Hmo1:A versatile member of the high mobility group box family of chromosomal architecture proteins

Eukaryotic chromatin consisting of nucleosomes connected by linker DNA is organized into higher order structures,which is facilitated by linker histone H1.Formation of chromatin compacts and protects the genome,but also hinders DNA transactions.Cells have evolved mechanisms to modify/remodel chromatin resulting in chromatin states suitable for genome functions.The high mobility group box(HMGB)proteins are non-histone chromatin architectural factors characterized by one or more HMGB motifs that bind DNA in a sequence nonspecific fashion.They play a major role in chromatin dynamics.The Saccharomyces cerevisiae(yeast hereafter)HMGB protein Hmo1 contains two HMGB motifs.However,unlike a canonical HMGB protein that has an acidic C-terminus,Hmo1 ends with a lysine rich,basic,C-terminus,resembling linker histone H1.Hmo1 exhibits characteristics of both HMGB proteins and linker histones in its multiple functions.For instance,Hmo1 promotes transcription by RNA polymerases I and II like canonical HMGB proteins but makes chromatin more compact/stable like linker histones.Recent studies have demonstrated that Hmo1 destabilizes/disrupts nucleosome similarly as other HMGB proteins in vitro and acts to maintain a common topological architecture of genes in yeast genome.This minireview reviews the functions of Hmo1 and the underlying mechanisms,highlighting recent discoveries.

Taq DNA聚合酶的分子改造及其在探针法qPCR直扩体系中的应用

Taq DNA聚合酶作为实时荧光定量聚合酶链式反应(qPCR)技术的核心组分,其性能优劣直接影响qPCR技术的进一步发展。然而,野生型Taq DNA聚合酶的耐抑制剂性能差、延伸性能不足。为获得具有高性能的Taq DNA聚合酶,采用基因工程技术将双链DNA结合蛋白Sso7d或Sto7d融合在野生型Taq DNA聚合酶的N端或C端,构建了4个均可溶表达的改造体,再经过耐受性测试筛选较优的改造体,结果显示:改造体Taq-Sto的耐受性最高,其热稳定性不受影响,且在1 s/kbp的延伸条件下能成功扩增靶标,表明Taq-Sto具有增强的延伸性能,在TaqMan探针法qPCR体系中对腐殖酸、单宁酸、全血等抑制剂同样表现出良好的耐受性。EMSA实验发现:Taq-Sto对DNA模板的结合亲和力有所提高,有利于增强Taq-Sto对模板的竞争力;将Taq-Sto应用于非洲猪瘟病毒(ASFV)的TaqMan探针法qPCR检测,与商品化试剂相比,Taq-Sto具有更低的ASFV检出限,且在体积分数为2%~6%的猪粪便样本或猪肉样本中的检测灵敏度分别为100.0%和85.4%,说明Taq-Sto在直扩qPCR检测领域更具有优势。

HPV16 E6、E7多表位DNA疫苗的构建及免疫效果评估

目的构建和评价HPV16 E6、E7多表位DNA疫苗诱导的特异性CTL细胞应答及其对肿瘤生长的干预作用,从而揭示其作为候选HPV治疗性疫苗的潜能。方法首先通过IEDB网站中的MHC I Processing Predictions和MHC I Binding Predictions方法,分别预测人类HLA-A^(*)02:01、HLA-A^(*)11:01、HLA-A^(*)24:02和C57BL/6小鼠H-2b的限制性CTL表位,然后根据评分以及ELISPOT实验筛选出二者共同呈递的CTL表位,并将其构建成多表位DNA疫苗(pVAX1-10P)。从预防性和治疗性二个方面研究pVAX1-10P对小鼠移植TC-1异位癌的免疫干预作用,流式细胞术检测特异性CTL应答。结果获得10条可被人与鼠MHC分子共呈递的CTL表位,ELISPOT结果表明这10条CTL表位均能诱导小鼠淋巴细胞产生特异性免疫应答;由此构建的多表位DNA疫苗pVAX1-10P无论在预防性实验还是治疗性实验中,均能诱导特异性的细胞免疫并抑制肿瘤的生长。结论构建的HPV16 E6、E7多表位DNA疫苗pVAX1-10P能够诱导特异性CTL应答,显著抑制肿瘤生长,有望作为候选HPV治疗性DNA疫苗。

七种蛋白酶抑制剂对多房棘球蚴DNA损伤诱导样1蛋白活性的影响

目前,多房棘球蚴病(alveolar echinococcosis, AE)尚无有效药物治疗手段,迫切需要开发新型治疗药物。前期研究表明,HIV蛋白酶抑制剂(HIV protease inhibitors, HIV PIs)具有潜在抗寄生虫功能。本文旨在研究HIV PIs对Echinococcus multilocularis(Emu)DNA损伤诱导样1蛋白(DNA damage inducible 1 protein, Ddi1)活性的影响。本研究通过构建真核表达重组载体pFastBac1-Emu Ddi1,在昆虫细胞系Sf9细胞中表达筛选出P1代和P2代,纯化出可溶性Ddi1重组蛋白,然后与目的蛋白的荧光底物检测纯化蛋白的活性,进一步检测沙奎那韦(saquinavir, SQV)、利托那韦(ritonavir, RTV)、安普那韦(amprenavir, APV)、阿扎那韦(atazanavir, ATV)、洛匹那韦(lopinavir, LPV)、福沙那韦(fosamprenavir, Fos)、达芦那韦(darunavir, DRV)等7种HIV PIs对Emu Ddi1重组蛋白活性的抑制能力。结果显示:细胞系内真核表达产物的酶活Km为1.422μmol·L^(-1),具有良好的亲和力和活性,最终筛到沙奎那韦对Ddi1蛋白二聚体活性位点的抑制率达67%,其IC_(50)为34,说明沙奎那韦对Emu Ddi1重组蛋白酶活性具有良好的抑制效果。以上结果提示:沙奎那韦抑制重组蛋白Ddi1的活性,可能成为Ddi1的靶向药物,以期为替代药物或开发联合用药提供基础。

DNA倍体定量分析结合P16蛋白在宫颈癌筛查中的意义

目的:探讨DNA定量分析结合P16蛋白免疫组化染色在宫颈筛查中的意义。方法:选取2020年3月~2021年3月淮安市肿瘤医院门诊及住院检查病例4334例为研究对象,对宫颈细胞学DNA定量分析提示异常者,在知情同意情况下,进行阴道镜下宫颈活检、组织学病理检查及P16蛋白染色检查,比较分析DNA倍体定量分析提示异常者与其组织学病理之间的关系,以及P16蛋白表达与病理组织学之间的关系,以评价衡量DNA定量分析结合P16染色在宫颈癌筛查中的意义。结果:4334例中369例查出倍体异常,369例倍体异常中202例建议阴道镜活检,发现150例为CIN1级以上,同时对活检202例进行P16蛋白染色发现随着病变级别增高,P16表达百分比也随之上升,通过χ2检验发现P16蛋白在宫颈上皮内瘤变中表达有明显统计学意义(P<0.05)。结论:DNA倍体定量分析在宫颈癌筛查中有一定意义,同时结合P16蛋白免疫组化染色及宫颈活检,对发现早期宫颈病变有意义。

TOPK Inhibition Enhances the Sensitivity of Colorectal Cancer Cells to Radiotherapy by Reducing the DNA Damage Response

Objective Abnormal expression of T-lymphokine-activated killer cell-originated protein kinase(TOPK)was reported to be closely related to the resistance of prostate cancer to radiotherapy and to targeted drug resistance in lung cancer.However,the role of TOPK inhibition in enhancing radiosensitivity of colorectal cancer(CRC)cells is unclear.This study aimed to evaluate the radiosensitization of TOPK knockdown in CRC cells.Methods The expression of TOPK was detected in CRC tissues by immunohistochemistry,and the effect of TOPK knockdown was detected in CRC cells by Western blotting.CCK-8 and clonogenic assays were used to detect the growth and clonogenic ability of CRC cells after TOPK knockdown combined with radiotherapy in CRC cells.Furthermore,proteomic analysis showed that the phosphorylation of TOPK downstream proteins changed after radiotherapy.DNA damage was detected by the comet assay.Changes in the DNA damage response signaling pathway were analyzed by Western blotting,and apoptosis was detected by flow cytometry.Results The expression of TOPK was significantly greater in CRC tissues at grades 2–4 than in those at grade 1.After irradiation,CRC cells with genetically silenced TOPK had shorter comet tails and reduced expression levels of DNA damage response-associated proteins,including phospho-cyclin-dependent kinase 1(p-CDK1),phospho-ataxia telangiectasia-mutated(p-ATM),poly ADP-ribose polymerase(PARP),and meiotic recombination 11 homolog 1(MRE11).Conclusions TOPK was overexpressed in patients with moderately to poorly differentiated CRC.Moreover,TOPK knockdown significantly enhanced the radiosensitivity of CRC cells by reducing the DNA damage response.

HPV DNA、HPV E6/E7蛋白和TCT在宫颈上皮内瘤变及宫颈癌筛查中的价值

目的 探讨人乳头瘤病毒(human papilloma virus,HPV)DNA、HPV E6/E7蛋白和液基薄层细胞学检查(thin-prep cytology test,TCT)在宫颈上皮内瘤变(cervical intraepithelial neoplasia,CIN)及宫颈癌筛查中的价值。方法 选取2021年7月至2022年6月于诸暨市人民医院妇科接受早期宫颈癌筛查的成年女性190例为研究对象,分别进行HPV DNA、HPVE6/E7蛋白及TCT检测,并进一步行阴道镜活检检查。比较不同病变患者的HPVDNA、HPVE6/E7蛋白和TCT对高级别病变的诊断效能。结果 CIN3及宫颈癌患者的HPV DNA、HPV E6/E7蛋白、TCT检查及三者联合检测的阳性率均显著高于宫颈炎患者(P<0.05),宫颈癌患者的HPV DNA、HPV E6/E7蛋白、TCT检查及三者联合检测的阳性率均显著高于CIN1患者(P<0.05)。CIN2+患者的HPV DNA、HPV E6/E7蛋白、TCT及三者联合检测的阳性率显著高于CIN1-患者。HPVDNA、HPVE6/E7蛋白、TCT三者联合诊断高级别病变的敏感度、特异性、阳性预测值和阴性预测值分别为90.80%、30.10%、52.32%、79.48%。结论 HPV DNA、HPV E6/E7蛋白及TCT可作为筛查宫颈癌和癌前病变的手段,且三者联合检测的敏感度最高。

Study on DNA Immunization by Recombinants Encoding Japanese Encephalitis Virus prME and E Proteins

To study the expression characteristic of Japanese encephalitis virus (JEV) prME and E proteins and the efficacy of DNA immunization by different recombinant plasmids containing JEV prME (2001 bp) and E (1500 bp) genes, two recombinants (pJME and pJE) containing JEV prME and E genes fused with FLAG were constructed and then transfected into HepG2 and COS-1 cells by liposome fusion. The expression feature of FLAG-prME (about 72 kDa) and FLAG-E (about 54 kDa) proteins in transfected cells were analyzed by Western blot and two antibody systems (anti-FLAG and anti-E). BALB/c mice were immunized with 100 μg of two kinds of recombinants by intramuscular injection, and JEV JaGAr-01 strains (10 5 PFU/100 μl)were given to BALB/c mice by intraperioneal injection 3 wk after twice DNA immunization by a lethal virus challenge. BALB/c mice were observed for 21 days after challenge. 80% plaque reduction neutralization test was performed to titrate neutralization antibody before and after viral challenge. It was found that the expression of proteins associated with pJME and pJE was determined in transfected cells with anti-FLAG and a new protein of 11 kDa was detected in HepG2 and COS-1 cells transfected with pJME. Only E (53 kDa) protein was identified as transfected with pJME using anti-E. Higher level of neutralization antibodies and the efficacy of protective immunity were induced with pJME immunization, and were similar to those induced by inactivated Japanese encephalitis vaccine, but were better than those induced with pJE. It concludes that the expression level from prM to E proteins of JEV is different in vitro, and the in vitro expression efficiency of pJME was better than that of pJE. FLAG-prME protein expressed by pJME could be cleaved by peptidase from host. The efficacy of DNA immunization is correlated to the expression characterization of related proteins expressed in vitro.

Implications of oxidative damage to proteins and DNA in aging and its intervention by caloric restriction and exercise

In this short review we describe implications of age-related changes of protein and DNA oxidation as a public mechanism of biological aging. Oxidatively modified protein and DNA have been demonstrated to increase with advancing age in rodents. Half-life of proteins is extended and DNA repair activity declines in old animals. Dietary restriction initiated late in life can shorten the half-life of proteins to levels of young animals, thus contributing to reduce level of altered proteins in old animals by the regimen. Regular exercise reduced oxidatively modified proteins in the brain with improved cognitive functions. It attenuated oxidative stress in the liver, i.e., ameliorating activation of nuclear factor κB, increasing reduced glutathione, and decreasing oxidized guanine base in nuclear and mitochondrial DNA. These findings suggest that regular exercise has systemic effects in reducing oxidative stress. Thus, life-styles such as diet and exercise may extend health span, by up-regulating overall anti-oxidant capacities that include proteins involved in protein turnover and DNA repair, resulting in reduction of damaged proteins and DNA that potentially promote physiological and pathological aging.

热处理对转基因秸秆中重组蛋白和重组DNA的降解作用

随着转基因作物种植面积的不断扩大,如何高效处理转基因秸秆成为了一个重要的科学问题。未经处理的转基因秸秆中的重组蛋白和重组DNA可以在土壤中存在很长时间,并对土壤生物多样性产生潜在负面影响。因此寻找一个既节约成本又对环境无害的秸秆处理方法非常重要。高温处理是降解转基因秸秆重组蛋白和重组DNA的有效手段,但目前对处理温度和处理时间的选择还缺乏系统的研究。本研究通过试纸条、聚合酶链反应(PCR)等方法检测不同温度和时间处理的转基因作物秸秆中重组蛋白和重组DNA的水平。结果表明,转基因大豆、棉花、玉米、水稻的秸秆在50℃处理3 h后,其体内的抗除草剂蛋白草胺膦乙酰转移酶(phosphinothricin acetyltransferase, PAT)等重组蛋白基本降解;但相同温度下,重组DNA的降解则需要4 d时间;提高处理温度可以在一定程度上缩短重组蛋白和重组DNA降解所需的时间。50℃处理4 d的条件在实际生产中通过堆肥就能实现。本研究从分子生物学的角度为转基因秸秆处理提供了依据。

Excess adsorption of biomolecules on soft surfaces: Adsorption of DNA, proteins and lactose on fatty surfaces

Insoluble fatty surfaces are involved in many important interactions such as in biomembranes with soluble biological macro and micromolecules. In this paper we have studied the adsorption interaction of aqueous solution of DNA, some proteins and lactose on several sparingly soluble fatty substances namely milk fat, stearic acid, palmitic acid, phosphatidyl choline and cholesterol surfaces by measuring the depletion of the adsorbates by analytical methods. Adsorption () of DNA on the soft surfaces of stearic acid, milk fat, phosphatidyl choline, palmitic acid and cholesterol was measured as a function of DNA concentration C2. In each case was found to increase with C2 until it reached the maximum value at a critical concentration . For different surfaces stands in the order: stearic acid > milk fat > phosphatidyl choline > cholesterol > palmitic acid. DNA forms multilayers on stearic acid surface. Adsorption of hemoglobin on cholesterol surface is found to be negative or zero but that of BSA on cholesterol is positive. Adsorption of gelatin on cholesterol surface is significantly higher than that of BSA. Lysozyme on cholesterol surface forms multilayers and on casein forms bilayer. The lowering of free energies ?DGo for all systems have been calculated using integrated form of the Gibbs adsorption and their values have been compared with each other. It is concluded that despite differences in the adsorption behavior of the biomolecules on various soft surfaces, free energy change expressed as Bull’s free energy change (Δ) remain nearly constant except for BSA-fatty acid interaction which may be likely due a specific interaction.

The effects of DNA intercalators on chromatin of chicken red blood cells---differential extraction on nonhistone proteins

Taking advantage of the effects on DNA secondary structure of two DNA-intercalators,ethidium bromide and chloroquine,we used each of them to treat nuclei from both mature erythrocytes and reticulocytes of chicken,as an alternative approach to study the relationships between DNA secondary structure,nuclear proteins and chromatin structure.We presented results of differential extraction of nuclear proteins from nuclei with DNA-intercalators,as well as preliminary characterization of these proteins.A 45kd protein is the major component in fractions extracted by both intercalators from nuclei from either mature erythrocytes or reticulocytes and seems to be a DNA-binding protein.Furthermore,from current concepts of functional aspects of DNA conformation and structural heterogeneity in chromatin and nuclear proteins,we have discussed both the significance of our results as well as technical aspects of this approach.

Affinity chromatography-dependent selection (ACDS)of genomic DNA fragments bound specifically to bacterial synthesized Myc/Myn proteins

This paper describes an approach to seek for mouse c-Myc/Myn proteins-bound specific sequences among ge-nomic DNA. cDNA fragment of myn gene was obtained through RT-PCR technique from RNA of NIH3T3 cells. DNA fragments encoding BR/HLH/LZ structure of Myc and Myn proteins were cloned in frame into pGEX-2T vec-tor respectively Fusion GST-Myc and GST-Myn synthe-sized in E.coli hosts showed affinity to CACGTG E-boxDNA and subsequently interacted with genomic fragments prepared through whole-genome-PCR. A PCR-assisted procedure which combines protein-DNA interaction and affinity chromatography was designed to enrich Myc/Myn bound DNA. At least two genomic DNA fragments ob- tained exhibit specifical binding capacity to Myc/Myn complex but not to GST alone. Significance of the work and of the technique itself as well as identification of the DNAs are discussed.

血清HMGB1、GP73、IL-37与HBV-ACLF患者HBV-DNA载量的关系及对预后的预测价值

目的探究乙型肝炎病毒相关慢加急性肝衰竭(HBV-ACLF)患者血清高迁移率族蛋白B1(HMGB1)、高尔基体蛋白73(GP73)、白细胞介素-37(IL-37)与HBV-DNA载量的关系及对预后的预测价值。方法选取2018年7月至2023年7月中国人民解放军联勤保障部队第九八〇医院收治的112例HBV-ACLF患者的临床资料进行回顾性分析,根据HBV-CALF患者入院90 d内临床结局分为死亡组(42例)与生存组(70例)。比较两组临床资料及血清HMGB1、GP73、IL-37水平,分析HBV-CALF患者预后的影响因素,分析血清HMGB1、GP73、IL-37与HBV-DNA载量的关系,评价血清HMGB1、GP73、IL-37对HBV-CALF患者预后的预测价值。结果死亡组在病情分期、腹膜炎、肝性脑病、肺部感染、HBV-DNA载量、终末期肝病评分模型(MELD)评分方面与生存组比较,差异有统计学意义(P<0.05);死亡组血清HMGB1、GP73、IL-37水平均较生存组高(P<0.05)。病情分期、腹膜炎、肝性脑病、肺部感染、HBV-DNA载量、MELD评分及血清HMGB1、GP73、IL-37水平均为HBV-ACLF患者预后的独立影响因素(P<0.05)。HBV-ACLF患者血清HMGB1、GP73、IL-37水平均与HBV-DNA载量呈负相关(P<0.05)。血清HMGB1、GP73、IL-37预测HBV-ACLF患者预后的曲线下面积(AUC)分别为0.781、0.790、0.782,三者联合预测的AUC最大,为0.944,灵敏度、特异度分别为86.33%、91.43%。结论血清HMGB1、GP73、IL-37水平与HBV-CALF患者HBV-DNA载量及预后密切相关,3项指标联合检测有助于提高对预后的预测效能。

急性脑出血患者血清E盒锌指结合蛋白1及DNA甲基化转移酶1与神经功能缺损和预后的相关性分析

目的探讨急性脑出血(ACH)患者血清E盒锌指结合蛋白1(ZEB1)、DNA甲基化转移酶1(DNMTl)与神经功能缺损、预后的关系。方法选取2019年7月—2022年7月本院收治的105例ACH患者为ACH组,依据ACH患者入院时美国国立卫生研究院卒中量表(NIHSS)评分将其分为轻度组(n=34)、中度组(n=41)、重度组(n=30)。根据改良Rankin量表(mRS)评分将ACH患者分为预后良好组(n=65)和预后不良组(n=40)。另纳入同期105例体检健康者为对照组。选取2021年7月—2022年7月本院诊治的45例ACH患者对构建的ACH预后模型的受试者工作特征(ROC)曲线进行验证。采用酶联免疫吸附试验检测血清ZEB1、DNMT1水平;采用Spearman法分析ACH患者ZEB1、DNMT1水平与NIHSS评分的关系;采用多因素Logistic回归模型分析ACH患者预后的影响因素,采用ROC曲线评估血清ZEB1、DNMT1水平对ACH患者预后的预测价值。结果与对照组相比,ACH组血清ZEB1、DNMT1水平升高,差异有统计学意义(P<0.05)。与轻度组相比,中度组和重度组ACH患者血清ZEB1、DNMT1、NIHSS评分均升高,差异有统计学意义(P<0.05);与中度组相比,重度组ACH患者血清ZEB1、DNMT1、NIHSS评分均升高,差异有统计学意义(P<0.05)。Spearman分析结果显示,ACH患者血清ZEB1、DNMT1水平与NIHSS评分均呈正相关(r=0.569、0.763,P均<0.001)。单因素分析结果显示,与预后良好组比较,预后不良组患者NIHSS评分、血肿体积、ZEB1及DNMT1水平均升高或增大,差异有统计学意义(P<0.05)。Logistic回归分析结果显示,ZEB1、DNMT1、NIHSS评分、血肿体积增大是ACH患者预后不良的危险因素(P<0.05)。血清ZEB1、DNMT1预测ACH患者预后的曲线下面积(AUC)分别为0.834、0.854,ZEB1、DNMT1联合预测ACH患者预后的AUC为0.944,灵敏度为95.0%,特异度为86.2%。以验证组人群对预测预后的ROC曲线进行验证,结果显示AUC为0.903(95%CI:0.854~0.951),提示预后预测曲线具有较好的区分度。结论ACH患者血清ZEB1、DNMT1水平较高,二者均与ACH患者神经功能缺损、预后显著相关,且血清ZEB1、DNMT1联合可能更有利于临床评估ACH患者预后情况。

血清PIVKA-Ⅱ、AFP与HBV-DNA联合检测对HBV所致肝癌的诊断及预后预测价值

目的探究血清异常凝血酶原Ⅱ(PIVKA-Ⅱ)、甲胎蛋白(AFP)与乙肝病毒脱氧核糖核酸(HBV-DNA)联合检测对HBV所致肝癌(HCC)的诊断及预后预测价值。方法选取2018年8月至2020年7月在本院接受治疗的98例HCC患者作为研究对象(肝癌组),另取同期95例体检健康人群作为健康组,95例肝硬化患者作为肝硬化组,观察3组受试者血清PIVKA-Ⅱ、AFP与HBV-DNA表达水平和一般资料差异。根据肝癌组3年内预后情况将患者分为生存组(57例)和死亡组(41例)。比较肝癌组一般资料和血清PIVKA-Ⅱ、AFP与HBV-DNA水平关系;多因素Logistic和COX回归分析分别分析影响受试者患肝癌和患者预后不良的影响因素;四格表法计算血清PIVKA-Ⅱ、AFP与HBV-DNA水平对HCC的预测价值;ROC曲线分析评估血清PIVKA-Ⅱ、AFP与HBV-DNA水平对HCC患者预后的预测价值。结果肝癌组患者血清PIVKA-Ⅱ、AFP与HBV-DNA水平显著高于健康组和肝硬化组(P<0.05);HCC发病与血清PIVKA-Ⅱ、AFP与HBV-DNA水平有关,且是危险因素(P<0.05)。HCC患者预后不良与血清PIVKA-Ⅱ、AFP与HBV-DNA水平以及肿瘤数量有关(P<0.05),且是危险因素。血清PIVKA-Ⅱ、AFP与HBV-DNA水平以及3项联合诊断HCC发病的准确度分别为77.43%、72.57%、77.43%和84.72%。血清PIVKA-Ⅱ、AFP与HBV-DNA水平以及3项联合诊断HCC预后不良的AUC分别为0.823、0.841、0.824和0.958,3项联合诊断效能优于单一诊断(P<0.05)。结论血清PIVKA-Ⅱ、AFP与HBV-DNA水平在HCC患者和预后不良患者中呈高表达,且3项联合可有效预测HCC发病和HCC患者预后情况。

PSD-95基因DNA甲基化在睡眠剥夺相关疾病的作用研究进展

睡眠剥夺(SD)已成为世界各地普遍存在的问题,许多疾病的发生与睡眠不足有关。已经发现表观遗传机制与SD及相关疾病的发生发展密切相关,其中,DNA甲基化是最常见的表观遗传修饰,可影响基因表达。突触后密度蛋白-95(PSD-95)被认为是兴奋性信号传递过程中重要的调节因子,SD后,PSD-95表达降低,表现出情绪改变和认知障碍等精神疾病症状。在慢性应激小鼠中,观察到血清素1A受体启动子区DNA甲基化水平增加,与抑郁症患者前额叶皮层PSD-95表达水平降低有关。然而,PSD-95基因的DNA甲基化水平与抑郁症表型无关。在精神分裂症患者中,SD的长度会加重疾病程度,且PSD-95基因DNA甲基化与精神分裂症有关。此外,结直肠癌的发病风险与SD或昼夜节律紊乱有关,而PSD-95基因DNA甲基化也可能成为治疗结直肠肿瘤的靶点。未来仍需要进一步深入探索PSD-95基因DNA甲基化在SD相关疾病中的作用及调节机制。

NS5ATP9与HBx相互作用促进HBV cccDNA的形成与转录

目的探讨丙型肝炎病毒NS5A反式调节蛋白9(hepatitis C virus NS5Atransactivated protein 9,NS5ATP9)在乙型肝炎病毒(hepatitis B virus,HBV)共价闭合环状DNA(covalently closed circular DNA,cccDNA)形成与转录中的作用机制。方法利用1.3拷贝HBV表达质粒转染Huh7和HepG2细胞、整合有4拷贝HBV基因组的HepG2.2.15细胞、在诱导型四环素启动子控制下表达HBV的HepAD38细胞构建NS5ATP9过表达或干扰的HBV细胞模型,收集样品和细胞上清液,提取RNA、HBV核心DNA(coreDNA)、cccDNA和蛋白,利用酶联免疫吸附试验、实时荧光定量聚合酶链反应(polymerase chain reaction,PCR)、Southern blot和Western blot技术检测HBV总RNA、前基因组RNA(pregenomic RNA,pgRNA)、乙型肝炎病毒s抗原(hepatitis B virus s antigene,HBsAg)、乙型肝炎病毒e抗原(hepatitis B virus e antigene,HBeAg)、松弛环状DNA(relax circular DNA,rcDNA)以及cccDNA水平。在HepG2细胞中转染乙型肝炎病毒x蛋白(hepatitis B virus x protein,HBx),通过免疫荧光成像及免疫共沉淀方法检测NS5ATP9与HBx的结合情况。双荧光素酶报告基因实验检测NS5ATP9对HBx启动子活性的影响。利用Huh7细胞转染HBV1.3及HBV稳定表达细胞株HepG2.2.15和HepAD38转染NS5ATP9过表达/干扰质粒,通过Western blot技术检测DDB1和SMC6的蛋白水平。结果在HBV病毒活跃的细胞中,NS5ATP9 mRNA水平[HepG2.2.15细胞:1.891±0.567比1.00±0.034,t=2.87,P=0.0351;HepAD38 tet+细胞:1.978±0.399比1.00±0.034,t=4.131,P=0.0091;HepAD38 tet-细胞:2.642±0.672比1.00±0.034,t=4.127,P=0.0091]和蛋白水平均显著增加。过表达NS5ATP9后可显著增加HBeAg[(5.402±0.327)S/COV比(2.68±0.552)S/COV,t=7.35,P=0.0018]、HBsAg[(2.846±0.185)S/COV比(1.512±0.221)S/COV,t=8.02,P=0.0013]、HBV pgRNA及rcDNA的表达水平,而干扰NS5ATP9后此增加作用消失[HBeAg:(2.029±0.09)S/COV比(3.733±0.445)S/COV,t=6.501,P=0.0029;HBsAg:(1.501±0.105)S/COV比(1.878±0.174)S/COV,t=3.216,P=0.0324)]。机制研究显示,NS5ATP9和HBx蛋白主要位于细胞核核仁内,并具有共定位信号,且NS5ATP9可显著提高HBx启动子(1071.06±79.44比488.47±40.12,t=13.09,P=0.00012)的转录活性。另外,过表达NS5ATP9可显著降低DDB1和SMC6的蛋白水平,而沉默NS5ATP9则可显著提高DDB1和SMC6的蛋白水平。结论HBV上调NS5ATP9的表达,形成HBV-NS5ATP9-HBV cccDNA-HBV的正反馈环路,NS5ATP9通过与HBx相互作用上调肝细胞中HBV cccDNA的形成与转录,进而促进慢性乙型肝炎的发生发展。

血浆游离胎儿DNA浓度联合血清妊娠相关血浆蛋白-A、β-人绒毛膜促性腺激素检测对孕妇不良妊娠结局的预测价值

目的探讨血浆游离胎儿DNA(cff-DNA)浓度联合血清妊娠相关血浆蛋白-A(PAPP-A)和β-人绒毛膜促性腺激素(β-hCG)检测对孕妇不良妊娠结局的预测价值。方法选取2022年8月至2023年2月佛山复星禅诚医院收治的进行产检、唐氏筛查和无创产前DNA检查(NIPT)的195例孕妇作为研究对象。将发生不良妊娠结局的孕妇设为研究组(n=36),无不良妊娠结局的孕妇设为对照组(n=159)。检测两组血浆cff-DNA浓度、血清PAPP-A和β-hCG水平;采用Spearman分析血浆cff-DNA浓度、血清PAPP-A和β-hCG水平与不良妊娠结局的相关性;采用受试者工作特征(ROC)曲线分析血浆cff-DNA浓度、血清PAPP-A和β-hCG水平对不良妊娠结局的预测价值。结果与对照组比较,研究组血浆cff-DNA浓度和血清PAPP-A水平显著更低,血清β-hCG水平显著更高,差异具有统计学意义(P<0.05);Spearman分析结果显示,血浆cff-DNA浓度、血清PAPP-A和β-hCG水平与妊娠期高血压、子痫前期、早产、死胎、新生儿窒息和胎儿生长受限不良妊娠结局具有显著相关性(P<0.05);ROC曲线结果显示,血浆cff-DNA浓度单独预测孕妇不良妊娠结局的曲线下面积为0.807,截断值为11.82%;血清PAPP-A单独预测孕妇不良妊娠结局的曲线下面积为0.804,截断值为0.41;血清β-hCG单独预测孕妇不良妊娠结局的曲线下面积为0.815,截断值为2.56;预测效能比较结果显示,血浆cff-DNA浓度、血清PAPP-A和β-hCG水平联合预测孕妇不良妊娠结局的特异度(97.48%)和准确度(96.41%)均显著高于三者单独预测(P<0.05),误诊率(2.52%)显著低于三者单独预测(P<0.05)。结论血浆cff-DNA浓度联合血清PAPP-A、β-hCG检测对孕妇不良妊娠结局具有较高的预测价值。

Analyses of Protein and Oil of Maize Offsprings Plants Introducing Soybean DNA

[Objective] The experiment was aimed to explore character variation between different families after DNA introduction and select variant plants with good stability. [Method] The method of pollen-tube-pathway was used to introduce total DNA of soybean into normal maize inbred line 7313 for selecting generation by generation. When field characters of maize, grain colors, grain traits and panicle axis colors were stable, the crude protein, gliadin, glutelin and oil content of grains which were selected from variant strains were detected and compared. [Result] The grain crude protein, gliadin, glutelin and oil content of line 26h-4-3 were significantly different from these of control treatment. The increments of D3 and D4 generation were 10.34% and 26.70%, 6.58% and 6.28%, 15.09% and 70.34%, 55.82% and 51.52% respectively. All indexes of line 26h-3-1 were also higher than these of control treatment and the increments of D3 and D4 generation were 5.67% and 21.63%,1.91% and 2.31%, 10.85% and 62.27%,22.49% and 9.67%. [Conclusion] The crude protein, gliadin, glutelin and oil content of variant line 26h-4-3 and 26h-3-1 were stable, so variant line 26h-4-3 and 26h-3-1 were excellent variant strains which satisfied the requirement of high protein breeding.