title: Altered cytoskeletal structure of smooth muscle cells in ureteropelvic junction obstruction.
abstract: OBJECTIVE
  Ureteropelvic junction obstruction is one of the most common causes of hydronephrosis in children. A malfunction of smooth muscle cells is believed to be the underlying mechanism causing obstruction. We investigated the expression of some integrins, talin and β-dystroglycan, considered the main compound of smooth muscle cell cytoskeleton, and active caspase 3 at the level of the ureteropelvic junction obstruction.
  
  
  METHODS
  Specimens were obtained at pyeloplasty in 12 children with ureteropelvic junction obstruction. Six control specimens were obtained during organ explantation. Specimens were divided into renal pelvis, ureteropelvic junction and ureter below the obstruction. Western blot analysis of active caspase 3, and immunofluorescence and polymerase chain reaction analysis were performed for α7A, β1A, α7B and β1D integrins, talin and β-dystroglycan.
  
  
  RESULTS
  Talin and β-dystroglycan were slightly impaired in ureteropelvic junction obstruction, while α7B and β1D integrins were severely reduced, and α7A, β1A and active caspase 3 were significantly enhanced compared to controls.
  
  
  CONCLUSIONS
  We demonstrated activation of apoptosis and a critical alteration of cytoskeleton that might explain the altered function and the increased apoptosis in smooth muscle cells in ureteropelvic junction obstruction. The delayed rearrangement of the cytoskeleton of smooth muscle cells in ureteropelvic junction obstruction might be linked to a postnatal splicing from α7A and β1A to α7B and β1D integrins, respectively. This relationship could explain the common clinical scenario of spontaneous improvement of hydronephrosis in children with suspected ureteropelvic junction obstruction.
authors.affiliation: Department of Biomorphology and Biotechnology, University of Messina, Messina, Italy.
authors.forename: Giuseppina
authors.initials: G
authors.lastname: Cutroneo
authors.forename: Salvatore
authors.initials: S
authors.lastname: Arena
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Anastasi
authors.forename: Raimondo M
authors.initials: RM
authors.lastname: Cervellione
authors.forename: Silvia
authors.initials: S
authors.lastname: Grimaldi
authors.forename: Debora
authors.initials: D
authors.lastname: Di Mauro
authors.forename: Francesco
authors.initials: F
authors.lastname: Speciale
authors.forename: Francesco
authors.initials: F
authors.lastname: Arena
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Di Benedetto
authors.forename: Angelo
authors.initials: A
authors.lastname: Favaloro
authors.forename: Carlo
authors.initials: C
authors.lastname: Magno
mesh_terms: D053148:Caspase 3 / Q000096:biosynthesis; D002675:Child, Preschool; D003599:Cytoskeleton / Q000648:ultrastructure*; D049030:Dystroglycans / Q000096:biosynthesis; D006801:Humans; D007150:Immunohistochemistry; D007223:Infant; D016023:Integrins / Q000096:biosynthesis; D007682:Kidney Pelvis / Q000473:pathology*; D009130:Muscle, Smooth / Q000473:pathology*; D016608:Talin / Q000096:biosynthesis; D014517:Ureteral Obstruction / Q000378:metabolism / Q000473:pathology*
chemical_list: D016023:Integrins; D016608:Talin; D049030:Dystroglycans; D053148:Caspase 3