ANG II is a mitogen for a murine cell line isolated from medullary thick ascending limb of Henle's loop.
A murine SV40-transformed renal epithelial cell line derived from medullary thick ascending limb of Henle's loop (MTAL) was established and characterized by morphology, antigen expression, and biochemical criteria. These MTAL cells express a single class of high-affinity receptors for angiotensin II (ANG II) and transcripts for the AT1 subtype of ANG II receptors. ANG II, in a dose-dependent manner, induced proliferation of MTAL cells. This observation is in striking contrast to syngeneic proximal tubular cells in which it was previously shown that the peptide induced cellular hypertrophy and slightly inhibited proliferation [G. Wolf and E. G. Neilson. Am. J. Physiol. 259 (Renal Fluid Electrolyte Physiol. 28: F768-F777, 1990]. The AT1-receptor antagonist losartan (10(-6) M), but not an AT2-receptor antagonist, blocked the mitogenic effects of ANG II in MTAL cells. Coincubation of quiescent MTAL cells with ANG II and 5% fetal calf serum further increased proliferation compared with cells grown only in serum. In contrast to proximal tubular cells, ANG II failed to induce transforming growth factor-beta 1 mRNA and protein synthesis in MTAL cells. Our data collectively suggest that ANG II is a mitogen for MTAL cells in vitro. Therefore, epithelial cells derived from different parts of the nephron, even when transformed with SV40 virus and while under cell culture conditions, exhibit a distinct pattern of growth behavior after stimulation with ANG II.
Wolf
G
G
Department of Medicine, University of Hamburg, Germany.
Ziyadeh
F N
FN
Helmchen
U
U
Zahner
G
G
Schroeder
R
R
Stahl
R A
RA
D000804:Angiotensin II / Q000494:pharmacology*; D000818:Animals; D002455:Cell Division / Q000187:drug effects; D002460:Cell Line; D002478:Cells, Cultured; D007679:Kidney Medulla; D008138:Loop of Henle / Q000166:cytology / Q000187:drug effects*; D051379:Mice; D008934:Mitogens / Q000494:pharmacology*; D012333:RNA, Messenger / Q000378:metabolism; D011945:Receptors, Angiotensin / Q000235:genetics / Q000378:metabolism; D016212:Transforming Growth Factor beta / Q000378:metabolism
D008934:Mitogens; D012333:RNA, Messenger; D011945:Receptors, Angiotensin; D016212:Transforming Growth Factor beta; D000804:Angiotensin II