OBJECTIVE To investigate the regulatory effect of Rasfonin on SOS1(Son of Seven-less,one of the major guanylate exchange factors)expressions and the underlying mechanism.METHODS① Human cancer cells MCF-7(breast cancer cells,KRASWT wild-type),Calu-1(non-small cell lung cancer,KRASG12C mutation),and UM-UC-3(bladder metastatic cell carcinoma,KRASG12C mutation)were divided into the control group and Rasfonin(1,5,10 and 15 μmol·L-1)treated groups.CCK-8 assay was used to observe the effects of Rasfonin on the proliferation of MCF-7,Calu-1,and UM-UC-3 cells after 24 h of Rasfonin treatment.In addition,these cells were divided into the control group,EGF stimulation group(EGF 50 μg·L-1,stimulated for 5 min),and Rasfonin treated groups(pretreated with 5 and 10 μmol·L-1 Rasfonin before 5 min EGF stimulation).Quantitative real-time PCR(real-time fluores-cence PCR)and Western blotting were employed to identify the expression levels of SOS1 mRNA and protein in MCF-7,Calu-1 and UM-UC-3 cells.② The co-expression systems of KRAS and SOS1 were established by transfecting plasmids(KRAS-NC,KRASWT,KRASG12C and SOS1)into 293T cells that were divided into the control group and Rasfonin(1,5 and 10 μmol·L-1)treated group.The dual luciferase reporter gene assay was used to evaluate the effects of Rasfonin on activities of the SOS1 promoter.Moreover,293T cells were divided into the EGF stimulation group(EGF 50 μg·L-1,stimulated for 5 min)and Rasfonin treated groups(12 h of treatment with 10 μmol·L-1 Rasfonin before 5 min EGF stimula-tion).Western blotting was performed to determine the role of KRASG12C protein in the inhibition of Rasfonin on SOS1 expression.RESULTS ① Compared with the control group,Rasfonin inhibited the prolifera-tion of Calu-1 and UM-UC-3 cells at concentrations of 5,10 and 15 μmol·L-1(IC50 was 8.22 and 4.94 μmol·L-1).But for MCF-7 cells,only 15 μmol·L-1 Rasfonin could decrease their viability(IC50 was 45.15 μmol·L-1).Compared with the EGF stimulation group,mRNA expressions of SOS1 were increased after Rasfonin treatment of 1 h.mRNA expressions of SOS1 were decreased in Calu-1 cells after 3 h of Rasfonin treatment.These changes also occurred after Rasfonin treatment of 3 h and 6 h in UM-UC-3 cells.Further-more,Rasfonin treatment did not influence SOS1 protein expressions in MCF-7 cells,but can signifi-cantly inhibit SOS1 expression of in UM-UC-3 and Calu-1 cells.② Rasfonin had no significant effects on the activity of SOS1 promoter and its protein level in 293T cells when only SOS1 was expressed,but significantly inhibited its activity and its protein level when SOS1 was co-expressed with KRAS protein.CONCLUSION One of the anti-tumor mechanisms of Rasfonin is to inhibit the activity of SOS1 promoter to decrease mRNA and protein expressions of SOS1 through KRASG12C protein.

ObjectiveTo evaluate the levels of physical exercise, mental health and social response in children with autism spectrum disorder (ASD), and explore the mediating effect of social response on physical exercise and mental health. MethodsFrom September, 2019 to April, 2024, 211 children with ASD from three special education schools in Haidian District and Shijingshan District of Beijing were selected. They were assessed with general data questionnaire, Physical Activity Rating Scale (PARS-3), Chinese version of Psycho-Educational Profile (C-PEP) and Social Response Scale-Short Form (SRS-SF). The correlation among physical exercise, mental health and social response was analyzed. The mediating effect of social response on physical exercise and mental health was explored. ResultsThe average physical exercise level was (58.72±3.34), the average mental health level was (14.85±1.67), and the average social response level was (24.98±3.79). Physical exercise was positively correlated with mental health (r = 0.546, P < 0.05) and negatively correlated with social response (r = -0.298, P < 0.05). Mental health was negatively correlated with social response (r = -0.397, P < 0.05). Average monthly family income, parental relationship, repeated transcranial magnetic stimulation therapy, physical exercise, social response were the influencing factors of mental health (P < 0.05). Social response was intermediary between physical exercise and mental health, accounting for 14.56%. ConclusionThe mental health level of children with ASD is poor, and there are many influencing factors. Physical exercise can directly affect the mental health of children with ASD, and can also play an indirect role through social response.

The aim of this study is to investigate the inhibitory effects and mechanism of three or-ganic acids,including formic acid(FA),butyric acid(BA)and lactic acid(LA),on the pathogenic-ity of Salmonella enteritidis(SE),Escherichia coli(EC)and Staphylococcus aureus(SA).The growth of pathogens was detected by Minimum Inhibitory Concentration(MIC)and Oxford Cup antimicrobial zone assays.The motility of pathogens was detected by soft agar plate method,and the biofilm of pathogens was detected by crystal violet staining.Quantitative real-time polymerase chain reaction(qRT-PCR)was used to measure the expression levels of genes related to the patho-genicity of SE.The results showed that FA and BA significantly inhibited the growth of SE,EC and SA,and FA had a superior inhibitory effect on EC(MIC:0.25 g/L;inhibition zone:20.0 mm)and SA(MIC:0.5 g/L;inhibition zone:25.0 mm).In addition,the three organic acids significantly inhibited the motility of SE,EC and SA as accessed by swimming and swarming assays,and FA showed the best inhibition effect.Besides,the three organic acids,especially FA,markedly inhibited the biofilm formation of SE,EC and SA.Finally,our results showed that the three organic acids in-hibited the expression of the main virulence genes encoded by SPI-1(InvA,InvF,SopE,SopB,SipB,HilA and SipA),SPI-2(SopD2),pili-related genes(FliF,LpfA,SefA and FimF)and flagellum-related genes(FlhD,FliC and FliD)of SE.This study demonstrates that FA,BA,and LA significantly inhibited the growth and pathogenicity of the four pathogens,among which FA showed the most obvious effect on inhibiting the growth,motility,biofilm formation and virulence gene expression.Our study provided a theoretical basis for the application of organic acids in the field of animal husbandry.

The aim of this study is to investigate the inhibitory effects and mechanism of three or-ganic acids,including formic acid(FA),butyric acid(BA)and lactic acid(LA),on the pathogenic-ity of Salmonella enteritidis(SE),Escherichia coli(EC)and Staphylococcus aureus(SA).The growth of pathogens was detected by Minimum Inhibitory Concentration(MIC)and Oxford Cup antimicrobial zone assays.The motility of pathogens was detected by soft agar plate method,and the biofilm of pathogens was detected by crystal violet staining.Quantitative real-time polymerase chain reaction(qRT-PCR)was used to measure the expression levels of genes related to the patho-genicity of SE.The results showed that FA and BA significantly inhibited the growth of SE,EC and SA,and FA had a superior inhibitory effect on EC(MIC:0.25 g/L;inhibition zone:20.0 mm)and SA(MIC:0.5 g/L;inhibition zone:25.0 mm).In addition,the three organic acids significantly inhibited the motility of SE,EC and SA as accessed by swimming and swarming assays,and FA showed the best inhibition effect.Besides,the three organic acids,especially FA,markedly inhibited the biofilm formation of SE,EC and SA.Finally,our results showed that the three organic acids in-hibited the expression of the main virulence genes encoded by SPI-1(InvA,InvF,SopE,SopB,SipB,HilA and SipA),SPI-2(SopD2),pili-related genes(FliF,LpfA,SefA and FimF)and flagellum-related genes(FlhD,FliC and FliD)of SE.This study demonstrates that FA,BA,and LA significantly inhibited the growth and pathogenicity of the four pathogens,among which FA showed the most obvious effect on inhibiting the growth,motility,biofilm formation and virulence gene expression.Our study provided a theoretical basis for the application of organic acids in the field of animal husbandry.

OBJECTIVE To investigate the regulatory effect of Rasfonin on SOS1(Son of Seven-less,one of the major guanylate exchange factors)expressions and the underlying mechanism.METHODS① Human cancer cells MCF-7(breast cancer cells,KRASWT wild-type),Calu-1(non-small cell lung cancer,KRASG12C mutation),and UM-UC-3(bladder metastatic cell carcinoma,KRASG12C mutation)were divided into the control group and Rasfonin(1,5,10 and 15 μmol·L-1)treated groups.CCK-8 assay was used to observe the effects of Rasfonin on the proliferation of MCF-7,Calu-1,and UM-UC-3 cells after 24 h of Rasfonin treatment.In addition,these cells were divided into the control group,EGF stimulation group(EGF 50 μg·L-1,stimulated for 5 min),and Rasfonin treated groups(pretreated with 5 and 10 μmol·L-1 Rasfonin before 5 min EGF stimulation).Quantitative real-time PCR(real-time fluores-cence PCR)and Western blotting were employed to identify the expression levels of SOS1 mRNA and protein in MCF-7,Calu-1 and UM-UC-3 cells.② The co-expression systems of KRAS and SOS1 were established by transfecting plasmids(KRAS-NC,KRASWT,KRASG12C and SOS1)into 293T cells that were divided into the control group and Rasfonin(1,5 and 10 μmol·L-1)treated group.The dual luciferase reporter gene assay was used to evaluate the effects of Rasfonin on activities of the SOS1 promoter.Moreover,293T cells were divided into the EGF stimulation group(EGF 50 μg·L-1,stimulated for 5 min)and Rasfonin treated groups(12 h of treatment with 10 μmol·L-1 Rasfonin before 5 min EGF stimula-tion).Western blotting was performed to determine the role of KRASG12C protein in the inhibition of Rasfonin on SOS1 expression.RESULTS ① Compared with the control group,Rasfonin inhibited the prolifera-tion of Calu-1 and UM-UC-3 cells at concentrations of 5,10 and 15 μmol·L-1(IC50 was 8.22 and 4.94 μmol·L-1).But for MCF-7 cells,only 15 μmol·L-1 Rasfonin could decrease their viability(IC50 was 45.15 μmol·L-1).Compared with the EGF stimulation group,mRNA expressions of SOS1 were increased after Rasfonin treatment of 1 h.mRNA expressions of SOS1 were decreased in Calu-1 cells after 3 h of Rasfonin treatment.These changes also occurred after Rasfonin treatment of 3 h and 6 h in UM-UC-3 cells.Further-more,Rasfonin treatment did not influence SOS1 protein expressions in MCF-7 cells,but can signifi-cantly inhibit SOS1 expression of in UM-UC-3 and Calu-1 cells.② Rasfonin had no significant effects on the activity of SOS1 promoter and its protein level in 293T cells when only SOS1 was expressed,but significantly inhibited its activity and its protein level when SOS1 was co-expressed with KRAS protein.CONCLUSION One of the anti-tumor mechanisms of Rasfonin is to inhibit the activity of SOS1 promoter to decrease mRNA and protein expressions of SOS1 through KRASG12C protein.

Objective:A SARS-CoV-2 pseudovirus(PsV)system was established for neutralizing antibody evaluation and virus entry inhibitor screening.Methods:Lentiviral vector plasmids psPAX2,pCDH-Luc and SARS-CoV-2 Spike(S)protein expres-sion plasmids were co-transfected,and harvested pseudoviral supernatant was used to infect ACE2-293T cells.Protein content of p24 was determined to reflect titer of PsV,and expression of S protein in PsV was detected by Western blot.Neutralization capacity of an S protein monoclonal antibody was evaluated using original strain,D614G,Gamma,Delta,Omicron PsV.Two reported virus entry inhibitors,chloroquine and carrageenin,were used to detect effect on entry of Omicron PsV.Results:Lentiviral vector successfully incorporated S protein.Western blot results showed that S protein mutated at 665Y showed a different cleavage form(90 kD)than wild-type full-length S protein(180 kD).Titer of PsV packaged by three plasmids system was higher.Ratio of S protein expression plasmid,transfer plasmid and packaging plasmid at 1∶3∶3 was optimum condition for viral packaging.Titer of PsV packaged under this condi-tion was over 20 ng/ml.PsV could effectively infect ACE2-293T cells,and double reporter gene GFP and firefly luciferase were expressed obviously,whose chemiluminescence values reached 106.Monoclonal antibodies of S protein effectively neutralized four types of PsVs,but neutralization of original strain was 10～30 times greater than that of variant PsV.Virus entry inhibitors,chloroquine and ι-carrageenan significantly inhibited entry of Omicron PsV.Conclusion:SARS-CoV-2 PsV infection system we conducted can simu-late entry of SARS-CoV-2 successfully.Effective pharmacodynamic evaluation of neutralizing antibodies and virus entry inhibitors can be performed efficiently by the system,which can provide a technical platform for evaluation of neutralizing antibody of SARS-CoV-2 and screening of virus entry inhibitors,and would benefit R&D of anti-SARS-CoV-2 drugs.

OBJECTIVE To investigate the damage effect and potential toxic mechanism of SARS-CoV-2 spike protein(S protein)on human neuroblastomacells(SH-SY5Y).METHODS SH-SY5Y were treated with S protein at concentrations of 25,50,75,and 100 mg·L-1 for 24 h.Cell viability of SH-SY5Y was detected using the CCK-8 assay.The cytotoxic lactate dehydrogenase(LDH)detection kit was used to measure the release rate of LDH,and the 5-ethynyl-2′-deoxyuridine(EdU)-488 cell prolifera-tion kit was used to assess cell proliferation.The ATP detection kit was used to measure intracellular ATP content.The JC-1 fluorescent probe method was employed to detect the mitochondrial membrane potential(MMP)of cells.Seahorse XF was used to measure mitochondrial respiratory and glycolytic capacity.RESULTS Compared with the cell control group,cell viability was significantly reduced in S protein 25,50,75 and 100 mg·L-1 groups(P<0.01),and the half-inhibition concentration(IC50)was 65.05 mg·L-1.The LDH release rate wassignificantly increased(P<0.01)and the proportion of EdU positive cellswas significantly reduced(P<0.01)in S protein 25,50,75 and 100 mg·L-1 groups.S protein signifi-cantly reduced intracellular ATP content(P<0.01)at the concentrations of 75 and 100 mg·L-1,while significantly reduced intracellular MMP(P<0.05,P<0.01)at the concentrations of 50 and 75 mg·L-1.S protein 50 mg·L-1 increased the maximum value of basal glycolysis levels and glycolytic capacity(P<0.05,P<0.01),and S protein 25 and 50 mg·L-1 increased the maximum value of respiration capacity(P<0.05,P<0.01).SH-SY5Y cell viability was positively correlated with the intracellular ATP content and the MMP level(r2=0.9209,P=0.001;r2=0.6170,P=0.0025),and negatively correlated with the maximum level of basal glycolysis and glycolytic capacity(r2=0.5194,P=0.0285;r2=0.6664,P=0.0073),and nega-tively correlated with ATP production capacity(r2=0.8204,P=0.0008).CONCLUSIONS protein decreases the viability of SH-SY5Y cells and inhibited cell proliferation.The mechanism may be closely related to the disorder of energy metabolism.

OBJECTIVE To establish a mouse model of diabetes mellitus(DM)combined with severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)infection to investigate the important pathophysiological changes in the development of DM combined with SARS-CoV-2 infection.METHODS Wild-type(WT)mice and transgenic mice expressing the human angiotensin-converting enzyme 2 receptor driven by the cytokeratin-18 gene promoter(K18-hACE2)were randomly divided into the control group,DM group,SARS-CoV-2 spike protein(S)infection group and DM combined with S protein infection group,with 10 to 12 mice in each group.All the mice were induced by 10 weeks of high-fat diet combined with 40 mg·kg-1 streptozotocin(STZ)for 3 days by ip,except those in the control group or S protein infection group.The control group was given the same volume of 0.1 mol·L-1 sodium citrate buffer.Mice in the S protein infection group and DM+S protein infection group were additionally given 50 μL mixture of 15 μg SARS-CoV-2 spike protein and 1 g·L-1 polyinosinic-polycytidylic acid(poly[I:C])via intranasal drops,while the control group was given an equal volume of sterile water.The glucose tolerance level and pancreatic islet β cell function of mice were evaluated via oral glucose tolerance test at the 6th week of high-fat feeding and 1 week after the administration of STZ by ip.From the 6th week of high-fat feeding to 2 weeks after the administration of STZ,the random blood glucose and fasting blood glucose of mice were measured by a blood glucose meter.Blood samples were taken from subman-dibular veins of 3 mice in each group at 24,48 and 120 h after S protein infection,and lung tissues were taken after euthanization.The pathological changes of lungs of DM mice before and after S protein infection were observed by HE staining.Except for the DM group,blood samples were collected before S protein infection and at 6,24,48,72 and 120 h after infection.The levels of plasma interleukin 1β(IL-1β),IL-2,IL-6,IL-10,IL-17,interferon gamma-induced protein 10(IP-10),interferon γ(IFN-γ),tumor necrosis factor α(TNF-α),monocyte chemotactic protein-1(MCP-1)and granulocyte-colony stimulating factor(G-CSF)were detected by Luminex.The plasma levels of heparan sulfate(HS)were measured by enzyme-linked immunosorbent assay.The levels of cytokines and HS were correlated with the degree of pathological damage by Spearman correlation analysis.RESULTS STZ and high-fat diet could induce DM-like expression in mice,and the random blood glucose(P<0.01)and fasting blood glucose(P<0.05)after 1 week in the hACE2-DM group were significantly higher than in the WT-DM group,and the degree of islet function damage in hACE2-DM mice was significantly higher than that of WT-DM mice(P<0.05).Compared with the DM group,the DM+S group showed more severe pulmonary pathological changes after S protein infection,accompanied by a large number of inflammatory infiltrations and thickening of lung interstitial.Compared with the control group,the levels of pro-inflammatory cytokines G-CSF,IL-6 and IP-10 in the plasma of the WT-S group were significantly increased at 6 h after S pro-tein infection(P<0.01),and those of pro-inflammatory cytokine IL-17 and anti-inflammatory cytokine IL-10 were significantly increased at 24 h after S protein infection(P<0.05).Compared with the control group,the plasma levels of pro-inflammatory cytokines IL-1β,IL-6,TNF-α,MCP-1,G-CSF and IP-10 in the hACE2-S group were significantly increased at 6 h after S protein infection(P<0.05,P<0.01).IL-17 was significantly increased at 24 h and 6 h after S protein infection in the WT-DM+S group and hACE2-DM+S group,respectively(P<0.01,P<0.05).In the hACE2-DM+S group,IFN-γ and IL-1β were signifi-cantly increased in delay to 48 h(P<0.05,P<0.01),and MCP-1 was significantly increased in delay to 72h(P<0.05).Compared with the control group,the level of HS in the plasma of the WT-S group increased significantly(P<0.05,P<0.01)at 6 h and 24 h after S protein infection,but began to decrease at 48 h.At the same time,compared with the WT-S group,the HS level in the WT-DM+S group was slightly increased at 6 h after infection and decreased at 24 h.Compared with the control group,the HS level in the hACE2-S group was significantly increased at 24 h(P<0.01),as was the case with the WT-S group 24 h,48 h and 120 h after S protein infection.At 6 h,24 h and 48 h after S protein infection,the plasma HS level of the hACE2-DM+S group was significantly increased(P<0.01,P<0.05),and the duration of the increase was longer than in the hACE2-S group.Moreover,the levels of IL-1β,IL-10,MCP-1,IP-10,G-CSF and HS in plasma were positively correlated with the degree of lung dam-age in the DM+S group.CONCLUSION In this study,the mouse model of diabetes combined with SARS-CoV-2 spike protein infection has mimicked part of the pathophysiological features of clinical patients,mainly manifested as blunted immune response and elevated HS levels with longer duration to infection alone.IL-1β,IL-10,MCP-1,IP-10,G-CSF and HS may keep track of the course of disease in patients with diabetes combined with SARS-CoV-2 infection.

Macrophage-capping protein(CapG)is a member of the gelsolin superfamily.It is a universal multifunctional actin binding protein in the body and highly expressed in breast cancer,bladder cancer,prostate cancer and other types of cancer,which can promote the metastasis and invasion of cancer cells.This article reviews the structure,function,related signal pathways and roles of CapG in tumor invasiveness.

OBJECTIVE To investigate the damage effect and mechanisms of cyclophosphamide(CTX)and its active metabolite derivative 4-hydroperoxycyclophosphamide(4-HC)to human neuroblas-toma SH-SY5Y cells.METHODS SH-SY5Y cells were treated with CTX[0(cell control),0.01,0.1,1,5,10,20,40 and 80 mmol·L-1]and 4-HC[0(cell control),0.01,0.1,1,5,10,20,40 and 80 μmol·L-1]for 48 h.Cell confluence and morphology were observed by the IncuCyte ZOOM system.Cell viability was assessed by CCK-8 assay.Lactate dehydrogenase(LDH)release was measured by LDH assay kit.SH-SY5Y cells were treated with CTX(0,1,5,10 and 20 mmol·L-1)and 4-HC(0,1,5,10 and 20 μmol·L-1)for 48 h before cell proliferation was analyzed by 5-ethynyl-2′-deoxyuridine(EdU)staining assay.Immunofluorescence was employed to assess the levels of the DNA double-strand break marker γ-H2AX and to evaluate changes in mitochondrial membrane potential.SH-SY5Y cells were treated with CTX(0,1,5 and 10 mmol·L-1)and 4-HC(0,1,5 and 10 μmol·L-1)for 48 h,and the alterations in glycolysis and oxidative phosphorylation levels were analyzed using the Seahorse XFe96 Analyzer.RESULTS Compared with the cell control group,cell confluence and cell viability were significantly reduced in the CTX and 4-HC groups(P<0.01),and the half-maximal inhibitory concentrations(IC50)for CTX and 4-HC were 4.44 mmol·L-1 and 4.78 μmol·L-1,respectively.The release rate of LDH was signif-icantly increased while the percentage of EdU+cells was significantly reduced in the CTX and 4-HC groups(P<0.01).The percentage of γ-H2AX+cells was significantly increased and mitochondrial membrane potential significantly decreased in the CTX and 4-HC group(P<0.05).Treatment with CTX and 4-HC resulted in reduced levels of maximum glycolytic capacity,glycolytic reserve,maximal respi-ration,and ATP production(P<0.05).CONCLUSION CTX and 4-HC exert significant cytotoxic effects on SH-SY5Y cells by disrupting cell membrane structure,impeding cell proliferation,and reducing cell viability.The mechanisms underlying these effects may involve intracellular DNA damage,disturbance of energy metabolism and mitochondrial dysfunction.