Making healthy new blood vessels

Hypoxia-inducible factor-1α (HIF-1α) transactivates genes required for energy metabolism and is overexpressed during carcinogenesis and myocardial infarction, but the biological consequences of this overexpression remain unknown. In October 1 Genes & Development David Elson and colleagues from University of California at San Francisco show that the continuous expression of a single gene, HIF-1α, can induce the formation of new blood vessels in mice (Genes & Dev 2001, 15:2520-2532).

Elson et al. studied transgenic mice constitutively expressing active HIF-1α in the epidermis and observed a significant increase in the number of dermal capillaries, a 13-fold elevation of total vascular endothelial growth factor (VEGF) expression and a six- to nine fold induction of each VEGF isoform. The hypervascularity induced by HIF-1α was not associated with inflammation or vascular leakage (as it is in transgenic mice overexpressing VEGF cDNA) and appeared to be independent of angiopoietin-1 or angiopoietin-2 up-regulation.

According to...