scholarly journals Perturbed Biochemical Pathways and Associated Oxidative Stress Lead to Vascular Dysfunctions in Diabetic Retinopathy

2019 ◽  
Vol 2019 ◽  
pp. 1-16 ◽  
Author(s):  
Nidhi Mahajan ◽  
Palkin Arora ◽  
Rajat Sandhir

Diabetic retinopathy (DR) is a vascular insult that accompanies the hyperglycemic state. Retinal vasculature holds a pivotal role in maintaining the integrity of the retina, and any alteration to retinal vasculature affects retinal functions. The blood retinal barrier, a prerequisite to vision acuity, is most susceptible to damage during the progression of DR. This is a consequence of impaired biochemical pathways such as the polyol, advanced end glycation products (AGE), hexosamine, protein kinase C (PKC), and tissue renin-angiotensin system (RAS) pathways. Moreover, the role of histone modification and altered miRNA expression is also emerging as a major contributor. Epigenetic changes create a link between altered protein function and redox status of retinal cells, creating a state of metabolic memory. Although various biochemical pathways underlie the etiology of DR, the major insult to the retina is due to oxidative stress, a unifying factor of altered biochemical pathways. This review primarily focuses on the critical biochemical pathways altered in DR leading to vascular dysfunctions and discusses antioxidants as plausible treatment strategies.

Antioxidants ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 520 ◽  
Author(s):  
Mong-Heng Wang ◽  
George Hsiao ◽  
Mohamed Al-Shabrawey

Oxidative stress is an important factor to cause the pathogenesis of diabetic retinopathy (DR) because the retina has high vascularization and long-time light exposition. Cyclooxygenase (COX), lipoxygenase (LOX), and cytochrome P450 (CYP) enzymes can convert arachidonic acid (AA) into eicosanoids, which are important lipid mediators to regulate DR development. COX-derived metabolites appear to be significant factors causative to oxidative stress and retinal microvascular dysfunction. Several elegant studies have unraveled the importance of LOX-derived eicosanoids, including LTs and HETEs, to oxidative stress and retinal microvascular dysfunction. The role of CYP eicosanoids in DR is yet to be explored. There is clear evidence that CYP-derived epoxyeicosatrienoic acids (EETs) have detrimental effects on the retina. Our recent study showed that the renin-angiotensin system (RAS) activation augments retinal soluble epoxide hydrolase (sEH), a crucial enzyme degrading EETs. Our findings suggest that EETs blockade can enhance the ability of RAS blockade to prevent or mitigate microvascular damage in DR. This review will focus on the critical information related the function of these eicosanoids in the retina, the interaction between eicosanoids and reactive oxygen species (ROS), and the involvement of eicosanoids in DR. We also identify potential targets for the treatment of DR.


2021 ◽  
Vol 22 ◽  
Author(s):  
Siddhi Dilip Chalke ◽  
Pravin Popatrao Kale

: Diabetic Retinopathy (DR) is one of the most severe ocular problems of diabetes. It is a microvascular complication that impairs the vision of diabetic individuals and can cause acquired blindness. Currently available treatment options like laser therapy, vitrectomy, intravitreal anti-vascular endothelial growth factor (VEGF) agents, and glucocorticoids help to reduce vision loss at advanced stages. In spite of the available therapies, patients with severe vision loss face difficulty in achieving normal vision. There is a need for development of newer treatment strategies to address the condition from the early stages. Multiple factors owing to complex pathophysiological events are responsible for this long-term complication. Neurodegeneration, inflammation, and oxidative stress are the three important factors associated with the development of DR. Oxidative stress is a major contributor to the onset and progression of DR. Pathological events like retinal neurodegeneration and inflammation damage the retina right in the early stages of DR. Different combinations of treatments targeting these pathological events are discussed in the present review. The first combination discussed is citicoline and resveratrol. The second combination is duloxetine and N-acetyl cysteine (NAC). These combinations may help in the early stages of DR. CD5-2 and angiopoietin-2 inhibitors is the third combination. This combination may help to manage diabetic macular edema. The main purpose of this article is to discuss the link between these pathologies and the three combination approaches with the objective of consideration of newer therapeutic approaches in research related to DR treatment.


2019 ◽  
Vol 19 (20) ◽  
pp. 1681-1693 ◽  
Author(s):  
Carlos S.M. Bezerra-Filho ◽  
Joice N. Barboza ◽  
Marilia T.S. Souza ◽  
Peter Sabry ◽  
Nasser S.M. Ismail ◽  
...  

Many phenolic compounds found in foods and medicinal plants have shown interesting therapeutic potential and have attracted the attention of the pharmaceutical industry as promising pharmacologically active compounds in health promotion and disease prevention. Vanillin is a phenolic aldehyde, widely used as a flavoring agent in the food, pharmaceutical, and cosmetics industries. A variety of pharmacological activities has been attributed to this compound and its main metabolites, vanillic acid and vanillyl alcohol, including their anti-inflammatory ability. The relationship of the anti- inflammatory effects of vanillin, vanillic acid, and vanillyl alcohol and their actions on oxidative stress is well established. Considering that the inflammatory process is related to several pathologies, including new diseases with few therapeutic options, and limited efficiency, the search for effective treatment strategies and discovery of new anti-inflammatory agents capable of modulating inflammation becomes necessary. Therefore, in this review, we discuss the therapeutic potential of vanillin and its main metabolites for the treatment of inflammatory diseases and their actions on redox status. In addition, the molecular docking evaluation of vanillin, its metabolites and isoeugenol were carried out into the phospholipase A2 binding site.


2008 ◽  
Vol 8 ◽  
pp. 98-120 ◽  
Author(s):  
Jennifer L. Wilkinson-Berka ◽  
Antonia G. Miller

Retinopathy is the most feared complication of diabetes, compromising quality of life in most sufferers. Almost all patients with type 1 diabetes will develop retinopathy over a 15- to 20-year period, and approximately 20–30% will advance to the blinding stage of the disease[1]. Greater than 60% of patients with type 2 diabetes will have retinopathy. This situation is highlighted by the frightening statistic that diabetic retinopathy (DR) remains the most common cause of vision impairment in people of working age in Western society. With the global epidemic of type 2 diabetes, this predicament is set to worsen as over 360 million people are projected to suffer from diabetes and its complications by 2030. Vision loss from diabetes is due to a number of factors, including haemorrhage from new and poorly formed blood vessels, retinal detachment due to contraction of deposited fibrous tissue, and neovascular glaucoma resulting in an increase in intraocular pressure. Diabetic macular oedema is now the principal cause of vision loss in diabetes and involves leakage from a disrupted blood-retinal barrier. In terms of treatment, there is clear evidence that strict metabolic and blood pressure control can lower the risk of developing DR and reduce disease progression. Laser photocoagulation and vitrectomy are effective in preventing severe vision loss in DR, particularly in the most advanced stages of the disease. However, both procedures have limitations. This review examines evidence from preclinical and clinical studies that shows that targeting inhibition of the renin-angiotensin system, vascular endothelial growth factor, corticosteroids, protein kinase C, growth hormone, and advanced glycation end-products are potential treatments for DR.


Antioxidants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1143
Author(s):  
Midori Sakashita ◽  
Tetsuhiro Tanaka ◽  
Reiko Inagi

Diabetic kidney disease (DKD) is a major cause of end-stage kidney disease, and it is crucial to understand the pathophysiology of DKD. The control of blood glucose levels by various glucose-lowering drugs, the common use of inhibitors of the renin–angiotensin system, and the aging of patients with diabetes can alter the disease course of DKD. Moreover, metabolic changes and associated atherosclerosis play a major role in the etiology of DKD. The pathophysiology of DKD is largely attributed to the disruption of various cellular stress responses due to metabolic changes, especially an increase in oxidative stress. Therefore, many antioxidants have been studied as therapeutic agents. Recently, it has been found that NRF2, a master regulator of oxidative stress, plays a major role in the pathogenesis of DKD and bardoxolone methyl, an activator of NRF2, has attracted attention as a drug that increases the estimated glomerular filtration rate in patients with DKD. This review outlines the altered stress responses of cellular organelles in DKD, their involvement in the pathogenesis of DKD, and discusses strategies for developing therapeutic agents, especially bardoxolone methyl.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Danilo Reymão Moreira ◽  
Ana Carolina Musa Gonçalves Uberti ◽  
Antonio Rafael Quadros Gomes ◽  
Michelli Erica Souza Ferreira ◽  
Aline da Silva Barbosa ◽  
...  

AbstractThe present study aimed to evaluate the effects of dexamethasone on the redox status, parasitemia evolution, and survival rate of Plasmodium berghei-infected mice. Two-hundred and twenty-five mice were infected with Plasmodium berghei and subjected to stimulation or inhibition of NO synthesis. The stimulation of NO synthesis was performed through the administration of L-arginine, while its inhibition was made by the administration of dexamethasone. Inducible NO synthase (iNOS) inhibition by dexamethasone promoted an increase in the survival rate of P. berghei-infected mice, and the data suggested the participation of oxidative stress in the brain as a result of plasmodial infection, as well as the inhibition of brain NO synthesis, which promoted the survival rate of almost 90% of the animals until the 15th day of infection, with possible direct interference of ischemia and reperfusion syndrome, as seen by increased levels of uric acid. Inhibition of brain iNOS by dexamethasone caused a decrease in parasitemia and increased the survival rate of infected animals, suggesting that NO synthesis may stimulate a series of compensatory redox effects that, if overstimulated, may be responsible for the onset of severe forms of malaria.


Antioxidants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1033
Author(s):  
Lorena Olivares-González ◽  
Sheyla Velasco ◽  
Isabel Campillo ◽  
David Salom ◽  
Emilio González-García ◽  
...  

Background: Retinitis pigmentosa (RP) is a group of inherited retinal dystrophies characterized by progressive degeneration of photoreceptor cells. Ocular redox status is altered in RP suggesting oxidative stress could contribute to their progression. In this study, we investigated the effect of a mixture of nutraceuticals with antioxidant properties (NUT) on retinal degeneration in rd10 mice, a model of RP. Methods: NUT was orally administered to rd10 mice from postnatal day (PD) 9 to PD18. At PD18 retinal function and morphology were examined by electroretinography (ERG) and histology including TUNEL assay, immunolabeling of microglia, Müller cells, and poly ADP ribose polymers. Retinal redox status was determined by measuring the activity of antioxidant enzymes and some oxidative stress markers. Gene expression of the cytokines IL-6, TNFα, and IL-1β was assessed by real-time PCR. Results: NUT treatment delayed the loss of photoreceptors in rd10 mice partially preserving their electrical responses to light stimuli. Moreover, it ameliorated redox status and reduced inflammation including microglia activation, upregulation of cytokines, reactive gliosis, and PARP overactivation. Conclusions: NUT ameliorated retinal functionality and morphology at early stages of RP in rd10 mice. This formulation could be useful as a neuroprotective approach for patients with RP in the future.


Sign in / Sign up

Export Citation Format

Share Document