Bacteriocin-like inhibitory substance (BLIS) activity of Streptococcus macedonicus MBF10-2 and its synergistic action in combination with antibiotics

Objective: To characterize the bacteriocin-like inhibitory-substances(BLIS) activity of Streptococcus macedonicus MBF10-2 [named BLIS(MBF10-2)], a bacteriocinogenic strain isolated from an Indonesian tofu byproduct.Methods: BLIS(MBF10-2) was obtained by culturing the bacterium, and standard deferred antagonism assays were used to demonstrate its activity. The antibacterial testing of fractions collected by filtration using 3–30 kDa cut-off membrane sizes were carried out by performing well diffusion method.Results: The growth of Micrococcus luteus, Streptococcus pyogenes, Lactococcus lactis,Leuconostoc mesenteroides and Weissella confusa were inhibited by BLIS(MBF10-2).Interestingly, BLIS-containing fractions obtained from sequential application on ultrafiltration membranes indicated that this bacterium Streptococcus macedonicus MBF10-2 could produces at least two antimicrobial peptides activities, one of which is likely to be a lantibiotic peptide. Potential synergistic activity against certain Gram-positive(but not Gram-negative) species when partnered with antibiotics(ampicillin, tetracycline or kanamycin) were observed.Conclusion: Combination of some BLIS(MBF10-2) active fractions with antibiotics(ampicillin, tetracycline or kanamycin) could demonstrate synergistic activities against certain Gram-positive species.

The roles of macrophage migration inhibitory factor in retinal diseases

Macrophage migration inhibitory factor(MIF),a multifunctional cytokine,is secreted by various cells and participates in inflammatory reactions,including innate and adaptive immunity.There are some evidences that MIF is involved in many vitreoretinal diseases.For example,MIF can exacerbate many types of uveitis;measurements of MIF levels can be used to monitor the effectiveness of uveitis treatment.MIF also alleviates trauma-induced and glaucoma-induced optic nerve damage.Furthermore,MIF is critical for retinal/choroidal neovascularization,especially complex neovascularization.MIF exacerbates retinal degeneration;thus,anti-MIF therapy may help to mitigate retinal degeneration.MIF protects uveal melanoma from attacks by natural killer cells.The mechanism underlying the effects of MIF in these diseases has been demonstrated:it binds to cluster of differentiation 74,inhibits the c-Jun N-terminal kinase pathway,and triggers mitogen-activated protein kinases,extracellular signal-regulated kinase-1/2,and the phosphoinositide-3-kinase/Akt pathway.MIF also upregulates Toll-like receptor 4 and activates the nuclear factor kappa-B signaling pathway.This review focuses on the structure and function of MIF and its receptors,including the effects of MIF on uveal inflammation,retinal degeneration,optic neuropathy,retinal/choroidal neovascularization,and uveal melanoma.

Exploration of cyclooxygenase-2 inhibitory peptides from walnut dreg proteins based on in silico and in vitro analysis

Walnut dreg protein hydrolysates(WDPHs)exhibit a variety of biological activities,however,the cyclooxygenase-2(COX-2)inhibitory peptide of WDPHs remain unclear.The aim of this study was to rapidly screen for such peptides in WDPHs through a combination of in silico and in vitro analysis.In total,1262 peptide sequences were observed by nano liquid chromatography/tandem mass spectrometry(nano LC-MS/MS)and 4 novel COX-2 inhibitory peptides(AGFP,FPGA,LFPD,and VGFP)were identified.Enzyme kinetic data indicated that AGFP,FPGA,and LFPD displayed mixed-type COX-2 inhibition,whereas VGFP was a non-competitive inhibitor.This is mainly because the peptides form hydrogen bonds and hydrophobic interactions with residues in the COX-2 active site.These results demonstrate that computer analysis combined with in vitro evaluation allows for rapid screening of COX-2 inhibitory peptides in walnut protein dregs.

A Pair of New Spirocyclic Alkaloid Enantiomers with TrxR Inhibitory Activities Were Isolated from Marine-Derived Aspergillus ruber TX-M4-1

One new spirocyclic alkaloid,5-isopentenyl-cryptoechinuline D(1),along with 11 known compounds(2–12),were iso-lated from a marine fungus Aspergillus ruber TX-M4-1.The structures of compounds 1–12 were elucidated by spectroscopic evi-dences.Compound 1 was initially isolated as an enantiomer,and further separation of 1 by chiral HPLC afforded a pair of enantio-mers,including(-)-5-isopentenyl-cryptoechinuline D(1a)and(+)-5-isopentenyl-cryptoechinuline D(1b).Their absolute configura-tions were elucidated by ECD spectroscopic data.Compounds 1a,5 and 10 could inhibit thioredoxin reductase(TrxR)activity with IC50 values of 6.2,36.3 and 18.6μmol L^(-1),respectively.Surface plasmon resonance(SPR)study also demonsrated the interactions between compounds 6,8 and Niemann-Pick C1 Like 1(NPC1L1)respectively,which indicate that compounds 6 and 8 are potential NPC1L1 inhibitors.

Paradoxical roles of inhibitory autapse and excitatory synapse in formation of counterintuitive anticipated synchronization

Different from the common delayed synchronization(DS)in which response appears after stimulation,anticipated synchronization(AS)in unidirectionally coupled neurons denotes a counterintuitive phenomenon in which response of the receiver neuron appears before stimulation of the sender neuron,showing an interesting function of brain to anticipate the future.The dynamical mechanism for the AS remains unclear due to complex dynamics of inhibitory and excitatory modulations.In this article,the paradoxical roles of excitatory synapse and inhibitory autapse in the formation of AS are acquired.Firstly,in addition to the common roles such that inhibitory modulation delays and excitatory modulation advances spike,paradoxical roles of excitatory stimulation to delay spike via type-II phase response and of inhibitory autapse to advance spike are obtained in suitable parameter regions,extending the dynamics and functions of the excitatory and inhibitory modulations.Secondly,AS is related to the paradoxical roles of the excitatory and inhibitory modulations,presenting deep understandings to the AS.Inhibitory autapse induces spike of the receiver neuron advanced to appear before that of the sender neuron at first,and then excitatory synapse plays a delay role to prevent the spike further advanced,resulting in the AS as the advance and delay effects realize a dynamic balance.Lastly,inhibitory autapse with strong advance,middle advance,and weak advance and delay effects induce phase drift(spike of the receiver neuron advances continuously),AS,and DS,respectively,presenting comprehensive relationships between AS and other behaviors.The results present potential measures to modulate AS related to brain function.

Novel insight into the formation and inhibition mechanism of dipeptidyl peptidase-Ⅳ inhibitory peptides from fermented mandarin fish(Chouguiyu)

Fermented foods are a potential source to produce novel dipeptidyl peptidase-IV inhibitory peptides(D4IPs).In this study,the fermented mandarin fish(Chouguiyu)was used to screen D4IPs and their formation mechanism was studied by metagenomics and peptidomics.A total of 400 D4IPs with DPP-IV inhibition structure and high hydrophobicity were identified.The correlation network map showed that Lactococcus,Bacillus,Lysobacter,Pelagivirga,Kocuria,Escherichia,Streptococcus,and Peptostreptococcus were significantly correlated with the most D4IPs.Four stable D4IPs,including KAGARALTDAETAT,GEKVDFDDIQK,VVDADEMYLKGK,and GQKDSYVGDEAQ were respectively from the precursor proteins parvalbumin,troponin,myosin,and actin,and were mainly formed by the hydrolysis of subtilisin(EC 3.4.21.62),aspartic proteinase(EC 3.4.23.1),thermolysin(EC 3.4.24.27),oligopeptidase B(EC 3.4.21.83),and proteinase P1(EC 3.4.21.96)from Bacillus,Kocuria,Lysobacter,Lactococcus,and Peptostreptococcus.The inhibition mainly resulted from the hydrogen bond and salt bridge between D4IPs and DPP-IV enzyme.This study provides important information on the proteases and related microbial strains to directionally prepare D4IPs in Chouguiyu.

Inhibitory effect induced by fractional Gaussian noise in neuronal system

We discover a phenomenon of inhibition effect induced by fractional Gaussian noise in a neuronal system. Firstly,essential properties of fractional Brownian motion(fBm) and generation of fractional Gaussian noise(fGn) are presented,and representative sample paths of fBm and corresponding spectral density of fGn are discussed at different Hurst indexes.Next, we consider the effect of fGn on neuronal firing, and observe that neuronal firing decreases first and then increases with increasing noise intensity and Hurst index of fGn by studying the time series evolution. To further quantify the inhibitory effect of fGn, by introducing the average discharge rate, we investigate the effects of noise and external current on neuronal firing, and find the occurrence of inhibitory effect about noise intensity and Hurst index of f Gn at a certain level of current. Moreover, the inhibition effect is not easy to occur when the noise intensity and Hurst index are too large or too small. In view of opposite action mechanism compared with stochastic resonance, this suppression phenomenon is called inverse stochastic resonance(ISR). Finally, the inhibitory effect induced by fGn is further verified based on the inter-spike intervals(ISIs) in the neuronal system. Our work lays a solid foundation for future study of non-Gaussian-type noise on neuronal systems.

Characterization of SARS-COV-2 main protease inhibitory peptides from Ulva prolifera proteins

The main protease(M^(pro))is essential for the replication of SARS-COV-2 and therefore represents a promising anti-viral target.In this study,we screened M^(pro)inhibitory peptides from Ulva prolifera protein on in-silico proteolysis.Cytotoxicity analysis using the online toxic prediction tool ToxinPred revealed that all the peptides were non-cytotoxic.The hexapeptide(SSGFID)exhibited high M^(pro)inhibitory activity in molecular docking and its IC_(50)value was 139.40±0.82μmol/L in vitro according to fluorescence resonance energy transfer assay(FRET).Quantitative real-time(qRT-)PCR results show that SSGFID could stimulate the expression of mitosis-related factors,including nuclear factor-κB,cyclin D1,and cyclin-dependent kinase 4,to promote the proliferation of mice splenocytes.Stability study revealed that SSGFID showed resistance against pepsin and trypsin but lost D(Asp)after pretreatment at121℃ for 15 min.Besides,SSGFID was mainly transported through the Caco-2 cell monolayer by the peptide transporter PepT1 and passive-mediated transport during the transport study.Unfortunately,the peptide was also degraded by Caco-2 intracellular enzymes,and the transfer rate of intact peptide was4.2%.Furthermore,Lineweaver–Burk plots demonstrated that SSGFID possessed a mixed inhibitory characteristic with M^(pro).Our study indicated the potential of Ulva prolifera as antiviral and immuneenhancing functional food ingredients and nutraceuticals.

Macrophage migration inhibitory factor facilitates astrocytic production of the CCL2 chemokine following spinal cord injury

Spinal cord injury causes accumulation of a large number of leukocytes at the lesion site where they contribute to excessive inflammation.Overproduced chemokines are responsible for the migratory process of the leukocytes,but the regulatory mechanism underlying the production of chemokines from resident cells of the spinal cord has not been fully elucidated.We examined the protein levels of macrophage migration inhibitory factor and chemokine C-C motif chemokine ligand 2 in a spinal cord contusion model at different time points following spinal cord injury.The elevation of macrophage migration inhibitory factor at the lesion site coincided with the increase of chemokine C-C motif chemokine ligand 2 abundance in astrocytes.Stimulation of primary cultured astrocytes with different concentrations of macrophage migration inhibitory factor recombinant protein induced chemokine C-C motif chemokine ligand 2 production from the cells,and the macrophage migration inhibitory factor inhibitor 4-iodo-6-phenylpyrimidine attenuated the stimulatory effect.Further investigation into the underlying mechanism on macrophage migration inhibitory factor-mediated astrocytic production of chemokine C-C motif chemokine ligand 2 revealed that macrophage migration inhibitory factor activated intracellular JNK signaling through binding with CD74 receptor.Administration of the macrophage migration inhibitory factor inhibitor 4-iodo-6-phenylpyrimidine following spinal cord injury resulted in the reduction of chemokine C-C motif chemokine ligand 2-recruited microglia/macrophages at the lesion site and remarkably improved the hindlimb locomotor function of rats.Our results have provided insights into the functions of astrocyte-activated chemokines in the recruitment of leukocytes and may be beneficial to develop interventions targeting chemokine C-C motif chemokine ligand 2 for neuroinflammation after spinal cord injury.

基于转录组学分析揭示蜡样芽胞杆菌(Bacillus cereus)AR1002阻控黄曲霉生长的生理机制研究

黄曲霉(Aspergillus flavus)极易侵染油料等农产品,其次级代谢产物黄曲霉毒素严重危害人体健康,阻控黄曲霉污染已成为亟待解决的国际难题。为探明蜡样芽胞杆菌(Bacillus cereus)AR1002抑制黄曲霉生长、阻控黄曲霉污染的生理及分子机制。该研究采用AR1002代谢产物对黄曲霉进行处理,并对黄曲霉生长及产孢表型进行鉴定,通过显微结构及转录组学分析,对AR1002的抑菌机制进行了初探。蜡样芽胞杆菌AR1002代谢物可抑制黄曲霉菌丝生长、干物质积累分别达24.73%,65.00%,减少孢子数量达98.80%;AR1002通过抑制glpA和AYR1等关键基因表达调控黄曲霉甘油磷酸代谢,通过抑制SEC61A、RAD23、ATP13A1、UBE2G2等关键基因的表达调控内质网中蛋白质加工;此外,AR1002代谢产物通过下调RAD51和RAD54B等DNA修复机制相关基因,抑制黄曲霉同源重组及非同源性末端连接过程,最终达到抑制黄曲霉生长及产孢的目的。上述结果表明,蜡样芽胞杆菌(Bacillus cereus)AR1002有望应用于实际生产中以应对黄曲霉污染问题。

C57BL/6小鼠大脑皮层区与基底神经节隆起区神经元突触发育过程比较

目的:观察小鼠皮层区和基底神经节隆起(GE)区神经元突触发育过程,阐明兴奋性突触和抑制性突触在不同脑区的体内外发育差异。方法:C57BL/6雌鼠于妊娠第13.5~15.5天断颈处死后,经无菌操作取胚胎小鼠,显微镜下逐步分离获取胚胎小鼠脑组织皮层区和GE区。体外原代培养胚胎小鼠神经元,于培养3、7、14和21 d分别收集细胞样品,并将其作为培养3、7、14和21 d组。采用实时荧光定量PCR(RT-qPCR)法检测各组小鼠皮层区和GE区原代培养神经元中突触后表达蛋白突触后密度蛋白95(PSD95)及桥尾蛋白(Gephyrin) mRNA表达水平。免疫荧光法检测各组小鼠皮层区和GE区原代培养神经元中囊泡谷氨酸转运蛋白1(vGLUT1)、 PSD95、囊泡γ-氨基丁酸(GABA)转运蛋白(vGAT)及Gephyrin蛋白表达水平。免疫荧光法检测胚胎小鼠脑组织皮层区和GE区神经元中vGLUT1及vGAT蛋白表达水平。结果:与培养3 d组比较,培养14和21 d组小鼠皮层区和GE区原代培养神经元中PSD95及Gephyrin mRNA表达水平明显升高(P<0.01);与皮层区比较,培养14 d组小鼠GE区原代培养神经元中Gephyrin mRNA表达水平明显降低(P<0.01)。显微镜下观察,培养14 d组小鼠皮层区和GE区原代培养神经元中兴奋性突触及抑制性突触均初步发育,相关蛋白呈阳性表达;其中兴奋性突触相关蛋白阳性表达在皮层区神经元中更为明显,且突触前分子vGLUT1和突触后分子PSD95在皮层区神经元的胞体及突起部位均呈现共定位的特征;抑制性突触前分子vGAT蛋白和突触后分子Gephyrin蛋白在GE区神经元胞体及突起中也呈现共定位的特征,且突触前分子较相应的突触后分子蛋白阳性表达更明显。与皮层区比较,培养14 d组小鼠GE区原代培养神经元中vGLUT1和PSD95蛋白表达水平明显降低(P<0.01),vGAT和Gephyrin蛋白表达水平明显升高(P<0.01)。培养21 d组小鼠皮层区和GE区原代培养神经元突触相关蛋白阳性表达增加,兴奋性突触和抑制性突触进一步成熟并完善。皮层区和GE区原代培养神经元的胞体及突起部位均形成了丰富的突触前后对应的表达模式,突触结构逐步发育良好,且突触前分子较相应的突触后分子蛋白阳性表达更明显。与皮层区比较,培养21 d组小鼠GE区原代培养神经元中vGLUT1和PSD95蛋白表达水平均明显降低(P<0.01),vGAT和Gephyrin蛋白表达水平均明显升高(P<0.01)。与皮层区比较,胚胎小鼠脑组织GE区神经元中vGLUT1蛋白表达水平明显降低(P<0.01),vGAT蛋白表达水平明显升高(P<0.05)。结论:皮层区和GE区神经元的突触发育具有明显的差异性,皮层区兴奋性突触发育较早,GE区抑制性突触发育较早。突触的脑区特异性发育提示不同细胞类型的神经疾病可能具有不同的发育来源。

绿豆蛋白α-淀粉酶抑制肽的制备与鉴定

采用胃-胰蛋白酶水解绿豆蛋白及其分级蛋白,以水解物α-淀粉酶活性抑制率为主要指标,结合水解度、氨基酸组成及分子质量分析其抑制效果差异及原因。结果表明,绿豆蛋白肽对α-淀粉酶活性抑制率最高,为16.51%;与绿豆分级蛋白相比,绿豆蛋白的疏水氨基酸含量和水解度最高,分别为32.68%和6.28%,水解物的肽分子质量最小,均小于20kDa,因此选用绿豆蛋白制备α-淀粉酶抑制肽。然后分离鉴定绿豆蛋白肽,新发现了17条有潜在α-淀粉酶抑制效果的肽。本研究表明绿豆蛋白较其分级蛋白具有更强的α-淀粉酶抑制效果,能够用于降血糖的功能性食品或药物中。

沉默cFLIP在重症急性胰腺炎肺损伤中的作用机制研究

目的探讨沉默细胞型Fas相关死亡区域蛋白样白介素-1β转换酶抑制蛋白(cFLIP)对重症急性胰腺炎(SAP)导致的肺损伤的影响及其可能的作用机制。方法分别取12只SD大鼠,随机分为对照组、cFLIPL(或cFLIPS)siRNA1组、cFLIPL(或cFLIPS)siRNA2组和cFLIPL(或cFLIPS)siRNA3组,筛选抑制率最高的cFLIPL siRNA和cFLIPS siRNA。50只SD大鼠随机分成假手术组、模型对照组、cFLIP siRNA-NC组、cFLIPS siRNA组、cFLIPL siRNA组,每组各10只。通过胰胆管内逆行注射3%牛磺胆酸钠溶液建立SAP模型,建模成功后,cFLIPS siRNA、cFLIPL siRNA和cFLIP siRNA-NC组大鼠尾静脉注射对应siRNA溶液,其余组注射等量0.9%NaCl溶液。HE染色检测肺组织病理学变化;ELISA检测IL-6、IL-1β和TNF-α含量;全自动分析仪检测静脉血白细胞数、中性粒细胞数;流式细胞术检测中性粒细胞凋亡;Western blotting检测中性粒细胞RIP1和caspase-8蛋白表达。结果cFLIPL siRNA2组以及cFLIPS siRNA1组干扰效率最明显,因此选择这2组进行后续实验(后续称为cFLIPL siRNA组和cFLIPL siRNA组)。与模型对照组大鼠相比,cFLIPL siRNA组和cFLIPS siRNA组大鼠肺泡结构损伤减轻,肺泡壁变薄,炎症细胞浸润减少;与模型对照组相比,cFLIPL siRNA组和cFLIPS siRNA组IL-6、IL-1β和TNF-α含量均明显降低,静脉血白细胞数、中性粒细胞数明显降低,中性粒细胞凋亡率明显升高,cFLIPL、cFLIPS和RIP1蛋白表达量明显降低,caspase-8蛋白表达量明显升高;以上差异均具有统计学意义(P<0.05)。结论本研究结果表明,靶向沉默cFLIP可能通过上调caspase-8和抑制RIP1的表达,促进中性粒细胞凋亡,减少炎症介质IL-6、IL-1β和TNF-α释放,抑制肺组织中的中性粒细胞浸润,缓解SAP导致的肺损伤,在SAP中发挥保护作用。

青钱柳叶化学成分及其α-葡萄糖苷酶抑制活性研究

目的 研究青钱柳Cyclocarya paliurus(Batal.) Iljinskaja叶的化学成分及其α-葡萄糖苷酶抑制活性。方法 青钱柳叶95%乙醇提取物采用大孔树脂、硅胶、Sephadex LH-20、聚酰胺、C18反相硅胶及半制备HPLC进行分离纯化,根据理化性质及波谱数据鉴定所得化合物的结构。采用PNPG法评价其α-葡萄糖苷酶抑制活性。结果 从中分离得到15个化合物,分别鉴定为cyclopaloside C(1)、cyclopaloside A(2)、juglanosides E(3)、vaccinin A(4)、ent-mururin A(5)、山柰酚-3-O-α-L-鼠李糖苷(6)、山柰酚-3-O-β-D-葡萄糖苷(7)、山柰酚-3-O-β-D-葡萄糖醛酸甲酯(8)、山柰酚-3-O-β-D-葡萄糖醛酸乙酯(9)、山柰酚-3-O-β-D-葡萄糖醛酸丁酯(10)、槲皮素-3-O-α-L-鼠李糖苷(11)、槲皮素-3-O-β-D-葡萄糖苷(12)、槲皮素-3-O-β-D-半乳糖苷(13)、槲皮素-3-O-β-D-葡萄糖醛酸丁酯(14)、香橙素(15)。总提取物抑制α-葡萄糖苷酶的IC_(50)值为(1.83±0.04)μg/mL,化合物1、4~5分别为(29.48±1.86)、(0.50±0.07)、(0.71±0.07)μmol/L。结论 化合物1为新四氢萘醇苷类,化合物4~5、8~10、14为首次从青钱柳叶中分离得到。化合物4~5为较少见的黄酮木脂素类化合物,对α-葡萄糖苷酶具有潜在的抑制活性。

miR-214-5p通过DNMT1介导的AXIN2基因DNA甲基化修饰在皮肤基底细胞癌中的作用机制

目的探讨皮肤基底细胞癌中轴抑制蛋白2(Axis inhibition protein 2,AXIN2)基因启动子甲基化对基因转录的影响及miR-214-5p通过靶向DNA甲基转移酶1(DNA methyltransferase1,DNMT1)对AXIN2甲基化率的调控机制。方法收集2022年1月-2023年6月在广州市皮肤病防治所就诊治疗的102例皮肤基底细胞癌(Cutaneous basal cell carcinoma,BCC)患者作为研究对象,提取癌组织和癌旁正常组织标本及基线资料。焦磷酸测序法检测AXIN2基因启动子区甲基化率。实时荧光定量PCR检测AXIN2、DNMT1基因mRNA和miR-214-5p的表达水平。将miR-214-5p模拟物(mimic)、抑制物(inhibitor)及其阴性对照(mimic NC和inhibitor NC)分别对基底细胞癌A431细胞进行转染,48 h后检测DNMT1基因mRNA表达水平和AXIN2基因甲基化率。结果BCC癌组织的AXIN2基因甲基化率显著高于癌旁正常组织(t=5.128,P<0.001),AXIN2基因mRNA相对表达水平显著低于癌旁正常组织(t=7.826,P<0.001),DNMT1基因mRNA表达水平显著高于癌旁正常组织(t=4.838,P<0.001),miR-214-5p表达水平显著低于癌旁正常组织(t=5.426,P<0.001)。BCC癌组织的AXIN2基因甲基化率与其mRNA表达水平呈负相关(r=-0.793,P<0.001),DNMT1基因mRNA水平与AXIN2基因甲基化率呈正相关(r=0.814,P<0.001),miR-214-5p表达水平与DNMT1基因mRNA水平呈负相关(r=-0.747,P<0.001)。双荧光素酶报告基因实验结果证实,DNMT1是miR-214-5p的靶基因。细胞转染后,与mimic NC、inhibitor和inhibitor NC比较,mimic的DNMT1基因mRNA水平、AXIN2基因甲基化率显著降低(P<0.001);而inhibitor的DNMT1基因mRNA水平和AXIN2基因甲基化率相较于其他三组明显上升(P<0.001)。结论miR-214-5p可通过调控下游靶蛋白DNMT1表达,影响AXIN2基因的DNA甲基化率,调控AXIN2基因的表达水平,参与皮肤基底细胞癌的发生机制。

栝楼根腐病镰孢菌拮抗菌SJ1623发酵代谢物的抑制活性

检测了6株拮抗菌发酵上清液对栝楼根腐病菌的抑制活性,采用菌丝生长速率法测定优势拮抗菌不同接种量和发酵时间对发酵上清液抑菌活性的影响,测定了不同稀释倍数的发酵上清液和脂肽粗提物对栝楼根腐病菌的抑制活性。结果表明,对栝楼根腐病菌抑制活性最高的拮抗菌为SJ1623,种子液培养时间为10 h,0.75%(体积比)的接种量效果较好;发酵上清液稀释10倍对病菌的抑制率为87.6%,脂肽粗提物50倍稀释液对病菌的抑制率为83.1%。

肝癌患者外周血中抑制树突状细胞分化的蛋白成分筛选及鉴定

目的肝癌患者外周血中靶向抑制树突状细胞分化成熟的蛋白成分筛选及鉴定。方法利用免疫磁珠分选健康人外周血CD14^(+)单核细胞,诱导分化为未成熟的树突状细胞(iDCs),进一步诱导分化为成熟的树突状细胞(mDCs),鉴定iDCs纯度。酶切健康人和肝癌患者血清孵育的iDCs的结合蛋白,回收酶切后的多肽,筛选对iDCs分化成熟有潜在调控作用的互作候选蛋白。靶向鉴定差异候选蛋白。构建过表达蛋白质粒,转染至正常肝细胞(HL7702),将细胞培养上清液与iDCs共同培养,诱导iDCs成熟,对特异性抑制iDCs成熟的肝癌源性血清蛋白进行特异性筛选和鉴定。结果TNF-α诱导前抗原标志物阳性细胞表达CD86^(+)比例为79.2%、黏附分子CD40^(+)比例为83.3%、MHC-Ⅱ抗原分子HLA-DR^(+)比例为67.6%、CD83^(+)比例为5.5%以及CD1a^(+)比例为13.7%,符合iDCs的抗原表型特征;TNF-α诱导后抗原标志物阳性细胞表达CD86^(+)比例为92.0%、CD40^(+)比例为89.0%、HLA-DR^(+)比例为68.3%、CD83^(+)比例为37%、CD1a^(+)比例为48.3%,提示iDCs已迅速分化成熟为mDCs,符合mDCs的抗原表型特征。初步确认40多种对iDCs分化成熟有潜在调控作用的互作候选蛋白。选择10种差异候选蛋白,对其过表达进行验证,显示AFP蛋白、AGXT蛋白、ATP1A1蛋白过表达能够明显抑制iDCs分化成熟为mDCs。结论共筛选出10种靶向抑制树突状细胞分化的肝癌外周血清蛋白,其中AFP蛋白、AGXT蛋白、ATP1A1蛋白能够显著抑制树突状细胞分化成熟。

急性脑梗死患者血清CFH、VASH-1表达与病情、疾病转归的关系

目的分析急性脑梗死患者血清补体H因子(CFH)、血管生成抑制蛋白-1(VASH-1)表达与病情、疾病转归的关系。方法选择96例急性脑梗死患者为研究组,根据美国国立卫生院卒中量表(NIHSS)评分分为轻度组、中度组、重度组,按疾病转归分为恶化组、转归组。另选取同期体检健康者80例为对照组。比较各组血清CFH、VASH-1水平。采用ROC评估血清CFH、VASH-1对急性脑梗死患者疾病转归的诊断价值,Logistic回归分析影响疾病转归的因素。结果血清CFH水平研究组<对照组,重度组<中度组<轻度组,恶化组<转归组;血清VASH-1水平研究组>对照组,重度组>中度组>轻度组,恶化组>转归组(P<0.05)。血清CFH、VASH-1及二者联合评估急性脑梗死疾病转归的AUC分别为0.830、0.866、0.915。血清低CFH、高VASH-1及高NHISS评分为急性脑梗死患者疾病转归的危险因素(P<0.05)。结论急性脑梗死患者血清CFH、VASH-1水平与病情、疾病转归有关,可作为评估急性脑梗死患者疾病转归的可靠生物学标志物。

血清VASH-1、VEGF对非心源性栓塞性卒中患者近期预后的预测价值

目的分析血清血管生成抑制蛋白-1(VASH-1)、血管内皮生长因子(VEGF)对非心源性栓塞性卒中患者近期预后的预测价值。方法选择2020年12月至2022年12月经商丘市第一人民医院收治的107例非心源性栓塞性卒中患者作为研究组,并根据改良Rankin量表分为预后不良组(38例)和预后良好组(69例),另选取同期93例体检健康人群作为对照组。所有纳入对象入院后24 h内采用酶联免疫吸附法检测血清VASH-1、VEGF水平。采用受试者工作特征曲线(ROC)评估血清VASH-1、VEGF对非心源性栓塞性卒中患者近期预后的评估价值,采用多因素logistic回归分析探讨影响非心源性栓塞性卒中患者近期预后的因素。结果研究组非心源性栓塞性卒中患者血清VASH-1、VEGF水平均高于对照组(P<0.05),预后不良组非心源性栓塞性卒中患者血清VASH-1、VEGF水平均高于预后良好组(P<0.05)。ROC曲线分析显示,血清VASH-1评估非心源性栓塞性卒中患者近期预后的AUC为0.833(95%CI:0.783~0.883);血清VEGF评估非心源性栓塞性卒中患者近期预后的AUC为0.845(95%CI:0.795~0.895);二者联合评估非心源性栓塞性卒中患者近期预后的AUC为0.905(95%CI:0.855~0.955)。多因素logistic回归分析发现,血清VASH-1(OR=3.662,95%CI:2.124~6.315)、VEGF(OR=3.034,95%CI:1.885~4.886)及美国国立卫生研究院卒中量表(NHISS)评分(OR=2.683,95%CI:1.771~4.065)、C反应蛋白(OR=3.721,95%CI:2.456~7.360)均为影响非心源性栓塞性卒中患者近期预后的危险因素(P<0.05)。结论血清VASH-1、VEGF在非心源性栓塞性卒中均升高,且二者水平变化与疾病近期预后密切相关,可作为预测非心源性栓塞性卒中患者近期预后的生物学标志物。

皖浙花猪干腌火腿源血糖调节肽的分离纯化、鉴定及量子化学表征

为探究小肽抑制糖类消化的机理,制备皖浙花猪干腌火腿肌肉的水提物和胃胰酶消化产物,分离纯化出α-淀粉酶和α-葡萄糖苷酶抑制活性较高的组分,鉴定、筛选其中的肽序列,采用量子化学方法计算分子前线轨道分布和能量、静电荷分布、键长等结构和电荷参数,推测活性位点。结果表明:1)酶解后火腿肌肉的粒径减小、降糖活性提高;2)水提物和胃胰酶消化产物经过葡聚糖凝胶分离后分别获得两个组分(S-Ⅰ、S-Ⅱ)和3个组分(WY-Ⅰ、WY-Ⅱ和WY-Ⅲ);3)利用质谱技术从高活性组分WY-Ⅱ中鉴定出104条长度8~24的肽序列,筛选出Peptide Ranker程序评分大于0.7的5条序列;4)前述序列的最高占据轨道多分布在精氨酸的胍基及氨基端附近基团,而最低未占轨道多分布在羧基端及附近基团;5)能级差ΔEL-H较低的序列GPMGPSGPR、LGFGGPSGPNAGR、APAPAPAPAPAPPK可能具有较高活性。根据库伦定律,其活性位点分别定位于精氨酸的C106H108、亮氨酸的C10H12和赖氨酸的C176H177,都位于C—H键。研究为探究肽的血糖调节机制,证明地方品种猪的营养价值提供了理论支撑。