Exploring New Inflammatory Biomarkers and Pathways during LPS-Induced M1 Polarization

Figure 6

M1 polarized N9 microglia have low intracellular content of HMGB1 and increased secretion of MMP-9, NO, and HMGB1 to the cell milieu. Extracellular medium was assessed for matrix metalloproteinase-9 (MMP-9) (a) and MMP-2 (b) activities by the gelatin zymography assay and results were expressed as fold versus nontreated cells (control). Nitrites that reflect nitric oxide (NO) production were assessed by the Griess reaction followed by Microplate Reader for Absorbance Assays (c). High mobility group box 1 (HMGB1) expression was determined in total extracts (d), nuclear fraction (e), and extracellular media (f) by Western blot analysis. Results are mean ± s.e.m. from six (a, b, d, e) or four (c, f) independent experiments. Nitrites measurement (c) was performed in duplicate. Comparisons between lipopolysaccharide- (LPS-) treated N9 cells and nontreated cells (control) were made via two-tailed Student’s -test (e) or unpaired -test with Welch’s correction (a, c, d, f). and versus nontreated cells (control).

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