Basic fibroblast growth factor can mediate the early inductive events in renal development.
The earliest characterized events during induction of tubulogenesis in renal anlage include the condensation or compaction of metanephrogenic mesenchyme with the concurrent upregulation of WT1, the gene encoding the Wilms tumor transcriptional activator/suppressor. We report that basic fibroblast growth factor (FGF2) can mimic the early effects of an inductor tissue by promoting the condensation of mesenchyme and inhibiting the tissue degeneration associated with the absence of an inductor tissue. By in situ hybridization, FGF2 was also found to mediate the transcriptional activation of WT1 and of the hepatocyte growth factor receptor gene, c-met. Although FGF2 can induce these early events of renal tubulogenesis, it cannot promote the epithelial conversion associated with tubule formation in metanephrogenic mesenchyme. For this, an undefined factor(s) from pituitary extract in combination with FGF2 can cause tubule formation in uninduced mesenchyme. These findings support the concept that induction in kidney is a multiphasic process that is mediated by more than a single comprehensive inductive factor and that soluble molecules can mimic these inductive activities in isolated uninduced metanephrogenic mesenchyme.
Perantoni
A O
AO
Laboratory of Comparative Carcinogenesis, National Cancer Institute-Frederick Cancer Research and Development Center, MD 21702, USA.
Dove
L F
LF
Karavanova
I
I
D000818:Animals; D002417:Cattle; D005314:Embryonic and Fetal Development / Q000187:drug effects; D005260:Female; D016222:Fibroblast Growth Factor 2 / Q000494:pharmacology*; D005786:Gene Expression Regulation / Q000187:drug effects*; D016162:Genes, Wilms Tumor; D006801:Humans; D017403:In Situ Hybridization; D007668:Kidney / Q000187:drug effects / Q000196:embryology* / Q000378:metabolism; D007684:Kidney Tubules / Q000187:drug effects / Q000648:ultrastructure; D008297:Male; D009924:Organ Culture Techniques; D010902:Pituitary Gland; D011247:Pregnancy; D019859:Proto-Oncogene Proteins c-met; D011519:Proto-Oncogenes; D051381:Rats; D011916:Rats, Inbred F344; D020794:Receptor Protein-Tyrosine Kinases / Q000096:biosynthesis; D014020:Tissue Extracts / Q000494:pharmacology; D014158:Transcription, Genetic / Q000187:drug effects
D014020:Tissue Extracts; D016222:Fibroblast Growth Factor 2; D019859:Proto-Oncogene Proteins c-met; D020794:Receptor Protein-Tyrosine Kinases