Acute lung injury(ALI)linked to sepsis has a high mortality rate,with limited treatment options available.In recent studies,medical ozone has shown the potential to alleviate inflammation and infection.Here,we aimed t...Acute lung injury(ALI)linked to sepsis has a high mortality rate,with limited treatment options available.In recent studies,medical ozone has shown the potential to alleviate inflammation and infection.Here,we aimed to evaluate therapeutic potential of medical ozone in a mouse model of the sepsis-induced ALI by measuring behavioral assessments,lung function,and blood flow.Protein levels were quantified by Western blotting.In vitro,we performed experiments on bone marrow-derived macrophages(BMDMs)to investigate the effect of adenosine monophosphate(AMP)-activated protein kinase(AMPK)inhibitors and agonists on their phagocytic activity.The results showed that medical ozone significantly improved the survival rate,ameliorated lung injury,and enhanced lung function and limb microcirculation in mice with ALI.Notably,medical ozone inhibited the formation of neutrophil extracellular traps(NETs),a crucial factor in the ALI development.Additionally,medical ozone counteracted the elevated levels of tissue factor,matrix metalloproteinase-9,and interleukin-1β.In the ALI mice,the effects of ozone were abolished,and BMDMs showed an impaired capacity to engulf NETs following the Sr-a1 knockout.Under normal physiological conditions,the administration of an AMPK antagonist showed similar effects on the Sr-a1 knockout,significantly inhibiting the phagocytosis of NETs by BMDMs.In contrast,AMPK agonists enhanced this phagocytic process.In conclusion,medical ozone may alleviate the sepsis-induced lung injury through the AMPK/SR-A1 pathway,thereby enhancing the phagocytosis of NETs by macrophages.展开更多
Macrophage death in advanced atherosclerosis promotes plaque necrosis and destabilization.Involvement of autophagy in bulk degradation of cellular components has been recognized recently as an important mechanism for ...Macrophage death in advanced atherosclerosis promotes plaque necrosis and destabilization.Involvement of autophagy in bulk degradation of cellular components has been recognized recently as an important mechanism for cell survival under endoplasmic reticulum（ER） stress.We previously found that the engagement of class A scavenger receptor（SR-A） triggered JNK-dependent apoptosis in ER-stressed macrophages.However,pro-apoptotic mechanisms mediated by SR-A are not fully understood.Therefore,we sought to see if SR-A mediated apoptosis was associated with autophagy in macrophages.Here,we showed that fucoidan inhibited microtubule-associated protein light chain 3-phospholipid conjugates（LC3-Ⅱ） formation as well as the number of autophagosomes under ER stress.The inhibition of LC3-Ⅱ formation was paralleled by the activation of the mTOR pathway,and the inhibition of mTOR allowed LC3-Ⅱ induction in macrophages treated with thapsigargin plus fucoidan.Furthermore,apoptosis induced by fucoidan was prevented under ER stress by the mTOR inhibitor.We propose that fucoidan,a SR-A agonist,may contribute to macrophage apoptosis during ER stress by inhibiting autophagy.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.82271252,82204542,and 81971047)the Lianyungang Science and Technology Program Project(Grant Nos.SF2122 and SF2214)+2 种基金the Scientific Research Project of Jiangsu Provincial Health Commission(Grant No.Z2021066)the Natural Science Foundation of the Jiangsu Higher Education Institutions of China(Grant No.21KJB310019)the Open Project of Jiangsu Province Key Laboratory of Anesthesiology,Xuzhou Medical University(Grant No.XZSYSKF2021014).
文摘Acute lung injury(ALI)linked to sepsis has a high mortality rate,with limited treatment options available.In recent studies,medical ozone has shown the potential to alleviate inflammation and infection.Here,we aimed to evaluate therapeutic potential of medical ozone in a mouse model of the sepsis-induced ALI by measuring behavioral assessments,lung function,and blood flow.Protein levels were quantified by Western blotting.In vitro,we performed experiments on bone marrow-derived macrophages(BMDMs)to investigate the effect of adenosine monophosphate(AMP)-activated protein kinase(AMPK)inhibitors and agonists on their phagocytic activity.The results showed that medical ozone significantly improved the survival rate,ameliorated lung injury,and enhanced lung function and limb microcirculation in mice with ALI.Notably,medical ozone inhibited the formation of neutrophil extracellular traps(NETs),a crucial factor in the ALI development.Additionally,medical ozone counteracted the elevated levels of tissue factor,matrix metalloproteinase-9,and interleukin-1β.In the ALI mice,the effects of ozone were abolished,and BMDMs showed an impaired capacity to engulf NETs following the Sr-a1 knockout.Under normal physiological conditions,the administration of an AMPK antagonist showed similar effects on the Sr-a1 knockout,significantly inhibiting the phagocytosis of NETs by BMDMs.In contrast,AMPK agonists enhanced this phagocytic process.In conclusion,medical ozone may alleviate the sepsis-induced lung injury through the AMPK/SR-A1 pathway,thereby enhancing the phagocytosis of NETs by macrophages.
基金supported by the National Basic Research Program(973) Grant(No.2012CB517503 and No.2011CB503903)National Natural Science Foundation of China(No.81230070 and No. 81070120) to Qi Chen+1 种基金the National Natural Science Foundation of China Grant(No.81000118) to Jingjing Benthe National Natural Science Foundation of China Grant(No.81100857) to Xiaoyu Li
文摘Macrophage death in advanced atherosclerosis promotes plaque necrosis and destabilization.Involvement of autophagy in bulk degradation of cellular components has been recognized recently as an important mechanism for cell survival under endoplasmic reticulum（ER） stress.We previously found that the engagement of class A scavenger receptor（SR-A） triggered JNK-dependent apoptosis in ER-stressed macrophages.However,pro-apoptotic mechanisms mediated by SR-A are not fully understood.Therefore,we sought to see if SR-A mediated apoptosis was associated with autophagy in macrophages.Here,we showed that fucoidan inhibited microtubule-associated protein light chain 3-phospholipid conjugates（LC3-Ⅱ） formation as well as the number of autophagosomes under ER stress.The inhibition of LC3-Ⅱ formation was paralleled by the activation of the mTOR pathway,and the inhibition of mTOR allowed LC3-Ⅱ induction in macrophages treated with thapsigargin plus fucoidan.Furthermore,apoptosis induced by fucoidan was prevented under ER stress by the mTOR inhibitor.We propose that fucoidan,a SR-A agonist,may contribute to macrophage apoptosis during ER stress by inhibiting autophagy.
