端粒长度与认知障碍及其中药治疗的研究现况

认知障碍是指记忆、语言、理解和判断等一个或多个方面的功能障碍,包括轻度认知障碍和各种类型的痴呆症。痴呆症是认知障碍最严重的表现,是一种导致患者日常生活、社会交往和工作能力发生显著变化的综合征。阿尔茨海默病(AD)是最常见的痴呆症类型,其次是血管性痴呆(VD)和其他神经退行性痴呆[1]。已知年龄与认知功能的退化密切相关。     

Alzheimer's Disease THErapy With NEuroaid (ATHENE): A Randomized Double-Blind Delayed-Start Trial

ObjectivesPreclinical and clinical studies indicate a role for MLC901 (NeuroAiD II) in Alzheimer's disease (AD). The primary aim was to investigate its safety as add-on therapy to standard treatment and the secondary aims its effect on cognition and slowing disease progression.DesignRandomized double-blind placebo-controlled delayed-start study.Setting and ParticipantPatients with mild to moderate probable AD by NINCDS-ADRDA criteria, stable on acetylcholinesterase inhibitors or memantine (n = 125), were randomized to receive MLC901 (early starters) or placebo (delayed starters) for 6 months, followed by a further 6 months when all patients received MLC901, in a delayed-start design (clinical trial registration: ClinicalTrials.gov, NCT03038035).MethodsThe primary outcome measure was occurrence of serious adverse events (SAEs) at 6 months. Secondary outcomes included the Alzheimer's Disease Assessment Scale–Cognitive subscale (ADAS-Cog) and other assessment scales.ResultsThere was no significant difference in the risk of SAEs between early and delayed starters at month (M) 6 (22.6% vs 27.0%, risk difference ?4.4%, 90% CI –16.9% to 8.3%). Similarly, there was no significant difference in the risk of adverse events and the occurrence of stroke or vascular events between early and delayed starters throughout the 12-month study period. Early starters did not differ significantly on ADAS-Cog from delayed starters at M6 [mean difference (MD) ?1.0, 95% CI –3.3 to 1.3] and M12 (MD –2.35, 95% CI –5.45 to 0.74) on intention-to-treat analysis. Other cognitive assessment scales did not show significant differences.Conclusions and ImplicationsThis study of 125 persons with dementia found no evidence of a significant increase in adverse events between MLC901 and placebo, thus providing support for further studies on both efficacy and safety. Analyses suggest the potential of MLC901 in slowing down AD progression, but this requires further confirmation in larger and longer studies using biomarkers for AD.     

Risk factors for falls in older people with cognitive impairment living in the community: Systematic review and meta-analysis

PurposeThis systematic review aimed to identify risk factors for prospectively ascertained falls, focusing on those that are potentially modifiable (physical and neuropsychological factors), in older people with cognitive impairment living in the community.ResultsA comprehensive search of five databases identified 16 high quality (Newcastle-Ottawa Scale ≥8/9) relevant articles. Meta-analyses were undertaken for five potential fall risk factors. Of these, fallers had significantly poorer balance (standardized mean difference = 0.62, 95 %CI 0.45, 0.79) with low heterogeneity. Global cognition was not significantly associated with faller status in a meta-analysis with low heterogeneity. Meta-analyses of mobility (Timed Up-and-Go), gait speed and depressive symptoms had high heterogeneity and were not statistically significant or were borderline significant (p = 0.05). Sensitivity analyses (removing one study sample’s results that differed markedly from the other included samples) reduced heterogeneity to 0% and revealed fallers had significantly poorer mobility and more depressive symptoms than non-fallers. Fallers also walked significantly slower, but heterogeneity remained high.ConclusionsIn older people with cognitive impairment, fallers presented with balance deficits, poor mobility, slow gait speed and depressive symptoms. Reduced global cognition was not associated with falls. These findings suggest that interventions should target balance impairment and reveal that more high-quality research is needed.     

Risk of seizures and subclinical epileptiform activity in patients with dementia: A systematic review and meta-analysis

BackgroundSeizures and subclinical epileptiform activity are common yet easily overlooked among demented patients. We aimed to investigate their epidemiological characteristics in patients with dementia from various aspects.MethodsWe retrieved relevant observational studies from PubMed and Embase Library until March 2021. Pooled estimate effects were calculated using random-effects models. This study is registered with PROSPERO, number CRD42020200949.ResultsOf the 19144 identified studies, 27 were eligible for inclusion. The pooled period prevalence rates of seizures were 4.86% (95%CI: 3.43–6.51%), 2.68% (95%CI: 2.13–3.28%), 2.81% (95%CI: 2.02–3.71%）and 7.13% (95%CI: 2.67–13.14%) among patients with Alzheimer’s disease (AD), Dementia of Lewy Body (DLB), Frontotemporal dementia (FTD) and Vascular dementia (VaD), respectively. The pooled incidence rate of seizures was [8.4 (95%CI: 4.2–12.7) per 1000 person-years] in AD patients. And the pooled relative risk of seizures in patients with AD was 3.35 (95%CI: 2.69–4.19). Besides, the pooled cumulative incidence rate and prevalence rate of subclinical epileptiform activity among AD patients were [21.41% (95%CI: 0.001–63.60%)] and 9.73% (95%CI: 0.26–28.38%), respectively.ConclusionsThe accurate rates of seizures and subclinical epileptiform activities in the four major dementia types are high. Besides, patients with AD are likely at a higher risk of seizures.     

Brain lipidomics as a rising field in neurodegenerative contexts: Perspectives with Machine Learning approaches

Lipids are essential for cellular functioning considering their role in membrane composition, signaling, and energy metabolism. The brain is the second most abundant organ in terms of lipid concentration and diversity only after adipose tissue. However, in the central system (CNS) lipid dysregulation has been linked to the etiology, progression, and severity of neurodegenerative diseases such as Alzheimeŕs, Parkinson, and Multiple Sclerosis. Advances in the human genome and subsequent sequencing technologies allowed us the study of lipidomics as a promising approach to diagnosis and treatment of neurodegeneration. Lipidomics advances rapidly increased the amount and quality of data allowing the integration with other omic types as well as implementing novel bioinformatic and quantitative tools such as machine learning (ML). Integration of lipidomics data with ML, as a powerful quantitative predictive approach, led to improvements in diagnostic biomarker prediction, clinical data integration, network, and systems approaches for neural behavior, novel etiology markers for inflammation, and neurodegeneration progression and even Mass Spectrometry image analysis. In this sense, by exploiting lipidomics data with ML is possible to improve the identification of new biomarkers or unveil new molecular mechanisms associated with lipid impairment across neurodegeneration. In this review, we present the lipidomic neurobiology state-of-the-art highlighting its potential applications to study neurodegenerative conditions. Also, we present theoretical background, applications, and advances in the integration of lipidomics with ML. This review opens the door to new approaches in this rising field.     

Identification of two pathogenic mutations in SORL1 in early-onset Alzheimer’s disease

The sortilin-related receptor 1 (SORL1) gene has been the subject of many studies focusing on frequent polymorphisms, which is associated with increased risk for Alzheimer’s Disease (AD). By whole-exome sequencing (WES), we identified two pathogenic missense mutations c.579C > G (p.F193L) and c.1397A > G (p.N466S) in SORL1. The two mutations were located in the same protein domain, and the two unrelated probands both had an onset of memory problems at less than 65 years of age, but their clinical manifestations and cranial imaging are different. The protein structure and function affected by these mutations were predicted using bioinformatics analysis, which suggested they were pathogenic. 3D protein structural analysis revealed that these amino acid substitutions might result in instability of protein structure and adverse intramolecular interactions. These findings suggest that both F193L and N466S should be thought as potential causative mutations in early-onset Alzheimer’s disease (EOAD) patients. Further functional studies are warranted to evaluate their roles in the pathogenesis of AD.     

Depression in a Patient With Alzheimer Disease

This is a case study of a 73-year-old woman recently diagnosed with Alzheimer disease living in an assisted living facility who presented to an outpatient behavioral health clinic with her son for evaluation and treatment of depression. This article highlights the presentation of depression (a diagnosis) versus apathy (a symptom of Alzheimer disease) and the need to assess for co-occurring mood disorders that warrant pharmacologic intervention as well as treatment for cognitive decline in Alzheimer disease.     

A review of dementia,focusing on the distinct roles of viral protein corona and MMP9 in dementia: Potential pharmacotherapeutic priorities

Dementia, in particular, is a defining feature of Alzheimer's and Parkinson's diseases. Because of the combination of motor and cognitive impairments, Parkinson's disease dementia (PDD) has a greater impact on affected people than Alzheimer's disease dementia (ADD) and others. If one family member develops dementia, the other members will suffer greatly in terms of social and occupational functioning. Currently, no relevant treatment is available based on an examination of the absolute pathophysiology of dementia. As a result, our objective of current review encouraged to look for dementia pharmacotherapy based on their pathogenesis. We systematically searched electronic databases such as PubMed, Scopus, and ESCI for information on the pathophysiology of demetia, as well as their treatment with allopathic and herbal medications. By modulating intermediate proteins, oxidative stress, viral protein corona, and MMP9 are etiological factors that cause dementia. The pathophysiology of ADD was described by two hypotheses: the amyloid cascade hypothesis and the tau and tangle hypothesis. ADD is caused by an increase in amyloid-beta (Aβ) and neurofibrillary tangles in the cerebrum. The viral protein corona (VPC) is more contagious and helps to form amyloid-beta (Aβ) plaques and neurofibrillary tangles in the cerebrum. Thioredoxin interacting protein (TXNIP) inside the BBB encourages Aβ to become more engaged. PDD is caused by decreased or absent dopamine secretion from nerve cells in the substantia nigra, as well as PRKN gene deletion/duplication mutations, and shift in the PRKN-PACRG organisation, all of which are linked to ageing. This article discussed the pathophysiology of dementia, as well as a list of herbal medications that can easily cross the BBB and have a therapeutic effect on dementia.     

生慧汤对APP/PS1雄性AD小鼠海马内APP代谢产物的昼夜变化影响＊

目的研究生慧汤对APP/PS1（β-amyloid precursor protein/presenilin 1246E）小鼠海马内β淀粉样前体蛋白（Amyloid precursor protein，APP）代谢产物昼夜表达的影响。方法 将56只雄性APP/PS1双转基因痴呆模型小鼠随机分为4组，分别为：痴呆模型组、褪黑素治疗组（0.78 mg·kg^-1·d^-1）、生慧汤高剂量组（27.0 g·kg^-1·d^-1）、生慧汤低剂量组（13.5 g·kg^-1·d^-1），每组14只；对照组为14只雄性C57BL/6J小鼠，连续给药30天。采用Morris水迷宫检测小鼠学习记忆能力，采用酶联免疫吸附检测（ELISA）检测不同时间段取出的海马组织sAPPα含量。对海马β淀粉样蛋白_1-40、β淀粉样蛋白_1-42表达进行免疫印迹分析。免疫组化（IHC）检测海马CA1区Aβ_1-40蛋白的表达。结果 Morris水迷宫结果表明，与对照组相比，模型组上平台潜伏期明显延长、穿越平台次数明显减少（P<0.01）；与模型组相比，生慧汤不同剂量组上平台潜伏期明显缩短（P<0.01、P<0.05），穿越平台次数明显增加（P<0.05）。ELISA结果表明，与对照组相比，模型组的sAPPα总量、各时间段（12：00、24：00）sAPPα含量明显减少（P<0.01）；与模型组相比，生慧汤不同剂量组sAPPα总量明显增多（P<0.01、P<0.05），生慧汤高剂量组仅能增加12：00 sAPPα含量（P<0.01），生慧汤低剂量组仅能增加24：00 sAPPα含量（P<0.05）。对照组sAPPα含量具有明显昼夜差异（P<0.01）。模型组sAPPα含量的昼夜差异性消失（P>0.05）。生慧汤高剂量组sAPPα含量具有昼夜差异（P<0.01），生慧汤低剂量组sAPPα含量不具有昼夜差异（P>0.05）。Western blot结果显示，与对照组相比，模型组Aβ_1-40、Aβ_1-42蛋白表达明显增加（P<0.01）；与模型组相比，生慧汤高剂量组Aβ_1-40、Aβ_1-42蛋白表达减少（P<0.05、P<0.01）；生慧汤低剂量组仅能减少Aβ_1-40蛋白的表达（P<0.05），对Aβ_1-42蛋白表达无影响（P>0.05）。免疫组化结果表明，与对照组相比，模型组Aβ_1-40表达明显增加（P<0.01）；与模型组相比，生慧汤不同剂量组Aβ_1-40表达不同程度减少（P<0.01、P<0.05）。结论 生慧汤能够改善5月龄APP/PS1阿尔茨海默病模型小鼠的学习记忆障碍，其机制可能与恢复海马内APP代谢产物sAPPα的昼夜节律性表达、从而减少Aβ的沉积有关。