The p53 inactivators pifithrin-μ and pifithrin-α mitigate TBI-induced neuronal damage through regulation of oxidative stress, neuroinflammation, autophagy and mitophagy

Traumatic brain injury (TBI) is one of the most common causes of death and disability worldwide. We investigated whether inhibition of p53 using pifithrin (PFT)-α or PFT-μ provides neuroprotective effects via p53 transcriptional dependent or -independent mechanisms, respectively. Sprague Dawley rats were subjected to controlled cortical impact TBI followed by the administration of PFTα or PFT-μ (2 mg/kg, i.v.) at 5 h after TBI. Brain contusion volume, as well as sensory and motor functions were evaluated at 24 h after TBI. TBI-induced impairments were mitigated by both PFT-α and PFT-μ. Fluoro-Jade C staining was used to label degenerating neurons within the TBI-induced cortical contusion region that, together with Annexin V positive neurons, were reduced by PFT-μ. Double immunofluorescence staining similarly demonstrated that PFT-μ significantly increased HO-1 positive neurons and mRNA expression in the cortical contusion region as well as decreased numbers of 4-hydroxynonenal (4HNE)-positive cells. Levels of mRNA encoding for p53, autophagy, mitophagy, anti-oxidant, anti-inflammatory related genes and proteins were measured by RT-qPCR and immunohistochemical staining, respectively. PFT-α, but not PFT-μ, significantly lowered p53 mRNA expression. Both PFT-α and PFT-μ lowered TBI-induced pro-inflammatory cytokines (IL-1β and IL-6) mRNA levels as well as TBI-induced autophagic marker localization (LC3 and p62). Finally, treatment with PFT-μ mitigated TBI-induced declines in mRNA levels of PINK-1 and SOD2. Our data suggest that both PFT-μ and PFT-α provide neuroprotective actions through regulation of oxidative stress, neuroinflammation, autophagy, and mitophagy mechanisms, and that PFT-μ, in particular, holds promise as a TBI treatment strategy.

Application of neuro-endoscopic target aspiration of the necrotic core for cerebral contusion with delayed progression: technical note

BACKGROUND

The optimal management strategy for cerebral contusion remains controversial, especially when standard craniotomy could not be used. We performed neuro-endoscopic target lesionectomy for the delayed progression of cerebral contusion in order to aspirate the necrotic core, which is the primal source of contusional edema.

METHODS

The present study included 10 consecutive patients (2 women and 8 men, with a mean age of 67 years old) with traumatic brain injury presenting with delayed deterioration of cerebral contusion where standard craniotomy could not be used. Neuro-endoscopic aspiration of the necrotic core was prospectively performed for all patients. We assessed the computed tomography findings after surgery to evaluate the efficacy of this procedure.

RESULTS

Endoscopic surgery was performed promptly after neurological deterioration, with a mean interval between trauma and surgery of 7 days, ranging from 2 to 16 days. During the operation, the centers of contusions comprised serous liquid components in all 10 patients and were easily aspirated by endoscopy. Contusional edemas were markedly decreased in all within 3 days after surgery.

CONCLUSIONS

Progression of contusional edema can be caused by the accumulation of water into the necrotic core due to the rapid increase in osmolality. In light of the highly liquefied demarcated characteristics of the necrotic core, neuro-endoscopic aspiration could be an optional treatment strategy for cerebral contusion with delayed progression in a minimally invasive manner.

Normobaric hyperoxia does not improve derangements in diffusion tensor imaging found distant from visible contusions following acute traumatic brain injury

We have previously shown that normobaric hyperoxia may benefit peri-lesional brain and white matter following traumatic brain injury (TBI). This study examined the impact of brief exposure to hyperoxia using diffusion tensor imaging (DTI) to identify axonal injury distant from contusions. Fourteen patients with acute moderate/severe TBI underwent baseline DTI and following one hour of 80% oxygen. Thirty-two controls underwent DTI, with 6 undergoing imaging following graded exposure to oxygen. Visible lesions were excluded and data compared with controls. We used the 99% prediction interval (PI) for zero change from historical control reproducibility measurements to demonstrate significant change following hyperoxia. Following hyperoxia DTI was unchanged in controls. In patients following hyperoxia, mean diffusivity (MD) was unchanged despite baseline values lower than controls (p < 0.05), and fractional anisotropy (FA) was lower within the left uncinate fasciculus, right caudate and occipital regions (p < 0.05). 16% of white and 14% of mixed cortical and grey matter patient regions showed FA decreases greater than the 99% PI for zero change. The mechanistic basis for some findings are unclear, but suggest that a short period of normobaric hyperoxia is not beneficial in this context. Confirmation following a longer period of hyperoxia is required.

[APPLICATION OF ALLOGENIC TISSUE OF THE FETAL BRAIN CORTEX AND THE OLFACTORY BULB TISSUE FOR TREATMENT OF THE BRAIN CONTUSION IN RATS]

Impact of the allogenic tissue transplantation of the fetal cerebral large hemispheres and the оlfactory bulb tissue (OBT) on the healing processes after the brain contusion was studied in experiment. The investigation was performed on mongrel male rats: in laboratory animals of the first group in the first day after open penetrating local cerebral trauma (OPLCT) the allogenic fetal nervous tissue fragment was transplanted into the formatted tissue defect; for the second group – in the first day after cerebral trauma the allogenic OBT fragment was transplanted into the formatted tissue defect; and for the third group (control) - the OPLCT was done without further transplantation of tissues. The impact of the allogenic fetal nervous tissue transplantation was demonstrated by more active participation of glial cells during the healing process course, and the OBT transplantation was followed by activation of neoangiogenesis processes , mainly in the injured brain. The experimental simulation choosed permits to study the possibilities of application of neurogenic tissues in the brain contusion treatment, and to determine the therapy tactics.

Nrf2 knockout: The effect on neurological dysfunction and the activation of glial cells of mice after brain injury

To investigate the protective role and possible mechanisms of Nrf2 gene in cerebral trauma in mice. The types Nrf2(-/-) and Nrf2(+/+) mice were confirmed by PCR, and the model of closed head injury was established. The severity of injury and the effect of the injury on neurological status were assessed by Neurological Severity Score (NSS) and fatality rate, and the activated conditions of microglia and astrocyte around the injured area were observed by immunohistochemical method. Compared with Nrf2(+/+) mice, the nerve dysfunction of the Nrf2(-/-) mice was obviously more severe (P<0.01). On the first day after injury, the activation of microglia around the injured area increased significantly in Nrf2 (-/-) mice, the difference was more significant on the third day, and there was still statistical difference until the 7th day (P<0.05). Moreover, On the days 1, 3, 7 after injury, the activation of astrocyte around the injured area also increased in Nrf2(-/-) mice, however, there was statistical difference only on the 3rd day (P<0.05). Nrf2 gene knockout can aggravate the nerve dysfunction after cerebral trauma, and this effect is achieved, at least partly, possibly via the effect of Nrf2 on glial activation.

[CRANIO—CEREBRAL TRAUMA WITH ESTIMATED SEVERITY OF 13—15 POINTS IN ACCORDANCE TO GLASGOW SCALE — A LIGHT TRAUMA]

Retrospective analysis of cranio—cerebral trauma (CCT) in 141 injured persons, ageing (38.3 ± 14.3) yrs at average, severity of which in accordance to Glasgow scale was estimated in 13 — 15 points, was performed. The injured persons were managed in accordance to actual recommendations of Ministry of Health of Ukraine. In accordance to CT data, the brain commotion was noted in 40 patients, the brain contusion type І — in 25, the brain contusion type ІІ with the skull fornix fracture — in 30, with linear fracture of the skull bones and traumatic hematomas into the brain—tunics — in 30, with fracture of the temporal bone pyramid — in 16. In indices 14 points and less (in accordance to Glasgow scale) in terms up to 24 h after CCT and absence of alcohol intoxication in 76.9% injured persons in accordance to CT data the intracranial traumatic affections were revealed. In indices of 15 points in 21% of injured persons false—negative results were determined, witnessing disparity of CCT signs with a CT data.