Resolvin D1 Induces mTOR-independent and ATG5-dependent Autophagy in BV-2 Microglial Cells

Objective The activation state of microglia is known to occupy a central position in the pathophysiological process of cerebral inflammation.Autophagy is a catabolic process responsible for maintaining cellular homeostasis.In recent years,autophagy has been demonstrated to play an important role in neuroinflammation.Resolvin D1(RvD1)is a promising therapeutic mediator that has been shown to exert substantial anti-inflammatory and proresolving activities.However,whether RvD1-mediated resolution of inflammation in microglia is related to autophagy regulation needs further investigation.The present study aimed to explore the effect of RvD1 on microglial autophagy and its corresponding pathways.Methods Mouse microglial cells(BV-2)were cultured,treated with RvD1,and examined by Western blotting,confocal immunofluorescence microscopy,transmission electron microscopy,and flow cytometry.Results RvD1 promoted autophagy in both BV-2 cells and mouse primary microglia by favoring the maturation of autophagosomes and their fusion with lysosomes.Importantly,RvD1 had no significant effect on the activation of mammalian target of rapamycin(mTOR)signaling.Furthermore,RvD1-induced mTOR-independent autophagy was confirmed by observing reduced cytoplasmic calcium levels and suppressed calcium/calmodulin-dependent protein kinase II(CaMK II)activation.Moreover,by downregulating ATG5,the increased phagocytic activity induced by RvD1 was demonstrated to be tightly controlled by ATG5-dependent autophagy.Conclusion The present work identified a previously unreported mechanism responsible for the role of RvD1 in microglial autophagy,highlighting its therapeutic potential against neuroinflammation.

Overview of point-of-care ultrasound in diagnosing intestinal obstruction

Intestinal obstruction(IO),which refers to a partial or complete blockage of the intestine,is an emergency gastrointestinal disorder commonly seen in the intensive care unit(ICU)and emergency department and associated with high morbidity and mortality.[1,2]Common etiologies of IO include adhesions,hernias,intussusception,foreign bodies,ischemia,tumors,etc.Delay in the diagnosis and management of IO is associated with higher mortality due to complications such as bowel necrosis,perforation,sepsis,and septic shock.[3]IO can be divided into small bowel obstruction(SBO)and colonic obstruction(CO).In SBO,74%of cases are caused by adhesions,which may respond to conservative management.It is critical to identify which of those cases may progress and require emergent surgical intervention with the help of the diagnostic and assessment tools.In contrast to SBO,most cases of CO demand surgery.In this instance,appropriate assessment tools are required to define the location of the obstruction,which will assist in the proper surgical procedure.[4]

PA-E18G substitution in influenza A virus confers resistance to ZX-7101,a cap-dependent endonuclease inhibitor

Cap-dependent endonuclease(CEN)in the polymerase acidic protein(PA)of influenza A virus(IAV)represents a promising drug target due to its critical role in viral gene transcription.The CEN inhibitor,baloxavir marboxil(BXM),was approved in Japan and the US in 2018 and several other countries subsequently.Along with the clinical use of BXM,the emergence and spread of IAV variants with reduced susceptibility to BXM have aroused serious concern.Herein,we comprehensively characterized the in vitro and in vivo antiviral activities of ZX-7101A,an analogue of BXM.The active form of prodrug ZX-7101 showed broad-spectrum antiviral potency against various IAV subtypes,including pH1N1,H3N2,H7N9 and H9N2,in MDCK cells,and the 50%effective concentration(EC_(50))was calculated to nanomole level and comparable to that of baloxavir acid(BXA),the active form of BXM.Furthermore,in vivo assays showed that administration of ZX-7101A conferred significant protection against lethal pH1N1 challenge in mice,with reduced viral RNA loads and alleviated pulmonary damage.Importantly,serial passaging of H1N1 virus in MDCK cells under selection pressure of ZX-7101 led to a resistant variant at the 15th passage.Reverse genetic and sequencing analysis demonstrated that a single E18G substitution in the PA subunit contributed to the reduced susceptibility to both ZX-7101 and BXA.Taken together,our results not only characterized a new CEN inhibitor of IAV but also identified a novel amino acid substitution responsible for CEN inhibitor resistance,which provides critical clues for future drug development and drug resistance surveillance.