Coexpression of CD9 augments the ability of membrane-bound heparin-binding epidermal growth factor-like growth factor (proHB-EGF) to preserve renal epithelial cell viability

Kidney Int. 1999 Jan;55(1):71-81. doi: 10.1046/j.1523-1755.1999.00259.x.


Background: Transfection of renal epithelial cells (NRK 52E) with membrane-associated heparin-binding epidermal growth factor-like growth factor (proHB-EGF) increased renal epithelial cell survival by promoting cell-cell and cell-extracellular matrix interactions. ProHB-EGF has been shown to form a complex in the plasma membrane with the tetraspanin CD9, an interaction that significantly increases the effectiveness of proHB-EGF as a juxtacrine mitogenic agent.

Methods: We examined whether the coexpression of proHB-EGF and CD9 would increase renal epithelial cell survival. CD9 was stably transfected into NRK 52E cells, either alone (NRKCD9) or together with proHB-EGF (NRKboth).

Results: Juxtacrine mitogenic activity of NRKCD9 was no different than in cells transfected with vector alone (NRKvector), but was increased by NRKboth; juxtacrine mitogenic activity by NRKboth was twofold greater than when proHB-EGF was transfected alone (NRKproHB-EGF). When grown in 10% fetal calf serum, growth rates were similar among all transfectants. However, in 1% fetal calf serum, NRKproHB-EGF grew 50% faster than NRKvector or NRKCD9, and NRKboth grew 20% to 50% faster than NRKproHB-EGF at one, two, and three days of culture. NRKproHB-EGF attachment to plastic substratum at one, two, and three hours was 250% greater than that of NRKvector, and NRKboth was 20% to 30% greater than that of NRKproHB-EGF. Coating plates with either poly 2-hydroxyethyl methacrylate or the GRGDTP peptide prevented normal cell-extracellular matrix attachment, and NRKvector or NRKCD9 failed to attach or form cell-cell attachments. NRKproHB-EGF exhibited 300% and NRKboth exhibited 600% greater cell viability under these conditions. Expression of type I and type III collagen mRNA was enhanced similarly in NRKproHB-EGF and NRKboth, but the expression of beta1 integrin was up-regulated only in NRKboth.

Conclusions: Coexpression of proHB-EGF and CD9 may render the renal epithelial cells more resistant to disruption of cell-cell and cell-matrix interactions and could accelerate the re-establishment of these attachments.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Antigens, CD / genetics
  • Antigens, CD / metabolism*
  • Apoptosis
  • Base Sequence
  • Cell Adhesion
  • Cell Line
  • Cell Membrane / metabolism
  • Cell Survival
  • DNA Primers / genetics
  • Epidermal Growth Factor / genetics
  • Epidermal Growth Factor / metabolism*
  • Epithelial Cells / cytology
  • Epithelial Cells / metabolism
  • Extracellular Matrix / metabolism
  • Gene Expression
  • Heparin-binding EGF-like Growth Factor
  • Intercellular Signaling Peptides and Proteins
  • Kidney / cytology*
  • Kidney / metabolism*
  • Membrane Glycoproteins*
  • Protein Precursors / genetics
  • Protein Precursors / metabolism*
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • Rats
  • Tetraspanin 29
  • Transfection


  • Antigens, CD
  • DNA Primers
  • Hbegf protein, rat
  • Heparin-binding EGF-like Growth Factor
  • Intercellular Signaling Peptides and Proteins
  • Membrane Glycoproteins
  • Protein Precursors
  • RNA, Messenger
  • Tetraspanin 29
  • epidermal growth factor precursor
  • Epidermal Growth Factor