Low-Intensity pulsed ultrasound enhances paracrine secretion of IGF and VEGF by bmscs, promoting osteogenesis and angiogenesis.

Abstract

<h4>Background</h4>Low-intensity pulsed ultrasound (LIPUS) is an effective therapy for craniofacial bone regeneration. Paracrine signaling from mesenchymal stem cells (MSCs) plays a critical role in bone repair, but the impact of LIPUS on MSC-derived secretome remains unclear. This study investigates whether LIPUS enhances the osteogenic and angiogenic potential of MSCs through modulation of growth factor secretion.<h4>Methods</h4>Bone marrow-derived MSCs (BMSCs) were treated with or without LIPUS to generate conditioned media (LIPUS-CM and Ctrl-CM). Concentrations of IGF-1, VEGF, and TGF-β were quantified. These media were applied to other BMSCs and rat aortic endothelial cells (RAOECs). In vitro assays evaluated cell proliferation, migration, osteogenic differentiation, and angiogenesis. Data were analyzed using GraphPad and Image J, with significance set at α = 0.05.<h4>Results</h4>LIPUS significantly upregulated IGF-1 and VEGF secretion in BMSCs, while TGF-β levels remained unchanged. RAOECs cultured in LIPUS-CM demonstrated enhanced proliferation, migration, and angiogenic capacity. Likewise, BMSCs cultured in LIPUS-CM showed improved proliferation, migration, and osteogenic differentiation compared to the Ctrl-CM group.<h4>Conclusion</h4>LIPUS promotes osteogenic differentiation of BMSCs and angiogenesis in RAOECs through the paracrine signaling of BMSCs, at least by increasing IGF-1 and VEGF secretion. This suggests that LIPUS can regulate the secretome of BMSCs and may serve as a key mechanism in promoting bone tissue regeneration.