RESUMO
Berberine chloride (BBR) is an isoquinoline derivative alkaloid isolated from medicinal herbs, including Coptis chinensis and Berberis aristate. This compound plays significant roles in the treatment of osteoarthritis (OA). The purpose of this study was to investigate the effects of BBR on the proliferation of sodium nitroprusside (SNP)-stimulated chondrocytes in vitro, the articular cartilage in a rat OA model, as well as to discuss the molecular mechanisms underlying these effects. In vitro, we demonstrated that BBR led to cell proliferation, increased the cell population in S-phase and decreased that in G0/G1-phase; moreover, the F-actin remodeling in SNP-stimulated chondrocytes were prevented. In addition, BBR markedly up-regulated ß-catenin, c-Myc, and cyclin D1 expression of genes and proteins, and down-regulated glycogen synthase kinase-3ß (GSK-3ß) and matrix metalloproteinase-7 (MMP-7) expression. Notably, inhibition of the Wnt/ß-catenin pathway by XAV939 partially blocked these effects. The in vivo results suggested that BBR promoted ß-catenin protein level and enhanced proliferating cell nuclear antigen (PCNA) expression in osteoarthritic rat cartilage. In conclusion, these findings indicate that BBR promotes SNP-stimulated chondrocyte proliferation by promoting G1/S phase transition and synthesis of PCNA in cartilage through activation of Wnt/ß-catenin signaling pathway.
Assuntos
Berberina/farmacologia , Cartilagem Articular/patologia , Condrócitos/citologia , Condrócitos/efeitos dos fármacos , Nitroprussiato/efeitos adversos , Osteoartrite/patologia , Via de Sinalização Wnt/efeitos dos fármacos , Animais , Ciclo Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Condrócitos/metabolismo , Condrócitos/patologia , Ciclina D1/genética , Citoesqueleto/efeitos dos fármacos , Citoesqueleto/metabolismo , Proteínas de Ligação a DNA/genética , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Glicogênio Sintase Quinase 3 beta/genética , Fator 1 de Ligação ao Facilitador Linfoide/metabolismo , Antígeno Nuclear de Célula em Proliferação/metabolismo , Proteínas Proto-Oncogênicas c-myc/genética , Ratos , Ratos Sprague-Dawley , Fator de Transcrição 4 , Fatores de Transcrição/genéticaRESUMO
Chondrocyte apoptosis is an important mechanism involved in osteoarthritis (OA). Berberine (BBR), a plant alkaloid derived from Chinese medicine, is characterized by multiple pharmacological effects, such as anti-inflammatory and anti-apoptotic activities. This study aimed to evaluate the chondroprotective effect and underlying mechanisms of BBR on sodium nitroprusside (SNP)-stimulated chondrocyte apoptosis and surgically-induced rat OA model. The in vitro results revealed that BBR suppressed SNP-stimulated chondrocyte apoptosis as well as cytoskeletal remodeling, down-regulated expressions of inducible nitric oxide synthase (iNOS) and caspase-3, and up-regulated Bcl-2/Bax ratio and Type II collagen (Col II) at protein levels, which were accompanied by increased adenosine monophosphate-activated protein kinase (AMPK) phosphorylation and decreased phosphorylation of p38 mitogen-activated protein kinase (MAPK). Furthermore, the anti-apoptotic effect of BBR was blocked by AMPK inhibitor Compound C (CC) and adenosine-9-ß-D-arabino-furanoside (Ara A), and enhanced by p38 MAPK inhibitor SB203580. In vivo experiment suggested that BBR ameliorated cartilage degeneration and exhibited an anti-apoptotic effect on articular cartilage in a rat OA model, as demonstrated by histological analyses, TUNEL assay and immunohistochemical analyses of caspase-3, Bcl-2 and Bax expressions. These findings suggest that BBR suppresses SNP-stimulated chondrocyte apoptosis and ameliorates cartilage degeneration via activating AMPK signaling and suppressing p38 MAPK activity.
