RESUMO
OBJECTIVE To investigate the effect of arctiin (ARC)relieving lipopolysaccharide (LPS)induced inflammatory injury of human nasopharyngeal epithelial cells NP- 69. METHODS The effects of 24 h treatment of 0.000 1,0.001,0.01,0.1, 1.0,10 μmol/L ARC on the proliferation of NP-69 were determined by MTS method. After 0.01,0.1,and 1.0 μmol/L ARC was applied to NP- 69 for 24 h and NP- 69 was pre-treated with 0.01,0.1 and 1.0 μmol/L ARC for 24 h,and then stimulated with 1.0 μg/mL LPS for 24 h,scratch tests were used to detect cell migration in both experiments. LPS stimulated NP- 69 to establish an inflammation injury model. The levels of nitric oxide (NO),tumor necrosis factor α(TNF-α)interleukin-6(IL-6),and IL- 1β in cell supernatants were detected ,and mRNA and protein expression of zonula oecludens protein 1(ZO-1),β-defensin 3(BD3), Janus kinase 1 (JAK1),signal transducer and activator of transcription 3 (STAT3) in cell supernatant were also detected. RESULTS Compared with normal group ,0.000 1,0.001,0.01,0.1,1.0,10 μmol/L ARC had no effect on the proliferation of NP-69 after 24 h treatment (P>0.05). ARC (0.1,1.0 μmol/L)could significantly promote the rate of cell migration (P<0.05). For the inflammatory injure of NP- 69 cells stimulated by LPS ,ARC(1.0 μmol/L)could significantly reduce the release of NO , TNF-α and IL-6(P<0.05),significantly increased mRNA and protein expression of ZO- 1 and BD 3 but decreased mRNA and protein expression of STAT 3(P<0.01 or P<0.05). CONCLUSIONS ARC has the effect of reducing the inflammatory injury of NP-69 cells induced by LPS ,promoting the physical and immune defense ability of the nasal mucosa epithelial barrierunder inflammatory environment. The mechanism of action may be related to inhibiting IL- 6/JAK1/STAT3 signaling pathway.
RESUMO
In the present study, the mechanism by which carboxyl terminal activating region 3 (CTAR3) of latent membrane protein 1 (LMP1), encoded by the EpsteinBarr virus, regulated cell proliferation and protein expression was investigated in the nasopharyngeal epithelial cell line NP69. The deletion mutant LMP1 (LMP1Δ232351; amino acid residues including 232351 codons in CTAR3 deleted) was generated by polymerase chain reaction. An NP69LMP1Δ232351 cell line was established by retroviral infection. Finally, cell proliferation and protein expression of NP69 cells expressing LMP1Δ232351 were examined using a cell growth curve and western blot analysis. The results demonstrated: i) The proliferation of NP69LMP1Δ232351 cells was significantly decreased compared with cells expressing wild type LMP1 (LMP1WT; n=3; P<0.05); ii) 17 proteins exhibited differential protein expression (>2fold change) in NP69LMP1Δ232351 cells compared with NP69LMP1WT cells; and iii) LMP1WT was involved in activating the Janus kinase 3 (JAK3) promoter and regulating the expression of JAK3 protein, while LMP1Δ232351 was almost defective in ability to activate the JAK promoter. These results suggested that LMP1CTAR3 may be an important functional domain for regulating cell proliferation and protein expression in nasopharyngeal epithelial cells.