The Mechanism Of Berberine Mediating Autophagy In Regulating 1,3-β-glucan-induced Lung Inflammation

Objective : 1,3-β-glucan is the main component of fungal cell wall,accounting for more than 50 % of fungal cell wall.Therefore,1,3-β-glucan induced pulmonary inflammation model was used to study fungal exposure induced hypersensitivity pneumonitis.Autophagy is a highly conserved intracellular degradation and energy recycling mechanism that helps maintain cell homeostasis.Berberine is an isoquinoline alkaloid isolated from coptis chinensis and other plants.It has a wide range of pharmacological properties and can be used to treat a variety of diseases,such as inflammation.At the same time,berberine,as an autophagy regulator,can affect the occurrence and development of diseases by mediating autophagy,so as to achieve the purpose of alleviating diseases.In conclusion,based on the above assumptions,this study established a lung inflammation model with 1,3-β-glucan,and on this basis was treated with berberine to explore whether berberine could mediate autophagy and then play a positive role in lung inflammation induced by 1,3-β-glucan.Methods : In this study,healthy male C57BL/6 mice were randomly divided into 4groups according to body weight.All mice were anesthetized by intraperitoneal injection of pentobarbital sodium.Mice in the experimental group were instillated with 50 μl 1,3-β-glucan suspension to establish pulmonary inflammation model.At the same time,control mice were given 50 μl sterile saline.One day after the establishment of the model,berberine suspension was injected intraperitoneally,and the injection frequency was once a day and once every two days,respectively.At 3 and 28 days after the establishment of the model,mice were killed and lung tissue and bronchoalveolar lavage fluid were collected.Giemsa staining counted the number of inflammatory cells in the bronchoalveolar lavage fluid.The pathological changes of lung tissue were observed by HE staining and Masson staining.The expression and secretion of inflammatory cytokines in lung tissue and bronchoalveolar lavage fluid were detected by Realtime PCR and ELISA.LDH kit was used to detect lactic dehydrogenase secretion in lung tissue.The number of autophagosomes in lung tissue was detected by transmission electron microscopy.The expression level of autophagy related proteins in lung tissues was detected by Western Blot.The expression and localization of autophagy related proteins in lung tissue were observed by immunofluorescence staining.Results : 1.1,3-β-glucan can induce the increase of inflammatory cells in mouse BALF,and berberine treatment can reduce the number of inflammatory cells in BALF.2.1,3-β-glucan can induce inflammatory related pathological changes in mouse lung tissue,such as the accumulation of inflammatory cells,and the degree of inflammatory related pathological changes in mouse lung tissue was reduced after berberine treatment.3.1,3-β-glucan can induce the production of blue collagen in mouse lung tissue,and the level of collagen deposition in mouse lung tissue is reduced after berberine treatment.4.1,3-β-glucan can induce the increase of inflammatory cytokine gene expression level in mouse lung tissue,and berberine treatment can reduce the inflammatory cytokine gene expression level in mouse lung tissue.5.1,3-β-glucan can induce increased secretion of inflammatory cytokines in mouse lung tissue,and berberine treatment can reduce the secretion of inflammatory cytokines in mouse lung tissue.6.1,3-β-glucan can induce increased lactic dehydrogenase secretion in lung tissue,while berberine treatment can reduce lactic dehydrogenase secretion in lung tissue.7.Berberine can reduce the number of lung autophagosomes induced by 1,3-β-glucan.8.Berberine can significantly reduce the expression levels of 1,3-β-glucan-induced autophagy related proteins LC3 and P62,and increase the expression level of LAMP1.9.1,3-β-glucan can cause the fusion of the autophagosome and lysosome,and berberine reverses this phenomenon caused by 1,3-β-glucan.Conclusion : 1.Berberine can inhibit the progression of 1,3-β-glucan-induced lung inflamamtion.2.Berberine inhibit 1,3-β-glucan-induced lung inflammation through facilitating autophagy.