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

• Published in: Kidney international Vol. 55; no. 1; pp. 71 - 81
• Main Authors: Takemura, Tsukasa, Hino, Satoshi, Murata, Yuka, Yanagida, Hidehiko, Okada, Mitsuru, Yoshioka, Kazuo, Harris, Raymond C.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: New York, NY Elsevier Inc 01.01.1999; Nature Publishing
• Subjects: Animals; Antigens, CD - genetics; Antigens, CD - metabolism; Apoptosis; Base Sequence; Biological and medical sciences; Cell Adhesion; cell growth; 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; Extracellular Matrix - metabolism; Fundamental and applied biological sciences. Psychology; Gene Expression; growth factor; heparin binding; Heparin-binding EGF-like Growth Factor; Intercellular Signaling Peptides and Proteins; Kidney - cytology; Kidney - metabolism; Membrane Glycoproteins; NRK 52E cells; Protein Precursors - genetics; Protein Precursors - metabolism; Rats; RNA, Messenger - genetics; RNA, Messenger - metabolism; Tetraspanin-29; Transfection; Vertebrates: urinary system; growth factor; cell growth; heparin binding; NRK 52E cells; extracellular matrix; Cell culture; Coexpression; Cell cell interaction; Experimental study; Kidney; Epidermal growth factor; Transfection; Urinary system; Epithelial cell; Extracellular matrix; Mitogen; Physiology; Biological effect; Survival curve
• ISSN: 0085-2538; 1523-1755
• DOI: 10.1046/j.1523-1755.1999.00259.x

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. 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. 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). 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 β1 integrin was up-regulated only in NRKboth. 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.