Hypoxia regulation of facilitated glucose transporter-1 and glucose transporter-3 in mouse chondrocytes mediated by HIF-1alpha.

Chondrocytes reside in a hypoxic environment; they utilize glucose as the main energy source. Facilitated glucose transport represents the first rate-limiting step in glucose metabolism. Here we demonstrated that hypoxia induced an elevated expression level of GLUT-1 and -3 in chondrocytes. Also elevated was hypoxia inducible factor-1alpha (HIF-1alpha) protein level. On the contrary, deletion of HIF-1alpha led to complete loss of the hypoxia-induced gene expression of GLUT-1 and 3. These results suggested that chondrocytes had the capacity to detect and respond to low oxygen availability with changes in expression of oxygen-regulated genes, and that hypoxia regulation of facilitated GLUT-1 and -3 was mediated by HIF-1alpha.