Protective Effect Of Nintedanib On Radiation-induced Pneumonitis

The first part:The effect of Nintedanib on the levels of serum IL-1,IL-6,TNF-α,TGF-β1,FGF-2 and histopathology in radiation-induced pneumonia miceObjective: To investigate the effect of Nintedanib on the levels of serum IL-1,IL-6,TNF-α,TGF-β1,and FGF-2 in radiation-induced pneumonia mice and its influence on histopathology.Methods: Sixty SPF-class C57BL/6 male mices were randomly divided into blank control group,glucocorticoid group,high-dose group,and low-dose group,with 15 mices in each group.Each mouse was given a single 20 Gy right lung irradiation,and the administration was started 2 h after the end of irradiation.The blank control group was given normal saline by gavage,the glucocorticoid group was given dexamethasone 2.4 mg/kg by gavage,and the high-dose group and low-dose group were given Nintedanib 60 mg/kg and 30 mg/kg by gavage,once /d for 4 weeks.The mice were sacrificed 4 weeks later,and the serum levels of IL-1β,IL-6,TNF-α,TGF-β1,and FGF-2 were detected by ELISA.The survival time of mice in each group was compared,Kaplan-Meier survival curve was drawn and Log rank test was performed.One mouse in each group was randomly selected to take the right lung tissue and perform HE staining and Masson staining to observe its inflammation,collagen deposition and fibrosis.Result: After intervention with Nintedanib,the serum levels of IL-1β,IL-6,TNF-α,TGF-β1,and FGF-2 in the high-dose group were lower than those in the blank control group,and the difference were statistically significant(P<0.05).The levels of serum IL-6,TNF-α,TGF-β1,and FGF-2 in the low-dose group were lower than those in blank control group,and the difference were statistically significant(P<0.05).The serum levels of IL-1β,IL-6,TNF-α,and FGF-2 in the high-dose group were lower than those in the glucocorticoid group(P<0.05);the serum IL-6 and FGF-2 levels in the low-dose group were lower than the glucocorticoid group(P<0.05).The survival time of mice in the high-dose group,low-dose group and glucocorticoid group were(27.62±2.54)d,(25.73±3.09)d,(24.65±3.16)d,which were longer than(21.62±3.42)d in blank control group,the difference were statistically significant(P<0.05).The survival time of mice in high-dose group was longer than those of low-dose group and glucocorticoid group(P<0.05).There was no significant difference in survival time between the glucocorticoid group and the low-dose group(P>0.05).Conclusion: High-dose Nintedanib can reduce the levels of IL-1β,IL-6,TNF-α,TGF-β1,and FGF-2 in the serum of mice,prolong the survival time of mice,and the effect was better than the glucocorticoid group.Low-dose Nintanib can reduce the levels of serum IL-6 and FGF-2 in mice,and the effect was better than the glucocorticoid group.Pathological sections showed that inflammatory cell infiltration,edema,and alveolar wall thickening in the high-dose group were less than those in the blank control group and glucocorticoid group.The second part: Study on the effect of Nintedanib on TGF-β1-Smad2/3 signal pathway in radiation pneumonia miceObjective: To explore the effect of Nintedanib on the expression of Smad2 and Smad3 protein in the lung tissue of mice with radiation pneumoniaMethods: Sixty SPF-class C57BL/6 male mices were randomly divided into blank control group,glucocorticoid group,high-dose group,low-dose group,with 15 mices in each group.Each mouse was irradiated with a single 20 Gy right lung.The administration started 2 hours after the end of irradiation.The blank control group was given normal saline by gavage,the glucocorticoid group was given dexamethasone 2.4 mg/kg by gavage,and the high-dose group and low-dose group were given Nintedanib 60 mg/kg,30 mg/kg by gavage once daily for 4 weeks.After 4weeks,the mice in each group were sacrificed,and the expression of Smad2 and Smad3 protein in the right lung tissue was detected by Western Blot method.Result: The expression levels of Smad2 and Smad3 protein in lung tissue of mice in high-dose group were lower than those in glucocorticoid group and blank control group(P<0.05),while the levels of Smad2 and Smad3 protein in low-dose group were not significantly different than those in glucocorticoid group and blank control group(P>0.05).Conclusion: The expression levels of Smad2 and Smad3 protein in lung tissue of mice in high-dose group were lower than those in glucocorticoid group and blank control group,suggesting that Nintedanib could inhibit the expression of Smad2 and Smad3 protein in lung tissue of mice with radiation pneumonia,reduce the level of downstream inflammatory factors,alleviate inflammation and oxidative stress,and alleviate RIP.