Hou Jing-Yu, Wu Hao, Li Shuang-Mei, Li Xiao-Jing, Yang Shu-Jun, Chen Xu-Xiang, Zhou Chang-Qing, Long Hui-Bao, Wu Hai-Dong, Fu Jia-Ying, Guo Ya-Jie, Wang Tong
Department of Emergency, The Eighth Affiliated Hospital of Sun Yat-sen University, Shenzhen, Guangdong, China.
Department of Emergency, Sun Yat-sen Memorial Hospital of Sun Yat-sen University, Guangzhou, Guangdong, China.
Front Pharmacol. 2025 Feb 3;16:1541869. doi: 10.3389/fphar.2025.1541869. eCollection 2025.
Bone marrow mesenchymal stem cells (BMSCs) hold promise for repairing myocardial injury following acute myocardial infarction (AMI), but their clinical application is hindered by poor migration, homing efficiency, and survival rates. Previously, we demonstrated that ELABELA (ELA), a small peptide, enhances the survival of rat BMSCs under hypoxia-reoxygenation (H/R) conditions by activating ERK1/2. However, the role of ELA in promoting BMSCs migration and homing to injured cardiomyocytes remains unclear.
Primary BMSCs and neonatal rat ventricular myocytes (NRVMs) were isolated and cultured. NRVMs were exposed to H/R to mimic the microenvironment of AMI in vitro. The migration of BMSCs toward the injured myocardium was assessed in different treatment groups using transwell and chemotaxis assays. Additionally, in vivo studies were performed using a rat myocardial infarction/reperfusion injury (MI/RI) model with DIR-labeled BMSCs. Cardiac repair was evaluated through fluorescence imaging, echocardiography, and histological analysis. Transcriptome sequencing and bioinformatics analysis were employed to identify and validate the mechanisms by which ELA promoted the migration of BMSCs. A dual luciferase assay was used to investigate the interaction between Exo70 and miR-299a-5p. Subsequently, a series of experimental procedures were performed, including sequential silencing of APJ or Exo70, overexpression of miR-299a-5p, inhibition of ERK1/2 phosphorylation, assessment of BMSCs migration through transwell and scratch assays, detection of F-actin polymerization via immunofluorescence, and evaluation of the expression levels of each factor using qPCR and Western blotting.
In vitro, the migration ability of ELA-pretreated BMSCs was significantly augmented in the H/R environment. ELA pretreatment effectively heightened the homing capacity of BMSCs to the site of myocardial injury and their proficiency in repairing myocardial damage in vivo. Transcriptome sequencing revealed upregulation of Exo70 in ELA pretreated BMSCs, which promoted F-actin polymerization and migration. Overexpression of miR-299a-5p reduced Exo70 expression and impaired BMSCs migration. ELA also activated ERK1/2 phosphorylation, while inhibition of ERK1/2·with U0126 abrogated F-actin polymerization and migration, increasing miR-299a-5p levels and reducing Exo70.
ELA enhances BMSCs migration and homing to injured cardiomyocytes by activating the APJ receptor, promoting ERK1/2 phosphorylation, downregulating miR-299a-5p, and upregulating Exo70, providing a potential therapeutic strategy for improving stem cell-based cardiac repair.
骨髓间充质干细胞（BMSCs）有望修复急性心肌梗死（AMI）后的心肌损伤，但其临床应用受到迁移、归巢效率和存活率低的阻碍。此前，我们证明了一种小肽ELABELA（ELA）通过激活ERK1/2来提高大鼠BMSCs在缺氧复氧（H/R）条件下的存活率。然而，ELA在促进BMSCs迁移和归巢至受损心肌细胞中的作用仍不清楚。
分离并培养原代BMSCs和新生大鼠心室肌细胞（NRVMs）。将NRVMs暴露于H/R以在体外模拟AMI的微环境。使用Transwell和趋化性试验评估不同治疗组中BMSCs向受损心肌的迁移。此外，使用DIR标记的BMSCs的大鼠心肌梗死/再灌注损伤（MI/RI）模型进行体内研究。通过荧光成像、超声心动图和组织学分析评估心脏修复情况。采用转录组测序和生物信息学分析来鉴定和验证ELA促进BMSCs迁移的机制。使用双荧光素酶报告基因检测法研究Exo70与miR-299a-5p之间的相互作用。随后，进行了一系列实验操作，包括依次沉默APJ或Exo70、过表达miR-299a-5p抑制ERK1/2磷酸化、通过Transwell和划痕试验评估BMSCs迁移、通过免疫荧光检测F-肌动蛋白聚合以及使用qPCR和蛋白质印迹法评估各因子的表达水平。
在体外，ELA预处理的BMSCs在H/R环境中的迁移能力显著增强。ELA预处理有效地提高了BMSCs在体内归巢至心肌损伤部位的能力及其修复心肌损伤的能力。转录组测序显示ELA预处理的BMSCs中Exo70上调，其促进了F-肌动蛋白聚合和迁移。miR-299a-5p的过表达降低了Exo70表达并损害了BMSCs迁移。ELA还激活了ERK1/2磷酸化，而用U0126抑制ERK1/2消除了F-肌动蛋白聚合和迁移，增加了miR-299a-5p水平并降低了Exo70。
ELA通过激活APJ受体、促进ERK1/2磷酸化、下调miR-299a-5p和上调Exo70来增强BMSCs向受损心肌细胞的迁移和归巢，为改善基于干细胞的心脏修复提供了一种潜在的治疗策略。
