Affiliations: Dipartimento di Biochimica "G. Moruzzi",
Università di Bologna, Via Irnerio 48, I-40126 Bologna, Italy
Note: [] Address for correspondence: Prof. Gabriele Hakim, Dipartimento
di Biochimica "G. Moruzzi", Via Irnerio, 48, I-40126 Bologna, Italy. Fax: +
39 0512091234; E-mail: [email protected]
Abstract: This work aims to elucidate the mechanisms involved in the early
activation of glucose transport in hematopoietic M07e cells by stem cell factor
(SCF) and a reactive oxygen species (ROS) as
H_2O_2. SCF and
H_2O_2 increase
V_{max} for glucose transport; this enhancement is due to a
higher content in GLUT1 in plasma membranes, possibly through a translocation
from intracellular stores. Inhibitors of tyrosine kinases or phospholipase C
(PLC) remove glucose transport enhancement and prevent translocation. The
inhibitory effect of STI-571 suggests a role for c-kit tyrosine kinase on
glucose transport activation not only by SCF, but also by
H_2O_2. On the other hand, neither
protein kinase C nor phosphoinositide-3-kinase appear to be involved in the
acute activation of glucose transport. Our data suggest that i) in M07e cells, SCF and exogenous
H_2O_2 elicit a short-term activation of
glucose transport through a translocation of GLUT1 from intracellular stores to
plasma membranes; ii) both stimuli could share at least some signaling pathways
leading to glucose uptake activation, involving protein tyrosine kinases and
PLC iii) H_2O_2 could act increasing the
level of tyrosine phosphorylation through the inhibition of tyrosine
phosphatases and mimicking the regulation role of endogenous ROS.
Keywords: glucose transport, reactive oxygen species, tyrosine kinases, phospholipase C
Journal: BioFactors, vol. 20, no. 2, pp. 97-108, 2004
