In multiple sclerosis (MS) and experimental autoimmune encephalomyelitis (EAE), inflammation is perpetuated by both infiltrating leukocytes and astrocytes. Recent work implicated SUR1-TRPM4 channels, expressed mostly by astrocytes, in murine EAE. We tested the hypothesis that pharmacological inhibition of SUR1 during the chronic phase of EAE would be beneficial. EAE was induced in mice using myelin oligodendrocyte glycoprotein (MOG) 35–55. Glibenclamide (10 μg/day) was administered beginning 12 or 24 days later. The effects of treatment were determined by clinical scoring and tissue examination. Drug within EAE lesions was identified using bodipy-glibenclamide. The role of SUR1-TRPM4 in primary astrocytes was characterized using patch clamp and qPCR. Demyelinating lesions from MS patients were studied by immunolabeling and immunoFRET. Administering glibenclamide beginning 24 days after MOG35–55 immunization, well after clinical symptoms had plateaued, improved clinical scores, reduced myelin loss, inflammation (CD45, CD20, CD3, p65), and reactive astrocytosis, improved macrophage phenotype (CD163), and decreased expression of tumor necrosis factor (TNF), B-cell activating factor (BAFF), chemokine (C-C motif) ligand 2 (CCL2) and nitric oxide synthase 2 (NOS2) in lumbar spinal cord white matter. Glibenclamide accumulated within EAE lesions, and had no effect on leukocyte sequestration. In primary astrocyte cultures, activation by TNF plus IFNγ induced de novo expression of SUR1-TRPM4 channels and upregulated Tnf, Baff, Ccl2, and Nos2 mRNA, with glibenclamide blockade of SUR1-TRPM4 reducing these mRNA increases. In demyelinating lesions from MS patients, astrocytes co-expressed SUR1-TRPM4 and BAFF, CCL2, and NOS2. SUR1-TRPM4 may be a druggable target for disease modification in MS.

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.