Einarsdottir Elisabet, Pekkinen Minna, Krjutškov Kaarel, Katayama Shintaro, Kere Juha, Mäkitie Outi, Viljakainen Heli
Folkhälsan Institute of Genetics, University of Helsinki, Helsinki, Finland.
Molecular Neurology Research Program, University of Helsinki, Helsinki, Finland.
Endocr Connect. 2019 May 1;8(5):559-570. doi: 10.1530/EC-18-0537.
The effect of vitamin D at the transcriptome level is poorly understood, and furthermore, it is unclear if it differs between obese and normal-weight subjects. The objective of the study was to explore the transcriptome effects of vitamin D supplementation.
We analysed peripheral blood gene expression using GlobinLock oligonucleotides followed by RNA sequencing in individuals participating in a 12-week randomised double-blinded placebo-controlled vitamin D intervention study. The study involved 18 obese and 18 normal-weight subjects (of which 20 males) with mean (±s.d.) age 20.4 (±2.5) years and BMIs 36 (±10) and 23 (±4) kg/m2, respectively. The supplemental daily vitamin D dose was 50 µg (2000 IU). Data were available at baseline, 6- and 12-week time points and comparisons were performed between the vitamin D and placebo groups separately in obese and normal-weight subjects.
Significant transcriptomic changes were observed at 6 weeks, and only in the obese subjects: 1724 genes were significantly upregulated and 186 genes were downregulated in the vitamin D group compared with placebo. Further analyses showed several enriched gene categories connected to mitochondrial function and metabolism, and the most significantly enriched pathway was related to oxidative phosphorylation (adjusted P value 3.08 × 10-14). Taken together, our data suggest an effect of vitamin D supplementation on mitochondrial function in obese subjects.
Vitamin D supplementation affects gene expression in obese, but not in normal-weight subjects. The altered genes are enriched in pathways related to mitochondrial function. The present study increases the understanding of the effects of vitamin D at the transcriptome level.
维生素D在转录组水平的作用尚未得到充分了解，此外，肥胖和正常体重受试者之间是否存在差异也不清楚。本研究的目的是探讨补充维生素D对转录组的影响。
我们在参与一项为期12周的随机双盲安慰剂对照维生素D干预研究的个体中，使用GlobinLock寡核苷酸分析外周血基因表达，随后进行RNA测序。该研究纳入了18名肥胖受试者和18名正常体重受试者（其中20名男性），平均（±标准差）年龄为20.4（±2.5）岁，体重指数分别为36（±10）和23（±4）kg/m²。每日维生素D补充剂量为50μg（2000IU）。在基线、第6周和第12周时间点获取数据，并分别在肥胖和正常体重受试者中对维生素D组和安慰剂组进行比较。
在第6周时观察到显著的转录组变化，且仅在肥胖受试者中：与安慰剂组相比，维生素D组有1724个基因显著上调，186个基因下调。进一步分析显示，有几个与线粒体功能和代谢相关的富集基因类别，最显著富集的途径与氧化磷酸化有关（校正P值为3.08×10⁻¹⁴）。综上所述，我们的数据表明补充维生素D对肥胖受试者的线粒体功能有影响。
补充维生素D会影响肥胖受试者的基因表达，但对正常体重受试者无影响。改变的基因在与线粒体功能相关的途径中富集。本研究增进了我们对维生素D在转录组水平作用的理解。
