Improved neurite outgrowth on central nervous system myelin substrate by siRNA-mediated knockdown of Nogo receptor.

PURPOSE: To investigate the in vitro effect of short interfering RNAs (siRNAs) against Nogo receptor (NgR) on neurite outgrowth under an inhibitory substrate of central nervous system (CNS) myelin. METHODS: Three siRNA sequences against NgR were designed and transfected into cerebellar granule cells (CGCs) to screen for the most effcient sequence of NgR siRNA by using reverse transcription polymerase chain reaction (RT-PCR) and immunofluorescence staining. NgR siRNA sequence 1 was found the most efficient which was then transfected into the CGCs grown on CNS myelin substrate to observe its disinhibition for neurite outgrowth. RESULTS: Compared with the scrambled control sequence of siRNA, the NgR siRNA sequence 1 significantly decreased NgR mRNA level at 24 h and 48 h (p <0.05), which was recovered by 96 h after transfection. NgR immunoreactivity was also markedly reduced at 24 and 48 h after the transfection of siRNA sequence 1 compared with that before transfection (p<0.05). The NgR immunoreactivity was recovered after 72 h post-transfection. Moreover, the neurite outgrowth on the myelin substrate was greatly improved within 72 h after the transfection with siRNA sequence 1 compared with the scrambled sequence-transfected group or non-transfected group (p<0.05). CONCLUSION: siRNA-mediated knockdown of NgR expression contributes to neurite outgrowth in vitro.

Apolipoprotein E, low-density lipoprotein receptor, and immune cells control blood-brain barrier penetration by AAV-PHP.eB in mice.

Rationale: The blood-brain barrier (BBB) prevents the effective delivery of therapeutic molecules to the central nervous system (CNS). A recently generated adeno-associated virus (AAV)-based vector, AAV-PHP.eB, has been found to penetrate the BBB more efficiently than other vectors including AAV-PHP.B. However, little is known about the mechanisms. In this study, we investigated how AAV-PHP.eB penetrates the BBB in mice. Methods: We injected AAV-PHP.eB into the bloodstream of wild-type C57BL/6 and BALB/c mice as well as mouse strains carrying genetic mutation in apolipoprotein E gene (Apoe) or low-density lipoprotein receptor gene (Ldlr), or lacking various components of the immune system. Then, we evaluated AAV-PHP.eB transduction to the brain and spinal cord in these mice. Results: We found that the transduction to the CNS of intravenous AAV-PHP.eB was more efficient in C57BL/6 than BALB/c mice, and significantly reduced in Apoe or Ldlr knockout C57BL/6 mice compared to wild-type C57BL/6 mice. Moreover, poor CNS transduction in BALB/c mice was dramatically increased by B-cell or natural killer-cell depletion. Conclusions: Our findings demonstrate that the ApoE-LDLR pathway underlies the CNS tropism of AAV-PHP.eB and that the immune system contributes to the strain specificity of AAV-PHP.eB.

Measurement of cerebrovascular reserve by multimodal imaging for cerebral arterial occlusion or stenosis patients: protocol of a prospective, randomized, controlled clinical study.

BACKGROUND: Cerebrovascular reactivity (CVR) is the change in cerebral blood flow in response to a vaso-active stimulus, and may assist the treatment strategy of ischemic stroke. However, previous studies reported that a therapeutic strategy for stroke mainly depends on the degree of vascular stenosis with steady-state vascular parameters (e.g., cerebral blood flow and CVR). Hence, measurement of CVR by multimodal imaging techniques may improve the treatment of ischemic stroke. METHODS/DESIGN: This is a prospective, randomized, controlled clinical trial that aimed to examine the capability of multimodal imaging techniques for the evaluation of CVR to improve treatment of patients with ischemic stroke. A total of 66 eligible patients will be recruited from Renji Hospital, Shanghai Jiaotong University School of Medicine. The patients will be categorized based on CVR into two subgroups as follows: CVR > 10% group and CVR < 10% group. The patients will be randomly assigned to medical management, percutaneous transluminal angioplasty and stenting, and intracranial and extra-cranial bypass groups in a 1:1:1 ratio. The primary endpoint is all adverse events and ipsilateral stroke recurrence at 6, 12, and 24 months after management. The secondary outcomes include the CVR, the National Institute of Health stroke scale and the Modified Rankin Scale at 6, 12, and 24 months. DISCUSSION: Measurement of cerebrovascular reserve by multimodal image is recommended by most recent studies to guide the treatment of ischemic stroke, and thus its efficacy and evaluation accuracy need to be established in randomized controlled settings. This prospective, parallel, randomized, controlled registry study, together with other ongoing studies, should present more evidence for optimal individualized accurate treatment of ischemic stroke. TRIAL REGISTRATION: Chinese Clinical Trial Registry, ID: ChiCTR-IOR-16009635; Registered on 16 October 2016. All items are from the World Health Organization Trial Registration Data Set and registration in the Chinese Clinical Trial Registry: ChiCTR-IOR-16009635.

Effects of dose-response of topical administration of nimodipine on cerebral vasospasm after subarachnoid hemorrhage in rabbits.

BACKGROUND: To explore the dose-response effects of topical administration of nimodipine on cerebral vasospasm (CVS) after subarachnoid hemorrhage (SAH) in rabbits. METHODS: The CVS model was established by injection of fresh autologous nonheparinized arterial blood into the subtemporal area of basilar cisterns. The 24 CVS animals were randomly divided into 4 groups, group I (n=7): nimodipine original stock solution/normal saline=1/19 (0.01 mg/mL); group II (n=6): nimodipine original stock solution/normal saline=1/9 (0.02 mg/mL); group III (n=5): nimodipine original stock solution/normal saline=1/4 (0.04 mg/mL); and group IV (n=6) with no nimodipine, but 5% ethanol dissolved in normal saline as the control group. The operative area was administrated with nimodipine at different concentrations or alcohol-saline at 3 days after SAH. The blood flow velocity of middle cerebral artery was measured at 5, 15, 30, and 60 minutes after topical administration of nimodipine by transverse cerebellar diameter monitoring. RESULTS: Blood flow velocity of middle cerebral artery in group II (0.02 mg/mL) and in group III (0.04 mg/mL) significantly decreased at 60 and 15 minutes, respectively, after topical administration of nimodipine (P<0.05), and even more significantly at 30 and 60 minutes after topical administration of nimodipine in group III (0.04 mg/mL) (P<0.01). CONCLUSION: Topical administration of nimodipine at the concentrations of 1:5 (0.04 mg/mL) and 1:10 (0.02 mg/mL) significantly alleviates CVS after SAH, which indicates that topical administration of nimodipine may be useful for CVS of patients with SAH during surgical clip of intracranial aneurysms.

Traumatic subdural effusion evolves into chronic subdural hematoma: two stages of the same inflammatory reaction?

Traumatic subdural effusion (TSE) is one of the main associated complications of brain trauma. About half of the asymptomatic TSEs ultimately evolve into chronic subdural hematomas (CSDHs), most of which will be inevitably treated by surgical evacuation. With the emergence of subdural hydroma (SDH), rupture of bridge-veins, bleeding of the hydroma wall, hyperfunction of fibrinolysis and increasing protein content in the hydroma are some of the traditionally cited explanations of the pathogenesis of TSE evolving into CSHD. Despite intensive research and subsequent advances in surgical techniques of CSDH, a single treatment with measurable clinical impact on the evolution interruption has yet to be investigated. Compared with peripheral venous blood, inflammatory cytokines were elevated in TSE and CSDH demonstrated by a number of investigators. Neoformation of capillaries, vascular hyper-permeability, serum protein exudation and other characteristics of aseptic inflammatory reaction were observed. Meanwhile, steroid was applied to treat CSDH in several groups, which was generally used as an effective anti-inflammatory agent. Based on systemic thinking, we hypothesize that TSE and CSDH are different stages, with different appearances, of the same inflammatory reaction. The evolution from TSE into CSDH and propagation of CSDH seem to be the results of local aseptic inflammation. Our hypothesis holds potential as a target for therapeutic intervention.

Expression of nerve growth factor carried by pseudotyped lentivirus improves neuron survival and cognitive functional recovery of post-ischemia in rats.

AIMS: Nerve growth factor (NGF) has been reported to prevent neuronal damage and contributes to the functional recovery in animal brain injury models and human ischemic disease as well. We aimed to investigate a potential therapeutic effect of NGF gene treatment in ischemic stroke and to estimate the functional recovery both at the cellular and cognitive levels in an ischemia rat model. METHODS: After microinjection of pseudolentivirus-delivered ß-NGF into an established ischemic stroke model in rats (tMCAO), we estimated neuronal cell apoptosis with TUNEL labeling and neurogenesis by cell proliferation marker Ki67 staining in both ischemic core and penumbra of striatum. Furthermore, we used behavioral functional tests, Morris water maze performance, to evaluate cognitive functional recovery in vivo and propose a potential underlying mechanism. RESULTS: We found that pseudolentivirus-mediated delivery of ß-NGF gene into the brain induced high expression in striatum of the infarct core area after ischemia in rats. The ß-NGF overexpression in the striatal infarction core after ischemia not only improved neuronal survival by reducing cell apoptosis and increasing cell proliferation, but also rescued cognitive functional impairment through upregulation of GAP-43 protein expression in tMCAO rat model of ischemia. CONCLUSION: This study demonstrates a potential ß-NGF gene therapy by utilization of pseudolentivirus in ischemia and indicates future applications of NGF gene treatment in ischemic patients.

Global transcriptomic study of atherosclerosis development in rats.

Atherosclerosis is a chronic disease of the arterial wall and a leading cause of death worldwide. Though the pathophysiology of atherosclerotic lesion formation has been studied, we still lack evidence of the global changes in the artery during atherosclerosis. In this report, we induced atherosclerosis in rats and conducted GeneChip analysis on carotid arteries with or without plaque formation. We found that molecular pathways underlying plaque formation in atherosclerosis were related to immune response, angiogenesis, cell proliferation, apoptosis and hypoxic microenvironments, suggesting that the pathophysiology of atherosclerosis is varied. In addition, we showed that three lncRNAs, GAS5, SNHG6 and Zfas1, were significantly increased in the plaque of atherosclerosis patients compared to normal people. A complex interaction of mRNA and lncRNA was identified in atherosclerosis. Our results provide a global transcriptomic network of atherosclerosis development in rats and possible targets that could lead to new clinical applications in the future.

Direct hippocampal injection of pseudo lentivirus-delivered nerve growth factor gene rescues the damaged cognitive function after traumatic brain injury in the rat.

Traumatic brain injury (TBI) treatment is a long-term process and requires repeated medicine administration, which, however, can cause high expense, infection, and hemorrhage to patients. To investigate how a long-term expression of nerve growth factor (Ngf) gene affects the injured hippocampus function post-TBI, in this study, a pseudo lentivirus carrying the ß-Ngf fusion gene, with green fluorescence protein (GFP) gene, was constructed to show the gene expression and its ability of protecting cells from oxidative damage in vitro. Then, the pseudo lentivirus-carried ß-Ngf fusion gene was directly injected into the injured brain to evaluate its influence on the injured hippocampus function post-TBI in vivo. We found that the expression of the pseudo lentivirus-delivered ß-Ngf fusion gene lasted more than four-week after the cell transduction and the encoded ß-NGF fusion protein could induce the neuron-like PC12 cell differentiation. Moreover, the hippocampal injection of the pseudo lentivirus-carried ß-Ngf fusion gene sped the injured cognitive function recovery of the rat subjected to TBI. Together, our findings indicate that the long-term expression of the ß-Ngf fusion gene, delivered by the pseudo lentivirus, can promote the neurite outgrowth of the neuron-like cells and protect the cells from the oxidative damage in vitro, and that the direct and single dose hippocampal injection of the pseudo lentivirus-carried ß-Ngf fusion gene is able to rescue the hippocampus function after the TBI in the rat.

Effect of arousal methods for 175 cases of prolonged coma after severe traumatic brain injury and its related factors.

OBJECTIVE: To determine the effect of arousal methods for prolonged coma of 175 patients with severe traumatic brain injury and related factors. METHODS: There were 175 cases with persistent coma longer than 1 month after severe traumatic brain injury. Coma lasted 1-12 months. Arousal procedures included hyperbaric oxygen, physical therapy and arousal drugs. RESULTS: In the 175 prolonged coma patients 110 got recovery of consciousness; in 118 cases with coma of 1-3 months, 86 cases recovered consciousness (72.9%); in 42 cases with coma of 4-6 months, 20 cases recovered consciousness (47.6); and in 15 cases with coma of longer than 6 months, only 4 cases recovered consciousness (26.7%). The recovery of consciousness depended on patient's primary brain stem damage, cerebral hernia, GCS score, and age. CONCLUSIONS: Application of appropriate arousal procedures improves recovery of consciousness in patients with prolonged coma.

Endovascular treatment of the extracranial carotid pseudoaneurysms resulting from stab penetrating injury using overlapping bare stents.

Injury pertaining to the common carotid artery may result in complete or partial arterial transection, pseudoaneurysms, or arteriovenous connections. Endovascular treatment option of the pseudoaneurysm has already been established with favorable success rate and minimal morbidity. Our purpose is to report one 18-year-old male patient having 2 traumatic pseudoaneurysms as a result of penetrating stab injury in the extracranial common carotid. The patient was successfully treated using 2 overlapping bare-metal stents. The 2 common carotid pseudoaneurysms had different degree inflow angles defined as the space between the lines indicating the direction of blood flow from the parent artery and through the aneurysmal neck to the dome. Computed tomography angiography was utilized to follow the evolution of the pseudoaneurysms until total occlusion was demonstrated. The treatment modality used in this report represents an alternative approach of the endovascular treatment for the extracranial carotid pseudoaneurysm.

Bilateral decompressive craniectomy for patients with malignant diffuse brain swelling after severe traumatic brain injury: a 37-case study.

Abstract In this study we retrospectively analyzed the outcome of bilateral decompressive craniectomy (BDC) for 37 patients with bilateral malignant diffuse brain swelling following severe traumatic brain injury (TBI). Our 37 patients (Glasgow Coma Scale [GCS] score 6 months of follow-up. The mean ICP was 37.7 +/- 6.4 mm Hg, and the mean CPP was 57.6 +/- 7.5 mm Hg before BDC. The ICP significantly decreased to 27.4 +/- 7.2 mm Hg (p < 0.05) after bone removal, and the CPP significantly increased to 63.3 +/- 8.4 mm Hg (p < 0.05). The ICP had a larger decrease, to 11.2 +/- 7.1 mm Hg (p < 0.05), after opening and enlargement of the dura mater (p < 0.05) compared to the levels seen after bone removal, and CPP significantly increased to 77.8 +/- 8.3 mm Hg (p < 0.05). After surgery, the ICP was elevated, but remained lower than the initial ICP (p < 0.05), and was easily controlled by routine medical treatment in the ensuing days, and the CPP remained above the optimal threshold of 70 mm Hg. The mean follow-up time was 9.4 +/- 3.2 months. In total, 20 patients (54.1%) had favorable outcomes, including 12 patients (32.5%; GOS 4) with moderate deficits, and 8 patients (21.6%; GOS 5) showed good recovery and social reintegration. Also, 17 patients (45.9%) had unfavorable outcomes, including 7 patients (18.9%; GOS 1) who died, 4 patients (10.8%; GOS 2) remained in a vegetative state, and 6 patients (16.2%; GOS 3) had severe deficits. The most common complication was hydrocephalus (7 patients, 18.9%). Our data show that BDC offers immediate reductions in intracranial hypertension, and perhaps contributes to satisfactory outcomes in patients with bilateral diffuse brain swelling following severe TBI.

Matrix metalloproteinase-9 expression and protein levels after fluid percussion injury in rats: the effect of injury severity and brain temperature.

The temporal and regional expression profiles of matrix metalloproteinase-9 (MMP-9), after moderate or severe traumatic brain injury (TBI) were measured to investigate the effects of post-traumatic hypothermia (33 degrees C) or hyperthermia (39 degrees C). In the first phase of this study, adult male Sprague-Dawley rats were randomly assigned to groups of moderate TBI (1.8-2.2 atm), severe TBI (2.4-2.7 atm), and sham-injured control. The rats were killed at 4, 6, 12, 24, 48, and 72 h, or 1 week after TBI, for mRNA and protein analysis. In the second phase, rats underwent moderate fluid percussion brain injury, followed immediately by 4 h of post-traumatic normothermia (37 degrees C), hyperthermia (39 degrees C), or hypothermia (32 degrees C). The rats were killed at 12 and 48 h after TBI for mRNA expression analyses, or killed at 24 and 72 h after TBI for protein expression analyses. Brain samples, including the cerebral cortex and hippocampus (both ipsilateral and contralateral hemispheres of each group), were assayed using RT-PCR and Western blot techniques. MMP-9 levels in both the ipsilateral and contralateral hemispheres were significantly increased after TBI compared with those of sham injured animals (p < 0.01). Two expression peaks of MMP-9 were observed in the ipsilateral cortex and hippocampus. An increase in injury severity was associated with an increase in mRNA (12 and 48 h), and protein (24 and 72 h) levels of MMP-9. Post-traumatic hypothermia attenuated the increase in both the mRNA and protein levels of MMP-9, compared with normothermia and hyperthermia (p < 0.01). In contrast, hyperthermia had no significant effect on mRNA (at 12 h) and protein levels (at 24 h) of MMP-9, compared with normothermic values (p > 0.05), but resulted in a significant increase in the levels of MMP-9 mRNA and protein at 24 and 72 h, respectively (p < 0.01). Increases in MMP-9 mRNA and protein after TBI were proportional to injury severity in this model. The effects of post-traumatic hypothermia on the expression of MMP-9 may partially explain the observed effects of post-traumatic temperature on secondary injury after TBI.