Annabel Biruete1,2, Shruthi Srinivasan1, Kalisha D O'Neill1, Colby J Vorland3,4, Kathleen M Hill Gallant1,4, Weijing Cai5, Jaime Uribarri5, Nancy Johnston6, Matthew R Allen1,2,7, Neal X Chen1, Sharon M Moe8,9,10. 1. Division of Nephrology, Indiana University School of Medicine, Indianapolis, Indiana, USA. 2. Department of Anatomy and Cell Biology, Indiana University School of Medicine, Indianapolis, Indiana, USA. 3. Department of Applied Health Science, School of Public Health-Bloomington, Indiana University, Bloomington, Indiana, USA. 4. Department of Nutrition Science, Purdue University, West Lafayette, Indiana, USA. 5. Division of Nephrology, Icahn School of Medicine at Mount Sinai, New York, New York, USA. 6. Laboratory Animal Resource Center, Indiana University School of Medicine, Indianapolis, Indiana, USA. 7. Roudebush Veterans Affairs Medical Center, Indianapolis, Indiana, USA. 8. Division of Nephrology, Indiana University School of Medicine, Indianapolis, Indiana, USA, smoe@iu.edu. 9. Department of Anatomy and Cell Biology, Indiana University School of Medicine, Indianapolis, Indiana, USA, smoe@iu.edu. 10. Roudebush Veterans Affairs Medical Center, Indianapolis, Indiana, USA, smoe@iu.edu.
Abstract
BACKGROUND: Autoclaving rodent diets is common in laboratory animals, but autoclaving increases the formation of dietary advanced glycation end-products (AGE). We studied the effect of autoclaved (AC) diet alone or in combination with a diet high in bioavailable phosphorus on biochemistries of chronic kidney disease-mineral and bone disorder (CKD-MBD), intestinal gene expression, and oxidative stress. METHODS: Male CKD rats (Cy/+) and normal littermates were fed 1 of 3 diets: AC 0.7% phosphorus grain-based diet for 28 weeks (AC); AC diet for 17 weeks followed by non-autoclaved (Non-AC) 0.7% phosphorus casein diet until 28 weeks (AC + Casein); or Non-AC diet for 16 weeks followed by a Non-AC purified diet until 30 weeks (Non-AC + Casein). RESULTS: AC diets contained ~3× higher AGEs and levels varied depending on the location within the autoclave. Rats fed the AC and AC + Casein diets had higher total AGEs and oxidative stress, irrespective of kidney function. Kidney function was more severely compromised in CKD rats fed AC or AC + Casein compared to Non-AC + Casein. There was a disease-by-diet interaction for plasma phosphorus, parathyroid hormone, and c-terminal fibroblast growth factor-23, driven by high values in the CKD rats fed the AC + Casein diet. Compared to Non-AC + Casein, AC and AC + Casein-fed groups had increased expression of receptor of AGEs and intestinal NADPH oxidase dual oxidase-2, independent of kidney function. CONCLUSIONS: Autoclaving rodent diets impacts the progression of CKD and CKD-MBD, highlighting the critical importance of standardizing diets in experiments.
BACKGROUND: Autoclaving rodent diets is common in laboratory animals, but autoclaving increases the formation of dietary advanced glycation end-products (AGE). We studied the effect of autoclaved (AC) diet alone or in combination with a diet high in bioavailable phosphorus on biochemistries of chronic kidney disease-mineral and bone disorder (CKD-MBD), intestinal gene expression, and oxidative stress. METHODS: Male CKD rats (Cy/+) and normal littermates were fed 1 of 3 diets: AC 0.7% phosphorus grain-based diet for 28 weeks (AC); AC diet for 17 weeks followed by non-autoclaved (Non-AC) 0.7% phosphorus casein diet until 28 weeks (AC + Casein); or Non-AC diet for 16 weeks followed by a Non-AC purified diet until 30 weeks (Non-AC + Casein). RESULTS: AC diets contained ~3× higher AGEs and levels varied depending on the location within the autoclave. Rats fed the AC and AC + Casein diets had higher total AGEs and oxidative stress, irrespective of kidney function. Kidney function was more severely compromised in CKD rats fed AC or AC + Casein compared to Non-AC + Casein. There was a disease-by-diet interaction for plasma phosphorus, parathyroid hormone, and c-terminal fibroblast growth factor-23, driven by high values in the CKD rats fed the AC + Casein diet. Compared to Non-AC + Casein, AC and AC + Casein-fed groups had increased expression of receptor of AGEs and intestinal NADPH oxidase dual oxidase-2, independent of kidney function. CONCLUSIONS: Autoclaving rodent diets impacts the progression of CKD and CKD-MBD, highlighting the critical importance of standardizing diets in experiments.
Authors: Jing Xue; Rashmi Ray; David Singer; David Böhme; David S Burz; Vivek Rai; Ralf Hoffmann; Alexander Shekhtman Journal: Biochemistry Date: 2014-05-13 Impact factor: 3.162