Wogonin protects human retinal pigment epithelium cells from LPS-induced barrier dysfunction and inflammatory responses by regulating the TLR4/NF-κB signaling pathway

Chen,Chen; Guo,Danni; Lu,Guohua

doi:10.3892/mmr.2017.6252

Wogonin protects human retinal pigment epithelium cells from LPS-induced barrier dysfunction and inflammatory responses by regulating the TLR4/NF-κB signaling pathway

Authors:
- Chen Chen
- Danni Guo
- Guohua Lu
View Affiliations

Affiliations: Eye Institute, Changzhou No. 2 People's Hospital of Nanjing Medical University, Changzhou, Jiangsu 213003, P.R. China, Department of Otorhinolaryngology Head & Neck Surgery, Hospital of Jiangnan University, Wuxi, Jiangsu 214062, P.R. China
Published online on: February 28, 2017 https://doi.org/10.3892/mmr.2017.6252
Pages: 2289-2295

Metrics: Total Views: 0 (Spandidos Publications: | PMC Statistics: )

Metrics: Total PDF Downloads: 0 (Spandidos Publications: | PMC Statistics: )

Cited By (CrossRef): 0 citations Loading Articles...

Abstract

Inflammation in the retinal pigment epithelium is an important contributor to the pathogenesis of age-related macular degeneration. Wogonin is a flavonoid isolated from the root of Scutellaria baicalensis and has multiple pharmacological effects, including anti‑inflammatory effects. The present study sought to determine if the pharmacological effects of wogonin were relevant to the treatment of AMD. ARPE‑19 cells were pre‑conditioned with different concentrations of wogonin (0‑50 µM) prior to induction of inflammation with LPS (2 µg/ml). Transepithelial electrical resistance analysis demonstrated that 24 h treatment with 10 and 50 µM wogonin ameliorated LPS‑induced changes. Reverse transcription-quantitative polymerase chain reaction (RT‑qPCR) and immunoﬂuorescence analyses revealed that wogonin restrained LPS-induced tight junction proteins, claudin‑1 and ZO‑1. LPS‑induced upregulation of inflammatory mediators in ARPE‑19 cells, including IL‑1β, IL‑6, IL‑8, cyclooxygenase‑2 (COX‑2), inducible nitric oxide synthase (iNOS) and TNF‑α was reduced after pre-treatment with wogonin. In addition, RT‑qPCR and western blotting demonstrated that wogonin inhibited the expression of TLR4 in LPS‑stimulated ARPE‑19 cells. This is a novel mechanism indicating that pre‑treatment with wogonin could attenuate the TLR4/NF‑κB‑mediated inflammatory response in LPS‑stimulated ARPE‑19 cells, and thus could be a potential therapy for the treatment of AMD.

View Figures

View References

1	Lu L, Hackett SF, Mincey A, Lai H and Campochiaro PA: Effects of different types of oxidative stress in RPE cells. J Cell Physiol. 206:119–125. 2006. View Article : Google Scholar : PubMed/NCBI
2	Ding X, Patel M and Chan CC: Molecular pathology of age-related macular degeneration. Prog Retin Eye Res. 28:1–18. 2009. View Article : Google Scholar : PubMed/NCBI
3	Anderson DH, Mullins RF, Hageman GS and Johnson LV: A role for local inflammation in the formation of drusen in the aging eye. Am J Ophthalmol. 134:411–431. 2002. View Article : Google Scholar : PubMed/NCBI
4	Salminen A, Kauppinen A, Hyttinen JM, Toropainen E and Kaarniranta K: Endoplasmic reticulum stress in age-related macular degeneration: Trigger for neovascularization. Mol Med. 16:535–542. 2010. View Article : Google Scholar : PubMed/NCBI
5	Nowak JZ: Age-related macular degeneration (AMD): Pathogenesis and therapy. Pharmacol Rep. 58:353–363. 2006.PubMed/NCBI
6	Chen C, Cano M, Wang JJ, Li J, Huang C, Yu Q, Herbert TP, Handa JT and Zhang SX: Role of unfolded protein response dysregulation in oxidative injury of retinal pigment epithelial cells. Antioxid Redox Signal. 20:2091–2106. 2014. View Article : Google Scholar : PubMed/NCBI
7	Kucuksayan E, Konuk EK, Demir N, Mutus B and Aslan M: Neutral sphingomyelinase inhibition decreases ER stress-mediated apoptosis and inducible nitric oxide synthase in retinal pigment epithelial cells. Free Radic Biol Med. 72:113–123. 2014. View Article : Google Scholar : PubMed/NCBI
8	Strauss O: The retinal pigment epithelium in visual function. Physiol Rev. 85:845–881. 2005. View Article : Google Scholar : PubMed/NCBI
9	Yoshikawa T, Ogata N, Izuta H, Shimazawa M, Hara H and Takahashi K: Increased expression of tight junctions in ARPE-19 cells under endoplasmic reticulum stress. Curr Eye Res. 36:1153–1163. 2011. View Article : Google Scholar : PubMed/NCBI
10	Du M, Wu M, Fu D, Chen J, Wilson K and Lyons TJ: Effects of modified LDL and HDL on retinal pigment epithelial cells: A role in diabetic retinopathy? Diabetologia. 56:2318–2328. 2013. View Article : Google Scholar : PubMed/NCBI
11	Yeh CH, Yang ML, Lee CY, Li YC, Chen CJ and Kuan YH: Wogonin attenuates endotoxin-induced prostaglandin E2 and nitric oxide production via Src-ERK1/2-NFκB pathway in BV-2 microglial cells. Environ Toxicol. 29:1162–1170. 2014. View Article : Google Scholar : PubMed/NCBI
12	Gibbons HM and Dragunow M: Microglia induce neural cell death via a proximity-dependent mechanism involving nitric oxide. Brain Res. 1084:1–15. 2006. View Article : Google Scholar : PubMed/NCBI
13	Lu H, Gao F, Shu G, Xia G, Shao Z, Lu H and Cheng K: Wogonin inhibits the proliferation of myelodysplastic syndrome cells through the induction of cell cycle arrest and apoptosis. Mol Med Rep. 12:7285–7292. 2015.PubMed/NCBI
14	Piao HZ, Choi IY, Park JS, Kim HS, Cheong JH, Son KH, Jeon SJ, Ko KH and Kim WK: Wogonin inhibits microglial cell migration via suppression of nuclear factor-kappa B activity. Int Immunopharmacol. 8:1658–1662. 2008. View Article : Google Scholar : PubMed/NCBI
15	Lin CM, Chen YH, Ong JR, Ma HP, Shyu KG and Bai KJ: Functional role of wogonin in anti-angiogenesis. Am J Chin Med. 40:415–427. 2012. View Article : Google Scholar : PubMed/NCBI
16	Chi YS, Lim H, Park H and Kim HP: Effects of wogonin, a plant flavone from Scutellaria radix, on skin inflammation: In vivo regulation of inflammation-associated gene expression. Biochem Pharmacol. 66:1271–1278. 2003. View Article : Google Scholar : PubMed/NCBI
17	Lin CM, Chang H, Chen YH, Li SY, Wu IH and Chiu JH: Protective role of wogonin against lipopolysaccharide-induced angiogenesis via VEGFR-2, not VEGFR-1. Int Immunopharmacol. 6:1690–1698. 2006. View Article : Google Scholar : PubMed/NCBI
18	Burke JM: Epithelial phenotype and the RPE Is the answer blowing in the Wnt? Prog Retin Eye Res. 27:579–595. 2008. View Article : Google Scholar : PubMed/NCBI
19	Chen S, Xiong J, Zhan Y, Liu W and Wang X: Wogonin inhibits LPS-induced inflammatory responses in rat dorsal root ganglion neurons via inhibiting TLR4-MyD88-TAK1-mediated NF-κB and MAPK signaling pathway. Cell Mol Neurobiol. 35:523–531. 2015. View Article : Google Scholar : PubMed/NCBI
20	Chen F, Wu R, Zhu Z, Yin W, Xiong M, Sun J, Ni M, Cai G and Zhang X: Wogonin protects rat dorsal root ganglion neurons against tunicamycin-induced ER stress through the PERK-eIF2α-ATF4 signaling pathway. J Mol Neurosci. 55:995–1005. 2015. View Article : Google Scholar : PubMed/NCBI
21	Xu S, Zhao X, Zhao Q, Zheng Q, Fang Z, Yang X, Wang H, Liu P and Xu H: Wogonin prevents rat dorsal root ganglion neurons death via inhibiting tunicamycin-induced ER stress in vitro. Cell Mol Neurobiol. 35:389–398. 2015. View Article : Google Scholar : PubMed/NCBI
22	Wang W, Xia T and Yu X: Wogonin suppresses inflammatory response and maintains intestinal barrier function via TLR4-MyD88-TAK1-mediated NF-κB pathway in vitro. Inflamm Res. 64:423–431. 2015. View Article : Google Scholar : PubMed/NCBI
23	Livak KJ and Schmittgen TD: Analysis of relative gene expression data using real-time quantitative PCR and the 2(−Delta Delta C(T)) Method. Methods. 25:402–408. 2001. View Article : Google Scholar : PubMed/NCBI
24	Shen W, Gao Y, Lu B, Zhang Q, Hu Y and Chen Y: Negatively regulating TLR4/NF-κB signaling via PPARα in endotoxin-induced uveitis. Biochim Biophys Acta. 1842:1109–1120. 2014. View Article : Google Scholar : PubMed/NCBI
25	Paeng SH, Park WS, Jung WK, Lee DS, Kim GY, Choi YH, Seo SK, Jang WH, Choi JS, Lee YM, et al: YCG063 inhibits Pseudomonas aeruginosa LPS-induced inflammation in human retinal pigment epithelial cells through the TLR2-mediated AKT/NF-κB pathway and ROS-independent pathways. Int J Mol Med. 36:808–816. 2015.PubMed/NCBI
26	Mateos MV, Kamerbeek CB, Giusto NM and Salvador GA: The phospholipase D pathway mediates the inflammatory response of the retinal pigment epithelium. Int J Biochem Cell Biol. 55:119–128. 2014. View Article : Google Scholar : PubMed/NCBI
27	Breccia M and Alimena G: NF-κB as a potential therapeutic target in myelodysplastic syndromes and acute myeloid leukemia. Expert Opin Ther Targets. 14:1157–1176. 2010. View Article : Google Scholar : PubMed/NCBI
28	He X, Wei Z, Zhou E, Chen L, Kou J, Wang J and Yang Z: Baicalein attenuates inflammatory responses by suppressing TLR4 mediated NF-κB and MAPK signaling pathways in LPS-induced mastitis in mice. Int Immunopharmacol. 28:470–476. 2015. View Article : Google Scholar : PubMed/NCBI
29	Wardill HR, Van Sebille YZ, Mander KA, Gibson RJ, Logan RM, Bowen JM and Sonis ST: Toll-like receptor 4 signaling: A common biological mechanism of regimen-related toxicities: An emerging hypothesis for neuropathy and gastrointestinal toxicity. Cancer Treat Rev. 41:122–128. 2015. View Article : Google Scholar : PubMed/NCBI