Slc7a9 knockout mouse is a good cystinuria model for antilithiasic pharmacological studies.

Abstract

Cystinuria is a hereditary disorder caused by a defect in the apical membrane transport system for cystine and dibasic amino acids in renal proximal tubules and intestine, resulting in recurrent urolithiasis. Mutations in SLC3A1 and SLC7A9 genes, that codify for rBAT/b(0,+)AT transporter subunits, cause type A and B cystinuria, respectively. In humans, cystinuria treatment is based on the prevention of calculi formation and its dissolution or breakage. Persistent calculi are treated with thiols [i.e., d-penicillamine (DP) and mercaptopropionylglycine (MPG)] for cystine solubilization. We have developed a new protocol with DP to validate our Slc7a9 knockout mouse model for the study of the therapeutic effect of drugs in the treatment of cystine lithiasis. We performed a 5-wk treatment of individually caged lithiasic mutant mice with a previously tested DP dose. To appraise the evolution of lithiasis throughout the treatment a noninvasive indirect method of calculi quantification was developed: calculi mass was quantified by densitometry of X-ray images from cystinuric mice before and after treatment. Urine was collected in metabolic cage experiments to quantify amino acids in DP-treated and nontreated, nonlithiasic mutant mice. We found significant differences between DP-treated and nontreated knockout mice in calculi size and in urinary cystine excretion. Histopathological analysis showed that globally nontreated mutant mice had more severe and diffuse urinary system damage than DP-treated mice. Our results validate the use of this mouse model for testing the efficacy of potential new drugs against cystinuria.

• Authors: Mariona Font-Llitjós, Lídia Feliubadaló, Meritxell Espino, Ramon Clèries, Sandra Mañas, Isabelle M Frey, Sara Puertas, Guillem Colell, Sergio Palomo, Jessica Aranda, Joana Visa, Manuel Palacín, Virginia Nunes
• Journal: American journal of physiology. Renal physiology (Am J Physiol Renal Physiol) Vol. 293 Issue 3 Pg. F732-40 (Sep 2007) ISSN: 1931-857X [Print] United States
• PMID: 17596531 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Amino Acid Transport Systems, Basic
• Slc7a9 protein, mouse
• Penicillamine

Topics

• Amino Acid Transport Systems, Basic (genetics)
• Animals
• Body Weight (drug effects)
• Cystinuria (genetics, metabolism, pathology)
• Disease Models, Animal
• Kidney Calculi (drug therapy, genetics, metabolism)
• Kidney Cortex (pathology)
• Lithiasis
• Mice
• Mice, Knockout
• Organ Size
• Penicillamine (therapeutic use)
• Time Factors
• Urinary Bladder (pathology)