Valproic Acid Treatment after Traumatic Brain Injury in Mice Alleviates Neuronal Death and Inflammation in Association with Increased Plasma Lysophosphatidylcholines.

The histone deacetylase inhibitor (HDACi) valproic acid (VPA) has neuroprotective and anti-inflammatory effects in experimental traumatic brain injury (TBI), which have been partially attributed to the epigenetic disinhibition of the transcription repressor RE1-Silencing Transcription Factor/Neuron-Restrictive Silencer Factor (REST/NRSF). Additionally, VPA changes post-traumatic brain injury (TBI) brain metabolism to create a neuroprotective environment. To address the interconnection of neuroprotection, metabolism, inflammation and REST/NRSF after TBI, we subjected C57BL/6N mice to experimental TBI and intraperitoneal VPA administration or vehicle solution at 15 min, 1, 2, and 3 days post-injury (dpi). At 7 dpi, TBI-induced an up-regulation of REST/NRSF gene expression and HDACi function of VPA on histone H3 acetylation were confirmed. Neurological deficits, brain lesion size, blood-brain barrier permeability, or astrogliosis were not affected, and REST/NRSF target genes were only marginally influenced by VPA. However, VPA attenuated structural damage in the hippocampus, microgliosis and expression of the pro-inflammatory marker genes. Analyses of plasma lipidomic and polar metabolomic patterns revealed that VPA treatment increased lysophosphatidylcholines (LPCs), which were inversely associated with interleukin 1 beta (Il1b) and tumor necrosis factor (Tnf) gene expression in the brain. The results show that VPA has mild neuroprotective and anti-inflammatory effects likely originating from favorable systemic metabolic changes resulting in increased plasma LPCs that are known to be actively taken up by the brain and function as carriers for neuroprotective polyunsaturated fatty acids.

FOXO1 reshapes neutrophils to aggravate acute brain damage and promote late depression after traumatic brain injury.

BACKGROUND: Neutrophils are traditionally viewed as first responders but have a short onset of action in response to traumatic brain injury (TBI). However, the heterogeneity, multifunctionality, and time-dependent modulation of brain damage and outcome mediated by neutrophils after TBI remain poorly understood. METHODS: Using the combined single-cell transcriptomics, metabolomics, and proteomics analysis from TBI patients and the TBI mouse model, we investigate a novel neutrophil phenotype and its associated effects on TBI outcome by neurological deficit scoring and behavioral tests. We also characterized the underlying mechanisms both in vitro and in vivo through molecular simulations, signaling detections, gene expression regulation assessments [including dual-luciferase reporter and chromatin immunoprecipitation (ChIP) assays], primary cultures or co-cultures of neutrophils and oligodendrocytes, intracellular iron, and lipid hydroperoxide concentration measurements, as well as forkhead box protein O1 (FOXO1) conditional knockout mice. RESULTS: We identified that high expression of the FOXO1 protein was induced in neutrophils after TBI both in TBI patients and the TBI mouse model. Infiltration of these FOXO1high neutrophils in the brain was detected not only in the acute phase but also in the chronic phase post-TBI, aggravating acute brain inflammatory damage and promoting late TBI-induced depression. In the acute stage, FOXO1 upregulated cytoplasmic Versican (VCAN) to interact with the apoptosis regulator B-cell lymphoma-2 (BCL-2)-associated X protein (BAX), suppressing the mitochondrial translocation of BAX, which mediated the antiapoptotic effect companied with enhancing interleukin-6 (IL-6) production of FOXO1high neutrophils. In the chronic stage, the "FOXO1-transferrin receptor (TFRC)" mechanism contributes to FOXO1high neutrophil ferroptosis, disturbing the iron homeostasis of oligodendrocytes and inducing a reduction in myelin basic protein, which contributes to the progression of late depression after TBI. CONCLUSIONS: FOXO1high neutrophils represent a novel neutrophil phenotype that emerges in response to acute and chronic TBI, which provides insight into the heterogeneity, reprogramming activity, and versatility of neutrophils in TBI.

Bi-directional neuro-immune dysfunction after chronic experimental brain injury.

BACKGROUND: It is well established that traumatic brain injury (TBI) causes acute and chronic alterations in systemic immune function and that systemic immune changes contribute to posttraumatic neuroinflammation and neurodegeneration. However, how TBI affects bone marrow (BM) hematopoietic stem/progenitor cells chronically and to what extent such changes may negatively impact innate immunity and neurological function has not been examined. METHODS: To further understand the role of BM cell derivatives on TBI outcome, we generated BM chimeric mice by transplanting BM from chronically injured or sham (i.e., 90 days post-surgery) congenic donor mice into otherwise healthy, age-matched, irradiated CD45.2 C57BL/6 (WT) hosts. Immune changes were evaluated by flow cytometry, multiplex ELISA, and NanoString technology. Moderate-to-severe TBI was induced by controlled cortical impact injury and neurological function was measured using a battery of behavioral tests. RESULTS: TBI induced chronic alterations in the transcriptome of BM lineage-c-Kit+Sca1+ (LSK+) cells in C57BL/6 mice, including modified epigenetic and senescence pathways. After 8 weeks of reconstitution, peripheral myeloid cells from TBI→WT mice showed significantly higher oxidative stress levels and reduced phagocytic activity. At eight months after reconstitution, TBI→WT chimeric mice were leukopenic, with continued alterations in phagocytosis and oxidative stress responses, as well as persistent neurological deficits. Gene expression analysis revealed BM-driven changes in neuroinflammation and neuropathology after 8 weeks and 8 months of reconstitution, respectively. Chimeric mice subjected to TBI at 8 weeks and 8 months post-reconstitution showed that longer reconstitution periods (i.e., time post-injury) were associated with increased microgliosis and leukocyte infiltration. Pre-treatment with a senolytic agent, ABT-263, significantly improved behavioral performance of aged C57BL/6 mice at baseline, although it did not attenuate neuroinflammation in the acutely injured brain. CONCLUSIONS: TBI causes chronic activation and progressive dysfunction of the BM stem/progenitor cell pool, which drives long-term deficits in hematopoiesis, innate immunity, and neurological function, as well as altered sensitivity to subsequent brain injury.

[Wakefulness-promoting agents for severe fatigue: to use or not to use?] / Medicatie tegen ernstige aanhoudende vermoeidheid.

About 20% of adults experience excessive daytime sleepiness or severe fatigue. Causes include somatic conditions, psychiatric disorders, and medication or drug use. Treatment depends on the underlying cause. If sleepiness persists despite optimal treatment of the underlying condition, exclusion of other causes, and behavioral interventions, wakefulness-promoting agents may be considered. However, no established pharmacological strategy exists for symptomatic treatment. Modafinil and stimulants like methylphenidate may offer some benefit based on experiences with narcolepsy or idiopathic hypersomnia. Studies in specific patient groups (e.g., multiple sclerosis, Parkinson's disease, traumatic brain injury, cancer-related fatigue) show variable results. The use of wakefulness-promoting agents is discouraged for addressing unexplained fatigue, as seen in the context of chronic fatigue syndrome.

Long-Term Impact of Diffuse Traumatic Brain Injury on Neuroinflammation and Catecholaminergic Signaling: Potential Relevance for Parkinson's Disease Risk.

Traumatic brain injury (TBI) is associated with an increased risk of developing Parkinson's disease (PD), though the exact mechanisms remain unclear. TBI triggers acute neuroinflammation and catecholamine dysfunction post-injury, both implicated in PD pathophysiology. The long-term impact on these pathways following TBI, however, remains uncertain. In this study, male Sprague-Dawley rats underwent sham surgery or Marmarou's impact acceleration model to induce varying TBI severities: single mild TBI (mTBI), repetitive mild TBI (rmTBI), or moderate-severe TBI (msTBI). At 12 months post-injury, astrocyte reactivity (GFAP) and microglial levels (IBA1) were assessed in the striatum (STR), substantia nigra (SN), and prefrontal cortex (PFC) using immunohistochemistry. Key enzymes and receptors involved in catecholaminergic transmission were measured via Western blot within the same regions. Minimal changes in these markers were observed, regardless of initial injury severity. Following mTBI, elevated protein levels of dopamine D1 receptors (DRD1) were noted in the PFC, while msTBI resulted in increased alpha-2A adrenoceptors (ADRA2A) in the STR and decreased dopamine beta-hydroxylase (DßH) in the SN. Neuroinflammatory changes were subtle, with a reduced number of GFAP+ cells in the SN following msTBI. However, considering the potential for neurodegenerative outcomes to manifest decades after injury, longer post-injury intervals may be necessary to observe PD-relevant alterations within these systems.

Long-term pituitary function and functional and patient-reported outcomes in severe acquired brain injury.

OBJECTIVE: Assessment of posttraumatic hypothalamic-pituitary dysfunctions is expected to be the most relevant assessment to offer patients with severe intracranial affection. In this study, we aim to investigate the prevalence of hypopituitarism in patients with severe acquired traumatic brain injury (TBI) compared with nontraumatic brain injury (NTBI) and to relate pituitary insufficiency to functional and patient-reported outcomes. DESIGN: This is a prospective study. METHODS: We included patients admitted for inpatient neurorehabilitation after severe TBI (N = 42) and NTBI (N = 18). The patients underwent a pituitary function assessment at a mean of 2.4 years after the injury. Functional outcome was assessed by using Functional Independence Measure and Glasgow Outcome Scale-Extended (both 1 year after discharge from neurorehabilitation) and patient-reported outcome was assessed by using Multiple Fatigue Inventory-20 and EQ-5D-3L. RESULTS: Hypopituitarism was reported in 10/42 (24%) patients with TBI and 7/18 (39%) patients with NTBI (P = .23). Insufficiencies affected 1 axis in 14/17 (82%) patients (13 hypogonadotropic hypogonadism and 1 growth hormone [GH] deficiency) and 2 axes in 3/17 (18%) patients (1 hypogonadotropic hypogonadism and GH deficiency, and 2 hypogonadotropic hypogonadism and arginin vasopressin deficiency). None had central hypoadrenalism or central hypothyroidism. In patients with both TBI and NTBI, pituitary status was unrelated to functioning and ability scores at 1 year and to patient-reported outcome scores at a mean of 2.4 years after the injury. CONCLUSION: Patients with severe acquired brain injury may develop long-term hypothalamus-pituitary insufficiency, with an equal occurrence in patients with TBI and NTBI. In both types of patients, mainly isolated deficiencies, most commonly affecting the gonadal axis, were seen. Insufficiencies were unrelated to functional outcomes and patient-reported outcomes, probably reflecting the complexity and heterogeneous manifestations in both patient groups.

Antibody-labeled gold nanoparticle based resonance Rayleigh scattering detection of S100B.

Traumatic brain injury (TBI) is a sudden brain injury due to an external force that causes a large number of deaths and permanent disabilities every year. S100B has been recognized as a potential objective quantitative biomarker for screening the prognosis of TBI and severe head injury. In this article, an anti-S100B monoclonal antibody was immobilized on cysteamine (Cy) functionalized gold nanoparticles (AuNPs) by EDC-NHS chemistry, which enabled S100B resonance Rayleigh scattering (RRS) detection based on antibody-labeled gold nanoparticles. The prepared conjugates were characterized by ultraviolet-visible spectroscopy (UV-vis), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), dynamic light scattering (DLS) and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Based on the specific binding of the antibody and antigen, the RRS intensities at 381 nm and 541 nm wavelengths were significantly enhanced, and thus a dual wavelength overlapping resonance Rayleigh scattering (DWO-RRS) method was established. The scattering intensity of the two overlapping peaks was proportional to the concentration of S100B in the range of 0.05-4.5 ng mL-1 with a detection limit of 0.002 ng mL-1. The proposed DWO-RRS method is time-saving, simple, sensitive, and can be used to determine the concentration of S100B in human serum with satisfactory results, which has a promising application in the early diagnosis of TBI.

Interaction of high-fat diet and brain trauma alters adipose tissue macrophages and brain microglia associated with exacerbated cognitive dysfunction.

Obesity increases the morbidity and mortality of traumatic brain injury (TBI). Detailed analyses of transcriptomic changes in the brain and adipose tissue were performed to elucidate the interactive effects between high-fat diet-induced obesity (DIO) and TBI. Adult male mice were fed a high-fat diet (HFD) for 12 weeks prior to experimental TBI and continuing after injury. High-throughput transcriptomic analysis using Nanostring panels of the total visceral adipose tissue (VAT) and cellular components in the brain, followed by unsupervised clustering, principal component analysis, and IPA pathway analysis were used to determine shifts in gene expression patterns and molecular pathway activity. Cellular populations in the cortex and hippocampus, as well as in VAT, during the chronic phase after combined TBI-HFD showed amplification of central and peripheral microglia/macrophage responses, including superadditive changes in selected gene expression signatures and pathways. Furthermore, combined TBI and HFD caused additive dysfunction in Y-Maze, Novel Object Recognition (NOR), and Morris water maze (MWM) cognitive function tests. These novel data suggest that HFD-induced obesity and TBI can independently prime and support the development of altered states in brain microglia and VAT, including the disease-associated microglia/macrophage (DAM) phenotype observed in neurodegenerative disorders. The interaction between HFD and TBI promotes a shift toward chronic reactive microglia/macrophage transcriptomic signatures and associated pro-inflammatory disease-altered states that may, in part, underlie the exacerbation of cognitive deficits. Thus, targeting of HFD-induced reactive cellular phenotypes, including in peripheral adipose tissue immune cell populations, may serve to reduce microglial maladaptive states after TBI, attenuating post-traumatic neurodegeneration and neurological dysfunction.

[Expression and significance of hypoxia-inducible factor 1α and Bcl-2/adenovirus E1B19kDa-interacting protein 3 in children with traumatic brain injury]. / ç¼ºæ°§è¯±å¯¼å› å­1α、Bcl-2/è ºç— æ¯’E1B19kDa相互作用蛋白3在儿童创伤性脑损伤中的表达及意义.

OBJECTIVES: To dynamically observe the changes in hypoxia-inducible factor 1α (HIF-1α) and Bcl-2/adenovirus E1B19kDa-interacting protein 3 (BNIP3) in children with traumatic brain injury (TBI) and evaluate their clinical value in predicting the severity and prognosis of pediatric TBI. METHODS: A prospective study included 47 children with moderate to severe TBI from January 2021 to July 2023, categorized into moderate (scores 9-12) and severe (scores 3-8) subgroups based on the Glasgow Coma Scale. A control group consisted of 30 children diagnosed and treated for inguinal hernia during the same period, with no underlying diseases. The levels of HIF-1α, BNIP3, autophagy-related protein Beclin-1, and S100B were compared among groups. The predictive value of HIF-1α, BNIP3, Beclin-1, and S100B for the severity and prognosis of TBI was assessed using receiver operating characteristic (ROC) curves. RESULTS: Serum levels of HIF-1α, BNIP3, Beclin-1, and S100B in the TBI group were higher than those in the control group (P<0.05). Among the TBI patients, the severe subgroup had higher levels of HIF-1α, BNIP3, Beclin-1, and S100B than the moderate subgroup (P<0.05). Correlation analysis showed that the serum levels of HIF-1α, BNIP3, Beclin-1, and S100B were negatively correlated with the Glasgow Coma Scale scores (P<0.05). After 7 days of treatment, serum levels of HIF-1α, BNIP3, Beclin-1, and S100B in both non-surgical and surgical TBI patients decreased compared to before treatment (P<0.05). ROC curve analysis indicated that the areas under the curve for predicting severe TBI based on serum levels of HIF-1α, BNIP3, Beclin-1, and S100B were 0.782, 0.835, 0.872, and 0.880, respectively (P<0.05), and for predicting poor prognosis of TBI were 0.749, 0.775, 0.814, and 0.751, respectively (P<0.05). CONCLUSIONS: Serum levels of HIF-1α, BNIP3, and Beclin-1 are significantly elevated in children with TBI, and their measurement can aid in the clinical assessment of the severity and prognosis of pediatric TBI.

Dantrolene alleviates mitochondrial dysfunction and neuroinflammation in traumatic brain injury by modulating the NF-ĸß/Akt pathway.

Traumatic brain injury (TBI) triggers a bevy of changes including mitochondrial dysfunction, apoptosis, oxidative stress, neurobehavioural impairment, and neuroinflammation, among others. Dantrolene (DNT), a muscle relaxant which inhibits intracellular Ca2+ signaling from the ER, has been repurposed as a potential neuroprotective agent in various neurological diseases. However, there have been limited studies on whether it can mitigate TBI-induced deficits and restore impaired mitochondrial dynamics. This study sought to evaluate whether Dantrolene can potentially provide neuroprotection in an in vivo model of TBI. Male wistar rats subjected to TBI were treated with DNT (10 mg/kg) 1 h and 12 h post surgery. Animals were assessed 24 h post-TBI to evaluate neurobehavioural deficits and cerebral edema. We evaluated the protein expressions of apoptotic, autophagic, and neuroinflammatory markers by immunoblotting, as well as Mitochondrial Membrane Potential (MMP) and Reactive Oxygen Species (ROS) via Flow Cytometry to ascertain the effects of DNT on TBI. We further analysed immunofluorescence staining with Glial Fibrillary Acidic Protein (GFAP) and immunohistochemistry with NF-κß to investigate neuroinflammation. H&E staining was also performed post-TBI. Our findings revealed DNT administration inhibits mitochondria-mediated apoptotis and reduces heightened oxidative stress. DNT treatment was also found to reverse neurobehavioural impairments and offer neuroprotection by preserving neuronal architechture. We also demonstrated that DNT inhibits neuronal autophagy and alleviates neuroinflammation following TBI by modulating the NF-κß/Akt signaling pathway. Thus, our results suggest a novel application of DNT in ameliorating the multitude of deficits induced by TBI, thereby conferring neuroprotection.

Increased ß2-adrenergic signaling promotes fracture healing through callus neovascularization in mice.

Traumatic brain injury (TBI) leads to skeletal changes, including bone loss in the unfractured skeleton, and paradoxically accelerates healing of bone fractures; however, the mechanisms remain unclear. TBI is associated with a hyperadrenergic state characterized by increased norepinephrine release. Here, we identified the ß2-adrenergic receptor (ADRB2) as a mediator of skeletal changes in response to increased norepinephrine. In a murine model of femoral osteotomy combined with cortical impact brain injury, TBI was associated with ADRB2-dependent enhanced fracture healing compared with osteotomy alone. In the unfractured 12-week-old mouse skeleton, ADRB2 was required for TBI-induced decrease in bone formation and increased bone resorption. Adult 30-week-old mice had higher bone concentrations of norepinephrine, and ADRB2 expression was associated with decreased bone volume in the unfractured skeleton and better fracture healing in the injured skeleton. Norepinephrine stimulated expression of vascular endothelial growth factor A and calcitonin gene-related peptide-α (αCGRP) in periosteal cells through ADRB2, promoting formation of osteogenic type-H vessels in the fracture callus. Both ADRB2 and αCGRP were required for the beneficial effect of TBI on bone repair. Adult mice deficient in ADRB2 without TBI developed fracture nonunion despite high bone formation in uninjured bone. Blocking ADRB2 with propranolol impaired fracture healing in mice, whereas the ADRB2 agonist formoterol promoted fracture healing by regulating callus neovascularization. A retrospective cohort analysis of 72 patients with long bone fractures indicated improved callus formation in 36 patients treated with intravenous norepinephrine. These findings suggest that ADRB2 is a potential therapeutic target for promoting bone healing.

A Novel Network Pharmacology Strategy Based on the Universal Effectiveness-Common Mechanism of Medical Herbs Uncovers Therapeutic Targets in Traumatic Brain Injury.

Purpose: Many herbs can promote neurological recovery following traumatic brain injury (TBI). There must lie a shared mechanism behind the common effectiveness. We aimed to explore the key therapeutic targets for TBI based on the common effectiveness of the medicinal plants. Material and methods: The TBI-effective herbs were retrieved from the literature as imputes of network pharmacology. Then, the active ingredients in at least two herbs were screened out as common components. The hub targets of all active compounds were identified through Cytohubba. Next, AutoDock vina was used to rank the common compound-hub target interactions by molecular docking. A highly scored compound-target pair was selected for in vivo validation. Results: We enrolled sixteen TBI-effective medicinal herbs and screened out twenty-one common compounds, such as luteolin. Ten hub targets were recognized according to the topology of the protein-protein interaction network of targets, including epidermal growth factor receptor (EGFR). Molecular docking analysis suggested that luteolin could bind strongly to the active pocket of EGFR. Administration of luteolin or the selective EGFR inhibitor AZD3759 to TBI mice promoted the recovery of body weight and neurological function, reduced astrocyte activation and EGFR expression, decreased chondroitin sulfate proteoglycans deposition, and upregulated GAP43 levels in the cortex. The effects were similar to those when treated with the selective EGFR inhibitor. Conclusion: The common effectiveness-based, common target screening strategy suggests that inhibition of EGFR can be an effective therapy for TBI. This strategy can be applied to discover core targets and therapeutic compounds in other diseases.

Transcranial direct current stimulation promotes angiogenesis and improves neurological function via the OXA-TF-AKT/ERK signaling pathway in traumatic brain injury.

Traumatic brain injury (TBI) and its resulting complications pose a major challenge to global public health, resulting in increased rates of disability and mortality. Cerebrovascular dysfunction is nearly universal in TBI cases and is closely associated with secondary injury after TBI. Transcranial direct current stimulation (tDCS) shows great potential in the treatment of TBI; however, the exact mechanism remains elusive. In this study, we performed in vivo and in vitro experiments to explore the effects and mechanisms of tDCS in a controlled cortical impact (CCI) rat model simulating TBI. In vivo experiments show that tDCS can effectively reduce brain tissue damage, cerebral edema and neurological deficits. The potential mechanism may be that tDCS improves the neurological function of rats by increasing orexin A (OXA) secretion, upregulating the TF-AKT/ERK signaling pathway, and promoting angiogenesis at the injury site. Cellular experiments showed that OXA promoted HUVEC migration and angiogenesis, and these effects were counteracted by the ERK1/2 inhibitor LY3214996. The results of Matrigel experiment in vivo showed that TNF-a significantly reduced the ability of HUVEC to form blood vessels, but OXA could rescue the effect of TNF-a on the ability of HUVEC to form blood vessels. However, LY3214996 could inhibit the therapeutic effect of OXA. In summary, our preliminary study demonstrates that tDCS can induce angiogenesis through the OXA-TF-AKT/ERK signaling pathway, thereby improving neurological function in rats with TBI.

Extracellular vesicles as carriers for noncoding RNA-based regulation of macrophage/microglia polarization: an emerging candidate regulator for lung and traumatic brain injuries.

Macrophage/microglia function as immune defense and homeostatic cells that originate from bone marrow progenitor cells. Macrophage/microglia activation is historically divided into proinflammatory M1 or anti-inflammatory M2 states based on intracellular dynamics and protein production. The polarization of macrophages/microglia involves a pivotal impact in modulating the development of inflammatory disorders, namely lung and traumatic brain injuries. Recent evidence indicates shared signaling pathways in lung and traumatic brain injuries, regulated through non-coding RNAs (ncRNAs) loaded into extracellular vesicles (EVs). This packaging protects ncRNAs from degradation. These vesicles are subcellular components released through a paracellular mechanism, constituting a group of nanoparticles that involve exosomes, microvesicles, and apoptotic bodies. EVs are characterized by a double-layered membrane and are abound with proteins, nucleic acids, and other bioactive compounds. ncRNAs are RNA molecules with functional roles, despite their absence of coding capacity. They actively participate in the regulation of mRNA expression and function through various mechanisms. Recent studies pointed out that selective packaging of ncRNAs into EVs plays a role in modulating distinct facets of macrophage/microglia polarization, under conditions of lung and traumatic brain injuries. This study will explore the latest findings regarding the role of EVs in the progression of lung and traumatic brain injuries, with a specific focus on the involvement of ncRNAs within these vesicles. The conclusion of this review will emphasize the clinical opportunities presented by EV-ncRNAs, underscoring their potential functions as both biomarkers and targets for therapeutic interventions.

Deciphering microglial activation and neuronal apoptosis post­traumatic brain injury: The role of TYROBP in inflammation regulation networks.

Traumatic Brain Injury (TBI) represents a significant public health challenge. Recovery from brain injury necessitates the collaborative efforts of various resident neural cells, predominantly microglia. The present study analyzed rat and mouse RNA expression micro­arrays, high­throughput RNA sequencing and single­cell sequencing data sourced from public databases. To construct an inflammation regulation network around TYRO protein tyrosine kinase­binding protein (TYROBP), to evaluate the role of TYROBP in cell death after TBI. These findings indicate that following TBI, neurons predominantly communicate with one another through the CXC chemokine ligand (CXCL) and CC chemokine ligand (CCL) signaling pathways, employing a paracrine mechanism to activate microglia. These activated microglia intensify the pathological progression of brain injury by releasing factors such as tumor necrosis factor α (TNF­α), vascular endothelial growth factor and transforming growth factor ß via the NF­κB pathway. Cells co­culture experiments demonstrated that neurons, impaired by mechanical injury, interact with microglia through non­contact mechanisms. Activated microglia secrete cytokines, including TNF­α, CXCL­8 and CCL2, which trigger an inflammatory response and facilitate neuronal apoptosis. TYROBP gene knockout in microglia was demonstrated to reduce this interaction and reduce neuronal cell apoptosis rates.

The effect of dexmedetomidine on the postoperative recovery of patients with severe traumatic brain injury undergoing craniotomy treatment: a retrospective study.

BACKGROUND: Traumatic brain injury (TBI) has been a worldwide problem for neurosurgeons. Patients with severe TBI may undergo craniotomy. These patients often require sedation after craniotomy. Dexmedetomidine (DEX) has been used in patients receiving anesthesia and in intensive care units. Not much is known about the postoperative effect of DEX in patients with severe TBIs undergoing craniotomy. The purpose of this study was to explore the effects of postoperative DEX administration on severe TBI patients who underwent craniotomy. METHODS: Patients who underwent craniectomy for severe TBI at our hospital between January 2019 and February 2022 were included in this study. The patients were admitted to the intensive care unit (ICU) after surgery to receive sedative medication. The patients were then divided into DEX and control groups. We analyzed the sedation, hemodynamics, and other conditions of the patients (hypoxemia, duration of ventilation during endotracheal intubation, whether tracheotomy was performed, and the duration in the ICU) during their ICU stay. Other conditions, such as delirium after the patients were transferred to the general ward, were also analyzed. RESULTS: A total of 122 patients were included in this study. Among them, 53 patients received DEX, and the remaining 69 did not. The incidence of delirium in the general ward in the DEX group was significantly lower than that in the control group (P < 0.05). The incidence of bradycardia in the control group was significantly lower than that in the DEX group (P < 0.05). Other data from the DEX group and the control group (hypotension, hypoxemia, etc.) were not significantly different (P > 0.05). CONCLUSION: The use of DEX in the ICU can effectively reduce the incidence of delirium in patients who return to the general ward after craniotomy. DEX had no adverse effect on the prognosis of patients other than causing bradycardia.

[Traumatic brain injury in patients over 65 years of age attended in the emergency department, characteristics and complications]. / Traumatismo craneoencefálico en pacientes mayores de 65 años atendidos en urgencias; características y complicaciones.

BACKGROUND AND OBJECTIVE: Ageing is associated with an increased risk of falls and trauma. The aim of the study was to assess the characteristics of patients over 65 years of age who consulted the ED for traumatic brain injury (TBI) in 2022, their relationship with cognitive impairment, functional dependence, use of oral antiplatelet/anticoagulant drugs and complications. MATERIALS AND METHODS: Retrospective study conducted from 1 January to 31 December 2022. Demographic data were collected: age, sex, origin; cardiovascular risk factors; cognitive impairment using the Pfeiffer questionnaire; physical disability according to the Barthel Index; number of drugs; use of antiplatelet and oral anticoagulant (OAC); mechanism of fall; performance of cranial X-ray/CT, and presence of complications: intracranial haemorrhage (ICH), death. RESULTS: 599 patients were included. The mean age was 82.3±8.2 years. 63.8% were female and 36.2% male. 75.3% were from home, 24.7% from residence. No dementia in 61.4%, moderate-severe dementia in 38.6%. 58.1% were functionally independent, 25.1% had moderate-severe dependence. 85.7% had CVRF: HT 476 (79.5%), dyslipidaemia 354 (59.1%), DM 217 (36.2%), obesity 173 (28.9%), smoking 15 (2.5%). The number of drugs per patient was 9.2±4.3. Polypharmacy was present in 94.7% of patients. 35.9% were taking antiplatelet drugs and 30.2% anticoagulants. Intracranial haemorrhage occurred in 11 (2.3%) patients. Four (0.7%) patients died. CONCLUSIONS: The TBI in our study was caused by low-energy trauma in a female patient, without dementia, functionally independent and with polypharmacy. There were few serious complications: 2.3% ICH and 0.7% deaths. 90.1% of ICH occurred in patients on antiplatelet and/or OAC therapy.

The emerging importance of skull-brain interactions in traumatic brain injury.

The recent identification of skull bone marrow as a reactive hematopoietic niche that can contribute to and direct leukocyte trafficking into the meninges and brain has transformed our view of this bone structure from a solid, protective casing to a living, dynamic tissue poised to modulate brain homeostasis and neuroinflammation. This emerging concept may be highly relevant to injuries that directly impact the skull such as in traumatic brain injury (TBI). From mild concussion to severe contusion with skull fracturing, the bone marrow response of this local myeloid cell reservoir has the potential to impact not just the acute inflammatory response in the brain, but also the remodeling of the calvarium itself, influencing its response to future head impacts. If we borrow understanding from recent discoveries in other CNS immunological niches and extend them to this nascent, but growing, subfield of neuroimmunology, it is not unreasonable to consider the hematopoietic compartment in the skull may similarly play an important role in health, aging, and neurodegenerative disease following TBI. This literature review briefly summarizes the traditional role of the skull in TBI and offers some additional insights into skull-brain interactions and their potential role in affecting secondary neuroinflammation and injury outcomes.

Prevalence of Cardiovascular Conditions After Traumatic Brain Injury: A Comparison Between the Traumatic Brain Injury Model Systems and the National Health and Nutrition Examination Survey.

BACKGROUND: The purpose of this study is to compare the prevalence of self-reported cardiovascular conditions among individuals with moderate to severe traumatic brain injury (TBI) to a propensity-matched control cohort. METHODS AND RESULTS: A cross-sectional study described self-reported cardiovascular conditions (hypertension, congestive heart failure [CHF], myocardial infarction [MI], and stroke) from participants who completed interviews between January 2015 and March 2020 in 2 harmonized large cohort studies, the TBI Model Systems and the National Health and Nutrition Examination Survey. Mixed-effect logistic regression models were used to compare the prevalence of cardiovascular conditions after 1:1 propensity-score matching based on age, sex, race, ethnicity, body mass index, education level, and smoking status. The final sample was 4690 matched pairs. Individuals with TBI were more likely to report hypertension (odds ratio [OR], 1.18 [95% CI, 1.08-1.28]) and stroke (OR, 1.70 [95% CI, 1.56-1.98]) but less likely to report CHF (OR, 0.81 [95% CI, 0.67-0.99]) or MI (OR, 0.66 [95% CI, 0.55-0.79]). There was no difference in rate of CHF or MI for those ≤50 years old; however, rates of CHF and MI were lower in the TBI group for individuals >50 years old. Over 65% of individuals who died before the first follow-up interview at 1 year post-TBI were >50 years old, and those >50 years old were more likely to die of heart disease than those ≤50 years old (17.6% versus 8.6%). CONCLUSIONS: Individuals with moderate to severe TBI had an increased rate of self-reported hypertension and stroke but lower rate of MI and CHF than uninjured adults, which may be due to survival bias.

Impact of menopause-associated frailty on traumatic brain injury.

Navigating menopause involves traversing a complex terrain of hormonal changes that extend far beyond reproductive consequences. Menopausal transition is characterized by a decrease in estradiol-17ß (E2), and the impact of menopause resonates not only in the reproductive system but also through the central nervous system, musculoskeletal, and gastrointestinal domains. As women undergo menopausal transition, they become more susceptible to frailty, amplifying the risk and severity of injuries, including traumatic brain injury (TBI). Menopause triggers a cascade of changes leading to a decline in muscle mass, accompanied by diminished tone and excitability, thereby restricting the availability of irisin, a crucial hormone derived from muscles. Concurrently, bone mass undergoes reduction, culminating in the onset of osteoporosis and altering the dynamics of osteocalcin, a hormone originating from bones. The diminishing levels of E2 during menopause extend their influence on the gut microbiota, resulting in a reduction in the availability of tyrosine, tryptophan, and serotonin metabolites, affecting neurotransmitter synthesis and function. Understanding the interplay between menopause, frailty, E2 decline, and the intricate metabolisms of bone, gut, and muscle is imperative when unraveling the nuances of TBI after menopause. The current review underscores the significance of accounting for menopause-associated frailty in the incidence and consequences of TBI. The review also explores potential mechanisms to enhance gut, bone, and muscle health in menopausal women, aiming to mitigate frailty and improve TBI outcomes.