Go to JCI Insight
  • About
  • Editors
  • Consulting Editors
  • For authors
  • Publication ethics
  • Publication alerts by email
  • Advertising
  • Job board
  • Contact
  • Clinical Research and Public Health
  • Current issue
  • Past issues
  • By specialty
    • COVID-19
    • Cardiology
    • Gastroenterology
    • Immunology
    • Metabolism
    • Nephrology
    • Neuroscience
    • Oncology
    • Pulmonology
    • Vascular biology
    • All ...
  • Videos
    • Conversations with Giants in Medicine
    • Video Abstracts
  • Reviews
    • View all reviews ...
    • Complement Biology and Therapeutics (May 2025)
    • Evolving insights into MASLD and MASH pathogenesis and treatment (Apr 2025)
    • Microbiome in Health and Disease (Feb 2025)
    • Substance Use Disorders (Oct 2024)
    • Clonal Hematopoiesis (Oct 2024)
    • Sex Differences in Medicine (Sep 2024)
    • Vascular Malformations (Apr 2024)
    • View all review series ...
  • Viewpoint
  • Collections
    • In-Press Preview
    • Clinical Research and Public Health
    • Research Letters
    • Letters to the Editor
    • Editorials
    • Commentaries
    • Editor's notes
    • Reviews
    • Viewpoints
    • 100th anniversary
    • Top read articles

  • Current issue
  • Past issues
  • Specialties
  • Reviews
  • Review series
  • Conversations with Giants in Medicine
  • Video Abstracts
  • In-Press Preview
  • Clinical Research and Public Health
  • Research Letters
  • Letters to the Editor
  • Editorials
  • Commentaries
  • Editor's notes
  • Reviews
  • Viewpoints
  • 100th anniversary
  • Top read articles
  • About
  • Editors
  • Consulting Editors
  • For authors
  • Publication ethics
  • Publication alerts by email
  • Advertising
  • Job board
  • Contact
Mutation in the key enzyme of sialic acid biosynthesis causes severe glomerular proteinuria and is rescued by N-acetylmannosamine
Belinda Galeano, … , William A. Gahl, Marjan Huizing
Belinda Galeano, … , William A. Gahl, Marjan Huizing
Published June 1, 2007
Citation Information: J Clin Invest. 2007;117(6):1585-1594. https://doi.org/10.1172/JCI30954.
View: Text | PDF
Research Article Article has an altmetric score of 15

Mutation in the key enzyme of sialic acid biosynthesis causes severe glomerular proteinuria and is rescued by N-acetylmannosamine

  • Text
  • PDF
Abstract

Mutations in the key enzyme of sialic acid biosynthesis, uridine diphospho–N-acetylglucosamine 2-epimerase/N-acetylmannosamine (ManNAc) kinase (GNE/MNK), result in hereditary inclusion body myopathy (HIBM), an adult-onset, progressive neuromuscular disorder. We created knockin mice harboring the M712T Gne/Mnk mutation. Homozygous mutant (GneM712T/M712T) mice did not survive beyond P3. At P2, significantly decreased Gne-epimerase activity was observed in GneM712T/M712T muscle, but no myopathic features were apparent. Rather, homozygous mutant mice had glomerular hematuria, proteinuria, and podocytopathy. Renal findings included segmental splitting of the glomerular basement membrane, effacement of podocyte foot processes, and reduced sialylation of the major podocyte sialoprotein, podocalyxin. ManNAc administration yielded survival beyond P3 in 43% of the GneM712T/M712T pups. Survivors exhibited improved renal histology, increased sialylation of podocalyxin, and increased Gne/Mnk protein expression and Gne-epimerase activities. These findings establish this GneM712T/M712T knockin mouse as what we believe to be the first genetic model of podocyte injury and segmental glomerular basement membrane splitting due to hyposialylation. The results also support evaluation of ManNAc as a treatment not only for HIBM but also for renal disorders involving proteinuria and hematuria due to podocytopathy and/or segmental splitting of the glomerular basement membrane.

Authors

Belinda Galeano, Riko Klootwijk, Irini Manoli, MaoSen Sun, Carla Ciccone, Daniel Darvish, Matthew F. Starost, Patricia M. Zerfas, Victoria J. Hoffmann, Shelley Hoogstraten-Miller, Donna M. Krasnewich, William A. Gahl, Marjan Huizing

×

Figure 2

Generation and identification of GneM712T/M712T knockin mice.

Options: View larger image (or click on image) Download as PowerPoint
Generation and identification of GneM712T/M712T knockin mice.
          ...
(A) Resultant murine Gne (Uea1) genomic locus, exons 11 and 12, after homologous recombination with the sequence-verified targeting vector. The M712T mutation was created in exon 12, and a neo cassette (under the PGK promoter) flanked by flippase recombinase target (FRT) sites was inserted. LoxP sites were inserted before exon 12 and after the PGK-neo gene. (B) Genotyping of mutant mice. A PCR-amplified 387-bp fragment of genomic DNA across the M712T (ATG to ACG) mutation was digested by the NlaIII restriction endonuclease into 265-bp, 89-bp, and 33-bp fragments in a wild-type allele (+) and into 354-bp and 33-bp fragments in a mutant M712T allele (–). c, cut; MW, molecular weight; u, uncut. (C) RT-PCR of kidney and skeletal muscle RNA. RNA was reverse transcribed and PCR-amplified using primers covering exons 11 and 12 (355 bp). Digestion by NlaIII cut the wild-type allele (+) into 225-bp, 89-bp, and 41-bp fragments and the mutant M712T allele (–) into 314-bp and 41-bp fragments. Digestion confirmed the exclusive presence of the mutant M712T allele in GneM712T/M712T (–/–) tissues. (D) Numbers of mice at E17–E19 and P21. At P21, genotyping of 76 mice from 13 litters (9 GneM712T/+ matings) identified only 1 GneM712T/M712T offspring. Subsequent genotyping of 35 E17–E19 embryos from 4 GneM712T/+ mice yielded a Mendelian distribution of genotypes. (E) At P2, GneM712T/M712T pups were smaller than their heterozygous (GneM712T/+) and wild-type (Gne+/+) littermates and lacked a prominent milkspot.

Copyright © 2025 American Society for Clinical Investigation
ISSN: 0021-9738 (print), 1558-8238 (online)

Sign up for email alerts

Referenced in 1 policy sources
Referenced in 19 patents
Referenced in 2 Wikipedia pages
111 readers on Mendeley
1 readers on CiteULike
See more details