Differential regulation of cytokine genes in gingival epithelial cells challenged by Fusobacterium nucleatum and Porphyromonas gingivalis

IL-8 mRNA in human gingival epithelial cells (HGECs) is up-regulated by Fusobacterium nucleatum, and up-/down-regulated by Porphyromonas gingivalis in a complex interaction in the early stages (< or = 4 h) after infection. The mechanisms involved in this regulation in response to F. nucleatum and/or P. gingivalis infection, and identification of co-regulated cytokine genes, are the focus of this investigation. Heat, formalin or protease treatment of F. nucleatum cells attenuated the IL-8 mRNA up-regulation. NF-kappaB, mitogen-activated protein kinase (MAPK) p38 and MAPK kinase/extracellular signal-regulated kinase (MEK/ERK) pathways were involved in IL-8 mRNA induction by F. nucleatum. Pretreatment of P. gingivalis with heat, formalin or protease enhanced IL-8 mRNA induction. NF-kappaB, MARK p38, and MEK/ERK pathways were also involved in this induction. In contrast, down-regulation of IL-8 mRNA by P. gingivalis involved MEK/ERK, but not NF-kappaB or MAPK p38 pathways. cDNA arrays analysis revealed that mRNA down-regulation by P. gingivalis is a specific reaction that only a number of genes, e.g. IL-1beta, IL-8, macrophage inflammatory protein-2alpha, and migration inhibitory factor-related protein-14, are affected based on examination of 278 cytokine/receptor genes. These data indicate that F. nucleatum and P. gingivalis trigger specific and differential gene regulation pathways in HGECs.     

BicD-dependent localization processes: from Drosophilia development to human cell biology

Many eukaryotic cells depend on proper cell polarization for their development and physiological function. The establishment of these polarities often involve the subcellular localization of a specific subset of proteins, RNAs and organelles. In Drosophila, the microtubule-dependent BicD (BicaudalD) localization machinery is involved in the proper localization of mRNA during oogenesis and embryogenesis and the proper positioning of the oocyte and photoreceptor nuclei. BicD acts together with the minus-end directed motor dynein as well as Egl and Lis-1. The finding that the mammalian homologs of BicD function in retrograde Golgi-to-ER transport has supported the view that BicD may be part of a repeatedly used and evolutionary conserved localization machinery. In this review we focus on the various processes in which BicD is involved during Drosophilian development and in mammals. In addition, we evaluate the interactions between BicD, the dynein localization machinery and associated factors.     

人外周血淋巴细胞激活与CD2mRNA表达

对 PHA、抗 CD3单克隆抗体 RW2—8C8、胸腺肽、抗 CD2与抗 CD3等对人 T 淋巴细胞的增殖现象及动力学进行了观察,除抗 CD3与抗 CD2单抗联合应用为抑制效应外,前三者均呈正效应且动力学完全一致.在此基础上,应用反义 CD2mRNA 探针检测了 mRNA 在激活24小时以后的变化,发现 T 细胞活化者均显示 mRNA 量呈上升;反之则不见变化或低于未激活 T 细胞对照组水平.本研究证明了小牛胸腺肽有激活 T 细胞和提高 mRNA 水平的作用,为首次报导.本文对上述在基因水平上观察的结果进行了讨论.     

含生长抑素mRNA神经元在移植视网膜发育中的表达

将６０例鼠龄１４ｄＳＤ大鼠视网膜移植到出生后１ｄ大鼠中脑偏左侧处，同时摘除新生鼠的右眼。术后１０ｄ至２２ｄ分别取移植视网膜及其中脑，在相应的年龄取正常视网膜作对照，应用原位杂交组化技术──地高辛标记的生长抑素的ｃＲＮＡ探针检测移植和正常视网膜中含生长抑素ｍＲＮＡ神经元出现时间、发育规律及定位分布。同时用免疫组化方法显示生长抑素免疫反应神经元的形态，以作对照和补充。原位杂交组化实验结果表明：在出生当天的移植视网膜节细胞层已出现阳性表达，出生后４ｄ，外核层也出现小的含生长抑素ｍＲＮＡ神经元，此种神经元随后减少、消失；与此同时内核层及节细胞层内含生长抑素ｍＲＮＡ神经元逐渐增多，至生后１２ｄ接近成年水平。通过对非移植大鼠视网膜进行正常对照观察，移植视网膜与非移植的正常视网膜生后发育的结果相似。生长抑素免疫反应神经元与原位杂交含生长抑素ｍＲＮＡ神经元的表达部位是一致的，但生长抑素免疫反应神经元可见其突起。     

老龄大鼠内侧隔核TrkB mRNA的表达及人参皂甙的保护作用

目的:探讨人参皂甙对老龄大鼠内侧隔核TrkB mRNA表达的影响,为老年记忆减退性疾病的发病机制及人参皂甙的临床应用提供分子生物学基础。方法:选用Wistar大鼠,分成青年组、老龄组、给药组,采用原位杂交组织化学方法检测大鼠内侧隔核TrkB mRNA含量的变化情况。结果:老龄组内侧隔核TrkB mRNA阳性反应物的平均灰度值与青年组相比呈非常显著增高,而给药组的平均灰度值比老龄组呈显著降低。结论:老龄时内侧隔核TrkB mRNA表达低于青年组,而给药组较老龄组明显增加。说明人参皂甙具有增强TrkB mRNA表达,防止中枢神经系统神经元退行性改变的作用。