Induction of Matrix Metalloproteinase-3 (MMP-3) Expression in the Microglia by Lipopolysaccharide (LPS) via Upregulation of Glycoprotein Nonmetastatic Melanoma B (GPNMB) Expression

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-1β 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-1β, iNOS, and NO in activated microglia. All of these results suggest that GPNMB is involved in the inflammatory responses of microglia.
Source: Journal of Molecular Neuroscience - Category: Neuroscience Source Type: research