Objective To investigate the effects and molecular mechanism of Homer protein homolog 1a (Homer 1a) overexpression on nerve injury in mice with traumatic brain injury (TBI). Methods Sixty male C57BL/6 mice were randomly divided into five groups: sham group, TBI group, empty lentivirus (Lv-NC) group, Homer 1a overexpression lentivirus (Lv-Homer 1a) group and Lv-Homer 1a + 740 Y-P group, with 12 mice in each group. The lentivirus was orthotopic injected into the cerebral cortex of mice 5 d before modeling, while 740 Y-P was injected intraperitoneally 1 d before modeling. The TBI model was established using the free-fall impact method, and the modified neurological severity scores (mNSS) of the mice was assessed 72 h post-surgery. The water content of brain tissue was quantified, and the histopathological damage and neuronal loss in brain tissue were assessed using HE staining and Nissl staining respectively. The formation of autophagosomes in brain tissue was observed by transmission electron microscopy. The protein expression levels of Homer 1a, microtubule-associated protein 1 light chain 3B (LC3B), Beclin 1, phosphatidylinositol 3-kinase (PI3K), phosphorylation PI3K(p-PI3K), protein kinase B (AKT), p-AKT, mammalian target of rapamycin (mTOR), and p-mTOR in brain tissue were detected by Western blot analysis. Results Compared to the sham group, the mice in the TBI group exhibited a significant increase in mNSS and cerebral water content. Moreover, severe brain tissue pathological damage was observed, accompanied by a substantial loss of neurons and an increase in autophagosome formation. The protein expressions of Homer 1a and Beclin 1, as well as the protein ratio of LC3B-II/LC3B-I, in brain tissues were significantly elevated, while the protein ratios of p-PI3K/PI3K, p-AKT/AKT, and p-mTOR/mTOR were significantly reduced. Compared to the TBI group, the Lv-Homer 1a group exhibited reduced mNSS and brain water content. Additionally, there was an improvement in pathological brain tissue damage and neuron loss. Furthermore, there was an increase in autophagosome formation and expression of autophagy-related proteins, while the protein ratios of p-PI3K/PI3K, p-AKT/AKT, and p-mTOR/mTOR were decreased. Compared to the Lv-Homer 1a group, the nerve injury in the Lv-Homer 1a+740 Y-P group was exacerbated, accompanied by a reduction in autophagosome formation and expression of autophagy-related proteins, while the PI3K/AKT/mTOR signaling pathway was activated. Conclusion Overexpression of Homer 1a effectively mitigates neurological damage in TBI mice, potentially through modulation of autophagy mediated by the PI3K/AKT/mTOR signaling pathway.
Animals ; TOR Serine-Threonine Kinases/genetics* ; Autophagy ; Brain Injuries, Traumatic/pathology* ; Male ; Proto-Oncogene Proteins c-akt/genetics* ; Phosphatidylinositol 3-Kinases/genetics* ; Homer Scaffolding Proteins/metabolism* ; Mice, Inbred C57BL ; Signal Transduction ; Mice

OBJECTIVE: To observe the dynamic changes of microvascular injury and repair in the penumbra of traumatic brain injury (TBI) rats with effective cerebral perfusion microvascular imaging using optical coherence tomography angiography (OCTA). METHODS: Transparent closed cranial windows were placed in craniotomy rats after TBI caused by weight drop. All the rats in TBI group and control group underwent head MRI examination on the first postoperative day, and the changes of cerebral cortical microvessel density were measured by OCTA through cranial windows on d0, d2, d4, d6, and d8. On the second day after the operation, the same number of rats in the two groups were selected to complete the immunohistochemical staining of brain tissue with pimonidazole, an indicator of hypoxia. RESULTS: MRI T2W1 and immunohistochemical staining demonstrated that edema and hypoxia in the traumatic brain tissue extended deeply throughout the entire cortex. OCTA showed that the cortical surface veins of the rats in both groups were significantly dilated and tortuous after operation, and recovered to the postoperative day level on d8. The effective perfusion microvessel density of the rats in both groups gradually recovered after a temporary decrease, and the TBI group decreased from 39.38%±4.48% on d0 to 27.84%±6.01% on d2, which was significantly lower than that on d0, d6, and d8 (P < 0.05). The highest value was 61.71%±7.69% on d8, which was significantly higher than that on d0, d2, and d4 (P < 0.05). The control group decreased from 44.59%±7.78% on d0 to 36.69%±5.49% on d2, which was significantly lower than that on d0, d6, and d8 (P < 0.05). The highest value was 51.92%±5.96% on d8, which was significantly higher than that on d2, and d4 (P < 0.05). Comparing the two groups, the effective perfusion microvessel density in the TBI group was significantly lower than that in the control group on d2 (P=0.021), and significantly higher than that in the control group on d8 (P=0.030). CONCLUSION OCTA can be used as a method of imaging and measurement of effective perfusion microvessels in the injured cerebral cortex of TBI rats. After TBI, the effective perfusion microvessel density in the wound penumbra gradually recovered after decreasing, and increased significantly on d8.
Animals ; Brain Injuries, Traumatic/physiopathology* ; Rats ; Tomography, Optical Coherence/methods* ; Male ; Rats, Sprague-Dawley ; Microvessels/pathology* ; Microvascular Density ; Cerebral Cortex/blood supply* ; Cerebrovascular Circulation

OBJECTIVES: To study the effect of early use of sodium valproate on neuroinflammation after traumatic brain injury (TBI). METHODS: A total of 45 children who visited in Xuzhou Children's Hospital Affiliated to Xuzhou Medical University from August 2021 to August 2022 were enrolled in this prospective study, among whom 15 healthy children served as the healthy control group, and 30 children with TBI were divided into a sodium valproate treatment group and a conventional treatment group using a random number table (n=15 each). The children in the sodium valproate treatment group were given sodium valproate in addition to conventional treatment, and those in the conventional group were given an equal volume of 5% glucose solution in addition to conventional treatment. The serum concentrations of nucleotide-binding oligomerization domain-like receptor protein 3(NLRP3), high-mobility group box 1 (HMGB1), tumor necrosis factor-α (TNF-α), and interleukin-1β (IL-1β) were measured in the healthy control group on the day of physical examination and in the children with TBI on days 1, 3, and 5 after admission. Glasgow Outcome Scale-Extended (GOS-E) score was evaluated for the children with TBI 2 months after discharge. RESULTS: Compared with the healthy control group, the children with TBI had significantly higher serum concentrations of NLRP3, HMGB1, TNF-α, and IL-1β on day 1 after admission (P<0.017). The concentration of NLRP3 on day 5 after admission was significantly higher than that on days 1 and 3 after admission in the children with TBI (P<0.017). On days 3 and 5 after admission, the sodium valproate treatment group had a significantly lower concentration of NLRP3 than the conventional treatment group (P<0.05). For the conventional treatment group, there was no significant difference in the concentration of HMGB1 on days 1, 3, and 5 after admission (P>0.017), while for the sodium valproate treatment group, the concentration of HMGB1 on day 5 after admission was significantly lower than that on days 1 and 3 after admission (P<0.017). On day 5 after admission, the sodium valproate treatment group had a significantly lower concentration of HMGB1 than the conventional treatment group (P<0.05). For the children with TBI, the concentration of TNF-α on day 1 after admission was significantly lower than that on days 3 and 5 after admission (P<0.017). On days 3 and 5 after admission, the sodium valproate treatment group had a significantly lower concentration of TNF-α than the conventional treatment group (P<0.05). The concentration of IL-1β on day 3 after admission was significantly lower than that on days 1 and 5 after admission (P<0.017) in the children with TBI. On days 3 and 5 after admission, the sodium valproate treatment group had a significantly lower concentration of IL-1β than the conventional treatment group (P<0.05). The GOS-E score was significantly higher in the sodium valproate treatment group than that in the conventional treatment group 2 months after discharge (P<0.05). CONCLUSIONS Early use of sodium valproate can reduce the release of neuroinflammatory factors and improve the prognosis of children with TBI.
Child ; Humans ; Valproic Acid/therapeutic use* ; HMGB1 Protein ; Pilot Projects ; Tumor Necrosis Factor-alpha ; Neuroinflammatory Diseases ; NLR Family, Pyrin Domain-Containing 3 Protein ; Prospective Studies ; Brain Injuries, Traumatic/pathology*

OBJECTIVES: To investigate the characteristics and objective assessment method of visual field defects caused by optic chiasm and its posterior visual pathway injury. METHODS: Typical cases of visual field defects caused by injuries to the optic chiasm, optic tracts, optic radiations, and visual cortex were selected. Visual field examinations, visual evoked potential (VEP) and multifocal visual evolved potential (mfVEP) measurements, craniocerebral CT/MRI, and retinal optical coherence tomography (OCT) were performed, respectively, and the aforementioned visual electrophysiological and neuroimaging indicators were analyzed comprehensively. RESULTS: The electrophysiological manifestations of visual field defects caused by optic chiasm injuries were bitemporal hemianopsia mfVEP abnormalities. The visual field defects caused by optic tract, optic radiation, and visual cortex injuries were all manifested homonymous hemianopsia mfVEP abnormalities contralateral to the lesion. Mild relative afferent pupil disorder (RAPD) and characteristic optic nerve atrophy were observed in hemianopsia patients with optic tract injuries, but not in patients with optic radiation or visual cortex injuries. Neuroimaging could provide morphological evidence of damages to the optic chiasm and its posterior visual pathway. CONCLUSIONS Visual field defects caused by optic chiasm, optic tract, optic radiation, and visual cortex injuries have their respective characteristics. The combined application of mfVEP and static visual field measurements, in combination with neuroimaging, can maximize the assessment of the location and degree of visual pathway damage, providing an effective scheme for the identification of such injuries.
Humans ; Optic Chiasm/pathology* ; Visual Pathways/pathology* ; Visual Fields ; Evoked Potentials, Visual ; Random Amplified Polymorphic DNA Technique ; Hemianopsia/complications* ; Vision Disorders/pathology* ; Optic Nerve Injuries/diagnostic imaging* ; Brain Injuries, Traumatic/diagnostic imaging*

The brain pericyte is a unique and indispensable part of the blood-brain barrier (BBB), and contributes to several pathological processes in traumatic brain injury (TBI). However, the cellular and molecular mechanisms by which pericytes are regulated in the damaged brain are largely unknown. Here, we show that the formation of neutrophil extracellular traps (NETs) induces the appearance of CD11b⁺ pericytes after TBI. These CD11b⁺ pericyte subsets are characterized by increased permeability and pro-inflammatory profiles compared to CD11b^- pericytes. Moreover, histones from NETs by Dectin-1 facilitate CD11b induction in brain pericytes in PKC-c-Jun dependent manner, resulting in neuroinflammation and BBB dysfunction after TBI. These data indicate that neutrophil-NET-pericyte and histone-Dectin-1-CD11b are possible mechanisms for the activation and dysfunction of pericytes. Targeting NETs formation and Dectin-1 are promising means of treating TBI.
Blood-Brain Barrier/metabolism* ; Brain/pathology* ; Brain Injuries, Traumatic/metabolism* ; Extracellular Traps/metabolism* ; Histones ; Humans ; Lectins, C-Type ; Pericytes/pathology*

The mechanisms underlying exercise-induced neuroprotective effects after traumatic brain injury (TBI) remained elusive, and there is a lack of effective treatments for TBI. In this study, we investigated the effects of an integrative approach of exercise and Yisaipu (TNFR-IgG fusion protein, TNF inhibitor) in a mouse TBI model. Male C57BL/6J mice were randomly assigned to a sedentary group or a group that followed a voluntary exercise regimen. The effects of 6-week prophylactic preconditioning exercise (PE) alone or in combination with post-TBI Yisaipu treatment on moderate TBI associated deficits were examined. The results showed that combined treatments of PE and post-TBI Yisaipu were superior to single treatments on reducing sensorimotor and gait dysfunctions in mice. These functional improvements were accompanied by reduced systemic inflammation largely via decreased serum TNF-α, boosted autophagic flux, and mitigated lesion volume after TBI. Given these neuroprotective effects, composite approaches such as a combination of exercise and TNF inhibitor may be a promising strategy for facilitating functional recovery from TBI and are worth further investigation.
Animals ; Brain Injuries, Traumatic/pathology* ; Disease Models, Animal ; Male ; Mice ; Mice, Inbred C57BL ; Neuroprotective Agents/pharmacology* ; Recovery of Function ; Tumor Necrosis Factor Inhibitors

We present the case of a 23-year-old man who suddenly collapsed during a physical altercation with his friends while in a drunken state. The post-mortem computed tomography (CT) with angiography revealed acute basal subarachnoid hemorrhage with rupture of the left middle cerebral artery. On autopsy, the head, face, mandible and neck showed multifocal hemorrhages with fracture of the hyoid bone, and the pathologic findings of the brain was consistent with CT findings. However, the vascular rupture site was not observed macroscopically. On histologic examination, a microscopic focal rupture was identified at the proximal portion of the middle cerebral artery, and possibility of arteriopathy was considered. This case illustrates that other parts of intracerebral arteries (other than the vertebral arteries) can be the culprit of rupture in the case of traumatic basal subarachnoid hemorrhage, and the post-mortem angiographic findings can be helpful in targeting the site of vascular injury. Furthermore, meticulous sampling of intracranial vessels could help find the vascular rupture site and identify any histologic findings suspicious of arteriopathy. Therefore, we suggest that post-mortem angiography can be an effective and adjunctive tool for a tailored approach in finding the vascular injury, and that histologic examination of both the intracranial and extracranial arteries be important to medicolegally ensure the death of traumatic basal subarachnoid hemorrhage and to examine presence of arteriopathy as a predisposing factor.
Angiography ; Arteries ; Autopsy ; Brain ; Causality ; Forensic Pathology ; Friends ; Head ; Hemorrhage ; Humans ; Hyoid Bone ; Mandible ; Middle Cerebral Artery ; Neck ; Rupture ; Subarachnoid Hemorrhage ; Subarachnoid Hemorrhage, Traumatic ; Vascular System Injuries ; Young Adult

PURPOSETo investigate the effects of estrogen G protein-coupled receptor 30 (GPR30) agonist G1 on hippocampal neuronal apoptosis and microglial polarization in rat traumatic brain injury (TBI).

METHODSMale SD rats were randomly divided into sham group, TBI + vehicle group, TBI + G1 group. Experimental moderate TBI was induced using Feeney's weigh-drop method. G1 (100μg/kg) or vehicle was intravenously injected from femoral vein at 30 min post-injury. Rats were sacrificed at 24 h after injury for detection of neuronal apoptosis and microglia polarization. Neuronal apoptosis was assayed by immunofluorescent staining of active caspase-3. M1 type microglia markers (iNOS and IL-1β) and M2 type markers (Arg1 and IL-4) were examined by immunoblotting or ELISA. Total protein level of Akt and phosphorylated Akt were assayed by immunoblotting.

RESULTSG1 significantly reduced active caspase-3 positive neurons in hippocampus. Meanwhile G1 increased the ratio of Arg1/iNOS. IL-1β production was decreased but IL-4 was increased after G1 treatment. G1 treatment also increased the active form of Akt.

CONCLUSIONSGPR30 agonist G1 inhibited neuronal apoptosis and favored microglia polarization to M2 type.

Animals ; Apoptosis ; drug effects ; Brain Injuries, Traumatic ; drug therapy ; pathology ; Cell Polarity ; Hippocampus ; drug effects ; Interleukin-1beta ; biosynthesis ; Male ; Microglia ; drug effects ; Neurons ; drug effects ; Proto-Oncogene Proteins c-akt ; metabolism ; Rats ; Rats, Sprague-Dawley ; Receptors, G-Protein-Coupled ; agonists

OBJECTIVETo examine the effect of icariin (ICA) on the cognitive impairment induced by traumatic brain injury (TBI) in mice and the underlying mechanisms related to changes in hippocampal acetylation level.

METHODSThe modifified free-fall method was used to establish the TBI mouse model. Mice with post-TBI cognitive impairment were randomly divided into 3 groups using the randomised block method (n=7): TBI (vehicle-treated), low-dose (75 mg/kg) and high-dose (150 mg/kg) of ICA groups. An additional sham-operated group (vehicle-treated) was employed. The vehicle or ICA was administrated by gavage for 28 consecutive days. The Morris water maze (MWM) test was conducted. Acetylcholine (ACh) content, mRNA and protein levels of choline acetyltransferase (ChAT), and protein levels of acetylated H3 (Ac-H3) and Ac-H4 were detected in the hippocampus.

RESULTSCompared with the sham-operated group, the MWM performance, hippocampal ACh content, mRNA and protein levels of ChAT, and protein levels of Ac-H3 and Ac-H4 were signifificantly decreased in the TBI group (P<0.05). High-dose of ICA signifificantly ameliorated the TBI-induced weak MWM performance, increased hippocampal ACh content, and mRNA and protein levels of ChAT, as well as Ac-H3 protein level compared with the TBI group (P<0.05).

CONCLUSIONICA improved post-TBI cognitive impairment in mice by enhancing hippocampal acetylation, which improved hippocampal cholinergic function and ultimately improved cognition.

Acetylation ; Acetylcholine ; metabolism ; Animals ; Brain Injuries, Traumatic ; complications ; Choline O-Acetyltransferase ; genetics ; metabolism ; Cognitive Dysfunction ; drug therapy ; etiology ; Flavonoids ; chemistry ; pharmacology ; therapeutic use ; Hippocampus ; pathology ; Histones ; metabolism ; Homeostasis ; drug effects ; Male ; Maze Learning ; drug effects ; Mice ; RNA, Messenger ; genetics ; metabolism

Traumatic brain injury (TBI) is a leading cause of death and disability worldwide. The finding that cellular microparticles (MPs) generated by injured cells profoundly impact on pathological courses of TBI has paved the way for new diagnostic and therapeutic strategies. MPs are subcellular fragments or organelles that serve as carriers of lipids, adhesive receptors, cytokines, nucleic acids, and tissue-degrading enzymes that are unique to the parental cells. Their sub-micron sizes allow MPs to travel to areas that parental cells are unable to reach to exercise diverse biological functions. In this review, we summarize recent developments in identifying a casual role of MPs in the pathologies of TBI and suggest that MPs serve as a new class of therapeutic targets for the prevention and treatment of TBI and associated systemic complications.
Animals ; Astrocytes ; metabolism ; pathology ; Biological Transport ; Blood Coagulation Factors ; genetics ; metabolism ; Brain ; metabolism ; pathology ; physiopathology ; Brain Injuries, Traumatic ; genetics ; metabolism ; pathology ; physiopathology ; Cell-Derived Microparticles ; chemistry ; metabolism ; pathology ; Cytokines ; blood ; genetics ; Disease Models, Animal ; Disseminated Intravascular Coagulation ; genetics ; metabolism ; pathology ; physiopathology ; Gene Expression Regulation ; Humans ; Microglia ; metabolism ; pathology ; Neurons ; metabolism ; pathology ; Signal Transduction