Chemotatic factor expression induced by angiotensin Ⅱ in A549 cells / 中华急诊医学杂志

ABSTRACT

Objective To investigate the effects of angiotensin Ⅱ on nuclear transcription factor-кB(NF-кB)and interleukin-8(A549 cells),and to explore the underlying mechanisms of ventilator-induced lung injure. MethodA549 cells were maintained in Dulbecco' s modified Eagle's culture medium at 37℃ with 5 ％ CO2 incubator. The cells were randomly (random number) divided into 4 groups (n =24 in each). The group A was control group. The group B,C and D had A549 cells co-incubated with Angiotensin Ⅱ 10-6 mmol/L (final concentration) for 1 h,2 h and 4 h, respectively. The samples of cell culture supematant,total cellular RNA and nuclear proteins were collected or extracted after culture of cells. The II-8 contents in cell culture supernatant were detected with enzyme linked immunosorbent assay(FLISA) .The expressions of IL-8 mRNA were measured by reverse ttanscription-polymerase chain reaction (RT-PCR).The NF-κB activities were assayed with electrophoretic mobility shift assay (EMSA). The levels of NF-κB p65 subunit were detected with Western blot. The overall differences were compared by using analysis of variance(ANOVA). Differences between two groups were assessed by q tests. ResultsThe levels of IL-8 content in cell culture supematant in groups A, B, C and D were (29.59+8.36) pg/mL,(135.35 + 28.93) pg/mL,(357.12+ 57.21) pg/mL,and (1732.13+ 261.73) pg/mL,respectively(group A vs. group B, P ＜0.01; group B vs group C, P ＜0.01;group C vs. group D, P ＜ 0.01 ) The overall differences between gtoups were statistically significant ( F =58.41,P ＜ 0.05). The expressions of IL-8 mRNA in groups A, B, C and D were (0.13±0.03)Au·nm,(0.49+0.08) Au·mm,(0.71 ±0.10) Au·mm and (0.88±0.11) Au·mm,respectively (group A vs. group B, P ＜0.01; group B vs. group C, P ＜ 0.01; group C vs. group D, P ＜ 0.05. The overall differences between groups were statistically significant (F = 19.08, P ＜ 0.05). The NF-κB activities in groups A, B, C and D were (70.37±6.57) Au·mm,(139.76± 11.72) Au·mm,(198.90± 18.95)Au·mm and (388.73±26.27) Au·mm, respectively (group A vs. group B, P ＜0.01,group B vs. groupC, P ＜0.05; group C vs. group D, P ＜ 0.01 ). The overall differences between groups were statistically significant ( F = 23.15, P ＜ 0.05). The levels of NF-κB p65 subunit in groups A, B＜ C and D were (33.05±6.23) Au·mm, (73.97 ± 5.34) Au·mm,(168.72± 8.40)Au·mm and (254.63 + 12.2) Au·mm, respectively (group A vs. group B, P ＜0.01; group B vs. group C, P ＜0.01; group C vs. group D, P ＜0.01). The overall differences between groups were statistically significant (F = 16.33,P ＜ 0.05). Conclusions The Ang Ⅱ can significantly activate the NF-κB system and up-regulate the expression of IL-8 in human lung adenocarcinoma cell line, which cause neutrophil infiltration and activation. This effect is time-dependent and induces acute lung injure, playing an important role in the underlying mechanisms of ventilator-induced lung injure.