中国组织工程研究 ›› 2016, Vol. 20 ›› Issue (7): 917-924.doi: 10.3969/j.issn.2095-4344.2016.07.001

• 骨组织构建 bone tissue construction •    下一篇

拉喹莫德抑制成骨细胞中缺氧诱导因子2α的表达及其功能

赵光宗,方 军,丁 刚,张龙强,李华壮,高克海   

  1. 潍坊市益都中心医院骨科,山东省潍坊市 252600
  • 收稿日期:2016-01-07 出版日期:2016-02-12 发布日期:2016-02-12
  • 通讯作者: 方军,潍坊市益都中心医院骨科,山东省潍坊市 252600
  • 作者简介:赵光宗,男,汉族,1980年生,山东省青州市人,2015年山东大学毕业,博士,主治医师。

Laquinimod inhibits the expression and function of hypoxia-inducible factor-2 alpha in osteoblasts

Zhao Guang-zong, Fang Jun, Ding Gang, Zhang Long-qiang, Li Hua-zhuang, Gao Ke-hai   

  1. Department of Orthopedics, Yidu Central Hospital of Weifang, Weifang 252600, Shandong Province, China
  • Received:2016-01-07 Online:2016-02-12 Published:2016-02-12
  • Contact: Fang Jun, Department of Orthopedics, Yidu Central Hospital of Weifang, Weifang 252600, Shandong Province, China
  • About author:Zhao Guang-zong, M.D., Attending physician, Department of Orthopedics, Yidu Central Hospital of Weifang, Weifang 252600, Shandong Province, China

摘要:

文章快速阅读:

文题释义:

拉喹莫德:是一种新型免疫调节剂,化学名称为N-乙基-N-苯基-5-氯-1,2二氢-1-甲基-2-氧-3-喹啉甲酰胺,其作用机制为通过消除中枢神经系统的白细胞浸润,对鼠类慢性实验性自身免疫性脑脊髓炎性因子子产生完全抑制作用,并且从暴露的剂量直接比较,拉喹莫德的免疫抑制作用是罗喹美克的20倍,可抑制炎症因子CD4+细胞和巨噬细胞进入中枢神经组织(即脊髓),并且改变包括Th2/Th3、白细胞介素4、白细胞介素10、β-转化生长因子等细胞因子的平衡。
缺氧诱导因子2α:是一种半衰期短的蛋白质,可诱导多种炎性因子的释放,细胞中缺氧诱导因子2α蛋白质的表达水平是蛋白质翻译和降解之间动态平衡的结果。

 

背景:由于骨折会诱导骨细胞缺氧,使骨细胞中的氧张力明显下降,现已证明,其中低氧诱导因子2α是机体在低氧状态下调剂机体功能的一种重要氧依赖转录激活因子,其介导骨折发生时多种炎性因子的释放。
目的:探讨拉喹莫德对成骨细胞中缺氧诱导因子2α的表达和功能的影响。
方法:缺氧处理前分别在蛋白酶体抑制剂MG132或N-乙酰基-亮氨酰-亮氨酰-正亮氨酸存在和不存在的情况下,用10-100 μmol/L的拉喹莫德处理小鼠成骨细胞MC3T3-E1(克隆14)。然后分别在体积分数1%或21%氧张力下进行1-24 h的预处理。
结果与结论:①缺氧诱导因子2α在成骨细胞缺氧中表达明显增高。而拉喹莫德可以抑制成骨细胞中缺氧诱导因子2α及其目标基因在小鼠成骨细胞(MC3T3-E1细胞)中的表达。②拉喹莫德以蛋白酶依赖、von Hippel-Lindau(VHL)蛋白不依赖的方式促进缺氧诱导因子2α的降解,可打断缺氧诱导因子2α和它的分子伴侣热休克蛋白90之间的相互作用,促进缺氧诱导因子2α和激活的蛋白酶C受体之间的相互作用。③结果显示拉喹莫德可能通过影响缺氧诱导因子2α蛋白的折叠和成熟从而促进其降解,可通过改变与伴侣蛋白热休克蛋白90和RACK1的功能性相互作用来抑制成骨细胞中的缺氧诱导因子2α。 
ORCID: 0000-0002-6880-9821(方军)

关键词: 组织构建, 成骨细胞, 拉喹莫德, 缺氧, 缺氧诱导因子2α, 热休克蛋白90, 活化的蛋白酶C(RACK1)受体, 蛋白酶体降解

Abstract:

BACKGROUND: Fractures can induce bone cell hypoxia, and remarkably reduce the oxygen tension in cells. Hypoxia-inducible factor-2α is a key oxygen-dependent transcriptional activator to regulate the body function under hypoxia and mediate the release of various inflammatory factors after fractures.
OBJECTIVE: To explore the role of Laquinimod in expression and function of hypoxia-inducible factor-2α in osteoblasts.
METHODS: Mouse osteoblasts MC3T3-E1 (clone 14) were pretreated with Laquinimod at various concentrations(10-100 μmol/L) before hypoxia in the presence or absence of specific proteasome inhibitors MG132 or N-acetyl-leucyl-leucyl-norleucine. Then, the media were pre-conditioned in 1% or 21% oxygen tension for 1 to 24 hours.
RESULTS AND CONCLUSION: Under hypoxia, the expression of hypoxia-inducible factor-2α in osteoblasts was increased remarkably, and Laquinimod could inhibit the expression of hypoxia-inducible factor-2α and its target genes in mouse MC3T3-E1 cells. Mechanistically, Laquinimod promoted hypoxia-inducible factor-2α degradation in a proteasome-dependent but von Hippel-Lindau protein-independent manner. Importantly, we found that Laquinimod disrupted the interaction between hypoxia-inducible factor-2α and its chaperone heat shock protein 90, but promoted the interaction between hypoxia-inducible factor-2α and the receptor of activated protein kinase C. These findings suggest that Laquinimod may promote the degradation of hypoxia-inducible factor-2α by affecting its folding and maturation. Laquinimod is a novel inhibitor of hypoxia-inducible factor-2α by changing its functional interaction with chaperone proteins heat shock protein 90 and receptor of activated protein kinase C.