Hypoxia Macrophage-Derived Exosomal miR-26b-5p Targeting PTEN Promotes the Development of Keloids

This study investigates the role of hypoxic macrophage-derived exosomes (HMDE) in keloid development, focusing on the microRNA miR-26b-5p. The research found that M2-type macrophages are prevalent in keloids and that hypoxia induces macrophage polarization towards this type. HMDE, compared to normoxic macrophage-derived exosomes, enhance the proliferation, migration, and invasion of human keloid fibroblasts (HKFs). Among 38 differentially expressed miRNAs, miR-26b-5p was notably enriched in HMDE and could be transferred to HKFs. Functional assays revealed that miR-26b-5p facilitates HKF migration, invasion, and proliferation through the PTEN-PI3K/AKT pathway, suggesting its significant role in promoting keloid development.