Zhang Lei, Song Kai, Zhou Ling, Xie Zhishen, Zhou Ping, Zhao Yiming, Han Yue, Xu Xiaojun, Li Ping
State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, China.
J Cell Biochem. 2015 Jun;116(6):1101-12. doi: 10.1002/jcb.25066.
Heparan sulfate (HS) are complex polysaccharides that reside on the plasma membrane of almost all mammalian cells, and play an important role in physiological and pathological conditions. Heparan sulfate D-glucosamine 3-O-sulfotransferase 3B1 (HS3ST3B1) participates in the last biosynthetic steps of HS and transfers sulfate to the 3-O-position of glucosamine residues to yield mature sugar chains. To date very few biological processes or proteins have been described that are modulated by HS3ST3B1. In this study, we observed that HS3ST3B1 positively contributed to acute myeloid leukemia (AML) progression in vitro and in vivo, and these activities were associated with an induction of the proangiogenic factor VEGF expression and shedding. Moreover, the effects of HS3ST3B1 on VEGF release can be attenuated after treatment of heparanase inhibitor suramin, which prevented VEGF secretion and subsequently blocked VEGF-induced activation of ERK and AKT, suggesting that 3-O-sulfation of HS by HS3ST3B1 facilitated VEGF shedding; the effects of HS3ST3B1 on activation of ERK and AKT can also be blocked by VEGFR inhibitor axitinib, suggestive of a relationship between 3-O-sulfation of HS and VEGF-activated signaling pathways. Taken together, our findings support that VEGF is an important functional target of HS3ST3B1 and provide a new mechanism of HS3ST3B1 in AML.
硫酸乙酰肝素(HS)是存在于几乎所有哺乳动物细胞质膜上的复合多糖,在生理和病理条件下发挥重要作用。硫酸乙酰肝素D - 葡萄糖胺3 - O - 磺基转移酶3B1(HS3ST3B1)参与HS的最后生物合成步骤,并将硫酸根转移至葡萄糖胺残基的3 - O位以产生成熟糖链。迄今为止,很少有生物过程或蛋白质被描述为受HS3ST3B1调节。在本研究中,我们观察到HS3ST3B1在体外和体内均对急性髓系白血病(AML)进展有正向作用,且这些作用与促血管生成因子VEGF表达及释放的诱导相关。此外,用乙酰肝素酶抑制剂苏拉明处理后,HS3ST3B1对VEGF释放的作用可被减弱,这阻止了VEGF分泌并随后阻断了VEGF诱导的ERK和AKT激活,表明HS3ST3B1介导的HS的3 - O - 硫酸化促进了VEGF脱落;VEGFR抑制剂阿西替尼也可阻断HS3ST3B1对ERK和AKT激活的作用,提示HS的3 - O - 硫酸化与VEGF激活的信号通路之间存在关联。综上所述,我们的研究结果支持VEGF是HS3ST3B1的重要功能靶点,并为HS3ST3B1在AML中的作用提供了新机制。