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Survival of the Fattest

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Science  13 Oct 2000:
Vol. 290, Issue 5490, pp. 235
DOI: 10.1126/science.290.5490.235c

After proliferation is complete, many mature cells require persistent stimulation by growth factors to ward off apoptosis. How cell death is avoided in such circumstances has not been elucidated. Stimulation by growth factors could block one or more events in a constitutive death pathway, or could simply maintain cellular metabolism at a level that supports cell survival.

Rathmell et al. studied the stimulatory requirements of a lymphoid cell line that requires interleukin-3 (IL-3) for survival, and of primary T cells that require stimulation of antigen receptors. They found that survival factors appear to function by altering basic nutrient uptake. In the absence of receptor stimulation, cells lost the glucose transporter Glut1 and showed diminished mitochondrial function. When glucose was removed from the culture medium, survival factors no longer prevented cell death. These results indicate that mature unstimulated lymphocytes do not inherently achieve metabolic homeostasis, but rather operate under dynamic regulation by extracellular signals. — LBR

Mol. Cell6, 683 (2000).

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