Interaction of Wip1 and NF-κB regulates neuroinflammatory response in astrocytes

Objective The aims of the present study were to detect the interaction of Wip1 and NF-κB P65 in retina of an LPS-induced astrocytes activation model. Methods The interaction between Wip1 and nuclear factor kappa B (NF-κB) P65 was observed in lipopolysaccharide (LPS)-stimulated primary rat astrocytes derived from retina. The expressions of Wip1 and NF-κB P65 were evaluated using Western blot and RT-PCR. Small interfering RNA (siRNA) against Wip1 was transfected into astrocytes to clarify the phosphorylation status and nuclear translocation of NF-κB P65 and expressions of these proinflammatory factors. Meanwhile, expression of Wip1 was assessed following treatment with NF-κB inhibitor. Results Wip1 and phospho-NF-κB P65 (p-P65) expressions were significantly increased and colocalization in astrocytes after LPS treatment. The expression of p-P65 was augmented by transfected with Wip1 siRNA followed by LPS. Furthermore, pre-treatment with Wip1 siRNA further enhanced LPS-induced NF-κB P65 translocation into the nuclei and proinflammatory cytokine release. Finally, inhibition of NF-κB decreases Wip1 expression and transcription in primary astrocytes. Conclusion These data provide a mechanism for the role for a negative feedback loop of Wip1 and NF-κB in LPS-induced astrocytic activation.