title: Aberrant expression of laminin-332 promotes cell proliferation and cyst growth in ARPKD.
abstract: Basement membrane abnormalities have often been observed in kidney cysts of polycystic kidney disease (PKD) patients and animal models. There is an abnormal deposition of extracellular matrix molecules, including laminin-α3,β3,γ2 (laminin-332), in human autosomal dominant PKD (ADPKD). Knockdown of PKD1 paralogs in zebrafish leads to dysregulated synthesis of the extracellular matrix, suggesting that altered basement membrane assembly may be a primary defect in ADPKD. In this study, we demonstrate that laminin-332 is aberrantly expressed in cysts and precystic tubules of human autosomal recessive PKD (ARPKD) kidneys as well as in the kidneys of PCK rats, an orthologous ARPKD model. There was aberrant expression of laminin-γ2 as early as postnatal day 2 and elevated laminin-332 protein in postnatal day 30, coinciding with the formation and early growth of renal cysts in PCK rat kidneys. We also show that a kidney cell line derived from Oak Ridge polycystic kidney mice, another model of ARPKD, exhibited abnormal lumen-deficient and multilumen structures in Matrigel culture. These cells had increased proliferation rates and altered expression levels of laminin-332 compared with their rescued counterparts. A function-blocking polyclonal antibody to laminin-332 significantly inhibited their abnormal proliferation rates and rescued their aberrant phenotype in Matrigel culture. Furthermore, abnormal laminin-332 expression in cysts originating from collecting ducts and proximal tubules as well as in precystic tubules was observed in a human end-stage ADPKD kidney. Our results suggest that abnormal expression of laminin-332 contributes to the aberrant proliferation of cyst epithelial cells and cyst growth in genetic forms of PKD.
authors.affiliation: Dept. of Natural Sciences and Mathematics, SUNY Cobleskill, 111 Schenectady Ave. WH200, Cobleskill, NY 12043. vijayas@cobleskill.edu.
authors.forename: Soundarapandian
authors.initials: S
authors.lastname: Vijayakumar
authors.forename: Suparna
authors.initials: S
authors.lastname: Dang
authors.forename: M Peter
authors.initials: MP
authors.lastname: Marinkovich
authors.forename: Zelmira
authors.initials: Z
authors.lastname: Lazarova
authors.forename: Bradley
authors.initials: B
authors.lastname: Yoder
authors.forename: Vicente E
authors.initials: VE
authors.lastname: Torres
authors.forename: Darren P
authors.initials: DP
authors.lastname: Wallace
mesh_terms: D000818:Animals; D001485:Basement Membrane / Q000473:pathology; D015815:Cell Adhesion Molecules / Q000096:biosynthesis*; D002460:Cell Line; D049109:Cell Proliferation; D002675:Child, Preschool; D006801:Humans; D052177:Kidney Diseases, Cystic / Q000378:metabolism / Q000473:pathology*; D007797:Laminin / Q000096:biosynthesis; D008297:Male; D051379:Mice; D008875:Middle Aged; D016891:Polycystic Kidney, Autosomal Dominant / Q000378:metabolism; D017044:Polycystic Kidney, Autosomal Recessive / Q000378:metabolism*; D051381:Rats; D000097794:Kalinin
chemical_list: D015815:Cell Adhesion Molecules; D007797:Laminin; D000097794:Kalinin
keywords: autosomal recessive polycystic kidney disease; cystogenesis; laminin-332; polycystic kidney disease rat; proliferation