deoxyribonuclease

脱氧核糖核酸酶
  • 文章类型: Journal Article
    在nu/nu雄性小鼠中植入的雄激素非依赖性人DU145前列腺转移癌的异种移植物显示,在由甲萘醌亚硫酸氢盐和抗坏血酸钠(VK3:VC)的组合组成的促氧化剂抗癌治疗后,具有显着的存活率。
    移植的隔膜癌样本来自存活时间最长的小鼠,腹膜内(IP),或口服和IP治疗组均采用光照评估,扫描,和透射电子显微镜来分析形态损伤。
    与先前未经处理的体外癌的精细结构数据相比,口腔引起的变化,IP,并口服IPVK3:VC治疗拆除了那些自体移植的异种移植物,坏死萎缩是通过细胞的氧化应激完成的,其损伤是由重新激活的脱氧核糖核酸酶和核糖核酸酶引起的。肿瘤破坏是由细胞核成分的不可逆损伤引起的,内质网,还有线粒体.其他改变包括细胞骨架的改变,这些改变导致了称为“自体分裂”的特征性自我切除。“所有这些损伤导致弹性癌细胞坏死细胞死亡。
    在人DU145前列腺异种移植物中由VK3:VC促氧化剂组合引起的精细结构损伤通过组织化学和生物分子研究证实了在体外和其他细胞系中显示的那些。这些破坏不会对正常组织造成损害;因此,我们的数据为上述联合治疗前列腺癌和其他癌症提供了支持.
    UNASSIGNED: Xenografts of androgen-independent human DU145 prostate metastatic carcinomas implanted in nu/nu male mice have revealed a significant survival after a prooxidant anticancer treatment consisting of a combination of menadione bisulfite and sodium ascorbate (VK3:VC).
    UNASSIGNED: Implanted samples of diaphragm carcinomas from longest survived mice from either oral, intraperitoneal (IP), or both oral and IP treatment groups were assessed with light, scanning, and transmission electron microscopy to analyze morphologic damages.
    UNASSIGNED: Compared with previous fine structure data of in vitro untreated carcinomas, the changes induced by oral, IP, and oral with IP VK3:VC treatment dismantled those xenografts with autoschizis, and necrotic atrophy was accomplished by cell\'s oxidative stress whose injuries were consequent to reactivated deoxyribonucleases and ribonucleases. Tumor destructions resulted from irreversible damages of nucleus components, endoplasmic reticulum, and mitochondria there. Other alterations included those of the cytoskeleton that resulted in characteristic self-excisions named \" autoschizis.\" All these injuries lead resilient cancer cells to necrotic cell death.
    UNASSIGNED: The fine structure damages caused by VK3:VC prooxidant combination in the human DU145 prostate xenografts confirmed those shown in vitro and of other cell lines with histochemistry and biomolecular investigations. These devastations incurred without damage to normal tissues; thus, our data brought support for the above combination to assist in the treatment of prostate cancers and other cancers.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    分泌的脱氧核糖核酸酶(DNases),如DNase-1和DNase-IL3,降解细胞外DNA,和内源性DNA酶在解决气道炎症和保护对核苷酸的自身免疫反应中具有作用。哮喘患者的亚组具有较高的气道DNA水平,但是缺乏有关健康和哮喘中DNase活性的信息。为了表征健康和哮喘中的DNase活性,我们使用Taqman探针序列开发了一种新的动力学测定,该序列被DNase-I快速切割以产生大的产物信号。我们使用这种动力学测定法来测量重症哮喘研究计划(SARP)-3参与者(n=439)和健康对照(n=89)的痰中的DNase活性。我们发现DNase活性低于正常哮喘患者(78.7RFU/minvs120.4RFU/min,p<0.0001)。与痰DNA酶活性水平在上界活动水平的哮喘患者相比,痰中DNase活性较低的患者在临床上表现为更严重的疾病,在病理上表现为气道嗜酸性粒细胞增多和气道粘液堵塞。DNase-I的氨基甲酰化,可以由嗜酸性粒细胞过氧化物酶介导的翻译后修饰,灭活的DNase-I.总之,基于Taqman探针的DNase活性测定揭示了哮喘气道中的低DNase活性,这与更严重的疾病和气道粘液堵塞有关,可能是由哮喘引起的,至少在某种程度上,通过嗜酸性粒细胞介导的氨基甲酰化。
    Secreted deoxyribonucleases (DNases), such as DNase-I and DNase-IL3, degrade extracellular DNA, and endogenous DNases have roles in resolving airway inflammation and guarding against autoimmune responses to nucleotides. Subsets of patients with asthma have high airway DNA levels, but information about DNase activity in health and in asthma is lacking. To characterize DNase activity in health and in asthma, we developed a novel kinetic assay using a Taqman probe sequence that is quickly cleaved by DNase-I to produce a large product signal. We used this kinetic assay to measure DNase activity in sputum from participants in the Severe Asthma Research Program (SARP)-3 (n = 439) and from healthy controls (n = 89). We found that DNase activity was lower than normal in asthma [78.7 relative fluorescence units (RFU)/min vs. 120.4 RFU/min, P < 0.0001]. Compared to patients with asthma with sputum DNase activity in the upper tertile activity levels, those in the lower tertile of sputum DNase activity were characterized clinically by more severe disease and pathologically by airway eosinophilia and airway mucus plugging. Carbamylation of DNase-I, a post-translational modification that can be mediated by eosinophil peroxidase, inactivated DNase-I. In summary, a Taqman probe-based DNase activity assay uncovers low DNase activity in the asthma airway that is associated with more severe disease and airway mucus plugging and may be caused, at least in part, by eosinophil-mediated carbamylation.NEW & NOTEWORTHY We developed a new DNase assay and used it to show that DNase activity is impaired in asthma airways.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    背景:本研究的目的是评估不同剂量的组织纤溶酶原激活剂(tPA)和脱氧核糖核酸酶(DNase)联合治疗复杂的肺炎旁积液和脓胸如何影响患者在市中心社区医院的预后。
    方法:这项回顾性分析是在位于罗利的市中心医院进行的,北卡罗来纳州。生成并筛选了2015年7月1日至2017年12月31日用tPA和DNase治疗的所有患者的列表。数据是通过回顾过去的医疗记录来收集的,包括人口统计,既往病史,以及他们医院课程的细节。
    结果:共有38例患者被发现同时使用tPA和DNase治疗复杂的肺炎旁积液或脓胸。20例(52.6%)患者接受了完整的六剂联合并发tPA/DNase。在18例(47.4%)没有接受全部6剂的患者中,11不需要完整的六个剂量的积液解决,7人因管道堵塞或疼痛而不得不停止治疗。只有7例(18.4%)患者出现与tPA/DNase给药相关的并发症,最常见的疼痛。19例(50%)患者的放射性积液完全清除,13(34.2%)有部分间隙,和六个(15.8%)的积液没有变化或恶化。八名(21.1%)患者需要进一步手术治疗其积液。
    结论:目前最常见的tPA和DNase联合治疗的给药模式可能并非对所有患者都是最佳的。给药方案应根据临床反应个体化。同时给药是安全的。
    BACKGROUND: The goal of this study was to evaluate how the administration of concurrent tissue plasminogen activator (tPA) and deoxyribonuclease (DNase) therapy with variable dosing for complicated parapneumonic effusions and empyema affects patient outcomes in an inner-city community hospital.
    METHODS: This retrospective analysis was performed at an inner-city hospital located in Raleigh, North Carolina. A list of all patients treated with tPA and DNase between July 1, 2015, and December 31, 2017, was generated and screened. Data were collected through a review of past medical records, including demographics, past medical history, and details about their hospital course.
    RESULTS: A total of 38 patients were found to have been treated with concurrent tPA and DNase for complicated parapneumonic effusion or empyema. Twenty (52.6%) patients received the full six doses of combined concurrent tPA/DNase. Of the 18 (47.4%) patients who did not receive the full six doses, 11 did not require the full six doses for effusion resolution, and seven had to discontinue therapy due to tube blockage or pain. Only seven (18.4%) patients had complications related to tPA/DNase administration, most commonly pain. Nineteen (50%) patients had complete radiological clearance of effusion, with 13 (34.2%) having partial clearance, and six (15.8%) having no change or worsening of their effusion. Eight (21.1%) patients needed further surgical management of their effusion.
    CONCLUSIONS: The current most common dosing pattern for combined tPA and DNase therapy of twice daily for three days may not be optimal for all patients. The dosing regimen should be individualized depending on clinical response. Concurrent dosing is safe.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Pubmed)

  • DOI:
    文章类型: Journal Article
    目的:在复杂的肺炎旁积液或脓胸中,大约25%的患者需要手术干预,这可能导致近20%的死亡风险.然而,rt-tPA和DNase在手术风险过高的老年患者中的联合使用改善了结局.我们研究的主要目标是强调胸膜腔内溶栓在手术风险过高的患者中的实用性。
    方法:对2015年1月1日至3月18日用tPA和DNase治疗的复杂肺炎旁胸腔积液或脓胸患者(n=23)进行回顾性记录回顾研究,2019年在VACHCS。收集的描述胸膜内溶栓治疗结果的数据包括人口统计,胸腔积液分析,手术风险评估,诊断和开始治疗日,剂量,胸部成像,排水率,胸管大小和平均到位天数,炎症标志物,微生物学,抗生素,和并发症。
    结果:只有21.7%的患者被认为是手术候选人。使用国家外科办公室(NSO)风险计算器,74%的患者术后30天死亡风险>2.5%。术后住院率为99.7%,术后ICU平均住院率为>80%。主要结果(胸膜引流改善)为73.9%。最常见的严重并发症包括脓毒症(52.2%),非严重并发症为残余液气胸(47.8%)。
    结论:这项研究表明,在选定的高龄人群中,通过经皮胸膜导管进行胸膜腔内溶栓治疗可安全地成功引流,无需手术干预。被认为是高手术风险的胸膜感染的老年患者。
    In complicated parapneumonic effusion or Empyema, approximately 25% of patients require surgical intervention which can be associated with a mortality risk of almost 20%. However, the use combination of rt-tPA and DNase in elderly patients with prohibitive surgical risk has improved outcomes. The main goal of our study is to highlight the utility of intrapleural thrombolysis in patients with prohibitive risk for surgery.
    A retrospective record review study of patients (n=23) with complicated parapneumonic pleural effusion or empyema treated with tPA and DNase from January 1st of 2015 to March 18th, 2019 at VACHCS. Data collected to describe the outcome of intrapleural thrombolytics included demographic, pleural fluid analysis, surgical risk assessment, diagnosis and initiation treatment day, doses, chest imaging, drainage rate, chest tube size and average days in place, inflammatory markers, microbiology, antibiotics, and complications.
    Only 21.7% of patients were considered surgical candidates. Seventy-four percent had a 30-day post-surgical mortality risk of > 2.5% using the National Surgery Office (NSO) risk calculator. Post-operative inpatient stay was 99.7% and estimated post operative ICU stay average was >80%. Primary outcome (pleural drainage improvement) obtained in 73.9%. Most common serious complications included sepsis (52.2%) and nonserious was residual hydropneumothorax (47.8%).
    This study demonstrates that administration of intrapleural thrombolytics through a percutaneous pleural catheter achieved successful drainage safely and without the need for surgical interventions in a selected group of advanced age, elderly patients with pleural infections who were deemed to be high surgical risk.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    深静脉血栓(DVT)是静脉血栓栓塞(VTE)的一部分,临床上表现为下肢肿胀和疼痛。DVT最严重的临床并发症是肺栓塞(PE),死亡率很高。迄今为止,其潜在机制尚未完全理解,患者通常只有在血栓形成后才会出现临床症状。因此,了解深静脉血栓形成的潜在机制对于DVT的早期诊断和治疗至关重要.近年来,许多研究认为中性粒细胞胞外陷阱(NETs)与DVT密切相关。这些是由中性粒细胞释放的,除了捕获病原体,可以介导深静脉血栓的形成,从而阻塞血管并导致疾病的发展。因此,本文介绍了NETs的发生、发展过程,探讨了NETs对深静脉血栓形成的作用机制。旨在为近期深静脉血栓的诊断和治疗提供方向。
    Deep venous thrombosis (DVT) is a part of venous thromboembolism (VTE) that clinically manifests as swelling and pain in the lower limbs. The most serious clinical complication of DVT is pulmonary embolism (PE), which has a high mortality rate. To date, its underlying mechanisms are not fully understood, and patients usually present with clinical symptoms only after the formation of the thrombus. Thus, it is essential to understand the underlying mechanisms of deep vein thrombosis for an early diagnosis and treatment of DVT. In recent years, many studies have concluded that Neutrophil Extracellular Traps (NETs) are closely associated with DVT. These are released by neutrophils and, in addition to trapping pathogens, can mediate the formation of deep vein thrombi, thereby blocking blood vessels and leading to the development of disease. Therefore, this paper describes the occurrence and development of NETs and discusses the mechanism of action of NETs on deep vein thrombosis. It aims to provide a direction for improved diagnosis and treatment of deep vein thrombosis in the near future.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Pubmed)

  • 文章类型: Journal Article
    脱氧核糖核酸酶(DNase)是催化DNA主链中磷酸二酯键断裂以降解DNA的酶。DNA酶在几种免疫相关疾病中起着至关重要的作用。本研究将DNase的表达与总生存期(OS)联系起来,进行了泛癌症共表达分析,并评估了DNase和免疫浸润亚型之间的关联,通过泛癌症研究的肿瘤微环境和药物敏感性。此外,基因表达数据和临床数据从癌症基因组图谱下载。接下来,通过一系列生物信息学分析,DNA酶表达和存活,免疫亚型,系统研究了33种肿瘤的微环境和药物敏感性。DNase基因家族的表达显示具有明显的肿瘤内异质性。DNA酶2、溶酶体(DNASE2)在肿瘤中的表达量最高,而DNASE2β的含量最低。DNA酶1样3(DNASE1L3)主要在肿瘤中下调,而其余DNA酶主要在肿瘤中上调。还发现DNase家族成员的表达与患者的OS率有关。DNase家族基因可能在肿瘤微环境中发挥重要作用。DNase家族基因表达与细胞毒性细胞含量有关,Immunescore,Stromalscore,估计值和肿瘤纯度。本研究还表明,DNase基因可能与癌细胞的耐药性有关。最后,DNase之间的相关性,研究了肝细胞癌(HCC)的临床分期和肿瘤微环境。此外,DNASE1L3在HCC和癌旁正常组织中的表达差异,通过分析基因表达综合数据集中的三组并进行免疫组织化学,验证了DNASE1L3表达与临床分期之间的关系。总之,本研究评估了DNase基因表达,分析了其与患者OS的关系,进行了泛癌症共表达分析,并评估了DNase和免疫浸润亚型之间的关联,肿瘤微环境和药物敏感性。本研究也证实了DNases进一步实验室研究的价值及其在临床癌症治疗中的前景。
    Deoxyribonuclease (DNase) is an enzyme that catalyzes the cleavage of phosphodiester bonds in the main chain of DNA to degrade DNA. DNase serves a vital role in several immune-related diseases. The present study linked the expression of DNase with overall survival (OS), performed pan-cancer co-expression analysis, and assessed the association between DNase and immune infiltration subtypes, tumor microenvironment and drug sensitivity through pan-cancer studies. Furthermore, gene expression data and clinical data were downloaded from The Cancer Genome Atlas. Next, through a series of bioinformatics analyses, DNase expression and survival, immune subtypes, tumor microenvironment and drug sensitivity in 33 tumor types were systematically studied. The expression of the DNase gene family was shown to have an apparent intratumoral heterogeneity. The expression of DNase 2, lysosomal (DNASE2) was the highest in tumors, whereas that of DNASE2 β was the lowest. DNase 1-like 3 (DNASE1L3) was mainly downregulated in tumors, whereas the rest of the DNases were mainly upregulated in tumors. The expression of DNase family members was also found to be associated with the OS rate of patients. DNase family genes may serve an essential role in the tumor microenvironment. DNase family gene expression was related to the content of cytotoxic cells, Immunescore, Stromalscore, Estimatescore and Tumorpurity. The present study also revealed that the DNase genes may be involved in the drug resistance of cancer cells. Finally, the correlation between DNase, and clinical stage and tumor microenvironment in hepatocellular carcinoma (HCC) was studied. In addition, the difference in DNASE1L3 expression between HCC and adjacent normal tissues, and the relationship between DNASE1L3 expression and clinical stage was verified by analyzing three groups in a Gene Expression Omnibus dataset and by performing immunohistochemistry. In conclusion, the present study assessed DNase gene expression, analyzed its relationship with patient OS, performed pan-cancer co-expression analysis, and assessed the association between DNase and immune infiltration subtypes, tumor microenvironment and drug sensitivity. The present study also confirmed the value of further laboratory research on DNases and their prospects in clinical cancer treatment.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Pubmed)

  • 文章类型: Journal Article
    类风湿性关节炎(RA),一种自身免疫性疾病,以损伤软骨的炎性细胞浸润为特征,破坏骨骼,并损害关节功能。尽管目前的治疗方法主要集中于抗炎活性,但严重受累侧的RA治疗的疗效仍不令人满意。很大程度上是因为复杂的病理机制。最近确定的RA发展机制涉及RA自身抗体与各种促炎细胞因子的相互作用,以促进中性粒细胞胞外陷阱(NETs)的形成,增加炎症反应以表达炎症细胞因子和趋化因子。因此,NETs结构消化可以抑制RA的正反馈炎症信号通路,减轻关节损伤。在这项工作中,脱氧核糖核酸酶I(DNase)通过席夫碱反应与氧化的透明质酸(OHA)连接,以延长DNase的半衰期。该修饰不影响DNA酶对质粒脱氧核糖核酸水解和NETs结构破坏的活性。羧甲基壳聚糖与DNase官能化的OHA(DHA)交联形成可注射,可降解,和生物相容性水凝胶(DHY)进一步增强DHA的粘附能力。重要的是,胶原诱导的关节炎模型表明关节内注射DHY能显著降低炎症细胞因子的表达,通过联合甲氨蝶呤可以显着改善。这里,通过不断降解NETs的新药物靶标以减少RA中的炎症反应,已经开发了DNase官能化水凝胶用于RA治疗。
    Rheumatoid arthritis (RA), an autoimmune disease, is characterized by inflammatory cell infiltration that damages cartilage, disrupts bone, and impairs joint function. The therapeutic efficacy of RA treatments with the severely affected side remains unsatisfactory despite current treatment methods that primarily focus on anti-inflammatory activity, largely because of the complicatedly pathological mechanisms. A recently identified mechanism for RA development involves the interaction of RA autoantibodies with various proinflammatory cytokines to facilitate the formation of neutrophil extracellular traps (NETs), which increased inflammatory responses to express inflammatory cytokines and chemokines. Therefore, NETs architecture digestion may inhibit the positive-feedback inflammatory signal pathway and lessen joint damage in RA. In this work, deoxyribonuclease I (DNase) is connected to oxidized hyaluronic acid (OHA) via Schiff base reaction to extend the half-life of DNase. The modification does not influence the DNase activity for plasmid deoxyribonucleic acid hydrolysis and NETs\' architecture disruption. Carboxymethyl chitosan is crosslinked with DNase-functionalised OHA (DHA) to form an injectable, degradable, and biocompatible hydrogel (DHY) to further strengthen the adhesive capability of DHA. Importantly, the collagen-induced arthritis model demonstrates that intra-articular injection of DHY can significantly reduce inflammatory cytokine expression and alleviate RA symptoms, which can be significantly improved by combining methotrexate. Here, a DNase-functionalised hydrogel has been developed for RA treatment by constantly degrading the novel drug target of NETs to decrease inflammatory response in RA.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    (1)在复苏研究中,双链DNA(dsDNA)和脱氧核糖核酸酶(DNase)作为累积炎症危害的替代参数尚未得到充分研究。(2)在入住ICU后24和96h分析了76例CA后的血液样本。dsDNA的血浆水平,白细胞介素-8和单核细胞趋化蛋白-1和DNase的活性与基线特征一起进行评估,重症监护措施,和结果数据。使用DsDNA/DNase比率作为主要预测参数。在计算结果预测的最佳经验截止值(6个月时死亡或大脑表现类别≥3)后,采用多变量logistic回归。(3)利用接收机工作特性(ROC)分析,24h后dsDNA/DNase的曲线下面积(AUC)为0.65(95%CI0.50-0.79),而96h后为0.83(95%CI0.73-0.92)(p=0.03).96h后dsDNA/DNA酶比率的经验截止值为149.97(Youden)。DsDNA/DNase比值与6个月时的不良结局相关(aOR1.006,95%CI1.0017-1.0094,p=0.005)。在多变量分析中,dsDNA/DNase比值的相关性在校正潜在的混杂因素后,作为连续变量独立预测结局(aOR1.004,95%CI1.0004-1.0079,p=0.029).(4)在96小时的DsDNA/DNase比率显示出用于估计CA后结果的良好预测性能。
    (1) Double-stranded DNA (dsDNA) and deoxyribonuclease (DNase) as surrogate parameters for accumulating inflammatory hazards are insufficiently studied in resuscitation research. (2) Blood samples of 76 individuals after CA were analyzed 24 and 96 h after ICU admission. Plasma levels of dsDNA, interleukin-8, and monocyte chemoattractant protein-1 and activity of DNase were assessed along with baseline characteristics, intensive care measures, and outcome data. DsDNA/DNase ratio was used as main prognostication parameter. After calculating an optimal empirical cut-off for outcome prediction (death or Cerebral Performance Category ≥3 at 6 months), multivariable logistic regression was applied. (3) Using receiver operating characteristic (ROC) analysis, an area under the curve (AUC) of 0.65 (95% CI 0.50-0.79) was found for dsDNA/DNase after 24 h versus 0.83 (95% CI 0.73-0.92) after 96 h (p = 0.03). The empirical cut-off for dsDNA/DNase ratio after 96 h was 149.97 (Youden). DsDNA/DNase ratio was associated with unfavorable outcome at six months (aOR 1.006, 95% CI 1.0017-1.0094, p = 0.005). In multivariable analysis, the association of dsDNA/DNase ratio independently predicted outcome as a continuous variable (aOR 1.004, 95% CI 1.0004-1.0079, p = 0.029) after adjusting for potential confounders. (4) DsDNA/DNase ratio at 96 h demonstrates good predictive performance for estimating outcome after CA.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    致病性钩端螺旋体血清型(Copenhageni和Lai)的基因组预计具有I-B和I-C亚型的CRISPR-Cas。Cas2是核心Cas蛋白之一,在针对外来核酸的适应性防御中起着至关重要的作用。然而,I-C亚型在其对RNA介导的针对外源核酸的适应性免疫所必需的基因座处缺乏CRISPR元件。在不存在CRISPR阵列的情况下,维持cas基因的费用的原因是未知的。因此,从两个充分研究的钩端螺旋体血清变型中选择Cas2C作为代表性Cas蛋白,以解决它是否有功能。在这项研究中,钩端螺旋体血清型Copenhageni的重组Cas2C(rLinCas2C,12kDa)和赖(rLinCas2C_Lai,8.6kDa)过表达并纯化。由于serovarLai的cas2c基因的自然移码突变,rLinCas2C_Lai被过表达并纯化为部分翻译的蛋白质。然而,来自每个血清变体的重组Cas2C表现出金属依赖性DNA酶和金属非依赖性RNA酶活性。以2.60µ的分辨率获得的rLinCas2C的晶体结构表明该蛋白质处于脱位构象,并包含N-(1-71个氨基酸)和C末端(72-90个氨基酸)区域,前者具有铁氧还蛋白褶皱。用丙氨酸取代保守的残基(Tyr7、Asp8、Arg33和Phe39)和环L2的缺失导致DNA酶活性受损。另一方面,RNase活性的适度降低仅在选择性rLinCas2C突变体中明显。总的来说,在没有数组的情况下,观察到的Cas2C的催化活性可能是不同于CRISPR-Cas相关功能的生物过程所需要的。
    The genome of pathogenic Leptospira interrogans serovars (Copenhageni and Lai) are predicted to have CRISPR-Cas of subtypes I-B and I-C. Cas2, one of the core Cas proteins, has a crucial role in adaptive defense against foreign nucleic acids. However, subtype I-C lacks the CRISPR element at its loci essential for RNA-mediated adaptive immunity against foreign nucleic acids. The reason for sustaining the expense of cas genes are unknown in the absence of a CRISPR array. Thus, Cas2C was chosen as a representative Cas protein from two well-studied serovars of Leptospira to address whether it is functional. In this study, the recombinant Cas2C of Leptospira serovars Copenhageni (rLinCas2C, 12 kDa) and Lai (rLinCas2C_Lai, 8.6 kDa) were overexpressed and purified. Due to natural frameshift mutation in the cas2c gene of serovar Lai, rLinCas2C_Lai was overexpressed and purified as a partially translated protein. Nevertheless, the recombinant Cas2C from each serovar exhibited metal-dependent DNase and metal-independent RNase activities. The crystal structure of rLinCas2C obtained at the resolution of 2.60 Å revealed the protein is in apostate conformation and contains N- (1-71 amino acids) and C-terminal (72-90 amino acids) regions, with the former possessing a ferredoxin fold. Substitution of the conserved residues (Tyr7, Asp8, Arg33, and Phe39) with alanine and deletion of Loop L2 resulted in compromised DNase activity. On the other hand, a moderate reduction in RNase activity was evident only in selective rLinCas2C mutants. Overall, in the absence of an array, the observed catalytic activity of Cas2C may be required for biological processes distinct from the CRISPR-Cas-associated function.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Pubmed)

  • 文章类型: Journal Article
    脱氧核糖核酸酶(DNA酶)是切割DNA的酶。一些DNA酶被分泌到细胞外,在那里它们可以切割细胞外DNA(ecDNA)。高浓度的ecDNA与脓毒症等疾病有关,先兆子痫,和系统性狼疮.DNA可以从垂死的细胞中释放并且是免疫原性的。DNA酶切割ecDNA并可能阻止免疫系统的激活。低DNA酶活性在从死亡细胞释放大量ecDNA的疾病中可能是不利的。DNase活性与ecDNA之间的关系仍然未知。缺乏DNA酶活性的标准值使得这些研究难以比较。这篇综述的重点是总结DNase活性测量方法,在疾病中DNase活性降低的可能含义,以及对高浓度ecDNA相关疾病的影响。
    Deoxyribonucleases (DNases) are enzymes that cleave DNA. Some DNases are secreted outside of cells where they can cleave extracellular DNA (ecDNA). High concentration of ecDNA is associated with diseases such as sepsis, preeclampsia, and systemic lupus. DNA can be released from dying cells and is immunogenic. DNases cleave ecDNA and might prevent activation of the immune system. Low DNase activity could be disadvantageous in diseases where high amounts of ecDNA are released from dying cells. The relationship between DNase activity and ecDNA remains unknown. The lack of standard values in DNase activity makes the studies difficult to compare. This review focuses on summarizing methods for DNase activity measurements, the possible implication of decreased DNase activity in diseases, and the impact on diseases associated with a high concentration of ecDNA.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

公众号