RESUMEN
Substantial evidence suggests that inflammation is an important contributor to many neurodegenerative disorders. Activated microglial cells play an important role in releasing pro-inflammatory factors, including tumor necrosis factor-α (TNF-α) and interleukin-1ß (IL-1ß) for inducing inflammation. Recently, some reports have suggested that glycoprotein nonmetastatic melanoma B (GPNMB) is highly expressed in microglia after LPS treatment. However, the role of GPNMB in activated microglia is not clearly understood. In this study, we used RT-PCR and Western blotting to detect GPNMB and matrix metalloproteinase-3 (MMP-3) expressions in activated microglia. GPNMB small interfering RNA (siRNA) or MMP-3 inhibitor was applied on microglial BV2 cells, and ELISA was performed to measure the expressions of TNF-α and IL-1ß in BV2 cells. Levels of iNOS and NO in BV2 cells were also determined. We found that the levels of GPNMB and MMP-3 were significantly increased in BV2 cells after LPS treatment. Moreover, we found that GPNMB significantly upregulated the expression of MMP-3 in BV2 cells, and high expression of MMP-3 was dependent on the level of GPNMB. Inhibition of GPNMB or MMP-3 expression by GPNMB siRNA or MMP-3 inhibitor dramatically suppressed the expressions of TNF-α, IL-1ß, iNOS, and NO in activated microglia. All of these results suggest that GPNMB is involved in the inflammatory responses of microglia.
Asunto(s)
Proteínas del Ojo/metabolismo , Metaloproteinasa 3 de la Matriz/metabolismo , Glicoproteínas de Membrana/metabolismo , Microglía/metabolismo , Regulación hacia Arriba , Animales , Línea Celular , Proteínas del Ojo/genética , Interleucina-1beta/genética , Interleucina-1beta/metabolismo , Lipopolisacáridos/farmacología , Metaloproteinasa 3 de la Matriz/genética , Glicoproteínas de Membrana/genética , Ratones , Microglía/efectos de los fármacos , Óxido Nítrico Sintasa de Tipo II/genética , Óxido Nítrico Sintasa de Tipo II/metabolismo , Factor de Necrosis Tumoral alfa/genética , Factor de Necrosis Tumoral alfa/metabolismoRESUMEN
It is reported that apple polysaccharide can prevent colon cancer growth and impede colon cancer progression. Apple oligosaccharide was prepared by the combination of alkaline hydrolysis and enzymolysis of apple polysaccharides, and purified by anion column chromatography. The aim of this study is to explore the effect of apple oligosaccharide on the cellular viability of human colon carcinoma cells (HT29 cells) and its mechanism. The results showed that apple oligosaccharide decreased the cellular viability of HT29 cells in dose-dependent manner. Meanwhile it enhanced the expression of Bax; and decreased the levels of Bcl-2 and Bcl-xl. Apple oligosaccharide induced cell cycle arrest in S phase, which correlated with the decreased expression of Cdk 2 and cyclin B1. These results indicated that apple oligosaccharide attenuated HT29 cell viability by inducing cell apoptosis and cell cycle arrest. Apple oligosaccharide is a potential chemoprevention agent or anti-tumor agent and is worthy of further study.