scholarly journals Repressed Wnt Signaling Accelerates the Aging Process in Mouse Eyes

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Yujin Zhang ◽  
Joseph Jeffrey ◽  
Fei Dong ◽  
Jianhua Zhang ◽  
Winston W.-Y. Kao ◽  
...  
Keyword(s):  
Wnt Signaling ◽  
Cellular Response ◽  
Aging Process ◽  
Functional Decline ◽  
Corneal Stroma ◽  
Accelerated Aging ◽  
Age Related Macular Degeneration ◽  
Age Related ◽  
Anterior Lens Capsule

Purpose. Ocular aging is a natural process of functional decline in vision. When the process reaches a point that compromised vision affects normal daily activity, it manifests as age-related ocular diseases, such as age-related macular degeneration, cataracts, glaucoma, and pseudoexfoliation syndrome. We previously reported that repressed Wnt signaling accelerated the maturation of corneal epithelium during tissue development. Here, we explore the hypothesis that repressed Wnt signaling is associated with accelerated aging in mouse eyes. Methods. Wnt ligand antagonist secreted frizzled-related protein 1 (sFRP1) was expressed in the corneal stroma by a tissue-specific, inducible, bitransgenic system. Tissue structure was analyzed for signs of aging. Signal transduction analysis was performed to determine the cellular response to sFRP1. Results. Mouse eyes with sFRP1 expression showed signs of accelerated aging, resembling those found in pseudoexfoliation (PEX) syndrome, a known age-related disease. Specific findings include granular deposition on the surface of the anterior lens capsule, pigment loss from the anterior surface of the iris, the presence of fibrillary material in the anterior chamber, and changes in cell size (polymegethism) and shape (pleomorphism) of the corneal endothelial cells. In vitro studies demonstrated that sFRP1 did not inhibit Wnt5a function and that cells responded to sFRP1 and Wnt5a in a very similar manner. Conclusion. The expression of sFRP1 accelerates the aging process in mouse eyes and future studies are warranted to elucidate the underlying mechanisms.

scholarly journals Complement C5 is not critical for the formation of sub-RPE deposits in Efemp1 mutant mice

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Donita L. Garland ◽  
Eric A. Pierce ◽  
Rosario Fernandez-Godino
Keyword(s):  
Macular Degeneration ◽  
Retinal Pigment ◽  
Age Related Macular Degeneration ◽  
Deposit Formation ◽  
Genetic Ablation ◽  
Age Related ◽  
Complement Dysregulation

AbstractThe complement system plays a role in the formation of sub-retinal pigment epithelial (RPE) deposits in early stages of age-related macular degeneration (AMD). But the specific mechanisms that connect complement activation and deposit formation in AMD patients are unknown, which limits the development of efficient therapies to reduce or stop disease progression. We have previously demonstrated that C3 blockage prevents the formation of sub-RPE deposits in a mouse model of EFEMP1-associated macular degeneration. In this study, we have used double mutant Efemp1R345W/R345W:C5-/- mice to investigate the role of C5 in the formation of sub-RPE deposits in vivo and in vitro. The data revealed that the genetic ablation of C5 does not eliminate the formation of sub-RPE deposits. Contrarily, the absence of C5 in RPE cultures promotes complement dysregulation that results in increased activation of C3, which likely contributes to deposit formation even in the absence of EFEMP1-R345W mutant protein. The results also suggest that genetic ablation of C5 alters the extracellular matrix turnover through an effect on matrix metalloproteinases in RPE cell cultures. These results confirm that C3 rather than C5 could be an effective therapeutic target to treat early AMD.

scholarly journals Accidental Corneal Intrastromal Intraocular Lens Implantation with the Wound-Assisted Technique and Clinical Course with Anterior Segment Optical Coherence Tomography

2021 ◽  
pp. 283-287
Author(s):  
Jo Moriya ◽  
Shinichi Sakamoto ◽  
Satoru Inoda ◽  
Hidenori Takahashi ◽  
Hidetoshi Kawashima
Keyword(s):  
Optical Coherence Tomography ◽  
Intraocular Lens ◽  
Anterior Segment ◽  
Corneal Stroma ◽  
Age Related Macular Degeneration ◽  
Optical Coherence ◽  
Corrected Visual Acuity ◽  
Age Related ◽  
Intracameral Injection ◽  
Air Tamponade

Accidental intraocular lens (IOL) implantation into the corneal stroma is a rare clinical entity that can occur during the wound-assisted technique. In this report, we describe a case of an 81-year-old man who underwent cataract surgery in which the IOL was implanted into the corneal stroma with the wound-assisted technique, and we present changes in anterior segment optical coherence tomography. The IOL was removed and reinserted after widening the incision. Air tamponade was created by intracameral injection. An anterior chamber tap was performed 10 h later to reduce increased intraocular pressure. Interlayer separation of the corneal stroma was confirmed 30 min postoperatively but was corrected 4 days later. The patient’s best-corrected visual acuity (BCVA) was logMAR 0.30, and he had been diagnosed with age-related macular degeneration before surgery. Although the opacity of the corneal stroma persisted, BCVA improved to logMAR 0. When using the wound-assisted technique for IOL insertion, surgeons should take care not to implant the IOL into the corneal stroma.

scholarly journals The anti-angiogenic isoforms of VEGF in health and disease

2009 ◽  
Vol 37 (6) ◽  
pp. 1207-1213 ◽  
Author(s):  
Yan Qiu ◽  
Coralie Hoareau-Aveilla ◽  
Sebastian Oltean ◽  
Steven J. Harper ◽  
David O. Bates
Keyword(s):  
Splice Site ◽  
Site Selection ◽  
Age Related Macular Degeneration ◽  
Splicing Factor ◽  
Splice Site Selection ◽  
Age Related ◽  
Normal Human ◽  
Radical Revision

Anti-angiogenic VEGF (vascular endothelial growth factor) isoforms, generated from differential splicing of exon 8, are widely expressed in normal human tissues but down-regulated in cancers and other pathologies associated with abnormal angiogenesis (cancer, diabetic retinopathy, retinal vein occlusion, the Denys–Drash syndrome and pre-eclampsia). Administration of recombinant VEGF165b inhibits ocular angiogenesis in mouse models of retinopathy and age-related macular degeneration, and colorectal carcinoma and metastatic melanoma. Splicing factors and their regulatory molecules alter splice site selection, such that cells can switch from the anti-angiogenic VEGFxxxb isoforms to the pro-angiogenic VEGFxxx isoforms, including SRp55 (serine/arginine protein 55), ASF/SF2 (alternative splicing factor/splicing factor 2) and SRPK (serine arginine domain protein kinase), and inhibitors of these molecules can inhibit angiogenesis in the eye, and splice site selection in cancer cells, opening up the possibility of using splicing factor inhibitors as novel anti-angiogenic therapeutics. Endogenous anti-angiogenic VEGFxxxb isoforms are cytoprotective for endothelial, epithelial and neuronal cells in vitro and in vivo, suggesting both an improved safety profile and an explanation for unpredicted anti-VEGF side effects. In summary, C-terminal distal splicing is a key component of VEGF biology, overlooked by the vast majority of publications in the field, and these findings require a radical revision of our understanding of VEGF biology in normal human physiology.

scholarly journals Functional optical coherence tomography of retinal photoreceptors

2018 ◽  
Vol 243 (17-18) ◽  
pp. 1256-1264 ◽  
Author(s):  
Xincheng Yao ◽  
Taeyoon Son ◽  
Tae-Hoon Kim ◽  
Yiming Lu
Keyword(s):  
Vision Loss ◽  
Objective Assessment ◽  
Age Related Macular Degeneration ◽  
Retinal Stimulation ◽  
Age Related ◽  
Retinal Photoreceptors ◽  
Severe Vision Loss ◽  
Further Development

Age-related macular degeneration (AMD) is the leading cause of severe vision loss and legal blindness. It is known that retinal photoreceptors are the primary target of AMD. Therefore, a reliable method for objective assessment of photoreceptor function is needed for early detection and reliable treatment evaluation of AMD and other eye diseases such as retinitis pigmentosa that are known to cause photoreceptor dysfunctions. Stimulus-evoked intrinsic optical signal (IOS) changes promise a unique opportunity for objective assessment of physiological function of retinal photoreceptor and inner neurons. Instead of a comprehensive review, this mini-review is to provide a brief summary of our recent in vitro and in vivo optical coherence tomography (OCT) studies of stimulus-evoked IOS changes in animal retinas. By providing excellent axial resolution to differentiate individual retinal layers, depth-resolved OCT revealed rapid IOS response at the photoreceptor outer segment. The fast photoreceptor-IOS occurred almost right away (∼ 2 ms) after the onset of retinal stimulation, differentiating itself from slow IOS changes correlated with inner neural and hemodynamic changes. Further development of the functional IOS instruments and retinal stimulation protocols may provide a feasible solution to pursue clinical application of functional IOS imaging for objective assessment of human photoreceptors. Impact statement Retinal photoreceptors are the primary target of age-related macular degeneration (AMD) which is the leading cause of severe vision loss and legal blindness. An objective method for functional assessment of photoreceptor physiology can benefit early detection and better treatment evaluation of AMD and other eye diseases that are known to cause photoreceptor dysfunctions. This article summarizes in vitro study of IOS mechanisms and in vivo demonstration of IOS imaging of intact animals. Further development of the functional IOS imaging may provide a revolutionary solution to achieve objective assessment of human photoreceptors.

scholarly journals Senescence and aging: Causes, consequences, and therapeutic avenues

2017 ◽  
Vol 217 (1) ◽  
pp. 65-77 ◽  
Author(s):  
Domhnall McHugh ◽  
Jesús Gil
Keyword(s):  
Neurodegenerative Disorders ◽  
Cellular Response ◽  
Aging Process ◽  
Normal Development ◽  
Growth Arrest ◽  
The Novel ◽  
Aging Research ◽  
Related Disease ◽  
Age Related ◽  
Stable Growth

Aging is the major risk factor for cancer, cardiovascular disease, diabetes, and neurodegenerative disorders. Although we are far from understanding the biological basis of aging, research suggests that targeting the aging process itself could ameliorate many age-related pathologies. Senescence is a cellular response characterized by a stable growth arrest and other phenotypic alterations that include a proinflammatory secretome. Senescence plays roles in normal development, maintains tissue homeostasis, and limits tumor progression. However, senescence has also been implicated as a major cause of age-related disease. In this regard, recent experimental evidence has shown that the genetic or pharmacological ablation of senescent cells extends life span and improves health span. Here, we review the cellular and molecular links between cellular senescence and aging and discuss the novel therapeutic avenues that this connection opens.

Molecular mechanisms of life- and health-span extension: role of calorie restriction and exercise intervention

2007 ◽  
Vol 32 (5) ◽  
pp. 954-966 ◽  
Author(s):  
Christy S. Carter ◽  
Tim Hofer ◽  
Arnold Y. Seo ◽  
Christian Leeuwenburgh
Keyword(s):  
Life Span ◽  
Calorie Restriction ◽  
Aging Process ◽  
Molecular Mechanisms ◽  
Geriatric Medicine ◽  
Functional Decline ◽  
Intervention Strategies ◽  
Health Span ◽  
Structural Deterioration ◽  
Age Related

The aging process results in a gradual and progressive structural deterioration of biomolecular and cellular compartments and is associated with many pathological conditions, including cardiovascular disease, stroke, Alzheimer’s disease, osteoporosis, sarcopenia, and liver dysfunction. Concomitantly, each of these conditions is associated with progressive functional decline, loss of independence, and ultimately disability. Because disabled individuals require care in outpatient or home care settings, and in light of the social, emotional, and fiscal burden associated with caring for an ever-increasing elderly population, research in geriatric medicine has recently focused on the biological mechanisms that are involved in the progression towards functional decline and disability to better design treatment and intervention strategies. Although not completely understood, the mechanisms underlying the aging process may partly involve inflammatory processes, oxidative damage, mitochondrial dysfunction, and apoptotic tissue degeneration. These hypotheses are based on epidemiological evidence and data from animal models of aging, as well as interventional studies. Findings from these studies have identified possible strategies to decrease the incidence of age-related diseases and delay the aging process. For example, lifelong exercise is known to extend mean life-span, whereas calorie restriction (CR) increases both mean and maximum life-span in a variety of species. Optimal application of these intervention strategies in the elderly may positively affect health-related outcomes and possibly longevity. Therefore, the scope of this article is to (i) provide an interpretation of various theories of aging from a “health-span” perspective; (ii) describe interventional testing in animals (CR and exercise); and (iii) provide a translational interpretation of these data.

Quantitative Action Spectroscopy Reveals ARPE-19 Sensitivity to Long-Wave Ultraviolet Radiation at 350 nm and 380 nm

2021 ◽  
Author(s):  
Graham Anderson ◽  
Andrew McLeod ◽  
Pierre Bagnaninchi ◽  
Baljean Dhillon
Keyword(s):  
Ultraviolet Radiation ◽  
Cell Viability ◽  
Age Related Macular Degeneration ◽  
Cell Dynamics ◽  
Cell Viability Assay ◽  
Cell Parameters ◽  
Viability Analysis ◽  
Age Related

The role of ultraviolet radiation (UVR) exposure in the pathology of age-related macular degeneration (AMD) has been debated for decades with epidemiological evidence failing to find a clear consensus for or against it playing a role. A key reason for this is a lack of foundational research into the response of living retinal tissue to UVR in regard to AMD-specific parameters of tissue function. We, therefore, explored the response of cultured retinal pigmented epithelium (RPE), the loss of which heralds advanced AMD, to specific wavelengths of UVR across the UV-B and UV-A bands found in natural sunlight. Using a bespoke in vitro UVR exposure apparatus coupled with bandpass filters we exposed the immortalised RPE cell line, ARPE-19, to 10nm bands of UVR between 290 and 405nm. Physical cell dynamics were assessed during exposure in cells cultured upon specialist electrode culture plates which allow for continuous, non-invasive electrostatic interrogation of key cell parameters during exposure such as monolayer coverage and tight-junction integrity. UVR exposures were also utilised to quantify wavelength-specific effects using a rapid cell viability assay and a phenotypic profiling assay which was leveraged to simultaneously quantify intracellular reactive oxygen species (ROS), nuclear morphology, mitochondrial stress, epithelial integrity and cell viability as part of a phenotypic profiling approach to quantifying the effects of UVR. Electrical impedance assessment revealed unforeseen detrimental effects of UV-A, beginning at 350nm, alongside previously demonstrated UV-B impacts. Cell viability analysis also highlighted increased effects at 350nm as well as 380nm. Effects at 350nm were further substantiated by high content image analysis which highlighted increased mitochondrial dysfunction and oxidative stress. We conclude that ARPE-19 cells exhibit a previously uncharacterised sensitivity to UV-A radiation, specifically at 350nm and somewhat less at 380nm. If upheld in vivo, such sensitivity will have impacts upon geoepidemiological risk scoring of AMD.

scholarly journals Antioxidant Role of PRGF on RPE Cells after Blue Light Insult as a Therapy for Neurodegenerative Diseases

2020 ◽  
Vol 21 (3) ◽  
pp. 1021 ◽  
Author(s):  
Carlota Suárez-Barrio ◽  
Susana del Olmo-Aguado ◽  
Eva García-Pérez ◽  
María de la Fuente ◽  
Francisco Muruzabal ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Human Cell Line ◽  
Antioxidant Effect ◽  
Age Related Macular Degeneration ◽  
Strong Impact ◽  
Retinal Diseases ◽  
Age Related ◽  
Gene And Protein Expression

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.

scholarly journals Thermostable small-molecule inhibitor of angiogenesis and vascular permeability that suppresses a pERK-FosB/ΔFosB–VCAM-1 axis

2020 ◽  
Vol 6 (31) ◽  
pp. eaaz7815
Author(s):  
Yue Li ◽  
Ahmad M. N. Alhendi ◽  
Mei-Chun Yeh ◽  
Mina Elahy ◽  
Fernando S. Santiago ◽  
...  
Keyword(s):  
Vascular Permeability ◽  
Small Molecule ◽  
Wound Repair ◽  
Network Formation ◽  
Small Molecule Inhibitor ◽  
Age Related Macular Degeneration ◽  
Endothelial Cell Proliferation ◽  
Age Related ◽  
Molecule Inhibitor

Vascular permeability and angiogenesis underpin neovascular age-related macular degeneration and diabetic retinopathy. While anti-VEGF therapies are widely used clinically, many patients do not respond optimally, or at all, and small-molecule therapies are lacking. Here, we identified a dibenzoxazepinone BT2 that inhibits endothelial cell proliferation, migration, wound repair in vitro, network formation, and angiogenesis in mice bearing Matrigel plugs. BT2 interacts with MEK1 and inhibits ERK phosphorylation and the expression of FosB/ΔFosB, VCAM-1, and many genes involved in proliferation, migration, angiogenesis, and inflammation. BT2 reduced retinal vascular leakage following rat choroidal laser trauma and rabbit intravitreal VEGF-A165 administration. BT2 suppressed retinal CD31, pERK, VCAM-1, and VEGF-A165 expression. BT2 reduced retinal leakage in rats at least as effectively as aflibercept, a first-line therapy for nAMD/DR. BT2 withstands boiling or autoclaving and several months’ storage at 22°C. BT2 is a new small-molecule inhibitor of vascular permeability and angiogenesis.

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