Background

Obesity promotes dysfunction and impairs the reparative capacity of mesenchymal stem/stromal cells (MSCs), and alters their transcription, protein content, and paracrine function. Whether these adverse effects are mediated by chromatin-modifying epigenetic changes remains unclear. We tested the hypothesis that obesity imposes global DNA hydroxymethylation and histone tri-methylation alterations in obese swine abdominal adipose tissue-derived MSCs compared to lean pig MSCs.

Methods

MSCs from female lean (n=7) and high-fat-diet fed obese (n=7) domestic pigs were assessed using global epigenetic assays, before and after in-vitro co-incubation with the epigenetic modulator vitamin-C (VIT-C) (50 µg/ml). Dot blotting was used to measure across the whole genome 5-hydroxyemthycytosine (5hmC) residues, and Western blotting to quantify in genomic histone-3 protein tri-methylated lysine-4 (H3K4me3), lysine-9 (H3K9me3), and lysine-27 (H3K27me3) residues. MSC migration and proliferation were studied in-vitro.

Results

Obese MSCs displayed reduced global 5hmC and H3K4m3 levels, but comparable H3K9me3 and H3K27me3, compared to lean MSCs. Global 5hmC, H3K4me3, and HK9me3 marks correlated with MSC migration and reduced proliferation, as well as clinical and metabolic characteristics of obesity. Co-incubation of obese MSCs with VIT-C enhanced 5hmC marks, and reduced their global levels of H3K9me3 and H3K27me3. Contrarily, VIT-C did not affect 5hmC, and decreased H3K4me3 in lean MSCs.

Conclusions

Obesity induces global genomic epigenetic alterations in swine MSCs, involving primarily genomic transcriptional repression, which are associated with MSC function and clinical features of obesity. Some of these alterations might be reversible using the epigenetic modulator VIT-C, suggesting epigenetic modifications as therapeutic targets in obesity.

中文翻译：

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肥胖间充质干细胞的全球表观遗传学改变：维生素C重新编程的作用

背景

肥胖会促进功能障碍并损害间充质干/基质细胞（MSC）的修复能力，并改变其转录，蛋白质含量和旁分泌功能。这些不良反应是否由染色质修饰的表观遗传变化介导尚不清楚。我们测试了以下假设：与瘦猪MSC相比，肥胖会导致肥胖猪腹部脂肪组织来源的MSC发生整体DNA羟甲基化和组蛋白三甲基化改变。

方法

在与表观遗传调节剂维生素C（VIT-）进行体外共孵育前后，使用整体表观遗传学分析评估了雌性瘦肉（n = 7）和高脂饮食肥胖（n = 7）家猪的MSC。 C）（50微克/毫升）。使用斑点印迹法测量整个基因组中的5-羟甲基胞嘧啶（5hmC）残基，通过蛋白质印迹法定量分析基因组蛋白3蛋白三甲基赖氨酸4（H3K4me3），赖氨酸9（H3K9me3）和赖氨酸27 （H3K27me3）残留物。体外研究了MSC的迁移和增殖。

结果

与瘦型MSC相比，肥胖MSC的整体5hmC和H3K4m3水平降低，但H3K9me3和H3K27me3却可比。全球5hmC，H3K4me3和HK9me3标记与MSC迁移和增殖减少以及肥胖的临床和代谢特征相关。肥胖MSC与VIT-C共​​同孵育可增强5hmC标记，并降低其H3K9me3和H3K27me3的总体水平。相反，在瘦MSC中，VIT-C不影响5hmC，并降低H3K4me3。

结论

肥胖症在猪MSC中诱导总体基因组表观遗传学改变，主要涉及基因组转录抑制，这与MSC功能和肥胖症的临床特征有关。使用表观遗传调节剂VIT-C，其中一些改变可能是可逆的，表明表观遗传修饰作为肥胖症的治疗靶标。