Experimental crescentic glomerulonephritis: a new bicongenic rat model

Abstract

SUMMARYCrescentic glomerulonephritis (CRGN) is a major cause of human kidney failure, but the underlying mechanisms are not fully understood. Wistar Kyoto (WKY) rats are uniquely susceptible to CRGN following injection of nephrotoxic serum, whereas Lewis (LEW) rats are resistant. Our previous genetic studies of nephrotoxic nephritis (NTN), a form of CRGN induced by nephrotoxic serum, identified Fcgr3 and Jund as WKY genes underlying the two strongest quantitative trait loci for NTN phenotypes: Crgn1 and Crgn2, respectively. We also showed that introgression of WKY Crgn1 or Crgn2 individually into a LEW background did not lead to the formation of glomerular crescents. We have now generated a bicongenic strain, LEW.WCrgn1,2, in which WKY Crgn1 and Crgn2 are both introgressed into the LEW genetic background. These rats show development of NTN phenotypes, including glomerular crescents. Furthermore, we characterised macrophage function and glomerular cytokine profiles in this new strain. Additionally, we show that LEW.WCrgn1,2 rats are resistant to the development of glomerular crescents that is usually induced following immunisation with recombinant rat α3(IV)NC1, the specific Goodpasture autoantigen located in the glomerular basement membrane against which the immune response is directed in experimental autoimmune glomerulonephritis. Our results show that the new bicongenic strain responds differently to two distinct experimental triggers of CRGN. This is the first time that CRGN has been induced on a normally resistant rat genetic background and identifies the LEW.WCrgn1,2 strain as a new, potentially valuable model of macrophage-dependent glomerulonephritis.

New Wistar Kyoto and Spontaneously Hypertensive rat transgenic models with ubiquitous expression of green fluorescent protein

“…Rat bone marrow-derived macrophages were isolated from femurs and differentiated using RPMI 1640 supplemented with 10% fetal bovine serum (Hyclone) and 5 ng/ml Rat M-CSF (Peprotech) as previously described ( D'Souza et al, 2013 ). Cells were cultured in 12-well plates for 5 or 10 days at 37°C, 5% CO 2 and GFP fluorescence images were taken using confocal microscopy.…”

“…Two well-studied strains, both originating from Wistar stock, are the Wistar Kyoto (WKY) and spontaneously hypertensive (SHR) inbred rats ( Kurtz and Morris, 1987 ; Okamoto and Aoki, 1963 ). The WKY rat has been studied extensively as a model of crescentic glomerulonephritis ( Aitman et al, 2006 ; Atanur et al, 2013 ; Behmoaras et al, 2008 , 2015 ; D'Souza et al, 2013 ; Kanno et al, 1998 ; Sado et al, 1984 ; Smith et al, 2007 ), as a control for the SHR strain and as a model of depression and behavioural abnormalities ( Will et al, 2003 ). The SHR strain has been widely used as a model of the human hypertension and metabolic syndrome as well as a large number of other pathophysiological phenotypes including cardiac hypertrophy and failure, insulin resistance and defects in lipid metabolism ( Aitman et al, 1999 , 1997 ; Lepretre et al, 2004 ; Pravenec et al, 2008 ; Yamori and Okamoto, 1974 ).…”

Deferiprone, an Iron Chelator, is Preventive and Therapeutic in Experimental Crescentic Glomerulonephritis

“…12,13 Superoxide anions are the precursor of most other ROS, 35 and their production by macrophages has been shown to be a prominent contributor to the glomerular injury in glomerulonephritis. 15,36,37 To test whether deferiprone protects cells from superoxide induced oxidative stress, we stimulated BMDMs with phorbol 12-myristate 13-acetate (PMA), which is a widely used superoxide inducer in innate immune cells such neutrophils and macrophages. 38,39 Deferiprone markedly decreased the superoxide anions detected in stimulated BMDMs ( Figure 3A).…”

“…Superoxide anions were assessed by chemiluminescence assays (LumiMax Superoxide Anion Detection Kit, Agilent; Superoxide Anion Assay Kit, Sigma), wherein relative luminescence unit (RLU) values corresponded to superoxide levels produced by BMDMs, as previously described with minor modifications. 37 Briefly, day-5 BMDMs were re-suspended in cell dissociation solution (Sigma) and re-plated in a 96-well optical flat bottom plate (CELLSTAR ® ) at a cell density of 2.5×10 5 cells per well, allowed to adhere and cultured in DMEM medium with 10% FBS overnight. The experiment was performed with four biological and two technical replicates.…”

Identification of a nutrient sensing transcriptional network in monocytes by using inbred rat models of cafeteria diet

“…Considering the isogenic and homozygous nature of these inbred strains and using the CAF diet as an inducer of obesity, both the genetic background and environmental factors can be controlled, providing a powerful tool for understanding the ‘gene–diet’ interactions that underlie the development of complex traits such as obesity. These inbred strains have been widely studied for their differential susceptibility to experimental glomerulonephritis through macrophage activation (Behmoaras et al, 2008, 2010, 2015) and present a markedly distinct macrophage transcriptome, which results in differential macrophage activation (D'Souza et al, 2013; Maratou et al, 2011). Here, we show that the peripheral monocyte transcriptome of LEW and WKY rats is modulated differentially by the CAF diet.…”