RAMPS

RAMPs
  • 文章类型: Journal Article
    受体活性修饰蛋白(RAMPs)是否在人类癌症预后和免疫中起关键作用仍然未知。我们使用了公共数据库的数据,癌症基因组图谱,产生有效治疗的治疗应用研究,和基因型-组织表达项目。我们利用生物信息学方法,R软件,和各种在线数据库来分析RAMP。总的来说,RAMPs在多个肿瘤中显著和差异表达,RAMP表达与预后密切相关,免疫检查点,RNA编辑基因,肿瘤突变负担,微卫星不稳定,倍性,和干性指数。此外,在人类癌症中,RAMPs的表达与肿瘤浸润淋巴细胞密切相关.此外,RAMP共表达网络主要参与许多免疫相关的生物学过程.定量逆转录聚合酶链反应和Westernblot证明RAMP3在胶质瘤中高表达,RAMP3促进肿瘤的增殖和迁移。RAMPs在人类癌症中显示出作为预后和免疫相关生物标志物的潜力。此外,RAMPs可以潜在地开发为治疗靶标或用于增强免疫疗法的功效。
    Whether receptor activity-modifying proteins (RAMPs) play a key role in human cancer prognosis and immunity remains unknown. We used data from the public databases, The Cancer Genome Atlas, Therapeutically Applicable Research to Generate Effective Treatments, and the Genotype-Tissue Expression project. We utilized bioinformatics methods, R software, and a variety of online databases to analyze RAMPs. In general, RAMPs were significantly and differentially expressed in multiple tumors, and RAMP expression was closely associated with prognosis, immune checkpoints, RNA-editing genes, tumor mutational burden, microsatellite instability, ploidy, and stemness indices. In addition, the expression of RAMPs is strongly correlated with tumor-infiltrating lymphocytes in human cancers. Moreover, the RAMP co-expression network is largely involved in many immune-related biological processes. Quantitative reverse transcription polymerase chain reaction and Western blot proved that RAMP3 was highly expressed in glioma, and RAMP3 promoted tumor proliferation and migration. RAMPs exhibit potential as prognostic and immune-related biomarkers in human cancers. Moreover, RAMPs can be potentially developed as therapeutic targets or used to enhance the efficacy of immunotherapy.
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  • 文章类型: Journal Article
    仔细的术前计划是微创根治性顺行模块化胰脾切除术(MI-RAMPS)的关键。这项回顾性研究旨在显示肿瘤右缘与脾系膜汇合(d-SMC)或胃十二指肠动脉(d-GDA)的左缘之间的计算机断层扫描距离的实际意义。在2011年1月至2022年6月之间,对胰腺癌或恶性导管内粘液性乳头状肿瘤进行了48例微创RAMPS。两个程序转换为开放手术(4.3%)。平均肿瘤大小为31.1±14.7mm。平均d-SMC为21.5±18.5mm。平均d-GDA为41.2±23.2mm。10例患者(20.8%)进行了静脉切除术,在19例手术中(43.1%)无法通过内窥镜吻合器分割胰颈。需要静脉切除的病人,平均d-SMC为10mm(1.5-15.5),无静脉切除者为18mm(10-37)(p=0.01).进行静脉切除的d-SMC的截止值为17mm(AUC0.75)。当无法使用内窥镜吻合器分割胰腺时,平均d-GDA为26mm(19-39)mm,和46毫米(30-65)时,胰腺的颈部被缝合(p=0.01)。d-GDA在胰腺颈部后安全通过内窥镜吻合器的截止值为43mm(AUC0.75)。计算机断层扫描d-SMC和d-GDA是计划MI-RAMPS时的关键测量值。
    Careful preoperative planning is key in minimally invasive radical antegrade modular pancreatosplenectomy (MI-RAMPS). This retrospective study aims to show the practical implications of computed tomography distance between the right margin of the tumor and either the left margin of the spleno-mesenteric confluence (d-SMC) or the gastroduodenal artery (d-GDA). Between January 2011 and June 2022, 48 minimally invasive RAMPS were performed for either pancreatic cancer or malignant intraductal mucinous papillary neoplasms. Two procedures were converted to open surgery (4.3%). Mean tumor size was 31.1 ± 14.7 mm. Mean d-SMC was 21.5 ± 18.5 mm. Mean d-GDA was 41.2 ± 23.2 mm. A vein resection was performed in 10 patients (20.8%) and the pancreatic neck could not be divided by an endoscopic stapler in 19 operations (43.1%). In patients requiring a vein resection, mean d-SMC was 10 mm (1.5-15.5) compared to 18 mm (10-37) in those without vein resection (p = 0.01). The cut-off of d-SMC to perform a vein resection was 17 mm (AUC 0.75). Mean d-GDA was 26 mm (19-39) mm when an endoscopic stapler could not be used to divide the pancreas, and 46 mm (30-65) when the neck of the pancreas was stapled (p = 0.01). The cut-off of d-GDA to safely pass an endoscopic stapler behind the neck of the pancreas was 43 mm (AUC 0.75). Computed tomography d-SMC and d-GDA are key measurements when planning for MI-RAMPS.
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  • 文章类型: Journal Article
    未经授权:Veratum属由含有多种甾体生物碱的植物组成。Veratrum植物材料已被用作草药几个世纪,然而,生物碱具有如此低的治疗指数,以至于它们不被用于现代医学。在这里,我们报告了佐治亚州徒步旅行者无意中摄入细小弧菌的事件,该事件允许检测,在几种情况下,从植物中鉴定生物碱,并将它们在患者血液和母乳标本中的存在相关。
    未经批准:8名患者,三男五女,在2020年春季和2021年出现的症状,需要在摄入小虫后紧急就医。所有患者都认为这些植物是当地的野生韭菜,葱白,在当地被称为坡道。使用照片以及患者提供的新鲜和煮熟的植物材料鉴定植物,与乔治亚大学植物标本室的植物学家协商。从所有患者获得书面同意书,用于收集血液和母乳标本以进行Veratum生物碱的实验室鉴定。
    未经评估:V.parviflorum植物材料,通过高效液相色谱-四极杆飞行时间质谱(HPLC-QTOF)分析患者血清和母乳以鉴定甾体生物碱。
    未经批准:确认小花弧菌提取物含有环巴胺,veratramine,Jervine,还有Muldamine.八名患者中有两名具有可检测浓度的Veratum生物碱。在植物中发现的生物碱中,在患者血清中检测到环巴胺和干草,观察到母乳中存在环巴胺和维拉他明。
    未经批准:Veratum甾体生物碱引起的毒性主要来自V.album和V.viride。这是小花弧菌中毒的第二次报告。本工作首次报道了小花弧菌中是否存在木尔丹明和叶尔文。这项工作提供了鉴定母乳中Veratum生物碱的第一个实例。因此,本文提供的研究结果补充了文献记录的病原体在摄入时导致小花弧菌的毒性,并可能通过母乳喂养继发中毒。
    未经评估:V.观察到旁瓣毒性会导致恶心,呕吐,低血压,心动过缓,腹痛,头脑清醒,视力模糊,手臂刺痛。经历轻度症状的患者通过支持治疗得到改善,静脉输液,和止吐药,但是血流动力学不稳定的患者需要阿托品和血管加压药。这项研究表明,更多的亲脂性Veratum生物碱可以在母乳中传递,这表明额外的预防措施可能对限制进一步的中毒至关重要。
    The Veratrum genus is composed of plants containing a diverse set of steroidal alkaloids. Veratrum plant material has been utilized for centuries as herbal medicines, however the alkaloids have such a low therapeutic index that they are not used in modern medicine. Here we report an incident of inadvertent ingestion of V. parviflorum by hikers in Georgia that allowed detection, and in several instances identification of alkaloids from the plant, and correlated their presence within patient blood and breast milk specimens.
    Eight patients, three male and five female, presented in the spring of 2020 and 2021 with symptoms requiring emergent medical attention after ingestion of Veratrum parviflorum. All patients believed the plants to be a local native species of wild leek, Allium tricoccum, locally known as ramps. Plants were identified using photographs as well as fresh and cooked plant material provided by patients, in consultation with botanists at the University of Georgia Herbarium. Written consent was obtained from all patients for collection of blood and breast milk specimens for laboratory identification of Veratrum alkaloids.
    V. parviflorum plant material, and patient serum and breast milk were analyzed by high performance liquid chromatography-quadrupole time-of-flight mass spectrometry (HPLC-QTOF) to identify steroidal alkaloids.
    The V. parviflorum extract was confirmed to contain cyclopamine, veratramine, jervine, and muldamine. Two out of the eight patients had detectable concentrations of Veratrum alkaloids. Of the alkaloids identified in the plant, cyclopamine and jervine were detected within patient serum, and cyclopamine and veratramine were observed to be present in breast milk.
    Toxicity resulting from Veratrum steroidal alkaloids has primarily been reported from V. album and V. viride. This is the second report of V. parviflorum poisoning. The present work reports for the first time the presence of muldamine and jervine within V. parviflorum. This work provides the first instance of identification of Veratrum alkaloids in breast milk. Thus, the findings presented herein add to literature record causative agents contributing to the toxicity of V. parviflorum when ingested and potential for secondary poisoning through breastfeeding.
    V. parviflorum toxicity was observed to cause nausea, vomiting, hypotension, bradycardia, abdominal pain, light-headedness, blurred vision, and tingling in the arms. Patients experiencing mild symptoms improved with supportive care, IV fluids, and antiemetics, but hemodynamically unstable patients required atropine and vasopressors. This study demonstrated that more lipophilic Veratrum alkaloids can be passed along in breast milk, which suggests additional precautions may be critical to limit further poisonings.
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  • 文章类型: Case Reports
    葱(通常称为“坡道”)是一种食用植物,以其强烈的大蒜味和洋葱味而闻名。不幸的是,诸如山谷百合(Convallariamajalis)和假Hellebore(Veratrumviride)之类的三occum模仿物可能导致觅食错误和随后的患者伤害/毒性。我们描述了3名成年人,他们觅食并吃了他们认为是三氯菌的东西,然后随后出现症状,地高辛浓度可检测。一个41岁的女人,41岁的男人,一名31岁的男子在摄入一种未知的植物后被送往急诊科。一到达急诊室,患者为低血压和心动过缓。他们可检测到的地高辛浓度范围为0.08ng·mL-1至0.13ng·mL-1。一名患者接受了20小瓶地高辛抗体片段。3例患者均痊愈,无并发症发生。植物标本的实验室分析对环巴胺呈阳性,在caliornicum中发现的一种致畸生物碱。考虑到它们与C.majalis和V.viride等植物的外观相似,三氯cum觅食错误可能是发病率的来源。cmajalis通过其类似于地高辛的心脏类固醇化合物(螺盐毒素)引起可检测的地高辛浓度。Vviride含有生物碱化合物(例如维拉替啶),可与地高辛测定法交叉反应,并导致地高辛浓度错误升高。应提示临床医生考虑摄入Cmajalis或Veratrumspp。当患者出现心动过缓时,胃肠道症状,和植物摄入和/或觅食后可检测到的地高辛浓度。
    Allium tricoccum (commonly known as \"ramps\") is an edible plant known for its strong garlic-like odor and onion flavor. Unfortunately, A tricoccum mimics such as Lily of the Valley (Convallaria majalis) and False Hellebore (Veratrum viride) can lead to foraging errors and subsequent patient harm/toxicity. We describe 3 adults who foraged and ate what they believed were A tricoccum and then subsequently became symptomatic with detectable digoxin concentrations. A 41-y-old woman, 41-y-old man, and a 31-y-old man presented to the emergency department after ingesting an unknown plant that was believed to be A tricoccum. On arrival to the emergency department, the patients were hypotensive and bradycardic. They had detectable digoxin concentrations ranging from 0.08 ng·mL-1 to 0.13 ng·mL-1. One patient received 20 vials of digoxin antibody fragments. All 3 patients recovered without complication. Laboratory analysis of plant specimen was positive for cyclopamine, a teratogenic alkaloid found in Veratrum californicum. A tricoccum foraging errors can be a source of morbidity given their similarity in appearance to plants like C majalis and V viride. C majalis causes a detectable digoxin concentration via its cardiac steroid compound (convallatoxin) that is similar to digoxin. V viride contains alkaloid compounds (such as veratridine) that can cross react with digoxin assays and lead to a falsely elevated digoxin concentration. Clinicians should be prompted to think about ingestion of C majalis or Veratrum spp. when patients present with bradycardia, gastrointestinal symptoms, and detectable digoxin concentrations after plant ingestion and/or foraging for A tricoccum.
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  • 文章类型: Journal Article
    环境信号的检测和转导,构成寄生虫成功入侵的先决条件;即,利什曼原虫传播,生存,发病机制和疾病表现和传播,具有作为细胞间信号配体的不同分子。受体[即,G蛋白偶联受体(GPCRs)]及其相关的转导机制,在进化过程中非常保守,专注于这个功能。然而,在利什曼原虫中尚未描述经典的GPCR相关信号转导系统,虽然直系同源,域和功能减少,已在锥虫科中鉴定。这些细胞间通讯手段似乎对多细胞和单细胞生物的生存至关重要。GPCRs的分子结构是灵活的,可能与所谓的受体活性修饰蛋白(RAMPs)相互作用。调节它们的功能,改变GPCRs药理学,充当伴侣并以受体依赖性方式调节信号传导和/或运输。在皮肤上,响应昆虫叮咬所代表的有害刺激而释放的血管活性和神经肽可能会触发寄生虫的生理反应。例如,趋化性。例如,在利什曼尼亚(V.)巴西,感官[物质P,SP,趋化因子]和自主神经[血管活性肠肽,VIP,和神经肽Y,NPY,生理水平的化学调理]神经肽刺激体外对寄生虫滑行的作用。VIP和NPY的趋化作用因其相应的受体拮抗剂而受损,提示刺激的反应可能由推定的GPCRs(具有必需保守的受体结构域)介导;SP的作用被[(D-Pro2,D-Trp7,9]-P物质(10-6M)]阻断,表明它可能由神经激肽-1跨膜受体介导。此外,血管活性分子,如降钙素基因相关肽[CGRP]和肾上腺髓质素[AM],通过(human-)-RAMP-2抗体,发挥化学抑制作用并增加蛋白质印迹分析中识别的24kDa条带的表达。针对GPCRs样受体和信号级联的计算机搜索检测到对应于利什曼原虫叶酸多谷氨酸合酶的RAMP-2比对序列和RAMP-3比对蛋白,一种功能未知的假设利什曼原虫蛋白,这表明在利什曼原虫,CGRP和AM活性可由MMP-(-2)和(-3)同源物调节。可能存在可能参与GPCRs级联反应的蛋白质和分子,即,RAMPs,与响应相关的古代信号系统的路标保护,细胞生存的基础,(即,出租车和迁移),并且可能构成描述针对利什曼原虫寄生虫的药效团的开放领域。
    Detection and transduction of environmental signals, constitute a prerequisite for successful parasite invasion; i.e., Leishmania transmission, survival, pathogenesis and disease manifestation and dissemination, with diverse molecules functioning as inter-cellular signaling ligands. Receptors [i.e., G protein-coupled receptors (GPCRs)] and their associated transduction mechanisms, well conserved through evolution, specialize in this function. However, canonical GPCR-related signal transduction systems have not been described in Leishmania, although orthologs, with reduced domains and function, have been identified in Trypanosomatidae. These inter-cellular communication means seem to be essential for multicellular and unicellular organism\'s survival. GPCRs are flexible in their molecular architecture and may interact with the so-called receptor activity-modifying proteins (RAMPs), which modulate their function, changing GPCRs pharmacology, acting as chaperones and regulating signaling and/or trafficking in a receptor-dependent manner. In the skin, vasoactive- and neuro- peptides released in response to the noxious stimuli represented by the insect bite may trigger parasite physiological responses, for example, chemotaxis. For instance, in Leishmania (V.) braziliensis, sensory [Substance P, SP, chemoattractant] and autonomic [Vasoactive Intestinal Peptide, VIP, and Neuropeptide Y, NPY, chemorepellent] neuropeptides at physiological levels stimulate in vitro effects on parasite taxis. VIP and NPY chemotactic effects are impaired by their corresponding receptor antagonists, suggesting that the stimulated responses might be mediated by putative GPCRs (with essential conserved receptor domains); the effect of SP is blocked by [(D-Pro 2, D-Trp7,9]-Substance P (10-6 M)] suggesting that it might be mediated by neurokinin-1 transmembrane receptors. Additionally, vasoactive molecules like Calcitonin Gene-Related Peptide [CGRP] and Adrenomedullin [AM], exert a chemorepellent effect and increase the expression of a 24 kDa band recognized in western blot analysis by (human-)-RAMP-2 antibodies. In-silico search oriented towards GPCRs-like receptors and signaling cascades detected a RAMP-2-aligned sequence corresponding to Leishmania folylpolyglutamate synthase and a RAMP-3 aligned protein, a hypothetical Leishmania protein with yet unknown function, suggesting that in Leishmania, CGRP and AM activities may be modulated by RAMP- (-2) and (-3) homologs. The possible presence of proteins and molecules potentially involved in GPCRs cascades, i.e., RAMPs, signpost conservation of ancient signaling systems associated with responses, fundamental for cell survival, (i.e., taxis and migration) and may constitute an open field for description of pharmacophores against Leishmania parasites.
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  • 文章类型: Journal Article
    背景:腹腔镜根治性顺行模块化胰脾切除术(1-RAMPS)为体尾胰腺癌患者提供了一种新的手术方法。然而,它是否可以实现与开放式RAMPS(o-RAMPS)相当的结果仍然是一个问题。
    方法:为了评估l-RAMPS的安全性和有效性,Medline数据库中的研究,Embase,检索2021年9月13日前发表的Cochrane图书馆,并使用2020年系统评价和荟萃分析首选报告项目(PRISMA)指南进行荟萃分析.分析围手术期和肿瘤学结果。
    结果:纳入5个回顾性队列,涉及189名患者,进行最终汇总分析。患者手术时间无显著差异,腹腔内出血率,腹腔感染率,轻度发病率(Clavien-Dindo分类=1),中度至重度发病率(Clavien-Dindo分类≥2),总体发病率,伤口感染率,胰瘘率,胃排空率延迟,再手术率,住院时间,术后死亡率,R0切除率,两种方法之间的2年总生存期。此外,1-RAMPS与较少的失血量(平均差异(MD)=-232.69,95%置信区间(CI)=-316.93至-148.46,P<0.00001)和较短的口服喂养天数(MD=-0.79,95%CI=-1.35至-0.22,P=0.006)相关。然而,汇总分析还显示,在l-RAMPS方法中,清扫的淋巴结明显较少(MD=-3.01,95%CI=-5.59~-0.43,P=0.02).
    结论:尽管与o-RAMPS相比,l-RAMPS提供了与最小侵入性相关的类似结果,它收集的淋巴结明显减少,这可能对患者的长期生存有潜在的负面影响。L-RAMPS仍处于起步阶段,需要进一步研究以验证其可行性。
    BACKGROUND: Laparoscopic radical antegrade modular pancreatosplenectomy (l-RAMPS) provides a new surgical approach for patients with pancreatic cancers of the body and tail. However, whether it can achieve comparable outcomes to the open RAMPS (o-RAMPS) remains an issue.
    METHODS: To evaluate the safety and effectiveness of l-RAMPS, the studies in the databases of Medline, Embase, and the Cochrane Library published before September 13, 2021 were searched and a meta-analysis was performed using the 2020 Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guideline. The perioperative and oncological outcomes were analyzed.
    RESULTS: Five retrospective cohorts involving 189 patients were included for final pooled analysis. There were no significant differences in the patients\' operation time, intra-abdominal bleeding rate, intra-abdominal infection rate, mild morbidity (Clavien-Dindo classification = 1), moderate to severe morbidity (Clavien-Dindo classification ≥2), overall morbidity, wound infection rate, pancreatic fistula rate, delayed gastric emptying rate, reoperation rate, length of hospital stay, postoperative mortality, R0 resection rate, and 2-year overall survival between the 2 approaches. Besides, l-RAMPS was associated with less blood loss (mean difference (MD) = -232.69, 95% confidence interval (CI) = -316.93 to -148.46, P < 0.00001) and shorter days until oral feeding (MD = -0.79, 95% CI = -1.35 to -0.22, P = 0.006). However, the pooled analysis also indicated a significantly fewer lymph nodes dissected (MD = -3.01, 95% CI = -5.59 to -0.43, P = 0.02) in l-RAMPS approach.
    CONCLUSIONS: Although l-RAMPS provides similar outcomes associated with benefits of minimal invasiveness compared to o-RAMPS, it harvested significantly fewer lymph nodes which might have potentially negative influence on the patients\' long-term survival. L-RAMPS is still in the infancy stage and further investigation is needed to verify its feasibility.
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  • 文章类型: Journal Article
    降钙素样受体(CLR)的信号是多方面的,由于其与受体活性修饰蛋白(RAMPs)的相互作用,和三种内源性肽激动剂。先前的研究集中在由CLR-RAMP复合物的受体和受体内化介导的G蛋白信号传导的偏向上,被认为遵循与其他B1类G蛋白偶联受体(GPCR)相同的模式。在这里,我们试图测量三种CLR-RAMP复合物对三种肽激动剂的脱敏反应。通过测量β-抑制素的招募和内部化。然后,我们通过调节β-抑制蛋白活性和GPCR激酶(GRKs)的表达进一步深入研究了脱敏机制。同源GPCR脱敏的关键组成部分。首先,我们已经表明,CLR-RAMP1能够有效地招募β-arrestin1和2,随后经历快速内吞,CLR-RAMP2和-RAMP3也利用了这些途径,虽然程度较小。在此之后,我们已经表明,CLR的激动剂依赖性内化是β-抑制蛋白依赖性,但不是完全痛苦所必需的。然后发现GRK2-6的过表达降低受体信号传导,由于非激动剂依赖性的CLR-RAMP复合物表面表达减少。这些结果代表了对β-抑制素和GRK在CLR-RAMP信号转导中的重要性的首次系统分析,并为进一步研究其他B1类GPCR铺平了道路。
    Signalling of the calcitonin-like receptor (CLR) is multifaceted, due to its interaction with receptor activity modifying proteins (RAMPs), and three endogenous peptide agonists. Previous studies have focused on the bias of G protein signalling mediated by the receptor and receptor internalisation of the CLR-RAMP complex has been assumed to follow the same pattern as other Class B1 G Protein-Coupled Receptors (GPCRs). Here we sought to measure desensitisation of the three CLR-RAMP complexes in response to the three peptide agonists, through the measurement of β-arrestin recruitment and internalisation. We then delved further into the mechanism of desensitisation through modulation of β-arrestin activity and the expression of GPCR kinases (GRKs), a key component of homologous GPCR desensitisation. First, we have shown that CLR-RAMP1 is capable of potently recruiting β-arrestin1 and 2, subsequently undergoing rapid endocytosis, and that CLR-RAMP2 and -RAMP3 also utilise these pathways, although to a lesser extent. Following this we have shown that agonist-dependent internalisation of CLR is β-arrestin dependent, but not required for full agonism. Overexpression of GRK2-6 was then found to decrease receptor signalling, due to an agonist-independent reduction in surface expression of the CLR-RAMP complex. These results represent the first systematic analysis of the importance of β-arrestins and GRKs in CLR-RAMP signal transduction and pave the way for further investigation regarding other Class B1 GPCRs.
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  • 文章类型: Journal Article
    基底神经节的强化学习模型将相位多巴胺信号映射到奖励预测误差(RPE)。传统模型断言,当刺激以固定的延迟预测奖励时,延迟期间的多巴胺活性应通过学习收敛到基线。然而,最近的研究发现,在某些条件下,即使在学习之后,多巴胺也会在奖励之前增加,从而挑战传统模型。在这项工作中,我们表明,感官反馈会导致无偏见的学习者产生RPE斜坡。我们的模型预测,当反馈在试验期间逐渐减少时,多巴胺活性应该像一个“肿块”,“谁的斜坡上升阶段应该,此外,大于反馈保持较高的条件。我们用不同亮度的虚拟导航任务训练老鼠,两种预测都是经验观察到的。总之,我们的理论和实验结果调和了RPE假设下多巴胺行为看似矛盾的数据。
    Reinforcement learning models of the basal ganglia map the phasic dopamine signal to reward prediction errors (RPEs). Conventional models assert that, when a stimulus predicts a reward with fixed delay, dopamine activity during the delay should converge to baseline through learning. However, recent studies have found that dopamine ramps up before reward in certain conditions even after learning, thus challenging the conventional models. In this work, we show that sensory feedback causes an unbiased learner to produce RPE ramps. Our model predicts that when feedback gradually decreases during a trial, dopamine activity should resemble a \"bump,\" whose ramp-up phase should, furthermore, be greater than that of conditions where the feedback stays high. We trained mice on a virtual navigation task with varying brightness, and both predictions were empirically observed. In sum, our theoretical and experimental results reconcile the seemingly conflicting data on dopamine behaviors under the RPE hypothesis.
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  • 文章类型: Journal Article
    G蛋白偶联受体(GPCRs)的第一个胞内环(ICL1)很少受到关注,尽管有证据表明,与第八螺旋(H8),它参与受体激活以及与G蛋白β亚基接触后的早期构象变化。在B1类GPCR中,ICL1的远端包含一个保守的R12.48KLRCxR2.46b基序,该基序延伸到第二个跨膜螺旋的基部;这在A类GPCR中作为[R/H]12.48KL[R/H]基序弱保守。在目前的研究中,ICL1和H8在通过cAMP的信号传导中的作用,iCa2+和ERK1/2已经在两个B1类GPCR中进行了检查,使用诱变和分子动力学。整个ICL1的突变可以增强或破坏CGRP在CGRP受体处的cAMP产生。丙氨酸诱变确定了iCa2+升高的细微差异,环的远端特别敏感。ERK1/2激活对ICL1突变几乎不敏感。在胰高血糖素受体上观察到了一个大致相似的模式,尽管单个残基的显著性存在差异。扩展研究表明,在CRF1受体,ICL1中的插入切换了iCa2+和cAMP之间的信号偏置。分子动力学表明,ICL1的变化改变了ICL2和H8/TM7连接(ICL4)的构象。对于H8,丙氨酸诱变显示E3908.49b对所有三个信号转导途径的重要性,CGRP受体,但其他残基的突变在很大程度上改变了ERK1/2的激活。因此,ICL1可以通过与ICL2、ICL4和Gβ亚基的相互作用来调节GPCR偏差。
    The first intracellular loop (ICL1) of G protein-coupled receptors (GPCRs) has received little attention, although there is evidence that, with the 8th helix (H8), it is involved in early conformational changes following receptor activation as well as contacting the G protein β subunit. In class B1 GPCRs, the distal part of ICL1 contains a conserved R12.48KLRCxR2.46b motif that extends into the base of the second transmembrane helix; this is weakly conserved as a [R/H]12.48KL[R/H] motif in class A GPCRs. In the current study, the role of ICL1 and H8 in signaling through cAMP, iCa2+ and ERK1/2 has been examined in two class B1 GPCRs, using mutagenesis and molecular dynamics. Mutations throughout ICL1 can either enhance or disrupt cAMP production by CGRP at the CGRP receptor. Alanine mutagenesis identified subtle differences with regard elevation of iCa2+, with the distal end of the loop being particularly sensitive. ERK1/2 activation displayed little sensitivity to ICL1 mutation. A broadly similar pattern was observed with the glucagon receptor, although there were differences in significance of individual residues. Extending the study revealed that at the CRF1 receptor, an insertion in ICL1 switched signaling bias between iCa2+ and cAMP. Molecular dynamics suggested that changes in ICL1 altered the conformation of ICL2 and the H8/TM7 junction (ICL4). For H8, alanine mutagenesis showed the importance of E3908.49b for all three signal transduction pathways, for the CGRP receptor, but mutations of other residues largely just altered ERK1/2 activation. Thus, ICL1 may modulate GPCR bias via interactions with ICL2, ICL4 and the Gβ subunit.
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  • 文章类型: Journal Article
    我们介绍了构建复杂动态系统的Java运行时可变更模型平台(RAMP)的方法。我们通过构建多变量SEIR(流行病)RAMP来说明我们的方法。我们的RAMP是基于个人的模型,包括自适应接触率,病原体遗传漂移,衰落和交叉豁免权。除了允许参数值,过程描述和可编写脚本的运行时驱动程序,以便在模拟过程中轻松修改,我们的RAMP可以在R-Studio和其他计算平台中使用。可以在我们的SEIRRAMP中进行运行时更改的过程描述包括病原体变体依赖性宿主脱落,环境持久性,宿主传播和宿主内病原体突变和复制。它们还包括适应性社会距离和疫苗接种率和疫苗变异价的适应性应用。我们使用与当前COVID-19大流行相关的参数值和过程描述提供模拟结果。我们的结果表明,如果免疫力下降超过疫苗接种率,那么疫苗接种推广可能无法包含最具传染性的变种,特别是如果疫苗效价不适合处理逃逸突变。我们的SEIRRAMP设计为易于他人使用。更一般地说,我们的RAMP概念有助于构建所有类型的高度灵活的复杂系统模型,然后可以作为独立应用程序轻松共享。
    We present methods for building a Java Runtime-Alterable-Model Platform (RAMP) of complex dynamical systems. We illustrate our methods by building a multivariant SEIR (epidemic) RAMP. Underlying our RAMP is an individual-based model that includes adaptive contact rates, pathogen genetic drift, waning and cross-immunity. Besides allowing parameter values, process descriptions and scriptable runtime drivers to be easily modified during simulations, our RAMP can used within R-Studio and other computational platforms. Process descriptions that can be runtime altered within our SEIR RAMP include pathogen variant-dependent host shedding, environmental persistence, host transmission and within-host pathogen mutation and replication. They also include adaptive social distancing and adaptive application of vaccination rates and variant-valency of vaccines. We present simulation results using parameter values and process descriptions relevant to the current COVID-19 pandemic. Our results suggest that if waning immunity outpaces vaccination rates, then vaccination rollouts may fail to contain the most transmissible variants, particularly if vaccine valencies are not adapted to deal with escape mutations. Our SEIR RAMP is designed for easy use by others. More generally, our RAMP concept facilitates construction of highly flexible complex systems models of all types, which can then be easily shared as stand-alone application programs.
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