Acute lung Injury (ALI) is the clinical syndrome of parenchymal lung disease, leading to an extremely high mortality. The pathogenesis of ALI is suggested to be a consequence of uncontrolled inflammation. Lipopolysaccharide (LPS)-induced ALI mice model is often used for the mechanism. Studies show that TGF-beta activated kinase 1 (MAP3K7) binding protein 1/2 (TAB2) plays a crucial role in LPS-induced inflammation response. Furthermore, microRNA-142a-3p (miR-142a-3p) has been observed to be involved in inflammation-induced disease. Thus, we investigated the role of miR-142a-3p and TAB2 on LPS-induced ALI, which involved the TLR4/TAB2/NF-κB signaling. ALI and normal lung tissues were collected to access the relative expression of pro-inflammatory cytokines and miR-142a-3p. Histopathological examination and Wet to Dry weight ratios of lung tissues were used to access the establishment of ALI models. Raw264.7 cells were transfected with si-TAB2 or miR-142a-3p mimics to elucidate the role of TAB2 or miR-142a-3p in the inflammatory cascade in ALI. Additionally, the relationship between miR-142a-3p and TAB2 was validated by dual-luciferase report system. Our study discovered that miR-142-3p was up-regulated both in LPS-induced ALI mice model and RAW264.7 cells model. MiR-142a-3p mimics group experienced significant decrease in the secretion of pro-inflammatory cytokines as a result of the inhibition of NF-κB signaling pathway. Bioinformatics database showed that the adaptor protein, TAB2, was critical in this pathway and it is the target gene of miR-142a-3p. Their relation was first confirmed by us via dual-luciferase report system. Results of our study demonstrated that miR-142a-3p exerts as a protective role in LPS-induced ALI through down-regulation of NF-κB signaling pathway.

Acute lung injury (ALI) is considered as an uncontrolled inflammatory response that can leads to acute respiratory distress syndrome (ARDS), which limits the therapeutic strategies. Ginsenosides Rb1 (Rb1), an active ingredient obtained from Panax ginseng, possesses a broad range of pharmacological and medicinal properties, comprising the anti-inflammatory, anti-oxidant, and anti-tumor activities. Therefore, the purpose of the present study was to investigate the protective effects of Rb1 against S. aureus-induced (ALI) through regulation of Nuclear factor erythroid 2-related factor 2 (Nrf2) and mitochondrial-mediated apoptotic pathways in mice (in-vivo), and RAW264.7 cells (in-vitro). For that purpose, forty Kunming mice were randomly assigned into four treatment groups; (1) Control group (phosphate buffer saline (PBS); (2) S. aureus group; (3) S. aureus + Rb1 (20 mg/kg) group; and (4) Rb1 (20 mg/kg) group. The 20 μg/mL dose of Rb1 was used in RAW264.7 cells. In the present study, we found that Rb1 treatment reduced ALI-induced oxidative stress via suppressing the accumulation of malondialdehyde (MDA) and myeloperoxidase (MPO) and increase the antioxidant enzyme activities of superoxidase dismutase 1 (SOD1), Catalase (CAT), and glutathione peroxidase 1 (Gpx1). Similarly, Rb1 markedly increased messenger RNA (mRNA) expression of antioxidant genes (SOD1, CAT and Gpx1) in comparison with ALI group. The histopathological results showed that Rb1 treatment ameliorated ALI-induced hemorrhages, hyperemia, perivascular edema and neutrophilic infiltration in the lungs of mice. Furthermore, Rb1 enhanced the antioxidant defense system through activating the Nrf2 signaling pathway. Our findings showed that Rb1 treated group significantly up-regulated mRNA and protein expression of Nrf2 and its downstream associated genes down-regulated by ALI in vivo and in vitro. Moreover, ALI significantly increased the both mRNA and protein expression of mitochondrial-apoptosis-related genes (Bax, caspase-3, caspase-9, cytochrome c and p53), while decreased the Bcl-2. In addition, Rb1 therapy significantly reversed the mRNA and protein expression of these mitochondrial-apoptosis-related genes, as compared to the ALI group in vivo and in vitro. Taken together, Rb1 alleviates ALI-induced oxidative injury and apoptosis by modulating the Nrf2 and mitochondrial signaling pathways in the lungs of mice.

Acute lung injury (ALI) is clinically characterized by excessive inflammation leading to acute respiratory distress syndrome (ARDS), having high morbidity and mortality both in human and animals. Ginsenoside Rb1 (Rb1) is a major primary bioactive component extracted by Panax ginseng, which has numerous pharmacological functions such as anti-cancer, anti-inflammatory, and antioxidant. However, the anti-inflammatory effects of Rb1 in Staphylococcus aureus (S. aureus)-induced ALI in mice have not been investigated. The aim of the current study was to determine the anti-inflammatory influence of Rb1 on S. aureus-induced ALI in mice, and to explore its possible underlying principle mechanisms in RAW 264.7 macrophage cells. The results of physical morphology, histopathological variation and wet-to-dry weight ratio of lungs revealed that Rb1 significantly attenuated S. aureus-induced lung injury. Furthermore, qPCR results displayed that Rb1 inhibited IL-1β, IL-6 and TNF-α production both in vivo and in vitro. The activation of Toll-like receptor 2 (TLR2) by S. aureus was inhibited by application of Rb1 as confirmed by results of immunofluorescence assay. The expression of NF-kB and MAPK signaling proteins revealed that Rb1 significantly attenuated the phosphorylation of p65, ERK, as well as JNK. Altogether, the results of this experiment presented that Rb1 has ability to protect S. aureus-induced ALI in mice by attenuating TLR-2-mediated NF-kB and MAPK signaling pathways. Consequently, Rb-1 might be a potential medicine in the treatment of S. aureus-induced lung inflammation.