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Inhibition of intestinal ascorbic acid uptake by lipopolysaccharide is mediated via transcriptional mechanisms. Biochim Biophys Acta Biomembr 2018 Feb;1860(2):556-565

Date

10/17/2017

Pubmed ID

29030247

Pubmed Central ID

PMC5732882

DOI

10.1016/j.bbamem.2017.10.010

Scopus ID

2-s2.0-85034947878   11 Citations

Abstract

Ascorbic acid (AA) accumulation in intestinal epithelial cells is an active transport process mainly mediated by two sodium-dependent vitamin C transporters (SVCT-1 and SVCT-2). To date, little is known about the effect of gut microbiota generated lipopolysaccharide (LPS) on intestinal absorption of water-soluble vitamins. Therefore, the objective of this study was to investigate the effects of bacterially-derived LPS on AA homeostasis in enterocytes using Caco-2 cells, mouse intestine and intestinal enteroids models. Pre-treating Caco-2 cells and mice with LPS led to a significant decrease in carrier-mediated AA uptake. This inhibition was associated with a significant reduction in SVCT-1 and SVCT-2 protein, mRNA, and hnRNA expression. Furthermore, pre-treating enteroids with LPS also led to a marked decrease in SVCT-1 and SVCT-2 protein and mRNA expression. Inhibition of SVCT-1 and SVCT-2 occurred at least in part at the transcriptional level as promoter activity of SLC23A1 and SLC23A2 was attenuated following LPS treatment. Subsequently, we examined the protein and mRNA expression levels of HNF1α and Sp1 transcription factors, which are needed for basal SLC23A1 and SLC23A2 promoter activity, and found that they were significantly decreased in the LPS treated Caco-2 cells and mouse jejunum; this was reflected on level of the observed reduction in the interaction of these transcription factors with their respective promoters in Caco-2 cells treated with LPS. Our findings indicate that LPS inhibits intestinal carrier- mediated AA uptake by down regulating the expression of both vitamin C transporters and transcriptional regulation of SLC23A1 and SLC23A2 genes.

Author List

Subramanian VS, Sabui S, Moradi H, Marchant JS, Said HM

Author

Jonathan S. Marchant PhD Chair, Professor in the Cell Biology, Neurobiology and Anatomy department at Medical College of Wisconsin




MESH terms used to index this publication - Major topics in bold

Animals
Ascorbic Acid
Biological Transport
Caco-2 Cells
Cells, Cultured
Enterocytes
Gene Expression Regulation
Humans
Intestinal Absorption
Intestinal Mucosa
Intestines
Lipopolysaccharides
Male
Mice, Inbred C57BL
Sodium-Coupled Vitamin C Transporters
Vitamins
jenkins-FCD Prod-482 91ad8a360b6da540234915ea01ff80e38bfdb40a