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Updated: Jul 4, 2025
Bronchoalveolar Lavage Exosomes in Lipopolysaccharide-induced Septic Lung Injury
Published on: May 21, 2018
CircRSU1 alleviates LPS-induced human pulmonary microvascular endothelial cell injury by targeting miR-1224-5p/ITGA5
Yongtao Cheng1, Fenggong Wang2, Cui Guo1
1Emergency Department, 521 Hospital of Norinco Group, Xi'an, China.
Abstract:
To investigate the potential functions and regulatory mechanism of circRSU1 on septic acute lung injury (sepsis-ALI) progression. We used lipopolysaccharide (LPS)-stimulated human pulmonary microvascular endothelial cells (HPMECs) to establish the cell model of sepsis-ALI in vitro. qRT-PCR and Western blotting were used for the detection of genes and proteins. The migration and tubulogenesis of HPMECs were assessed by transwell, wound healing, and tube formation assays. Inflammatory factors were detected by ELISA analysis. Cell permeability (PA) was determined by transendothelial resistance (TEER) and fluorescein isothiocyanate (FITC) with transwell assay. The interaction between miR-1224-5p and circRSU1 or ITGA5 (Integrin Subunit Alpha 5) was studied by dual-luciferase reporter and RNA pull-down assays. CircRSU1 expression was decreased after LPS treatment in HPMECs. Functionally, re-expression of circRSU1 in HPMECs could alleviate LPS-induced inflammatory response, the inhibition of cell migration and tube formation and enhancement of cell permeability. Mechanistically, circRSU1 acted as a sponge for miR-1224-5p. LPS treatment enhanced miR-1224-5p expression, and inhibition of miR-1224-5p reversed LPS-evoked HPMEC dysfunction mentioned above. Moreover, miR-1224-5p could abolish the protective effects of circRSU1 on HPMECs. In addition, miR-1224-5p directly targeted ITGA5, and circRSU1 was able to regulate ITGA5 expression via interacting with miR-1224-5p. CircRSU1 could alleviate LPS-induced HPMEC injury by miR-1224-5p/ITGA5 axis, indicating the potential molecular contribution of circRSU1 in sepsis-ALI.
Insights
Circular RNA circRSU1 protects against septic acute lung injury (sepsis-ALI) by regulating the miR-1224-5p/ITGA5 axis. Restoring circRSU1 alleviates inflammation and endothelial cell dysfunction in sepsis-ALI models.
Area of Science:
- Molecular Biology
- Cell Biology
- Immunology
Background:
- Septic acute lung injury (sepsis-ALI) is a severe condition with high mortality.
- The molecular mechanisms underlying sepsis-ALI progression require further elucidation.
- Circular RNAs (circRNAs) are emerging as critical regulators in various diseases.
Purpose of the Study:
- To investigate the role and regulatory mechanism of circRSU1 in sepsis-ALI.
- To explore the interaction between circRSU1, miR-1224-5p, and ITGA5 in the context of sepsis-ALI.
Main Methods:
- Established a cell model of sepsis-ALI using lipopolysaccharide (LPS)-stimulated human pulmonary microvascular endothelial cells (HPMECs).
- Utilized qRT-PCR, Western blotting, transwell, wound healing, and tube formation assays to assess cellular functions.
- Employed ELISA for inflammatory factor detection and TEER/FITC assays for cell permeability.
- Investigated molecular interactions using dual-luciferase reporter and RNA pull-down assays.
Main Results:
- circRSU1 expression was decreased in LPS-treated HPMECs.
- Re-expression of circRSU1 ameliorated LPS-induced inflammation, cell migration/tubulogenesis inhibition, and increased cell permeability.
- circRSU1 acted as a sponge for miR-1224-5p, which was upregulated by LPS.
- miR-1224-5p targeted ITGA5, and circRSU1 regulated ITGA5 expression via miR-1224-5p.
Conclusions:
- circRSU1 exerts protective effects against LPS-induced HPMEC injury.
- The circRSU1/miR-1224-5p/ITGA5 axis plays a crucial role in sepsis-ALI pathogenesis.
- circRSU1 represents a potential therapeutic target for sepsis-ALI.
