Histone acetylation together with DNA demethylation empowers higher plasticity in adipocytes to differentiate into osteoblasts

• Published in: Gene Vol. 733; p. 144274
• Main Authors: Cho, Young-Dan, Kim, Bong-Su, Kim, Woo-Jin, Kim, Hyun-Jung, Baek, Jeong-Hwa, Woo, Kyung-Mi, Seol, Yang-Jo, Ku, Young, Ryoo, Hyun-Mo
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 05-04-2020
• Subjects: 3T3-L1 Cells; Acetylation; Adipocyte; Adipocytes - drug effects; Adipocytes - metabolism; Animals; Bone regeneration; Cell Differentiation - drug effects; Cell Differentiation - genetics; Cell Differentiation - physiology; Cell transdifferentiation; CpG Islands; Decitabine - metabolism; Decitabine - pharmacology; DNA Demethylation - drug effects; DNA Methylation - drug effects; DNA Methylation - genetics; Epigenesis, Genetic - drug effects; Epigenesis, Genetic - genetics; Epigenomics - methods; Histone Deacetylase Inhibitors - pharmacology; Histones - genetics; Histones - metabolism; Hydroxamic Acids - metabolism; Hydroxamic Acids - pharmacology; Mice; Osteoblast; Osteoblasts - drug effects; Osteoblasts - metabolism; Promoter Regions, Genetic - drug effects; Promoter Regions, Genetic - genetics; Protein Processing, Post-Translational - drug effects; Protein Processing, Post-Translational - genetics; Tissue engineering; iPSCs; Adipocyte; TSA; miRNAs; Bone regeneration; Tissue engineering; Cell transdifferentiation; Osteoblast; HAT; DNMTi; 5-aza-dC; HDACi
• ISSN: 0378-1119; 1879-0038
• DOI: 10.1016/j.gene.2019.144274

•Epigenetic modification permits the direct cell trans-differentiation.•Histone acetylation together with DNA demethylation provides high plasticity in trans-differentiation.•Trans-differentiation provides a promising alternative to iPSCs and a novel therapeutic avenue in the bone regeneration.
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.