scholarly journals 4-(Phenylsulfanyl) Butan-2-One Attenuates the Inflammatory Response Induced by Amyloid-β Oligomers in Retinal Pigment Epithelium Cells

Marine Drugs ◽  
2020 ◽  
Vol 19 (1) ◽  
pp. 1
Author(s):  
Peeraporn Varinthra ◽  
Shun-Ping Huang ◽  
Supin Chompoopong ◽  
Zhi-Hong Wen ◽  
Ingrid Y. Liu

Age-related macular degeneration (AMD) is a progressive eye disease that causes irreversible impairment of central vision, and effective treatment is not yet available. Extracellular accumulation of amyloid-beta (Aβ) in drusen that lie under the retinal pigment epithelium (RPE) has been reported as one of the early signs of AMD and was found in more than 60% of Alzheimer’s disease (AD) patients. Extracellular deposition of Aβ can induce the expression of inflammatory cytokines such as IL-1β, TNF-α, COX-2, and iNOS in RPE cells. Thus, finding a compound that can effectively reduce the inflammatory response may help the treatment of AMD. In this research, we investigated the anti-inflammatory effect of the coral-derived compound 4-(phenylsulfanyl) butan-2-one (4-PSB-2) on Aβ1-42 oligomer (oAβ1-42) added to the human adult retinal pigment epithelial cell line (ARPE-19). Our results demonstrated that 4-PSB-2 can decrease the elevated expressions of TNF-α, COX-2, and iNOS via NF-κB signaling in ARPE-19 cells treated with oAβ1-42 without causing any cytotoxicity or notable side effects. This study suggests that 4-PSB-2 is a promising drug candidate for attenuation of AMD.

2021 ◽  
Vol 22 (16) ◽  
pp. 8387
Author(s):  
Alexa Klettner ◽  
Johann Roider

(1) Background: Inflammation is a major pathomechanism in the development and progression of age-related macular degeneration (AMD). The retinal pigment epithelium (RPE) may contribute to retinal inflammation via activation of its Toll-like receptors (TLR). TLR are pattern recognition receptors that detect the pathogen- or danger-associated molecular pattern. The involvement of TLR activation in AMD is so far not understood. (2) Methods: We performed a systematic literature research, consulting the National Library of Medicine (PubMed). (3) Results: We identified 106 studies, of which 54 were included in this review. Based on these studies, the current status of TLR in AMD, the effects of TLR in RPE activation and of the interaction of TLR activated RPE with monocytic cells are given, and the potential of TLR activation in RPE as part of the AMD development is discussed. (4) Conclusion: The activation of TLR2, -3, and -4 induces a profound pro-inflammatory response in the RPE that may contribute to (long-term) inflammation by induction of pro-inflammatory cytokines, reducing RPE function and causing RPE cell degeneration, thereby potentially constantly providing new TLR ligands, which could perpetuate and, in the long run, exacerbate the inflammatory response, which may contribute to AMD development. Furthermore, the combined activation of RPE and microglia may exacerbate neurotoxic effects.


2020 ◽  
Author(s):  
YiFan Hu ◽  
JieQiong Chen ◽  
JunRan Sun ◽  
YuWei Wang ◽  
PeiRong Huang ◽  
...  

Abstract Background Amyloid-β (Aβ), a component of age-related macular degeneration (AMD) hallmark drusen, induces retinal pigment epithelium (RPE) cell degeneration and promotes the progress of AMD. Evidence shows that epigenetics mechanism is involved in the regulation of AMD. In this study, we aimed to investigate the roles of N6-methyladenosine (m6A) and its demethylase the fat mass and obesity-associated gene (FTO) in Aβ-mediated degeneration. Methods The molecular characteristics and morphology of FTO were examined by quantitative Real-Time PCR (qRT-PCR), Western blot and immunofluorescence. Inhibition of FTO was conducted to analyze its function on cell survival. Ocular Coherence Tomography and Fundus Photography was performed to evaluate the fundus of animal models. m6A-mRNA Epi-transcriptomic microarray, bioinformatics analysis and experimental verification were used to explore the potential molecular mechanism and signaling pathway. Results We found overexpression of FTO in Aβ model and demonstrated that inhibition of FTO by the sodium form of Meclofenamic acid (MA1) aggravated RPE impairment. Mechanistically, we identified protein kinase A (PKA) as FTO’s mediating target and found that FTO epigenetically demethylated PKA mRNA and decreased PKA expression, leading to suppressed PKA/ cyclin AMP-responsive element binding (CREB) signaling pathway. Moreover, inhibition of FTO promoted PKA/CREB signaling pathway inducing greater RPE degeneration and death. Conclusions These data demonstrated the functional significance of FTO in Aβ-induced RPE degeneration and the regulatory mechanism of PKA/CREB signaling pathway, implying FTO as a potentially therapeutic target for AMD.


2021 ◽  
Vol 6 (1) ◽  
pp. e000774
Author(s):  
Minwei Wang ◽  
Shiqi Su ◽  
Shaoyun Jiang ◽  
Xinghuai Sun ◽  
Jiantao Wang

Age-related macular degeneration (AMD) is the most common eye disease in elderly patients, which could lead to irreversible vision loss and blindness. Increasing evidence indicates that amyloid β-peptide (Aβ) might be associated with the pathogenesis of AMD. In this review, we would like to summarise the current findings in this field. The literature search was done from 1995 to Feb, 2021 with following keywords, ‘Amyloid β-peptide and age-related macular degeneration’, ‘Inflammation and age-related macular degeneration’, ‘Angiogenesis and age-related macular degeneration’, ‘Actin cytoskeleton and amyloid β-peptide’, ‘Mitochondrial dysfunction and amyloid β-peptide’, ‘Ribosomal dysregulation and amyloid β-peptide’ using search engines Pubmed, Google Scholar and Web of Science. Aβ congregates in subretinal drusen of patients with AMD and participates in the pathogenesis of AMD through enhancing inflammatory activity, inducing mitochondrial dysfunction, altering ribosomal function, regulating the lysosomal pathway, affecting RNA splicing, modulating angiogenesis and modifying cell structure in AMD. The methods targeting Aβ are shown to inhibit inflammatory signalling pathway and restore the function of retinal pigment epithelium cells and photoreceptor cells in the subretinal region. Targeting Aβ may provide a novel therapeutic strategy for AMD.


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