Synergistic epigenetic modulation by 5-aza-2’-deoxycytidine and Wnt3a drives osteogenic trans-differentiation of 3T3-L1 pre-adipocytes through <i>Ywhah</i> and <i>Ywhae</i>

In elderly patients, bone regeneration is impeded by age-related shifts in mesenchymal stem cell differentiation propensity toward adipogenesis over osteogenesis. We investigated whether DNA demethylation by 5‑aza‑2′‑deoxycytidine (5azaC) synergizes with Wnt Family Member 3A (Wnt3a) signaling to induce osteogenic potential in 3T3‑L1 pre-adipocytes, generating osteoblast-like cells. 3T3‑L1 pre-adipocytes were treated with 5azaC and/or Wnt3a. Osteogenic differentiation was assessed via ALP activity, mineralization assays, and marker expression. Transcriptomic and epigenomic profiling were performed and compared with MC3T3-E1 cells. Functional relevance of candidate genes was examined using siRNA knockdown. Transcriptomic and epigenomic profiling revealed that 5azaC and Wnt3a co-treatment induced broader gene expression and methylation changes than either treatment alone, closely resembling the osteogenic profile of MC3T3-E1 pre-osteoblasts. Among the overlapping differentially methylated and steadily expressed genes, Tyrosine 3-Monooxygenase/Tryptophan 5-Monooxygenase Activation Protein Eta (<i>Ywhah)</i> and Tyrosine 3-Monooxygenase/Tryptophan 5-Monooxygenase Activation Protein Epsilon (<i>Ywhae)</i> emerged as key regulators, whose knockdown notably enhanced Alpl expression even without 5azaC. Combining 5azaC-induced demethylation with Wnt3a is a potent strategy to redirect pre-adipocytes toward osteogenesis. Identification of key targets like Ywhah and Ywhae provides mechanistic insight into trans-differentiation and suggests therapeutic potential for bone regeneration, particularly in elderly periodontal patients. When people get older, their bones don’t heal as well. This is partly because the special cells in bone marrow that can make bone tend to make more fat instead. Our study looked for a way to help these fat-making cells change into bone-making cells instead. We tested two treatments in the lab: one that changes chemical marks on DNA (like flipping switches on or off) and one that sends signals to cells (like a message). We treated lab-grown fat precursor cells with these substances and looked closely at their genes and DNA tags to see how they changed. We found that using both treatments together worked better than using either one alone. It caused big changes, making the cells look and act more like bone-making cells. We also found two important “controller genes,” called <i>Ywhah</i> and <i>Ywhae</i>, that play key roles in this change. When we turned down the activity of these control genes, it helped the cells make bone markers. This research shows a powerful way to potentially guide cells that would normally make fat toward making bone instead, using a combination of treatments. Finding the specific control genes gives us new ideas for developing more precise treatments to help bones heal better in the future, which could be especially helpful for older adults.