Mouse lung contains endothelial progenitors with high capacity to form blood and lymphatic vessels

<p>Abstract</p> <p>Background</p> <p>Postnatal endothelial progenitor cells (EPCs) have been successfully isolated from whole bone marrow, blood and the walls of conduit vessels. They can, therefore, be classified into circulating and resident progenitor cells. The differentiation capacity of resident lung endothelial progenitor cells from mouse has not been evaluated.</p> <p>Results</p> <p>In an attempt to isolate differentiated mature endothelial cells from mouse lung we found that the lung contains EPCs with a high vasculogenic capacity and capability of <it>de novo </it>vasculogenesis for blood and lymph vessels.</p> <p>Mouse lung microvascular endothelial cells (MLMVECs) were isolated by selection of CD31⁺cells. Whereas the majority of the CD31⁺cells did not divide, some scattered cells started to proliferate giving rise to large colonies (> 3000 cells/colony). These highly dividing cells possess the capacity to integrate into various types of vessels including blood and lymph vessels unveiling the existence of local microvascular endothelial progenitor cells (LMEPCs) in adult mouse lung. EPCs could be amplified > passage 30 and still expressed panendothelial markers as well as the progenitor cell antigens, but not antigens for immune cells and hematopoietic stem cells. A high percentage of these cells are also positive for Lyve1, Prox1, podoplanin and VEGFR-3 indicating that a considerabe fraction of the cells are committed to develop lymphatic endothelium. Clonogenic highly proliferating cells from limiting dilution assays were also bipotent. Combined <it>in vitro </it>and <it>in vivo </it>spheroid and matrigel assays revealed that these EPCs exhibit vasculogenic capacity by forming functional blood and lymph vessels.</p> <p>Conclusion</p> <p>The lung contains large numbers of EPCs that display commitment for both types of vessels, suggesting that lung blood and lymphatic endothelial cells are derived from a single progenitor cell.</p

Elevated expression of VEGFR-3 in lymphatic endothelial cells from lymphangiomas

<p>Abstract</p> <p>Background</p> <p>Lymphangiomas are neoplasias of childhood. Their etiology is unknown and a causal therapy does not exist. The recent discovery of highly specific markers for lymphatic endothelial cells (LECs) has permitted their isolation and characterization, but expression levels and stability of molecular markers on LECs from healthy and lymphangioma tissues have not been studied yet. We addressed this problem by profiling LECs from normal dermis and two children suffering from lymphangioma, and also compared them with blood endothelial cells (BECs) from umbilical vein, aorta and myometrial microvessels.</p> <p>Methods</p> <p>Lymphangioma tissue samples were obtained from two young patients suffering from lymphangioma in the axillary and upper arm region. Initially isolated with anti-CD31 (PECAM-1) antibodies, the cells were separated by FACS sorting and magnetic beads using anti-podoplanin and/or LYVE-1 antibodies. Characterization was performed by FACS analysis, immunofluorescence staining, ELISA and micro-array gene analysis.</p> <p>Results</p> <p>LECs from foreskin and lymphangioma had an almost identical pattern of lymphendothelial markers such as podoplanin, Prox1, reelin, cMaf and integrin-α1 and -α9. However, LYVE-1 was down-regulated and VEGFR-2 and R-3 were up-regulated in lymphangiomas. Prox1 was constantly expressed in LECs but not in any of the BECs.</p> <p>Conclusion</p> <p>LECs from different sources express slightly variable molecular markers, but can always be distinguished from BECs by their Prox1 expression. High levels of VEGFR-3 and -2 seem to contribute to the etiology of lymphangiomas.</p

Elevated expression of VEGFR-3 in lymphatic endothelial cells from lymphangiomas-4

<p><b>Copyright information:</b></p><p>Taken from "Elevated expression of VEGFR-3 in lymphatic endothelial cells from lymphangiomas"</p><p>http://www.biomedcentral.com/1471-2407/7/105</p><p>BMC Cancer 2007;7():105-105.</p><p>Published online 21 Jun 2007</p><p>PMCID:PMC1925108.</p><p></p>efore and after podoplanin-mediated cell sorting with a FACS sorte

Elevated expression of VEGFR-3 in lymphatic endothelial cells from lymphangiomas-2

<p><b>Copyright information:</b></p><p>Taken from "Elevated expression of VEGFR-3 in lymphatic endothelial cells from lymphangiomas"</p><p>http://www.biomedcentral.com/1471-2407/7/105</p><p>BMC Cancer 2007;7():105-105.</p><p>Published online 21 Jun 2007</p><p>PMCID:PMC1925108.</p><p></p>y podoplanincells are found in gate R3 and podoplanin/LYVE-1cells are found in gate R4. A total number of 9,6 × 10cells from passage 6 have been used for cell sorting

Elevated expression of VEGFR-3 in lymphatic endothelial cells from lymphangiomas-5

<p><b>Copyright information:</b></p><p>Taken from "Elevated expression of VEGFR-3 in lymphatic endothelial cells from lymphangiomas"</p><p>http://www.biomedcentral.com/1471-2407/7/105</p><p>BMC Cancer 2007;7():105-105.</p><p>Published online 21 Jun 2007</p><p>PMCID:PMC1925108.</p><p></p>of Prox1 was detected by immunocytology in HDMECs. Nuclei were counter-stained with DAPI in some specimens. One representative staining out of several independent experiments is shown. Magnification, × 200

Elevated expression of VEGFR-3 in lymphatic endothelial cells from lymphangiomas-1

<p><b>Copyright information:</b></p><p>Taken from "Elevated expression of VEGFR-3 in lymphatic endothelial cells from lymphangiomas"</p><p>http://www.biomedcentral.com/1471-2407/7/105</p><p>BMC Cancer 2007;7():105-105.</p><p>Published online 21 Jun 2007</p><p>PMCID:PMC1925108.</p><p></p>uclear localization of Prox1 was detected by immunocytology in HUVEC and HAEC. Nuclei were counter-stained with DAPI. One representative staining out of several independent experiments is shown. Magnification, × 200

Elevated expression of VEGFR-3 in lymphatic endothelial cells from lymphangiomas-0

<p><b>Copyright information:</b></p><p>Taken from "Elevated expression of VEGFR-3 in lymphatic endothelial cells from lymphangiomas"</p><p>http://www.biomedcentral.com/1471-2407/7/105</p><p>BMC Cancer 2007;7():105-105.</p><p>Published online 21 Jun 2007</p><p>PMCID:PMC1925108.</p><p></p>ECAM-1, Tie2 and CD105/endoglin on primary HUVECs and HAECs (passage 3–5). Profiles obtained with lymphatic markers podoplanin and LYVE-1 on both of the control cell types are also indicated. The mean fluorescence intensities were normalized to the background fluorescence of the secondary antibody alone (grey)

Elevated expression of VEGFR-3 in lymphatic endothelial cells from lymphangiomas-6

<p><b>Copyright information:</b></p><p>Taken from "Elevated expression of VEGFR-3 in lymphatic endothelial cells from lymphangiomas"</p><p>http://www.biomedcentral.com/1471-2407/7/105</p><p>BMC Cancer 2007;7():105-105.</p><p>Published online 21 Jun 2007</p><p>PMCID:PMC1925108.</p><p></p>-1 and the lymphendothelial markers LYVE-1 and podoplanin. Immunostaining for CD31, Prox1, podoplanin and LYVE-1. Nuclei were counter-stained with DAPI. One representative staining out of several independent experiments is shown. Magnification, × 200