Hypofucosylation of Unc5b regulated by Fut8 enhances macrophage emigration and prevents atherosclerosis

Cell & Bioscience

Research

Lei Zhang¹  Jun Chen¹  Limei Ma¹  Xia Qin¹  Chao Yu¹  Zhiyi Yuan¹  Jun Zhang²  Di Shen²  Zhen Zou²  Hui He²  Linmu Chen²  Xi Yang³ 

[1] College of Pharmacy, Chongqing Medical University, 400016, Chongqing, China;Institute of Life Sciences, Chongqing Medical University, 400016, Chongqing, China;Institute of Life Sciences, Chongqing Medical University, 400016, Chongqing, China;College of Basic Medicine, Inner Mongolia Medical University, 010110, Hohhot, China;

关键词: Unc5b;    Fut8;    Fucosylation;    Macrophages;    Atherosclerosis;   

DOI  :  10.1186/s13578-023-00959-y

 received in 2022-06-13, accepted in 2023-01-08,  发布年份 2023

来源: Springer

【 摘 要 】

BackgroundAtherosclerosis (AS) is the leading underlying cause of the majority of clinical cardiovascular events. Retention of foamy macrophages in plaques is the main factor initiating and promoting the atherosclerotic process. Our previous work showed that ox-LDL induced macrophage retention in plaques and that the guidance receptor Uncoordinated-5 homolog B (Unc5b) was involved in this process. However, little is known about the role of Unc5b in regulating macrophage accumulation within plaques.ResultsIn the present study, we found that Unc5b controls macrophage migration and thus promotes plaque progression in ApoE−/− mice. The immunofluorescence colocalization assay results first suggested that fucosyltransferase 8 (Fut8) might participate in the exacerbation of atherosclerosis. Animals with Unc5b overexpression showed elevated levels of Fut8 and numbers of macrophages and an increased lesion size and intimal thickness. However, these effects were reversed in ApoE−/− mice with Unc5b knockdown. Furthermore, Raw264.7 macrophages with siRNA-mediated silencing of Unc5b or overexpression of Unc5b were used to confirm the regulatory mechanisms of Unc5b and Fut8 in vitro. In response to ox-LDL exposure, Unc5b and Fut8 were both upregulated, and macrophages showed reduced pseudopod formation and migratory capacities. However, these capacities were restored by blocking Unc5b or Fut8. Furthermore, the IP assay indicated that Fut8 regulated the level of α-1,6 fucosylation of Unc5b, which mainly occurs in the endoplasmic reticulum (ER), and genetic deletion of the main fucosylation sites or Fut8 resulted in hypofucosylation of Unc5b. Moreover, the macrophage migration mediated by Unc5b depended on inactivation of the p-CDC42/p-PAK pathway. Conversely, macrophages with Unc5b overexpression displayed activation of the p-CDC42/p-PAK pathway and decreased migration both in vivo and in vitro.ConclusionThese results demonstrated that hypofucosylation of Unc5b regulated by Fut8 is positively associated with the delay of the atherosclerotic process by promoting the migration of foamy macrophages. These findings identify a promising therapeutic target for atherosclerosis.

【 授权许可】

CC BY   
© The Author(s) 2023

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