Altun Sevda, Budak Harun
Science Faculty, Department of Molecular Biology and Genetics, Atatürk University, Erzurum, Turkey; Rafet Kayış Faculty of Engineering, Department of Genetic and Bioengineering, Alaaddin Keykubat University, Antalya, Turkey.
Science Faculty, Department of Molecular Biology and Genetics, Atatürk University, Erzurum, Turkey.
J Trace Elem Med Biol. 2021 Mar;64:126704. doi: 10.1016/j.jtemb.2020.126704. Epub 2020 Dec 14.
Iron, which is essential for many vital biological processes, causes significant clinical pathologies in the case of its deficiency or excess. Cardiovascular protective pathways are activated by iron therapy. However, determining the appropriate iron concentration is essential to protect heart tissue from iron-induced oxidative stress. The thioredoxin system is one of the antioxidant systems that protect cells against oxidative stress. Moreover, it allows the binding of many transcription factors for apoptosis, myocardial protection, the stimulation of cell proliferation, and angiogenesis processes, especially the regulation of the cardiovascular system. This study's goal was to understand how iron overload affects the gene and protein levels of the thioredoxin system in the mouse heart.
BALB/c mice were randomly separated into two groups. The iron overload group was administered with intraperitoneal injections of an iron-dextran solution twice a week for three weeks. In parallel, the control group was intraperitoneally given Dextran 5 solution. The total iron content, the total GSH level, the reduced glutathione/oxidized glutathione (GSH/GSSG) ratio, and thioredoxin reductase 1 (TXNRD1) activity were demonstrated spectroscopically. Changes in the iron metabolism marker genes and thioredoxin system genes were examined by qPCR. The quantitative protein expression of TXNRD1 and thioredoxin-interacting protein (TXNIP) was examined by western blotting.
The iron content of the heart increased in the iron overload group. The expression of hepcidin (Hamp) and ferroportin (Fpn) increased with iron overload. However, decreased expression was observed for ferritin (Fth). No changes were revealed in the GSH level and GSH/GSSG ratio. The gene expression of thioredoxin 1 (Txn1), Txnrd1, and Txnip did not change. TXNRD1 activity and protein expression increased significantly, while the protein expression of TXNIP decreased significantly.
In the case of iron overload, the cardiac thioredoxin system is affected by the protein level rather than the gene level. The amount and duration of iron overload used in this study may be considered as a starting point for further studies to determine appropriate conditions for the iron therapy of cardiovascular diseases.
铁对许多重要的生物过程至关重要，但其缺乏或过量都会导致严重的临床病理状况。铁疗法可激活心血管保护途径。然而，确定合适的铁浓度对于保护心脏组织免受铁诱导的氧化应激至关重要。硫氧还蛋白系统是保护细胞免受氧化应激的抗氧化系统之一。此外，它允许许多转录因子结合，参与细胞凋亡、心肌保护、细胞增殖刺激和血管生成过程，特别是心血管系统的调节。本研究的目的是了解铁过载如何影响小鼠心脏中硫氧还蛋白系统的基因和蛋白水平。
将BALB/c小鼠随机分为两组。铁过载组每周两次腹腔注射右旋糖酐铁溶液，共三周。同时，对照组腹腔注射右旋糖酐5溶液。通过光谱法测定总铁含量、总谷胱甘肽水平、还原型谷胱甘肽/氧化型谷胱甘肽（GSH/GSSG）比值和硫氧还蛋白还原酶1（TXNRD1）活性。通过qPCR检测铁代谢标记基因和硫氧还蛋白系统基因的变化。通过蛋白质印迹法检测TXNRD1和硫氧还蛋白相互作用蛋白（TXNIP）的定量蛋白表达。
铁过载组心脏铁含量增加。铁过载时，铁调素（Hamp）和铁转运蛋白（Fpn）的表达增加。然而，观察到铁蛋白（Fth）表达降低。谷胱甘肽水平和GSH/GSSG比值未发现变化。硫氧还蛋白1（Txn1）、Txnrd1和Txnip的基因表达没有变化。TXNRD1活性和蛋白表达显著增加，而TXNIP的蛋白表达显著降低。
在铁过载情况下，心脏硫氧还蛋白系统受蛋白水平而非基因水平的影响。本研究中使用的铁过载量和持续时间可作为进一步研究的起点，以确定心血管疾病铁疗法的合适条件。
