Generation of reactive oxygen species in the anterior eye segment. Synergistic codrugs of N-acetylcarnosine lubricant eye drops and mitochondria-targeted antioxidant act as a powerful therapeutic platform for the treatment of cataracts and primary open-angle glaucoma

Acute aflatoxin B1-induced hepatic and cardiac oxidative damage in rats: Ameliorative effects of morin

Aflatoxins (AFs) are secondary metabolites produced by the fungus Aspergillus flavus, of which Aflatoxin-B1 (AFB1) appears to be the most cancerogenic and of the highest toxicity. AFB1 causes serious effects on several organs including the liver. Morin is a flavonol that exists in many fruits and plants and has diverse biological properties including anticancer, anti-atherosclerotic, antioxidant, anti-inflammatory, immunomodulatory, and multi-organ protective activities. The present study aims to evaluate the potential protective effects of morin against acute AFB1-induced hepatic and cardiac toxicity in rats. Forty rats were divided into five groups (n = 8) as follows: control received the vehicle, morin was orally administered 30/mg/kg body weight (MRN30), the AFB1 was administered orally at a dose of 2.5 mg/kg, twice on days 12 and 14 of the experiment for the 3rd, 4th, and 5th groups., AFB1-MRN15 was orally given morin at a dose of 15 mg/kg body weight, and AFB1-MRN30 orally received morin at 30 mg/kg body weight. The results indicated a significant decrease in serum AST, ALP, LDH, GGT, CK, CK-MB, 8-OHdG, IL-1β, IL-6, TNF-a levels in MRN30 compared to AFB1, and AFB1-MRN15 groups. However, the results indicated non-significant differences in the serum levels between MRN30, control, and AFB1-MRN30 groups. Meanwhile, regarding the hepatic and cardiac parameters, there were significant differences in the levels of MDA, NO, GSH, GSH-Px, SOD, and CAT in MRN30 compared to AFB1, and AFB1-MRN15 groups, overall implying the protective effects of morin. To conclude, morin at a dose of 30 mg/kg b. wt. showed significant enhancements in acute AFB1-induced hepatic and cardiac toxicity in rats, which could play a role in limiting the public health hazards of AFs.

DCLRE1A Contributes to DNA Damage Repair and Apoptosis in Age-Related Cataracts by Regulating the lncRNA/miRNA/mRNA Axis

PURPOSE

Age-related cataract (ARC) is associated with the deregulation of transcription and defects in DNA repair in lens epithelial cells (LECs). DCLRE1A acted in DNA interstrand cross-links pathway to improve DNA replication and transcription. The aim of this study was to examined the further regulatory effect on DCLRE1A in the lncRNA-miRNA-mRNA network using a cell model of DCLRE1A overexpression (OE-DCLRE1A) in LECs.

METHODS

The expression level of DCLRE1A in ARC tissues and SRA01/04 cells after H2O2 treatment was measured as protein and mRNA by qRT-PCR and Western Blot(WB). CCK8, and TUNEL assays detected the change in cell viability and apoptosis, respectively. Furthermore, Immunofluorescence assays detect the expression of DNA damaged and repair marker proteins after OE-DCLRE1A. The global expression profiles of lncRNAs, miRNAs, and mRNAs were determined using high-throughput sequencing. KEGG and GO enrichment analysis disclose the possible function of differentially expressed (DE) lncRNA, miRNA, and mRNA.

RESULTS

The protein and mRNA of DCLRE1A were decreased in the anterior capsule of ARC and SRA01/04 cells treated by H2O2. OE-DCLRE1A improved damaged-DNA repair and enhanced cell viability against apoptosis after H2O2 treatment. Furthermore, we demonstrated the DE-molecules between the OE-DCLRE1A and control groups including 595 DE-lncRNAs, 221 DE-miRNAs, and 4718 DE-mRNAs. Next, bioinformatics analysis not only found that the DE-mRNAs are mainly involved in DNA repair-related signaling pathways after OE-DCLRE1A, but also screened two lncRNA-miRNA-mRNA networks focusing on DNA damage activated by OE-DCLRE1A, which involved 2 lncRNAs, 2 miRNAs, and 53 mRNAs.

CONCLUSION

We revealed that DCLRE1A activated the lncRNA/miRNA/DNA-repair network to take part in DNA repair processes, which not only represents a new regulatory mechanism employed by DCLRE1A but also uncovers the screening lncRNA may hold potential therapeutic values in ARC formation. However, these conclusions will need to be confirmed by future studies in vitro and in vivo models.

Nanomaterial-based ophthalmic drug delivery

The low bioavailability and side effects of conventional drugs for eye disease necessitate the development of efficient drug delivery systems. Accompanying the developments of nanofabrication techniques, nanomaterials have been recognized as promising tools to overcome these challenges due to their flexible and programmable properties. Given the advances achieved in material science, a broad spectrum of functional nanomaterials capable of overcoming various ocular anterior and posterior segment barriers have been explored to satisfy the demands for ocular drug delivery. In this review, we first highlight the unique functions of nanomaterials suitable for carrying and transporting ocular drugs. Then, various functionalization strategies are emphasized to endow nanomaterials with superior performance in enhanced ophthalmic drug delivery. The rational design of several affecting factors is essential for ideal nanomaterial candidates and is depicted as well. Lastly, we introduce the current applications of nanomaterial-based delivery systems in the therapy of different ocular anterior and posterior segment diseases. The limitations of these delivery systems as well as potential solutions are also discussed. This work will inspire innovative design thinking for the development of nanotechnology-mediated strategies for advanced drug delivery and treatment toward ocular diseases.

Mitochondrial-Targeted Antioxidant Peptide SS31 Prevents RPE Cell Death under Oxidative Stress

This work aims at investigating the protective effects of the mitochondria-targeted peptide SS31, on mitochondria function, preventing human retinal pigment epithelial cell-19 (ARPE-19) cell apoptosis. The ARPE-19 cells were subjected to 24 h of intervention with H2O2 of various concentrations (0, 100, 150, 200, 250, 300, and 500 μmol/L). Various concentrations of SS31 (10 nM, 100 nM, and 1 μmol/L) pretreated the cells for 2 h. The MTT assay determined cell viability. ARPE-19 cell apoptosis was observed by 4',6-diamidino-2-phenylindole (DAPI) staining under fluorescence microscope and detected by Annexin-V/PI staining under flow cytometry. The measurement of reactive oxygen species (ROS) release level used MitoSOX Red (a mitochondrial superoxide indicator) and the probe 2'-7'dichlorofluorescin diacetate (DCFH-DA). And with the use of a JC-1 probe, the mitochondrial membrane potential (MMP; ΔΨm) was analyzed. Reverse transcription polymerase chain reaction (RT-PCR) and real-time PCR were responsible for measuring the levels of apoptosis related genes (Bcl-2, Bax, and Caspase-3). The cell viability increased significantly with SS31 pretreated (P < 0.05). In the SS31 + H2O2 group, the fluorescence of the cell nuclei with DAPI staining was weaker than H2O2 along group accordance with the decreased ratio of apoptotic cells (P < 0.05). The ROS generation decreased in SS31 pretreated group, with the increased ΔΨm. The RT-PCR result showed decreased Bax gene and Caspase-3 gene expression with SS31 pretreatment, while increased antiapoptotic gene Bcl-2 (P < 0.05). We provide evidence that SS31 promotes resilience of RPE cells to oxidative stress by stabilizing mitochondrial function.

Restoring the oxidative balance in age-related diseases - An approach in glaucoma

As human life expectancy increases, age-related health issues including neurodegenerative diseases continue to rise. Regardless of genetic or environmental factors, many neurodegenerative conditions share common pathological mechanisms, such as oxidative stress, a hallmark of many age-related health burdens. In this review, we describe oxidative damage and mitochondrial dysfunction in glaucoma, an age-related neurodegenerative eye disease affecting 80 million people worldwide. We consider therapeutic approaches used to counteract oxidative stress in glaucoma, including untapped treatment options such as novel plant-derived antioxidant compounds that can reduce oxidative stress and prevent neuronal loss. We summarize the current pre-clinical models and clinical work exploring the therapeutic potential of a range of candidate plant-derived antioxidant compounds. Finally, we explore advances in drug delivery systems, particular those employing nanotechnology-based carriers which hold significant promise as a carrier for antioxidants to treat age-related disease, thus reviewing the key current state of all of the aspects required towards translation.

MiR-34a-5p negatively regulates oxidative stress on lens epithelial cells by silencing GPX3 - a novel target

Purpose MiR-34a-5p is reported to be related with age-related nuclear cataract. This study investigated the mechanism of miR-34a-5p in the regulation of oxidative stress on lens epithelial cells.Methods The three candidate miRNAs were screened by CCK-8 assays after transfection of mimics or inhibitor in H₂O₂-treated HLE-B3 cells. The apoptosis, ROS level and GPX activity of HLE-B3 cells transfected with miR-34a-5p mimics or inhibitor were analysed by flow cytometry, cellular ROS and GPX activity test. The target genes of miR-34a-5p were predicted by proteomic and bioinformatic analysis. The relationship between miR-34a-5p and GPX3 were internally validated by qRT-PCR and Western blot and externally verified by dual-luciferase reporter assay. The effect of miR-34a-5p-GPX3 axis on regulation of oxidative stress in HLE-B3 cells were conducted by overexpression of GPX3 and tested by flow cytometry analysis, cellular ROS and GPX detection.Results The viability of H₂O₂-treated HLE-B3 cells were weakened by up-regulated miR-34a-5p. Cell apoptosis and oxidative damage were also induced by overexpression of miR-34a-5p. GPX3 and SRC were identified as target genes of miR-34a-5p by combined analysis of proteomic and bioinformatics, while GPX3 was selected for further research for its connection with anti-oxidation. Western blot and qRT-PCR tests proved that GPX3 is negatively regulated by miR-34a-5p. Dual-luciferase reporter assay verified that GPX3 is the direct target of miR-34a-5p. The increased oxidative stress induced by transfection of miR-34a-5p mimics in H₂O₂-treated HLE-B3 cells was attenuated by overexpression of GPX3.Conclusions MiR-34a-5p is a negative regulator of oxidative stress on lens epithelial cells and the mechanism is by silencing the expression of GPX3. These data suggests that miR-34a-5p may be a potential novel therapeutic target for the prevention and treatment of age-related cataract.

Case Report: Vogt-Koyanagi-Harada Syndrome Mimicking Acute Angle-Closure Glaucoma in a Patient Infected With Human Immunodeficiency Virus

Vogt-Koyanagi-Harada disease (VKH) is a rare multisystemic inflammatory autoimmune disorder. Glaucoma secondary to VKH frequently occurs during the recurrent phase of anterior uveitis; however, acute angle-closure glaucoma (ACG) secondary to both VKH and human immunodeficiency virus (HIV) infection has rarely been reported. We describe a case of secondary acute ACG involving VKH, characterized by sudden vision loss, moderately elevated intraocular pressure (IOP), shallow anterior chamber, and fully or partially closed angle, in an HIV-infected patient. Both VKH and HIV infection contributed to the occurrence of ACG due to the leakage and forward rotation of the ciliary body, as well as choroidal effusion. The deterioration of IOP and serous macular detachment were observed after initial corticosteroid therapy. Visual acuity and IOP were improved with subretinal fluid absorption after continued corticosteroid therapy. Understanding the response of IOP and serous macular detachment after corticosteroid therapy is important for clinical practice.

Melatonin counteracts oxidative damage in lens by regulation of Nrf2 and NLRP3 inflammasome activity

Oxidative stress, generated because of an imbalance between reactive oxygen species (ROS) generation and elimination, is associated with lens damage and cataract progression. ROS generation is known to activate NLRP3 (nucleotide-binding oligomerization domain-like receptor family, pyrin domain-cointaining 3) inflammasome, and is believed to be an important link between oxidative stress and inflammation, that is also related to cataract development. Potential oxidative hazard to the lens by white light-emitting diode (LED) light, a source of illumination commonly used nowadays, has been suggested, although available information is limited. In this work, we evaluated the cytotoxicity induced by hydrogen peroxide (an oxidative stressor agent) and white LED light in lens epithelial cells as well as melatonin ability to counteract the effects induced by them. Melatonin is a neurohormone secreted by different ocular structures that could be useful to alleviate oxidative damage induced by different oxidative stressors in lens. Particularly, the modulation of Nrf2 (nuclear erythroid 2-related factor)/Keap 1 (Kelch-like ECH-associated protein 1), an essential oxidative stress regulator, and NLRP3 activity by melatonin was evaluated in lens epithelial cells. ROS levels rose after white LED light exposure and cell viability was reduced after challenge with oxidative stressor agents. Melatonin prevented cell death triggered by hydrogen peroxide and white LED light, precluded ROS generation induced by white LED light and promoted antioxidant lens capacity through upregulation of Nrf2 protein levels and SOD activity. NLRP3, caspase-1 and IL1-β expression significantly increased in human lens cells exposed to H₂O₂ or irradiated with white LED light. Activation of NLRP3 inflammasome triggered by oxidative stressors was also abrogated by melatonin. Attenuation of inflammatory and cytotoxic effects induced by oxidative stressors provided by melatonin in lens indicate the interest of this molecule as a potential therapeutic agent for cataract prevention/management.

Nutritional supplementation in the prevention and treatment of Glaucoma

Glaucoma is a chronic optic neuropathy that creates a significant burden on public health. Oxidative stress is hypothesised to play a role to glaucoma progression, and its reduction is being analysed as a therapeutic target. Dietary antioxidants play a crucial role in helping provide insight into this hypothesis. We reviewed 71 trials, interventional, I -vivo and I -vitro, including 11 randomised controlled trials, to determine if adjunctive nutritional supplementation could lead to a reduction in oxidative stress and prevent glaucomatous progression. Many laboratory findings show that vitamins and natural compounds contain an abundance of intrinsic antioxidative, neuroprotective and vasoprotective properties that show promise in the treatment and prevention of glaucoma. Although there is encouraging early evidence, most clincial findings are inconclusive. The group of B vitamins appear to have the greatest amount of evidence. Other compounds such as flavonoids, carotenoids, curcumin, saffron, CoQ10, Ggngko Biloba and Resveratrol however warrant further investigation in glaucoma patients. Studies of these antioxidants and other nutrients could create adjunctive or alternative preventative and treatment modalities for glaucoma to those currently available.

Meta-inhibition of ocular and gastrointestinal dysfunctions by phenolic-rich fraction of Croton zambsicus leaves in a rat model exposed to chronic mixed metals

PURPOSE

This study was aimed at investigating the protective effect of antioxidant-rich fraction of Croton zambsicus (C-ZAMB) leaves on ocular-gastrointestinal dysfunction in rats exposed to environmental mixed-metal (EOMABRSL).

MATERIALS AND METHODS

The rats were divided into five (n = 10) groups. Group I designates the control which received 0.5 mL of distilled water. Group II and III received 0.5 mL of EOMABRSL for 98 days (non-withdrawal) and 70 days (withdrawal for 28 days), respectively. Group IV received 0.5 mL EOMABRSL for 70 days and 400 mg/kg C-ZAMB fraction for 28 days. Group V received 400 mg/kg C-ZAMB only for 28 days via oral route.

RESULTS

Exposure of the animals to EOMARBSL for 98 days and 70 days significantly up-regulated the activities of ocular-gastrointestinal aldolase-reductase, α-amylase, α-glucosidase and eco-5¹-nucleotidase with corresponding depletion of lactate dehydrogenase activity. Furthermore, exposure to EOMABRSL significantly altered the antioxidant proteins with up-production of MDA content. Apparently, management with 400 mg/kg C-ZAMB fraction significantly inhibited the key markers linked with ocular-gastrointestinal disorders.

CONCLUSION

Hence, this study underscores the biochemical mechanisms for managing ocular-gastrointestinal lesions by 400 mg/kg C-ZAMB fraction on exposure to mixture of environmental metals.

Modeling the antioxidant properties of the eye reduces the false-positive rate of a nonanimal eye irritation test (OptiSafe)

We recently identified a group of chemicals that are misclassified by most, if not all, in vitro alternative ocular irritation tests, suggesting that nonanimal tests may not fully model the ocular environment in which these chemicals interact. To address this, we evaluated the composition of tears, the first defense against foreign substances, and identified the presence of antioxidants that could detoxify reactive chemicals that otherwise may be falsely identified as irritants in alternative irritation tests. In this study, we evaluated the effects of tear antioxidants on the ocular irritation scoring of commonly overclassified chemicals (false positives) using the OptiSafe™ ocular irritation test. Six tear-related antioxidants were individually added to the OptiSafe formulation, and the effects on test outcome were determined. Ascorbic acid, the most abundant water-soluble antioxidant in tears, specifically reduced the OptiSafe false-positive rate. Titration curves showed that this reduction occurs at in vivo concentrations and is specific to chemicals identified either as producing reactive oxygen species or as crosslinkers. Importantly, the addition of tear antioxidants did not impact the detection of true negatives, true positives, or other false positives unassociated with reactive oxygen species or crosslinking. These results suggest that the addition of tear antioxidants to in vitro alternative test systems may substantially reduce the false-positive rate and improve ocular irritant detection.

Potential health benefits of carotenoid lutein: An updated review

Carotenoids in food substances are believed to have health benefits by lowering the risk of diseases. Lutein, a carotenoid compound, is one of the essential nutrients available in green leafy vegetables (kale, broccoli, spinach, lettuce, and peas), along with other foods, such as eggs. As nutrition plays a pivotal role in maintaining human health, lutein, as a nutritional substance, confers promising benefits against numerous health issues, including neurological disorders, eye diseases, skin irritation, etc. This review describes the in-depth health beneficial effects of lutein. As yet, a minimal amount of literature has been undertaken to consider all its promising bioactivities. The step-by-step biosynthesis of lutein has also been taken into account in this review. Besides, this review demonstrates the drug interactions of lutein with β-carotene, as well as safety concerns and dosage. The potential benefits of lutein have been assessed against neurological disorders, eye diseases, cardiac complications, microbial infections, skin irritation, bone decay, etc. Additionally, recent studies ascertained the significance of lutein nanoformulations in the amelioration of eye disorders, which are also considered in this review. Moreover, a possible approach for the use of lutein in bioactive functional foods will be discussed.

Potential protective effects of Spirulina platensis on liver, kidney, and brain acrylamide toxicity in rats

Acrylamide (AA) is a hazardous chemical that is widely used in industrial practices. Spirulina platensis (SP) is a blue green alga that is rich in bioactive compounds with many medicinal benefits. The aim of the present study was to evaluate the ameliorative effect of SP against AA toxicity in rats. Animals were divided into six groups: Group (1) was normal rats, groups (2) and (3) received SP at 500 and 1000 mg/kg BW orally respectively for 21 days, group (4) was administered 20 mg/kg BW AA daily for 14 days, while groups (5) and (6) were given orally SP at the same doses of groups (2) and (3), then AA at similar dose of group (4). Rats that received AA alone displayed markedly increased serum levels of liver enzymes (ALT, AST, and ALP), kidney function parameters (urea and creatinine), DNA damage marker (8-OHdG), and proinflammatory cytokines (IL-1β, IL-6, and TNF-α), compared to control rats. Furthermore, tissue analysis revealed marked increases in hepatic, renal, and brain MDA and NO, as well as marked reductions in the antioxidant biomarkers (GSH, GSH-Px, SOD, and CAT) in acrylamide-intoxicated rats. Spirulina ameliorated the alterations in serum biochemical parameters and reduced MDA and NO, as well as improved antioxidant biomarkers in AA-intoxicated rats in a dose-dependent manner. Our results show that SP has a powerful protective effect on serum biochemistry and liver, kidney, and brain antioxidant machinery in AA-intoxicated rats.

Extraction of capsanthin from Capsicum annum L fruits and its effect on carbomer-induced intraocular pressure in Albino Wistar rats

The present study was aimed to explore the antiglaucoma activity of capsanthin enriched fraction (CEF) of Capsicum annum L fruits against carbomer-induced experimental glaucoma in Albino Wistar rats. CEF was orally administered to carbomer-induced glaucomatous rats, and pilocarpine 2% eye drops were used as a standard drug. Intraocular pressure (IOP) levels were determined after oral administration of a low, medium, and a high dose of CEF (20, 40, and 80 mg/kg bwt) in glaucomatous rats. In rats with elevated IOP in both eyes, oral administration of CEF resulted in a significant reduction in IOP (p < .05) even at a low dose of 20 mg/Kg body weight. There were no treatment-related changes in histopathology, hematology, and clinical chemistry parameters. Thus, CEF when administered orally in IOP-bearing rats successfully reduced IOP without any adverse effects. PRACTICAL APPLICATIONS: Capsanthin enriched fraction can be used to prevent permanent vision loss due to age-related macular diseases and high intraocular pressure. The intraocular pressure reduction action of capsanthin can be useful in the treatment of glaucoma. The medication available to treat glaucoma are topical drugs, and for the first time, we proved the oral supplementation of capsanthin from a food source can reduce the intraocular pressure in rats.

In vitro antioxidant and ex vivo anti-cataract activity of ethanolic extract of Cineraria maritima: a traditional plant from Nilgiri hills

Background

Cineraria maritima has a long history of use in the treatment of cataract and other eye-related problems in the homeopathic system of medicines. High oxidative stress is one of the major underlying causes of cataract which results in the precipitation of natural protein present in the lenses with aging. This research has been carried out to determine the anti-cataract activity of C. maritima by performing various antioxidant techniques such as 1,1-diphenyl-2-picrylhydrazyl, nitric oxide, hydrogen peroxide, and studies in oxidative stress–induced ex vivo cataract model.

Results

Results of the study conducted in the ethanolic extract of aerial parts (leaves and stems) of C. maritima revealed the presence of various phytoconstituents such as alkaloids, phenols, flavonoids, etc. Total phenol and total flavonoid content was found to be 6.31 ± 0.06 % w/w and 2.14 ± 0.09% w/w respectively, which revealed that the plant contains a good amount of these compounds and hence possesses good antioxidant activity. Furthermore, IC50 values obtained from all the methods gave strong evidence regarding the antioxidant potential of this plant. Anti-cataract activity was also investigated using goat eye lenses and promising results were obtained which speak voluminously about its anti-cataract potential and support its well-prescribed use.

Conclusion

Results obtained with this study clearly supported the significant antioxidant potential and anti-cataract activity of this plant. Further, this plant demands great attention for the development of suitable novel dosage forms for the effective treatment of cataract.

Synthesis, Characterization, and Specific Localization of Mitochondrial-Targeted Antioxidant Peptide SS31 Probe

The aim of this study is to investigate the targeting efficiency of FITC-SS31 to mitochondria in both normal and H2O2-induced oxidative damaged 661W cells, characterizing the properties of FITC-SS31 in the biological assays. The purity and molecular weight of FITC-SS31 were identified using HPLC and MS. MTT and LDH assays were used to evaluate the cytotoxicity and cell permeability. The binding ability of FITC-SS31 to cells was demonstrated by flow cytometry. The colocalization of FITC-SS31 and MitoTracker both in normal and oxidative cells was analyzed by a laser confocal microscope. We detected the DEGs between SS31+H2O2 and H2O2-alone-treated cells by RNA seq. GO and KEGG analyses were performed to predict the functional gene of SS31. The molecular weight of FITC-SS31 was 1142.2 with the 97.76% purity. The flow cytometry results showed that the MFI (mean fluorescence intensity) of FITC-SS31 in normal cells in the 4 h probe treatment group was higher than that in the 2 h and the 0 h group. The MFI in the 2 h probe treatment group was much higher than that in the 4 h and 0 h groups in damaged cells. The positive rate of 10 μM FITC-SS31 was higher than that of 1 μM and 5 μM. Fluorescein imaging analysis confirmed that FITC-SS31 was overlapped with MitoTracker. Through the analysis, DEGs were highly expressed in "localization, organelle, antioxidant activity, binding" functions and enriched in "AMPK signaling pathway, MAPK targets/nuclear events mediated by MAP kinase pathway and PI3K-Akt signaling pathway." It is speculated that SS31 exerts an antioxidant effect through one of these pathways. We hypothesized that SS31 could play a more efficient role in the pathological cells in the half-life period to avoid cell death due to oxidative damage. The functions of the DEGs in SS31+H2O2 and H2O2-alone samples are related to the localization and antioxidant activity of SS31. DEGs are mostly enriched in the AMPK signaling pathway, which needs further studies.

L-Carnosine Stimulation of Coenzyme Q10 Biosynthesis Promotes Improved Mitochondrial Function and Decreases Hepatic Steatosis in Diabetic Conditions

Mitochondrial dysfunction in type 2 diabetes leads to oxidative stress, which drives disease progression and diabetes complications. L-carnosine, an endogenous dipeptide, improves metabolic control, wound healing and kidney function in animal models of type 2 diabetes. Coenzyme Q (CoQ), a component of the mitochondrial electron transport chain, possesses similar protective effects on diabetes complications. We aimed to study the effect of carnosine on CoQ, and assess any synergistic effects of carnosine and CoQ on improved mitochondrial function in a mouse model of type 2 diabetes. Carnosine enhanced CoQ gene expression and increased hepatic CoQ biosynthesis in db/db mice, a type 2 diabetes model. Co-administration of Carnosine and CoQ improved mitochondrial function, lowered ROS formation and reduced signs of oxidative stress. Our work suggests that carnosine exerts beneficial effects on hepatic CoQ synthesis and when combined with CoQ, improves mitochondrial function and cellular redox balance in the liver of diabetic mice. (4) Conclusions: L-carnosine has beneficial effects on oxidative stress both alone and in combination with CoQ on hepatic mitochondrial function in an obese type 2 diabetes mouse model.

Advances in pharmacotherapy of cataracts

Cataracts, the leading cause of vision impairment worldwide, arise from abnormal aggregation of lens proteins. According to the World Health Organization, cataracts cause more than 40% of blindness cases. As the population ages, the prevalence of cataracts will increase rapidly. Although cataract surgery is regarded as effective, it still suffers from complications and high cost, and could not meet the increasingly surgery demand. Therefore, pharmacological treatment for cataracts is a cheaper and more readily available option for patients, which is also a hot topic for years. Anti-cataract drug screening was previously mainly based on the specific pathogenic factors: oxidative stress, excess of quinoid substances, and aldose reductase (AR) activation. And several anti-cataract drugs have been applied in the clinic, while the effect is still unsatisfied. Makley and Zhao recently identified two kinds of novel pharmacological substances (25-hydroxycholesterol, lanosterol) that can reverse lens opacity by dissolving the aggregation of crystallin proteins, indicating that protein aggregation is not an endpoint and could be reversed with specific small-molecule drugs, significantly boosting the development of the cataract pharmacopeia and being regarded as a new dawn for cataract treatment. Our team built a novel optimized platform and had screened several potential therapeutic agents from a collection of lanosterol derivatives. In this review, we would mainly focus on the advancement of cataract pharmacotherapy based on the targets for anti-cataract drugs.

Effects of Sodium Selenite on Oxidative Damage in the Liver, Kidney and Brain in a Selenite Cataract Rat Model

Selenite cataracts are effective and convenient animal models for simulation of human senile nuclear cataracts. These models are widely used to study the effects of various stresses on eye lenses and to screen anticataract drugs. However, there have been no comprehensive toxicological evaluations of these animal models. To investigate the effects of sodium selenite on some important organs in selenite cataract model animals, this study analyzed (1) histopathology by hematoxylin and eosin (H&E) staining; (2) methionine sulfoxide reductase (Msr) A and B1 protein expression; (3) glutathione peroxidase (GPx), thioredoxin reductase (TrxR) and superoxide dismutase (SOD) activity; and (4) malondialdehyde (MDA) levels in the liver, kidney, and brain in a selenite cataract rat model. The results showed that sodium selenite induced severe oxidative damage, especially in the hippocampus and corpus striatum of the brain, in Sprague-Dawley (SD) rats. This damage was evidenced by mild gliocyte proliferation, significant disorder of neuronal arrangement with acidophilic changes in the hippocampus, and significant occurrence of focal microglia or lymphocytic infiltration in the corpus striatum after selenite injection for cataract simulation. The damage was closely related to significant decreases in antioxidant enzyme expression and activity and significant increases in lipid peroxidation (MDA) levels. Furthermore, nonsignificant swelling and scattered spotty necrosis were observed in the liver. These results imply that physiological changes in model animals should be considered when carrying out anticataract drug screening and that pathological changes in other nontarget organs should be prevented.

TGFβ2-Hepcidin Feed-Forward Loop in the Trabecular Meshwork Implicates Iron in Glaucomatous Pathology

Purpose

Elevated levels of transforming-growth-factor (TGF)-β2 in the trabecular meshwork (TM) and aqueous humor are associated with primary open-angle glaucoma (POAG). The underlying mechanism includes alteration of extracellular matrix homeostasis through Smad-dependent and independent signaling. Smad4, an essential co-Smad, upregulates hepcidin, the master regulator of iron homeostasis. Here, we explored whether TGF-β2 upregulates hepcidin, implicating iron in the pathogenesis of POAG.

Methods

Primary human TM cells and human and bovine ex vivo anterior segment organ cultures were exposed to bioactive TGF-β2, hepcidin, heparin (a hepcidin antagonist), or N-acetyl carnosine (an antioxidant), and the change in the expression of hepcidin, ferroportin, ferritin, and TGF-β2 was evaluated by semiquantitative RT-PCR, Western blotting, and immunohistochemistry. Increase in reactive oxygen species (ROS) was quantified with dihydroethidium, an ROS-sensitive dye.

Results

Primary human TM cells and bovine TM tissue synthesize hepcidin locally, which is upregulated by bioactive TGF-β2. Hepcidin downregulates ferroportin, its downstream target, increasing ferritin and iron-catalyzed ROS. This causes reciprocal upregulation of TGF-β2 at the transcriptional and translational levels. Heparin downregulates hepcidin, and reduces TGF-β2-mediated increase in ferritin and ROS. Notably, both heparin and N-acetyl carnosine reduce TGF-β2-mediated reciprocal upregulation of TGF-β2.

Conclusions

The above observations suggest that TGF-β2 and hepcidin form a self-sustained feed-forward loop through iron-catalyzed ROS. This loop is partially disrupted by a hepcidin antagonist and an anti-oxidant, implicating iron and ROS in TGF-β2-mediated POAG. We propose that modification of currently available hepcidin antagonists for ocular use may prove beneficial for the therapeutic management of TGF-β2-associated POAG.

Esculetin and idebenone ameliorate galactose-induced cataract in a rat model

Cataract is the principal cause of blindness. The enzyme, aldose reductase (AR) is a key player in polyol pathway. Buildup of polyols and oxidative stress are the main causes of cataractogenesis. This study investigated the cytoprotective properties of esculetin and idebenone in galactose-induced cataract. Rats were partitioned into four groups each of ten rats. Control group was fed with normal diet; group 2 rats were fed with galactose diet (50%); groups 3, 4 rats were fed with galactose diet concurrently with either esculetin (50 mg/kg BW) or idebenone (100 mg/kg BW), for 20 days. The study revealed that esculetin and idebenone significantly reduced the elevated levels of Bax/Bcl-2 ratio, malondialdehyde, and DNA fragmentation and increased total antioxidant capacity level in lenses compared to the cataract-induced group. Only esculetin decreased AR, galactitol, and advanced glycated end products levels in lenses. Histopathological examinations supported the biochemical findings. Esculetin and idebenone may have chemopreventive effects for sugar cataract. PRACTICAL APPLICATIONS: Cataract is an age-related disease that might cause blindness in older adult people. Presently, no absolute pharmacological treatment is accessible for cataract. The use of natural products or their derivatives attract particular attention in modern medicines as they are believed to be safer with few or no side effects. Esculetin is a polyphenolic compound found in many medicinal plants. Idebenone is a synthetic analogue of coenzyme Q10. The current study is an approach to explore the anticataract effects of esculetin and idebenone in galactose-induced cataract in rats. Our study proved that both agents have anticataractogenic potentials due to their antioxidant and antiapoptotic properties.

Cross-talk between MYOC p. Y437H mutation and TGF-β2 in the pathology of glaucoma

Objective: To identify the interaction between the MYOC Y437H mutation and TGF-β2 in a family with primary open-angle glaucoma (POAG). Methods: The MYOC Y437H mutation was identified in a family with POAG; the family was a fourth-generation family with 27 members, of which 6 members were affected. Analysis focused on the secreted myocilin protein and TGF-β2 found in the aqueous humor. Samples were taken both from normal controls and MYOC mutant carriers and cross-talk between MYOC Y437H and TGF-β2 were evaluated in the trabecular meshwork (TM) cells. Results: Aqueous humor secreted myocilin protein levels were reduced while TGF-β2 levels were increased in patients with the MYOC (c.1309T>C) mutation. This inverse relationship indicated that elevated TGF-β2 may be an important pathogenic mechanism in the progression of myocilin-related POAG. In TM cells expressing the MYOC Y437H mutant, exogenous TGF-β2 also significantly increased myocilin expression as well as the endoplasmic reticulum (ER) stress markers GRP94 and CHOP. This increase in TGF-β2 was also associated with increased cell death in cells carrying the MYOC Y437H mutation. Conclusion: These data collectively suggest that the mutual interaction between glaucomatous MYOC mutation and TGF-β2 contributed to the cell death of TM cells. This relationship also provides a new, therapeutic targets for the treatment of glaucoma.

Local synthesis of hepcidin in the anterior segment of the eye: A novel observation with physiological and pathological implications

PURPOSE

The avascular cornea, trabecular meshwork (TM), and lens obtain iron, an essential biometal, from the aqueous humor (AH). The mechanism by which this exchange is regulated, however, is unclear. Recently we reported that non-pigmented ciliary epithelial cells express ferroportin (Fpn) (Ashok, 2018b), an iron export protein modulated by hepcidin, the master regulator of iron homeostasis secreted mainly by the liver. Here, we explored whether ciliary epithelial and other cells in the anterior segment synthesize hepcidin, suggesting local regulation of iron exchange at this site.

METHODS

Human and bovine eyes were dissected to isolate the ciliary body (CB), corneal endothelial (CE), TM, lens epithelial (LE), and outer epithelial cell layer of the iris. Total mRNA and protein lysates were processed to evaluate the synthesis and expression of hepcidin, the iron regulatory peptide hormone, Fpn, the only known iron export protein, ceruloplasmin (Cp), a ferroxidase necessary for iron export, transferrin receptor (TfR), a major iron uptake protein, and ferritin, a major iron storage protein. A combination of techniques including reverse transcription polymerase chain reaction (RT-PCR) of total mRNA, Western blotting of protein lysates, and immunofluorescence of fixed tissue sections were used to accomplish these goals.

RESULTS

RT-PCR of isolated tissue samples revealed hepcidin-specific mRNA in the CB, TM, CE, and LE of the bovine eye. Western blotting of protein lysates from these tissues showed reactivity for hepcidin, Fpn, ferritin, and TfR. Western blotting and immunohistochemistry of similar tissues isolated from cadaveric human eyes showed expression of hepcidin, Fpn, and Cp in these samples. Notably, Fpn and Cp were expressed on the basolateral membrane of non-pigmented ciliary epithelial cells, facing the AH.

CONCLUSIONS

Synthesis and expression of hepcidin and Fpn in the ciliary epithelium suggests local regulation of iron transport from choroidal plexus in the ciliary body to the AH across the blood-aqueous barrier. Expression of hepcidin and Fpn in CE, TM, and LE cells indicates additional regulation of iron exchange between the AH and cornea, TM, and lens, suggesting autonomous regulation of iron homeostasis in the anterior segment. Physiological and pathological implications of these observations are discussed.

Upregulation of miR-630 Induced by Oxidative Damage Resists Cell Migration Through Targeting ALCAM in Human Lens Epithelium Cells

Purpose: To investigate the role of miRNAs in regulating oxidative damage during cataract formation.Methods: Microarray analysis and gene expression profiling assay were used to separately evaluate the miRNAs and mRNAs profiles in normal human lens epithelium cell line HLE-B3 treated by H₂O₂. The expression level of miR-630 was detected by RT-qPCR and the gene expression profiles were performed with gene ontology analysis using Bio Informatical database. The targets of miR-630 were predicted using miRecords and the results were used for screening targets of miR-630 combined with the GO analysis above. The mRNA levels of ALCAM, PCDH7, COL12A2, and EDIL3 in HLE-B3 cells after oxidative stimulation or miR-630 mimics transfection were measured by RT-qPCR, and the expression of ALCAM regulated by miR-630 was confirmed by Western blot and dual-luciferase reporter gene assay. The level of cell migration was measured by transwell assay and scratching test after transfection of miR-630 mimics and ALCAM siRNAs.Results: The microarray analysis demonstrated that miR-630 was significantly increased in HLE-B3 cells after oxidative stimulation. ALCAM, PCDH7, COL12A2, and EDIL3 were screened to be the possible targets of miR-630 by miRecords combined with GO analysis, but the results of RT-qPCR, Western blot and dual-luciferase reporter gene assay showed that only the expression of ALCAM was repressed by miR-630 transfection. Cell migration was inhibited through transfection of miR-630 mimics or ALCAM siRNAs and the upregulation of miR-630 partly reduced the cell migration increased by oxidative stimulation.Conclusion: miR-630 is one of the miRNAs increased by oxidative stimulation in human lens epithelium cells. Its upregulation may inhibit cell migration by targeting on ALCAM, which is important for HLECs to resist behavioral changes induced by oxidative damage and may delay the progression of cataract.

Protective effects of hesperidin and diosmin against acrylamide-induced liver, kidney, and brain oxidative damage in rats

Acrylamide (AA) is a heat-induced toxin formed during thermal processing of many commonly consumed foods, including meat products, French fries, potato crisps, bread, cereals, cookies, and coffee. There is thus potentially high dietary exposure of humans to AA, which can induce significant oxidative stress. Hesperidin (HS) and diosmin (DS) are flavone glycosides that have antioxidant properties. The aim of this study was to investigate the protective effects of HS and DS against AA toxicity. Fifty-six adult male Wistar albino rats were divided into seven groups. The first group was orally administered 0.5% (w/v) dimethyl sulfoxide (DMSO) and considered as the control group. The second and third groups were orally administered 10 mg/kg/day of HS or DS, respectively. The fourth group received 20 mg/kg/day of AA orally for 14 days. The fifth and sixth groups were given 10 mg/kg/day of HS or DS, respectively, followed by AA. The seventh group was given both HS and DS after AA administration. AA intoxication significantly (p ≤ 0.05) increased serum levels of liver function enzymes (ALT, AST, and ALP), kidney function products (urea and creatinine), oxidative DNA damage marker (OHdG), proinflammatory markers (TNF-α, IL-1β, and IL-6), lipid peroxidation marker (malondialdehyde), and nitric oxide (NO). On the other hand, it significantly (p ≤ 0.05) decreased levels of reduced glutathione (GSH) in the liver, kidney, and brain. The activities of glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), and catalase (CAT) in the liver, kidney, and brain tissues were also reduced. HS and DS supplementation prevented lipid peroxidation, normalized the serum parameters altered by AA, and enhanced the tissue concentrations and activities of antioxidant biomarkers. It could be concluded that HS and DS have potent protective effects against oxidative stress, lipid peroxidation, and DNA damage induced by AA toxicity in rats.

(Z)-7,4'-Dimethoxy-6-hydroxy-aurone-4-O-β-glucopyranoside mitigates retinal degeneration in Rd10 mouse model through inhibiting oxidative stress and inflammatory responses

Purpose: As an inherited retinal dystrophy characterised by progressive degeneration of photoreceptor cells, retinitis pigmentosa (RP) leads to partial or total blindness eventually. Possible causes of the photoreceptor cell death are oxidative stress and inflammatory responses. (Z)-7,4'-Dimethoxy-6-hydroxy-aurone-4-O-β-glucopyranoside (DHAG) is a novel compound with potent antioxidant properties. The aim of this study was to investigate whether DHAG could mitigate photoreceptor cell degeneration in an established mouse model of RP.Materials and method: Rd10 mice were treated with DHAG daily by gavage from postnatal day 12 (P12) to P33. Retinal morphology was evaluated by haematoxylin and eosin staining. Apoptosis-positive cells were detected by terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL) assay. Oxidative stress markers and inflammatory factors were measured by enzyme-linked immunosorbent assay (ELISA). Real-time polymerase chain reaction, immunostaining and western blot were applied to measure the gene and protein change to explore the underlying mechanisms.Results: Results showed that DHAG significantly preserved the retinal morphology, reducing photoreceptor cell apoptosis, decreasing oxidative stress and inhibiting inflammatory responses in Rd10 mice. The mechanism might be related to inhibit the activation of P38 pathway.Conclusions: This study showed the beneficial effects of DHAG, a compound possessing antioxidant properties, and provided scientific rationale to develop DHAG as a potential agent to treat RP.

Ursolic acid modulates MMPs, collagen-I, α-SMA, and TGF-β expression in isoproterenol-induced myocardial infarction in rats

In the present study, the modulatory effect of ursolic acid (UA) on cardiac fibrosis and mitochondrial and lysosomal enzymes activity in isoproterenol-induced myocardial infarction (MI) in rats were examined. Isoproterenol hydrochloride (ISO; 85 mg/kg body weight) was administered subcutaneously for first two consecutive days. ISO-induced MI in rats significantly decreased the activities of mitochondrial tricarboxylic acid cycle enzymes and respiratory chain enzymes while increased the activities of lysosomal glycohydrolases and cathepsins. The expression of matrix metalloproteinase 2 (MMP-2), MMP-9, collagen type I, α-smooth muscle actin (α-SMA), and transforming growth factor-β (TGF-β) were upregulated in ISO-induced MI in rats. UA administration to rats showed increased activities of mitochondrial tricarboxylic acid cycle enzymes and respiratory chain enzymes and decreased activities of lysosomal glycohydrolases and cathepsins in ISO-induced rats. Furthermore, expression of MMP-2, MMP-9, collagen type I, α-SMA, and TGF-β downregulated in UA-administered rats. Thus, our results demonstrate that UA has an anti-fibrotic effect and attenuates the mitochondrial and lysosomal dysfunction in ISO-induced MI in rats.

Conjunctival dysbiosis in mucosa-associated lymphoid tissue lymphoma

To investigate the conjunctival microbiota and the association between the development of conjunctival mucosa-associated lymphoid tissue (MALT) lymphoma and dysbiosis, DNA samples were collected from 25 conjunctival MALT lymphoma patients and 25 healthy controls. To compare the microbiota, samples were collected from the following four body locations: conjunctiva, meibomian gland, periocular skin and hand. Extracted DNA was analyzed by 16S rRNA sequences, and libraries were sequenced on an Illumina MiSeq sequencer. The differences in bacteria were characterized by using principal coordinate analysis of metagenomics data, and the differences in bacterial compositions were evaluated by linear discriminant analysis effect size. The conjunctival microbiota of MALT lymphoma patients was compositionally different from that of healthy controls. For the conjunctival MALT lymphoma patients, alterations in the microbial composition were detected, and a remarkable change was detected at the conjunctiva. Detailed analysis showed that a specific population of the microbiota, the genus Delftia, was significantly more abundant in conjunctival MALT lymphoma patients, and the genera Bacteroides and Clostridium were less abundant in the MALT lymphoma patients. A specific microbiota on the ocular surface in conjunctival MALT lymphoma patients was detected, and dysbiosis may play an important role in the pathophysiology of conjunctival MALT lymphoma.

Down-regulated LAMA4 inhibits oxidative stress-induced apoptosis of retinal ganglion cells through the MAPK signaling pathway in rats with glaucoma

Glaucoma is a neurodegenerative disorder that is generally accepted as the main cause of vision loss. In this study, we tested the hypothesis that laminin α4 (LAMA4) is implicated in glaucoma development by controlling apoptosis of retinal ganglion cells (RGCs) through the mitogen-activated protein kinase (MAPK) signaling pathway. Expression profiles and genes associated with glaucoma were searched to determine the objective gene. Intraocular pressure (IOP) rats model were established and IOP was measured. The mRNA and protein expression of LAMA4, JNK, p38 MAPK, ERK, Bcl-2, Bax, Caspase-9, and p53 was determined in concert with the treatment of H₂O₂, si-NC, or si-LAMA4 in cultured RGCs. Viability of RGCs, reactive oxygen species (ROS) and cell apoptosis was also measured. LAMA4 was selected as the study object because of its significant difference in two expression profiles. IOP of rats with glaucoma increased significantly after model establishment, and the LAMA4 protein expression in retinal tissue of rats with glaucoma was elevated. Down-regulation of LAMA4 could inhibit the mRNA and protein expression of LAMA4, JNK, p38 MAPK, ERK, Bax, Caspase-9, and p53, as well as restrain the apoptosis and ROS of RGCs, but improve Bcl-2 expression and viability of RGCs. Collectively, the obtained data supported that downregulated LAMA4 might reduce the oxidative stress-induced apoptosis of glaucoma RGCs by inhibiting the activation of the MAPK signaling pathway.

Antioxidant effects of piperine in in-vivo chick embryo cataract model induced by steroids

PURPOSE

The etiopathogenesis of steroid-induced cataracts is unknown. One hypothesis is that the higher reactive oxygen species (ROS) levels play an important role in the pathogenesis of several disorders, including the evolution of cataracts. This study investigated the antioxidant effects of piperine in our steroid-induced chick embryo lens model.

METHODS

The study included 36 specific pathogen-free (SPF) fertilized eggs divided into six groups: phosphate buffer saline (PBS, pH 7.4 Saline Solution (0.9%) isotonic) group (G1), hydrocortisone succinate sodium (HC)-treated group (G2), 100 mg/kg piperine and HC treated group (G3), 50 mg/kg piperine and HC treated group (G4), 25 mg/kg piperine and HC treated group (G5), and 10 mg/kg piperine and HC treated group (G6). On the 15th day of incubation, the SPF eggs in the six groups were removed from the incubator; all were injected using insulin injectors into the chorioallantoic membrane. On day 17, all of the chick embryos were removed from the eggs and all lenses were dissected from the embryos. Cataract formation was evaluated in all lenses, and total antioxidant status (TAS), total oxidant status (TOS), reduced glutathione (GSH), and lipid peroxidation (MDA, malondialdehyde) levels were measured in all lens.

RESULTS

The lenses in the G1 group had higher levels of GSH and TAS (p < 0.01), and lower levels of MDA and TOS than the G2 group (p < 0.05 and p < 0.01, respectively). Group 3 had higher levels of GSH and TAS (p < 0.001 and p < 0.001 respectively), and lower levels of MDA and TOS than the G2 group (p < 0.01 and p < 0.001, respectively).

CONCLUSION

Steroid therapy causes a decrease in GSH and TAS levels and an increase in TOS and MDA levels in lens tissues, indicating increased oxidative stress. Piperine exerts its effects as an antioxidant substance, in increasing doses.

S-Allylmercapro-N-Acetylcysteine Attenuates the Oxidation-Induced Lens Opacification and Retinal Pigment Epithelial Cell Death In Vitro

The capacity of S-Allylmercapto-N-acetylcysteine (ASSNAC) to protect human retinal pigment epithelial (RPE) cells (line ARPE-19) and porcine lenses from oxidative stress was studied. Confluent ARPE-19 cultures were incubated with ASSNAC or N-acetyl-cysteine (NAC) followed by exposure to oxidants and glutathione level and cell survival were determined. Porcine lenses were incubated with ASSNAC and then exposed to H₂O₂ followed by lens opacity measurement and determination of glutathione (reduced (GSH) and oxidized (GSSG)) in isolated lens adhering epithelial cells (lens capsule) and fiber cells consisting the lens cortex and nucleus (lens core). In ARPE-19 cultures, ASSNAC (0.2 mM; 24 h) increased glutathione level by 2–2.5-fold with significantly higher increase in GSH compared to NAC treated cultures. Similarly, ex-vivo exposure of lenses to ASSNAC (1 mM) significantly reduced the GSSG level and prevented H₂O₂ (0.5 mM)-induced lens opacification. These results demonstrate that ASSNAC up-regulates glutathione level in RPE cells and protects them from oxidative stress-induced cell death as well as protects lenses from oxidative stress-induced opacity. Further validation of these results in animal models may suggest a potential use for ASSNAC as a protective therapy in retinal degenerative diseases as well as in attenuation of oxidative stress-induced lens opacity.

Natural Preservatives for Extending the Shelf-Life of Seafood: A Revisit

Consumer demand for minimally processed seafood that retains its sensory and nutritional properties after handling and storage is increasing. Nevertheless, quality loss in seafood occurs immediately after death, during processing and storage, and is associated with enzymatic, microbiological, and chemical reactions. To maintain the quality, several synthetic additives (preservatives) are promising for preventing the changes in texture and color, development of unpleasant flavor and rancid odor, and loss of nutrients of seafood during storage at low temperature. However, the use of these preservatives has been linked to potential health hazards. In this regard, natural preservatives with excellent antioxidant and antimicrobial properties have been extensively searched and implemented as safe alternatives in seafood processing, with the sole purpose of extending shelf-life. Natural preservatives commonly used include plants extracts, chitosan and chitooligosaccharide, bacteriocins, bioactive peptides, and essential oils, among others. This review provides updated information about the production, mode of action, applications, and limitations of these natural preservatives in seafood preservation.

Oxidative stress and reactive oxygen species: a review of their role in ocular disease

For many years, oxidative stress arising from the ubiquitous production of reactive oxygen species (ROS) has been implicated in the pathogenesis of various eye diseases. While emerging research has provided some evidence of the important physiological role of ROS in normal cell function, disease may arise where the concentration of ROS exceeds and overwhelms the body’s natural defence against them. Additionally, ROS may induce genomic aberrations which affect cellular homoeostasis and may result in disease. This literature review examines the current evidence for the role of oxidative stress in important ocular diseases with a view to identifying potential therapeutic targets for future study. The need is particularly pressing in developing treatments for conditions which remain notoriously difficult to treat, including glaucoma, diabetic retinopathy and age-related macular degeneration.

Ghrelin Protects Human Lens Epithelial Cells against Oxidative Stress-Induced Damage

Oxidative stress has been recognized as an important mediator in the pathogenesis of age-related cataracts; using antioxidant supplements is one plausible strategy to protect the antioxidative defense system against oxidative stress. Ghrelin administration is expected to reduce ROS, preventing the onset of different diseases. The role of ghrelin, if any, in protecting against oxidative stress in HLECs has never been examined. In the present study, we investigated the effects of ghrelin against H₂O₂-induced oxidative stress and the associated molecular mechanisms in HLECs and rat lenses. The results showed that pretreatment with ghrelin reduced H₂O₂-induced cellular apoptosis and ROS accumulation, increased the expression levels of SOD and CAT, and decreased the expression level of MDA. The morphological examination showed that the ghrelin-treated lens organ culture maintained transparency. This is the first report to show that ghrelin can protect HLECs from H₂O₂-induced oxidative stress. Our findings suggest that ghrelin may prevent the progression of cataracts, which has treatment value for ophthalmologists.

Molecular Age-Related Changes in the Anterior Segment of the Eye

Purpose

To examine the current knowledge about the age-related processes in the anterior segment of the eye at a biological, clinical, and molecular level.

Methods

We reviewed the available published literature that addresses the aging process of the anterior segment of the eye and its associated molecular and physiological events. We performed a search on PubMed, CINAHL, and Embase using the MeSH terms “eye,” “anterior segment,” and “age.” We generated searches to account for synonyms of these keywords and MESH headings as follows: (1) “Eye” AND “ageing process” OR “anterior segment ageing” and (2) “Anterior segment” AND “ageing process” OR “anterior segment” AND “molecular changes” AND “age.” Results. Among the principal causes of age-dependent alterations in the anterior segment of the eye, we found the mutation of the TGF-β gene and loss of autophagy in addition to oxidative stress, which contributes to the pathogenesis of degenerative diseases.

Conclusions

In this review, we summarize the current knowledge regarding some of the molecular mechanisms related to aging in the anterior segment of the eye. We also introduce and propose potential roles of autophagy, an important mechanism responsible for maintaining homeostasis and proteostasis under stress conditions in the anterior segment during aging.

Bioinformatics Study of m.9053G>A Mutation at the ATP6 Gene in Relation to Type 2 Diabetes Mellitus and Cataract Diseases

The mitochondrial disease often associated with various illnesses in relation to the activity of cells metabolites and the synthesis of adenosine triphosphate (ATP), including alteration in the mitochondrial DNA. The mutation of m.9053G>A at the ATP6 gene was found in patients with type 2 diabetes mellitus (DM type 2) and cataract. Therefore, this mutation is predicted to be clinical features of the 2 diseases. ATP6 gene encodes protein subunit of ATPase6, a part of ATP synthase, which is important in the electron transfer and proton translocation in intracellular respiration system. This study aims to investigate the mutation effect of m.9053G>A at the ATP6 gene (S167N) to the structure and function of ATPase6 using bioinformatics method. The structure of ATPase6 was constructed using homology modeling method. The crystal structure of bovine’s ATP synthase (Protein Data Bank ID 5FIL) was used as a template because of high sequence similarity (77%) and coverage (96%) of the input sequence. The effect of mutation was investigated at the proton translocation channel of ATPase6. It is predicted that the channel was disrupted due to changes in electrostatic potential from serine to asparagine. Furthermore, molecular docking suggests that water binding on the proton translocation channel in the S167N mutant was different from the wild type. The result of this study is hoped to be useful in the development of a new genetic marker for DM type 2 and cataract.