LPC 18:2-Driven Apoptosis In Neutrophils Is Non-Inflammatory and Lipid Raft Dependent
Lysophosphatidylcholines (LPCs) are potent bioactive lipids whose fatty acid composition dictates their immunomodulatory effects. Here, we delineate how unsaturated LPC 18:2 and saturated LPC 16:0 differentially regulate neutrophil survival and inflammatory programs. LPC 18:2 markedly increased reactive oxygen species (ROS) generation and caspase-3/7 activation, accompanied by Annexin V positivity, mitochondrial membrane depolarization, and cytochrome C release, f. Features consistent with intrinsic apoptosis. In contrast, LPC 16:0 induced robust LDH and HMGB-1 release, indicating membrane rupture and pyroptosis-like death. Bulk RNA sequencing revealed that LPC 16:0 strongly upregulated inflammatory and cytokine genes. Disruption of lipid-raft integrity abolished LPC 18:2–induced ROS and apoptosis, underscoring the dependence of these effects on membrane organization. Collectively, these results identify LPC 18:2 as a non-inflammatory, mitochondria-dependent inducer of neutrophil apoptosis, whereas LPC 16:0 promotes inflammatory, lytic death programs. These findings highlight how lipid saturation determines neutrophil fate and immune tone, providing mechanistic insight into how distinct LPC species shape inflammation and tissue injury. Overall design: The experiment was conducted using Homo sapiens primary peripheral blood neutrophils. Cells were subjected to three treatment conditions: unstimulated (vehicle control), LPC 16:0 at 10 µM for 45 minutes, and LPC 18:2 at 10 µM for 45 minutes. A single time point of 45 minutes post-treatment was analyzed. Each condition included three independent biological replicates derived from distinct healthy donors, resulting in a total of nine RNA-seq libraries. Each donor served as a unique biological replicate, and within a given donor, only one treatment was applied per sample without any technical pooling.