paracrine signaling

Definition

Target type: biologicalprocess

The transfer of information from one cell to another, where the signal travels from the signal-producing cell to the receiving cell by passive diffusion or bulk flow in intercellular fluid. The signaling cell and the receiving cell are usually in the vicinity of each other. [GOC:mtg_signaling_feb11, ISBN:3527303782]

Paracrine signaling is a type of cell-to-cell communication where a cell secretes a signaling molecule that acts on nearby target cells. This is distinct from autocrine signaling, where a cell signals to itself, and endocrine signaling, where a cell secretes a hormone that travels through the bloodstream to act on distant target cells.

Here are the key steps involved in paracrine signaling:

1. **Signal Production:** The signaling cell produces a signaling molecule, which can be a protein, lipid, or other small molecule.
2. **Signal Release:** The signaling molecule is released from the signaling cell, typically through exocytosis.
3. **Signal Transport:** The signaling molecule diffuses through the extracellular space to reach nearby target cells.
4. **Signal Reception:** The signaling molecule binds to a specific receptor protein on the surface of the target cell.
5. **Signal Transduction:** Binding of the signaling molecule to the receptor activates a cascade of intracellular signaling events, often involving a series of protein kinases.
6. **Cellular Response:** The activated signaling pathway ultimately leads to a specific cellular response, which can include changes in gene expression, protein synthesis, cell growth, or other cellular processes.

Paracrine signaling plays a crucial role in many biological processes, including:

* **Development:** Paracrine signaling is essential for embryonic development, where it helps to regulate cell differentiation, growth, and migration.
* **Tissue Homeostasis:** Paracrine signaling helps to maintain the balance and function of tissues by regulating cell proliferation, differentiation, and survival.
* **Immune Response:** Paracrine signaling plays a critical role in the immune response, where it helps to activate and coordinate the activity of immune cells.
* **Nervous System:** Paracrine signaling is used by neurons to communicate with each other and with other cells.

Some common examples of paracrine signaling include:

* **Growth Factors:** These proteins stimulate cell growth and division. For example, epidermal growth factor (EGF) is a paracrine signaling molecule that stimulates the growth and proliferation of skin cells.
* **Cytokines:** These proteins are involved in immune responses and inflammation. For example, interleukin-1 (IL-1) is a paracrine signaling molecule that promotes inflammation.
* **Neurotransmitters:** These signaling molecules are used by neurons to communicate with each other. For example, acetylcholine is a neurotransmitter that is released at neuromuscular junctions to stimulate muscle contraction.

Overall, paracrine signaling is a vital form of cell-to-cell communication that is essential for the proper functioning of all multicellular organisms.'
"

Proteins (4)

Compounds (51)