(A) The effect of HSM around the count of LC3B positive cells (total cells, CD45+ leukocytes, alveolar macrophages and interstitial macrophages) in lung tissue, n=10. alveolar macrophages infiltration into the BALF and inhibited their accumulation in the fibrotic lung tissue. Flow cytometry analysis showed that HSM administration inhibited the autophagy marker LC3B expression in CD11bloCD11chi alveolar macrophages in BLM-induced lung fibrosis without affecting CD11bhiCD11clo interstitial macrophages. Transmission electron microscopy and JC-1 staining for mitochondrial membrane potential of alveolar macrophages also verified that this HSM significantly decreased autophagy in the alveolar macrophages of BLM-treated mice. mycelium, pulmonary fibrosis, alveolar macrophage, autophagy, TLR4 signal pathway. Introduction Idiopathic pulmonary fibrosis (IPF), the archetypal fibrotic lung disease, is usually a serious disorder with unknown cause and increasing incidence 1-3. The median survival after diagnosis is usually estimated to be 2-5 years 4, 5. To treat IPF, Pirfenidone and Nintedanib have been included in an update of clinical treatment guidelines in 2015 2. However, these two anti-fibrotic medications are conditionally recommended, and have not been shown to reduce all-cause mortality in sufficiently powered studies 6, 7. A recent conditionally recommended treatment for IPF is usually anti-acid therapy, proton pump inhibitors or histamine-2-receptor antagonists 8. However, the scientific evidence of their potential beneficial effects on survival remains uncertain 9. Thus, treatment strategies for the pathogenesis of IPF are needed. In the studies on effective IPF treatments, mycelium (HSM), which is an asexual stage of reported that an ethanol extract of HSM inhibited transforming growth factor-1 (TGF-1)-induced differentiation of lung fibroblasts into myofibroblasts and reactive oxygen species production in lung epithelial cells 10. Our laboratory also observed that HSM suppressed mTOR activation stimulated by recombinant TGF-1 in A549 cells during fibroblast-myofibroblast trans-differentiation 11. These studies were helpful to analyze the anti-fibrosis therapeutic mechanism of HSM, but the exact cause remains unknown. The bleomycin (BLM)-induced infiltration of inflammatory cells into bronchoalveolar lavage fluid (BALF) was found to be reduced by HSM ethanol extract treatment 10. Interestingly, HSM relieved fibrotic damage, accompanied by a decrease in macrophage counts in our previous studies 11, 15. Hence, it is important to examine whether the HSM effect on pulmonary fibrosis is related to macrophages. Macrophages are the main innate immune cells in the lung tissue 16, and play key functions in the pulmonary fibrosis repair and homeostasis 17. Collagen deposition can be regulated by macrophages, thereby participating in the processing of extracellular matrix 18. Macrophages have been exhibited to participate in regulating the survival of myofibroblasts 19. Importantly, it has been exhibited in a rodent BLM model that pulmonary macrophages could be the predominant source of TGF-, a prominent fibrosis-inducing molecule 20-22. Moreover, patients who developed an accelerated form of fibrotic lung disease were found to have dysregulated alveolar macrophages 23. Some scientists have even suggested that targeting macrophages might have a resolution-promoting role during pulmonary fibrosis 24. Autophagy is a conserved intracellular degradation pathway, and its disruption compromises homeostasis, which leads to pulmonary diseases 25-27. Increased Light Chain 3 (LC3B) expression in alveolar macrophages was observed in IPF patients, suggesting that excessive macrophage autophagy worsened the disease 28. Similarly, autophagy-related proteins, such as Beclin1 and P62, were expressed in macrophages from the fibrosis areas of paraquat-induced pulmonary fibrosis 29. Autophagosomes accumulated in alveolar macrophages of human silicosis, and promoted macrophage activation to induce the development of fibrosis 30, 31. Taken together, these data suggested that macrophage autophagy might play a vital role in pulmonary fibrosis. The current study aimed to investigate the relationship between HSM alleviation of pulmonary fibrosis and macrophage autophagy, as well as the underlying molecular mechanism. The results showed that HSM could effectively inhibit excessive macrophage autophagy in BLM-induced pulmonary fibrosis mouse model, and the TLR4/NF-B signaling pathway was required for HSM effect on macrophage autophagy. Materials and Methods Chemicals and reagents HSM.All animal Gallamine triethiodide experiments were strictly in accordance with the National Institutes of Health (NIH) Guidelines for the Care and Use of Laboratory Animals, and approved by the Institutional Animal Care and Use Committee of Nanjing University (Nanjing, China). increased the protein level of P62 during the development of pulmonary fibrosis. Meanwhile, HSM reduced alveolar macrophages infiltration into the BALF and inhibited their accumulation in the fibrotic lung tissue. Flow cytometry analysis showed that HSM administration inhibited the autophagy marker LC3B expression in CD11bloCD11chi alveolar macrophages in BLM-induced lung fibrosis without affecting CD11bhiCD11clo interstitial macrophages. Transmission electron microscopy and JC-1 staining for mitochondrial membrane potential of alveolar macrophages also verified that the HSM significantly decreased autophagy in the alveolar macrophages of BLM-treated mice. mycelium, pulmonary fibrosis, alveolar macrophage, autophagy, TLR4 signal pathway. Introduction Idiopathic pulmonary fibrosis (IPF), the archetypal fibrotic lung disease, is a serious disorder with unknown cause and increasing incidence 1-3. The median survival after diagnosis is estimated to be 2-5 years 4, 5. To treat IPF, Pirfenidone and Nintedanib have been included in an update of clinical treatment guidelines in 2015 2. However, these two anti-fibrotic medications are conditionally recommended, and have not been shown to reduce all-cause mortality in sufficiently powered studies 6, 7. A recent conditionally recommended treatment for IPF is anti-acid therapy, proton pump inhibitors or histamine-2-receptor antagonists 8. However, the scientific evidence of their potential beneficial effects on survival remains uncertain 9. Thus, treatment strategies for the pathogenesis of IPF are needed. In the studies on effective IPF treatments, mycelium (HSM), which is an asexual stage of reported that an ethanol extract of HSM inhibited transforming growth factor-1 (TGF-1)-induced differentiation of lung fibroblasts into myofibroblasts and reactive oxygen species production in lung epithelial cells 10. Our laboratory also observed that HSM suppressed mTOR activation stimulated by recombinant TGF-1 in Gallamine triethiodide A549 cells during fibroblast-myofibroblast trans-differentiation 11. These studies were helpful to analyze the anti-fibrosis therapeutic mechanism of HSM, but the exact cause remains unknown. The bleomycin (BLM)-induced infiltration of inflammatory cells into bronchoalveolar lavage fluid (BALF) was found to be reduced by HSM ethanol extract treatment 10. Interestingly, HSM relieved fibrotic damage, accompanied by a decrease in macrophage counts in our previous studies 11, 15. Hence, it is important to examine whether the HSM effect on pulmonary fibrosis is related to macrophages. Macrophages are the main innate immune cells in the lung tissue 16, and play key roles in the pulmonary fibrosis repair and homeostasis 17. Collagen deposition can be regulated by macrophages, thereby participating in the processing of extracellular matrix 18. Macrophages have been demonstrated to participate in regulating the survival of myofibroblasts 19. Importantly, it has been demonstrated in a rodent BLM model that pulmonary macrophages could be the predominant source of TGF-, a prominent fibrosis-inducing molecule 20-22. Moreover, patients who developed an accelerated form of fibrotic lung disease were found to have dysregulated alveolar macrophages 23. Some scientists have even suggested that targeting macrophages might have a resolution-promoting role during pulmonary fibrosis 24. Autophagy is a conserved intracellular degradation pathway, and its disruption compromises homeostasis, which leads to pulmonary diseases 25-27. Increased Light Chain 3 (LC3B) expression in alveolar macrophages was observed in IPF patients, suggesting that excessive macrophage autophagy worsened the disease 28. Similarly, autophagy-related proteins, such as Beclin1 and P62, were expressed in macrophages from the fibrosis areas of paraquat-induced pulmonary fibrosis 29. Autophagosomes accumulated in alveolar macrophages of human silicosis, and promoted macrophage activation to induce the development of fibrosis 30, 31. Taken together, these data suggested that macrophage autophagy might play a vital role in pulmonary fibrosis. The current study aimed to investigate the relationship between HSM alleviation of pulmonary fibrosis and macrophage autophagy, as well as the underlying molecular mechanism. The results showed that HSM could effectively inhibit excessive macrophage autophagy in BLM-induced pulmonary fibrosis mouse model, and the TLR4/NF-B signaling pathway was required for HSM effect on macrophage autophagy. Materials and Methods Chemicals and reagents HSM was obtained from Nanjing Zhongke Group (Nanjing, China), and the HSM solution was prepared as previously described 11. BLM was purchased from Hisun Pharmaceutical Co., Ltd. (Zhejiang, China). Chloroquine (CQ), lipopolysaccharide (LPS), collagenase I and collagenase IV were from Sigma (St. Louis, MO, USA). DNase I had been purchased from Roche (Switzerland, UK). Dulbecco’s Modified Eagle’s Medium (DMEM) and Roswell Park Memorial Institute (RPMI) 1640 medium were from Hyclone Laboratories (South Logan, UT, USA). Fetal bovine serum (FBS) was.Level pub: 40 m. Results: First, we found that HSM decreased the number of autophagosomes, as well as the levels of LC3B and ATG5, and improved the protein level of P62 during the development of pulmonary fibrosis. In the mean time, HSM reduced alveolar macrophages infiltration into the BALF and inhibited their build up in the fibrotic lung cells. Flow cytometry analysis showed that HSM administration inhibited the autophagy marker LC3B manifestation in CD11bloCD11chi alveolar macrophages in BLM-induced lung fibrosis without influencing CD11bhiCD11clo interstitial macrophages. Transmission electron microscopy and JC-1 staining for mitochondrial membrane potential of alveolar macrophages also verified the HSM significantly decreased autophagy in the alveolar macrophages of BLM-treated mice. mycelium, pulmonary fibrosis, alveolar macrophage, autophagy, TLR4 transmission pathway. Intro Idiopathic Gallamine triethiodide pulmonary fibrosis (IPF), the archetypal fibrotic lung disease, is definitely a serious disorder with unfamiliar cause and increasing incidence 1-3. The median survival after diagnosis is definitely estimated to be 2-5 years 4, 5. To treat IPF, Pirfenidone and Nintedanib have been included in an upgrade of medical treatment recommendations in 2015 2. However, AKAP12 these two anti-fibrotic medications are conditionally recommended, and have not been shown to reduce all-cause mortality in sufficiently powered studies 6, 7. A recent conditionally recommended treatment for IPF is definitely anti-acid therapy, proton pump inhibitors or histamine-2-receptor antagonists 8. However, the scientific evidence of their potential beneficial effects on survival remains uncertain 9. Therefore, treatment strategies for the pathogenesis of IPF are needed. In the studies on effective IPF treatments, mycelium (HSM), which is an asexual stage of reported that an ethanol draw out of HSM inhibited transforming growth element-1 (TGF-1)-induced differentiation of lung fibroblasts into myofibroblasts and reactive oxygen species production in lung epithelial cells 10. Our laboratory also observed that HSM suppressed mTOR activation stimulated by recombinant TGF-1 in A549 cells during fibroblast-myofibroblast trans-differentiation 11. These studies were helpful to analyze the anti-fibrosis restorative mechanism of HSM, but the precise cause remains unfamiliar. The bleomycin (BLM)-induced infiltration of inflammatory cells into bronchoalveolar lavage fluid (BALF) was found to be reduced by HSM ethanol extract treatment 10. Interestingly, HSM relieved fibrotic damage, accompanied by a decrease in macrophage counts in our earlier studies 11, 15. Hence, it is important to examine whether the HSM effect on pulmonary fibrosis is related to macrophages. Macrophages are the main innate immune cells in the lung cells 16, and play important tasks in the pulmonary fibrosis restoration and homeostasis 17. Collagen deposition can be controlled by macrophages, therefore participating in the processing of extracellular matrix 18. Macrophages have been shown to participate in regulating the survival of myofibroblasts 19. Importantly, it has been shown inside a rodent BLM model that pulmonary macrophages could be the predominant source of TGF-, a prominent fibrosis-inducing molecule 20-22. Moreover, individuals who developed an accelerated form of fibrotic lung disease were found to have dysregulated alveolar macrophages 23. Some scientists have even suggested that focusing on macrophages might have a resolution-promoting part during pulmonary fibrosis 24. Autophagy is definitely a conserved intracellular degradation pathway, and its disruption compromises homeostasis, which leads to pulmonary diseases 25-27. Improved Light Chain 3 (LC3B) manifestation in alveolar macrophages was observed in IPF individuals, suggesting that excessive macrophage autophagy worsened the disease 28. Similarly, autophagy-related proteins, such as Beclin1 and P62, were indicated in macrophages from your fibrosis areas of paraquat-induced pulmonary fibrosis 29. Autophagosomes accumulated in alveolar macrophages of human being silicosis, and advertised macrophage activation to induce the development of fibrosis 30, 31. Taken collectively, these data suggested that macrophage autophagy might play a vital part in pulmonary fibrosis. The current study aimed to investigate the relationship between HSM alleviation of pulmonary fibrosis and macrophage autophagy, as well as the underlying molecular mechanism. The results showed that HSM could efficiently inhibit excessive macrophage autophagy in BLM-induced pulmonary fibrosis mouse model, and the TLR4/NF-B signaling pathway was required for HSM effect on macrophage autophagy. Materials and Methods Chemicals and reagents HSM was acquired.