OBJECTIVES: Subarachnoid hemorrhage (SAH) is a serious cerebrovascular disease. Early brain injury (EBI) and cerebral vasospasm are the main reasons for poor prognosis of SAH patients. The specific inhibitor of histone deacetylase 6 (HDAC6), tubastatin A (TubA), has been proved to have a definite neuroprotective effect on a variety of animal models of acute and chronic central nervous system diseases. However, the neuroprotective effect of TubA on SAH remains unclear. This study aims to investigate the expression and localization of HDAC6 in the early stage of SAH, and to evaluate the protective effects of TubA on EBI and cerebral vasospasm after SAH and the underlying mechanisms. METHODS: Adult male SD rats were treated with modified internal carotid artery puncture to establish SAH model. In the first part of the experiment, rats were randomly divided into 6 groups: a sham group, a SAH-3 h group, a SAH-6 h group, a SAH-12 h group, a SAH-24 h group, and a SAH-48 h group. At 3, 6, 12, and 24 h after SAH modeling, the injured cerebral cortex of rats in each group was taken for Western blotting to detect the expression of HDAC6. In addition, the distribution of HDAC6 in the cerebral cortex of the injured side was measured by immunofluorescence double staining in SAH-24 h group rats. In the second part, rats were randomly divided into 4 groups: a sham group, a SAH group, a SAH+TubA_L group (giving 25 mg/kg TubA), and a SAH+TubA_H group (giving 40 mg/kg TubA). At 24 h after modeling, the injured cerebral cortex tissue was taken for Western blotting to detect the expression levels of HDAC6, endothelial nitric oxide synthase (eNOS), and inducible nitric oxide synthase (iNOS), terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) staining to detect apoptosis, and hematoxylin and eosin (HE) staining to detect the diameter of middle cerebral artery. RESULTS: The protein expression of HDAC6 began to increase at 6 h after SAH (P<0.05), peaked at 24 h (P<0.001), and decreased at 48 h, but there was still a difference compared with the sham group (P<0.05). HDAC6 is mainly expressed in the cytoplasm of the neurons. Compared with the sham group, the neurological score was decreased significantly and brain water content was increased significantly in the SAH group (both P<0.01). Compared with the SAH group, the neurological score was increased significantly and brain water content was decreased significantly in the SAH+TubA_H group (both P<0.05), while the improvement of the above indexes was not significant in the SAH+TubA_L group (both P>0.05). Compared with the sham group, the expression of eNOS was significantly decreased (P<0.01) and the expressions of iNOS and HDAC6 were significantly increased (P<0.05 and P<0.01, respectively) in the SAH group. Compared with the SAH group, the expression of eNOS was significantly increased, and iNOS and HDAC6 were significantly decreased in the SAH+TubA group (all P<0.05). Compared with the SAH group, the number of TUNEL positive cells was significantly decreased and the diameter of middle cerebral artery was significantly increased in the SAH+TubA group (both P<0.05) . CONCLUSIONS HDAC6 is mainly expressed in neurons and is up-regulated in the cerebral cortex at the early stage of SAH. TubA has protective effects on EBI and cerebral vasospasm in SAH rats by reducing brain edema and cell apoptosis in the early stage of SAH. In addition, its effect of reducing cerebral vasospasm may be related to regulating the expression of eNOS and iNOS.
Rats ; Male ; Animals ; Rats, Sprague-Dawley ; Subarachnoid Hemorrhage/drug therapy* ; Vasospasm, Intracranial/metabolism* ; Histone Deacetylase Inhibitors/therapeutic use* ; Neuroprotective Agents/therapeutic use* ; Histone Deacetylase 6/pharmacology* ; Apoptosis ; Brain Injuries/drug therapy*

Insufficient remyelination due to impaired oligodendrocyte precursor cell (OPC) differentiation and maturation is strongly associated with irreversible white matter injury (WMI) and neurological deficits. We analyzed whole transcriptome expression to elucidate the potential role and underlying mechanism of action of lipocalin-2 (LCN2) in OPC differentiation and WMI and identified the receptor SCL22A17 and downstream transcription factor early growth response protein 1 (EGR1) as the key signals contributing to LCN2-mediated insufficient OPC remyelination. In LCN-knockdown and OPC EGR1 conditional-knockout mice, we discovered enhanced OPC differentiation in developing and injured white matter (WM); consistent with this, the specific inactivation of LCN2/SCl22A17/EGR1 signaling promoted remyelination and neurological recovery in both atypical, acute WMI due to subarachnoid hemorrhage and typical, chronic WMI due to multiple sclerosis. This potentially represents a novel strategy to enhance differentiation and remyelination in patients with white matter injury.
Mice ; Animals ; Remyelination/physiology* ; Oligodendrocyte Precursor Cells/metabolism* ; White Matter ; Subarachnoid Hemorrhage/metabolism* ; Lipocalin-2/metabolism* ; Early Growth Response Protein 1/metabolism* ; Oligodendroglia/metabolism* ; Mice, Knockout ; Cell Differentiation/physiology* ; Brain Injuries/metabolism*

OBJECTIVE: To determine whether Schisandrin B (Sch B) attenuates early brain injury (EBI) in rats with subarachnoid hemorrhage (SAH). METHODS: Sprague-Dawley rats were divided into sham (sham operation), SAH, SAH+vehicle, and SAH+Sch B groups using a random number table. Rats underwent SAH by endovascular perforation and received Sch B (100 mg/kg) or normal saline after 2 and 12 h of SAH. SAH grading, neurological scores, brain water content, Evan's blue extravasation, and terminal transferase-mediated dUTP nick end-labeling (TUNEL) staining were carried out 24 h after SAH. Immunofluorescent staining was performed to detect the expressions of ionized calcium binding adapter molecule 1 (Iba-1) and myeloperoxidase (MPO) in the rat brain, while the expressions of B-cell lymphoma 2 (Bcl-2), Bax, Caspase-3, nucleotide-binding oligomerization domain-like receptor family pyrin domain-containing 3 (NLRP3), apoptosis-associated specklike protein containing the caspase-1 activator domain (ASC), Caspase-1, interleukin (IL)-1β, and IL-18 in the rat brains were detected by Western blot. RESULTS: Compared with the SAH group, Sch B significantly improved the neurological function, reduced brain water content, Evan's blue content, and apoptotic cells number in the brain of rats (P<0.05 or P<0.01). Moreover, Sch B decreased SAH-induced expressions of Iba-1 and MPO (P<0.01). SAH caused the elevated expressions of Bax, Caspase-3, NLRP3, ASC, Caspase-1, IL-1β, and IL-18 in the rat brain (P<0.01), all of which were inhibited by Sch B (P<0.01). In addition, Sch B increased the Bcl-2 expression (P<0.01). CONCLUSION Sch B attenuated SAH-induced EBI, which might be associated with the inhibition of neuroinflammation, neuronal apoptosis, and the NLRP3 inflammatory signaling pathway.
Animals ; Apoptosis ; Brain/pathology* ; Brain Injuries/pathology* ; Caspase 3/metabolism* ; Cyclooctanes ; Evans Blue ; Inflammasomes/metabolism* ; Interleukin-18/metabolism* ; Lignans ; NLR Family, Pyrin Domain-Containing 3 Protein/metabolism* ; Polycyclic Compounds ; Proto-Oncogene Proteins c-bcl-2/metabolism* ; Rats ; Rats, Sprague-Dawley ; Subarachnoid Hemorrhage/drug therapy* ; Water ; bcl-2-Associated X Protein/metabolism*

Animals ; Apoptosis ; Brain/metabolism* ; Male ; Phosphatidylinositol 3-Kinases/metabolism* ; Rats ; Rats, Sprague-Dawley ; Subarachnoid Hemorrhage/drug therapy* ; Thyroxine/pharmacology*

Gastrodin is a phenolic glycoside that has been demonstrated to provide neuroprotection in preclinical models of central nervous system disease, but its effect in subarachnoid hemorrhage (SAH) remains unclear. In this study, we showed that intraperitoneal administration of gastrodin (100 mg/kg per day) significantly attenuated the SAH-induced neurological deficit, brain edema, and increased blood-brain barrier permeability in rats. Meanwhile, gastrodin treatment significantly reduced the SAH-induced elevation of glutamate concentration in the cerebrospinal fluid and the intracellular Ca overload. Moreover, gastrodin suppressed the SAH-induced microglial activation, astrocyte activation, and neuronal apoptosis. Mechanistically, gastrodin significantly reduced the oxidative stress and inflammatory response, up-regulated the expression of nuclear factor erythroid 2-related factor 2, heme oxygenase-1, phospho-Akt and B-cell lymphoma 2, and down-regulated the expression of BCL2-associated X protein and cleaved caspase-3. Our results suggested that the administration of gastrodin provides neuroprotection against early brain injury after experimental SAH.
Animals ; Apoptosis ; drug effects ; Astrocytes ; drug effects ; metabolism ; Benzyl Alcohols ; administration & dosage ; Blood-Brain Barrier ; drug effects ; metabolism ; Brain ; drug effects ; metabolism ; Brain Edema ; etiology ; prevention & control ; Calcium ; metabolism ; Glucosides ; administration & dosage ; Glutamic Acid ; metabolism ; Male ; Microglia ; drug effects ; metabolism ; Neurons ; drug effects ; Neuroprotective Agents ; administration & dosage ; Oxidative Stress ; drug effects ; Rats, Sprague-Dawley ; Subarachnoid Hemorrhage ; complications ; metabolism ; prevention & control

Fluoxetine, an anti-depressant drug, has recently been shown to provide neuroprotection in central nervous system injury, but its roles in subarachnoid hemorrhage (SAH) remain unclear. In this study, we aimed to evaluate whether fluoxetine attenuates early brain injury (EBI) after SAH. We demonstrated that intraperitoneal injection of fluoxetine (10 mg/kg per day) significantly attenuated brain edema and blood-brain barrier (BBB) disruption, microglial activation, and neuronal apoptosis in EBI after experimental SAH, as evidenced by the reduction of brain water content and Evans blue dye extravasation, prevention of disruption of the tight junction proteins zonula occludens-1, claudin-5, and occludin, a decrease of cells staining positive for Iba-1, ED-1, and TUNEL and a decline in IL-1β, IL-6, TNF-α, MDA, 3-nitrotyrosine, and 8-OHDG levels. Moreover, fluoxetine significantly improved the neurological deficits of EBI and long-term sensorimotor behavioral deficits following SAH in a rat model. These results indicated that fluoxetine has a neuroprotective effect after experimental SAH.
Animals ; Apoptosis ; drug effects ; Blood-Brain Barrier ; drug effects ; Brain Edema ; drug therapy ; etiology ; Cytokines ; genetics ; metabolism ; Disease Models, Animal ; Fluoxetine ; pharmacology ; therapeutic use ; In Situ Nick-End Labeling ; Male ; Neuroprotective Agents ; pharmacology ; therapeutic use ; Pain Measurement ; Psychomotor Performance ; drug effects ; RNA, Messenger ; metabolism ; Rats ; Rats, Sprague-Dawley ; Subarachnoid Hemorrhage ; complications ; drug therapy ; pathology ; Time Factors ; Vasospasm, Intracranial ; drug therapy ; etiology

Early brain injury (EBI) plays a key role in the pathogenesis of subarachnoid hemorrhage (SAH). This study investigated the role of glucose-regulated protein 78 (GRP78) in EBI after SAH. Male Sprague-Dawley rats (n=108) weighing 260±40 g were divided into control, sham-operated, and operated groups. Blood was injected into the prechiasmatic cistern of rats in the operated group. Neurological scores, ultrastructures of neurons, apoptosis, and GRP78 expression in the hippocampus were examined using Garcia scoring system, transmission electron microscopy, terminal deoxynucleotidyl transferase-mediated dUTP nick-end labelling, and Western blotting at 1, 6, 12, 24, 48, and 72 h after SAH, respectively. The results showed that neurological scores were significantly decreased in the operated group as compared with those in control and sham-operated groups at 12, 24, 48, and 72 h. Metachromatin, chromatin pyknosis at the edge, endoplasmic reticulum swelling, and invagination of nuclear membrane were observed at 24 h in the operated group, indicating the early morphological changes of apoptosis. The number of apoptotic cells was significantly increased in the operated group as compared with that in control and sham-operated groups at 6, 12, 24, 48, and 72 h. The GRP78 protein expression levels in the operated group were significantly elevated at all time points and reached the peak at 12 h. GRP78 expression was positively associated with apoptosis cells and negatively with neurological scores. In conclusion, EBI was demonstrated to occur after SAH and GRP78 was involved in the development of EBI after SAH.
Animals ; Apoptosis ; Brain Injuries ; complications ; metabolism ; pathology ; Chromatin ; pathology ; Endoplasmic Reticulum Stress ; Heat-Shock Proteins ; genetics ; metabolism ; Male ; Rats ; Rats, Sprague-Dawley ; Subarachnoid Hemorrhage ; etiology ; metabolism ; pathology

OBJECTIVETo investigate the risk factors of progressive brain contusion and to evaluate their impact on patients' outcome.

METHODSOne hundred and thirty two patients with traumatic brain contusion were enrolled in the study, including 70 cases with progressive contusion and 62 cases with non-progressive contusion. The risk factors were investigated with univariate and multivariate Logistic regression analysis.

RESULTSThe univariate analysis showed that Glasgow Coma Score (GCS) at admission, contusion volume at the first brain CT scans, midline shift, combined with skull fracture, subarachnoid hemorrhage, epidural hematoma, subdural hematoma, location of brain contusion, D-dimer levels, combined with type 2 diabetes were associated with progressive brain contusion. Multivariate Logistic regression analysis showed that GCS at admission, contusion volume at the first CT scans, combined with subarachnoid hemorrhage, combined with type 2 diabetes were the independent risk factors for disease progression. The outcome in the progressive group was more aggravated than that in non-progressive group (P = 0.001).

CONCLUSIONPatients with disturbance of consciousness, the larger contusion volume, combined with subarachnoid hemorrhage and diabetes are at risk for progressive brain contusion and unfavorable outcome.

Brain Injuries ; complications ; pathology ; Diabetes Mellitus, Type 2 ; complications ; Disease Progression ; Fibrin Fibrinogen Degradation Products ; metabolism ; Glasgow Coma Scale ; Hematoma, Epidural, Cranial ; complications ; Hematoma, Subdural ; complications ; Humans ; Risk Factors ; Subarachnoid Hemorrhage ; complications ; Tomography, X-Ray Computed

OBJECTIVETo assess the relationship between protease-activated receptor 1 (PAR1) expression in the basilar artery and cerebral vasospasm (CVS) in a rat model of subarachnoid hemorrhage (SAH).

METHODSTwenty-four SD rats were randomized into normal control group, SAH 3-days group, SAH 5-days group and SAH 7-days group. Rat models of SAH were established by two injections of blood into the cisterna magna and the behavioral changes of the rats were observed. The basilar arteries were taken at 3, 5, or 7 days following the modeling for measuring the cross-sectional area of the basilar artery and for immunohistochemical detection of PAR1 expression.

RESULTSThe SAH model rats, especially those in SAH 3-days group, presented with obvious neurological deficits, which was not found in the normal control group. CVS was not observed in the normal control group but occurred in the SAH model rats, which showed reduced cross-sectional area of the basilar artery and worsening spasm over time. The expression level of PAR1 tended to increase gradually in SAH 3-days, SAH 5-days and SAH 7-days groups. Pearson correlation analysis showed an inverse correlation between the expression of PAR1 and the cross-sectional area of the basilar artery (r=-0.779, P<0.01).

CONCLUSIONSThe expression of PAR1 increases significantly in rat basilar artery wall following SAH in positive correlation with the severity of CVS, suggesting the role of thrombin in the pathological process of CVS after SAH.

Animals ; Basilar Artery ; metabolism ; Rats ; Rats, Sprague-Dawley ; Receptor, PAR-1 ; metabolism ; Subarachnoid Hemorrhage ; metabolism ; Vasospasm, Intracranial ; metabolism

OBJECTIVETo investigate the association of hypoxia-inducible factor-1α (HIF-1α) expression and apoptosis in the cerebral cortex following subarachnoid hemorrhage (SAH).

METHODSSubarachnoid hemorrhage was induced by modified monofilament puncture method in rats. Thirty-five adult male Sprague-Dawley rats were randomly assigned to five groups: sham-operated group, SAH 6 h, SAH 12 h, SAH 24 h and SAH 72 h groups. HIF-1α expression was assessed by immunofluorescence staining. TdT-mediated dUTP-biotin nick end-labeling (TUNEL) technique was adopted to detect apoptotic cells. Double immunolabeling was used to identify cell types with positive HIF-1α expression.

RESULTSThe expression of HIF-1α was increased at 6 h (4.65%±1.01%), peaked at 24 h (18.55%±4.23%), and decreased at 72 h (6.31%±1.15%) after SAH (P<0.05). TUNEL-positive cells were up-regulated in the brain at 6 h (7.09%±2.34%), peaked at 24 h (25.54%±7.36%), and down-regulated at 72 h (14.11%±3.03%) after SAH (P<0.05). A significant positive correlation was noted between HIF-1α positive rates and TUNEL positive rates following SAH (r=0.738, P<0.05). Double immunolabeling indicated that HIF-1α was expressed predominantly in neurons and some nuclei with positive HIF-1α were co-stained with TUNEL.

CONCLUSIONThe data indicate that HIF-1α might participate in the pathological progression of early brain injury after SAH.

Animals ; Apoptosis ; Brain ; metabolism ; pathology ; Disease Models, Animal ; Hypoxia-Inducible Factor 1, alpha Subunit ; metabolism ; Male ; Rats ; Rats, Sprague-Dawley ; Subarachnoid Hemorrhage ; metabolism ; pathology