| First Author | Wu Y | Year | 2021 |
| Journal | PLoS One | Volume | 16 |
| Issue | 7 | Pages | e0242236 |
| PubMed ID | 34292972 | Mgi Jnum | J:308480 |
| Mgi Id | MGI:6728013 | Doi | 10.1371/journal.pone.0242236 |
| Citation | Wu Y, et al. (2021) The effects of Cstb duplication on APP/amyloid-beta pathology and cathepsin B activity in a mouse model. PLoS One 16(7):e0242236 |
| abstractText | People with Down syndrome (DS), caused by trisomy of chromosome 21 have a greatly increased risk of developing Alzheimer's disease (AD). This is in part because of triplication of a chromosome 21 gene, APP. This gene encodes amyloid precursor protein, which is cleaved to form amyloid-beta that accumulates in the brains of people who have AD. Recent experimental results demonstrate that a gene or genes on chromosome 21, other than APP, when triplicated significantly accelerate amyloid-beta pathology in a transgenic mouse model of amyloid-beta deposition. Multiple lines of evidence indicate that cysteine cathepsin activity influences APP cleavage and amyloid-beta accumulation. Located on human chromosome 21 (Hsa21) is an endogenous inhibitor of cathepsin proteases, CYSTATIN B (CSTB) which is proposed to regulate cysteine cathepsin activity in vivo. Here we determined if three copies of the mouse gene Cstb is sufficient to modulate amyloid-beta accumulation and cathepsin activity in a transgenic APP mouse model. Duplication of Cstb resulted in an increase in transcriptional and translational levels of Cstb in the mouse cortex but had no effect on the deposition of insoluble amyloid-beta plaques or the levels of soluble or insoluble amyloid-beta42, amyloid-beta40, or amyloid-beta38 in 6-month old mice. In addition, the increased CSTB did not alter the activity of cathepsin B enzyme in the cortex of 3-month or 6-month old mice. These results indicate that the single-gene duplication of Cstb is insufficient to elicit a disease-modifying phenotype in the dupCstb x tgAPP mice, underscoring the complexity of the genetic basis of AD-DS and the importance of multiple gene interactions in disease. |
