Qiu Fubin, Li Rui, Gu Siyu, Zhao Yimin, Yang Linxue
Department of Nutrition and Food Hygiene, School of Public Health, Shanxi Medical University, 56 Xinjian South Road, Taiyuan, China.
Nutr Metab (Lond). 2022 Jul 16;19(1):47. doi: 10.1186/s12986-022-00681-5.
Iron and vitamin D (VD) is essential to health. Previous studies have shown that iron homeostasis has a potential effect on VD metabolism, but the mechanism is not fully understood.
To explore the relationship between VD metabolism and iron metabolism, as well as the regulatory mechanism of iron on VD metabolism.
40 male rats were fed adaptively for 7 days and randomly divided into control (C, n = 6 normal diet) group and model (M, n = 24 iron deficient diet) by simple randomization, the latter was used to establish iron deficiency anemia (IDA) model. After 6 weeks of feeding, the M group was randomly divided into: iron deficiency group (DFe), low iron group (LFe), medium iron group (MFe) and high iron group (HFe) by block randomization. Different doses of iron dextran (based on iron content (100 g·bw·d)): 0, 1.1, 3.3 and 9.9 mg) were given respectively. After 4 weeks, the rats were anesthetized with 8% chloral hydrate, Blood (collected from the abdominal aorta), liver and kidney tissues were collected. The serum and tissues were separately packed and frozen at -80℃ for testing.
The results showed that the levels of hemoglobin (Hb), red blood cell (RBC), serum iron (SI), liver iron, and kidney iron in DFe group were lower than those in the other four groups, while the levels of total iron-binding capacity (TIBC), transferrin (TF) and transferrin receptor (Tfr) in DFe group were higher than those in other groups; The serum levels of 25-(OH)D and 1,25-(OH)D in DFe group were significantly lower than those in C group (P < 0.05). The correlation analysis showed that the levels of 25-(OH)D and 1,25-(OH)D were negatively correlated with TIBC, TF and Tfr no correlation with SI. Western blotting, immunofluorescence, and q-PCR results showed that compared with C group, the protein and gene expressions of CYP2R1, CYP27A1, and CYP24A1 in DFe group were down-regulated, and the expression of CYP27B1 protein and gene was up-regulated in DFe group.
Iron may be involved in the metabolism of VD by regulating the expression of VD hydroxylase, suggesting that appropriate iron supplementation might promote the activation of VD.
铁和维生素D（VD）对健康至关重要。先前的研究表明，铁稳态对VD代谢有潜在影响，但其机制尚未完全明确。
探讨VD代谢与铁代谢之间的关系以及铁对VD代谢的调控机制。
40只雄性大鼠适应性喂养7天，通过简单随机化分为对照组（C，n = 6，正常饮食）和模型组（M，n = 24，缺铁饮食），后者用于建立缺铁性贫血（IDA）模型。喂养6周后，模型组通过区组随机化再分为：缺铁组（DFe）、低铁组（LFe）、中铁组（MFe）和高铁组（HFe）。分别给予不同剂量的右旋糖酐铁（基于铁含量（100 g·bw·d））：0、1.1、3.3和9.9 mg）。4周后，用8%水合氯醛麻醉大鼠，采集血液（从腹主动脉采集）、肝脏和肾脏组织。血清和组织分别包装并于-80℃冷冻待测。
结果显示，DFe组血红蛋白（Hb）、红细胞（RBC）、血清铁（SI）、肝脏铁和肾脏铁水平低于其他四组，而DFe组总铁结合力（TIBC）、转铁蛋白（TF）和转铁蛋白受体（Tfr）水平高于其他组；DFe组血清25-(OH)D和1,25-(OH)D水平显著低于C组（P < 0.05）。相关性分析表明，25-(OH)D和1,25-(OH)D水平与TIBC、TF和Tfr呈负相关，与SI无相关性。蛋白质免疫印迹、免疫荧光和q-PCR结果显示，与C组相比，DFe组CYP2R1、CYP27A1和CYP24A1的蛋白质和基因表达下调，DFe组CYP27B1蛋白质和基因表达上调。
铁可能通过调节VD羟化酶的表达参与VD代谢，提示适当补充铁可能促进VD的活化。
