铁摄入量对小鼠棕色脂肪活性的影响

EFFECT OF IRON INTAKE ON BROWN ADIPOSE TISSUE ACTIVITY IN MICE

目的探讨铁摄入量对棕色脂肪活性的影响。方法健康6 w龄雄性C57BL/6j小鼠30只,随机分为3组,分别给予正常(NI组:35 mg/100g)、低(LI组:4 mg/100g)、高(HI组:2000 mg/100g)铁饲料喂养8 w。8 w后取小鼠肩胛间区棕色脂肪组织进行线粒体呼吸功能检测、UCP-1蛋白质荧光共聚焦显像、免疫印迹检测、棕色脂肪产热相关基因qRT-PCR检测。结果LI组棕色脂肪线粒体呼吸链复合物Ⅰ的态4呼吸速率(CI-LEAK)和复合物I+II的电子传递能力(CI+II-ETS)低于NI组(P<0.05)。HI组棕色脂肪线粒体呼吸链复合物Ⅰ的态4呼吸速率(CI-LEAK)、复合物II的电子传递能力(CII-ETS)、复合物I+II的态3呼吸速率(CI+II-OXPHOS)和电子传递能力(CI+II-ETS)均低于NI组(P<0.05)。HI组棕色脂肪标志性蛋白UCP-1及相关基因Ucp-1、Pgc-1α、Prdm16、Pparγ表达低于NI组(P<0.05)。结论铁元素摄入过多或过少均能够对BAT及机体代谢不利影响。特别是过量摄入铁能够导致BAT功能明显退化,进而促进肥胖发生、葡萄糖耐量变差,是代谢性疾病的潜在危险因素。

Objective To investigate the effect of iron intake on the activity of brown adipose tissue.Methods 30 healthy 6-week-old male C57BL/6j mice were randomly divided into 3 groups and fed low(4mg/100g),normal(35mg/100g)and high(2000mg/100g)iron diets for 8 weeks,respectively.At the end of experiment,the brown adipose tissue in the interscapular area of mice was collected for assessing mitochondrial respiratory function.The uncoupling protein 1 was examined with fluorescence confocal imaging.The mRNA expression of thermogenesis related gene was analysed with qRT-PCR.Results CI-LEAK and CI+II-ETS of brown fat mitochondria in the low iron group were lower than those in the normal iron group(P<0.05).The levels of CI-LEAK,CII-ETS,CI+II-OXPHOS and CI+II-ETS of brown fat mitochondria in the high iron group were lower than those in the normal iron group(P<0.05).The expression of brown fat marker protein UCP-1 and related genes Ucp-1,Pgc-1α,Prdm16,parrγin the high iron group was lower than that in the normal iron group(P<0.05).Conclusion Excessive or insufficient iron intake can adversely affect BAT and metabolism.In particular,excessive intake of iron can lead to significantly imparied BAT function,and then promote the occurrence of obesity and poor glucose tolerance,which is a potential risk factor for metabolic diseases.