Abstract:
Endocrine disruptors interfere with normal sexual and reproductive development of numerous organisms. Widely
used in several chemical and manufacturing industries, nonylphenol (NP), a potent xenoestrogen, has the potential
to perturb immune system. Using rat splenic macrophages (SMΦ) as the model system, NP-modulation of lipo polysaccharide (LPS)-induced inflammatory response has been investigated. Our results demonstrate that NP
(0.1–10 µM) attenuates catalase activity, reactive oxygen species (ROS) generation and nitric oxide (NO) synthesis
in LPS-treated SMΦ in vitro. NP inhibition of LPS-induced nuclear factor kappa B (NF-κB) activation and pro inflammatory cytokine gene expression corroborate well with attenuation of suppressor of cytokine signalling 3
(SOCS3). Besides, elevated expression of anti-inflammatory factors reveals inverse correlation with suppression of
endotoxin-induced M1 polarization in NP pre-incubated cells. While LPS promotes, NP prevents ERK1/2 (extra cellular-signa1-regulated kinase 1/2) phosphorylation and MEK-inhibitor abrogates SOCS3 expression and NO
production suggesting involvement of ERK1/2 in NP inhibition of SOCS3 expression. Further, translational in hibitor cycloheximide prevents LPS-induced NF-κB activation indicating functional importance of de novo synthesis
of SOCS3, at least in part, in toll-like receptor 4 (TLR4)-mediated inflammatory response. Collectively, present
study provides evidence favouring participation of SOCS3 in NP modulation of inflammatory response in rat SMΦ.
