Pluto Bioinformatics

GSE136894: 2-adrenergic agonists rescue lysosome acidification and function in PSEN1 deficiency by reversing defective ER to lysosome delivery of ClC-7

Bulk RNA sequencing

Lysosomal dysfunction is considered pathogenic in Alzheimer Disease (AD). Loss of Presenilin-1(PSEN1) function causing early onset AD impedes acidification via defective vATPase V0a1 subunit delivery to lysosomes. We report that isoproterenol and related 2-adrenergic agonists re-acidify lysosomes in PSEN1 KO cells and fibroblasts from PSEN1 familial AD(FAD) patients, restores lysosomal calcium homeostasis and proteolysis, and reverses impaired autophagy flux. We identify a novel rescue mechanism involving PKA-mediated facilitated delivery of ClC-7 to lysosomes, which stimulates chloride influx and reverses markedly lowered Cl- content of PSEN1 KO lysosomes. Notably, PSEN1 loss-of-function impedes ER-to-lysosome delivery of ClC-7, thus accounting for lysosomal Cl- deficits that compound pH deficits due to deficient vATPase function. Transcriptomics of PSEN1-deficient cells reveal strongly down-regulated ER-to-lysosome transport pathways and reversibility by isoproterenol. Our findings uncover a broadened PSEN1 role in lysosomal ion homeostasis and novel pH modulation of lysosomes through -adrenergic regulation of ClC-7, which can be therapeutically modulated. SOURCE: Sandipkumar Darji (sdarji@nki.rfmh.org) - Nathan Kline Institute for Psychiatric Research