To characterize human antibodies against low-calcium response V(LcrV)antigen of Yersinia pestis,the mono-clonal antibodies were screened and assayed.Antibody gene was derived from peripheral blood mononuclear cells of the vaccin-ees immunized by plague subunit vaccine in phase Ⅱb clinical trial.Human ScFv antibody library was constructed by phage dis-play.After panning library by using recombinant LcrV antigen,antibody variable genes were sequenced and converted into IgG1 format to evaluate its binding specificity and relevant parameters.An anti-plague human ScFv antibody library was estab-lished contained 7.54× 108 independent clones.After panning by LcrV antigen,3 human antibodies named as RV-B4,RV-D1 and RV-E8,respectively,were identified.Using indirect enzyme-linked immunosorbent assay(ELISA)and Western blot(WB),the specific bindings of the mAbs to LcrV antigen were confirmed.The dissociation constant(KD)of them to LcrV is 2.1 nmol/L,1.24 nmol/L and 42 nmol/L,respectively.Minor protective efficacy was found among 3 human antibodies in Y.pestis 141-infected mice.Three anti-LcrV monoclonal antibodies generated from immunized vaccinees were binding specific antibod-ies and could not block plague infection in mice.These antibodies are the potential candidate reagents for basic research of plague immunity and the application of plague diagnosis.

Lipopolysaccharides (LPS) are major outer membrane components of Gram-negative bacteria. Unlike most Gram-negative bacteria, Acinetobacter baumannii can still survive and acquire polymyxin resistance after complete loss of LPS. Previous studies of LPS-deficient Acinetobacter baumannii mostly focused on LPS-deficient strains induced by polymyxin, whose background was complex and unstable. To investigate LPS loss-mediated polymyxin resistant-Acinetobacter baumannii, this study constructed a stable and clear background LPS-deficient strain by knocking out lpxC gene in Acinetobacter baumannii ATCC 19606 with CIRSPR/Cas9, and then studied the phenotypic changes of the lpxC-deficient strain including morphology, growth rate, antibiotic susceptibility, virulence, membrane permeability, and membrane potential. Animal experiments were approved by the Animal Care and Welfare Committee Institute of Medicinal Biotechnology, CAMS and PUMC (approval number: IMB-20240119D₉). The results indicated that the lpxC gene of Acinetobacter baumannii ATCC 19606 was successfully knocked out. After losing the lpxC, the strain underwent the morphological change from rod-shaped to spherical. Furthermore, it leads to reduced growth rate, enhanced membrane permeability, decreased membrane potential, lower virulence, and increased antibiotic susceptibility to β-lactams, quinolones, aminoglycosides, macrolides, glycopeptides. The lpxC deletion results in significant changes in membrane homeostasis and adaptability of Acinetobacter baumannii. Understanding the phenotypic changes of colistin-resistant Acinetobacter baumannii mediated by LPS loss is useful for exploring the resistance mechanism of Acinetobacter baumannii and developing new therapeutic strategies.

Objective To explore the effect of CircCSNK1G1 on the proliferation,apoptosis and migration of gastric cancer(GC)cells by regulating the miR-381-3p/S kinase-related protein 2(Skp2)axis.Methods HGC-27 cells were divided into non transfected group,si-NC group,si-CircCSNK1G1 group,si-CircCSNK1 G1+anti-miR-NC group,and si-CircCSNK1G1+anti-miR-381-3p group.The expressions of CircCSNK1G1,miR-381-3p and Skp2 mRNA in GC tumor tissues and GC cell lines were detected by qRT-PCR respectively;cell proliferation was detected by MTT assay;the number of cell clones was detected by clonogenic assay;apoptosis was detected by flow cytometry;cell migration and invasion ability were determined by transwell;the expression of E-cadherin and Vimentin was detected by Western Blot;and the targeting relationship among CircCSNK1G1,miR-381-3p and Skp2 was verified by double luciferase experiment.Results Compared with GES-1 in normal tissues adjacent to cancer and normal human gastric mucosal epithelial cells,the expression of CircCSNK1 G1 and Skp2 mRNA in GC tumor tissues and GC cell lines is high,and the expression of miR-381-3p is low(P＜0.05),and the expression level of miR-381-3p in HGC-27 cells is the lowest,and the expression level of CircCSNK1G1 and Skp2 mRNA is the highest,therefore,HGC-27 cells were selected and CircCSNK1G1 was knocked down for the experiment.Compared with untransfected group and si-CircCSNK1G1-NC group,transfection of si-CircCSNK1G1 could reduce the expression of CircCSNK1G1,Skp2 mRNA,cell proliferation activity,cell migration number,and the expression of Vimentin protein in HGC-27 cells(P＜0.05),the expression of miR-381-3p,apoptosis rate,and the expression of E-cadherin protein were increased(P＜0.05).The double luciferase experiment verified that CircCSNK1G1 and Skp2 had a targeting relationship with miR-381-3p,moreover,CircCSNK1G1 could be used as sponge RNA of miR-381-3p to further regulate the expression and activity of Skp2.Conclusion Knockdown of CircCSNK1G1 can target up-regulate the expression of miR-381-3p,and inhibit the expression of Skp2,thus promoting the apoptosis of GC cells,and inhibiting their proliferation and migration.

Objective To investigate the correlation between the level of N-terminal pro-Brain natriuretic peptide(NT-proBNP)and cardiorespiratory fitness following acute exposure to high altitude.Methods Forty-six subjects were recruited from the Second Affiliated Hospital of Army Medical University in June 2022,including 19 males and 27 females.After completing cardiopulmonary exercise test(CPET),serological detection of myocardial cell-related markers,and multiple metabolites at a plain altitude(300 meters above sea level),all subjects flew to a high-altitude location(3900 meters above sea level).Biomarker testing and CPET were repeated on the second and third days after arrival at high altitude.Changes in serum biomarker and key CPET indicators before and after rapid ascent to high altitude were compared,and the correlation between serum levels of various myocardial cell-related markers and metabolites and high altitude cardiorespiratory fitness was analyzed.Results Compared with the plain altitude,there was a significant decrease in maximal oxygen uptake after rapid ascent to high altitude[(25.41±6.20)ml/(kg.min)vs.(30.17±5.01)ml/(kg.min),P<0.001].Serum levels of NT-proBNP,Epinephrine(E),plasma renin activity(PRA),angiotensin Ⅱ(Ang Ⅱ),angiotensin-converting enzyme 2(ACE2)and leptin(LEP)significantly increased,with all differences being statistically significant(P<0.05)after acute high altitude exposure.In contrast,no statistically significant differences were observed for creatine kinase MB(CK-MB),cardiac troponin I(cTnI),myoglobin(Myo)and norepinephrine(NE)(P>0.05).Correlation analysis showed a significant negative correlation between NT-proBNP at plain altitude(r=-0.768,P<0.001)and at high altitude(r=-0.791,P<0.001)with maximal oxygen uptake at high altitude.Multivariate linear regression analysis indicated that maximal oxygen uptake at plain altitude(t=2.069,P=0.045),NT-proBNP at plain altitude(t=-2.436,P=0.020)and at high altitude(t=-3.578,P=0.001)were independent influencing factors of cardiorespiratory fitness at high altitude.Conclusion Cardiorespiratory fitness significantly decreases after rapid ascent to high altitude,and the baseline NT-proBNP level at plain altitude is closely related to cardiorespiratory fitness at high altitude,making it a potential predictor indicator for high altitude cardiorespiratory fitness.

This study was aimed at understanding the genomic characteristics of the Vibrio cholerae O1 group isolated from humans in Fujian Province,to provide essential data for the molecular epidemiological study of cholera.From 2008 to 2022,16 strains of the V.cholerae O1 group from patients and carriers were collected,and antibiotic sensitivity was determined accord-ing to the minimum inhibitory concentration(MIC).The whole genome sequences obtained through second generation sequen-cing were analyzed in open source software,including snippy,Roary,and Prokka,as well as online analysis websites,inclu-ding NCBI and BacWGSTdb,for core-genome multilocus sequence typing(cgMLST),core-genome single nucleotide polymor-phism analysis(cgSNP),virulence gene analysis,drug resistance gene prediction,and pan-genomic diversity analysis.The whole genome sequences of V.cholerae were divided into five sequence types(STs),among which the newly discovered ST182 and ST1480 were the evolutionary branches of the current dominant clonal group ST75 in China,and were highly related to two strains isolated from Taiwan in 2010 and 2013,respectively.Both toxigenic strains and non-toxigenic strains carried a variety of virulence factors and showed gene variation to varying degrees.Thirteen drug resistance genes in seven categories were predicted,among which the distribution of colistin and tetracycline resistance genes was consistent with the drug resistance phenotype.Pan-ge-nomic analysis indicated that V.cholerae had an open pan-genome,and Roary cluster analysis showed higher resolution than cgMLST.In summary,V.cholerae O1 group isolates from humans in Fujian Province have polymorphisms in genome structure and function,and the newly discovered ST1480 clone group has epidemic potential.Therefore,the monitoring of such strains must be strengthened.

Objective To investigate the effects of trigonelline combined with aerobic exercise on hyperlipidemia rats and its mechanism.Methods SD rats were randomly divided into control group(normal diet),model group(hyperlipidemia rat model was established by feeding high fat diet),experimental-L,-H groups(high fat diet+15,45 mg·kg-1 trigonelline)and combine group(high fat diet+45 mg·kg-1 trigonelline+aerobic exercise).Each group had 11 rats.Serum lipid metabolism related indexes were detected by automatic biochemical analyzer.Serum levels of 6 ketone prostaglandin F1a(6-keto-PGF1a);the levels of glutamic oxaloacetic transaminase(GOT)in liver tissue were detected by enzyme-linked immunosorbent assay;the mRNA levels of interleukin-1β(IL-1β)in liver tissue were detected by real-time fluorescence quantitative polymerase chain reaction(RT-qPCR);Western blot assay was used to detect the expression of proprotein convertase subtilin/kexin 9 type(PCSK9)and low density lipoprotein receptor(LDLR)protein in liver tissue.Results The serum TC levels in control group,model group,experimental-L group,experimental-H group and combine group were(1.81±0.10),(6.68±0.77),(5.10±0.44),(3.57±0.47)and(2.40±0.35)mmol·L-1;the levels of 6-keto-PGF1a were(841.47±86.74),(536.03±36.50),(664.06±52.44),(759.19±52.30)and(824.45±67.62)pg·mL-1;GOT levels were(11.95±0.88),(18.20±1.81),(15.05±1.10),(13.32±0.98)and(12.47±0.83)U·L-1;IL-1β mRNA expression levels were 1.00±0.09,2.21±0.17,1.57±0.10,1.26±0.16 and 1.14±0.09;the expression of PCSK9 protein were 0.39±0.07,0.88±0.08,0.71±0.08,0.60±0.04 and 0.52±0.07;LDLR protein levels were 1.12±0.13,0.52±0.07,0.74±0.11,0.84±0.08 and 0.96±0.11,respectively.Model group was compared with the control group,experimental-L group and experimental-H group were compared with model group respectively,combine group was compared with the experimental-H group,the differences of the above indexes were statistically significant(all P＜0.05).Conclusion Trigonelline combined with aerobic exercise may inhibit the expression of PCSK9 and up-regulate the expression of LDLR to improve lipid metabolism,so as to play a lipid-lowering role in hyperlipidemia rats.

Objective To observe the effect of Ginkgo biloba extract(GBE)on depression like behavior in post stroke depression(PSD)model rats,and explore the mechanism of regulating Toll like receptor 4/nuclear factor-κ B(TLR4/NF-κB)pathway to inhibit neuroinflammation.Methods Rats were randomly divided into 6 groups,sham,cerebral ischemia,PSD,paroxetine,low-dose Ginkgo biloba extract(GBE-L)and high-dose Ginkgo biloba extract(GBE-H)groups,10 rats in each group.Except for the sham group,middle cerebral artery occlusion(MCAO)was performed to prepare a left focal cerebral ischemia model.Except for the sham group and cerebral ischemia group,other groups were subjected to chronic unpredictable mild stress(CUMS)to establish PSD rat model for 8 weeks.After 4 weeks of CUMS,the paroxetine group,GBE-L,and GBE-H were treated with paroxetine 5 mg·kg-1,GBE 50 mg·kg-1,and GBE 100 mg·kg-1,respectively.The sham group,cerebral ischemia group,and PSD group were treated with the same volume of 0.9％NaCl and continuously administered by gavage for 28 d.After 4 weeks and 8 weeks of CUMS,the body weight and sugar preference test were measured.Levels of serum tumor necrosis factor-α(TNF-α),interleukin-1 β(IL-1 β)and levels of norepinephrine(NE),serotonin(5-HT),and dopamine(DA)in the cerebral cortex were measured by enzyme-linked immunosorbent assay(ELISA).The mRNA levels of Tlr4,Nfkb1,and nuclear factor κ B-kinase subunit β inhibitory factor(Ikbkb)in the hippocampus of rats were detected by polymerase chain reaction.The protein levels of NF-κB,nuclear factor κB inhibitory protein α(IKBα)and phosphorylation nuclear factor κB inhibitory protein α(p-IKB)in hippocampal tissue were detected by Western blot.Results The body weights of rats in the sham group,cerebral ischemia group,PSD group,paroxetine group,GBE-L group and GBE-H group were(427.10±6.36),(403.10±7.37),(310.10±9.71),(355.00±4.03),(347.90±9.88)and(391.90±5.07)g;sugar preference rate were(93.93±1.78)％,(91.57±1.03)％,(54.72±7.34)％,(88.35±4.36)％,(63.55±12.73)％and(81.04±4.31)％;the levels of NE in the cerebral cortex were(1 951.14±52.86),(1 827.27±23.63),(1 662.12±35.92),(2 033.58±72.28),(1 887.31±33.07)and(2 175.00±42.54)pg·mL-1;the levels of 5-HT in the cerebral cortex were(237.07±8.86),(226.15±10.27),(214.51±3.46),(297.13±5.79),(274.14±7.63)and(285.34±8.72)ng·mL-1;the levels of DA in the cerebral cortex were(1 531.11±47.26),(1 209.89±58.09),(1 143.15±36.31),(1 812.67±51.28),(1 651.56±31.82)and(1 853.33±20.42)pg·mL-1.Compared with the PSD group,GBE significantly increased the body weight of rats(P＜0.01)and increased the preference rate of sugar water in rats,showing the antidepressant like behavioral.GBE significantly reduced the levels of serum TNF-α,IL-1 β(all P＜0.01),increased the levels of NE,5-HT,and DA in the cerebral cortex(all P＜0.01),down regulate the mRNA levels of Tlr4,Nfkb1 and Ikbkb(P＜0.05,P＜0.01),reduced the expression of NF-κB(P＜0.01),and reduced the phosphorylation of IKBα(P＜0.01).Conclusion Ginkgo biloba extract can improve depression-like behavior in PSD model rats,and has antidepressant effect.Its mechanism is related to the inhibition of TLR4/NF-κB pathway,thus reducing neuroinflammation.

Objective To investigate the effect and mechanism of rosuvastatin on liver injury induced by high fat diet in hyperlipidemia rats.Methods All rats were randomly divided into control group,model group and experimental group,with 10 rats in each group.Except the control group,hyperlipidiosis model rats were fed with high-fat diet combined with alcohol to construct hyperlipidiosis model rats.The experimental group was given 10 mg·kg-1 rosuvastatin by gavage,control group and model group were given gavage with 10 mL·kg-1 distilled water,once a day for 4 weeks.Serum lipids and liver function were measured by enzyme-linked immunosorbent assay(ELISA).Quantitative real-time polymerase chain reaction(qRT-PCR)was used to analyze the expression of microRNA(miR)-185-3p and mastermind like transcription coactivator 1(MAML1);the expression levels of MAML1 and inducible nitric oxide synthase(iNOS)were detected by Western blot.Results The liver tissue injury scores of control group,model group and experimental group were 0.32±0.15,4.03±1.62 and 2.36±1.14;the TG levels were(4.95±0.86),(6.75±1.42)and(5.51±0.91)mmol·L-1;the TC were(2.36±0.48),(5.11±2.05)and(3.24±1.39)mmol·L-1;the LDL-C were(0.67±0.16),(1.73±0.42)and(1.03±0.25)mmol·L-1;the HDL-C were(0.72±0.23),(0.51±0.14)and(0.64±0.11)mmol·L-1;the GOT were(158.31±32.46),(253.19±49.27)and(187.52±53.46)U·L-1;the GPT values were(53.17±6.81),(79.64±13.92)and(55.63±9.11)U·L-1.Compared with the control group,the expression of miR-185-3p in the model group was significantly down-regulated,the expression of MAML1 and iNOS was significantly increased.Compared with the model group,the expression of miR-185-3p in the liver tissue of experimental group was significantly up-regulated,while the expression of MAML1 and iNOS was significantly decreased(all P＜0.05).There were statistically significant differences in the above indexes between the control group and the model group(P＜0.05);the above data in the model group were statistically significant compared with the experimental group(P＜0.05).Conclusion Rosuvastatin inhibits the expression of MAML1 and iNOS by regulating miR-185-3p,thereby improving the liver injury induced by hyperlipidemia in rats.

Objective To investigate the effect of naringin on hyperlipidemia in mice and to elucidate its mechanism.Methods C57BL/6 mice were randomly divided into control group,hyperlipidemia group and naringin group.Mice in hyperlipidemia group and naringin group were fed high-fat diet for 4 weeks,and hyperlipidemia model was established.The control group was fed normal diet.After successful modeling,naringin group mice were intragastric with 200 mg·kg-1 naringin per day,and mice in control group and hyperlipemia group were intragastric with 0.9％NaCl per day for 5 weeks.The blood of mice was collected for lipid detection.The activities of superoxide dismutase(SOD)and catalase(CAT)and the contents of malondialdehyde(MDA)and glutathione(GSH)were detected by biochemical method.Western blot was used to detect the protein expression.Results The activity of SOD in liver tissue of mice in control group,hyperlipidemia group and naringin group were(58.43±6.27),(37.16±4.10)and(51.23±4.81)U·mg prot-1,respectively;CAT activities were(176.11±13.59),(112.65±10.02)and(158.46±14.37)U·mg prot-1,respectively;the contents of MDA were(3.15±0.74),(12.62±2.07)and(5.76±1.83)U·mg prot-1;the contents of GSH were(91.52±11.47),(34.16±4.62)and(71.64±8.79)U·mg prot-1,respectively;the relative protein expression levels of induced nitric oxide synthase(iNOS)were 0.28±0.05,4.26±1.13 and 0.94±0.19;the relative protein expression levels of adenosine 5'-monophosphate activated protein kinase(AMPK)were 1.32±0.18,0.84±0.11 and 1.49±0.16,respectively;the relative protein expression levels of cholesterol regulatory element binding protein(SREBP)were 1.76±0.24,5.78±1.21 and 2.93±0.42;the relative protein expression levels of 3-hydroxy-3-methyl glutaryl coenzyme A reductase(HMGCR)were 1.69±0.18,6.13±1.38 and 3.26±0.43,respectively.The above indexes in the control group and the naringin group were significantly different from those in the hyperlipidemia group(P＜0.05,P＜0.01,P＜0.001).Conclusion Naringin can effectively regulate the level of blood lipids,inhibit oxidative stress and apoptosis in hyperlipidemia mice,and its mechanism may be related to the regulation of AMPK/HMGCR/SREBP signaling pathway.

Objective To investigate the effect and mechanism of hypericin on osteoporosis(OP)in rats with chronic obstructive pulmonary disease(COPD).Methods COPD combined with OP rat model was established by cigarette combined with bacteria.The rats were randomly divided into control group,model group(COPD combined with OP model was constructed),experimental-L group(50 mg·kg-1 hypericin was given by intragastric administration after constructing COPD combined with OP model),experimental-H group(100 mg·kg-1 hypericin was given intragastric administration after constructing COPD combined with OP model),positive group(subcutaneous injection of 16 U·kg-1 salmon calcitonin after constructing COPD combined with OP model);each group was given 12 rats for 90 days.The lung function of rats was detected by pulmonary function apparatus;bone mineral density(BMD)was detected by micro-computed tomography(CT);serum bone metabolism and inflammatory factors were detected by enzyme-linked immunosorbent assay(ELISA);Western blot assay was used to detect the relevant indicators of the pathway.Results The levels of forced vital capacity(FVC)in control group,model group,experimental-H group and positive group were(10.42±1.40),(4.10±0.60),(6.75±0.37),(4.18±0.33)mL,respectively;BMD levels were(0.31±0.04),(0.12±0.02),(0.28±0.03),(0.29±0.04)g·mm-3,respectively;bone alkaline phosphatase(BALP)levels were(200.04±20.03),(80.80±6.00),(148.16±14.23),(173.97±23.55)U·L1,respectively;interleukin-1β(IL-1β)levels were(122.60±8.70),(695.59±74.84),(422.41±44.86),(527.90±39.36)pg·mL-1,respectively;phosphorylated p38 mitogen-activated protein kinase(p-P38)protein expression levels were 0.99±0.11,0.36±0.05,0.79±0.08,0.36±0.04,respectively.Compared with the control group,the above indexes in the model group had statistical significance(all P＜0.05);the above indexes in experimental-H group were significantly different from those in model group(all P＜0.05).Conclusion Hypericin can inhibit inflammatory response,improve bone metabolism and biomechanics.