Histone acetylation together with DNA demethylation empowers higher plasticity in adipocytes to differentiate into osteoblasts
Histone acetylation together with DNA demethylation empowers higher plasticity in adipocytes to differentiate into osteoblasts
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DOI：
10.1016/j.gene.2019.144274
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发表时间：
2020-04-05
期刊：
影响因子：
3.5
通讯作者：
Ryoo, Hyun-Mo
中科院分区：
文献类型：
--
作者：
Cho, Young-Dan;Kim, Bong-Su;Ryoo, Hyun-Mo
骨再生对研究人员和临床医生都是一个挑战。在组织工程领域，已经做出了很多努力来鉴定包括干细胞在内的细胞来源。本研究旨在使用表观遗传修饰剂5-aza-dC和/或阿司他丁-A（TSA）诱导脂肪细胞向成骨细胞的转分化。用TSA（100 nM）处理3个T3-L1前脂肪细胞，然后用Wnt 3a（50 ng/ml）处理。显微镜观察显示转分化细胞形态。甲基化特异性PCR和免疫印迹分析DNA甲基化和组蛋白乙酰化模式。通过实时荧光定量PCR测定基因表达。基于这些体外实验，体内小鼠实验补充了通过表观遗传修饰进行转分化的可能性。TSA诱导组蛋白H3上赖氨酸9的乙酰化，并且连续Wnt 3a处理刺激脂肪细胞中骨标记基因的表达，抑制脂肪生成并刺激骨生成。此外，TSA诱导DNA低甲基化，并与TSA和5-aza-dC的联合治疗表现出协同效应的表观遗传修饰。老年（15个月）和年轻（6周）小鼠的脂肪细胞数量和DNA甲基化模式存在显著差异，TSA和连续Wnt 3a治疗增加了老年小鼠的骨形成。总之，我们的研究结果证实了细胞转分化通过表观遗传修饰和成骨信号从脂肪细胞到成骨细胞的骨再生在体外和体内，并表明组蛋白乙酰化可以诱导DNA低甲基化，提高转分化的机会。
Bone regeneration has been a challenge for both researchers and clinicians. In the field of tissue engineering, much effort has been made to identify cell sources including stem cells. The present study aimed to induce trans differentiation from adipocytes to osteoblasts using epigenetic modifiers; 5-aza-dC and/or trichostatin-A (TSA). 3 T3-L1 preadipocytes were treated with TSA (100 nM) and then with Wnt3a (50 ng/ml). Microscopic observation showed trans-differentiated cell morphology. Methylation-specific PCR and immunoblotting were performed to analyze the DNA methylation and histone acetylation patterns. The gene expression was determined by real-time PCR. Based on these in vitro experiments, in vivo mouse experiments supplemented the possibility of trans-differentiation by epigenetic modification. TSA induced the acetylation of lysine9 on histone H3, and a sequential Wnt3a treatment stimulated the expression of bone marker genes in adipocytes, suppressing adipogenesis and stimulating osteogenesis. Furthermore, TSA induced DNA hypomethylation, and a combined treatment with TSA and 5-aza-dC showed a synergistic effect in epigenetic modifications. The number of adipocytes and DNA methylation patterns of old (15 months) and young (6 weeks) mice were significantly different, and TSA and sequential Wnt3a treatments increased bone formation in the old mice. Collectively, our results confirmed cell trans-differentiation via epigenetic modifications and osteogenic signaling from adipocytes to osteoblasts for the bone regeneration in vitro and in vivo, and indicated that histone acetylation could induce DNA hypomethylation, enhancing the chance of trans-differentiation.