Journal of Alzheimer's disease : JAD
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Research in Caucasian populations has begun to examine the broad associations between physical and mental health in dementia caregivers. However, the examination of this relationship in Latin America is largely absent from the literature despite the fact that the region will see a major increase in dementia cases over the next 20 years. The current study examined the associations between health-related quality of life (HRQOL) and mental health in 90 dementia caregivers from Colombia, South America. ⋯ Follow-up multiple regressions found that caregiver role limitations due to physical problems was uniquely associated with satisfaction with life, whereas vitality, role limitations due to physical problems, and pain were uniquely associated with burden (although the pain effect was likely error due to a suppressor effect). Additionally, vitality and social functioning were uniquely negatively related to depression. Because of the extremely high overlap between these two sets of variables, dementia interventions are needed in Latin America that target both caregiver mental and physical health, as both likely operate in unison and influence each other.
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Alzheimer's disease (AD) is an age-related neurological disorder characterized by the deposition of amyloid-β (Aβ), cognitive deficits, and neuronal loss. The decline in neurogenic capacity could participate in neuronal vulnerability and contribute to memory impairment in AD. In our longitudinal study with AD model mice (5XFAD mice), we found that the number of doublecortin (neurogenesis marker)-positive cells in 5XFAD mice was significantly decreased compared to wild-type littermate mice. ⋯ We found that treatment with ghrelin increased the number of doublecortin, HH3, and calretinin-stained cells in the hippocampus of 5XFAD mice. In 5XFAD mice treated with ghrelin, the 4G8-positive area was not significantly different from the saline-treated 5XFAD mice. Together, these findings suggest that hippocampal neurogenesis is impaired in 5XFAD mice and that treatment with ghrelin successfully rescued the abnormality of neurogenesis in 5XFAD mice without affecting Aβ pathology.
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Neurodegenerative disease is one of the greatest health crises in the world and as life expectancy rises, the number of people affected will continue to increase. The most common neurodegenerative disease, Alzheimer's disease, is a tauopathy, characterized by the presence of aggregated tau, namely in the form of neurofibrillary tangles. Historically, neurofibrillary tangles have been considered the main tau species of interest in Alzheimer's disease; however, we and others have shown that tau oligomers may be the most toxic form and the species responsible for the spread of pathology. ⋯ Additionally, we injected pure brain-derived tau oligomers intracerebrally in 3-month-old wild-type and Htau mice and treated animals with biweekly injections of 60 μg TOMA or non-specific IgG. We found that long-term administration of TOMA was effective as a preventative therapy, inhibiting oligomeric tau and preserving memory function. These results support the critical role of oligomeric tau in disease progression and validate tau oligomers as a potential drug target.
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In the quest for biomarkers of onset and progression of Alzheimer's disease, a 1H NMR-based metabolomic study was performed on the simple single-transgenic Tg2576 mouse model. These mice develop a slow cognitive decline starting by 6 months and express amyloid plaques from 10 months of age. The metabolic profiles of extracts from five brain regions (frontal cortex, rhinal cortex, hippocampus, midbrain, and cerebellum) of Tg2576 male mice were compared to those of controls, at 1, 3, 6 and 11 months of age. ⋯ At this time point, the chemical profile of the cerebellum was slightly affected. At 11 months, all the brain regions analyzed (except the frontal cortex) were metabolically altered, with mainly a marked increase in the formation of the neuroprotective metabolites creatine and taurine. Our findings demonstrate that metabolic modifications occur long before the onset of behavioral impairment.
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Progressively increased proinflammatory status is a major characteristic of the aging process and associated with age-related diseases such as Alzheimer's diseases (AD). However, the regulation and role of common proinflammatory cytokines, including interleukin-12 (IL-12) and IL-23, in the aged brain are still unclear. Using the senescence-accelerated mouse prone-8 (SAMP8) model, we screened the cerebral expression of IL-12/23 in 3-, 7-, and 11-month-old mice and observed that their levels in the brain were upregulated during aging. ⋯ We found that these p40-deficient mice had significantly decreased cerebral amyloid-β levels, reduced synaptic and neuronal loss, and reversed cognitive impairments. Furthermore, in vivo delivery of a neutralizing p40-specific antibody likewise ameliorated AD-associated pathology and cognitive deficits in SAMP8 mice. Thus, our data indicate that the upregulated cerebral IL-12/23 during aging is involved in age-associated brain dysfunction and point to the modulation of IL-12/23 signaling molecule p40 as a promising strategy for the development of an AD therapy.