ABSTRACT
<p><b>OBJECTIVE</b>To investigate the transduction pathway of triggering receptor-1 expressed on myeloid cells (TREM-1) in acute lung injure induced by paraquat in rats through the activating or blocking TREM-1, to observe the effect of signal transduction pathway in the acute lung injure induced-paraquat.</p><p><b>METHODS</b>80 SD rats were randomly divided into normal saline control group (n=20) , PQ poisoning group (n=20) , antibody group (n=20) , and LP17 group (n=20). poisoning group, antibody group and LP17 group were given saline diluting PQ 80 mg/kg of disposable lavage after 2 h, a single set of intraperitoneal injection of anti-TREM-1 mAb (250 g/kg) , tail intravenous LP17 group synthetic peptide (3.5 mg/kg) , poisoning group was given equal normal saline intraperitoneal injection, control group given normal saline 1 mg/kg after 2 h after lavage, given the amount of intraperitoneal injection of saline solution. The expression of NF-κB in lung tissue was determined by immunohistochemistry.The levels of TNF-a, IL-10, TREM-1, and soluble TREM-1 (sTREM-1) in lung tissue and serum were measured by ELISA. Pathology changes of lung were observed under light microscope, and lung score of pathology was compared.</p><p><b>RESULTS</b>Administration of anti-TREM-1 mAb after PQ poisoning modeling significantly increased the NF-κB expression in lung tissue at 48 h, resulting in a large number of pro-inflammatory cytokines releasing in the lung tissue and serum and lung pathology injury score increasing.Administration of LP17 after modeling significantly down-·regulated the expressions of NF-κB and proinflammatory cytokines, while led to a slight increase of anti-inflammatory cytokines and a decline of lung pathology injury score.</p><p><b>CONCLUSION</b>TREM-1 may involve in inflammatory response by promoting the generation of inflammatory factors via NF-κB pathway, thus lead to lung pathological changes.</p>
Subject(s)
Animals , Rats , Acute Lung Injury , Metabolism , Interleukin-10 , Metabolism , NF-kappa B , Metabolism , Paraquat , Toxicity , Rats, Sprague-Dawley , Receptors, Immunologic , Metabolism , Signal Transduction , Triggering Receptor Expressed on Myeloid Cells-1 , Tumor Necrosis Factor-alpha , MetabolismABSTRACT
<p><b>OBJECTIVE</b>To evaluate the changes of CD(4)(+) IL-17+T (Th17) and CD(4)(+)Foxp3+regulatory T (Treg) cells in peripheral blood and bronchoalveolar lavage fluid (BALF) , and therefore to explore the role of Th17 and Treg in acrolein exposure airway inflammation in rats.</p><p><b>METHODS</b>Forty male Wistar rats were randomly divided into 4 groups: a 2 wk acrolein exposure group, a 4 wk acrolein exposure group, a 2 wk control group and a 4 wk control group (n=10 each). Cells in BALF were collected and analyzed by absolute and differential cell counts.IL-17 and IL-6 levels in serum and BALF were tested by enzyme linked immunosorbent assay (ELISA). The proportion of CD(4)(+)IL-17+T and CD(4)(+) Foxp3+Treg in peripheral blood and BALF were determined by flow cytometry.The mRNA expressions of IL-17 and Foxp3 were measured by real-time PCR. Comparisons of the data between different groups were performed using one-way ANOVA, and SNK and Games-Howell test were used for comparison between 2 groups.</p><p><b>RESULTS</b>Levels of IL-17 were remarkable increased in the 2 wk acrolein exposure group and the 4 wk acrolein exposure group in serum [(52.64 ± 1.89) ng/L, (76.73 ± 5.57) ng/L], and BALF [(79.07 ± 5.67) ng/L, (96.61 ± 6.44) ng/L] compared with the 2 wk control group [(40.05 ± 3.12) ng/L, (56.75 ± 4.37) ng/L] and the 4 wk control group [(38.75 ± 3.23) ng/L, (53.27 ± 4.48) ng/L], all P<0.01. IL-6 was increased in the 2 wk and the 4 wk acrolein exposure group [ (33.28 ± 2.27) ng/L, (46.24 ± 3.16) ng/L] compared with the 2 wk and the 4 wk control group [ (16.37 ± 1.49) ng/L, (17.02 ± 1.43) ng/L] in BALF.Ratio of Th17 was higher in the 2 wk and the 4 wk acrolein exposure groups in peripheral blood (1.82 ± 0.18) %, (3.75 ± 0.48) % and BALF [(7.23 ± 0.27) %, (8.12 ± 0.38) %] compared with the 2 wk [(0.96 ± 0.07) %, (5.64 ± 0.63) %] and the 4 wk control group [(1.01 ± 0.08) %, (5.86 ± 0.57) %]. Ratio of Treg in BALF was higher in the acrolein exposure groups [ (8.83 ± 0.52) %, (12.05 ± 0.74) %] compared with the control groups [(4.37 ± 0.27) %, (5.01 ± 0.37) %]. The level of IL-17 mRNA was increased in the 2 wk and the 4 wk acrolein exposure group in peripheral blood [(25.78 ± 2.31), (34.69 ± 2.01) ] and in BALF [(23.04 ± 1.78), (34.56 ± 3.12)] compared with the 2 wk [(11.04 ± 2.53), (11.08 ± 2.05)] and the 4 wk [(12.03 ± 2.34), (12.69 ± 2.69)] control groups. Foxp3 mRNA was increased in the acrolein exposure groups [ (26.37 ± 3.24), (33.19 ± 2.98)] (24.4 ± 2.7), (30.3 ± 2.7) compared with the control groups [(12.37 ± 2.56), (13.12 ± 3.08)]. Th17 in acrolein exposure groups was positively correlated with counts of total cells and macrophages (r=0.5126, 0.5437, all P<0.01).</p><p><b>CONCLUSIONS</b>A changed expression of Th17 and Treg cells and an vary of inflammatory cytokines were evident in airway inflammation of acrolein exposed rats, suggesting that Treg was involved in the immunological regulation and Th17 was associated with the persistent inflammation in acrolein induced airway inflammation in rats.</p>