title: Epithelial-to-mesenchymal transition in cyst lining epithelial cells in an orthologous PCK rat model of autosomal-recessive polycystic kidney disease.
abstract: In polycystic kidney disease (PKD), cyst lining cells show polarity abnormalities. Recent studies have demonstrated loss of cell contact in cyst cells, suggesting induction of epithelial-to-mesenchymal transition (EMT). Recently, EMT has been implicated in the pathogenesis of PKD. To explore further evidence of EMT in PKD, we examined age- and segment-specific expression of adhesion molecules and mesenchymal markers in PCK rats, an orthologous model of human autosomal-recessive PKD. Kidneys from 5 male PCK and 5 control rats each at 0 days, 1, 3, 10, and 14 wk, and 4 mo of age were serially sectioned and stained with segment-specific markers and antibodies against E-cadherin, Snail1, β-catenin, and N-cadherin. mRNAs for E-cadherin and Snail1 were quantified by real-time PCR. Vimentin, fibronectin, and α-smooth muscle actin (α-SMA) expressions were assessed as mesenchymal markers. E-cadherin expression pattern was correlated with the disease pathology in that tubule segments showing the highest expression in control had much severer cyst formation in PCK rats. In PCK rats, E-cadherin and β-catenin in cystic tubules was attenuated and localized to lateral areas of cell-cell contact, whereas nuclear expression of Snail1 increased in parallel with cyst enlargement. Some epithelial cells in large cysts derived from these segments, especially in adjacent fibrotic areas, showed positive immunoreactivity for vimentin and fibronectin. In conclusion, these findings suggest that epithelial cells in cysts acquire mesenchymal features in response to cyst enlargement and participate in progressive renal fibrosis. Our study clarified the nephron segment-specific cyst profile related to EMT in PCK rats. EMT may play a key role in polycystic kidney disease.
authors.affiliation: Department of Pediatrics, Wakayama Medical University, Wakayama, Japan.
authors.forename: Hiroko
authors.initials: H
authors.lastname: Togawa
authors.forename: Koichi
authors.initials: K
authors.lastname: Nakanishi
authors.forename: Hironobu
authors.initials: H
authors.lastname: Mukaiyama
authors.forename: Taketsugu
authors.initials: T
authors.lastname: Hama
authors.forename: Yuko
authors.initials: Y
authors.lastname: Shima
authors.forename: Mayumi
authors.initials: M
authors.lastname: Sako
authors.forename: Masayasu
authors.initials: M
authors.lastname: Miyajima
authors.forename: Kandai
authors.initials: K
authors.lastname: Nozu
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Nishii
authors.forename: Shizuko
authors.initials: S
authors.lastname: Nagao
authors.forename: Hisahide
authors.initials: H
authors.lastname: Takahashi
authors.forename: Kazumoto
authors.initials: K
authors.lastname: Iijima
authors.forename: Norishige
authors.initials: N
authors.lastname: Yoshikawa
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000032:analysis / Q000378:metabolism; D015815:Cell Adhesion Molecules / Q000032:analysis / Q000378:metabolism; D004195:Disease Models, Animal; D058750:Epithelial-Mesenchymal Transition / Q000235:genetics*; D007668:Kidney / Q000378:metabolism / Q000473:pathology; D007684:Kidney Tubules / Q000737:chemistry / Q000378:metabolism; D008297:Male; D007690:Polycystic Kidney Diseases / Q000378:metabolism; D017044:Polycystic Kidney, Autosomal Recessive / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D051381:Rats
chemical_list: D015415:Biomarkers; D015815:Cell Adhesion Molecules