白细胞介素-6信号通路在银屑病发病机制中的研究进展

银屑病是一种病因不明的自身免疫性炎症性多基因遗传的皮肤疾病,其病理变化的形成需要多种信号通路和细胞因子的共同参与.近年来关于银屑病相关细胞因子信号转导通路及细胞调控信号的研究受到广泛关注,其中IL-6触发的三条途径,包括Ras/Raf/MEK/ERK途径、PI3K/AKt途径和JAK/STAT途径,共同促进银屑病角质形成细胞增殖、炎症反应及血管生成等病理变化;下面针对IL-6信号通路在银屑病发病机制中的研究进展做一综述.     

角质形成细胞在银屑病中作用的研究进展

银屑病是慢性复发性皮肤疾病,其发生与免疫功能失调、环境因素、信号转导通路紊乱及银屑病易感基因相关。既往研究表明角质形成细胞(KC)在银屑病的发生发展中发挥重要作用。银屑病中KC如何影响炎症细胞的募集、活化,及炎症因子如何导致炎症级联放大尚不明确。KC作为银屑病治疗的靶标,具有广泛的应用前景。本文从银屑病中KC的屏障功能、增殖分化及角质形成细胞与免疫细胞的相互作用作综述。     

降钙素基因相关肽通过ERK1/2信号通路对角质形成细胞增殖的影响

目的： 研究降钙素基因相关肽（CGRP）对角质形成细胞增殖活性的影响，并探讨其可能涉及的信号转导通路。方法： ①胸腺嘧啶掺入法（［3H］-TdR）观察CGRP诱导的角质形成细胞株HaCaT细胞增殖，及CGRP受体拮抗剂CGRP8-37、细胞外信号调节激酶ERK1/2特异性抑制剂PD98059对CGRP诱导的增殖活性的影响；②免疫印迹技术观察CGRP诱导后ERK1/2的磷酸化，及CGRP8-37、PD98059对ERK1/2磷酸化的影响。结果： ①CGRP在一定范围内可剂量依赖性地诱导HaCaT细胞增殖，该作用可被CGRP8-37和 PD98059阻断；②CGRP可时间依赖性地诱导HaCaT细胞ERK1/2的磷酸化，CGRP8-37和PD98059可减弱其作用。结论： CGRP可诱导HaCaT细胞增殖，CGRP受体及其相关的ERK1/2信号通路参与其调控机制。     

雷帕霉素在银屑病治疗中的研究进展

银屑病是一种免疫介导的炎症性皮肤病，已有研究表明PI3K/AKT/mTORC1信号通路在银屑病疾病过程中发挥重要作用。雷帕霉素作为mTORC1抑制剂，可以通过改善银屑病患者角质形成细胞异常功能状态、血管异常增生以及调节Th17细胞免疫功能等机制在银屑病治疗中发挥一定的作用。     

Notch通路介导的microRNAs对肝癌干细胞的调节作用

肝癌干细胞(hepatic cancer stem cells,HSCs)是存在于肝细胞癌中的一类具有干细胞特性的细胞,与肝癌的形成、 生长、 转移、 药物耐受和复发有密切关系.microRNAs(miRNAs)是一种长约19~22 nt的短链非编码RNA,在细胞众多的生化活动中起着重要的调节作用,通过作用于细胞中关键信号通路的重要节点分子调控肿瘤的发生发展.而Notch信号通路是调控肿瘤干细胞自我更新、 增殖和分化过程的最重要的信号通路之一.miRNAs在Notch信号通路中的作用如何?miRNAs通过靶向作用于Notch信号通路进而发挥调控肝癌干细胞的自我更新、 分化及致癌性作用的机制是什么?这均是本文重点阐述的问题.     

角质细胞生长因子及氯化锂诱导毛囊干细胞定向分化中的信号通路

背景:毛囊干细胞的增殖分化受到自身基因及外来信号的共同作用,Wnt/β-catenin信号通路在毛囊毛发发育中起重要作用,但详细机制尚未明确。目的:探讨在角质细胞生长因子及氯化锂干预下,Wnt/β-catenin信号通路在人毛囊干细胞向毛囊乳突细胞或表皮细胞定向分化中的作用及与其他信号分子的相互关系。方法:获取毛囊隆突区干细胞进行培养,检测其生长曲线,观察1×106 L-1、1×107 L-1、1×108 L-1和1×109 L-1培养的毛囊干细胞在不同时间点的增殖效应;使用免疫荧光染色法对毛囊干细胞及其分化细胞进行鉴定。分别以0,0.5,1.5,10,25 mmol/L氯化锂及0,10,25,50,100μg/L角质细胞生长因子诱导毛囊干细胞分化,对比各组细胞的增殖效应,探索促毛囊干细胞分化的最佳氯化锂及角质细胞生长因子浓度。使用RT-PCR检测未处理对照组、10 mmol/L氯化锂组和10μg/L角质细胞生长因子组干预后3,5,7,9 d细胞的β-catenin、APC、GSK-3β、Axin和Lef1的mRNA转录水平。结果与结论:分离培养的毛囊干细胞在体外经多次传代后仍具有很强的增殖能力和多向分化潜能,随氯化锂浓度升高,细胞增殖效应减弱;而随角质细胞生长因子组质量浓度增高细胞增殖能力增强。含有氯化锂的K-SFM条件培养基中毛囊干细胞形态改变明显,各组间有明显差别,氯化锂10 mmol/L时分化比例高,β-catenin表达量增高;而含有角质细胞生长因子K-SFM条件培养基中毛囊干细胞向表皮细胞分化,β-catenin变化不明显。提示氯化锂在促毛囊干细胞分化中,激活Wnt/β-catenin信号通路,抑制降解复合物重要成分GSK-3β的表达下降,促使β-catenin在细胞浆表达增加并转入核内,增加靶基因转录,促使毛囊干细胞向毛囊细胞方向分化。氯化锂10 mmol/L是促毛囊干细胞分化的最佳浓度,但增殖效应减弱。角质细胞生长因子可促进毛囊干细胞向表皮分化,可促进毛囊干细胞增殖和迁移,促进创面再上皮化及创面愈合。氯化锂和角质细胞生长因子促毛囊干细胞定向分化的作用机制可能为激活Wnt/β-catenin信号通路,促使β-catenin表达改变,从而激活Wnt信号通路中Lef介导相关靶基因的转录。     

流体剪切力对人牙周膜细胞作用的研究进展

为了明确流体剪切力对牙周膜细胞的作用以及为后续相关研究提供理论依据,通过查阅文献发现流体剪切力可通过miRNA-132/PI3K/mTOR信号通路、ERK/p38/JNK MAPK信号通路和Wnt/LEF-1信号通路促进牙周膜细胞成骨分化,此外,还可调控牙周膜细胞的增殖,抑制细胞的迁移,还可影响炎症因子COX-2的表达。未来可进一步研究流体剪切力对牙周膜细胞确切的增殖效应及其具体机制。     

体外研究银屑病患者外周血T淋巴细胞对角质形成细胞Ki67、c-Myc及Bcl-xL蛋白表达的影响

目的：探讨银屑病患者外周血T淋巴细胞对角质形成细胞增殖的影响及其机制。方法：将T淋巴细胞与角质形成细胞共培养，免疫组化法检测T细胞对角质形成细胞Ki67、c—Myc及Bcl-xL蛋白表达的影响。结果：受银屑病患者外周血T淋巴细胞作用的角质形成细胞Ki67、c-Myc及Bcl-xL蛋白表达与自然增殖组及正常人T细胞作用组相比显著增强；受正常人T细胞作用后角质形成细胞Ki67、c-Myc及Bcl-xL蛋白表达与自然增殖组相比无显著性差异。结论：银屑病患者外周血T淋巴细胞具有特殊的活性，可诱导角质形成细胞增殖动力学发生改变，这一效应可能与影响c—Myc及Bcl-xL等增殖凋亡调控基因的表达有关．     

胰岛素样生长因子1对早孕滋养细胞增殖的作用及机制研究

目的探讨胰岛素样生长因子1(IGF-1)对体外培养的早孕滋养细胞增殖的影响,以及滋养细胞增殖的细胞内信号转导机制。方法取原代培养传代后生长良好的滋养层细胞,加入不同浓度的IGF-1继续培养,用四唑盐(MTT)比色法测定细胞的增殖活性,并且以ERK(细胞外信号调节蛋白激酶)通路的特异性抑制剂U0126处理细胞,间接反映ERK通路的作用。结果①与对照组相比,IGF-1浓度≥1nM时,其促进滋养细胞增殖效果有显著性意义(P<0.05),且在0.1-100nM范围内,此种作用与浓度呈正相关。②ERK通路阻滞剂U0126可抑制滋养细胞的增殖(P<0.05),并且可显著抑制IGF-1对滋养细胞的促增殖作用(P<0.05)。结论①IGF-1对滋养层细胞的增殖活性具有促进作用。②ERK通路可能是滋养细胞增殖过程中的主要信号转导通路之一。     

PGRN基因沉默对人非小细胞肺癌A549细胞增殖及迁移的影响

目的:探讨小干扰RNA(small interference RNA,si RNA)介导的颗粒蛋白前体(progranulin,PGRN)基因沉默对非小细胞肺癌A549细胞增殖、迁移和凋亡的影响及其机制。方法:分别用q PCR和Western blot法检测A549细胞和正常人支气管上皮(HBE)细胞中PGRN的m RNA和蛋白表达水平。采用脂质体转染法将PGRNsi RNA转染A549细胞,采用q PCR和Western blot法验证PGRN表达的变化;应用MTT实验检测细胞活力;活细胞计数法和结晶紫染色实验检测细胞增殖能力;划痕愈合实验和Transwell实验检测细胞迁移能力;并用Western blot法检测增殖细胞核抗原(PCNA)、细胞周期蛋白D1(cyclin D1)、Bcl-2和Bax的蛋白表达水平以及PGRN下游信号通路中细胞外信号调节激酶1/2(ERK1/2)和蛋白激酶B(Akt)的磷酸化水平。结果:PGRN在A549细胞中的m RNA和蛋白水平均明显高于HBE细胞(P0.05);转染PGRN-si RNA后A549细胞中PGRN的m RNA和蛋白水平均明显下调,细胞活力、增殖能力以及迁移能力均明显降低(P0.05)。沉默PGRN基因的表达,可下调PCNA、cyclin D1和Bcl-2的蛋白表达,而上调Bax的蛋白表达,且磷酸化的ERK1/2(p-ERK1/2)和磷酸化的Akt(p-Akt)的蛋白水平明显降低(P0.05)。结论:PGRN基因沉默能明显抑制非小细胞肺癌A549细胞的增殖和迁移能力,PI3K/Akt和MAPK/ERK信号通路可能在该过程中发挥重要作用。     

The mitogen-activated/extracellular signal-regulated kinase kinase 1/2 inhibitor U0126 induces glial fibrillary acidic protein expression and reduces the proliferation and migration of C6 glioma cells

The extracellular signal-regulated kinase (ERK) signaling pathway has been implicated in diverse cellular functions. ERK and its activating kinase, mitogen-activated/extracellular signal-regulated kinase kinase (MEK), are downstream of cell surface receptors known to be up-regulated in many malignant gliomas. We sought to investigate the role of ERK in glioma cell migration, proliferation and differentiation using the rat-derived C6 glioma cell line and the MEK inhibitor, U0126. Treatment of C6 cells with U0126 caused a significant concentration-dependent reduction in cell proliferation and migration and also induced expression of glial fibrillary acidic protein, a marker of astrocytic differentiation. These results suggest that the ERK pathway regulates glioma cell proliferation, migration and differentiation.     

JNK信号通路调控大鼠再生肝8种细胞的增殖和凋亡

目的 从基因转录水平了解JNK信号通路在大鼠再生肝8种细胞中的作用。方法 用密度梯度离心和免疫磁珠等方法分离肝细胞（HC）、胆管上皮细胞（BEC）、卵圆细胞（OC）、肝星形细胞（HSC）、窦内皮细胞（SEC）、库普弗细胞（KC）、陷窝细胞（PC）、树突状细胞（DC）等8种肝脏细胞,用大鼠Genome 230 2.0芯片检测大鼠再生肝8种细胞的基因表达谱,用生物信息学和系统生物学等方法分析基因表达变化预示的JNK信号通路在调控大鼠再生肝8种细胞增殖、凋亡中的作用。用实时荧光定量PCR方法验证了芯片结果的可靠性。结果 JNK信号通路涉及240个基因和42条途径,其中,225个基因与大鼠肝再生相关。基因协同作用分析显示,在大鼠肝再生启动阶段,JNK信号通路启动HC和KC增殖,促进OC凋亡,启动部分PC和SEC增殖和促进部分PC和SEC凋亡;在进展阶段,JNK信号通路促进HC、BEC、KC和DC增殖,促进部分PC增殖、部分PC凋亡。在终止阶段,JNK信号通路促进HC、OC和PC凋亡,促进部分KC增殖、部分KC凋亡。结论 大鼠肝再生中JNK信号通路的42条途径和225个基因参与调控大鼠再生肝8种细胞的增殖和凋亡。     

Tetramethylpyrazine promotes proliferation and differentiation of neural stem cells from rat brain in hypoxic condition via mitogen-activated protein kinases pathway in vitro

This study investigated the effects of tetramethylpyrazine (TMP), an active element of traditional Chinese medicine Ligusticum Chuanxiong, on proliferation and differentiation of neural stem cells (NSCs) from rat brain in hypoxia condition and the activation of mitogen-activated protein kinases (MAPKs) signaling pathway during the processes. The results showed that TMP promoted the proliferation and differentiation of the NSCs into neurons. TMP increased the phosphorylation of ERK1/2 and decreased the phosphorylation of p38 at different time points. ERK inhibitor (U0126) in part blocked the differentiation of the NSCs into neurons induced by TMP. Our findings demonstrated that TMP enhanced the proliferation and differentiation of NSCs of rat after hypoxia in vitro, in which the phosphorylation of ERK and p38 was involved.     

Osteogenic response of mesenchymal stem cells to continuous mechanical strain is dependent on ERK1/2-Runx2 signaling

Mechanical stimuli are responsible for bone remodeling during orthodontic tooth movement. The role of mechanical stimulation in the regulation of the fate of bone mesenchymal stem cells (BMSCs) is of interest in bone regeneration and tissue engineering applications. However, the signaling pathway involved in strain-induced biochemical events in BMSCs is not well established and can be controversial. This study investigated strain-induced proliferation and differentiation of BMSCs, as well as the mechanism of mechanotransduction. BMSCs were exposed to continuous mechanical strain (CMS) of 10% at 1 Hz. The results showed that CMS reduced the proliferation of BMSCs and stimulated osteogenic differentiation by activating Runx2, followed by increased alkaline phosphatase (ALP) activity and mRNA expression of osteogenesis-related genes (ALP, collagen type I and osteocalcin). Furthermore, the phosphorylation level of extracellular regulated protein kinase (ERK)1/2 increased significantly at the onset of strain. However, the presence of U0126, a selective inhibitor of ERK1/2, blocked the induction of Runx2 and subsequent osteogenic events. These findings demonstrate that CMS regulated Runx2 activation and favored osteoblast differentiation through activation of the ERK1/2 signaling pathway. These results will contribute to a better understanding of strain-induced bone remodeling and will form the basis for the correct choice of applied force in orthodontic treatment.     

Kupffer cell restoration after partial hepatectomy is mainly driven by local cell proliferation in IL-6-dependent autocrine and paracrine manners

Kupffer cells (KCs), which are liver-resident macrophages, originate from the fetal yolk sac and represent one of the largest macrophage populations in the body. However, the current data on the origin of the cells that restore macrophages during liver injury and regeneration remain controversial. Here, we address the question of whether liver macrophage restoration results from circulating monocyte infiltration or local KC proliferation in regenerating livers after partial hepatectomy (PHx) and uncover the underlying mechanisms. By using several strains of genetically modified mice and performing immunohistochemical analyses, we demonstrated that local KC proliferation mainly contributed to the restoration of liver macrophages after PHx. Peak KC proliferation was impaired in Il6-knockout (KO) mice and restored after the administration of IL-6 protein, whereas KC proliferation was not affected in Il4-KO or Csf2-KO mice. The source of IL-6 was identified using hepatocyte- and myeloid-specific Il6-KO mice and the results revealed that both hepatocytes and myeloid cells contribute to IL-6 production after PHx. Moreover, peak KC proliferation was also impaired in myeloid-specific Il6 receptor-KO mice after PHx, suggesting that IL-6 signaling directly promotes KC proliferation. Studies using several inhibitors to block the IL-6 signaling pathway revealed that sirtuin 1 (SIRT1) contributed to IL-6-mediated KC proliferation in vitro. Genetic deletion of the Sirt1 gene in myeloid cells, including KCs, impaired KC proliferation after PHx. In conclusion, our data suggest that KC repopulation after PHx is mainly driven by local KC proliferation, which is dependent on IL-6 and SIRT1 activation in KCs.     

骨髓间充质干细胞增殖与成骨分化中电磁场激活ERK通路的作用

背景：研究表明电磁场可调节骨髓间充质干细胞的增殖和分化,但其具体机制尚不清楚。 目的：从ERK信号途径探讨电磁场诱导大鼠骨髓间充质干细胞增殖与分化成骨的作用。 方法：取第3代生长良好的大鼠骨髓间充质干细胞,暴磁组给予15 Hz、1 mT的正弦波电磁场刺激,PD98059+暴磁组在电磁场刺激前给予20 μmol/L ERK阻断剂PD98059,PD98059组仅给PD98059不进行电磁场刺激,对照组正常培养。电磁场刺激后,收集各组细胞,Western blot法检测ERK通路的活性,MTT法检测细胞增殖活性,碱性磷酸酶试剂盒检测细胞碱性磷酸酶活性。 结果与结论：电磁场刺激后,细胞ERK1/2磷酸化水平、细胞的增殖活性、及碱性磷酸酶活性均明显升高(P < 0.01);PD98059可明显抑制ERK1/2磷酸化水平及细胞增殖活性的升高(P < 0.01),而在一定程度上提高细胞的碱性磷酸酶活性(P < 0.01)。说明电磁场刺激可通过激活骨髓间充质干细胞ERK信号通路,并且主要通过该途径促进骨髓间充质干细胞的增殖;而在脉冲电磁场促进骨髓间充质干细胞分化成骨的过程中,激活ERK信号通路所起的作用较小。     

SPREDs (Sprouty Related Proteins with EVH1 Domain) promote self‐renewal and inhibit mesodermal differentiation in murine embryonic stem cells

Background : Pluripotency, self‐renewal, and differentiation are special features of embryonic stem (ES) cells, thereby providing valuable perspectives in regenerative medicine. Developmental processes require a fine‐tuned organization, mainly regulated by the well‐known JAK/STAT, PI3K/AKT, and ERK/MAPK pathways. SPREDs (Sprouty related proteins with EVH1 domain) were discovered as inhibitors of the ERK/MAPK signaling pathway, whereas nothing was known about their functions in ES cells and during early differentiation, so far. Results: We generated SPRED1 and SPRED2 overexpressing and SPRED2 knockout murine ES cells to analyze the functions of SPRED proteins in ES cells and during early differentiation. Overexpression of SPREDs increases significantly the self‐renewal and clonogenicity of murine ES cells, whereas lack of SPRED2 reduces proliferation and increases apoptosis. During early differentiation in embryoid bodies, SPREDs promote the pluripotent state and inhibit differentiation whereby mesodermal differentiation into cardiomyocytes is considerably delayed and inhibited. LIF‐ and growth factor‐stimulation revealed that SPREDs inhibit ERK/MAPK activation in murine ES cells. However, no effects were detectable on LIF‐induced activation of the JAK/STAT3, or PI3K/AKT signaling pathway by SPRED proteins. Conclusions: We show that SPREDs promote self‐renewal and inhibit mesodermal differentiation of murine ES cells by selective suppression of the ERK/MAPK signaling pathway in pluripotent cells. Developmental Dynamics 244:591–606, 2015. © 2015 Wiley Periodicals, Inc.     

Analysis of extracellular signal-regulated kinase 2 function in neural stem/progenitor cells via nervous system-specific gene disruption

Extracellular signal-regulated kinase 2 (ERK2) is involved in a variety of cell fate decisions during development, but its exact role in this process remains to be determined. To specifically focus on the role of ERK2 in the brain, and to avoid early lethalities, we used a conditional gene-targeting approach to preferentially inactivate Erk2 in the embryonic mouse brain. The resulting mutant mice were viable and were relatively normal in overall appearance. However, the loss of Erk2 resulted in a diminished proliferation of neural stem cells in the embryonic ventricular zone (VZ), although the survival and differentiation of these cells was unaffected. The multipotent neural progenitor cells (NPCs) isolated from ERK2-deficient brains also showed impaired proliferation, reduced self-renewal ability, and increased apoptosis. By neurosphere differentiation analysis we further observed that lineage-restricted glial progenitors were increased in ERK2-deficient mice. The decline in the self-renewal ability and multipotency of NPCs resulting from the loss of ERK2 was found to be caused at least in part by upregulation of the JAK-STAT signaling pathway and reduced G1/S cell cycle progression. Furthermore, by global expression analysis we found that neural stem cell markers, including Tenascin C NR2E1 (Tlx), and Lgals1 (Galectin-1), were significantly downregulated, whereas several glial lineage markers were upregulated in neurospheres derived from ERK2-deficient mice. Our results thus suggest that ERK2 is required both for the proliferation of neural stem cells in the VZ during embryonic development and in the maintenance of NPC multipotency by suppressing the commitment of these cells to a glial lineage.     

ERK信号通路对人表皮干细胞增殖分化的影响

BACKGROUND:Epidermal stem cells (ESCs) cultured in vitro can easily become differentiated and aged, but have limited proliferation ability. These characters limit the application and development of ESCs in skin tissue engineering. Increasing understanding of the regulatory mechanism of ESCs proliferation and differentiation would lay the theoretical foundation for the clinical application of ESCs. OBJECTIVE:To identify the role of the ERK pathway in the proliferation and differentiation of ESCs. METHODS:ESCs were isolated and cultured in vitro. The activity of the ERK pathway was blocked by PD98059 and the activation of the ERK pathway was conducted by PMA or transfecting MEK1 recombinant plasmid to enable the overexpression of MEK1. The effect of activation or blockage of the ERK pathway on the proliferation and colony formation ability of ESCs was detected by MTT and colony formation assay, respectively. The expression of ESCs markers K19 and β1-integrin and differentiated cell marker K10 was detected by western blot. RESULTS AND CONCLUSION:When the activity of the ERK pathway was blocked by PD98059, the proliferation and colony formation abilities of ESCs were inhibited and the differentiation was enhanced. On the contrary, activating the ERK pathway by PMA or upregulation of MEK1 enhanced the proliferation and colony formation abilities of ESCs but inhibited the cell differentiation. These results indicate that the ERK pathway plays an important role in the proliferation and differentiation of ESCs.