Regulation of apoptosis in thymocytes

IMMATURE THYMOCYTES have served as an important model system for the study of biochemical mechanisms involved in the regulation of apoptosis (programmed cell death). From this work, it has become clear that the process is tightly regulated by cellular signaling pathways previously implicated in the control of cell proliferation and differentiation. In particular, elevations in the cytosolic Ca²⁺ concentration commonly trigger the response, and increases in cyclic adenosine monophosphate and activation of protein kinase C also appear to be involved. Ongoing research is aimed at characterizing how these and other signal transduction systems influence transcription and translation in apoptotic cells, as well as determining how their involvement in apoptosis differs from their role in other cellular responses.