The ROS/CaMK II/β-Catenin Signaling Axis Affects the Osteogenic Potential of BMSCs and Disrupts Implant Osseointegration: An In Vitro Study.

Objectives

High glucose (HG)-induced oxidative stress affects implant osseointegration through various pathways. Oxidative stress is widely recognized to suppress the Wnt/β-catenin signaling pathway, thereby impairing bone metabolism and homeostasis. However, there are few reports on whether excessive reactive oxygen species (ROS) influence osteogenic differentiation of stem cells via the noncanonical Wnt/calmodulin-dependent protein kinase II (CaMK II) pathway. An investigation of the mechanism by which ROS/CaMK II/β-catenin signaling axis influences the osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) on titanium surfaces is being carried out in this investigation. Materials and

Methods

In this study, titanium plates were specially treated to simulate implant surfaces. An osteogenic medium containing HG was used to cultivate BMSCs on titanium surfaces. The effects of excessive ROS induced by HG on the osteogenic differentiation of BMSCs, as well as on the expression of β-catenin and CaMK II, were examined using methods such as alkaline phosphatase (ALP) activity assay, quantitative real-time PCR (qRT-PCR), and immunofluorescence staining. Additionally, the effects of the Wnt/β-catenin and Wnt/CaMK II pathways on the osteogenesis of BMSCs on the titanium surface were observed by separately adding activators or inhibitors of β-catenin and CaMK II.

Results

Excessive ROS induced by HG inhibited osteogenic differentiation. In a HG environment, β-catenin expression decreased, while CaMK II expression increased. Moreover, we observed that activation of the Wnt/β-catenin pathway promoted osteogenesis, whereas activation of the Wnt/CaMK II pathway inhibited it.

Conclusions

In summary, BMSC osteogenesis on titanium surfaces is suppressed by HG-induced oxidative stress via the ROS/CaMK II/β-catenin signaling axis, which may subsequently impair implant osseointegration.