Bone Abstracts

Caffeine is a methylxanthine found in many foods and is widely consumed by the human population. Therefore, its effects and mechanisms in various tissues have been widely studied. But despite changing the postnatal bone growth, there are few studies about its effect on growth cartilage. The objective of this study was to evaluate the In vitro effects of caffeine on proliferation, apoptosis and gene transcripts expression of chondrogenic differentiation in growth cartilage. There had been used the femoral epiphyseal cartilage of 80 newborn rats which were divided into two groups, i.e. group treated with caffeine and control group of 0, 7, 14, and 21 days of life. The cartilaginous epiphyses of four femurs from each group and each time point were subjected to histomorphometric and immunohistochemical analysis and TUNEL to evaluate cell proliferation and apoptosis respectively. The cartilaginous epiphyses of six femurs were subjected to RT-PCR in real time to evaluate the expression of caspase-3, Runx-2, and Sox-9. In this model, it is observed naturally the decrease of proliferative activity and the increase of chondroblasts in apoptosis up to 21 days, regardless of group. However, the decrease in cell proliferation caused by caffeine was significantly lower compared to the control group and significantly increased the expression of gene transcripts for chondrogenic differentiation, represented by Sox-9 and the Runx-2. However, the In vitro treatment with caffeine had antagonistic effects, since despite the positive effect on the proliferation and differentiation of chondroblasts, caffeine increased apoptosis, characterized by increased expression of caspase 3 and of the number of cells undergoing apoptosis (P<0.05). It follows that the caffeine presents antagonistic effects In vitro on growth cartilage, increasing the proliferation, differentiation and apoptosis.