miRNA-206-3p alleviates LPS-induced acute lung injury via inhibiting inflammation and pyroptosis through modulating TLR4/NF-κB/NLRP3 pathway.

Acute lung injury (ALI) is life-threatening. MicroRNAs (miRNAs) are often abnormally expressed in inflammatory diseases and are closely associated with ALI. This study investigates whether miRNA-206-3p attenuates pyroptosis in ALI and elucidates the underlying molecular mechanisms. ALI mouse and cell models were established through lipopolysaccharide (LPS) treatment for 24 h. Subsequently, the models were evaluated based on ultrasonography, the lung tissue wet/dry (W/D) ratio, pathological section assessment, electron microscopy, and western blotting. Pyroptosis in RAW264.7 cells was then assessed via electron microscopy, immunofluorescence, and western blotting. Additionally, the regulatory relationship between miRNA-206-3p and the Toll-like receptor (TLR)4/nuclear factor (NF)-κB/Nod-like receptor protein-3 (NLRP3) pathway was verified. Finally, luciferase reporter gene and RNA pull-down assays were used to verify the targeting relationship between miRNA-206-3p and TLR4. miRNA206-3p levels are significantly decreased in the LPS-induced ALI model. Overexpression of miRNA-206-3p improves ALI, manifested as improved lung ultrasound, improved pathological changes of lung tissue, reduced W/D ratio of lung tissue, release of inflammatory factors in lung tissue, and reduced pyroptosis. Furthermore, overexpression of miRNA-206-3p contributed to reversing the ALI-promoting effect of LPS by hindering TLR4, myeloid differentiation primary response 88 (MyD88), NF-κB, and NLRP3 expression. In fact, miRNA-206-3p binds directly to TLR4. In conclusion, miRNA-206-3p alleviates LPS-induced ALI by inhibiting inflammation and pyroptosis via TLR4/NF-κB/NLRP3 pathway modulation.

Chen M ，Zhang J ，Huang H ，Wang Z ，Gao Y ，Liu J ... -  《Scientific Reports》

MicroRNA-27a alleviates LPS-induced acute lung injury in mice via inhibiting inflammation and apoptosis through modulating TLR4/MyD88/NF-κB pathway.

Ju M ，Liu B ，He H ，Gu Z ，Liu Y ，Su Y ，Zhu D ，Cang J ，Luo Z ... -  《-》

Fortunellin ameliorates LPS-induced acute lung injury, inflammation, and collagen deposition by restraining the TLR4/NF-κB/NLRP3 pathway.

Acute lung injury (ALI) is the prevalent respiratory disease of acute inflammation with high morbidity and mortality. Fortunellin has anti-inflammation property, but its role in ALI remains elusive. Thus, this study clarified the function of fortunellin on ALI pathogenesis. The ALI mouse model was established by lipopolysaccharide (LPS) induction, and lung tissue damage was evaluated utilizing hematoxylin-eosin (HE) staining. The edema of lung tissue was measured by the lung wet/dry (W/D) ratio. The lung capillary permeability was reflected by the protein content in bronchoalveolar lavage fluid (BALF). Inflammatory cell infiltration was measured by the evaluation of the content of myeloperoxidase (MPO), neutrophils, and leukocytes in BALF. Cell apoptosis was measured by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay. The secretions of inflammatory cytokines were quantified using enzyme-linked immunosorbent assay (ELISA) assays. Lung tissue collagen deposition was evaluated by Masson staining. Fortunellin attenuated LPS-induced lung tissue damage and reduced the W/D ratio, the content of MPO in lung tissue, the total protein contents in BALF, and the neutrophils and leukocytes number. Besides, fortunellin alleviated LPS-stimulated lung tissue apoptosis, inflammatory response, and collagen deposition. Furthermore, Fortunellin repressed the activity of the Toll-like receptor 4 (TLR4)/nuclear factor kappa-B (NF-κB)/NLR Family Pyrin Domain Containing 3 (NLRP3) pathway in the LPS-stimulated ALI model and LPS-induced RAW264.7 cells. Moreover, fortunellin attenuated LPS-stimulated tissue injury, apoptosis, inflammation, and collagen deposition of the lung via restraining the TLR4/NF-κB/NLRP3 pathway. Fortunellin attenuated LPS-stimulated ALI through repressing the TLR4/NF-κB/NLRP3 pathway. Fortunellin may be a valuable drug for ALI therapy.

Liu D ，Guo R ，Shi B ，Chen M ，Weng S ，Weng J ... -  《Immunity Inflammation and Disease》

MiR-124-3p targeting PDE4B attenuates LPS-induced ALI through the TLR4/NF-κB signaling pathway.

A large number of studies have found that microRNAs (miRNAs) and phosphodiesterase 4 (PDE4) are crucial regulators of inflammatory responses in acute lung injury (ALI). This study will explore the protective effect of miR-124-3p on ALI and its related mechanism. The ALI mouse model was established by intratracheal administration of lipopolysaccharide (LPS) and evaluated by haematoxylin and eosin (HE) staining, lung injury score, inflammation factors, polymorphonuclear leukocyte (PMN) count, total protein and lung wet weight/dry weight (W/D) ratio. MiR-124-3p was overexpressed in vivo by intratracheal administration of miR-agomir, and PDE4B was expressed at low level in vivo by intratracheal administration of a PDE4B inhibitor. The mRNA expression level was detected by qRT-PCR, and the protein expression level was detected by Western blot. The relationship between miR-124-3p and PDE4B was detected by dual-luciferase activity assay. We found that miR-124-3p was downregulated in LPS-induced ALI. Overexpression of miR-124-3p alleviated lung injury by inhibiting the Toll-like receptor 4 (TLR4)/nuclear factor-kappa B (NF-κB) signaling pathway. Furthermore, we confirmed that miR-124-3p suppressed the TLR4/NF-κB signaling pathway by directly targeting PDE4B. miR-124-3p targeting PDE4B had a protective effect on LPS-induced ALI by inhibiting the TLR4/NF-κB signaling pathway.

Zhou Q ，He DX ，Deng YL ，Wang CL ，Zhang LL ，Jiang FM ，Irakoze L ，Liang ZA ... -  《-》

Yemazhui () ameliorates lipopolysaccharide-induced acute lung injury modulation of the toll-like receptor 4/nuclear factor kappa-B/nod-like receptor family pyrin domain-containing 3 protein signaling pathway and intestinal flora in rats.

Li R ，Yang H ，Xue Y ，Xianqin L ... -  《-》