Anti-inflammatory properties of antiangiogenic fucoidan in retinal pigment epithelium cells

Philipp Dörschmann; Charlotte Seeba; Tabea Thalenhorst; Johann Roider; Alexa Klettner

doi:10.1016/j.heliyon.2023.e15202

Anti-inflammatory properties of antiangiogenic fucoidan in retinal pigment epithelium cells

Heliyon. 2023 Apr 10;9(4):e15202. doi: 10.1016/j.heliyon.2023.e15202. eCollection 2023 Apr.

Authors

Philipp Dörschmann¹, Charlotte Seeba¹, Tabea Thalenhorst¹, Johann Roider¹, Alexa Klettner¹

Affiliation

¹ Kiel University, University Medical Center, Department of Ophthalmology, Arnold-Heller-Str. 3, Haus B2, 24105 Kiel, Germany.

Abstract

Age-related macular degeneration (AMD) is a multifactorial disease in which angiogenesis, oxidative stress and inflammation are important contributing factors. In this study, we investigated the anti-inflammatory effects of a fucoidan from the brown algae Fucus vesiculosus (FV) in primary porcine RPE cells. Inflammation was induced by lipopolysaccharide (LPS), polyinosinic:polycytidylic acid (Poly I:C), Pam2CSK4 (Pam), or tumor necrosis factor alpha (TNF-α). Cell viability was tested with thiazolyl blue tetrazolium bromide (MTT) test, barrier function by measuring transepithelial electric resistance (TEER), interleukin 6 (IL-6) and interleukin 8 (IL-8) secretion in ELISA, retinal pigment epithelium-specific 65 kDa protein (RPE65) and protectin (CD59) expression in Western blot, gene expression with quantitative polymerase chain reaction (qPCR) (IL6, IL8, MERTK, PIK3CA), and phagocytotic activity in a microscopic assay. FV fucoidan did not influence RPE cell viability. FV fucoidan reduced the Poly I:C proinflammatory cytokine secretion of IL-6 and IL-8. In addition, it decreased the expression of IL-6 and IL-8 in RT-PCR. LPS and TNF-α reduced the expression of CD59 in Western blot, this reduction was lost under FV fucoidan treatment. Also, LPS and TNF-α reduced the expression of visual cycle protein RPE65, this reduction was again lost under FV fucoidan treatment. Furthermore, the significant reduction of barrier function after Poly I:C stimulation is ameliorated by FV fucoidan. Concerning phagocytosis, however, the inflammation-induced reduction was not improved by FV fucoidan. FV and proinflammatory milieu did not relevantly influence phagocytosis relevant gene expression either. In conclusion, we show that fucoidan from FV can reduce proinflammatory stimulation in RPE induced by toll-like receptor 3 (TLR-3) activation and is of high interest as a potential compound for early AMD treatment.

Keywords: Age-related macular degeneration; Fucoidan; Inflammation; Interleukin 6; Poly I:C; Retinal pigment epithelium; Toll-like receptor 3.