Induction of collecting duct morphogenesis in vitro by heparin-binding epidermal growth factor-like growth factor.
Heparin-binding epidermal growth factor-like growth factor (HB-EGF), a member of the epidermal growth factor family of growth factors, is synthesized as a membrane-an-chored precursor (proHB-EGF) that is capable of stimulating adjacent cells in a juxtacrine manner. ProHB-EGF is cleaved in a protein kinase C-dependent process, to yield the soluble form. It was observed that HB-EGF acts as a morphogen for the collecting duct system in developing kidneys. HB-EGF protein was expressed in the ureteric bud of embryonic kidneys. Cultured mouse ureteric bud cells (UBC) produced HB-EGF via protein kinase C activation. After stimulation with phorbol ester (12-O-tetradecanoylphorbol-13-acetate) or recombinant soluble HB-EGF, UBC cultured in three-dimensional collagen gels formed short tubules with varied abundant branches. When proHB-EGF-transfected UBC were stimulated with 12-O-tetradecanoylphorbol-13-acetate and cultured in collagen gels, they exhibited linear growth, forming long tubular structures with few branches at the time of appearance of proHB-EGF on the cell surface. The structures exhibited a strong resemblance to the early branching ureteric bud of embryonic kidneys. When UBC were cultured in the presence of transforming growth factor-beta and soluble HB-EGF, they formed long tubules and few branches, similar to the structures observed in proHB-EGF-transfected UBC. These cells exhibited apical-basolateral polarization and expression of the water channel aquaporin-2. These findings indicate that soluble HB-EGF and proHB-EGF induce branching tubulogenesis in UBC in different ways. Juxtacrine activation by proHB-EGF or the synergic action of soluble HB-EGF with transforming growth factor-beta is important for well balanced morphogenesis of the collecting duct system.
Takemura
Tsukasa
T
Department of Pediatrics, Kinki University School of Medicine, Osaka-Sayama, Japan.
Hino
Satoshi
S
Department of Pediatrics, Kinki University School of Medicine, Osaka-Sayama, Japan.
Kuwajima
Hiroaki
H
Department of Pediatrics, Kinki University School of Medicine, Osaka-Sayama, Japan.
Yanagida
Hidehiko
H
Department of Pediatrics, Kinki University School of Medicine, Osaka-Sayama, Japan.
Okada
Mitsuru
M
Department of Pediatrics, Kinki University School of Medicine, Osaka-Sayama, Japan.
Nagata
Michio
M
Department of Pathology, Institute of Basic Medical Science, University of Tsukuba, Tsukuba, Japan.
Sasaki
Sei
S
Second Department of Internal Medicine, Tokyo Medical and Dental University, Tokyo, Japan.
Barasch
Jonathan
J
Department of Medicine, College of Physicians and Surgeons, Columbia University, New York, New York.
Harris
Raymond C
RC
Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee.
Yoshioka
Kazuo
K
Department of Pediatrics, Kinki University School of Medicine, Osaka-Sayama, Japan.
D000818:Animals; D001483:Base Sequence; D002478:Cells, Cultured; D003094:Collagen; D003470:Culture Media; D017931:DNA Primers / Q000235:genetics; D004815:Epidermal Growth Factor / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology*; D005782:Gels; D066257:Heparin-binding EGF-like Growth Factor; D066298:In Vitro Techniques; D036341:Intercellular Signaling Peptides and Proteins; D007685:Kidney Tubules, Collecting / Q000187:drug effects* / Q000196:embryology* / Q000378:metabolism; D051379:Mice; D009024:Morphogenesis / Q000187:drug effects; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014162:Transfection; D016212:Transforming Growth Factor beta / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology
D003470:Culture Media; D017931:DNA Primers; D005782:Gels; C587884:Hbegf protein, mouse; D066257:Heparin-binding EGF-like Growth Factor; D036341:Intercellular Signaling Peptides and Proteins; D012333:RNA, Messenger; D016212:Transforming Growth Factor beta; D004815:Epidermal Growth Factor; D003094:Collagen; D013755:Tetradecanoylphorbol Acetate