Background: Bone healing is a complex biological process influenced by various cellular and molecular factors. Piezo-type mechanosensitive ion channel component 1 (Piezo1) is closely associated with function of bone cells. This study aims to investigate the effects of Piezo1 on bone healing, specifically examining its ability to enhance the growth and osteogenic differentiation of bone marrow-derived mesenchymal stem cells (BM-MSCs), as well as assessing its effect on the Phosphoinositide 3-kinase/Protein kinase B (PI3K/AKT) signaling pathway.

Methods: This study utilized a rat fracture model to evaluate the effects of rat Piezo1 recombinant proteins on bone healing. Micro-computed tomography (Micro-CT) scans were performed during weeks 6 and 8 after fracture to assess the formation of callus during the healing process, including trabecular thickness (Tb.Th), trabecular number (Tb.N), and bone mineral density (BMD). The serum levels of alkaline phosphatase (ALP) and transforming growth factor beta 1 (TGF-β1) were evaluated using an enzyme-linked immunosorbent assay. Histological evaluation included hematoxylin–eosin staining to examine tissue composition and quantitative analysis of bone morphogenetic protein (BMP)-2 expression through immunohistochemistry. Furthermore, BM-MSCs were treated with different doses of Piezo1, and cell viability was assessed using the Cell Counting Kit-8 (CCK-8) assay. ALP staining and alizarin red staining were conducted to evaluate osteogenic differentiation. Additionally, the expression levels of osteogenic markers and the activation of the PI3K/AKT signaling pathway were examined using Western blot analysis.

Results: Piezo1 significantly enhanced trabecular bone formation in a rat fracture model, with micro-CT analysis showing amplified callus formation and improved Tb.Th, Tb.N, and BMD at weeks 6 and 8 (p < 0.05). The serum levels of ALP and TGF-β1 were elevated in the Piezo1 group (p < 0.05). Histological evaluation revealed more mature bone in the Piezo1 group than in the fracture group, especially by week 8, along with increased BMP-2 expression (p < 0.05). In vitro, CCK-8 assays indicated that Piezo1 promoted BM-MSC growth in a dose- and exposure duration-dependent manner (p < 0.05). After 7 days of osteogenic differentiation, ALP and alizarin red staining showed enhanced osteogenic activity and calcium deposition in Piezo1-treated cells (p < 0.05). Western blot analysis confirmed increased expression of osteogenic markers in treated BM-MSCs, and Piezo1 activated the PI3K/AKT signaling pathway by increasing the phosphorylation levels of PI3K and AKT (p < 0.05).

Conclusions: Piezo1 significantly enhances the growth and osteogenic differentiation of BM-MSCs, accelerating bone healing by activating the PI3K/AKT signaling pathway and increasing osteogenic marker expression. These findings support the potential use of Piezo1 as a bone healing enhancer.