Browsing by Subject "LYMPHANGIOGENESIS"

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Now showing items 21-22 of 22
  • Nurmi, Harri; Saharinen, Pipsa; Zarkada, Georgia; Zheng, Wei; Robciuc, Marius R.; Alitalo, Kari (2015)
    Vascular endothelial growth factor C (VEGF-C) binding to its tyrosine kinase receptor VEGFR-3 drives lymphatic vessel growth during development and in pathological processes. Although the VEGF-C/VEGFR-3 pathway provides a target for treatment of cancer and lymphedema, the physiological functions of VEGF-C in adult vasculature are unknown. We show here that VEGF-C is necessary for perinatal lymphangiogenesis, but required for adult lymphatic vessel maintenance only in the intestine. Following Vegfc gene deletion in adult mice, the intestinal lymphatic vessels, including the lacteal vessels, underwent gradual atrophy, which was aggravated when also Vegfd was deleted. VEGF-C was expressed by a subset of smooth muscle cells adjacent to the lacteals in the villus and in the intestinal wall. TheVegfc-deleted mice showed defective lipid absorption and increased fecal excretion of dietary cholesterol and fatty acids. When fed a high-fat diet, the Vegfc-deficient mice were resistant to obesity and had improved glucose metabolism. Our findings indicate that the lymphangiogenic growth factors provide trophic and dynamic regulation of the intestinal lymphatic vasculature, which could be especially important in the dietary regulation of adiposity and cholesterol metabolism.
  • Hominickn, Devon; Silva, Asitha; Khurana, Noor; Liu, Ying; Dechow, Paul C.; Feng, Jian Q.; Pytowski, Bronislaw; Rutkowski, Joseph M.; Alitalo, Kari; Dellinger, Michael T. (2018)
    Patients with Gorham-Stout disease (GSD) have lymphatic vessels in their bones and their bones gradually disappear. Here, we report that mice that overexpress VEGF-C in bone exhibit a phenotype that resembles GSD. To drive VEGF-C expression in bone, we generated Osx-tTA; TetO-Vegfc double-transgenic mice. In contrast to Osx-tTA mice, Osx-tTA; TetO-Vegfc mice developed lymphatics in their bones. We found that inhibition of VEGFR3, but not VEGFR2, prevented the formation of bone lymphatics in Osx-tTA; TetO-Vegfc mice. Radiological and histological analysis revealed that bones from Osx-tTA; TetO-Vegfc mice were more porous and had more osteoclasts than bones from Osx-tTA mice. Importantly, we found that bone loss in Osx-tTA; TetO-Vegfc mice could be attenuated by an osteoclast inhibitor. We also discovered that the mutant phenotype of Osx-tTA; TetO-Vegfc mice could be reversed by inhibiting the expression of VEGF-C. Taken together, our results indicate that expression of VEGF-C in bone is sufficient to induce the pathologic hallmarks of GSD in mice.