Restoring impaired osteogenic differentiation of diabetic rat stromal cells using epigenetic inhibitors

Epigenetic regulation plays a crucial role in gene expression and is recognized as a key contributor to diabetes-related complications. This study explores the osteogenic differentiation potential of stem cells isolated from the periodontal ligament (PDL) and bone marrow (BM) of diabetic rats. It investigates the effects of DNA methyltransferase and histone deacetylase inhibitors on the differentiation capacity of diabetic stem cells, searching for underlying mechanisms.

Diabetes was induced in 5-week-old male Wistar rats using streptozotocin (STZ). Bone parameters were assessed via micro-CT, and stem cells isolated from mandibles and femurs were treated with 5-azacytidine or Trichostatin A in osteogenic medium. Osteogenic differentiation was evaluated through alkaline phosphatase (ALP) activity, Alizarin Red staining, and mRNA expression of osteogenic markers using real-time PCR.

A significant decrease in total BMD and BV/TV of the femur and mandible was observed in STZ-induced diabetic rats compared to control. Cells isolated from diabetic PDL and BM showed impaired mineralization capacity and downregulated osteogenic markers. Treatment with Trichostatin A or 5-azacytidine restored mineralization potential, increased ALP activity, and upregulated the expression of RUNX2 and β-catenin.

Our results revealed the underlying epigenetic mechanisms responsible for the impaired osteogenic differentiation capacity of stem cells in diabetes. These findings highlight the potential of epigenetic modulators to restore stem cell function and enhance bone regeneration. This approach holds promise for improving diabetes-related skeletal complications and advancing tissue engineering strategies, including the development of scaffold-based therapies for fracture repair, periodontal regeneration, and implant integration in diabetic patients.