No amelioration of uromodulin maturation and trafficking defect by sodium 4-phenylbutyrate in vivo: studies in mouse models of uromodulin-associated kidney disease.

Abstract

Uromodulin (UMOD)-associated kidney disease (UAKD) belongs to the hereditary progressive ER storage diseases caused by maturation defects of mutant UMOD protein. Current treatments of UAKD patients are symptomatic and cannot prevent disease progression. Two in vitro studies reported a positive effect of the chemical chaperone sodium 4-phenylbutyrate (4-PBA) on mutant UMOD maturation. Thus, 4-PBA was suggested as a potential treatment for UAKD. This study evaluated the effects of 4-PBA in two mouse models of UAKD. In contrast to previous in vitro studies, treatment with 4-PBA did not increase HSP70 expression or improve maturation and trafficking of mutant UMOD in vivo. Kidney function of UAKD mice was actually deteriorated by 4-PBA treatment. In transfected tubular epithelial cells, 4-PBA did not improve maturation but increased the expression level of both mutant and wild-type UMOD protein. Activation of NF-κB pathway in thick ascending limb of Henle's loop cells of UAKD mice was detected by increased abundance of RelB and phospho-IκB kinase α/β, an indirect activator of NF-κB. Furthermore, the abundance of NF-κB1 p105/p50, NF-κB2 p100/p52, and TRAF2 was increased in UAKD. NF-κB activation was identified as a novel disease mechanism of UAKD and might be a target for therapeutic intervention.

• Authors: Elisabeth Kemter, Stefanie Sklenak, Birgit Rathkolb, Martin Hrabě de Angelis, Eckhard Wolf, Bernhard Aigner, Ruediger Wanke
• Journal: The Journal of biological chemistry (J Biol Chem) Vol. 289 Issue 15 Pg. 10715-10726 (Apr 11 2014) ISSN: 1083-351X [Electronic] United States
• PMID: 24567330 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• HSP70 Heat-Shock Proteins
• Molecular Chaperones
• NF-kappa B
• Phenylbutyrates
• Relb protein, mouse
• Uromodulin
• Transcription Factor RelB
• 4-phenylbutyric acid

Topics

• Animals
• Cytoplasm (metabolism)
• Disease Models, Animal
• Gout (genetics)
• HSP70 Heat-Shock Proteins (metabolism)
• Homozygote
• Hyperuricemia (genetics)
• Kidney (metabolism)
• Kidney Diseases (genetics, metabolism)
• Kidney Tubules (metabolism)
• Male
• Mice
• Molecular Chaperones (metabolism)
• Mutagenesis
• Mutation
• NF-kappa B (metabolism)
• Phenotype
• Phenylbutyrates (chemistry)
• Phosphorylation
• Protein Transport
• Signal Transduction
• Transcription Factor RelB (metabolism)
• Uromodulin (genetics, metabolism)