cytochrome-c-t and Fractures--Bone

The primary objective of this study was to investigate whether or not apoptosis is induced following bone fracture, and if so, to investigate whether the extrinsic or intrinsic pathway of cell death is stimulated.. A total of 30 patients who presented at our clinic and were diagnosed with bone fracture following trauma were included in the study group. A control group was formed of 37 age and gender-matched volunteers. On the day after the fracture, blood samples taken from the patients were examined for cytochrome C, granzyme B and caspase-8 with the ELISA method.. A total of 67 individuals were evaluated (fracture group: 30, control group: 37) in this study. Caspase-8 was found to be statistically significantly high in the patient group (0.37±0.06 ng/mL, p=0.002). No significant difference was determined between the groups in respect to cytochrome C values (p=0.173). The granzyme B values were determined to be significantly high in the patient group (52.56±8.51 pg/mL, p=0.007).. These results obtained from patients with a long bone fracture demonstrated that serum caspase-8 and granzyme B levels were higher in patients than in the control group, thereby showing activation of the extrinsic pathway. However, no significant difference was determined between the groups concerning serum cytochrome C levels. This study may guide future studies designed for better understanding of the molecular pathways that govern the events during a fracture, which will be important for the future advancement of fracture treatment.

Topics: Apoptosis; Biomarkers; Case-Control Studies; Caspase 8; Cytochromes c; Fractures, Bone; Granzymes; Humans

Fracture healing is regulated by proinflammatory mediators such as tumor necrosis factor-α (TNF-α), which poses influence on the balance between bone formation and remodeling. And the diabetes is thought to contribute to the delayed diabetic fracture healing. In the present study, we examined the promotion to proinflammatory cytokines and chemokines in type 2 diabetes mellitus (T2DM) patients with bone fractures, and then evaluated the promotion to TNF-α by the high glucose treatment in human osteoblast-like MG-63 cells and the regulatory role of the promoted TNF-α on the MG-63 cell apoptosis. It was demonstrated that there were significantly-upregulated high-sensitivity C-reactive protein (hsCRP) TNF-α, IL-1β, IL-6, IFN-γ-inducible protein 10 (IP-10) and RANTES in T2DM patients with bone fracture. And the promotion to TNF-α and IL-1β was confirmed in vitro in both mRNA and protein levels in high glucose-treated MG-63 cells. And either TNF-α or high glucose reduced the viability of MG-63 cells, promoted apoptosis and upregulated apoptosis-associated markers, such as released cytochrome c, cleaved caspase 3 and lyzed PARP. Moreover, there was a synergistic effect between TNF-α and high glucose. The viability reduction and the apoptosis induction of MG-63 cells were significantly higher in the group with both TNF-α and high glucose treatments, than in the group with singular TNF-α treatment. In conclusion, our study demonstrated that proinflammatory cytokines and chemokines were promoted in T2DM patients with bone fracture or in osteoblasts by the high glucose stimulation. TNF-α and high glucose synergistically reduced the viability and induced the apoptosis in the osteoblast-like MG-63 cells in vitro. It implies the significant regulatory role of TNF-α in the delayed fracture healing in T2DM.

Topics: Aged; Apoptosis; Bone and Bones; C-Reactive Protein; Caspase 3; Cell Line, Tumor; Cell Survival; Chemokines; Cytochromes c; Cytokines; Diabetes Mellitus, Type 2; Female; Fracture Healing; Fractures, Bone; Glucose; Humans; Interleukin-1beta; Male; Middle Aged; Osteoblasts; Tumor Necrosis Factor-alpha; Up-Regulation