CCR1 antagonist as a therapeutic strategy in CNS trauma: effects of BX471 on neuroinflammation, autophagy, and apoptosis in spinal cord and traumatic brain injury

Central nervous system (CNS) traumatic events, such as spinal cord injury (SCI) and traumatic brain injury (TBI), result in severe and often irreversible neurological deficits with limited treatment options. Neuroinflammation, autophagy dysregulation, and apoptosis are key drivers of secondary injury. Chemokine receptor 1 (CCR1) plays a central role in mediating the post-traumatic inflammatory cascade, making it a promising therapeutic target. Using complementary in vitro (SH-SY5Y scratch injury) and in vivo (mouse SCI) models, we investigated the neuroprotective effects of BX471, a selective CCR1 antagonist. In vitro, BX471 (0.1–10 μM) reduced cytotoxicity, suppressed the CCR1/chemokine axis, attenuated nuclear factor kappa-B (NF-κB)-mediated pro-inflammatory cytokine production, including tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β), and interleukin-6 (IL-6), and downregulated CCR1 ligands regulated on activation, normal T cell expressed and secreted (RANTES) and macrophage inflammatory protein-1 alpha (MIP-1α). BX471 also modulated apoptosis markers, increasing B-cell lymphoma 2 (Bcl-2) while reducing Bcl-2-associated X protein (BAX), tumor protein p53, and cleaved caspase-3. In vivo, BX471 (3 or 10 mg/kg intraperitoneally) reduced tissue damage, inhibited glial activation and mast cell infiltration, restored autophagic flux as evidenced by decreased ribosomal protein S6 kinase beta-1 (p70S6K) and sequestosome-1 (p62), increased microtubule-associated protein 1 light chain 3-II (LC3-II), and enhanced Beclin-1/neuronal nuclei (NeuN) co-localization and preserved myelin integrity. Together, these findings identify CCR1 blockade as a strategy to simultaneously reduce neuroinflammation and apoptosis while restoring autophagy in the early stages of CNS trauma.