Interleukin-1β and Interleukin-6 Stimulate Matrix Metalloproteinase-9 Secretion in Cultured Myenteric Glia

Western blotting of culture media of myenteric glia stained positive for GFAP revealed increased secretion of matrix metalloproteinase-9 (MMP-9) in interleukin-1β (IL-1β) stimulated cells (10 ng/mL) versus control (142 ± 19 versus 42 ± 19, P < 0.05). Interleukin-6 (IL-6) stimulated cells also showed increased expression of MMP-9 (10 ng/mL) versus control (69 ± 14 versus 4 ± 2, P < 0.01). Control and cytokine-stimulated cells secreted MMP-2 constituitively. Gelatin zymography demonstrated that products were biologically active. Cytoplasmic staining for MMP-9 was detected in IL-1β and IL-6-stimulated cells but was negligible in controls. Cultured myenteric glia are responsive to IL-1β and IL-6 stimulation by secreting MMPs into the extracellular environment.