Intercellular signaling pathways via transfer of proteins, RNAs, and lipids

Intercellular signaling pathways via transfer of proteins, RNAs, and lipids refer to a collection of biological communication mechanisms where cells exchange functional macromolecules to regulate gene expression, modulate cellular behavior, or alter the local microenvironment. This can occur through direct cell–cell contacts (e.g., via tunneling nanotubes), or via secretion and uptake of extracellular vesicles (such as exosomes, microvesicles, and apoptotic bodies) and lipoprotein complexes that carry proteins, RNAs (including mRNAs and microRNAs), and lipids between cells. These processes are fundamental for regulation of development, immunity, tissue repair, and disease progression (notably cancer), but do not represent an individual molecular drug target; rather, they are emergent properties or collections of targets/processes that include many specific molecules (e.g., vesicle surface proteins, cargo RNAs, lipid composition), none of which individually define the pathway as a discrete druggable entity. Manipulation of these pathways is emerging as a strategy in therapeutics and diagnostics, especially through the use of lipid nanoparticles for drug delivery or using circulating miRNAs as biomarkers. Note: This entry is not a valid "target" by standard pharmacological or molecular definitions and should be flagged as a conceptual/process-level pathway rather than a single actionable molecule or receptor.

Other names

Intercellular communication via extracellular vesiclesIntercellular macromolecule transferExtracellular vesicle-mediated signalingTNT-mediated macromolecule transfer (via tunneling nanotubes)

Modulation of extracellular vesicle biogenesis or uptake Inhibition of macromolecule transfer (e.g., using inhibitors of tunneling nanotubes or vesicle fusion) Delivery of therapeutic agents via lipid nanoparticles or engineered vesicles