Human Umbilical Cord Mesenchymal Stem Cell Exosome-derived miR-335-5p Alleviated Lipopolysaccharide-induced Acute Lung Injury by Regulating the m6A Level of ITGβ4 Gene

Abstract

Background: Acute lung injury (ALI) is a serious complication that may accompany severe pneumonia in children. Derived from exosomes of human umbilical cord mesenchymal stem cell exosome (HucMSC-Exo) can contribute to the regeneration of damaged lung tissue. This study aims to investigate the impact of HucMSC-Exo on ALI and its potential mechanisms. Methods: Firstly, RT-qPCR was performed to assess the expression of miR-335-5p. Subsequently, Pearson correlation analysis was performed to examine the correlation between METTL14 and miR-335-5p, as well as the correlation between METTL14 and ITGB4., while RNA immunoprecipitation (RIP) was used to determine the m6A modification level of ITGβ4. Additionally, molecular biology techniques were employed to evaluate the expression of glycolysis-related factors. Definitively, an LPS-induced ALI model was established to investigate the effect of miR-335-5p on mice lung tissue. Results: miR-335-5p was found to be highly expressed in HucMSC-Exo. Transfection with miR-335-5p mimics resulted in increased glucose uptake. Pearson correlation analysis revealed a negative correlation between METTL14 and miR-335-5p, as well as between METTL14 and ITGβ4. The m6A level of ITGβ4 was elevated in ALI. Overexpression of METTL14 was found to reduce the expression and glucose uptake of ITGβ4, while overexpression of ITGβ4 reversed the effects of METTL14 overexpression. in vivo, results demonstrated that miR-335-5p can improve the extent of lung tissue lesions and reduce glycolytic levels. method: HucMSC-Exos were successfully cultured and identified. The LPS-induced ALI model was established using A549 cells and BALB/c mice. Pearson correlation coefficient analyzed the association between METTL14 and miR-335-5p or ITGβ4 in clinical specimens. The modification level of m6A was detected using RNA m6A colorimetry and RNA immunoprecipitation. The cell damage, apoptosis, expression of inflammatory factors, and glycolytic-related factors were determined molecularly and immunohistochemically in various groups. Conclusion: This study reveals the mechanism by which miR-335-5p derived from HucMSC-Exo could alleviate LPS-induced ALI by regulating the m6A modification of ITGβ4, providing a new direction for the treatment of ALI.