Embryonic veins are the source of cells that multiply and migrate in the embryo to give rise to the entire network of lymphatic vessels, a finding that suggests that these cells might one day be used to grow new vessels
MEMPHIS, Tenn., Oct. 3 /PRNewswire-USNewswire/ -- Investigators at St. Jude Children's Research Hospital settled a century-old debate on the origin of the mammalian lymphatic vasculature -- the network of vessels and capillaries critical to various essential housekeeping functions in the body. The finding holds the promise for the development of new therapies for lymphatic system disorders, the researchers said.
The St. Jude team used various mouse models to demonstrate that the lymphatic vasculature arises in the embryo from veins by means of continuous release from the veins of cells that multiply and then migrate to different parts of the body.
Conclusively determining how the lymphatic vasculature develops in the embryo is an important step in fully understanding the mechanisms that form this vital network of vessels, according to Guillermo Oliver, Ph.D., a member of the St. Jude Department of Genetics and Tumor Cell Biology.
"This work is a major contribution in the long-term strategy of promoting the growth of new lymphatic vessels in people suffering from different forms of lymphatic disease that are either inherited or acquired after birth," Oliver said. "The detailed characterization of the formation of a normal healthy lymphatic vasculature is central to our efforts to prevent, diagnose and cure lymphatic vasculature disorders." Oliver is senior author of a report on this work that appears in the October 1 issue of "Genes & Development."
The St. Jude team studied the origin of the mammalian lymphatic vasculature using a powerful technique called Cre/loxP-based lineage-tracing. This technique enables researchers to label specific progenitor cells in the embryo and follow them as they reach their final destinations in the developing body. Progenitor cells are parent cells that multiply and give rise to distinct populations of cells with different, specific functions in the body.
"We showed that venous-derived LECs sprout from the lymph sacs, multiply and then migrate to their ultimate destination to give rise to the entire lymphatic vasculature; and that hematopoietic cells do not contribute significantly to this process," said R. Sathish Srinivasan, Ph.D. "Therefore, we concluded that in mammals, such as mice and humans, the lymphatic vasculature arises directly and solely from the embryonic veins." Srinivasan is a postdoctoral fellow in Oliver's laboratory and did most of the work on this project.
Other authors of this study include Miriam Dillard and Oleg Lagutin (St. Jude); Fu-Jung Lin, Sophia Tsai, and Ming-Jer Tsai (Baylor College of Medicine, Houston) and Igor Samokhvalov (Center for Developmental Biology, Kobe, Japan).
This work was support in part by the National Heart, Lung, and Blood Institute, a Cancer Center support grant and ALSAC. Srinivasan is a recipient of a Lymphatic Research Foundation postdoctoral fellowship.
St. Jude Children's Research Hospital
St. Jude Children's Research Hospital is internationally recognized for its pioneering work in finding cures and saving children with cancer and other catastrophic diseases. Founded by late entertainer Danny Thomas and based in Memphis, Tenn., St. Jude freely shares its discoveries with scientific and medical communities around the world. No family ever pays for treatments not covered by insurance, and families without insurance are never asked to pay. St. Jude is financially supported by ALSAC, its fundraising organization. For more information, please visit http://www.stjude.org.
|SOURCE St. Jude Children's Research Hospital|
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