Nanovibrational stimulation of osteogenesis engages non-canonical Wnt signalling and NF-κB regulator BCL3 as a mechanotransducer

Enhancing osteogenesis in mesenchymal stromal (stem) cells is essential for advancing cellular therapies that target and alleviate skeletal pathologies. By employing a bespoke bioreactor capable of delivering nano-amplitude vibration (30 nm, 1kHz) to human adipose-derived mesenchymal stromal cells, we observed osteo-specific differentiation. We related this to the mechanotransductive mechanism by showing that inhibition of intracellular tension results in the loss of cytoskeletal organisation and myosin activation driven by nanovibration. Further, we dissect the mechanism of osteogenesis using a panel of Wnt agonists and antagonists and highlight the role of non-canonical Wnt. Then, using Bcl3-/- cells and by stimulating with BCL3 peptide, we show that non-canonical Wnt, osteogenesis-related inflammation and osteogenesis itself are all regulated by BCL3. This is important as nanoscale direct cell-stimulation is gaining interest, and there is an emerging consensus that such signals can be osteogenic. While prior research has only broadly hinted at how nanovibrational signals convert to an osteogenic phenotype, this new work pinpoints critical mechanistic insights, thereby advancing our understanding of this promising avenue in musculoskeletal cell therapy.