Early lymph vessel development from embryonic stem cells

Researching the Cure for Lymphedema

May 2006

Early lymph vessel development from embryonic stem cells.

Kreuger J, Nilsson I, Kerjaschki D, Petrova T, Alitalo K, Claesson-Welsh L. Department of Genetics and Pathology, Uppsala University, Sweden. johan.kreu...@genpat.uu.se

OBJECTIVE:

The purpose of this study was to establish a model system for lymph vessel development based on directed differentiation of murine embryonic stem cells.

METHODS AND RESULTS:

Stem cells were aggregated to form embryoid bodies, and subsequently cultured in 3-dimensional collagen matrix for up to 18 days. Treatment with vascular endothelial growth factor (VEGF)-C and VEGF-A individually enhanced formation of lymphatic vessel structures, although combined treatment with VEGF-C and VEGF-A was most potent and gave rise to a network of LYVE-1, podoplanin, Prox1, and VEGF receptor-3 positive lymphatic vessel structures running parallel to and apparently emanating from, capillaries. In contrast, fibroblast growth factor-2, hepatocyte growth factor, or hypoxia had little or no effect on the development of the early lymphatics. Further, cells of hematopoietic origin were shown to express lymphatic markers. In summary, different subpopulations of lymphatic endothelial cells were identified on the basis of differential expression of several lymphatic and blood vessel markers, indicating vascular heterogeneity.

CONCLUSIONS:

We conclude that the present model closely mimics the early steps of lymph vessel development in mouse embryos.

PMID: 16543496 [PubMed - indexed for MEDLINE]

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Differentiation of Lymphatic Endothelial Cells From Embryonic Stem Cells on OP9 Stromal Cells.

Kono T, Kubo H, Shimazu C, Ueda Y, Takahashi M, Yanagi K, Fujita N, Tsuruo T, Wada H, Yama****a JK. Molecular and Cancer Research Unit, HMRO and Department of Thoracic Surgery, Graduate School of Medicine, Kyoto University, Japan; Laboratory of Stem Cell Differentiation, Stem Cell Research Center, Institute for Frontier Medical Sciences, Kyoto University, Japan; Institute of Molecular and Cellular Biosciences, The University of Tokyo, Japan; and PRESTO, Japan Science and Technology Agency, Japan.

OBJECTIVE:

The discovery of vascular endothelial growth factor C (VEGF-C) and VEGF receptor-3 (VEGFR-3) has started to provide an understanding of the molecular mechanisms of lymphangiogenesis. The homeobox gene prox1 has been proven to specify lymphatic endothelial cells (ECs) from blood ECs. We investigated the process of lymphatic EC (LEC) differentiation using embryonic stem (ES) cells.

METHODS AND RESULTS:

VEGFR-2(+) cells derived from ES cells differentiated into LECs at day 3 on OP9 stromal cells defined by the expression of prox1, VEGFR-3, and another lymphatic marker podoplanin. VEGFR-2(+) cells gave rise to LYVE-1(+) embryonic ECs, which were negative for prox1 on day 1 but turned to prox1(+) LECs by day 3. VEGFR-3-Fc or Tie2-Fc, sequestering VEGF-C or angiopoietin1 (Ang1), suppressed colony formation of LECs on OP9 cells. However, addition of VEGF-C and Ang1 in combination with VEGF to the culture of VEGFR-2(+) cells on collagen-coated dishes failed to induce LECs. LEC-inducing activity of OP9 cells was fully reproduced on paraformaldehyde-fixed OP9 cells with the conditioned medium.

CONCLUSIONS: We succeeded in differentiating LECs from ES cells and revealed the requirements of VEGF-C, Ang1, and other unknown factors for LEC differentiation.

PMID: 16690875 [PubMed - as supplied by publisher]

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