| 1. |
- Bell, Joanne, et al.
(författare)
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A novel BACE inhibitor (PF-05297909): : A two-part adaptive design to evaluate safety, pharmacokinetics and pharmacodynamics for modifying beta-amyloid in a first-in-human study
- 2013
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Ingår i: Alzheimer's & Dementia. - : Wiley. - 1552-5260 .- 1552-5279. ; 9:4, s. P287-
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundThe accumulation of amyloid beta (Aβ) peptides is believed to be a central contributor to the neurodegeneration seen in the Alzheimer's disease (AD) brain. Given the central role of Aβ42 in AD pathogenesis, a therapeutic strategy to lower central Aβ42 (and Aβ40) levels via inhibition of BACE was adopted in a first in human trial in a 2-part adaptive design.MethodsPart 1 evaluated PF-05297909 plasma PK and the PK/PD relationship for the reduction of plasma Aβ40, Aβ42 and AβX levels; Part 2 evaluated the exposure-response relationship between PF-05297909 and CSF levels of Aβ40, Aβ42 and AβX. Sufficient safety and tolerability, plasma exposure and reduction in plasma Aβ were necessary to initiate Part 2. Part 1 was a sequential parallel group dose escalation (25, 100, 250 and 325 mg) with n=8 (6:2, active:placebo) healthy volunteers (HV) in each cohort. Part 2 consisted of 3 cohorts of n=8 (6:2, active:placebo) HV. Doses selected for Part 2 started with the highest safe dose in Part 1 and then adapted for subsequent cohorts. The PK/PD relationship between PF-05297909 and Aβ42 was determined using a non-linear mixed effects (NLME) analysis. The doses for Part 2 - cohort 2 and 3 were to be chosen to improve the relative standard error in the estimate of the BACE IC50 as quantified by evaluating the determinant of the Fisher information matrix for the NLME model.ResultsPF-05297909 was well-tolerated. Reduction in plasma Aβ (Aβ40 and Aβ42) was exposure related with an apparent maximum at the 250 mg dose with a greater duration of activity at the 325 mg dose of PF-05297909. A 325 mg dose was selected for Part 2 - cohorts 1 and 2 without further cohorts being run, as stopping criteria for futility were met following analysis of cohort 2. A PK/PD relationship in CSF was not observed.ConclusionsThe adaptive designed PF-05297909 FIH study allowed efficient testing of safety and of the PK/PD relationship between PF-05297909 exposure and Aβ (Aβ40 and Aβ42). PF-05297909 was safe and well tolerated in HV at exposures tested. A robust effect on plasma Aβ did not translate to CSF pharmacodynamic effects.
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| 2. |
- Benedict, Christian, et al.
(författare)
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Self-reported sleep disturbance is associated with Alzheimer's disease risk in men
- 2015
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Ingår i: Alzheimer's & Dementia. - : Wiley. - 1552-5260 .- 1552-5279. ; 11:9, s. 1090-1097
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To study the association between self-reported sleep disturbances and dementia risk.METHODS: Self-reported sleep disturbances and established risk factors for dementia were measured in men at ages 50 (n = 1574) and 70 (n = 1029) years. Dementia incidence was determined by reviewing their patient history between ages 50 and 90 years. In addition, plasma levels of β-amyloid (Aβ) peptides 1-40 and 1-42 were measured at ages 70, 77, and 82 years.RESULTS: Cox regression demonstrated that men with self-reported sleep disturbances had a higher risk of developing dementia (+33%) and Alzheimer's disease (AD, +51%) than men without self-reported sleep disturbances (both P < .05). Binary logistic regression showed the increased risk for both dementia (+114%) and AD (+192%) were highest when sleep disturbance was reported at age 70 years (both P < .001). No group differences were found in Aβ levels.CONCLUSION: Improving sleep quality may help reduce the neurodegenerative risk in older men.
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| 5. |
- Elobeid, Adila, et al.
(författare)
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Alzheimer's disease-related plaques in nondemented subjects
- 2014
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Ingår i: Alzheimer's & Dementia. - : Wiley. - 1552-5260 .- 1552-5279. ; 10:5, s. 522-529
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Tidskriftsartikel (refereegranskat)abstract
- Alzheimer's disease (AD) pathology was assessed in 587 nondemented subjects, with age at death at or more than 50 years. In 307 subjects, amyloid-beta (A beta) immunoreactive (IR) plaques were seen; in 192 subjects, neuritic plaques (NPs) stained with modified Bielschowsky silver stain (mBky) were observed. In 20% of the whole cohort and in 62% of the 192 subjects with NPs in mBky, hyperphosphorylated tau (HPtau) IR NPs were seen. In most cases in this nondemented cohort, the HPtau IR NPs were observed either sparsely or to a moderate extent. The correlation between the NP score and Braak stage was best (r = 0.6, P < .001) when HPtau immunohistochemistry was used. Eighty-three percent of the subjects could not be categorized following the 1997 National Institute on Aging and the Reagan Institute (NIA-RI) recommendations, whereas the 2012 National Institute on Aging Alzheimer's Association (NIA-AA) guidelines were applicable for all study subjects. Twenty-eight subjects had an intermediate level of AD neuropathological change according to the 2012 NIA-AA guidelines, and 25 of these 28 subjects displayed HPtau IR NPs in the temporal cortex. It is noteworthy, however, that as many as 119 out of the 192 subjects with NPs in mBky displayed HPtau IR NPs in the temporal cortex. Ninety-four of these 119 subjects with neocortical HPtau IR NPs had a low level of neuropathological AD change according to the 2012 NIA-AA guidelines because they were in Braak stages I and II. Thus, 94 subjects were not acknowledged as being at risk for AD when applying the 2012 NIA-AA guidelines. We suggest that to identify all subjects with cortical HPtau pathology and, consequently, probably being at risk for developing AD, in addition to the level of AD neuropathological change as recommended by the 2012 NIA-AA guidelines, assessment of HPtau IR NPs in the neocortex should be carried out.
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| 6. |
- Jones, Lesley, et al.
(författare)
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Convergent genetic and expression data implicate immunity in Alzheimer's disease
- 2015
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Ingår i: Alzheimer's & Dementia. - : Wiley. - 1552-5260 .- 1552-5279. ; 11:6, s. 658-671
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Tidskriftsartikel (refereegranskat)abstract
- Background: Late-onset Alzheimer's disease (AD) is heritable with 20 genes showing genome-wide association in the International Genomics of Alzheimer's Project (IGAP). To identify the biology underlying the disease, we extended these genetic data in a pathway analysis. Methods: The ALIGATOR and GSEA algorithms were used in the IGAP data to identify associated functional pathways and correlated gene expression networks in human brain. Results: ALIGATOR identified an excess of curated biological pathways showing enrichment of association. Enriched areas of biology included the immune response (P = 3.27 X 10(-12) after multiple testing correction for pathways), regulation of endocytosis (P = 1.31 X 10(-11)), cholesterol transport (P = 2.96 X 10(-9)), and proteasome-ubiquitin activity (P = 1.34 X 10(-6)). Correlated gene expression analysis identified four significant network modules, all related to the immune response (corrected P = .002-.05). Conclusions: The immime response, regulation of endocytosis, cholesterol transport, and protein ubiquitination represent prime targets for AD therapeutics.
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| 7. |
- Karami, Azadeh, et al.
(författare)
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Changes in CSF cholinergic biomarkers in response to cell therapy with NGF in patients with Alzheimer's disease
- 2015
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Ingår i: Alzheimer's & Dementia. - : Wiley. - 1552-5260 .- 1552-5279. ; 11:11, s. 1316-1328
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: The extensive loss of central cholinergic functions in Alzheimer's disease (AD) brain is linked to impaired nerve growth factor (NGF) signaling. The cardinal cholinergic biomarker is the acetylcholine synthesizing enzyme, choline acetyltransferase (ChAT), which has recently been found in cerebrospinal fluid (CSF). The purpose of this study was to see if EC-NGF therapy will alter CSF levels of cholinergic biomarkers, ChAT, and acetylcholinesterase. Method: Encapsulated cell implants releasing NGF (EC-NGF) were surgically implanted bilaterally in the basal forebrain of six AD patients for 12 months and cholinergic markers in CSF were analyzed. Results: Activities of both enzymes were altered after 12 months. In particular, the activity of soluble ChAT showed high correlation with cognition, CSF tau and amyloid-beta, in vivo cerebral glucose utilization and nicotinic binding sites, and morphometric and volumetric magnetic resonance imaging measures. Discussion: A clear pattern of association is demonstrated showing a proof-of-principle effect on CSF cholinergic markers, suggestive of a beneficial EC-NGF implant therapy.
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| 8. |
- Kivimäki, Mika, et al.
(författare)
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Body mass index and risk of dementia : Analysis of individual-level data from 1.3 million individuals
- 2018
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Ingår i: Alzheimer's & Dementia. - : Elsevier. - 1552-5260 .- 1552-5279. ; 14:5, s. 601-609
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Higher midlife body mass index (BMI) is suggested to increase the risk of dementia, but weight loss during the preclinical dementia phase may mask such effects. Methods: We examined this hypothesis in 1,349,857 dementia-free participants from 39 cohort studies. BMI was assessed at baseline. Dementia was ascertained at follow-up using linkage to electronic health records (N = 6894). We assumed BMI is little affected by preclinical dementia when assessed decades before dementia onset and much affected when assessed nearer diagnosis. Results: Hazard ratios per 5-kg/m(2) increase in BMI for dementia were 0.71 (95% confidence interval = 0.66-0.77), 0.94 (0.89-0.99), and 1.16 (1.05-1.27) when BMI was assessed 10 years, 10-20 years, and >20 years before dementia diagnosis. Conclusions: The association between BMI and dementia is likely to be attributable to two different processes: a harmful effect of higher BMI, which is observable in long follow-up, and a reverse-causation effect that makes a higher BMI to appear protective when the follow-up is short. (C) 2017 The Authors. Published by Elsevier Inc. on behalf of the Alzheimer's Association.
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| 9. |
- Kumar, Rajnish, et al.
(författare)
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Proton pump inhibitors act with unprecedented potencies as inhibitors of the acetylcholine biosynthesizing enzyme - A plausible missing link for their association with incidence of dementia
- 2020
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Ingår i: Alzheimer's & Dementia. - : WILEY. - 1552-5260 .- 1552-5279. ; 16:7, s. 1031-1042
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Several pharmacoepidemiological studies indicate that proton pump inhibitors (PPIs) significantly increase the risk of dementia. Yet, the underlying mechanism is not known. Here, we report the discovery of an unprecedented mode of action of PPIs that explains how PPIs may increase the risk of dementia.Methods: Advanced in silico docking analyses and detailed enzymological assessments were performed on PPIs against the core-cholinergic enzyme, choline-acetyltransferase (ChAT), responsible for biosynthesis of acetylcholine (ACh).Results: This report shows compelling evidence that PPIs act as inhibitors of ChAT, with high selectivity and unprecedented potencies that lie far below their in vivo plasma and brain concentrations.Discussion: Given that accumulating evidence points at cholinergic dysfunction as a driving force of major dementia disorders, our findings mechanistically explain how prolonged use of PPIs may increase incidence of dementia. This call for restrictions for prolonged use of PPIs in elderly, and in patients with dementia or amyotrophic lateral sclerosis.
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