Lysine

赖氨酸
  • 文章类型: Journal Article
    设计了一种新型的自糊化粉末,通过增强止血和组织恢复来加速伤口愈合。重要的是,这项研究通过提出一种新颖的方法来解决对创新伤口管理解决方案的关键需求。采用离子交换法合成羧甲基纤维素钙(CMC-Ca),和赖氨酸(Lys)通过物理混合来增强材料的功能特性。对制备的粉末进行了自胶凝能力的综合评价,凝胶化时间,附着力,溶胀率,混凝效率,止血效果,和促进伤口愈合。结果表明,自糊化粉末表现出显著的吸水能力,吸收液体高达其重量的30倍,并在3分钟内实现快速凝固。Lys的加入显著增强了粉末的凝胶形成性能。使用旋转流变仪确定胶凝时间在4s内,粉末在皮肤表面迅速形成稳定的凝胶。此外,在小鼠皮肤损伤模型中,在14天内观察到接近完全的皮肤恢复,强调了粉末令人印象深刻的自我修复属性和在伤口管理中的应用前景。
    A novel self-gelatinizing powder was designed to accelerate wound healing through enhanced hemostasis and tissue recovery. Significantly, this research addresses the critical need for innovative wound management solutions by presenting a novel approach. Carboxymethylcellulose calcium (CMC-Ca) was synthesized using an ion exchange method, and lysine (Lys) was integrated through physical mixing to augment the material\'s functional characteristics. The prepared powder underwent comprehensive evaluation for its self-gelling capacity, gelation time, adhesion, swelling rate, coagulation efficiency, hemostatic effectiveness, and wound healing promotion. Results indicate that the self-gelatinizing powder exhibited remarkable water absorption capabilities, absorbing liquid up to 30 times its weight and achieving rapid coagulation within 3 min. The inclusion of Lys notably enhanced the powder\'s gel-forming properties. The gelation time was determined to be within 4 s using a rotational rheometer, with the powder rapidly forming a stable gel on the skin surface. Furthermore, in a mouse skin injury model, near-complete skin recovery was observed within 14 days, underscoring the powder\'s impressive self-healing attributes and promising application prospects in wound management.
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  • 文章类型: Journal Article
    叶片衰老对于下一季落叶乔木的生长发育至关重要。兴安落叶松,一棵落叶针叶树,通过在秋天变黄并最终脱落叶子来展示其最鲜明的特征,导致其外观在秋季的显著变化。赖氨酸乙酰化在不同的细胞过程中起着重要的作用;然而,关于格氏乳杆菌针叶衰老中乙酰化的知识有限。在这项研究中,两种表型叶片的蛋白质组学和乙酰化修饰组学,黄色和绿色(衰老和非衰老)针,在秋季落叶之前进行了分析。总的来说,在2414个赖氨酸酰化蛋白中鉴定出5022个蛋白和4469个独特的乙酰化位点,这导致在黄色与绿色针中发现了1335种差异表达的蛋白质(DEP)和605种差异表达的乙酰化蛋白质(DAP)。蛋白质组和乙酰组之间存在显著差异;只有269个蛋白质被发现是DEP和DAP,其中136种蛋白质在DEP和DAP中一致表达,91种蛋白质上调,45种蛋白质被下调。DEPs参与淀粉和蔗糖的代谢,而DAP参与糖酵解和三羧酸循环。其中,DEP在糖酵解和柠檬酸循环中发生了显着变化。参与糖酵解和柠檬酸盐循环的大多数酶是乙酰化的。DAP在糖酵解中下调,在柠檬酸盐循环中上调。总之,本研究结果揭示了赖氨酸乙酰化在叶衰老中的重要作用,为理解叶衰老和树木季节生长的分子机制提供了新的视角。
    Leaf senescence is essential for the growth and development of deciduous trees in the next season. Larix gmelinii, a deciduous coniferous tree, exhibits its most distinctive feature by turning yellow in the autumn and eventually shedding its leaves, resulting in significant changes in its appearance during the fall. Lysine acetylation plays an important role in diverse cellular processes; however, limited knowledge is available regarding acetylations in the needle senescence of L. gmelinii. In this study, the proteomics and acetylated modification omics of two phenotypic leaves, yellow and green (senescent and non-senescent) needles, were analyzed before autumn defoliation. In total, 5022 proteins and 4469 unique acetylation sites in 2414 lysine acylated proteins were identified, and this resulted in the discovery of 1335 differentially expressed proteins (DEPs) and 605 differentially expressed acetylated proteins (DAPs) in yellow versus green needles. There are significant differences between the proteome and acetylome; only 269 proteins were found to be DEP and DAP, of which 136 proteins were consistently expressed in both the DEP and DAP, 91 proteins were upregulated, and 45 proteins were down-regulated. The DEPs participate in the metabolism of starch and sucrose, while the DAPs are involved in glycolysis and the tricarboxylic acid cycle. Among them, DEPs underwent significant changes in glycolysis and citric acid cycling. Most of the enzymes involved in glycolysis and the citrate cycle were acetylated. DAPs were down-regulated in glycolysis and up-regulated in the citrate cycle. In all, the results of this study reveal the important role of lysine acetylation in the senescence of L. gmelinii needles and provide a new perspective for understanding the molecular mechanism of leaf senescence and tree seasonal growth.
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  • 文章类型: Journal Article
    背景:通过1,3-偶极环加成用赖氨酸官能化并与半乳糖或甘露糖缀合的多壁碳纳米管(MWCNT)是潜在的纳米载体,可以有效地结合MDA-MB-231或MCF-7乳腺癌细胞中的凝集素受体。在这项工作中,使用基于分子动力学(MD)模拟的方法来预测这些功能化的MWCNT与阿霉素的相互作用,并获得结构证据,从而更好地了解药物的加载和释放过程。MD模拟表明,尽管阿霉素仅通过π-π堆叠相互作用与原始MWCNT相互作用,功能化的MWCNT也能够建立氢键,这表明官能化基团改善了阿霉素的负载。此外,对于官能化纳米管观察到的升高的吸附水平进一步支持负载效率的这种增强。MD模拟还揭示了多柔比星从功能化MWCNT的肿瘤内pH特异性释放,这是由daunosamine部分的质子化诱导。模拟显示质子化的这种变化导致多柔比星对MWCNT的较低吸收。然后对MD研究进行了实验验证,与原始MWCNT相比,官能化MWCNT在水性介质中的分散性得到改善,与计算预测一致,增加药物装载能力。负载阿霉素的官能化MWCNT显示阿霉素在肿瘤微环境(pH=5.0)中的特异性释放,而在生理pH(pH=7.4)中的释放可忽略。此外,不含多柔比星的MWNCT纳米制剂表现出微不足道的细胞毒性。实验研究产生了与MD研究几乎相同的结果,强调该方法的有用性。我们的功能化MWCNT代表了有希望的无毒纳米平台,具有增强的水分散性和与配体缀合的潜力,用于将抗癌药物靶向递送至乳腺癌细胞。
    方法:原始碳纳米管的计算模型是使用buildClstruct1.2Python脚本创建的。用PyMOL和VMD加入裂解的官能化基团。使用一般的AMBER力场对碳纳米管和阿霉素分子进行参数化,和RESP电荷使用高斯09测定。使用AMBER20软件包进行分子动力学模拟。使用cpptraj的水壳函数计算吸附水平。通过使用MDA-MB-231和MCF-7乳腺癌细胞的MTT测定来评估细胞毒性。通过荧光显微镜测量阿霉素和负载阿霉素的MWCNT的药物摄取。
    BACKGROUND: Multiwalled carbon nanotubes (MWCNTs) functionalized with lysine via 1,3-dipolar cycloaddition and conjugated to galactose or mannose are potential nanocarriers that can effectively bind to the lectin receptor in MDA-MB-231 or MCF-7 breast cancer cells. In this work, a method based on molecular dynamics (MD) simulation was used to predict the interaction of these functionalized MWCNTs with doxorubicin and obtain structural evidence that allows a better understanding of the drug loading and release process. The MD simulations showed that while doxorubicin only interacted with pristine MWCNTs through π-π stacking interactions, functionalized MWCNTs were also able to establish hydrogen bonds, suggesting that the functionalized groups improve doxorubicin loading. Moreover, the elevated adsorption levels observed for functionalized nanotubes further support this enhancement in loading efficiency. MD simulations also shed light on the intratumoral pH-specific release of doxorubicin from functionalized MWCNTs, which is induced by protonation of the daunosamine moiety. The simulations show that this change in protonation leads to a lower absorption of doxorubicin to the MWCNTs. The MD studies were then experimentally validated, where functionalized MWCNTs showed improved dispersion in aqueous medium compared to pristine MWCNTs and, in agreement with the computational predictions, increased drug loading capacity. Doxorubicin-loaded functionalized MWCNTs demonstrated specific release of doxorubicin in tumor microenvironment (pH = 5.0) with negligible release in the physiological pH (pH = 7.4). Furthermore, doxorubicin-free MWNCT nanoformulations exhibited insignificant cytotoxicity. The experimental studies yielded nearly identical results to the MD studies, underlining the usefulness of the method. Our functionalized MWCNTs represent promising non-toxic nanoplatforms with enhanced aqueous dispersibility and the potential for conjugation with ligands for targeted delivery of anti-cancer drugs to breast cancer cells.
    METHODS: The computational model of a pristine carbon nanotube was created with the buildCstruct 1.2 Python script. The lysinated functionalized groups were added with PyMOL and VMD. The carbon nanotubes and doxorubicin molecules were parameterized using the general AMBER force field, and RESP charges were determined using Gaussian 09. Molecular dynamics simulations were carried out with the AMBER 20 software package. Adsorption levels were calculated using the water-shell function of cpptraj. Cytotoxicity was evaluated via a MTT assay using MDA-MB-231 and MCF-7 breast cancer cells. Drug uptake of doxorubicin and doxorubicin-loaded MWCNTs was measured by fluorescence microscopy.
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  • 文章类型: Journal Article
    对于在磁共振成像(MRI)检查中出现前列腺成像报告和数据系统(PI-RADS)3/4发现的患者,标准建议通常包括进行活检以进行病理评估,以确定病变的性质。这一行动方针,尽管对于准确诊断至关重要,总是会放大患者所经历的心理困扰,并引入许多与活检程序相关的潜在并发症。然而,[18F]DCFPyLPET/CT成像成为一种有前途的替代方案,在辨别良性前列腺病变和恶性前列腺病变方面表现出相当大的诊断功效。本研究旨在探讨[18F]DCFPyLPET/CT显像对前列腺癌患者PI-RADS3/4病灶的诊断价值,协助临床决策,以避免不必要的活检。30例通过mpMRI诊断为PI-RADS3/4病变的患者接受[18F]DCFPyLPET/CT成像,以最终活检病理结果作为“参考标准”。通过受试者工作特性(ROC)分析评估诊断性能,在[18F]DCFPyLPET/CT成像中评估分子影像学PSMA(miPSMA)视觉分析和半定量分析的诊断效能。根据前列腺癌分子影像学标准化评估标准对病变进行miPSMA评分。在30名患者中,13例经病理证实为前列腺癌。敏感性,特异性,正预测值,负预测值,视觉分析[18F]DCFPyLPET/CT显像诊断PI-RADS3/4病灶的准确率为61.5%,88.2%,80.0%,75.0%,76.5%,分别。使用SUVmax4.17作为最佳阈值,灵敏度,特异性,正预测值,负预测值,诊断准确率为92.3%,88.2%,85.7%,93.8%,90.0%,分别。半定量分析的ROC曲线下面积(AUC)为0.94,明显高于视觉分析的0.80。[18F]DCFPyLPET/CT显像在15例(50%)PI-RADS3/4患者中准确诊断良性病变。对于PI-RADS4病变的患者,[18F]DCFPyLPET/CT显像的阳性预测值达到100%。[18F]DCFPyLPET/CT成像提供了对mpMRIPI-RADS3/4患者的病变性质的潜在术前预测,这可能有助于治疗决策和减少不必要的活检。
    For patients presenting with prostate imaging reporting and data system (PI-RADS) 3/4 findings on magnetic resonance imaging (MRI) examinations, the standard recommendation typically involves undergoing a biopsy for pathological assessment to ascertain the nature of the lesion. This course of action, though essential for accurate diagnosis, invariably amplifies the psychological distress experienced by patients and introduces a host of potential complications associated with the biopsy procedure. However, [18F]DCFPyL PET/CT imaging emerges as a promising alternative, demonstrating considerable diagnostic efficacy in discerning benign prostate lesions from malignant ones. This study aims to explore the diagnostic value of [18F]DCFPyL PET/CT imaging for prostate cancer in patients with PI-RADS 3/4 lesions, assisting in clinical decision-making to avoid unnecessary biopsies. 30 patients diagnosed with PI-RADS 3/4 lesions through mpMRI underwent [18F]DCFPyL PET/CT imaging, with final biopsy pathology results as the \"reference standard\". Diagnostic performance was assessed through receiver operating characteristic (ROC) analysis, evaluating the diagnostic efficacy of molecular imaging PSMA (miPSMA) visual analysis and semi-quantitative analysis in [18F]DCFPyL PET/CT imaging. Lesions were assigned miPSMA scores according to the prostate cancer molecular imaging standardized evaluation criteria. Among the 30 patients, 13 were pathologically confirmed to have prostate cancer. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of visual analysis in [18F]DCFPyL PET/CT imaging for diagnosing PI-RADS 3/4 lesions were 61.5%, 88.2%, 80.0%, 75.0%, and 76.5%, respectively. Using SUVmax 4.17 as the optimal threshold, the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy for diagnosis were 92.3%, 88.2%, 85.7%, 93.8%, and 90.0%, respectively. The area under the ROC curve (AUC) for semi-quantitative analysis was 0.94, significantly higher than visual analysis at 0.80. [18F]DCFPyL PET/CT imaging accurately diagnosed benign lesions in 15 (50%) of the PI-RADS 3/4 patients. For patients with PI-RADS 4 lesions, the positive predictive value of [18F]DCFPyL PET/CT imaging reached 100%. [18F]DCFPyL PET/CT imaging provides potential preoperative prediction of lesion nature in mpMRI PI-RADS 3/4 patients, which may aid in treatment decision-making and reducing unnecessary biopsies.
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  • 文章类型: Journal Article
    背景:赖氨酸甲基转移酶2D(KMT2D)介导哺乳动物中组蛋白H3赖氨酸4(H3K4me1)的单甲基化。H3K4me1标记参与建立活性染色质结构以促进基因转录。然而,KMT2D介导的H3K4me1标记在三阴性乳腺癌(TNBC)进展中调节基因表达的确切分子机制尚未解决.
    结果:我们认为Y盒结合蛋白1(YBX1)是H3K4me1标记的“阅读器”,YBX1(E121A)的点突变破坏了这种相互作用。我们发现KMT2D和YBX1在体外和体内协同促进TNBC细胞的生长和转移。肿瘤组织中KMT2D和YBX1的表达水平均上调,并与乳腺癌患者的不良预后相关。对ChIP-seq和RNA-seq数据的组合分析表明,YBX1与KMT2D介导的H3K4me1共定位在c-Myc和SENP1的启动子区域,从而激活它们在TNBC细胞中的表达。此外,我们证明YBX1以KMT2D依赖的方式激活c-Myc和SENP1的表达。
    结论:我们的结果表明,KMT2D介导的H3K4me1通过c-Myc和SENP1的表观遗传激活招募YBX1促进TNBC进展。这些结果共同揭示了组蛋白标记和基因调控在TNBC进展中的关键相互作用。从而为靶向KMT2D-H3K4me1-YBX1轴治疗TNBC提供了新的见解。
    结论:YBX1是一种KMT2D介导的H3K4me1结合效应蛋白,YBX1(E121A)的突变破坏了其与H3K4me1的结合。KMT2D和YBX1通过在体内外激活c-Myc和SENP1表达共同促进TNBC的增殖和转移。YBX1在TNBC细胞的c-Myc和SENP1启动子区域与H3K4me1共定位,并且YBX1表达增加预测乳腺癌患者的预后不良。
    BACKGROUND: Lysine methyltransferase 2D (KMT2D) mediates mono-methylation of histone H3 lysine 4 (H3K4me1) in mammals. H3K4me1 mark is involved in establishing an active chromatin structure to promote gene transcription. However, the precise molecular mechanism underlying the KMT2D-mediated H3K4me1 mark modulates gene expression in triple-negative breast cancer (TNBC) progression is unresolved.
    RESULTS: We recognized Y-box-binding protein 1 (YBX1) as a \"reader\" of the H3K4me1 mark, and a point mutation of YBX1 (E121A) disrupted this interaction. We found that KMT2D and YBX1 cooperatively promoted cell growth and metastasis of TNBC cells in vitro and in vivo. The expression levels of KMT2D and YBX1 were both upregulated in tumour tissues and correlated with poor prognosis for breast cancer patients. Combined analyses of ChIP-seq and RNA-seq data indicated that YBX1 was co-localized with KMT2D-mediated H3K4me1 in the promoter regions of c-Myc and SENP1, thereby activating their expressions in TNBC cells. Moreover, we demonstrated that YBX1 activated the expressions of c-Myc and SENP1 in a KMT2D-dependent manner.
    CONCLUSIONS: Our results suggest that KMT2D-mediated H3K4me1 recruits YBX1 to facilitate TNBC progression through epigenetic activation of c-Myc and SENP1. These results together unveil a crucial interplay between histone mark and gene regulation in TNBC progression, thus providing novel insights into targeting the KMT2D-H3K4me1-YBX1 axis for TNBC treatment.
    CONCLUSIONS: YBX1 is a KMT2D-mediated H3K4me1-binding effector protein and mutation of YBX1 (E121A) disrupts its binding to H3K4me1. KMT2D and YBX1 cooperatively promote TNBC proliferation and metastasis by activating c-Myc and SENP1 expression in vitro and in vivo. YBX1 is colocalized with H3K4me1 in the c-Myc and SENP1 promoter regions in TNBC cells and increased YBX1 expression predicts a poor prognosis in breast cancer patients.
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  • 文章类型: English Abstract
    赖氨酸(K)被广泛用于赖氨酸靶向交联剂的设计,蛋白质复合物的结构阐明,以及蛋白质-蛋白质相互作用的分析。在“鸟枪”蛋白质组学中,基于液相色谱-串联质谱(LC-MS/MS),来自复杂样品的蛋白质被酶消化,产生数千种肽,并为直接分析含K肽提出了重大挑战。鉴于目前缺乏有效的含K肽富集方法,这项工作开发了一种基于疏水标记试剂C10-S-S-NHS和反相色谱(称为HYTARP)的方法,以实现对复杂样品中含K肽的有效富集和鉴定。在这项工作中合成的C10-S-S-NHS成功地标记了含有各种数量的K的标准肽,并且对于HeLa细胞蛋白胰蛋白酶消化物,标记效率达到高达96%。通过研究这些标记肽在C18RP柱中的保留行为,我们发现,当乙腈百分比达到57.6%(v/v)时,大多数K标记的肽被洗脱一次。洗脱梯度的进一步优化使得能够通过逐步洗脱梯度有效分离和富集HeLa消化物中的K标记的肽。K标记的肽在富集肽中占90%,表示与没有富集的肽的数量相比提高了35%。从富集的含K肽定量的蛋白质的动态范围跨越5-6个数量级,并实现了复杂样品中低丰度蛋白的检测。总之,HYTARP策略为降低样品复杂性和提高含钾肽和低丰度蛋白质的鉴定覆盖率提供了一种简单有效的方法.
    Lysine (K) is widely used in the design of lysine-targeted crosslinkers, structural elucidation of protein complexes, and analysis of protein-protein interactions. In \"shotgun\" proteomics, which is based on liquid chromatography-tandem mass spectrometry (LC-MS/MS), proteins from complex samples are enzymatically digested, generating thousands of peptides and presenting significant challenges for the direct analysis of K-containing peptides. In view of the lack of effective methods for the enrichment of K-containing peptides, this work developed a method which based on a hydrophobic-tag-labeling reagent C10-S-S-NHS and reversed-phase chromatography (termed as HYTARP) to achieve the efficient enrichment and identification of K-containing peptides from complex samples. The C10-S-S-NHS synthesized in this work successfully labeled standard peptides containing various numbers of K and the labeling efficiency achieved up to 96% for HeLa cell protein tryptic digests. By investigating the retention behavior of these labeled peptides in C18 RP column, we found that most K-labeled peptides were eluted once when acetonitrile percentage reached 57.6% (v/v). Further optimization of the elution gradient enabled the efficient separation and enrichment of the K-labeled peptides in HeLa digests via a stepwise elution gradient. The K-labeled peptides accounted for 90% in the enriched peptides, representing an improvement of 35% compared with the number of peptides without the enrichment. The dynamic range of proteins quantified from the enriched K-containing peptides spans 5-6 orders of magnitude, and realized the detection of low-abundance proteins in the complex sample. In summary, the HYTARP strategy offers a straightforward and effective approach for reducing sample complexity and improving the identification coverage of K-containing peptides and low-abundance proteins.
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  • 文章类型: Journal Article
    背景:BRAF抑制剂广泛用于治疗具有BRAFV600E突变的黑素瘤。然而,耐药性的发展损害了它们的治疗功效。在BRAF抑制剂抗性黑色素瘤中发现了不同的基因组和转录组改变,迫切需要收敛,具有不同耐药机制的逆转治疗耐药肿瘤的药物靶标。
    方法:进行CRISPR-Cas9筛选以鉴定新的靶基因,其抑制选择性靶向A375VR,对vemurafenib具有获得性抗性的BRAFV600E突变细胞系。各种体外和体内试验,包括细胞竞争试验,水溶性四唑(WST)测定,进行活死试验和异种移植试验以确认协同细胞死亡.液相色谱-质谱分析定量多胺生物合成和维罗非尼耐药黑色素瘤蛋白质组的变化。EIF5A催眠依赖的蛋白质翻译和随后的线粒体生物发生和活性的变化通过O-炔丙基-嘌呤霉素标记测定,mitotracker,mitoSOX标记和海马测定。生物信息学分析用于确定多胺生物合成与BRAF抑制剂抗性和黑色素瘤患者队列中不良预后的关联。
    结果:我们阐明了多胺生物合成及其调节机制在促进BRAF抑制剂抗性中的作用。利用CRISPR-Cas9屏幕,我们鉴定了AMD1(S-腺苷甲硫氨酸脱羧酶1),多胺生物合成的关键酶,作为一种药物靶标,其抑制作用降低了维罗非尼的耐药性。代谢组学和蛋白质组学分析显示,维罗非尼耐药癌症中多胺生物合成上调,导致增强的EIF5A催眠,线粒体蛋白的翻译和氧化磷酸化。我们还确定维罗非尼耐药癌症中持续的c-Myc水平是多胺生物合成升高的原因。在体外细胞系模型和在异种移植模型中体内抑制多胺生物合成或c-Myc逆转维罗非尼抗性。多胺生物合成特征与黑色素瘤患者BRAF/MAPK抑制剂治疗后的不良预后和较短的无进展生存期相关,强调我们的研究结果的临床相关性。
    结论:我们的发现描述了在黑色素瘤中涉及多胺-EIF5A催眠-线粒体呼吸途径赋予BRAF抑制剂抗性的分子机制。这些靶标将作为有效的治疗靶标,其可以最大化现有BRAF抑制剂的治疗功效。
    BACKGROUND: BRAF inhibitors are widely employed in the treatment of melanoma with the BRAF V600E mutation. However, the development of resistance compromises their therapeutic efficacy. Diverse genomic and transcriptomic alterations are found in BRAF inhibitor resistant melanoma, posing a pressing need for convergent, druggable target that reverse therapy resistant tumor with different resistance mechanisms.
    METHODS: CRISPR-Cas9 screens were performed to identify novel target gene whose inhibition selectively targets A375VR, a BRAF V600E mutant cell line with acquired resistance to vemurafenib. Various in vitro and in vivo assays, including cell competition assay, water soluble tetrazolium (WST) assay, live-dead assay and xenograft assay were performed to confirm synergistic cell death. Liquid Chromatography-Mass Spectrometry analyses quantified polyamine biosynthesis and changes in proteome in vemurafenib resistant melanoma. EIF5A hypusination dependent protein translation and subsequent changes in mitochondrial biogenesis and activity were assayed by O-propargyl-puromycin labeling assay, mitotracker, mitoSOX labeling and seahorse assay. Bioinformatics analyses were used to identify the association of polyamine biosynthesis with BRAF inhibitor resistance and poor prognosis in melanoma patient cohorts.
    RESULTS: We elucidate the role of polyamine biosynthesis and its regulatory mechanisms in promoting BRAF inhibitor resistance. Leveraging CRISPR-Cas9 screens, we identify AMD1 (S-adenosylmethionine decarboxylase 1), a critical enzyme for polyamine biosynthesis, as a druggable target whose inhibition reduces vemurafenib resistance. Metabolomic and proteomic analyses reveal that polyamine biosynthesis is upregulated in vemurafenib-resistant cancer, resulting in enhanced EIF5A hypusination, translation of mitochondrial proteins and oxidative phosphorylation. We also identify that sustained c-Myc levels in vemurafenib-resistant cancer are responsible for elevated polyamine biosynthesis. Inhibition of polyamine biosynthesis or c-Myc reversed vemurafenib resistance both in vitro cell line models and in vivo in a xenograft model. Polyamine biosynthesis signature is associated with poor prognosis and shorter progression free survival after BRAF/MAPK inhibitor treatment in melanoma cohorts, highlighting the clinical relevance of our findings.
    CONCLUSIONS: Our findings delineate the molecular mechanisms involving polyamine-EIF5A hypusination-mitochondrial respiration pathway conferring BRAF inhibitor resistance in melanoma. These targets will serve as effective therapeutic targets that can maximize the therapeutic efficacy of existing BRAF inhibitors.
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  • 文章类型: Journal Article
    本研究探讨了微波(MW)场下l-赖氨酸干预小麦面筋蛋白(WG)凝胶形成的机理。结果表明,在相同的升温速率下,MW处理具有较高的ζ电位值。加入L-赖氨酸后,溶液电导率和介电损耗显著增加。此外,在MW处理下,WG凝胶强度提高了4.40%。傅里叶光谱显示,随着赖氨酸的加入,α-螺旋含量降低了13.78%。紫外吸收光谱和荧光光谱表明,MW辐射比水浴加热更有效地影响WG分子之间的相互作用。促进蛋白质结构的变性和展开。此外,扫描电镜分析表明,赖氨酸的掺入促进了蛋白质有序网络结构的形成,这增强了凝胶特性。这表明1-赖氨酸的两性离子在MW场中蛋白质的聚集中起调节作用。
    This study explored the mechanism of l-lysine intervention in wheat gluten protein (WG) gel formation under a microwave (MW) field. The results showed that the MW treatment had higher ζ-potential values at the same heating rate. After adding l-lysine, the solution conductivity and dielectric loss were significantly increased. Moreover, the WG gel strength enhanced 4.40% under the MW treatment. The Fourier spectra showed that the α-helix content was decreased 13.78% with the addition of lysine. The ultraviolet absorption spectra and fluorescence spectra indicated that MW irradiation impacted the interactions between WG molecules more effectively than the water bath heating, promoting the denaturation and unfolding of the protein structure. In addition, scanning electron microscopy analysis showed that the incorporation of lysine promoted an ordered network structure formation of the protein, which enhanced the gel properties. This indicated that the zwitterion of l-lysine played a regulatory role in the aggregation of proteins in the MW field.
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  • 文章类型: Journal Article
    背景:巨噬细胞的异常激活与急性肺损伤(ALI)的发病机制有关。然而,潜在的发病机制尚未被探索。
    目的:我们旨在确定组蛋白脱乙酰酶(HDAC)10是否与脂多糖(LPS)暴露的ALI有关,并揭示其通过修饰P62去乙酰化促进LPS暴露的ALI中肺部炎症的潜在发病机制。
    方法:我们构建了用LPS刺激的ALI小鼠模型,以确定Hdac10缺乏的积极作用。此外,我们培养小鼠肺泡巨噬细胞系(MH-S细胞)和原代骨髓源性巨噬细胞(BMDMs),以探讨LPS攻击后HDAC10的促炎活性和机制。
    结果:HDAC10在小鼠肺组织和巨噬细胞系中的表达增加,并促进暴露于LPS的炎性细胞因子的产生。Hdac10缺乏抑制LPS刺激后的自噬和炎症反应。在体内,Hdac10fl/fl-LysMCre小鼠显著减弱暴露于LPS的肺部炎症和炎性细胞因子释放。机械上,HDAC10与P62相互作用,并在赖氨酸165(K165)处介导P62脱乙酰,通过它促进P62表达并增加炎性细胞因子的产生。重要的是,我们确定丹酚酸B(SAB),HDAC10抑制剂,减少LPS刺激的ALI中的肺部炎症反应。
    结论:这些结果揭示了HDAC10在调节LPS诱导的ALI中P62去乙酰化和加重肺部炎症中的作用,暗示靶向HDAC10是LPS暴露的ALI的有效疗法。
    BACKGROUND: Aberrant activation of macrophages is associated with pathogenesis of acute lung injury (ALI). However, the potential pathogenesis has not been explored.
    OBJECTIVE: We aimed to identify whether histone deacetylase (HDAC) 10 is involved in lipopolysaccharide (LPS)-exposed ALI and reveal the underlying pathogenesis by which it promotes lung inflammation in LPS-exposed ALI via modifying P62 with deacetylation.
    METHODS: We constructed an ALI mice model stimulated with LPS to determine the positive effect of Hdac10 deficiency. Moreover, we cultured murine alveolar macrophage cell line (MH-S cells) and primary bone marrow-derived macrophages (BMDMs) to explore the pro-inflammatory activity and mechanism of HDAC10 after LPS challenge.
    RESULTS: HDAC10 expression was increased both in mice lung tissues and macrophage cell lines and promoted inflammatory cytokines production exposed to LPS. Hdac10 deficiency inhibited autophagy and inflammatory response after LPS stimulation. In vivo, Hdac10fl/fl-LysMCre mice considerably attenuated lung inflammation and inflammatory cytokines release exposed to LPS. Mechanistically, HDAC10 interacts with P62 and mediates P62 deacetylation at lysine 165 (K165), by which it promotes P62 expression and increases inflammatory cytokines production. Importantly, we identified that Salvianolic acid B (SAB), an HDAC10 inhibitor, reduces lung inflammatory response in LPS-stimulated ALI.
    CONCLUSIONS: These results uncover a previously unknown role for HDAC10 in regulating P62 deacetylation and aggravating lung inflammation in LPS-induced ALI, implicating that targeting HDAC10 is an effective therapy for LPS-exposed ALI.
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  • 文章类型: Journal Article
    上皮细胞是细菌进入呼吸道的第一个接触点。肺炎链球菌是一种专性的人类鼻粘膜病变,携带无症状,但也是严重肺炎的原因。目前对上皮在维持稳态相互作用或建立对侵袭性肺炎链球菌的炎症反应中的作用知之甚少。然而,研究表明,染色质修饰,在组蛋白水平,由细菌引起的病原体干扰宿主的转录程序并促进感染。这里,我们发现由肺炎链球菌感染诱导的组蛋白修饰在抗生素清除细菌后维持至少9天。组蛋白H3在赖氨酸4(H3K4me2)上的二甲基化通过细菌附着于宿主细胞以活性方式诱导。我们证明感染建立了一个影响上皮细胞转录反应的独特表观遗传程序,使他们在继发感染时更加宽容。我们的结果确立了H3K4me2作为感染诱导的独特修饰,与H3K4me3或me1不同,后者位于全基因组的增强子区域。因此,这项研究揭示了细菌感染在细菌清除后在上皮细胞中留下记忆的证据,在表观基因组标记中,从而改变细胞对随后感染的反应并促进感染。
    Epithelial cells are the first point of contact for bacteria entering the respiratory tract. Streptococcus pneumoniae is an obligate human pathobiont of the nasal mucosa, carried asymptomatically but also the cause of severe pneumoniae. The role of the epithelium in maintaining homeostatic interactions or mounting an inflammatory response to invasive S. pneumoniae is currently poorly understood. However, studies have shown that chromatin modifications, at the histone level, induced by bacterial pathogens interfere with the host transcriptional program and promote infection. Here, we uncover a histone modification induced by S. pneumoniae infection maintained for at least 9 days upon clearance of bacteria with antibiotics. Di-methylation of histone H3 on lysine 4 (H3K4me2) is induced in an active manner by bacterial attachment to host cells. We show that infection establishes a unique epigenetic program affecting the transcriptional response of epithelial cells, rendering them more permissive upon secondary infection. Our results establish H3K4me2 as a unique modification induced by infection, distinct from H3K4me3 or me1, which localizes to enhancer regions genome-wide. Therefore, this study reveals evidence that bacterial infection leaves a memory in epithelial cells after bacterial clearance, in an epigenomic mark, thereby altering cellular responses to subsequent infections and promoting infection.
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