stress resistance

耐应力性
  • 文章类型: Journal Article
    革兰氏阳性,杆状,有氧,能动,和孢子形成细菌,命名为SCL10,是从暴露于Co-60辐射的Acaudinamolpadioides中分离出来的。在这项研究中,进行了全基因组测序,以鉴定菌株为蜡样芽孢杆菌和功能表征,专注于抗压力。对蜡状芽孢杆菌SCL10菌株的基因组进行测序和组装,揭示了4,979,182bp的大小和5167个编码基因。通过使用GO注释参与生物学功能的基因,COG,KEGG,NR,和Swiss-Prot数据库。结果表明,与烷基过氧化氢还原酶(ahpC,ahpF),来自饥饿细胞的DNA结合蛋白(dps),孢子和生物膜的形成(spoVG,spo0A,GerP),冷休克样蛋白(cspC,cspE),ATP依赖性伴侣(clpB),和光解酶,小,酸溶性孢子蛋白(SASP)和DNA修复蛋白(recA,radD)可以解释抗应力性。这些发现表明,抗氧化活性,孢子形成,生物膜的形成,和DNA保护可能被认为是蜡状芽孢杆菌SCL10菌株在暴露于辐射下的主要抗性机制。
    A Gram-positive, rod-shaped, aerobic, motile, and spore-forming bacterium, designated SCL10, was isolated from Acaudina molpadioides exposure to Co-60 radiation. In this study, whole-genome sequencing was performed to identify the strain as Bacillus cereus and functional characterization, with a focus on stress resistance. The genome of the B. cereus SCL10 strain was sequenced and assembled, revealing a size of 4,979,182 bp and 5167 coding genes. The genes involved in biological functions were annotated by using the GO, COG, KEGG, NR, and Swiss-Prot databases. The results showed that genes related to alkyl hydroperoxide reductase (ahpC, ahpF), DNA-binding proteins from starved cells (dps), spore and biofilm formation (spoVG, spo0A, gerP), cold shock-like protein (cspC, cspE), ATP-dependent chaperone (clpB), and photolyase, small, acid-soluble spore protein (SASP) and DNA repair protein (recA, radD) could explain the stress resistance. These findings suggest that antioxidant activity, sporulation, biofilm formation, and DNA protection may be considered as the main resistance mechanisms under exposure to radiation in the B. cereus SCL10 strain.
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  • 文章类型: Journal Article
    丝氨酸羧肽酶(SCPL)基因家族在植物生长调控中起着至关重要的作用,发展,通过植物次生代谢途径中的酰基转移酶等活性进行胁迫响应。尽管SCPL基因已在各种植物物种中被鉴定,它们在大豆(Glycinemax)中的特定功能和特性尚未被研究。我们鉴定并鉴定了73个SCPL基因,根据基因结构和系统发育关系分为三个亚组。这些基因在20个大豆染色体上分布不均,并显示出受突变和选择压力影响的不同密码子使用模式。基因本体论(GO)富集表明这些基因参与植物细胞壁调节和胁迫响应。在各种组织和应激条件下的表达分析,包括许多与压力相关的顺式作用元素的存在,表明这些基因具有不同的表达模式。这表明它们起着特殊的作用,例如调节植物对线虫感染的防御机制,增强对干旱和高盐度的耐受性,应对寒冷的压力,从而帮助大豆适应环境胁迫。此外,暴露于线虫感染后,特定GmSPLs的表达受到显着影响,干旱,高盐(NaCl),冷压力。我们的发现强调了SCPL基因在增强大豆抗逆性方面的潜力,为未来的遗传改良和育种策略提供了宝贵的资源。
    The serine carboxypeptidase-like (SCPL) gene family plays a crucial role in the regulation of plant growth, development, and stress response through activities such as acyltransferases in plant secondary metabolism pathways. Although SCPL genes have been identified in various plant species, their specific functions and characteristics in soybean (Glycine max) have not yet been studied. We identified and characterized 73 SCPL genes, grouped into three subgroups based on gene structure and phylogenetic relationships. These genes are distributed unevenly across 20 soybean chromosomes and show varied codon usage patterns influenced by both mutation and selection pressures. Gene ontology (GO) enrichment suggests these genes are involved in plant cell wall regulation and stress responses. Expression analysis in various tissues and under stress conditions, including the presence of numerous stress-related cis-acting elements, indicated that these genes have varied expression patterns. This suggests that they play specialized roles such as modulating plant defense mechanisms against nematode infections, enhancing tolerance to drought and high salinity, and responding to cold stress, thereby helping soybean adapt to environmental stresses. Moreover, the expression of specific GmSCPLs was significantly affected following exposure to nematode infection, drought, high salt (NaCl), and cold stresses. Our findings underscore the potential of SCPL genes in enhancing stress resistance in soybean, providing a valuable resource for future genetic improvement and breeding strategies.
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  • 文章类型: Journal Article
    接种物对生物反应器初始化和性能具有至关重要的影响。然而,目前缺乏选择适合环境生物技术应用的接种物的指导。在这项研究中,我们应用微生物电解池(MECs)作为模型来研究从四种不同的接种物(天然或人工)开发的阳极生物膜内的电活性微生物(EAMs)的功能电位的差异,使用鸟枪宏基因组技术。我们特别关注细胞外电子转移(EET)功能和抗应力,这影响了MEC的性能和稳定性。群落分析显示,地细菌科是所有生物膜中关键的EAM分类单元,以Geobacter为优势属。c型细胞色素基因imcH对地杆菌科EET具有普遍的重要性,并被用作评估EAM的EET潜力的标记基因。应激反应功能基因用于评估Geobacter物种的抗逆性潜力。imcH基因丰度的比较分析表明,人工和天然接种物可以富集具有相当整体EET潜力的EAM(P>0.05)。然而,基因组中应激反应基因拷贝数的定量表明,源自天然接种物的EAM具有优异的抗应激潜力(196vs.163).总的来说,本研究为生物反应器中接种物效应的研究提供了新的视角,为环境工程应用中接种物的选择提供了理论指导。
    The inoculum has a crucial impact on bioreactor initialization and performance. However, there is currently a lack of guidance on selecting appropriate inocula for applications in environmental biotechnology. In this study, we applied microbial electrolysis cells (MECs) as models to investigate the differences in the functional potential of electroactive microorganisms (EAMs) within anodic biofilms developed from four different inocula (natural or artificial), using shotgun metagenomic techniques. We specifically focused on extracellular electron transfer (EET) function and stress resistance, which affect the performance and stability of MECs. Community profiling revealed that the family Geobacteraceae was the key EAM taxon in all biofilms, with Geobacter as the dominant genus. The c-type cytochrome gene imcH showed universal importance for Geobacteraceae EET and was utilized as a marker gene to evaluate the EET potential of EAMs. Additionally, stress response functional genes were used to assess the stress resistance potential of Geobacter species. Comparative analysis of imcH gene abundance revealed that EAMs with comparable overall EET potential could be enriched from artificial and natural inocula (P > 0.05). However, quantification of stress response gene copy numbers in the genomes demonstrated that EAMs originating from natural inocula possessed superior stress resistance potential (196 vs. 163). Overall, this study provides novel perspectives on the inoculum effect in bioreactors and offers theoretical guidance for selecting inoculum in environmental engineering applications.
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  • 文章类型: Journal Article
    药用植物的抗逆性对药理活性成分的积累至关重要,但生物因子和非生物因子对药用植物的调控机制尚不清楚。探讨土壤养分和微生态对毛虫抗逆性的作用机制,闽县四个季节采集根际土壤和根系,甘肃,以及它们的物理化学性质,以及与根相关的微生物,进行了检查。结果表明,从夏季到秋季,细菌α多样性指数在内圈和根际增加。同时,社区组成和功能发生了很大变化。内生细菌群落的稳定性高于根际细菌,内生细菌群落的复杂性低于根际细菌。土壤有机质(OM),含水量(WC),总钾(TK),总氮(TN)和总氮(TN)已被确定为影响毛虫细菌群落多样性和抗逆性的关键因素。WC,TN,OM和OM从夏季到秋季表现出显著差异(P<0.5)。4个关键土壤理化因子在季节间变化显著(P<0.01)。TN和OM主要通过改变抗氧化酶的活性来改变毛囊的抗逆性。OM和内生细菌多样性的变化会影响可溶性糖的积累,从而改变抗逆性。这四个关键的土壤理化因子显著影响内生细菌的多样性。WC和OM被确定为内生和根际细菌的最重要因素,分别。本研究为毛竹的科学种植提供了研究依据。
    The stress resistance of medicinal plants is essential to the accumulation of pharmacological active ingredients, but the regulation mechanism of biological factors and abiotic factors on medicinal plants is still unclear. To investigate the mechanism of soil nutrient and microecology on the stress resistance of C. pilosula, rhizosphere soil and roots were collected across the four seasons in Minxian, Gansu, and their physicochemical properties, as well as root-associated microorganisms, were examined. The results showed that the bacterial α-diversity indexes increased in the endosphere and rhizosphere from summer to autumn. At the same time, the community composition and function changed considerably. The stability of the endophytic bacterial community was higher than that rhizospheric bacteria, and the complexity of the endophytic bacterial community was lower than rhizospheric bacteria. Soil organic matter (OM), water content (WC), total potassium (TK), and total nitrogen (TN) have been identified as the key factors affecting bacterial community diversity and stress resistance of C. pilosula. WC, TN, and OM showed significant differences from summer to autumn (P < 0.5). Four key soil physiochemical factors changed significantly between seasons (P < 0.01). TN and OM change the stress resistance of C. pilosula mainly by changing the activity of antioxidant enzymes. Changes of OM and endophytic bacterial diversity affect the accumulation of soluble sugars to alter stress resistance. These four key soil physicochemical factors significantly influenced the diversity of endophytic bacteria. WC and OM were identified as the most important factors for endophytic and rhizospheric bacteria, respectively. This study provided the research basis for the scientific planting of C. pilosula.
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  • 文章类型: Journal Article
    变穷了,地衣固有地暴露于交替的干燥和水合循环。它们可以在脱水状态下对极端温度表现出非凡的抵抗力,但水合地衣的热阈值较低。高温处理后(40°C,60°C)在不同的空气湿度水平(相对湿度[RH]:<15%,25%,50%,75%,检查了38%),以发现地衣的被动脱水与其对热应激的生理抗性之间的联系。通过在恢复2小时和24小时后测量与光合作用和呼吸相关的参数来确定对加热的响应。较高的RH水平导致水合thalli中相对水含量(RWC)下降较慢。反过来,活性thalli的抗逆性取决于环境湿度和相关的RWC减少。温度升高对生物能量过程有负面影响,但是只有在热应激期间永久完全水合的不自然状态才会导致致命的效果。在40°C和50%相对湿度(RH)下加热的水合地衣thalli往往最不容易受到应力引起的损伤。尽管非典型的气候条件可能会导致地衣达到致命的阈值,由于高温事件本身对地衣造成致命威胁的实际可能性是有争议的。
    Being poikilohydric, lichens are inherently exposed to alternating desiccation and hydration cycles. They can exhibit extraordinary resistance to extreme temperatures in a dehydrated state but thermal thresholds for hydrated lichens are lower. The ability of the lichen Cetraria aculeata to recovery after high temperature treatment (40°C, 60°C) at different air humidity levels (relative humidity [RH]: <15%, 25%, 50%, 75%, ≅100%) was examined to find a linkage between passive dehydration of the lichen and its physiological resistance to heat stress. The response to heating was determined by measuring parameters related to photosynthesis and respiration after 2- and 24-h recovery. A higher RH level resulted in a slower decline in relative water content (RWC) in hydrated thalli. In turn, the stress resistance of active thalli depended on the ambient humidity and associated RWC reduction. Elevated temperature had a negative impact on bioenergetic processes, but only an unnatural state of permanent full hydration during heat stress resulted in a lethal effect. Hydrated lichen thalli heated at 40°C and 50% relative humidity (RH) tended to be least susceptible to stress-induced damage. Although atypical climatic conditions may lead lichens to lethal thresholds, the actual likelihood of deadly threat to lichens due to heat events per se is debatable.
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  • 文章类型: Journal Article
    沙漠草原生态系统容易受到干旱胁迫,影响草原生态平衡和可持续发展。除了直接限制植物生长,干旱胁迫通过改变根相关微生物组的多样性和功能间接影响植物适应性。这就引出了一个问题,即牧草植物的功能微生物组,以合成微生物群落(SynComs)为代表,可以用来减轻沙漠草原的干旱胁迫,促进这些脆弱生态系统的生态恢复。
    进行了一个盆栽实验,以评估SynComs在提高新果胶酶的植物生长和抗旱性中的作用(Pall。)内蒙古荒漠草原的Poljak,中国。六个SynComs来自沙漠草原中12种优势牧草物种的根际和根内圈。每个SynCom包含两到三个细菌属(芽孢杆菌,原微单孢菌,和链霉菌)。我们检查了不同SynComs的营养溶解能力,植物激素分泌,和酶活性。
    在没有水分胁迫的情况下(土壤持水量为75%,WHC),单菌株在促进植物生长的茎直径方面比SynComs表现更好,根长,和植物干重,对蓝链霉菌ATCC13740的影响最大(p<0.05)。然而,在轻度至中度干旱胁迫(55%和35%WHC)下,SynComs在增强植物生物量积累和诱导抗性相关物质的产生方面优于单个菌株(p<0.05)。单株和SynComs在极端干旱胁迫(20%WHC)下没有出现显著的效应。
    这项研究强调了SynComs在促进牧草植物对抗沙漠草原干旱胁迫方面的潜力。轻度至中度干旱胁迫刺激SynComs有利于N.pectinata植物的生长,尽管土壤湿度阈值(21%WHC)存在微生物效应。SynComs的使用通过操纵饲草植物的功能微生物组,为沙漠草原的生态恢复和可持续利用提供了有希望的策略。
    UNASSIGNED: Desert steppe ecosystems are prone to drought stress, which influences the ecological balance and sustainable development of grasslands. In addition to directly restrict plant growth, drought stress indirectly impacts plant fitness by altering the diversity and function of root-associated microbiomes. This begs the question of whether the functional microbiome of forage plants, represented by synthetic microbial communities (SynComs), can be leveraged to mitigate drought stress in desert steppes and promote the ecological restoration of these fragile ecosystems.
    UNASSIGNED: A pot experiment was conducted to evaluate the role of SynComs in improving the plant growth and drought stress resistance of Neopallasia pectinata (Pall.) Poljak in desert steppe in Inner Mongolia, China. Six SynComs were derived from the rhizosphere and root endosphere of 12 dominant forage species in the desert steppe. Each SynCom comprised two to three bacterial genera (Bacillus, Protomicromonospora, and Streptomyces). We examined the capacities of different SynComs for nutrient solubilization, phytohormone secretion, and enzymatic activity.
    UNASSIGNED: Under no water stress (75% soil water holding capacity, WHC), single strains performed better than SynComs in promoting plant growth in terms of stem diameter, root length, and plant dry weight, with the greatest effects observed for Streptomyces coeruleorubidus ATCC 13740 (p < 0.05). However, under mild to moderate drought stress (55% and 35% WHC), SynComs outperformed single strains in enhancing plant biomass accumulation and inducing the production of resistance-related substances (p < 0.05). No significant effect of single strains and SynComs emerged under extreme drought stress (20% WHC).
    UNASSIGNED: This study underscores the potential of SynComs in facilitating forage plants to combat drought stress in desert steppe. Mild to moderate drought stress stimulates SynComs to benefit the growth of N. pectinata plants, despite a soil moisture threshold (21% WHC) exists for the microbial effect. The use of SynComs provides a promising strategy for the ecological restoration and sustainable utilization of desert steppes by manipulating the functional microbiome of forage plants.
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  • 文章类型: Journal Article
    大豆植物的生长和发育可以受到非生物和生物胁迫的影响,如盐碱胁迫和疫霉根腐病。在这项研究中,我们确定了一个应激相关基因-GmARM-其启动子含有几个激素反应和应激调节元件,包括ABRE,TCA元件,STRE,和MBS。qRT-PCR分析表明,开花后55天,GmARM在种子中的表达最高。此外,该基因在苗期暴露于盐碱胁迫和疫霉根腐病感染后上调。因此,我们使用CRISPR-Cas9系统产生了GmARM突变体,以了解该基因在应激反应中的作用。T3植株表现出显著提高的耐盐性,耐碱性,和抗病性,具有明显高于野生型植物的存活率。此外,GmARM的突变影响了相关抗逆基因的表达,表明GmARM突变体实现了多重胁迫耐受性。因此,本研究为进一步探索大豆抗多种胁迫的基因提供了基础,这些基因可用于选育多种抗逆大豆品种。
    The growth and development of soybean plants can be affected by both abiotic and biotic stressors, such as saline-alkali stress and Phytophthora root rot. In this study, we identified a stress-related gene-GmARM-whose promoter contained several hormone-response and stress-regulatory elements, including ABRE, TCA element, STRE, and MBS. qRT-PCR analysis showed that the expression of GmARM was the highest in seeds at 55 days after flowering. Furthermore, this gene was upregulated after exposure to saline-alkali stress and Phytophthora root rot infection at the seedling stage. Thus, we generated GmARM mutants using the CRISPR-Cas9 system to understand the role of this gene in stress response. T3 plants showed significantly improved salt tolerance, alkali resistance, and disease resistance, with a significantly higher survival rate than the wildtype plants. Moreover, mutations in GmARM affected the expression of related stress-resistance genes, indicating that GmARM mutants achieved multiple stress tolerance. Therefore, this study provides a foundation for further exploration of the genes involved in resistance to multiple stresses in soybean that can be used for breeding multiple stress-resistance soybean varieties.
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  • 文章类型: Journal Article
    转录因子通常包含几个不同的功能区域,包括DNA结合结构域,并在植物生长中起着重要的调节作用,发展,以及对外界刺激的反应。YABYY转录因子是植物特异性的,并且包含两个必不可少的特殊结构域(N端C2C2锌指和C端螺旋-环-螺旋结构域)。具体来说,YABBY转录因子在维持叶片的前轴-后轴极性中起关键作用,以及在调节:营养生长和生殖生长,激素反应,抗应力,和植物的次生代谢产物合成。最近,YABBY转录因子在不同植物中的鉴定和功能验证有所增加。在此基础上,我们总结了在以下方面的最新进展:识别,分类,表达模式,和YABBY转录因子家族的功能。YABBY转录因子的正常表达和功能依赖于通过YABBY家族成员与其他基因相互作用而建立的调节网络。我们讨论了YABBY转录因子在叶片极性建立和花器官发育过程中的相互作用网络。本文为YABBY函数的研究提供了参考,植物遗传改良,和分子育种。
    Transcription factors often contain several different functional regions, including DNA-binding domains, and play an important regulatory role in plant growth, development, and the response to external stimuli. YABYY transcription factors are plant-specific and contain two special domains (N-terminal C2C2 zinc-finger and C-terminal helix-loop-helix domains) that are indispensable. Specifically, YABBY transcription factors play key roles in maintaining the polarity of the adaxial-abaxial axis of leaves, as well as in regulating: vegetative and reproductive growth, hormone response, stress resistance, and secondary metabolite synthesis in plants. Recently, the identification and functional verification of YABBY transcription factors in different plants has increased. On this basis, we summarize recent advances in the: identification, classification, expression patterns, and functions of the YABBY transcription factor family. The normal expression and function of YABBY transcription factors rely on a regulatory network that is established through the interaction of YABBY family members with other genes. We discuss the interaction network of YABBY transcription factors during leaf polarity establishment and floral organ development. This article provides a reference for research on YABBY function, plant genetic improvement, and molecular breeding.
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  • 文章类型: Journal Article
    细胞中各种各样的无膜细胞器在调节基因表达中起着至关重要的作用,RNA加工,植物生长发育,帮助生物体应对不断变化的外部环境。在生物学中,液-液相分离(LLPS)通常是指一种或多种特定分子组分自发地从本体环境中分离出来的可逆过程,产生两个不同的液相:浓缩和稀释。LLPS可能是一种强大的细胞区室化机制,当生物分子在发现它们的环境中超过临界或饱和浓度时,将产生通过LLPS形成的生物缩合物。它已被广泛用于解释生物体中无膜细胞器的形成。植物生理学背景下的LLPS研究现在很普遍,但是大多数研究仍然集中在非植物系统上;植物中的相分离研究需要更加彻底。蛋白质和核酸是LLPS的主要成分。这篇综述总结了植物中经历LLPS的生物分子的特定特征和性质。我们详细描述了这些生物分子的结构特征,凝析油的形成机理,以及这些冷凝物的功能。最后,我们总结了植物生长中的相分离机制,发展,和压力适应。
    A wide variety of membrane-less organelles in cells play an essential role in regulating gene expression, RNA processing, plant growth and development, and helping organisms cope with changing external environments. In biology, liquid-liquid phase separation (LLPS) usually refers to a reversible process in which one or more specific molecular components are spontaneously separated from the bulk environment, producing two distinct liquid phases: concentrated and dilute. LLPS may be a powerful cellular compartmentalisation mechanism whereby biocondensates formed via LLPS when biomolecules exceed critical or saturating concentrations in the environment where they are found will be generated. It has been widely used to explain the formation of membrane-less organelles in organisms. LLPS studies in the context of plant physiology are now widespread, but most of the research is still focused on non-plant systems; the study of phase separation in plants needs to be more thorough. Proteins and nucleic acids are the main components involved in LLPS. This review summarises the specific features and properties of biomolecules undergoing LLPS in plants. We describe in detail these biomolecules\' structural characteristics, the mechanism of formation of condensates, and the functions of these condensates. Finally, We summarised the phase separation mechanisms in plant growth, development, and stress adaptation.
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  • 文章类型: Journal Article
    小儿神经母细胞瘤(NBs)是异质性的,侵略性,治疗抗性胚胎肿瘤,起源于神经c起源的细胞,致力于交感肾上腺祖细胞谱系。压力和耐药机制驱动治疗后复发和转移进展,表征和抑制是改善治疗反应的主要目标。NBs的抗性机制和耐药机制包括神经营养蛋白受体原肌球蛋白相关激酶A(NTRK1/TrkA)的选择性TrkAIII剪接,这与治疗后复发和晚期转移性疾病有关。TrkAIII受体变体通过包括应激诱导的线粒体输入和激活的机制在NB模型中发挥致癌活性。在这项研究中,我们在表达TrkAIII的SH-SY5YNB细胞中描述了这种促存活机制中的新型可靶向和非靶向参与者,使用二硫苏糖醇(DTT)作为激活剂和多种抑制剂,通过常规和免疫沉淀对纯化的线粒体进行Western印迹和IncuCyte细胞毒性测定。我们报告说,应激诱导的TrkAIII错误折叠启动了这种机制,产生Grp78,Ca2+-钙调蛋白,腺苷核糖基化因子(Arf)和Hsp90调节线粒体输入。导入线粒体内膜的TrkAIII被Omi/高温要求蛋白A2(HtrA2)裂解,然后通过依赖于钙调蛋白激酶II(CaMKII)的机制激活,α丝氨酸/苏氨酸激酶(Akt),线粒体Ca2+单向转运蛋白和活性氧(ROS),涉及线粒体抑制性蛋白酪氨酸磷酸酶(PTPase)氧化,导致线粒体Akt的磷酸肌醇3激酶(PI3K)激活,这增强了抗逆性。错误折叠的TrkAIII的这种新的促生存功能减轻了在整合应激反应过程中破坏的线粒体Ca2稳态的细胞毒性。并通过临床批准的Trk和Akt抑制剂以及78kDa葡萄糖调节蛋白(Grp78)的抑制剂来预防,热休克蛋白90(Hsp90),Ca2+-钙调蛋白和PI3K。这确定了Grp78,Ca2+-钙调蛋白,Hsp90、PI3K和Akt作为该机制中的新型可靶向参与者,除了TrkAIII,抑制其具有增强应激诱导的表达TrkAIII的NB细胞的消除的潜力,具有改善表现出TrkAIII表达和激活的NBs的治疗结果的潜力。
    Pediatric neuroblastomas (NBs) are heterogeneous, aggressive, therapy-resistant embryonal tumors that originate from cells of neural crest origin committed to the sympathoadrenal progenitor cell lineage. Stress- and drug-resistance mechanisms drive post-therapeutic relapse and metastatic progression, the characterization and inhibition of which are major goals in improving therapeutic responses. Stress- and drug-resistance mechanisms in NBs include alternative TrkAIII splicing of the neurotrophin receptor tropomyosin-related kinase A (NTRK1/TrkA), which correlates with post-therapeutic relapse and advanced-stage metastatic disease. The TrkAIII receptor variant exerts oncogenic activity in NB models by mechanisms that include stress-induced mitochondrial importation and activation. In this study, we characterize novel targetable and non-targetable participants in this pro-survival mechanism in TrkAIII-expressing SH-SY5Y NB cells, using dithiothreitol (DTT) as an activator and a variety of inhibitors by regular and immunoprecipitation Western blotting of purified mitochondria and IncuCyte cytotoxicity assays. We report that stress-induced TrkAIII misfolding initiates this mechanism, resulting in Grp78, Ca2+-calmodulin, adenosine ribosylating factor (Arf) and Hsp90-regulated mitochondrial importation. TrkAIII imported into inner mitochondrial membranes is cleaved by Omi/high temperature requirement protein A2 (HtrA2) then activated by a mechanism dependent upon calmodulin kinase II (CaMKII), alpha serine/threonine kinase (Akt), mitochondrial Ca2+ uniporter and reactive oxygen species (ROS), involving inhibitory mitochondrial protein tyrosine phosphatase (PTPase) oxidation, resulting in phosphoinositide 3 kinase (PI3K) activation of mitochondrial Akt, which enhances stress resistance. This novel pro-survival function for misfolded TrkAIII mitigates the cytotoxicity of mitochondrial Ca2+ homeostasis disrupted during integrated stress responses, and is prevented by clinically approved Trk and Akt inhibitors and also by inhibitors of 78kDa glucose regulated protein (Grp78), heat shock protein 90 (Hsp90), Ca2+-calmodulin and PI3K. This identifies Grp78, Ca2+-calmodulin, Hsp90, PI3K and Akt as novel targetable participants in this mechanism, in addition to TrkAIII, the inhibition of which has the potential to enhance the stress-induced elimination of TrkAIII-expressing NB cells, with the potential to improve therapeutic outcomes in NBs that exhibit TrkAIII expression and activation.
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