Alzheimer's disease and dementia with Lewy bodies: Special focus on the role of serpins

Serine protease inhibitors (Serpins) are involved in the pathogenesis of neurodegenerative dementia, including the two most common types, Alzheimer’s disease (AD) and dementia with Lewy bodies (DLB). The pathological characteristics of AD include senile plaques, mainly composed of aggregated amyloid-beta peptide (Abeta1-42), but also serpins, and neurofibrillary tangles of hyperphosphorylated tau protein. Pathological hallmarks of DLB include aggregates of alpha-synuclein (Lewy bodies), however, co-existing AD pathology is also frequently found. In the present work, we have investigated the role of three serpins, namely alpha1-antichymyotrypsin, alpha1-antitrypsin and neuroserpin, in the context of AD and DLB. We have shown that alpha1-antichymotrypsin: (i) renders the oligomer formation profile of incubated Abeta1-42, favouring dimer formation; (ii) under certain conditions appears to protect Abeta1-42 from chymotrypsin digestion and;(iii) in combination with soluble forms of Abeta1-42, significantly affects the global gene expression of primary fetal human astrocytes; (iv) can influence binding and, potentially, uptake of aggregated Abeta1-42 in primary adult human astrocytes. In two clinical studies we have: (i) for the first time, determined cerebrospinal fluid levels of neuroserpin and established a link to AD as significantly higher levels of neuroserpin were found in AD patients than in non-demented controls and DLB patients; (ii) showed that higher levels of cerebrospinal fluid alpha1-antitrypsin and plasma alpha1-antichymotrypsin correlate to lower cognitive function in patients with DLB and AD, respectively; (iii) showed that patients with AD and DLB have higher levels of intercellular adhesion molecule-1 and platelet endothelial cell adhesion molecule-1. Our findings support the statement that inflammatory and vascular mechanisms are involved in dementia pathogenesis and suggest that serpins most likely are involved in the processes leading to cognitive dysfunction. Further research is needed to assess the distinct actions of serpins in the mechanisms leading to neurodegeneration and dementia

Apolipoprotein E lipoprotein particles inhibit amyloid-β uptake through cell surface heparan sulphate proteoglycan

Binding affinity of heparin-apoE3 interaction. (A) Representative dot blot of heparin and apoE3 particles. Heparin was spotted onto nitrocellulose membrane along with mouse monoclonal anti-apoE antibody, WUE4, as a positive control and normal mouse IgG as a background. Membrane strips were incubated with increasing concentrations of apoE3 particles from immortalized astrocytes. Membrane-bound apoE was then visualized by biotin-conjugate anti-apoE antibody and infrared streptavidin secondary antibody. (B) Integrated infrared signal intensities from each dot were obtained and the average intensities from three independent experiments were plotted to acquire binding affinity curve and the dissociation constant (Kd). (TIF 2432 kb

CCL2 Is Associated with a Faster Rate of Cognitive Decline during Early Stages of Alzheimer's Disease

Chemokine (C-C motif) receptor 2 (CCR2)-signaling can mediate accumulation of microglia at sites affected by neuroinflammation. CCR2 and its main ligand CCL2 (MCP-1) might also be involved in the altered metabolism of beta-amyloid (Aβ) underlying Alzheimer's disease (AD). We therefore measured the levels of CCL2 and three other CCR2 ligands, i.e. CCL11 (eotaxin), CCL13 (MCP-4) and CCL26 (eotaxin-3), in the cerebrospinal fluid (CSF) and plasma of 30 controls and 119 patients with mild cognitive impairment (MCI) at baseline. During clinical follow-up 52 MCI patients were clinically stable for five years, 47 developed AD (i.e. cases with prodromal AD at baseline) and 20 developed other dementias. Only CSF CCL26 was statistically significantly elevated in patients with prodromal AD when compared to controls (p = 0.002). However, in patients with prodromal AD, the CCL2 levels in CSF at baseline correlated with a faster cognitive decline during follow-up (rs = 0.42, p = 0.004). Furthermore, prodromal AD patients in the highest tertile of CSF CCL2 exhibited a significantly faster cognitive decline (p<0.001) and developed AD dementia within a shorter time period (p<0.003) compared to those in the lowest tertile. Finally, in the entire MCI cohort, CSF CCL2 could be combined with CSF Tau, P-tau and Aβ42 to predict both future conversion to AD and the rate of cognitive decline. If these results are corroborated in future studies, CCL2 in CSF could be a candidate biomarker for prediction of future disease progression rate in prodromal AD. Moreover, CCR2-related signaling pathways might be new therapeutic targets for therapies aiming at slowing down the disease progression rate of AD

Barriers to Treatment for Female Problem Gamblers: A UK Perspective

There is a paucity of research in the UK which examines problem gambling and that which does exist is mainly quantitative, focuses on male samples and fails to look at treatment seeking populations or obstacles preventing problem gamblers from seeking treatment. This paper presents findings from part of a larger qualitative study that explored the experience of treatment for female problem gamblers. Data were collected using semi-structured interviews with eight women who had received individual cognitive-behavioural therapy in the National Health Service for their gambling problem. An interpretative phenomenological analysis approach was applied in the research process, identifying three main themes, of which the subtheme ‘Barriers to Treatment’ is examined here. Internal and external barriers to treatment organically emerged in all female participants’ accounts and appear to have an impact on service utilisation. Input directly from gamblers can be combined with findings from other studies to devise better ways of reaching female problem gamblers. A better understanding of barriers to treatment can also provide valuable direction for future research and suggest applications in clinical service provision and treatment planning

Altered CSF Orexin and α-Synuclein Levels in Dementia Patients.

Neurodegenerative dementia, most frequently represented by Alzheimer's disease (AD) and dementia with Lewy bodies (DLB), is often accompanied by altered sleeping patterns and excessive daytime sleepiness. Studies showing an association between the neuropeptide orexin and AD/DLB-related processes such as amyloid-β (Aβ)1-42 plaque formation, α-synuclein accumulation, and inflammation indicate that orexin might play a pathogenic role similar to the situation in narcolepsy. Our study of patients with AD (n = 26), DLB (n = 18), and non-demented controls (n = 24) shows a decrease in cerebrospinal fluid (CSF) orexin concentrations in DLB versus AD patients and controls. The observed differences in orexin levels were found to be specific to female DLB patients. We also show that the female DLB patients exclusively displayed lower levels of α-synuclein compared to AD patients and controls. Orexin was linked to α-synuclein and total-tau in female non-demented controls whereas associations between orexin and Aβ1-42 concentrations were absent in all groups regardless of gender. Thus, the proposed links between orexin, Aβ, and α-synuclein pathology could not be monitored in CSF protein concentrations. Interestingly, α-synuclein was strongly correlated to the CSF levels of total-tau in all groups, suggesting α-synuclein to be an unspecific marker of neurodegeneration. We conclude that lower levels of CSF orexin are specific to DLB versus AD and appear unrelated to Aβ1-42 and α-synuclein levels in AD and DLB. Alterations in CSF orexin and α-synuclein levels may be related to gender which warrants further investigation

Binding and Uptake of A beta 1-42 by Primary Human Astrocytes In Vitro

Clearance of the amyloid-P peptide (A beta) as a remedy for Alzheimer's disease (AD) is a major target in on-going clinical trials. In vitro studies confirmed that A beta is taken up by rodent astrocytes, but knowledge on human astrocyte-mediated A beta clearance is sparse. Therefore, by means of flow cytometry and confocal laser scanning microscopy (CLSM), we evaluated the binding and internalization of A beta 1-42 by primary human fetal astrocytes and adult astrocytes, isolated from nondemented subjects (n = 8) and AD subjects (n = 6). Furthermore, we analyzed whether alpha 1-antichymotrypsin (ACT), which is found in amyloid plaques and can influence A beta fibrillogenesis, affects the A beta uptake by human astrocytes. Upon over night exposure of astrocytes to FAM-labeled A beta 1-42 (10 mu M) preparations, (80.7 +/- 17.7)% fetal and (52.9 +/- 20.9)% adult A beta-positive astrocytes (P = 0.018) were observed. No significant difference was found in A beta 1-42 uptake between AD and non-AD astrocytes, and no influence of ApoE genotype on A beta 1-42 uptake was observed in any group. There was no difference in the percentage of A beta-positive cells upon exposure to A beta 1-42 (10 mu M) combined with ACT (1,000:1, 100:1, and 10:1 molar ratio), versus A beta 1-42 alone. CLSM revealed binding of A beta 1-42 to the cellular surfaces and cellular internalization of smaller A beta 1-42 fragments. Under these conditions, there was no increase in cellular release of the proinflammatory chemokine monocyte-chemoattractant protein 1, as compared with nontreated control astrocytes. Thus, primary human astrocytes derived from different sources can bind and internalize A beta 1-42, and fetal astrocytes were more efficient in A beta 1-42 uptake than adult astrocytes. (C) 2008 Wiley-Liss, Inc

Involvement of Matrix Metalloproteinase-9 in Amyloid-β 1-42-Induced Shedding of the Pericyte Proteoglycan NG2.

Deposition of amyloid-β (Aβ) 1-42, the major component of senile plaques characteristic of Alzheimer disease, affects brain microvascular integrity and causes blood-brain barrier dysfunction, increased angiogenesis, and pericyte degeneration. To understand the cellular events underlying Aβ1-42 effects on microvascular alterations, we investigated whether different aggregation forms of Aβ1-42 affect shedding of the pericyte proteoglycan NG2 and whether they affect proteolytic cleavage mediated by matrix metalloproteinase (MMP)-9. We found decreased levels of soluble NG2, total MMP-9, and MMP-9 activity in pericyte culture supernatants in response to fibril-enriched preparations of Aβ1-42. Conversely, oligomer-enriched preparations of Aβ1-42 increased soluble NG2 levels in the supernatants. This increase was ablated by the MMP-9/MMP-2 inhibitor SB-3CT. There was also a trend toward increased MMP-9 activity observed after oligomeric Aβ1-42 exposure. Our results, demonstrating an Aβ1-42 aggregation-dependent effect on levels of NG2 and MMP-9, support previous studies showing an impact of Aβ1-42 on vascular integrity and thereby add to our understanding of mechanisms behind the microvascular changes commonly found in patients with Alzheimer disease

Soluble adhesion molecules and angiotensin-converting enzyme in dementia.

We aimed to determine plasma and cerebrospinal fluid (CSF) levels of angiotensin-converting enzyme (ACE) and the soluble forms of intercellular adhesion molecule-1 (sICAM-1), vascular cell adhesion molecule-1 (sVCAM-1) and platelet endothelial cell adhesion molecule-1 (sPECAM-1) as surrogate markers for endothelial cell activation in clinically diagnosed patients with Alzheimer's disease (AD, n=260), dementia with Lewy bodies (DLB, n=39) and non-demented controls (n=34). Plasma sICAM-1 and sPECAM-1 were higher and CSF sVCAM-1 were lower in AD and DLB patients than in controls (p < 0.001). DLB patients had higher CSF sICAM-1, but lower CSF sVCAM-1 (p < 0.001). No difference in ACE levels was found between the dementia groups and controls. In controls and AD patients CSF sICAM and sVCAM-1 strongly correlated with each other and with blood barrier permeability whereas in DLB group these correlations were weaker. The observed patterns in adhesion molecules may reflect distinctions in the pathophysiological basis of their generation in dementia patients

The Relationship between Ethnicity, Christian Orthodoxy, and Mental Health

Although researchers have noted differences in the role of religiosity in the lives of people from different ethnic backgrounds, the components of religion’s influence (i.e., membership and orthodoxy) on mental health have not been previously examined. In the current study, Christian participants’ Christian Orthodox Scale (COS) scores were used to predict scores on mental health. As hypothesized, African Americans with higher COS scores exhibited fewer mental-health problems than did all ethnicities studied with lower COS scores. Implications and future directions for understanding the cultural influence of religion on African Americans are discussed