Tardive dyskinetic syndrome in rats infected with Borna disease virus

Tardive Dyskinesia (TD) is a hyperkinetic movement disorder caused by chronic treatment of psychiatric patients with dopamine (DA) receptor blocking drugs (Stacy & Jankovic 1991). Although TD is one of the most important and frequently encountered iatrogenic disorders in clinical medicine, its pathophysiology is poorly understood. We have observed a hyperkinetic movement disorder in rats experimentally infected with a neurotropic RNA virus, Borna disease virus, that may provide important insights into the pathophysiology of TD. Like TD patients, infected rats show prominent orofacial dyskinesias. In keeping with the dopamine (Goetz & Klawans 1982) and anatomic (Fibiger & Lloyd 1984) hypotheses of TD, the Borna disease rat model shows enhanced behavioural sensitivity to DA agonists and selective striatal cell damage. There is also evidence of DA deafferentation and heterogeneous reduction of D2 binding in the caudate-putamen, particularly from sites implicated in oral behaviour. These observations on a virus-induced movement disorder offer novel approaches to TD pathogenesis.     

Restricted expression of Borna disease virus glycoprotein in brains of experimentally infected Lewis rats

Aim: Borna disease virus (BDV) induces a persistent infection in the central nervous system (CNS) accompanied by a non‐purulent meningoencephalitis. BDV‐infection of Lewis rats provides an important model to investigate basic principles of neurotropism, viral persistence and resulting dysfunctions. To date, the in vivo strategies of BDV to persist in the CNS are not fully understood. Viral glycoproteins are main targets of the antiviral defence implicating a controlled expression in case of persistent infections. Therefore, we analysed the expression profiles of the BDV‐glycoprotein (BDV‐GP) and corresponding BDV‐intron II RNA in experimentally infected rat brains, focusing on their spatio‐temporal occurrence, regional, cellular and intracellular locations. Methods: This was carried out by immunohistochemistry and in situ hybridization. The expression pattern of the most abundantly expressed BDV‐nucleoprotein (BDV‐N) served as a reference. Results: BDV‐N mRNA was detected preferentially in the cytoplasm of neurones, whereas BDV‐intron II mRNA was found predominantly in the nucleus of brain cells. The genomic RNA was restricted to the nucleus. Expression of BDV‐GP was significantly lower than BDV‐N expression and mainly limited to cerebral cortex, hippocampus, amygdala and thalamus. BDV‐GP was restricted to larger neurones; BDV‐N occurred also in astrocytes, oligodendrocytes and ependymal cells. Conclusions: The expression profiles of BDV‐GP, BDV‐N and their mRNAs are significantly different, indicating that BDV‐GP expression is regulated in vivo. This might be achieved by restricted nuclear export and/or maturation of BDV‐intron II mRNA or limited translation as a viral mechanism to escape from the immune response and enable persistence in the CNS.     

博尔纳病病毒感染与神经胶质瘤发生的相关性

目的 探讨博尔纳病病毒(BDV)感染与神经胶质瘤发生的可能相关性.方法 用Western-blot方法,对114例神经胶质瘤患者和110例脑外伤患者血清中BDV-p24特异性抗体进行检测.结果 114例神经胶质瘤患者血清中BDV-p24抗体阳性16例,阳性检出率为14.03％;作为实验正常对照的脑外伤患者血清,阳性3例,阳性检出率为2.72％.两组比较差异有统计学意义(P＜0.01).结论 神经胶质瘤患者血清中存在BDV的感染;BDV感染可能与神经胶质瘤的发生相关.     

Induction of immunoreactive interleukin-1β and tumor necrosis factor-α in the brains of rabies virus infected rats

Interleukin-1β (IL-1β) and tumor necrosis factor-α (TNFα) are important cytokines in the development of brain inflammation during pathological process. During rabies virus infection, the level of these proinflammatory cytokines are enhanced in the brain. In the present study we determined the cellular localization of these two cytokines by immunocytochemistry in brains of rats infected with rabies virus, at different time-intervals of the disease (day 1, 3, 4, 5 and at final stage day 6 post-infection (p.i.)). Cellular identification of IL-1β (irIL-1β) and TNFα (irTNFα) immunopositive cells was studied using a polyclonal antibody against these cytokines and against glial fibrillary acidic protein (GFAP) to detect astrocytes and GSA-I-B4 isolectin to detect microglial cells and/or infiltrating macrophages. In brains of control and early infected rats, irIL-1β was only detected in fibers located in the hypothalamus, supraoptic and tractus optic nuclei and infundibular nucleus. From day 4 onwards until day 6 p.i., enhanced irIL-1β was found and identified either in activated ameboid and/or infiltrated macrophages (amygdala, thalamus, internal capsula, subtantia nigra, septal nuclei and around blood vessels), or in activated ramified cells (hypothalamus and periventricular nucleus, piriformis and cingulate cortex, hippocampus). IrTNFα was observed in the brains of rats at a final stage of disease (day 5 and 6 p.i.): in the hypothalamus, the amygdala, the internal capsula, the thalamus, the septal nuclei, the hippocampus, the habenular nuclei and around the blood vessels. Ir-TNFα was detected in round cells identified as ameboid microglia and/or infiltrated macrophages. A marked activation of microglial and astroglial cells was observed mainly in the hypothalamus, the thalamus and hippocampus and around the blood vessels, at day 4 p.i. and later, revealing a high central inflammatory reaction in brains of rabies virus infected rats. These results showed that IL-1β and TNFα are produced in the brain both by local microglial cells and infiltrating macrophages during rabies infection. Thus, these cytokines may play an important role in coordinating the dramatic inflammatory response associated with the rabies-encephalopathy as well as in the neural modification and alteration of brain functions.     

Activities of key glycolytic enzymes in the brains of patients with Alzheimer's disease

Summary. The activities of hexokinase, aldolase, pyruvate kinase, lactate dehydrogenase and glucose 6-phosphate dehydrogenase were determined in brains of patients with Alzheimer's disease (AD) and in age matched controls. For pyruvate kinase and lactate dehydrogenase a significant increase in specific activity was found in frontal and temporal cortex of AD brains, while the activities of aldolase and hexokinase are not changed. Glucose 6-phosphate dehydrogenase activity was significantly reduced in hippocampus. The increase of some glycolytic enzyme activities is correlated with increased contents of lactate dehydrogenase and glial fibrillary acidic protein (GFAP) in homogenates of frontal and temporal cortex and elevated phosphofructokinase (PFK) and GFAP in astrocytes from the same brain areas. The data extend previous findings on an increase in brain PFK specific activity in AD and suggest that the increased activity of some glycolytic enzymes may be, at least in part, the result of the reactive astrocytosis developing in the course of AD. Received August 3, 1998; accepted November 2, 1998     

Clinical investigation of the relationship between Borna disease virus (BDV) infection and schizophrenia in 67 patients in Japan

The relationship between Borna disease virus (BDV) infection and schizophrenia in the clinical time course was investigated. By nested reverse-transcribed polymerase chain reaction (RT-PCR) and Western blotting, BDV-specific RNA and anti-BDV antibodies were examined in the EDTA-treated blood from 67 schizophrenic patients (according to DSM-III-R) in Japan. A significantly higher proportion (45%) of anti-BDV antibody and/ or BDV RNA carriers were found among these 67 schizophrenic patients than in 26 controls (0%). There were no apparent associations of BDV infection with age, age at onset, period of hospitalization, accompanying somatic diseases, a past history of tuberculosis, a history of transfusion, a family history, or doses of psychotropic drugs. It is possible that, at least, BDV infection in schizophrenic patients may not be a nosocomial (hospital-acquired) infection, although the route of BDV infection in humans remains unidentified. More studies on the relationship between BDV infection and clinical psychosomatic features should be performed in order to elucidate the pathogenesis of schizophrenia.     

病毒性脑炎患者脑脊液博尔纳病病毒p40基因片段的检测

目的探讨贵州遵义地区病毒性脑炎中博尔纳病病毒(Borna disease virus,BDV)的感染情况以及BDV与病毒性脑炎的关系。方法采用荧光定量逆转录聚合酶链反应(FQ RT-PCR)方法检测了54例病毒性脑炎患者和45例外科手术患者(除外神经系统疾病及其他常见病毒感染性疾病)脑脊液(CSF)中BDV p40基因片段,对阳性产物进行基因序列测定及分析。结果病毒性脑炎患者CSF中BDV p40基因片段阳性率为11.1%(6/54),明显高于对照组(0),Fisher精确概率检验,P0.05;其中2例外周血单核细胞(PBMC)及CSF BDV p40基因片段均为阳性。PCR扩增的目的基因片段阳性产物测序后,与NCBI网站GenBank提供的BDV标准病毒株V核苷酸序列比较同源性为100%,未发生突变。结论遵义及周边地区部分病毒性脑炎患者中存在BDV感染;感染人体的BDV p40中段基因片段存在高度的保守性,变异小,BDV p40中段基因片段可能是证实BDV感染的敏感标记物。     

病毒性脑炎患者Borna病病毒P24基因片段的检测

目的探讨Borna病病毒(BDV)感染与人类病毒性脑炎的关系。方法采用荧光定量套式逆转录酶聚合酶链反应(FQ nRT PCR)检测了59例临床诊断的原因未明的病毒性脑炎及112名健康人外周血单个核细胞(PBMC)中BDVP24基因片段。结果59例原因未明的病毒性脑炎患者中有3例PBMC中检出BDVP24基因片段,而112名健康对照均未检出。病毒性脑炎患者BDV阳性率(5.08%)高于健康对照,差异有统计学意义(P<0.05),且BDVP24基因片段检测阳性病例的脑脊液中其他常见致脑炎病毒(单纯疱疹病毒、带状疱疹病毒、腮腺炎病毒、柯萨奇病毒和巨细胞病毒)检查均为阴性。结论中国的部分病毒性脑炎患者中存在BDV感染,BDV感染与病毒性脑炎的发病可能有关。     

Immunoreactivity of the central nervous system in cats with a Borna disease-like meningoencephalomyelitis (staggering disease)

The inflammatory cell composition and the expression of major histocompatibility complex (MHC) antigens in the central nervous system (CNS) of 13 cats with a spontaneous, Borna disease-like meningoencephalomyelitis (staggering disease) was investigated by immunohistochemistry with a panel of monoclonal and polyclonal antibodies. T lymphocytes were the predominating inflammatory cells within the adventitial space. CD4⁺ T cells were more abundant than CD8⁺ T cells. Scattered IgG-, IgA- and IgM-containing cells were found in the adventitial space and surrounding neuropil, often adjacent to neurons. There was a markedly increased MHC class II expression in cells morphologically resembling microglia. In several cats, Borna disease virus specific antigen was detected, but only in a few cells, mainly of macrophage character. Our findings indicate a long-standing inflammatory reaction in the CNS of cats with staggering disease, possibly triggered and sustained by a persistent viral infection.     

Developmental brain injury associated with abnormal play behavior in neonatally Borna disease virus-infected Lewis rats: a model of autism

Play behavior, nonsocial exploratory activity, and nonplay social interaction were observed in male juvenile Lewis rats with brain developmental injury following neonatal infection with Borna disease virus (BDV). These behaviors were tested using the ‘intruder-resident' paradigm, with social isolation of residents for six days prior to testing. Four experimental pairings of infected (BDV) and uninfected (NL) rats were studied as follows: NL–NL; NL–BDV; BDV–NL; and BDV–BDV (the first member is the resident, the second member is the intruder). Observation of social activities was carried out for 10 min on two consecutive days. Nonsocial exploratory activity (e.g. ambulation and rearing) was similar in BDV and NL residents. Duration of nonplay social investigation (e.g. sniffing, approach, and follow) was higher in BDV residents as compared to NL residents when tested on the first test day. On the second day, all rats showed similar level of nonplay social interaction. When confronted with NL intruders, NL residents exhibited significantly more play behavior compared to the NL–BDV, BDV–NL and BDV–BDV pairs, when play behavior was measured by the number of ‘pins'. Moreover, irrespective of a type of intruder, NL residents demonstrated higher play soliciting behavior than BDV residents, indicating attenuated readiness to play in BDV-infected rats. The number of pins and play solicitations in BDV–NL pairs significantly increased over the two days of testing, while play activity in NL–BDV pairs declined on the second test day. This pattern suggests that the degree of social reinforcement on the first day of testing affected the level of play on the second day. These data demonstrate deficits in play behavior and other social interactions following BDV-associated developmental brain injury, thus supporting the value of the neonatally BDV-infected rat as an animal model of autism.     

Argininosuccinate synthetase: Localization in astrocytes and role in the production of glial nitric oxide

An antiserum raised against the peptide representing the partial sequence 196–222 of mouse liver argininosuccinate synthetase (ASS) was used to detect and localize the enzyme in cells of neural primary cultures. No ASS immunoreactivity was detected by Western blotting in homogenates of mouse pure astroglial cultures and rat astroglia-rich cultures. However, when the cultures had been treated with bacterial lipopolysaccharide, interferon-γ, or a combination of both, ASS immunoreactivity was disclosed. Immunocytochemical examination of rat astroglia-rich cultures revealed a colocalization of ASS with the astroglial marker glial fibrillary acidic protein (GFAP) in many cells. However, there were some GFAP-positive cells showing no specific staining for ASS, and vice versa. Colocalization of ASS with the inducible isoform of nitric oxide synthase in the same cell was shown only occasionally; nitric oxide synthase was predominantly expressed in microglial cells. In rat neuron-rich primary cultures astroglial cells as well as neurons expressed ASS. Cells of mouse pure astroglial cultures were able to synthesize arginine and, consequently, nitric oxide from citrulline, but not from ornithine. The findings demonstrate that ASS is expressed in astroglial cells under conditions that stimulate long-lasting production of nitric oxide; a functional role of this enzyme in the latter process is implicated. GLIA 24:428–436, 1998. © 1998 Wiley-Liss, Inc.     

戊四氮点燃慢性癫痫大鼠海马及颞叶皮质γ-氨基丁酸转运体1及胶质纤维酸性蛋白的表达

BACKGROUND： Gamma-aminobutyric acid transporter plays an important role in gamma-aminobutyric acid metabolism, and is highly associated with epilepsy seizures. Pathologically, astrocytes release active substances that alter neuronal excitability, and it has been demonstrated that astrocytes play a role in epileptic seizures. OBJECTIVE： To observe changes in gamma-aminobutyric acid transporter 1 and glial fibrillary acidic protein expression in the hippocampus and cortex of the temporal lobe in rats with pentylenetetrazol-induced chronic epilepsy. DESIGN, TIME AND SETTING： Randomized, controlled, animal experiment was performed at the Department of Neurobiology, Third Military University of Chinese PLA between January 2006 and December 2007. MATERIALS： Pentylenetetrazol was purchased from Sigma, USA; rabbit anti-rat gammaaminobutyric acid transporter 1 and glial fibrillary acidic protein were from Chemicon, USA. METHODS： A total of 40 Sprague Dawley rats were divided into model and control groups. Rat models of chronic epilepsy were created by pentylenetetrazol kindling, and were subdivided into 3-, 7-, and 14-day kindling subgroups. MAIN OUTCOME MEASURES： Gamma-aminobutyric acid transporter 1 and glial fibrillary acidic protein expression, as well as the number of positive cells in the hippocampus and cortex of temporal lobe of rats, were determined by immunohistochemistry and Western blot analyses. RESULTS： Compared with the control group, the number of gamma-aminobutyric acid transporter 1 and glial fibrillary acidic protein -positive cells in the hippocampus and cortex of rats with pentylenetetrazol-induced epilepsy significantly increased, gamma-aminobutyric acid transporter 1 and glial fibrillary acidic protein expression increased after 3 days of kindling, reached a peak on day 7, and remained at elevated levels at day 14 （P〈 0.05）. CONCLUSION： Astrocytic activation and gamma-aminobutyric acid transporter 1 overexpression may contribute to pentylenetetrazol-induced epilepsy.     

Detection of JC virus by anti-VP1 immunohistochemistry in brains with progressive multifocal leukoencephalopathy

We have assessed the diagnostic efficacy of a novel polyclonal rabbit antiserum directed to the recombinant major capsid protein VP1 of JC virus (JCV). Immunohistochemistry for VP1 was compared to non-radioactive JCV DNA in situ hybridization (ISH) in ten cases of progressive multifocal leukoencephalopathy (PML). Tissue sections from postmortem brains were studied from PML patients suffering from immunodeficient conditions of various causes: immunodeficiency syndrome (AIDS, n = 7), severe combined immune deficiency due to adenosine deaminase deficiency (n = 1), sarcoidosis (n = 1) and leukemia (n = 1). VP1 immunohistochemistry demonstrated the presence of JCV in lesional oligodendrocytes of all PML patients, whereas ISH was able to detect JCV in nine out of ten cases. We conclude that VP1 immunohistochemistry is a specific, sensitive and rapid method for confirming the diagnosis of PML. Received: 11 September 1996 / Revised, accepted: 12 March 1997     

Expression of caspase-3 in brains from paediatric patients with HIV-1 encephalitis

Apoptosis of neurones, macrophages, and microglia occurs in the brains of paediatric patients with human immunodeficiency virus (HIV) type 1 encephalitis, which is often associated with pre-mortem neurological disease (progressive encephalopathy). We have previously reported that TUNEL-positive neurones in brain tissue from paediatric patients with HIV type 1 encephalitis and progressive encephalopathy are strikingly devoid of the pro-apoptotic gene product Bax, in marked contrast to brain-resident macrophages and microglia. Using immunocytochemical methods, the present study demonstrate that neurones in patients with HIV type 1 encephalitis and progressive encephalopathy, as well as macrophages and microglia, but not astrocytes, overexpress caspase-3, a pro-apoptotic enzyme that is proteolytically activated downstream of Bax-Bcl-2 dysregulation. Co-localization of neuronal cytoplasmic caspase-3 and nuclear TUNEL staining, a marker for fragmented DNA, was also infrequently observed in brain tissue from patients with HIV type 1 encephalitis and progressive encephalopathy. These findings suggest that vulnerable neurones in brain tissue from patients with HIV virus type 1 encephalitis and progressive encephalopathy undergo apoptosis by a mechanism that involves upregulation of caspase-3 in a pathway that is independent of Bax-Bcl-2 dysregulation. Furthermore, caspase-3 upregulation in apoptotic neurones likely occurs prior to DNA fragmentation.