The Protective Effects of VVN001 on LPS-Induced Inflammatory Responses in Human RPE Cells and in a Mouse Model of EIU.

Abstract

To investigate protective effects of VVN001 on lipopolysaccharide (LPS)-induced inflammatory response in human retinal pigment epithelial (RPE) cells and in a mouse model of endotoxin-induced uveitis (EIU), and to explore the underlying mechanisms. Human primary RPE (hRPE) and ARPE-19 cells were pretreated with or without VVN001 for 1h followed by 10μg/mL LPS stimulation for 24h. mRNA, and protein levels of inflammatory cytokines were analyzed with real-time PCR, western blotting, and ELISA. EIU was induced by intravitreal injection of 125ng LPS in female BALB/c mice. VVN001 eye drops (1%) were locally administrated every 4h for 24h after LPS injection. Clinical scores were assessed with a slit lamp. mRNA and protein levels of inflammatory cytokines were investigated simultaneously. Compared with the LPS group, VVN001 pretreatment significantly reduced mRNA expressions of intercellular adhesion molecule-1 (ICAM-1), IL-6, IL-8, TNF-α, IL-1β, IL-18, caspase-1 in hRPE, and ARPE-19 cells. Protein overproduction of ICAM-1, TNF-α, IL-1β, NLRP3, caspase-1 P20, and p-IκBα/IκBα stimulated by LPS was suppressed by VVN001 pretreatment. In vivo, VVN001 significantly reduced the average clinical score from 5.0 to 1.3 in EIU mice. Furthermore, overproduction of ICAM-1, IL-1β, NLRP3, caspase-1 P20, and p-IκBα/IκBα at mRNA and protein levels were remarkably suppressed by VVN001. VVN001 alleviated the inflammatory response induced by LPS both in vitro and in vivo. The effect of anti-inflammation is associated with inhibiting the overproduction of ICAM-1 and blocking the activation of NLRP3 inflammasome and the NF-κB signaling pathway.