JNK信号转导通路及其在组织损伤中的作用

丝裂原活化蛋白激酶(mitogen-activated protein kinase,MAPK)是广泛表达的丝氨酸/酪氨酸激酶,在哺乳动物细胞多种信号转导通路中起重要作用。MAPK有4个主要亚族:ERK、JNK、p38MAPK和ERK5。JNK信号转导通路是MAPK通路的一重要分支,它在细胞周期、生产、凋亡和细胞应激等多种生理和病理过程中起重要作用。本文就JNK的分型、分布、信号通路的组成及其在组织损伤中的作用进行综述,旨在为组织损伤程度和伤后时间推断的法医病理学研究提供参考资料。     

p38MAPK信号转导通路与组织损伤

丝裂原活化蛋白激酶(mitogen-activated protein kinase,MAPK)是广泛表达的丝氨酸/酪氨酸激酶,在哺乳动物细胞多种信号转导通路中起重要作用。MAPK有4个主要亚族:ERK、p38MAPK、JNK和ERK5。p38信号通路是MAPK通路的一重要分支,它在炎症、细胞应激、凋亡、细胞周期和生长等多种生理和病理过程中起重要作用。本文就p38MAPK的分型、分布、信号通路的组成及其在法医损伤学领域中的应用现状做一综述,旨在进一步对组织损伤程度和伤后时间推断的法医病理学研究提供参考资料。     

Spry1和MAPK蛋白在病毒性心肌炎心肌组织中的表达

目的通过探讨Spry1和MAPK蛋白在病毒性心肌炎(viral myocarditis,VMC)心肌组织中的表达,揭示其发病及猝死机制,并为法医学心源性猝死的鉴定提供指导。方法 30只Balb/c雄性小鼠随机分为VMC组和对照组,分别腹腔注射柯萨奇B3病毒和Eagel’s培养液,处死小鼠取心脏,进行常规病理检查,并通过免疫组织化学、Western印迹法及real-time PCR方法检测心肌组织中Spry1蛋白及mRNA、MAPK蛋白表达变化。结果 VMC组在光镜下可见心肌间质水肿,广泛炎症细胞浸润,心肌细胞坏死,心肌纤维形成多处灶性、大片状坏死,心肌组织中Spry1蛋白表达水平低于对照组(P0.05),Spry1 mRNA水平略降低(P0.05);而MAPK蛋白表达水平在VMC组高于对照组(P0.05)。结论 Spry1参与的MAPK/ERK通路在病毒性心肌炎心肌纤维化过程中起着促进胶原表达的作用,从而导致心律失常、心功能减退甚至心源性猝死。     

calpain与细胞凋亡

calpain是钙激活中性蛋白酶,属于半胱氨酸蛋白水解酶超家族成员。是由分子量为80KD的催化亚单位和分子量为30KD的调解亚单位组成的异二聚体。研究最多的是calpain1和2,它们又称μ-calpain和m-calpain。calpain被认为与细胞骨架重塑、信号转导途径、调控细胞周期、基因表达调控、某些凋亡途径以及长程增强效应等有关。calpain参与了细胞凋亡,而calpain抑制剂可以阻止细胞的凋亡。     

小鼠皮肤切创愈合过程中磷酸化 p38MAPK 表达及其与时间的相关性

目的探讨小鼠皮肤切创愈合过程中损伤区磷酸化p38MAPK(p-p38MAPK)的表达情况,以及不同损伤时间p-p38MAPK的变化规律。方法应用免疫组织化学和Westernblot的方法检测33例小鼠皮肤切创后各个时间段p-p38MAPK表达情况。结果正常组织中有少量的p-p38MAPK表达。伤后3～12h损伤区p-p38MAPK主要表达于中性粒细胞中,1～5dp-p38MAPK阳性表达主要为单核细胞和成纤维细胞。7～14dp-p38MAPK阳性表达主要以成纤维细胞为主。阳性细胞率3～12h逐渐升高,1d有所下降,3、5d阳性细胞率保持在高水平,7～14d阳性细胞率逐渐降低。Westernblot显示各个时间段均有p-p38MAPK的表达。其中12h和3d为2个p-p38MAPK含量的高峰。结论在小鼠切创愈合过程中p-p38MAPK在损伤区对诱导中性粒细胞、单核细胞和成纤维细胞的凋亡起重要的作用,同时p-p38MAPK的规律性表达可用于损伤时间的推断。     

大鼠急性肾缺血再灌注损伤早期的基因表达

目的研究急性肾缺血再灌注损伤早期的差异基因表达,探索其潜在的分子机制。方法通过单纯夹闭大鼠肾动脉制备肾缺血再灌注模型,进行基因表达芯片检测和生物信息学分析,筛选急性肾损伤早期的差异基因表达及其所涉及的细胞活动和信号通路。同时,通过构建差异表达基因的生物网络来寻找与急性肾损伤关系密切的分子,并进行荧光定量PCR验证。结果在检测出的151个差异表达基因中,132个基因显著上调,19个基因显著下调,GO与KEGG通路富集分析结果显示主要与细胞增殖、细胞因子介导的信号通路和免疫反应等有关。荧光定量PCR结果显示,与对照组相比,挑选出的3个与急性肾损伤高度相关的基因(ANXA1、PHLDA1、KLF6)在疾病早期具有显著的表达差异,上升倍数与芯片检测出的倍数基本一致。结论本研究揭示了急性肾损伤早期的差异基因表达特征以及所涉及的生物学过程和信号通路,其中ANXA1、PHLDA1、KLF6可能在急性肾损伤的发病机制中起到一定作用。     

甲基苯丙胺致多巴胺能神经元毒性机制的研究进展

甲基苯丙胺属于苯丙胺类中枢兴奋剂,目前其滥用趋势严重。研究表明,甲基苯丙胺对动物及人类大脑纹状体多巴胺能神经元具有毒性作用。其毒性机制包括多巴胺信号转导影响和多巴胺的氧化作用、谷氨酸介导的兴奋性毒性作用、氧化应激和细胞因子的形成、线粒体功能紊乱、神经细胞凋亡、神经胶质细胞的活化以及高热等。但甲基苯丙胺对多巴胺能神经元的毒性机制并不完全清楚,本文结合文献对此进行综述,以期为相关研究提供参考。     

FAK—ERK的研究进展及其法医学应用价值

细胞内黏着斑激酶（focal adhesion kinase，FAK）和细胞外信号调节蛋白激酶（extracellular signal—regulated protein kinase，ERK）均是重要的信号转导分子，二者在信号从表面受体转导至细胞核过程中起到关键作用。当受到细胞外刺激时，FAK被激活而发生磷酸化，磷酸化的FAK激活下游的ERK，通过ERK改变细胞行为。这样，FAK-ERK信号传导因子就参与了细胞增殖、分化、应激、凋亡和恶变等多种生物学反应。本文对FAK—ERK的生物学特性以及其在组织损伤中作用的研究进展作一综述，以期为组织损伤时间推断的法医学研究提供更为有效的方法。     

缝隙连接、连接蛋白与冠心病猝死

缝隙连接(gapjunction,GJ)构成细胞之间的跨膜水相通道,协调细胞间化学及电信息的交流。心脏上缝隙连接的主要功能是为心肌细胞间的电冲动提供低压传导通路,并维持心肌的协调运动。近年来的研究显示,心肌细胞(特别是心室肌工作细胞)上构成缝隙连接的连接蛋白含量、分布及功能的异常与各种心律失常的产生和持续关系密切。这很可能为临床及法医实践中,诊断冠心病猝死心肌早期病变提供一个新的思路。     

远离电击部位电流通路上骨骼肌的病理学研究

研究电损伤时骨骼肌中肌红蛋白(Mb)和纤维连接蛋白(Fn)的异常分布情况。采用大鼠模型和人体电击死标本,对电流通路上骨骼肌组织进行肌红蛋白、纤维连接蛋白免疫组化(LSAB)检测。结果显示:电流通路上肌细胞呈现深浅不同竹节样改变,免疫组化法见Mb脱失,Fn呈阳性,呈蟒蛇状纹理。电流通路上骨骼肌竹节样和蟒蛇纹理改变对无典型电流斑法医学鉴定有实用价值。     

The informative aspects of the wound surface for determining vitality and wound age in skin cuts

A histological study was carried out on skin cut wounds of guinea pigs at various time intervals during the first day after infliction of the cut. At the same time intervals, blood cells were obtained from the wound surface prints and analyzed cytologically and cytochemically. Histological examination showed that a central and peripheral zone formed in the wound area, demonstrating that necrobiotic and inflammatory processes were even occurring in the early hours after injury. However, changes in the quantitative relationships between individual kinds of cells were much more differentiated cytologically and reflected much more precisely. Functional and structural macrophage and lymphocyte changes in the wound region during inflammation were also revealed. In correlation, cytochemical analysis confirmed the concept concerning the development of the inflammatory process in the wound area, as enzyme-activity changes clearly detectable, which reflected the rapid, energetic, plastic cellular processes on the wound surface. Our combined results suggest that the wound surface is a zone of vital processes, but that it is not a "dead," "necrobiotic" area. The dynamics of the cellular alterations in the wound surface, reflecting the vital processes developing there, can be successfully used when the problem of vitality, especially the time lapse after the skin injury, is to be resolved.     

Mechanism responsible for the formation of focal swellings on injured neuronal processes using a novel in vitro model of axonal injury

A novel in vitro model of axonal injury using PC12 cells was designed to introduce traumatic alterations on neuronal processes and to identify mechanisms responsible for the formation of focal swellings by observation with phase-contrast and transmission electron microscopes. The injury on the processes was developed by one-dimensional, horizontal oscillation. Phase-contrast microscopic observation on the injured processes showed their terminal increase in diameter. Long term observation of cellular responses to the mechanical insult disclosed that the terminal swelling coincided with the detachment of growth cones from the culture plate. The finding suggests that the detachment of the growth cone would destroy a cytoskeletal network, which determines and maintains the cell shapes, and then cause the spherical deformation of the processes. Ultramicroscopically, the processes with terminal swellings regenerated the growth cones by the cytoskeletal reconstruction.     

转化生长因子β1的研究进展及其法医学应用价值

转化生长因子pl（transforminggrowthfactor-β1,TGF-β1）是一种具有多种生物学活性的细胞因子,存在于多种生物的不同组织中,广泛参与调节细胞增殖和分化等过程。本文综述TGF-β1的生物学特性及其在法医学中的应用价值,以期为损伤时间推断的基础研究和实际检案工作提供参考资料。     

The effects of sarin-like and soman-like organophosphorus agents on MAPK and JNK in rat brains

One sarin-like and one soman-like organophosphorus agent [bis(isopropyl methyl)phosphonate, BIMP and bis(pinacolyl methyl)phosphonate, BPMP] were injected intravenously (iv) in rats. An increase in the tyrosine phosphorylation of several proteins in the cytosol fraction of the brain was observed. Activation of c-Jun N-terminal kinase (JNK) and slight activation of mitogen-activated protein kinase (MAPK) in the cytosol were also observed. The activation of these enzymes may be related to the high toxicity of these nerve agents.     

Mucosal Cell Isolation and Analysis from Cellular Mixtures of Three Contributors

In forensic genetic analyses, mixtures of various biological materials are common samples. Micromanipulation, which is performed based on differences in cellular morphology, is an effective method for the isolation of cells from mixtures. In this study, mucosal cell was isolated from somatic cellular mixtures (blood and saliva) based on micromanipulation and a low volume‐PCR (LV‐PCR) platform. One hundred and twenty‐six parallel LV‐PCR processes were performed using an Identifiler^® kit, with 107 reactions yielding single‐source DNA profiles. Among them, 54 full profiles (50%) and 37 partial profiles (13–15 loci) were obtained. Based on the above method, we obtained a single‐source DNA profile from a cigarette butt contaminated by two victims’ blood in a murder case. The generated genotype was used to query a DNA database, and a perfect match was found.     

Out of Africa: The human trade between Libya and Lampedusa

Smuggling and trafficking in persons is ipso facto illegal. Is this criminal activity organised or diffuse? Recent objective indicators show that between 2000-2005 the reported incidence of people trafficking and smuggling from North Africa to Europe has escalated. The article examines the nature of criminality involved in people smuggling and trafficking with specific reference to the sea route between Libya and the Italian island of Lampedusa, 180 miles north of the Libyan coast. In 2006 almost 19,000 illegal migrants arrived on this small island. Recent major operations conducted by the Italian anti-mafia unit and the state police suggest transnational criminal organisation of the trade. The networks involved in this trade, however, do not conform to mafia-like hierarchical organisations but rather smaller, more complex and fluid criminal networks. The article aims to cast light on how people are smuggled and trafficked. The background to the rise in illegal immigration from Libya is sketched underlining the ‘push’ and ‘pull’ factors involved in the human trade. The article’s chief objective is to provide a greater understanding of the mechanisms and processes involved in smuggling/trafficking. A better knowledge of the processes involved is vital if domestic, regional and international authorities and bodies are to counter the practice and/or to formalise it.