Function of discoidin domain receptor I in HGF-induced branching tubulogenesis of MDCK cells in collagen gel.
Discoidin domain receptor I (DDR1) is a receptor tyrosine kinase (RTK) and serves as the receptor for collagen in addition to integrins. It has been well established that Madin-Darby canine kidney (MDCK) cells develop branching tubules in three-dimensional collagen gel in the presence of hepatocyte growth factor (HGF). MDCK cells normally express DDR1. However, the function of DDR1 in this in vitro model system has not been understood. We established stable-transfected MDCK cells harboring DDR1a, DDR1b, or dominant-negative (DN) DDR1 and cultured these transfectants in collagen gel with HGF (2 ng/ml) for the studies of branching tubule morphogenesis. Whether DDR1 played roles in cell growth, apoptosis, and migration was examined. We found that cells over-expressing DDR1a and DDR1b developed shorter tubules with fewer branches in collagen gel. In contrast, DN DDR1 over-expressed cells could not form tubule structure, but instead developed mostly cell aggregates with multiple long extended processes. Over-expression of DDR1a and 1b in MDCK cells resulted in reduction of cell growth when cells were cultured on collagen gel-coated dishes or collagen gel. On the other hand, DN DDR1 enhanced cell death on collagen gel, suggesting that DDR1 is involved in maintenance of cell survival. Moreover, over-expression of DDR1a and DDR1b markedly reduced collagen-induced migration capability, whereas DN DDR1 enhanced it, suggesting that DDR1a and 1b may serve as a negative regulator for alpha2beta1 integrin during migration on collagen substratum. These results indicate that DDR1 plays important role in regulation of HGF-induced branching tubulogenesis by modulating cell proliferation, survival, and cell migration.
Wang
Chau-Zen
CZ
Institute of Basic Medical Sciences, and Department of Physiology, National Cheng-Kung University Medical College, Tainan, Taiwan.
Hsu
Yuei-Mei
YM
Tang
Ming-Jer
MJ
D000818:Animals; D017209:Apoptosis / Q000502:physiology; D018929:Cell Culture Techniques / Q000379:methods; D002455:Cell Division / Q000502:physiology; D002460:Cell Line; D002465:Cell Movement / Q000502:physiology; D048430:Cell Shape; D003094:Collagen; D000070818:Discoidin Domain Receptors; D004285:Dogs; D005782:Gels; D017228:Hepatocyte Growth Factor / Q000494:pharmacology*; D007536:Isomerism; D007684:Kidney Tubules / Q000166:cytology* / Q000187:drug effects* / Q000378:metabolism; D016296:Mutagenesis; D020794:Receptor Protein-Tyrosine Kinases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D011975:Receptors, Mitogen / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D014162:Transfection
D005782:Gels; D011975:Receptors, Mitogen; D017228:Hepatocyte Growth Factor; D003094:Collagen; D000070818:Discoidin Domain Receptors; D020794:Receptor Protein-Tyrosine Kinases