Regulation Of NF-?B Signaling In Neodymium Oxide Induced Lung Acute Injury

Objective To observe the inflammatory injury on rats caused by rare earth neodymium oxide particles(Nd2O3),NF-kappa B inflammatory pathway and its mechanism of action.Method A total of 70 healthy adult male SD rats [SPF grade;body weight,(200±10)g] were treated by unexposed tracheal intubation perfusion.The different exposure time groups were exposed to 0.8mL of 100 mg/kg RENOD suspension(experimental rats)and 0.8 mL of 0.9% normal saline(control rats);7 experimental and 7control rats were neutralized at each designed interval(at the 3rd,7th,14 th,21st,and28 th days after dust exposure).The Lung tissue HE staining.The lung tissues were dyed by the sirius red,and the levels of type I,III collagen were observed under polarized light microscope.EMSA determined content of NF-kappa B in fresh rat lung tissue.Western blot method determined in fresh lung tissue of rats with p65,p-p65,PIKK beta protein.The content of ELISA were measured by the methods of the experimental group and the control group BALF cell factor in rat.Results(1)The lung histopathology HE staining showed that models of inflammatory injury model was successed.The levels of type I,III collagen significantly increased in the process of pulmonary fibrosis induced by rare earth neodymium oxide dust in rats,and type I collagen hyperplasia was predominant in the early period of dust-exposure.The levels of type I,III collagen in the experimental group were significantly higher than those in the control group(P < 0.05);(2)EMSA results showed that the NF-kappa B activity in experimental of rats were increased;The groups were first increased,then increased to the highest at 14 d,and declined again thereafter,but the values at each time point were higher than those of the control rats(P <0.05);(3)The expression of p-p65 and PIKK beta protein appeared first increased and then decreased in lung tissue in the experimental group,and reached the maximum and then decrease trend in 14 days,but was higher than that of control group(P<0.05).There is no significant difference between the P65 group and the control group(P>0.05);(4)Pro-inflammatory and anti-inflammatory cytokines of the experimental group were higher than the control group in BALF(P<0.05).The pro-inflammatory and antiinflammatory cytokines appeared first increased and then decreased in the experimental group.Pro-inflammatory and anti-inflammatory cytokines achieved the maximum and then decreased trend in 14 days,but were higher than the control group(P<0.05).Conclusions Rare earth neodymium oxide particles into the lung tissue of rats,TheNF-?B inflammatory pathways was launched that leading to lung tissue of proinflammatory cytokines and anti-inflammatory cytokines,and protein content undergone significant changes.The levels of type I,III collagen significantly increase in the process of pulmonary fibrosis induced by rare earth neodymium oxide dust in rats,eventually leading to lung injury in rats.