bp(GO:"lysosomal protein catabolic process")
In many of these cases, the modification leads to targeting of the tagged substrate for degradation in the lysosome/vacuole PubMed:14556719
The accumulated autophagic vacuoles in AD mainly reflect defected lysosomal clearance instead of induced autophagy. PubMed:23528736
Even early autophagic activation may become impaired due to progressively diminishing lysosomal clearance of substrates. PubMed:29758300
While wild-type α-synuclein protein efficiently clears via CMA, the pathogenic A53T and A30P variants remain bound to LAMP-2, blocking lysosomal degradation by preventing binding of other substrate complexes to the receptor [64]. PubMed:29758300
While wild-type α-synuclein protein efficiently clears via CMA, the pathogenic A53T and A30P variants remain bound to LAMP-2, blocking lysosomal degradation by preventing binding of other substrate complexes to the receptor [64]. PubMed:29758300
Such evidence of lysosomal proteolytic failure in AD brain further strengthens the concept that impaired macroautophagy in AD is a critical event PubMed:29758300
Similar autophagy pathology is observed when lysosomal proteolysis is inhibited (Ivy et al. 1984; Koike et al. 2005; Yang et al. 2008). PubMed:22908190
Accelerated endocytosis also increases protein and lipid accumulation in endosomes and slows lysosomal degradation of endocytic cargoes (Cataldo et al. 2008), leading to lysosomal instability and neurodegeneration, as discussed below. PubMed:22908190
That presenilin 1 mutations, which are a cause of early-onset familial AD, impede lysosome proteolysis and accelerate neuritic dystrophy also supports a primary role for failure of proteolytic clearance (Lee et al. 2010). PubMed:22908190
It is this abnormal rab5 activation that causes protein and lipid accumulation in endosomes, slowed lysosomal degradation of endocytic cargoes,endosome swelling (Cataldo et al. 2008), and disrupted retrograde transport of endosomes (S Kim and RA Nixon, unpubl.). PubMed:22908190
A continuum of pathological changes of the lysosomal network unfolds in neurons as Alzheimer disease progresses, including dysregulation of endocytosis, increased lysosome biogenesis and, later, progressive failure of lysosomal clearance mechanisms (Fig. 6; Nixon et al. 2006). PubMed:22908190
Other studies have also demonstrated the accumulation of autolysosomes in the AD brain and experimentally when lysosomal proteolysis is compromised via genetic knockdown of specific cathepsins or use of pharmacological inhibition of lysosomes [2,3,15] PubMed:29758300
Such evidence of lysosomal proteolytic failure in AD brain further strengthens the concept that impaired macroautophagy in AD is a critical event PubMed:29758300
Even early autophagic activation may become impaired due to progressively diminishing lysosomal clearance of substrates. PubMed:29758300
A continuum of pathological changes of the lysosomal network unfolds in neurons as Alzheimer disease progresses, including dysregulation of endocytosis, increased lysosome biogenesis and, later, progressive failure of lysosomal clearance mechanisms (Fig. 6; Nixon et al. 2006). PubMed:22908190
Similar autophagy pathology is observed when lysosomal proteolysis is inhibited (Ivy et al. 1984; Koike et al. 2005; Yang et al. 2008). PubMed:22908190
It is this abnormal rab5 activation that causes protein and lipid accumulation in endosomes, slowed lysosomal degradation of endocytic cargoes,endosome swelling (Cataldo et al. 2008), and disrupted retrograde transport of endosomes (S Kim and RA Nixon, unpubl.). PubMed:22908190
Indeed, when lysosomal proteolysis is inhibited by blocking acidification or directly inhibiting cathepsins,axonal transport of autophagy-related compartments is selectively slowed and intermittently interrupted. PubMed:22908190
Accelerated endocytosis also increases protein and lipid accumulation in endosomes and slows lysosomal degradation of endocytic cargoes (Cataldo et al. 2008), leading to lysosomal instability and neurodegeneration, as discussed below. PubMed:22908190
Accelerated endocytosis also increases protein and lipid accumulation in endosomes and slows lysosomal degradation of endocytic cargoes (Cataldo et al. 2008), leading to lysosomal instability and neurodegeneration, as discussed below. PubMed:22908190
A close connection between lysosomal network dysfunction and mechanisms of neurodegeneration is well documented (McCray et al. 2008; Nixon et al. 2008; Bellettato et al. 2010; Cherra et al. 2010). PubMed:22908190
In APP transgenic mouse models of AD, undigested autophagy substrates including LC3-II, p62, and ubiquitinated proteins accumulate in neuronal AVs, establishing that autophagic protein turnover in lysosomes is impeded (Yang et al. 2011). PubMed:22908190
In APP transgenic mouse models of AD, undigested autophagy substrates including LC3-II, p62, and ubiquitinated proteins accumulate in neuronal AVs, establishing that autophagic protein turnover in lysosomes is impeded (Yang et al. 2011). PubMed:22908190
In APP transgenic mouse models of AD, undigested autophagy substrates including LC3-II, p62, and ubiquitinated proteins accumulate in neuronal AVs, establishing that autophagic protein turnover in lysosomes is impeded (Yang et al. 2011). 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
Chronic low-level stimulation of autophagy through peripheral administration of rapamycin or other agents (Tian et al. 2011), or enhancing lysosomal proteolysis selectively (Sun et al. 2008; Yang et al. 2011), can markedly diminish Ab levels and amyloid load in APP transgenic mice, underscoring the importance of lysosomal clearance of Ab. PubMed:22908190
Endocytic pathway up-regulation in AD stemming in part from pathological rab 5 activation generates higher levels of Ab (Mathews et al. 2002; Grbovic et al. 2003) that must be cleared in part by lysosomes. PubMed:22908190
Stimulating lysosomal proteolytic efficiency in the TgCRND8 APP mouse model by deleting an endogenous inhibitor of lysosomal cysteine proteases (cystatin B) rescues lysosomal pathology, eliminates abnormal autolysosomal accumulation of autophagy substrates, including Ab, decreases Ab and amyloid deposition, and ameliorates learning and memory deficits (Yang et al. 2011) PubMed:22908190
Stimulating lysosomal proteolytic efficiency in the TgCRND8 APP mouse model by deleting an endogenous inhibitor of lysosomal cysteine proteases (cystatin B) rescues lysosomal pathology, eliminates abnormal autolysosomal accumulation of autophagy substrates, including Ab, decreases Ab and amyloid deposition, and ameliorates learning and memory deficits (Yang et al. 2011) PubMed:22908190
Stimulating lysosomal proteolytic efficiency in the TgCRND8 APP mouse model by deleting an endogenous inhibitor of lysosomal cysteine proteases (cystatin B) rescues lysosomal pathology, eliminates abnormal autolysosomal accumulation of autophagy substrates, including Ab, decreases Ab and amyloid deposition, and ameliorates learning and memory deficits (Yang et al. 2011) PubMed:22908190
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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.