SLC26A6 Deficiency Differentially Alters the Expression of MicroRNAs and RNA Binding Proteins in the Intestine

Abstract

BACKGROUND: Putative anion transporter 1 (PAT1, SLC26A6), expressed at the luminal membrane of the intestinal epithelial cells, plays a key role in oxalate homeostasis and bicarbonate secretion. Additionally, we have recently shown that PAT1 knockout mice (PKO) exhibit compromised barrier integrity, gut dysbiosis and enhanced susceptibility to colitis. As defective PAT1 function and/or expression alters intestinal vulnerability to inflammation and miRNAs and RNA binding proteins are implicated in pathophysiology of gut inflammation, the focus of the current study was to investigate if loss of PAT1 modulates the expression of these post transcriptional regulators. Methods: microRNA was extracted from the colonic mucosa of age-matched PKO and wild type (WT) littermates (Qiagen miRNeasy mini kit) and subjected to miRNA expression profiling by Nanostring nCounter Mouse miRNA panel. Acquired raw data was further analyzed using the nSolver Analysis Software and ROSALIND online software platform to identify the differential gene expression. RT-PCR and western blotting was used to analyze the mRNA and protein expression of RNA binding proteins. Results: Genetic deficiency of PAT-1 resulted in differential expression of miRNAs compared to WT mice, where 60 miRNAs were notably upregulated, and 5 miRNAs were significantly downregulated in the colon. miR-150, known to be downregulated in ulcerative colitis patients, showed the maximum decrease (~6.9-fold change, P< 0.02) in PKO mice. Of note, miR-767 (known to promote tumor progression) was the top upregulated miRNA (~5.2-fold change, p<0.01). Interestingly, in silico analysis using TargetScan revealed that most of the upregulated miRNAs have been associated with the decrease in gut barrier function as previously shown in PKO mice. Further, a remarkable decrease in the protein expression of RNA binding proteins, HUR (0.82 ± 0.07 WT vs 0.49 + 0.03 PKO, P< 0.5) and CUGBP-1(0.37 ± 0.08 WT vs 0. 0.12 ± 0.03 PKO, P< 0.5) was also noted in PKO compared to WT mice. CONCLUSION: Our data provide evidence that PAT-1 deficiency in mice results in differential expression of several posttranscriptional regulators including miRNAs and RNA binding proteins with gene targets implicated in maintenance of epithelial barrier integrity. We speculate that altered expression of posttranscriptional regulators may potentially contribute to altered gut homeostasis observed in diseases associated with PAT1 deficiency. Supported by VA/NIH. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.