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Updated: Nov 11, 2025
A Controlled Mouse Model for Neonatal Polymicrobial Sepsis
Published on: January 27, 2019
MiR-490 alleviates sepsis-induced acute lung injury by targeting MRP4 in new-born mice
Jie Lin1, Zongze Lin1, Liqun Lin1
1Department of Paediatrics, Ruian People's Hospital, Ruian Ciy, Wenzhou City, Zhejiang Province, 325200, China.
Abstract:
The aim of this study was to investigate whether the effects of miR-490 on acute lung injury (ALI) induced by sepsis in vitro and in vivo were through targeting multi-drug resistance-associated protein 4 (MRP4). MiR-490 agomir/NC agomir was injected into mice before cecal ligation and puncture (CLP). Pulmonary microvascular endothelial cells (PMVECs) were transfected with or without miR-490 agomir/NC agomir/MRP4/empty vector before lipopolysaccharide (LPS) stimulation. Histopathology, injure score, and Wet/Dry (W/D) of lung tissues were assessed. The number of neutrophils, macrophages and total cells, total protein concentration, TNF-α and IL-1β level in bronchoalveolar lavage fluid (BALF) were measured. The levels of caspase-3, Bcl-2, TNF-α, and IL-1β were measured in MPVECs. Dual-luciferase reporter assay was used to analyze the relationship between MRP4 and miR-490. When compared to the sham group, in CLP mice, the alveolar lung tissue showed significantly hyperemic, alveolar collapse, the W/D ratio was increased, and the injury index was increased. The number of neutrophils, macrophages and total cells, total protein concentration, TNF-α and IL-1β levels were significantly increased in BALF from CLP mice. The levels of TNF-α and IL-1β were significantly increased in lung tissue from CLP mice. Overexpression of miR-490 alleviated lung injury caused by CLP and inhibited inflammation in mice. The levels of TNF-α, IL-1β and caspase-3 were significantly increased, but the level of Bcl-2 was significantly decreased in MPVECs treated with LPS compared to the control group. Overexpression of miR-490 also reversed the increase of TNF-α, IL-1β, cleaved caspase-3 and Bcl-2 caused by LPS in MPVECs. Dual-luciferase reporter assay confirmed that the target gene of miR-490 was MRP4. Besides, overexpression of MRP4 upregulated TNF-α, IL-1β, and cleaved caspase-3, but downregulated the increase of Bcl-2 induced by miR-490 agomir transfection. These data suggested that miR-490 could relieve sepsis-induced acute lung injury in neonatal mice via targeting MRP4.
Insights
MicroRNA-490 (miR-490) alleviates sepsis-induced acute lung injury by targeting multi-drug resistance-associated protein 4 (MRP4). This study demonstrates miR-490
Area of Science:
- Biomedical Science
- Molecular Biology
- Pathology
Background:
- Sepsis-induced acute lung injury (ALI) is a severe condition with high mortality.
- The role of microRNAs (miRNAs) in regulating ALI pathogenesis is increasingly recognized.
- Multi-drug resistance-associated protein 4 (MRP4) has been implicated in cellular stress responses.
Purpose of the Study:
- To investigate the role of miR-490 in sepsis-induced ALI.
- To determine if miR-490 targets MRP4 in the context of ALI.
- To explore the therapeutic potential of miR-490 in ALI.
Main Methods:
- Cecal ligation and puncture (CLP) model in mice to induce sepsis-induced ALI.
- In vitro studies using pulmonary microvascular endothelial cells (PMVECs) stimulated with lipopolysaccharide (LPS).
- Transfection with miR-490 agomir, negative control (NC) agomir, MRP4, or empty vector.
- Histopathological analysis, injury scoring, Wet/Dry ratio assessment, bronchoalveolar lavage fluid (BALF) analysis, and Western blotting.
- Dual-luciferase reporter assay to confirm the interaction between miR-490 and MRP4.
Main Results:
- CLP mice exhibited significant lung injury, including hyperemia, alveolar collapse, increased W/D ratio, and elevated inflammatory markers in BALF and lung tissue.
- Overexpression of miR-490 attenuated CLP-induced lung injury and reduced inflammation.
- In vitro, LPS stimulation increased pro-inflammatory cytokines (TNF-α, IL-1β) and caspase-3, while decreasing Bcl-2 in PMVECs.
- miR-490 overexpression reversed LPS-induced changes in PMVECs.
- Dual-luciferase assay confirmed MRP4 as a direct target of miR-490.
- MRP4 overexpression counteracted the protective effects of miR-490.
Conclusions:
- miR-490 plays a protective role in sepsis-induced acute lung injury.
- miR-490 exerts its protective effects by targeting and downregulating MRP4.
- Modulating miR-490 levels may represent a novel therapeutic strategy for ALI.
