Toll-like receptor-9 (TLR-9) deficiency alleviates optic nerve injury (ONI) by inhibiting inflammatory response in vivo and in vitro

Physcion prevents induction of optic nerve injury in rats via inhibition of the JAK2/STAT3 pathway

Optic nerve injury is a type of neurodegenerative disease. Physcion is an anthraquinone that exerts a protective role against various diseases. However, its function in regulating optic nerve injury remains largely unknown. An in vitro model of optic nerve injury was established in HAPI cells treated with IFN-β. Functional assays were used to detect HAPI cell viability and apoptosis. The levels of inflammation and the expression levels of oxidative stress-related genes were measured in HAPI cells. In addition, western blot analysis was used to detect the expression levels of Janus kinase 2 (JAK2)/STAT3-linked genes in HAPI cells. Treatment of the cells with physcion prevented cells against IFN-β-induced neuronal injury. Physcion restrained IFN-β-induced inflammatory response and oxidative stress in HAPI cells. In addition, it improved IFN-β-induced injury in HAPI cells by suppressing the JAK2/STAT3 pathway. In conclusion, the present study revealed that physcion improved optic nerve injury in vitro by inhibiting the JAK2/STAT3 pathway. Physcion may be a promising therapeutic target for the treatment of this disease.

High-Mobility Group Box 1 Inhibitor BoxA Alleviates Neuroinflammation-Induced Retinal Ganglion Cell Damage in Traumatic Optic Neuropathy

Traumatic optic neuropathy (TON) is a significant cause of vision loss and irreversible blindness worldwide. It is defined as retinal ganglion cell death and axon degeneration caused by injury. Optic nerve crush (ONC), a well-validated model of TON, activates retinal microglia and initiates neuroinflammation. High-mobility group box 1 (HMGB1), a non-histone chromosomal binding protein in the nucleus of eukaryotic cells, is an important inducer of microglial activation and pro-inflammatory cytokine release. The purpose of this study was to examine the protective effects and mechanism of the HMGB1 inhibitor BoxA to neuroinflammation-induced retinal ganglion cells (RGCs) damage in traumatic optic neuropathy. For that purpose, an optic nerve crush model was established in C57BL/6J mice at 10–12 weeks. Model mice received an intravitreal injection of PBS and the HMGB1 inhibitor BoxA. Our data demonstrated that HMGB1 expression increased after optic nerve crush. Retinal ganglion cell function and morphology were damaged, and retinal ganglion cell numbers were reduced after optic nerve crush. Intravitreal injection of BoxA after ONC can alleviate damage. Furthermore, BoxA reduced microglial activation and expression levels of nuclear factor κB (NF-kB), nucleotide-binding domain, leucine-rich repeat containing protein 3 (NLRP3), and apoptosis-associated speck-like protein containing a CARD (ASC) in experimental ONC mice. In summary, HMGB1 mediates NLRP3 inflammasome via NF-kB to participate in retinal inflammatory injury after ONC. Thus, intravitreal injection of BoxA has potential therapeutic benefits for the effective treatment of RGC death to prevent TON.