Pertussis toxin in involves the development of interstitial lung disease in an experimental autoimmune myositis mice modelby inducing the formation of neutrophil extracellular traps / 中华风湿病学杂志

ABSTRACT

Objective:To test the hypothesis that Pertussis toxin (PTX) can promote the occurrence of interstitial lung disease (ILD) in experimental autoimmune myositis (EAM) model and clarify the potential pathogenic mechanism.Methods:EAM mice model were induced by Skeletal muscle thomogenate with or without PTX, and the relationship between ILD phenotypes and neutrophil extracellular traps (NETs) infiltration was analyzed by histopathological and serological studies in EAM with PTX group and EAM without PTX group. Healthy mice were given PTX alone intraperitoneally to clarify whether NETs formation could be induced in vivo, and neutrophils separated from healthy human blood were intervened with PTX to induce NETs formation in vitro. The data was tested for normality using Shapiro-Wilk. Statistical methods and were analyzed using t-test or ANOVA, and multiple comparisons between different groups were tested using Tukey test. Results:Compared with EAM without PTX group, lung tissues in EAM with PTX group had multiple pathological changes similar to polymyositis/dermatomyositis-related ILD. Nonspecific interstitial pneumonia and usual interstitial pneumonia were the main pathological types. The pulmonary interstitial lesions were accompanied by significant infiltration of NETs; and serum NETs markers levels were obviously elevated in EAM with PTX group, compared with the control group [ n=5, (87±10) ng/ml], cfDNA levels were statistically significantly elevated in both the EAM without PTX group [ n=4, (115±27) ng/ml] and the EAM with PTX group [ n=7, (150±50) ng/ml] ( F=4.24, P=0.038); Cit-H3-DNA levels were elevated in the EAM without PTX group ( n=4, 0.24±0.09), and in the EAM EAM with PTX group ( n=6, 0.33±0.11) compared with the control group ( n=4, 0.13±0.02) ( F=6.21, P=0.016). After PTX intervention, serum cfDNA levels were higher in the PTX group [ n=3, (100±40) ng/ml] than in the control group [ n=3, (45±12) ng/ml, t=2.27, P=0.086]; PTX also induced neutrophils to form NETs in vitro. Conclusion:PTX may promote the development of ILD in EAM mice model by inducing the formation of NETs, indicating that EAM mice can serve as a model for targeting NETs to study the pathogenesis ILD.