A ureteric bud cell line induces nephrogenesis in two steps by two
distinct signals.
Barasch, Jonathan, Lee Pressler, John Connor, and Abha Malik.
Departments of Medicine and Urology, Columbia College of Physicians
and Surgeons, New York, N.Y. 10032
APStracts 3:0017F, 1996.
Nephrons develop from mesenchymal cells that have contacted the
ureteric bud. To determine whether cell surface or secreted ureteric
molecules induce the mesenchyme, we have isolated ureteric bud cell
lines from mice transgenic for T-antigen. These cells express
epithelial and ureteric (Dolichos lectin staining, c-ret, c-met
without HGF) specific markers, identifying them as authentic UB
cells. Media conditioned by our cells rescues mesenchyme from
apoptosis without inducing the appearance of epithelial aggregates.
The same was found by culturing mesenchymes upon the apical surface
of a UB monolayer. In contrast, tubules were induced in mesenchymes
contacting trypsinized pellets of UB cells. As revealed by staining
for T-antigen and Dolichos lectin, and by pre-labeling UB cells with
DiI, we found that our cells encapsulated the mesenchyme but did not
incorporate in the tubules. These data demonstrate that nephrogenesis
is stimulated by two distinct ureteric signals, secreted molecules
rescue the mesenchyme from apoptosis, while diffusion limited,
basolateral molecules trigger mesenchymal/epithelial conversion.
Received 7 September 1995; accepted in final form 26 December
1995.
APS Manuscript Number F299-5.
Article publication pending Am. J. Physiol. (Renal Fluid Electrolyte
Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 29 January 96