Suppression of FoxO3a attenuates neurobehavioral deficits after traumatic brain injury through inhibiting neuronal autophagy

Traumatic brain injury (TBI) produces a tissue-specific decrease in protein levels of microtubule-associated protein 2 (MAP2), an important cross-linking component of the neuronal cytoskeleton. Because moderate brain hypothermia (30°C) reduces certain neurobehavioral deficits produced by TBI, we examined the efficacy of moderate hypothermia (30°C) in reversing the TBI-induced loss of MAP2 protein. Naive, sham-injured, and moderate (2.1 atm) fluid percussion-injured rats were assessed for MAP2 protein content 3 h post injury using quantitative immunoreactivity measurements. Parallel groups of sham-injured and fluid percussion-injured animals were maintained in moderate hypothermia (30°C), as measured by temporalis muscle temperature, for MAP2 quantitation 3 h post injury. No difference in MAP2 levels was observed between naive and sham-injured normothermic animals. Hypothermia alone had no effect on soluble MAP2 levels in sham-injured animals compared with normothermic sham-injured controls (88.0 ± 7.3%; p > 0.10). Fluid percussion injury dramatically reduced MAP2 levels in he normothermic group (44.3 ± 5.9%; p < 0.0005) compared with normothermic sham-injured controls. No significant reduction of MAP2 was seen in the hypothermic injured group (95.2 ± 4.6%; compared with hypothermic sham-injured controls, p > 0.20). Although it is premature to infer any causal link, the data suggest that the attenuation of injury-induced MAP2 loss by hypothermia may contribute to its overall neuroprotective action.

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Vitamin D Receptor Activation Influences NADPH Oxidase (NOX2) Activity and Protects against Neurological Deficits and Apoptosis in a Rat Model of Traumatic Brain Injury

Oxidative Medicine and Cellular Longevity ◽

10.1155/2017/9245702 ◽

2017 ◽

Vol 2017 ◽

pp. 1-13 ◽

Cited By ~ 6

Author(s):

Changmeng Cui ◽

Sixin Song ◽

Jianzhong Cui ◽

Yan Feng ◽

Junling Gao ◽

...

Keyword(s):

Traumatic Brain Injury ◽

Vitamin D ◽

Brain Injury ◽

Nadph Oxidase ◽

Neurological Diseases ◽

Receptor Activation ◽

Neurological Deficits ◽

Protective Effects ◽

Ca1 Region ◽

Neurobehavioral Deficits

Traumatic brain injury (TBI) is a worldwide phenomenon which results in significant neurological and cognitive deficits in humans. Vitamin D (VD) is implicated as a therapeutic strategy for various neurological diseases now. Recently, inhibition of the NADPH oxidase (NOX2) was reported to protect against oxidative stress (ROS) production. However, whether alterations in NOX2expression and NOX activity are associated with calcitriol (active metabolite of VD) treatment following TBI remains unclear. In the present study, rats were randomly assigned to the sham, TBI, and calcitriol-treated groups. Calcitriol was administered intraperitoneally (2 μg/kg) at 30 min, 24 h, and 48 h after TBI insult. We observed that calcitriol treatment alleviated neurobehavioral deficits and brain edema following TBI. At the molecular levels, administration of calcitriol activated the expression of VDR and downregulated NOX2as well as suppressed apoptosis cell rate in the hippocampus CA1 region of TBI rats. In conclusion, our findings indicate that the protective effects of calcitriol may be related to the modulation of NADPH oxidase and thereby ultimately inhibited the progression of apoptosis. Calcitriol may be promising as a protective intervention following TBI, and more study is warranted for its clinical testing in the future.

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