title: A molecular profile of focal segmental glomerulosclerosis from formalin-fixed, paraffin-embedded tissue.
abstract: Focal segmental glomerulosclerosis (FSGS) is a common form of idiopathic nephrotic syndrome defined by the characteristic lesions of focal glomerular sclerosis and foot process effacement; however, its etiology and pathogenesis are unknown. We used mRNA isolated from laser-captured glomeruli from archived formalin-fixed, paraffin-embedded renal biopsies, until recently considered an unsuitable source of mRNA for microarray analysis, to investigate the glomerular gene expression profiles of patients with primary classic FSGS, collapsing FSGS (COLL), minimal change disease (MCD), and normal controls (Normal). Amplified mRNA was hybridized to an Affymetrix Human X3P array. Unsupervised (unbiased) hierarchical clustering revealed two distinct clusters delineating FSGS and COLL from Normal and MCD. Class comparison analysis of FSGS + COLL combined versus Normal + MCD revealed 316 significantly differentially regulated genes (134 up-regulated, 182 down-regulated). Among the differentially regulated genes were those known to be part of the slit diaphragm junctional complex and those previously described in the dysregulated podocyte phenotype. Analysis based on Gene Ontology categories revealed overrepresented biological processes of development, differentiation and morphogenesis, cell motility and migration, cytoskeleton organization, and signal transduction. Transcription factors associated with developmental processes were heavily overrepresented, indicating the importance of reactivation of developmental programs in the pathogenesis of FSGS. Our findings reveal novel insights into the molecular pathogenesis of glomerular injury and structural degeneration in FSGS.
authors.affiliation: Department of Pathology, College of Physicians and Surgeons, Columbia University, New York, New York, USA. jhodgin@med.umich.edu
authors.forename: Jeffrey B
authors.initials: JB
authors.lastname: Hodgin
authors.forename: Alain C
authors.initials: AC
authors.lastname: Borczuk
authors.forename: Samih H
authors.initials: SH
authors.lastname: Nasr
authors.forename: Glen S
authors.initials: GS
authors.lastname: Markowitz
authors.forename: Viji
authors.initials: V
authors.lastname: Nair
authors.forename: Sebastian
authors.initials: S
authors.lastname: Martini
authors.forename: Felix
authors.initials: F
authors.lastname: Eichinger
authors.forename: Courtenay
authors.initials: C
authors.lastname: Vining
authors.forename: Celine C
authors.initials: CC
authors.lastname: Berthier
authors.forename: Matthias
authors.initials: M
authors.lastname: Kretzler
authors.forename: Vivette D
authors.initials: VD
authors.lastname: D'Agati
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000378:metabolism*; D015153:Blotting, Western; D002648:Child; D002675:Child, Preschool; D005260:Female; D005557:Formaldehyde; D020869:Gene Expression Profiling; D005923:Glomerulosclerosis, Focal Segmental / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D006801:Humans; D007124:Immunoenzyme Techniques; D008297:Male; D008875:Middle Aged; D020411:Oligonucleotide Array Sequence Analysis; D016612:Paraffin Embedding; D050199:Podocytes / Q000166:cytology / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D055815:Young Adult
chemical_list: D015415:Biomarkers; D012333:RNA, Messenger; D005557:Formaldehyde