Blood is thicker than lymph.
Growth of blood and lymphatic vessels is essential in the developing embryo and in the pathogenesis of human diseases such as cancer, but the signaling pathways that regulate vessel growth and function are not yet well characterized. In this issue of the JCI, studies by Fritz-Six et al. and Ichikawa-Shindo et al. demonstrate that loss of signaling by the adrenomedullin peptide results in embryonic edema and death (see the related articles beginning on pages 40 and 29, respectively). Remarkably, this phenotype is attributed to defects in lymphatic vessels by one group and to defects in blood vessels by the other. In addition to defining what I believe to be a novel angiogenic signaling pathway, these studies demonstrate the intricate molecular, genetic, and physiologic relationships between blood and lymphatic vessels that must be considered by investigators of vascular biology.
Kahn
Mark L
ML
Department of Medicine and University of Pennsylvania Cardiovascular Institute, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA. markkahn@mail.med.upenn.edu
D053607:Adrenomedullin / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D001158:Arteries / Q000378:metabolism / Q000473:pathology; D058286:Calcitonin Receptor-Like Protein; D002199:Capillary Permeability / Q000502:physiology*; D002318:Cardiovascular Diseases / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D002478:Cells, Cultured; D004487:Edema / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D020964:Embryo Loss / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D053595:Embryonic Stem Cells / Q000378:metabolism / Q000473:pathology; D004730:Endothelium, Vascular / Q000378:metabolism / Q000473:pathology; D005260:Female; D006706:Homeostasis / Q000502:physiology*; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics; D008297:Male; D008565:Membrane Proteins / Q000096:biosynthesis* / Q000235:genetics; D051379:Mice; D018345:Mice, Knockout; D018919:Neovascularization, Physiologic / Q000502:physiology*; D011247:Pregnancy; D058261:Receptor Activity-Modifying Proteins; D058265:Receptors, Adrenomedullin; D018003:Receptors, Calcitonin / Q000235:genetics / Q000378:metabolism; D018000:Receptors, Peptide / Q000235:genetics / Q000378:metabolism*; D019108:Tight Junctions / Q000235:genetics / Q000378:metabolism / Q000473:pathology
C545578:CALCRL protein, human; D058286:Calcitonin Receptor-Like Protein; C545579:Calcrl protein, mouse; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins; D058261:Receptor Activity-Modifying Proteins; D058265:Receptors, Adrenomedullin; D018003:Receptors, Calcitonin; D018000:Receptors, Peptide; D053607:Adrenomedullin