TY - JOUR
T1 - Neuronal clearance of amyloid-β by endocytic receptor LRP1
AU - Kanekiyo, Takahisa
AU - Cirrito, John R.
AU - Liu, Chia Chen
AU - Shinohara, Mitsuru
AU - Li, Jie
AU - Schuler, Dorothy R.
AU - Shinohara, Motoko
AU - Holtzman, David M.
AU - Bu, Guojun
PY - 2013
Y1 - 2013
N2 - Alzheimer's disease (AD) is the most prevalent form of dementia in the elderly population. Accumulation, aggregation, and deposition of amyloid-β (Aβ) peptides generated through proteolytic cleavage of amyloid precursor protein (APP) are likely initiating events in the pathogenesis of AD. While Aβ production is accelerated in familial AD, increasing evidence indicates that impaired clearance of Aβ is responsible for late-onset AD. Because Aβ is mainly generated in neurons, these cells are predicted to have the highest risk of encountering Aβ among all cell types in the brain. However, it is still unclear whether they are also involved in Aβ clearance. Here we show that receptor-mediated endocytosis in neurons by the low-density lipoprotein receptor-related protein 1 (LRP1) plays a critical role in brain Aβ clearance. LRP1 is known to be an endocytic receptor for multiple ligands including Aβ. Conditional knock-out of Lrp1 in mouse forebrain neurons leads to increased brain Aβ levels and exacerbated amyloid plaque deposition selectively in the cortex of amyloid model APP/PS1 mice without affecting Aβ production. In vivo microdialysis studies demonstrated that Aβ clearance in brain interstitial fluid is impaired in neuronal Lrp1 knock-out mice. Because the neuronal LRP1-deletion did not affect the mRNA levels of major Aβ degrading enzymes, neprilysin and insulin-degrading enzyme, the disturbed Aβ clearance is likely due to the suppression of LRP1- mediated neuronal Aβ uptake and degradation. Together, our results demonstrate that LRP1 plays an important role in receptormediated clearance of Aβ and indicate that neurons not only produce but also clear Aβ.
AB - Alzheimer's disease (AD) is the most prevalent form of dementia in the elderly population. Accumulation, aggregation, and deposition of amyloid-β (Aβ) peptides generated through proteolytic cleavage of amyloid precursor protein (APP) are likely initiating events in the pathogenesis of AD. While Aβ production is accelerated in familial AD, increasing evidence indicates that impaired clearance of Aβ is responsible for late-onset AD. Because Aβ is mainly generated in neurons, these cells are predicted to have the highest risk of encountering Aβ among all cell types in the brain. However, it is still unclear whether they are also involved in Aβ clearance. Here we show that receptor-mediated endocytosis in neurons by the low-density lipoprotein receptor-related protein 1 (LRP1) plays a critical role in brain Aβ clearance. LRP1 is known to be an endocytic receptor for multiple ligands including Aβ. Conditional knock-out of Lrp1 in mouse forebrain neurons leads to increased brain Aβ levels and exacerbated amyloid plaque deposition selectively in the cortex of amyloid model APP/PS1 mice without affecting Aβ production. In vivo microdialysis studies demonstrated that Aβ clearance in brain interstitial fluid is impaired in neuronal Lrp1 knock-out mice. Because the neuronal LRP1-deletion did not affect the mRNA levels of major Aβ degrading enzymes, neprilysin and insulin-degrading enzyme, the disturbed Aβ clearance is likely due to the suppression of LRP1- mediated neuronal Aβ uptake and degradation. Together, our results demonstrate that LRP1 plays an important role in receptormediated clearance of Aβ and indicate that neurons not only produce but also clear Aβ.
UR - http://www.scopus.com/inward/record.url?scp=84889041948&partnerID=8YFLogxK
U2 - 10.1523/JNEUROSCI.3487-13.2013
DO - 10.1523/JNEUROSCI.3487-13.2013
M3 - Article
C2 - 24305823
AN - SCOPUS:84889041948
SN - 0270-6474
VL - 33
SP - 19276
EP - 19283
JO - Journal of Neuroscience
JF - Journal of Neuroscience
IS - 49
ER -