1.A Novel Scorpion Toxin LmKTx13 Inhibits the Voltage-gated Potassium Channel Kv1.3
Jia-Xin QIN ; Xiao-Qing LUO ; Min-Juan LU ; Jun-Xian JU ; Qing ZHOU ; Wen-Xing WANG ; Zhong-Hua LIU ; Min-Zhi CHEN ; Xi ZHOU
Chinese Journal of Biochemistry and Molecular Biology 2025;41(10):1392-1401
Kv1.3,a voltage-gated potassium channel,is highly expressed in T lymphocytes,the nervous system,and vascular smooth muscle cells.It plays a critical role in membrane excitability and electrical signal transduction,serving as an important target for studying T-cell function and providing a promising direction for developing therapeutics against autoimmune and inflammatory diseases.Therefore,the de-velopment of specific inhibitors of Kv1.3 channel has emerged as a novel therapeutic strategy for these disorders.In this study,we isolated and purified a novel Kv1.3-inhibitory peptide toxin,LmKTx13,from the venom of the scorpion Lychas mucronatus using reversed-phase high-performance liquid chroma-tography(RP-HPLC).LmKTx13 consists of 38 amino acid residues,including six cysteines that form three disulfide bonds.Whole-cell patch-clamp recordings revealed that LmKTx13 potently inhibited Kv1.3 with an IC50 of 7.92±3.0 nmol/L.Selectivity analysis showed that 2 μmol/L LmKTx13 also in-hibited Kv1.2 and Kv1.7,but exhibited no significant effects on other potassium channel subtypes or voltage-gated sodium channels.Further investigation into the mechanism demonstrated that LmKTx13 acts as a pore-blocking inhibitor of Kv1.3.By analyzing the effects of LmKTx13 on Kv1.3 channel gating ki-netics and performing sequence alignment of the pore regions of Kv1.3 and Kv1.5,we constructed site-directed mutants and identified the pore region of Kv1.3 as the critical binding site for LmKTx13.Key residues involved in the interaction included T425,G427,and H451.In summary,we discovered a no-vel pore-blocking Kv1.3 inhibitor,LmKTx13,from L.mucronatus venom,which exhibits high affinity and selectivity for Kv1.3.These findings highlight its potential as a potential lead molecule for developing Kv1.3-targeted therapeutics.
2.In vitro fluorescent substrate assay for the activity of leucine aminopeptidase(LAP)in Echinococcus multilocularis
Jia-yu CHEN ; Yao DAI ; Shun-juan WANG ; Yang XIAO ; Xin-zong YAN ; Tong LIU ; Zhi-hao YUAN ; Kai-li SHI ; Run-le LI ; Feng TANG
Chinese Journal of Zoonoses 2025;41(1):23-31
This study was aimed at developing an in vitro fluorescent substrate assay for the activity of leucyl aminopeptid-ase(LAP)from Echinococcus multilocularis and comparing it with the chemical chromogenic substrate enzyme activity assay.Through the establishment of reaction conditions for the fluorescent substrate-based in vitro enzyme activity assay,we com-pared the differences between the fluorescent substrate L-Leucine-7-amido-4-methylocoumarin(Leu-AMC)and the chemical chromogenic substrate L-Leucine-4-nitroanilide(Leu-pNA)through molecular docking,inhibition rates,and precision measures.Molecular docking revealed that the fluorescent substrate Leu-AMC had higher affinity for the protein than the chemical chromogenic substrate Leu-pNA.Through analysis of the effects of varying reaction conditions on fluorescence intensi-ty,we optimized the fluorescent substrate enzyme activity assay to demonstrate favorable performance at a reaction temperature of 37℃,a pH of 9.0,a protein concentration of 800 nmol/L,and a reaction duration of 60 minutes.Leu-AMC exhibited significant and distinct responses at a 5 μmol/L substrate concentration,under varying substrate conditions.The fluo-rescent substrate assay demonstrated more significant intergroup differences than the chemical chromogenic substrate assay when various inhibitors were added.This study established a fluorescence-based enzyme activity assay for leucyl aminopeptidase from Echinococcus multilocularis by using Leu-AMC as the substrate;this method demonstrated a more significant intergroup difference and sensitivity than the chemical chromogenic substrate assay.
3.Effects of fangchinoline derivative LYY-32 on biological properties of BLM DNA helicase
Wang-ming ZHANG ; Qin-ying FENG ; Xiao-yu SONG ; Xin-zhong ZHOU ; Juan LU ; Wan-qing XIE ; Zhi-wen LAI ; Wei-dong PAN ; Jie-lin LIU
Chinese Pharmacological Bulletin 2025;41(9):1680-1686
Aim To investigate the effects of the fangchinoline derivative LYY-32 on the biological prop-erties of the BLM642-1290 DNA helicase,in order to lay a foundation for further research on its antitumor activity.Methods Fluorescence polarization assay,malachite green-phosphate and ammonium molybdate colorime-try,and fluorescein-labeled DNA gel electrophoresis experiments were conducted to study the effects of fangchinoline derivative LYY-32 on the DNA binding activity,ATPase activity,and DNA unwinding activity of BLM642-1290 DNA helicase.The effects of LYY-32 on the DNA unwinding activity of DNA helicase in cells were studied using fluorescent techniques and time-lapse microscopy.Ultraviolet spectral scanning was used to investigate the effects of LYY-32 on the confor-mation of the BLM642-1290 DNA helicase.Results At a concentration of 10 μmol·L-1,the inhibition rate of LYY-32 on BLM642-1290 DNA helicase binding to dsDNA was 53.17%.At a concentration of 5 μmol·L-1,the inhibition rate of LYY-32 on BLM642-1290 DNA helicase binding to ssDNA was 88.49%.The inhibition rate of LYY-32 on the ATPase activity of BLM642-1290 DNA he-licase was 89.3%at a concentration of 50 μmol·L-1.When the concentration of LYY-32 exceeded 5μmol·L-1,its inhibition rate on the DNA unwinding activity of BLM642-1290 DNA helicase was 100%.LYY-32 also significantly inhibited the DNA unwinding ac-tivity of DNA helicase in cells.However,LYY-32 had no effect on the conformation of BLM642-1290 DNA heli-case.Conclusion The DNA binding activity,AT-Pase activity,and DNA unwinding activity of BLM642-1290 DNA helicase could be significantly inhibi-ted by the fangchinoline derivative LYY-32.
4.A Novel Scorpion Toxin LmKTx13 Inhibits the Voltage-gated Potassium Channel Kv1.3
Jia-Xin QIN ; Xiao-Qing LUO ; Min-Juan LU ; Jun-Xian JU ; Qing ZHOU ; Wen-Xing WANG ; Zhong-Hua LIU ; Min-Zhi CHEN ; Xi ZHOU
Chinese Journal of Biochemistry and Molecular Biology 2025;41(10):1392-1401
Kv1.3,a voltage-gated potassium channel,is highly expressed in T lymphocytes,the nervous system,and vascular smooth muscle cells.It plays a critical role in membrane excitability and electrical signal transduction,serving as an important target for studying T-cell function and providing a promising direction for developing therapeutics against autoimmune and inflammatory diseases.Therefore,the de-velopment of specific inhibitors of Kv1.3 channel has emerged as a novel therapeutic strategy for these disorders.In this study,we isolated and purified a novel Kv1.3-inhibitory peptide toxin,LmKTx13,from the venom of the scorpion Lychas mucronatus using reversed-phase high-performance liquid chroma-tography(RP-HPLC).LmKTx13 consists of 38 amino acid residues,including six cysteines that form three disulfide bonds.Whole-cell patch-clamp recordings revealed that LmKTx13 potently inhibited Kv1.3 with an IC50 of 7.92±3.0 nmol/L.Selectivity analysis showed that 2 μmol/L LmKTx13 also in-hibited Kv1.2 and Kv1.7,but exhibited no significant effects on other potassium channel subtypes or voltage-gated sodium channels.Further investigation into the mechanism demonstrated that LmKTx13 acts as a pore-blocking inhibitor of Kv1.3.By analyzing the effects of LmKTx13 on Kv1.3 channel gating ki-netics and performing sequence alignment of the pore regions of Kv1.3 and Kv1.5,we constructed site-directed mutants and identified the pore region of Kv1.3 as the critical binding site for LmKTx13.Key residues involved in the interaction included T425,G427,and H451.In summary,we discovered a no-vel pore-blocking Kv1.3 inhibitor,LmKTx13,from L.mucronatus venom,which exhibits high affinity and selectivity for Kv1.3.These findings highlight its potential as a potential lead molecule for developing Kv1.3-targeted therapeutics.
5.Effect of Graft Composition on Viral Infection and Survival after Allogeneic Hematopoietic Stem Cell Transplantation
Fan LIU ; Shan WANG ; Qiu-Juan ZHU ; Tao WANG ; Wei-Wei TIAN ; Rong GONG ; Zhi-Lin GAO
Journal of Experimental Hematology 2025;33(6):1803-1808
Objective:To investigate the effect of infusing different doses of graft cells on viral infections and survival after allogeneic hematopoietic stem cell transplantation(allo-HSCT).Methods:Clinical data of 99 patients with hematological diseases who underwent allo-HSCT in Shanxi Bethune Hospital were retrospectively analysed.The proportion of mononuclear cells(MNC)was counted microscopically,the proportions and absolute counts of CD34+cells and lymphocyte subsets(including CD3+T,CD4+T,CD8+T,CD4+CD8+T,B,and NK cells)were detected by flow cytometry,and the infusion dose of each cell types was calculated.The patients were divided into high-dose group and low-dose group based on the median value of the infused cell dose.The effects of different doses of various graft cells on post-transplant viral infections(CMV,EBV,BKV)and survival were analyzed.Results:The low-dose MNC(<7.97 × 108/kg)and high-dose CD4+CD8+T cell(≥3.02 × 106/kg)groups had a higher Epstein-Barr virus(EBV)infection rate(P=0.031;P=0.020).The high-dose CD34+cell group and low-dose CD3+T,CD8+T and natural killer(NK)cell groups showed a trend toward higher EBV infection rates,but the differences were not statitsically significant(P>0.05).There was no significant difference in the rates of EBV infection between the high-dose and low-dose groups of CD4+T and B cells(P>0.05).Multivariate analysis revealed that the doses of MNC and CD4+CD8+T cells in the graft were independent factors influencing EBV infection(P=0.023;P=0.016).The doses of cells in the graft showed no significant impact on CMV and BKV infection,or patient survival(P>0.05).Conclusion:Infusing a lower dose of MNC and a higher dose of CD4+CD8+T cells increases the risk of EBV infection,but does not affect the survival outcome.
6.Epidemiological distribution characteristics and transmission patterns of Campylobacter in a Shandong broiler slaughterhouse
Shuai MIAO ; Xiu-mei HUANG ; Lin WANG ; Jun-hui LIU ; Jian-mei ZHAO ; Yu-bin GAO ; Shi-ping SONG ; Si-yu ZHANG ; Na LIU ; Ge ZHAO ; Xi-yue ZHANG ; Jun-wei WANG ; Juan WANG ; Zhi-na QU
Chinese Journal of Zoonoses 2025;41(6):583-591
This research investigated the contamination level,distribution of drug-resistant strains,and molecular epidemiologi-cal characteristics of Campylobacter,and further explored transmission pathways and prevention strategies.Cecum,chicken carcass,chicken product,and environmental samples,as well as swabs from workers'hands,were collected from a slaughterhouse in a large broiler group in the Jiaodong area between August 2023 and July 2024.Quantitative contamination assessment of Campylobacter in chicken carcasses and chicken products was performed.After microbial mass spectrometry identification,the representative strains of different links were selected for drug resistance testing and whole genome sequencing(WGS).On the basis of the sequencing results,the resistance genes,virulence genes,multilocus sequence typing(MLST),and phylogenetic characteristics of representative strains were analyzed.Homology comparisons were performed between isolates and strains from patients with diarrhea in the NCBI database.A total of 297 Campylobacter strains were isolated from 806 samples,and the overall detection rate was 36.85%.The detection rate of Campylobacter was highest in the evisceration process(47.33%),followed by the cutting process(35.64%).Overall,the Campylo-bacter detection rate first increased,then decreased,and subsequently increased.Drug sensitivity testing revealed that 90 isolates were resistant to nalidixic acid and ciprofloxacin,and 94.97%of isolates were resistant to tetracycline.WGS showed that both Campylo-bacter jejuni(C.jejuni)and Campylobacter coli(C.coli)carried many drug resistance and virulence genes.ST-14176 of C.jejuni was isolated for the first time herein.The predominant ST-8261 strain of C.jejuni and ST-860,ST-829,and ST-1586 strains of C.coli are known to cause human diarrhea.LOS expression genes associated with Guillain-Barré syndrome(GBS)were detected in both C.jejuni isolates from the slaughter chain and patients with GBS.Some strains exhibited close genetic relatedness to human-derived Campylo-bacter strains from the NCBI database.The detection rate of Campylobacter in the slaughterhouse first increased,then decreased,and subsequently increased,and the quantitative contamination level of each link was similar to the detection rate.Quantitative analysis of chicken carcasses/products revealed that the average bacterial load was highest in eviscerated carcasses(102.80 cfu/g),and the high-est amount of Campylobacter in chicken products reached 451.80 cfu/g.Abundant drug resistance genes and virulence genes were iden-tified,and the drug resistance genes were highly correlated with the drug resistance rate.Therefore,surveillance intensity and control measures for Campylobacter in slaughter processes should be strengthened.
7.In vitro fluorescent substrate assay for the activity of leucine aminopeptidase(LAP)in Echinococcus multilocularis
Jia-yu CHEN ; Yao DAI ; Shun-juan WANG ; Yang XIAO ; Xin-zong YAN ; Tong LIU ; Zhi-hao YUAN ; Kai-li SHI ; Run-le LI ; Feng TANG
Chinese Journal of Zoonoses 2025;41(1):23-31
This study was aimed at developing an in vitro fluorescent substrate assay for the activity of leucyl aminopeptid-ase(LAP)from Echinococcus multilocularis and comparing it with the chemical chromogenic substrate enzyme activity assay.Through the establishment of reaction conditions for the fluorescent substrate-based in vitro enzyme activity assay,we com-pared the differences between the fluorescent substrate L-Leucine-7-amido-4-methylocoumarin(Leu-AMC)and the chemical chromogenic substrate L-Leucine-4-nitroanilide(Leu-pNA)through molecular docking,inhibition rates,and precision measures.Molecular docking revealed that the fluorescent substrate Leu-AMC had higher affinity for the protein than the chemical chromogenic substrate Leu-pNA.Through analysis of the effects of varying reaction conditions on fluorescence intensi-ty,we optimized the fluorescent substrate enzyme activity assay to demonstrate favorable performance at a reaction temperature of 37℃,a pH of 9.0,a protein concentration of 800 nmol/L,and a reaction duration of 60 minutes.Leu-AMC exhibited significant and distinct responses at a 5 μmol/L substrate concentration,under varying substrate conditions.The fluo-rescent substrate assay demonstrated more significant intergroup differences than the chemical chromogenic substrate assay when various inhibitors were added.This study established a fluorescence-based enzyme activity assay for leucyl aminopeptidase from Echinococcus multilocularis by using Leu-AMC as the substrate;this method demonstrated a more significant intergroup difference and sensitivity than the chemical chromogenic substrate assay.
8.Epidemiological distribution characteristics and transmission patterns of Campylobacter in a Shandong broiler slaughterhouse
Shuai MIAO ; Xiu-mei HUANG ; Lin WANG ; Jun-hui LIU ; Jian-mei ZHAO ; Yu-bin GAO ; Shi-ping SONG ; Si-yu ZHANG ; Na LIU ; Ge ZHAO ; Xi-yue ZHANG ; Jun-wei WANG ; Juan WANG ; Zhi-na QU
Chinese Journal of Zoonoses 2025;41(6):583-591
This research investigated the contamination level,distribution of drug-resistant strains,and molecular epidemiologi-cal characteristics of Campylobacter,and further explored transmission pathways and prevention strategies.Cecum,chicken carcass,chicken product,and environmental samples,as well as swabs from workers'hands,were collected from a slaughterhouse in a large broiler group in the Jiaodong area between August 2023 and July 2024.Quantitative contamination assessment of Campylobacter in chicken carcasses and chicken products was performed.After microbial mass spectrometry identification,the representative strains of different links were selected for drug resistance testing and whole genome sequencing(WGS).On the basis of the sequencing results,the resistance genes,virulence genes,multilocus sequence typing(MLST),and phylogenetic characteristics of representative strains were analyzed.Homology comparisons were performed between isolates and strains from patients with diarrhea in the NCBI database.A total of 297 Campylobacter strains were isolated from 806 samples,and the overall detection rate was 36.85%.The detection rate of Campylobacter was highest in the evisceration process(47.33%),followed by the cutting process(35.64%).Overall,the Campylo-bacter detection rate first increased,then decreased,and subsequently increased.Drug sensitivity testing revealed that 90 isolates were resistant to nalidixic acid and ciprofloxacin,and 94.97%of isolates were resistant to tetracycline.WGS showed that both Campylo-bacter jejuni(C.jejuni)and Campylobacter coli(C.coli)carried many drug resistance and virulence genes.ST-14176 of C.jejuni was isolated for the first time herein.The predominant ST-8261 strain of C.jejuni and ST-860,ST-829,and ST-1586 strains of C.coli are known to cause human diarrhea.LOS expression genes associated with Guillain-Barré syndrome(GBS)were detected in both C.jejuni isolates from the slaughter chain and patients with GBS.Some strains exhibited close genetic relatedness to human-derived Campylo-bacter strains from the NCBI database.The detection rate of Campylobacter in the slaughterhouse first increased,then decreased,and subsequently increased,and the quantitative contamination level of each link was similar to the detection rate.Quantitative analysis of chicken carcasses/products revealed that the average bacterial load was highest in eviscerated carcasses(102.80 cfu/g),and the high-est amount of Campylobacter in chicken products reached 451.80 cfu/g.Abundant drug resistance genes and virulence genes were iden-tified,and the drug resistance genes were highly correlated with the drug resistance rate.Therefore,surveillance intensity and control measures for Campylobacter in slaughter processes should be strengthened.
9.Effect Analysis of Different Interventions to Improve Neuroinflammation in The Treatment of Alzheimer’s Disease
Jiang-Hui SHAN ; Chao-Yang CHU ; Shi-Yu CHEN ; Zhi-Cheng LIN ; Yu-Yu ZHOU ; Tian-Yuan FANG ; Chu-Xia ZHANG ; Biao XIAO ; Kai XIE ; Qing-Juan WANG ; Zhi-Tao LIU ; Li-Ping LI
Progress in Biochemistry and Biophysics 2025;52(2):310-333
Alzheimer’s disease (AD) is a central neurodegenerative disease characterized by progressive cognitive decline and memory impairment in clinical. Currently, there are no effective treatments for AD. In recent years, a variety of therapeutic approaches from different perspectives have been explored to treat AD. Although the drug therapies targeted at the clearance of amyloid β-protein (Aβ) had made a breakthrough in clinical trials, there were associated with adverse events. Neuroinflammation plays a crucial role in the onset and progression of AD. Continuous neuroinflammatory was considered to be the third major pathological feature of AD, which could promote the formation of extracellular amyloid plaques and intracellular neurofibrillary tangles. At the same time, these toxic substances could accelerate the development of neuroinflammation, form a vicious cycle, and exacerbate disease progression. Reducing neuroinflammation could break the feedback loop pattern between neuroinflammation, Aβ plaque deposition and Tau tangles, which might be an effective therapeutic strategy for treating AD. Traditional Chinese herbs such as Polygonum multiflorum and Curcuma were utilized in the treatment of AD due to their ability to mitigate neuroinflammation. Non-steroidal anti-inflammatory drugs such as ibuprofen and indomethacin had been shown to reduce the level of inflammasomes in the body, and taking these drugs was associated with a low incidence of AD. Biosynthetic nanomaterials loaded with oxytocin were demonstrated to have the capability to anti-inflammatory and penetrate the blood-brain barrier effectively, and they played an anti-inflammatory role via sustained-releasing oxytocin in the brain. Transplantation of mesenchymal stem cells could reduce neuroinflammation and inhibit the activation of microglia. The secretion of mesenchymal stem cells could not only improve neuroinflammation, but also exert a multi-target comprehensive therapeutic effect, making it potentially more suitable for the treatment of AD. Enhancing the level of TREM2 in microglial cells using gene editing technologies, or application of TREM2 antibodies such as Ab-T1, hT2AB could improve microglial cell function and reduce the level of neuroinflammation, which might be a potential treatment for AD. Probiotic therapy, fecal flora transplantation, antibiotic therapy, and dietary intervention could reshape the composition of the gut microbiota and alleviate neuroinflammation through the gut-brain axis. However, the drugs of sodium oligomannose remain controversial. Both exercise intervention and electromagnetic intervention had the potential to attenuate neuroinflammation, thereby delaying AD process. This article focuses on the role of drug therapy, gene therapy, stem cell therapy, gut microbiota therapy, exercise intervention, and brain stimulation in improving neuroinflammation in recent years, aiming to provide a novel insight for the treatment of AD by intervening neuroinflammation in the future.
10.Correlation Analysis between Immune Cells in Graft and Early Immune Reconstitution after Allogeneic Hematopoietic Stem Cell Transplantation
Shan WANG ; Fan LIU ; Qiu-Juan ZHU ; Tao WANG ; Rong GONG ; Wei-Wei TIAN ; Zhi-Lin GAO
Journal of Experimental Hematology 2025;33(4):1173-1180
Objective:To investigate the correlation between the types and quantities of immune cells in the graft and early immune reconstitution after allogeneic hematopoietic stem cell transplantation(allo-HSCT)and their influence on clinical prognosis.Methods:The clinical data of 83 patients with hematological diseases who received allo-HSCT in Shanxi Bethune Hospital from September 2020 to June 2023 were retrospectively analyzed.The number of mononuclear cells(MNC),CD34+cells and lymphocyte subsets(including CD3+T,CD3+CD4+T(Th),CD3+CD8+T(Ts),NK cells and B cells)infused into the recipients was counted,and the peripheral blood lymphocytes were detected before conditioning and on days 14,30,60 and 100 post-HSCT.Results:Multivariate analysis showed that the number of MNC in the graft affected the recovery of CD4+T lymphocytes after HSCT,and the number of CD4+T lymphocytes in the graft affected the recovery of NK cells and B cells after HSCT.The patient age,donor sex,stem cell source,degree of HLA matching,use of ATG before HSCT,the occurrence of acute graft-versus-host disease(aGVHD)after HSCT,and viral infection all affect the early cellular immune reconstitution post-HSCT.The number of infused cells had no significant impact on the median engraftment time for neutrophils and platelets after HSCT.Patients with lower numbers of CD3+T,CD4+T and B cells in the graft were more prone to viral infection after HSCT.However,the cells in the graft had no significant effect on disease recurrence or mortality.Conclusion:The recovery rate of lymphocyte count after allo-HSCT varies.The numbers of MNC and CD4+T cells in the graft may be related to the cellular immune reconstitution after HSCT,while the numbers of CD34+,CD3+T,CD8+T,NK and B cells have no significant effect on the cellular immune reconstruction.The numbers of CD3+T,CD4+T and B cells in the graft were negatively correlated with viral infection after HSCT,but the cellular components of the graft have no obvious influence on hematopoietic reconstitution,disease recurrence,death,recurrence-free survival(RFS)and overall survival(OS)after HSCT.

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