Lysophosphatidylcholine acyltransferase 1 promotes pathology and toxicity in two distinct cell-based alpha-synuclein models

•LPCAT1 is upregulated by αSyn 3K and is elevated in human PD tissue.•Suppression of LPCAT1 reduces αSyn 3K accumulations and cytotoxicity.•LPCAT1 and DPPC promote αSyn PFF seeded aggregation in neurons.•LPCAT1 may alter αSyn PFF endo-lysosomal processing. Alpha-synuclein (αSyn) pathology is a hallmark of Parkinson’s disease. Here we show that lysophosphatidylcholine acyltransferase 1 (LPCAT1) is a regulator of αSyn pathology and cytotoxicity. LPCAT1 is upregulated by αSyn E35K E46K E61K (3K) in human M17 neuroblastoma cells and primary rat cortical neurons, and in postmortem brain tissue from PD patients with confirmed αSyn aggregate pathology. Suppression of LPCAT1 reduces αSyn accumulations and toxicity in our neuroblastoma αSyn 3K overexpression model. Further overexpression of LPCAT1 promotes pS129 αSyn positive aggregation in primary neurons in the αSyn pre-formed fibril (PFF) model. A phospholipid product of LPCAT1 enzymatic activity, 1,2-dipalmitoyl-sn-glycero-3-phosphocholine, similarly promotes neuronal PFF seeded aggregation. Using a pH sensitive PFF model we provide evidence that αSyn fibrils have altered endo-lysosomal processing under LPCAT1 enhancement, suggesting less aggregate degradation. Our data demonstrates that LPCAT1 and associated phospholipids can regulate αSyn pathology.