Signaling molecules are substances that enable communication between cells and play a crucial role in regulating the behavior and function of stem cells. These molecules include growth factors, cytokines, hormones, neurotransmitters, small proteins, and lipids. They are released by cells into their environment or sent directly to target cells, where they bind to specific receptors.

Importance in Stem Cell Regulation

In relation to stem cells, signaling molecules:

Determine whether a stem cell will divide, remain in a resting state, or begin differentiating into a specialized cell type.

Support self-renewal or initiate transformation into different cell types depending on the surrounding microenvironment and the needs of the tissue.

Regulate growth, migration, survival, and programmed cell death based on the signaling composition in their environment.

Examples of Key Signaling Molecules

Important categories of signaling molecules involved in stem cell regulation include:

Growth factors (e.g., bFGF, EGF)

Cytokines (e.g., interleukins)

Wnt, Notch, and Hedgehog signaling pathways

Hormones and neurotransmitters (e.g., insulin, serotonin)

Small signaling molecules such as nitric oxide (NO)