A new mouse model for renal lesions produced by intravenous injection of diphtheria toxin A-chain expression plasmid.

Shingo Nakamura,Minoru Kimura,Akira Saito,Tadaaki Maehara,Masahiro Sato,Masuo Terashima,Natsuko Kikuchi

doi:10.1186/1471-2369-5-4

Shingo Nakamura, Minoru Kimura + Show 5 more

Open Access

https://doi.org/10.1186/1471-2369-5-4

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Abstract

BackgroundVarious animal models of renal failure have been produced and used to investigate mechanisms underlying renal disease and develop therapeutic drugs. Most methods available to produce such models appear to involve subtotal nephrectomy or intravenous administration of antibodies raised against basement membrane of glomeruli. In this study, we developed a novel method to produce mouse models of renal failure by intravenous injection of a plasmid carrying a toxic gene such as diphtheria toxin A-chain (DT-A) gene. DT-A is known to kill cells by inhibiting protein synthesis.MethodsAn expression plasmid carrying the cytomegalovirus enhancer/chicken β-actin promoter linked to a DT-A gene was mixed with lipid (FuGENE™6) and the resulting complexes were intravenously injected into adult male B6C3F1 mice every day for up to 6 days. After final injection, the kidneys of these mice were sampled on day 4 and weeks 3 and 5.ResultsH-E staining of the kidney specimens sampled on day 4 revealed remarkable alterations in glomerular compartments, as exemplified by mesangial cell proliferation and formation of extensive deposits in glomerular basement membrane. At weeks 3 and 5, gradual recovery of these tissues was observed. These mice exhibited proteinuria and disease resembling sub-acute glomerulonephritis.ConclusionsRepeated intravenous injections of DT-A expression plasmid DNA/lipid complex caused temporary abnormalities mainly in glomeruli of mouse kidney. The disease in these mice resembles sub-acute glomerulonephritis. These DT-A gene-incorporated mice will be useful as animal models in the fields of nephrology and regenerative medicine.

Highlights

Various animal models of renal failure have been produced and used to investigate mechanisms underlying renal disease and develop therapeutic drugs
To search for therapeutic drugs for renal failure, it is of importance to use renal disease models in animals
Role of the CAG promoter in kidney-targeted gene expression In this study, we used CAG promoter for expression of DTA in mouse kidney, since it has been suggested to be active in murine kidney, glomeruli [9]

Summary

Introduction

Various animal models of renal failure have been produced and used to investigate mechanisms underlying renal disease and develop therapeutic drugs. We developed a novel method to produce mouse models of renal failure by intravenous injection of a plasmid carrying a toxic gene such as diphtheria toxin A-chain (DT-A) gene. To search for therapeutic drugs for renal failure, it is of importance to use renal disease models in animals. Transgenic mice overexpressing megsin, a novel protein of Kunitz-type plasminogen activator inhibitor, under a ubiquitous promoter system CAG [8] (composed of cytomegalovirus enhancer and chicken β-actin promoter) are reported to exhibit glomerular nephritis associated with mesangial proliferation, accumulation of extracellular matrix and deposits of IgG [9]. It is often difficult to obtain transgenic animals by the classical pronuclear injection method, [10] and molecular characterization of the introduced gene (genotyping) and its expression must often be performed

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