哺乳动物雷帕霉素靶蛋白在脑生理和病理中的作用

哺乳动物雷帕霉素靶蛋白（mTOR）常被用于研究免疫抑制剂药物雷帕霉素的功能和作用机制。作为丝氨酸/苏氨酸激酶,mTOR有两种功能明显不同的复合体--mTORC1和mTORC2,控制诸如蛋白质合成,能量代谢,细胞大小,脂质代谢,自噬,线粒体功能和溶酶体形成等细胞的基本功能。此外,mTOR控制的信号通路还参与调节神经系统的许多生理功能,包括神经系统的发育,突触可塑性,记忆储存和认知功能。因此, mTOR信号通路失调可能与许多神经和精神疾病的发生有关。前期研究表明,抑制mTORC1对癫痫、认知障碍和脑部肿瘤等疾病的治疗有利,而直接或间接刺激mTORC1一方面可促进脑细胞轴突再生和骨髓鞘形成,另一方面该通路可成为治疗抑郁症的靶点之一。     

mTOR激活剂磷脂酸对SH-SY5Y细胞氧化应激和Tau蛋白磷酸化的调节

哺乳动物雷帕霉素靶蛋白复合体1(mTORC1)包括mTOR、丝氨酸/苏氨酸激酶、G蛋白亚基样蛋白(GL),在营养素的作用下参与转录、翻译和自噬的调节。mTORC1有两个主要靶点:一是核糖体蛋白S6激酶(p70S6K),一种丝氨酸/苏氨酸激酶,     

mTORC1信号通路对能量代谢调控作用及其机制

哺乳动物雷帕霉素靶蛋白（mTORC1）通路是细胞内最主要的能量感受器,能感受营养和激素、与能量需求相关的多个细胞功能的调节相关的上游调节信号。调节下游信号从而影响不同的细胞代谢,从蛋白质和脂质合成到线粒体活性等不同方面调节细胞代谢。作为对细胞代谢过程的调节,mTORC1的活性在外周激活有利于脂肪细胞活化,脂肪生成,葡萄糖摄取和β细胞数量的增加。本文综述了现有的知识对mTORC1的作用在能量平衡和能量代谢的调节,特别是旨在提供有关mTORC1在功能细胞中心能够整合不同激素的作用的背景下的研究进展进行了综述。     

mTOR信号通路与相关疾病的研究进展

哺乳动物雷帕霉素靶蛋白(mTOR)是一种进化上高度保守的非典型丝氨酸/苏氨酸蛋白激酶,属于磷脂酰肌醇激酶相关激酶家族,主要调控细胞生长、增殖、凋亡和自噬。生理和病理状态下,mTOR信号通路在蛋白质翻译、合成、细胞代谢和应激反应中发挥重要作用。mTOR与特定的接头蛋白形成复合体mTORC1和mTORC2。近年研究表明,mTOR和mTOR信号通路与心血管疾病(高血压和心肌梗死)、葡萄糖和脂质代谢相关疾病(糖尿病)及自身免疫性疾病(多发性硬化症)密切相关。因此,ATP竞争性mTOR激酶抑制剂、PI3K/mTOR双重抑制剂和mTORC1/mTORC2选择性抑制剂及mTOR和mTOR信号通路靶向抑制剂在上述疾病的临床治疗中具有一定的价值。     

mTORC1抑制剂通过影响肿瘤浸润T淋巴细胞生物学活性抑制KRAS基因突变型结肠癌的进展北大核心CSCD

目的研究mTORC1抑制剂通过肿瘤浸润T淋巴细胞生物学活性影响KRAS基因突变型结肠癌的进展。方法建立KRAS突变型结肠癌小鼠模型,将小鼠随机分为4组:对照组,KRAS突变组,mTORC1抑制剂组和KRAS突变+mTORC1抑制剂组;流式细胞术检测肿瘤组织中肿瘤浸润淋巴T细胞的数量;ELISA法检测小鼠血清中IL-2、IL-10、IFN-γ、TGF-β的表达情况;另外构建KRAS突变型结肠癌细胞系HT29,将细胞分为4组:HT-29组,KRAS突变组,mTORC1抑制剂组和KRAS突变+mTORC1抑制剂组;CCK-8法检测结肠癌细胞的增殖情况;流式细胞术检测其凋亡情况;Western blot法检测p53、Bcl-2、Bax、cleaved caspase3蛋白的表达水平。结果与KRAS突变组结肠癌小鼠相比较,KRAS突变+mTORC1抑制剂组小鼠肿瘤组织中CD4^(+)T细胞、CD8^(+)T细胞数量增加(P<0.01,P<0.001),Foxp3^(+)Treg细胞的数量减少(P<0.0001),小鼠血清中IL-2、IFN-γ的水平升高(P<0.0001,P<0.001),IL-10、TGF-β的水平降低(均P<0.001);另外,与KRAS突变型HT29组细胞相比,KRAS突变+mTORC1抑制剂组细胞的增殖能力减弱(P<0.05),并且凋亡情况显著提高(P<0.0001),并且Bcl-2蛋白水平降低(P<0.001),Bax、cleaved caspase3、p53蛋白水平显著升高(P<0.01,P<0.001,P<0.001)。结论mTORC1抑制剂通过影响肿瘤浸润淋巴细胞的分布情况以及通过p53/caspase相关通路抑制KRAS基因突变型结肠癌的进展。     

mTORC1 信号促进前成骨细胞MC3T3-E1 的分化成熟

目的:研究mTORC1 信号对前成骨细胞MC3T3-E1 向成骨细胞分化成熟的调控作用。方法:通过向MC3T3-E1 转染pcDNA3.1-Raptor,对mTORC1 信号相关蛋白Raptor 进行过表达。向MC3T3-E1 转染Raptor siRNA,对mTORC1 信号蛋白Raptor 进行基因沉默。通过Real-time PCR 方法测定Raptor 的基因表达,通过蛋白免疫印迹法测定Raptor 蛋白水平,并通过茜素红染色检测成骨矿化情况,以测定成骨分化程度。通过Real-time PCR 检测成骨分化指标的基因表达。结果:与对照组相比,Raptor 过表达组的Raptor mRNA 和蛋白水平明显增加;茜素红染色结果显示Raptor 过表达组染色更深,说明成骨矿化程度更高;荧光定量PCR 结果显示,Raptor 过表达组的成骨分化标记基因以及成骨转录因子的表达量均高于对照组。与对照组相比,Raptor siRNA 组的Raptor mRNA 和蛋白水平明显降低;茜素红染色结果显示Raptor siRNA 组染色更浅,说明成骨矿化程度更低;荧光定量PCR 结果显示,Raptor siRNA 组的成骨分化标记基因以及成骨转录因子的表达量均低于对照组。结论:mTORC1 信号促进前成骨细胞MC3T3-E1 向成骨细胞分化成熟。     

晚期糖基化终产物通过mTORC1/uPAR途径促进足细胞移动

 目的:足细胞哺乳动物雷帕霉素靶蛋白复合体1（mTORC1）活化是糖尿病肾病的重要发病机制。我们前期在db/db小鼠中观察到调控足细胞活动度的尿激酶型纤溶酶原激活物受体（uPAR）表达增加。本研究旨在研究晚期糖基化处理的牛血清白蛋白（AGE-BSA）对mTORC1、uPAR和足细胞活动度的影响并初步探索其可能的分子联系。方法: 体外培养小鼠肾小球足细胞,MTT法和免疫荧光分析各刺激物及干预剂对足细胞存活率及细胞骨架的影响。Western blotting检测正常对照组、对照BSA组及AGE-BSA处理组mTORC1的活性及uPAR的表达水平,划痕实验检测足细胞的活动度。进一步采用雷帕霉素抑制AGE-BSA组mTORC1的活性,观察uPAR和细胞活动性的改变。结果: 在预设浓度及干预时间下各刺激物及干预剂对细胞存活率及细胞骨架无明显影响。AGE-BSA 可上调足细胞mTORC1的活性和uPAR的水平,并促进足细胞移动。雷帕霉素能抑制AGE-BSA引起的uPAR表达水平的上调和细胞活动性的增强。结论: AGE-BSA 可能通过mTORC1/uPAR途径导致足细胞移动性增强。     

细胞自噬在神经胶质瘤治疗中的研究进展

<正>1 自噬概述"Autophagy"即自噬,这个词是de Duve等~([1])于1966年发现溶酶体的同时创造出来的,描述的是具有单层或双层膜的结构吞噬受损的蛋白质和细胞器等功能失调的细胞组分形成自噬体,之后与溶酶体融合形成自噬溶酶体,最后将包裹物降解的一个过程。通过自噬降解的包裹物包括糖、核苷酸、氨基酸和脂肪酸,最终自噬体会同溶酶体进行融合进而将细胞器降解,这一过程可以为细胞提供大量的营养物质以及用于细胞再生的结构基础。直到1992年T     

基于生物信息学方法研究脑源性神经营养因子前体蛋白功能

目的 脑源性神经营养因子前体蛋白(proBDNF)分布于中枢神经系统,在情绪障碍和神经退行性病变中起重要作用.为了深入理解proBDNF结构与功能的关系.方法 从NCBI下载了人类proBDNF基因序列,并对基因及其编码的氨基酸序列进行生物信息学分析.结果 序列分析结果显示,该基因编码247个氨基酸序列多肽,预测蛋白质相对分子质量为27.82×103,理论等电点为9.01.信号序列分析结果发现,该蛋白主要定位于细胞的内质网、溶酶体及细胞基质中,提示为细胞内蛋白及分泌性蛋白两种存在形式.结论 结构与功能分析发现,该蛋白含有1个结构域及1个信号肽,推测proBDNF在真核细胞的信号转导、转录调控及胁迫表达等过程中发挥重要功能.     

基于MMP7/mTORC1信号通路探讨小鼠脓毒症急性肾损伤的分子机制

目的：探讨基质金属蛋白酶7(MMP7)在小鼠脓毒症相关急性肾损伤模型中的表达及作用。方法：通过盲肠结扎穿孔（CLP）手术在具有C57BL/6J遗传背景的MMP7敲除（MMP7-KO）小鼠和野生型（WT）C57BL/6J小鼠中诱导脓毒症。采用外源性MMP7重组蛋白对MMP7-KO小鼠进行预处理。通过脂多糖（LPS）刺激正常人近端肾小管上皮细胞系HKC-8建立体外模型。采用Western blot检测MMP7和哺乳动物雷帕霉素靶蛋白复合体1(mTORC1)表达。HE和TUNEL染色评估小鼠的肾损伤。Hoechst 33342染色评估细胞凋亡。结果：与假手术组相比,CLP组在CLP后6 h肾脏组织中MMP7蛋白表达降低,这种降低趋势持续到48 h。MMP7-KO的CLP组小鼠肾小管损伤病理评分和TUNEL阳性肾小管细胞显著高于WT的CLP组（P<0.01）。MMP7重组蛋白孵育可很大程度上降低LPS诱导的HKC-8细胞凋亡。LPS诱导了HKC-8细胞的mTORC1表达,而MMP7可以抑制mTORC1表达。MMP7能够明显促进mTORC1降解,产生分子量为18 kD的较小片段。此外,MM...     

Renal dysplasia and asplenia in two sibs

A family is reported in which two sibs, one male and the other female, both died within 24 hours of birth with enlarged polycystic kidneys. Postmortem histology in the second child showed gross renal dysplasia. In both children the pancreas was enlarged, nodular and cystic but the liver appeared macroscopically normal. In the second child, histological examination confirmed pancreatic fibrosis with cystic dilation of ducts, but showed portal fibrosis with bile duct proliferation in the liver.
This combination of findings is very reminiscent of those in a girl and her brother reported by Ivemark et al. (1959). The children reported here also showed absence or hypoplasia of the spleen, cardiac anomalies and other features of the Ivemark syndrome (Ivemark 1955), a quite different, usually sporadic, congenital disorder. It is suggested that the children described here have a distinct lethal congenital disorder, probably inherited in an autosomal recessive manner.     

Schizophrenia in a North Swedish geographical isolate, 1900–1977. Epidemiology, genetics and biochemistry

Over 200 schizophrenic patients belonging to three major and interrelated pedigree complexes have been investigated over the past 30 years in a North Swedish geographically isolated population, presently numbering about 6,000. An intensive investigation of a number of biochemical correlates and genetic markers in a few selected families belonging to one of the major pedigrees has indicated new strategies for the current research program.
Schizophrenia, as defined operationally, is significantly associated with decreased activities of two enzymes (1) blood platelet monoamine oxidase, (2) plasma dopamine-β-hydroxylase, and (3) with the genetic marker Gc² (group specific antigen). Both enzymes are subject to genetic variation. A positive score for linkage between schizophrenia and low plasma DBH activity has been calculated, but, so far, available data are insufficient for discrimination between linkage and partial contribution of genetically controlled low plasma DBH to the pathogenesis of the disease. Alternatively, both mechanisms could be involved.
As a model for continued research, schizophrenia is explained as based on a double dominant-recessive genotype (Aabb), representing a vulnerability which in about 50 % of cases develops into clinical schizophrenia. It is suggested that the dominant mutation (A) operates on or affects MAO activity, and that the recessive genotype (bb) is instrumental in low variates of DBH activity and very likely such variates within the normal range of physiological variation. Moreover, it is suggested that the combined effects of MAO- and DBH-reduced efficiency on the metabolism of e.g. dopamine could be an essential pathogenic mechanism for the schizophrenic illness which is segregating in this population.     

The dominant diseases of modernized societies as omega-3 essential fatty acid deficiency syndrome: Substrate beriberi

About 1900, modern food selection and processing caused widespread $\text{epidemics}$ of the B vitamin deficiency diseases of beriberi and pellagra which, for genetic reasons, often expressed as different diseases ranging from bowel and heart disease to dermatoses and psychoses. But the B vitamins merely help convert essential fatty acids (EFA) into the prostaglandin (PG) tissue regulators and it now turns out that, through hydrogenation, milling and selection of w3-poor southern foods, we have also been systematically depleting, by as much as 90%, a newly discovered trace Nordic EFA (w3) of special importance to primates and sole precursor of the PG3(4) series, even as a concurrent fiber deficiency increases body demand for EFA. Since substrate EFA is processed by many B vitamin catalysts, an EFA deficiency will mimic a $\text{panh}$ypovitaminosis B, i.e., a mixture of $\text{substrate}$ beriberi and $\text{substrate}$ pellagra resembling vitamin beriberi and pellagra but exhibiting as even more diverse $\text{endemic}$ disease. This would consitute a second stage of the Modern Malnutrition and explain why some workers now hold the dominant diseases of modermized societies to be new, nutritionally based, pellagraform yet lipid-related and to range, once again, from heart disease to psychosis. It is an assumption that our dominant diseases are unrelated to each other or are merely revealed by our diagnostic acumen and therapeutic success; and that hydrogenating millions of tons of food oils annually, to destroy the rancidity producing w3-EFA, is safe for $\text{primates}$. Extensive beriberiform disease is reported here in 32 typical cases taken from medical practice which responds strikingly to linseed oil supplements (60% w3-EFA) in confirmation of identical results in Capuchins.     

What will studies of Fulani individuals naturally exposed to malaria teach us about protective immunity to malaria?

There are an estimated over 200 million yearly cases of malaria worldwide. Despite concerted international effort to combat the disease, it still causes approximately half a million deaths every year, the majority of which are young children with Plasmodium falciparum infection in sub-Saharan Africa. Successes are largely attributed to malaria prevention strategies, such as insecticide-treated mosquito nets and indoor spraying, as well as improved access to existing treatments. One important hurdle to new approaches for the treatment and prevention of malaria is our limited understanding of the biology of Plasmodium infection and its complex interaction with the immune system of its human host. Therefore, the elimination of malaria in Africa not only relies on existing tools to reduce malaria burden, but also requires fundamental research to develop innovative approaches. Here, we summarize our discoveries from investigations of ethnic groups of West Africa who have different susceptibility to malaria.     

'Very sore nights and days': the child's experience of illness in early modern England, c.1580-1720

Sick children were ubiquitous in early modern England, and yet they have received very little attention from historians. Taking the elusive perspective of the child, this article explores the physical, emotional, and spiritual experience of illness in England between approximately 1580 and 1720. What was it like being ill and suffering pain? How did the young respond emotionally to the anticipation of death? It is argued that children’s experiences were characterised by profound ambivalence: illness could be terrifying and distressing, but also a source of emotional and spiritual fulfilment and joy. This interpretation challenges the common assumption amongst medical historians that the experiences of early modern patients were utterly miserable. It also sheds light on children’s emotional feelings for their parents, a subject often overlooked in the historiography of childhood. The primary sources used in this article include diaries, autobiographies, letters, the biographies of pious children, printed possession cases, doctors’ casebooks, and theological treatises concerning the afterlife.     

Guidelines for the Validation and Use of Immunoassays for Determination of Introduced Proteins in Biotechnology Enhanced Crops and Derived Food Ingredients

Recent advancements in agricultural biotechnology have created a need for analytical techniques to determine introduced proteins in crops enhanced through modern biotechnology techniques. These proteins are expressed in plant tissues and may be present in food ingredients. Immunoassays are ideally suited for protein detection and may be used as both quantitative and threshold methods. Microplate ELISA and lateral flow devices are two of the most commonly used immunoassay formats for agricultural biotechnology applications. This paper provides general background information and a discussion of criteria for the validation and application of immunochemical methods to the analysis of proteins introduced into plants and food ingredients using biotechnology methods. It is the result of a collaborative effort of members of the Analytical Environmental Immunochemical Consortium. This collaborative effort represents the combined expertise of several organizations to reach consensus on establishing guidelines for the validation and use of immunoassays. Further, the paper offers developers and users a consistent approach to adopting the technology as well as aid in producing accurate and meaningful results.     

HLA in North Colombia Chimila Amerindians

HLA-A,-B,-C,-DRB1 and -DQB1 alleles have been studied in Chimila Amerindians from Sabana de San Angel (North Colombian Coast) by using high resolution molecular typing. A frequent extended haplotype was found:HLA-A*24:02-B*51:10-C*15:02-BRB1*04:07-DQB1*03:02 (28.7%) which has also been described in Amerinndian Mayos Mexican population (Mexico, California Gulf, Pacific Ocean). Other haplotypes had already been found in Amerindians from Mexico (Pacific and Atlantic Coast), Peru (highlands and Amazon Basin), Bolivia and North USA. A geographic pattern according to HLA allele or haplotype frequencies is lacking in Amerindians, as already known. Also, five new extended haplotypes were found in Chimila Amerindians. Their HLA-A*24:02 high frequencies characteristic is shared with aboriginal populations of Taiwan; also, HLA-C*01:02 high frequencies are found in New Zealand Maoris, New Caledonians and Kimberly Aborigines from Australia. Finally, this study may show a model of evolutionary factors acting and rising one HLA allele frequency (-A*24:02), but not in others that belong to the same or different HLA loci.     

Ultracryotomy: development and application (with examples from the yeast cytology) (author's transl)

The preparation steps usually necessary for obtaining ultrathin frozen sections of biological material (chemical prefixation, enclosing, cryoprotective treatment, freezing, sectioning, and post-staining the sections for transmission electron microscopy) are submitted to a critical analysis. The application of cryo-ultramicrotomy, in particularly for cytochemical purposes, is reviewed. Fundamental considerations of chemical prefixation and poststaining are supported by examples from yeast cytology. Furthermore, the efficiency of the cryo-ultramicrotomy (electron optical resolution of ultrastructural details) is demonstrated on yeast cells and protoplasts.     

The universal muscular chamber. A basic unit of the genitourinary, cardiovascular, gastro-intestinal, skeletal, cutaneous, respiratory and other systems, endocameral hypertension; and spasm, the key to their idiopathic diseases and arthropathies

Starting with the integument, we see many organs are contractile sacs or multiples thereof, which tubes or bags constitute the major part of the entire body. Recognition of this basic unit and its characteristics sheds new light, individually and collectively, on many disorders previously considered unrelated. Muscular tears and perforations develop in the walls of these chambers, being no way peculiar to those organs, wherein, hydrochloric acid occurs. So, it is not necessary to explain the absence of excessive acid from patients who exhibit holes in the gastric, uterine, aortic, duodenal, rectal, pulmonary, retina, and other walls. Muscle, not acid is the great common factor relating idiopathic disorders in the gastrointestinal tract to each other and to similar diseases in other systems. When the units are linked together, the lesions tend to appear as arthropathies, i.e. at the joints. Rephrasing common-place observations, frees us from conventional, conceptual cul-de-sacs. An observation is only as good as its interpretation, so all possibilities must be considered, otherwise, we will remain blinded by our misconceptions.