Can the cGAS-STING Pathway Play a Role in the Dry Eye?

Efficacy and Safety of Quantum Molecular Resonance Electrotherapy in Dry Eye Disease: A Systematic Review with Meta-analysis

INTRODUCTION

This study aimed to investigate the efficacy and safety of quantum molecular resonance (QMR) electrotherapy in patients with dry eye disease (DED).

METHODS

A systematic review with meta-analysis, reporting the effects of QMR electrotherapy in three databases, PubMed, Scopus and Web of Science, was performed according to the PRISMA statement with a search period ending on December 24, 2024.

RESULTS

Seven studies, including four open-label, non-comparative trials and three randomized controlled studies (RCTs), were included. Although all studies reported significant improvements in most outcome measures after QMR electrotherapy, the meta-analysis indicated that overall efficacy did not significantly favor either group when comparing QMR electrotherapy to controls (SMD 0.40; 95% CI - 0.06 to 0.86; P = 0.09; I2 = 85%). However, only the change in DED symptoms was significantly favorable for QMR electrotherapy compared to controls (SMD 0.69; 95% CI 0.30-1.08; P = 0.0005; I2 = 28%). In sensitivity analyses, overall efficacy remained non-significant when comparing QMR electrotherapy to placebo QMR electrotherapy (SMD 0.14; 95% CI - 0.24 to 0.52; P = 0.46; I2 = 65%). Additionally, changes in DED symptoms, TBUT, ST, and CFS also showed no statistically significant differences between both groups. Regarding safety, most studies reported no AEs, with a satisfactory tolerability profile for QMR electrotherapy. However, a meta-analysis could not be performed.

CONCLUSIONS

With the current scientific literature available to date, QMR electrotherapy seems to show some evidence of alleviating DED symptoms. However, evidence supporting its efficacy in improving DED signs and safety remains limited. Therefore, further RCTs with robust designs are needed to confirm these findings.

The alterations of ocular surface metabolism and the related immunity inflammation in dry eye

Background

Dry eye disease (DED) stands as a prominent ocular condition of global prevalence, emerging as a growing concern within public health. However, the underlying mechanisms involved in its pathogenesis remain largely unknown. In recent years, with the development of metabolomics, numerous studies have reported alterations in ocular surface metabolism in DED and offered fresh perspectives on the development of DED.

Main text

The metabolic changes of the ocular surface of DED patients are closely intertwined with the cellular metabolism process and immune inflammation changes. This article expounds upon the correlation between ocular surface metabolism and immune inflammation alterations in DED in terms of glycolysis, lipid metabolism, amino acid metabolism, cellular signaling pathways, and immune inflammation regulation.

Conclusions

The alterations in ocular surface metabolism of patients with dry eye are closely associated with their inflammatory status. Our work contributes novel insights into the pathogenesis of dry eye diseases and offers innovative molecular targets for diagnosing, detecting, and managing DED patients.

Multidimensional immunotherapy for dry eye disease: current status and future directions

Dry Eye Disease (DED) is a multifactorial condition driven by tear film hyperosmolarity, immune dysregulation, and neuro-immune interactions. The immune system plays a central role in its pathogenesis, influencing both inflammation and ocular surface damage. While traditional immunotherapies like anti-inflammatory agents and immunosuppressants offer symptom relief, their long-term use is limited by side effects. This review focuses on emerging immunotherapies, including biologics, stem cell therapy, gene therapy, nanotechnology, and exosome-based treatments, all of which hold promise in modulating immune responses and promoting tissue repair. The relationship between the ocular microbiome and DED is also explored, with an emphasis on personalized immunotherapy. Key challenges for future research include identifying novel therapeutic targets, optimizing clinical translation, and evaluating the long-term efficacy of these innovative treatments.

The role of cGAS/STING signaling in ophthalmological diseases

The eye is one of the most vulnerable parts of the human body. There are many kinds of ophthalmic diseases, which are caused by multiple factors. Generally, ophthalmic diseases have the characteristics of complicated etiology and difficult therapy. With the development of the times, ophthalmic diseases have become a major problem that affects people's lives. Inflammation, a major factor inducing ocular diseases, is one of the most popular research directions. The cGAS/STING pathway is a recently discovered inflammatory signaling pathway, which recognizes double-stranded DNA (dsDNA) as an activation signal to promote the expression of downstream cytokines that promote inflammatory response or autoimmune response. Since most of the current treatments for ophthalmic diseases mainly rely on surgery, it is of positive significance to explore the pathogenesis for the discovery of drug targets. This review summarize the research progress of the cGAS/STING pathway in major ophthalmic diseases by introducing the correlation between classical inflammatory pathway and ophthalmic diseases, in order to predict the research direction and methods targeting the cGAS/STING pathway in the pathogenesis of ophthalmic diseases, and also provide guidance for the mechanism as well as molecular targets of ophthalmic diseases.

Unleashing Novel Therapeutic Strategies for Dry Eye: Targeting ROS and the cGAS-STING Signaling Pathway with Tetrahedral Framework Nucleic Acids

Dry eye affects majority of the global population, causing significant discomfort or even visual impairment, of which inflammation plays a crucial role in the deterioration process. This highlights the need for effective and safe anti-inflammatory treatments to achieve satisfactory therapeutic outcomes. This study focuses on the potential of tetrahedral framework nucleic acids (tFNA), a self-assembled nucleic acid material, as a simple and rapid treatment for oxidative stress and inflammation-induced disorders associated with dry eye. Mechanistically, tFNA is found to effectively alleviate dry eye damage by promoting corneal epithelial healing, restoring goblet cell function, and facilitating tear secretion recovery. Through RNA-seq analysis, it is observed that tFNA treatment normalizes the expression levels of most genes. Further exploration of the mechanism reveals that tFNA reduces excessive production of reactive oxygen species and modulates the inflammatory microenvironment, especially through cGAS-STING pathway thereby levels of inflammatory cytokines, including MMP9 and IL-6, are reduced. Additionally, tFNA demonstrates excellent safety performance without causing damage to the eye. Importantly, this study represents a successful application of nanophase materials with nucleic acid biological features for the effective treatment of dry eye, highlighting the potential clinical use of tFNA in the treatment of dry eye.

Aurantio-obtusin Alleviates Dry Eye Disease by Targeting NF-κB/NLRP3 Signaling in Rodent Models

Dry eye disease (DED) is a common inflammatory ocular surface disorder, seriously affecting the quality of life of patients. Aurantio-obtusin (AO) is a bioactive anthraquinone compound isolated from Semen Cassiae which has multiple pharmacological activities. Nonetheless, the specific function of AO in DED is unclarified. In this study, a rodent DED model was established by benzalkonium chloride (BAC) induction, followed by topical administration of AO. The results showed that topical application of AO increased tear production, mitigated ocular surface disruption and maintained the number of goblet cells in BAC-induced DED rats (p˂0.05). ELISA revealed that AO treatment significantly (p˂0.001) reduced the production of proinflammatory cytokines and chemokines in the conjunctiva and cornea of BAC-induced DED rats. Immunohistochemical staining and western blotting showed that AO treatment suppressed the expression levels of NLR family pyrin domain containing 3 (NLRP3) inflammasome-related proteins, and inhibited activation of nuclear factor kappa B (NF-κB) signaling pathway in rat conjunctiva and cornea (p˂0.001). In conclusion, AO treatment alleviates BAC-induced DED in rats by inhibiting NF-κB/NLRP3 inflammasome signaling pathway.

Enhancing Ocular Surface in Dry Eye Disease Patients: A Clinical Evaluation of a Topical Formulation Containing Sesquiterpene Lactone Helenalin

The aim of this work was to assess the tolerability, safety, and efficacy of an ophthalmic topical formulation containing helenalin from Arnica montana and hyaluronic acid 0.4% (HA) in patients with mild-to-moderate Dry Eye Disease (DED) exhibiting positive Matrix Metalloproteinase 9 (MMP-9) test results. Tolerability and safety were evaluated in 24 healthy subjects. Participants were instructed to apply one drop of the formulation three times a day in the study eye, for 2 weeks, followed by a clinical follow-up of 21 days. Efficacy was studied in 48 DED patients randomized into Study (Group 1/receiving the studied formulation) or Control (Group 2/Receiving HA 0.4% eye lubricant) groups for 1 month. Assessments included an MMP-9 positivity test, conjunctival impression cytology (CIC), Ocular Surface Disease Index (OSDI), non-invasive film tear breakup time (NIBUT), non-invasive average breakup time (NIAvg-BUT), ocular surface staining, Schirmer's test, and meibomiography. A crossover design with an additional 1-month follow-up was applied to both groups. Healthy subjects receiving the studied formulation exhibited good tolerability and no adverse events. Regarding the efficacy study, Group 1 exhibited a statistically significant reduction in the MMP-9 positivity rate compared to Group 2 (p < 0.001). Both Group 1 and Group 2 exhibited substantial improvements in OSDI and NIBUT scores (p < 0.001). However, Group 1 demonstrated a significant improvement in NI-Avg-BUT and Schirmer's test scores (p < 0.001), whereas Group 2 did not (p > 0.05). Finally, after the crossover, the proportion of MMP-9-positive subjects in Group 1 increased from 25% to 91.6%, while Group 2 showed a significant decrease from 87.5% to 20.8%. Overall, the topical formulation containing sesquiterpene helenalin from Arnica montana and hyaluronic acid was well tolerated and exhibited a favorable safety profile. Our formulation reduces DED symptomatology and modulates the ocular surface inflammatory process; this is evidenced by the enhancement of CIC, the improvement of DED-related tear film status, and the reduction of the MMP-9 positivity rate.

Visual analysis of autoimmune dry eye studies based on bibliometrics

BACKGROUND

Dry eye is a chronic ocular surface disease caused by the instability of tear film or the imbalance of the ocular surface microenvironment which can lead to a diverse range of ocular discomfort symptoms. At present, the relevant mechanism of autoimmunity and treatment of dry eye is still unclear. Due to the proliferation of research papers in this field, visual analysis of existing papers can provide reference for future research.

METHODS

The academic papers of Web of Science were searched with the topics of "autoimmunity" and "dry eye," and the countries, institutions and keywords of the literatures selected in this domain were visualized by Citespace and Vosviewer software.

RESULTS

A total of 787 valid international papers were detected, and the publication count exhibited a consistent upward trend year by year. Within this field, the US has produced the highest number of papers (363), with Baylor College of Medicine being the most prolific institution (28 publications). High-producing authors in this field include Artemis P. Simopoulos and Stephen C. Pflugfelder.

CONCLUSION

International research in this field has focused on the pathogenesis, symptoms, and treatment of dry eye. It is predicted that the future international research hotspots will be the pathophysiology of autoimmune dry eye disease, data analysis of artificial intelligence-related diseases, and research on improving patients' quality of life.

The cGAS-STING pathway-dependent sensing of mitochondrial DNA mediates ocular surface inflammation

The innate immune response is the main pathophysiological process of ocular surface diseases exposed to multiple environmental stresses. The epithelium is central to the innate immune response, but whether and how innate immunity is initiated by ocular epithelial cells in response to various environmental stresses in ocular surface diseases, such as dry eye, is still unclear. By utilizing two classic experimental dry eye models-a mouse ocular surface treated with benzalkonium chloride (BAC) and a mouse model with surgically removed extraorbital lachrymal glands, as well as dry eye patient samples-along with human corneal epithelial cells (HCE) exposed to hyperosmolarity, we have discovered a novel innate immune pathway in ocular surface epithelial cells. Under stress, mitochondrial DNA (mtDNA) was released into the cytoplasm through the mitochondrial permeability transition pore (mPTP) and further activated the cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) pathway, aggravating downstream inflammatory responses and ocular surface damage. Genetic deletion or pharmacological suppression of STING and inhibition of mtDNA release reduced inflammatory responses, whereas mtDNA transfection supported cytoplasmic mtDNA-induced inflammatory responses by activating the cGAS-STING pathway. Our study clarified the cGAS-STING pathway-dependent sensing of mitochondrial DNA-mediated ocular surface inflammation, which elucidated a new mechanism of ocular surface diseases in response to multiple environmental stresses.

Nucleic acid-sensing toll-like receptors: Important players in Sjögren’s syndrome

Sjögren’s syndrome (SS) is a chronic systemic autoimmune disease that affects the salivary and lacrimal glands, as well as other organ systems like the lungs, kidneys and nervous system. SS can occur alone or in combination with another autoimmune disease, such as systemic lupus erythematosus (SLE) or rheumatoid arthritis. The etiology of SS is unknown but recent studies have revealed the implication of the activation of innate immune receptors, including Toll-like receptors (TLRs), mainly through the detection of endogenous nucleic acids, in the pathogenesis of systemic autoimmune diseases. Studies on SS mouse models suggest that TLRs and especially TLR7 that detects single-stranded RNA of microbial or endogenous origin can drive the development of SS and findings in SS patients corroborate those in mouse models. In this review, we will give an overview of the function and signaling of nucleic acid-sensing TLRs, the interplay of TLR7 with TLR8 and TLR9 in the context of autoimmunity, summarize the evidence for the critical role of TLR7 in the pathogenesis of SS and present a possible connection between SARS-CoV-2 and SS.