Drebrin和SYP在APP/PS1转基因AD小鼠海马内的表达与认知障碍的关系

已知Alzheimer病(AD)患者脑内的主要病理变化之一是树突棘与突触的退化,而树突棘与突触的正常发育及病理改变均与树突棘肌动蛋白结合蛋白drebrin和突触前成分内突触素(synaptophysin,SYP)的表达水平密切相关。为探讨drebrin和SYP的表达与AD认知障碍之间的关系,本实验先采用Morris水迷宫法观测了6、9、12月龄APP/PS1转基因小鼠和同种野生型小鼠的学习记忆能力;再用Western blot法检测了其海马内drebrin和SYP蛋白表达水平。结果显示:9月龄APP/PS1转基因小鼠海马内drebrin蛋白的表达水平已有下降,其学习记忆能力也相应地降低,12月龄时二者下降明显;但作为突触前成分中的SYP蛋白表达水平的下降则较前二者的出现为迟。本结果提示,drebrin的表达下降在AD早期行为学改变的分子机制中发挥重要的作用,而SYP的表达下降则在drebrin下降之后参与AD的进一步发展。     

Augmented potassium current is a shared phenotype for two genetic defects associated with familial atrial fibrillation

Mutations in multiple genes have been implicated in familial atrial fibrillation (AF), but the underlying mechanisms, and thus implications for therapy, remain ill-defined. Among 231 participants in the Vanderbilt AF Registry, we found a mutation in KCNQ1 (encoding the α-subunit of slow delayed rectifier potassium current [I_Ks]) and separately a mutation in natriuretic peptide precursor A (NPPA) gene (encoding atrial natriuretic peptide, ANP), both segregating with early onset lone AF in different kindreds. The functional effects of these mutations yielded strikingly similar I_Ks “gain-of-function.” In Chinese Hamster Ovary (CHO) cells, coexpression of mutant KCNQ1 with its ancillary subunit KCNE1 generated ∼ 3-fold larger currents that activated much faster than wild-type (WT)-I_Ks. Application of the WT NPPA peptide fragment produced similar changes in WT-I_Ks, and these were exaggerated with the mutant NPPA S64R peptide fragment. Anantin, a competitive ANP receptor antagonist, completely inhibited the changes in I_Ks gating observed with NPPA S64R. Computational simulations identified accelerated transitions into open states as the mechanism for variant I_Ks gating. Incorporating these I_Ks changes into computed human atrial action potentials (AP) resulted in 37% shortening (120 vs. 192 ms at 300 ms cycle length), reflecting loss of the phase II dome which is dependent on L-type calcium channel current. We found striking functional similarities due to mutations in KCNQ1 and NPPA genes which led to I_Ks “gain-of-function”, atrial AP shortening, and consequently altered calcium current as a common mechanism between diverse familial AF syndromes.     

Effects of carbonyl cyanide p-(trifluoromethoxy) phenylhydrazone on the growth inhibition in human pulmonary adenocarcinoma Calu-6 cells

Carbonyl cyanide p-(trifluoromethoxy) phenylhydrazone (FCCP) is an uncoupler of mitochondrial oxidative phosphorylation in eukaryotic cells. Here, we evaluated the in vitro effects of FCCP on the growth of Calu-6 lung cancer cells. FCCP inhibited the growth of Calu-6 cells with an IC₅₀ of approximately 6.64 ± 1.84 μM at 72 h, as shown by MTT. DNA flow cytometric analysis indicated that FCCP induced G1 phase arrest below 20 μM of FCCP. Treatment with FCCP decreased the level of CDKs and cyclines in relation to G1 phase. In addition, FCCP not only increased the p27 level but also enhanced its binding with CDK4, which was associated with hypophosphorylation of Rb protein. While transfection of p27 siRNA inhibited G1 phase arrest in FCCP-treated cells, it did not enhance Rb phosphorylation. FCCP also efficiently induced apoptosis. The apoptotic process was accompanied with an increase in sub-G1 cells, annexin V staining cells, mitochondria membrane potential (MMP) loss and cleavage of PARP protein. All of the caspase inhibitors (caspase-3, -8, -9 and pan-caspase inhibitor) markedly rescued the Calu-6 cells from FCCP-induced cell death. However, knock down of p27 protein intensified FCCP-induced cell death. Moreover, FCCP induced the depletion of GSH content in Calu-6 cells, which was prevented by all of the caspase inhibitors. In summary, our results demonstrated that FCCP inhibits the growth of Calu-6 cells in vitro. The growth inhibitory effect of FCCP might be mediated by cell cycle arrest and apoptosis via decrease of CDKs and caspase activation, respectively. These findings now provide a better elucidation of the mechanisms involved in FCCP-induced growth inhibition in lung cancer.     

An interaction between the norepinephrine transporter and monoamine oxidase A polymorphisms, and novelty-seeking personality traits in Korean females

The personality traits associated with the noradrenergic system have not yet been clearly established. In the present study, we investigated the variable number of tandem repeats (VNTR) polymorphism of the norepinephrine transporter (NET) and monoamine oxidase A (MAOA), which are major components of the adrenergic system, to elucidate their relationship with personality. A total of 245 normal female Koreans (age 23.05+/-3.07 years, mean+/-SD) volunteered to take part in this study. They filled out a Korean version of the Temperament and Character Inventory (TCI) and were genotyped for the NET and MAOA-VNTR; the NET T-182C and MAOA-uVNTR polymorphisms were checked. We found significant main effect of NET genotype on novelty seeking (NS) score (F=5.43, p=0.021) and significant interaction between the NET and MAOA-uVNTR polymorphisms on NS score (F=11.06, p=0.001). However, there were no relationship between MAOA-uVNTR polymorphisms and NS score, and no association with other temperamental dimensions and these two polymorphisms. Our findings suggest that this functional polymorphism in the noradrenergic gene is associated with novelty seeking in Korean females.     

Emerging amyloid beta (Ab) peptide modulators for the treatment of Alzheimer's disease (AD)

Background: According to the ‘amyloid cascade hypothesis’ of Alzheimer's disease (AD), abnormal processing of beta-amyloid precursor protein (βAPP) into toxic amyloid beta (Aβ)-peptides is central to the etiopathology of this uniquely human brain disorder. Objective: To review current AD drugs, pharmacological approaches and strategies aimed at modulating Aβ-peptide generation and/or aggregation in the treatment of AD. Methods: Data searches at various websites: Alzheimer Research Forum; individual drug company databases; Medline; Pharmaprojects database; unpublished research; inter-University research communications. Results/conclusion: Considerable research effort has focused on secretase-mediated mechanisms of βAPP processing, and the latest pharmacological strategies have used selective Aβ-peptide-lowering agents (SALA) to provide therapeutic benefit against Aβ-initiated neurodegenerative pathology. Currently, dedicated anticholinesterase, glutamatergic agonist and Aβ-peptide immunization have had little impact in the clinical treatment of AD. One unexpected benefit of statins (HMG-CoA inhibitors), besides their cholesterol lowering abilities, has been their ancillary effects in potentiating the enzymatic mechanisms that generate Aβ-peptides. The long-term benefits or complications of statin-based therapies for use in the clinical management of AD are not known.     

新生大鼠缺氧缺血性脑损伤时Bcl-2和P53蛋白的表达

目的研究Bcl-2的P53蛋白在新生儿缺氧缺血性脑损伤(HIBD)中的表达及与细胞凋亡的关系。方法将新生7日龄Wistar大鼠制成HlBD模型，应用免疫组织化学-SP法及原位缺口末端标记(TUNEL)研究Bcl-2和P53蛋白在新生大鼠及缺氧缺血(HI)后脑中表达及与凋亡的关系。结果新生大鼠HIBD时凋亡与坏死并存，以凋亡为主。Bcl-2免疫蛋白在正常新生大鼠脑内广泛表达(+～++++)；Hl后脑病变处Bcl-2免疫强度明显下降(-～+)；P53蛋白在正常新生大鼠脑内基本无表达；HI后病变部位散在分布阳性凋亡细胞。结论Hl后Bcl-2免疫表达减弱，P53的免疫表达增强，提示Bcl-2可抑制凋亡，P53可能促进凋亡。     

Determinants of quality of life in Brazilian patients with Parkinson's disease.

Our objective was to identify determinants of health-related quality of life (HRQoL) in a cohort of Brazilian patients with Parkinson's disease (PD). Patients were evaluated by means of the Hoehn and Yahr staging (H&Y), Unified Parkinson's Disease Rating Scale (UPDRS), Schwab and England scale (S&E), Mini-Mental State Exam, Geriatric Depression Scale, and Hospital Anxiety and Depression Scale (HADS). HRQol was assessed using the MOS-Short-Form 36 (SF-36), the Parkinson's disease Questionnaire (PDQ-39), and the Scales for Outcomes in Parkinson's Disease-Psychosocial Questionnaire (SCOPA-PS). 144 patients were evaluated (mean age 62 years; 53.5% men; mean duration of illness 6.6 years; median H&Y, 2 (range: 1-4). Mean SCOPA-PS and PDQ-39 Summary Index (SI) were 39.2 and 40.7, respectively. Both, PDQ-39 and SCOPA-PS SIs correlated at a moderate level (r = 0.30-0.50) with H&Y, S&E, total UPDRS, HADS subscales, and SF-36 Physical and Mental Components. PDQ-39 and SCOPA-PS were closely associated (r = 0.73). HRQoL significantly deteriorated as H&Y progressed, as a whole. Mood disturbances, disability, motor complications, and education were independent predictors of HRQoL in the multivariate analysis model. In PD Brazilian patients, HRQoL correlated significantly with diverse measures of severity. Depression showed to be the most consistent determinant of HRQoL, followed by disability, motor complications, and education years. There was a close association between the PDQ-39 and SCOPA-PS summary scores.     

肺表面活性物质在防治早产儿肺透明膜病中的应用

目的 观察肺表面活性物质(PS)在防治早产儿呼吸窘迫综合征(NRDS),改善其生存质量中的作用.方法 生后立即气管内滴注单剂PS28例,并与同期未用PS的20例早产儿进行临床对照研究.结果 治疗组在吸氧方式,吸氧时间,经皮血氧饱和度监测,血气分析值,以及其他并发症的产生都优于对照组.结论 早期应用对早产儿改善缺氧,减少并发症,最终提高其生存质量有积极作用.     

芍药苷对APP/PS1小鼠的神经细胞保护作用及机制研究

目的:探讨芍药苷(paeoniflorin,PF)通过抑制细胞凋亡通路而产生神经细胞保护作用的机制。方法:分别选用15只5月龄雄性APP/PS1非显性小鼠作为正常对照组,15只5月龄雄性APP/PS1双转基因小鼠为模型组和15只5月龄雄性APP/PS1双转基因小鼠为给药组(5 mg/kg的PF腹腔注射)。采用水迷宫实验检测各组小鼠的学习和记忆能力。采用TUNEL荧光染色法检测脑内神经细胞凋亡情况。采用Western Blot检测脑内皮层及海马区PI3K、Akt、p-PI3K、p-Akt、caspase-3、caspase-9、Bcl-2和Bax的蛋白表达水平,并用免疫组化分析caspase-3和caspase-9的蛋白表达水平及分布情况。结果:(1)与正常对照组相比,APP/PS1模型组小鼠的学习和记忆能力明显下降;与APP/PS1模型组相比,PF明显改善小鼠的学习和记忆能力。(2)与正常对照组相比,APP/PS1模型组小鼠脑内神经细胞凋亡明显增多,分布区域较广,而PF给药组小鼠凋亡细胞明显减少。(3)与APP/PS1模型组相比,PF给药组能显著下调促凋亡因子caspase-3、caspase-9和Bax的表达水平(P0.05),同时上调抑凋亡因子pPI3K、p-Akt和Bcl-2的表达水平(P0.05)。结论:PF可能通过激活PI3K/Akt通路而上调Bcl-2,下调caspase-9、caspase-3和Bax的蛋白表达水平,从而抑制神经细胞凋亡和保护神经细胞,以治疗神经退行性疾病。