h CALCRL mutation causes autosomal recessive nonimmune hydrops fetalis with lymphatic dysplasia

J Exp Med. 2018 Sep 3;215(9):2339-2353. doi: 10.1084/jem.20180528. Epub 2018 Aug 16.

Abstract

We report the first case of nonimmune hydrops fetalis (NIHF) associated with a recessive, in-frame deletion of V205 in the G protein-coupled receptor, Calcitonin Receptor-Like Receptor (hCALCRL). Homozygosity results in fetal demise from hydrops fetalis, while heterozygosity in females is associated with spontaneous miscarriage and subfertility. Using molecular dynamic modeling and in vitro biochemical assays, we show that the hCLR(V205del) mutant results in misfolding of the first extracellular loop, reducing association with its requisite receptor chaperone, receptor activity modifying protein (RAMP), translocation to the plasma membrane and signaling. Using three independent genetic mouse models we establish that the adrenomedullin-CLR-RAMP2 axis is both necessary and sufficient for driving lymphatic vascular proliferation. Genetic ablation of either lymphatic endothelial Calcrl or nonendothelial Ramp2 leads to severe NIHF with embryonic demise and placental pathologies, similar to that observed in humans. Our results highlight a novel candidate gene for human congenital NIHF and provide structure-function insights of this signaling axis for human physiology.

Publication types

  • Case Reports
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence*
  • Animals
  • Calcitonin Receptor-Like Protein* / genetics
  • Calcitonin Receptor-Like Protein* / metabolism
  • Craniofacial Abnormalities* / genetics
  • Craniofacial Abnormalities* / metabolism
  • Craniofacial Abnormalities* / pathology
  • Disease Models, Animal
  • Female
  • HEK293 Cells
  • Heterozygote
  • Homozygote
  • Humans
  • Hydrops Fetalis* / genetics
  • Hydrops Fetalis* / metabolism
  • Hydrops Fetalis* / pathology
  • Lymphangiectasis, Intestinal* / genetics
  • Lymphangiectasis, Intestinal* / metabolism
  • Lymphangiectasis, Intestinal* / pathology
  • Lymphedema* / genetics
  • Lymphedema* / metabolism
  • Lymphedema* / pathology
  • Male
  • Mice
  • Mice, Transgenic*
  • Placenta
  • Pregnancy
  • Sequence Deletion*

Substances

  • CALCRL protein, human
  • Calcitonin Receptor-Like Protein
  • Calcrl protein, mouse

Supplementary concepts

  • Hennekam lymphangiectasia lymphedema syndrome

Associated data

  • PIR/235510
  • PIR/228000
  • RefSeq/NM_005795
  • PDB/4K5Y