Abstract
Iron regulatory protein-1 (IRP-1) is a central factor in the regulation of iron metabolism. Stress causes elevated glucocorticoid secretion and is also associated with iron accumulation in liver; however, the relation between these two processes is not known. Whether glucocorticoids alter the expression of liver IRP-1 and if this contributes to the iron accumulation is presently investigated. Administration (i.v.) of corticosterone daily to rats for 7 days resulted in the upregulation of IRP-1 and transferrin receptor-1 and accumulation of iron in liver. However, expression of ferritin was decreased. The effects of corticosterone were reduced by the prior administration of glucocorticoid antagonist, RU486 to the rats. Similarly, in vitro studies using HL7702 liver cells showed that hydrocortisone increases the expression of IRP-1 while decreasing ferritin. It is also observed that Stat-5 phosphorylation is enhanced in HL7702 cells by hydrocortisone. The electrophoretic mobility shift assays revealed that the binding of glucocorticoid receptor and phospho-STAT5 to the promoter region of IRP-1 gene was enhanced in rats of stress group. Combination of both RU486 and STAT5 inhibitor, PIAS resulted in a stronger reduction of IRP-1 expression than when these inhibitors were used separately. These results strongly implicate glucocorticoid receptor and STAT5 in stress-induced up-regulation of IRP-1, which subsequently enhances transferrin receptor-1 expression and down-regulates ferritin, causing iron accumulation in the liver.
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Hentze, M. W., Muckenthaler, M. U., & Andrews, N. C. (2004). Balancing acts: Molecular control of mammalian iron metabolism. Cell, 117, 285–297.
Zhao, M., Chen, J., Wang, W., Wang, L., Ma, L., et al. (2008). Psychological stress induces hypoferremia through the IL-6-hepcidin axis in rats. Biochemical and Biophysical Research Communications, 373, 90–93.
Bonkovsky, H. L. (1991). Iron and the liver. American Journal of the Medical Sciences, 301, 32–43.
Eisenstein, R. S. (2000). Iron regulatory proteins and the molecular control of mammalian iron metabolism. Annual Review of Nutrition, 20, 627–662.
Wallander, M. L., Leibold, E. A., & Eisenstein, R. S. (2006). Molecular control of vertebrate iron homeostasis by iron regulatory proteins. Biochimica et Biophysica Acta, 1763, 668–689.
Cairo, G., Castrusini, E., Minotti, G., & Bernelli-Zazzera, A. (1996). Superoxide and hydrogen peroxide-dependent inhibition of iron regulatory protein activity: A protective stratagem against oxidative injury. The FASEB Journal, 10, 1326–1335.
Gray, N. K., & Hentze, M. W. (1994). Iron regulatory protein prevents binding of the 43S translation pre-initiation complex to ferritin and eALAS mRNAs. The EMBO Journal, 13, 3882–3891.
Ma, L., Wang, W., Zhao, M., & Li, M. (2008). Foot-shock stress-induced regional iron accumulation and altered iron homeostatic mechanisms in rat brain. Biological Trace Element Research, 126, 204–213.
Wang, L., Wang, W., Zhao, M., Ma, L., & Li, M. (2008). Psychological stress induces dysregulation of iron metabolism in rat brain. Neuroscience, 155, 24–30.
Yeh, K. Y., Yeh, M., & Glass, J. (2000). Glucocorticoids and dietary iron regulate postnatal intestinal heavy and light ferritin expression in rats. American Journal of Physiology. Gastrointestinal and Liver Physiology, 278, G217–G226.
Roberts, K. P., & Griswold, M. D. (1990). Characterization of rat transferrin receptor cDNA: The regulation of transferrin receptor mRNA in testes and in Sertoli cells in culture. Molecular Endocrinology, 4, 531–542.
Kerenyi, M. A., Grebien, F., Gehart, H., Schifrer, M., Artaker, M., et al. (2008). Stat5 regulates cellular iron uptake of erythroid cells via IRP-2 and TfR-1. Blood, 112, 3878–3888.
Starzynski, R. R., Goncalves, A. S., Muzeau, F., Tyrolczyk, Z., Smuda, E., et al. (2006). STAT5 proteins are involved in down-regulation of iron regulatory protein 1 gene expression by nitric oxide. Biochemical Journal, 400, 367–375.
Hellman, L. M., & Fried, M. G. (2007). Electrophoretic mobility shift assay (EMSA) for detecting protein–nucleic acid interactions. Nature Protocols, 2, 1849–1861.
Bassett, M. L., Halliday, J. W., & Powell, L. W. (1986). Value of hepatic iron measurements in early hemochromatosis and determination of the critical iron level associated with fibrosis. Hepatology, 6, 24–29.
Neonaki, M., Graham, D. C., White, K. N., & Bomford, A. (2002). Down-regulation of liver iron-regulatory protein 1 in haemochromatosis. Biochemical Society Transactions, 30, 726–728.
Meyron-Holtz, E. G., Ghosh, M. C., & Rouault, T. A. (2004). Mammalian tissue oxygen levels modulate iron-regulatory protein activities in vivo. Science, 306, 2087–2090.
Drapier, J. C., Hirling, H., Wietzerbin, J., Kaldy, P., & Kuhn, L. C. (1993). Biosynthesis of nitric oxide activates iron regulatory factor in macrophages. The EMBO Journal, 12, 3643–3649.
Qian, Z. M., Xiao, D. S., Ke, Y., & Liao, Q. K. (2001). Increased nitric oxide is one of the causes of changes of iron metabolism in strenuously exercised rats. American Journal of Physiology: Regulatory, Integrative and Comparative Physiology, 280, R739–R743.
Schalinske, K. L., Anderson, S. A., Tuazon, P. T., Chen, O. S., Kennedy, M. C., et al. (1997). The iron-sulfur cluster of iron regulatory protein 1 modulates the accessibility of RNA binding and phosphorylation sites. Biochemistry, 36, 3950–3958.
Hanson, E. S., & Leibold, E. A. (1998). Regulation of iron regulatory protein 1 during hypoxia and hypoxia/reoxygenation. The Journal of Biological Chemistry, 273, 7588–7593.
Martins, E. A., Robalinho, R. L., & Meneghini, R. (1995). Oxidative stress induces activation of a cytosolic protein responsible for control of iron uptake. Archives of Biochemistry and Biophysics, 316, 128–134.
Thomson, A. M., Rogers, J. T., & Leedman, P. J. (2000). Thyrotropin-releasing hormone and epidermal growth factor regulate iron-regulatory protein binding in pituitary cells via protein kinase C-dependent and -independent signaling pathways. The Journal of Biological Chemistry, 275, 31609–31615.
Wang, L., Wang, H., Li, L., Li, W., Dong, X., et al. (2009). Corticosterone induces dysregulation of iron metabolism in hippocampal neurons in vitro. Biological Trace Element Research. Retrieved December 3, 2009.
Zhang, X., Xiong, J., Liu, Y., Zeng, L., Long, Z., et al. (2006). Effects of high dose glucocorticoid on expression of protein and mRNA transcription of corticotrophin releasing hormone in hypothalamus paraventricular nucleus of rats. Journal of Medical Colleges of PLA, 21, 30–33.
Smoak, K. A., & Cidlowski, J. A. (2004). Mechanisms of glucocorticoid receptor signaling during inflammation. Mechanisms of Ageing and Development, 125, 697–706.
Rhen, T., & Cidlowski, J. A. (2005). Antiinflammatory action of glucocorticoids—new mechanisms for old drugs. New England Journal of Medicine, 353, 1711–1723.
Stocklin, E., Wissler, M., Gouilleux, F., & Groner, B. (1996). Functional interactions between Stat5 and the glucocorticoid receptor. Nature, 383, 726–728.
Decker, T., & Kovarik, P. (2000). Serine phosphorylation of STATs. Oncogene, 19, 2628–2637.
Darnell, J. E, Jr. (1997). STATs and gene regulation. Science, 277, 1630–1635.
Liu, B., Liao, J., Rao, X., Kushner, S. A., Chung, C. D., et al. (1998). Inhibition of Stat1-mediated gene activation by PIAS1. Proceedings of the National Academy of Sciences of the United States of America, 95, 10626–10631.
Horvath, C. M. (2000). STAT proteins and transcriptional responses to extracellular signals. Trends in Biochemical Sciences, 25, 496–502.
Starzynski, R. R., Lipinski, P., Drapier, J. C., Diet, A., Smuda, E., et al. (2005). Down-regulation of iron regulatory protein 1 activities and expression in superoxide dismutase 1 knock-out mice is not associated with alterations in iron metabolism. The Journal of Biological Chemistry, 280, 4207–4212.
Oliveira, L., & Drapier, J. C. (2000). Down-regulation of iron regulatory protein 1 gene expression by nitric oxide. Proceedings of the National Academy of Sciences of the United States of America, 97, 6550–6555.
Lipinski, P., Drapier, J. C., Oliveira, L., Retmanska, H., Sochanowicz, B., et al. (2000). Intracellular iron status as a hallmark of mammalian cell susceptibility to oxidative stress: A study of L5178Y mouse lymphoma cell lines differentially sensitive to H(2)O(2). Blood, 95, 2960–2966.
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This work was supported by National Natural Science Foundation of China (Grant No. 30872120). There is no potential conflict of interest for any of the authors. The authors wish to thank all the people contributing time and energy to carefully read the manuscript and for suggestions to improve the English language.
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He, F., Ma, L., Wang, H. et al. Glucocorticoid Causes Iron Accumulation in Liver by Up-Regulating Expression of Iron Regulatory Protein 1 Gene Through GR and STAT5. Cell Biochem Biophys 61, 65–71 (2011). https://doi.org/10.1007/s12013-011-9162-z
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DOI: https://doi.org/10.1007/s12013-011-9162-z