Molecular profile and proliferative responses of rat lymphatic endothelial cells in culture.
BACKGROUND
Lymphangiogenesis plays an important role in metastasis of many solid tumors. To study lymphangiogenesis under controlled conditions, an in vitro model is needed. The goal of this work was to establish such an in vitro model by determining a molecular profile of rat mesenteric lymphatic endothelial cells (RMLEC) and characterizing their proliferative responses to angiogenic and lymphangiogenic factors, such as vascular endothelial growth factor A and C (VEGF-A and VEGF-C).


RESULTS
RMLEC strongly expressed most lymphatic-specific markers, including Prox-1, LYVE-1, and VEGFR-3. Proliferation of RMLEC was serum and heparin dependent. In the presence of low (2%) serum concentration, exogenously added VEGF-A and VEGFC stimulated RMLEC in a linear and dose-dependent manner. This effect was abrogated by anti-VEGF-A and VEGF-C antibodies, as well as by soluble Tie-2 and Flt-4 fusion proteins. Abrogation was reversed by VEGF-A, suggesting that this factor as an important regulator of lymphangiogenesis.


CONCLUSIONS
Cultured RMLEC preserved a molecular profile consistent with the phenotype of lymphatic endothelium in vivo and respond to either VEGF-A or VEGF-C factors. VEGFA was able to rescue RMLEC proliferation inhibited by a neutralizing VEGF-C antibody or soluble Tie-2 fusion protein. These results support the existence of cross-talk among angiogenic and lymphangiogenic factors. This work established experimental conditions that allow in vitro modeling of lymphatic endothelial responses to lymphangiogenic regulators. Preliminary results using this model suggest that VEGF-A, VEGF-C, and angiopoietins work in concert to promote lymphangiogenesis in vivo.
Whitehurst
Brandt
B
Department of Medical Microbiology, Immunology, and Cell Biology, Southern Illinois University School of Medicine, Springfield, Illinois 62702-9678, USA.
Eversgerd
Chad
C
Flister
Michael
M
Bivens
Christopher M
CM
Pickett
Brent
B
Zawieja
David C
DC
Ran
Sophia
S
D000809:Angiotensins / Q000235:genetics / Q000378:metabolism; D000818:Animals; D000911:Antibodies, Monoclonal / Q000494:pharmacology; D002460:Cell Line; D049109:Cell Proliferation / Q000187:drug effects*; D002470:Cell Survival / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D042783:Endothelial Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D015870:Gene Expression / Q000187:drug effects* / Q000235:genetics; D006493:Heparin / Q000494:pharmacology; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism; D008562:Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism; D008643:Mesentery / Q000166:cytology; D039921:Neuropilins / Q000235:genetics / Q000378:metabolism; D051381:Rats; D042787:Receptor, TIE-2 / Q000235:genetics / Q000378:metabolism; D042764:Receptors, TIE / Q000235:genetics / Q000378:metabolism; D040262:Receptors, Vascular Endothelial Growth Factor / Q000235:genetics / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000494:pharmacology; D025521:Tumor Suppressor Proteins; D042461:Vascular Endothelial Growth Factor A / Q000097:blood / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D040321:Vascular Endothelial Growth Factor Receptor-3 / Q000235:genetics / Q000378:metabolism; D042442:Vascular Endothelial Growth Factors / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology; D000098551:Prospero-Related Homeobox 1 Protein; D000098853:Podoplanin
D000809:Angiotensins; D000911:Antibodies, Monoclonal; D006493:Heparin; D018398:Homeodomain Proteins; D008562:Membrane Glycoproteins; D039921:Neuropilins; D042787:Receptor, TIE-2; D042764:Receptors, TIE; D040262:Receptors, Vascular Endothelial Growth Factor; D011993:Recombinant Fusion Proteins; D025521:Tumor Suppressor Proteins; D042461:Vascular Endothelial Growth Factor A; D040321:Vascular Endothelial Growth Factor Receptor-3; D042442:Vascular Endothelial Growth Factors; D000098551:Prospero-Related Homeobox 1 Protein; C092025:Pdpn protein, rat; D000098853:Podoplanin; C467498:vascular endothelial growth factor A, rat