miRNA-6515-5p regulates particulate matter-induced inflammatory responses by targeting CSF3 in human bronchial epithelial cells.

Particulate matter (PM) is associated with the incidence, exacerbation, and mortality of variable respiratory diseases. However, the molecular mechanisms of PM10-mediated inflammation are unclear. We identified microRNAs (miRNAs) and messenger RNAs (mRNAs) related to the inflammatory response in PM10-exposed bronchial epithelial cells using next-generation sequencing. Of the miRNAs, miR-6515-5p was significantly downregulated in PM10-exposed human bronchial epithelial BEAS-2B cells. miR-6515-5p regulated the production of pro-inflammatory cytokines (IL-6 and IL-8) and the expression of inflammatory genes (IL-1ß, IL-6, IL-8, TNF-α, CXCL-1, and MCP-1) via MAPK/ERK signaling; overexpression of miR-6515-5p using a mimic inhibited PM10-induced inflammatory responses via inactivation of the ERK pathway, whereas downregulation of miR-6515-5p via an inhibitor significantly increased inflammation in PM10-exposed cells via activation of ERK. Furthermore, we identified colony stimulating factor 3 (CSF3) as a target gene of miR-6515-5p using TargetScanHuman, and confirmed the association between miR-6515-5p and CSF3 using a luciferase reporter assay. Furthermore, we found that mRNA and protein levels of CSF3 were negatively regulated by miR-6515-5p. Inhibition of CSF3 by small interfering RNA significantly reduced the expression and production of inflammatory markers in PM10-exposed cells by inactivating the MAPK/ERK signaling pathway. Therefore, we suggest that miR-6515-5p regulates PM10-induced inflammatory responses by targeting CSF3 via MAPK/ERK signaling in bronchial epithelial cells.

Astragaloside IV Suppresses Hepatic Proliferation in Regenerating Rat Liver after 70% Partial Hepatectomy via Down-Regulation of Cell Cycle Pathway and DNA Replication.

Astragaloside IV (AS-IV) is one of the major bio-active ingredients of huang qi which is the dried root of Astragalus membranaceus (a traditional Chinese medicinal plant). The pharmacological effects of AS-IV, including anti-oxidative, anti-cancer, and anti-diabetic effects have been actively studied, however, the effects of AS-IV on liver regeneration have not yet been fully described. Thus, the aim of this study was to explore the effects of AS-IV on regenerating liver after 70% partial hepatectomy (PHx) in rats. Differentially expressed mRNAs, proliferative marker and growth factors were analyzed. AS-IV (10 mg/kg) was administrated orally 2 h before surgery. We found 20 core genes showed effects of AS-IV, many of which were involved with functions related to DNA replication during cell division. AS-IV down-regulates MAPK signaling, PI3/Akt signaling, and cell cycle pathway. Hepatocyte growth factor (HGF) and cyclin D1 expression were also decreased by AS-IV administration. Transforming growth factor ß1 (TGFß1, growth regulation signal) was slightly increased. In short, AS-IV down-regulated proliferative signals and genes related to DNA replication. In conclusion, AS-IV showed anti-proliferative activity in regenerating liver tissue after 70% PHx.