scholarly journals Electrical Stimulation Induces Retinal Müller Cell Proliferation and Their Progenitor Cell Potential

Cells ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 781 ◽  
Author(s):  
Sam Enayati ◽  
Karen Chang ◽  
Hamida Achour ◽  
Kin-Sang Cho ◽  
Fuyi Xu ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
Progenitor Cell ◽  
Underlying Mechanism ◽  
Age Related Macular Degeneration ◽  
Gene Profiling ◽  
Trophic Factors ◽  
Retinal Neuron ◽  
Cell Potential ◽  
Age Related ◽  
Pathway Activation

Non-invasive electrical stimulation (ES) is increasingly applied to improve vision in untreatable eye conditions, such as retinitis pigmentosa and age-related macular degeneration. Our previous study suggested that ES promoted retinal function and the proliferation of progenitor-like glial cells in mice with inherited photoreceptor degeneration; however, the underlying mechanism remains obscure. Müller cells (MCs) are thought to be dormant residential progenitor cells that possess a high potential for retinal neuron repair and functional plasticity. Here, we showed that ES with a ramp waveform of 20 Hz and 300 µA of current was effective at inducing mouse MC proliferation and enhancing their expression of progenitor cell markers, such as Crx (cone–rod homeobox) and Wnt7, as well as their production of trophic factors, including ciliary neurotrophic factor. RNA sequencing revealed that calcium signaling pathway activation was a key event, with a false discovery rate of 5.33 × 10−8 (p = 1.78 × 10−10) in ES-mediated gene profiling changes. Moreover, the calcium channel blocker, nifedipine, abolished the observed effects of ES on MC proliferation and progenitor cell gene induction, supporting a central role of ES-induced Ca2+ signaling in the MC changes. Our results suggest that low-current ES may present a convenient tool for manipulating MC behavior toward neuroregeneration and repair.

scholarly journals Homocysteine and Age-Related Central Nervous System Diseases: Role of Inflammation

2021 ◽  
Vol 22 (12) ◽  
pp. 6259
Author(s):  
Amany Tawfik ◽  
Nehal M. Elsherbiny ◽  
Yusra Zaidi ◽  
Pragya Rajpurohit
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Barrier Function ◽  
Underlying Mechanism ◽  
Age Related Macular Degeneration ◽  
Barrier Dysfunction ◽  
Age Related ◽  
The Central Nervous System ◽  
Underlying Mechanisms

Hyperhomocysteinemia (HHcy) is remarkably common among the aging population. The relation between HHcy and the development of neurodegenerative diseases, such as Alzheimer’s disease (AD) and eye diseases, and age-related macular degeneration (AMD) and diabetic retinopathy (DR) in elderly people, has been established. Disruption of the blood barrier function of the brain and retina is one of the most important underlying mechanisms associated with HHcy-induced neurodegenerative and retinal disorders. Impairment of the barrier function triggers inflammatory events that worsen disease pathology. Studies have shown that AD patients also suffer from visual impairments. As an extension of the central nervous system, the retina has been suggested as a prominent site of AD pathology. This review highlights inflammation as a possible underlying mechanism of HHcy-induced barrier dysfunction and neurovascular injury in aging diseases accompanied by HHcy, focusing on AD.

scholarly journals Pathway activation profiling reveals new insights into Age-related Macular Degeneration and provides avenues for therapeutic interventions

Aging ◽  
2014 ◽  
Vol 6 (12) ◽  
pp. 1064-1075 ◽  
Author(s):  
Evgeny Makarev ◽  
Charles Cantor ◽  
Alex Zhavoronkov ◽  
Anton Buzdin ◽  
Alexander Aliper ◽  
...  
Keyword(s):  
Macular Degeneration ◽  
Age Related Macular Degeneration ◽  
Therapeutic Interventions ◽  
Age Related ◽  
Pathway Activation

Circulating endothelial and progenitor cells in age-related macular degeneration

2019 ◽  
Vol 30 (5) ◽  
pp. 956-965
Author(s):  
Dario Pasquale Mucciolo ◽  
Rossella Marcucci ◽  
Andrea Sodi ◽  
Francesca Cesari ◽  
Vittoria Murro ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Macular Degeneration ◽  
Progenitor Cells ◽  
Endothelial Progenitor Cell ◽  
Progenitor Cell ◽  
Age Related Macular Degeneration ◽  
Circulating Endothelial Cells ◽  
Control Group ◽  
Endothelial Progenitor ◽  
Age Related

Purpose: To evaluate circulating endothelial and circulating progenitor cells as biomarkers in age-related macular degeneration patients (both exudative and atrophic forms) in order to establish the possible clinical implication of their assessment. Methods: We have enrolled 44 age-related macular degeneration patients: 22 patients with a recently diagnosed exudative (neovascular) form (Group A) and 22 patients with an atrophic (dry) form (Group B). The control group consisted of 22 age and sex-matched healthy subjects (Group C). The number of circulating endothelial progenitor cells (CD34+/KDR+, CD133+/KDR+, and CD34+/KDR+/CD133+), circulating progenitor cells (CD34+, CD133+, and CD34+/CD133+), and circulating endothelial cells were determined in the peripheral venous blood samples by flow cytometry. Neovascular age-related macular degeneration patients were evaluated at baseline and 4 weeks after a loading phase of three consequent intravitreal injections of ranibizumab. Results: Comparing age-related macular degeneration patients with the control group, endothelial progenitor cell and circulating progenitor cell levels were not significantly different, while age-related macular degeneration patients showed significantly higher levels of circulating endothelial cells ( p = 0.001). Anti–vascular endothelial growth factor treatment with intravitreal ranibizumab was associated with a significant reduction of endothelial progenitor cell levels, with no significant influence on circulating progenitor cells and circulating endothelial cells. Conclusion: We reported higher levels of circulating endothelial cells in age-related macular degeneration patients in comparison with the control group, thereby supporting the hypothesis of an involvement of endothelial dysregulation in the age-related macular degeneration and a reduction of the endothelial progenitor cell level in neovascular age-related macular degeneration patients after three intravitreal injections of ranibizumab.

scholarly journals Homocysteine Induces Inflammation in Retina and Brain

Biomolecules ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 393 ◽  
Author(s):  
Nehal M. Elsherbiny ◽  
Isha Sharma ◽  
Dina Kira ◽  
Suhib Alhusban ◽  
Yara A. Samra ◽  
...  
Keyword(s):  
Folic Acid ◽  
Inflammatory Cytokines ◽  
Inflammatory Responses ◽  
Retinal Pigment ◽  
Underlying Mechanism ◽  
Multiplex Assay ◽  
Retinal Pigment Epithelial Cells ◽  
Age Related Macular Degeneration ◽  
Age Related ◽  
Hippocampal Area

Homocysteine (Hcy) is an amino acid that requires vitamins B12 and folic acid for its metabolism. Vitamins B12 and folic acid deficiencies lead to hyperhomocysteinemia (HHcy, elevated Hcy), which is linked to the development of diabetic retinopathy (DR), age-related macular degeneration (AMD), and Alzheimer’s disease (AD). The goal of the current study was to explore inflammation as an underlying mechanism of HHcy-induced pathology in age related diseases such as AMD, DR, and AD. Mice with HHcy due to a lack of the enzyme cystathionine-β-synthase (CBS) and wild-type mice were evaluated for microglia activation and inflammatory markers using immuno-fluorescence (IF). Tissue lysates isolated from the brain hippocampal area from mice with HHcy were evaluated for inflammatory cytokines using the multiplex assay. Human retinal endothelial cells, retinal pigment epithelial cells, and monocyte cell lines treated with/without Hcy were evaluated for inflammatory cytokines and NFκB activation using the multiplex assay, western blot analysis, and IF. HHcy induced inflammatory responses in mouse brain, retina, cultured retinal, and microglial cells. NFκB was activated and cytokine array analysis showed marked increase in pro-inflammatory cytokines and downregulation of anti-inflammatory cytokines. Therefore, elimination of excess Hcy or reduction of inflammation is a promising intervention for mitigating damage associated with HHcy in aging diseases such as DR, AMD, and AD.

Age related macular degeneration (ARMD) – pathophysiological and clinical features and therapeutic concepts

2001 ◽  
Vol 58 (1) ◽  
pp. 28-35 ◽  
Author(s):  
Ursula Körner-Stiefbold
Keyword(s):  
Macular Degeneration ◽  
Clinical Features ◽  
Altersbedingte Makuladegeneration ◽  
Age Related Macular Degeneration ◽  
Genetische Faktoren ◽  
Age Related ◽  
Therapeutic Concepts

Die altersbedingte Makuladegeneration (AMD) ist eine der häufigsten Ursachen für einen irreversiblen Visusverlust bei Patienten über 65 Jahre. Nahezu 30% der über 75-Jährigen sind von einer AMD betroffen. Trotz neuer Erkenntnisse in der Grundlagenforschung ist die Ätiologie, zu der auch genetische Faktoren gehören, noch nicht völlig geklärt. Aus diesem Grund sind die Behandlungsmöglichkeiten zum jetzigen Zeitpunkt noch limitiert, so dass man lediglich von Therapieansätzen sprechen kann. Die derzeit zur Verfügung stehenden Möglichkeiten wie medikamentöse, chirurgische und laser- und strahlentherapeutische Maßnahmen werden beschrieben.

Nutrition in Age-Related Macular Degeneration Survey

2018 ◽  
Author(s):  
Rebekah Stevens ◽  
Richard Cooke ◽  
Hannah Bartlett
Keyword(s):  
Macular Degeneration ◽  
Age Related Macular Degeneration ◽  
Age Related
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