Glucocorticoid regulation and glycosylation of mouse intestinal type IIb Na-Pi cotransporter during ontogeny

Kayo Arima, Eric R. Hines, Pawel R. Kiela, Jason B. Drees, James F. Collins, Fayez K. Ghishan

Research output: Contribution to journalArticlepeer-review

72 Scopus citations


We sought to characterize expression of an apically expressed intestinal Na-Pi cotransporter (Na-Pi-IIb) during mouse ontogeny and to assess the effects of methylprednisolone (MP) treatment. In control mice, Na-Pi uptake by intestinal brush-border membrane vesicles was highest at 14 days of age, lower at 21 days, and further reduced at 8 wk and 8-9 mo of age. Na-Pi-IIb mRNA and immunoreactive protein levels in 14-day-old animals were markedly higher than in older groups. MP treatment significantly decreased Na-Pi uptake and Na-Pi-IIb mRNA and protein expression in 14-day-old mice. Additionally, the size of the protein was smaller in 14-day-old mice. Deglycosylation of protein from 14-day-old and 8-wk-old animals with peptide N-glycosidase reduced the molecular weight to the predicted size. We conclude that intestinal Na-Pi uptake and Na-Pi-IIb expression are highest at 14 days and decrease with age. Furthermore, MP treatment reduced intestinal Na-Pi uptake approximately threefold in 14-day-old mice and this reduction correlates with reduced Na-Pi-IIb mRNA and protein expression. We also demonstrate that Na-Pi-IIb is an N-linked glycoprotein and that glycosylation is age dependent.

Original languageEnglish (US)
Pages (from-to)G426-G434
JournalAmerican Journal of Physiology - Gastrointestinal and Liver Physiology
Issue number2 46-2
StatePublished - 2002


  • Development
  • Methylprednisolone
  • Na-P-IIb

ASJC Scopus subject areas

  • Physiology
  • Hepatology
  • Gastroenterology
  • Physiology (medical)


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