Current Alzheimer Research - Volume 10, Issue 1, 2013

The γ-secretase complex cleaves the carboxy-terminal 99 residue (C99) fragment of the amyloid precursor protein (APP) to generate the amyloid-β (Aβ) peptide. The catalytic activity of this complex is mediated either by the presenilin- 1 (PS1) or the presenilin-2 (PS2) subunit. In vitro and in vivo studies have demonstrated that PS1-containing complexes generate more total Aβ product than PS2-containing complexes, indicating g Read More

Amyloid-β protein (Aβ) accumulates in the neurons of Alzheimer’s disease (AD) patients at an early stage of the disease. Recently, we found that Aβ with a toxic turn at positions 22 and 23 accumulates in neurons in AD brain. Here, we studied the accumulation of Aβ, toxic turn Aβ and high-molecular-weight Aβ oligomers in presenilin 1 (PS1) gene-transfected SH-SY5Y cells as well as in the brains of 3xTg-AD mice and AD pati Read More

Current strategies for the treatment of Alzheimer's disease (AD) involve tackling the formation or clearance of the amyloid-beta peptide (Aβ) and/or hyper-phosphorylated tau, or the support and stabilization of the remaining neuronal networks. However, as we gain a clearer idea of the large number of molecular mechanisms at work in this disease, it is becoming clearer that the treatment of AD should take a combined appro Read More

We have characterized the myelin changes observed within the hippocampal complex (HC) of a transgenic (Tg) mouse model of Alzheimer's disease (AD). Individual myelinated fibers were labeled with Black-Gold II while amyloid plaques were labeled with either Congo Red or Pan-A-beta immunofluoresence. Myelinated fibers were never seen passing through amyloid plaques in any region, while conspicuous myelin pathol Read More

Previously, we have shown that chronic treatment with allopregnanolone (ALLO) for three months impaired learning function in the Swe/PS1 mouse model. ALLO is a neurosteroid, produced in the CNS and a GABAA receptor agonist. ALLO modulates the general inhibitory system in the CNS by enhancing the effect of GABA. Chronic treatment with other GABAA receptor active compounds, such as benzodiazepines, ethanol and Read More

Background: Previous studies have demonstrated alterations in the peripheral cholinergic system in Alzheimer's disease (AD), though results have been inconsistent and not linked to in vivo biomarkers of pathology. We examined the relationship between amyloid-beta (Aβ) plaques and plasma cholinesterase activity in a heterogeneous dementia population. Methods: 29 participants with clinical AD and 35 with non-AD diagnoses Read More

Background: We recently reported elevated cerebrospinal fluid (CSF) levels of soluble tumor necrosis factor (TNF) receptors and TNF-α converting enzyme (TACE) activity in subjects with Alzheimer's disease (AD) in a Caucasian population. The TNF receptor-mediated signaling pathway contributes to the production of Aβ and the subsequent cytotoxicity that is observed in AD brains. However, whether the plasma levels o Read More

Association studies between Alpha-1-antichymotrypsin (ACT)-17(A>T) polymorphisms and Alzheimer's disease (AD) susceptibility have shown conflicting results. In this investigation, we performed a meta-analysis to assess the purported associations. Subgroup analyses based on ethnicity (Caucasians, East-Asian and American mixed) were also performed including a total of 5,676 AD patients and 5,460 controls for ACT-17. Read More

Objective: Alzheimer's Disease (AD) is often associated with depressive symptoms developing at any time before and after AD onset. The aetiology of depression in AD has not sufficiently been characterized, but biological aspects due to neurodegeneration and/ or genetic risk factors may play a plausible role and may distinguish it from common depressive disorders. Method: To investigate the possible relationship between geneti Read More

Background: Mild cognitive impairment (MCI) is a syndrome heterogeneous with regards to etiology and prognosis. Amyloid imaging enables to visualize a hallmark pathology of Alzheimer's disease (AD). Therefore we aimed to assess the usefulness of [11C]PiB PET for predicting clinical outcome of MCI patients after an interval of 2 years. Methods: In 28 MCI participants with a global CDR rating at baseline of 0.5 a baselin Read More

Introduction. Neuropsychiatric symptoms (NPS) are common in mild cognitive impairment (MCI) but its role as a predictive factor for the progression to dementia is still not clear. The objective of this study is to identify NPS that predict the progression from amnestic MCI (a-MCI) to dementia using an easy to administer screening tool for NPS. Material and Methods. 132 patients with a-MCI were assessed for NPS by t Read More

Background: Many early-stage Alzheimer's disease (AD) patients suffer from spatial navigational impairment even in familiar environments. Growing evidence shows that the retrosplenial cortex (RSC) is more damaged in youngonset AD patients (YOAD, onset age before 65) than in late-onset AD (LOAD) in the early-stage of AD. Impaired translation between egocentric and allocentric representations of the environment, Read More

A lower incidence of dementia in bipolar patients treated with lithium has been described. This metal inhibits the phosphorylation of glycogen-synthase-kinase 3-α and β, which are related to amyloid precursor protein processing and tau hyperphosphorylation in pathological conditions, respectively. Following the same rationale, a group just found that lithium has disease-modifying properties in amnestic mild cognitive im Read More

Despite over one hundred years of intense effort studying Alzheimer's disease (AD), we still do not understand its cause(s) and this adversely affects our ability to develop strongly effective treatments and means to prevent it. This is because our research efforts are not aligned to decipher this age-related disorder that, well after its discovery, has become a major cause of death throughout the world. We are therefore recomm Read More