SIRT1调控miR-124抗抑郁的机制研究进展

抑郁症是一类严重危害人类身心健康的重性精神疾病,其病理生理学机制极其复杂.沉默信息调节因子2相关酶Ⅰ(Sirtuin 1,SIRT1)的抗抑郁作用被广泛论证,但其作用机制仍不明确.同时研究发现miR-124的调控作用在抑郁发病中也具有重要意义.现旨在介绍SIRT1如何调控miR-124,缓解下丘脑-垂体-肾上腺轴(HP...     

MicroRNA-124对帕金森病中多巴胺能神经元的神经保护作用

目的 研究microRNA(miR)-124对帕金森病模型小鼠中脑多巴胺能神经元的神经保护作用,并探讨其免疫炎性调控机制. 方法 采用小胶质细胞系BV2细胞制备炎性反应的细胞模型,实时荧光定量PCR (qRT-PCR)检测miR-21、miR-124、miR-155、miR-146a、miR-181c、miR-221-3p等中枢炎性相关rniRNAs表达;腹腔内注射1-甲基-4-苯基-1,2,3,6-四氢吡啶(MPTP)制备帕金森病小鼠模型,尾静脉注射miR-124治疗,免疫组织化学染色观察治疗前后多巴胺能神经元凋亡情况(TH蛋白表达)、小胶质细胞活化情况(Iba1蛋白表达),Western blotting及qRT-PCR检测治疗前后细胞凋亡相关蛋白酶caspase-3、caspase-8的表达情况. 结果 miR-124在BV2细胞中表达量明显高于其他5种miRNAs,差异有统计学意义(P＜0.05),且致炎后表达下调幅度最大;与帕金森病模型鼠相比,miR-124治疗后黑质区TH阳性细胞数明显增多,而Iba1阳性细胞数明显减少,caspase-3、caspase-8的表达量亦明显减少,差异有统计学意义(P＜0.05). 结论 miR-124可通过抑制黑质区小胶质细胞活性缓解多巴胺能神经元凋亡进程,可能是帕金森病发病机制中的一个关键因子.     

生长激素腺瘤中差异表达的微小RNAs及其靶基因的相关生物信息学分析

目的探讨垂体生长激素(GH)细胞腺瘤中差异表达的微小RNAs(miRNAs)及其靶基因的生物学功能和两者的调控关系。方法利用miRDB、miRwalk、Targetscan7.2及starbase数据库对差异表达的miRNAs进行靶基因预测并对靶基因进行GO、KEGG和蛋白-蛋白相互作用网(PPI)分析,随后筛选出有意义的核心靶基因,取核心靶基因和数据库的mRNAs测序结果进行对比,构建可视化的miRNAs-靶基因调控关系网。结果以蛋白相互作用程度≥20为标准,本研究得到113个上调的miRNAs核心靶基因和128个下调的miRNAs核心靶基因,进一步取交集得到13个目的核心靶基因,这些基因主要涉及的通路为泛素介导蛋白水解通路,其相对应的调控miRNAs为miR-15b、miR-365、miR-32-3p、miR-486-5p。结论本研究应用生物信息学分析工具构建了与GH细胞腺瘤密切相关的miRNAs-核心靶基因相互调控网,发掘了一些可能与GH细胞腺瘤发病机制和病理过程有关的蛋白和通路。     

miR-127-3p通过下调靶基因MAPK4抑制神经胶质瘤增殖的机制研究

目的 探讨miR-127-3p在神经胶质瘤中的表达水平差异及生物学作用。方法 用RT-PCR法检测神经胶质瘤患者及健康人群脑脊液中miR-127-3p相对表达水平; 用RT-PCR法检测人神经胶质瘤细胞株和人正常神经胶质细胞中的miR-127-3p相对表达水平; 用瞬时转染法上调神经胶质瘤细胞U251中的miR-127-3p相对表达水平,用MTT法检测细胞增殖,用流式细胞术检测细胞凋亡,用Western blot检测凋亡相关蛋白bcl-2、Mcl-1和bax表达水平; Targetscan等在线靶基因预测软件预测miR-127-3p的靶基因,并采用双荧光素酶报告试验和Western blot验证miR-127-3p与靶基因之间的直接作用关系。结果 神经胶质瘤患者(1.33±0.12)脑脊液中的miR-127-3p相对表达水平低于健康人群(3.62±0.26)(t=5.867,P=0.004); U251(0.59±0.05)、U373(0.96±0.08)、U87(0.77±0.03)、SHG44(1.28±0.05)中miR-127-3p相对表达水平均低于人脑正常胶质细胞株HEB(3.64±0.26)(P<0.01); 转染后24、48、72 h 150组、100组和50组细胞吸光度值均低于对照组(P<0.05),并且随着miR-127-3p mimics转染水平增高,U251细胞吸光度值越低; miR-127-3p mimics转染组(39.3±4.6%)细胞早期凋亡率高于对照组(7.2±0.6%)(P<0.05); miR-127-3p mimics转染组(9.3±2.3%)细胞晚期凋亡率高于对照组(2.4±0.5%)(P<0.05); mimic转染组(0.119±0.008)U251细胞bcl-2蛋白表达水平低于对照组(0.556±0.039),mimic转染组(0.168±0.015)U251细胞bax蛋白表达水平高于对照组(0.086±0.006),mimic转染组(0.144±0.009)U251细胞Mcl-1蛋白表达水平低于对照组(0.426±0.028)(P均<0.05); 双荧光素酶报告基因实验显示,只有当MAPK4-WT-3' UTR与miR-127-3p mimic共同转染时荧光素酶活性被抑制,这提示miR-127-3p能与MAPK4直接结合,miR-127-3p mimic转染组(0.121±0.003)U251细胞MAPK4蛋白表达水平低于对照组(0.467±0.028)(P<0.05)。结论 miR-127-3p在神经胶质瘤患者脑脊液中呈低表达,上调miR-127-3p能抑制神经胶质瘤U251细胞增殖,促进其凋亡,其机制可能与调控Bcl凋亡相关基因及抑制靶基因MAPK4有关。     

乙酰胆碱受体抗体阳性重症肌无力外周血单个核细胞miRNA表达谱

目的本研究对比乙酰胆碱受体抗体阳性重症肌无力患者(AchR-MG)和正常对照组外周血单个核细胞miRNA,预测对AchR-MG发病可能产生影响的通路,为进一步探讨发病机制打下基础。方法采用病例对照研究方法,基于高通量测序,筛选了AchR-MG特异性表达的miRNA。利用TargetScan、miRanda进行靶基因交叉预测,利用基因条目(GO)和京都基因与基因组百科全书(KEGG)进行富集分析。结果共筛选出差异性miRNA 28种,其中上调17种,下调11种。差异最显著的前5个为:mmu-miR-3968、miR-4785、miR-210-3p、miR-664a-3p、miR-2277-5p。miR-4785预测到METTL22、TMEM38A、ZNF324、ITGB4、CDC34等395种靶基因。最终识别了319条GO term(P 0.01),获得了119个的风险通路(P0.05)。结论 AchR-MG特异性表达miR-4785、miR-210-3p、miR-664a-3p、miR-2277-5p等28种miRNA。以Wnt信号通路为代表的多种通路可能参与AchR-MG的发病。     

基于缺氧诱导因子探讨高原抑郁症发病机制的研究进展

抑郁症是严重威胁生命健康的精神疾病, 发病机制错综复杂。近期研究发现海拔高度是导致抑郁症发病的重要因素之一。缺氧诱导因子为低氧条件下的重要转录因子, 其中缺氧诱导因子-1参与急性低氧调控, 介导神经营养因子和5-羟色胺等上调, 促进大脑代谢, 对抗抑郁;缺氧诱导因子-2参与慢性低氧调控, 促进炎症反应, 加重抑郁。本文重点介绍缺氧诱导因子与高原抑郁症发病的相关研究, 旨在为深入探究高原抑郁症的发病机制及防治提供新思考。     

微小RNA调节缺血诱导的内源性神经再生研究进展

成年哺乳动物的脑内存在神经干细胞,能够被脑缺血等刺激激活,诱导内源性神经再生。微小RNA(miRNA)能够在转录后水平调控蛋白质的表达,参与调节缺血性脑卒中的各个环节,在疾病的病理过程中发挥关键作用。miR-124和miR-9可能是脑缺血诱导的内源性神经再生的核心调控因子,研究miRNA对内源性神经再生的调节作用有助于阐明内源性神经修复机制和发现新的治疗靶点。利用药物或非药物手段调节特异性miRNA增强内源性神经再生可能是中风的有效治疗途径。     

精神分裂症患者转录因子4基因mRNA水平的分析对照研究

目的:探讨首发未用药的精神分裂症患者治疗前后转录因子4(TCF4)的基因表达水平及其与精神分裂症症状之间的相关性。方法:于2013年4月至10月期间入组首发未用药的精神分裂症患者28例(研究组),接受非典型抗精神病药治疗12周,同时入组正常对照者40名。采用实时定量聚合酶链反应(RT-qPCR)比较研究组与正常对照组、研究组治疗前后外周血中TCF4基因mRNA水平,并进一步分析患者治疗前后TCF4基因表达水平的差异与阳性与阴性症状量表(PANSS)评分之间的相关性。结果:与正常对照组相比,研究组TCF4的基因表达水平显著增高(P=0.000);与治疗前相比,研究组治疗12周后TCF4的基因表达水平显著降低(P=0.007)。研究组治疗前后TCF4基因表达水平差异与PANSS的各个子项目得分及总分之间的差异均无显著相关(P均0.05)。结论:精神分裂症患者存在TCF4基因的过度表达;抗精神病药治疗能够显著降低其TCF4基因的表达水平。     

BDNF 基因的表观遗传调控在精神分裂症中的研究进展

精神分裂症（Schizophrenia）是一种病因不明的重性精神疾病,神经发育障碍假说是目前重要的病理机制假说。脑源性神经营养因子（Brain Derived Neurotrophic Factor ,BDNF）作为神经营养素家族的重要成员,广泛表达于大脑及其他组织,通过对神经元的生长、分化进行调节从而影响神经发育。研究显示,包括精神分裂症和情感障碍在内的精神疾病均存在中枢和外周组织BDN F基因表达的改变。近年的研究发现,表观遗传调控对BDN F基因的表达具有重要作用,这些研究为精神疾病的发病机制提供了新的方向,同时为药物治疗提供了新的作用靶点。现对BDN F基因的表观遗传调控与精神分裂症的相关研究作一综述。     

血清miR-124 miR-145检测对急性缺血性脑卒中的诊断价值

目的探讨血清microRNA-124(miR-124)、miR-145检测对急性缺血性脑卒中(AIS)的诊断价值及与颈动脉粥样硬化(CAS)斑块性质的关联性。方法选取新乡市第一人民医院收治的AIS患者82例为AIS组,同期健康体检者82例为对照组。对比2组血清miR-124、miR-145水平及与神经缺损程度的关系,探究AIS发病影响因素及各血清的诊断价值,并检测不同CAS斑块性质患者血清miR-124、miR-145水平,分析二者关联性。结果AIS组血清miR-124水平低于对照组,miR-145水平高于对照组(P<0.05);重度患者血清miR-124水平低于中度、轻度患者,血清miR-145水平高于中度、轻度患者(P<0.05);血清miR-124、miR-145为AIS发病的重要影响因素(P<0.05);血清miR-145诊断AIS的AUC(0.791)>miR-124(0.717);易损斑块患者血清miR-124低于稳定斑块患者,血清miR-145水平高于稳定斑块患者(P<0.05);血清miR-124水平与神经功能缺损程度、CAS斑块性质呈负相关,血清miR-145水平与神经功能缺损程度、CAS斑块性质呈显著正相关(P<0.05)。结论血清miR-124、miR-145作为诊断AIS的潜在特异性生物标志物,与神经功能缺损程度、CAS斑块性质存在一定相关性,在AIS患者治疗过程中可通过调节血清miR-124、miR-145表达,发挥保护神经功能、抑制CAS斑块病变进展的作用。     

Denervation study of synapses of organ of corti of old world monkeys

Fine structural characteristics of synapses in the spiral organ of Corti were examined, with reference to differences between inner and outer haircell systems, and to location of neurons of origin of efferent axons. Surgical interruption of crossed olivocochlear bundle, of vestibular nerve, of facial nerve, and excision of superior cervical ganglia were used to determine the pathways of efferent axons. Interruption of the vestibular nerve near the brainstem results in degeneration of all efferent terminals on outer hair cells. Mid-line lesions at, and caudal to, the facial colliculus result in degeneration of about half of these efferent terminals. Efferent synaptic bulbs to the inner hair-cell system are small, of the order of one micron, and form type 2 junctions with afferent dendrites. They tend to have more large dense-core vesicles (about 80 nm) than the large efferent terminals of the outer hair-cell system, and appear to be the terminals of axons in the habenula perforata, which exhibit varicosities laden with large dense core vesicles. The varicosities are unaffected by excision of the superior cervical ganglia. So far as our material can reveal, it appears that the varicosities in the habenula perforata do not survive vestibular root interruption, nor do the efferent processes in the internal spiral bundle or at the base of inner hair cells. Most interestingly, the afferent processes of the inner hair-cell system, as identified for example by their relation to pre-synaptic bodies in the inner hair cells, are subject to a trans-synaptic reaction after severance of the vestibular root. They undergo a dramatic cytological transformation, characterized by increase of volume, engorgement with microtubules, microfilaments, microvesicles of various sizes, and clusters of lysosomes. Thus, both the efferent and afferent terminals of the inner hair-cell system show marked cytological differences from the corresponding terminals of the outer hair cell system.     

Mechanism of action of tubocurarine on nicotinic cholinoreceptors of neurons of the sympathetic ganglia of rats

Tubocurarine (Tc) effect on membrane currents elicited by acetylcholine (ACh) was studied in isolated superior cervical ganglion neurons of rat using patch-clamp method in the whole-cell recording mode. The "use-dependent" block of ACh current by Tc was revealed in the experiments with ACh applications, indicating that Tc blocked the channels opened by ACh. Mean lifetime of Tc-open channel complex, tau, was found to be 9.8 +/- 0.5 s (n = 7) at -50 mV and 20-24 degrees C. tau exponentially increased with membrane hyperpolarization (e-fold change in tau corresponded to the membrane potential shift by 61 mV). Inhibition of the ACh-induced current by Tc (3-30 microM/1) was completely abolished by membrane depolarization to the level of 80-100 mV. Inhibition of ACh-induced current was augmented at increased ACh doses. It is concluded that the open channel block produced by Tc is likely to be the only mechanism for Tc action on nicotinic acetylcholine receptors in superior cervical ganglion neurons of rat.     

The effect of age of onset of PD on risk of dementia

Background Dementia occurs in the majority of patients with Parkinson’s disease (PD). Late onset of PD has been reported to be associated with a higher risk for dementia. However, age at onset (AAO) and age at baseline assessment are often correlated. The aim of this study was to explore whether AAO of PD symptoms is a risk factor for dementia independent of the general effect of age. Methods Two community-based studies of PD in New York (n = 281) and Rogaland county, Norway (n = 227) and two population-based groups of healthy elderly from New York (n = 180) and Odense, Denmark (n = 2414) were followed prospectively for 3–4 years and assessed for dementia according to DSM-IIIR. All PD and control cases underwent neurological examination and were followed with neurological and neuropsychological assessments. We used Cox proportional hazards regression based on three different time scales to explore the effect of AAO of PD on risk of dementia, adjusting for age at baseline and other demographic and clinical variables. Findings In both PD groups and in the pooled analyses, there was a significant effect of age at baseline assessment on the time to develop dementia, but there was no effect of AAO independent of age itself. Consistent with these results, there was no increased relative effect of age on the time to develop dementia in PD cases compared with controls. Interpretation This study shows that it is the general effect of age, rather than AAO that is associated with incident dementia in subjects with PD. Received in revised form: 22 December 2005     

Limits of deinstitutionalization--perspectives of relatives of psychiatric patients

After a hopeful beginning, the social process of the reintegration of those with severe mental illness has come to a standstill. I am led to wonder whether "the community" really wants to live together with people suffering from severe mental illness, and if so, how closely? As long as the medical treatment of mental illness provided by the general practitioners is fundamentally deficient, as they are not able to prescribe the necessary interventions--such as out-patient psychiatric nursing, and service providers in the out-patient sector are content with offering increasingly intensive forms of care for the less seriously ill at the cost of the Social Welfare System--the reintegration of those with serious mental illness remains an illusion--which is mainly to the benefit of providers of residential care in homes and hostels.