Objective:To analyze and identify the expression profiles of oxidative stress-related genes and circular RNAs(circRNAs)in ricin toxin(RT)-induced pyroptosis of mouse mononuclear macrophages(RAW264.7)using transcriptome sequencing and bioinformatics technology,and to preliminarily analyze their potential functions.Methods:The macrophages(RAW264.7 cells)were treated with RT to establish a cell pyroptosis model and divided into control group,40 μg·L-1 RT group,and 80 ng/mL RT group.Transmission electron microscope(TEM)was used to observe the morphology of the RAW264.7 cells in various groups;Western blotting method was used to detect the expression levels of the pyroptosis pathway-related proteins in the cells in various groups;80 μg·L-1 RT was selected for subsequent experiments.Transcriptome sequencing(RNA-Seq)was performed to obtain the circRNA and mRNA expression profiles in the RAW264.7 cells in control group and RT-treated group,followed by bioinformatics analysis.Results:Compared with control group,the cells in 40 and 80 μg·L-1 RT groups underwent morphological changes;the cells in RT groups showed obvious pyroptosis-like morphological changes,characterized by significant swelling of dying cells and the appearance of characteristic large bubbles on the plasma membrane.Compared with control group,the expression level of gasdermin DN-terminal fragment(GSDMD-N)protein in 40 and 80 μg·L-1 RT groups was increased(P<0.05);compared with 40 μg·L-1 RT group,the expression level of GSDMD-N protein in the cells in 80 μg·L-1 RT group was increased(P<0.05);therefore,the subsequent experiments used the RT concentration of 80 μg·L-1.A total of 2930 differentially expressed messenger RNAs(mRNAs)and 24 differentially expressed circRNAs were identified.The constructed circRNA-microRNA(miRNA)-mRNA competing endogenous RNA(ceRNA)regulatory network consisted of 7 circRNAs,12 miRNAs and 13 mRNAs.Gene Ontology(GO)functional enrichment analysis showed that in biological process(BP),the functions regulated by differentially expressed genes mainly included immune response and oxidative stress response;in cellular component(CC),differentially expressed genes were mainly localized to the external side of plasma membrane and cell leading edge;in molecular function(MF),they were mainly involved in transporter transmembrane activity and hormone receptor binding.Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway enrichment analysis showed that differentially expressed genes were mainly enriched in Toll-like receptor signaling pathway,Forkhead box O(FoxO)signaling pathway and nuclear factor kappa-light-chain-enhancer of activated B cells(NF-κB)signaling pathway.In the protein-protein interaction(PPI)network,the top 10 hub genes with the highest connectivity were screened by CytoHubba,including matrix metalloproteinase 9(MMP9),superoxide dismutase 2(SOD2),and v-src sarcoma viral oncogene homolog(Src).Conclusion:The expression profiles of oxidative stress-related genes and circRNAs in RAW264.7 cells are altered after RT treatment.The screened differentially expressed circRNAs and mRNAs may serve as potential targets to regulate RT-induced pyroptosis in RAW264.7 cells through oxidative stress pathways.

OBJECTIVE To investigate the roles and mechanisms of γ-bungarotoxin(γ-BGT)in inducing respiratory distress in mice.METHODS Six male Kunming mice were selected and anesthe-tized before tracheal intubation and respiratory recording.After stabilizing respiration,the mice were intraperitoneally injected with γ-BGT at a dose of 6 mg·kg-1.Once a decrease in respiratory frequency was observed,the mice were intravenously injected with nikethamide at a dose of 12.5 mg·kg-1.Respi-ratory frequency was monitored using the BL420 signal acquisition and processing system.Male Kunming mice were randomly divided into the normal control group(saline,ip),γ-BGT group(6 mg·kg-1,ip),and γ-BGT+nikethamide group(γ-BGT 6 mg·kg-1,ip,followed by nikethamide 12.5 mg·kg-1,ip,when shal-low breathing and enhanced abdominal respiration were observed).The levels of Glu and GABA in the medulla oblongata were measured using ELISA.The protein expression levels of GAD65 and GAD67 in the medulla oblongata were determined by Western blotting.Primary mouse medullary neurons were cultured in vitro and divided into the following groups:cell control group,γ-BGT group,carbachol group,gallamine group,γ-BGT+H-89 group,and γ-BGT+Y-27632 group.The γ-BGT group,carbachol group,and gallamine group were incubated with γ-BGT(40 mg·L-1),carbachol(100 mmol·L-1),and gallamine(100 mmol·L-1),respectively,for 4 h.The γ-BGT+H-89 and γ-BGT+Y-27632 groups were pretreated with γ-BGT(40 mg·L-1)for 4 h,followed by incubation with the protein kinase A(PKA)inhibitor H-89(50 mmol·L-1)and the Ca2+channel inhibitor Y-27632(50 mmol·L-1)for another 2 h,respectively.ELISA was used to measure the levels of Glu,GABA,cAMP,and calpain in the primary mouse medul-lary neurons.Western blotting was employed to assess the protein expression levels of GAD65 and GAD67,and PKA phosphorylation levels.Fluo-4 fluorescent probe was used to detect the intracellular Ca2+level.RESULTS The respiratory rate of mice significantly decreased after iv administration of γ-BGT(γ-BGT group)(P<0.05).After treatment with nikethamide(nikethamide group),the respiratory rate significantly recovered(P<0.05).Compared with the normal control group,the γ-BGT group exhib-ited a significant decrease in Glu content(P<0.05),a significant increase in GABA content(P<0.05),and a significant decrease in the Glu/GABA ratio.Additionally,the protein expression levels of GAD65 and GAD67 were significantly elevated(P<0.05).Compared with the γ-BGT group,the γ-BGT+niketh-amide group showed a significant increase in Glu content(P<0.05),a significant decrease in GABA content(P<0.05),a significant increase in the Glu/GABA ratio,and a significant reduction in GAD65 and GAD67 protein expression levels(P<0.05).Compared to the cell control group,the γ-BGT group demonstrated a significant decrease in Glu content(P<0.05),a significant increase in GABA content(P<0.05),and a significant reduction in the Glu/GABA ratio.Furthermore,the protein expression levels of GAD65 and GAD67 were significantly elevated(P<0.05).Additionally,cAMP content,PKA phosphor-ylation levels,Ca2+levels,and calpain activity were all significantly increased(all P<0.05).Glu,GABA,Glu/GABA ratio,and GAD expression levels in the γ-BGT group changed in the same way as in the gallamine group;In the γ-BGT+Y-27632 group,calpain activity and expression levels of GAD65 and GAD67 were all significantly decreased(all P<0.05).In the γ-BGT+H-89 group,Ca2+levels and calpain activity were significantly reduced(all P<0.05).CONCLUSION γ-BGT-induced poisoning can lead to respiratory distress in mice,possibly through the antagonism of M2 muscarinic acetylcholine receptors in medullary neurons,activation of the cAMP/PKA signaling pathway,elevation of intracellular Ca2+levels,and increased expression and activity of GAD,resulting in an imbalance of Glu and GABA in the medulla.

Objective:To explore mechanism of Caspase-11/GSDMD non-classical cell pyroptosis pathway in inflammatory response of RAW264.7 monocyte macrophages induced by ricin toxin.Methods:Cell pyroptosis model induced by LPS+Nigericin was used as a positive control,and cells were induced with 40 ng/ml and 80 ng/ml of ricin toxin for 8 hours.Cell release of lactate dehydro-genase(LDH)was measured by LDH cell release assay;cell viability was assessed by flow cytometry(Annexin Ⅴ/PI double staining);gene expressions of Caspase-11,GSDMD,IL-1β and IL-18 were measured by RT-qPCR;protein levels of Caspase-11 and GSDMD were measured by Western blot;secretion levels of inflammatory cytokines IL-1β and IL-18 in cell supernatant were measured by ELISA.Results:Compared with normal control group,RAW264.7 cells treated with ricin toxin showed swelling,cell membrane rupture,significantly increased LDH release(P<0.001),significantly increased pyroptosis rate(P<0.001),significantly increased expression of pyroptosis-related genes Caspase-11,GSDMD,IL-1β and IL-18(P<0.05),significantly increased protein expressions of Caspase-11 and GSDMD(P<0.05),and significantly increased secretion levels of IL-1β and IL-18 in cell supernatant(P<0.05).Results of ricin toxin treatment group were consistent with LPS+Nigericin cell pyroptosis positive control group.Conclu-sion:Ricin toxin may induce cell pyroptosis in RAW264.7 cells through Caspase-11/GSDMD non-classical pathway,thereby promoting inflammatory response.

OBJECTIVE To investigate the roles and mechanisms of γ-bungarotoxin(γ-BGT)in inducing respiratory distress in mice.METHODS Six male Kunming mice were selected and anesthe-tized before tracheal intubation and respiratory recording.After stabilizing respiration,the mice were intraperitoneally injected with γ-BGT at a dose of 6 mg·kg-1.Once a decrease in respiratory frequency was observed,the mice were intravenously injected with nikethamide at a dose of 12.5 mg·kg-1.Respi-ratory frequency was monitored using the BL420 signal acquisition and processing system.Male Kunming mice were randomly divided into the normal control group(saline,ip),γ-BGT group(6 mg·kg-1,ip),and γ-BGT+nikethamide group(γ-BGT 6 mg·kg-1,ip,followed by nikethamide 12.5 mg·kg-1,ip,when shal-low breathing and enhanced abdominal respiration were observed).The levels of Glu and GABA in the medulla oblongata were measured using ELISA.The protein expression levels of GAD65 and GAD67 in the medulla oblongata were determined by Western blotting.Primary mouse medullary neurons were cultured in vitro and divided into the following groups:cell control group,γ-BGT group,carbachol group,gallamine group,γ-BGT+H-89 group,and γ-BGT+Y-27632 group.The γ-BGT group,carbachol group,and gallamine group were incubated with γ-BGT(40 mg·L-1),carbachol(100 mmol·L-1),and gallamine(100 mmol·L-1),respectively,for 4 h.The γ-BGT+H-89 and γ-BGT+Y-27632 groups were pretreated with γ-BGT(40 mg·L-1)for 4 h,followed by incubation with the protein kinase A(PKA)inhibitor H-89(50 mmol·L-1)and the Ca2+channel inhibitor Y-27632(50 mmol·L-1)for another 2 h,respectively.ELISA was used to measure the levels of Glu,GABA,cAMP,and calpain in the primary mouse medul-lary neurons.Western blotting was employed to assess the protein expression levels of GAD65 and GAD67,and PKA phosphorylation levels.Fluo-4 fluorescent probe was used to detect the intracellular Ca2+level.RESULTS The respiratory rate of mice significantly decreased after iv administration of γ-BGT(γ-BGT group)(P<0.05).After treatment with nikethamide(nikethamide group),the respiratory rate significantly recovered(P<0.05).Compared with the normal control group,the γ-BGT group exhib-ited a significant decrease in Glu content(P<0.05),a significant increase in GABA content(P<0.05),and a significant decrease in the Glu/GABA ratio.Additionally,the protein expression levels of GAD65 and GAD67 were significantly elevated(P<0.05).Compared with the γ-BGT group,the γ-BGT+niketh-amide group showed a significant increase in Glu content(P<0.05),a significant decrease in GABA content(P<0.05),a significant increase in the Glu/GABA ratio,and a significant reduction in GAD65 and GAD67 protein expression levels(P<0.05).Compared to the cell control group,the γ-BGT group demonstrated a significant decrease in Glu content(P<0.05),a significant increase in GABA content(P<0.05),and a significant reduction in the Glu/GABA ratio.Furthermore,the protein expression levels of GAD65 and GAD67 were significantly elevated(P<0.05).Additionally,cAMP content,PKA phosphor-ylation levels,Ca2+levels,and calpain activity were all significantly increased(all P<0.05).Glu,GABA,Glu/GABA ratio,and GAD expression levels in the γ-BGT group changed in the same way as in the gallamine group;In the γ-BGT+Y-27632 group,calpain activity and expression levels of GAD65 and GAD67 were all significantly decreased(all P<0.05).In the γ-BGT+H-89 group,Ca2+levels and calpain activity were significantly reduced(all P<0.05).CONCLUSION γ-BGT-induced poisoning can lead to respiratory distress in mice,possibly through the antagonism of M2 muscarinic acetylcholine receptors in medullary neurons,activation of the cAMP/PKA signaling pathway,elevation of intracellular Ca2+levels,and increased expression and activity of GAD,resulting in an imbalance of Glu and GABA in the medulla.

Objective:To explore mechanism of Caspase-11/GSDMD non-classical cell pyroptosis pathway in inflammatory response of RAW264.7 monocyte macrophages induced by ricin toxin.Methods:Cell pyroptosis model induced by LPS+Nigericin was used as a positive control,and cells were induced with 40 ng/ml and 80 ng/ml of ricin toxin for 8 hours.Cell release of lactate dehydro-genase(LDH)was measured by LDH cell release assay;cell viability was assessed by flow cytometry(Annexin Ⅴ/PI double staining);gene expressions of Caspase-11,GSDMD,IL-1β and IL-18 were measured by RT-qPCR;protein levels of Caspase-11 and GSDMD were measured by Western blot;secretion levels of inflammatory cytokines IL-1β and IL-18 in cell supernatant were measured by ELISA.Results:Compared with normal control group,RAW264.7 cells treated with ricin toxin showed swelling,cell membrane rupture,significantly increased LDH release(P<0.001),significantly increased pyroptosis rate(P<0.001),significantly increased expression of pyroptosis-related genes Caspase-11,GSDMD,IL-1β and IL-18(P<0.05),significantly increased protein expressions of Caspase-11 and GSDMD(P<0.05),and significantly increased secretion levels of IL-1β and IL-18 in cell supernatant(P<0.05).Results of ricin toxin treatment group were consistent with LPS+Nigericin cell pyroptosis positive control group.Conclu-sion:Ricin toxin may induce cell pyroptosis in RAW264.7 cells through Caspase-11/GSDMD non-classical pathway,thereby promoting inflammatory response.

Objective:To discuss the damage effect of vesicular stomatitis virus(VSV)on the vascular endothelial(VE)barrier,and to clarify its mechanism.Methods:The canine kidney cells were used to amplify VSV.The half tissue culture infective dose(TCID50)of VSV was determined using mouse brain endothelial tumor bEnd.3 cells,and subsequent experiment was conducted using 300 times the TCID50.The bEnd.3 cells were divided into infection 0 h group,infection 4 h group,infection 8 h group,and infection 12 h group for VE barrier damage experiments due to VSV infection.The bEnd.3 cells were also divided into control group,infection group,and correction group for experiments to inhibit the VSV replication and restore the VE barrier.The bEnd.3 cells were inoculated into Transwell chambers to construct an in vitro VE barrier model.Cell voltage resistance meter was used to detect the transepithelial resistance(TER)in various groups after the bEnd.3 cells were infected with VSV at different time points;fluorescein isothiocyanate-dextran leakage assay was used to detect the permeability coefficients of the cells in various groups;immunofluorescence staining was used to observe the localization changes of VE-cadherin,β-catenin,and phosphorylated β-catenin(p-β-catenin)in cytoskeleton and adherens junctions(AJs)of the bEnd.3 cells after VSV infection;real-time fluorescence quantitative PCR(RT-qPCR)method was used to detect the expression levels of Wnt and β-catenin mRNA in the cells in various groups;Western blotting method was used to detect the expression levels of Wnt,β-catenin,and p-β-catenin proteins in the cells in various groups.Results:The TCID50 of VSV was 10-4.5·100 μL-1.TheTranswell chamber experiment results showed that compared with infection 0 h group,the TERs in the cells in the other groups were significantly decreased(P＜0.05),and the permeability coefficients were significantly increased(P＜0.05).The immunofluorescence staining results showed that compared with control group,the cytoskeleton of the bEnd.3 cells in infection group was disordered,the cell gaps was increased,the linear index of AJs was significantly decreased(P＜0.05),and β-catenin and p-β-catenin translocated from the cell membrane to the perinuclear area.The RT-qPCR results showed that compared with infection 0 h group,the expression levels of Wnt mRNA in the cells in the other groups were significantly decreased(P＜0.05),while the expression levels of β-catenin mRNA showed no statistically significant difference(P＞0.05).The Western blotting results showed that compared with infection 0 h group,the expression levels of Wnt protein in the cells in the other groups were significantly decreased(P＜0.05),the expression levels of β-catenin showed no statistically significant differences(P＞0.05),and the expression levels of p-β-catenin were significantly increased(P＜0.05).After inhibiting the VSV replication and correcting the low density lipoprotein receptor(LDLR)abnormalities,the Transwell chamber experiment results showed that compared with infection group,the TER in the cells in correction group was significantly increased(P＜0.05),and the permeability coefficient was significantly decreased(P＜0.05).The immunofluorescence staining results showed that compared with infection group,the gaps in the cells in correction group were reduced,and the perinuclear aggregation of β-catenin and p-β-catenin in the cells was restrained.The RT-qPCR results showed that compared with infection group,the expression level of Wnt mRNA in the cells in correction group was significantly increased(P＜0.05).The Western blotting results showed that compared with infection group,the expression level of Wnt protein in the cells in correction group was significantly increased(P＜0.05),the expression level of β-catenin showed no statistically significant difference(P＞0.05),and the expression level of p-P-catenin was significantly decreased(P＜0.05).Conclusion:VSV infection can cause the LDLR inactivation,reduce the expression level of Wnt protein,increase the phosphorylation level of β-catenin and cause its internalization,disrupt the stability of AJs,and ultimately lead to VE barrier damage.