Role of miR-584-5p in Lipopolysaccharide-Stimulated Human Bronchial Epithelial Cell Inflammation and Apoptosis.

Acute lung injury (ALI)/acute respiratory distress syndrome is a common clinical syndrome characterized by respiratory failure. MicroRNAs (miRNAs) are closely related to ALI and acute respiratory distress syndrome. TargetScan software analysis showed that miR-584-5p can bind to the 3' noncoding region of TLR4, which is involved in the occurrence and development of ALI, thereby affecting the inflammatory pathway and inflammation development. Thus, we aimed to determine whether miR-584-5p affects ALI. Human bronchial epithelial (16-HBE) cells were transfected with miR-584-5p mimics or inhibitors and then stimulated with lipopolysaccharide (LPS).The cell viability, apoptosis, release of proinflammatory factors, mTOR, and NF-κB pathway protein expression were evaluated respectively. Mimic584 increased, whereas inhibitor584 decreased, LPS-stimulated inflammation. The protein expression of inflammatory factors was significantly increased in 16-HBE cells in the mimic584 + LPS group and decreased in the inhibitor584 + LPS group. Mimic584 activated mTOR and the NF-κB-related proteins P65 and p-p65, whereas inhibitor584 inactivated the proteins in 16-HBE cells. Overexpression of miR-584 significantly promoted apoptosis in LPS-stimulated 16-HBE cells. There were no differences in the proliferation and cell cycle of LPS-stimulated 16-HBE cells regardless of mimic584 or inhibitor584 transfection. Collectively, we demonstrated that inhibitor584 can alleviate ALI-induced expression of inflammatory factors via mTOR signaling and the NF-κB pathway. In conclusion, we found that inhibitor584 transfection could be a potential therapeutic strategy for ALI.

Transcriptome analysis provides insights into the root response of Chinese fir to phosphorus deficiency.

BACKGROUND: Phosphorus is one of the essential elements for plant growth and development, but available phosphorus (Pi) content in many soil types is low. As a fast-growing tree species for timber production, Chinese fir is in great demand of Pi, and the lack of Pi in soil restricts the increase of productivity of Chinese fir plantation. Root morphology and the synthesis and secretion of organic acids play an important role in the uptake of phosphorus, but the molecular mechanisms of Chinese fir root responses to Pi deficiency are largely unexplored. In this study, seedlings of Yang 061 clone were grown under three Pi supply levels (0, 5 and 10 mg·L-1 P) and morphological attributes, organic acid content and enzyme activity were measured. The transcriptome data of Chinese fir root system were obtained and the expression levels of phosphorus responsive genes and organic acid synthesis related genes on citric acid and glyoxylate cycle pathway were determined. RESULTS: We annotated 50,808 Unigenes from the transcriptome of Chinese fir roots. Among differentially expressed genes, seven genes of phosphate transporter family and 17 genes of purple acid phosphatase family were up-regulated by Pi deficiency, two proteins of SPX domain were up-regulated and one was down-regulated. The metabolic pathways of the citric acid and glyoxylate cycle pathway were mapped, and the expression characteristics of the related Unigenes under different phosphorus treatments were analyzed. The genes involved in malic acid and citric acid synthesis were up-regulated, and the activities of the related enzymes were significantly enhanced under long-term Pi stress. The contents of citric acid and malic acid in the roots of Chinese fir increased after 30 days of Pi deficiency. CONCLUSION: Chinese fir roots showed increased expression of genes related with phosphorus starvation, citrate and malate synthesis genes, increased content of organic acids, and enhanced activities of related enzymes under Pi deficiency. The results provide a new insight for revealing the molecular mechanism of adaption to Pi deficiency and the pathway of organic acid synthesis in Chinese fir roots.

Antitumor activity of the Ailanthus altissima bark phytochemical ailanthone against breast cancer MCF-7 cells.

Ailanthone is isolated from the bark of Ailanthus altissima (Mill.) Swingle (Simaroubaceae). The mechanism that underlies the activity of ailanthone on MCF-7 cells was investigated by MTT assay. Breast cancer MCF-7 cells were treated with 0.5, 1.0, 2.0, 4.0 and 8.0 µg/ml ailanthone for 24, 48 and 72 h. The inhibition of proliferation induced by treatment with ailanthone was assessed by MTT assay. Apoptosis and cell cycle distribution in MCF-7 cells with the same doses of ailanthone for 48 h were determined by flow cytometry. Expression of apoptosis-associated genes and proteins were analyzed by reverse transcription-polymerase chain reaction (RT-PCR) and western blot analysis, respectively. The results revealed that ailanthone inhibited MCF-7 cell proliferation. Flow cytometry assay demonstrated that ailanthone induced apoptosis and G0/G1 cell cycle arrest in MCF-7 cells. Western blotting and RT-PCR assays demonstrated that upregulation of pro-apoptotic caspase-3 and Bcl-associated X, and downregulation of anti-apoptotic apoptosis regulator B-cell lymphoma-2 in MCF-7 cells may be associated with the induction of apoptosis and inhibition of proliferation. To the best of our knowledge, the present study is the first to investigate the antitumor activity of ailanthone from A. altissima on MCF-7 cells and to attempt to elucidate the underlying mechanism. The present study revealed the presence of ailanthone-mediated antitumor effects, indicating that ailanthone may be a novel phytomedicine with potential use in breast cancer therapy.