Andzelika Borkowska1, Wieslaw Ziolkowski2, Katarzyna Kaczor1, Anna Herman-Antosiewicz3, Narcyz Knap4, Agata Wronska5, Jedrzej Antosiewicz6. 1. Department of Bioenergetics and Physiology of Exercise, Medical University of Gdansk, 1 Debinki St., 80-210, Gdańsk, Poland. 2. Department of Rehabilitation Medicine, Medical University of Gdansk, 80-219, Gdańsk, Poland. 3. Department of Medical Biology and Genetics, Faculty of Biology, University of Gdansk, 80-308, Gdańsk, Poland. 4. Department of Medical Chemistry, Medical University of Gdansk, 80-210, Gdańsk, Poland. 5. Department of Histology, Medical University of Gdansk, 80-210, Gdańsk, Poland. 6. Department of Bioenergetics and Physiology of Exercise, Medical University of Gdansk, 1 Debinki St., 80-210, Gdańsk, Poland. jant@gumed.edu.pl.
Abstract
PURPOSE: Hyperhomocysteinemia is an independent risk factor for cardiovascular diseases and also promotes neuronal death in various neurodegenerative diseases. There is evidence that iron can mediate homocysteine (Hcy) toxicity. Thus, the aim of this study was to investigate the effect of Hcy on iron metabolism in HUVEC and SH-SY5Y cells. METHODS: HUVEC and SH-SY5Y cells were treated with 3 mM Hcy for a defined time. RESULTS: We demonstrate that Hcy induced the upregulation of ferritins type L and H in HUVEC cells in a time-dependent manner and had no effect on the ferritins in SH-SY5Y cells. The change in ferritin expression was preceded by a significant decrease in the cellular level of the active form of Akt kinase in HUVEC but not in SH-SY5Y cells. An increase in ferritin L and H protein levels was observed in the Akt1, Akt2, Akt3 siRNA transfected cells, while in the cells transfected with FOXO3a siRNA, a decrease in both ferritins levels was noticed. Moreover, in the HUVEC cells treated with Hcy for 6 days, the active form of kinase Akt returned to the control level and it was accompanied by a drop in ferritin L and H protein levels. Cytotoxicity of hydrogen peroxide significantly increased in HUVEC cells pre-treated with Hcy for 24 h. CONCLUSIONS: These data indicate that Hcy induces an increase in cellular ferritin level, and the process is mediated by alterations in Akt-FOXO3a signaling pathway.
PURPOSE:Hyperhomocysteinemia is an independent risk factor for cardiovascular diseases and also promotes neuronal death in various neurodegenerative diseases. There is evidence that iron can mediate homocysteine (Hcy) toxicity. Thus, the aim of this study was to investigate the effect of Hcy on iron metabolism in HUVEC and SH-SY5Y cells. METHODS:HUVEC and SH-SY5Y cells were treated with 3 mM Hcy for a defined time. RESULTS: We demonstrate that Hcy induced the upregulation of ferritins type L and H in HUVEC cells in a time-dependent manner and had no effect on the ferritins in SH-SY5Y cells. The change in ferritin expression was preceded by a significant decrease in the cellular level of the active form of Akt kinase in HUVEC but not in SH-SY5Y cells. An increase in ferritin L and H protein levels was observed in the Akt1, Akt2, Akt3 siRNA transfected cells, while in the cells transfected with FOXO3a siRNA, a decrease in both ferritins levels was noticed. Moreover, in the HUVEC cells treated with Hcy for 6 days, the active form of kinase Akt returned to the control level and it was accompanied by a drop in ferritin L and H protein levels. Cytotoxicity of hydrogen peroxide significantly increased in HUVEC cells pre-treated with Hcy for 24 h. CONCLUSIONS: These data indicate that Hcy induces an increase in cellular ferritin level, and the process is mediated by alterations in Akt-FOXO3a signaling pathway.