title: Discovery of new glomerular disease-relevant genes by translational profiling of podocytes in vivo.
abstract: Identifying new biomarkers and therapeutic targets for podocytopathies such as focal segmental glomerulosclerosis (FSGS) requires a detailed analysis of transcriptional changes in podocytes over the course of disease. Here we used translating ribosome affinity purification (TRAP) to isolate and profile podocyte-specific mRNA in two different models of FSGS. We expressed enhanced green fluorescent protein-tagged to ribosomal protein L10a in podocytes under the control of the collagen-1α1 promoter, enabling one-step podocyte-specific mRNA isolation over the course of disease. This TRAP protocol robustly enriched known podocyte-specific mRNAs. We crossed Col1α1-eGFP-L10a mice with the Actn4(-/-) and Actn4(+/K256E) models of FSGS and analyzed podocyte transcriptional profiles at 2, 6, and 44 weeks of age. Two upregulated podocyte genes in murine FSGS (CXCL1 and DMPK) were found to be upregulated at the protein level in biopsies from patients with FSGS, validating this approach. There was no dilution of podocyte-specific transcripts during disease. These are the first podocyte-specific RNA expression data sets during aging and in two models of FSGS. This approach identified new podocyte proteins that are upregulated in FSGS and defines novel biomarkers and therapeutic targets for human glomerular disease.
authors.affiliation: 1] Renal Division, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA [2] Department of Internal Medicine and Nephrology, Philipps-University, Marburg, Germany.
authors.forename: Ivica
authors.initials: I
authors.lastname: Grgic
authors.affiliation: 1] Renal Division, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA [2] Department of Internal Medicine and Nephrology, Philipps-University, Marburg, Germany.
authors.forename: Andreas F
authors.initials: AF
authors.lastname: Hofmeister
authors.affiliation: 1] Division of Nephrology, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA [2] Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA.
authors.forename: Giulio
authors.initials: G
authors.lastname: Genovese
authors.affiliation: Division of Nephrology, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA.
authors.forename: Andrea J
authors.initials: AJ
authors.lastname: Bernhardy
authors.affiliation: Division of Nephrology, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA.
authors.forename: Hua
authors.initials: H
authors.lastname: Sun
authors.affiliation: Renal Division, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA.
authors.forename: Omar H
authors.initials: OH
authors.lastname: Maarouf
authors.affiliation: Department of Pathology and Laboratory Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA.
authors.forename: Vanesa
authors.initials: V
authors.lastname: Bijol
authors.affiliation: 1] Division of Nephrology, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA [2] Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA.
authors.forename: Martin R
authors.initials: MR
authors.lastname: Pollak
authors.affiliation: 1] Renal Division, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA [2] Kidney Group, Harvard Stem Cell Institute, Cambridge, Massachusetts, USA.
authors.forename: Benjamin D
authors.initials: BD
authors.lastname: Humphreys
mesh_terms: D000185:Actinin / Q000235:genetics*; D000375:Aging / Q000235:genetics* / Q000378:metabolism; D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D054360:Chemokine CXCL1 / Q000235:genetics / Q000378:metabolism; D024042:Collagen Type I / Q000235:genetics; D000090602:Collagen Type I, alpha 1 Chain; D004195:Disease Models, Animal; D020869:Gene Expression Profiling / Q000379:methods; D005923:Glomerulosclerosis, Focal Segmental / Q000235:genetics* / Q000378:metabolism*; D049452:Green Fluorescent Proteins / Q000235:genetics; D006801:Humans; D051379:Mice; D018345:Mice, Knockout; D065636:Myotonin-Protein Kinase / Q000235:genetics / Q000378:metabolism; D009363:Neoplasm Proteins; D020411:Oligonucleotide Array Sequence Analysis; D050199:Podocytes / Q000378:metabolism*; D014176:Protein Biosynthesis; D012333:RNA, Messenger / Q000032:analysis*; D000080882:Ribosomal Protein L10; D012269:Ribosomal Proteins / Q000235:genetics; D059467:Transcriptome
chemical_list: C491752:Actn4 protein, mouse; D015415:Biomarkers; C475829:CXCL1 protein, human; D054360:Chemokine CXCL1; D024042:Collagen Type I; D000090602:Collagen Type I, alpha 1 Chain; C475895:Cxcl1 protein, mouse; C585517:DMPK protein, human; C585516:DMPK protein, mouse; D009363:Neoplasm Proteins; D012333:RNA, Messenger; C000630686:RPL10 protein, human; D012269:Ribosomal Proteins; C000630690:Rpl10 protein, mouse; C470990:URGCP protein, human; D000185:Actinin; D049452:Green Fluorescent Proteins; D065636:Myotonin-Protein Kinase