Lineage-specific expression of bestrophin-2 and bestrophin-4 in human intestinal epithelial cells

PLoS One. 2013 Nov 5;8(11):e79693. doi: 10.1371/journal.pone.0079693. eCollection 2013.

Abstract

Intestinal epithelial cells (IECs) regulate the absorption and secretion of anions, such as HCO3(-) or Cl(-). Bestrophin genes represent a newly identified group of calcium-activated Cl(-) channels (CaCCs). Studies have suggested that, among the four human bestrophin-family genes, bestrophin-2 (BEST2) and bestrophin-4 (BEST4) might be expressed within the intestinal tissue. Consistently, a study showed that BEST2 is expressed by human colonic goblet cells. However, their precise expression pattern along the gastrointestinal tract, or the lineage specificity of the cells expressing these genes, remains largely unknown. Here, we show that BEST2 and BEST4 are expressed in vivo, each in a distinct, lineage-specific manner, in human IECs. While BEST2 was expressed exclusively in colonic goblet cells, BEST4 was expressed in the absorptive cells of both the small intestine and the colon. In addition, we found that BEST2 expression is significantly down-regulated in the active lesions of ulcerative colitis, where goblet cells were depleted, suggesting that BEST2 expression is restricted to goblet cells under both normal and pathologic conditions. Consistently, the induction of goblet cell differentiation by a Notch inhibitor, LY411575, significantly up-regulated the expression of not BEST4 but BEST2 in MUC2-positive HT-29 cells. Conversely, the induction of absorptive cell differentiation up-regulated the expression of BEST4 in villin-positive Caco-2 cells. In addition, we found that the up- or down-regulation of Notch activity leads to the preferential expression of either BEST4 or BEST2, respectively, in LS174T cells. These results collectively confirmed that BEST2 and BEST4 could be added to the lineage-specific genes of humans IECs due to their abilities to clearly identify goblet cells of colonic origin and a distinct subset of absorptive cells, respectively.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bestrophins
  • Caco-2 Cells
  • Cell Differentiation*
  • Chloride Channels / genetics*
  • Colitis, Ulcerative / genetics
  • Colitis, Ulcerative / pathology
  • Epithelial Cells / cytology*
  • Epithelial Cells / metabolism*
  • Epithelial Cells / pathology
  • Eye Proteins / genetics*
  • Gene Expression Regulation*
  • Goblet Cells / cytology
  • HT29 Cells
  • Humans
  • Intestines / cytology*
  • Receptors, Notch / metabolism
  • Signal Transduction

Substances

  • BEST2 protein, human
  • BEST4 protein, human
  • Bestrophins
  • Chloride Channels
  • Eye Proteins
  • Receptors, Notch

Grants and funding

This study was supported by Grants-in-Aid for Young Scientists (B) (to RO and JA-M), Scientific Research (C) (to KI), Scientific Research (B) (to TN), Scientific Research (S) (to MW), Exploratory Research (to MW) and Scientific Research on Innovative Areas “ Chemical Biology of Natural Products” (to RO and TN) from the Ministry of Education, Culture, Sports, Science and Technology of Japan; Health and Labor Sciences Research Grant (to RO and MW) from the Ministry of Health, Labor and Welfare of Japan. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.