Abstract

Background: Aberrant activation of fibroblasts is the main cause of the occurrence and development of fibrotic diseases and poses a serious threat to human health. Excessive reactive oxygen species (ROS), traditionally induces oxidative stress damage, are recently found in some fibroblasts’ pathological transformation. However, the roles of the increased ROS in fibroblasts activation and the potential interventions have not been reported.
Methods: Single-cell RNA sequencing was performed to demonstrated that the elevated ROS drives fibroblasts activation and promotes hypertrophic scar fibroblasts' (HSFBs) features, such as excessive proliferation and collagen synthesis. Flow cytometry and immunofluorescence was conducted to evaluate Glucocorticoids effected ROS level. Two ROS-activated models were performed to evaluate intracellular ROS generation specifically increase collagen synthesis and proliferation. Differentially expressed proteins and lncRNA were analyzed by high-resolution spatial proteomics analysis and lncRNA sequencing. The role and mechanism by which lncRNA LINC00605-dependent mRNA decay pathway, leading to ROS reduction and normalization of HSFBs were investigated in ROS-activated models.
Results: ROS drives fibroblasts activation and inhibiting ROS reduced proliferation and fibrosis phenotypes of HSFBs. Notably, glucocorticoids suppress ROS generation in HSFBs. This effect was mediated by downregulating NOXA1, a key gene responsible for promoting ROS production. Mechanistically, the GR bound to NOXA1 mRNA, while glucocorticoid-upregulated LINC00605 directly bound to the glucocorticoid receptor-mediated mRNA degradation (GMD) factor YBX1. This LINC00605-YBX1 complex was then specifically recruited to NOXA1 mRNA through lncRNA-mRNA interactions, facilitating the assembly of the GMD complex and ultimately triggering NOXA1 mRNA decay.
Conclusion: These results indicated that elevated ROS-drived fibrotic phenotypes and cellular proliferation but glucocorticoids could suppress ROS and subsequently reverse pathological transformation of fibroblasts, highlighting ROS-targeted strategies as promising avenues for early interventions in fibrotic diseases.

Keywords

Reactive oxygen species, fibroblasts activation, hypertrophic scar fibroblast, glucocorticoid, LINC00605, glucocorticoid receptor-mediated mRNA decay