Hypertonic induction of the cell adhesion molecule beta 1-integrin in MDCK cells

Am J Physiol. 1997 Sep;273(3 Pt 1):C902-8. doi: 10.1152/ajpcell.1997.273.3.C902.


Cells of many organisms adapt to osmotic stress by accumulating compatible organic osmolytes. In Madin-Darby canine kidney (MDCK) cells, a renal epithelial cell line widely used as a culture model for the study of osmotic regulation in mammals, extracellular hypertonicity induces genes responsible for the accumulation of organic osmolytes. We have recently cloned from these cells a partial cDNA corresponding to a member of the transmembrane 4 superfamily (tetraspan) family, CD9 antigen, and demonstrated its induction by hypertonicity [D. Sheikh-Hamad, J. D. Ferraris, J. Dragolovich, H. G. Preuss, M. B. Burg, and A. García-Pérez. Am. J. Physiol. 270 (Cell Physiol. 39): C253-C258, 1996]. An association between CD9 and potential regulatory proteins, such as the heparin-binding epidermal growth factor-like protein and the cell adhesion molecule beta 1-integrin, has been reported. Here, using beta 1-integrin-specific monoclonal antibodies and an antisense oligonucleotide probe, we demonstrate expression and hypertonic induction of beta 1-integrin in MDCK cells. Induction of the mRNA and protein occurs in 2 h and is maximal at 6 h, consistent with a regulatory role in the adaptation to osmotic stress. In addition, we show that accumulation of organic osmolytes markedly attenuates the hypertonic induction of the mRNA, a feature shared with genes involved in hyperosmotic stress response. Finally, we demonstrate that CD9 and beta 1-integrin are expressed in association at the cell membrane. Our findings suggest the existence of a cluster of integral membrane proteins that includes but may not be limited to CD9 and the adhesion molecule beta 1-integrin, which may play a role in the adaptation of kidney cells to osmotic stress, possibly at the regulatory level.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Base Sequence
  • Cell Line
  • Cell Membrane / physiology
  • Chlorocebus aethiops
  • Dogs
  • Epithelium
  • Hypertonic Solutions
  • Integrin beta1 / biosynthesis*
  • Kidney
  • Molecular Sequence Data
  • Oligonucleotides, Antisense
  • RNA, Messenger / biosynthesis
  • Transcription, Genetic*
  • Vero Cells
  • Water-Electrolyte Balance


  • Hypertonic Solutions
  • Integrin beta1
  • Oligonucleotides, Antisense
  • RNA, Messenger