Measures of kidney function by minimally invasive techniques correlate with histological glomerular damage in SCID mice with adriamycin-induced nephropathy.

Lauren Scarfe,B Kevin Park,Darsy Darssan,Aleksandra Rak-Raszewska,Raphaël Lévy,Patricia Murray,Norbert Gretz,Stefania Geraci,Parisa Ranjzad,David Mason,Jiaguo Huang,Bettina Wilm,Simon Kenny,Neal C Burton,Marta García-Fiñana,Adrian S Woolf,Jack Sharkey

doi:10.1038/srep13601

Abstract

Maximising the use of preclinical murine models of progressive kidney disease as test beds for therapies ideally requires kidney function to be measured repeatedly in a safe, minimally invasive manner. To date, most studies of murine nephropathy depend on unreliable markers of renal physiological function, exemplified by measuring blood levels of creatinine and urea, and on various end points necessitating sacrifice of experimental animals to assess histological damage, thus counteracting the principles of Replacement, Refinement and Reduction. Here, we applied two novel minimally invasive techniques to measure kidney function in SCID mice with adriamycin-induced nephropathy. We employed i) a transcutaneous device that measures the half-life of intravenously administered FITC-sinistrin, a molecule cleared by glomerular filtration; and ii) multispectral optoacoustic tomography, a photoacoustic imaging device that directly visualises the clearance of the near infrared dye, IRDye 800CW carboxylate. Measurements with either technique showed a significant impairment of renal function in experimental animals versus controls, with significant correlations with the proportion of scarred glomeruli five weeks after induction of injury. These technologies provide clinically relevant functional data and should be widely adopted for testing the efficacies of novel therapies. Moreover, their use will also lead to a reduction in experimental animal numbers.

Highlights

We have evaluated the ability of two minimally invasive in vivo technologies to monitor kidney function in an adriamycin-induced nephropathy mouse model
Given that glomerular filtration rate (GFR) is inversely correlated to the FITC-sinistrin half-life[10,18], these results suggest that GFR is slightly impaired 2 weeks after ADR administration and deteriorates further between weeks 3 and 4, reflecting the progressive nature of the nephropathy[19]
We report for the first time the use of transcutaneous measurement of FITC-sinistrin decay and multispectral optoacoustic tomography (MSOT) detection of IRDye clearance as measures of glomerular filtration function in severe combined immunodeficient (SCID) mice with ADR-induced nephropathy

Summary

Introduction

We have evaluated the ability of two minimally invasive in vivo technologies to monitor kidney function in an adriamycin (doxorubicin)-induced nephropathy mouse model. In the second phase of disease, glomeruli become scarred or ‘sclerotic’ and this leads to the loss of total filtration surface This occurs long after ADR has been cleared and it exemplifies the ‘progression of CKD’ often observed in clinical practice. The two minimally invasive technologies comprised firstly, a transcutaneous electronic device for measuring the clearance from the blood of (FITC)-sinistrin, a molecule of approximately 4000 Da cleared by glomerular filtration[10,11] This device can be applied in conscious animals, which is a key advantage, given the well-described confounding effects of general anaesthesia on GFR12,13. The technique is not harmful and offers very good temporal and spatial resolution in live animals; it requires the animals to be studied under general anaesthesia Results obtained with these techniques were compared with standard biochemical and histological indicators of kidney damage. We assessed whether both technologies could be used to predict histological damage during progression to CKD in the ADR model

Objectives

Methods

Results

Conclusion