ERK1/2信号通路参与人滋养层细胞中转化生长因子-β1对MMP-9表达的抑制作用(英文)

正常滋养层细胞的侵润受转化生长因子-β(TGF-β)的调控。该文研究了人正常细胞滋养层细胞(CTB)中TGF-β1对MMP-2和-9表达的调控。结果表明,TGF-β1抑制CTB细胞中MMP-9mRNA的表达和酶原MMP-9的分泌,但不影响MMP-2 mRNA和蛋白的表达。IL-1β和TGF-β1均能抑制MMP-9 mRNA的表达和酶原MMP-9的分泌,但二者的效应互相拮抗。抑制ERK1/2信号通路导致TGF-β1对MMP-9 mRNA和酶原MMP-9的抑制作用受阻。以上结果表明ERK1/2信号通路参与TGF-β31对人滋养层细胞MMP-9表达的抑制作用。     

去整合素基质金属蛋白酶19抑制人正常胎盘来源滋养层细胞的侵润能力

去整合素基质金属蛋白酶19(ADAM-19)是新近发现的ADAMs家族成员,在胎盘组织中有较高水平的表达,但其在胎盘发生过程和滋养层细胞侵润中的功能还是未知的.我们以人正常胎盘来源的细胞滋养层细胞(NPC)为体外模型,利用基因转染、RT-PCR、蛋白质印迹、免疫组织化学及细胞侵润分析等手段,证实ADAM-19在人胎盘组织中有特异表达,存在于多种滋养层细胞中;转化生长因子β1(TGF-β1)可以显著上调NPC细胞中ADAM-19的表达,呈现剂量依赖性;过表达hADAM-19可使NPC细胞中MMP-9的mRNA和蛋白质表达下调,并降低细胞的侵润能力.研究结果表明,人滋养层细胞中存在ADAM-19表达的旁分泌调节机制,而ADAM-19在调节滋养层细胞侵润中发挥一定作用.这一结果为阐明ADAM-19在胎盘发生中的功能提供了新的科学资料.     

金属蛋白酶-2(MMP-2)和金属蛋白酶抑制因子(TIMP-1,-3)mRNA在小鼠胎盘中的表达

本实验利用原位杂交对小鼠妊娠不同时期胎盘中MMP－2,TIMP－2,－3mRNA的表达进行了研究。结果表明;MMP－2主要在具有很强的侵润能力的海绵滋养层细胞中表达,到妊娠13．5天时,MMP－2的表达明显降低,说明此时的滋养层细胞基本上失去侵润能力。TMIP－1和TMIP－3在滋养层细胞和蜕膜细胞中都有表达,这两种抑制因子的协同表达,一方面能够调控滋养层细胞侵入子宫内膜的深度,另一方面,滋养层细胞自身既表达MMP－2又表达TIMPs,可能对其自身有保护作用,使得MMP的水解功能局限于子宫蜕膜的特定区域。在妊娠10．5天,滋养层巨细胞同时表达TIMP－1,－3mRNA,这可能与其功能的转换是一致的;因为此时小鼠滋养层巨细胞体积最大,且不再增殖,同时其功能屯从侵入型向内分泌型转换。所以,MMPs和TIMPs在小鼠滋养层细胞和子宫蜕膜中的协同表达表明其在着床过程中可能发挥重要作用。     

TGF-β1对人正常胎盘滋养层细胞表达E-钙粘素的调节

E-钙粘素是在胚胎发育中最早表达的分子之一,它可以与Catenin家族成员形成钙粘素/Catenin复合物参与多种细胞功能,对于胚胎植入和胎盘发生具有重要作用.通过RT-PCR、免疫组织化学、细胞粘附分析等方法,在人正常妊娠和输卵管妊娠母胎界面上,发现E-钙粘素主要定位于绒毛细胞滋养层细胞和滋养层细胞柱,从滋养层细胞柱近端向远端,其蛋白质水平逐渐降低.正常胎盘组织中E-钙粘素水平在妊娠早期较高,妊娠中期直至分娩期均维持低水平.在体外培养的人正常胎盘细胞滋养层细胞系(NPC细胞)中,转化生长因子β(TGFβ1)显著上调E-钙粘素蛋白和mRNA的表达,并呈现时间和剂量依赖性,同时,TGFβ1促进NPC细胞之间的粘附.上述结果表明,胎盘中存在E-钙粘素的旁分泌调节机制,E-钙粘素可通过调节滋养层细胞粘附而参与细胞侵润的有节制调控.     

促性腺激素释放激素(GnRH)对人绒毛膜上皮癌细胞系JEG-3侵润性的调节

促性腺激素释放激素(gonadotropin-releasing hormone,GnRH)是生殖过程中起重要调节作用的激素．近年来的研究发现,Ⅰ型GnRH(GnRHⅠ)和Ⅱ型GnRH(GnRHⅡ)在胎盘和胎盘来源的滋养层细胞中发挥生理功能．利用人滋养层细胞模型人绒毛膜上皮癌细胞系(JEG-3)细胞,探讨GnRHⅠ和GnRHⅡ对人滋养层细胞侵润的调节作用．荧光实时定量PCR证实,GnRHⅠ和GnRHⅡ可调节JEG-3细胞中经典GnRH受体(GnRHRⅠ)的表达．RNA干扰实验显示,特异性针对GnRHRⅠ的siRNA可显著阻断GnRHⅠ对JEG-3细胞的促侵润作用,但不能影响GnRHⅡ的促细胞侵润功能,提示GnRHⅡ可能通过经典GnRH受体以外的其他受体介导,以发挥促进滋养层细胞侵润的功能．对信号通路的进一步研究表明,GnRHⅠ和GnRHⅡ通过ERK和JNK激酶级联促进基质金属蛋白酶-2(MMP-2)的表达,以调节细胞的侵润．     

MMP-26 在人正常胎盘滋养层细胞中的表达及激活素 A 对其表达的调节

胚胎植入和胎盘形成涉及细胞外基质的降解和重建,以及细胞的增殖、凋亡、迁移和分化,基质金属蛋白酶 (MMPs) 是参与这些事件的主要蛋白水解酶系统 . MMP-26 是近年来发现的 MMPs 家族的新成员,但其功能所知甚少 . 通过半定量 RT-PCR 、免疫组织化学、荧光免疫细胞化学等手段,发现人胎盘中 MMP-26 主要定位于绒毛滋养层细胞,在绒毛间质细胞中也有少量表达 . 妊娠早期,胎盘中 MMP-26 表达水平较高,至妊娠中期降至最低,但在足月胎盘中其表达又有显著提高,提示 MMP-26 可能参与妊娠早期滋养层细胞的侵润和分娩时的胎盘剥离 . 体外培养的妊娠早期人细胞滋养层细胞能产生一定水平的 MMP-26 ,而其表达受到激活素 A 的剂量依赖性刺激,表明滋养层细胞中存在 MMP-26 表达的自分泌 / 旁分泌调节 .     

层粘连蛋白(LN)和纤维连接蛋白(FN)在植入期地鼠子宫内膜中的表达——形态学和免疫组织化学研究

选用未孕及怀孕4－8天地鼠子宫内膜,用组织学、免疫组织化学染色及图像分析法,研究植入前后地鼠子宫内膜中LN、FN分布及含量的变化,探讨其与植入过程的相关关系。结果：在未孕地鼠,LN主要分布于宫内膜各类上皮基膜内,FN存在于基膜及细胞外基质中。孕4－8天,各类上皮基膜中LN、FN表达明显增多,与未孕地鼠相比,差异显（P＜0.01）。随着蜕膜形成,蜕膜（基质）细胞周围LN及FN表达增多。上述结果表明,LN、FN与植入过程及蜕膜功能密切相关。     

葛根素对糖尿病大鼠肾组织MMP-2的表达及活性的影响

为探讨葛根素对糖尿病大鼠肾组织基质金属蛋白酶2(MMP-2)及活性表达的影响,采用单侧肾切除大鼠ip链脲佐菌素诱发糖尿病模型的方法,每日ip葛根素注射液,共16周。采用原位杂交法检测肾小球MMP-2、TIMP-2mRNA表达,流式细胞术和免疫组织化学检测肾皮质MMP-2、TIMP-2及Ⅳ型胶原表达;酶谱分析检测肾皮质MMP-2活性变化。结果发现糖尿病组较对照组肾小球MMP-2mRNA及蛋白表达降低而TIMP-2mRNA及蛋白表达升高,Ⅳ型胶原表达亦增加,MMP-2活性降低,肾功能恶化;葛根素用药组较糖尿病组MMP-2mRNA及蛋白表达升高而TIMP-1、Ⅳ型胶原表达减少,MMP-2活性部分恢复,肾功能改善。表明葛根素可能部分是通过调节肾小球MMP-2蛋白表达及活性的改变从而减轻肾小球细胞外基质沉积,保护糖尿病大鼠的肾功能和形态。     

葛根素对糖尿病大鼠肾功能及肾组织MMP-3、TIMP-1表达的影响

目的 探讨葛根素对糖尿病大鼠肾小球结构、功能及肾组织基质金属蛋白酶3(MMP-3)、组织抑制剂1(TIMP-1)表达的影响。方法 腹腔注射链脲佐菌素诱发大鼠糖尿病模型,每日ip葛根素注射液,共16周。采用原位杂交法检测肾小球TIMP-1 mRNA表达,流式细胞术和免疫组化检测肾皮质MMP-3、TIMP-1及Ⅳ型胶原、层粘连蛋白表达。结果 糖尿病组较对照组肾小球TIMP-l mRNA及蛋白表达增加,MMP-3、TIMP-1及Ⅳ型胶原、层粘连蛋白表达亦增加;葛根素用药组较糖尿病组TIMP-1 mRNA、蛋白及MMP-3、Ⅳ型胶原、层粘连蛋白表达减少。结论 葛根素对糖尿病大鼠肾功能、形态的影响具有保护作用,除降低血糖外,调节肾小球MMP-3、TIMP-1表达式从而减轻肾小球细胞外基质沉积也可能是其作用途径之一。     

基质金属蛋白酶-9及其抑制剂mRNA在吸烟大鼠肺组织中的表达

目的 研究吸烟大鼠肺组织和肺泡巨噬细胞中基质金属蛋白酶9(MMP-9)和金属蛋白酶组织抑制剂-1(TIMP-1)基因的表达,探讨其在细胞外基质重塑中的作用。方法 建立吸烟大鼠模型,随机分为对照组和吸烟1、2、3、4、5及6月组(每组10只),用原位杂交技术检测肺组织和肺泡巨噬细胞MMP-9和TIMP-1 mRNA表达,用免疫组织化学技术观察Ⅳ型胶原在肺内的表达。结果 吸烟组肺组织和肺泡巨噬细胞MMP-9 mRNA的表达逐渐上升,至吸烟6月时均达高峰;而TIMP-1 mRNA的表达渐上升,至吸烟3～4月时达高峰,后逐步下降;肺组织Ⅳ型胶原的表达在吸烟3月时达高峰,然后渐降。结论 MMP-9／TIMP-1的动态平衡在吸烟大鼠肺气肿模型肺组织的细胞外基质重塑中有重要作用。     

Ectogenesis and the case against the right to the death of the foetus

Ectogenesis, or the use of an artificial womb to allow a foetus to develop, will likely become a reality within a few decades, and could significantly affect the abortion debate. We first examine the implications for Judith Jarvis Thomson’s violinist analogy, which argues for a woman’s right to withdraw life support from the foetus and so terminate her pregnancy, even if the foetus is granted full moral status. We show that on Thomson’s reasoning, there is no right to the death of the foetus, and abortion is not permissible if ectogenesis is available, provided it is safe and inexpensive. This raises the question of whether there are persuasive reasons for the right to the death of the foetus that could be exercised in the context of ectogenesis. Eric Mathison and Jeremy Davis have examined several arguments for this right, doubting that it exists, while Joona Räsänen has recently criticized their reasoning. We respond to Räsänen’s analysis, concluding that his arguments are unsuccessful, and that there is no right to the death of the foetus in these circumstances.     

On the diversity of the Cladocera in the tropics

The mythical concept of an impoverished tropical cladoceran fauna is refuted. On a planetary scale, around half of the cladoceran species presently known occur exclusively in the tropics-subtropics, often with considerable restriction to particular geographical subzones. On a regional (political) scale, the situation is often unclear because of the continued fragmentary nature of studies, and because political units are not a good basis for biogeographical comparisons. At the finest level of resolution (lake-perlake comparisons), there appears to be an upper limit of c. 50 cladoceran species per individual lake. No significant difference between lakes in the temperate zone and in the tropics could be established here. Daphnia is largely absent from the tropics, but is replaced by more Sidids, Moinids, and Bosminids, such that the average cladoceran community in the limnetic zone of a tropical lake is not characterized by less species but rather by lower population densities. This, in turn, is considered a consequence of higher prevalent predation levels in the tropics.     

Tubular networks in the terminal endings of the visual receptor cells in the human,the monkey,the cat and the dog

Summary A tubular network was found in the terminal endings of the visual receptor cells in the human, the monkey (Macaca mulatta), the cat and the dog. These tubules are arranged in close groups in the vicinity of the synaptic lamellae and the invaginated dendrites. According to the form, diameter, density of the tubules and to the consistence of the network formed by them one can distinguish at these places an initial type (type I), a transitory (type II) and a vesicular one (type III). In the the type III branching, bizarre forms are frequent. The diameter of all the tubules reaches 500–600 Å, their density and walls being the same as in the synaptic vesicles.Similar networks also occur in the axons of the visual receptor cells of the monkey.

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Zusammenfassung In den Endigungen der Photorezeptorzellen von Mensch, Affe (Macaca mulatta), Katze und Hund kommen aus Tubuli bestehende Komplexe vor. Organellenartig in geschlossenen Gruppen angeordnet, liegen sie in Nähe der synaptischen Lamellen und der invaginierten Dendriten. An diesen Stellen kann man nach Form, Durchmesser, Dichte und Konsistenz der von den Tubuli gebildeten Komplexe drei Typen unterscheiden: 1. einen initialen (Typus I), 2. einen Übergangstypus (Typus II) und 3. einen vesiculären Typus (Typus III). In letzterem kommen häufig verzweigte, bizarre Formen vor. Der Durchmesser sämtlicher Tubuli erreicht 500–600 Å. Ihre Dichte und ihre Wand gleicht denen der synaptischen Vesikel.Ähnliche Komplexe fanden wir auch in den Axonen der Photorezeptorzellen vom Affen.

     

Assessing the Physiological State of the Fucoids from the Barents Sea Littoral by the End of the Polar Night

Methods of amperometry and potentiometric titration were used to follow dark respiration (DR) and apparent photosynthesis (AP) in the fucoids Ascophyllum nodosum (L.) Le Jol, Fucus vesiculosus L., and F. serratus L. from the Barents Sea littoral by the end of the 40-day-long polar night. The macroalgae were shown to manifest species-specific low rates of photosynthesis and respiration. However, in spite of their low photosynthetic status due to the effects of subzero temperature and prolonged low or zero illumination, the macroalgae have been able to restore DR and AP to the initial level already by the day 9; the ability to restore AP depended on the level of illumination. The study of the changes in the carbonate–bicarbonate system in the light and darkness demonstrated that the macroalgae grown in darkness, in contrast to those grown in twilight, could absorb bicarbonate in darkness; however, they lost this capacity after two-day-long illumination at an irradiance of 7 mol/(m² s). Bicarbonate uptake in darkness and the capacity to restore the systems of photosynthesis and respiration in fucoid cells are discussed in the context of algal energy metabolism under the polar night conditions.     

Arranging the elements of the potassium channel: the T1 domain occludes the cytoplasmic face of the channel

The voltage-gated potassium channel is currently one of the few membrane proteins where functional roles have been mapped onto specific segments of sequence. Although high-resolution structures of the transmembrane portions of three bacterial potassium channels, the tetramerization domain and the cytoplasmic ball are available, their relative spatial arrangement in mammalian channels remains a matter of ongoing debate. Cryo-electron microscopic images of the six transmembrane voltage-gated Kv channel have been reconstructed at up to 18 Å resolution, revealing that the T1 domain tetramerizes and is suspended below the transmembrane segments. However, the resolution of these images is insufficient to reveal the location of the third piece of the puzzle, the inactivating ball domain. We have used the aberrant interactions observed in a series of chimæric channels to establish that an assembled T1 domain restricts access to the cytoplasmic face of the channel, suggesting that the N-terminal ball and chain may be confined in the space between the T1 domain and the transmembrane portion of the channel.     

Feeding the vertebrate retina from the Cambrian to the Tertiary

The retina of the vertebrate eye is metabolically active and requires nutritive support. During the last 540 million years it has evolved into forms as complicated and nutritionally demanding as those found in avian or primate eyes. Diffusion from the choroid is generally able to supply the metabolic needs of thin retinae. However, when the thickness exceeds the limits of diffusion, structures are needed to supplement the vascular supply from the choroid. These supplemental nutritive devices include the choroidal gland, the falciform process and preretinal vascular plexus of fish, the conus papillaris of lizards, the pecten oculi of birds, the intraretinal vessels of mammals and a few novel systems that remain difficult to classify. These vascular systems are among the most variable features of the vertebrate eye. Here, we review classical and recent findings regarding such retinal nutrition systems, propose a three category classification for them based on histologic origins and speculate on the evolutionary forces which drove their development.     

Observations on the permeability of the choriocapillaris of the eye

Summary The choriocapillaris is a fenestrated capillary bed located posterior to the retinal pigment epithelium. It serves as the main source of supply to the photoreceptors, retinal pigment epithelium, and other cells of the outer retina. The permeability of these capillaries to intravenously injected ferritin (MW — approx. 480,000; mol. diam. 11 nm) was examined in the mouse, rabbit, and guinea pig, each of which is characterized by a different type of retinal vascularization. In all three species, the bulk of the ferritin remained in the capillary lumina, where it appeared to be blocked at the level of the diaphragmed fenestrae. Some ferritin was present in endothelial cell vacuoles. The results confirm previous work on the rat choriocapillaris and indicate that the barrier function of the choriocapillary endothelium is present even among species in which the retinal circulation differs significantly.Supported by NIH grant EY03418     

Separation of the pineal vesicle from the wall of the third ventricle during the post-hatching development of the chicken

Summary According to light- and electron-microscopic observations the pineal organ of the 3-day-old chicken consists of a prominent end vesicle and a tapering parenchymal stalk. During this stage the pineal lumen is in open communication with the third ventricle. However, in the 40-day-old chicken, which still possesses a well-developed end vesicle, the proximal portion of the pineal stalk displays regressive changes leading to local fragmentation. At this stage the pineal stalk is reduced, and the pineal lumen is missing. In 1-year-old chickens the parenchyma of the proximal portion of the stalk is further diminished, and in 3-year-old domestic fowl is completely displaced by bundles of collagenous fibers, only some nerve fibers being present. This post-hatching pineal development may reflect the sequence of changes leading from pineal sense organs to pineal glands.This work was supported by a grant-in-aid for Scientific Research from the Ministry of Education, Science and Culture of Japan