Ceramide Connects TNF-α Signaling to Organelle Biophysical Remodeling
Ceramides are essential bioactive lipids involved in cell physiology and stress responses, yet the mechanisms linking their biophysical effects on membranes to downstream cellular outcomes remain incompletely understood. Here, we demonstrate that endogenous ceramide generation in response to TNF--induced stress results in the rapid remodeling of the plasma membrane, triggering a cascade of cellular events. Ceramide accumulation increases membrane order and drives the formation of internalizing vesicles enriched in ceramides, which traffic through the endolysosomal system. These vesicles act as carriers that transmit membrane remodeling signals to intracellular compartments, altering their biophysical properties and function. In parallel, ceramide production reprograms lipid droplet metabolism, decreasing polarity and modifying gene expression related to lipid storage. Our findings provide direct evidence that ceramides function as biophysical integrators of the TNF- stress response, coupling membrane order, vesicle trafficking, and lipid metabolic adaptation. This work reveals how localized lipid remodeling at the plasma membrane propagates intracellularly to support cellular adaptation and homeostasis under inflammatory stress.