Open AccessLipopolysaccharide-induced innate immune responses are exacerbated by Prohibitin 1 deficiency and mitigated by S-adenosylmethionine in murine macrophages
Author(s) -
Soohan Jung,
Jaehee Park,
Kwang Suk Ko
Publication year - 2020
Publication title -
plos one
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.99
H-Index - 332
ISSN - 1932-6203
DOI - 10.1371/journal.pone.0241224
Subject(s) - prohibitin , lipopolysaccharide , immune system , gene knockdown , luciferase , proinflammatory cytokine , innate immune system , biology , microbiology and biotechnology , inflammation , macrophage , chemistry , cell culture , biochemistry , immunology , transfection , mitochondrion , in vitro , apoptosis , genetics
Prohibitin 1 (Phb1) is a pleiotropic protein with multiple functions in mammalian cells including cell cycle regulation and mitochondrial protein stabilization. It has been proposed as a potential therapeutic target for a variety of diseases including inflammatory diseases. In this study, we investigated the potential immune-modulatory functions of Phb1 and anti-inflammatory properties of S-adenosylmethionine (SAMe) using macrophages, which play a major role in the innate immune system. The results showed that expressions of Phb1 mRNA and protein were reduced in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells ( p <0.05). Phb1 knockdown further ameliorated the mRNA expression of pro- and anti-inflammatory cytokines such as TNF-α, IL-1α, IL-1β, IL-6, and IL10 in LPS-stimulated RAW 264.7 cells. SAMe significantly attenuated LPS-induced inflammatory responses such as IL-1β, IL-10, Nos2, and NO production in the presence of siPhb1 . Luciferase reporter assay was conducted to determine the mechanisms underlying the effects of Phb1 and SAMe on the immune system. The luciferase activity of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) was significantly increased in LPS-treated RAW 264.7 cells. In addition, the luciferase reporter assay showed increased NF-κB activation in Phb1 knockdown RAW 264.7 cells ( p <0.1) and SAMe treatment attenuated the NF-κB luciferase activity in Phb1 knockdown RAW 264.7 cells. Based on the results, we concluded that Phb1 possibly modulates the inflammatory response whereas SAMe has an anti-inflammatory effect on Phb1 knockdown macrophage cells. Furthermore, Phb1 expression level has potential properties of affecting on innate immune system by modulating the NF-κB signaling pathway.