Hydrops fetalis, cardiovascular defects, and embryonic lethality in mice lacking the calcitonin receptor-like receptor gene.
Adrenomedullin (AM) is a multifunctional peptide vasodilator that is essential for life. To date, numerous in vitro studies have suggested that AM can mediate its biological effects through at least three different receptors. To determine the in vivo importance of the most likely candidate receptor, calcitonin receptor-like receptor, a gene-targeted knockout model of the gene was generated. Mice heterozygous for the targeted Calcrl allele appear normal, survive to adulthood, and reproduce. However, heterozygote matings fail to produce viable Calcrl-/- pups, demonstrating that Calcrl is essential for survival. Timed matings confirmed that Calcrl-/- embryos die between embryonic day 13.5 (E13.5) and E14.5 of gestation. The Calcrl-/- embryos exhibit extreme hydrops fetalis and cardiovascular defects, including thin vascular smooth muscle walls and small, disorganized hearts remarkably similar to the previously characterized AM-/- phenotype. In vivo assays of cellular proliferation and apoptosis in the hearts and vasculature of Calcrl-/- and AM-/- embryos support the concept that AM signaling is a crucial mediator of cardiovascular development. The Calcrl gene targeted mice provide the first in vivo genetic evidence that CLR functions as an AM receptor during embryonic development.
Department of Cell & Molecular Physiology, CB #7545, 6330 MBRB, 103 Mason Farm Rd., The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA.
Ryan T
RT
Dackor
Kimberly
K
Fritz-Six
William P
WP
Dunworth
Carrie L
CL
Gibbons
Oliver
O
Smithies
Kathleen M
KM
Caron
D053607:Adrenomedullin; D000818:Animals; D017209:Apoptosis; D018376:Cardiovascular Abnormalities / Q000378:metabolism* / Q000473:pathology; D049109:Cell Proliferation; D020964:Embryo Loss / Q000378:metabolism*; D005313:Fetal Death; D005865:Gestational Age; D015160:Hydrops Fetalis / Q000378:metabolism*; D051379:Mice; D018345:Mice, Knockout; D009131:Muscle, Smooth, Vascular / Q000473:pathology; D009206:Myocardium / Q000473:pathology; D032383:Myocytes, Cardiac / Q000473:pathology; D010455:Peptides / Q000172:deficiency; D018003:Receptors, Calcitonin / Q000172:deficiency* / Q000235:genetics; D011995:Recombination, Genetic
D010455:Peptides; D018003:Receptors, Calcitonin; D053607:Adrenomedullin