protein promotes human herpesvirus-8 viral interleukin-6-induced angiogenesis: role of glycogen synthase kinase-3β/β-catenin signaling pathway / 中华传染病杂志

ABSTRACT

Objective To explore the role of glycogen synthase kinase (GSK)-3β/β-catenin signaling pathway on human immunodeficiency virus 1 (HIV-1) negative factor (Nef) protein promoting of human herpesvirus-8 (HHV-8) viral interleukin-6 (vIL-6)-induced angiogenesis.Methods GSK-3β mutant plasmid GSK-3β-S9A,dominant negative (DN) form GSK-3β-DN and the control vector pcDNA3.1+ were transfected into endothelial cells which stably expressed HHV-8 vIL-6 or HIV-1 Nef,or co-expressed vIL-6 and Nef protein.Microtubule formation assay was performed to explore microtubule formation ability.A chick embryo chorioallantoic membrane (CAM) model was used to detect angiogenesis.The expression of GSK-3β/β-catenin signaling pathway-related kinases in transfected cells and CAM tissue were further detected by Western blot.The measurement data were compared by t test.Results The activity of GSK-3β was decreased and the ability of HIV-1 Nef protein was enhanced by transfection with GSK-3β-DN in promoting vIL-6 induced microtubule formation (3.42 vs 2.51,t =3.67,P＜0.01) and angiogenesis (6.25 vs 3.97,t=4.06,P＜0.01).In contrast,the activity of GSK-3β was significantly increased and these functions of HIV-1 Nef protein mentioned above were inhibited by transfection with GSK-3β-S9A (0.62 vs2.51,t=8.48,P＜0.01; 0.39 vs 3.97,t=8.59,P＜0.01).The results of Western blot showed that with the elevated level of,β-catenin (in cells3.53 vs 2.07,t=6.60,P＜0.05; in tissues2.76 vs 1.74,t=17.40,P＜0.01) and vascular endothelial growth factor (VEGF,in cells2.68 vs 1.87,t=4.28,P＜0.01; in tissues2.20 vs 1.39,t=7.08,P＜0.01) were increased in the GSK-3β-DN transfected cells or tissues,while the opposite results were achieved in the GSK-3β-S9A-transfected cells (GSK-3β phosphorylation0.50 vs 1.47,t=7.33,P＜0.01; β-catenin1.05 vs 2.62,t=29.50,P＜0.01; VEGF0.74 vs 2.16,t=20.95,P＜0.01) or tissues (GSK-3β phosphorylation0.35 vs 1.97,t=10.72,P＜0.01; β-catenin0.79 vs 1.77,t=5.72,P＜0.01; VEGF0.43 vs 1.65,t=11.89,P＜ 0.01).Conclusion GSK-3β/β-catenin signaling pathway is involved in vIL-6-induced angiogenesis promoted by HIV-1 Nef protein,which would be valuable for the therapy of Kaposi's sarcoma,an acquired immunodeficiency syndrome,as a potential molecular target.