ABSTRACT
PURPOSE: This study aimed to evaluate the effects of thymosin ß4 (TB4) on bone formation. METHODS: A 5mm diameter bone defect was created in the skulls of Wistar rats. Two types of experimental models were prepared: one with atelocollagen sponges used to fill the bone defect and one without. In each experimental model, bone formation in calvarial defects was compared between the group receiving synthetic partial peptides of TB4 intraperitoneally (TB group) and the control group, which received an equivalent amount of phosphate-buffered saline. Calvarial defect sections collected on postoperative days 5, 10, and 20 were analyzed, and the area of newly formed bone was measured. Furthermore, the sections on postoprerative day 5 were immunostained with anti-osterix antibody and the osterix-positive cells were counted. The total RNA extracted from granulation tissue obtained on postoperative day 10 was analyzed using reverse transcriptase-polymerase chain reaction (RT-PCR). RESULTS: In both models, with or without atelocollagen sponges, new bone formation was significantly greater in the TB4 group than in the control group. In some TB4 group individuals, the entire bone defect region of diameter 5mm was almost covered with newly formed bone by postoperative day 20. Immunostaining revealed a significant number of osterix-positive cells in the TB4 group. On postoperative day 10, the expression levels of bone-related genes were analyzed by RT-PCR, which showed no statistically significant differences between the two groups. CONCLUSION: The osteogenesis-promoting effects of TB4 observed in critical-sized defects could be of practical use in bone regeneration therapy.
Subject(s)
Bone Regeneration/drug effects , Osteogenesis/drug effects , Skull/abnormalities , Skull/physiology , Thymosin/pharmacology , Alkaline Phosphatase/analysis , Animals , Bone Morphogenetic Protein 2/analysis , Bone Regeneration/genetics , Collagen/pharmacology , Male , Osteocalcin/analysis , Osteogenesis/genetics , Rats , Reverse Transcriptase Polymerase Chain Reaction , Skull/injuries , Stimulation, Chemical , Time Factors , Transcription Factors/analysisABSTRACT
OBJECTIVES: The aim of this study was to evaluate the effects of thymosin ß4 (TB4) on wound healing after tooth extraction in rats. STUDY DESIGN: After extraction of the rats' mandibular first molar teeth, a synthetic partial peptide of TB4 was injected intraperitoneally at the time of extraction and every day thereafter for 6 days. Control subjects for the treatment received identical amounts of phosphate-buffered saline solution in the same manner. Histologic analysis, apoptosis assay, and reverse-transcription polymerase chain reaction were performed. RESULTS: The overall data showed that TB4 treatment suppressed apoptosis and inflammation; it accelerated the process of wound healing, including new bone formation. CONCLUSIONS: The findings demonstrated not only the usefulness of the TB4 partial peptide in wound healing of tooth extraction sockets, but also its potential application for bone regeneration and osteogenesis in bone and bone-related tissues.
