Glutathione-related antioxidant defense system in patients with hypertensive retinopathy

Microfluidic contact lens for continuous monitoring of ocular oxidative stress

Oxidative stress-induced ocular dysfunctions are a significant global health concern. Glutathione (GSH), an abundant antioxidant in tears, can serve as an index for oxidative stress (OS). A coumarin-based fluorescent probe named CCAE was synthesized for GSH monitoring, functioning through structural changes via Michael's addition with GSH and elimination by H2O2, which restores the conjugation structure to assess the severity of OS-induced ocular diseases. CCAE demonstrated a high sensitivity with a detection limit (LOD) of 0.12 mM and reversibility for 15 cycles. A wearable contact lens sensor was developed featuring a microfluidic lens patterned with a 365 nm pulsed laser, requiring 6 μL of tears. CCAE was encapsulated in citric acid-crosslinked poly(vinyl alcohol) film and embedded in poly((hydroxyethyl)methacrylate-co-ethylene glycol)/polyvinylpyrrolidone (poly(HEMA-co-EG)/PVP) lenses. A customized smartphone readout device enabled quantitative GSH readings for point-of-care applications. Tested on an ex vivo porcine anterior eye model, the sensor achieved an LOD of 0.204 mM, within a detection range of 0.62-1.17 mM and 0.13-0.73 mM under mild and severe OS conditions respectively. The sensors maintained operational stability for 2 days and storage stability for 1 week. This reversible GSH contact lens sensor offers a unique platform for diagnosing and monitoring OS-related ocular conditions at point-of-care settings.

Evaluation of Ocular and Systemic Oxidative Stress Markers in Patients with Diabetic Retinopathy

Proliferative diabetic retinopathy (PDR) is the most severe complication of chronic hyperglycaemi stimulates oxidative stress that changes the retinal basement membrane function and provokes neovascularization, macular edema and retinal detachment. But an oxidative-antioxidant biomarker assessment in ocular matrices, such as aqueous humor (AH) and vitreous, might show the oxidative stress (OS) status in the posterior segment. Here, we show a cross-sectional analytical study of 39 patients who had a vitrectomy and assess the levels of different oxidative-antioxidant biomarkers in blood, aqueous and vitreous humor in three groups: diabetes mellitus 2 (DM2) with PDR [DM(+)PDR(+)] (n =13), DM2 without PDR [DM(+)PDR(-)] (n = 13) and non-DM2 non-PDR [DM(-)PDR(-)] as the control group (n = 13). Our finding suggests the presence of oxidative stress in diabetic retinopathy, as evidenced by increased levels of 8-isoprostanes and decreased levels of total antioxidant capacity from stages before the development of diabetic retinopathy. Our results reveal a notable increment in catalase levels in the DM(+)PDR(+) group in blood and vitreous humor. Likewise, we identified that the DM(+)PDR(-) group presents significant levels in 8-IP and SOD in vitreous humor and blood versus aqueous humor. These finding suggest the role of antioxidant enzymes in compensating oxidative stress mechanisms in PDR development.

Identifying the signature of NAD+ metabolism-related genes for immunotherapy of gastric cancer

NAD (Nicotinamide Adenine Dinucleotide) -related metabolic reprogramming in tumor cells involves multiple vital cellular processes. However, the role of NAD metabolism in immunity and the prognosis of gastric cancer (GC) remains not elucidated. Here we identified and clustered 33 NAD + metabolism-related genes (NMRGs) based on 808 GC samples from the Cancer Genome Atlas (TCGA) and the Gene Expression Omnibus (GEO) databases. Survival analysis between different groups found a poor prognosis in the GC patients with high NMRGs expression. Gene SGCE, APOD, and PPP1R14A were identified and performed high expression in GC samples, while the qRT-PCR results further confirmed that their expression levels in GC cell lines were significantly higher than those from normal human gastric mucosa epithelial cells. Based on the single-cell analysis, Gene SGCE, APOD, and PPP1R14A can potentially be novel biomarkers of tumor-associated fibroblasts (CAFs). In parallel, the proliferation and migration of GC cells were significantly hampered following the knockdown of SGCE, APOD, and PPP1R14A, particularly APOD, we confirmed that APOD knockdown can inhibit β-catenin and N-cadherin expression, while promote E-cadherin expression. This study unveils a novel NMRGs-related gene signature, highlighting APOD as a prognostic biomarker linked to the tumor microenvironment. APOD drives GC cell proliferation and metastasis through the Wnt/β-catenin/EMT signaling pathway, establishing it as a promising therapeutic target for GC patients.

Tear Protein Markers for Diabetic Retinopathy and Diabetic Macular Edema - Towards an Early Diagnosis and Better Prognosis

BACKGROUND

Diabetic eye disease is a highly prevalent and sight-threatening disorder. It is a disease of neuro-vascular unit of the retina, if left untreated can cause blindness. Therapeutic approaches followed for its treatment can only restrict the progression of the disease with highly variable results. There is no known biomarker for an early diagonsis of this disease, therefore by the time it is detected it goes beyond repair. This creates a massive demand for development of such biomarkers that help detect disease in its earlier stages.

METHODS

PUBMED (https://pubmed.ncbi.nlm.nih.gov/) was searched for articles relevant to the topic published till November 2023. The search was made using keywords such as Diabetic Retinopathy, inflammation, tear, biomarker, proteomics etc. The studies providing relevant information to prove the importance of biomarker discovery were chosen. After compiling the data, the manuscript writing was planned under relevant headings and sub-headings.

RESULTS

The review provides a comprehensive overview of all the tear protein biomarker studies in the field of DR and DME. Briefly, their potential in other diseases is also elucidated. While there are many studies pertaining to DR biomarkers, the identified markers lack validations which has restricted their usage in clinics. In case of DME, there was no such study towards biomarker discovery for its diagnosis and prognosis.

CONCLUSIONS

The review highlights major studies and their lacunae in the field of biomarkers discovery for DR and DME.

Investigating wound healing potential of sesamol loaded solid lipid nanoparticles: Ex-vivo, in vitro and in-vivo proof of concept

Sesamol, a lignan, obtained from sesame seeds (Sesamum indicum Linn., Pedaliaciae) has a promising antioxidant, and anti-inflammatory profile. When applied topically, free sesamol rapidly crosses skin layers and gets absorbed in systemic circulation. Its encapsulation into solid lipid nanoparticles not only improved its localised delivery to skin but also resulted in better skin retention, as found in ex-vivo skin retention studies. Free and encapsulated sesamol was compared for antimicrobial and antibiofilm activity against some common skin pathogens and it was found that encapsulation improved the antimicrobial profile by 200%. In vivo evaluation in diabetic open excision wound model suggested that encapsulation of sesamol in SLNs substantially enhanced its wound healing potential when investigated for biophysical, biochemical and histological parameters. It was envisaged that this was achieved via inhibiting bacterial growth and clearing the bacterial biofilm at the wound site, and by regulating oxidative stress in skin tissue.

Facile and Green Fabrication of Highly Competent Surface-Modified Chlorogenic Acid Silver Nanoparticles: Characterization and Antioxidant and Cancer Chemopreventive Potential

The eco-friendly, cost-effective, and green fabrication of nanoparticles is considered a promising area of nanotechnology. Here, we report on the green synthesis and characterization of bovine serum albumin (BSA)-decorated chlorogenic acid silver nanoparticles (AgNPs-CGA-BSA) and the studies undertaken to verify their plausible antioxidant and antineoplastic effects. High-resolution transmission electron microscopy (HR-TEM), dynamic light scattering, X-ray diffraction, and Fourier transform infrared analyses depict an average mean particle size of ∼96 nm, spherical morphology, and nanocrystalline structure of AgNPs-CGA-BSA. DPPH scavenging and inhibition of lipid peroxidation signify the noticeable in vitro antioxidant potential of the nanoparticles. The in vitro experimental results demonstrate that AgNPs-CGA-BSA shows significant cytotoxicity to Dalton's lymphoma ascites (DLA) cells and generates an enhanced intracellular reactive oxygen species and oxidized glutathione (GSSG) and reduced glutathione (GSH) in DLA cells. Furthermore, mechanism investigation divulges the pivotal role of the downregulated expression of superoxide dismutase (SOD) and catalase (CAT), and these ultimately lead to apoptotic chromatin condensation in AgNPs-CGA-BSA-treated DLA cells. In addition, in vivo experiments reveal an excellent decrease in tumor cell count, an increase in serum GSH and CAT, SOD, and glutathione peroxidase activities, and a decrease in the malondialdehyde (MDA) level in DLA-bearing mice after AgNPs-CGA-BSA treatment. These findings suggest that the newly synthesized biogenic green silver nanoparticles have remarkable in vitro antioxidant and antineoplastic efficacy that triggers cytotoxicity, oxidative stress, and chromatin condensation in DLA cells and in vivo anticancer efficacy that enhances the host antioxidant status, and these might open a new path in T-cell lymphoma therapy.