Neuroprotective effects of neuroglobin after mechanical injury.

Neuroglobin (NGB) is a recently discovered globin, which is widely expressed in vertebrates central and peripheral nervous systems. Previous studies have shown that NGB is important in protecting neurons from hypoxic/ischemic brain injuries. However, there are no reports on the neuroprotective effects of NGB after mechanical injury. Currently, we showed that the NGB expression level in neurons increased continuously from 2 h after injury, and reached a peak at 16 h (p<0.01), after which it decreased sharply. NGB that was overexpressed in mechanically injured B104 cells showed significant neuroprotective effects. Lactate dehydrogenase (LDH) activity decreased and cell survival rates increased (p<0.01, n=5). In the rat model of focal brain trauma, the NGB expression increased sharply at 1 h, after which it increased continuously until it reached a peak at 6 h, and then gradually decreased (p<0.01, n=5). Furthermore, moderate and severe injury resulted in significantly higher NGB levels than did mild injury (p<0.01, n=5). Our results indicate that NGB exerts significant neuroprotective effects after mechanical injury, and thus has important implications for the prognosis and cure of traumatic brain injury.