BCR-ABL阴性的骨髓增殖性疾病发病机制

骨髓增殖性疾病（MPD）中除慢性粒细胞性白血病（CML）发病机制已明确外，真性红细胞增多症（PV）,原发性血小板增多症（ET）,原发性骨髓纤维化（IMF）等BCR-ABL阴性的MPD均尚不明确。JAK2V617F点突变的发现对于BCR-ABL阴性的MPD（尤其是PV）的分子发病机制是一个重大的突破，这是一个获得性的激活突变，与患者对细胞生长因子的高敏感性密切相关。在ET,IMF中发现了促血小板生成素受体（TPOR）的点突变MPLW515LK，虽突变率低，但其存在在ET，IMF发病机制中可能有独特作用。     

SOCS3与中枢神经再生的研究进展

细胞因子信号转导抑制因子（suppressors of cytokine signaling,SOCS）家族是一类对细胞因子信号通路具有负反馈调节作用的蛋白分子,参与多种细胞因子、生长因子和激素的信号调节。细胞因子对中枢神经系统中的各种生物效应具有广泛多样的调节作用,SOCS家族的许多成员（比如SOCS1,SOCS2和SOCS3等）在发育时期和成年脑内均有表达。近来发现,SOCS3在中枢神经再生中有重要作用。     

Taqman-MGB探针检测慢性骨髓增殖性疾病患者的JAK2V617F突变

目的:采用不同方法检测慢性骨髓增殖性疾病(CMPD)患者的JAK2V617F突变率,评估临床应用的可能性.方法:提取84例Ph阴性CMPD患者单个核细胞DNA,利用Real time PCR联合Taqman-MGB探针检测骨髓增殖性疾病患者的JAK2V6A7F的发生率,并利用限制性片段长度多态性(RFLP)对照检测CMPD患者的JAK2V617F突变率,用基因测序验证两种结果.结果:Real time PCR联合Taqman-MGB探针检测84例Ph(-)CMPD患者,42例存在JAK2V617F,突变率为50%;其中PV、ET、IMF患者的突变率分别为76.7%(23/30)、25.9%(7/27)、42.5%(9/20),经RFLP检测84例Ph(-)CMPD总的突变率为33.3%,测序结果验证了Real time PCR联合Taqman-MGB探针检测结果.结论:Taqman-MGB探针联合Real time PCR方法有较高的准确率,可以作为检测JAK2V617F突变的方法.     

SOCS及其免疫学作用研究进展

SOCS蛋白是细胞因子信号通路重要的抑制剂,最近的研究表明SOCS蛋白是天然免疫和获得性免疫系统中关键的生理性调节剂,它们可以调节树突状细胞的激活和T细胞的发育和分化等活动,并且在免疫性疾病中发挥重要的作用。     

SOCS和IFN对JAK/STAT活化的影响和意义

信号抑制因子(SOCS)是在细胞因子诱导下依赖JAK/STAT通路的信号传导而产生的,继而抑制细胞因子的信号传导,因此SOCS蛋白质被认为可以形成局部经典负反馈回路.IFN是由辅助性T细胞Ⅰ类亚群和自然杀伤细胞等分泌的一种细胞因子,具有多种免疫调节功能.在炎症反应中IFN首先激活JAK,然后再活化与之相结合的STATI和STAT3,从而引起iNOS诱生型一氧化氮表达增强而诱发炎症反应,而IFN在诱导细胞的抗病毒和抗生长反应中也起关键作用.IFN可正向调节SOCS的表达,但是SOCS的过度表达又可以抑制IFN受体的磷酸化及STAT1、STAT3的活化.     

SOCS1在人骨髓间充质干细胞中的表达以及稳定表达SOCS1间充质干细胞株的建立

目的 探讨不同炎性因子刺激下细胞因子信号转导抑制分子-1(suppressor of cytokine signaling1,SOCS1)在人骨髓间充质干细胞(mesenchymal stem cells,MSCs)中的表达情况,并研究稳定表达SOCS1的MSCs细胞株的建立方法.方法 用SOCS1相关炎性因子刺激剂处理24小时后裂解MSCs,Westen Blot检测各组细胞SOCS1的表达.通过Gateway技术,构建出表达SOCS1基因的载体质粒pFinal/PGK-puro-EF1 α-SOCS1-IRES-EGFP,将其与包装质粒共转染293FT细胞产生慢病毒,通过多次感染将载体导入人骨髓间充质干细胞,流式细胞术筛选出稳定表达SOCS1的人骨髓间充质干细胞,并用Westen Blotting、流式细胞术、成骨成脂肪诱导分化来鉴定.结果 SOCS1蛋白在IFN-γ、Pam3CSK4、Poly(I∶C)、LPS和ODN 2006刺激的MSCs中表达升高(P＜0.01).表达载体包装出的病毒感染后的MSCs中SOCS1蛋白水平提高,流式细胞检测表达(＞95％)CD29、CD44、CD73、CD90、CD105、CD166,不表达(＜2％)CD34和CD45,在相应诱导剂诱导下可分化为成骨细胞和脂肪细胞.结论 多种炎性因子能诱导MSCs内SOCS1表达升高,说明SOCS1可能参与了MSCs的免疫调节功能;成功建立了稳定表达SOCS1的MSCs细胞株.     

骨髓增殖性疾病Bcr／Abl融合基因的表达及其意义

目的：为探讨几种骨髓增殖性疾病bcr／abl 融合基因出现的频率及临床意义．方法：采用逆转录多聚酶键反应（RT－PCR）技术,研究了慢性粒细胞白血病（CML）,真性红细胞增多症（PV）,原发性血小板增多症（ET）,原发性骨髓纤维化（MF）bcr／abl基因的变化．结果：48例慢性期CML,43例呈现bcr／abl基因阳性,占90％,14例加速,急变期CML,6例出现bcr／abl基因,阳性率为43％,与慢性CML相比P＜0.01;10例PV出现1例bcr／abl基因阳性,占10％,6例ET中未发出bcr／abl基因．2例MF中发现1例bcr／abl基因阳性．结论：bcr／abl基因检测对于CML的临床分型有重要意义,bcr／abl阴性的CML预后差,而bcr／abl基因的阳性有助于初诊时的CML急变与急性非淋巴细胞白血病（AML）M2的鉴别和CML与慢性粒单细地白血病（CMML）的鉴别．在其它三种骨髓增殖性疾病中MF可能与CML关系最为密切,而ET关系较远,少数PV可能转化为CML．     

STAT3和SOCS3与子宫内膜异位症的相关性研究

目的: 探讨信号转导和转录活化因子3(STAT3)和细胞因子信号转导抑制因子3(SOCS3)的表达与子宫内膜异位症的相关性。方法: 采用Western blotting方法检测30例子宫内膜异位症患者异位(异位组)、在位子宫内膜(在位组)和25例正常子宫内膜(对照组)中总STAT3、磷酸化STAT3(p-STAT3)和SOCS3蛋白的表达情况。结果: 总STAT3蛋白在3组内膜中表达无差异,而其活化水平(p-STAT3/STAT3)在异位组最高,SOCS3蛋白表达在异位组最低,两者与在位和对照组相比较差异有统计学意义(P<0.05),相关性分析显示内异症患者中STAT3活化水平与SOCS3蛋白表达呈负相关(r=-0.499, P<0.01)。结论: 在子宫内膜异位症患者的异位子宫内膜组织中存在STAT3过度活化和SOCS3蛋白表达下降,两者呈负相关。     

牡荆素通过调节JAK2/STAT3/SOCS3通路改善哮喘幼鼠肺部炎症

目的 探究牡荆素对哮喘幼鼠的作用及其可能的作用机制。方法 卵清蛋白联合氢氧化铝制备BALB/c幼鼠哮喘模型,正常对照组、哮喘组、牡荆素组和地塞米松组各纳入9只BALB/c幼鼠。无创肺功能检测系统记录气道反应性;H-E染色检测肺组织病理学变化;PAS染色检测杯状细胞增生;收集肺泡灌洗液（BALF）并进行炎症细胞计数;ELISA试剂盒检测IgE、IL-4、IL-6、IL-13、IL-17和TNF-α水平;Western blot检测Bcl-2、Bax、c-caspase3、p-JAK2、JAK2、p-STAT3、STAT3和SOCS3蛋白表达。结果 与正常对照组相比,哮喘组幼鼠气道阻力、炎症评分和杯状细胞增生评分明显升高（P<0.05）,BALF中炎症细胞数量显著上升（P<0.05）,IgE、IL-4、IL-6、IL-13、IL-17和TNF-α水平明显升高（P<0.05）,Bax、c-caspase3、p-JAK2/JAK2、p-STAT3/STAT3和SOCS3蛋白表达水平显著升高（P<0.05）,而Bcl-2蛋白表达水平显著降低（P<0.05）;与哮喘组...     

JAK/STAT信号转导通路在树突状细胞分化成熟过程中的作用

树突状细胞(DC)是目前发现的效能最高的专职性抗原提呈细胞,其分化成熟过程对机体免疫功能的发挥起着至关重要的作用.大量研究表明JAK/STAT信号转导通路与DC分化成熟密切相关.JAK/STAT是一种多效联级的信号转导通路,是大量细胞因子和生长因子传递信号的主要途径,参与细胞生长发育繁殖凋亡等过程的调节.多种肿瘤病人体内DC分化成熟障碍可能与JAK/STAT通路的异常表达有关.     

Reconstruction of an active SOCS3-based E3 ubiquitin ligase complex in vitro: identification of the active components and JAK2 and gp130 as substrates

Abstract

SOCS3 (suppressor of cytokine signaling 3) inhibits the intracellular signaling cascade initiated by exposure of cells to cytokines. SOCS3 regulates signaling via two distinct mechanisms: directly inhibiting the catalytic activity of Janus kinases (JAKs) that initiate the intracellular signaling cascade and catalysing the ubiquitination of signaling components by recruiting components of an E3 ubiquitin ligase complex. Here we investigate the latter mode-of-action biochemically by reconstructing a SOCS3-based E3 ubiquitin ligase complex in vitro using fully purified, recombinant components and examining its ability to promote the ubiquitination of molecules involved in the cytokine signaling cascade. We show that SOCS3 is an active substrate recruitment module for a Cullin5-based E3 ligase and have defined the core protein components required for ubiquitination. SOCS3-induced polyubiquitination was rapid and could proceed through a number of different ubiquitin lysines. SOCS3 catalyzed the ubiquitination of both the IL-6 receptor common chain (gp130) and JAK2.     

Inhibition of IL-6 family cytokines by SOCS3

IL-6 a multi-functional cytokine with important effects in both inflammation and haematopoiesis. SOCS3 is the primary inhibitor of IL-6 signalling, interacting with gp130, the common shared chain of the IL-6 family of cytokines, and JAK1, JAK2 and TYK2 to control both the duration of signalling and the biological response. Recent biochemical and structural studies have shown SOCS3 binds to only these three JAKs, all of which are associated with IL-6 signalling, and not JAK3. This specificity is determined by a three residue “GQM” motif in the kinase domain of JAK1, JAK2 and TYK2. SOCS3 binds to JAK and gp130 simultaneously, and inhibits JAK activity in an ATP-independent manner by partially occluding the kinase's substrate binding groove with its kinase inhibitory region. We therefore propose a model in which each of gp130, JAK and SOCS3 are directly bound to the other two, allowing SOCS3 to inhibit IL6 signalling with high potency and specificity.     

A link between the driver mutations and dysregulated apoptosis in BCR-ABL1 negative myeloproliferative neoplasms

The current understanding of BCR-ABL1 negative myeloproliferative neoplasms pathogenesis is centred on the phenotypic driver mutations in JAK2, MPL, or CALR genes, and the constitutive activation of JAK-STAT pathway. Nonetheless, there is still a need to better characterize the cellular processes that are triggered by these genetic alterations, such as apoptosis that might play a role in the pathological expansion of the myeloid lineages and, especially, in the morphological anomalies of the bone marrow megakaryocytes. In this article we will explore the connection between the driver mutations in MPN and the abnormal apoptosis that might be translated in new therapeutic strategies.     

Putting out the fire: coordinated suppression of the innate and adaptive immune systems by SOCS1 and SOCS3 proteins

Summary: The mounting of an effective immune response requires the coordinated function of both the innate and the adaptive arm of the immune system. Cells from both types of immunity respond to antigenic stimuli through a variety of surface and intracellular receptors and produce cytokines that tightly orchestrate the inflammatory response. The operation of feedback control mechanisms that regulate the duration and the amplitude of antigenic and cytokine receptor signaling is therefore required to prevent hyper-activation of the immune system that could lead to tissue destruction or autoimmunity. Suppressor of cytokine signaling (SOCS) proteins have been identified as a negative feedback loop to cytokine signaling. Recently, the generation of genetically engineered mouse models permitted the evaluation of their function in different processes of the immune responses. In this article, we review new insights into the modular structure of SOCS proteins and the function of SOCS1 and SOCS3 to negatively regulate activation and/or differentiation pathways in macrophages, dendritic cells, and T lymphocytes. Thus, SOCS family proteins are components of an emerging immunoregulatory mechanism that maintains the coordinated balance of both innate and adaptive immune responses.