Interleukin-33 modulates lipopolysaccharide-mediated inflammatory response in rat primary astrocytes

Astrocytes have a crucial role in the modulation of the neuroinflammatory response. However, the underlying mechanisms have yet to be fully defined. Interleukin-33 (IL-33) is constitutively expressed in astrocytes, which has been found to orchestrate inflammatory responses in a large variety of immune-mediated and inflammatory diseases of the nervous system. Thus, the purpose of this study was to elucidate the potential effect of IL-33 in the regulation of inflammatory response in primary cultured astrocytes. We investigated the role of IL-33 in the regulation of inflammatory responses in the lipopolysaccharide-stimulated astrocytes. This study utilized lentiviral short hairpin RNA vectors to target IL-33 (LV-shIL-33) for gene silencing. After lipopolysaccharide stimulation, the expression levels of interleukin-1β (IL-1β), IL-6, and tumor necrosis factor-α (TNF-α), as well as the activation of nuclear factor-kappa B (NF-κB) and extracellular signal-regulated kinase (ERK) signaling pathways, were evaluated to elucidate the mechanisms related to the contributions of IL-33 to the inflammatory response in astrocytes. We found that the expression IL-33 has increased in rat primary cultured astrocytes after lipopolysaccharide stimulation. Administration of LV-shIL-33 knocked down the expression of IL-33 and markedly reduced the overexpression of spinal IL-1β, IL-6, and TNF-α, and attenuated the activation of ERK and NF-κB/p65. This study shows that IL-33 participates in regulating inflammatory responses in primary cultured astrocytes, which might provide additional targets for controlling inflammatory responses following neurological diseases. See Video abstract, http://links.lww.com/WNR/A627.