Paracrine signaling (via secretion of bioactive molecules)

Paracrine signaling is a form of cell-to-cell communication in which cells secrete bioactive molecules—such as growth factors, cytokines, chemokines, peptides, and small gaseous mediators—that diffuse over short distances to act on neighboring cells within the same tissue[1][2][6]. This localized mode of signal transmission allows rapid and spatially restricted cellular responses that are essential for processes such as development, tissue repair/wound healing, immune regulation, angiogenesis (formation of new blood vessels), synaptic transmission between neurons, and local inflammatory reactions[3][4][8]. Unlike endocrine signals that travel through the bloodstream to distant targets or autocrine signals that affect the secreting cell itself, paracrine signals are typically short-lived due to rapid degradation or uptake by nearby cells. Prominent examples include fibroblast growth factor (FGF), vascular endothelial growth factor (VEGF), transforming growth factor-beta family members (TGF-beta), nitric oxide in vasodilation pathways, neurotransmitters at synapses between nerve cells—and many others depending on context[1][6]. While individual components involved in paracrine signaling—such as receptors for FGF or VEGF—can be considered therapeutic targets with associated drugs and safety profiles ("receptor tyrosine kinases," "cytokine receptors," etc.), "paracrine signaling via secretion of bioactive molecules" describes an entire class/mechanism rather than a discrete molecular entity. Therefore it is not considered a canonical therapeutic target but rather an overarching biological concept/process.

Other names

Paracrine communicationParacrine functionLocal cell signaling