Alzheimer's disease (AD) is an irreversible progressive neurodegenerative disease affecting approximately 50 million people worldwide. It is estimated to reach 152 million by the year 2050. AD is the fifth leading cause of death among Americans age 65 and older.
View Article and Find Full Text PDFAlzheimer's disease (AD) is by far the most prevalent neurodegenerative disease of aging and is a major burden for patients, caregivers, and the overall health care system. The complexity of AD pathophysiology and the lack of deep understanding of disease mechanisms impeded the development of AD therapy. Currently approved treatments for AD only modestly improve cognitive function but do not modify disease course.
View Article and Find Full Text PDFOur recent findings link the apolipoprotein E4 (ApoE4)-specific changes in brain phosphoinositol biphosphate (PIP) homeostasis to the susceptibility of developing Alzheimer's Disease (AD). In the present study, we have identified miR-195 as a top micro-RNA candidate involved in the ApoE/PIP pathway using miRNA profiles in human ROSMAP datasets and mouse microarray studies. Further validation studies have demonstrated that levels of miR-195 are significantly lower in human brain tissue of ApoE4 patients with clinical diagnosis of mild cognitive impairment (MCI) or early AD when compared to ApoE4 subjects.
View Article and Find Full Text PDFSynaptojanin1 (synj1) is a phosphoinositide phosphatase with dual SAC1 and 5'-phosphatase enzymatic activities in regulating phospholipid signaling. The brain-enriched isoform has been shown to participate in synaptic vesicle (SV) recycling. More recently, recessive human mutations were identified in the two phosphatase domains of SYNJ1, including R258Q, R459P and R839C, which are linked to rare forms of early-onset Parkinsonism.
View Article and Find Full Text PDFBackground: Multiomic studies by several groups in the NIH Accelerating Medicines Partnership for Alzheimer's Disease (AMP-AD) identified VGF as a major driver of Alzheimer's disease (AD), also finding that reduced VGF levels correlate with mean amyloid plaque density, Clinical Dementia Rating (CDR) and Braak scores. VGF-derived peptide TLQP-21 activates the complement C3a receptor-1 (C3aR1), predominantly expressed in the brain on microglia. However, it is unclear how mouse or human TLQP-21, which are not identical, modulate microglial function and/or AD progression.
View Article and Find Full Text PDFThe apolipoprotein E4 (ApoE4) genotype combines with traumatic brain injury (TBI) to increase the risk of developing Alzheimer's Disease (AD). However, the underlying mechanism(s) is not well-understood. We found that after exposure to repetitive blast-induced TBI, phosphoinositol biphosphate (PIP) levels in hippocampal regions of young ApoE3 mice were elevated and associated with reduction in expression of a PIP degrading enzyme, synaptojanin 1 (synj1).
View Article and Find Full Text PDFBrain lipid homeostasis plays an important role in Alzheimer's disease (AD) and other neurodegenerative disorders. Aggregation of amyloid-β peptide is one of the major events in AD. The complex interplay between lipids and amyloid-β accumulation has been intensively investigated.
View Article and Find Full Text PDFUnderstanding how brief synaptic events can lead to sustained changes in synaptic structure and strength is a necessary step in solving the rules governing learning and memory. Activation of ERK1/2 (extracellular signal regulated protein kinase 1/2) plays a key role in the control of functional and structural synaptic plasticity. One of the triggering events that activates ERK1/2 cascade is an NMDA receptor (NMDAR)-dependent rise in free intracellular Ca(2+) concentration.
View Article and Find Full Text PDFCaMKII is an abundant synaptic protein strongly implicated in plasticity. Overexpression of autonomous (T286D) CaMKII in CA1 hippocampal cells enhances synaptic strength if T305/T306 sites are not phosphorylated, but decreases synaptic strength if they are phosphorylated. It has generally been thought that spine size and synaptic strength covary; however, the ability of CaMKII and its various phosphorylation states to control spine size has not been previously examined.
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