Abnormal expression and processing of uromodulin in Fabry disease reflects tubular cell storage alteration and is reversible by enzyme replacement therapy
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Uromodulin (UMOD) malfunction has been found in a range of autosomal dominant tubulointerstitial nephropathies associated with hyperuricaemia, gouty arthritis, medullary cysts and renal failure—labelled as familial juvenile hyperuricaemic nephropathy, medullary cystic disease type 2 and glomerulocystic kidney disease. To gain knowledge of the spectrum of UMOD changes in various genetic diseases with renal involvement we examined urinary UMOD excretion and found significant quantitative and qualitative changes in 15 male patients at various clinical stages of Fabry disease. In untreated patients, the changes ranged from normal to a marked decrease, or even absence of urinary UMOD. This was accompanied frequently by the presence of aberrantly processed UMOD lacking the C-terminal part following the K432 residue. The abnormal patterns normalized in all patients on enzyme replacement therapy and in some patients on substrate reduction therapy. Immunohistochemical analysis of the affected kidney revealed abnormal UMOD localization in the thick ascending limb of Henle’s loop and the distal convoluted tubule, with UMOD expression inversely proportional to the degree of storage. Our observations warrant evaluation of tubular functions in Fabry disease and suggest UMOD as a potential biochemical marker of therapeutic response of the kidney to therapy. Extended comparative studies of UMOD expression in kidney specimens obtained during individual types of therapies are therefore of great interest.
KeywordsEnzyme Replacement Therapy Fabry Disease Nephrogenic Diabetes Insipidus Distal Convolute Tubule Outer Medulla
- Clapp WL, Croker BP (1997) Adult kidney. In: Sternberg SS, ed. Histology for Pathologists, 2nd edn. Philadelphia: Lippincott-Raven, 799–834.Google Scholar
- Fukuoka S, Kobayashi K (2001) Analysis of the C-terminal structure of urinary Tamm-Horsfall protein reveals that the release of the glycosyl phosphatidylinositol-anchored counterpart from the kidney occurs by phenylalanine-specific proteolysis. Biochem Biophys Res Commun 289: 1044–1048.PubMedCrossRefGoogle Scholar
- Morel-Maroger L, Ganter P, Ardaillou R, Cathelineau G, Richet G (1966) [Histochemical study of a lipid thesaurismosis with renal, cutaneous and neurologic involvement. Its relation to Fabry’s angiokeratosis and familial renal cytodystrophy]. Bull Mem Soc Med Hop Paris 117: 49–57.PubMedGoogle Scholar