Long Noncoding RNA H19 Inhibits Differentiation and Function of Secretory Lineage Cells in the Intestinal Epithelium...

Background/Objectives: Intestinal mucosal function relies on the integrated contribution of multiple cell lineages, including secretory cells. Long noncoding RNA H19 modulates many cell processes essential for human pathologies. Here, we investigated the role of H19 in development and function of secretory lineage cells and elucidated the implication of altered ATOH1 by H19 in dysfunction of the secretory cells. Methods: Studies were conducted in H19-transgenic (H19-Tg) and H19-knockout (H19^-/-) mice, intestinal organoids, and Caco-2 cells. Secretory lineage cells were examined by fluorescent immunostaining with their specific cell markers, including Lysozyme, Mucin2, DCLK1, and Chromogranin A. Intestinal mucosal growth was measured by BrdU incorporation, and intestinal permeability was detected by paracellular tracer flux assay using FITC-Dextran. Single cell RNA-sequence, quantitative real-time PCR, and Western immunoblotting analyses were used to monitor changes in gene expression. Results: Tissue-specific transgenic expression of H19 in the intestinal epithelium caused defects in Paneth, goblet, tuft, and enteroendocrine cells in mice, whereas targeted deletion of the H19 gene increased the function of secretory lineage cells. Locally increasing the levels of H19 in the epithelium impaired gut barrier function in H19-Tg mice, although it failed to alter mucosal growth. The intestinal mucosal tissues of H19-Tg mice exhibited a remarkable decrease in the levels of differentiation-associated transcription factors including ATOH1. Ectopically expressed ATOH1 in the H19-enriched intestinal organoids derived from H19-Tg mice rescued development of the secretory lineage cells. Mechanistically, H19 inhibited ATOH1 expression via inhibition of its translation. Conclusions: These findings indicate that H19 functions as a negative regulator of differentiation and function of secretory lineage cells in the intestinal mucosa at least partially via the inhibition of ATOH1 translation.