Expression of bone morphogenetic protein-7 (bmp-7) mrna in the
normal and ischemic adult rat kidney.
Simon, Matthias, John G. Maresh, Stephen E. Harris, James D.
Hernandez, Mazen Arar, Merle S. Olson and Hanna E. Abboud.
1Division of Nephrology and 2Division of Endocrinology, Department
of Medicine and 3Division of Pediatric Nephrology and 4Department of
Biochemistry, University of Texas Health Science Center, and Audie L.
Murphy Memorial Veterans Affairs Hospital San Antonio, Texas
78284
APStracts 5:0192F, 1998.
BMP-7, a member of the bone morphogenic protein subfamily (BMPs) of
the TGFb-superfamily of secreted growth factors, is abundantly
expressed in the fetal kidney. The precise role of this protein in
renal physiology or pathology is unknown. A cDNA that encodes rat
BMP-7 was cloned and used as a probe to localize BMP-7 mRNA
expression by in situ hybridization in the adult rat kidney. The
highest expression of BMP-7 mRNA could be seen in tubules of the
outer medulla. In glomeruli, a few cells, mainly located at the
periphery of the glomerular tuft, showed specific and strong signals.
Also, high BMP-7 mRNA expression could be localized to the adventitia
of renal arteries, as well as to the epithelial cell layer of the
renal pelvis and the ureter. Preliminary evidence suggests that BMP-7
enhances recovery when infused into rats with ischemia-induced acute
renal failure. We examined BMP-7 mRNA expression in kidneys with
acute renal failure induced by unilateral renal artery clamping. BMP
-7 mRNA abundance as analyzed by solution hybridization was reduced in
ischemic kidneys after 6 and 16 hrs of reperfusion compared to the
contralateral kidney. In situ hybridization in ischemic kidneys
showed a marked decrease of BMP-7 mRNA in the outer medulla and in
glomeruli. Utilizing rat metanephric mesenchymal cells in culture, we
also demonstrate that BMP-7 induces epithelial cell differentiation.
Taken together these data suggest that BMP-7 is important in both
stimulating and maintaining a healthy differentiated epithelial cell
phenotype.
Received 21 July 1998; accepted in final form 8 October 1998.
APS Manuscript Number F178-8.
Article publication pending Am. J. Physiol. (Renal Physiology).
ISSN 1080-4757 Copyright 1998 The American Physiological Society.
Published in APStracts on 10 November 1998