2020/12/16
Keio University School of Medicine
Blood and lymphatic vessels form separate networks throughout the body, each performing its own unique functions. The two systems form independent networks, never connecting until their final junction at the venous angle in the neck. However, the characteristics and structures of blood vessels and lymphatic vessels, especially veins and lymphatic vessels, are so strikingly similar that they are almost indistinguishable. How they distinguish each other and ensure their independence has long been a mystery.
This was revealed in a joint study by Senior Lecturer Ikue Tai and Professor Yoshiaki Kubota of the Department of Anatomy, Keio University School of Medicine, in collaboration with the university's Department of Internal Medicine (Cardiology), Department of Surgery (General and Gastroenterological), Department of Plastic and Reconstructive Surgery, and the Institute for Advanced Medical Research, as well as Yokohama City University, Kumamoto University, and the National Institutes of Health (NIH) in the United States.
The team has now found that when folliculin (Flcn)—the gene known to cause Birt-Hogg-Dube (BHD) syndrome, which is characterized by multiple pulmonary cysts, kidney cancer, and fibrofolliculomas—is deleted in vascular endothelial cells, "lymphatic-like" venous endothelial cells emerge in parts of the blood vessels, causing them to misidentify lymphatic vessels as targets for connection.
These results hold the potential for the development of treatments for lymphedema, a condition that can occur as a complication of cancer surgery. In lymphedema, lymph node dissection results in reduced lymphatic return function, causing severe edema (swelling) in the upper and lower limbs. It is believed that if a venous-lymphatic shunt could be created locally and pharmacologically by intervening in the Flcn signaling pathway, it would represent a groundbreaking treatment for lymphedema.
The results of this research were published in the online edition of "Nature Communications" on December 9, 2020 (US Eastern Time).
Please see below for the full press release.