AMPK通过抑制STING调节干扰素免疫应答通路的研究

目的探索腺苷酸活化蛋白激酶(AMPK)与cGAS-STING通路之间的联系及其在先天免疫中扮演的角色。方法利用CRISPR/Cas9技术、蛋白质印迹、RT-qPCR等方法,探究AMPK对DNA相关免疫通路的调控机制。结果在HT-DNA和cGAMP刺激下,AMPK-/-细胞株的IFN-β的表达量明显高于野生型细胞株,但这种变化在RNA信号通路中并不明显;激活AMPK可以抑制细胞内的DNA信号通路;在DNA信号通路中,AMPK-/-细胞株相较于野生型细胞株,STING在RNA和蛋白水平上都明显升高,即AMPK对cGAS-STING通路的抑制很可能是通过抑制STING起作用。结论AMPK在调节cGAS-STING介导的干扰素免疫应答中起重要作用。     

cGAS-STING信号通路和疾病

在宿主抵抗病毒感染和细菌入侵的过程中,cGAS-STING通路发挥着重要作用.在这一过程中胞质游离DNA作为危险信号被DNA感受器环GMP-AMP合酶(cGAS)所识别.cGAS可识别双链DNA,催化三磷酸腺苷(ATP)和三磷酸鸟苷(GTP)合成非经典环二核苷酸2'5'-cGAMP.其下游的干扰素刺激基因(STING)作为衔接分子,既可直接识别细菌产生的第二信使——环磷酸腺苷(cAMP)和环磷酸鸟苷(cGMP),也可作为信号受体,识别cGAS感受胞质DNA产生的cGAMP;随后激活下游信号,促进Ⅰ型干扰素和其他细胞因子的产生,从而产生相应的免疫应答.不仅外源细菌或病毒DNA,自身胞质DNA的异常沉积也会激活该通路,从而导致自身炎症和自身免疫疾病.后续研究发现,这一通路在肿瘤放射治疗和化学治疗中同样发挥重要作用,通过激活cGAS-STING通路产生或增强对肿瘤的治疗.研究结果表明,特异性干扰cGAS-STING通路的激活可能对肿瘤、感染、免疫疾病的治疗提供依据.对cGAS-STING通路激活机制及其与疾病治疗的关系作了全面概述,并对cGAS-STING通路的调节作了详细介绍.     

cGAS-STING信号通路在自身免疫性疾病中的研究进展

存在于细胞质中的游离DNA可被机体固有免疫系统识别清除,但其具体机制尚不明确。近年来越来越多的研究发现,环鸟苷酸-腺苷酸合成酶(cyclic guanosine monophosphate-adenosine monophosphate synthase, cGAS)-干扰素基因刺激蛋白(stimulator of interferon gene, STING)通路参与固有免疫并发挥重要的免疫调控作用。cGAS-STING信号通路参与胞内微生物和自身胞质中异常核酸的识别。该综述阐述cGAS-STING信号通路介导自身免疫性疾病发生发展的相关研究,旨在为自身免疫性疾病的防治寻找有效的靶点。     

TLR4/MD2/NF-κB信号通路与疾病的研究进展

TLR4/MD2/NF-κB是细胞内一条重要的信号通路,该通路主要参与脂多糖和软脂酸等刺激信号的识别及转导,既往认为该通路主要与感染性炎症有关;近年研究表明,它与肿瘤、自身免疫性疾病、代谢性疾病等密切相关,靶向TLR4/MD2成为治疗这些疾病的新策略。本文就TLR4/MD2/NF-κB信号通路转导及相关疾病研究进展进行阐述。     

Wnt/β-连环蛋白信号通路在骨关节炎发生过程中的作用**

背景：研究表明经典Wnt/β-连环蛋白信号通路与骨关节炎的发生发展有重要联系,Wnt蛋白家族、β-连环蛋白以及相关抑制因子可以调节软骨细胞功能和代谢。 目的：综述Wnt/β-连环蛋白信号通路与骨关节炎的关系。 方法：通过计算机检索 CNKI 和Elsevier数据库中2000/2011文献,关键词为“Wnt/β-catenin,OA,骨关节炎,软骨细胞”。选择与Wnt/β-连环蛋白信号通路对骨关节炎影响有关的文章内容。 结果与结论：目前研究表明经典Wnt/β-连环蛋白信号通路是维持关节完整性,调节关节软骨代谢的重要途径之一,对骨关节炎有重要影响。Wnt信号通路以及下游信号OPG/RANKL/RANK通过调节和控制关节软骨代谢,引发骨关节炎疾病,但具体机制有待进一步研究。研究Wnt通路的组分及其作用,不仅有助于骨关节炎的特定治疗,而且有利于预防骨质疏松及其他关节性疾病。 关键词：软骨代谢;Wnt/β-连环蛋白;信号通路;骨关节炎;软骨细胞 doi:10.3969/j.issn.1673-8225.2012.13.029     

模式识别受体DNA依赖的干扰素调节因子激活物(DAI)的免疫学研究进展

DNA感受器是一类广泛表达于固有免疫细胞的模式识别受体(PRR),通过识别病原体或异常宿主细胞DNA激活相关炎症信号通路触发固有免疫应答。DNA依赖的干扰素调节因子激活物(DAI)是首个被发现的细胞质DNA感受器,在调控以干扰素诱导和程序性细胞死亡为特征的固有免疫应答中发挥重要作用。我们总结了DAI的分子特性,下游信号通路及其在抗感染免疫、肿瘤免疫和炎症性疾病中的作用及机制,并初步探讨了DAI与移植免疫的相关性,为临床治疗多种免疫性疾病提供新的靶点。     

粉防己碱通过cGAMP介导的cGAS-STING信号通路增强宿主的抗病毒反应

目的研究粉防己碱是否可以联合cGAMP作为cGAMP的激动剂增强cGAS-STING信号通路, 从而探究粉防己碱的抗病毒功能。方法采用不同浓度的粉防己碱联合cGAMP分别处理THP1-Lucia-ISRE及RAW-Lucia-ISRE细胞, 荧光素酶报告试验探究IRF3免疫应答水平;Western blot检测cGAS-STING信号通路激活情况;实时荧光定量PCR检测IFN-β、CXCL10及CCL5的mRNA表达水平;ELISA检测IFN-β表达情况。构建稳定表达STING-GFP基因的HeLa细胞(HeLa-STNG-GFP), 粉防己碱联合cGAMP处理该细胞后, 观察STING-GFP点聚集现象。Ⅰ型疱疹病毒(herpes simplex virus type 1, HSV-1)感染THP1-Lucia-ISG细胞, 粉防己碱联合cGAMP处理细胞, Western blot及荧光强度探究粉防己碱的抗病毒能力。结果粉防己碱能够增强cGAMP介导的IRF3免疫应答, 与cGAMP联用可激活cGAS-STING信号通路。粉防己碱联合cGAMP处理HeLa-STNG-GFP细胞后,...     

炎症信号通路的DNA甲基化在类风湿关节炎发病机制中的研究进展

类风湿关节炎（RA）是一种慢性炎症性疾病,以进行性滑膜炎为主要特点,最终导致不可逆的关节破坏和全身并发症。越来越多的研究表明,DNA甲基化在RA的发病机制中起着关键作用。DNA甲基化通过调节基因表达,参与编码DNA的最终翻译。多个差异性DNA甲基化相互作用,可引起炎症信号通路的激活,从而导致免疫系统紊乱,免疫疾病活动。信号通路参与RA的发病和进展,是病理机制及差异性DNA甲基化位点研究的热点。本文总结了近几年RA的信号通路DNA甲基化研究进展,以期为该病发病机制的研究提供更多思路。     

代谢性疾病中巨噬细胞极化的机制及运动对其调控作用的研究进展

本文综述了运动对代谢性疾病中巨噬细胞极化的影响及其发挥作用的可能机制。近年来，巨噬细胞极化以其在代谢性疾病中的重要调控作用而在运动科学研究领域备受关注。随着研究的深入，发现不同方式运动均可通过增加巨噬细胞M2型极化产生抗炎效应以改善机体代谢，促进健康。因此，运动作为防治代谢性疾病的有效手段，其促进健康的机制可能与促进巨噬细胞M2型极化有关。可能的调控机制如下：(1)运动通过抑制TLR4活性、下调NF-κB信号下调TLR通路，减少巨噬细胞M1型极化；(2)运动通过改善肥胖下调JNK通路，抑制巨噬细胞M1型极化；(3)运动通过增加机体IL-13和IL-4分泌促进AMPK磷酸化、PPAR激活、SCOS1表达并抑制SCOS3表达激活AMPK通路、JAK/STAT通路和PI3K/AKT通路以促进巨噬细胞M2型极化。综上，运动可通过调节多条信号通路发挥促进巨噬细胞M2型极化并抑制M1型极化作用，这可能是运动改善机体代谢以促进健康的途径之一。     

cGAS-cGAMP-STING信号通路的功能及研究进展

cGAS-cGAMP-STING信号通路是固有免疫系统重要组成部分,通过识别胞浆DNA诱导I型干扰素(interferons,IFNs)和其他细胞因子产生,介导抗微生物先天免疫,同时也在肿瘤进展及远处转移中发挥作用。深入了解cGAS-cGAMP-STING信号通路与炎症性疾病、自身免疫性疾病及肿瘤发生发展的关系,以及S...     

Emerging role of the cGAS-STING signaling pathway in autoimmune diseases: Biologic function,mechanisms and clinical prospection

The cyclic GMP-AMP synthase-stimulator of interferon genes (cGAS–STING) signaling pathway, as vital component of innate immune system, acts a vital role in distinguishing invasive pathogens and cytosolic DNA. Cytosolic DNA sensor cGAS first binds to cytosolic DNA and catalyzes synthesis of cyclic guanosine monophosphate-adenosine monophosphate (cGAMP), which is known as the second messenger. Next, cGAMP activates the adaptor protein STING, triggering a molecular chain reaction to stimulate cytokines including interferons (IFNs). Recently, many researches have revealed that the regulatory role of cGAS-STING signaling pathway in autoimmune diseases (AIDs) such as Rheumatoid arthritis (RA), Aicardi Goutières syndrome (AGS) and systemic lupus erythematosus (SLE). Moreover, accumulated evidence have showed inhibition of the cGAS-STING signaling pathway could remarkably suppress the joint swelling and inflammatory cell infiltration in RA mice. Therefore, in this review, we describe the molecular properties, biologic function and mechanisms of the cGAS-STING signaling pathway in AIDs. In addition, potential clinical applications especially selective small molecule inhibitors targeting the cGAS-STING signaling pathway are also discussed.     

STING signalling: an emerging common pathway in autoimmunity and cancer

The equipoise between the disease states of cancer and autoinflammation has perhaps been underappreciated in clinical practice and biomedical research. However, since the discover of STING (stimulator of interferon genes) as an integral regulator of innate immunity, a wealth of information has implicated this signaling pathway in both of these diseases. Under cellular homeostasis, STING serves to detect – and promote immune defense against – DNA viruses and intracellular bacteria, as described in its initial discovery. The role of STING has since been expanded to include tumor surveillance and immune responses to cancer; indeed, defective STING responses are associated with certain cancers. Conversely, constitutive activation of this pathway can result in autoinflammatory disease, whereby STING is over-stimulated by self-DNA. This review explores the current state of STING research, concluding that further elucidation of the details of the STING pathway may offer novel therapeutics for these diseases, which are of considerable clinical gravity.     

DNA virus oncoprotein HPV18 E7 selectively antagonizes cGAS-STING-triggered innate immune activation

Cellular infections by DNA viruses trigger innate immune responses mediated by DNA sensors. The cyclic GMP–AMP synthase (cGAS)-stimulator of interferon gene (STING) signaling pathway has been identified as a DNA-sensing pathway that activates interferons in response to viral infection and, thus, mediates host defense against viruses. Previous studies have identified oncogenes E7 and E1A of the DNA tumor viruses, human papillomavirus 18 (HPV18) and adenovirus, respectively, as inhibitors of the cGAS-STING pathway. However, the function of STING in infected cells and the mechanism by which HPV18 E7 antagonizes STING-induced Interferon beta production remain unknown. We report that HPV18 E7 selectively antagonizes STING-triggered nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) activation but not IRF3 activation. HPV18 E7 binds to STING in a region critical for NF-κB activation and blocks the nuclear accumulation of p65. Moreover, E7 inhibition of STING-triggered NF-κB activation is related to HPV pathogenicity but not E7–Rb binding. HPV18 E7, severe acute respiratory syndrome coronavirus-2 open reading frame 3a, human immunodeficiency virus-2 viral protein X, and Kaposi's sarcoma-associated herpesvirus KSHV viral interferon regulatory factor 1 selectively inhibited STING-triggered NF-κB or IRF3 activation, suggesting a convergent evolution among these viruses toward antagonizing host innate immunity. Collectively, selective suppression of the cGAS-STING pathway by viral proteins is likely to be a key pathogenic determinant, making it a promising target for treating oncogenic virus-induced tumor diseases.     

Nicotinic Cholinergic Signaling in Adipose Tissue and Pancreatic Islets Biology: Revisited Function and Therapeutic Perspectives

Nicotinic acetylcholine receptors (nAChRs) are membrane ligand-gated cation channels whose activation is triggered by the binding of the endogenous neurotransmitter acetylcholine or other biologic compounds including nicotine. Their roles in synaptic transmission in the central and peripheral nervous system as well as in the neuromuscular junction have been extensively studied. Recent implications of nAChRs in intracellular signaling and their detection in peripheral nonneural cells (including epithelial cells and immune cells) have renewed the interest for this class of ionotropic receptors. In the present review, we focus our attention on the potential use of nicotinic cholinergic signaling in the treatment of metabolic diseases (such as obesity and diabetes) in browsing functions of nAChRs in adipose tissue and pancreatic islet biology. In fact, different nAChR subunits can be detected in these metabolic tissues, as well as in immune cells interacting with them. Various rodent models of obesity and diabetes benefit from stimulation of the nicotinic cholinergic pathway, whereas mice deficient for some nAChRs, in particular the α7 nAChR subunit, harbor a worsened metabolic phenotype. In contrast to potential therapeutic applications in metabolic diseases, an overstimulation of this signaling pathway during the early stage of development (typically through nicotine exposure during fetal life) presents deleterious consequences on ontogeny and functionality of adipose tissue and the endocrine pancreas which persist throughout life.     

UNC93B1 curbs cytosolic DNA signaling by promoting STING degradation

UNC93B1 is a trafficking chaperone of endosomal Toll-like receptors (TLRs) and plays an essential role in the TLR-mediated innate signaling. However, whether it is also involved in other innate immune sensing or cellular pathways remains largely unexplored. Here we investigated the role of UNC93B1 in cytosolic DNA-triggered cGAS-STING signaling in mouse and human cell lines. We showed that while UNC93B1 deficiency blunts the signal transduction by TLR3, it augments innate immune responses to cytosolic DNA stimulation and DNA virus infection. Mechanistic study reveals a distinct action of UNC93B1 upon STING, but not other parts along the cGAS-STING-TBK1 axis, through regulating the protein level of STING at both resting and cytosolic DNA-stimulated conditions. UNC93B1 can directly interact and traffic along with STING, and the disruption of this interaction causes accumulation of STING that subsequently leads to augmented signaling responses upon its activation. These findings reveal a new function of UNC93B1 in negatively regulating STING-mediated signaling responses.     

The emerging role of Notch pathway in ageing: Focus on the related mechanisms in age-related diseases

Notch signaling is an evolutionarily conserved pathway, which is fundamental for the development of all tissues, organs and systems of human body. Recently, a considerable and still growing number of studies have highlighted the contribution of Notch signaling in various pathological processes of the adult life, such as age-related diseases. In particular, the Notch pathway has emerged as major player in the maintenance of tissue specific homeostasis, through the control of proliferation, migration, phenotypes and functions of tissue cells, as well as in the cross-talk between inflammatory cells and the innate immune system, and in onset of inflammatory age-related diseases. However, until now there is a confounding evidence about the related mechanisms. Here, we discuss mechanisms through which Notch signaling acts in a very complex network of pathways, where it seems to have the crucial role of hub. Thus, we stress the possibility to use Notch pathway, the related molecules and pathways constituting this network, both as innovative (predictive, diagnostic and prognostic) biomarkers and targets for personalised treatments for age-related diseases.     

P38丝裂原活化蛋白激酶信号转导通路在免疫性疾病中的研究进展

P38丝裂原活化蛋白激酶(P38 mitogen activated protein kinase,P38MAPK)信号转导通路在机体的免疫应答反应中发挥着重要作用,包括与类风湿性关节炎、原发性干燥综合征、寻常型天疱疮、炎症性肠病、系统性红斑狼疮、骨关节病、银屑病、自身免疫性脑脊髓炎等疾病密切相关.其不仅参与免疫性疾病炎性介质的调节,还参与其发生发展相关基因的调控,因此探讨P38MAPK信号转导通路在免疫性疾病中的作用可为免疫性疾病在临床中的治疗研究提供新的思路.