Effects of Tenascin-C Knockout on Cerebral Vasospasm After Experimental Subarachnoid Hemorrhage in Mice

A matricellular protein tenascin-C (TNC) has been suggested to play a role in the pathogenesis of cerebral vasospasm after subarachnoid hemorrhage (SAH), but the direct evidence remains lacking. In this study, we examined effects of TNC knockout (TNKO) on cerebral vasospasm after experimental SAH in mice. C57BL/6 wild-type (WT) or TNKO mice were subjected to SAH by endovascular puncture. Ten WT and ten TNKO mice were randomized to WT sham (n = 4), TNKO sham (n = 4), WT SAH (n = 6), and TNKO SAH (n = 6) groups. In addition to neurobehavioral impairments and severity of SAH, cerebral vasospasm was assessed by morphometric measurements of the left internal carotid artery (ICA). Infiltration of inflammatory cells in the subarachnoid periarterial space was also assessed, and expressions of TNC and mitogen-activated protein kinases (MAPKs) in the ICA were immunohistochemically evaluated at 24 h post-surgery. TNC was induced in the smooth muscle cell layers and the adventitia in the spastic ICAs as well as the periarterial inflammatory cells in WT SAH mice. Compared with WT SAH mice, TNKO SAH mice showed better neurological scores and less severe cerebral vasospasm, as well as fewer inflammatory cell infiltration in the periarterial space. Post-SAH activation of MAPKs in the smooth muscle cell layers of the ICAs was also prevented in TNKO SAH mice. The findings in the present study suggest that TNC causes the development of cerebral vasospasm via pro-inflammatory effects and activation of MAPKs.     

SRC-3 Deficiency Exacerbates Neurological Deficits in a Mouse Model of Intracerebral Hemorrhage: Role of Oxidative Stress

Intracerebral hemorrhage (ICH) causes long term neurological abnormality or death. Oxidative stress is closely involved in ICH mediated brain damage. Steroid receptor cofactor 3 (SRC-3), a p160 family member, is widely expressed in the brain and regulates transactivation of Nrf2, a key component of antioxidant response. Our study aims to test if SRC-3 is implicated in ICH mediated brain injury. We first examined levels of SRC-3 and oxidative stress in the brain of mice following ICH and analyzed their correlation. Then ICH was induced in wild type (WT) and SRC-3 knock out mice and how SRC-3 deletion affected ICH induced brain damage, oxidative stress and behavioral outcome was assessed. We found that SRC-3 mRNA and protein expression levels were reduced gradually after ICH induction in WT mice along with an increase in oxidative stress levels. Correlation analysis revealed that SRC-3 mRNA levels negatively correlated with oxidative stress. Deletion of SRC-3 further increased ICH induced brain edema, neurological deficit score and oxidative stress and exacerbated ICH induced behavioral abnormality including motor dysfunction and cognitive impairment. Our findings suggest that SRC-3 is involved in ICH induced brain injury, probably through modulation of oxidative stress.

     

Influence of Plasma and Cerebrospinal Fluid Levels of Endothelin-1 and No in Reducing Cerebral Vasospasm after Subarachnoid Hemorrhage During Treatment with Mild Hypothermia,in a Dog Model

Using vascular heat-exchange controller implemented mild hypothermia treatment, the authors established the cerebral vasospasm model in which blood was injected twice into dog’s foramen magnum; and it was discussed the influence of the concentration of endothelin-1 and NO in blood plasma and cerebrospinal fluid through continuing treatment of mild hypothermia at different times in secondary brain vasospasm model after subarachnoid hemorrhage. Thirty healthy mongrel dogs were randomly divided into five groups; artificial cerebrospinal fluid group (group A), normal temperature control group (group C), mild hypothermia 8 h group (group H1), mild hypothermia 16 h group (group H2), and mild hypothermia 32 h group (group H3). The authors injected the artificial CSF into dog’s foramen magnum in group A while the other four groups were injected with autologous arterial blood. The normal group’s temperature maintained 38.5°C. The authors set the temperature at 33.5°C in mild hypothermia groups and this was maintained for 8, 16, and 32 h, respectively. ET-1 and NO levels in the cerebrospinal fluid and plasma were assayed in each group on days 0, 7, 14, and 21. Then the changes of the diameter of blood vessels of cerebral basilar artery and overall performance categories score in each group through application of CT angiography were recorded. In the cerebral vasospasm model which was constructed by injecting the blood to dog twice, mild hypothermia treatment, through the application of vascular heat-exchange controller, could reduce cerebral vasospasm. It was observed that the duration of the mild hypothermia is directly proportional to the longer duration of the relieving of cerebral vasospasm. The reciprocal changes observed in the levels of ET-1 and NO in cerebrospinal fluid and plasma revealed that it might be possible to reduce the cerebral vasospasm by regulating the rising amplitude of ET-1 and the decrease in NO in CSF and plasma.     

EMMPRIN Promotes the Expression of MMP-9 and Exacerbates Neurological Dysfunction in a Mouse Model of Intracerebral Hemorrhage

Neurochemical Research - Extracellular matrix metalloproteinase inducer (EMMPRIN) has been shown to be a vital inflammatory mediator in several neurological and neurodegenerative diseases. However,...     

Cerebrospinal Fluid from Patients with Subarachnoid Haemorrhage and Vasospasm Enhances Endothelin Contraction in Rat Cerebral Arteries

Introduction

Previous studies have suggested that cerebrospinal fluid from patients with subarachnoid hemorrhage (SAH) leads to pronounced vasoconstriction in isolated arteries. We hypothesized that only cerebrospinal fluid from SAH patients with vasospasm would produce an enhanced contractile response to endothelin-1 in rat cerebral arteries, involving both endothelin ET_A and ET_B receptors.

Methods

Intact rat basilar arteries were incubated for 24 hours with cerebrospinal fluid from 1) SAH patients with vasospasm, 2) SAH patients without vasospasm, and 3) control patients. Arterial segments with and without endothelium were mounted in myographs and concentration-response curves for endothelin-1 were constructed in the absence and presence of selective and combined ET_A and ET_B receptor antagonists. Endothelin concentrations in culture medium and receptor expression were measured.

Results

Compared to the other groups, the following was observed in arteries exposed to cerebrospinal fluid from patients with vasospasm: 1) larger contractions at lower endothelin concentrations (p<0.05); 2) the increased endothelin contraction was absent in arteries without endothelium; 3) higher levels of endothelin secretion in the culture medium (p<0.05); 4) there was expression of ET_A receptors and new expression of ET_B receptors was apparent; 5) reduction in the enhanced response to endothelin after ET_B blockade in the low range and after ET_A blockade in the high range of endothelin concentrations; 6) after combined ET_A and ET_B blockade a complete inhibition of endothelin contraction was observed.

Conclusions

Our experimental findings showed that in intact rat basilar arteries exposed to cerebrospinal fluid from patients with vasospasm endothelin contraction was enhanced in an endothelium-dependent manner and was blocked by combined ET_A and ET_B receptor antagonism. Therefore we suggest that combined blockade of both receptors may play a role in counteracting vasospasm in patients with SAH.     

辛伐他汀对大鼠蛛网膜下腔出血后脑血管痉挛的治疗效果研究

目的:观察辛伐他汀对大鼠蛛网膜下腔出血后脑血管痉挛的治疗效果并探讨其可能机制。方法:将48只健康Wistar大鼠随机分为正常对照组、模型组、辛伐他汀组,每组各16只。模型组以及辛伐他汀组给予枕大池注入自体动脉血法以建立大鼠蛛网膜下腔出血后脑血管痉挛的动物模型,辛伐他汀组于第1次注血后开始给予辛伐他汀皮下注射,其余两组给予等体积生理盐水皮下注射。比较各组大鼠情况、组织学检查结果、蛛网膜下腔出血量评分、神经功能缺损评分、血管内径、血管舒张度、血管痉挛程度、eNOS以及TNF-α蛋白表达水平。结果:实验过程中,正常对照组无大鼠死亡,模型组大鼠死亡率为33.33%,辛伐他汀死亡率为6.67%,较模型组显著降低(P0.05)。治疗后,与正常对照组相比,模型组及辛伐他汀组大鼠蛛网膜下腔出血量评分及TNF-α阳性表达率较高(P0.05),神经功能缺损评分、血管内径、D/T及eNOS阳性表达率较低(P0.05);与模型组相比,辛伐他汀组蛛网膜下腔出血量评分及TNF-α阳性表达率较低(P0.05),神经功能缺损评分、血管内径、D/T及eNOS阳性表达率较高(P0.05)。结论:辛伐他汀可有效改善蛛网膜下腔出血后脑血管痉挛,这可能与其上调eNOS蛋白表达并下调TNF-α蛋白表达有关。     

Advancing Paternal Age Is Associated with Deficits in Social and Exploratory Behaviors in the Offspring: A Mouse Model

Background

Accumulating evidence from epidemiological research has demonstrated an association between advanced paternal age and risk for several psychiatric disorders including autism, schizophrenia and early-onset bipolar disorder. In order to establish causality, this study used an animal model to investigate the effects of advanced paternal age on behavioural deficits in the offspring.

Methods

C57BL/6J offspring (n = 12 per group) were bred from fathers of two different ages, 2 months (young) and 10 months (old), and mothers aged 2 months (n = 6 breeding pairs per group). Social and exploratory behaviors were examined in the offspring.

Principal Findings

The offspring of older fathers were found to engage in significantly less social (p = 0.02) and exploratory (p = 0.02) behaviors than the offspring of younger fathers. There were no significant differences in measures of motor activity.

Conclusions

Given the well-controlled nature of this study, this provides the strongest evidence for deleterious effects of advancing paternal age on social and exploratory behavior. De-novo chromosomal changes and/or inherited epigenetic changes are the most plausible explanatory factors.     

Alterations of Voltage-Dependent Calcium Channel Currents in Basilar Artery Smooth Muscle Cells at Early Stage of Subarachnoid Hemorrhage in a Rabbit Model

Objective

To investigate the changes in the currents of voltage-dependent calcium channels (VDCCs) in smooth muscle cells of basilar artery in a rabbit model of subarachnoid hemorrhage (SAH).

Methods

New Zealand white rabbits were randomly divided into five groups: sham (C), normal (N), 24 hours (S1), 48 hours (S2) and 72 hours (S3) after SAH. Non-heparinized autologous arterial blood (1ml/kg) was injected into the cisterna magna to create SAH after intravenous anesthesia, and 1 ml/kg of saline was injected into cisterna magna in the sham group. Rabbits in group N received no injections. Basilar artery in S1, S2, S3 group were isolated at 24, 48, 72 hours after SAH. Basilar artery in group C was isolated at 72 hours after physiological saline injection. Basilar artery smooth muscle cells were isolated for all groups. Whole-cell patch-clamp technique was utilized to record cell membrane capacitance and VDCCs currents. The VDCCs antagonist nifedipine was added to the bath solution to block the Ca⁺⁺ channels currents.

Results

There were no significant differences in the number of cells isolated, the cell size and membrane capacitance among all the five groups. VDCC currents in the S1–S3 groups had higher amplitudes than those in control and sham groups. The significant change of current amplitude was observed at 72 hours after SAH, which was higher than those of 24 and 48 hours. The VDCCs were shown to expression in human artery smooth muscle cells.

Conclusions

The changes of activation characteristics and voltage-current relationship at 72 hours after SAH might be an important event which leads to a series of molecular events in the microenvironment of the basilar artery smooth muscle cells. This may be the key time point for potential therapeutic intervention against subarachnoid hemorrhage.     

Deficits in Tactile Learning in a Mouse Model of Fragile X Syndrome

The fragile X mental retardation 1 mutant mouse (Fmr1 KO) recapitulates several of the neurologic deficits associated with Fragile X syndrome (FXS). As tactile hypersensitivity is a hallmark of FXS, we examined the sensory representation of individual whiskers in somatosensory barrel cortex of Fmr1 KO and wild-type (WT) mice and compared their performance in a whisker-dependent learning paradigm, the gap cross assay. Fmr1 KO mice exhibited elevated responses to stimulation of individual whiskers as measured by optical imaging of intrinsic signals. In the gap cross task, initial performance of Fmr1 KO mice was indistinguishable from WT controls. However, while WT mice improved significantly with experience at all gap distances, Fmr1 KO mice displayed significant and specific deficits in improvement at longer distances which rely solely on tactile information from whiskers. Thus, Fmr1 KO mice possess altered cortical responses to sensory input that correlates with a deficit in tactile learning.     

Deficiency of Tenascin-C Alleviates Neuronal Apoptosis and Neuroinflammation After Experimental Subarachnoid Hemorrhage in Mice

Tenascin-C (TNC), a matricellular protein, is upregulated in brain parenchyma after experimental subarachnoid hemorrhage (SAH). Recent studies emphasize that early brain injury (EBI) should be overcome to improve post-SAH outcomes. The aim of this study was to investigate effects of TNC knockout (TNKO) on neuronal apoptosis and neuroinflammation, both of which are important constituents of EBI after SAH. C57BL/6 wild-type (WT) mice or TNKO mice underwent sham or filament perforation SAH modeling. Twenty-five WT mice and 25 TNKO mice were randomly divided into sham+WT (n?=?10), sham+TNKO (n?=?8), SAH+WT (n?=?15), and SAH+TNKO (n?=?17) groups. Beam balance test, neurological score, terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling staining, immunostaining of Toll-like receptor 4 (TLR4), and Western blotting were performed to evaluate neurobehavioral impairments, neuronal apoptosis, and neuroinflammation at 24 h post-SAH. Deficiency of TNC significantly alleviated post-SAH neurobehavioral impairments and neuronal apoptosis. The protective effects of TNKO on neurons were associated with the inhibition of a caspase-dependent apoptotic pathway, which was at least partly mediated by TLR4/nuclear factor-κB/interleukin-1β and interleukin-6 signaling cascades. This study first provided the direct evidence that TNC causes post-SAH neuronal apoptosis and neuroinflammation, potentially leading to the development of a new molecular targeted therapy against EBI.     

尼莫地平联合丁基苯酞对外伤性蛛网膜下腔出血患者脑微循环的影响

目的:探究尼莫地平联合丁基苯酞对外伤性蛛网膜下腔出血患者脑微循环的影响。方法:选取我院外伤性蛛网膜下腔出血患者36例,随机分为实验组和对照组,每组18例。对照组给予尼莫地平治疗,实验组给予尼莫地平联合丁基苯酞治疗。观察并比较两组患者治疗前后脑微循环的变化情况。结果:实验组总有效率(88.9%)高于对照组(61.1%),差异有统计学意义(P0.05);与治疗前相比,两组脑血容量(CBV)、脑血流量(CBF)水平均增高,平均通过时间(MTT)水平降低(P0.05);与对照组相比,实验组CBV和CBF水平较高,MTT较低(P0.05);与对照组相比,实验组格拉斯哥昏迷评分(GOS)评分较高、临床并发症发生率较低、6个月病死率较低,差异有统计学意义(P0.05)。结论:尼莫地平联合丁基苯酞可有效改善外伤性蛛网膜下腔出血患者的脑微循环,提高患者的生存率。     

Alterations at the Cross-Bridge Level Are Associated with a Paradoxical Gain of Muscle Function In Vivo in a Mouse Model of Nemaline Myopathy

Nemaline myopathy is the most common disease entity among non-dystrophic skeletal muscle congenital diseases. The first disease causing mutation (Met9Arg) was identified in the gene encoding α-tropomyosin_slow gene (TPM3). Considering the conflicting findings of the previous studies on the transgenic (Tg) mice carrying the TPM3 ^Met9Arg mutation, we investigated carefully the effect of the Met9Arg mutation in 8–9 month-old Tg(TPM3)^Met9Arg mice on muscle function using a multiscale methodological approach including skinned muscle fibers analysis and in vivo investigations by magnetic resonance imaging and 31-phosphorus magnetic resonance spectroscopy. While in vitro maximal force production was reduced in Tg(TPM3)^Met9Arg mice as compared to controls, in vivo measurements revealed an improved mechanical performance in the transgenic mice as compared to the former. The reduced in vitro muscle force might be related to alterations occuring at the cross-bridges level with muscle-specific underlying mechanisms. In vivo muscle improvement was not associated with any changes in either muscle volume or energy metabolism. Our findings indicate that TPM3(Met9Arg) mutation leads to a mild muscle weakness in vitro related to an alteration at the cross-bridges level and a paradoxical gain of muscle function in vivo. These results clearly point out that in vitro alterations are muscle-dependent and do not necessarily translate into similar changes in vivo.     

Ablation of Tumor Necrosis Factor Is Associated with Decreased Inflammation and Alterations of the Microbiota in a Mouse Model of Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is associated with prolonged, excess secretions of Tumor Necrosis Factor (TNF). Many patients with IBD have successful management of IBD symptoms by blocking TNF secretion or signaling. However, some patients are non-responsive to this therapy, eventually become refractory to therapy, or Alterations in the microbiota that are associated with the lack of TNF could be a contributing cause of this therapeutic insufficiency seen in some patients. Here we use wildtype (WT) and mice lacking Tnf (Tnf ^-/-) in an acute TNBS colitis model to investigate the role of TNF in colitis and how its presence or absence affects the colonic microbiota. As expected, Tnf ^-/- had less severe inflammation than WT mice. Microbiome analysis revealed significant Tnf dependent-differences in alpha and beta diversity. There were also notable differences in many species that were also primarily Tnf dependent. Taken together, our data indicates that TNF contributes significantly to the inflammation and microbiotal alterations in that occur in IBD.     

二次造影对首次造影阴性的自发性蛛网膜下腔出血的价值

目的:探讨二次造影对首次血管造影阴性的自发性蛛网膜下腔出血(Subarachnoid hemorrhage,SAH)的价值.方法:回顾性分析2009年7月至2011年7月我院共收治的自发性蛛网膜下腔出血患者115例,在确诊蛛网膜下腔出血后1-3天行股动脉插管全脑血管造影并3D重建和颅脑CT平扫.首次DSA结果阴性者于2-8周行二次全脑血管造影.结果:115例中83例共发现颅内动脉瘤87个,9例为脑血管畸形、Moyamoya病等,23例首次造影阴性.但23颅脑CT显示弥漫性蛛网膜下腔出血16例,中脑周围蛛网膜下腔出血5例,局限于一个脑池或脑叶内蛛网膜下腔出血1例,颅脑CT阴性1例.二次造影后在16例弥漫性蛛网膜下腔出血患者中共发现动脉瘤3例.结论:二次造影对首次血管造影阴性的自发性蛛网膜下腔出血患者具有较高的临床意义,尤其是对于首次造影高度怀疑动脉瘤的弥漫性蛛网膜下腔出血患者,进行二次造影是必要的.     

如意珍宝丸联合依达拉奉治疗蛛网膜下腔出血后脑血管痉挛的临床研究

摘要 目的：探讨如意珍宝丸联合依达拉奉治疗蛛网膜下腔出血（SAH）后脑血管痉挛（CVS）的临床疗效。方法：选取我院2021年3月~2022年4月期间收治的138例SAH后CVS患者。按照随机数字表法分为对照组（69例,依达拉奉治疗）和研究组（69例,如意珍宝丸联合依达拉奉治疗）。对比两组临床疗效、格拉斯哥昏迷指数（GCS）评分、Barthel指数、神经功能缺损评分（NIHSS）评分、大脑血流动力学相关指标、血管内皮功能指标及不良反应发生率。结果：研究组的临床总有效率高于对照组（P<0.05）。治疗2周后,研究组的GCS评分、Barthel指数高于对照组,NIHSS低于对照组（P<0.05）。治疗2周后,研究组的血管内皮生长因子（VEGF）、内皮素-1（ET-1）低于对照组,一氧化氮（NO）、降钙素基因相关肽（CGRP）高于对照组（P<0.05）。治疗2周后,研究组的大脑中动脉平均流速（MCA-Vm）、颈内动脉颅外段平均流速（VICA-Vm）、Li指数较对照组低（P<0.05）。两组不良反应发生率对比无差异（P>0.05）。结论：如意珍宝丸联合依达拉奉治疗SAH后CVS患者,可减轻神经功能损伤,改善血管内皮功能和脑血流速度,提高生活自理能力。     

Metformin Attenuates Neurological Deficit after Intracerebral Hemorrhage by Inhibiting Apoptosis,Oxidative Stress and Neuroinflammation in Rats

Intracerebral hemorrhage (ICH) can lead to brain damage and even death, and there is lack of effective therapeutic methods for treating ICH. Although recent studies have focused on the administration of metformin in treating stroke, there is no literature to support whether it can be used to treat ICH. Therefore, the aim of this study was to evaluate the possible effects of metformin on ICH and the underlying mechanisms of those effects. An ICH model was established in adult male Sprague–Dawley rats. Rats were randomly divided into three groups: sham group, ICH group, and ICH+metformin group. The neurobehavioral deficit scoring method was used to examine neurological function in rats. The levels of lipid peroxidation antioxidant enzyme and 8-iso-PGF2α were detected to evaluate oxidative stress. Survival of striatal neurons was examined by TUNEL staining, immunohistochemistry and HE staining. The levels of p-JNK, p-c-Jun and cleaved caspase-3 in the striatum were measured by western blotting. The results demonstrated that metformin protected rats from neurological deficits induced by ICH. Moreover, metformin reduced oxidative stress and preserved the survival of striatal neurons under ICH conditions. Furthermore, metformin downregulated the levels of apoptotic factors (p-JNK3, p-c-Jun and cleaved caspase-3) as well as pro-inflammatory cytokines (IL-1β, IL-4 and IL-6 and TNF-α). Collectively, we speculate that metformin may be a potential clinical treatment for ICH patients.

     

Long-Term Physiological Alterations and Recovery in a Mouse Model of Separation Associated with Time-Restricted Feeding: A Tool to Study Anorexia Nervosa Related Consequences

Background

Anorexia nervosa is a primary psychiatric disorder, with non-negligible rates of mortality and morbidity. Some of the related alterations could participate in a vicious cycle limiting the recovery. Animal models mimicking various physiological alterations related to anorexia nervosa are necessary to provide better strategies of treatment.

Aim

To explore physiological alterations and recovery in a long-term mouse model mimicking numerous consequences of severe anorexia nervosa.

Methods

C57Bl/6 female mice were submitted to a separation-based anorexia protocol combining separation and time-restricted feeding for 10 weeks. Thereafter, mice were housed in standard conditions for 10 weeks. Body weight, food intake, body composition, plasma levels of leptin, adiponectin, IGF-1, blood levels of GH, reproductive function and glucose tolerance were followed. Gene expression of several markers of lipid and energy metabolism was assayed in adipose tissues.

Results

Mimicking what is observed in anorexia nervosa patients, and despite a food intake close to that of control mice, separation-based anorexia mice displayed marked alterations in body weight, fat mass, lean mass, bone mass acquisition, reproductive function, GH/IGF-1 axis, and leptinemia. mRNA levels of markers of lipogenesis, lipolysis, and the brown-like adipocyte lineage in subcutaneous adipose tissue were also changed. All these alterations were corrected during the recovery phase, except for the hypoleptinemia that persisted despite the full recovery of fat mass.

Conclusion

This study strongly supports the separation-based anorexia protocol as a valuable model of long-term negative energy balance state that closely mimics various symptoms observed in anorexia nervosa, including metabolic adaptations. Interestingly, during a recovery phase, mice showed a high capacity to normalize these parameters with the exception of plasma leptin levels. It will be interesting therefore to explore further the central and peripheral effects of the uncorrected hypoleptinemia during recovery from separation-based anorexia.