NEP1-40促进高苯丙氨酸损伤大鼠神经元Nogo A表达

目的 了解神经元NgR受体拮抗剂NEP1-40对高苯丙氨酸(Phe)作用下大鼠大脑皮质层神经元Nogo A蛋白表达的影响.方法 原代培养胎龄16～18 d的SD大鼠皮质神经元,体外模拟高Phe(0.9 mmol/L)环境,并用不同浓度NEP1-40干预;用免疫荧光方法检测神经元轴突生长和生长锥塌陷情况,实时荧光定量PCR和Western blot检测Nogo A mRNA和蛋白表达.结果 Nogo A可以在神经元胞体和突起表达;高Phe作用12、24和48 h神经元NogoA mRNA与α微管蛋白(α-Tub)的相对表达量明显减低(P<0.05);高Phe作用后神经元Nogo A蛋白明显降低(P<0.05);NEP1-40对正常神经元无促进作用,但对高phe作用下的神经元呈浓度依赖性地促进其Nogo A的表达.结论 NEP1-40可以促进高Phe损伤时神经元Nogo A的表达增高,从而促进神经元轴突的生长.     

Gait analysis of spinal cord injured rats after delivery of chondroitinase ABC and adult olfactory mucosa progenitor cell transplantation

Chondroitin sulfate proteoglycan (CSPG) is a major component of glial scar to restrict axonal regeneration in the lesion site after spinal cord injury (SCI). Chondroitinase ABC (ChABC), a bacteria enzyme, which has been demonstrated to digest the glycosaminoglycan (GAG) side chain of CSPG to promote axonal re-growth across the injured site. Our previous study suggested that long-term delivery of ChABC (1 U/ml, injection volume 0.6 μl for one animal) via intrathecal catheter could decrease the inhibitory effect of limiting axonal re-growth after SCI. The functional behavior has been shown to improve following ChABC treatment. Little axons re-grow across the lesion site of the spinal cord but not enough to support axon innervations to targets. In this article, we show that ChABC administration combining olfactory mucosa progenitor cell (OMPC) transplantation can promote axonal re-growth across the lesion site and enhance the consistency of stepping in spinally transected rats. These OMPCs generated NG2⁺ cell lineages after transplanting into the spinal cord parenchyma, and OMPCs were found to spread and migrate toward the lesion region of spinal cord. Moreover, the spatial and temporal characteristics of the step cycle in rats that receive a complete spinal cord transaction following continuous ChABC supply and OMPC transplantation. The gait characteristics of treated rats on a treadmill were consistent and approached that of intact rats. In future, the mechanism of restoring the injured spinal cord will be further investigated.     

The effect of systemic PTEN antagonist peptides on axon growth and functional recovery after spinal cord injury

Knockout studies suggest that PTEN limits the regenerative capacities of CNS axons as a dominant antagonist of PI3 kinase, but the transgenic approach is not feasible for treating patients. Although application of bisperoxovanadium may block PTEN function, it is a general inhibitor of phosphotyrosine phosphatases and may target enzymes other than PTEN, causing side effects and preventing firm conclusions about PTEN inhibition on regulating neuronal growth. A pharmacological method to selectively suppress PTEN post-injury could be a valuable strategy for promoting CNS axon regeneration. We identified PTEN antagonist peptides (PAPs) by targeting PTEN critical functional domains and evaluated their efficacy for promoting axon growth. Four PAPs (PAP 1–4) bound to PTEN protein expressed in COS7 cells and blocked PTEN signaling in vivo. Subcutaneous administration of PAPs initiated two days after dorsal over-hemisection injury significantly stimulated growth of descending serotonergic fibers in the caudal spinal cord of adult mice. Systemic PAPs induce significant sprouting of corticospinal fibers in the rostral spinal cord and limited growth of corticospinal axons in the caudal spinal cord. More importantly, PAP treatment enhanced recovery of locomotor function in adult rodents with spinal cord injury. This study may facilitate development of effective therapeutic agents for CNS injuries.     

Effect of cervical spinal cord hemisection on the expression of axon growth markers

To evaluate the plasticity processes occurring in the spared and injured tissue after partial spinal cord injury, we have compared the level of axon growth markers after a C2 cervical hemisection in rats between the contralateral (spared) and ipsilateral (injured) cervical cord using western blotting and immunohistochemical techniques. In the ipsilateral spinal cord 7 days after injury, although GAP-43 levels were increased in the ventral horn caudal to the injury, they were globally decreased in the whole structure (C1–C6). By contrast, in the contralateral intact side 7 days and 1 month after injury, we have found an increase of GAP-43 and βIII tubulin levels, suggesting that processes of axonal sprouting may occur in the spinal region contralateral to the injury. This increase of GAP-43 in the contralateral spinal cord after cervical hemisection may account, at least partially, to the spontaneous ipsilateral recovery observed after a cervical hemisection.     

硫酸软骨素酶ABC联合高压氧预处理对脊髓损伤大鼠后肢运动功能的影响

目的探讨硫酸软骨素酶ABC(ChABC)联合高压氧预处理对成年大鼠脊髓损伤后不同时期后肢运动功能及腓肠肌运动终板内乙酰胆碱酯酶(AChE)含量的影响。方法雌性成年Wistar大鼠80只,体重250～300g,随机分为假手术组(Sham组)、脊髓损伤组(SCI组)、高压氧预处理组(HBOP组)、高压氧预处理后硫酸软骨素酶ABC治疗组(HBOP+ChABC组)各20只。采用脊髓半横断法制作模型,分别于伤后3d、7d、14d和28d随机选取5只大鼠,采用BBB评分(Basso,Beattie and Bresnaban score)法进行行为学观察,评分后经灌注固定,取大鼠患侧下肢腓肠肌,进行酶化学染色并应用Image-Pro Plus 6.0图像分析系统测量腓肠肌中AChE染色阳性部位平均光密度值(AOD值)。结果 Sham组大鼠BBB评分及AChE活性明显高于SCI组(P<0.01),HBOP组与HBOP+ChABC组在术后14d之后BBB评分明显高于SCI组(P<0.05),CHABC+HBOP组在术后28天BBB评分高于HBOP组(P<0.05)。HBOP组患侧腓肠肌AchE活性高于SCI组,HBOP+ChABC组高于HBOP组(P<0.05)。结论高压氧预处理可以改善大鼠患肢的运动功能和提高AChE的活性,联合硫酸软骨素酶ABC作用更强。     

硫酸软骨素酶ABC对大鼠脊髓损伤后硫酸软骨素蛋白多糖与生长相关蛋白43表达的影响

目的:探讨硫酸软骨素酶ABC对严重的大鼠脊髓损伤蛋白多糖及生长相关蛋白43(GAP-43)基因表达的影响。方法:制作大鼠脊髓横断伤模型,分为脊髓损伤组和脊髓损伤治疗组,给于治疗组硫酸软骨素酶ABC鞘内注射,用免疫荧光组织化学观察硫酸软骨素蛋白多糖(CSPGs)的表达,半定量RT-PCR、Western印迹法观察GAP-43 mR- NA及蛋白的表达。结果:治疗组与损伤组比较,CSPGs的表达减少,差异具有显著性,而GAP-43mRNA及蛋白表达增多。结论:硫酸软骨素酶ABC能够裂解CSPGs,改善脊髓损伤区的微环境,促进GAP-43 mRNA及蛋白的表达,是修复脊髓损伤和促进神经再生的机制之一。     

原位胶原凝胶对大鼠脊髓损伤后功能恢复的影响

目的研究脊髓损伤后原位形成胶原凝胶对神经功能恢复的影响。方法15只健康雌性SD大鼠随机分为胶原组、对照组和假手术组．Allen撞击法制作脊髓损伤模型。用微量注射器将胶原溶液注入损伤部位,在体温作用下让其原位形成凝胶,对照组注入PBS溶液,每周进行运动评分,6周后取脊髓组织进行免疫荧光染色,观察损伤部位的胶质瘢痕和轴突生长情况。结果胶原组大鼠第5周起BBB评分显著高于对照组,免疫荧光显示损伤部位胶质瘢痕少于对照组,且长入损伤部位的轴突也多于对照组。结论原位形成的胶原凝胶能抑制损伤部位胶质瘢痕的形成,并能促进轴突再生长入损伤部位。证明胶原是一种较好的能用于修复脊髓损伤的可注射材料。     

Transplantation of mesenchymal stem cells enhances axonal outgrowth and cell survival in an organotypic spinal cord slice culture

Mesenchymal stem cells (MSCs) have demonstrated a measurable therapeutic effect following transplantation into animal models of spinal cord injury. However, the mechanism(s) by which transplanted cells promote nerve regeneration and/or functional recovery remains indeterminate. Several studies have suggested that MSCs promote tissue repair via secretion of trophic factors, but delineating the effect of such factors is difficult due to the complexity of the in vivo systems. Therefore, we developed an organotypic spinal cord slice culture system that can be sustained for sufficient periods of time in vitro to evaluate nerve regeneration as an ex vivo model of spinal cord injury. Using this model, we demonstrate that treatment of lumbar slices of spinal cord with lysolecithin induced a significant degree of cell death and demyelination of nerve fibers, but that these effects were ameliorated to a significant extent following co-culture of slices with human MSCs (hMSCs). The results indicate that transplanted hMSCs alter the tissue microenvironment in a way that promotes survival of endogenous cells, including injured neurons, immature oligodendrocytes and oligodendrocyte progenitor cells. This ex vivo culture system represents a useful tool to further dissect the mechanism(s) by which MSCs promote regeneration of injured nervous tissue.     

Stretch growth of integrated axon tracts: Extremes and exploitations

Although virtually ignored in the literature until recently, the process of ‘stretch growth of integrated axon tracts’ is perhaps the most remarkable axon growth mechanism of all. This process can extend axons at seemingly impossible rates without the aid of chemical cues or even growth cones. As animals grow, the organization and extremely rapid expansion of the nervous system appears to be directed purely by mechanical forces on axon tracts. This review provides the first glimpse of the astonishing features of axon tracts undergoing stretch growth and how this natural process can be exploited to facilitate repair of the damaged nervous system.     

Chondroitinase对成年大鼠脊髓完全性横断损伤后胶质瘢痕的影响

目的研究Chondroitinase(chABC)对成年大鼠脊髓完全性横断性损伤(spinal cord injury,SCI)后胶质瘢痕及纤维浸润的长期影响。方法 Wistar大鼠24只,在第10胸段脊髓(T10)给予破坏脊膜的完全性横切术,然后随机分为2组,在SCI处分别给予chABC或生理盐水。14周后,脊髓横断从胸9至胸11(10mm组织块)连续切片,首先用Trichrome组织学染色切片确定SCI中心及距中心头侧和尾侧各500μm位置,Trichrome染色和免疫组织化学染色测量损伤脊髓中胶原蛋白浸润的面积,硫酸软骨素蛋白聚糖(CSPGs)的免疫反应强度。免疫荧光共聚焦显微成像检测pCREB(1:25)和GFAP表达,以及测量在SCI处纵向的最短GFAP阴性距离。结果应用chABC治疗可降低脊髓完全性横断后结缔组织的浸润。在SCI处胶原蛋白的纵向最大浸润距离以及在脊髓横断切片上的浸润面积,在chABC组显著减小(p0.05)。在SCI处纵向的最短GFAP平均阴性距离在chABC组中显著低于未治疗组(p0.05),表明更多的剩余正常组织在SCI后得以保留。chABC还能有效地清除轴突再生的抑制因子CSPGs(p0.05)。结论 Chondroitinase通过减少纤维浸润和胶质瘢痕以及清除抑制性细胞外基质分子CSPGs,可为脊髓损伤后神经功能恢复和轴突再生提供有利的局部环境。     

miR-144-3p对大鼠脊髓损伤后巨噬细胞炎症反应和功能恢复的影响

目的 探究miR-144-3p对脊髓损伤大鼠的巨噬细胞炎症反应和运动功能恢复的影响。方法 分析脊髓损伤大鼠miRNA表达数据集GSE19890中miR-144的表达情况;在ENCORI网站中预测miR-144-3p的靶基因,并通过双荧光素酶报告基因实验验证miR-144-3p与靶基因的结合情况;构建脊髓损伤大鼠模型,采用RT-qPCR和Western blot实验验证损伤区域miR-144-3p和Notch1的变化情况;用miR-144-3p mimics或miR-144-3p NC转染LPS诱导的巨噬细胞或经鞘内注射脊髓损伤的大鼠,探究miR-144-3p对体内外巨噬细胞炎症反应和大鼠运动功能恢复的影响。结果 数据集GSE19890中miR-144在大鼠脊髓损伤7 d时明显下调。Notch1作为miR-144-3p的靶基因被其负调控。miR-144-3p在脊髓损伤大鼠模型损伤7 d时明显下调,而Notch1的表达则明显上调。miR-144-3p能够明显抑制LPS体外诱导的M1型巨噬细胞炎症反应和脊髓损伤导致的体内巨噬细胞炎症反应,并且促进脊髓损伤大鼠的运动功能恢复。结论 miR-144-3p靶向调控Notch1的表达,并且通过抑制巨噬细胞炎症反应来促进大鼠脊髓损伤后运动功能的恢复。     

联合检测D2-40、calretinin及HBME-1在浆膜腔积液细胞学鉴别诊断中的意义

目的 观察D2-40、calretinin及HBME-1在浆膜腔积液间皮和转移性癌细胞中的表达,评价其用于鉴别诊断的价值.方法 用细胞块技术对87例浆膜腔积液标本进行免疫组化检测,观察D2-40、calretinin和HBME-1在癌细胞和间皮细胞中的表达.结果 D2-40、calretinin和HBME-1标记间皮细胞的敏感度分别为48.1%、81.0%、77.2%,特异度分别为90.2%、69.5%、61.0%.三者联合的敏感度和特异度分别为70.9%和81.7%.三者标记卵巢癌腹水间皮细胞的特异性都不高.结论 D2-40、calretinin和HBME-1合用可辅助鉴别诊断转移性癌与间皮.     

Intravenously transplanted human neural stem cells migrate to the injured spinal cord in adult mice in an SDF-1- and HGF-dependent manner

Neural stem cell (NSC) transplantation has exhibited considerable therapeutic potential in spinal cord injury. However, most experiments in animals have been performed by injecting these cells directly into the injured spinal cord. A cardinal feature of NSCs is their exceptional migratory ability through the nervous system. Based on the migratory ability of NSCs, we investigated whether minimally invasive intravenous delivery of NSCs could facilitate their migration to the injured spinal cord and identified the chemo-attractants secreted by the lesions. Nude mice were injected intravenously with labelled human NSCs at 3, 7 and 10 days after the compression of the spinal cord at the T8 level. The migration of NSCs to the lesioned spinal cord was highest at 7 days after injury; this correlated with the peak of hepatocyte growth factor and stromal cell-derived factor-1 mRNA expressions in the lesion but not with the disruption of the blood-brain barrier. Finally, the grafted NSCs differentiated into neuronal and glial subpopulations at 21 days after transplantation. Our study suggests that intravenously administered NSCs can be employed as a renewable source for replacing lost cells for the treatment of spinal cord injuries.     

Convergence of skin reflex and corticospinal effects in segmental and propriospinal pathways to forelimb motoneurones in the cat

The organization of facilitatory convergence from cutaneous afferents (Skin) and the corticospinal tract (pyramidal tract, Pyr) in pathways to forelimb motoneurones of mainly distal muscles was studied in anaesthetized cats by analysing postsynaptic potentials (PSPs), which were spatially facilitated by combinations of stimuli to the two sources at different time intervals. Conditioning Pyr volleys facilitated Skin-evoked PSPs of fixed (1.2–3.6 ms) central latencies (Skin PSPs), suggesting that disynaptic and polysynaptic skin reflex pathways are facilitated from the pyramidal tract. The shortest latencies (1.2–1.7 ms) of pyramidal facilitation suggested direct connection of pyramidal fibres with last order neurones of skin reflex pathways. Conditioning Skin volleys facilitated Pyr-evoked PSPs of fixed, mostly disynaptic latencies (1.0–2.5 ms; Pyr PSPs), suggesting that pyramido-motoneuronal pathways are facilitated from Skin at a premotoneuronal level. The shortest pathway from skin afferents to the premotor neurones appeared to be monosynaptic. Although Pyr and Skin volleys were mutually facilitating, the facilitation curve of Pyr PSPs and that of Skin PSPs were discontinuous to each other, with the peak facilitation at different Skin-Pyr volley intervals. Transection of the dorsal column (DC) at the C5/C6 border had little effect on the latencies or amplitudes evoked by maximal stimulation and the pyramidal facilitation of Skin PSPs. In contrast, the facilitation of Pyr PSPs by Skin stimulation was greatly decreased after the DC transection, and the facilitation curve of Pyr PSPs was continuous to that of Skin PSPs, with no separate peak. Latencies of Pyr PSPs ranged similarly to those in DC intact preparations. More rostral DC transection (C4/C5 border) reduced Skin-facilitated Pyr excitatory PSPs (EPSPs) less than C5/C6 lesions, suggesting that the C5 segment also contains neurones mediating Skin-facilitated Pyr EPSPs. The results show that convergence from skin afferents and the corticospinal tract occurs at premotor pathways of different cervical segments. We suggest that corticospinal facilitation of skin reflex occurs mostly in the brachial segments and Skin facilitation of cortico-motoneuronal effects takes place largely in the rostral cervical segments and partly in the brachial segments.     

嗅鞘细胞移植对大鼠脊髓半横断损伤后轴突再生及后肢功能恢复的作用

为了对嗅鞘细胞移植治疗大鼠脊髓损伤(spinal cord injury, SCI)后轴突再生及后肢功能恢复进行综合性的评价,本实验采用22只雌性成年SD大鼠,并随机分成A、B、C、D 4组。其中A、B、D组行左侧T11 ～T12节段脊髓半横断手术,然后A组移植嗅鞘细胞(olfactory ensheathing cells,OECs)悬液;B组移植DMEM/F12培养液;D组移植核荧光试剂(Hoechst33342)标记的嗅鞘细胞,用于鉴定嗅鞘细胞在体内的存活情况;C组作为正常对照组。术后6周内,对大鼠进行BBB评分、IP斜板试验并观察皮质体感诱发电位(cortical somatosensory evoked potential, CSEP)、运动诱发电位(motor evoked potential, MEP)的潜伏期。将辣根过氧化物酶(HRP)注射到横断面尾段脊髓,逆行追踪观察横断面头段脊髓及对侧中脑红核内HRP逆标细胞数,并观察左侧后肢小腿三头肌肌细胞横截面积及直径的变化。结果显示:(1)移植后的OECs数量未见明显减少,细胞核形态较好,细胞未向头、尾侧迁移;(2)移植3周后BBB评分及IP斜板,试验A、B组较C组明显低(P<0.05),但A组明显高于B组(P<0.05);(3)A、B组的CSEP及MEP潜伏期较C组明显延长(P<0.05),但A组要比B组明显缩短(P<0.05);(4)HRP逆行追踪观察到对侧中脑红核大细胞区及脊髓T9 ～T11节段逆标细胞的数量,A组明显多于B组,但A、B组均少于C组;(5)左侧后肢小腿三头肌肌细胞的横截面积及直径,A、B组均较C组减少,但A组减小的幅度明显小于B组。以上结果表明OECs移植能促进半横断脊髓轴突的再生及后肢功能的恢复。     

Neurophysiological examination of the corticospinal system and voluntary motor control in motor-incomplete human spinal cord injury

This study employed neurophysiological methods to relate the condition of the corticospinal system with the voluntary control of lower-limb muscles in persons with motor-incomplete spinal cord injury. It consisted of two phases. In a group of ten healthy subjects, single and paired transcranial magnetic stimulation (TMS) of the motor cortex was used to study the behavior of the resulting motor evoked potentials (MEP) in lower-limb muscles. Interstimulus intervals (ISIs) of 15–100 ms were examined for augmentation of test MEPs by threshold or subthreshold conditioning stimuli. The second phase of this study examined eight incomplete spinal cord injured (iSCI) subjects, American Spinal Injury Association Impairment Scale C (n =5) and D (n =3) in whom voluntary motor control was quantified using the surface EMG (sEMG) based Voluntary Response Index (VRI). The VRI is calculated to characterize relative output patterns across ten lower-limb muscles recorded during a standard protocol of elementary voluntary motor tasks. VRI components were calculated by comparing the distribution of sEMG in iSCI subjects with prototype patterns collected from 15 healthy subjects using the same rigidly administered protocol, The resulting similarity index (SI) and magnitude values provided the measure of voluntary motor control. Corticospinal system connections were characterized by the thresholds for MEPs in key muscles. Key muscles were those that function as the prime-movers, or agonists for the voluntary movements from which the VRI data were calculated. Results include healthy-subject data that showed significant increases in conditioned MEP responses with paired stimuli of 15–50 ms ISI. Stimulus pairs of 75 and 100 ms showed no increase in MEP peak amplitude over that of the single-pulse conditioning stimulus alone, usually no response. For the iSCI subjects, 42% of the agonists responded to single-pulse TMS and 25% required paired-pulse TMS to produce an MEP. American Spinal Injury Association Impairment Scale component motor scores for agonist muscles, Quadriceps, Tibialis Anterior, and Triceps Surae, were significantly lower where MEPs could not be obtained (p <0.05). VRI values were also significantly lower for motor tasks with agonists that had no resting MEP (p <0.01). Therefore, the presence of a demonstrable connection between the motor cortex and spinal motor neurons in persons with SCI was related to the quality of post-injury voluntary motor control as assessed by the VRI.     

Effects of estrogen on temporal expressions of IL-1beta and IL-1ra in rat organotypic hippocampal slices exposed to oxygen-glucose deprivation

Anti-inflammatory action of estrogen is involved in neuroprotection but the effects of estrogen on IL-1beta and its endogenous antagonist (IL-1 ra) have not been clearly defined in the ischemic brain. This study was performed to evaluate whether estrogen affects the expression of IL-1beta or IL-1ra and the ratio of the two in the ischemic hippocampus. Rat organotypic hippocampal slices were treated with 17beta estradiol (E2, 1 nM) for 7 days, exposed to oxygen-glucose deprivation (OGD) for 30 min, and then reperfused for 72 h. CA1 neuronal death quantified by propidium iodide (PI) staining and expressions of IL-1beta and IL-1ra in slices measured by real-time PCR and Western blotting were examined. PI intensities in CA1 in slices treated with E2 were significantly reduced at 24 h and 72 h post-OGD, and IL-1beta mRNA expressions were reduced at 6 h and 24 h post-OGD. In addition, IL-1ra mRNA was significantly overexpressed and the ratio of IL-1beta to IL-1ra mRNA expression was reduced by E2 especially at 24 h. In terms of protein levels, E2 downregulated IL-1beta but upregulated IL-1ra and thereby decreased the IL-1beta/IL-1 ra ratio at 24h. These findings demonstrate that estrogen-induced protection is associated with a decrease in IL-1beta and an increase in IL-1ra expression in the ischemic hippocampus during early reperfusion periods, which suggests that modulation of IL-1beta/IL-1ra might be a part of anti-inflammatory effects of estrogen.     

Comparison of input-output patterns in the corticospinal system of normal subjects and incomplete spinal cord injured patients

We have examined input-output patterns in the corticospinal system after incomplete spinal cord injury. The amplitude of the motor evoked potential (MEP) to transcranial magnetic stimulation (TMS) was used to study the patterns of recruitment, with increasing stimulus intensity, and facilitation, with increasing voluntary contraction, in thenar muscles of 12 patients with incomplete spinal cord injuries and 13 control subjects. The patients had all suffered spinal cord injury at a segmental level rostral to C8 and T1, the segments supplying innervation of thenar muscles. The patients showed a less pronounced increase in MEP amplitude with increasing strength of TMS compared with the controls. Specifically, at a stimulus strength of 120% threshold and above, the patients showed significantly smaller MEPs relative to the maximum ulnar nerve M-wave response than the controls. The patients also showed a less steep pattern of facilitation with voluntary drive. The MEP continued to increase up to 50% maximum voluntary contraction (MVC) whereas the controls reached a plateau around 10% MVC. The results indicate that the patients show modified corticospinal recruitment and facilitation of the motoneurone pool. We speculate that the function of the adapted corticospinal system after spinal cord injury might be to regulate and modulate drive to motoneurones originating from segmental and other descending inputs. We discuss how such a modified corticospinal system might be of functional benefit to the patients. Received: 25 August 1998 / Accepted: 24 March 1999     

BMP7蛋白对大鼠急性脊髓损伤后神经元修复作用的研究

目的探索骨形态发生蛋白7(bone morphogenetic protein 7,BMP7)是否具有促进大鼠急性脊髓损伤后神经元修复的作用。方法实验大鼠分为阴性对照组(negative control,NC)和BMP7实验组,以Allen's打击法建立大鼠脊髓损伤模型,BMP7组大鼠每天在脊髓损伤处注射50ng BMP7蛋白,连续7天,NC组对应注射等体积的0.9%氯化钠注射液。两组大鼠分别于术后6小时、3天、1周、2周、4周、8周进行HE染色以观察脊髓损伤处病理学改变;两组大鼠分别于术后6小时、3天、1周、2周、4周、8周进行免疫组化实验以检测损伤节段脊髓神经丝蛋白200(neurofilament protein 200,NF200)、胶质纤微酸性蛋白(glial fibrillary acidic protein,GFAP)及突触素(Synaptophysin,SYP)蛋白表达水平。结果 HE染色结果表明两组大鼠造模后脊髓损伤处神经元数量减少,神经突触数量减少,尼式体淡染且数量减少,组织中可见空洞形成,1周后,BMP7实验组大鼠脊髓损伤处尼式体染色逐渐加深,神经突触数量增多,变化较NC组明显。免疫组化结果表明BMP7实验组大鼠NF200阳性表达细胞数造模3天后逐渐增多,至第4周时达到高峰,且在1周、2周、4周及8周时均大于NC组;BMP7实验组及NC组术后GFAP阳性表达细胞数变化均不明显,且两组阳性细胞数差异不显著;BMP7实验组大鼠SYP阳性表达细胞数造模3天后逐渐增多,且在1周、2周、4周及8周时均大于NC组。结论 BMP7蛋白可以促进大鼠脊髓损伤后神经元的修复。     

地塞米松对哮喘豚鼠嗜酸细胞凋亡及bc1-2 mRNA表达的影响

目的观察地塞米松(DM)对哮喘豚鼠体外不同密度的嗜酸性粒细胞(Eos)凋亡及bc1-2表达的影响, 并探讨激素促进哮喘Eos凋亡的机制.方法以卵蛋白激发哮喘豚鼠模型48 h后, 进行支气管肺泡灌洗, 分离灌洗液中不同密度的Eos.加入DM(10 10～10 5mol/L),以原位杂交法检测Eos的bc1-2表达, TUNEL法检测Eos的凋亡.结果 DM干预24 h,可见Eos凋亡增加,bc1-2 mRNA表达降低,且呈剂量依赖性.bc1-2mRNA的表达与Eos凋亡呈负相关.结论 DM可抑制bc1-2的表达,促进Eos凋亡.bc1-2表达的减少可能是DM调节Eos凋亡的机制之一.