Osteopontin is a biomarker for early autoimmune uveoretinitis

Eugenol ameliorates uveitis in mice with experimental autoimmune encephalomyelitis through the suppression of key inflammatory genes

Visual impairment associated with uveitis is among the potential complications in multiple sclerosis (MS) and its animal model, experimental autoimmune encephalomyelitis (EAE). Bioinformatics analyses have shown that some hub genes are closely associated with the molecular mechanisms underlying uveitis in EAE. This study evaluated whether 4-allyl-2-methoxyphenol (eugenol) can mitigate the pathogenesis of uveitis in EAE through the interruption of key uveitogenic gene expression. Myelin oligodendrocyte glycoprotein35-55 (MOG) peptide-immunized C57BL/6 mice were injected intraperitoneally with eugenol. The eyeballs and spinal cords of EAE mice with or without eugenol treatment were collected simultaneously and immunohistochemical and molecular biological analyses were conducted. Eugenol treatment significantly ameliorated hindlimb paralysis. Ionized calcium-binding adapter molecule 1 (Iba-1) immunohistochemistry showed that the inflammatory response was significantly reduced in the uvea of eugenol-treated EAE mice compared with vehicle-treated controls. Eugenol also significantly reduced the expression of key uveitogenic genes including C1qb and Tyrobp. The suppressive effect of eugenol on inflammation was also observed in the spinal cord, as determined by the suppression of Iba-1-positive microglial cells. Together, these results suggest that the ameliorative effect of eugenol against EAE uveitis is associated with the suppression of key proinflammatory genes, which may represent targets for the treatment of uveitis.

Blood-retina barrier dysfunction in experimental autoimmune uveitis: the pathogenesis and therapeutic targets

Experimental autoimmune uveitis (EAU), an animal model of human uveitis, is characterized by infiltration of autoimmune T cells in the uvea as well as in the retina of susceptible animals. EAU is induced by the immunization of uveitogenic antigens, including either retinal soluble-antigen or interphotoreceptor retinoid-binding proteins, in Lewis rats. The pathogenesis of EAU in rats involves the proliferation of autoimmune T cells in peripheral lymphoid tissues and breakdown of the blood-retinal barrier, primarily in the uvea and retina, finally inducing visual dysfunction. In this review, we describe recent EAU studies to facilitate the design of a therapeutic strategy through the interruption of uveitogenic factors during the course of EAU, which will be helpful for controlling human uveitis.

Osteopontin in autoimmune disorders: current knowledge and future perspective

Osteopontin (OPN) is a multifunctional cytokine and adhesion molecule, as well as an unusual regulator for both innate and adaptive immune responses. Several immune cells can produce OPN, including dendritic cells (DCs), macrophages, and T lymphocytes. OPN expression is reported to be increased in a wide range of disorders, including autoimmunity, cancer, and allergy. The overexpression of OPN in several autoimmune disorders, such as rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), multiple sclerosis (MS), Type 1 diabetes (T1D), inflammatory bowel disease (IBD), Sjögren's, and myasthenia gravis, have been shown to be correlated with disease severity. Regarding the important regulatory roles of OPN in the immune system, this study aimed to review the role of this molecule in autoimmune disorders and to provide a complete view of the current knowledge in this field.