GIT 27 modulates TLR4/Src/NOX2 signaling pathway: A potential therapeutic strategy to decrease neuroinflammation, oxidative stress and neuronal cell death in Parkinson's disease

Parkinson's disease (PD) is a progressive neurodegenerative disorder of the central nervous system, characterized by the selective degeneration of dopaminergic neurons, particularly in the substantia nigra. Increasing evidence points to a central role of the immune system and chronic neuroinflammation in PD pathogenesis. Among the innate immune sensors, Toll-like receptor 4 (TLR4) has emerged as a key mediator of neuroinflammatory responses and disease progression. In this study, we investigated the neuroprotective effects of GIT 27, an immunomodulatory compound known to inhibit TLR4, in a murine model of MPTP-induced nigrostriatal degeneration. Mice received four intraperitoneal injections of MPTP (total dose: 80 mg/kg), followed by daily intraperitoneal administration of GIT 27 (5 or 10 mg/kg) for seven days. GIT 27 treatment significantly ameliorated behavioral deficits and pathological markers of PD. It restored tyrosine hydroxylase (TH) expression and reduced alpha-synuclein accumulation in the substantia nigra. Mechanistically, GIT 27 markedly suppressed glial activation and neuroinflammation through the inhibition of the TLR4/Src/NOX2 signaling pathway, leading to a downregulation of oxidative stress and neuronal damage as well as modulating ferroptosis. These findings highlight the TLR4/Src/NOX2 axis as a key driver of neurodegeneration and support, for the first time, the potential of GIT 27 as a therapeutic strategy for modulating neuroinflammation and preserving neuronal integrity in PD through this signaling pathway.