血管内皮生长因子在大鼠乳腺炎中的作用

应用组织化学方法及免疫组化技术对正常组和急性攻毒组大鼠乳腺组织血管内皮生长因子（Vascular Endothelial Growth Factor,VEGF）的表达水平、肥大细胞的活力和炎性细胞的动态变化进行了研究.结果表明,急性攻毒后6 h乳腺组织VEGF在腺泡间、小叶间质、血管周围及部分肥大细胞内的表达出现一个峰值,而后表达开始减弱,攻毒48 h后表达又迅速增强;攻毒组大鼠的肥大细胞及其脱颗粒和炎性细胞随着攻毒时间的延长急剧增多,均极显著高于正常组（P〈0.01）,且其变化趋势均与VEGF表达趋势相吻合;同时,小叶间质内的小血管内皮细胞开始出现裂隙、脱落损伤.由此表明,VEGF和肥大细胞参与大鼠乳腺炎的发病过程.     

反义VEGF165基因对肝癌细胞生长的抑制作用

人肝癌细胞株SMMC-7721体外转染反义VEGR_(165)基因,观察反义VEGF_(165)基因对肝癌细胞生长的作用。用分子克隆的方法构建反义VEGF_(165)基因其核表达载体 pcDNA_3-as-VEGF_(165),用阳离子脂质体介导的基因转染技术,将反义基因转入SMMG-7721肝癌细胞株,观察反义VEGF_(165)基因抑制肝癌细胞 VEGF蛋白表达,抑制细胞增殖,促进细胞凋亡的作用。RT-PCR结果显示转染反义VEGF_(165)基因后肝癌细胞内 VEG mRNA水平显著下降;ELISA方法显示转染反义基因 2 d后培养液上清 VEGF蛋白分泌显著下降((142.01±7.95)vs(1 625.52±64.46)pg/mL,n=4,P<0.01);免疫组织化学染色显示在培养板中转染及义VEGF_(165)基因的肝癌细胞细胞数显著减少,仅有少数细胞表达VEGF蛋白。流式细胞仪结果显示转染反义VEGF_(165)基因2 d后肝癌细胞的存活率下降了 12.53％(n=4,P<0.05),而凋亡率则上升了 13.12％(n=4,P<0.01)。MTT法显示反义VEGF_(165)基因能显著抑制肝癌细胞的增殖。反义VEGF_(165)基因能显著的抑制肝癌细胞VEGF蛋白的表达,抑制细胞的增殖,促进肝癌细胞凋亡。因此反义VEGF_(165)基因治疗有望成为一种新的治疗肝癌的方法。     

VEGF在大鼠局灶性脑缺血再灌注损伤中的表达变化

目的 研究局灶性脑缺血再灌注中心区、半影区VEGF表达的动态变化及意义．方法 采用线检法制备大鼠局灶性脑缺血再灌注模型．采用神经病学评分、TTC染色、光镜检测对模型予以评价．在此基础上采用免疫组化技术，观察缺血3h及缺血3h再灌注3，6，24，72h缺血中心区及半影区VEGF表达的动态变化，以及观察相应时间点缺血中心区及半影区病理组织学变化．结果 正常对照组及假手术组VEGF呈阳性表达，缺血3h及缺血3h再灌注3，6h中心区及半影区VEGF表达明显增强，缺血3h再灌注24，72h缺血中心区VEGF表达接近正常，而此时半影区呈升高趋势，24h达到高峰，72h有所下降(与假手术组相比，P＜0．05)．相应神经元的病理组织学变化也随再灌注时间的延长而加重．结论 正常脑组织中VEGF呈弱阳性表达，缺血半影区随缺血再灌注时间延长表达增强．随着缺血再灌注时间延长，中心区神经细胞以坏死为主，半影区以神经细胞以凋亡为主．提示VEGF对脑缺血损伤后的神经细胞有保护和修复作用．     

Development of epipods and gills in some pagurids and brachyurans

Sepedon trichrooscelis is a semiaquatic, multivoltine species whose larvae feed on snails of the genus Succinea. The duration of the various developmental periods and larval biology are presented. The egg, three larval instars, and puparium of Sepedon trichrooscelis are described and illustrated. The distribution of the cuticular sensorial receptors, the shape of the hydrofuge setae on the posterior disc, and the details of the egg are illustrated by scanning electron micrographs.     

Central role of dendritic cells in the regulation and deregulation of immune responses

Dendritic cells (DCs) play a critical role in orchestrating the innate and adaptive components of the immune system so that appropriate, coordinated responses are mounted against infectious agents. Tissue-resident DCs interact with microbes through germline-encoded pattern-recognition receptors (PRRs), which recognize molecular patterns expressed by various microorganisms. Antigens use PRR activation to instruct DCs for the appropriate priming of natural killer (NK) cells, followed by specific T-cell responses. Due to the central role of DCs in regulating the activation and progression of immune responses, minor imbalances in the feedback control of Toll-like receptor (TLR)-activated cells have been associated with autoimmunity in genetically prone individuals. We review here recent findings on the role of DCs in the priming of innate and adaptive immune responses and the possible involvement of DCs in inducing and maintaining autoimmune reactions.     

Purinergic systems in microglia

Accumulating findings indicate that nucleotides play an important role in microglia through P2 purinoceptors. P2 purinoceptors are divided into two families, ionotropic receptors (P2X) and metabotropic receptors (P2Y). P2X receptors (7 types; P2X₁ – P2X₇) contain intrinsic pores that open by binding with ATP. P2Y receptors (8 types; P2Y_{1, 2, 4, 6, 11, 12, 13 and 14}) are activated by nucleotides and couple to intracellular second-messenger systems through heteromeric G-proteins. Nucleotides are released or leaked from non-excitable cells as well as neurons in physiological and pathophysiological conditions. Microglia express many types of P2 purinoceptors and are known as resident macrophages in the CNS. ATP and other nucleotides work as ‘warning molecules’ especially through activating microglia in pathophysiological conditions. Microglia play a key role in neuropathic pain, chemotaxis and phagocytosis through nucleotide-evoked activation of P2X₄, P2Y₁₂ and P2Y₆ receptors, respectively. These findings indicate that extracellular nucleotides are important players in the central stage of microglial function. Received 19 April 2008; received after revision 20 May 2008; accepted 23 May 2008     

Autotaxin (NPP-2) in the brain: cell type-specific expression and regulation during development and after neurotrauma

Autotaxin is a secreted cell motility-stimulating exo-phosphodiesterase with lysophospholipase D activity that generates bioactive lysophosphatidic acid. Lysophosphatidic acid has been implicated in various neural cell functions such as neurite remodeling, demyelination, survival and inhibition of axon growth. Here, we report on the in vivo expression of autotaxin in the brain during development and following neurotrauma. We found that autotaxin is expressed in the proliferating subventricular and choroid plexus epithelium during embryonic development. After birth, autotaxin is mainly found in white matter areas in the central nervous system. In the adult brain, autotaxin is solely expressed in leptomeningeal cells and oligodendrocyte precursor cells. Following neurotrauma, autotaxin is strongly up-regulated in reactive astrocytes adjacent to the lesion. The present study revealed the cellular distribution of autotaxin in the developing and lesioned brain and implies a function of autotaxin in oligodendrocyte precursor cells and brain injuries. Received 18 September 2006; received after revision 30 October 2006; accepted 4 December 2006     

The Membrane Protein Data Bank

The Membrane Protein Data Bank (MPDB) is an online, searchable, relational database of structural and functional information on integral, anchored and peripheral membrane proteins and peptides. Data originates from the Protein Data Bank and other databases, and from the literature. Structures are based on X-ray and electron diffraction, nuclear magnetic resonance and cryoelectron microscopy. The MPDB is searchable online by protein characteristic, structure determination method, crystallization technique, detergent, temperature, pH, author, etc. Record entries are hyperlinked to the PDB and Pfam for viewing sequence, three-dimensional structure and domain architecture, and for downloading coordinates. Links to PubMed are also provided. The MPDB is updated weekly in parallel with the Protein Data Bank. Statistical analysis of MPDB records can be performed and viewed online. A summary of the statistics as applied to entries in the MPDB is presented. The data suggest conditions appropriate for crystallization trials with novel membrane proteins. Received 3 August 2005; received after revision 18 September 2005; accepted 26 September 2005 This paper and the Membrane Protein Data Bank celebrate the 20^th anniversary of the landmark paper in Nature (1985, 318: 618–624) describing the first ‘high-resolution’ three-dimensional structure of a membrane protein, the photosynthetic reaction center from Rhodopseudomonas (Blastochloris) viridis.