Diet Significantly Influences the Immunopathology and Severity of Kidney Injury in Male C57Bl/6J Mice in a Model Dependent Manner

Abstract

Diet is a leading causative risk factor for morbidity and mortality worldwide, yet it is rarely considered in the design of preclinical animal studies. Several of the nutritional inadequacies reported in Americans have been shown to be detrimental to kidney health; however, the mechanisms responsible are unclear and have been largely attributed to the development of diabetes or hypertension. Here, we set out to determine whether diet influences the susceptibility to kidney injury in male C57Bl/6 mice. Mice were fed a standard chow diet, a commercially available “Western” diet (WD), or a novel Americanized diet (AD) for 12 weeks prior to the induction of kidney injury using the folic acid nephropathy (FAN) or unilateral renal ischemia reperfusion injury (uIRI) models. In FAN, the mice that were fed the WD and AD had worse histological evidence of tissue injury and greater renal expression of genes associated with nephrotoxicity as compared to mice fed chow. Mice fed the AD developed more severe renal hypertrophy following FAN, and gene expression data suggest the mechanism for FAN differed among the diets. Meanwhile, mice fed the WD had the greatest circulating interleukin-6 concentrations. In uIRI, no difference was observed in renal tissue injury between the diets; however, mice fed the WD and AD displayed evidence of suppressed inflammatory response. Taken together, our data support the hypothesis that diet directly impacts the severity and pathophysiology of kidney disease and is a critical experimental variable that needs to be considered in mechanistic preclinical animal studies.

Shared and Distinct Renal Transcriptome Signatures in 3 Standard Mouse Models of Chronic Kidney Disease

“…Kidney damage in the three CKD models was further supported by significant regulation of gene expression markers of acute and chronic renal injury. In agreement with previous studies in ADI, UUO, and uIRI mice, we observed a marked upregulation of key markers of kidney injury, including Havcr1 [47,48,68], Lcn2 [68][69][70], and Spp1 [40,71]. These genes have been demonstrated to play an important role in renal regeneration and inflammatory responses in preclinical studies [72][73][74][75] and also implicated in human CKD pathogenesis [76,77].…”