Anorexia is Associated with Stress‐Dependent Orexigenic Responses to Exogenous Neuropeptide Y

Chicken lines that have been divergently selected for either low (LWS) or high (HWS) body weight at 56 days of age for more than 57 generations have different feeding behaviours in response to a range of i.c.v. injected neurotransmitters. The LWS have different severities of anorexia, whereas the HWS become obese. Previously, we demonstrated that LWS chicks did not respond, whereas HWS chicks increased food intake, after central injection of neuropeptide Y (NPY). The present study aimed to determine the molecular mechanisms underlying the loss of orexigenic function of NPY in LWS. Chicks were divided into four groups: stressed LWS and HWS on day of hatch, and control LWS and HWS. The stressor was a combination of food deprivation and cold exposure. On day 5 post‐hatch, each chick received an i.c.v. injection of vehicle or 0.2 nmol of NPY. Only the LWS stressed group did not increase food intake in response to i.c.v. NPY. Hypothalamic mRNA abundance of appetite‐associated factors was measured at 1 h post‐injection. Interactions of genetic line, stress and NPY treatment were observed for the mRNA abundance of agouti‐related peptide (AgRP) and synaptotagmin 1 (SYT1). Intracerebroventricular injection of NPY decreased and increased AgRP and SYT1 mRNA, respectively, in the stressed LWS and increased AgRP mRNA in stressed HWS chicks. Stress was associated with increased NPY, orexin receptor 2, corticotrophin‐releasing factor receptor 1, melanocortin receptor 3 (MC3R) and growth hormone secretagogue receptor expression. In conclusion, the loss of responsiveness to exogenous NPY in stressed LWS chicks may be a result of the decreased and increased hypothalamic expression of AgRP and MC3R, respectively. This may induce an intensification of anorexigenic melanocortin signalling pathways in LWS chicks that block the orexigenic effect of exogenous NPY. These results provide insights onto the anorexic condition across species, and especially for forms of inducible anorexia such as human anorexia nervosa.     

奥氮平与阿立哌唑对精神分裂症患者体质量、血浆神经肽Y及瘦素影响的比较

目的:比较奥氮平和阿立哌唑对精神分裂症患者体质量、血浆神经肽Y及瘦素水平的影响。方法:60例精神分裂症患者随机分为奥氮平组和阿立哌唑组各30例分别治疗8周。在治疗前、治疗后4周和8周测定两组体质量、血浆神经肽Y和瘦素水平并进行治疗前后比较。结果:奥氮平组在治疗4周和8周时体质量(F=287.207,F=506.777)、血浆神经肽Y水平(F=725.697,F=5152.624)明显高于治疗前(P均=0.000);瘦素水平治疗4周时与治疗前差异无统计学意义(F=3.908,P=0.058),治疗8周时高于治疗前(F=1589.726,P=0.000)。阿立哌唑组治疗4周和8周时体质量(F=2.810,F=1.819)、血浆神经肽Y(F=0.232,F=0.376)及瘦素水平(F=0.975,F=1.295)与治疗前比较差异无统计学意义(均P0.05)。奥氮平组治疗4周和8周时体质量的变化与神经肽Y的变化明显正相关(r=0.632,r=0.576;均P0.001),与瘦素的变化无相关(r=0.254,r=0.085;P均0.05)。逐步回归分析显示,奥氮平组神经肽Y变化进入以体质量变化为因变量的回归方程,治疗4周和8周时,神经肽Y变化可以解释体质量变化变异的40.0%和33.1%。结论:与阿立哌唑相比,奥氮平能显著增加精神分裂症患者体质量;血浆神经肽Y水平的变化可能是体质量增加的原因之一。     

Neuropeptide Y Y1 receptor hippocampal overexpression via viral vectors is associated with modest anxiolytic-like and proconvulsant effects in mice

Neuropeptide Y (NPY) exerts anxiolytic- and antidepressant-like effects in rodents that appear to be mediated via Y1 receptors. Gene therapy using recombinant viral vectors to induce overexpression of NPY in the hippocampus or amygdala has previously been shown to confer anxiolytic-like effect in rodents. The present study explored an alternative and more specific approach: overexpression of Y1 receptors. Using a recombinant adeno-associated viral vector (rAAV) encoding the Y1 gene (rAAV-Y1), we, for the first time, induced overexpression of functional transgene Y1 receptors in the hippocampus of adult mice and tested the animals in anxiety- and depression-like behavior. Hippocampal Y1 receptors have been suggested to mediate seizure-promoting effect, so the effects of rAAV-induced Y1 receptor overexpression were also tested in kainate-induced seizures. Y1 receptor transgene overexpression was found to be associated with modest anxiolytic-like effect in the open field and elevated plus maze tests, but no effect was seen on depression-like behavior using the tail suspension and forced swim tests. However, the rAAV-Y1 vector modestly aggravated kainate-induced seizures. These data indicate that rAAV-induced overexpression of Y1 receptors in the hippocampus could confer anxiolytic-like effect accompanied by a moderate proconvulsant adverse effect. Further studies are clearly needed to determine whether Y1 gene therapy might have a future role in the treatment of anxiety disorders.     

The effects of ciliary neurotrophic factor on the hypothalamo-pituitary gonadal axis in vitro in female rats

Ciliary neurotrophic factor (CNTF) is a member of the neuropoietic family of cytokines. CNTF exerts its actions through activation of a receptor complex, which shows similarity of sequence, second messenger systems and distribution to the leptin receptor. Leptin has been demonstrated to exert profound effects on the hypothalamo-pituitary gonadal axis. This study examines the in vitro effects of CNTF on hypothalamic luteinizing hormone releasing hormone release (LHRH) and pituitary luteinizing hormone (LH) release compared to those of leptin in the female. We report that CNTF stimulates LHRH release from medial basal hypothalamic explants harvested from proestrous female rats and this effect is of similar magnitude to that seen with leptin. In contrast, CNTF suppresses LHRH-stimulated LH release from dispersed anterior pituitary cells harvested from proestrous female rats but has no effect on basal LH release. Leptin stimulates basal LH release but has no effect on LHRH-stimulated LH release. The suppressive effect of CNTF on LHRH-stimulated LH release has been confirmed in perifused anterior hemipituitaries. These results suggest a differential effect of CNTF on the hypothalamo-pituitary gonadal axis and a possible role in the modulation of pituitary gonadal function.     

睫状神经营养因子对体外培养星形胶质细胞的激活作用(英文)

目的观察睫状神经营养因子(ciliary neurotrophic factor, CNTF)对体外培养星形胶质细胞的细胞激活作用。方法分别给予不同浓度(0、2、20、200 ng/ml)的CNTF孵育有血清培养和无血清培养的星形胶质细胞,采用免疫细胞化学技术及流式细胞术,观察星形胶质细胞形态及细胞周期的变化。结果有血清培养和无血清培养时CNTF均使星形胶质细胞GFAP表达增强,胞核增大。有血清培养时CNTF还可以促进星形胶质细胞进入细胞周期进行增殖;无血清培养时CNTF无此效应。结论无血清培养时CNTF可以刺激星形胶质细胞进入活化状态,但不刺激其增殖;有血清培养时CNTF可以协助血清中的丝裂原引起星形胶质细胞增殖。     

睫状神经营养因子对体外培养星形胶质细胞的激活作用

目的观察睫状神经营养因子（ciliary neurotrophic factor,CNTF）对体外培养星形胶质细胞的细胞激活作用。方法分别给予不同浓度（0、2、20、200ng／ml）的CNTF孵育有血清培养和无血清培养的星形胶质细胞,采用免疫细胞化学技术及流式细胞术,观察星形胶质细胞形态及细胞周期的变化。结果有血清培养和无血清培养时CNTF均使星形胶质细胞GFAP表达增强,胞核增大。有血清培养时CNTF还可以促进星形胶质细胞进入细胞周期进行增殖：无血清培养时CNTF无此效应。结论无血清培养时CNTF可以刺激星形胶质细胞进入活化状态,但不刺激其增殖：有血清培养时CNTF可以协助血清中的丝裂原引起星形胶质细胞增殖。     

神经肽Y受体在人垂体腺瘤中的基因表达

目的研究NPY受体在人垂体腺瘤中表达及其规律。方法收集2004年1月~2005年8月期间我院神经外科手术切除垂体腺瘤获取标本57例。通过巢式聚会酶链反应(N-PCR)测定NPY的Y1R和Y2R受体。结果不同类型垂体腺瘤中均有NPY的Y1R、Y2R mRNA表达。Y1R基因表达的差异无统计学意义(F=1.97,P=0.098);Y2R表达的差异有显著统计学意义(F=2.703,P=0.03)。NPY与Y2R呈正相关(r=0.414,P=0.003),但与Y1R无相关性(r=-0.123,P=0.405),且Y1R与Y2R之间也无相关性(r=0.158,P=0.284)。PRL腺瘤中Y2R的表达明显低于GH腺瘤和促性腺瘤。GH腺瘤中NPY与Y2R表达呈正相关(r=0.558,P=0.025)。结论垂体腺瘤中存在NPY和Y1R及Y2R表达;Y2R表达的差异有显著统计学意义。Y2R在GH腺瘤和促性腺细胞腺瘤中的表达水平明显高于PRL腺瘤,而Y1R的表达无显著性差异。NPY受体的表达差异可能与不同类型垂体腺瘤的发生、发展及其内分泌行为有关。     

Monoclonal antibody that inhibits biological activity of a mammalian ciliary neurotrophic factor

Four monoclonal antibodies to a purified ciliary neurotrophic factor have been produced by a combination of in vivo and in vitro immunization of mouse lymphocytes. Three of the antibodies--3D12, an 1gA subtype, and 5G9 and 2B11, both IgM subtypes--bound to the single band on immunoblots of the purified factor. Of the four clones only one, 3D12, produced antibodies able to inhibit the biological activity of the neurotrophic factor in promoting the survival of ciliary neurones in dissociated culture.     

Endocrine Actions of Central Neuropeptide Y in the Ewe: Activation of the Hypothalamo-Pituitary-Adrenal Axis by Exogenous Neuropeptide Y and Role of Endogenous Neuropeptide Y in the Secretion of Luteinizing Hormone During the Oestrous Cycle

Neurons immunoreactive for neuropeptide Y (NPY) are abundant in the hypophysiotrophic areas of the brain. In particular, there is considerable anatomical evidence for the influence of this neuropeptide on the reproductive and hypothalamo-pituitary-adrenal axes. We therefore investigated whether central administration of NPY can alter the activities of the reproductive and hypothalamo-pituitary-adrenal axes in the ewe, and whether ovarian steroids are involved in the modulation of these events. We also attempted to investigate whether endogenous NPY is important in the control of luteinizing hormone-releasing hormone/luteinizing hormone (LHRH/LH) secretion in the sheep oestrous cycle. Central injection of NPY (0.15 and 1.5 nmol in 50 μl saline), delivered by gravity flow into the third cerebral ventricle, had no effect on LH levels in ovariectomized (OVX) ewes (n = 6) or OVX ewes implanted with oestradiol (OVX/E₂) (n = 7), nor was LH secretion altered by central NPY (1.5 nmol) in intact cycling animals in either the follicular or the luteal phase (n = 5). However, central administration of 1.5 nmol NPY to intact ewes during both the follicular (P> 0.05) and the luteal phase (P> 0.01), and in OVX/E₂ ewes (P<0.5) caused a large and significant increase in plasma cortisol levels. High litre antibodies were raised to NPY in sheep and the effects of peripheral and central (intracerebroventricular) administration of anti-NPY antibodies on the timing and/or characteristics of the E₂-induced LH surge in anoestrous ewes and of the preovulatory surge of LH in cycling ewes were determined. Intravenous administration of anti-NPY antibodies (n = 6) had no effect on the oestradiol benzoate-induced LH surge, compared with the control injection of non-immune plasma (n = 6). Likewise, passive systemic immunization against NPY (n = 10) was without effect on the characteristics of the preovulatory LH surge, compared with the control group (n = 10). However, central (intracerebroventricular) administration of anti-NPY antibodies (n = 4) delayed or abolished the preovulatory LH surge when compared with non-immune plasma treatment in the same animals. In summary, tonic LHRH/LH secretion is unaffected by centrally administered NPY at the doses used in this study. However, the same doses of NPY activate the hypothalamo-pituitary-adrenal axis, thus lending clear support to the hypothesis that NPY is involved in the multifactorial regulation of adrenocorticotrophin and cortisol secretion in this species, probably by stimulating corticotrophin-releasing hormone and/or arginine vasopressin secretion within the hypothalamus. The results of the immunization experiments further suggest that hypothalamic NPY may play a part in the modulation of the tinning of the LHRH/LH surge in the ewe. In contrast to the role of NPY in this regard in the rat, this only occurs at the level of the hypothalamus. The function of NPY in the regulation of reproduction in the sheep may therefore be to provide a means whereby the efficient generation of a preovulatory LHRH/LH surge is ensured.     

人体血浆和垂体腺瘤组织中的神经肽Y含量及其临床意义

目的 :研究垂体腺瘤患者血浆和肿瘤组织中的神经肽Y(NPY)浓度与垂体腺瘤的关系。方法 :放射免疫分析方法测定 3 3例垂体腺瘤组织和 2 0例病人血浆的NPY浓度。结果 :不同类型垂体腺瘤组织中NPY含量有显著差别 ,侵袭性垂体腺瘤NPY含量高于非侵袭性垂体腺瘤。肿瘤组织与血浆NPY水平呈正相关。结论 :不同类型垂体腺瘤组织和血浆中NPY含量有显著差别 ,NPY水平可作为垂体腺瘤侵袭性的参考指标之一     

神经肽Y对免疫细胞活性的影响

神经肽Y（NPY）是广泛分布于中枢神经系统和外周神经各部位的神经肽类物质。本实验观察NPY在体外对几种免疫细胞活性的直接作用。结果表明，NPY对小鼠T淋巴细胞丝裂原反应性和NK细胞的杀伤活性均无明显影响（P＞0．05），对巨噬细胞分泌溶菌酶有明显抑制作用（P＜0．05）；而对B淋巴细胞丝裂原反应性则有明显的促进作用（P＜0．05）。上述结果提示，NPY对部分免疫细胞功能的影响因细胞种类而异。     

神经肽Y基因启动子多态性与缺血性脑卒中的相关性研究

目的：探讨神经肽Y（NPY）基因启动子多态性与缺血性脑卒中的相关性。方法：采用聚合酶链反应（PCR）及基因测序技术,对450例缺血性脑卒中患者及423名正常对照者NPY基因启动子-399T／C（rs16147）基因型及等位基因频率进行检测。Logistic回归分析去除混杂因素影响,分析其与缺血性脑卒中发病的相关性。结果：脑卒中组NPY基因型和等位基因频率与正常对照组比差异有显著统计学意义,特别是在小动脉闭塞性脑卒中类型中。-399C等位基因与缺血性脑卒中存在相关性,是其重要危险因素（OR=2．398,95％CI=1．036-5．553,P=0．041）。结论：NPY基因启动子多态性可能与缺血性脑卒中的发病存在相关,具有-399C等位基因的个体发生缺血性脑卒中的风险可能显著增加。     

Endogenous Control of Hippocampal Epileptogenesis: A Molecular Cascade Involving Brain-Derived Neurotrophic Factor and Neuropeptide Y

Summary: Purpose : Seizures increase the expression of brain-derived neurotrophic factor (BDNF) in the hippocampus. Because this neurotrophin exerts modulatory effects on hippocampal neuronal excitability, it may play an important role in epileptogenesis initiated in this structure. Moreover BDNF is known to regulate the expression of neuropeptide Y (NPY), which displays modulatory properties on seizure activity. This suggests that the effects of BDNF on epileptogenesis may be mediated by NPY.
Methods : Adult male rats received a 7-day chronic intrahippocampal infusion of BDNF, BDNF antisense oligodeoxy-nucleotides, NPY, or anti-NPY immunoglobulin G during kindling of the hippocampus. The long-term regulation of NPY expression by BDNF was also studied by immunohistochemistry and radioimmunoassay.
Results : BDNF applied during the first week of hippocampal stimulation significantly delayed the progression of kindling, an effect that outlasted the end of the infusion by at least 7 days. Conversely, infusion of BDNF antisense oligodeoxynucleotides to reduce the expression of endogenous BDNF in the hippocampus aggravated the electroencephalographic expression of seizures. Chronic infusion of BDNF increased the expression of NPY in the hippocampus, with a time course similar to that of the protective effect of the neurotrophin on kindling. Finally, chronic infusion of NPY in the hippocampus delayed the progression of hippocampal kindling, whereas anti-NPY antibodies had an aggravating effect.
Conclusions : Our results suggest that the seizure-induced increase in BDNF expression in the hippocampus may constitute an endogenous protective mechanism able to counteract hippocampal epileptogenesis. This protective effect appears to be mediated at least in part through the regulation of NPY expression.     

脊髓全横断大鼠椎管内睫状神经营养因子抗体封闭模型的建立

【摘要】　目的 建立一种特异性中和内源性CNTF表达的模型,用于研究CNTF在脊髓全横断损伤后的作用机制。方法 健康成年SD雌性大鼠45只,随机分为3组：假手术组15只、对照组15只、抗体封闭组15只。对照组和抗体封闭组大鼠行T11 脊髓全横断术和椎管内置管术,对照组大鼠经导管推注人工脑脊液20μl/只,抗体封闭组大鼠推注CNTF抗体（0.1g/ml）20μl/只。假手术组仅行T9椎板切除术。观察动物术后存活情况及24h时BBB评分,应用免疫组织化学和Western-blot技术检测术后24h、48h、72h 脊髓颈、胸、腰段CNTF的分布及表达变化。 结果　术后动物存活率100％,对照组和抗体封闭组BBB评分显著低于假手术组（Ρ<0.01）;对照组术后各时间点大量CNTF阳性细胞分布于灰质前角及白质前索、后索和外侧索;抗体封闭组T9、L2节段术后24h时未见CNTF阳性细胞,术后48h、72h出现阳性细胞,C5节段术后3个时间点均可见阳性细胞分布;Western-blot显示对照组脊髓各节段术后3个时间点CNTF表达量均较假手术组增加（Ρ<0.05）,抗体封闭组T10、L1脊髓术后24h时CNTF表达较对照组减少（Ρ<0.05）,而于48h、72h回升（Ρ<0.01）,C6节段术后各时点CNTF的变化无差异（Ρ>0.05）。 结论 该模型在24h内能够有效封闭内源性CNTF表达,为研究脊髓损伤后CNTF的作用和机制奠定了基础,并能推广应用于其它细胞因子的相关研究。 【关键词】　睫状神经营养因子(CNTF),抗体封闭,脊髓全横断,模型     

Recombinant human ciliary neurotrophic factor stimulates the metabolic activity of SH-SY5Y cells as measured by a cytosensor microphysiometer

Information on the transmembrane signaling events and subsequent biochemical processes initiated by ciliary neurotrophic factor (CNTF) receptor activation in neurons is lacking. SH-SY5Y cells, a human neuroblastoma cell line expressing CNTF receptors, were used to study metabolic changes associated with functional ligand-receptor interactions. Real-time measurements quantifying the rate of extracellular acidification by SH-SY5Y cells (a measure of metabolic activity) were made using a silicon-based cytosensor. Application of recombinant human CNTF (rhCNTF) to resting SH-SY5Y cells increased their acidification rate in a concentration and time-dependent manner with an apparent EC₅₀ of 60 ng/ml. Pretreatment of cells with phosphatidylinositol-specific phospholipase C (PI-PLC) prevented the CNTF, but not an NGF-stimulated increase in acidification rate. Collectively, these results demonstrate that: (1) SH-SY5Y cells express functional CNTF receptors; and (2) the initial signal transduction mechanism activated by the CNTF receptor in SH-SY5Y cells is distinct from that activated by the NGF receptor; however, both may ultimately stimulate the same downstream biochemical messengers to increase cellular metabolism.     

Neuropeptide Y and leptin receptor expression in the hypothalamus of rats with chronic immobilization stress

In this study, Sprague-Dawley rats were immobilized to a frame for 3 hours a day for 21 days to establish a model of chronic immobilization stress. The body weight and food intake of rats subjected to chronic immobilization stress were significantly decreased compared with the control group. Dual-labeling immunofluorescence revealed that the expression of leptin receptor and the co-localization coeffient in these leptic receptor neurons in the arcuate nucleus of the hypothalamus were both upregulated, while the number of neuropeptide Y neurons was decreased. Chronic immobilization stress induced high expression of leptin receptor in the arcuate nucleus and suppressed the synthesis and secretion of neuropeptide Y, thereby disrupting the pathways in the arcuate nucleus that regulate feeding behavior, resulting in diminished food intake and reduced body weight.     

Potential implications of a ciliary neurotrophic factor gene mutation in a german population of patients with motor neuron disease

The frequency of a recently described point mutation of the ciliary neurotrophic factor (CNTF) gene was investigated in a population of 154 German patients with motor neuron disease (MND). Twenty-two percent of the patients were heterozygous, 2% homozygous for the CNTF mutation. Since the gene defect is per se not linked to MND, the identification of additional gene defects occurring simultaneously with this mutation could be informative for the understanding of pathogenic mechanisms of MND. © 1998 John Wiley & Sons, Inc. Muscle Nerve 21: 236–238, 1998