Lipidomic and Transcriptomic Basis of Lysosomal Dysfunction in Progranulin Deficiency

• Main Authors: Bret M. Evers, Carlos Rodriguez-Navas, Rachel J. Tesla, Janine Prange-Kiel, Catherine R. Wasser, Kyoung Shin Yoo, Jeffrey McDonald, Basar Cenik, Thomas A. Ravenscroft, Florian Plattner, Rosa Rademakers, Gang Yu, Charles L. White, III, Joachim Herz
• Format: Article
• Language: English
• Published: Elsevier 2017-09-01
• Series: Cell Reports
• Subjects: neurodegeneration; Alzheimer’s disease; frontotemporal lobar degeneration; lipids; lipidomics; transcriptomics; lysosome; lysosomal storage disorders; neuronal ceroid lipofuscinoses
• Online Access: http://www.sciencedirect.com/science/article/pii/S2211124717311816

Defective lysosomal function defines many neurodegenerative diseases, such as neuronal ceroid lipofuscinoses (NCL) and Niemann-Pick type C (NPC), and is implicated in Alzheimer’s disease (AD) and frontotemporal lobar degeneration (FTLD-TDP) with progranulin (PGRN) deficiency. Here, we show that PGRN is involved in lysosomal homeostasis and lipid metabolism. PGRN deficiency alters lysosome abundance and morphology in mouse neurons. Using an unbiased lipidomic approach, we found that brain lipid composition in humans and mice with PGRN deficiency shows disease-specific differences that distinguish them from normal and other pathologic groups. PGRN loss leads to an accumulation of polyunsaturated triacylglycerides, as well as a reduction of diacylglycerides and phosphatidylserines in fibroblast and enriched lysosome lipidomes. Transcriptomic analysis of PGRN-deficient mouse brains revealed distinct expression patterns of lysosomal, immune-related, and lipid metabolic genes. These findings have implications for the pathogenesis of FTLD-TDP due to PGRN deficiency and suggest lysosomal dysfunction as an underlying mechanism.