Glia
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The pro-inflammatory cytokines interleukin-1beta (IL-1beta), IL-6, tumor necrosis factor-alpha (TNF-alpha), and nitric oxide (NO) can be produced by activated glial cells and play a critical role in various neurological diseases. Using primary co-cultures of rat microglial and astroglial cells, we investigated the effects of the anti-inflammatory cytokines transforming growth factor-beta1 (TGF-beta1)/beta2, IL-4, and IL-10 on the production of (pro-) inflammatory mediators after stimulation of the cells with lipopolysaccharide (LPS; 0.1 micrograms/ml, 24 h). IL-10 (10 and 100 ng/ml) and IL-4 (5 and 50 U/ml) suppressed the LPS-induced production of NO, IL-6, and TNF-alpha in a dose-dependent manner, whereas TGF-beta1/beta2 (2 and 20 ng/ml) only suppressed NO production. ⋯ This finding strongly suggests that effective concentrations of TGF-beta1/beta2 and IL-10 are produced by LPS-stimulated glial cell co-cultures. Production of IL-10 in these co-cultures was confirmed by measurement of rat IL-10 by radioimmunoassay. We conclude that anti-inflammatory cytokines affect the production of inflammatory mediators in LPS-activated co-cultures of microglial and astroglial cells differentially.