a(GO:autophagosome)
We found that abundance of autophagic vacuoles (autophagosomes + autolysosomes) significantly increased in cells expressing either of the two tau mutants (Fig. 4d,e). This increase was mainly due to higher content of autolysosomes (red puncta) (Fig. 4d,e), in support of increased macroautophagic flux PubMed:29024336
We found that abundance of autophagic vacuoles (autophagosomes + autolysosomes) significantly increased in cells expressing either of the two tau mutants (Fig. 4d,e). This increase was mainly due to higher content of autolysosomes (red puncta) (Fig. 4d,e), in support of increased macroautophagic flux PubMed:29024336
Paclitaxel reversed Aβ-induced microtubule disruption and restored autophagosomal transport in neurons [161], while a similar compound, epothilone D/BMS-241027, reduced tauopathy and improved cognition in P301S transgenic mice [162] although the compound did not progress beyond Phase I clinical testing PubMed:29758300
Recently, a comprehensive investigation utilizing gene expression analysis of the hippocampal region (CA1) of patients with Alzheimer’s disease identified that autophagosome formation and lysosomal biogenesis genes were upregulated at early stages of AD [21] PubMed:29758300
AV accumulations are not specific to the degenerative phenomena of AD; however, in AD brain, the extensive numbers of dystrophic neurites (Masliah et al. 1993; Schmidt et al. 1994), their characteristic marked distension, and the fact that they are predominantly filled with AVs distinguish the pattern and magnitude of this pathology from that of other aging-related neurodegenerative diseases (Benzing et al. 1993). PubMed:22908190
During macroautophagy, an elongated “isolation” membrane created from a preautophagosomal structure sequesters a region of cytoplasm to form a double- membrane-limited autophagosome (Fig. 5). PubMed:22908190
AVs are also enriched in APP substrates and secretases and, during autophagy, Ab peptide is generated from APP (Yu et al. 2005), although it is subsequently degraded in lysosomes under normal circumstances (Heinrich et al. 1999; Bahr et al. 2002; Florez-McClure et al. 2007). PubMed:22908190
For example, p62, an adaptor protein for autophagy, also influences proteasomal degradation, whereas VCP/p97 acting through p62 and ubiquitin regulates both the proteasome-dependent endoplasmic reticulum–associated degradation (ERAD) pathway and aspects of autophagosome maturation (Tresse et al. 2010). PubMed:22908190
The profuse and selective accumulation of AVs in neurons in AD reflects a defect in the clearance of AVs by lysosomes rather than an abnormally elevated induction of autophagy PubMed:22908190
Indeed, primary lysosomal dysfunction in inherited congenital “lysosomal storage disorders” has long been recognized to cause severe neurodegenerative phenotypes characterized pathologically by accumulations of lysosomes and autophagic vacuoles [38] PubMed:18930136
The initial step in autophagy involves expansion of a membranous structure called the “isolation membrane” or “phagophore” that engulfs a portion of the cell; the membrane eventually fuses to form a new double-membraned structure known as an autophagosome (Figure 1). PubMed:18930136
LC3-II staining is also used as a primary histological marker of autophagosomes. PubMed:18930136
The consequences of impaired lysosome function, for example, may be observed in cathepsin D knockout mice and Drosophila melanogaster cathepsin D mutants which show neurodegeneration and associated accumulation of autophagosomes and lysosomes [33–35]. PubMed:18930136
Indeed, a mouse model of distal-SBMA that expresses mutant p150/dynactin is characterized by accumulation of ubiquitin-positive aggregates and autophagic vacuoles in affected neurons [49]. PubMed:18930136
This suggestion originates from the observed accumulation of autophagic vacuoles in neurons from affected brain regions in a number of neurodegenerative diseases, including Alzheimer’s disease, Parkinson’s disease, Creutzfeldt- Jakob disease, and many of the polyglutamine diseases [21–24]. PubMed:18930136
Alzheimer’s disease pathology features massive accumulation of autophagic vacuoles within large swellings along dystrophic and degenerating neurites in neocortical and hippocampal pyramidal neurons [21]. PubMed:18930136
This suggestion originates from the observed accumulation of autophagic vacuoles in neurons from affected brain regions in a number of neurodegenerative diseases, including Alzheimer’s disease, Parkinson’s disease, Creutzfeldt- Jakob disease, and many of the polyglutamine diseases [21–24]. PubMed:18930136
This suggestion originates from the observed accumulation of autophagic vacuoles in neurons from affected brain regions in a number of neurodegenerative diseases, including Alzheimer’s disease, Parkinson’s disease, Creutzfeldt- Jakob disease, and many of the polyglutamine diseases [21–24]. PubMed:18930136
Similar to pimozide, clozapine activates the autophagy process via the AMPK–ULK1–Beclin1 pathway, as evidenced by increased levels of autophagy markers (i.e., LC3-II and Atg5–Atg12 conjugate); increased phosphorylation of AMPK and its downstream substrates, namely ULK1 and beclin1; and an increased number of autophagosomes in the frontal cortex in clozapine-treated rats PubMed:30061532
AV accumulations are not specific to the degenerative phenomena of AD; however, in AD brain, the extensive numbers of dystrophic neurites (Masliah et al. 1993; Schmidt et al. 1994), their characteristic marked distension, and the fact that they are predominantly filled with AVs distinguish the pattern and magnitude of this pathology from that of other aging-related neurodegenerative diseases (Benzing et al. 1993). PubMed:22908190
The profuse and selective accumulation of AVs in neurons in AD reflects a defect in the clearance of AVs by lysosomes rather than an abnormally elevated induction of autophagy PubMed:22908190
AVs and lysosomes constitute more than 95% of the organelles in dystrophic neuritic swellings in AD and AD mouse models, implying a cargo-specific defect in axonal transport, rather than a global one. PubMed:22908190
AVs are also enriched in APP substrates and secretases and, during autophagy, Ab peptide is generated from APP (Yu et al. 2005), although it is subsequently degraded in lysosomes under normal circumstances (Heinrich et al. 1999; Bahr et al. 2002; Florez-McClure et al. 2007). PubMed:22908190
The initial step in autophagy involves expansion of a membranous structure called the “isolation membrane” or “phagophore” that engulfs a portion of the cell; the membrane eventually fuses to form a new double-membraned structure known as an autophagosome (Figure 1). PubMed:18930136
Once formed, new autophagosomes move through a stepwise maturation process that culminates with fusion to a lysosome permitting degradation of the lumenal contents. PubMed:18930136
In mammals, autophagosomes first fuse with endosomes and multivesicular bodies to form amphisomes, which subsequently fuse with lysosomes to create degradative vacuoles termed autolysosomes [17]. PubMed:18930136
LC3-II staining is also used as a primary histological marker of autophagosomes. PubMed:18930136
This suggestion originates from the observed accumulation of autophagic vacuoles in neurons from affected brain regions in a number of neurodegenerative diseases, including Alzheimer’s disease, Parkinson’s disease, Creutzfeldt- Jakob disease, and many of the polyglutamine diseases [21–24]. PubMed:18930136
Alzheimer’s disease pathology features massive accumulation of autophagic vacuoles within large swellings along dystrophic and degenerating neurites in neocortical and hippocampal pyramidal neurons [21]. PubMed:18930136
This suggestion originates from the observed accumulation of autophagic vacuoles in neurons from affected brain regions in a number of neurodegenerative diseases, including Alzheimer’s disease, Parkinson’s disease, Creutzfeldt- Jakob disease, and many of the polyglutamine diseases [21–24]. PubMed:18930136
This suggestion originates from the observed accumulation of autophagic vacuoles in neurons from affected brain regions in a number of neurodegenerative diseases, including Alzheimer’s disease, Parkinson’s disease, Creutzfeldt- Jakob disease, and many of the polyglutamine diseases [21–24]. PubMed:18930136
The consequences of impaired lysosome function, for example, may be observed in cathepsin D knockout mice and Drosophila melanogaster cathepsin D mutants which show neurodegeneration and associated accumulation of autophagosomes and lysosomes [33–35]. PubMed:18930136
Indeed, a mouse model of distal-SBMA that expresses mutant p150/dynactin is characterized by accumulation of ubiquitin-positive aggregates and autophagic vacuoles in affected neurons [49]. PubMed:18930136
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If you find BEL Commons useful in your work, please consider citing: Hoyt, C. T., Domingo-Fernández, D., & Hofmann-Apitius, M. (2018). BEL Commons: an environment for exploration and analysis of networks encoded in Biological Expression Language. Database, 2018(3), 1–11.