坐骨神经瓦勒变性大鼠许旺细胞生物学特性及分泌功能变化

背景：研究表明外周神经损伤后,许旺细胞在基底膜管内形成Bunger带,引导再生轴突延伸,但具体作用机制目前尚不清楚。 目的：观察大鼠坐骨神经损伤后瓦勒变性对许旺细胞生物学特性及分泌功能的影响。 方法：建立大鼠坐骨神经横切模型,分为坐骨神经瓦勒变性组(坐骨神经横断组)和手术对照组。采用神经段单酶消化法分离培养许旺细胞,光镜下观察细胞形态变化,S-100免疫荧光鉴定。取第1代许旺细胞,利用计数法绘制14 d内许旺细胞的生长曲线,MTT法检测14 d内许旺细胞增殖活性,酸性磷酸酶法检测许旺细胞黏附能力,ELISA法检测神经生长因子浓度。 结果与结论：坐骨神经段培养第14天,坐骨神经横断组神经段边缘可见大量许旺细胞,呈线形排列;手术对照组许旺细胞数量少,呈散在分布,两组许旺细胞S-100均呈阳性表达。许旺细胞传代培养第3天,两组许旺细胞均进入对数增长期,随时间延长,细胞数及细胞增殖吸光度值均呈上升趋势,坐骨神经横断组细胞数及增殖吸光度值明显高于手术对照组(P < 0.05);坐骨神经横断组许旺细胞黏附能力明显高于手术对照组(P < 0.05);ELISA法检测示,坐骨神经横断组神经生长因子浓度在培养第4,6,8,10,12,14天时均高于手术对照组(P < 0.05)。结果表明大鼠坐骨神经损伤后两三周,瓦勒变性对许旺细胞生物学功能具有显著影响,可诱导许旺细胞幼稚化,促使许旺细胞在短期内迅速分裂增殖,并分泌大量神经营养因子及细胞外黏附成分,为再生轴突的延伸提供适宜的神经微环境;并增加细胞黏附能力,为外周神经损伤修复提供适宜的神经微环境。 中国组织工程研究杂志出版内容重点：组织构建;骨细胞;软骨细胞;细胞培养;成纤维细胞;血管内皮细胞;骨质疏松;组织工程全文链接：     

施万细胞来源的Toll样受体在外周神经损伤及修复中的作用和机制

Toll样受体参与组成机体抵抗外来病原微生物入侵的第一道防线,在非感染性疾病中与内源性配体结合可触发免疫炎症反应。在外周神经损伤后,各种内源性配体释放,可与外周神经中表达的Toll样受体结合,通过信号级联传导,参与免疫炎症反应过程。本文将着重阐述施万细胞来源的Toll样受体在外周神经损伤后瓦勒变性及外周神经修复中的作用和机制。     

Toll样受体2和Toll样受体4在HBV感染后的免疫作用

Toll样受体（TLR）是启动固有免疫和调节适应性免疫的重要分子,参与肝脏对病毒及细菌的免疫TLR2、TLR4过程。在HBV的慢性化进程中,TLR2、TLR4与Thl和Th2的免疫平衡及调节性T细胞（Treg）的免疫抑制相关,HBV感染后,HBcAg刺激巨噬细胞产生TNF—α的作用需要TLR2参与,HBeAg的表达与否与TLR2的表达状态有关,而TLR4通过诱导iNOS的表达和激发HBV特异性免疫在体内抗HBV过程中起重要作用：     

人脐血血清对巨噬细胞Toll样受体4表达及功能的影响

目的研究人脐血血清(cord blood serum,CBS)对巨噬细胞RAW264.7 Toll样受体4(Toll like receptor4,TLR4)表达及功能的影响。方法取足月孕妇脐带血和外周血血清,与RAW264.7细胞共孵育,电镜下观察形态学变化,MTT法检测血清对RAW264.7细胞活性的影响;RT-PCR和流式细胞术检测RAW264.7细胞TLR4基因和蛋白表达水平;免疫荧光技术检测RAW264.7细胞I_κB_α水平,RR-PCR检测RAW264.7细胞COX-2的表达,以反映TLR4信号途径活化程度。结果人脐血血清可下调RAW264.7细胞TLR4的mRNA和蛋白表达水平;人脐血血清预孵育可抑制由LPS诱导的RAW264.7细胞NF-_κB激活和COX-2的表达。结论人脐血血清能抑制巨噬细胞TLR4的表达及其下游信号传递,这为阐明脐血血清对脐血细胞免疫功能调节的机制提供了新的实验线索。     

TOLL样受体在皮肤中的表达和功能

Toll样受体在皮肤角质形成细胞、树突状细胞、成纤维细胞和肥大细胞中都有表达,但表达的种类有明显区别.不同细胞的同一Toll受体激活后引起的反应亦有所不同.Toll样受体与其相应的配体结合可以诱导细胞产生多种炎症因子和抗菌肽,在皮肤介导的固有免疫和炎症反应中有重要作用.     

TLR4抑制剂TAK-242预处理改善急性缺血性脑卒中诱导的肠黏膜屏障损伤

目的:探讨Toll样受体4(TLR4)抑制剂TAK-242预处理对大鼠急性缺血性脑卒中(AIS)所致肠黏膜屏障损伤的影响.方法:将45只雄性SD大鼠随机分成假手术组(sham)、模型组(model)和AK-242预处理组(TAK-242),每组15只,采用改良Longa线栓法制作AIS大鼠模型.于造模后24 h评估各组...     

Toll样受体2和Toll样受体4在免疫应答衣原体感染中的作用

衣原体是重要的人类病原体,其能够导致多种疾病的发生.由衣原体引起的许多人类疾病被认为是免疫病理学介导的.已经证明Toll样受体(TLRs)是多种病原体感染的主要模式识别受体( PRRs),在起始固有免疫应答,建立适应性免疫应答中发挥着重要作用.在TLR家族中,TLR2和TLR4与衣原体感染的相关性研究备受关注,在识别衣原体感染、调节宿主的早期免疫应答、炎症反应和病理形成中执行着关键性的作用.研究TLR2和TLR4在免疫应答衣原体感染中的作用可以更好地理解TLRs介导的分子免疫机制,可能有助于研发免疫治疗的分子靶标,最终有效预防、控制衣原体感染引起的疾病.     

沉默Toll样受体4基因表达的RNAi慢病毒载体的构建

背景：Toll样受体4 (toll-like receptor4,TLR4)是介导内毒素/脂多糖应答的主要受体,在由内毒素诱导的炎性反应的信号通路中发挥着重要作用。 目的：构建人TLR4基因的RNA干扰慢病毒载体,并观察其对人脐静脉内皮细胞TLR4在蛋白水平的沉默效应。 方法：利用Invitrogen在线软件设计人TLR4基因shRNA序列,合成、退火形成双链寡核苷酸后克隆到线性载体pENTRTM/H1/TO的黏性末端,并进行DNA测序。得到的阳性重组子再与慢病毒载体进行重组反应,从而获得干扰TLR4基因真核表达的慢病毒载体。在脂质体的介导下将慢病毒包装辅助复合体和TLR4基因的真核表达慢病毒载体导入293FT细胞包装病毒,测定病毒滴度,感染人脐静脉内皮细胞,检验其干扰TLR4基因表达的有效性。 结果与结论：实验成功构建TLR4基因真核表达慢病毒干扰载体并获得相应的慢病毒,病毒滴度为8.7×10⁶ U/mL。免疫印迹杂交结果表明,所获得的慢病毒感染人脐静脉内皮细胞TLR4基因在蛋白水平的表达显著降低。实验成功构建了人TLR4基因慢病毒RNA干扰表达载体,并验证了其在人脐静脉内皮细胞上的有效性。     

Toll样受体4信号转导研究进展

Toll样受体4(TLR4)作为LPS信号转导受体,在与LPS反应时可形成一个由TLR4和MD 2构成的复合体,其在细胞内的信号转导依赖于不同的接头蛋白。在早期反应时,TLR4依赖MyD88和Mal可导致NF кB激活;而在后期反应中,通过TRIF和TRAM可引起NF кB和IRF3的迟发激活。由此诱导细胞因子、化学趋化因子和其他转录因子的表达。     

Toll样受体4在大鼠胰腺组织特异性分布表达

目的探索Toll样受体4(TLR4)在大鼠胰腺组织的特异性分布表达。方法采用逆转录聚合酶链式反应(RT-PCR)和免疫组化SP方法 ,检测Wistar大鼠胰腺组织中TLR4mR NA及TLR4蛋白的分布表达。结果通过RT-PCR方法 (31个循环 ) ,从正常大鼠胰腺组织检测到549bp目的基因片段。免疫组化方法检测到大鼠胰腺内有TLR4表达 ,主要位于胰管上皮、血管、微血管内皮及胰岛组织 ,胰腺外分泌腺泡细胞未见TLR4表达。结论TLR4在大鼠正常胰腺组织内有分布表达 ,主要定位于上皮组织 (胰管上皮 )和内皮组织(动脉静脉及微血管内皮) ,提示大鼠胰腺内、外分泌部均具有天然免疫TLR4参与胰腺病理生理的相关受体基础     

颅脑损伤促进的坐骨神经再生

BACKGROUND:Studies have shown that craniocerebral injury can promote the repair of sciatic nerve injury in rats, but its precise mechanism remains unclear. OBJECTIVE:To further explore the action mechanism of craniocerebral injury on the repair of sciatic nerve injury using morphology and histology. METHODS:Sixty specific-pathogen-free healthy male Sprague-Dawley rats were randomly divided into two groups. Rats with craniocerebral injury and sciatic nerve injury were considered as the experimental group. Rats with simple sciatic nerve injury were considered as the control group. Classical Feeney method was used in models of craniocerebral injury and SunderlandV sciatic nerve injury. At 8 and 12 weeks after modeling, sciatic nerve index was detected. Masson staining and NF200 immunofluorescence staining were used to observe the nerve regeneration at the anstomotic site. Transmission electron microscope was used to observe the number of regenerative axons. RESULTS AND CONCLUSION:At 8 and 12 weeks after modeling, compared with the control group, gait and sciatic nerve index recovered better in the experimental group. In the experimental group, Masson staining showed fewer nerve membrane collagen fibers, and the axon arranged neatly. NF200 immunohistochemistry showed that in the experimental group, the density of regenerated nerves was high, and nerves were regularly distributed. Transmission electron microscopy showed that in the experimental group, regenerative axons were regularly arranged, collagen scar was less, and myelin layer arranged regularly. Results suggested that the craniocerebral injury in rats may promote the repair of peripheral nerve injury by reducing scar collagen in nerve endings.     

脑白质损伤模型中Lingo-1的动态变化

BACKGROUND:Lingo-1 has been identified as a negative regulator of oligodendrocyte differentiation and myelination, which may be closely related to the white matter damage, but there is no systematic report on the dynamic changes of Lingo-1 after white matter damage.  OBJECTIVE: Toexplore the dynamic expression of Lingo-1 at different time points after white matter injury in newborn rats. METHODS:Seventy-eight Sprague-Dawley rats aged 3 days old were equally and randomly divided into sham operation group and model group. In the model group, models of white matter injury were established by unilateral ligation of the right common carotid artery combined with hypoxia. In the sham operation group, the right common carotid artery was isolated only, without ligation or hypoxia.  RESULTS AND CONCLUSION:At 7 days after model induction, hematoxylin-eosin staining and immunohistochemical staining for myelin basic protein showed that a selective white matter injury was seen at the injury site of a rat model, suggesting successful model establishment. Fluorescent quantitative PCR and western blot assay results demonstrated that the expression levels of Lingo-1 mRNA and protein were significantly up-regulated at 1 day and reached a peak at 7 days post-surgery. After 7 days, above expression was gradually decreased and the up-regulation of Lingo-1 protein lasted to the 28 days post-surgery compared to the sham operation group. These results show that Lingo-1 protein was closely related to the brain white matter injury.     

骨髓间充质干细胞与新型神经导管复合材料修复周围神经缺损

背景：随着医学模式的不断发展进步,人们对于外周神经缺损的治疗以及后期康复水平提出更高的要求,这就使得以干细胞培养为基础的神经组织工程技术为神经缺损治疗提供了新策略。 目的：探讨骨髓间充质干细胞与新型神经导管复合材料修复周围神经缺损的可行性。 方法：选取清洁级纯种新西兰大白兔50只,采用随机数字表法分为实验组与对照组,每组25只,于兔前肢桡骨中段约15 mm处造成外周神经损伤,造模后1周,实验组外周神经损伤处移植骨髓间充质干细胞联合新型神经导管复合材料,对照组外周神经损伤处移植骨髓间充质干细胞。移植后4周,取神经损伤处的神经纤维长约5 mm,进行苏木精-伊红染色和扫描电镜观察,对比两组再生神经组织内神经纤维的密度和直径。 结果与结论：实验组神经纤维密度明显高于对照组,神经纤维直径明显低于对照组,组间相比差异有显著性意义(P < 0.05);实验组再生神经组织表面细胞数较多,细胞生长状态良好,体积较大,胞体发出多个突起,并且细胞之间相互连接交织成网状,其轴突较长和较粗,呈典型的神经元样细胞表现,且生长密度和状态优于对照组,可见骨髓间充质干细胞与新型神经导管复合材料可以用于修复周围神经缺损,且效果确切。 中国组织工程研究杂志出版内容重点：干细胞;骨髓干细胞;造血干细胞;脂肪干细胞;肿瘤干细胞;胚胎干细胞;脐带脐血干细胞;干细胞诱导;干细胞分化;组织工程     

过敏性紫癜患儿外周血单核细胞TLR2表达及与免疫应答的相关性

背景：Toll样受体及其信号通路在自身免疫性疾病、超敏反应、炎症反应、细胞凋亡及移植排斥反应中发挥重要的作用,其在过敏性紫癜患儿免疫发病机制中的地位尚未完全阐明。目的：探讨过敏性紫癜患儿外周血单核细胞TLR2的表达及其与免疫应答的相关性。方法：64例过敏性紫癜患儿分为2组,即过敏性紫癜无肾损害组(36例)、过敏性紫癜肾损害组(28例),选择同期入院的30例健康体检儿童设置为对照组,采用流式细胞术检测外周血单核细胞TLR2表达,荧光定量PCR技术检测外周血单核细胞TLR2 mRNA相对表达量, ELISA检测血浆干扰素γ、白细胞介素4水平, ELISA法测定Treg细胞分泌的转化生长因子β、白细胞介素10水平。结果与结论：过敏性紫癜组干扰素γ、干扰素γ/白细胞介素4水平均显著低于对照组(P < 0.05),白细胞介素4水平显著高于对照组(P < 0.05);过敏性紫癜组TLR2 mRNA和蛋白表达显著高于对照组(P < 0.05);过敏性紫癜肾损害组TLR2 mRNA和蛋白表达显著高于过敏性紫癜无肾损害组(P < 0.05);过敏性紫癜组患者白细胞介素10和转化生长因子β表达显著高于对照组(P < 0.05)。结果表明过敏性紫癜患儿外周单核细胞TLR2 mRNA及蛋白表达增高,且患儿存在免疫表达失衡现象,TLR2参与过敏性紫癜免疫发病机制,转化生长因子β表达量能够评估Treg的免疫应答,可作为过敏性紫癜患儿诊断、治疗及预后参考依据。 中国组织工程研究杂志出版内容重点：干细胞;骨髓干细胞;造血干细胞;脂肪干细胞;肿瘤干细胞;胚胎干细胞;脐带脐血干细胞;干细胞诱导;干细胞分化;组织工程     

Soluble complement receptor 1 protects the peripheral nerve from early axon loss after injury

Complement activation is a crucial early event in Wallerian degeneration. In this study we show that treatment of rats with soluble complement receptor 1 (sCR1), an inhibitor of all complement pathways, blocked both systemic and local complement activation after crush injury of the sciatic nerve. Deposition of membrane attack complex (MAC) in the nerve was inhibited, the nerve was protected from axonal and myelin breakdown at 3 days after injury, and macrophage infiltration and activation was strongly reduced. We show that both classical and alternative complement pathways are activated after acute nerve trauma. Inhibition of the classical pathway by C1 inhibitor (Cetor) diminished, but did not completely block, MAC deposition in the injured nerve, blocked myelin breakdown, inhibited macrophage infiltration, and prevented macrophage activation at 3 days after injury. However, in contrast to sCR1 treatment, early signs of axonal degradation were visible in the nerve, linking MAC deposition to axonal damage. We conclude that sCR1 protects the nerve from early axon loss after injury and propose complement inhibition as a potential therapy for the treatment of diseases in which axon loss is the main cause of disabilities.     

缺血后调适对骨骼肌缺血再灌注损伤的保护及其机制的初步探讨

BACKGROUND: Reperfusion injury salvage kinase (RISK) pathway plays an important role in protective mechanism against ischemia reperfusion injury (IRI) induced by both ischemic pre- and post-conditioning. Many researches have been carried out on RISK pathway mechanism underlying ischemic post-conditioning conferring cardioprotection against IRI; however, there is less research about its effect on IRI in the skeletal muscle. OBJECTIVE: To investigate the protective effect of an optimized protocol of ischemic post-conditioning on   IRI in rat skeletal muscle and its underlying mechanism. METHODS: Eighteen male Sprague-Dawley rats were equivalently randomized into IRI, ischemic post-conditioning and control groups. Rats were given occlusion or disocclusion of the right femoral artery of the right lower limb. Subsequently, the IRI group rats were subjected to 24 hours of reperfusion; the ischemic post-conditioning group immediately given 4 cycles of 30 seconds reperfusion/30 seconds ischemia, followed by 24 hours of reperfusion; the control group given no intervention. RESULTS AND CONCLUSION: Hematoxylin-eosin staining showed that in the ischemic post-conditioning group, the morphology of muscle fibers changed little, with fewer inflammatory lesions and milder edema compared with the IRI group. The infarct size with TTC staining in the ischemic post-conditioning group was smaller than that in the IRI group. Western blot analysis revealed that the expressions of phospho-Akt and phosphorylated endothelial nitric oxide synthase-S1177 were significantly increased, but the expression of phosphorylated type endothelial nitric oxide synthase-Thr495 was much decreased in the ischemic post-conditioning group compared with the IRI group. The measurement of mitochondrial permeability transition pore opening with Ca2+ induction showed that the absorbance values in the ischemic post-conditioning group were significantly lower than those in the IRI group (P < 0.05). These results indicate that ischemia-reperfusion injury can be improved by applying an optimal protocol of ischemic post-conditioning in rat skeletal muscle. The underlying mechanism may be associated with the activation of RISK signaling pathway to inhibit opening of mitochondrial permeability transition pore, thereby contributing to the enhanced tolerance to IRI in rat skeletal muscle. 中国组织工程研究杂志出版内容重点：组织构建;骨细胞;软骨细胞;细胞培养;成纤维细胞;血管内皮细胞;骨质疏松;组织工程     

Bac-to-Bac杆状病毒表达系统表达鼠IL-4受体拮抗体蛋白的研究

目的 利用Bac-to-Bac杆状病毒表达系统表达鼠IL-4受体拮抗体 (mIL-4RA)蛋白.方法 PCR方法扩增小鼠IL-4 C118截断型基因,定向克隆入转移质粒pFastBacHTB中,转化感受态DH10Bac细胞,在DH10Bac细胞内重组pFastBacHTB与杆粒发生转座.筛选阳性克隆,提取重组杆粒,转染sf9昆虫细胞株,获取完整重组杆状病毒.反复感染sf9细胞,扩增病毒同时表达目的 蛋白;用ELISA方法进行蛋白鉴定并初步定量.结果 经核苷酸序列测定及PCR方法,鉴定成功获得含mIL-4RA基因的重组杆粒;通过杆粒转染后sf9细胞所表现出来的细胞病变,推断成功转染并获得重组杆状病毒;最后ELISA方法初步定量sf9细胞培养上清中mIL-4RA蛋白表达量为(1.15±0.12) ng/mL.结论 本研究利用Bac-to-Bac杆状病毒表达系统成功表达mIL-4RA蛋白,为进一步研究其生物学活性及功能奠定了实验基础,同时亦为其他蛋白质的真核表达提供了方法学的参考.     

脊髓压迫性损伤神经纤维溃变和髓鞘碱性蛋白的表达变化

目的　观察脊髓压迫性损伤中白质神经纤维溃变及MBP的表达变化。 方法　采用自行设计的压迫装置制作脊髓压迫性损伤模型,运用luxol fast blue（LFB）、免疫荧光和western blot等方法来检测脊髓受压1、3、7 d后的白质纤维变化及MBP表达变化。 结果　脊髓受压后,白质髓鞘化神经纤维出现水肿,排列疏松、髓鞘缺失等退行性溃变;髓鞘化纤维数目逐渐减少。蛋白MBP表达随着压迫时间进行性下降。 结论　脊髓压迫性损伤可导致神经纤维溃变,MBP表达下调是神经纤维溃变的原因之一。     

大鼠脊髓挤压伤后小胶质细胞Toll样受体4表达的变化

目的探讨脊髓挤压伤后各时间点小胶质细胞Toll样受体4(TLR4)的表达变化及其与损伤面积和免疫球蛋白G渗出范围的关系。方法 48只成年雄性SD大鼠建立T8节段脊髓挤压伤模型,随机分为6组,每组8只;假手术对照组及挤压伤组动物在手术后0h、3h、24h、72h和7d用4%多聚甲醛灌注固定,取以挤压点为中心的2cm脊髓,冷冻切片后进行HE染色和免疫荧光染色,分别观察损伤面积的变化,TLR4表达和TLR4阳性小胶质细胞的分布,以及与血浆免疫球蛋白G(IgG)渗出范围的比较,并用IPP6.0软件计算各组的阳性数目。结果脊髓损伤后TLR4主要表达在小胶质细胞,在3～24h之间开始表达,伤后在72h达到高峰,7d时已经显著下降。阳性小胶质细胞的分布与IgG渗出范围一致。结论大鼠脊髓挤压伤模型中,表达在脊髓小胶质细胞上的TLR4可在脊髓继发性损伤中发挥重要作用,并与血脊髓屏障开放有关。     

紫癜性肾炎患者外周血单个核细胞Toll样受体3和4的信号转导途径

背景：目前关于Toll样受体3和Toll样受体4介导的信号转导通路在紫癜性肾炎的发病机制中的作用尚不清楚。目的：分析Toll样受体3和Toll样受体4在过敏性紫癜和紫癜性肾炎发病机制中的作用。方法：选取过敏性紫癜患儿64例,分为过敏性紫癜无肾损害组36例及过敏性紫癜性肾炎组28例,另选健康儿童30例作为正常对照组。实时荧光定量PCR检测外周血单核细胞Toll样受体3、Toll样受体4、髓样分化蛋白2、髓样细胞分化因子88、白细胞介素1β、白细胞介素6、白细胞介素12 mRNA的基因相对表达量;应用流式细胞术检测外周血单核细胞Toll样受体3、Toll样受体4蛋白表达率。结果与结论：①过敏性紫癜患儿Toll样受体4 mRNA及蛋白表达显著高于正常对照组(P < 0.05)。紫癜性肾炎组Toll样受体4 mRNA及蛋白表达均显著高于紫癜无肾损害组(P < 0.05)。②过敏性紫癜组髓样分化蛋白2、髓样细胞分化因子88、白细胞介素1β、白细胞介素6 mRNA的表达均显著高于正常对照组(P < 0.05),白细胞介素12 mRNA的表达显著低于正常对照组(P < 0.05);紫癜性肾炎组髓样分化蛋白2、髓样细胞分化因子88、白细胞介素1β、白细胞介素6 mRNA的表达显著高于紫癜无肾损害组(P < 0.05),紫癜性肾炎组白细胞介素12 mRNA的表达显著低于紫癜无肾损害组(P < 0.05)。③过敏性紫癜组患儿外周血单核细胞Toll样受体4 mRNA与蛋白表达呈正相关(r=0.60,P < 0.01);过敏性紫癜患儿Toll样受体4 mRNA与髓样分化蛋白2、髓样细胞分化因子88、白细胞介素1β、白细胞介素6表达均呈正相关(P < 0.01),与白细胞介素12 mRNA表达呈负相关(r=-0.66,P < 0.01)。提示Toll样受体4可能通过髓样细胞分化因子88依赖信号转导途径介导过敏性紫癜的免疫发病机制,Toll样受体4的过度活化可能与过敏性紫癜的肾损伤有关。 中国组织工程研究杂志出版内容重点：肾移植;肝移植;移植;心脏移植;组织移植;皮肤移植;皮瓣移植;血管移植;器官移植;组织工程全文链接：