Hospital of Stomatology, Sun Yat-sen University, Guangzhou, 510055, China; Guangdong Provincial Key Laboratory of Stomatology, Guangzhou, 510080, China; Guanghua School of Stomatology, Sun Yat-sen University, Guangzhou, 510055, China.
Hospital of Stomatology, Sun Yat-sen University, Guangzhou, 510055, China; Guangdong Provincial Key Laboratory of Stomatology, Guangzhou, 510080, China; Guanghua School of Stomatology, Sun Yat-sen University, Guangzhou, 510055, China.
Exp Cell Res. 2023 Apr 15;425(2):113543. doi: 10.1016/j.yexcr.2023.113543. Epub 2023 Mar 7.
Hypoxia was proved to enhance the angiogenesis of stem cells. However, the mechanism of the angiogenic potential in hypoxia-pretreated dental pulp stem cells (DPSCs) is poorly understood. We previously confirmed that hypoxia enhances the angiogenic potential of DPSC-derived exosomes with upregulation of lysyl oxidase-like 2 (LOXL2). Therefore, our study aimed to illuminate whether these exosomes promote angiogenesis via transfer of LOXL2. Exosomes were generated from hypoxia-pretreated DPSCs (Hypo-Exos) stably silencing LOXL2 after lentiviral transfection and characterized with transmission electron microscopy, nanosight and Western blot. The efficiency of silencing was verified using quantitative real-time PCR (qRT-PCR) and Western blot. CCK-8, scratch and transwell assays were conducted to explore the effects of LOXL2 silencing on DPSCs proliferation and migration. Human umbilical vein endothelial cells (HUVECs) were co-incubated with exosomes to assess the migration and angiogenic capacity through transwell and matrigel tube formation assays. The relative expression of angiogenesis-associated genes was characterized by qRT-PCR and Western blot. LOXL2 was successfully silenced in DPSCs and inhibited DPSC proliferation and migration. LOXL2 silencing in Hypo-Exos partially reduced promotion of HUVEC migration and tube formation and inhibited the expression of angiogenesis-associated genes. Thus, LOXL2 is one of various factors mediating the angiogenic effects of Hypo-Exos.
缺氧被证明可以增强干细胞的血管生成能力。然而，缺氧预处理牙髓干细胞（DPSCs）的血管生成潜力的机制尚不清楚。我们之前证实，缺氧通过上调赖氨酰氧化酶样 2（LOXL2）增强了 DPSC 衍生的外泌体的血管生成潜力。因此，我们的研究旨在阐明这些外泌体是否通过转移 LOXL2 促进血管生成。外泌体是通过慢病毒转染稳定沉默 LOXL2 的缺氧预处理 DPSCs（Hypo-Exos）产生的，并通过透射电子显微镜、纳米粒子跟踪分析和 Western blot 进行了表征。通过定量实时 PCR（qRT-PCR）和 Western blot 验证了沉默的效率。CCK-8、划痕和 Transwell 实验用于研究 LOXL2 沉默对 DPSCs 增殖和迁移的影响。人脐静脉内皮细胞（HUVECs）与外泌体共孵育，通过 Transwell 和基质胶管形成实验评估迁移和血管生成能力。通过 qRT-PCR 和 Western blot 描述与血管生成相关基因的相对表达。LOXL2 在 DPSCs 中成功沉默，并抑制了 DPSC 的增殖和迁移。Hypo-Exos 中 LOXL2 的沉默部分减少了对 HUVEC 迁移和管形成的促进作用，并抑制了与血管生成相关基因的表达。因此，LOXL2 是介导 Hypo-Exos 血管生成作用的多种因素之一。
