Benzyl isothiocyanate alleviates neural damage in experimental autoimmune uveitis by modulating the TREM-1/PI3K/AKT...

Purpose: To investigate whether Benzyl isothiocyanate (BITC) can improve experimental autoimmune uveitis (EAU) and explore its potential mechanism. Methods: To evaluate the therapeutic efficacy of BITC, EAU was induced in C57BL/6 mice via immunization with IRBP_651-670. Clinical scores and histopathological staining were employed to evaluate the severity of the disease. The integrity of the blood-retinal barrier (BRB) was assessed using Evans blue staining and Western blot analysis. Nissl staining, Brn3a immunofluorescence, and TUNEL assay were employed to assess retinal neuronal damage. In vitro, BV2 cells were exposed to lipopolysaccharide (LPS) and interferon-γ (IFN-γ). Biochemical markers of oxidative stress, mRNA levels of phagocytosis-related markers, protein and mRNA levels of neurotrophic factors, and triggering receptor expressed on myeloid cells-1 (TREM-1) were measured. Additionally, conditioned medium from BV2 cells was co-cultured with primary retinal ganglion cells (RGCs) to detect apoptosis. The functional relevance of TREM-1 in the protective effects of BITC was evaluated by overexpressing TREM-1 (oe-TREM-1). Results: In vivo, BITC alleviated clinical symptoms of EAU mice. Treatment significantly maintained BRB integrity and mitigated oxidative stress and neuronal damage. In vitro, BITC suppressed oxidative stress and phagocytic activity. The co-culture study of BV2 cells and primary RGCs showed that BITC can alleviate LPS + IFN-γ induced primary RGCs damage and inhibit apoptosis. Furthermore, BITC downregulated the expression of TREM-1/PI3K/AKT signaling pathway in EAU mice and LPS + IFN-γ induced BV2 cells. Oe-TREM-1 partially eliminated the inhibitory effects of BITC on oxidative stress and phagocytosis, as well as its protective effect against neuronal damage. Conclusion: BITC alleviates neural damage in EAU by down-regulating the TREM-1/PI3K/AKT signaling pathway, reducing oxidative stress and excessive phagocytosis, and promoting the secretion of neurotrophic factors.