JCI Insight (Oct 2020)

Pleiotropic ZIP8 A391T implicates abnormal manganese homeostasis in complex human disease

  • Laxmi Sunuwar,
  • Azra Frkatović,
  • Sodbo Sharapov,
  • Qinchuan Wang,
  • Heather M. Neu,
  • Xinqun Wu,
  • Talin Haritunians,
  • Fengyi Wan,
  • Sarah Michel,
  • Shaoguang Wu,
  • Mark Donowitz,
  • Dermot McGovern,
  • Gordan Lauc,
  • Cynthia Sears,
  • Joanna Melia

Journal volume & issue
Vol. 5, no. 20

Abstract

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ZIP8 is a metal transporter with a role in manganese (Mn) homeostasis. A common genetic variant in ZIP8 (rs13107325; A391T) ranks in the top 10 of pleiotropic SNPs identified in GWAS; A391T has associations with an increased risk of schizophrenia, obesity, Crohn’s disease, and reduced blood Mn. Here, we used CRISPR/Cas9-mediated knockin (KI) to generate a mouse model of ZIP8 A391T (Zip8 393T-KI mice). Recapitulating the SNP association with blood Mn, blood Mn was reduced in Zip8 393T-KI mice. There was restricted abnormal tissue Mn homeostasis, with decreases in liver and kidney Mn and a reciprocal increase in biliary Mn, providing in vivo evidence of hypomorphic Zip8 function. Upon challenge in a chemically induced colitis model, male Zip8 393T-KI mice exhibited enhanced disease susceptibility. ZIP8 391-Thr associated with reduced triantennary plasma N-glycan species in a population-based cohort to define a genotype-specific glycophenotype hypothesized to be linked to Mn-dependent glycosyltransferase activity. This glycophenotype was maintained in a cohort of patients with Crohn’s disease. These data and the pleiotropic disease associations with ZIP8 391-Thr suggest underappreciated roles of Mn homeostasis in complex human disease.

Keywords