SDF1 (red) calls progenitor cells to endothelial cells (green) lacking oxygen.

Gurtner/Macmillan

Cells gasping for air call out to progenitor cells for help, according to results from Daniel Ceradini, Geoffrey Gurtner, and colleagues (NYU School of Medicine, New York, NY).

Stem cells and progenitor cells do not start making new tissue just anywhere—most often, they are recruited to injury sites. The chemokine SDF-1 is known to trigger this recruitment, but what causes injured tissues to make SDF-1 was unclear.

Gurtner's group shows that SDF-1 expression is activated by HIF-1, a transcription factor known to be stabilized at low oxygen levels. Tissues with low oxygen and high SDF-1—either injury sites or bone marrow, where progenitors normally hang out—were hot spots for endothelial progenitor cells (EPCs) carrying the SDF-1 receptor, CXCR4. These EPCs adhered better to endothelial cells expressing SDF-1, and they also migrated toward SDF-1 gradients...

The Rockefeller University Press
2004
The Rockefeller University Press
2004
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