Search

Background: Adiponectin (APN) has been reported to promote bone formation. However, it is difficult to utilize a conventional method that administers sufficient APN to the implant site. The present study investigated the efficacy of an APN transgene to accelerate the implant osseointegration in ovariectomized (OVX) rats., Methods: In vitro, bone marrow stromal cells were transduced with reconstructed adenovirus (Ad-APN-EGFP) and osteoclast precursor RAW264.7 cells were co-cultured with the conditioned medium secreted by transduced bone marrow stromal cells. Tartrate-resistant acid phosphatase staining and bone slice resorption assay were performed to evaluate the activity of osteoclastogenesis. In vivo, Ad-APN-EGFP was administered into the bone defect prior to implant placement in OVX rats. At 7 and 28 days post implantation, the femurs were harvested and prepared for a real-time reverse transcriptase-polymerase chain reaction, hemotoxylin and eosin staining, immunohistochemical staining, micro-computed tomography analysis and biomechanical testing., Results: The results showed the formation and function of osteoclasts were significantly suppressed in vitro. Successful transgene expression was confirmed, and a significant increase of OCN, Runx2 and ALP expression was detected in the Ad-APN-EGFP group in vivo. Interestingly, we also found that the overexpression of APN decreased the expression level of potent adipogenic transcription factors such as PPARγ2 and C/EBP-α. At 28 days after implantation, the Ad-APN-EGFP group revealed a significantly increased osseointegration and implant stability in OVX rats compared to the control groups (Ad-EGFP and PBS groups)., Conclusions: APN via direct adenovirus-mediated gene transfer could ameliorate osseointegration surrounding titanium implants in OVX-related osteoporosis rats. Furthermore, it may be an effective strategy for promoting bone regeneration under osteoporotic conditions., (© 2019 John Wiley & Sons, Ltd.)

Type 2 diabetes mellitus (T2DM) is the most common form of diabetes. Compared with the general population, a higher failure rate is seen in T2DM patients. There is also evidence that chronically high levels of plasma glycemia leads to inflammatory effect and a negative influence on bone formation and remodeling, and reduce osseointegration of implants. Recently studies reveal that adiponectin is an insulin-sensitizing adipokine, and closely associated with T2DM. Adiponectin has potent anti-inflammatory properties and has been shown to increase bone density by inhibiting osteoclast formation and promoting the formation of osteoblasts. We therefore hypothesize systemically infused or locally used adiponectin could accelerate osseointegration of dental implants in T2DM. Our hypothesis could help to create an option to improve success ratio of dental implants in T2DM by the replenishment of adiponectin in T2DM patients., (Copyright © 2011 Elsevier Ltd. All rights reserved.)