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Series GSE127880 Query DataSets for GSE127880
Status Public on May 30, 2019
Title Lysosomal dysfunction in Down syndrome is APP-dependent and mediated by APP-βCTF (C99)
Organism Homo sapiens
Experiment type Expression profiling by high throughput sequencing
Third-party reanalysis
Summary Lysosomal failure underlies pathogenesis of numerous congenital neurodegenerative disorders and is an early and progressive feature of Alzheimer’s disease (AD) pathogenesis. Here, we report that lysosomal dysfunction in Down Syndrome (Trisomy 21) requires the extra gene copy of amyloid precursor protein (APP) and is mediated by the beta cleaved carboxy terminal fragment of APP (APP-βCTF, C99). In primary fibroblasts from individuals with Down Syndrome (DS), lysosomal degradation of autophagic and endocytic substrates is selectively impaired causing them to accumulate in enlarged autolysosomes/lysosomes. Direct measurements of lysosomal pH uncovered a significant elevation (0.6 units) associated with slowed LC3 turnover and the inactivation of cathepsin D (CTSD) and other lysosomal hydrolases known to be unstable or less active when lysosomal pH is persistently elevated. RNA sequencing analysis excluded a transcriptional contribution to hydrolase declines. Normalizing lysosome pH by delivering acidic nanoparticles to lysosomes ameliorated lysosomal deficits, implicating pH elevation as their primary basis. Cortical neurons cultured from the Ts2 mouse model of DS exhibited lysosomal deficits similar to those in DS cells. Lowering APP expression with siRNA or BACE1 inhibition reversed cathepsin deficits in both fibroblasts and neurons. Deleting one BACE1 allele from adult Ts2 mice had similar rescue effects in vivo. The modest elevation of endogenous APP-βCTF needed to disrupt lysosomal function in DS is relevant to sporadic AD where APP-βCTF, but not APP, is also elevated. Our results extend evidence that impaired lysosomal acidification drives progressive lysosomal failure in multiple forms of AD.
 
Overall design (1) mRNA-Seq profiling of six Trisomic and six Disomic human fibroblasts samples (3 replicates from 2 individuals in each group) from 5 months (3 replicates) and 2 years (3 replicates) old unrelated inviduals treated with either siRNA against human APP (siAPP) or a negative control DsiRNA (siNC). (2) A separate Differential Gene Expression (DGE) analysis was also carried out to compare transcriptomic profile of human Disomic and Trisomic fibroblasts using Disomic samples treated with siNC (3 replicates each of 5 months and 2 years individuals; Total = 6) in conjunction with age matched untreated human Disomic fibroblasts samples already deposited by Letourneau et al. (GSM1338333, GSM1338336) and Sullivan et al. (GSM2105075, GSM2105077); and Trisomic samples treated with siNC (3 replicates each of 5 months and 2 years individuals; Total = 6) in conjunction with age matched untreated human Trisomic fibroblasts samples from Letourneau et al. (GSM1338325, GSM1338326, GSM1338327) and Sullivan et al. (GSM2105044, GSM2105047). The final count of samples for the Disomic and Trisomic group is 11 and 10 respectively.
 
Contributor(s) Jiang Y, Sato Y, Im E, Berg M, Bordi M, Darji S, Kumar A, Mohan PS, Bandyopadhyay U, Diaz A, Cuervo AM, Nixon RA
Citation(s) 31043483
Submission date Mar 05, 2019
Last update date Jun 05, 2019
Contact name Sandipkumar Darji
E-mail(s) sdarji@nki.rfmh.org
Organization name Nathan Kline Institute for Psychiatric Research
Department Center for Dementia Research
Street address 140 Old Orangeburg Rd, Bldg 39
City Orangeburg
State/province NY
ZIP/Postal code 10962
Country USA
 
Platforms (1)
GPL11154 Illumina HiSeq 2000 (Homo sapiens)
Samples (24)
GSM3640444 Trisomic, -ve control DsiRNA treated, 5 months, replicate 1
GSM3640445 Trisomic, -ve control DsiRNA treated, 5 months, replicate 2
GSM3640446 Trisomic, -ve control DsiRNA treated, 5 months, replicate 3
Relations
Reanalysis of GSM1338333
Reanalysis of GSM1338336
Reanalysis of GSM2105075
Reanalysis of GSM2105077
Reanalysis of GSM1338325
Reanalysis of GSM1338326
Reanalysis of GSM1338327
Reanalysis of GSM2105044
Reanalysis of GSM2105047
BioProject PRJNA525687
SRA SRP187586

Download family Format
SOFT formatted family file(s) SOFTHelp
MINiML formatted family file(s) MINiMLHelp
Series Matrix File(s) TXTHelp

Supplementary file Size Download File type/resource
GSE127880_TMM_normalized_CountsPerMillion.txt.gz 654.7 Kb (ftp)(http) TXT
GSE127880_TMM_normalized_CountsPerMillion_siRNA_treatment.txt.gz 799.3 Kb (ftp)(http) TXT
GSE127880_TMM_normalized_TPMCounts.txt.gz 3.1 Mb (ftp)(http) TXT
GSE127880_TMM_normalized_TPMCounts_siRNA_treatment.txt.gz 5.4 Mb (ftp)(http) TXT
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Raw data are available in SRA
Processed data are available on Series record

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