BDNF 和 TERT 联合转染 BMSCs 对血管性痴呆大鼠学习记忆功能恢复及海马 CA1 区超微结构的影响

目的：研究脑源性神经营养因子（BDNF）和端粒酶逆转录酶（TERT）联合转染的骨髓基质干细胞（BMSCs）对血管性痴呆（VD）大鼠学习记忆功能恢复的作用,进一步探讨VD的有效治疗途径。方法：经大鼠股骨分离并鉴定BMSCs,构建pLXSN—TERT重组子后转化至BMSCs,软琼脂克隆形成实验检测体外培养的TERT—BMSCs的成瘤性。应用Ad5一BDNF转染TERT—BMSCs,构建BDNF—TERT联合转染的BMSCs。将40只雄性Wistar大鼠随机分为4组：对照组、VD组、BMSCs组、BDNF—TERT—BMSCs组。采用两血管阻断法制备VD模型。采用Morns水迷宫测试方法测试各组大鼠空间学习记忆力。应用RT—PCR和Westemblot方法分别检测各组大鼠海马CA1区BDNF、TrkB、SYN基因mRNA和蛋白表达情况,应用透射电镜观察各组大鼠海马CAl区超微结构变化。结果：行为学实验Mo州s水迷宫测试结果及超微病理透射电镜观察均显示BMSCs和BDNF—TERT—BMSCs对血管性痴呆大鼠有改善作用,且BDNF—TERT—BMSCs较BMSCs的作用更为显著。荧光实时定量RT—PCR和Westernblot结果显示,BMSCs组和BDNF—TERT—BMSCs组中BDNF、TrkB、SYNmRNA及蛋白表达水平均较痴呆模型组增高（P〈0．05）,且BDNF—TERT—BMSCs组较BMSCs组增加更为显著,差异有统计学意义（P〈0．05）。结论：BDNF—TERT联合转染BMSCs较普通的BMSCs对VD有更好的治疗效果,可明显改善VD大鼠的学习记忆功能的恢复。     

Prognostic significance of immunohistochemical markers in adrenocortical carcinoma

Abstract

Background: To present basic demographic and clinical characteristics of patients with adrenocortical carcinoma (ACC), to determine the overall survival rate and to analyze the results of immunohistochemical staining and its correlation with the length of survival.

Material and methods: The study was conducted during the period between 1996 and 2010 and included 30 patients with ACC. Immunohistochemical staining (MMP9, melan A, inhibin, caltretinin, D2-40, synaptophysin and Ki-67) was performed.

Results: ACC was diagnosed in 19 females and 11 men (1.7:1). The average age was 50.1 years. The median tumor size was 10?cm, the median weight 400?g. Majority of subjects had positive immunohistochemical staining for the markers of interest. Patients with any negative staining had shorter cancer-specific survival than ones with positive staining. According to the log-rank test results as well as according to the results of the univariate Cox analysis, negative staining for inhibin, D2-40 and synaptophysin and Ki-67 expression ≥7% were associated with poorer prognosis.

Conclusions: The results of our study suggest that the absence of staining for some immunohistochemical markers and increased expression of Ki-67 are associated with a poorer prognosis and shorter survival of patients with ACC. Immunohistochemical markers may serve as a prognostic factor for ACC.     

Stable maintenance of glutamate receptors and other synaptic components in long-term hippocampal slices

Cultured hippocampal slices retain many in vivo features with regard to circuitry, synaptic plasticity, and pathological responsiveness, while remaining accessible to a variety of experimental manipulations. The present study used ligand binding, immunostaining, and in situ hybridization assays to determine the stability of AMPA- and NMDA-type glutamate receptors and other synaptic proteins in slice cultures obtained from 11 day postnatal rats and maintained in culture for at least 4 weeks. Binding of the glutamate receptor ligands [³H]AMPA and [³H]MK-801 exhibited a small and transient decrease immediately after slice preparation, but the binding levels recovered by culture day (CD) 5–10 and remained stable for at least 30 days in culture. Autoradiographic analyses with both ligands revealed labeling of dendritic fields similar to adult tissue. In addition, slices at CD 10–20 expressed a low to high affinity [³H]AMPA binding ratio that was comparable with that in the adult hippocampus (10:1). AMPA receptor subunits GluR1 and GluR2/3 and an NMDA receptor subunit (NMDAR1) exhibited similar postcutting decreases as that exhibited by the ligand binding levels, followed by stable recovery. The GluR4 AMPA receptor subunit was not evident during the first 10 CDs but slowly reached detectable levels thereafter in some slices. Immunocytochemistry and in situ hybridization techniques revealed adult-like labeling of subunit proteins in dendritic processes and their mRNAs in neuronal cell body layers. Long-term maintenance was evident for other synapse-related proteins, including synaptophysin, neural cell adhesion molecule isoforms (NCAMs), and an AMPA receptor related antigen (GR53), as well as for certain structural and cytoskeletal components (e. g., myelin basic protein, spectrin, microtubule-associated proteins). In summary, following an initial and brief depression, many synaptic components were expressed at steady-state levels in long-term hippocampal slices, thus allowing the use of such a culture system for investigations into mechanisms of brain synapses. © 1995 Wiley-Liss, Inc.     

Synaptic and photoreceptor components in retinal pigment epithelial cell transplanted retinas of Royal College of Surgeons dystrophic rats

Plexiform layer synaptic and photoreceptor cell components were investigated in retinas of Royal College of Surgeons (RCS) dystrophic rats transplanted with normal retinal pigment epithelial (RPE) cells by immunocytochemistry using previously characterized monoclonal antibodies. In retinas of normal adult rats and RPE-cell transplanted retinas of 4 month-old RCS rats, HNK-1, a marker for a carbohydrate of the neural cell adhesion molecule (N-CAM), was detected immunocytochemically in the inner and outer plexiform layers and ganglion cell bodies and their axons. HNK-1 was also detected in the inner plexiform layer of nontreated retinas of 4 month-old RCS rats, but was reduced to scattered patches in the outer plexiform layer. In addition, immunoreactivity for the SVP-38 antibody recognizing synaptophysin was found in both plexiform layers of normal adult rat retinas and RPE-transplanted retinas of 4 month-old RCS rats. Furthermore, photoreceptor cell bodies and their inner and outer segments were immunostained for the opsin monoclonal antibody RET-P1 in retinas of normal adult rats and RPE-cell transplanted retinas of 4 month-old RCS rats. However, in nontreated retinas of 4 month-old RCS rats, only immunostained debris material was detected. These results strongly suggest that normal RPE transplants not only rescue photoreceptor cells in RCS rats, but also maintain an essential functional capacity, in this case, synaptic components in the plexiform layers. © 1993 Wiley-Liss, Inc.     

Expression of synaptophysin and neuron-specific enolase during neuronal differentiation in vitro: effects of dimethyl sulfoxide

Neural development in dissociated cell cultures of fetal rat brain can be expected to depend on synaptic interactions between cultured neurons. Therefore, an attempt was made to obtain a quantitative measure of the time course of synaptogenesis in such a culture system by assessing the level of the secretory vesicle-associated protein synaptophysin (p38). The developmental schedule of p38 was compared to that of neuron-specific enolase (NSE), an established marker of neuronal differentiation. Cultures were raised from dissociated 14 day-old fetal rat diencephalon. In cultures grown for 1-2 days in vitro (DIV), p38-immunoreactivity was preferentially located in neuronal perikarya. After 10-16 DIV, neurons in culture had formed a dense neuritic network, and almost all of the p38-immunoreactivity occurred in the form of fine punctate deposits associated with neuronal processes that often outlined neuronal cell bodies in a basket-like fashion. Electron-microscopic immunocytochemistry proved the punctate deposits to be presynaptic elements, mostly in the form of axonal varicosities. Quantitative immunoblotting showed that levels of p38 increased from the start of cultivation to DIV 4, stayed fairly constant from DIV 4 to DIV 8, and rose again steeply to peak at DIV 12. In contrast, levels of NSE rose continuously up to DIV 12. After DIV 12, levels of both p38 and NSE fell again. Treatment of cultures with dimethyl sulfoxide (DMSO), an agent known to induce differentiation in various normal and malignant cell types, resulted in a significant increase of p38 levels and in a decrease of NSE levels. The amount of p38 continued to increase beyond DIV 12, whereas NSE diminished after having reached a maximum at DIV 12.(ABSTRACT TRUNCATED AT 250 WORDS)     

Regeneration of Hypoglossal Nerve Axons Following Blockade of the Axotomy-induced Microglial Cell Reaction in the Rat

The aim of the present study was to examine whether inhibition of the microglial cell reaction around axotomized motoneurons affects the subsequent regeneration process of the injured axons. The microglial cell reaction in the hypoglossal nucleus of the rat was blocked by infusion of cytosine-arabinoside (ARA-C) into the ventricular system. Axon regeneration was evaluated by determining the number and size distribution of myelinated axons at a defined level distal to the crush site, the number of neurons which could be retrogradely labelled from the distal stump as well as the number of motor endplates in the tongue at various times following injury. No significant difference was observed for any of these parameters between ARA-C-treated and untreated animals. Therefore, it is concluded that the microglial cell reaction is not necessary for peripheral nerves to regenerate and restore target contact at a normal rate and to a normal extent.     

Neural cell adhesion molecule and D3 protein in the cerebellum of weaver mutant mice

Weaver (wv/wv) mutant mice are characterized by extensive granule cell degeneration and can therefore be used as a model for brain degeneration that does not involve blood-brain barrier damage. The ontogeny of the neural cell adhesion molecule (NCAM) and the neuronal antigen D3 protein were investigated in cerebellum and forebrain of weaver mutant mice up to post-natal day 60. In the forebrain the concentration of both proteins was virtually unchanged. In cerebellum, in contrast, the concentration of D3 decreased markedly whereas that of NCAM remained unchanged. Similar findings were obtained at post-natal day 30 in the cerebellum of other neurologic mutants, namely the staggerer (sg/sg) and reeler (rl/rl). At this age the concentration of a synaptic vesicle marker, synaptophysin. was severely decreased in the cerebellum of all three mutants. The concentration of neuron-specific enolase was less affected, whereas the concentrations of the glial markers glutamine synthetase and glial fibrillary acidic protein were both increased. The concentration ratio, which probably reflects the ongoing rate of synaptic remodelling, was increased during the whole ontogeny of weaver mutant mice as compared with heterozygous controls. At post-natal day 30, the ratio was increased by 180% in weaver, by 170% in staggerer and by 60% in reeler cerebellum. These findings lend further support to the usefulness of the ratio as a marker of neural plasticity and synaptic remodelling in both animals and man.     

Treatment with phytoestrogen alpha-zearalanol might protect neurons of hippocampus in ovariectomized rats

Although neuroprotective effects of estrogen on postmenopausal women have been recognized, an associated increased incidence of uterine and breast tumors has jeopardized the clinical use of estrogen. This study was designed to evaluate the neuroprotective effects of a novel phytoestrogen α-zearalanol (α-ZAL), on ovariectomized (OVX) rats. Adult Wistar rats were ovariectomized or sham-operated and treatment with equivalent doses of 17β-estradiol or α-ZAL for 5 wk. Uteruses have been weighted and stained by hematoxylin and eosin for morphology analysis. The expression of synaptophysin and parvalbumin in hippocampus were evaluated by immunohistochemistry assays. Our experiments indicated that the synaptophysin and paravalbuminpositive areas were significantly decreased in the OVX group compared to the sham group, α-ZAL or 17β-estradiol administration can reverse the effects. Although α-ZAL and 17β-estradiol treatments reconciled uterus weight loss which was induced by ovariectomy, the effect of α-ZAL was less than 17β-estradiol. This result suggests that α-ZAL may effectively abate neurons loss in the hippocampus while slightly promoting weight gain of the uterus. Yi-Long Dong and Yun Yue contributed equally to this work.     

突触可塑性在血管性认知障碍中的作用

突触损伤在血管性认知障碍(vascular cognitive impairment, VCT)发病的早期即存在,与认知功能障碍关系密切,其具体机制尚不明确.研究突触形态结构的可塑性、突触传递效能的可塑性以及突触蛋白在VCI发病中的作用和机制,有助于进一步阐明VCI的发病机制,从而更有效地防治VCI.