Lipoic acid lessens Th1-mediated inflammation in lipopolysaccharide-induced uveitis reducing selectively Th1 lymphocytes-related cytokines release

Update on non-infectious uveitis treatment: anti-TNF-alpha and beyond

Non-infectious uveitis (NIU) encompasses a range of conditions marked by inflammation within various layers of the eye. NIU is a significant contributor to irreversible vision loss among the working-age population in developed countries. The aim of treating uveitis is to manage inflammation, prevent its recurrences and to restore or salvage vision. Presently, the standard treatment protocol for NIU involves initiating corticosteroids as the primary therapeutic agents, although more aggressive approaches and steroid sparing agent may be necessary in certain cases. These advanced treatments option include synthetic immunosuppressants like antimetabolites, calcineurin inhibitors and alkylating agents. For patients who exhibit an intolerance or resistance to corticosteroids and conventional immunosuppressive therapies, biologic agents have emerged as a promising alternative. Notably, among the biologic treatments evaluated, TNF-α inhibitors, anti-CD20 therapy and alkylating agents have shown considerable efficacy. In this review, we delve into the latest evidence surrounding the effectiveness of biologic therapy and introduce novel therapeutic strategies targeting immune components as potential avenues for advancing treatment of NIU.

T cells in ocular autoimmune uveitis: Pathways and therapeutic approaches

Autoimmune uveitis is a non-infectious intraocular condition that affects the uveal tract of the eye and threatens vision if not treated properly. Increasing evidence suggests that activated CD4⁺ T cells are associated with progressive and permanent destruction of photoreceptors in ocular autoimmune diseases. As such, the purpose of this review is to offer an overview of the role of CD4⁺ T cells in autoimmune uveitis as well as a justification for the current development and assessment of innovative autoimmune uveitis medications targeting CD4⁺ T cells. With an emphasis on T helper (Th)17, Th1, and Th2 cells, follicular helper CD4⁺ T cells, and regulatory T cells, this review presents a summary of recent research related to the pathways and signaling that encourage CD4⁺ T cells to develop into specialized effector cells. We also describe immunotherapeutic approaches based on CD4⁺ T cell subsets and their potential as therapeutic agents for autoimmune disorders.

Alpha-Lipoic Acid Inhibits Spontaneous Diabetes and Autoimmune Recurrence in Non-Obese Diabetic Mice by Enhancing Differentiation of Regulatory T Cells and Showed Potential for Use in Cell Therapies for the Treatment of Type 1 Diabetes

Type 1 diabetes (T1D) is caused by the destruction of β cells in pancreatic islets by autoimmune T cells. Islet transplantation has been established as an effective treatment for T1D. However, the survival of islet grafts is often disrupted by recurrent autoimmunity. Alpha-lipoic acid (ALA) has been reported to have immunomodulatory effects and, therefore, may have therapeutic potential in the treatment of T1D. In this study, we investigated the therapeutic potential of ALA in autoimmunity inhibition. We treated non-obese diabetic (NOD) mice with spontaneous diabetes and islet-transplantation mice with ALA. The onset of diabetes was decreased and survival of the islet grafts was extended. The populations of Th1 cells decreased, and regulatory T cells (Tregs) increased in ALA-treated mice. The in vitro Treg differentiation was significantly increased by treatment with ALA. The adoptive transfer of ALA-differentiated Tregs into NOD recipients improved the outcome of the islet grafts. Our results showed that in vivo ALA treatment suppressed spontaneous diabetes and autoimmune recurrence in NOD mice by inhibiting the Th1 immune response and inducing the differentiation of Tregs. Our study also demonstrated the therapeutic potential of ALA in Treg-based cell therapies and islet transplantation used in the treatment of T1D.

Licarin A as a Novel Drug for Inflammatory Eye Diseases

Purpose: This study investigated the safety and therapeutic efficacy of licarin A (LCA) in the treatment of intraocular inflammation. Methods: In vitro safety of LCA in retinal pigmented epithelial cells (ARPE-19) and human embryonic stem cell derived-retinal pigmented epithelial cells (hES-RPE) was evaluated using CellTiter-Blue^® kit. The chorioallantoic membrane (CAM) assay was used to investigate LCA safety and antiangiogenic activity. In vivo safety of intravitreal LCA was accomplished by clinical examination (including assessment of intraocular pressure), electroretinography (ERG), and histopathology. Uveitis was induced in rats by subcutaneous and intravitreal injection of bacillus Calmette-Guérin (BCG) antigen of Mycobacterium bovis. Intraocular inflammation was graded by slit-lamp and fundus examination, ERG, and histopathology. Results: LCA was safe to cells and to the CAM at concentration below 12.0 μM. LCA significantly reduced the percentage of blood vessels in the CAM. Retinal safety and anti-inflammatory efficacy of intravitreal injection of LCA 6.0 μM were confirmed through clinical, functional, and histopathological evaluation. Significant reduction of inflammatory cytokines (tumor necrosis factor-α and interleukin-6) was also found, when compared to untreated animals. Conclusion: The results suggest that LCA is a potential new drug for the treatment of inflammatory eye disease.

Bevacizumab Diminishes Inflammation in an Acute Endotoxin-Induced Uveitis Model

Introduction: Uveitis is an eye disease characterized by inflammation of the uvea and an early and exhaustive diagnosis is essential for its treatment. The aim of our study is to assess the potential toxicity and anti-inflammatory efficacy of Bevacizumab in an experimental uveitis model by subcutaneously injecting lipopolysaccharide into Lewis rats and to clarify its mechanism. Material and Methods: Blood-aqueous barrier integrity was assessed 24 h after endotoxin-induced uveitis (EIU) by analyzing two parameters: cell count and protein concentration in aqueous humors. Histopathology of all eye structures was also studied. Enzyme-linked immunosorbent analyses of the aqueous humor samples were performed in order to calculate the diverse chemokine and cytokine protein levels and oxidative stress-related markers were also evaluated. Results: The aqueous humor's cellular content significantly increased in the group treated with only Bevacizumab, but it had no effect on retina histopathological grading. Nevertheless, the inflammation noted in ocular structures when administering Bevacizumab with endotoxin was mostly prevented since aqueous humor cell content considerably lowered, and concomitantly with a sharp drop in uveal, vitreous, and retina histopathological grading. The values of the multi-faceted cytokine IL-2 also significantly decreased (p < 0.05 vs. endotoxin group), and the protective IL-6 and IL-10 cytokines values rose with related anti-oxidant system recovery (p < 0.05 vs. endotoxin group). Concurrently, some related M1 macrophage chemokines substantially increased, e.g., GRO/KC, a chemokine that also displays any kind of protective role. Conclusion: All these results revealed that 24 h after being administered, Bevacizumab treatment in EIU significantly prevented inflammation in various eye structures and correct results in efficacy vs. toxicity balance were obtained.

New Immunosuppressive Therapies in Uveitis Treatment

Uveitis is an inflammatory process that initially starts in the uvea, but can also affect other adjacent eye structures, and is currently the fourth cause of blindness in developed countries. Corticoids are probably the most widespread treatment, but resorting to other immunosuppressive treatments is a frequent practice. Since the implication of different cytokines in uveitis has been well demonstrated, the majority of recent treatments for this disease include inhibitors or antibodies against these. Nevertheless, adequate treatment for each uveitis type entails a difficult therapeutic decision as no clear recommendations are found in the literature, despite the few protocolized clinical assays and many case-control studies done. This review aims to present, in order, the mechanisms and main indications of the most modern immunosuppressive drugs against cytokines.

Macrophages and Uveitis in Experimental Animal Models

Resident and infiltrated macrophages play relevant roles in uveitis as effectors of innate immunity and inductors of acquired immunity. They are major effectors of tissue damage in uveitis and are also considered to be potent antigen-presenting cells. In the last few years, experimental animal models of uveitis have enabled us to enhance our understanding of the leading role of macrophages in eye inflammation processes, including macrophage polarization in experimental autoimmune uveoretinitis and the major role of Toll-like receptor 4 in endotoxin-induced uveitis. This improved knowledge should guide advantageous iterative research to establish mechanisms and possible therapeutic targets for human uveitis resolution.

Oxidative stress in myopia

Myopia affected approximately 1.6 billion people worldwide in 2000, and it is expected to increase to 2.5 billion by 2020. Although optical problems can be corrected by optics or surgical procedures, normal myopia and high myopia are still an unsolved medical problem. They frequently predispose people who have them to suffer from other eye pathologies: retinal detachment, glaucoma, macular hemorrhage, cataracts, and so on being one of the main causes of visual deterioration and blindness. Genetic and environmental factors have been associated with myopia. Nevertheless, lack of knowledge in the underlying physiopathological molecular mechanisms has not permitted an adequate diagnosis, prevention, or treatment to be found. Nowadays several pieces of evidence indicate that oxidative stress may help explain the altered regulatory pathways in myopia and the appearance of associated eye diseases. On the one hand, oxidative damage associated with hypoxia myopic can alter the neuromodulation that nitric oxide and dopamine have in eye growth. On the other hand, radical superoxide or peroxynitrite production damage retina, vitreous, lens, and so on contributing to the appearance of retinopathies, retinal detachment, cataracts and so on. The objective of this review is to suggest that oxidative stress is one of the key pieces that can help solve this complex eye problem.

An anti-interleukin-2 receptor drug attenuates T- helper 1 lymphocytes-mediated inflammation in an acute model of endotoxin-induced uveitis

The aim of the present study was to evaluate the anti-inflammatory efficacy of Daclizumab, an anti-interleukin-2 receptor drug, in an experimental uveitis model upon a subcutaneous injection of lipopolysaccharide into Lewis rats, a valuable model for ocular acute inflammatory processes. The integrity of the blood-aqueous barrier was assessed 24 h after endotoxin-induced uveitis by evaluating two parameters: cell count and protein concentration in aqueous humors. The histopathology of all the ocular structures (cornea, lens, sclera, choroid, retina, uvea, and anterior and posterior chambers) was also considered. Enzyme-linked immunosorbent assays of the aqueous humor samples were performed to quantify the levels of the different chemokine and cytokine proteins. Similarly, a biochemical analysis of oxidative stress-related markers was also assessed. The inflammation observed in the anterior chamber of the eyes when Daclizumab was administered with endotoxin was largely prevented since the aqueous humor protein concentration substantially lowered concomitantly with a significant reduction in the uveal and vitreous histopathological grading. Th1 lymphocytes-related cytokines, such as Interleukin-2 and Interferon-γ, also significantly reduced with related anti-oxidant systems recovery. Daclizumab treatment in endotoxin-induced uveitis reduced Th1 lymphocytes-related cytokines, such as Interleukin-2 and Interferon gamma, by about 60–70% and presented a preventive role in endotoxin-induced oxidative stress. This antioxidant protective effect of Daclizumab may be related to several of the observed Daclizumab effects in our study, including IL-6 cytokine regulatory properties and a substantial concomitant drop in INFγ. Concurrently, Daclizumab treatment triggered a significant reduction in both the uveal histopathological grading and protein concentration in aqueous humors, but not in cellular infiltration.