title: The phenotypes of podocytes and parietal epithelial cells may overlap in diabetic nephropathy.
abstract: Reversal of diabetic nephropathy (DN) has been achieved in humans and mice, but only rarely and under special circumstances. As progression of DN is related to podocyte loss, reversal of DN requires restoration of podocytes. Here, we identified and quantified potential glomerular progenitor cells that could be a source for restored podocytes. DN was identified in 31 human renal biopsy cases and separated into morphologically early or advanced lesions. Markers of podocytes (WT-1, p57), parietal epithelial cells (PECs) (claudin-1), and cell proliferation (Ki-67) were identified by immunohistochemistry. Podocyte density was progressively reduced with DN. Cells marking as podocytes (p57) were present infrequently on Bowman's capsule in controls, but significantly increased in histologically early DN. Ki-67-expressing cells were identified on the glomerular tuft and Bowman's capsule in DN, but rarely in controls. Cells marking as PECs were present on the glomerular tuft, particularly in morphologically advanced DN. These findings show evidence of phenotypic plasticity in podocyte and PEC populations and are consistent with studies in the BTBR ob/ob murine model in which reversibility of DN occurs with podocytes potentially regenerating from PEC precursors. Thus, our findings support, but do not prove, that podocytes may regenerate from PEC progenitors in human DN. If so, progression of DN may represent a modifiable net balance between podocyte loss and regeneration.
authors.affiliation: Department of Pathology, University of Washington, Seattle, Washington, USA.
authors.forename: Nicole K
authors.initials: NK
authors.lastname: Andeen
authors.affiliation: Department of Pathology, University of Washington, Seattle, Washington, USA.
authors.forename: Tri Q
authors.initials: TQ
authors.lastname: Nguyen
authors.affiliation: Department of Pathology, University of Washington, Seattle, Washington, USA.
authors.forename: Floor
authors.initials: F
authors.lastname: Steegh
authors.affiliation: Department of Pathology, University of Washington, Seattle, Washington, USA.
authors.forename: Kelly L
authors.initials: KL
authors.lastname: Hudkins
authors.affiliation: Department of Pathology, University of Washington, Seattle, Washington, USA.
authors.forename: Behzad
authors.initials: B
authors.lastname: Najafian
authors.affiliation: Department of Pathology, University of Washington, Seattle, Washington, USA.
authors.forename: Charles E
authors.initials: CE
authors.lastname: Alpers
mesh_terms: D050476:Bowman Capsule / Q000737:chemistry / Q000473:pathology; D000066670:Cell Plasticity; D049109:Cell Proliferation; D062445:Claudin-1 / Q000032:analysis; D050761:Cyclin-Dependent Kinase Inhibitor p57 / Q000032:analysis; D003928:Diabetic Nephropathies / Q000473:pathology*; D004847:Epithelial Cells / Q000737:chemistry / Q000166:cytology / Q000502:physiology; D006801:Humans; D019394:Ki-67 Antigen / Q000032:analysis; D007678:Kidney Glomerulus / Q000473:pathology; D008840:Microfilament Proteins / Q000032:analysis; D010641:Phenotype; D050199:Podocytes / Q000737:chemistry / Q000166:cytology* / Q000502:physiology; D012038:Regeneration; D012189:Retrospective Studies; D013234:Stem Cells / Q000166:cytology / Q000502:physiology*; D025721:WT1 Proteins / Q000032:analysis
chemical_list: C493964:CDKN1C protein, human; C568108:CLDN1 protein, human; D062445:Claudin-1; D050761:Cyclin-Dependent Kinase Inhibitor p57; D019394:Ki-67 Antigen; D008840:Microfilament Proteins; C503967:SYNPO protein, human; D025721:WT1 Proteins; C583751:WT1 protein, human