Localization of fibroblast growth factor-2 (basic FGF) and FGF receptor-1 in adult human kidney.
BACKGROUND
The expression pattern of fibroblast growth factor-2 (FGF-2; basic FGF), a pleiotrophic growth factor, as well as one of its receptors (FGFR1), in the kidney is highly controversial.


METHODS
Using an approach that combines multiple antibodies for immunohistochemistry and correlative in situ hybridization, we assessed the intrarenal expression of both FGF-2 and FGFR1 in 13 specimens of adult kidney removed during tumor nephrectomy.


RESULTS
The FGF-2 expression pattern in the kidneys as detected by immunohistochemistry was variable and depended on the antibody used. The most consistent expression of FGF-2 protein was demonstrated in glomerular parietal epithelial cells, tubular cells (mainly of the distal nephron), as well as arterial endothelial cells. These locations also corresponded to areas of FGF-2 mRNA expression. Additionally, by immunohistochemistry, FGF-2 protein was detected in arterial smooth muscle cells and occasional podocytes. The expression of FGFR1 protein and mRNA was most consistently present in tubular cells of the distal nephron and in vascular smooth muscle cells. In situ hybridization, but not immunohistochemistry, also suggested FGFR1 expression in cells that could not be precisely identified within the glomerular tuft as well as some interstitial cells.


CONCLUSIONS
These data suggest potential autocrine and paracrine pathways within the FGF-2 system, particularly within the vascular walls and in the distal nephron, and thereby provide information for further mechanistic understanding of the role of the FGF-2 system in human renal disease.
Floege
J
J
Division of Nephrology, Medical School, Hannover, Germany.
Hudkins
K L
KL
Eitner
F
F
Cui
Y
Y
Morrison
R S
RS
Schelling
M A
MA
Alpers
C E
CE
D000328:Adult; D001808:Blood Vessels / Q000378:metabolism; D016222:Fibroblast Growth Factor 2 / Q000235:genetics / Q000378:metabolism*; D015870:Gene Expression; D006801:Humans; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D007668:Kidney / Q000033:anatomy & histology / Q000098:blood supply / Q000378:metabolism*; D007678:Kidney Glomerulus / Q000378:metabolism; D007684:Kidney Tubules / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D020794:Receptor Protein-Tyrosine Kinases / Q000235:genetics / Q000378:metabolism*; D051496:Receptor, Fibroblast Growth Factor, Type 1; D017468:Receptors, Fibroblast Growth Factor / Q000235:genetics / Q000378:metabolism*; D014018:Tissue Distribution
D012333:RNA, Messenger; D017468:Receptors, Fibroblast Growth Factor; D016222:Fibroblast Growth Factor 2; C496348:FGFR1 protein, human; D020794:Receptor Protein-Tyrosine Kinases; D051496:Receptor, Fibroblast Growth Factor, Type 1