Valproic acid treatment rescues injured tissues after traumatic brain injury

Testing Neuroprotective Strategies in Prolonged Field Care Model of Traumatic Brain Injury and Hemorrhagic Shock

BACKGROUND

Prolonged field care is a military adaptation of tactical combat casualty care providing extended prehospital management during delayed extrication. Effects of addition of valproic acid (VPA) to fresh-frozen plasma (FFP) in a prolonged field care model of hemorrhagic shock and traumatic brain injury are not known. We hypothesized that VPA is associated with decreased neurological impairment, and its protective changes are detected at the transcriptomic level.

STUDY DESIGN

Swine underwent traumatic brain injury and 40% blood volume hemorrhage. After 2 hours of shock, they were randomized to (1) normal saline (NS), (2) NS + 250 mL FFP (NS + FFP), or (3) NS + FFP + 150 mg/kg VPA (NS + FFP + VPA). At 72 hours, they were transfused packed RBCs before being euthanized. Intraoperative variables and neurological outcomes were compared. Brain lesion size was measured, and gene expression profiles were analyzed using RNA sequencing. Pathway and network analyses were performed on differentially expressed genes. Real-time polymerase chain reaction was performed to validate key genes.

RESULTS

NS + FFP and NS + FFP + VPA required significantly less crystalloid resuscitation (974 mL: NS + FFP; 1,461 mL: NS + FFP + VPA vs 4,540 mL: NS, p < 0.001), had smaller brain lesion size (2,477 mm 3 : NS + FFP; 3,018.0 mm 3 : NS + FFP + VPA vs 4,517.0 mm 3 : NS, p < 0.01), and required less functional neurologic impairment compared with NS. Per pathway analysis of differentially expressed genes, VPA was associated with enrichment of numerous metabolic changes in injured brains, which were not observed with FFP. Network analysis showed enrichment of various gene networks. Mitochondrially encoded ATP synthase membrane subunit 8 gene was downregulated in VPA-treated animals.

CONCLUSIONS

The addition of FFP to the resuscitation protocol resulted in a significant reduction in crystalloid requirements. Both the NS + FFP and NS + FFP + VPA groups showed improved neurological recovery compared with NS alone and had distinctive transcriptomic profiles in injured brains at 72 hours. The mitochondrially encoded ATP synthase membrane subunit 8 gene, involved in worsening ischemia following brain injury, was downregulated in VPA-treated animals.

Desorption Electrospray Ionization Cyclic Ion Mobility-Mass Spectrometry Imaging for Traumatic Brain Injury Spatial Metabolomics

Lipidomics focuses on investigating alterations in a wide variety of lipids that harness important information on metabolic processes and disease pathology. However, the vast structural diversity of lipids and the presence of isobaric and isomeric species creates serious challenges in feature identification, particularly in mass spectrometry imaging experiments that lack front-end separations. Ion mobility has emerged as a potential solution to address some of these challenges and is increasingly being utilized as part of mass spectrometry imaging platforms. Here, we present the results of a pilot mass spectrometry imaging study on rat brains subjected to traumatic brain injury (TBI) to evaluate the depth and quality of the information yielded by desorption electrospray ionization cyclic ion mobility mass spectrometry (DESI cIM MSI). Imaging data were collected with one and six passes through the cIM cell. Increasing the number of passes increased the ion mobility resolving power and the resolution of isobaric lipids, enabling the creation of more specific maps. Interestingly, drift time data enabled the recognition of multiply charged phosphoinositide species in the complex data set generated. These species have not been previously reported in TBI MSI studies and were found to decrease in the hippocampus region following injury. These changes were attributed to increased enzymatic activity after TBI, releasing arachidonic acid that is converted to eicosanoids to control inflammation. A substantial reduction in NAD and alterations in other adenine metabolites were also observed, supporting the hypothesis that energy metabolism in the brain is severely disrupted in TBI.

Comparison of the efficacy and safety of sodium valproate versus levetiracetam in the treatment of severe traumatic brain injury

OBJECTIVE

To observe the efficacy and safety of sodium valproate (VPA) compared to levetiracetam (LEV) in the treatment of severe traumatic brain injury (sTBI).

METHODS

In this blind, prospective study, eighty-four sTBI patients who had craniotomy from August 2021 to August 2023 were randomly split into two groups through random number table method: LEV and VPA, each with 42 patients. Both received comprehensive treatment post-craniotomy. LEV group: LEV injection on surgery day, transitioning to LEV tablets from day two. VPA group: VPA injection on surgery day, switching to VPA extended-release tablets from day two. The study compared hospital stay, neurological function, clinical outcomes, seizures, and drug reactions between groups.

RESULTS

The length of hospital stay showed no significant difference between the LEV and VPA groups. Both groups demonstrated improved neurological function post-treatment (NIHSS and BI scores), with no significant between-group differences. Clinical outcomes at 3 months post-treatment were similar in both groups. Seizure occurrence within 3 months after treatment showed no significant difference between the LEV (19.05%) and VPA (23.81%) groups. However, the VPA group experienced a significantly higher rate of drug-related adverse reactions (40.48%) compared to the LEV group (21.43%).

CONCLUSION

Both VPA and LEV are effective in treating sTBI, showing no significant difference in improving neurological function, daily life abilities, treatment outcomes, and seizure occurrence. However, VPA treatment exhibited a significantly higher incidence of drug-related adverse reactions compared to LEV, indicating that LEV might be a safer option for sTBI treatment.

Effect of valproic acid combined with transplantation of olfactory ensheathing cells modified by neurotrophic 3 gene on nerve protection and repair after traumatic brain injury

BACKGROUND

Traumatic brain injury (TBI) often leads to cognitive and neurological dysfunction. Valproic acid (VPA) has a neuroprotective effect in acute central nervous system diseases; the neurotrophin 3 gene (NT-3) can maintain the survival of neurons, and olfactory ensheathing cells (OECs) can promote the growth of nerve axons. This study aimed to evaluate the restorative effect of VPA combined with NT-3 modified OECs (NT-3-OECs) on neurological function after TBI.

METHODS

The neurological severity score (NSS) of rats was evaluated on the 1st, 7th, 14th, and 28th day after TBI modeling and corresponding intervention. Hematoxylin-eosin (HE) staining, p75 nerve growth factor receptor (P75), glial fibrillary acidic protein (GFAP), and neurofilament protein (NF)staining, and argyrophilic staining were used to observe the morphology of brain tissue 28 days after modeling. Moreover, TdT-mediated dUTP Nick-End Labeling (TUNEL) was used to detect the apoptosis rate of neurons. The changes in synapses and mitochondria in the injured area were observed by electron microscope.

RESULTS

NT-3-OECs transplantation can increase the content of NT-3 in brain tissue, and NT-3-OECs can survive for >28 days. The NSS score of the TBI-VPA-NT-3-OECs group 28 days after cell transplantation was significantly lower than that of the other model treatment groups (P < 0.05). The morphological structure of the brain tissue was more complete, and the neurofilament fibers were neatly arranged, achieving better results than those of the other groups. The apoptosis rate of nerve cells in the TBI-VPA-NT-3-OECs group was significantly lower than in the other treatment groups (P < 0.05). Furthermore, the number of synapses in the combined intervention group was significantly higher than in the other treatment groups, and the mitochondrial structure was more complete.

CONCLUSION

NT-3-OECs have good biological function, and VPA combined with NT-3-OECs transplantation can effectively improve the prognosis of TBI rats.

Emerging Neuroprotective Strategies: Unraveling the Potential of HDAC Inhibitors in Traumatic Brain Injury Management

Traumatic brain injury (TBI) is a significant global health problem, leading to high rates of mortality and disability. It occurs when an external force damages the brain, causing immediate harm and triggering further pathological processes that exacerbate the condition. Despite its widespread impact, the underlying mechanisms of TBI remain poorly understood, and there are no specific pharmacological treatments available. This creates an urgent need for new, effective neuroprotective drugs and strategies tailored to the diverse needs of TBI patients. In the realm of gene expression regulation, chromatin acetylation plays a pivotal role. This process is controlled by two classes of enzymes: histone acetyltransferase (HAT) and histone deacetylase (HDAC). These enzymes modify lysine residues on histone proteins, thereby determining the acetylation status of chromatin. HDACs, in particular, are involved in the epigenetic regulation of gene expression in TBI. Recent research has highlighted the potential of HDAC inhibitors (HDACIs) as promising neuroprotective agents. These compounds have shown encouraging results in animal models of various neurodegenerative diseases. HDACIs offer multiple avenues for TBI management: they mitigate the neuroinflammatory response, alleviate oxidative stress, inhibit neuronal apoptosis, and promote neurogenesis and axonal regeneration. Additionally, they reduce glial activation, which is associated with TBI-induced neuroinflammation. This review aims to provide a comprehensive overview of the roles and mechanisms of HDACs in TBI and to evaluate the therapeutic potential of HDACIs. By summarizing current knowledge and emphasizing the neuroregenerative capabilities of HDACIs, this review seeks to advance TBI management and contribute to the development of targeted treatments.

Prolonging the therapeutic window for valproic acid treatment in a swine model of traumatic brain injury and hemorrhagic shock

BACKGROUND

It has previously been shown that administration of valproic acid (VPA) can improve outcomes if given within an hour following traumatic brain injury (TBI). This short therapeutic window (TW) limits its use in real-life situations. Based upon its pharmacokinetic data, we hypothesized that TW can be extended to 3 hours if a second dose of VPA is given 8 hours after the initial dose.

METHOD

Yorkshire swine (40-45 kg; n = 10) were subjected to TBI (controlled cortical impact) and 40% blood volume hemorrhage. After 2 hours of shock, they were randomized to either (1) normal saline resuscitation (control) or (2) normal saline-VPA (150 mg/kg × two doses). First dose of VPA was started 3 hours after the TBI, with a second dose 8 hours after the first dose. Neurologic severity scores (range, 0-36) were assessed daily for 14 days, and brain lesion size was measured via magnetic resonance imaging on postinjury day 3.

RESULTS

Hemodynamic and laboratory parameters of shock were similar in both groups. Valproic acid-treated animals had significantly less neurologic impairment on days 2 (16.3 ± 2.0 vs. 7.3 ± 2.8) and 3 (10.9 ± 3.6 vs. 2.8 ± 1.1) postinjury and returned to baseline levels 54% faster. Magnetic resonance imaging showed no differences in brain lesion size on day 3. Pharmacokinetic data confirmed neuroprotective levels of VPA in the circulation.

CONCLUSION

This is the first study to demonstrate that VPA can be neuroprotective even when given 3 hours after TBI. This expanded TW has significant implications for the design of the clinical trial.

Head Kinematics, Blood Biomarkers, and Histology in Large Animal Models of Traumatic Brain Injury and Hemorrhagic Shock

Traumatic brain injury (TBI) and severe blood loss resulting in hemorrhagic shock (HS) are each leading causes of mortality and morbidity worldwide, and present additional treatment considerations when they are comorbid (TBI+HS) as a result of competing pathophysiological responses. The current study rigorously quantified injury biomechanics with high precision sensors and examined whether blood-based surrogate markers were altered in general trauma as well as post-neurotrauma. Eighty-nine sexually mature male and female Yucatan swine were subjected to a closed-head TBI+HS (40% of circulating blood volume; n = 68), HS only (n = 9), or sham trauma (n = 12). Markers of systemic (e.g., glucose, lactate) and neural functioning were obtained at baseline, and at 35 and 295 min post-trauma. Opposite and approximately twofold differences existed for both magnitude (device > head) and duration (head > device) of quantified injury biomechanics. Circulating levels of neurofilament light chain (NfL), glial fibrillary acidic protein (GFAP), and ubiquitin C-terminal hydrolase L1 (UCH-L1) demonstrated differential sensitivity for both general trauma (HS) and neurotrauma (TBI+HS) relative to shams in a temporally dynamic fashion. GFAP and NfL were both strongly associated with changes in systemic markers during general trauma and exhibited consistent time-dependent changes in individual sham animals. Finally, circulating GFAP was associated with histopathological markers of diffuse axonal injury and blood-brain barrier breach, as well as variations in device kinematics following TBI+HS. Current findings therefore highlight the need to directly quantify injury biomechanics with head mounted sensors and suggest that GFAP, NfL, and UCH-L1 are sensitive to multiple forms of trauma rather than having a single pathological indication (e.g., GFAP = astrogliosis).

Neuroprotective agents effective against radiation damage of central nervous system

Ionizing radiation caused by medical treatments, nuclear events or even space flights can irreversibly damage structure and function of brain cells. That can result in serious brain damage, with memory and behavior disorders, or even fatal oncologic or neurodegenerative illnesses. Currently used treatments and drugs are mostly targeting biochemical processes of cell apoptosis, radiation toxicity, neuroinflammation, and conditions such as cognitive-behavioral disturbances or others that result from the radiation insult. With most drugs, the side effects and potential toxicity are also to be considered. Therefore, many agents have not been approved for clinical use yet. In this review, we focus on the latest and most effective agents that have been used in animal and also in the human research, and clinical treatments. They could have the potential therapeutical use in cases of radiation damage of central nervous system, and also in prevention considering their radioprotecting effect of nervous tissue.

Valproic Acid Protects Against Acute Kidney Injury in Hemorrhage and Trauma

INTRODUCTION

Trauma is the leading cause of death among young people. These patients have a high incidence of kidney injury, which independently increases the risk of mortality. As valproic acid (VPA) treatment has been shown to improve survival in animal models of lethal trauma, we hypothesized that it would also attenuate the degree of acute kidney injury.

METHODS

We analyzed data from two separate experiments where swine were subjected to lethal insults.  Model 1: hemorrhage (50% blood volume hemorrhage followed by 72-h damage control resuscitation). Model 2: polytrauma (traumatic brain injury, 40% blood volume hemorrhage, femur fracture, rectus crush and grade V liver laceration). Animals were resuscitated with normal saline (NS) +/- VPA 150 mg/kg after a 1-h shock phase in both models (n = 5-6/group). Serum samples were analyzed for creatinine (Cr) using colorimetry on a Liasys 330 chemistry analyzer. Proteomic analysis was performed on kidney tissue sampled at the time of necropsy.

RESULTS

VPA treatment significantly (P < 0.05) improved survival in both models. (Model 1: 80% vs 20%; Model 2: 83% vs. 17%). Model 1 (Hemorrhage alone): Cr increased from a baseline of 1.2 to 3.0 in NS control animals (P < 0.0001) 8 h after hemorrhage, whereas it rose only to 2.1 in VPA treated animals (P = 0.004). Model 2 (Polytrauma): Cr levels increased from baseline of 1.3 to 2.5 mg/dL (P = 0.01) in NS control animals 4 h after injury but rose to only 1.8 in VPA treated animals (P = 0.02). Proteomic analysis of kidney tissue identified metabolic pathways were most affected by VPA treatment.

CONCLUSIONS

A single dose of VPA (150 mg/kg) offers significant protection against acute kidney injury in swine models of polytrauma and hemorrhagic shock.

Brain proteomic changes by histone deacetylase inhibition after traumatic brain injury

Background

Traumatic brain injury (TBI) is a leading cause of morbidity and mortality. There are currently no cytoprotective treatments for TBI. There is growing evidence that the histone deacetylase inhibitor valproic acid (VPA) may be beneficial in the treatment of TBI associated with hemorrhagic shock and in isolation. We sought to further evaluate the mechanistic underpinnings of this demonstrated efficacy via proteomic analysis of injured brain tissue.

Methods

Swine were subjected to TBI via controlled cortical impact, randomized to treatment with VPA or control and observed for 6 hours. The brains of the pigs were then sectioned, and tissue was prepared and analyzed for proteomic data, including gene ontology (GO), gene-set enrichment analysis and enrichment mapping, and network mapping.

Results

Proteomic analysis demonstrated differential expression of hundreds of proteins in injured brain tissue after treatment with VPA. GO analysis and network analyses revealed groups of proteins and processes that are known to modulate injury response after TBI and impact cell fate. Processes affected included protein targeting and transport, cation and G-protein signaling, metabolic response, neurotransmitter response and immune function.

Discussion

This proteomic analysis provides initial mechanistic insight into the observed rescue of injured brain tissue after VPA administration in isolated TBI.

Level of evidence

Not applicable (animal study).

Validation of intraosseous delivery of valproic acid in a swine model of polytrauma

Background

Intraosseous (IO) drug delivery may be necessary in emergency situations when intravenous access is unattainable. Valproic acid (VPA) is a histone deacetylase inhibitor that has previously been shown to improve survival in preclinical models of lethal polytrauma. In this study, we sought to compare serum levels of intravenously and IO-delivered VPA, and to analyze the effect of IO-delivered VPA.

Methods

Swine were subjected to 40% blood volume hemorrhage, brain injury, femur fracture, rectus crush injury and liver laceration. After 1 hour of shock, animals were randomized (n=3/group) to receive normal saline resuscitation (control), normal saline+intravenous VPA 150 mg/kg (intravenous group) or normal saline +IO VPA 150 mg/kg (IO group). Serum levels of VPA were assessed between groups, and proteomics analyses were performed on IO and control groups on heart, lung and liver samples.

Results

Intravenous and IO serum VPA levels were similar at 1, 3, 5 and 7 hours after starting the infusion (p>0.05). IO-delivered VPA induced significant proteomics changes in the heart, lung and liver, which were most pronounced in the lung. Biologic processes affected included inflammation, metabolism and transcriptional & translational machinery. The control group had 0% survival, and the intravenous and IO group both had 100% survival to the end of the experiment (p<0.05).

Discussion

IO-delivered VPA is noninferior to intravenous administration and is a viable option in emergent situations when intravenous access is unattainable.

Level of evidence

Not applicable (animal study).