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Incomplete lysosomal acidification in microglia inhibits the degradation of fibrillar forms of Alzheimer's amyloid β peptide (fAβ). Here we show that in primary microglia a chloride transporter, ClC-7, is not delivered efficiently to lysosomes, causing incomplete lysosomal acidification. ClC-7 protein is synthesized by microglia but it is mistargeted and appears to be degraded by an endoplasmic re
β-Amyloid peptide accumulation plays a central role in the pathogenesis of Alzheimer's disease. Aberrant β-amyloid buildup in the brain has been shown to be present both in the extracellular space and within neurons. Synapses are important targets of β-amyloid, and alterations in synapses better correlate with cognitive impairment than amyloid plaques or neurofibrillary tangles. The link between β
Accumulation of β-amyloid (Aβ) and loss of synapses are hallmarks of Alzheimer's disease (AD). How synaptic activity relates to Aβ accumulation and loss of synapses is a current topic of major interest. Synaptic activation promotes Aβ secretion, and chronic reduction of synaptic activity reduced Aβ plaques in an AD transgenic mouse model. This suggested beneficial effects of reducing synaptic acti
Dementia is a decline in cognitive function that impairs a person's previous level of social and occupational function. Dementia is a very common medical condition that can result from diverse causes. Dementias are classified based on common clinical, genetic, and neuropathological features. The most common cause of dementia is Alzheimer's disease. Other major classes of disorders that cause demen
Background: The mammalian target of rapamycin (mTOR) is an evolutionarily conserved Ser/Thr protein kinase that plays a pivotal role in multiple fundamental biological processes, including synaptic plasticity. We explored the relationship between the mTOR pathway and β-amyloid (Ab)-induced synaptic dysfunction, which is considered to be critical in the pathogenesis of Alzheimer's disease (AD). Met
The aberrant accumulation of aggregated β-amyloid peptides (Aβ) as plaques is a hallmark of Alzheimer's disease (AD) neuropathology and reduction of Ab has become a leading direction of emerging experimental therapies for the disease. The mechanism(s) whereby Aβ is involved in the pathophysiology of the disease remain(s) poorly understood. Initially fibrils, and subsequently oligomers of extracell
Although β-amyloid (Aβ) plaques and tau neurofibrillary tangles are hallmarks of Alzheimer's disease (AD) neuropathology, loss of synapses is considered the best correlate of cognitive decline in AD, rather than plaques or tangles. How pathological Aβ and tau aggregation relate to each other and to alterations in synapses remains unclear. Since aberrant tau phosphorylation occurs in amyloid precur
A central question in Alzheimer's disease research is what role synaptic activity plays in the disease process. Synaptic activity has been shown to induce β-amyloid peptide release into the extracellular space, and extracellular β-amyloid has been shown to be toxic to synapses. We now provide evidence that the well established synaptotoxicity of extracellular β-amyloid requires β-secretase process
Immunotherapy against β-amyloid peptide (Aβ) is a leading therapeutic direction for Alzheimer disease (AD). Experimental studies in transgenic mouse models of AD have demonstrated that Aβ immunization reduces Aβ plaque pathology and improves cognitive function. However, the biological mechanisms by which Aβ antibodies reduce amyloid accumulation in the brain remain unclear. We provide evidence tha
I denna avhandling står släktinghemsföräldrar i fokus och stor vikt har lagts vidderas erfarenheter av att ta hand om ett släktingbarn, något som sällanuppmärksammas i forskning kring släktingplacering. Det övergripande syftet med studien har varit att utifrån ett livsloppsperspektiv och med familjeteoretiska begrepp analysera vad det kan innebära att ta hand om en familjemedlems barn genom ett foThis dissertation focuses on kinship foster parents and their experiences caring for their kinship children, something that is rarely touched on in kinship care research. The primary purpose of this study is to, based on a life-course perspective and with family theoretical concepts, analyze what it might mean to take care of a family member’s child through a formal commitment such as a foster car
Increasing evidence links intraneuronal β-amyloid (Aβ 42) accumulation with the pathogenesis of Alzheimer's disease (AD). In Aβ precursor protein (APP) mutant transgenic mice and in human AD brain, progressive intraneuronal accumulation of Aβ42 occurs especially in multivesicular bodies (MVBs). We hypothesized that this impairs the MVB sorting pathway. We used the trafficking of the epidermal grow
Synaptic dysfunction is increasingly viewed as an early manifestation of Alzheimer's disease (AD), but the cellular mechanism by which β-amyloid (Aβ) may affect synapses remains unclear. Since cultured neurons derived from APP mutant transgenic mice secrete elevated levels of Aβ and parallel the subcellular Aβ accumulation seen in vivo, we asked whether alterations in synapses occur in this settin
Amyloid-β peptide is elevated in the brains of patients with Alzheimer disease and is believed to be causative in the disease process. Amyloid-β reduces glutamatergic transmission and inhibits synaptic plasticity, although the underlying mechanisms are unknown. We found that application of amyloid-β promoted endocytosis of NMDA receptors in cortical neurons. In addition, neurons from a genetic mou
Plaques are a defining neuropathological hallmark of Alzheimer's disease (AD) and the major constituent of plaques, the β-amyloid peptide (Aβ), is considered to play an important role in the pathophysiology of AD. But the biological origin of Aβ plaques and the mechanism whereby Aβ is involved in pathogenesis have been unknown. Aβ plaques were thought to form from the gradual accumulation and aggr
Intrinsic optical emissions, such as autofluorescence and second harmonic generation (SHG), are potentially useful for functional fluorescence imaging and biomedical disease diagnosis for neurodegenerative diseases such as Alzheimer's disease (AD). Here, using multiphoton and SHG microscopy, we identified sources of intrinsic emissions in ex vivo, acute brain slices from AD transgenic mouse models
Histochemical analysis of postmortem human brains from subjects who suffered from dementia led to the discovery of Alzheimer’s disease a century ago. The histological lesions that characterized this common age-related dementia were the accumulation of senile plaques (SPs) and neurofibrillary tangles (NFTs). Subsequently, NFTs were found in a variety of degenerative diseases of the brain, while pla
A growing body of evidence suggests a relationship between oxidative stress and β-amyloid (Aβ) peptide accumulation, a hall-mark in the pathogenesis of Alzheimer's disease (AD). However, a direct causal relationship between oxidative stress and Aβ pathology has not been established in vivo. Therefore, we crossed mice with a knockout of one allele of manganese superoxide dismutase (MnSOD), a critic
Multiple lines of evidence implicate β-amyloid (Aβ) in the pathogenesis of Alzheimer's disease (AD), but the mechanisms whereby Aβ is involved remain unclear. Addition of Aβ to the extracellular space can be neurotoxic. Intraneuronal Aβ42 accumulation is also associated with neurodegeneration. We reported previously that in Tg2576 amyloid precursor protein mutant transgenic mice, brain Aβ42 locali
Molecular chaperones and their functions in protein folding have been implicated in several neurodegenerative diseases, including Parkinson's disease and Huntington's disease, which are characterized by accumulation of protein aggregates (e.g., α-synuclein and huntingtin, respectively). These aggregates have been shown in various experimental systems to respond to changes in levels of molecular ch
A central question in Alzheimer's disease concerns the mechanism by which β-amyloid contributes to neuropathology, and in particular whether intracellular versus extracellular β-amyloid plays a critical role. Alzheimer transgenic mouse studies demonstrate brain dysfunction, as β-amyloid levels rise, months before the appearance of β-amyloid plaques. We have now used immunoelectron microscopy to de
