scholarly journals Pyroptosis: A New Insight Into Eye Disease Therapy

2021 ◽  
Vol 12 ◽  
Author(s):  
Yun Zhang ◽  
Yan Jiao ◽  
Xun Li ◽  
Sheng Gao ◽  
Nenghua Zhou ◽  
...  

Pyroptosis is a lytic form of programmed cell death mediated by gasdermins (GSDMs) with pore-forming activity in response to certain exogenous and endogenous stimuli. The inflammasomes are intracellular multiprotein complexes consisting of pattern recognition receptors, an adaptor protein ASC (apoptosis speck-like protein), and caspase-1 and cause autocatalytic activation of caspase-1, which cleaves gasdermin D (GSDMD), inducing pyroptosis accompanied by cytokine release. In recent years, the pathogenic roles of inflammasomes and pyroptosis in multiple eye diseases, including keratitis, dry eyes, cataracts, glaucoma, uveitis, age-related macular degeneration, and diabetic retinopathy, have been continuously confirmed. Inhibiting inflammasome activation and abnormal pyroptosis in eyes generally attenuates inflammation and benefits prognosis. Therefore, insight into the pathogenesis underlying pyroptosis and inflammasome development in various types of eye diseases may provide new therapeutic strategies for ocular disorders. Inhibitors of pyroptosis, such as NLRP3, caspase-1, and GSDMD inhibitors, have been proven to be effective in many eye diseases. The purpose of this article is to illuminate the mechanism underlying inflammasome activation and pyroptosis and emphasize its crucial role in various ocular disorders. In addition, we review the application of pyroptosis modulators in eye diseases.

Antioxidants ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 67
Author(s):  
Niina Bhattarai ◽  
Niina Piippo ◽  
Sofia Ranta-aho ◽  
Yashavanthi Mysore ◽  
Kai Kaarniranta ◽  
...  

Age-related macular degeneration (AMD) is an eye disease in which retinal pigment epithelium (RPE) cells play a crucial role in maintaining retinal homeostasis and photoreceptors’ functionality. During disease progression, there is increased inflammation with nucleotide-binding domain, leucine-rich repeat, and Pyrin domain 3 (NLRP3) inflammasome activation, oxidative stress, and impaired autophagy in RPE cells. Previously, we have shown that the dietary supplement Resvega reduces reactive oxygen species (ROS) production and induces autophagy in RPE cells. Here, we investigated the ability of Resvega to prevent NLRP3 inflammasome activation with impaired protein clearance in human RPE cells. Cell viability was measured using the lactate dehydrogenase (LDH) and the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays. Enzyme-linked immunosorbent assays (ELISA) were utilized to determine the secretion of cytokines, NLRP3, and vascular endothelial growth factor (VEGF). Caspase-1 activity was measured with a fluorescent labeled inhibitor of caspase-1 (FLICA; FAM-YVAD-FMK) and detected microscopically. Resvega improved the cell membrane integrity, which was evident as reduced LDH leakage from cells. In addition, the caspase-1 activity and NLRP3 release were reduced, as was the secretion of two inflammatory cytokines, interleukin (IL)-1β and IL-8, in IL-1α-primed ARPE-19 cells. According to our results, Resvega can potentially reduce NLRP3 inflammasome-mediated inflammation in RPE cells with impaired protein clearance.


Antioxidants ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 25
Author(s):  
Lara Macchioni ◽  
Davide Chiasserini ◽  
Letizia Mezzasoma ◽  
Magdalena Davidescu ◽  
Pier Luigi Orvietani ◽  
...  

Age-related retinal degenerations, including age-related macular degeneration (AMD), are caused by the loss of retinal pigmented epithelial (RPE) cells and photoreceptors. The pathogenesis of AMD, deeply linked to the aging process, also involves oxidative stress and inflammatory responses. However, the molecular mechanisms contributing to the shift from healthy aging to AMD are still poorly understood. Since RPE cells in the retina are chronically exposed to a pro-oxidant microenvironment throughout life, we simulated in vivo conditions by growing ARPE-19 cells in the presence of 10 μM H2O2 for several passages. This long-term oxidative insult induced senescence in ARPE-19 cells without affecting cell proliferation. Global proteomic analysis revealed a dysregulated expression in proteins involved in antioxidant response, mitochondrial homeostasis, and extracellular matrix organization. The analyses of mitochondrial functionality showed increased mitochondrial biogenesis and ATP generation and improved response to oxidative stress. The latter, however, was linked to nuclear factor-κB (NF-κB) rather than nuclear factor erythroid 2–related factor 2 (Nrf2) activation. NF-κB hyperactivation also resulted in increased pro-inflammatory cytokines expression and inflammasome activation. Moreover, in response to additional pro-inflammatory insults, senescent ARPE-19 cells underwent an exaggerated inflammatory reaction. Our results indicate senescence as an important link between chronic oxidative insult and detrimental chronic inflammation, with possible future repercussions for therapeutic interventions.


2021 ◽  
Vol 22 (13) ◽  
pp. 6800
Author(s):  
Maria Hytti ◽  
Eveliina Korhonen ◽  
Heidi Hongisto ◽  
Kai Kaarniranta ◽  
Heli Skottman ◽  
...  

Inflammation is a key underlying factor of age-related macular degeneration (AMD) and inflammasome activation has been linked to disease development. Induced pluripotent stem-cell-derived retinal pigment epithelial cells (iPSC-RPE) are an attractive novel model system that can help to further elucidate disease pathways of this complex disease. Here, we analyzed the effect of dysfunctional protein clearance on inflammation and inflammasome activation in iPSC-RPE cells generated from a patient suffering from age-related macular degeneration (AMD) and an age-matched control. We primed iPSC-RPE cells with IL-1α and then inhibited both proteasomal degradation and autophagic clearance using MG-132 and bafilomycin A1, respectively, causing inflammasome activation. Subsequently, we determined cell viability, analyzed the expression levels of inflammasome-related genes using a PCR array, and measured the levels of pro-inflammatory cytokines IL-1β, IL-6, IL-8, and MCP-1 secreted into the medium. Cell treatments modified the expression of 48 inflammasome-related genes and increased the secretion of mature IL-1β, while reducing the levels of IL-6 and MCP-1. Interestingly, iPSC-RPE from an AMD donor secreted more IL-1β and expressed more Hsp90 prior to the inhibition of protein clearance, while MCP-1 and IL-6 were reduced at both protein and mRNA levels. Overall, our results suggest that cellular clearance mechanisms might already be dysfunctional, and the inflammasome activated, in cells with a disease origin.


Author(s):  
Luciano Mesquite Simmo ◽  
Carissa Fouad Ibrahim ◽  
Senice Alvarenga Rodrigues Silva ◽  
Thai Nunes Andrade ◽  
Doora Faleiros Leite ◽  
...  

Objective: To compare the vision-targeted health related quality of life (HRQOL) between neuro-ophthalmological patients and other eye diseases by the National Eye Institute 25-Item Visual Function Questionnaire. Methods: Cross sectional study with a control group and patients with the following pathologies: primary open-angle glaucoma (POAG), diabetic retinopathy (DR), age-related macular degeneration (ARMD), non-arteritic ischemic optic neuropathy (NAION), intracranial hypertension (IH), optic neuritis (ON), ptosis and cataract. Results: All comparisons of the subscales scores among the control group and the patient groups were statistically significant (p<0.05) except for “ocular pain” (p=0.160), “social functioning” (p=0.052) and “peripheral vision” (p=0.112). The control group had the best scores across all dimensions of the NEI VFQ-25. Interestingly, the ARMD and cataract groups presented the best and worst total scores of NEI VFQ-25, respectively. The lowest subscales scores were found in the cataract, in the NAION/ON, and in the POAG groups. Finally, the comparison between the NAION/ON/IH patients and the other eye diseases did not show statistical significance in any subscale. Conclusion: The NEI VFQ-25 showed the impact of various eye conditions in vision-targeted HRQOL, and no difference was measured between neuro-ophthalmological patients and other eye diseases


Author(s):  
Tayo Julius Bogunjoko ◽  
Adekunle O. Hassan ◽  
Adunola Ogunro ◽  
Toyin Akanbi ◽  
Bidemi Abudu

Background: To review cases of posterior segment eye diseases (PSEDs) seen at the Eye Foundation Centre Ijebu, Nigeria in a 5 year period for planning purposes.Methods: Data was collected from patients’ case notes from January 2006 to December 2011. A systematic sampling of 468 patients from 1173 case notes of patient with (PSEDs) was done. Information retrieved was: age, sex, state of residence and diagnosis. All patients were examined by the glaucoma and the vitroretinal specialist as the case may be. They had visual acuity, refraction, slit lamp examination (including intraocular pressure (IOP) with Goldman applanation tonometer), and dilated fundoscopy with (bilateral indirect ophthalmoscopy) BIO, slit lamp using 20 D, 78 D and 90 D respectively. The glaucoma patients in addition had central visual field (CVF), Central cornea thickness (CCT), fundus photograph and in some cases optical coherence tomography (OCT) done in addition to the above.Results: The mean age was 59.98 years (SD 17.67) and the age range is 5-95 years. Males outnumbered females by 63% to 37%. The diseases were more common in age group 61 to 80. Patients’ attendances were mostly from Ijebu division of Ogun state (57%). Glaucoma is the commonest cause of attendance 262 (56%) followed by diabetic retinopathy 29 (6.2%) and age-related macular degeneration (ARMD) 28 (6.0%).Conclusions: Glaucoma, diabetic retinopathy and ARMD were noted as the commonest PSEDs in Ijebu division in Southwestern Nigeria.


2021 ◽  
Vol 22 (19) ◽  
pp. 10279
Author(s):  
Gabriella D. Hartman ◽  
Nathan A. Lambert-Cheatham ◽  
Mark R. Kelley ◽  
Timothy W. Corson

Proliferative diabetic retinopathy (PDR), neovascular age-related macular degeneration (nvAMD), retinopathy of prematurity (ROP) and other eye diseases are characterized by retinal and/or choroidal neovascularization, ultimately causing vision loss in millions of people worldwide. nvAMD and PDR are associated with aging and the number of those affected is expected to increase as the global median age and life expectancy continue to rise. With this increase in prevalence, the development of novel, orally bioavailable therapies for neovascular eye diseases that target multiple pathways is critical, since current anti-vascular endothelial growth factor (VEGF) treatments, delivered by intravitreal injection, are accompanied with tachyphylaxis, a high treatment burden and risk of complications. One potential target is apurinic/apyrimidinic endonuclease 1/reduction-oxidation factor 1 (APE1/Ref-1). The multifunctional protein APE1/Ref-1 may be targeted via inhibitors of its redox-regulating transcription factor activation activity to modulate angiogenesis, inflammation, oxidative stress response and cell cycle in neovascular eye disease; these inhibitors also have neuroprotective effects in other tissues. An APE1/Ref-1 small molecule inhibitor is already in clinical trials for cancer, PDR and diabetic macular edema. Efforts to develop further inhibitors are underway. APE1/Ref-1 is a novel candidate for therapeutically targeting neovascular eye diseases and alleviating the burden associated with anti-VEGF intravitreal injections.


2021 ◽  
Vol 14 (8) ◽  
pp. 1260-1273
Author(s):  
Zi-Yan Cai ◽  
◽  
Ke Liu ◽  
Xuan-Chu Duan ◽  
◽  
...  

Age-related eye diseases, including cataract, glaucoma, diabetic retinopathy (DR), and age-related macular degeneration (AMD), are the leading causes of vision loss in the world. Several studies have shown that the occurrence and development of these diseases have an important relationship with oxidative stress in the eye. The Keap1-Nrf2-ARE pathway is a classical pathway that resists oxidative stress and inflammation in the body. This pathway is also active in the development of age-related eye diseases. A variety of drugs have been shown to treat age-related eye diseases through the Keap1-Nrf2-ARE (Kelch-like ECH-Associating protein 1- nuclear factor erythroid 2 related factor 2-antioxidant response element) pathway. This review describes the role of oxidative stress in the development of age-related eye diseases, the function and regulation of the Keap1-Nrf2-ARE pathway, and the therapeutic effects of drugs associated with this pathway on age-related eye diseases.


2011 ◽  
Vol 52 (1) ◽  
pp. 93 ◽  
Author(s):  
Anna Machalinska ◽  
Krzysztof Safranow ◽  
Violetta Dziedziejko ◽  
Katarzyna Mozolewska-Piotrowska ◽  
Edyta Paczkowska ◽  
...  

2021 ◽  
Vol 21 ◽  
Author(s):  
Hui Zhang ◽  
Xiaomin Zhang ◽  
Xiaorong Li

: Exosomes, nanosized extracellular vesicles with a size of 30–150nm, contain many biological materials, such as messenger RNA (mRNA), microRNA (miRNA), proteins, and transcription factors. It has been identified in all biological fluids and recognized as an important part of intercellular communication. While the role of exosomes in cancer has been studied in-depth, our understanding of their relevance for ocular tissues has just begun to evolve. Intraocular fluids, including aqueous humor and vitreous humor, play a role in nourishing eye tissues and in expelling metabolites. In the pathological state, intraocular exosomes can mediate pathological processes such as ECM remodeling, retinal inflammation, and blood-retinal barrier dysfunction. Herein, we reviewed the latest advances of intraocular exosomes in the research of several eye diseases, including glaucoma, age-related macular degeneration, myopia, and ocular tumors, and discuss how intraocular exosomes contribute to the pathogenesis and progression of multiple eye diseases.


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