Emerging evidences have indicated the role of ferroptosis in the progression of metabolic-associated fatty liver disease (MAFLD); thus, inhibiting ferroptosis is a promising strategy for the development of MAFLD therapeutics. Recent studies have demonstrated the antioxidative effect of the gut commensal bacterium Akkermansia muciniphila (A. muc); however, whether it can alleviate ferroptosis remains unclear. The current study indicates A. muc intervention efficiently reversed high-fat high-fructose diet (HFHFD)-induced lipid peroxidation and ferroptosis in the liver. These beneficial effects were mediated by activation of the hepatic AMPK/SIRT1/PGC-1α axis, as evidenced by the finding that AMPK deficiency abrogated the amelioration of lipid peroxidation in vitro and in vivo. Furthermore, the short-chain fatty acids (SCFAs) were enriched upon A. muc treatment, and acetate was identified as a key activator of hepatic AMPK signalling. Mechanistically, microbiota-derived acetate was transported to the liver and metabolized to adenosine monophosphate (AMP), which triggered AMPK activation. Furthermore, a colonization assay in germ-free mice confirmed that A. muc mediated antiferroptotic effects in the absence of other microbes. These data indicated that A. muc exerts antiferroptotic effects against MAFLD, at least partially by producing acetate, which activates the hepatic AMPK/SIRT1/PGC-1α axis to alleviate ferroptosis via the inhibition of polyunsaturated fatty acid (PUFA) synthesis.

Objective:To investigate the essential determinants that are critical to initiating the assembly of outer membrane proteins by replacing the POTRA domains of the translocator protein FhaC and the insertase protein TtOmp85 of the Omp85 family. Methods:FhaC, TtOmp85 proteins and their recombinant chimeric proteins after replacing the POTRA domain were obtained by overexpression and purification in vitro. An in vitro reconstitution system was used to investigate the effects of the different domains on the transport efficiency of the substrate outer membrane protein FhaB and the membrane insertion efficiency of OmpA. Results:Replacing the POTRA domain of FhaC with that of TtOmp85 led to the loss of the transport function of FhaB. During the membrane insertion process of OmpA, the FhaC mutant containing the POTRA of TtOmp85 protein acquired the ability to assemble OmpA. Conclusion:The compositional differences in the POTRA domain of Omp85 family proteins determine their abilities to recognize their substrate proteins.

Objective To observe the depressive behavior and neuronal damage induced by different doses of corticosterone(CORT)in mice,and to explore the optimal dose for a corticosterone-induced depression model in mice.Methods Forty male C57BL/6J mice were divided randomly into four groups:control group and low,medium,and high CORT groups(20,40,and 60 mg/kg,respectively),treated with the corresponding drug dose by subcutaneous injection for 4 weeks.Behavioral c hanges in mice after corticosterone administration for 3 and 4 weeks were detected by sugar water preference,forced swimming,tail suspension,and open field tests.Morphological changes in neurons in the hippocampal CA1 area and forebrain cortex area were observed by hematoxylin-eosin(HE)and Nissl staining.Serum levels of 5-hydroxytryptamine(5-HT)were detected by enzyme-linked immunosorbent assay.Depression-related behavioral changes induced by different doses of corticosterone were compared.Results The bodyweights of mice in all three CORT groups(20,40,and 60 mg/kg)decreased(P＜0.05)and the preference for sucrose solution decreased(P＜0.01)compared with the findings in the control group.The immobility time in the forced swimming test was prolonged in the CORT 20 and 40 mg/kg groups(P＜0.01)and the immobility time of mice in the tail suspension test was prolonged in the CORT 40 mg/kg group(P＜0.05).The total distance,the length of time spent in the peripheral area was prolonged and the time entering the central area in the open-field experiment were decreased in the CORT 40 and 60 mg/kg groups(P＜0.05),and average speed were decreased in the CORT 40 mg/kg group(P＜0.05).In addition,CORT injection result ed in abnormal neuronal cell morphology,cell deformation,and nuclear condensation in the hippocampal CA1 and forebrain cortex areas,to different degrees.Serum 5-hydroxytryptamine levels were reduced in the CORT 40 and 60 mg/kg groups(P＜0.05).Conclusions CORT 20,40,and 60 mg/kg can induce depression-like behavioral changes and neuronal damage in mice to varying degrees,with the most notable effect at 40 mg/kg.Under experimental conditions,we consider that 40 mg/kg is the best dose for replicating corticosterone-induced depression in model mice.

Objective To observe the depressive behavior and neuronal damage induced by different doses of corticosterone(CORT)in mice,and to explore the optimal dose for a corticosterone-induced depression model in mice.Methods Forty male C57BL/6J mice were divided randomly into four groups:control group and low,medium,and high CORT groups(20,40,and 60 mg/kg,respectively),treated with the corresponding drug dose by subcutaneous injection for 4 weeks.Behavioral c hanges in mice after corticosterone administration for 3 and 4 weeks were detected by sugar water preference,forced swimming,tail suspension,and open field tests.Morphological changes in neurons in the hippocampal CA1 area and forebrain cortex area were observed by hematoxylin-eosin(HE)and Nissl staining.Serum levels of 5-hydroxytryptamine(5-HT)were detected by enzyme-linked immunosorbent assay.Depression-related behavioral changes induced by different doses of corticosterone were compared.Results The bodyweights of mice in all three CORT groups(20,40,and 60 mg/kg)decreased(P＜0.05)and the preference for sucrose solution decreased(P＜0.01)compared with the findings in the control group.The immobility time in the forced swimming test was prolonged in the CORT 20 and 40 mg/kg groups(P＜0.01)and the immobility time of mice in the tail suspension test was prolonged in the CORT 40 mg/kg group(P＜0.05).The total distance,the length of time spent in the peripheral area was prolonged and the time entering the central area in the open-field experiment were decreased in the CORT 40 and 60 mg/kg groups(P＜0.05),and average speed were decreased in the CORT 40 mg/kg group(P＜0.05).In addition,CORT injection result ed in abnormal neuronal cell morphology,cell deformation,and nuclear condensation in the hippocampal CA1 and forebrain cortex areas,to different degrees.Serum 5-hydroxytryptamine levels were reduced in the CORT 40 and 60 mg/kg groups(P＜0.05).Conclusions CORT 20,40,and 60 mg/kg can induce depression-like behavioral changes and neuronal damage in mice to varying degrees,with the most notable effect at 40 mg/kg.Under experimental conditions,we consider that 40 mg/kg is the best dose for replicating corticosterone-induced depression in model mice.

Objective:To investigate the essential determinants that are critical to initiating the assembly of outer membrane proteins by replacing the POTRA domains of the translocator protein FhaC and the insertase protein TtOmp85 of the Omp85 family. Methods:FhaC, TtOmp85 proteins and their recombinant chimeric proteins after replacing the POTRA domain were obtained by overexpression and purification in vitro. An in vitro reconstitution system was used to investigate the effects of the different domains on the transport efficiency of the substrate outer membrane protein FhaB and the membrane insertion efficiency of OmpA. Results:Replacing the POTRA domain of FhaC with that of TtOmp85 led to the loss of the transport function of FhaB. During the membrane insertion process of OmpA, the FhaC mutant containing the POTRA of TtOmp85 protein acquired the ability to assemble OmpA. Conclusion:The compositional differences in the POTRA domain of Omp85 family proteins determine their abilities to recognize their substrate proteins.

Idiopathic pulmonary fibrosis （IPF）， as a progressive lung disease， has a poor prognosis and no reliable and effective therapies. IPF is mainly treated by organ transplantation and administration of chemical drugs， which are ineffective and induce side effects， failing to meet the clinical needs. Therefore， developing safer and more effective drugs has become an urgent task， which necessitates clear understanding of the pathogenesis of IPF. The available studies about the pathogenesis of IPF mainly focus on macrophage polarization， epithelial-mesenchymal transition （EMT）， oxidative stress， and autophagy， while few studies systematically explain the principles and links of the pathogeneses. According to the traditional Chinese medicine theory， Qi deficiency and blood stasis and Qi-Yang deficiency are the key pathogeneses of IPF. Therefore， the Chinese medicines or compound prescriptions with the effects of replenishing Qi and activating blood， warming Yang and tonifying Qi， and eliminating stasis and resolving phlegm are often used to treat IPF. Modern pharmacological studies have shown that such medicines play a positive role in inhibiting macrophage polarization， restoring redox balance， inhibiting EMT， and regulating cell autophagy. However， few studies report how Chinese medicines regulate the pathways in the treatment of IPF. By reviewing the latest articles in this field， we elaborate on the pathogenesis of IPF and provide a comprehensive overview of the mechanism of the active ingredients or compound prescriptions of Chinese medicines in regulating IPF. Combining the pathogenesis of IPF with the modulating effects of Chinese medicines， we focus on exploring systemic treatment options for IPF， with a view to providing new ideas for the in-depth study of IPF and the research and development of related drugs.

Objective:To screen active antibacterial components from licorice extract using BamA and BamD, the core components of Escherichia coli ( E. coli) β-barrel assembly machinery (BAM), as targets in order to combat the increasingly serious problem of antibiotic resistance. Methods:Affinity ultrafiltration combined with high performance liquid chromatography-mass spectrometry (HPLC-MS) was used to screen the potential components interacting with BamA and BamD from licorice extract. Changes in the expression of bamA and bamD genes of E. coli after treatment with the compounds were detected by fluorescence quantitative PCR, and the effects of the compounds on the function of the BAM complex to integrate outer membrane proteins into the bacterial outer membrane were analyzed using an in vitro recombination system. The influence of the compounds on the integrity of bacterial membranes was evaluated through analyzing the accumulation of SDS within the bacterial cells. Results:Bioaffinity ultrafiltration combined with HPLC-MS screening revealed that 18β-glycyrrhetinic acid could interact with BamD. After 18β-glycyrrhetinic acid treatment, the expression of bamA gene increased by 1.5 times, and the expression of bamD gene increased by 2 times. However, the inhibitory effect of 18β-glycyrrhetinic acid on the membrane insertion function of the BAM complex was not observed in the in vitro recombinant system assay, and the cell membrane integrity assay experiments did not reveal any disruption of the E. coli cell membrane by 18β-glycyrrhetinic acid. Conclusions:Using BamA and BamD proteins as targets, a natural product screening method using affinity ultrafiltration combined with HPLC-MS is established. The screening result shows that 18β-glycyrrhetinic acid can interact with BamD and affect the expression of outer membrane proteins in E. coli. Therefore, the screening and experimental procedures established in this study are of good reference value for the screening of novel antimicrobial drugs from other sources targeting outer membrane proteins, and this study also suggests that the selection of the relevant target sites is crucial for the successful screening of the corresponding natural products.

Looking retrospectively at the development of humanity, vaccination is an unprecedented medical landmark that saves lives by harnessing the human immune system. During the ongoing coronavirus disease 2019 (COVID-19) pandemic, vaccination is still the most effective defense modality. The successful clinical application of the lipid nanoparticle-based Pfizer/BioNTech and Moderna mRNA COVID-19 vaccines highlights promising future of nanotechnology in vaccine development. Compared with conventional vaccines, nanovaccines are supposed to have advantages in lymph node accumulation, antigen assembly, and antigen presentation; they also have, unique pathogen biomimicry properties because of well-organized combination of multiple immune factors. Beyond infectious diseases, vaccine nanotechnology also exhibits considerable potential for cancer treatment. The ultimate goal of cancer vaccines is to fully mobilize the potency of the immune system as a living therapeutic to recognize tumor antigens and eliminate tumor cells, and nanotechnologies have the requisite properties to realize this goal. In this review, we summarize the recent advances in vaccine nanotechnology from infectious disease prevention to cancer immunotherapy and highlight the different types of materials, mechanisms, administration methods, as well as future perspectives.

Objective To analyze the epidemiological characteristics of aggregative vomiting and diarrhea outbreak in Jing'an District of Shanghai in 2017 and 2018，and provide data support for further development of effective prevention and control measures. Methods A descriptive epidemiological method was used to analyze aggregative vomiting and diarrhea outbreak data in Jing'an District in 2017 and 2018. Results A total of 49 outbreaks were reported in Jing'an District in 2017 and 2018，involving 565 cases，with the overall attack rate of 1.89%. The median duration of the outbreak was 5 days and outbreaks mainly occurred in spring and autumn. The attack rate in kindergartens was higher than that in primary and secondary schools, while the total number of outbreak cases in kindergartens was less. The main clinical symptoms of the cases were vomiting, with a higher proportion than that of diarrhea and fever. The vomiting proportion was higher in kindergartens and elementary schools, while the diarrhea proportion was higher in middle schools. Conclusion There were some differences in the epidemic characteristics between kindergartens and primary and secondary schools, therefore different control measures should be adopted according to the characteristics of different institutions. The outbreaks were mainly spread through human-to-human transmission. Early detection and early reporting of epidemics in collective institutions had a positive impact on the control of the spread of the epidemic.

Ferroptosis is a new programmed cell death characterized by iron dependent and intracellular oxidative accumulation. Current studies have confirmed that ferroptosis is involved in the occurrence and development of neurotoxicity injury, tumors, cardiovascular diseases and other diseases. This paper reviews the mechanisms of ferroptosis and its role in related diseases based on recent studies.