VEGF-C is required for intestinal lymphatic vessel maintenance and lipid absorption.
Bottom Line: We show here that VEGF-C is necessary for perinatal lymphangiogenesis, but required for adult lymphatic vessel maintenance only in the intestine.VEGF-C was expressed by a subset of smooth muscle cells adjacent to the lacteals in the villus and in the intestinal wall.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.
Affiliation: Wihuri Research Institute and Translational Cancer Biology Program, Biomedicum Helsinki University of Helsinki, Helsinki, Finland.Show MeSH
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Mentions: In Vegfc gene-deleted embryos, lymphatic vessel sprouting from the major embryonic veins at embryonic day (E) 10.5 is arrested and the embryos die between E15.5 and E17.5 (Karkkainen et al, 2004). To study how the loss of VEGF-C affects lymphatic vessel development during the last trimester of fetal development, we crossed the Vegfcflox/flox mice (Aspelund et al, 2014) with mice expressing the universal deletor R26Cre-ERT2 (Ventura et al, 2007). To delete Vegfc in the R26Cre-ERT2;Vegfcflox/flox embryos, pregnant females were injected with 4-OH tamoxifen at E12.5 and E13.5. Analysis at E18.5 indicated that the Vegfc-deleted (VCiΔR26) embryos lack mesenteric lymphatic vessels either completely (data not shown) or exhibit lymphatic vessel fragments and blind-ended lymphatic stubs that extend toward the intestinal wall (Fig1A and B). Deletion of Vegfc at E14.5 blocked the maturation of the mesenteric collecting lymphatic vessels. The developing vessels lacked valves and were much thinner than in the wild-type (WT) Vegfcflox/flox embryos (Fig1C and D). In addition, the lymphatic vessels in the intestinal wall failed to develop in the VCiΔR26 embryos, whereas the blood vessels were not affected (Fig1E–H).
Affiliation: Wihuri Research Institute and Translational Cancer Biology Program, Biomedicum Helsinki University of Helsinki, Helsinki, Finland.