ABNORMAL LYMPHATIC PHENOTYPE IN A CRISPR MOUSE MODEL OF THE HUMAN LYMPHEDEMA-CAUSING CONNEXIN47 R260C POINT MUTATION

D. J. Mustacich, R. I. Kylat, Michael J Bernas, R. J. Myles, J. A. Jones, J. D. Kanady, Alex Simon, T. G. Georgieva, M. H. Witte, R. P. Erickson, Paulo W. Pires

Research output: Contribution to journalArticlepeer-review

Abstract

Connexin proteins form gap junctions controlling exchange of ions and small molecules between cells and play an important role in movement of lymph within lymphatic vessels. Connexin47 (CX47) is highly expressed in lymphatic endothelial cells and CX47 missense mutations, i.e., R260C, cosegregate with primary lymphedema in humans. However, studies utilizing CX47 knockout mice have failed to demonstrate any lymphatic anomalies. To unravel the lymphatic consequences of expressing a mutant CX47 protein, we used CRISPR technology to create a mouse carrying a Cx47 missense mutation (Cx47R259C) equivalent to the human CX47R260C missense mutation associated with human primary lymphedema. Intradermal Evans Blue dye injection identified a 2-fold increase in regional lymph nodes in homozygous Cx47R259C mice compared to wildtype, particularly in the jugular region (4.8 ± 0.4 and 2.0 ± 0.0, respectively, p<0.01). Associated lymphatic channels were increased in Cx47R259C mice and mesenteric lymph reflux occurred in homozygous Cx47R259C mice but not in wildtype. Contractility of superficial cervical lymphatics, assessed by pressure myography, was reduced in homozygous Cx47R259C mice compared to wildtype. In conclusion, our data are the first to demonstrate a role for the Cx47 protein in lymphatic anatomy and function. This phenotype is similar to that found with other valve deficient mouse mutants, e.g., in Foxc2. Of significance, this study is the first to use CRISPR technology to develop a pre-clinical model of primary lymphedema and demonstrates the importance of distinguishing between lack of and presence of mutant protein when developing clinically relevant animal models for translation of pre-clinical findings.

Original languageEnglish (US)
Pages (from-to)78-91
Number of pages14
JournalLymphology
Volume54
Issue number2
DOIs
StatePublished - 2021

Keywords

  • CRISPR mouse
  • Connexins
  • Gap junctions
  • Genotype-phenotype correlations
  • Hereditary lymphedema
  • Lymphatic contractility

ASJC Scopus subject areas

  • Immunology and Allergy
  • Hematology

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