Neuroimmunophilin ligand V-10,367 is neuroprotective after 24-hour delayed administration in a mouse model of diffuse traumatic brain injury

The authors present two studies that investigate the biochemical and histologic effects of the nonimmunosuppressive neuroimmunophilin (NIMM) ligand V-10,367 in a mouse model of traumatic brain injury (TBI). In study 1, the authors examined the effect of V-10,367 (50 mg/kg x 2 per day, by mouth) on neurofilament M (NFM) protein levels and on alpha-spectrin breakdown products (SBDPs) when dosed for 2 days, starting 24 hours after TBI and killed on day 3. In study 2, V-10,367 was given for 10 days, starting 24 hours after TBI and the mice killed 6 weeks after TBI, to measure the extent of neurodegeneration (amino CuAg stain). The results in study 1 revealed that V-10,367-treatment significantly increased NFM protein levels in both sham and TBI mice. In addition, V-10,367 attenuated SBDP 150 levels in the cortex, striatum, and hippocampus. The results of study 2 indicated that TBI mice treated with V-10,367 demonstrated significantly less neurodegeneration compared to injured, vehicle-treated mice. In summary, these results suggest that NIMMs may be neuroprotective indirectly through inhibition of calpain-mediated cytoskeletal damage and perhaps via maintenance of neuronal plasticity. In the context of this mouse model of TBI, the therapeutic window for V-10,367's positive effects is at least 24 hours after injury, which, in the case of TBI models, is largely unprecedented for a neuroprotective compound.