Neuroinflammation and blood-brain barrier disruption following traumatic brain injury: Pathophysiology and potential therapeutic targets

Injectable nanocomposite hydrogel for localized precision delivery of dexamethasone after traumatic brain injury: dual modulation of neuroinflammation and blood-brain barrier restoration

BACKGROUND

Glucocorticoids (GCs) have been widely used in the treatment of severe traumatic brain injury (TBI) to inhibit neuroinflammation and alleviating brain edema and cannot be replaced by other drugs. However, their systemic application still faces many obstacles, such as the poor blood-brain-barrier (BBB) penetration and severe side effects. Therefore, new treatment strategy or compounds are urgently needed in clinic.

METHODS

Herein, an injectable nanocomposite hydrogel is developed as a biofunctionalized delivery platform for intraoperative administration of dexamethasone (DEX) after TBI. By using a mice TBI model, the safety and efficacy of the nanohydrogels in treating BBB disruption, brain edema and nerve injury were evaluated after TBI.

RESULTS

The hydrogel is composed of polysaccharide matrix (carboxymethyl chitosan and oxidized dextran) and mesoporous polydopamine (MPDA) nanoparticles loaded with DEX (MPDA@DEX@gel) that could realize in situ injection, self-assembly, a high DEX loading rate and sustained release around the lesion. The MPDA@DEX@gel exhibits excellent antibacterial and hemostatic properties, good biocompatibility and antioxidation, and self-healing capability in vitro. These in vitro and in vivo results show that local application of MPDA@DEX@gel not only alleviates brain edema, promotes neuronal survival, and improves neurological function by restoring the integrity of BBB and inhibiting neuroinflammation after TBI, but also effectively avoids the peripheral and central side effects.

CONCLUSION

Our study provides a promising treatment strategy for the rational use of GCs in patients with severe TBI.

Pharmacological therapies for early and long-term recovery in disorders of consciousness: current knowledge and promising avenues

INTRODUCTION

Disorders of consciousness (DoC) are characterized by impaired arousal and/or awareness, ranging from coma to unresponsive wakefulness syndrome, minimally conscious state, and cognitive motor dissociation. Pharmacological treatment options remain limited, complicated by the heterogeneity of etiologies, such as traumatic brain injury, stroke, and infections. The lack of rigorous clinical trials has led to off-label use of treatments, often without clear mechanistic understanding, posing challenges for effective patient care.

AREAS COVERED

In this perspective, the authors report on key studies concerning the effectiveness of pharmacological interventions, including dopaminergic and GABAergic agents, antidepressants, statins, and anticonvulsants, in promoting recovery of consciousness in DoC.

EXPERT OPINION

Robust longitudinal clinical trials are needed, with priority given to early subacute phase intervention. Outcomes should be better defined, considering immediate responses to medication while also increasing the emphasis on long-term quality of life. Unified functional and mechanistic frameworks are needed to guide research and foster collaboration. Furthermore, a shift toward personalized medicine would benefit this heterogeneous population. Moving forward, assessing the efficacy of more unconventional or 'paradoxical' pharmacological options in treatment plans will be essential. The authors also expect an increased use of AI tools to identify factors that best predict treatment responses.

Attenuation of Blood-Brain Barrier Disruption in Traumatic Brain Injury via Inhibition of NKCC1 Cotransporter: Insights into the NF-κB/NLRP3 Signaling Pathway

Following traumatic brain injury (TBI), inhibition of the Na+-K+-Cl- cotransporter1 (NKCC1) has been observed to alleviate damage to the blood-brain barrier (BBB). However, the underlying mechanism for this effect remains unclear. This study aimed to investigate the mechanisms by which inhibiting the NKCC1 attenuates disruption of BBB integrity in TBI. The TBI model was induced in C57BL/6 mice through a controlled cortical impact device, and an in vitro BBB model was established using Transwell chambers. Western blot (WB) analysis was used to evaluate NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasome and nuclear factor-kappaB (NF-κB) pathway proteins. Flow cytometry and transendothelial electrical resistance (TEER) were employed to assess endothelial cell apoptosis levels and BBB integrity. ELISA was utilized to measure cytokines interleukin-1β (IL-1β) and matrix metalloproteinase-9 (MMP-9). Immunofluorescence techniques were used to evaluate protein levels and the nuclear translocation of the rela (p65) subunit. The Evans blue dye leakage assay and the brain wet-dry weight method were utilized to assess BBB integrity and brain swelling. Inhibition of NKCC1 reduced the level of NLRP3 inflammasome and the secretion of IL-1β and MMP-9 in microglia. Additionally, NKCC1 inhibition suppressed the activation of the NF-κB signaling pathway, which in turn decreased the level of NLRP3 inflammasome. The presence of NLRP3 inflammasome in BV2 cells led to compromised BBB integrity within an inflammatory milieu. Following TBI, an upregulation of NLRP3 inflammasome was observed in microglia, astrocytes, vascular endothelial cells, and neurons. Furthermore, inhibiting NKCC1 resulted in a decrease in the positive rate of NLRP3 inflammasome in microglia and the levels of inflammatory cytokines IL-1β and MMP-9 after TBI, which correlated with BBB damage and the development of cerebral edema. These findings demonstrate that the suppression of the NKCC1 cotransporter protein alleviates BBB disruption through the NF-κB/NLRP3 signaling pathway following TBI.

Implications and pathophysiology of neuroinflammation in pediatric patients with traumatic brain injury: an updated review

Traumatic Brain Injury (TBI) in children is a profound public health issue with the potential to disrupt cognitive, behavioral, and psychosocial development significantly. This review provides an updated examination of the role of neuroinflammation in pediatric TBI, emphasizing its dual impact on injury progression and recovery. Highlighted is the complex interplay of primary and secondary injury mechanisms, including the critical contributions of neuroinflammatory responses mediated by central and peripheral immune cells. Advances in biomarker identification and imaging techniques are discussed, showcasing how tools like diffusion tensor imaging (DTI) and positron emission tomography (PET) enhance our understanding of neuroinflammatory processes. The review also explores current therapeutic strategies targeting neuroinflammation, underscoring emerging treatments such as pharmacologic agents that modulate immune responses and novel therapies like stem cell interventions. This comprehensive review seeks to deepen the understanding of neuroinflammation's pathophysiological roles in pediatric TBI and propose directions for future clinical and research efforts.

Neuroprotective effects of Saxagliptin in traumatic brain injury: ameliorating oxidative stress, neuroinflammation, and apoptosis

Traumatic Brain Injury (TBI) is a significant global health issue characterized by disruptions in normal brain function due to external mechanical forces. Saxagliptin, a Dipeptidyl Peptidase-4 (DPP-4) inhibitor primarily used for diabetes management, has demonstrated potential anti-inflammatory effects that may offer therapeutic benefits for Central Nervous System (CNS) disorders. Using a network pharmacology approach, we identified Saxagliptin's molecular targets relevant to TBI pathology. Male Sprague Dawley rats were subjected to TBI via a weight-drop method and were randomly assigned to one of four groups (n = 10 per group): sham, TBI + vehicle, TBI + Saxagliptin (1 mg/kg/day), and TBI + Saxagliptin (3 mg/kg/day). Neuroprotective effects were assessed through neurobehavioral tests, brain water content measurement, biochemical assays for oxidative stress and inflammatory markers, and histopathological analysis of brain tissue. Network pharmacology identified 49 intersecting targets between Saxagliptin and TBI, with key roles in apoptosis and neuroinflammation pathways. In vivo results revealed that saxagliptin treatment markedly improved neurobehavioral outcomes. Histological analysis showed a decrease in neuronal cell death following Saxagliptin treatment. Biochemical assessments revealed that Saxagliptin mitigated TBI-induced oxidative stress markers, including oxidative DNA damage. Furthermore, Saxagliptin attenuated neuroinflammation, as shown by reduced levels of iNOS, COX-2, IL-6, and TNF-α, and ameliorated blood-brain barrier (BBB) damage. Additionally, Saxagliptin reduced apoptosis by lowering Bax, Caspase 3 levels and increasing Bcl-2 levels. Saxagliptin exhibits notable neuroprotective effects in TBI by mitigating oxidative stress, reducing neuroinflammation, and preventing neuronal apoptosis. These findings suggest that Saxagliptin could be a viable therapeutic agent for improving outcomes in TBI management.

A randomized controlled trial investigating the impact of early goal-directed sedation dominated by dexmedetomidine on cerebral oxygen metabolism and inflammatory mediators in patients with severe brain injury

OBJECTIVE

The aim of this study is to assess the neuroprotective efficacy of early goal-directed sedation (EGDS) primarily governed by dexmedetomidine in patients experiencing severe traumatic brain injury, and to elucidate its potential underlying mechanisms.

DATA AND METHODS

All participants were randomly allocated into two groups: the experimental group-dexmedetomidine-dominated EGDS group (group D, n = 30) and the control group-the standard propofol sedation group (group P, n = 30). Patients in the experimental group received sedation primarily with dexmedetomidine, while those in the control group received propofol sedation. Subsequently, retrograde catheterization of the internal jugular vein on the affected side was performed, blood gas analysis samples were collected, cerebral oxygen extraction rates were computed, and levels of interleukin 6 (IL-6) and interleukin 1β (IL-1β) were assessed. One-way ANOVA and Chi-square tests were used for statistical analysis.

RESULTS

In group D, significant reductions were observed in the duration of ventilator dependency (p < 0.05).Compared to those documented in group P, tracheostomy incidence, and pulmonary infection rates were no different (p > 0.05). On the second, third and the seventh day, the SjvO2 levels in group D exhibited a statistically significant elevation compared to group P, while the CERO2 levels were notably lower in group D than in group P (p < 0.05). The GCS scores of patients in group D was significantly higher than that of the patients in group P and the baseline value on the seventh day and the time of discharge (p < 0.05). Additionally, the IL-6 levels in group D were significantly lower than those in group P and their corresponding baseline levels on the third and seventh days (p < 0.05). The IL-1β levels were no significant difference between the two groups.

CONCLUSION

A predominance of dexmedetomidine in EGDS demonstrates efficacy in reducing the duration of ICU stay and ventilator dependency, enhancing cerebral oxygen metabolism, and attenuating the infiltration of inflammatory factors.

Predictive value of hematologic indices on weaning from mechanical ventilation and 30-day mortality in patients with traumatic brain injury in an intensive care unit: A retrospective analysis of MIMIC-IV data

The management of traumatic brain injury (TBI) in intensive care units is dependent on the wise use of life-support systems. This study investigated the utility of various hematologic indices to predict successful weaning and risk of short-term mortality in TBI patients. Data of patients with TBI requiring mechanical ventilation were extracted from the MIMIC-IV database and retrospectively reviewed. Successful weaning was defined as no re-intubation or death within 48 ​h, non-invasive ventilation under 48 ​h post-extubation, and passing a spontaneous breathing test with specific respiratory and cardiovascular stability criteria. The systemic inflammatory response index (SIRI), neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), monocyte-to-lymphocyte ratio (MLR), and glucose-to-lymphocyte ratio (GLR) were evaluated for their predictive value using logistic regression and receiver operating characteristic (ROC) analyses. A total of 414 patients were included. After adjustment, higher PLR and GLR (adjusted odds ratio [aOR] ​= ​0.766, 95 ​% confidence interval [CI]: 0.66-0.89) and GLR (aOR ​= ​0.761, 95 ​% CI: 0.65-0.89) were significantly associated with a lower likelihood of weaning success, while higher NLR (aOR ​= ​1.70, 95 ​% CI: 1.18-2.45) was associated with increased 30-day mortality. The area under the ROC curve (AUC) values for predicting weaning success were 0.636 for PLR and 0.634 for GLR. NLR showed good predictive accuracy for 30-day mortality with an AUC ​= ​0.752. In conclusions, in patients with TBI, PLR, GLR, and NLR may serve as predictors of mechanical ventilation weaning success and 30-day mortality.

Traumatic Brain Injury and Gut Microbiome: The Role of the Gut-Brain Axis in Neurodegenerative Processes

PURPOSE OF REVIEW

A deeper understanding of the communication network between the gut microbiome and the central nervous system, termed the gut-brain axis (GBA), has revealed new potential targets for intervention to prevent the development of neurodegenerative disease associated with tramatic brain injury (TBI). This review aims to comprehensively examine the role of GBA post-traumatic brain injury (TBI).

RECENT FINDINGS

The GBA functions through neural, metabolic, immune, and endocrine systems, creating bidirectional signaling pathways that modulate brain and gastrointestinal (GI) tract physiology. TBI perturbs these signaling pathways, producing pathophysiological feedback loops in the GBA leading to dysbiosis (i.e., a perturbed gut microbiome, impaired brain-blood barrier, impaired intestinal epithelial barrier (i.e., "leaky gut"), and a maladaptive, systemic inflammatory response. Damage to the CNS associated with TBI leads to GI dysmotility, which promotes small intestinal bacterial overgrowth (SIBO). SIBO has been associated with the early stages of neurodegenerative conditions such as Parkinson's and Alzheimer's disease. Many of the bacteria associated with this overgrowth promote inflammation and, in rodent models, have been shown to compromise the structural integrity of the intestinal mucosal barrier, causing malabsorption of essential nutrients and further exacerbating dysbiosis. TBI-induced pathophysiology is strongly associated with an increased risk of neurodegenerative diseases, including Parkinson's and Alzheimer's diseases, which represents a significant public health burden and challenge for patients and their families. A healthy gut microbiome has been shown to promote improved recovery from TBI and prevent the development of neurodegenerative disease, as well as other chronic complications. The role of the gut microbiome in brain health post-TBI demonstrates the potential for microbiome-targeted interventions to mitigate TBI-associated comorbidities. Promising new evidence on prebiotics, probiotics, diet, and fecal microbiota transplantation may lead to new therapeutic options for improving the quality of life for patients with TBI. Still, many of these preliminary findings must be explored further in clinical settings. This review covers the current understanding of the GBA in the setting of TBI and how the gut microbiome may provide a novel therapeutic target for treatment in this patient population.

Low serum calcium promotes traumatic intracerebral hematoma expansion by the response of immune cell: A multicenter retrospective cohort study

To explore the potential role of serum calcium levels at admission in the expansion of acute traumatic intracerebral hematoma (tICH) and to construct a novel nomogram to predict tICH expansion. In this multicenter retrospective study, 640 and 237 patients were included in the training and validation datasets, respectively. Risk factors for acute tICH expansion were selected by logistic regression analysis. Causal mediation and interaction analysis were used to explore the relationship between serum calcium promotion of tICH expansion and inflammatory response. Receiver operating characteristic, calibration and clinical decision curves were applied to estimate the performance of multivariate models. Low serum calcium level was strongly associated with acute tICH expansion in patients with brain contusion. There was no significant interaction of hypocalcemia across multiple subgroups including sex, age, and coagulation dysfunction. 24.5% of the mechanisms by which hypocalcemia promotes acute tICH expansion can be explained by an inflammatory response. The addition of serum calcium made the modified model (serum calcium plus basic model) more accurate than basic model with subdural hematoma, multihematoma fuzzy sign, time to baseline CT, level on Glasgow Coma Scale score, platelet count, baseline tICH volume ≥ 5 mL, and monocyte-to-lymphocyte ratio. Low serum calcium level is a novel risk factor for acute tICH expansion, the mechanism of which may be mediated in part through the response of immune cell. The online dynamic nomogram provides a user-friendly tool for the prediction of acute tICH expansion.

Neuroprotection in traumatic brain injury: effects of alpha-asarone and Acorus calamus extract in mice using weight drop model

Traumatic brain injury (TBI) is a significant public health concern characterized by severe neurological consequences. The management of TBI remains a formidable challenge, necessitating a multifaceted approach aimed at reducing secondary injury and promoting neuroprotection. This study assessed the neuroprotective potential of Alpha-asarone (AA) at 12.5, 25, 50 mg/kg, p.o (phytoconstituent of Acorus calamus) at, and Acorus calamus (AC) extract at 190 mg/kg, p.o in a murine TBI model induced by weight drop method. Blood-Brain Barrier (BBB) permeability and oxidative stress were evaluated on 1st and 3rd day, while Neurological Severity Score (NSS) was assessed on 1st, 3rd, 7th, 14th, and 21st day after TBI. The administration of AA and AC extract at all tested doses demonstrated a dose-dependent restoration of blood-brain barrier (BBB) integrity and oxidative stress markers. Specifically, AA at doses of 25 mg/kg and 50 mg/kg, as well as AC extract at 190 mg/kg, administered orally, exhibited significant effects on BBB integrity and oxidative stress at 1st and 3rd day post-treatment. Furthermore, enhanced neurological outcomes were observed at 14th and 21st day post TBI, evidenced by improved NSS, particularly with the 50 mg/kg dose of AA and the 190 mg/kg dose of AC extract. This research underscores the potential of AA and AC extract as neuroprotective agents. The findings highlight their efficacy in improving BBB integrity, mitigating oxidative stress-induced cellular damage and enhancing neurological impairments following TBI. These results hold promise for the development of innovative neuroprotective therapies and advocate for the exploration of natural compounds as adjunctive interventions in TBI management.

Responsive nanoparticles synergize with Curcumin to break the "reactive oxygen Species-Neuroinflammation" vicious cycle, enhancing traumatic brain injury outcomes

Traumatic brain injury (TBI) disrupts oxygen homeostasis in the brain, leading to excessive reactive oxygen species (ROS) production and dysregulated antioxidant mechanisms, which fail to clear excess ROS. This ROS overload promotes the expression of pro-inflammatory genes, releasing cytokines and chemokines and creating a vicious "ROS-neuroinflammation" cycle, making it essential to break this cycle for effective TBI treatment. In this study, we developed cysteine-alanine-glutamine-lysine (CAQK) peptide-modified antioxidant nanoparticles (C-PPS/C) for co-delivery of curcumin (Cur) to modulate oxidative and neuroinflammatory disturbances after TBI. In TBI mice, C-PPS/C nanoparticles accumulated in injured brain regions, where poly (propylene sulfide)120 scavenged ROS, reducing oxidative stress, while Cur release further suppressed ROS and inflammation. C-PPS/C nanoparticles broke the "ROS-neuroinflammation" cycle, protecting the blood-brain barrier (BBB), reducing acute brain edema, and promoting long-term neurological recovery. Further investigation showed that C-PPS/C nanoparticles inhibited the NF-κB pathway, reducing pro-inflammatory gene expression and mitigating inflammation, suggesting a promising approach for TBI treatment.

Activity-Based Proteome Profiling of Serum Serine Hydrolases: Application in Pediatric Abusive Head Trauma

PURPOSE

Traumatic brain injury (TBI), including pediatric abusive head trauma (AHT), is the leading cause of death and disability in children and young adults worldwide. The current understanding of trauma-induced molecular changes in the brain of human subjects with intracranial hemorrhage (ICH) remains inadequate and requires further investigation to improve the outcome and management of TBI in the clinic. Calcium-mediated damage at the site of brain injury has been shown to activate several catalytic enzymes.

EXPERIMENTAL DESIGN

Serine hydrolases (SHs) are major catalytic enzymes involved in the biochemical pathways of blood coagulation, systemic inflammation, and neuronal signaling. Here, we investigated activity-based protein profiling (ABPP) coupled to liquid chromatography-mass spectrometry (LC-MS) by measuring the activity status of SH enzymes in the serum of infants with severe ICH as a consequence of AHT or atraumatic infants who died of sudden infant death syndrome (SIDS).

RESULTS

Our proof-of-principle study revealed significantly reduced physiological activity of dozens of metabolic SHs in the serum of infants with severe AHT compared to the SIDS group, with some of the enzymes being related to neurodevelopment and basic brain metabolism.

CONCLUSIONS AND CLINICAL RELEVANCE

To our knowledge, this is the first study to investigate the ABPP of the SHs enzyme family to detect changes in their physiological activity in blood serum in severe TBI. We used antemortem (AM) serum from infants under the age of 2 years who were victims of AHT with a severe form of ICH. The analytical approach used in the proof-of-principle study shows reduced activities of serum serine lipases in AHT cases and could be further investigated in mild forms of AHT, which currently show 30% of misdiagnosed cases in clinics.

Trends of Mortality due to Traumatic Brain Injury in the USA: A Comprehensive Analysis of CDC WONDER Data from 1999 to 2020

Traumatic brain injury (TBI) poses a significant public health challenge in the United States, with diverse causes and outcomes. Understanding the trends in TBI-related mortality is crucial for effective prevention and intervention strategies. This comprehensive analysis utilized data from the Centers for Disease Control and Prevention's Wide-ranging Online Data for Epidemiologic Research (CDC WONDER) database, covering the period from 1999 to 2020. Cause-of-death records were examined using the 10th Edition of the International Classification of Diseases and Related Health Problems diagnostic code S06 for TBI-related fatalities. Mortality rates were calculated per 100,000 individuals, adjusted for age and urban/rural status. Joinpoint Regression analysis was employed to identify significant trends over time. Between 1999 and 2020, 1,218,667 TBI-related deaths occurred, with varying mortality rates across demographic groups and geographic regions. Within the overall population, the highest annual average mortality rates were observed in the non-Hispanic (NH) American Indian or Alaska Native cohort, followed by NH white, NH black or African American, Hispanic or Latino, and NH Asian or Pacific Islander groups. Overall, there was an initial decrease in mortality rate from 1999 to 2012, followed by a subsequent significant increase. Males consistently exhibited higher mortality rates than females across all age groups. Disparities were also observed based on race/ethnicity, with NH American Indian or Alaska Native populations showing the highest mortality rates. Regional variations were evident, with the southern region consistently exhibiting the highest mortality rates. Evolving trends in TBI-related mortality in the United States highlight the need for targeted interventions, particularly in high-risk demographic groups and regions.

Repetitive Low-Level Blast Exposure Alters Circulating Myeloperoxidase, Matrix Metalloproteinases, and Neurovascular Endothelial Molecules in Experienced Military Breachers

Repeated exposure to low-level blast overpressure, frequently experienced during explosive breaching and heavy weapons use in training and operations, is increasingly recognised as a serious risk to the neurological health of military personnel. Although research on the underlying pathobiological mechanisms in humans remains limited, this study investigated the effects of such exposure on circulating molecular biomarkers associated with inflammation, neurovascular damage, and endothelial injury. Blood samples from military breachers were analysed for myeloperoxidase (MPO), matrix metalloproteinases (MMPs), and junctional proteins indicative of blood-brain barrier (BBB) disruption and endothelial damage, including occludin (OCLN), zonula occludens-1 (ZO-1), aquaporin-4 (AQP4), and syndecan-1 (SD-1). The results revealed significantly elevated levels of MPO, MMP-3, MMP-9, and MMP-10 in breachers compared to unexposed controls, suggesting heightened inflammation, oxidative stress, and vascular injury. Increased levels of OCLN and SD-1 further indicated BBB disruption and endothelial glycocalyx degradation in breachers. These findings highlight the potential for chronic neurovascular unit damage/dysfunction from repeated blast exposure and underscore the importance of early targeted interventions-such as reducing oxidative stress, reinforcing BBB integrity, and managing inflammation-that could be essential in mitigating the risk of long-term neurological impairment associated with blast exposure.

Trajectories of systemic immune inflammation index and mortality risk in patients with moderate-to-severe traumatic brain injury: a retrospective cohort study

Background

Some studies have shown a strong link between the central nervous system and peripheral immune system, but the prognostic implications of dynamic peripheral immune-inflammatory responses in patients with traumatic brain injury (TBI) remain unclear. This study aimed to determine the dynamic trajectory patterns of the Systemic Immune Inflammation Index (SII) in patients with TBI and assess its association with all-cause hospital mortality.

Methods

This retrospective cohort study utilized a large public database of patients with TBI sourced from the eICU Collaborative Research Database (eICU-CRD). Group-Based Trajectory Modeling (GBTM) was used to analyze daily SII trajectories during the initial 0-7 days of hospitalization. Logistic regression was employed to assess the relationship between different SII trajectory groups and hospital mortality. Receiver Operating Characteristic (ROC) curves were generated based on the logistic regression model.

Results

A total of 312 patients were included in this study, 52 of whom died during hospitalization. Using GBTM, three distinct SII trajectories were identified: Group 1 (low-level, rapid decline; 18.90%), Group 2 (moderate-level, slow decline; 60.20%), and Group 3 (sustained high-level; 20.80%). Compared to patients in Group 1, those in Groups 2 and 3 had a higher risk of all-cause hospital mortality (odds ratio [OR] 4.09; 95% confidence interval [CI] 1.21, 19.75) and (OR 5.84; 95% CI 1.52, 30.67), respectively. ROC analysis revealed an area under the curve (AUC) of 0.838, sensitivity: 75.0%, and specificity: 83.8% for mortality in this cohort.

Conclusion

This study identified three distinct SII trajectories, suggesting that post-TBI SII trajectories are heterogeneous patterns associated with mortality. The sustained high-level SII trajectory may serve as a marker of disease deterioration, highlighting the need for targeted interventions. Describing the evolution of SII through GBTM and its correlation with clinical outcomes can enhance our understanding of the link between neuroinflammation and the peripheral immune system.

Olfactory mucosa-mesenchymal stem cells with overexpressed Nrf2 modulate angiogenesis and exert anti-inflammation effect in an in vitro traumatic brain injury model

BACKGROUND

Traumatic brain injury (TBI) is a major cause of disability and mortality among children and adults in developed countries. Transcription factor nuclear factor erythroid-derived 2-like 2 (Nrf2) has antioxidant, anti-inflammatory and neuroprotective effects and is closely related to TBI. Olfactory mucosa-mesenchymal stem cells (OM-MSCs) could promote neural regeneration. At present, the effects of OM-MSCs with overexpressed Nrf2 in brain diseases remain to be explored.

METHODS

The OM-MSCs were prepared and transfected with Nrf2 overexpression plasmid. Those transfected cells were termed as OM-MSCs with Nrf2 overexpression (OM-MSCsNrf2) and co-cultured with rat pheochromocytoma cells PC12 or murine microglia BV2. The effects of OM-MSCsNrf2 on the survival and angiogenesis of PC12 cells were evaluated through cell counting kit-8 (CCK-8) and tube formation assay, and extracellular acidification rate (ECAR) and oxygen consumption rate (OCR) were calculated to reflect glycolysis. Immunofluorescence assay was applied to determine the effects of OM-MSCsNrf2 on microglial polarization, and the underlying molecular mechanisms were analyzed based on the quantification tests of RT-qPCR and immunoblotting.

RESULTS

Co-culture of OM-MSCsNrf2 and PC12 cells increased the levels of anti-inflammatory cytokines and pro-angiogenesis factors, enhanced the cell survival and angiogenesis. Moreover, we also observed elevated phosphorylation of PI3K/AKT and suppressed BAX protein expression. Meanwhile, OM-MSCsNrf2 inhibited the levels of pro-inflammatory genes and affected the glycolysis in PC12 cells. In the co-cultured system of OM-MSCsNrf2 and BV2 cells, M2 microglial polarization was observed, and the levels of M2 microglia-relevant genes and the phosphorylation of STAT6/AMPKα/SMAD3 were elevated.

CONCLUSION

This study proved the effects of OM-MSCsNrf2 on modulating PC12 and BV2 cells in vitro, which, however, necessitates further in vivo validation.

Partially hydrolyzed guar gum alleviates neurological deficits and gastrointestinal dysfunction in mice with traumatic brain injury

Traumatic brain injury (TBI)-associated neuroinflammation and neurotoxicity can induce gastrointestinal dysfunction through the brain-gut axis. Partially hydrolyzed guar gum (PHGG) was demonstrated to exert beneficial health effects by altering gut microbiota and short-chain fatty acids (SCFAs) production. Our study aimed to explore the effects of PHGG on gastrointestinal dysfunction in TBI mouse models. Controlled cortical impact (CCI)-induced TBI mouse models were administrated with PHGG (600 mg/kg/d) for 21 consecutive days. Behavioral tests (modified neurological severity score and beam walk test) and Y‑maze assay were performed to evaluate neurological functions and cognitive impairment. Enzyme-linked immunosorbent assay, reverse transcription-quantitative polymerase chain reaction, and western blotting examined the levels of inflammatory cytokines, intestinal mucosal damage markers, intestinal tight junction proteins, and NLRP3 inflammasome-related molecules in the serum, cerebral cortex, and colon tissues. The histological changes in the cerebral cortex and colon tissues were observed through hematoxylin and eosin and Nissl staining. Liquid chromatography/mass spectrometry analyzed SCFA amounts in the cecum contents and bile acid levels in the serum. PHGG administration alleviated neurological deficits and cognitive perturbations, reduced neuroinflammation, and attenuated cortical tissue damage and neuron loss in TBI mice. PHGG ameliorated intestinal barrier impairment, upregulated intestinal production of SCFAs, and elevated serum bile acid levels in TBI mice. Besides, PHGG treatment repressed NLRP3 inflammasome activation in TBI mice. Overexpressing NLRP3 reversed the beneficial effects of PHGG against TBI in mice. PHGG ameliorates neuroinflammation and gastrointestinal dysfunction in TBI murine models by inhibiting NLRP3 inflammasome activation.

Advances in the Regulation of Inflammatory Mediators in Nitric Oxide Synthase: Implications for Disease Modulation and Therapeutic Approaches

Nitric oxide synthases (NOS) are crucial enzymes responsible for the production of nitric oxide (NO), a signaling molecule with essential roles in vascular regulation, immune defense, and neurotransmission. The three NOS isoforms, endothelial NOS (eNOS), neuronal NOS (nNOS), and inducible NOS (iNOS), are tightly regulated by inflammatory mediators and cellular signaling pathways. While physiological NO production is vital for maintaining homeostasis, dysregulated NOS activity contributes to the pathogenesis of numerous diseases, including cardiovascular disorders, neurodegenerative conditions, and cancer. Recent advances in understanding the molecular mechanisms of NOS regulation have unveiled novel therapeutic opportunities, including isoform-specific modulators, upstream pathways, and nanotechnology-enhanced delivery systems. This review highlights these advancements, offering insights into how targeting NOS and its regulatory network can enable precise and effective therapeutic strategies for managing inflammation-driven pathologies.

Targeting Cytokine-Mediated Inflammation in Brain Disorders: Developing New Treatment Strategies

Cytokine-mediated inflammation is increasingly recognized for playing a vital role in the pathophysiology of a wide range of brain disorders, including neurodegenerative, psychiatric, and neurodevelopmental problems. Pro-inflammatory cytokines such as interleukin-1 (IL-1), tumor necrosis factor-alpha (TNF-α), and interleukin-6 (IL-6) cause neuroinflammation, alter brain function, and accelerate disease development. Despite progress in understanding these pathways, effective medicines targeting brain inflammation are still limited. Traditional anti-inflammatory and immunomodulatory drugs are effective in peripheral inflammatory illnesses. Still, they face substantial hurdles when applied to the central nervous system (CNS), such as the blood-brain barrier (BBB) and unwanted systemic effects. This review highlights the developing treatment techniques for modifying cytokine-driven neuroinflammation, focusing on advances that selectively target critical cytokines involved in brain pathology. Novel approaches, including cytokine-specific inhibitors, antibody-based therapeutics, gene- and RNA-based interventions, and sophisticated drug delivery systems like nanoparticles, show promise with respect to lowering neuroinflammation with greater specificity and safety. Furthermore, developments in biomarker discoveries and neuroimaging techniques are improving our ability to monitor inflammatory responses, allowing for more accurate and personalized treatment regimens. Preclinical and clinical trial data demonstrate the therapeutic potential of these tailored techniques. However, significant challenges remain, such as improving delivery across the BBB and reducing off-target effects. As research advances, the creation of personalized, cytokine-centered therapeutics has the potential to alter the therapy landscape for brain illnesses, giving patients hope for better results and a higher quality of life.

Xuefu Zhuyu Decoction Improves Blood-Brain Barrier Integrity in Acute Traumatic Brain Injury Rats via Regulating Adenosine

OBJECTIVE

To explore the neuroprotective effects of Xuefu Zhuyu Decoction (XFZYD) based on in vivo and metabolomics experiments.

METHODS

Traumatic brain injury (TBI) was induced via a controlled cortical impact (CCI) method. Thirty rats were randomly divided into 3 groups (10 for each): sham, CCI and XFZYD groups (9 g/kg). The administration was performed by intragastric administration for 3 days. Neurological functions tests, histology staining, coagulation and haemorheology assays, and Western blot were examined. Untargeted metabolomics was employed to identify metabolites. The key metabolite was validated by enzyme-linked immunosorbent assay and immunofluorescence.

RESULTS

XFZYD significantly alleviated neurological dysfunction in CCI model rats (P<0.01) but had no impact on coagulation function. As evidenced by Evans blue and IgG staining, XFZYD effectively prevented blood-brain barrier (BBB) disruption (P<0.05, P<0.01). Moreover, XFZYD not only increased the expression of collagen IV, occludin and zona occludens 1 but also decreased matrix metalloproteinase-9 (MMP-9) and cyclooxygenase-2 (COX-2), which protected BBB integrity (all P<0.05). Nine potential metabolites were identified, and all of them were reversed by XFZYD. Adenosine was the most significantly altered metabolite related to BBB repair. XFZYD significantly reduced the level of equilibrative nucleoside transporter 2 (ENT2) and increased adenosine (P<0.01), which may improve BBB integrity.

CONCLUSIONS

XFZYD ameliorates BBB disruption after TBI by decreasing the levels of MMP-9 and COX-2. Through further exploration via metabolomics, we found that XFZYD may exert a protective effect on BBB by regulating adenosine metabolism via ENT2.

Protective Role of Electroacupuncture Against Cognitive Impairment in Neurological Diseases

Many neurological diseases can lead to cognitive impairment in patients, which includes dementia and mild cognitive impairment and thus create a heavy burden both to their families and public health. Due to the limited effectiveness of medications in treating cognitive impairment, it is imperative to develop alternative treatments. Electroacupuncture (EA), a required method for Traditional Chinese Medicine, has the potential treatment of cognitive impairment. However, the molecular mechanisms involved have not been fully elucidated. Considering the current research status, preclinical literature published within the ten years until October 2022 was systematically searched through PubMed, Web of Science, MEDLINE, Ovid, and Embase. By reading the titles and abstracts, a total of 56 studies were initially included. It is concluded that EA can effectively ameliorate cognitive impairment in preclinical research of neurological diseases and induce potentially beneficial changes in molecular pathways, including Alzheimer's disease, vascular cognitive impairment, chronic pain, and Parkinson's disease. Moreover, EA exerts beneficial effects through the same or diverse mechanisms for different disease types, including but not limited to neuroinflammation, neuronal apoptosis, neurogenesis, synaptic plasticity, and autophagy. However, these findings raise further questions that need to be elucidated. Overall, EA therapy for cognitive impairment is an area with great promise, even though more research regarding its detailed mechanisms is warranted.

Chronic glial activation and behavioral alterations induced by acute/subacute pioglitazone treatment in a mouse model of traumatic brain injury

Traumatic brain injury (TBI) is a disabling neurotraumatic condition and the leading cause of injury-related deaths and disability in the United States. Attenuation of neuroinflammation early after TBI is considered an important treatment target; however, while these inflammatory responses can induce secondary brain injury, they are also involved in the repair of the nervous system. Pioglitazone, which activates peroxisome proliferator-activated receptor gamma, has been shown to decrease inflammation acutely after TBI, but the long-term consequences of its use remain unknown. For this reason, the impacts of treatment with pioglitazone during the acute/subacute phase (30 min after injury and each subsequent 24 h for 5 days) after TBI were interrogated during the chronic phase (30- and 274-days post-injury (DPI)) in mice using the controlled cortical impact model of experimental TBI. Acute/subacute pioglitazone treatment after TBI results in long-term deleterious consequences, including disruption of tau homeostasis, chronic glial cell activation, neuronal pathology, and worsened injury severity particularly at 274 DPI, with male mice being more susceptible than female mice. Further, male pioglitazone-treated TBI mice exhibited increased dominant and offensive-like behavior while having a decreased non-social exploring behavior at 274 DPI. After TBI, both sexes exhibited glial activation at 30 DPI when treated with pioglitazone; however, while injury severity was increased in females it was not impacted in male mice. This work reveals that although pioglitazone has been shown to lead to attenuated TBI outcomes acutely, sex-based differences, timing and long-term consequences of treatment with glitazones must be considered and further studied prior to their clinical use for TBI therapy.

Unravelling Secondary Brain Injury: Insights from a Human-Sized Porcine Model of Acute Subdural Haematoma

Traumatic brain injury (TBI) remains one of the leading causes of death. Because of the individual nature of the trauma (brain, circumstances and forces), humans experience individual TBIs. This makes it difficult to generalise therapies. Clinical management issues such as whether intracranial pressure (ICP), cerebral perfusion pressure (CPP) or decompressive craniectomy improve patient outcome remain partly unanswered. Experimental drug approaches for the treatment of secondary brain injury (SBI) have not found clinical application. The complex, cellular and molecular pathways of SBI remain incompletely understood, and there are insufficient experimental (animal) models that reflect the pathophysiology of human TBI to develop translational therapeutic approaches. Therefore, we investigated different injury patterns after acute subdural hematoma (ASDH) as TBI in a post-hoc approach to assess the impact on SBI in a long-term, human-sized porcine TBI animal model. Post-mortem brain tissue analysis, after ASDH, bilateral ICP, CPP, cerebral oxygenation and temperature monitoring, and biomarker analysis were performed. Extracerebral, intraparenchymal-extraventricular and intraventricular blood, combined with brainstem and basal ganglia injury, influenced the experiment and its outcome. Basal ganglia injury affects the duration of the experiment. Recognition of these different injury patterns is important for translational interpretation of results in this animal model of SBI after TBI.

An apolipoprotein E receptor mimetic peptide decreases blood-brain barrier permeability following intracerebral hemorrhage by inhibiting the CypA/MMP-9 signaling pathway via LRP1 activation

Apolipoprotein (Apo) E mimetic peptides down-regulate the inflammatory response and alleviate damage to secondary neurons after intracerebral hemorrhage (ICH). We designed a novel apoE receptor mimetic composed of the low-density lipoprotein receptor-associated protein-1 (LRP1) receptor-binding domain of apoE with 6 lysines (6KApoEp). The 6KApoEp peptide is small enough to penetrate the blood-brain barrier (BBB) and modulate the inflammatory response during damage to the central nervous system. LRP1 inhibits the CypA/MMP-9 pathway and reduces BBB damage. Thus, we examined the effects of 6KApoEp-LRP1 interaction. LRP1 and 6KApoEp interacted and co-localized in the pericytes. We established a Sprague-Dawley (SD) male rat model of ICH to observe the role of 6KApoEp in secondary injury after ICH. The expression levels of cyclophilin A (CypA), nuclear factor kappa-B (NF-κB) p65, and matrix metalloproteinase 9 (MMP-9) were increased, the expression levels of ZO-1, claudin-5, and occludin were decreased, and brain water content and BBB permeability increased in the ICH model. The expression of CypA, NF-κB, and MMP-9 decreased significantly around the hematoma, while the expression of tight junction-related proteins increased significantly in response to 6KApoEp, especially at the 100 μg/kg dose. LRP expression increased around the ICH focus in response to 6KApoEp treatment, thus increasing the influence on the expression of CypA, NF-κB, and MMP-9. We conclude that 6KApoEp inhibits the CypA/NF-κB/MMP-9 pathway by activating LRP1, resulting in reduced BBB damage and less brain edema around the ICH. These results provide the theoretical basis for improving the prognosis and treatment of ICH. Our results suggest that 6KApoEp activates LRP1, resulting in the attenuation of tight junction protein degradation (ZO-1, occludin, and claudin-5) via the CypA/NF-κB/MMP-9 signaling pathway. The increased tight junction protein levels improve the BBB and attenuate edema development in brain tissue around the hematoma following ICH.

Neuroinflammatory Response in the Traumatic Brain Injury: An Update

The central nervous system (CNS) comprises membranes and barriers that are vital to brain homeostasis. Membranes form a robust shield around neural structures, ensuring protection and structural integrity. At the same time, barriers selectively regulate the exchange of substances between blood and brain tissue, which is essential for maintaining homeostasis. Another highlight is the glymphatic system, which cleans metabolites and waste from the brain. Traumatic brain injury (TBI) represents a significant cause of disability and mortality worldwide, resulting from the application of direct mechanical force to the head that results in a primary injury. Therefore, this review aims to elucidate the mechanisms associated with the secondary injury cascade, in which there is intense activation of glial cells, dysfunction of the glymphatic system, glutamatergic neurotoxicity, additional molecular and biochemical changes that lead to a neuroinflammatory process, and oxidative stress and in which way they can be associated with cognitive damage that is capable of lasting for an extended period.

Neurological Biomarker Profiles in Royal Canadian Air Force (RCAF) Pilots and Aircrew

BACKGROUND/OBJECTIVES

Military aviators can be exposed to extreme physiological stressors, including decompression stress, G-forces, as well as intermittent hypoxia and/or hyperoxia, which may contribute to neurobiological dysfunction/damage. This study aimed to investigate the levels of neurological biomarkers in military aviators to assess the potential risk of long-term brain injury and neurodegeneration.

METHODS

This cross-sectional study involved 48 Canadian Armed Forces (CAF) aviators and 48 non-aviator CAF controls. Plasma samples were analyzed for biomarkers of glial activation (GFAP), axonal damage (NF-L, pNF-H), oxidative stress (PRDX-6), and neurodegeneration (T-tau), along with S100b, NSE, and UCHL-1. The biomarker concentrations were quantified using multiplexed immunoassays.

RESULTS

The aviators exhibited significantly elevated levels of GFAP, NF-L, PRDX-6, and T-tau compared to the CAF controls (p < 0.001), indicating increased glial activation, axonal injury, and oxidative stress. Trends toward higher levels of S100b, NSE, and UCHL-1 were observed but were not statistically significant. The elevated biomarker levels suggest cumulative brain damage, raising concerns about potential long-term neurological impairments.

CONCLUSIONS

Military aviators are at increased risk for neurobiological injury, including glial and axonal damage, oxidative stress, and early neurodegeneration. These findings emphasize the importance of proactive monitoring and further research to understand the long-term impacts of high-altitude flight on brain health and to develop strategies for mitigating cognitive decline and neurodegenerative risks in this population.

Tailoring glioblastoma treatment based on longitudinal analysis of post-surgical tumor microenvironment

Glioblastoma (GBM), an incurable primary brain tumor, typically requires surgical intervention followed by chemoradiation; however, recurrences remain fatal. Our previous work demonstrated that a nanomedicine hydrogel (GemC12-LNC) delays recurrence when administered post-surgery. However, tumor debulking also triggers time-dependent immune reactions that promote recurrence at the resection cavity borders. We hypothesized that combining the hydrogel with an immunomodulatory drug could enhance therapeutic outcomes. A thorough characterization of the post-surgical microenvironment (SMe) is crucial to guide combinatorial approaches.In this study, we performed cellular resolution imaging, flow cytometry and spatial hyperplexed immunofluorescence imaging to characterize the SMe in a syngeneic mouse model of tumor resection. Owing to our dynamic approach, we observed transient opening of the blood-brain barrier (BBB) during the first week after surgery. BBB permeability post-surgery was also confirmed in GBM patients. In our murine model, we also observed changes in immune cell morphology and spatial location post-surgery over time in resected animals as well as the accumulation of reactive microglia and anti-inflammatory macrophages in recurrences compared to unresected tumors since the first steps of recurrence growth. Therefore we investigated whether starting a systemic treatment with the SMAC mimetic small molecule (GDC-0152) directly after surgery would be beneficial for enhancing microglial anti-tumoral activity and decreasing the number of anti-inflammatory macrophages around the GemC12-LNC hydrogel-loaded tumor cavity. The immunomodulatory effects of this drug combination was firstly shown in patient-derived tumoroids. Its efficacy was confirmed in vivo by survival analysis and correlated with reversal of the immune profile as well as delayed tumor recurrence.This comprehensive study identified critical time frames and immune cellular targets within the SMe, aiding in the rational design of combination therapies to delay recurrence onset. Our findings suggest that post-surgical systemic injection of GDC-0152 in combination with GemC12-LNC local treatment is a promising and innovative approach for managing GBM recurrence, with potential for future translation to human patient.

Non-Invasive Monitoring of Cerebral Edema Using Ultrasonic Echo Signal Features and Machine Learning

OBJECTIVES

Cerebral edema, a prevalent consequence of brain injury, is associated with significant mortality and disability. Timely diagnosis and monitoring are crucial for patient prognosis. There is a pressing clinical demand for a real-time, non-invasive cerebral edema monitoring method. Ultrasound methods are prime candidates for such investigations due to their non-invasive nature.

METHODS

Acute cerebral edema was introduced in rats by permanently occluding the left middle cerebral artery (MCA). Ultrasonic echo signals were collected at nine time points over a 24 h period to extract features from both the time and frequency domains. Concurrently, histomorphological changes were examined. We utilized support vector machine (SVM), logistic regression (LogR), decision tree (DT), and random forest (RF) algorithms for classifying cerebral edema types, and SVM, RF, linear regression (LR), and feedforward neural network (FNNs) for predicting the cerebral infarction volume ratio.

RESULTS

The integration of 16 ultrasonic features associated with cerebral edema development with the RF model enabled effective classification of cerebral edema types, with a high accuracy rate of 97.9%. Additionally, it provided an accurate prediction of the cerebral infarction volume ratio, with an R2 value of 0.8814.

CONCLUSIONS

Our proposed strategy classifies cerebral edema and predicts the cerebral infarction volume ratio with satisfactory precision. The fusion of ultrasound echo features with machine learning presents a promising non-invasive approach for the monitoring of cerebral edema.

Enriched environment may improve secondary brain injury after traumatic brain injury by regulating the TLR2/NF-κB signaling pathway

Background

Traumatic brain injury (TBI) can cause damage to the blood-brain barrier, resulting in neuroinflammatory reactions and brain edema that seriously affect the recovery of neurological function. We hypothesize that an enriched environment (EE) regulates the TLR2/NF-κB signaling pathway and thereby modulates the integrity of the blood-brain barrier to achieve neuroprotective effects.

Objective

This study evaluated the expression of toll-like receptor (TLR)-2 after TBI in a rat model, with the aim of determining whether TLR2/NF-κB improves secondary brain injury by inhibiting the release of inflammatory factors and reducing brain edema.

Methods

We established a TBI model using Sprague-Dawley rats and implemented EE intervention or TLR2 siRNA to reduce TLR2. Western-blot analysis, real-time PCR, immunofluorescence staining, ELISA, TUNEL and FJC staining, wet-dry methods, rotarod testing, and neurological scoring were then applied for analysis.

Results

Our results revealed that TLR2 was activated after TBI in rats and that EE or silencing of TLR2 with TLR2 siRNA reduced the level of inflammation, significantly alleviating brain edema, neuronal apoptosis, and degeneration. TBI exacerbated brain edema and nerve damage caused by TLR2/NF-κB signaling, and EE appeared to regulate neuroinflammation and brain edema by reducing TLR2.

Conclusions

Inhibition of TLR2 with EE might constitute a successful approach in the management of TBI.

Pre-admission opioid use disorder as a new predictor of in-hospital mortality and six-month outcomes in traumatic brain injury patients: a retrospective longitudinal cohort study

BACKGROUND

The present study aimed to investigate the effect of pre-admission Opioid Use Disorder (OUD) on in-hospital mortality and 6-month follow-up TBI outcomes.

DESIGN

This study included 2804 patients with TBI admitted to the Intensive Care Unit of Emtiaz (Rajaee) Hospital, a referral trauma center in Shiraz, Iran. Finally, 1087 eligible participants were selected from included patients. Then, 872 discharged patients were followed for six months. Subsequently, unfavorable neurological outcomes (Glasgow Outcome Scale-Extended ≤ 4) and the mortality rate were compared among the patients with and without OUD.

RESULTS

The mean age of the patients was 38.0 ± 18.9 years old (84.7% men). About 9.2% of patients had OUD. Opioid users had a slightly lower risk of in-hospital mortality (OR = 0.62, 95% CI = [0.328, 1.183], P-value = 0.148). In contrast, 6-month follow-up mortality significantly increased in the survived patients with a history of pre-admission OUD (OR = 2.49, 95%CI= [1.29, 2.80], P-value = 0.007). Moreover, 6-month unfavorable outcomes were raised in OUD, though it was not significant (OR = 1.59, 95%CI= [0.89, 2.84], P-value = 0.121).

CONCLUSIONS

Our results revealed that patients with OUD are at increased risk of 6-month follow-up complications and also death following moderate to severe TBI. Although OUD decreased in-hospital mortality, 6-month follow-up indicated that mortality and unfavorable outcomes were increased in the OUD group. Based on the existing evidence, this effect is probably not only due to the destructive impact of pre-admission OUD on brain physiology. However, it may also be due to an increase in opioid consumption to alleviate pain and withdrawal symptoms after hospital discharge.

Uncovering the therapeutic efficacy and mechanisms of Quercetin on traumatic brain injury animals: a meta-analysis and network pharmacology analysis

Quercetin, a flavonoid and natural antioxidant derived from fruits and vegetables, has shown promising results in the improvement of traumatic brain injury (TBI). This study aims to elucidate the therapeutic role and potential mechanisms of quercetin in TBI through systematic evaluations and network pharmacology approaches. First, the meta-analysis was conducted via Review Manager 5.4 software. The meta-analysis results confirmed that quercetin could improve TBI, primarily by inhibiting inflammation, oxidative stress, and apoptosis. Subsequently, targets related to quercetin and those related to TBI were extracted from drug-related databases and disease-related databases, respectively. We found that the potential mechanism by which quercetin treats TBI is largely associated with ferroptosis, as indicated by functional analysis. Based on this, we identified 29 ferroptosis-related genes (FRGs) associated with quercetin and TBI, and then performed Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis using the DAVID database. The functional enrichment results revealed that these FRGs mainly involve the HIF-1 signaling pathway, IL-17 signaling pathway, and PI3K-Akt signaling pathway. Subsequently, we constructed a PPI network and identified the top 10 targets-HIF1A, IL6, JUN, TP53, IL1B, PTGS2, PPARG, EGFR, IFNG, and GSK3B-as hub targets. Meanwhile, molecular docking results further demonstrated that quercetin could stably bind to the top 10 hub targets. In conclusion, the above results elucidated that quercetin could effectively attenuates TBI by inhibiting inflammation, oxidative stress, and apoptosis. Notably, quercetin may also target these hub targets to regulate ferroptosis and improve TBI.

Antisecretory Factor 16 (AF16): A Promising Avenue for the Treatment of Traumatic Brain Injury-An In Vitro Model Approach

Traumatic brain injury (TBI) is caused by an external mechanical force to the head, resulting in abnormal brain functioning and clinical manifestations. Antisecretory factor (AF16) is a potential therapeutic agent for TBI treatment due to its ability to inhibit fluid secretion and decrease inflammation, intracranial pressure, and interstitial fluid build-up, key hallmarks presented in TBI. Here, we investigated the effect of AF16 in an in vitro model of neuronal injury, as well as its impact on key components of the autophagy pathway and mitochondrial dynamics. N2Awt cells were treated with AF16, injured using a scratch assay, and analysed using confocal microscopy, correlative light and electron microscopy (CLEM), flow cytometry, and western blotting. Our results reveal that AF16 enhances autophagy activity, regulates mitochondrial dynamics, and provides protection as early as 6 h post-injury. Fluorescently labelled AF16 was observed to localise to lysosomes and the autophagy compartment, suggesting a role for autophagy and mitochondrial quality control in conferring AF16-associated neuronal protection. This study concludes that AF16 has potential as a therapeutic agent for TBI treatment through is regulation of autophagy and mitochondrial dynamics.

Effect of Bevacizumab on traumatic penumbra brain edema in rats at different time points

Traumatic penumbra (TP) is a secondary injury area located around the core area of traumatic brain injury after brain trauma, and is an important factor affecting the outcome of traumatic brain injury (TBI). The main pathological change caused by TP is brain edema, including (cellular brain edema and vascular brain edema). The formation and development of brain edema in the TP area are closely related to the blood-brain barrier (BBB) and vascular endothelial growth factor (VEGF). VEGF is a vascular permeability factor that can promote angiogenesis and increase BBB permeability, and there is a debate on the pros and cons of its role in early TBI. Therefore, in the early stage of TBI, when using the VEGF inhibitor bevacizumab to treat TP area brain edema, the timing of bevacizumab administration is particularly important, and there are currently no relevant literature reports. This article explores the treatment time window and optimal treatment time point of bevacizumab in the treatment of cerebral edema in the TP area by administering the same dose of bevacizumab at different time points after brain injury in rats. The results showed that there was traumatic brain edema in TP area, BBB structure and function were damaged, VEGF expression and angiogenesis were increased. Compared with TBI + NS Group, after Bevacizumab treatment, brain edema in TP area was alleviated, BBB structure and function were improved, VEGF expression and angiogenesis were decreased in each treatment group, and the effect of TBI + Bevacizumab 1 h group was the most significant. Bevacizumab can be used as a targeted therapy for traumatic brain edema. The therapeutic time window of bevacizumab for traumatic brain edema is within 12 hours after TBI, and 1 h is the optimal therapeutic time point.

Dose-Dependent Tranexamic Acid Blunting of Penumbral Leukocyte Mobilization and Blood-Brain Barrier Permeability Following Traumatic Brain Injury: An In Vivo Murine Study

BACKGROUND

Early posttraumatic brain injury (TBI) tranexamic acid (TXA) may reduce blood-brain barrier (BBB) permeability, but it is unclear if this effect is fixed regardless of dose. We hypothesized that post-TBI TXA demonstrates a dose-dependent reduction of in vivo penumbral leukocyte mobilization, BBB microvascular permeability, and enhancement of neuroclinical recovery.

METHODS

CD1 male mice (n = 40) were randomly assigned to TBI by controlled cortical impact (injury [I]) or sham TBI (S), followed by intravenous bolus of either saline (placebo [P]) or TXA (15, 30, or 60 mg/kg). At 48 h, in vivo pial intravital microscopy visualized live penumbral BBB microvascular leukocytes and albumin leakage. Neuroclinical recovery was assessed by Garcia Neurological Test scores and animal weight changes at 24 h and 48 h after injury.

RESULTS

I + TXA60 reduced live penumbral leukocyte rolling compared with I + P (p < 0.001) and both lower TXA doses (p = 0.017 vs. I + TXA15, p = 0.012 vs. I + TXA30). Leukocyte adhesion was infrequent and similar across groups. Only I + TXA60 significantly reduced BBB permeability compared with that in the I + P (p = 0.004) group. All TXA doses improved Garcia Test scores relative to I + P at both 24 h and 48 h (p < 0.001 vs. I + P for all at both time points). Mean 24-h body weight loss was greatest in the I + P (- 8.7 ± 1.3%) group and lowest in the I + TXA15 (- 4.4 ± 1.0%, p = 0.051 vs. I + P) group.

CONCLUSIONS

Only higher TXA dosing definitively abrogates penumbral leukocyte mobilization, preserving BBB integrity post TBI. Some neuroclinical recovery is observed, even with lower TXA dosing. Better outcomes with higher dose TXA after TBI may occur secondary to blunting of leukocyte-mediated penumbral cerebrovascular inflammation.

Development and validation of a nomogram for predicting mortality in patients with acute severe traumatic brain injury: A retrospective analysis

BACKGROUND

Recent evidence links the prognosis of traumatic brain injury (TBI) to various factors, including baseline clinical characteristics, TBI specifics, and neuroimaging outcomes. This study focuses on identifying risk factors for short-term survival in severe traumatic brain injury (sTBI) cases and developing a prognostic model.

METHODS

Analyzing 430 acute sTBI patients from January 2018 to December 2023 at the 904th Hospital's Neurosurgery Department, this retrospective case-control study separated patients into survival outcomes: 288 deceased and 142 survivors. It evaluated baseline, clinical, hematological, and radiological data to identify risk and protective factors through univariate and Lasso regression. A multivariate model was then formulated to pinpoint independent prognostic factors, assessing their relationships via Spearman's correlation. The model's accuracy was gauged using the Receiver Operating Characteristic (ROC) curve, with additional statistical analyses for quantitative factors and model effectiveness. Internal validation employed ROC, calibration curves, Decision Curve Analysis (DCA), and Clinical Impact Curves (CIC) to assess model discrimination, utility, and accuracy. The International Mission for Prognosis and Analysis of Clinical Trials in TBI (IMPACT) and Corticosteroid Randomization After Significant Head injury (CRASH) models were also compared through multivariate regression.

RESULTS

Factors like unilateral and bilateral pupillary non-reactivity at admission, the derived neutrophil to lymphocyte ratio (dNLR), platelet to lymphocyte ratio (PLR), D-dimer to fibrinogen ratio (DFR), infratentorial hematoma, and Helsinki CT score were identified as independent risk factors (OR > 1), whereas serum albumin emerged as a protective factor (OR < 1). The model showed superior predictive performance with an AUC of 0.955 and surpassed both IMPACT and CRASH models in predictive accuracy. Internal validation confirmed the model's high discriminative capability, clinical relevance, and effectiveness.

CONCLUSIONS

Short-term survival in sTBI is significantly influenced by factors such as pupillary response, dNLR, PLR, DFR, serum albumin levels, infratentorial hematoma occurrence, and Helsinki CT scores at admission. The developed nomogram accurately predicts sTBI outcomes, offering significant clinical utility.

Targeting astrocytic TDAG8 with delayed CO2 postconditioning improves functional outcomes after controlled cortical impact injury in mice

T-cell death-associated gene 8 (TDAG8), a G-protein-coupled receptor sensing physiological or weak acids, regulates inflammatory responses. However, its role in traumatic brain injury (TBI) remains unknown. Our recent study showed that delayed CO2 postconditioning (DCPC) has neuroreparative effects after TBI. We hypothesized that activating astrocytic TDAG8 is a key mechanism for DCPC. WT and TDAG8-/- mice received DCPC daily by transiently inhaling 10% CO2 after controlled cortical impact (CCI). HBAAV2/9-GFAP-m-TDAG8-3xflag-EGFP was used to overexpress TDAG8 in astrocytes. The beam walking test, mNSS, immunofluorescence and Golgi-Cox staining were used to evaluate motor function, glial activation and dendritic plasticity. DCPC significantly improved motor function; increased total dendritic length, neuronal complexity and spine density; inhibited overactivation of astrocytes and microglia; and promoted the expression of astrocytic brain-derived neurotrophic factor in WT but not TDAG8-/- mice. Overexpressing TDAG8 in astrocytes surrounding the lesion in TDAG8-/- mice restored the beneficial effects of DCPC. Although the effects of DCPC on Days 14-28 were much weaker than those of DCPC on Days 3-28 in WT mice, these effects were further enhanced by overexpressing astrocytic TDAG8. Astrocytic TDAG8 is a key target of DCPC for TBI rehabilitation. Its overexpression is a strategy that broadens the therapeutic window and enhances the effects of DCPC.

Improvement in edema and cognitive recovery after moderate traumatic brain injury with the neurosteroid prodrug NTS-104

Neuroactive steroids reduce mortality, decrease edema, and improve functional outcomes in preclinical and clinical traumatic brain injury (TBI) studies. In this study, we tested the efficacy of two related novel neuroactive steroids, NTS-104 and NTS-105, in a rat model of TBI. NTS-104 is a water-soluble prodrug of NTS-105, a partial progesterone receptor agonist. To investigate the effects of NTS-104 on TBI recovery, adult male Sprague Dawley rats received moderate parasagittal fluid-percussion injury or sham surgery and were treated with vehicle or NTS-104 (10 ​mg/kg, intramuscularly) at 4, 10, 24, and 48 ​h post-TBI. The therapeutic time window was also assessed using the neuroactive steroid NTS-105 (3 ​mg/kg, intramuscularly). Edema in the parietal cortex and hippocampus, measured at 3 days post-injury (DPI), was reduced by NTS-104 and NTS-105. NTS-105 was effective in reducing edema when given at 4, 10, or 24 ​h post-injury. Sensorimotor deficits in the cylinder test at 3 DPI were ameliorated by NTS-104 and NTS-105 treatment. Cognitive recovery, assessed with cue and contextual fear conditioning and retention of the water maze task assessed subacutely 1-3 weeks post-injury, also improved with NTS-104 treatment. Cortical and hippocampal atrophy at 22 DPI did not improve, indicating that NTS-104/NTS-105 may promote post-TBI cognitive recovery by controlling edema and other processes. These results demonstrate that NTS-104/NTS-105 is a promising therapeutic approach to improve motor and cognitive recovery after moderate TBI.

Tentative Causes of Brain and Neuropsychological Alterations in Women Victims of Intimate Partner Violence

Victims of Intimate Partner Violence Against Women (IPVAW) experience neuropsychological and cerebral changes, which have been linked to several tentative causal mechanisms, including elevated cortisol levels, psychopathological disorders, traumatic brain injury (TBI), hypoxic/ischemic brain damage, and medical conditions related to IPVAW. While these mechanisms and their effects on brain function and neuropsychological health are well-documented in other clinical populations, they manifest with unique characteristics in women affected by IPVAW. Specifically, IPVAW is chronic and repeated in nature, and mechanisms are often cumulative and may interact with other comorbid conditions. Thus, in light of existing literature on neuropsychological alterations in other populations, and recognizing the distinct features in women who experience IPVAW, we propose a new theoretical model-the Neuro-IPVAW model. This framework aims to explain the complex interplay between these mechanisms and their impact on cognitive and brain health in IPVAW victims. We anticipate that this theoretical model will be valuable for enhancing our understanding of neuropsychological and brain changes related to intimate partner violence, identifying research gaps in these mechanisms, and guiding future research directions in this area.

Hydrogel in the Treatment of Traumatic Brain Injury

The high prevalence of traumatic brain injury (TBI) poses an important global public health challenge. Current treatment modalities for TBI primarily involve pharmaceutical interventions and surgical procedures; however, the efficacy of these approaches remains limited. In the field of regenerative medicine, hydrogels have garnered significant attention and research efforts. This review provides an overview of the existing landscape and pathological manifestations of TBI, with a specific emphasis on delineating the therapeutic potential of hydrogels incorporated with various bioactive agents for TBI management. Particularly, the review delves into the utilization and efficacy of hydrogels based on extracellular matrix (ECM), stem cell-loaded, drug-loaded, self-assembled peptide structures or conductive in the context of TBI treatment. These applications are shown to yield favorable outcomes such as tissue damage mitigation, anti-inflammatory effects, attenuation of oxidative stress, anti-apoptotic properties, promotion of neurogenesis, and facilitation of angiogenesis. Lastly, a comprehensive analysis of the merits and constraints associated with hydrogel utilization in TBI treatment is presented, aiming to steer and advance future research endeavors in this domain.

Disrupted Hippocampal Theta-Gamma Coupling and Spike-Field Coherence Following Experimental Traumatic Brain Injury

Traumatic brain injury (TBI) often results in persistent learning and memory deficits, likely due to disrupted hippocampal circuitry underlying these processes. Precise temporal control of hippocampal neuronal activity is important for memory encoding and retrieval and is supported by oscillations that dynamically organize single unit firing. Using high-density laminar electrophysiology, we discovered a loss of oscillatory power across CA1 lamina, with a profound, layer-specific reduction in theta-gamma phase amplitude coupling in injured rats. Interneurons from injured animals were less strongly entrained to theta and gamma oscillations, suggesting a mechanism for the loss of coupling, while pyramidal cells were entrained to a later phase of theta. During quiet immobility, we report decreased ripple amplitudes from injured animals during sharp-wave ripple events. These results reveal deficits in information encoding and retrieval schemes essential to cognition that likely underlie TBI-associated learning and memory impairments, and elucidate potential targets for future neuromodulation therapies.

Microglia and Astrocytes Responses Contribute to Alleviating Inflammatory Damage by Repetitive Transcranial Magnetic Stimulation in Rats with Traumatic Brain Injury

Repetitive transcranial magnetic stimulation (rTMS) is a therapeutic strategy that shows promise in ameliorating the clinical sequelae following traumatic brain injury (TBI). These improvements are associated with neuroplastic changes in neurons and their synaptic connections. However, it has been hypothesized that rTMS may also modulate microglia and astrocytes, potentially potentiating their neuroprotective capabilities. This study aims to investigate the effects of high-frequency rTMS on microglia and astrocytes that may contribute to its neuroprotective effects. Feeney's weight-dropping method was used to establish rat models of moderate TBI. To evaluate the neuroprotective effect of high frequency rTMS on rats by observing the synaptic ultrastructure and the level of neuron apoptosis. The levels of several important inflammation-related proteins within microglia and astrocytes were assessed through immunofluorescence staining and western blot. Our findings demonstrate that injured neurons can be rescued through the modulation of microglia and astrocytes by rTMS. This modulation plays a key role in preserving the synaptic ultrastructure and inhibiting neuronal apoptosis. Among microglia, we observed that rTMS inhibited the levels of proinflammatory factors (CD16, IL-6 and TNF-α) and promoted the levels of anti-inflammatory factors (CD206, IL-10 and TNF-β). rTMS also reduced the levels of pyroptosis within microglia and pyroptosis-related proteins (NLRP3, Caspase-1, GSDMD, IL-1β and IL-18). Moreover, rTMS downregulated P75NTR expression and up-regulated IL33 expression in astrocytes. These findings suggest that regulation of microglia and astrocytes is the mechanism through which rTMS attenuates neuronal inflammatory damage after moderate TBI.

Systemic inflammation following traumatic injury and its impact on neuroinflammatory gene expression in the rodent brain

BACKGROUND

Trauma can result in systemic inflammation that leads to organ dysfunction, but the impact on the brain, particularly following extracranial insults, has been largely overlooked.

METHODS

Building upon our prior findings, we aimed to understand the impact of systemic inflammation on neuroinflammatory gene transcripts in eight brain regions in rats exposed to (1) blast overpressure exposure [BOP], (2) cutaneous thermal injury [BU], (3) complex extremity injury, 3 hours (h) of tourniquet-induced ischemia, and hind limb amputation [CEI+tI+HLA], (4) BOP+BU or (5) BOP+CEI and delayed HLA [BOP+CEI+dHLA] at 6, 24, and 168 h post-injury (hpi).

RESULTS

Globally, the number and magnitude of differentially expressed genes (DEGs) correlated with injury severity, systemic inflammation markers, and end-organ damage, driven by several chemokines/cytokines (Csf3, Cxcr2, Il16, and Tgfb2), neurosteroids/prostaglandins (Cyp19a1, Ptger2, and Ptger3), and markers of neurodegeneration (Gfap, Grin2b, and Homer1). Regional neuroinflammatory activity was least impacted following BOP. Non-blast trauma (in the BU and CEI+tI+HLA groups) contributed to an earlier, robust and diverse neuroinflammatory response across brain regions (up to 2-50-fold greater than that in the BOP group), while combined trauma (in the BOP+CEI+dHLA group) significantly advanced neuroinflammation in all regions except for the cerebellum. In contrast, BOP+BU resulted in differential activity of several critical neuroinflammatory-neurodegenerative markers compared to BU. t-SNE plots of DEGs demonstrated that the onset, extent, and duration of the inflammatory response are brain region dependent. Regardless of injury type, the thalamus and hypothalamus, which are critical for maintaining homeostasis, had the most DEGs. Our results indicate that neuroinflammation in all groups progressively increased or remained at peak levels over the study duration, while markers of end-organ dysfunction decreased or otherwise resolved.

CONCLUSIONS

Collectively, these findings emphasize the brain's sensitivity to mediators of systemic inflammation and provide an example of immune-brain crosstalk. Follow-on molecular and behavioral investigations are warranted to understand the short- to long-term pathophysiological consequences on the brain, particularly the mechanism of blood-brain barrier breakdown, immune cell penetration-activation, and microglial activation.

Current Concepts in Early Mobilization of Critically Ill Patients Within the Context of Neurologic Pathology

Neurocritical patients (NCPs) in the intensive care unit (ICU) rapidly progress to respiratory and peripheral muscle dysfunctions, which significantly impact morbidity and death. Early mobilization in NCPs to decrease the incidence of ICU-acquired weakness has been showing rapid growth, although pertinent literature is still scarce. With this review, we summarize and discuss current concepts in early mobilization of critically ill patients within the context of neurologic pathology in NCPs. A narrative synthesis of literature was undertaken trying to answer the following questions: How do the respiratory and musculoskeletal systems in NCPs behave? Which metabolic biomarkers influence physiological responses in NCPs? Which considerations should be taken when prescribing exercises in neurocritically ill patients? The present review detected safety, feasibility, and beneficial response for early mobilization in NCPs, given successes in other critically ill populations and many smaller intervention trials in neurocritical care. However, precautions should be taken to elect the patient for early care, as well as monitoring signs that indicate interruption for intervention, as worse outcomes were associated with very early mobilization in acute stroke trials.

Logic "AND Gate Circuit" Based Mussel Inspired Polydopamine Nanocomposite as Bioactive Antioxidant for Management of Oxidative Stress and Neurogenesis in Traumatic Brain Injury

In the intricate landscape of Traumatic Brain Injury (TBI), the management of TBI remains a challenging task due to the extremely complex pathophysiological conditions and excessive release of reactive oxygen species (ROS) at the injury site and the limited regenerative capacities of the central nervous system (CNS). Existing pharmaceutical interventions are limited in their ability to efficiently cross the blood-brain barrier (BBB) and expeditiously target areas of brain inflammation. In response to these challenges herein, we designed novel mussel inspired polydopamine (PDA)-coated mesoporous silica nanoparticles (PDA-AMSNs) with excellent antioxidative ability to deliver a new potential therapeutic GSK-3β inhibitor lead small molecule abbreviated as Neuro Chemical Modulator (NCM) at the TBI site using a neuroprotective peptide hydrogel (PANAP). PDA-AMSNs loaded with NCM (i.e., PDA-AMSN-D) into the matrix of PANAP were injected into the damaged area in an in vivo cryogenic brain injury model (CBI). This approach is specifically built while keeping the logic AND gate circuit as the primary focus. Where NCM and PDA-AMSNs act as two input signals and neurological functional recovery as a single output. Therapeutically, PDA-AMSN-D significantly decreased infarct volume, enhanced neurogenesis, rejuvenated BBB senescence, and accelerated neurological function recovery in a CBI.

Regulation of blood-brain barrier integrity by Dmp1-expressing astrocytes through mitochondrial transfer

The blood-brain barrier (BBB) acts as the crucial physical filtration structure in the central nervous system. Here, we investigate the role of a specific subset of astrocytes in the regulation of BBB integrity. We showed that Dmp1-expressing astrocytes transfer mitochondria to endothelial cells via their endfeet for maintaining BBB integrity. Deletion of the Mitofusin 2 (Mfn2) gene in Dmp1-expressing astrocytes inhibited the mitochondrial transfer and caused BBB leakage. In addition, the decrease of MFN2 in astrocytes contributes to the age-associated reduction of mitochondrial transfer efficiency and thus compromises the integrity of BBB. Together, we describe a mechanism in which astrocytes regulate BBB integrity through mitochondrial transfer. Our findings provide innnovative insights into the cellular framework that underpins the progressive breakdown of BBB associated with aging and disease.

Crocetin protects mouse brain from apoptosis in traumatic brain injury model through activation of autophagy

BACKGROUND

Autophagy is recognized as a promising therapeutic target for traumatic brain injury (TBI). Crocetin is an aglycone of crocin naturally occurring in saffron and has been found to alleviate brain injury diseases. However, whether crocetin affects autophagy after TBI remains unknown. Therefore, we explore crocetin roles in autophagy after TBI.

METHODS

We used a weight-dropped model to induce TBI in C57BL/6J mice. Neurological severity scoring (NSS) and grip tests were used to evaluate the neurological level of injury. Brain edema, neuronal apoptosis, neuroinflammation and autophagy were detected by measurements of brain water content, TUNEL staining, ELISA kits and western blotting.

RESULTS

Crocetin ameliorated neurological dysfunctions and brain edema after TBI. Crocetin reduced neuronal apoptosis and neuroinflammation and enhanced autophagy after TBI.

CONCLUSION

Crocetin alleviates TBI by inhibiting neuronal apoptosis and neuroinflammation and activating autophagy.

Association Between Monocyte-to-Lymphocyte Ratio and Hematoma Progression After Cerebral Contusion

BACKGROUND

The objective of this research was to examine the impact of the monocyte-to-lymphocyte ratio (MLR) on the advancement of hematoma after cerebral contusion.

METHODS

The clinical information and laboratory test findings of people with cerebral contusion were retrospectively analyzed. Using the tertiles of MLR, the study participants were categorized into three groups, enabling the evaluation of the correlation between MLR and the advancement of hematoma after cerebral contusion.

RESULTS

Among the cohort of patients showing progression, MLR levels were significantly higher compared with the nonprogress group (P < 0.001). The high MLR group had a significantly higher proportion of patients with hematoma progression compared with the medium and low MLR groups. However, the medium MLR group had a lower proportion of patients with hematoma progression compared with the low MLR group. High MLR levels were independently linked to a higher risk of hematoma progression (Odds Ratio 3.546, 95% Confidence Interval 1.187-10.597, P = 0.024). By incorporating factors such as Glasgow Coma Scale score on admission, anticoagulant/antiplatelet therapy, white blood cell count, and MLR into the model, the predictive performance of the model significantly improved (area under the curve 0.754).

CONCLUSIONS

Our study suggests that MLR may serve as a potential indicator for predicting the progression of hematoma after cerebral contusion. Further research is necessary to investigate the underlying pathological and physiological mechanisms that contribute to the association between MLR and the progression of hematoma after cerebral contusion and to explore its clinical implications.

Multiorgan Dysfunction Syndrome in Abusive and Accidental Pediatric Traumatic Brain Injury

BACKGROUND

Abusive head trauma (AHT) is a mechanism of pediatric traumatic brain injury (TBI) with high morbidity and mortality. Multiorgan dysfunction syndrome (MODS), defined as organ dysfunction in two or more organ systems, is also associated with morbidity and mortality in critically ill children. Our objective was to compare the frequency of MODS and evaluate its association with outcome between AHT and accidental TBI (aTBI).

METHODS

This was a single center, retrospective cohort study including children under 3 years old admitted to the pediatric intensive care unit with nonpenetrating TBI between 2014 and 2021. Presence or absence of MODS on days 1, 3, and 7 using the Pediatric Logistic Organ Dysfunction-2 score and new impairment status (Functional Status Scale score change > 1 compared with preinjury) at hospital discharge (HD), short-term timepoint, and long-term timepoint were abstracted from the electronic health record. Multiple logistic regression was performed to examine the association between MODS and TBI mechanism with new impairment status.

RESULTS

Among 576 children, 215 (37%) had AHT and 361 (63%) had aTBI. More children with AHT had MODS on days 1 (34% vs. 23%, p = 0.003), 3 (28% vs. 6%, p < 0.001), and 7 (17% vs. 3%, p < 0.001) compared with those with aTBI. The most common organ failures were cardiovascular ([AHT] 66% vs. [aTBI] 66%, p = 0.997), neurologic (33% vs. 16%, p < 0.001), and respiratory (34% vs. 15%, p < 0.001). MODS was associated with new impairment in multivariable logistic regression at HD (odds ratio 19.1 [95% confidence interval 9.8-38.6, p < 0.001]), short-term discharge (7.4 [3.7-15.2, p < 0.001]), and long-term discharge (4.3 [2.0-9.4, p < 0.001])]. AHT was also associated with new impairment at HD (3.4 [1.6-7.3, p = 0.001]), short-term discharge (2.5 [1.3-4.7, p = 0.005]), and long-term discharge (2.1 [1.1-4.1, p = 0.036]).

CONCLUSIONS

Abusive head trauma as a mechanism was associated with MODS following TBI. Both AHT mechanism and MODS were associated with new impairment at all time points.

Mechanical and Functional Responses in Astrocytes under Alternating Deformation Modes Using Magneto-Active Substrates

This work introduces NeoMag, a system designed to enhance cell mechanics assays in substrate deformation studies. NeoMag uses multidomain magneto-active materials to mechanically actuate the substrate, transmitting reversible mechanical cues to cells. The system boasts full flexibility in alternating loading substrate deformation modes, seamlessly adapting to both upright and inverted microscopes. The multidomain substrates facilitate mechanobiology assays on 2D and 3D cultures. The integration of the system with nanoindenters allows for precise evaluation of cellular mechanical properties under varying substrate deformation modes. The system is used to study the impact of substrate deformation on astrocytes, simulating mechanical conditions akin to traumatic brain injury and ischemic stroke. The results reveal local heterogeneous changes in astrocyte stiffness, influenced by the orientation of subcellular regions relative to substrate strain. These stiffness variations, exceeding 50% in stiffening and softening, and local deformations significantly alter calcium dynamics. Furthermore, sustained deformations induce actin network reorganization and activate Piezo1 channels, leading to an initial increase followed by a long-term inhibition of calcium events. Conversely, fast and dynamic deformations transiently activate Piezo1 channels and disrupt the actin network, causing long-term cell softening. These findings unveil mechanical and functional alterations in astrocytes during substrate deformation, illustrating the multiple opportunities this technology offers.