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

Abstract

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.