Intestinal lncRNA H19 and miRNA-675 expression Influenced by Metal Transporter ZIP14

Zinc has been shown to influence intestinal barrier function. To function properly, zinc must be placed at specific sites of action in cells. Previously, we demonstrated that the zinc transporter Zip14 (Slc39a14) is highly expressed in the small intestine and is localized to the basolateral membrane of enterocytes. Ablation of Zip14 in mice produces a phenotype that includes increased intestinal permeability and metabolic endotoxemia. To investigate the mechanism involved, we performed genome‐wide examination of gene expression in the small intestine from WT and Zip14 KO mice using Illumina RNA sequencing. This RNAseq analysis revealed that among 1079 long non‐coding (lnc) RNAs profiled, 36 annotated lncRNAs were identified as overexpressed in intestines of Zip14 KO mice. H19 RNA was the most highly overexpressed lncRNA. Read densities of other selected lncRNAs demonstrated specificity in the differential expression of H19 in the intestine of the KO mice. Upon confirmation using qPCR, we found that H19 was significantly up‐regulated in intestines of the Zip14 KO mice. Up‐regulation of miR‐675‐5p , a microRNA derived from H19, was also demonstrated. Intestinal epithelial cells (IEC) isolated by a chelation method revealed high expression of intestinal alkaline phosphatase and Zip14 mRNAs, indicative of substantial enterocyte‐enrichment. Expression of H19, but not miR‐675‐5p , was localized to the isolated IECs. Markedly enhanced expression of H19 was detected in IECs from the Zip14 KO mice compared to WT mice. The increased H19 expression in Zip14 KO mice was limited to IECs and skeletal muscle of the six tissues examined. IECs were also isolated from intestine‐specific Zip14 KO (I‐KO) mice. The up‐regulation of H19 was observed in IECs from the I‐KO mice compared to those from flox/flox controls, but miR‐675‐5p expression was not different between cells from the two genotypes. These data suggest that intestinal H19 is produced by IECs and is up‐regulated with Zip14 ablation. H19 overexpression suggests it is involved in a molecular defect in intestinal function of Zip14, perhaps including intestinal barrier dysfunction. Support or Funding Information NIH Grant R01 DK 094244