Monocytes can be induced to express lymphatic phenotypes

Abstract

Although it has been recently shown that monocytes can transdifferentiate into blood vascular endothelial cells which are involved in angiogenesis, little attention has been paid to their potential to transdifferentiate into lymphatic endothelial cells. Therefore, we examined this question in our study. We first stimulated monocytes with either fibronectin (FN), VEGF-C, TNF-alpha, LPS, or IL-3 for 24h. Then we examined the expression of several markers of lymphatic endothelium and found that the monocytes expressed specific lymphatic endothelial markers, LYVE-1, Podoplanin, and Prox-1, but not common endothelial markers vWF or eNOS. Next, monocytes were incubated in endothelial growth medium with FN and VEGF-C for 6d. These monocytes were also found to express LYVE-1, Podoplanin and Prox-1, but not vWF or eNOS. Our results indicate that monocytes in vitro can be easily induced to present lymphatic phenotypes in an inflammatory environment.