| ?Objective?Using rats staining model,study the intervention effect of Dihydroartemisinin(DHA)on pulmonary fibrosis in silicosis rats and its possible mechanism,and compare the effect of intervention on silicosis in rats with tetrandrine.?Methods?Eighty male Sprague-Dawley rats were randomly divided into 4 groups: control group,model group,dihydroartemisinin group,and tetrandrine group,20 rats in each group.The blank control group was not stained with dust,model group,DHA group and tetrandrine group.A silica-induced rat staining model was established using a non-exposure intratracheal infusion method.The drug was administered to the stomach the next day after the dusting.The DHA group was given DHA 75 mg/kg every day,and the tetrandrine group was given tetrandrine 22 mg/kg daily.The model group and the control group were given an equal volume of 0.9% normal saline,administered 6 days a week for 3 months,and a detailed observation of the general condition of the rats.And the rats were sacrificed in batches on the7 th day,14 days,28 days,and 3 months after the modeling.The lung tissues of the rats were taken.The pathological changes of the rats were observed by HE staining and Masson staining.The lung tissue was detected for hydroxyproline.ELISA was used to detect transforming growth factor-?1(TGF-?1),tumor necrosis factor-?(TNF-?),and human ?smooth muscle actin(?-SMA),interleukin-6(1L-6),Smad2/3 in lung tissue of rats at different time points,detection the protein expression of TGF-?1,Col-?,Smad2/3 in rat lung tissue by immunohistochemistry.The expression levels of TGF-?1,TNF-?,Col-? and Smad2/3 in rat lung tissues were determined by Western blot.?Results?1 Pathological examination of lung tissue The results of HE staining showed that the whole lung tissue of the control group was basically normal at each time point,the lung tissue structure was clear,the alveolar structure was intact,the alveolar has no obvious atrophy and expansion,and the lung interval was normal.On the 7th day,the lung tissue of the model group showed hyperemia,thickened alveolar wall,and inflammatory cell infiltration in the alveolar space and interstitial lung.On the 14 th day,there were a large number of inflammatory cell infiltration in the alveolar cavity and interstitial lung of the model group,and the alveolar wall thickened obviously,and the local alveoli began to fuse.On the 28 th day,the alveolar structure of the model group was destroyed,the alveolar wall interval was thickened,and the amount of inflammatory cell infiltration was significantly increased.In the 3 months model group,fibrous nodules were seen in the lung tissue,most of the alveoli disappeared,and the alveolar structure was severely damaged.Compared with the model group,the damage of lung tissue in rats treated with DHA and tetrandrine was improved,and the inflammatory cells in the alveolar cavity and interstitial lung were decreased.Masson staining showed that the alveolar structure of the lung tissue in the control group was clear and complete at each time point,and no obvious blue collagen fiber deposition.On the 7th day,a small amount of collagen fibers appeared in the alveolar of the model group.On the 14 th day,there were many blue collagen fibers deposited in the alveolar of the rats,and the alveolar wall was thickened.On the 28 th day,more blue collagen fibers were deposited.Rats has obvious sputum nodules,and there was a large amount of blue collagen fibers deposited in the alveolar,and collagen fiber deposition was reduced compared with the model group after DHA and tetrandrine treatment.2 Detection of HYP content in rats in each group Compared with the control group,the content of HYP in DHA group,tetrandrine group and model group increased,the difference was statistically significant(P<0.05).Combined with Masson staining,the rat model of dyeing was successful.Compared with the model group,the HYP content in the lung tissue of DHA and tetrandrine group was decreased(P<0.05),but there was no significant difference in the content of hydroxyproline between DHA group and tetrandrine group(P>0.05).3 Changes of TGF-?1,?-SMA,TNF-?,1L-6 and Smad2/3 in lung tissue of rats in each group Compared with the control group,the levels of TGF-?1,?-SMA,TNF-?,1L-6 and Smad2/3 in the lung tissue of DHA group,tetrandrine group and model group were increased,the difference was statistically significant(P<0.05).Compared with the model group,the levels of TGF-?1,?-SMA,TNF-?,1L-6,Smad2/3 in the lung tissue of DHA and tetrandrine group were decreased,the difference was statistically significant(P<0.05),but there was no significant difference in the levels of inflammatory markers between the DHA and tetrandrine group(P>0.05). 4 Expression of Smad2/3,TNF-?,TGF-?1,Col-? protein in lung tissue of rats in each group Compared with the control group,the expression levels of Smad2/3,TNF-?,TGF-?1 and Col-? protein in DHA group,tetrandrine group and model group were increased,the difference was statistically significant(P<0.01).Compared with the model group,the expression levels of Smad2/3,TNF-?,TGF-?1,and Col-? protein in DHA group and tetrandrine group were decreased,the difference was statistically significant(P<0.01),but there was no significant difference in the expression of Smad2/3,TNF-?,TGF-?1 and Col-? between the the DHA and tetrandrine group(P>0.05).?Conclusions?1 A non-exposure intratracheal infusion method was used to establish a silica-induced rat silicosis model,which resulted in lung tissue damage in rats,which in turn promoted the development and progression of pulmonary fibrosis.After DHA intervention,the level of inflammatory factors in the lung tissue of silicosis rats was reduced,thereby reducing the degree of lung tissue damage in silicosis rats.2 DHA can inhibit the release of fibrogenic factor TGF-?1 in the lung tissue of rats exposed to silica,reduce the expression of Smad2/3 protein in the lung tissue of silicosis rats.It blocks the TGF-?1/Smad signaling pathway and inhibits the occurrence and development of pulmonary fibrosis.3 There was no significant difference in the therapeutic effect between DHA and tetrandrine during the three-month treatment period.This may be related to the dose of dihydroartemisinin designed in this experiment,which needs further verification.We will increase the dosage of dihydroartemisinin in the later experiments,and further observe the therapeutic effect of dihydroartemisinin and tetrandrine,and provide new research ideas for clinical diagnosis and treatment of silicosis. |
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