Effects of TNFα receptor TNF-Rp55- or TNF-Rp75- deficiency on corneal neovascularization and lymphangiogenesis in the mouse

Platelet-derived extracellular vesicle drug delivery system loaded with kaempferol for treating corneal neovascularization

Platelet-derived extracellular vesicles (PEVs) have drawn attention due to their multifunctionality, ease of procurement, and abundant supply from clinical-grade platelet concentrates. PEVs can be readily endocytosed due to their lipid bilayer membrane and nanoscale structure, enhancing the bioavailability and efficacy of their therapeutic effects. PEVs also contain various trophic factors that enhance their effectiveness as therapeutic agents. Given that nanomedicine provides benefits over traditional treatments for eye diseases by surpassing physical ocular barriers, PEVs combined with the anti-angiogenic agent, kaempferol (KM), were assessed for their capacity to inhibit abnormal blood vessel formation in the cornea. Characterization of the nanoparticles suggested the successful preparation of KM-loaded PEVs (PEV-KM) with a mean diameter of approximately 160 nm and an encapsulation efficiency of around 61 %. PEV-KM was effectively internalized into human vascular endothelial cells, resulting in inhibited function, as evidenced by lower wound closure rates, decreased tube formation capacity, and downregulation of angiogenesis-related gene expression. Moreover, prolonged ocular retention was observed following the topical application of PEV and PEV-KM in mouse eyes. In an alkali-burned corneal neovascularization (CoNV) mouse model, PEV (1 %) was found to decrease vessel formation in the injured cornea. However, the combination of PEV and KM (1 % PEV with KM 6 μg/mL) showed an even stronger effect in inhibiting CoNV and decreasing the expression of proangiogenic and inflammatory cytokines. Overall, our data suggests that the topical administration of PEVs, either alone or alongside KM (PEV-KM), is a promising therapy for the management of CoNV.

Healing the cornea: Exploring the therapeutic solutions offered by MSCs and MSC-derived EVs

Affecting a large proportion of the population worldwide, corneal disorders constitute a concerning health hazard associated to compromised eyesight or blindness for most severe cases. In the last decades, mesenchymal stem/stromal cells (MSCs) demonstrated promising abilities in improving symptoms associated to corneal diseases or alleviating these affections, especially through their anti-inflammatory, immunomodulatory and pro-regenerative properties. More recently, MSC therapeutic potential was shown to be mediated by the molecules they release, and particularly by their extracellular vesicles (EVs; MSC-EVs). Consequently, using MSC-EVs emerged as a pioneering strategy to mitigate the risks related to cell therapy while providing MSC therapeutic benefits. Despite the promises given by MSC- and MSC-EV-based approaches, many improvements are considered to optimize the therapeutic significance of these therapies. This review aspires to provide a comprehensive and detailed overview of current knowledge on corneal therapies involving MSCs and MSC-EVs, the strategies currently under evaluation, and the gaps remaining to be addressed for clinical implementation. From encapsulating MSCs or their EVs into biomaterials to enhance the ocular retention time to loading MSC-EVs with therapeutic drugs, a wide range of ground-breaking strategies are currently contemplated to lead to the safest and most effective treatments. Promising research initiatives also include diverse gene therapies and the targeting of specific cell types through the modification of the EV surface, paving the way for future therapeutic innovations. As one of the most important challenges, MSC-EV large-scale production strategies are extensively investigated and offer a wide array of possibilities to meet the needs of clinical applications.

Research progress on the correlation between corneal neovascularization and lymphangiogenesis (Review)

The cornea is a clear connective tissue membrane at the front of the outer layer of the eyeball wall. It plays a crucial role in the refractive system of the eyeball, making it essential to maintain its transparency. Neovascularization and lymphangiogenesis in the cornea significantly impact corneal transparency and immune privilege. The growth of corneal neovascularization (CNV) and corneal lymphangiogenesis (CL) vessels is interconnected yet independent. Currently, there is a substantial amount of clinical and experimental research on CNV and CL vessels. However, due to the relatively recent focus on CL vessel research compared with CNV research, most scholars tend to concentrate on CNV, with few articles offering a comprehensive comparison and discussion of the two processes. The present review emphasizes the similarities and differences between CNV and CL and summarizes recent research progress on their correlation in animal models, growth characteristics, cytokine effects and related diseases.

Exploring TNFR1: from discovery to targeted therapy development

This review seeks to elucidate the therapeutic potential of tumor necrosis factor receptor 1 (TNFR1) and enhance our comprehension of its role in disease mechanisms. As a critical cell-surface receptor, TNFR1 regulates key signaling pathways, such as nuclear factor kappa-B (NF-κB) and mitogen-activated protein kinase (MAPK), which are associated with pro-inflammatory responses and cell death. The intricate regulatory mechanisms of TNFR1 signaling and its involvement in various diseases, including inflammatory disorders, infectious diseases, cancer, and metabolic syndromes, have attracted increasing scholarly attention. Given the potential risks associated with targeting tumor necrosis factor-alpha (TNF-α), selective inhibition of the TNFR1 signaling pathway has been proposed as a promising strategy to reduce side effects and enhance therapeutic efficacy. This review emphasizes the emerging field of targeted therapies aimed at selectively modulating TNFR1 activity, identifying promising therapeutic strategies that exploit TNFR1 as a drug target through an evaluation of current clinical trials and preclinical studies. In conclusion, this study contributes novel insights into the biological functions of TNFR1 and presents potential therapeutic strategies for clinical application, thereby having substantial scientific and clinical significance.

Nanoceria-Mediated Cyclosporin A Delivery for Dry Eye Disease Management through Modulating Immune-Epithelial Crosstalk

Dry eye disease (DED) affects a substantial worldwide population with increasing frequency. Current single-targeting DED management is severely hindered by the existence of an oxidative stress-inflammation vicious cycle and complicated intercellular crosstalk within the ocular microenvironment. Here, a nanozyme-based eye drop, namely nanoceria loading cyclosporin A (Cs@P/CeO2), is developed, which possesses long-term antioxidative and anti-inflammatory capacities due to its regenerative antioxidative activity and sustained release of cyclosporin A (CsA). In vitro studies showed that the dual-functional Cs@P/CeO2 not only inhibits cellular reactive oxygen species production, sequentially maintaining mitochondrial integrity, but also downregulates inflammatory processes and repolarizes macrophages. Moreover, using flow cytometric and single-cell sequencing data, the in vivo therapeutic effect of Cs@P/CeO2 was systemically demonstrated, which rebalances the immune-epithelial communication in the corneal microenvironment with less inflammatory macrophage polarization, restrained oxidative stress, and enhanced epithelium regeneration. Collectively, our data proved that the antioxidative and anti-inflammatory Cs@P/CeO2 may provide therapeutic insights into DED management.

Cellular toxicity profile of a new ophthalmic sponge

Introduction: Ophthalmic sponges are used for cleaning the eye surface and absorbing fluids during ophthalmic procedures. This study compared the biological safety and stability of a new ophthalmic sponge, Occucell® (OccuTech Inc, Seongnam, Korea), on the human conjunctival epithelial cells with those of preexisting products to evaluate its clinical application.Materials and Methods: The cytotoxicity of four products, Occucell, a new product, Ultracell®, Eyetec-1, and Eyetec-2, on conjunctival epithelial cells, was evaluated using the MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) analysis. Additionally, human conjunctival epithelial cells were stained with a Live & Dead marker and observed using a fluorescence microscope. To evaluate the effect of the ophthalmic sponges on the secretion of IL-1β and TNF-α, cultured conjunctival epithelial cells were treated with 0.5% DMSO eluates of the ophthalmic sponges, and IL-1β and TNF-α mRNA levels were estimated using real-time polymerase chain reaction assays.Results: Cells treated with Occucell showed comparable viability to those treated with other preexisting products. Conjunctival epithelial cells showed more than 90% viability when treated with the ophthalmic sponge extracts, as determined by the MTT assay. No significant differences in the number of live & dead cells were observed between the control and treatment groups. Cells treated with all four ophthalmic sponge eluates showed similar IL-1β and TNF-α mRNA levels.Discussion: Occucell, an eye sponge used during ophthalmic surgery in clinical practice, did not affect the viability of conjunctival epithelial cells, and more than 90% of the cells were viable after the treatment. Further, Occucell showed similar effects on IL-1β and TNF-α secretion as that of other ophthalmic sponges used in the clinic. This suggested that Occucell is a safe product comparable to the preexisting products.

Targeting Differential Roles of Tumor Necrosis Factor Receptors as a Therapeutic Strategy for Glaucoma

Glaucoma is an irreversible sight-threatening disorder primarily due to elevated intraocular pressure (IOP), leading to retinal ganglion cell (RGC) death by apoptosis with subsequent loss of optic nerve fibers. A considerable amount of empirical evidence has shown the significant association between tumor necrosis factor cytokine (TNF; TNFα) and glaucoma; however, the exact role of TNF in glaucoma progression remains unclear. Total inhibition of TNF against its receptors can cause side effects, although this is not the case when using selective inhibitors. In addition, TNF exerts its antithetic roles via stimulation of two receptors, TNF receptor I (TNFR1) and TNF receptor II (TNFR2). The pro-inflammatory responses and proapoptotic signaling pathways predominantly mediated through TNFR1, while neuroprotective and anti-apoptotic signals induced by TNFR2. In this review, we attempt to discuss the involvement of TNF receptors (TNFRs) and their signaling pathway in ocular tissues with focus on RGC and glial cells in glaucoma. This review also outlines the potential application TNFRs agonist and/or antagonists as neuroprotective strategy from a therapeutic standpoint. Taken together, a better understanding of the function of TNFRs may lead to the development of a treatment for glaucoma.

Topical application of TAK1 inhibitor encapsulated by gelatin particle alleviates corneal neovascularization

Rationale: Corneal neovascularization (CoNV) is a severe complication of various types of corneal diseases, that leads to permanent visual impairment. Current treatments for CoNV, such as steroids or anti-vascular endothelial growth factor agents, are argued over their therapeutic efficacy and adverse effects. Here, we demonstrate that transforming growth factor-β (TGF-β)-activated kinase 1 (TAK1) plays an important role in the pathogenesis of CoNV. Methods: Angiogenic activities were assessed in ex vivo and in vitro models subjected to TAK1 inhibition by 5Z-7-oxozeaenol, a selective inhibitor of TAK1. RNA-Seq was used to examine pathways that could be potentially affected by TAK1 inhibition. A gelatin-nanoparticles-encapsulated 5Z-7-oxozeaenol was developed as the eyedrop to treat CoNV in a rodent model. Results: We showed that 5Z-7-oxozeaenol reduced angiogenic processes through impeding cell proliferation. Transcriptome analysis suggested 5Z-7-oxozeaenol principally suppresses cell cycle and DNA replication, thereby restraining cell proliferation. In addition, inhibition of TAK1 by 5Z-7-oxozeaenol blocked TNFα-mediated NFκB signalling, and its downstream genes related to angiogenesis and inflammation. 5Z-7-oxozeaenol also ameliorated pro-angiogenic activity, including endothelial migration and tube formation. Furthermore, topical administration of the gelatin-nanoparticles-encapsulated 5Z-7-oxozeaenol led to significantly greater suppression of CoNV in a mouse model compared to the free form of 5Z-7-oxozeaenol, likely due to extended retention of 5Z-7-oxozeaenol in the cornea. Conclusion: Our study shows the potential of TAK1 as a therapeutic target for pathological angiogenesis, and the gelatin nanoparticle coupled with 5Z-7-oxozeaenol as a promising new eyedrop administration model in treatment of CoNV.

Corneal Epithelial Stem Cells-Physiology, Pathophysiology and Therapeutic Options

In the human cornea, regeneration of the epithelium is regulated by the stem cell reservoir of the limbus, which is the marginal region of the cornea representing the anatomical and functional border between the corneal and conjunctival epithelium. In support of this concept, extensive limbal damage, e.g., by chemical or thermal injury, inflammation, or surgery, may induce limbal stem cell deficiency (LSCD) leading to vascularization and opacification of the cornea and eventually vision loss. These acquired forms of limbal stem cell deficiency may occur uni- or bilaterally, which is important for the choice of treatment. Moreover, a variety of inherited diseases, such as congenital aniridia or dyskeratosis congenita, are characterized by LSCD typically occurring bilaterally. Several techniques of autologous and allogenic stem cell transplantation have been established. The limbus can be restored by transplantation of whole limbal grafts, small limbal biopsies or by ex vivo-expanded limbal cells. In this review, the physiology of the corneal epithelium, the pathophysiology of LSCD, and the therapeutic options will be presented.