miR-18a-5p Reduces Inflammatory Response and Human Dermal Microvascular Endothelial Cells Permeability by Targeting Thrombospondin 1 in Chronic Idiopathic Urticaria

Abstract

Chronic idiopathic urticaria (CIU) is a skin disease that has an acute attack when patient encounters an allergen. Previous research demonstrated that microRNA (miRNA) has a crucial role in CIU occurrence and development. This study aimed to investigate the role and mechanism of miR-18a-5p in CIU. StarBase and dual luciferase reporter gene assay confirmed that thrombospondin 1 (THBS1) was a direct target of miR-18a-5p. miR-18a-5p negatively regulated THBS1 expression in human mast cell line HMC-1 and human dermal microvascular endothelial cells (HDMECs). Further analysis indicated that miR-18a-5p mimic significantly reduced inflammatory factors including interleukin (IL)-6, IL-8, IL-1β and tumor necrosis factor (TNF)-α release, decreased the degranulation rate and histamine release rate of HMC-1 cells. Besides, we found that miR-18a-5p reduced the permeability of HDMECs by suppressing THBS1 expression. Finally, the data indicated that miR-18a-5p inhibited the transforming growth factor beta (TGF-β)/SMAD family member 3 (Smad3) signaling pathway in HDMECs by inhibiting the expression of THBS1. Taken together, the results suggested that miR-18a-5p reduced inflammation and human skin microvascular endothelial cell permeability in CIU by targeting THBS1. miR-18a-5p might be a new target for CIU treatment.