Summary
Urokinase-type plasminogen activator receptor (uPAR) plays a role in cellular responses
which include cellular adhesion, differentiation, proliferation and migration. The
aim of this study was to clarify the role of uPAR on the development of adipose tissue.
To clarify the role of uPAR on adipogenesis, we examined the effect of uPAR overexpression
and uPAR deficiency on the adipocyte differentiation. Adipocyte differentiation was
induced by incubation of 3T3-L1 cells with differentiation media containing insulin,
dexamethasone, and 1-methyl-3-isobutylxanthin. uPAR overexpression by transfection
of uPAR expression vector induced adipocyte differentiation. In addition, we examined
the difference in adipocyte differentiation of mesenchymal stem cells from wild-type
mice and uPAR knockout (uPAR-/-) mice. The uPAR deficiency attenuated differentiation media-induced adipocyte differentiation.
Moreover, we found that the inhibition of phosphatidylinositol 3-kinase (PI3K) pathway
attenuated uPAR overexpression-induced adipocyte differentiation, and uPAR overexpression
induced the activation of Akt. We also found that an increase of the adipose tissue
mass in uPAR-/- mice was less than that observed in wild-type mice. The present results suggest that
uPAR plays a pivotal role in the development of adipose tissue through PI3K/Akt pathway.
Keywords
uPAR - adipose tissue - adipogenesis