ANRIL regulating the secretion of Muc5ac induced by atmospheric PM2.5 via NF‐κB pathway in Beas‐2B cells

Abstract

AbstractPM2.5 can cause airway inflammation and promote the excessive secretion of mucin 5ac (Muc5ac), which can further induce many respiratory diseases. Antisense non‐coding RNA in the INK4 locus (ANRIL) might regulate the inflammatory responses mediated by nuclear factor kappa‐B (NF‐κB) signaling pathway. Beas‐2B cells were used to clarify the role of ANRIL in the secretion of Muc5ac induced by PM2.5. The siRNA was used to silence ANRIL expression. Normal and gene silenced Beas‐2B cells were respectively exposed to different doses of PM2.5 for 6, 12, and 24 h. The survival rate of Beas‐2B cells was detected by methyl thiazolyl tetrazolium (MTT) assay. Tumor necrosis factor‐α (TNF‐α), interleukin‐1β (IL‐1β) and Muc5ac levels were determined by enzyme linked immunosorbent assay (ELISA). The expression levels of NF‐κB family genes and ANRIL were detected by real time polymerase chain reaction (PCR). The levels of NF‐κB family proteins and NF‐κB family phosphorylated proteins were determined using Western blot. Immunofluorescence experiments were performed to observe the nuclear transposition of RelA. PM2.5 exposure increased the levels of Muc5ac, IL‐1β and TNF‐α, and ANRIL gene expression (p < .05). With the dose and time of PM2.5 exposure increasing, the protein levels of inhibitory subunit of nuclear factor kappa‐B alpha (IκB‐α), RelA, and NF‐κB1 decreased, the protein levels of phosphorylated RelA (p‐RelA) and phosphorylated NF‐κB1 (p‐NF‐κB1) increased, and RelA nuclear translocation increased, which indicated that the NF‐κB signaling pathway was activated (p < .05). Silencing ANRIL could decrease the levels of Muc5ac, IL‐1β, TNF‐α, decrease NF‐κB family genes expression, inhibit the degradation of IκB‐α and the activation of NF‐κB pathway (p < .05). ANRIL played a regulatory role in the secretion of Muc5ac and the inflammation induced by atmospheric PM2.5 via NF‐κB pathway in Beas‐2B cells. ANRIL could be a target for prevention and treatment of the respiratory diseases caused by PM2.5.