Update on the endocannabinoid-mediated regulation of gelatinase release in arterial wall physiology and atherosclerotic pathophysiology

Endocannabinoids are endogenous bioactive lipids ubiquitously distributed in several tissues (e.g., brain, adipose tissue, liver, heart and arterial vessels), which play a crucial role in atherosclerosis. Endocannabinoids have been shown to promote cell homeostasis and modulate inflammatory bioactivities mainly via the binding to transmembrane receptors (called cannabinoid type 1 and cannabinoid type 2 receptors, respectively). Although other cannabinoid receptors have been recently identified and shown to play a crucial role in cardiovascular pathophysiology, so far, the pharmacological targeting of both cannabinoid type 1 and cannabinoid type 2 receptors has been described as a promising therapeutic target in atherogenesis and associated inflammatory processes. In particular, endocannabinoids have been shown to modulate the release and activation of matrix degrading enzymes (i.e., matrix metalloproteinases [MMPs]) increasing intraplaque vulnerability. In this article the authors describe the pivotal regulatory activity of the endocannabinoid system on gelatinase (MMP-2 and -9) bioactivity in the arterial wall physiology and pathophysiology.     

Hear the beat: decellularized mouse heart regenerated with human induced pluripotent stem cells

Heart tissue engineering holds a great potential for human heart disease therapy. Regeneration of whole biofunctional human heart is the ultimate goal of tissue engineering. Recent advances take the first step towards whole heart regeneration. However, a substantial amount of challenges have to be overcome.     

Design and characterization of a dynamic vibrational culture system

To engineer a functional vocal fold tissue, the mechanical environment of the native tissue needs to be emulated in vitro. We have created a dynamic culture system capable of generating vibratory stimulations at human phonation frequencies. The novel device is composed of a function generator, a power amplifier, an enclosed loudspeaker and a circumferentially‐anchored silicone membrane. The vibration signals are translated to the membrane aerodynamically by the oscillating air pressure underneath. The vibration profiles detected on the membrane were symmetrical relative to the centre of the membrane as well as the resting position over the range of frequencies (60–300 Hz) and amplitudes tested (1–30 µm). The oscillatory motion of the membrane gave rise to two orthogonal, in‐plane strain components that are similar in magnitude (0.47%) and are strong functions of membrane thickness. Neonatal foreskin fibroblasts (NFFs) attached to the membrane were subjected to a 1 h vibration at 60, 110 and 300 Hz, with the displacement at the centre of the membrane varying in the range 1–30 µm, followed by a 6 h rest. These regimens did not cause morphological changes to the cells. An increase in cell proliferation was detected when NFFs were driven into oscillation at 110 Hz with a normal displacement of 30 µm. qPCR results showed that the expression of genes encoding some extracellular matrix proteins was altered in response to changes in vibratory frequency and amplitude. The dynamic culture device provides a potentially useful in vitro platform for evaluating cellular responses to vibration. Copyright © 2011 John Wiley & Sons, Ltd.     

中空多孔钛假体复合松质骨基质兔体内骨生成组织学研究

目的：利用复合松质骨基质(Cancellous bone matrix ,CBM)的中空多孔钛假体(Hollow porous titanium prostheses, HPTP)观察兔体内假体周围及内部骨生成情况,探讨人工假体与骨质整合的改进方法。方法设计中空多孔(孔径2 mm)和无孔两种假体,表面行羟基磷灰石(Hydroxyapatite ,HA)喷涂。实验组分为无孔假体组(A组)、HPTP组(B组)和HPTP＋CBM组(C组),每组16例。将假体分别植入48只4~6个月龄新西兰大白兔右侧股骨外侧髁,饲养至第3、8、12周时取材,以X线、显微镜、电镜及形态计量软件观察复合假体表面及内部骨生成情况。采用SPSS13.0进行t检验分析。结果三组植入物外表面HA涂层的组织生长情况类似;A组无孔,未见骨长入,B组和C组中骨组织最终可长入假体2 mm大的圆孔;各时间点C组中空腔内骨生长率均明显高于B组(P<0.01)。结论骨质可经HPTP假体孔洞长入腔内,达到交锁固定,较无孔假体更稳定;中空腔复合CBM后可明显加快骨长入并诱导骨生成,使假体与骨质更好整合。     

基质金属蛋白酶-2,9及其抑制因子在增生性瘢痕中的表达特征及意义

 目的 探讨3种不同的基质金属蛋白酶-2, 9(MMP-2, 9)及其抑制因子(TIMP-2)在不同形成时期的增生性瘢痕中的基因表达和蛋白含量的变化.方法 用病理学技术检测增生性瘢痕和正常皮肤的结构特征后,分别用RT-PCR和Western blot方法检测这3种基因在16例不同发生时期的增生性瘢痕和8例正常皮肤组织中的基因表达和蛋白含量的变化规律.结果 在正常皮肤组织内,MMP-2, 9和TIMP-2的基因表达较弱,蛋白含量较低;而在增殖期的增生性瘢痕中这2种MMPs和TIMP2基因表达水平和蛋白含量都显著升高(P＜0.05),在成熟期的瘢痕中,MMP-2, 9基因表达量降低至正常皮肤水平,但蛋白含量仍保持较高水平,明显高于正常皮肤(P＜0.05),TIMP-2的mRNA水平和蛋白含量则降低至正常皮肤相近的水平.结论 MMP-2, 9和TIMP-2表达增强可能是增生性瘢痕形成的机制之一,而MMP-2, 9蛋白含量的增多,TIMP-2蛋白含量减少可能与增生性瘢痕达到相对稳定的成熟期有关.     

不同种属脱细胞真皮与自体皮复合移植的比较性研究

目的　观察不同种属脱细胞真皮基质 (acellulardermalmatrix,ADM)与自体皮复合移植的效果 ,为异种ADM的临床应用提供理论依据。　方法　本地产白色小猪 6头 ,分为异种 (人 )ADM +自体刃厚皮组 (A组 )、同种异体 (猪 )ADM +自体刃厚皮组 (B组 )、单纯自体刃厚皮组 (C组 )及单纯自体中厚皮组 (D组 )。观察术后 2、4、8、12、2 4周内移植物存活率 ,以及移植皮片收缩程度、移植区组织学变化等情况。　结果　A、B组移植后皮片外观光滑、有弹性 ;两组均获得了满意的皮片成活率 ,并可迅速诱导成纤维细胞、血管内皮细胞等宿主修复细胞的长入 ;两组移植皮片收缩面积有大于C、D组的趋势 (P <0.0 5);术后 2 4周移植区组织与单纯中厚皮移植组织结构一致。　结论　在观察期内(复合移植后 2 4周 ) ,与自体皮复合移植时 ,同、异种ADM具有相近的生物学作用 ,异种来源的ADM可能具有更广阔的应用前景     

细胞因子对异种脱细胞真皮基质免疫调节作用的临床研究

目的　探讨烧伤患者接受异种 /异体脱细胞真皮基质 (xeno /allo ADM )移植后全身和局部多种细胞因子与移植物近期转归的关系。　方法　在大面积烧伤患者的四肢切痂创面上 ,移植xeno ADM (12例 ,19块 )或allo ADM(15例 ,18块 ) ,其上覆盖自体超薄断层皮片 ,并以 6例单纯移植自体中厚断层皮片 (auto TTS)的烧伤患者为对照。移植物成活后 4～ 8周 ,收集局部组织标本、血清和xeno ADM排斥后的创面渗出液 ,采用免疫组织化学染色与酶联免疫吸附法 (ELISA) ,检测白细胞介素 (IL) 1β、IL 4、IL 6、肿瘤坏死因子α(TNF α)和γ型干扰素 (IFN γ)的含量。　结果　免疫组织化学染色结果显示 ,移植物内IL 1β、IL 4、IL 6、TNF α和IFN γ的阳性细胞密度或着色强度相比较 ,xeno ADM >allo ADM >auto TTS (P <0 .0 5 )。ELISA检测结果显示 ,xeno ADM被排斥后创面渗出液中IL 4、IL 6、TNF α和IFN γ水平明显高于自体血清 ,但其血清IL 4与IFN γ水平分别低于和高于未排斥时。xeno ADM移植后血清中IL 4、IFN γ水平明显高于allo ADM和auto TTS(P <0 .0 5～ 0 .0 1)。　结论　xeno ADM移植后可在局部检测到高水平的IL 1β、IL 4、IL 6、IFN γ ,可能与细胞杀伤和细胞因子介导的免疫放大作用有关。这些细胞因子的动态变     

自体皮源奇缺条件下瘢痕挛缩畸形的晚期临床修复

目的寻找对烧伤后畸形伴自体皮源奇缺患进行晚期修复的新方法。方法5例特重度、特大面积烧伤患治愈后伴较严重畸形，且自体皮源奇缺。采用柔软成熟的瘢痕皮肤作为修复的皮源，用扩张器扩张瘢痕皮肤后，切取中厚瘢痕皮片进行修复；不宜行瘢痕皮肤扩张术时，切取刃厚瘢痕皮片与异体脱细胞真皮基质组成复合皮进行修复。观察两种方法的疗效。结果所移植的扩张瘢痕皮片和复合皮均成活，功能和外形恢复良好，远期疗效近似正常自体中厚皮移植。结论采用不同厚度的瘢痕皮片修复烧伤畸形是可行的，可扩大自体皮源。此法对于皮源奇缺的瘢痕患尤其适用。     

高糖对基质金属蛋白酶2及其抑制剂在人腹膜间皮细胞中表达的影响

目的 研究高糖对人腹膜间皮细胞(HPMC)基质金属蛋白酶2(MMP2)及其组织抑制剂(TIMP)1、TIMP2基因及蛋白表达的影响,以及对人腹膜间皮下细胞外基质(ECM)降解的可能作用。方法 利用腹膜透析(腹透)患者腹透流出液标本原代培养HPMC并进行传代,采用半定量RT-PCR方法研究高糖高渗对HPMC的MMP2、TIMP1、TIMP2基因表达的影响。利用免疫组织化学(组化)及Zymography方法检测HPMC的MMP2、TIMP1、TIMP2蛋白表达。结果 HPMC存在MMP2、TIMP1、TIMP2基因及蛋白表达,4.25%葡萄糖显著上调HPMC的TIMP1基因表达(P<0.01),高渗对HPMC的TIMP1基因表达无明显影响(P>0.05),高糖高渗对HPMC的MMP2、TIMP2基因表达无明显影响(P>0.05)。结论 HPMC能够通过MMP/TIMP系统影响到腹膜ECM的降解,高糖可能通过诱导HPMC的TIMP1与MMP间表达失衡,在促进腹膜纤维化的进展中发挥一定作用。     

软骨寡聚基质蛋白在慢性胰腺炎损伤中退变腺泡细胞内的表达

目的 研究正常胰腺、慢性胰腺炎与胰腺癌组织中软骨寡聚基质蛋白(cartilage oligomeric matrix protein,COMP)mRNA和蛋白表达水平的差异,揭示COMP在慢性胰腺炎样损伤中的意义。方法 采用Northern印迹法、Western印迹法、原位杂交法与免疫组化方法对14例慢性胰腺炎、14例胰腺癌及15例正常胰腺组织进行分析。结果 在慢性胰腺炎组织中和胰腺癌组织中类似慢性胰腺炎损伤的退变腺泡细胞胞浆内,存在高水平的COMP mRNA信号与免疫反应;而在胰腺癌细胞、正常胰腺组织的导管细胞与胰岛细胞的胞浆内,COMP mRNA信号与免疫反应微弱或缺如。结论 COMP在慢性胰腺炎及胰腺癌中类似慢性胰腺炎损伤的退变腺泡细胞内高表达,可能与慢性胰腺炎中腺泡细胞功能异常有关。