title: Expression of transcription factor Snai1 and tubulointerstitial fibrosis in progressive nephropathy.
abstract: BACKGROUND
  Tubulointerstitial fibrosis (TIF) is seen as the final stage of progressive nephropathy, and the degree of TIF is reported to be a major determinant in renal outcomes. In recent years, epithelial-mesenchymal transition (EMT) and the zinc-finger transcription factor snail homolog 1 (Snai1) have each been implicated in the mechanism of TIF. The relationship between EMT and these transcription factors is unclear, however, so in this study we attempted to elucidate the correlation between the expression of Snai1 and clinical markers.
  
  
  METHODS
  We performed immunohistochemical staining on human renal tissue obtained from patients with diabetic nephropathy (DN), IgA nephropathy (IgAN), minimal change disease (MCD) and minor glomerular abnormality (MGA) using anti-Snai1 and anti-vimentin antibodies. We counted Snai1-positive and Snai1/vimentin double positive tubular epithelial cells.
  
  
  RESULTS
  Snai1 protein was mainly observed in the nuclei of flattened, damaged tubular epithelial cells, especially in IgAN and DN, and positive cell numbers were significantly higher in IgAN than in MGA, MCD or DN. Snai1/vimentin double staining showed that some vimentin-positive tubular epithelial cells also contained Snai1-positive nuclei, and double positive cell numbers were increased in IgAN and DN. Statistical analysis revealed positive correlations between Snai1/vimentin double positive cell numbers and proteinuria and creatinine in IgAN. Positive correlations were also seen between Snai1/vimentin double positive cell numbers and the severity of proteinuria in DN.
  
  
  CONCLUSIONS
  The results of this study indicate that Snai1 plays an important role in TIF in patients with progressive nephropathy.
authors: Division of Nephrology and Metabolism, Department of Internal Medicine, School of Medicine, Tokai University, Isehara, Kanagawa, Japan.
authors: Keiko
authors: K
authors: Ohnuki
authors: Tomoya
authors: T
authors: Umezono
authors: Makiko
authors: M
authors: Abe
authors: Takako
authors: T
authors: Kobayashi
authors: Mayuko
authors: M
authors: Kato
authors: Masaaki
authors: M
authors: Miyauchi
authors: Naoyuki
authors: N
authors: Yamamoto
authors: Moritsugu
authors: M
authors: Kimura
authors: Masao
authors: M
authors: Toyoda
authors: Daisuke
authors: D
authors: Suzuki
mesh_terms: D000328:Adult; D018450:Disease Progression; D058750:Epithelial-Mesenchymal Transition; D005260:Female; D005355:Fibrosis; D006801:Humans; D007150:Immunohistochemistry; D007668:Kidney / Q000473:pathology*; D007674:Kidney Diseases / Q000378:metabolism / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D000071250:Snail Family Transcription Factors; D014157:Transcription Factors / Q000032:analysis / Q000502:physiology*; D014746:Vimentin / Q000032:analysis
chemical_list: C000604407:SNAI1 protein, human; D000071250:Snail Family Transcription Factors; D014157:Transcription Factors; D014746:Vimentin