scholarly journals Cellular Senescence in Age-Related Macular Degeneration: Can Autophagy and DNA Damage Response Play a Role?

2017 ◽  
Vol 2017 ◽  
pp. 1-15 ◽  
Author(s):  
Janusz Blasiak ◽  
Malgorzata Piechota ◽  
Elzbieta Pawlowska ◽  
Magdalena Szatkowska ◽  
Ewa Sikora ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Dna Damage ◽  
Macular Degeneration ◽  
Dna Damage Response ◽  
Cellular Senescence ◽  
Cell Senescence ◽  
Age Related Macular Degeneration ◽  
Rpe Cells ◽  
Age Related ◽  
Damage Response

Age-related macular degeneration (AMD) is the main reason of blindness in developed countries. Aging is the main AMD risk factor. Oxidative stress, inflammation and some genetic factors play a role in AMD pathogenesis. AMD is associated with the degradation of retinal pigment epithelium (RPE) cells, photoreceptors, and choriocapillaris. Lost RPE cells in the central retina can be replaced by their peripheral counterparts. However, if they are senescent, degenerated regions in the macula cannot be regenerated. Oxidative stress, a main factor of AMD pathogenesis, can induce DNA damage response (DDR), autophagy, and cell senescence. Moreover, cell senescence is involved in the pathogenesis of many age-related diseases. Cell senescence is the state of permanent cellular division arrest and concerns only mitotic cells. RPE cells, although quiescent in the retina, can proliferate in vitro. They can also undergo oxidative stress-induced senescence. Therefore, cellular senescence can be considered as an important molecular pathway of AMD pathology, resulting in an inability of the macula to regenerate after degeneration of RPE cells caused by a factor inducing DDR and autophagy. It is too early to speculate about the role of the mutual interplay between cell senescence, autophagy, and DDR, but this subject is worth further studies.

scholarly journals Potential of Telomerase in Age-Related Macular Degeneration—Involvement of Senescence, DNA Damage Response and Autophagy and a Key Role of PGC-1α

2021 ◽  
Vol 22 (13) ◽  
pp. 7194
Author(s):  
Janusz Blasiak ◽  
Joanna Szczepanska ◽  
Michal Fila ◽  
Elzbieta Pawlowska ◽  
Kai Kaarniranta
Keyword(s):  
Dna Damage ◽  
Macular Degeneration ◽  
Dna Damage Response ◽  
Vision Loss ◽  
Retinal Pigment ◽  
Ectopic Expression ◽  
Age Related Macular Degeneration ◽  
Rpe Cells ◽  
Age Related ◽  
Damage Response

Age-related macular degeneration (AMD), the main cause of vision loss in the elderly, is associated with oxidation in the retina cells promoting telomere attrition. Activation of telomerase was reported to improve macular functions in AMD patients. The catalytic subunit of human telomerase (hTERT) may directly interact with proteins important for senescence, DNA damage response, and autophagy, which are impaired in AMD. hTERT interaction with mTORC1 (mTOR (mechanistic target of rapamycin) complex 1) and PINK1 (PTEN-induced kinase 1) activates macroautophagy and mitophagy, respectively, and removes cellular debris accumulated over AMD progression. Ectopic expression of telomerase in retinal pigment epithelium (RPE) cells lengthened telomeres, reduced senescence, and extended their lifespan. These effects provide evidence for the potential of telomerase in AMD therapy. Peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) may be involved in AMD pathogenesis through decreasing oxidative stress and senescence, regulation of vascular endothelial growth factor (VEGF), and improving autophagy. PGC-1α and TERT form an inhibitory positive feedback loop. In conclusion, telomerase activation and its ectopic expression in RPE cells, as well as controlled clinical trials on the effects of telomerase activation in AMD patients, are justified and should be assisted by PGC-1α modulators to increase the therapeutic potential of telomerase in AMD.

scholarly journals PGC-1α Protects RPE Cells of the Aging Retina against Oxidative Stress-Induced Degeneration through the Regulation of Senescence and Mitochondrial Quality Control. The Significance for AMD Pathogenesis

2018 ◽  
Vol 19 (8) ◽  
pp. 2317 ◽  
Author(s):  
Kai Kaarniranta ◽  
Jakub Kajdanek ◽  
Jan Morawiec ◽  
Elzbieta Pawlowska ◽  
Janusz Blasiak
Keyword(s):  
Oxidative Stress ◽  
Cellular Senescence ◽  
Mitochondrial Biogenesis ◽  
Vision Loss ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Sirtuin 1 ◽  
Age Related Macular Degeneration ◽  
Rpe Cells ◽  
Age Related

PGC-1α (peroxisome proliferator-activated receptor gamma coactivator 1-alpha) is a transcriptional coactivator of many genes involved in energy management and mitochondrial biogenesis. PGC-1α expression is associated with cellular senescence, organismal aging, and many age-related diseases, including AMD (age-related macular degeneration), an important global issue concerning vision loss. We and others have developed a model of AMD pathogenesis, in which stress-induced senescence of retinal pigment epithelium (RPE) cells leads to AMD-related pathological changes. PGC-1α can decrease oxidative stress, a key factor of AMD pathogenesis related to senescence, through upregulation of antioxidant enzymes and DNA damage response. PGC-1α is an important regulator of VEGF (vascular endothelial growth factor), which is targeted in the therapy of wet AMD, the most devastating form of AMD. Dysfunction of mitochondria induces cellular senescence associated with AMD pathogenesis. PGC-1α can improve mitochondrial biogenesis and negatively regulate senescence, although this function of PGC-1α in AMD needs further studies. Post-translational modifications of PGC-1α by AMPK (AMP kinase) and SIRT1 (sirtuin 1) are crucial for its activation and important in AMD pathogenesis.

scholarly journals Role of histone deacetylase 2 in epigenetics and cellular senescence: implications in lung inflammaging and COPD

2012 ◽  
Vol 303 (7) ◽  
pp. L557-L566 ◽  
Author(s):  
Hongwei Yao ◽  
Irfan Rahman
Keyword(s):  
Oxidative Stress ◽  
Dna Damage ◽  
Histone Deacetylase ◽  
Dna Damage Response ◽  
Cellular Senescence ◽  
Premature Aging ◽  
Epigenetic Mechanism ◽  
Histone Deacetylase 2 ◽  
Damage Response

Histone deacetylase 2 (HDAC2) is a class I histone deacetylase that regulates various cellular processes, such as cell cycle, senescence, proliferation, differentiation, development, apoptosis, and glucocorticoid function in inhibiting inflammatory response. HDAC2 has been shown to protect against DNA damage response and cellular senescence/premature aging via an epigenetic mechanism in response to oxidative stress. These phenomena are observed in patients with chronic obstructive pulmonary disease (COPD). HDAC2 is posttranslationally modified by oxidative/carbonyl stress imposed by cigarette smoke and oxidants, leading to its reduction via an ubiquitination-proteasome dependent degradation in lungs of patients with COPD. In this perspective, we have discussed the role of HDAC2 posttranslational modifications and its role in regulation of inflammation, histone/DNA epigenetic modifications, DNA damage response, and cellular senescence, particularly in inflammaging, and during the development of COPD. We have also discussed the potential directions for future translational research avenues in modulating lung inflammaging and cellular senescence based on epigenetic chromatin modifications in diseases associated with increased oxidative stress.

scholarly journals CCN2 Aggravates the Immediate Oxidative Stress–DNA Damage Response following Renal Ischemia–Reperfusion Injury

Antioxidants ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 2020
Author(s):  
Floris A. Valentijn ◽  
Sebastiaan N. Knoppert ◽  
Georgios Pissas ◽  
Raúl R. Rodrigues-Diez ◽  
Laura Marquez-Exposito ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Lipid Peroxidation ◽  
Dna Damage ◽  
Reperfusion Injury ◽  
Dna Damage Response ◽  
Cellular Senescence ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Damage Response ◽  
Renal Ischemia Reperfusion Injury

AKI, due to the fact of altered oxygen supply after kidney transplantation, is characterized by renal ischemia–reperfusion injury (IRI). Recent data suggest that AKI to CKD progression may be driven by cellular senescence evolving from prolonged DNA damage response (DDR) following oxidative stress. Cellular communication factor 2 (CCN2, formerly called CTGF) is a major contributor to CKD development and was found to aggravate DNA damage and the subsequent DDR–cellular senescence–fibrosis sequence following renal IRI. We therefore investigated the impact of CCN2 inhibition on oxidative stress and DDR in vivo and in vitro. Four hours after reperfusion, full transcriptome RNA sequencing of mouse IRI kidneys revealed CCN2-dependent enrichment of several signaling pathways, reflecting a different immediate stress response to IRI. Furthermore, decreased staining for γH2AX and p-p53 indicated reduced DNA damage and DDR in tubular epithelial cells of CCN2 knockout (KO) mice. Three days after IRI, DNA damage and DDR were still reduced in CCN2 KO, and this was associated with reduced oxidative stress, marked by lower lipid peroxidation, protein nitrosylation, and kidney expression levels of Nrf2 target genes (i.e., HMOX1 and NQO1). Finally, silencing of CCN2 alleviated DDR and lipid peroxidation induced by anoxia-reoxygenation injury in cultured PTECs. Together, our observations suggest that CCN2 inhibition might mitigate AKI by reducing oxidative stress-induced DNA damage and the subsequent DDR. Thus, targeting CCN2 might help to limit post-IRI AKI.

scholarly journals Dietary Polyphenols in Age-Related Macular Degeneration: Protection against Oxidative Stress and Beyond

2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Elzbieta Pawlowska ◽  
Joanna Szczepanska ◽  
Ali Koskela ◽  
Kai Kaarniranta ◽  
Janusz Blasiak
Keyword(s):  
Oxidative Stress ◽  
Macular Degeneration ◽  
Retinal Pigment ◽  
Janus Kinase ◽  
Age Related Macular Degeneration ◽  
Hydroxyl Groups ◽  
Ros Scavenging ◽  
Rpe Cells ◽  
Dietary Polyphenols ◽  
Age Related

Age-related macular degeneration (AMD) is a multifactorial disease of the retina featured by degeneration and loss of photoreceptors and retinal pigment epithelium (RPE) cells with oxidative stress playing a role in its pathology. Although systematic reviews do not support the protective role of diet rich in antioxidants against AMD, dietary polyphenols (DPs) have been reported to have beneficial effects on vision. Some of them, such as quercetin and cyanidin-3-glucoside, can directly scavenge reactive oxygen species (ROS) due to the presence of two hydroxyl groups in their B ring structure. Apart from direct ROS scavenging, DPs can lower oxidative stress in several other pathways. Many DPs induce NRF2 (nuclear factor, erythroid 2-like 2) activation and expression of phase II enzymes that are under transcriptional control of this factor. DPs can inhibit A2E photooxidation in RPE cells, which is a source of oxidative stress. Anti-inflammatory action of DPs in RPE cells is associated with regulation of various interleukins and signaling pathways, including IL-6/JAK2 (Janus kinase 2)/STAT3. Some DPs can improve impaired cellular waste clearance, including AMD-specific deficient phagocytosis of the Aβ42 peptide and autophagy.

scholarly journals Protective Effects of Curcumin Ester Prodrug, Curcumin Diethyl Disuccinate against H2O2-Induced Oxidative Stress in Human Retinal Pigment Epithelial Cells: Potential Therapeutic Avenues for Age-Related Macular Degeneration

2019 ◽  
Vol 20 (13) ◽  
pp. 3367 ◽  
Author(s):  
Chawanphat Muangnoi ◽  
Umar Sharif ◽  
Pahweenvaj Ratnatilaka Na Bhuket ◽  
Pornchai Rojsitthisak ◽  
Luminita Paraoan
Keyword(s):  
Oxidative Stress ◽  
Macular Degeneration ◽  
Retinal Pigment ◽  
Parent Drug ◽  
Retinal Pigment Epithelial Cells ◽  
Age Related Macular Degeneration ◽  
Protective Effects ◽  
Rpe Cells ◽  
Age Related ◽  
Potent Drug

Oxidative stress-induced damage to the retinal pigmented epithelium (RPE), a specialised post-mitotic monolayer that maintains retinal homeostasis, contributes to the development of age-related macular degeneration (AMD). Curcumin (Cur), a naturally occurring antioxidant, was previously shown to have the ability to protect RPE cells from oxidative stress. However, poor solubility and bioavailability makes Cur a poor therapeutic agent. As prodrug approaches can mitigate these limitations, we compared the protective properties of the Cur prodrug curcumin diethyl disuccinate (CurDD) against Cur in relation to oxidative stress induced in human ARPE-19 cells. Both CurDD and Cur significantly decreased H2O2-induced reactive oxygen species (ROS) production and protected RPE cells from oxidative stress-induced death. Both drugs exerted their protective effects through the modulation of p44/42 (ERK) and the involvement of downstream molecules Bax and Bcl-2. Additionally, the expression of antioxidant enzymes HO-1 and NQO1 was also enhanced in cells treated with CurDD and Cur. In all cases, CurDD was more effective than its parent drug against oxidative stress-induced damage to ARPE-19 cells. These findings highlight CurDD as a more potent drug compared to Cur against oxidative stress and indicate that its protective effects are exerted through modulation of key apoptotic and antioxidant molecular pathways.

scholarly journals Autophagy in Age-Related Macular Degeneration: A Regulatory Mechanism of Oxidative Stress

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Zi-Yuan Zhang ◽  
Xiao-Li Bao ◽  
Yun-Yi Cong ◽  
Bin Fan ◽  
Guang-Yu Li
Keyword(s):  
Oxidative Stress ◽  
Oxidative Damage ◽  
Macular Degeneration ◽  
Retinal Pigment ◽  
The Elderly ◽  
Age Related Macular Degeneration ◽  
Therapeutic Interventions ◽  
Cell Degeneration ◽  
Rpe Cells ◽  
Age Related

Age-related macular degeneration (AMD) is a leading cause of severe visual loss and irreversible blindness in the elderly population worldwide. Retinal pigment epithelial (RPE) cells are the major site of pathological alterations in AMD. They are responsible for the phagocytosis of shed photoreceptor outer segments (POSs) and clearance of cellular waste under physiological conditions. Age-related, cumulative oxidative stimuli contribute to the pathogenesis of AMD. Excessive oxidative stress induces RPE cell degeneration and incomplete digestion of POSs, leading to the continuous accumulation of cellular waste (such as lipofuscin). Autophagy is a major system of degradation of damaged or unnecessary proteins. However, degenerative RPE cells in AMD patients cannot perform autophagy sufficiently to resist oxidative damage. Increasing evidence supports the idea that enhancing the autophagic process can properly alleviate oxidative injury in AMD and protect RPE and photoreceptor cells from degeneration and death, although overactivated autophagy may lead to cell death at early stages of retinal degenerative diseases. The crosstalk among the NFE2L2, PGC-1, p62, AMPK, and PI3K/Akt/mTOR pathways may play a crucial role in improving disturbed autophagy and mitigating the progression of AMD. In this review, we discuss how autophagy prevents oxidative damage in AMD, summarize potential neuroprotective strategies for therapeutic interventions, and provide an overview of these neuroprotective mechanisms.

scholarly journals Mitophagy in the Retinal Pigment Epithelium of Dry Age-Related Macular Degeneration Investigated in the NFE2L2/PGC-1α-/- Mouse Model

2020 ◽  
Vol 21 (6) ◽  
pp. 1976 ◽  
Author(s):  
Iswariyaraja Sridevi Gurubaran ◽  
Johanna Viiri ◽  
Ali Koskela ◽  
Juha M.T. Hyttinen ◽  
Jussi J. Paterno ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Mouse Model ◽  
Macular Degeneration ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Retinal Pigment Epithelial Cells ◽  
Age Related Macular Degeneration ◽  
Double Knockout ◽  
Rpe Cells ◽  
Age Related

Increased oxidative stress and mitochondrial damage are observed in protein aggregation diseases, such as age-related macular degeneration (AMD). We have recently reported elevated levels of oxidative stress markers, damaged mitochondria, accumulating lysosomal lipofuscin and extracellular drusen-like structures in the retinal pigment epithelial cells (RPE) of the dry AMD-resembling NFE2L2/PGC1α double knockout (dKO) mouse model. Here, we provide evidence of a disturbance in the autolysosomal machinery handling mitochondrial clearance in the RPE cells of one-year-old NFE2L2/PGC1α-deficient mice. Confocal immunohistochemical analysis revealed an upregulation of autophagosome marker microtubule-associated proteins 1A/1B light chain 3B (LC3B) as well as numerous mitophagy markers, such as PTE-induced putative kinase 1 (PINK1) and E3 ubiquitin ligase (PARKIN) together with damaged mitochondria. However, we detected no evidence of increased autolysosome formation in transmission electron micrographs or of colocalization of lysosomal marker LAMP2 (lysosome-associated membrane protein 2) and the mitochondrial marker ATP synthase β in confocal micrographs. Interestingly, we observed an upregulation of late autolysosomal fusion Ras-related protein (Rab7) in the perinuclear space of RPE cells together with autofluorescence aggregates. Our results reveal that there is at least a relative decrease of mitophagy in the RPE cells of NFE2L2/PGC1α dKO mice. This further supports the hypothesis that mitophagy is a putative therapy target in AMD-like pathology.

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