Molecular events involved in the morphogenesis of multicystic dysplastic kidney.
BACKGROUND
Wnt-1 is capable of inducing metanephric mesenchyme to undergo tubulogenesis. A relationship between the degree of cystogenesis and reduced E-cadherin (E-cad) expression was described. Syndecan-1 (Sdc-1) has a critical role in kidney development.


METHODS
Ten multicystic dysplastic kidneys (MCDKs) were stained with hematoxylin and eosin and immunohistochemistry was performed using Wnt-1, E-cad and Sdc-1 antibodies. Eight unaffected kidneys were used as controls.


RESULTS
Strong Wnt-1 immunostaining occurred inside cystic/tubular epithelial cells and in blastematous foci. An immunoreaction was observed in glomerular epithelial cells. In controls, just weak cytoplasmic Wnt-1 positivity was seen in tubular epithelial cells. E-cad reaction was negative in MCDKs while strong immunostaining was common in tubular cells of controls. A strong Sdc-1 immunoreaction depicted cystic, tubular and glomerular epithelial cells in MCDKs while Sdc-1 expression documented weak positivity in tubular epithelium alone.


CONCLUSIONS
Our data are in accordance with an involvement of Wnt-1 in normal nephrogenesis and with its role in altered epithelial differentiation of metanephric mesenchyme in MCDKs. Wnt-1 signal may function to suppress E-cad expression, a predisposing event for cystogenesis. High expression of Sdc-1 in tubular/cystic epithelial cells of MCDKs might alter the normal transition of stages of the developmental process and modify the anion charge of the glomerular barrier.
Arena
Salvatore
S
Unit of Pediatric Surgery, Department of Pediatric Surgery, University of Catania, Catania, Italy. arenasal @ inwind.it
Fazzari
Carmine
C
Scuderi
Maria Grazia
MG
Implatini
Alessandra
A
Villari
Daniela
D
Torre
Santo
S
Arena
Francesco
F
Di Benedetto
Vincenzo
V
D015703:Antigens, CD; D015820:Cadherins / Q000032:analysis; D016022:Case-Control Studies; D006801:Humans; D007150:Immunohistochemistry; D007223:Infant; D007668:Kidney / Q000737:chemistry* / Q000196:embryology / Q000254:growth & development; D009024:Morphogenesis; D021782:Multicystic Dysplastic Kidney / Q000196:embryology / Q000378:metabolism*; D015398:Signal Transduction; D053668:Syndecan-1 / Q000032:analysis; D051155:Wnt1 Protein / Q000032:analysis
D015703:Antigens, CD; C513384:CDH1 protein, human; D015820:Cadherins; C508241:SDC1 protein, human; D053668:Syndecan-1; C495247:WNT1 protein, human; D051155:Wnt1 Protein