Mapping of Post-translational Modifications of Transition Proteins,TP1 and TP2, and Identification of Protein Arginine Methyltransferase 4 and Lysine Methyltransferase 7 as Methyltransferase for TP2

In a unique global chromatin remodeling process during mammalian spermiogenesis, 90% of the nucleosomal histones are replaced by testis-specific transition proteins, TP1, TP2, and TP4. These proteins are further substituted by sperm-specific protamines, P1 and P2, to form a highly condensed sperm chromatin. In spermatozoa, a small proportion of chromatin, which ranges from 1 to 10% in mammals, retains the nucleosomal architecture and is implicated to play a role in transgenerational inheritance. However, there is still no mechanistic understanding of the interaction of chromatin machinery with histones and transition proteins, which facilitate this selective histone replacement from chromatin. Here, we report the identification of 16 and 19 novel post-translational modifications on rat endogenous transition proteins, TP1 and TP2, respectively, by mass spectrometry. By in vitro assays and mutational analysis, we demonstrate that protein arginine methyltransferase PRMT4 (CARM1) methylates TP2 at Arg⁷¹, Arg⁷⁵, and Arg⁹² residues, and lysine methyltransferase KMT7 (Set9) methylates TP2 at Lys⁸⁸ and Lys⁹¹ residues. Further studies with modification-specific antibodies that recognize TP2K88me1 and TP2R92me1 modifications showed that they appear in elongating to condensing spermatids and predominantly associated with the chromatin-bound TP2. This work establishes the repertoire of post-translational modifications that occur on TP1 and TP2, which may play a significant role in various chromatin-templated events during spermiogenesis and in the establishment of the sperm epigenome.     

少弱精子症患者精子候选差异蛋白Trx 2、TrxR 1的验证及在少精、弱精子症中的表达研究

目的:根据TMT技术筛选少弱精子症患者精子差异蛋白的结果,选取硫氧还蛋白2(thioredoxin 2,Trx 2)、硫氧还蛋白还原酶1(thioredoxin reductase 1,TrxR 1)进行验证,探讨二者在少精、弱精和少弱精子症中的表达变化及其意义。方法:收集105例少精子症组(O组)、150例弱精子症组(A组)、50例少弱精子症组(OA组)和106例正常精液男性(N组)精液,分离出精子,对少弱精子症进行串联质谱标签(Tandem Mass Tag,TMT)技术蛋白质组学分析,根据少弱精子症组的精子差异蛋白结果选取Trx 2、TrxR 1,通过免疫荧光和免疫印迹方法检测其在O组、A组、OA组的表达情况。结果:TMT技术蛋白质组学结果显示Trx 2为上调差异蛋白(为N组的1.31倍),TrxR 1为下调差异蛋白(为N组的0.82倍)。免疫荧光和免疫印迹结果显示O组、A组、OA组Trx 2表达显著高于N组(P0.05),O组、OA组TrxR 1的表达显著低于N组(P0.05)。二者在OA组的结果与蛋白质组学结果一致。结论:Trx 2、TrxR 1可能在少精、弱精及少弱精子症的发生中起着重要的作用,并有望成为少弱精子症患者精子的候选标志物及治疗靶点。     

Deep Structural Analysis of RPAP3 and PIH1D1, Two Components of the HSP90 Co-chaperone R2TP Complex

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The lncRNA TP73‐AS1 promotes ovarian cancer cell proliferation and metastasis via modulation of MMP2 and MMP9

Ovarian cancer is one of the most common gynecologic malignancy with poor prognosis. Recently, long noncoding RNAs (lncRNAs) have been identified as key regulators in cancer development. The current study investigated the role of lncRNA P73 antisense RNA 1T (TP73‐AS1) in ovarian cancer. Quantitative real‐time polymerase chain reaction determined the expression levels of TP‐73AS1, matrix metallopeptidases (MMPs) messenger RNA. Cell proliferative ability, cell invasion, and migration were CCK‐8 and colony formation, and transwell invasion and migration assays, respectively. The protein levels of matrix metallopeptidase 2 (MMP2) and MMP9 were measured by Western blot. TP73‐AS1 was upregulated in the ovarian cancer tissues and ovarian cancer cells, and upregulation of TP73‐AS1 was associated with poor prognosis. Knockdown of TP73‐AS1 significantly suppressed cell proliferation, invasion, and migration of SKOV3 cells, and overexpression of TP73‐AS1 promoted cell proliferation, invasion, and migration of OVCA429 cells. In addition, knockdown of TP73‐AS1 suppressed the in vivo tumor growth. Tumor metastasis RT² profiler polymerase chain reaction array showed that MMP2 and MMP9 was significantly upregulated by TP73‐AS1 overexpression in ovarian cancer cells. TP73‐AS1 overexpression enhanced the expression of MMP2 and MMP9 in ovarian cancer cells. Knockdown of MMP2 and MMP9 attenuated the effects of TP73‐AS1 overexpression on cell invasion and migration. The clinical data showed that MMP2 and MMP9 were upregulated and positively correlated with TP73‐AS1 expression in ovarian cancer tissues. Collectively, our results demonstrated the oncogenic role of TP73‐AS1 in ovarian cancer, and targeting TP73‐AS1 may represent a novel approach in battling against ovarian cancer.     

呼吸道合胞病毒非结构蛋白NS1、NS2的研究进展

呼吸道合胞病毒(reespiratory syncytial virus,RSV)是引起婴幼儿和老年人下呼吸道感染的重要病原体之一.由于该病毒的致病机理还不太清楚导致目前尚无有效治疗RSV的方法.研究表明,呼吸道合胞病毒的非结构蛋白NS1、NS2具有抗细胞凋亡的作用,同时可以逃避宿主免疫系统(IFN)对病毒的干扰,有利于病毒复制.敲除这两种基因的减毒活疫苗和袁达沉默NS1的小干扰RNA(siRNA)的质粒研究已经取得了一定的进展.对非结构蛋白功能的深入研究有助于了解RSV的致病机理,同时为预防和治疗RSV感染奠定理论基础.     

Tah1, A Key Component of R2TP Complex that Regulates Assembly of snoRNP,is Involved in De Novo Generation and Maintenance of Yeast Prion [URE3]

The cellular chaperone machinery plays key role in the de novo formation and propagation of yeast prions (infectious protein). Though the role of Hsp70s in the prion maintenance is well studied, how Hsp90 chaperone machinery affects yeast prions remains unclear. In the current study, we examined the role of Hsp90 and its co-chaperones on yeast prions [PSI⁺] and [URE3]. We show that the overproduction of Hsp90 co-chaperone Tah1, cures [URE3] which is a prion form of native protein Ure2 in yeast. The Hsp90 co-chaperone Tah1 is involved in the assembly of small nucleolar ribonucleoproteins (snoRNP) and chromatin remodelling complexes. We found that Tah1 deletion improves the frequency of de novo appearance of [URE3]. The Tah1 was found to interact with Hsp70. The lack of Tah1 not only represses antagonizing effect of Ssa1 Hsp70 on [URE3] but also improves the prion strength suggesting role of Tah1 in both fibril growth and replication. We show that the N-terminal tetratricopeptide repeat domain of Tah1 is indispensable for [URE3] curing. Tah1 interacts with Ure2, improves its solubility in [URE3] strains, and affects the kinetics of Ure2 fibrillation in vitro. Its inhibitory role on Ure2 fibrillation is proposed to influence [URE3] propagation. The present study shows a novel role of Tah1 in yeast prion propagation, and that Hsp90 not only promotes its role in ribosomal RNA processing but also in the prion maintenance.SummaryPrions are self-perpetuating infectious proteins. What initiates the misfolding of a protein into its prion form is still not clear. The understanding of cellular factors that facilitate or antagonize prions is crucial to gain insight into the mechanism of prion formation and propagation. In the current study, we reveal that Tah1 is a novel modulator of yeast prion [URE3]. The Hsp90 co-chaperone Tah1, is required for the formation of small nucleolar ribonucleoprotein complex. We show that the absence of Tah1 improves the induction of [URE3] prion. The overexpressed Tah1 cures [URE3], and this function is promoted by Hsp90 chaperones. The current study thus provides a novel cellular factor and the underlying mechanism, involved in the prion formation and propagation     

Assembly principles of the human R2TP chaperone complex reveal the presence of R2T and R2P complexes

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鸡贫血病毒VP1和VP1蛋白在家蚕中的联合表达

将鸡贫血病毒vp1和vp2基因分别克隆入转移载体pBacPAK8中,获得重组转移质粒pBac-vp1和pBac-vp2。以上两质粒分别与CunI酶切线性化的亲本病毒Bm-Bacpak6DNA共转染家蚕细胞,通过蓝白斑筛选,纯化得到重组病毒Bm-vp1和Bm-vp2。PCR分析表明vp1和vp2基因已整合进杆状病毒基因组中。将Bm-vp1和Bm-vp2共感染5龄家蚕,通过表达产物免疫SPF鸡产生的抗血清与CAV感染的MDCC－MSB1细胞的间接荧光抗体分析,证明表达产物能诱导鸡产生的抗体,而且能够保护子代鸡免受CAV的攻击。该研究表明,表达VP1和VP2蛋白的重组家蚕杆状病毒（Recombinant BmNP)是很有前途的CAV亚单位疫苗的生产系统。     

Density Dependent Change of Myristoylated Proteins in C3H10T1/2 Fibroblasts and Their Transformants

We have examined the pattern of protein myristoylation in C3H10T1/2 fibroblasts during cell growth. During the growing phase of 10T1/2 cells, several proteins were radiolabelled with [³H]myristate, and among them proteins with molecular masses of 22, 35, a doublet of 42–45 and 67 kDa were labelled predominantly. The extent of myristoylation in each of these proteins changed with cell density. The amount of radioactivity incorporated into the 22 kDa protein in 10T1/2 cells decreased with increasing cell density and remained at a low level during the stationary phase. In contrast, the incorporation into the 67 kDa protein increased parallel to cell density. The density-dependent change of myristoylation was not observed in any of the transformants of 10T1/2 cells thus far examined. The 67 kDa protein was identified as MARCKS (myristoylated alanine-rich C kinase substrate) by immunoprecipitation with an anti-MARCKS antibody. By Western blot analysis, we found that the amount of MARCKS in 10T1/2 cells increased significantly analogous with cell density. Therefore, it is possible that MARCKS and the 22 kDa protein play a role in contact-mediated cell signalling in 10T1/2 cells, but the mechanism is lost in transformed cells. © 1997 John Wiley & Sons, Ltd.     

Association between length of gestation and cervical DNA methylation of PTGER2 and LINE 1-HS

Worldwide, more than 1 in 10 infants is born prior to 37 weeks gestation. Preterm birth can lead to increased mortality risk and poor life-long health and neurodevelopmental outcomes. Whether environmental risk factors affect preterm birth through epigenetic phenomena is largely unstudied. We sought to determine whether preterm risk factors, such as smoke exposure and education, were associated with cervical DNA methylation in the prostaglandin E receptor 2 gene (PTGER2) and a repetitive element, long interspersed nuclear element-1 Homo sapiens-specific (LINE 1-HS). Second, we aimed to determine whether mid-pregnancy DNA methylation of these regions in cervical samples could predict the length of gestation. We obtained a cervical swab between 16–19 weeks gestation from 80 women participating in a Mexico City birth cohort, used pyrosequencing to analyze DNA methylation of PTGER2 and LINE 1-HS, and examined associations with maternal covariates. We used accelerated failure time models to analyze associations of DNA methylation with the length of gestation. DNA methylation of both sequences was associated with Pap smear inflammation. LINE 1-HS methylation was associated with smoke exposure, BMI and parity. In adjusted models, gestations were 3.3 days longer (95%CI 0.6, 6.0) for each interquartile range of PTGER2 DNA methylation. Higher LINE 1-HS methylation was associated with shorter gestations (-3.3 days, 95%CI -6.5, -0.2). In conclusion, cervical DNA methylation was associated with risk factors for preterm birth and the length of gestation.     

Tolerance of DNA Mismatches in Dmc1 Recombinase-mediated DNA Strand Exchange

Recombination between homologous chromosomes is required for the faithful meiotic segregation of chromosomes and leads to the generation of genetic diversity. The conserved meiosis-specific Dmc1 recombinase catalyzes homologous recombination triggered by DNA double strand breaks through the exchange of parental DNA sequences. Although providing an efficient rate of DNA strand exchange between polymorphic alleles, Dmc1 must also guard against recombination between divergent sequences. How DNA mismatches affect Dmc1-mediated DNA strand exchange is not understood. We have used fluorescence resonance energy transfer to study the mechanism of Dmc1-mediated strand exchange between DNA oligonucleotides with different degrees of heterology. The efficiency of strand exchange is highly sensitive to the location, type, and distribution of mismatches. Mismatches near the 3′ end of the initiating DNA strand have a small effect, whereas most mismatches near the 5′ end impede strand exchange dramatically. The Hop2-Mnd1 protein complex stimulates Dmc1-catalyzed strand exchange on homologous DNA or containing a single mismatch. We observed that Dmc1 can reject divergent DNA sequences while bypassing a few mismatches in the DNA sequence. Our findings have important implications in understanding meiotic recombination. First, Dmc1 acts as an initial barrier for heterologous recombination, with the mismatch repair system providing a second level of proofreading, to ensure that ectopic sequences are not recombined. Second, Dmc1 stepping over infrequent mismatches is likely critical for allowing recombination between the polymorphic sequences of homologous chromosomes, thus contributing to gene conversion and genetic diversity.     

DNA damage causes TP53-dependent coupling of self-renewal and senescence pathways in embryonal carcinoma cells

Comment on: Wu R, et al. Clin Cancer Res 2011; 17:7359–72     

TP53INP2/DOR的生物学功能

肿瘤蛋白p53诱导的核蛋白2(TP53INP2),也称糖尿病与肥胖调控蛋白(DOR),在骨骼肌、心肌和脑等代谢旺盛的组织中表达水平较高。TP53INP2在细胞核内主要发挥转录辅激活因子的作用,如作为甲状腺激素受体的辅激活因子调控甲状腺激素相关基因的表达。后续研究发现,TP53INP2为细胞内重要的分解代谢途径—细胞自噬所必需,饥饿时TP53INP2出核参与自噬的起始。在骨骼肌中,TP53INP2通过促进自噬导致肌肉流失,而在白色脂肪组织中,TP53INP2则通过促进自噬抑制脂肪前体细胞的分化。此外,在营养丰富的条件下,TP53INP2能够定位于核仁,协助rDNA转录起始前复合物的组装,促进rDNA的转录,参与细胞内重要的合成代谢—核糖体的生物发生。临床统计数据表明,TP53INP2的表达水平与糖尿病和某些类型的癌症早期的发生发展密切相关。本文对TP53INP2在转录调控、细胞自噬和相关疾病如癌症与糖尿病中的生物学功能进行综述。     

Life-Long Effects of Perinatal Asphyxia on Stress-Induced Proteins and Dynamin 1 in Rat Brain

In previous work, we have shown that perinatal asphyxia (PA) in the rat leads to life-long neurotransmitter deficits and impairment of cognitive functions and behavior. This observation made us examine protein expression in hippocampus of rats with PA at the end of the life span. We applied a well-documented and characterized animal model of PA. Pups, normoxic and asphyxiated for 20 min, were brought up until the age of 24 months and then were sacrificed. Hippocampal tissue was dissected from the brains, and proteins were run on two-dimensional gel electrophoresis with in-gel digestion and subsequent identification of proteins by MALDI-TOF followed by quantification of protein spots by specific software. In hippocampus of rats with PA, the stress proteins protein disulfide isomerase A3 precursor and stress-induced phosphoprotein-1 were significantly increased, whereas the microtubule-associated protein dynamin-1 was significantly reduced. Increased stress protein levels may represent long-term effects of PA or, alternatively, could reflect conditioning of the stress protein machinery known to occur as a neuroprotective principle following hypoxic-ischemic conditions. Decreased dynamin-1 levels may be considered as a long-term effect on the exocytotic system possibly reflecting or leading to impaired neuronal transport and vesicle-trafficking in PA of the rat of advanced age.     

人参多糖注射液联合TP方案对晚期非小细胞肺癌患者Th1/Th2免疫平衡和血清肿瘤标志物的影响

摘要 目的：探讨人参多糖注射液联合多西他赛和顺铂（TP方案）治疗晚期非小细胞肺癌（NSCLC）的疗效及对患者辅助性T细胞（Th）1/Th2免疫平衡和血清肿瘤标志物的影响。方法：选取我院2019年3月~2021年2月收治的80例晚期NSCLC患者。按随机数字表法分为对照组（TP方案治疗,40例）和观察组（人参多糖注射液联合TP方案治疗,40例）。对比两组疗效、血清肿瘤标志物、Th1/Th2免疫平衡指标、生存质量和不良反应发生率。结果：观察组的客观缓解率、疾病控制率分别为55.00%、85.00%,分别高于对照组的32.50%、57.50%,差异有统计学意义（P<0.05）。两组治疗4个疗程后肺癌患者生存质量量表（FACT-L）各领域评分均较治疗前升高,且观察组高于对照组（P<0.05）。两组治疗4个疗程后血清肿瘤标志物糖类抗原19-9（CA19-9）、细胞角蛋-19片段（CYFRA21-1）、癌胚抗原（CEA）水平下降,且观察组低于对照组（P<0.05）。两组治疗4个疗程后血清γ-干扰素（INF-γ）、白介素-2（IL-2）水平升高,且观察组高于对照组（P<0.05）。两组治疗4个疗程后血清白介素-4（IL-4）、白介素-5（IL-5）水平降低,且观察组低于对照组（P<0.05）。两组不良反应发生率对比无统计学差异（P>0.05）。结论：晚期NSCLC在TP化疗基础上结合人参多糖注射液治疗,可更好的降低血清肿瘤标志物水平,控制疾病进展,同时还可调节Th1/Th2免疫平衡,促进患者生存质量改善。     

PRDX1、HMGA2、FMNL2在胃癌组织中的表达及与临床病理特征、上皮间充质转化和预后的关系研究

摘要 目的：探讨过氧化物酶1（PRDX1）、高迁移率族蛋白A2（HMGA2）、同源形成素样蛋白2（FMNL2）在胃癌组织中的表达及与临床病理特征、上皮-间充质转化（EMT）和预后的关系。方法：选取2017年1月～2018年2月我院收治的153例胃癌患者,收集术中癌组织和癌旁组织。采用免疫组化法检测PRDX1、HMGA2、FMNL2、波形蛋白（VIM）、上皮细胞钙黏蛋白（E-cad）阳性表达情况,采用实时定量PCR（qRT-PCR）法检测PRDX1、HMGA2、FMNL2、VIM、E-cad mRNA相对表达量。分析胃癌组织中PRDX1、HMGA2、FMNL2表达与临床病理特征、EMT和预后的关系。结果：与癌旁组织比较,胃癌组织中PRDX1、HMGA2、FMNL2、VIM阳性表达率和mRNA相对表达量升高,E-cad阳性表达率和mRNA相对表达量降低（P＜0.05）。胃癌组织中PRDX1、HMGA2、FMNL2阳性表达率与患者TNM分期、淋巴结转移、远处转移有关（P＜0.05）。Pearson相关性分析结果显示,胃癌组织中PRDX1、HMGA2、FMNL2 mRNA相对表达量与VIM mRNA相对表达量呈正相关（r=0.562、0.517、0.621,P均＜0.05）,与E-cad mRNA相对表达量呈负相关（r=-0.603、-0.544、-0.574,P均＜0.05）。153例胃癌患者术后3年累积生存率为68.44%（106/153）。Kaplan-Meier生存曲线分析结果显示,PRDX1、HMGA2、FMNL2阳性组术后3年累积生存率均低于阴性组（P＜0.05）。结论：胃癌组织中PRDX1、HMGA2、FMNL2表达升高,其表达与TNM分期、淋巴结转移、远处转移、EMT以及预后有关,可作为胃癌病情和预后的辅助评估指标。     

P 7IkZP i、EF Z- 1在胃癌中的表达及其相关性研究

目的：研究p27^kip1蛋白、转录因子E2F-1在胃癌中的表达及其与胃癌病理参数乏问的关系,并探讨二者相关性。方法：应用免疫组化S-P法,对90例胃癌患者的癌组织、34例癌旁正常胃黏膜进行检测,分析p27^kip1、E2F-1蛋白表达及其与胃癌病理参数之间的关系。结果：p27^kip1在正常胃组织、胃癌组织中的阳性率分别为55．9％（19／34）、31．1％（28／90）,二者差异有统计学意义（p〈0．05）。其阳性表达率与胃癌组织的浸润深度（p〈0．05）、组织学分型（p〈0．01）、分化程度（p〈0．01）、淋巴结转移（p〈0．05）均相关;E2F-1在正常胃组织、胃癌组织中的阳性率分别为17．6％（6／34）、36．7％（33／90）,二者差异有统计学意义（p〈0．05）,其阳性表达率与胃癌的组织学分型相关。而与胃癌的浸润深度（p〉0．05）、分化程度（p〉0．05）、淋巴结转移无关（p〉0．05）。结论：p27^kip1在胃癌组织中的表达明显低于在正常组织,相反,E2F-1蛋白在胃癌组织中的表达却明显增强;p27^kip1蛋白表达与胃癌的浸润深度、组织学分型、分化程度、淋巴结转移等病理参数相关;E2F-1表达与胃癌的组织学分型相关;p27^kip1、E2F-1在胃癌中的表迭呈负相关。