Attenuation of Experimental Autoimmune Uveitis in Lewis Rats by Betaine

Microglial-mediated immune mechanisms in autoimmune uveitis: Elucidating pathogenic pathways and targeted therapeutics

This review offers a comprehensive examination of the role of microglia in the pathogenesis of autoimmune uveitis, an inflammatory eye disease with significant potential for vision impairment. Central to our discussion is the dual nature of microglial cells, which act as both protectors and potential perpetrators in the immune surveillance of the retina. We explore the mechanisms of microglial activation, highlighting the key signaling pathways involved, such as NF-κB, JAK/STAT, MAPK, and PI3K/Akt. The review also delves into the genetic and environmental factors influencing microglial behavior, underscoring their complex interaction in disease manifestation. Advanced imaging techniques and emerging biomarkers for microglial activation, pivotal in diagnosing and monitoring the disease, are critically assessed. Additionally, we discuss current and novel therapeutic strategies targeting microglial activity, emphasizing the shift towards more precise and personalized interventions. This article aims to provide a nuanced understanding of microglial dynamics in autoimmune uveitis, offering insights into potential avenues for effective treatment and management.

Microglial mediators in autoimmune Uveitis: Bridging neuroprotection and neurotoxicity

Autoimmune uveitis, a severe inflammatory condition of the eye, poses significant challenges due to its complex pathophysiology and the critical balance between protective and detrimental immune responses. Central to this balance are microglia, the resident immune cells of the central nervous system, whose roles in autoimmune uveitis are multifaceted and dynamic. This review article delves into the dual nature of microglial functions, oscillating between neuroprotective and neurotoxic outcomes in the context of autoimmune uveitis. Initially, we explore the fundamental aspects of microglia, including their activation states and basic functions, setting the stage for a deeper understanding of their involvement in autoimmune uveitis. The review then navigates through the intricate mechanisms by which microglia contribute to disease onset and progression, highlighting both their protective actions in immune regulation and tissue repair, and their shift towards a pro-inflammatory, neurotoxic profile. Special emphasis is placed on the detailed pathways and cellular interactions underpinning these dual roles. Additionally, the review examines the potential of microglial markers as diagnostic and prognostic indicators, offering insights into their clinical relevance. The article culminates in discussing future research directions, and the ongoing challenges in translating these findings into effective clinical applications. By providing a comprehensive overview of microglial mechanisms in autoimmune uveitis, this review underscores the critical balance of microglial activities and its implications for disease management and therapy development.

Role of Serine Protease Inhibitors A1 and A3 in Ocular Pathologies

Serine protease inhibitors A1 (SerpinA1) and A3 (SerpinA3) are important members of the serpin family, playing crucial roles in the regulation of serine proteases and influencing various physiological processes. SerpinA1, also known as α-1-antitrypsin, is a versatile glycoprotein predominantly synthesized in the liver, with additional production in inflammatory and epithelial cell types. It exhibits multifaceted functions, including immune modulation, complement activation regulation, and inhibition of endothelial cell apoptosis. SerpinA3, also known as α-1-antichymotrypsin, is expressed both extracellularly and intracellularly in various tissues, particularly in the retina, kidney, liver, and pancreas. It exerts anti-inflammatory, anti-angiogenic, antioxidant, and antifibrotic activities. Both SerpinA1 and SerpinA3 have been implicated in conditions such as keratitis, diabetic retinopathy, age-related macular degeneration, glaucoma, cataracts, dry eye disease, keratoconus, uveitis, and pterygium. Their role in influencing metalloproteinases and cytokines, as well as endothelial permeability, and their protective effects on Müller cells against oxidative stress further highlight their diverse and critical roles in ocular pathologies. This review provides a comprehensive overview of the etiology and functions of SerpinA1 and SerpinA3 in ocular diseases, emphasizing their multifaceted roles and the complexity of their interactions within the ocular microenvironment.

Osteopontin is a biomarker for early autoimmune uveoretinitis

Osteopontin (OPN) is an extracellular matrix protein with a diverse range of functions, including roles in cell adhesion, migration, and immunomodulation, which are associated with the modulation of neuroinflammation in the central nervous system. The present study was performed to evaluate the involvement of OPN in the eyes of an experimental autoimmune uveoretinitis (EAU) model. The EAU model was developed by immunization of Lewis rats with interphotoreceptor retinoid-binding protein. The results showed the OPN level was remarkably upregulated in the eye of EAU rats on day 9 post-immunization. The level of CD44, a ligand of OPN, was increased in the ciliary body of EAU rats. Furthermore, OPN was also detected in the ciliary body and activated microglia/macrophages in the EAU retina. The results suggest that OPN was significantly upregulated in the eyes of EAU rats, and that it may be useful as an early biomarker of ocular autoimmune diseases. All animal experiments were approved by the Institutional Animal Care and Use Committee of Jeju National University (approval No. 2020-0012) on March 11, 2020.