Paracrine cell–cell communication does not require cell–cell contact, rather depending on the diffusion of signalling molecules from one cell to another after secretion. To understand the role of each cell within its local community, one must identify the protein messages passed between cells measuring expressed messenger molecules and their associated pathways is fundamental to understanding the directionality, magnitude and biological relevance of CCC.Ī | ‘Autocrine signalling’ refers to intracellular communication whereby cells secrete ligands that are used to induce a cellular response through cognate receptors for those molecules expressed on the same cell. These cells with altered expression further interact with their microenvironment.
Receiver cells trigger downstream signalling through cognate receptors, generally culminating in altered transcription factor activity and gene expression. The signalling events behind CCC are often mediated by interactions of various types of protein, encompassing ligand–receptor, receptor–receptor and extracellular matrix–receptor interactions. Some molecules support structural CCIs (for example, cell adhesion molecules), whereas ligands such as hormones, growth factors, chemokines, cytokines and neurotransmitters mediate cell–cell communication (CCC) (Fig. CCIs leverage diverse molecules, including ions, metabolites, integrins, receptors, junction proteins, structural proteins, ligands and secreted proteins of the extracellular matrix. Thus, studies on cellular functions increasingly require consideration of the community context of each cell 4.
Multicellular life relies on the coordination of cellular activities, which depend on cell–cell interactions (CCIs) across an organism’s diverse cell types and tissues 1, 2, 3.