Basic fibroblast growth factor increases intracellular magnesium concentration through the specific signaling pathways

Basic fibroblast growth factor (bFGF) plays an important role in angiogenesis. However, the underlying mechanisms are not clear. Mg²⁺ is the most abundant intracellular divalent cation in the body and plays critical roles in many cell functions. We investigated the effect of bFGF on the intracellular Mg²⁺ concentration (Mg²⁺]_i) in human umbilical vein endothelial cells (HUVECs). bFGF increased Mg²⁺]_i in a dose-dependent manner, independent of extracellular Mg²⁺. This bFGF-induced Mg²⁺]_i increase was blocked by tyrosine kinase inhibitors (tyrphostin A-23 and genistein), phosphatidylinositol 3-kinase (PI3K) inhibitors (wortmannin and LY294002) and a phospholipase Cγ (PLCγ) inhibitor (U73122). In contrast, mitogen-activated protein kinase inhibitors (SB202190 and PD98059) did not affect the bFGF-induced Mg²⁺]_i increase. These results suggest that bFGF increases the Mg²⁺]_i from the intracellular Mg²⁺ stores through the tyrosine kinase/PI3K/PLCγ-dependent signaling pathways.