Ureteric bud cells secrete multiple factors, including bFGF, which rescue renal progenitors from apoptosis.
Kidney development requires reciprocal interactions between the ureteric bud and the metanephrogenic mesenchyme. Whereas survival of mesenchyme and development of nephrons from mesenchymal cells depends on signals from the invading ureteric bud, growth of the ureteric bud depends on signals from the mesenchyme. This codependency makes it difficult to identify molecules expressed by the ureteric bud that regulate mesenchymal growth. To determine how the ureteric bud signals the mesenchyme, we previously isolated ureteric bud cell lines (UB cells). These cells secrete soluble factors which rescue the mesenchyme from apoptosis. We now report that four heparin binding factors mediate this growth activity. One of these is basic fibroblast growth factor (bFGF), which is synthesized by the ureteric bud when penetrating the mesenchyme. bFGF rescues three types of progenitors found in the mesenchyme: precursors of tubular epithelia, precursors of capillaries, and cells that regulate growth of the ureteric bud. These data suggest that the ureteric bud regulates the number of epithelia and vascular precursors that generate nephrons by secreting bFGF and other soluble factors.
Barasch
J
J
Columbia College of Physicians and Surgeons, Department of Medicine, Cornell Medical School, New York, New York 10028, USA.
Qiao
J
J
McWilliams
G
G
Chen
D
D
Oliver
J A
JA
Herzlinger
D
D
D000818:Animals; D000957:Antigens, Viral, Tumor / Q000096:biosynthesis / Q000235:genetics; D017209:Apoptosis; D002460:Cell Line; D002470:Cell Survival; D017077:Culture Media, Conditioned; D016220:Fibroblast Growth Factor 1 / Q000096:biosynthesis; D051526:Fibroblast Growth Factor 10; D016222:Fibroblast Growth Factor 2 / Q000096:biosynthesis* / Q000494:pharmacology*; D051521:Fibroblast Growth Factor 5; D051523:Fibroblast Growth Factor 7; D051525:Fibroblast Growth Factor 9; D005346:Fibroblast Growth Factors / Q000096:biosynthesis; D006133:Growth Substances / Q000096:biosynthesis; D007668:Kidney / Q000166:cytology / Q000196:embryology*; D008648:Mesoderm / Q000166:cytology* / Q000187:drug effects / Q000502:physiology; D051379:Mice; D008822:Mice, Transgenic; D016133:Polymerase Chain Reaction; D015398:Signal Transduction; D013539:Simian virus 40 / Q000235:genetics; D013234:Stem Cells / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D014513:Ureter / Q000196:embryology* / Q000502:physiology
D000957:Antigens, Viral, Tumor; D017077:Culture Media, Conditioned; C496450:Fgf5 protein, mouse; C496454:Fgf7 protein, mouse; C496460:Fgf9 protein, mouse; D051526:Fibroblast Growth Factor 10; D051525:Fibroblast Growth Factor 9; D006133:Growth Substances; D016222:Fibroblast Growth Factor 2; D016220:Fibroblast Growth Factor 1; D051523:Fibroblast Growth Factor 7; D051521:Fibroblast Growth Factor 5; D005346:Fibroblast Growth Factors