Photobiomodulation for the Treatment of Retinal Injury and Retinal Degenerative Diseases

Author(s):  
Janis T. Eells ◽  
Kristina D. DeSmet ◽  
Diana K. Kirk ◽  
Margaret Wong-Riley ◽  
Harry T. Whelan ◽  
...  
2020 ◽  
Author(s):  
Xia Feng ◽  
Peng Chen ◽  
Xin Zhao ◽  
Jing Wang ◽  
Hong Wang

Abstract Background: Stem cell transplantation has been reported as one of the promising strategies to treat retinal degenerative diseases. But, the application and the role of retina stem cells (RSCs) in the treatment of patients with retinal degenerative diseases have not been fully revealed. This study aimed to investigate the potential role of transplantation of the embryo-derived RSCs into the vitreous cavity in repairing the damaged retina in mice. Methods: RSCs were isolated from Kunming mice E17 embryonic retina and ciliary body tissues, and labeled with 5-bromo-2’-deoxyuridin (BrdU). Retinal injury was induced in left eyes in male Kunming mice by ring clamping the optic nerve. The 6th-generation of BrdU-labeled RSCs were transplanted into the damaged retina by the intravitreal injection, and saline injected eyes were used as the control. Hematoxylin and eosin histological staining, and BrdU, Nestin and Pax6 immunostaining were performed. Electroretinogram (ERG) was used for assessing the electrical activity of the retina. Results: Embryo-derived RSCs were identified by the positive stains of Pax6 and Nestin. BrdU incorporation was detected in the majority of RSCs. The damaged retina showed cellular nuclear disintegration and fragmentation in the retinal tissue which progressed over the periods of clamping time, and decreased amplitudes of a and b waves in ERG. In the damaged retina with RSCs transplantation, the positive staining for BrdU, Pax6 and Nestin were revealed on the retinal surface. Notably, a small amount of RSCs migrated into the retinal ganglion cell layer and inner nuclear. Transplanted RSCs significantly elevated the amplitudes of a waves in retina injured eyes. Conclusions: Embryonic RSCs have similar characteristics to neural stem cells. Transplantation of RSCs by intravitreal injection would be able to repair the damaged retina.


2020 ◽  
Vol 53 (383) ◽  
pp. MISC1-MISC3
Author(s):  
Andrea Maugeri

Retinal degenerative diseases are the leading causes of blindness and low vision among working-age and older adults worldwide, with 170 and 130 million individuals suffering from age-related macular degeneration (AMD) and diabetic retinopathy, respectively. Although several studies began to show benefits from dietary interventions against retinal degenerative disease, an integrated approach is needed to understand molecular mechanisms underpinning the protective or risky effect of dietary factors. A specific area of research that elucidates mechanisms involved in gene-diet interaction is the Nutri-epigenomics, the study of the impact of diet on gene expression by modulating epigenetic mechanisms. The present research investigated the role of DNA methylation – one of the most commonly analysed epigenetic mechanisms - in the pathophysiology of retinal degenerative diseases, by exploiting a multiple integrated approach. In vitro studies initially helped us to understand how pathological features of retinal degeneration (e.g. oxidative stress, inflammation and hyperglycaemia) modulated functions of enzymes involved in the methylation of Long Interspersed Nuclear Element 1 (LINE-1) sequences in retinal cells. We also proved that some nutrients (e.g. resveratrol and curcumin) might counteract these effects and restore DNA methylation level in retinal cells under oxidative, inflammatory and high glucose conditions. We further analysed whether LINE-1 methylation level differed between patients with AMD and controls without posterior segment eye diseases. Interestingly, we noted a significant difference between the two groups, with higher LINE-1 methylation level in blood samples from AMD patients. This evidence -albeit promising for biomarker discovery- requires confirmation by further large-size prospective studies taking into account different factors. Our research, in fact, also suggested that the risk of retinal degenerative diseases derives from the combination of genetic risk variants, clinical characteristics, environmental exposures and unhealthy lifestyles, which in turn are interrelated. Thus, it would be interesting to study how the exposome -the totality of exposures individuals experience over the course of life- might induce epigenetic mechanisms able to reduce or increase the risk for retinal degenerative diseases.


2018 ◽  
Vol 19 (7) ◽  
pp. 2118 ◽  
Author(s):  
Andrea Maugeri ◽  
Martina Barchitta ◽  
Maria Mazzone ◽  
Francesco Giuliano ◽  
Guido Basile ◽  
...  

The role of epigenetic alterations in the pathogenesis of retinal degenerative diseases, including age-related macular degeneration (AMD), has been pending so far. Our study investigated the effect of oxidative stress and inflammation on DNA methyltransferases (DNMTs) and Sirtuin 1 (SIRT1) functions, as well as on long interspersed nuclear element-1 (LINE-1) methylation, in human retinal pigment epithelial (ARPE-19) cells. Therefore, we evaluated whether treatment with resveratrol may modulate DNMT and SIRT1 functions and restore changes in LINE-1 methylation. Cells were treated with 25 mU/mL glucose oxidase (GOx) or 10 µg/mL lipopolysaccharide (LPS) to mimic oxidative or inflammatory conditions, respectively. Oxidative stress decreased DNMT1, DNMT3a, DNMT3b, and SIRT1 expression (p-values < 0.05), as well as total DNMTs (−28.5%; p < 0.0001) and SIRT1 (−29.0%; p < 0.0001) activities. Similarly, inflammatory condition decreased DNMT1 and SIRT1 expression (p-values < 0.05), as well as total DNMTs (−14.9%; p = 0.007) and SIRT1 (−20.1%; p < 0.002) activities. Interestingly, GOx- and LPS-treated cells exhibited lower LINE-1 methylation compared to controls (p-values < 0.001). We also demonstrated that treatment with 10 μM resveratrol for 24 h counteracted the detrimental effect on DNMT and SIRT1 functions, and LINE-1 methylation, in cells under oxidative and inflammatory conditions. However, further studies should explore the perspectives of resveratrol as a suitable strategy for the prevention and/or treatment of retinal degenerative diseases.


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