scholarly journals Sirtuins Expression and Their Role in Retinal Diseases

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Sankarathi Balaiya ◽  
Khaled K. Abu-Amero ◽  
Altaf A. Kondkar ◽  
Kakarla V. Chalam

Sirtuins have received considerable attention since the discovery that silent information regulator 2 (Sir2) extends the lifespan of yeast. Sir2, a nicotinamide adenine dinucleotide- (NAD-) dependent histone deacetylase, serves as both a transcriptional effector and energy sensor. Oxidative stress and apoptosis are implicated in the pathogenesis of neurodegenerative eye diseases. Sirtuins confer protection against oxidative stress and retinal degeneration. In mammals, the sirtuin (SIRT) family consists of seven proteins (SIRT1–SIRT7). These vary in tissue specificity, subcellular localization, and enzymatic activity and targets. In this review, we present the current knowledge of the sirtuin family and discuss their structure, cellular location, and biological function with a primary focus on their role in different neuroophthalmic diseases including glaucoma, optic neuritis, and age-related macular degeneration. The potential role of certain therapeutic targets is also described.

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Rawshan Choudhury ◽  
Nadhim Bayatti ◽  
Richard Scharff ◽  
Ewa Szula ◽  
Viranga Tilakaratna ◽  
...  

AbstractRetinal pigment epithelial (RPE) cells that underlie the neurosensory retina are essential for the maintenance of photoreceptor cells and hence vision. Interactions between the RPE and their basement membrane, i.e. the inner layer of Bruch’s membrane, are essential for RPE cell health and function, but the signals induced by Bruch’s membrane engagement, and their contributions to RPE cell fate determination remain poorly defined. Here, we studied the functional role of the soluble complement regulator and component of Bruch’s membrane, Factor H-like protein 1 (FHL-1). Human primary RPE cells adhered to FHL-1 in a manner that was eliminated by either mutagenesis of the integrin-binding RGD motif in FHL-1 or by using competing antibodies directed against the α5 and β1 integrin subunits. These short-term experiments reveal an immediate protein-integrin interaction that were obtained from primary RPE cells and replicated using the hTERT-RPE1 cell line. Separate, longer term experiments utilising RNAseq analysis of hTERT-RPE1 cells bound to FHL-1, showed an increased expression of the heat-shock protein genes HSPA6, CRYAB, HSPA1A and HSPA1B when compared to cells bound to fibronectin (FN) or laminin (LA). Pathway analysis implicated changes in EIF2 signalling, the unfolded protein response, and mineralocorticoid receptor signalling as putative pathways. Subsequent cell survival assays using H2O2 to induce oxidative stress-induced cell death suggest hTERT-RPE1 cells had significantly greater protection when bound to FHL-1 or LA compared to plastic or FN. These data show a non-canonical role of FHL-1 in protecting RPE cells against oxidative stress and identifies a novel interaction that has implications for ocular diseases such as age-related macular degeneration.


2021 ◽  
Vol 22 (3) ◽  
pp. 1296
Author(s):  
Yue Ruan ◽  
Subao Jiang ◽  
Adrian Gericke

Age-related macular degeneration (AMD) is a common irreversible ocular disease characterized by vision impairment among older people. Many risk factors are related to AMD and interact with each other in its pathogenesis. Notably, oxidative stress and choroidal vascular dysfunction were suggested to be critically involved in AMD pathogenesis. In this review, we give an overview on the factors contributing to the pathophysiology of this multifactorial disease and discuss the role of reactive oxygen species and vascular function in more detail. Moreover, we give an overview on therapeutic strategies for patients suffering from AMD.


2020 ◽  
Vol 21 (3) ◽  
pp. 1021 ◽  
Author(s):  
Carlota Suárez-Barrio ◽  
Susana del Olmo-Aguado ◽  
Eva García-Pérez ◽  
María de la Fuente ◽  
Francisco Muruzabal ◽  
...  

Oxidative stress has a strong impact on the development of retinal diseases such as age-related macular degeneration (AMD). Plasma rich in growth factors (PRGF) is a novel therapeutic approach in ophthalmological pathologies. The aim of this study was to analyze the antioxidant effect of PRGF in retinal epithelial cells (EPR) in in vitro and ex vivo retinal phototoxicity models. In vitro analyses were performed on ARPE19 human cell line. Viability and mitochondrial status were assessed in order to test the primary effects of PRGF. GSH level, and protein and gene expression of the main antioxidant pathway (Keap1, Nrf2, GCL, HO-1, and NQO1) were also studied. Ex vivo analyses were performed on rat RPE, and HO-1 and Nrf2 gene and protein expression were evaluated. The results show that PRGF reduces light insult by stimulating the cell response against oxidative damage and modulates the antioxidant pathway. We conclude that PRGF’s protective effect could prove useful as a new therapy for treating neurodegenerative disorders such as AMD.


Planta Medica ◽  
2019 ◽  
Vol 85 (17) ◽  
pp. 1292-1303 ◽  
Author(s):  
Isabel Martínez-Solís ◽  
Nuria Acero ◽  
Francisco Bosch-Morell ◽  
Encarna Castillo ◽  
María Eugenia González-Rosende ◽  
...  

AbstractLike other tissues of the central nervous system, the retina is susceptible to damage by oxidative processes that result in several neurodegenerative disease such as age-related macular degeneration, diabetic retinopathy, glaucoma, ischaemic retinal disease, retinal disease produced by light oxidation, and detached retina, among other diseases. The use of antioxidant substances is a solution to some health problems caused by oxidative stress, because they regulate redox homeostasis and reduce oxidative stress. This is important for neurodegeneration linked to oxidation processes. In line with this, Ginkgo biloba is a medicinal plant with excellent antioxidant properties whose effects have been demonstrated in several degenerative processes, including retinal diseases associated with neurodegeneration. This review describes the current literature on the role of ginkgo in retinal diseases associated with neurodegeneration. The information leads to the conclusion that G. biloba extracts might be a good option to improve certain neurodegenerative retinal diseases, but more research is needed to determine the safety and efficacy of G. biloba in these retinal degenerative processes.


2020 ◽  
Author(s):  
Rawshan Choudhury ◽  
Nadhim Bayatti ◽  
Richard Scharff ◽  
Ewa Szula ◽  
Viranga Tilakaratna ◽  
...  

AbstractRetinal pigment epithelial (RPE) cells that underlie the neurosensory retina are essential for the maintenance of photoreceptor cells and hence vision. Interactions between the RPE and their basement membrane, i.e. the inner layer of Bruch’s membrane, are essential for RPE cell health and function, but the signals induced by Bruch’s membrane engagement, and their contributions to RPE cell fate determination remain poorly defined. Here, we studied the functional role of the soluble complement regulator and component of Bruch’s membrane, Factor H-like protein 1 (FHL-1). Human primary RPE cells adhered to FHL-1 in a manner that was eliminated by either mutagenesis of the integrin-binding RGD motif in FHL-1 or by using competing antibodies directed against the α5 and β1 integrin subunits. The results obtained from primary RPE cells were replicated using the hTERT-RPE cell line. RNAseq expression analysis of hTERT-RPE cells bound to FHL-1 showed an increased expression of the heat-shock protein genes HSPA6, CRYAB, HSPA1A and HSPA1B when compared to cells bound to fibronectin (FN) or laminin (LA). Pathway analysis implicated changes in EIF2 signalling, the unfolded protein response, and mineralocorticoid receptor signalling as putative pathways. Subsequent cell survival assays using H2O2 to induce oxidative stress-induced cell death showed hTERT-RPE cells had significantly greater protection when bound to FHL-1 or LA compared to plastic or FN. These data show a non-canonical role of FHL-1 in protecting RPE cells against oxidative stress and identifies a novel interaction that has implications for ocular diseases such as age-related macular degeneration.


2019 ◽  
Vol 20 (14) ◽  
pp. 3578 ◽  
Author(s):  
Ioana-Sandra Tarau ◽  
Andreas Berlin ◽  
Christine A. Curcio ◽  
Thomas Ach

The retinal pigment epithelium (RPE) is a unique epithelium, with major roles which are essential in the visual cycle and homeostasis of the outer retina. The RPE is a monolayer of polygonal and pigmented cells strategically placed between the neuroretina and Bruch membrane, adjacent to the fenestrated capillaries of the choriocapillaris. It shows strong apical (towards photoreceptors) to basal/basolateral (towards Bruch membrane) polarization. Multiple functions are bound to a complex structure of highly organized and polarized intracellular components: the cytoskeleton. A strong connection between the intracellular cytoskeleton and extracellular matrix is indispensable to maintaining the function of the RPE and thus, the photoreceptors. Impairments of these intracellular structures and the regular architecture they maintain often result in a disrupted cytoskeleton, which can be found in many retinal diseases, including age-related macular degeneration (AMD). This review article will give an overview of current knowledge on the molecules and proteins involved in cytoskeleton formation in cells, including RPE and how the cytoskeleton is affected under stress conditions—especially in AMD.


Antioxidants ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 920
Author(s):  
Ayana Suzumura ◽  
Ryo Terao ◽  
Hiroki Kaneko

Oxidative stress and inflammation play crucial roles in the development and progression of retinal diseases. Retinal damage by various etiologies can result in retinopathy of prematurity (ROP), diabetic retinopathy (DR), and age-related macular degeneration (AMD). n-3 fatty acids are essential fatty acids and are necessary for homeostasis. They are important retinal membrane components and are involved in energy storage. n-3 fatty acids also have antioxidant and anti-inflammatory properties, and their suppressive effects against ROP, DR, and AMD have been previously evaluated. α-linolenic acid (ALA), eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and their metabolites have been shown to alleviate retinal oxidative stress and inflammation involving various biological signaling pathways. In this review, we summarize the current understanding of the n-3 fatty acids effects on the mechanisms of these retinal diseases and how they exert their therapeutic effects, focusing on ALA, EPA, DHA, and their metabolites. This knowledge may provide new remedial strategies for n-3 fatty acids in the prevention and treatment of retinal diseases associated with oxidative stress and inflammation.


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