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The cartilaginous epiphyses of 80 femurs of newborn rats, which were divided into two subgroups: treated with caffeine and control group, both observed the time of 0, 7, 14 and 21 days. The cartilaginous epiphyses of four femurs of each subgroup and each time span were subjected to histomorphometric and immunohistochemical analysis and Tunel in order 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. Caffeine is a methylxanthine found in several foods, therefore widely consumed by humans. A variety of its effects and mechanisms on tissues have been widely studied, however, despite the fact that it alters post-natal bone growth, there have been only a few studies on its effects on growth cartilage. The objective of this study is to evaluate the in vitro effects of caffeine on proliferation, apoptosis and gene transcripts expression of chondrogenic differentiation in growth cartilage.

OBJETIVO: Avaliar os efeitos in vitro da cafeína na proliferação, apoptose e expressão de transcriptos gênicos de diferenciação condrogênica na cartilagem de crescimento. MÉTODO: As epífises cartilaginosas de fêmures de ratos neonatos foram divididas em dois subgrupos: os tratados com cafeína e o grupo controle, ambos observados nos tempos de 0, 7, 14 e 21 dias. As epífises cartilaginosas de fêmures de cada subgrupo e de cada tempo foram submetidas à histomorfometria, análise imunoistoquímica, técnica de túnel e RT-PCR em tempo real. RESULTADO: A diminuição da atividade proliferativa e o aumento de condroblastos em apoptose aos 21 dias foram encontrados em ambos os subgrupos. Entretanto a diminuição da proliferação celular causada pela cafeína foi menor quando comparada ao grupo controle e aumentou significativamente a expressão de transcriptos gênicos para diferenciação condrogênica, representada pelo SOX-9 e pelo RUNX-2. Entretanto o cultivo in vitro com cafeína demostrou efeitos antagônicos: apesar dos efeitos positivos na proliferação e diferenciação de condroblatos, cafeína aumentou a apoptose, caracterizada pelo aumento da expressão de caspase-3 e do numero de células em apoptose (p< 0.05). CONCLUSÃO: A cafeína apresenta efeitos antagônicos in vitro na cartilagem em crescimento, aumentando a proliferação, diferenciação e apoptose celular. Estudo experimental. OBJECTIVE: To evaluate the in vitro effects of caffeine on proliferation, apoptosis and gene transcripts expression of chondrogenic differentiation in growth cartilage. METHODS: The cartilaginous epiphyses of femurs of newborn rats, were divided into two subgroups: treated with caffeine and control group, both observed over the time periods of 0, 7, 14 and 21 days. The cartilaginous epiphyses of femurs of each subgroup and each time span were subjected to histomorphometrics, immunohistochemical analysis, tunel technique and RT-PCR in real time. RESULTS: The decrease in proliferative activity and the increase of apoptotic chondroblasts at 21 days were found regardless of the subgroup. However, the decrease in cell proliferation caused by caffeine was lower than in the control group and significantly increased the expression of gene transcripts for chondrogenic differentiation, represented by SOx-9 and RUNx-2. However, the in vitro culture with caffeine revealed antagonistic effects: despite the positive effect on chondroblasts proliferation and differentiation, caffeine increased apoptosis, characterized by increased expression of caspase-3 and of the number of cells undergoing apoptosis (p

Objective To evaluate the in vitro effetcs of caffeine on proliferation, apoptosis a nd gene transcripts expression of chondrogenic differentiation in growth cartilage. Methods The cartilaginous epiphyses of femurs of newborn rats, which were divided into two subgroups: treated with caffeine and control group, both observed over the time periods of 0, 7, 14 and 21 days. The cartilaginous epiphyses of femurs of each subgroup and each time span were subjected to histomorphometric, immunohistochemical analysis, Tunel technique and RT-PCR in real time. Results The decrease in proliferative activity and the increase of apoptotic chondroblasts at 21 days were found regardless of the subgroup. However, the decrease in cell proliferation caused by caffeine was lower than in the control group and significantly increased the expression of gene transcripts for chondrogenic differentiation, represented by Sox-9 and Runx-2. However, the in vitro culture with caffeine revealed antagonistic effects: despite the positive effect on chondroblasts proliferation and differentiation, caffeine increased apoptosis, characterized by increased expression of caspase 3 and of the number of cells undergoing apoptosis (p