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Oxidative Medicine and Cellular Longevity
Volume 2012 (2012), Article ID 291087, 12 pages
http://dx.doi.org/10.1155/2012/291087
Research Article

Low-Dose Radiation Activates Akt and Nrf2 in the Kidney of Diabetic Mice: A Potential Mechanism to Prevent Diabetic Nephropathy

1School of Public Health of Jilin University, Changchun 130021, China
2Chinese-American Research Institute for Diabetic Complications, Wenzhou Medical College, Chashan University Park, Wenzhou 325035, China
3The Department of Pediatrics, School of Medicine, The University of Louisville, 570 South Preston Street, Baxter I Building Suite 304F, Louisville, KY 40059, USA
4Norman Bethune College of Medicine, Jilin University, Changchun 130021, China
5Norman Bethune First Hospital, Jilin University, Changchun 130021, China
6Engineering Research Center of Bioreactor and Pharmaceutical Development, Jilin Agricultural University, Changchun 130118, China
7Departments of Pharmacology and Toxicology and Radiation Oncology, School of Medicine, The University of Louisville, 570 South Preston Street, Baxter I Building Suite 304F, Louisville, KY 40059, USA

Received 9 October 2012; Revised 22 October 2012; Accepted 24 October 2012

Academic Editor: Jingbo Pi

Copyright © 2012 Xiao Xing et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Repetitive exposure of diabetic mice to low-dose radiation (LDR) at 25 mGy could significantly attenuate diabetes-induced renal inflammation, oxidative damage, remodeling, and dysfunction, for which, however, the underlying mechanism remained unknown. The present study explored the effects of LDR on the expression and function of Akt and Nrf2 in the kidney of diabetic mice. C57BL/6J mice were used to induce type 1 diabetes with multiple low-dose streptozotocin. Diabetic and age-matched control mice were irradiated with whole body X-rays at either single 25 mGy and 75 mGy or accumulated 75 mGy (25 mGy daily for 3 days) and then sacrificed at 1–12 h for examining renal Akt phosphorylation and Nrf2 expression and function. We found that 75 mGy of X-rays can stimulate Akt signaling pathway and upregulate Nrf2 expression and function in diabetic kidneys; single exposure of 25 mGy did not, but three exposures to 25 mGy of X-rays could offer a similar effect as single exposure to 75 mGy on the stimulation of Akt phosphorylation and the upregulation of Nrf2 expression and transcription function. These results suggest that single 75 mGy or multiple 25 mGy of X-rays can stimulate Akt phosphorylation and upregulate Nrf2 expression and function, which may explain the prevention of LDR against the diabetic nephropathy mentioned above.