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The accumulation of lysosomes and their hydrolases within neurons is a well-established neuropathologic feature of Alzheimer disease (AD). Here we show that lysosomal pathology in AD brain involves extensive alterations of macroautophagy, an inducible pathway for the turnover of intracellular constituents, including organelles. Using immunogold labeling(More)
Macroautophagy, which is a lysosomal pathway for the turnover of organelles and long-lived proteins, is a key determinant of cell survival and longevity. In this study, we show that neuronal macroautophagy is induced early in Alzheimer's disease (AD) and before beta-amyloid (Abeta) deposits extracellularly in the presenilin (PS) 1/Abeta precursor protein(More)
Endocytosis is critical to the function and fate of molecules important to Alzheimer's disease (AD) etiology, including the beta protein precursor (betaPP), amyloid beta (Abeta) peptide, and apolipoprotein E (ApoE). Early endosomes, a major site of Abeta peptide generation, are markedly enlarged within neurons in the Alzheimer brain, suggesting altered(More)
The formation of beta-amyloid in the brains of individuals with Alzheimer disease requires the proteolytic cleavage of a membrane-associated precursor protein. The proteases that may be involved in this process have not yet been identified. Cathepsins are normally intracellular proteolytic enzymes associated with lysosomes; however, when sections from(More)
The early endosome is the first vacuolar compartment along the endocytic pathway. It is the site of internalization and initial processing of amyloid precursor protein (APP) and apolipoprotein E (ApoE), two proteins of etiological importance in Alzheimer's disease, and a putative site of beta-amyloid peptide (Abeta) formation. Here, we identify early(More)
The neuronal lysosomal system is a major degradative pathway, induced by cell stress and closely linked to Alzheimer disease (AD) and other neurodegenerative diseases. Here, we show that mutations of presenilin (PS) 1 and 2, which cause familial early-onset AD (FAD), induce more severe lysosomal system neuropathology in humans than does sporadic AD (SAD).(More)
Calpain proteases influence intracellular signaling pathways and regulate cytoskeleton organization, but the neuronal and pathological roles of individual isoenzymes are unknown. In Alzheimer's disease (AD), the activated form of calpain I is significantly increased while the fate of calpain II has been more difficult to address. Here, calpain II antibodies(More)
Intracellular glycogen and glucose-6-phosphatase (G6Pase) activity were identified cytochemically within epithelia of the choroid plexus and ependyma of the cerebral ventricles including the median eminence and area postrema, the cerebral endothelium and pericytes from control, salt-stressed and fasted adult mice. Identification of glycogen was obtained by(More)
Early endosomes are a major site of amyloid precursor protein (APP) processing and a convergence point for molecules of pathologic relevance to Alzheimer's disease (AD). Neuronal endosome enlargement, reflecting altered endocytic function, is a disease-specific response that develops years before the earliest stage of AD and Down syndrome (DS). We examined(More)
In Alzheimer's disease brains, more than 90% of pyramidal neurons in lamina V and 70% in lamina III displayed 2- to 5-fold elevated levels of cathepsin D (Cat D) mRNA by in situ hybridization compared with neurologically normal controls. Most of these cells appeared histologically normal. The less vulnerable nonpyramidal neuron population in lamina IV had(More)