Influence of Neuropeptide Y and Neuropeptide Y 2 Receptor Variants in Acute Coronary Syndrome

Abstract Background The neuropeptide Y (NPY) is one of the most abundant neurotransmitters in the nervous system. NPY acts as a potent stimulator of angiogenesis, inflammation, and adipogenesis, through the NPY 2 receptor (NPY2R). Changes in the NPY signaling pathway have been linked to Acute Coronary Syndrome (ACS). Objectives The purpose of this study is to determine the association between variants in the NPY and NPY2R genes, as well as the severity of acute coronary syndrome (ACS). Methods Approximately 221 ACS patients and 278 healthy controls were selected for this study. Four variants in NPY and two variants in NPY2R genes were genotyped using Taqman allelic discrimination and sequencing. The Chi-square and Fisher's exact tests were used to verify the genotype frequencies. The logistic regression analyses were used for the evaluation of the studied variables. Haplotype analysis was used to evaluate the linkage disequilibrium (LD) between the variants (p<0.05). Results An association of NPY c.20T>C variant was found with the ACS group when compared to the healthy group. In the analysis between variants and risk factors in the ACS group, NPY c.84G>A was associated with hypertension. The analysis between TIMI risk showed a significance for NPY c.20T>C between the low and intermediate/high TIMI risk groups. In the haplotype analysis, strong linkage disequilibrium (LD) was found between the variants NPY c.150G>A and NPY c.-485T>C. Conclusion The NPY c.20T>C variant appears to contribute to the development of ACS. The NPY2R c.-1116A>G variant may contribute to the early development of ACS and the NPY c.84G>A variant appears to contribute to the development of hypertension. In addition, the NPY c.20T>C is associated with a protective effect in ACS severity.

Inhibition of peripheral NPY Y1 and Y2 receptors ameliorates the aberrant baroreceptor reflex sensitivity in streptozotocin induced diabetic rats / 生理学报

Neuropeptide Y (NPY), a sympathetic neurotransmitter, is highly associated with baroreflex dysfunction and multiple cardiac diseases such as diabetic myocardiopathy. In the present study, we aimed to explore the role of peripheral NPY Y1 receptor (Y1R) and Y2 receptor (Y2R), which are dominantly present in peripheral cardiovascular control, in baroreflex sensitivity (BRS) of streptozotocin (STZ)-induced diabetic rats. Peripheral Y1R and Y2R were antagonized by specific antagonists (BIBP 3226 and BIIE 0246, respectively) from subcutaneously implanted ALZET mini-osmotic pump in STZ-induced diabetic rats for 4 weeks. Then baseline systolic blood pressure, heart rate, cardiac function, BRS, plasma NPY and lipid levels were evaluated. We found that STZ led to increased plasma NPY and lipid level. And the STZ-increased lipid levels were reduced by BIBP 3226 and BIIE 0246. BIBP 3226 ameliorated the aberrant BRS, but had little effect on the impaired cardiac function of the STZ rats. BIIE 0246 alleviated sodium nitroprusside (SNP)-induced but not phenylephrine (PE)-induced aberrant baroreflex control of heart rate in the STZ rats. In addition, BIIE 0246 alleviated the bradycardia, but further impaired cardiac contractility in the STZ rats. These results suggest that peripheral Y1R and Y2R play different roles in STZ-induced impairment of BRS.

Lin28 regulates the expression of neuropeptide Y receptors and oocyte-specific homeobox genes in mouse embryonic stem cells / 대한생식의학회지

OBJECTIVE: Lin28 has been known to control the proliferation and pluripotency of embryonic stem cells. The purpose of this study was to determine the downstream effectors of Lin28 in mouse embryonic stem cells (mESCs) by RNA interference and microarray analysis. METHODS: The control siRNA and Lin28 siRNA (Dharmacon) were transfected into mESCs. Total RNA was prepared from each type of transfected mESC and subjected to reverse transcription-polymerase chain reaction (RT-PCR) analysis to confirm the downregulation of Lin28. The RNAs were labeled and hybridized with an Affymetrix Gene-Chip Mouse Genome 430 2.0 array. The data analysis was accomplished by GenPlex 3.0 software. The expression levels of selected genes were confirmed by quantitative real-time RT-PCR. RESULTS: According to the statistical analysis of the cDNA microarray, a total of 500 genes were altered in Lin28-downregulated mESCs (up-regulated, 384; down-regulated, 116). After differentially expressed gene filtering, 31 genes were selected as candidate genes regulated by Lin28 downregulation. Among them, neuropeptide Y5 receptor and oocyte-specific homeobox 5 genes were significantly upregulated in Lin28-downregulated mESCs. We also showed that the families of neuropeptide Y receptor (Npyr) and oocyte-specific homeobox (Obox) genes were upregulated by downregulation of Lin28. CONCLUSION: Based on the results of this study, we suggest that Lin28 controls the characteristics of mESCs through the regulation of effectors such as the Npyr and Obox families.

Drugs and the mechanism for reversing the tolerance of flurazepan in rats / 中国当代儿科杂志

<p><b>OBJECTIVE</b>Benzodiazepines (BDZ) have many effects on various kinds of epilepsies, but long-term treatment with BDZ often leads to drug tolerance. This study aimed to seek drugs which can reverse the tolerance of flurazepam (FZP), and to explore the role of neuropeptide Y (NPY) in the reversal effect.</p><p><b>METHODS</b>A rat model of anticonvulsant tolerance to FZP was prepared. The rats with FZP tolerance were randomly assigned to seven groups: FZP-tolerance, and nifedipine, levetiracetam, topiramate, flumazenil, L-NAME and pyridoxamine treatment groups. The tolerance to FZP was evaluated through pentylenetetrazol (PTZ) infusion into a tail vein. The latency to onset of clonic seizure and the PTZ threshold were recorded. The mRNA of NPY receptor Y2 in the hippocampus was determined by RT-PCR, and the distribution of NPY in the hippocampus was examined by immunohistochemistry.</p><p><b>RESULTS</b>In comparison with the blank control group, the average latency to the onset of clonic seizure was shortened, the average PTZ threshold decreased and the expression of NYT and NPY receptor Y2 mRNA decreased significantly in the FZP-tolerance group (p<0.01). In comparison with the FZP-tolerance group, the average latency to onset of clonic seizure was prolonged by 2 times and the average PTZ threshold doubled in the topiramate treatment group. The average latency to onset of clonic seizure was prolonged by 1 time and the average PTZ threshold increased 1 time in the nifedipine, the levetiracetam and the flumazenil treatment groups. The mRNA expression of NPY receptor Y2 increased by 1 or 2 times in the flumazenil, the nifedipine and the topiramate treatment groups when compared with the FZP-tolerance group.</p><p><b>CONCLUSIONS</b>Nifedipine, levetiracetam, topiramate and flumazenil can reverse the anticonvulsant tolerance to flurazepam. NPY may play a role in mediating the reversal effect.</p>

Antidepressant effect of microinjection of neuropeptide Y into the hippocampus is mediated by decreased expression of nitric oxide synthase / 生理学报

Accumulating evidence indicates an important role of hippocampal dendrite atrophy in the development of depression, while neuropeptide Y (NPY) participates in hippocampal dendrite growth. The present study was aimed to investigate the relationship between NPY and nitric oxide synthase (NOS) in chronic unpredictable mild stress (CUMS)-induced depression. CUMS-induced depression model was established in Sprague-Dawley rats. Intrahippocampal microinjections of NPY, NPY-Y1 receptor antagonist GR231118 and non-specific NOS inhibitor N-nitro-L-arginine methyl ester (L-NAME) were respectively adopted by rat brain stereotaxic coordinates. The behavioral observations were conducted by sucrose consumption test, open field test and forced swimming test. The expressions of NPY, neuronal nitric oxide synthase (nNOS) and inducible nitric oxide synthase (iNOS) in hippocampus were detected by immunohistochemistry. The results showed that, compared with the control group, rats receiving CUMS for 21 d or intrahippocampal microinjection of GR231118 showed a significant reduction in body weight and depression-like behavior, which included reductions in sucrose preference, locomotor activity, rearing and grooming in open field test, and increased duration of immobility in forced swimming test. Moreover, the expression of NPY significantly decreased (P<0.01), while the expressions of nNOS and iNOS increased obviously in the hippocampal dentate gyrus (DG) and CA3 regions (P<0.01). Intrahippocampal microinjections of NPY prevented the depression-like behavioral changes induced by CUMS and decreased the expressions of nNOS and iNOS in the hippocampal DG and CA3 regions (P<0.01). Intrahippocampal microinjections of GR231118 reduced behavioral ability of the rats dramatically and significantly increased the expressions of hippocampal nNOS and iNOS (P<0.01). Intrahippocampal microinjections of L-NAME suppressed the depression-like behavioral changes induced by CUMS or intrahippocampal microinjection of GR231118. In conclusion, reduced expression of NPY and increased expression of NOS in hippocampus may make significant contributions to CUMS-induced depression. These results suggest that the antidepressant function of NPY associates with down-regulation of NOS expression in hippocampus, possibly mediated via NPY-Y1 receptor.

Neuropeptide Y promotes TGF-beta1 production in RAW264.7 cells by activating PI3K pathway via Y1 receptor / 神经科学通报·英文版

<p><b>OBJECTIVE</b>To examine the effect of neuropeptide Y (NPY) on TGF-beta1 production in RAW264.7 macrophages.</p><p><b>METHODS</b>Enzyme linked immunosorbent assay (ELISA) was used to detect TGF-beta1 production. Cell counting kit 8 (CCK-8) was used to assay the viability of RAW264.7 cells. Western blot was used to detect the phosphorylation of PI3K p85.</p><p><b>RESULTS</b>NPY treatment could promote TGF-beta1 production and rapid phosphorylation of PI3K p85 in RAW264.7 cells via Y1 receptor. The elevated TGF-beta1 production induced by NPY could be abolished by wortmannin pretreatment.</p><p><b>CONCLUSION</b>NPY may elicit TGF-beta1 production in RAW264.7 cells via Y1 receptor, and the activated PI3K pathway may account for this effect.</p>

Different Regulation of Atrial ANP Release through Neuropeptide Y2 and Y4 Receptors

Neuropeptide Y (NPY) receptors are present in cardiac membranes. However, its physiological roles in the heart are not clear. The aim of this study was to define the direct effects of pancreatic polypeptide (PP) on atrial dynamics and atrial natriuretic peptide (ANP) release in perfused beating atria. Pancreatic polypeptides, a NPY Y4 receptor agonist, decreased atrial contractility but was not dose-dependent. The ANP release was stimulated by PP in a dose-dependent manner. GR 23118, a NPY Y4 receptor agonist, also increased the ANP release and the potency was greater than PP. In contrast, peptide YY (3-36) (PYY), an NPY Y2 receptor agonist, suppressed the release of ANP with positive inotropy. NPY, an agonist for Y1, 2, 5 receptor, did not cause any significant changes. The pretreatment of NPY (18-36), an antagonist for NPY Y3 receptor, markedly attenuated the stimulation of ANP release by PP but did not affect the suppression of ANP release by PYY. BIIE0246, an antagonist for NPY Y2 receptor, attenuated the suppression of ANP release by PYY. The responsiveness of atrial contractility to PP or PYY was not affected by either of the antagonists. These results suggest that NPY Y4 and Y2 receptor differently regulate the release of atrial ANP.

Analysis of Gene Expression Profile of AGS Cells Stimulated by Helicobacter pylori Adhesion

BACKGROUND/AIMS: Interactions between H. pylori and gastric epithelial cells contribute to gastric inflammation and epithelial damage. This study was performed to evaluate the gene expression profile of AGS cells by adhesion of H. pylori. METHODS: Changes in AGS cell gene expression induced by co-culturing with H. pylori (G69a strain) (4, 12, 24, 48 hours) were monitored using oligonucleotide microarray. Real-time reverse transcription-polymerase chain reaction (RT-PCR) was performed for data validation by the Assay-on-Demand Gene Expression product method. RESULTS: A total of 270 (2.66%) and 19 genes (0.19%) were up-regulated in AGS cells by H. pylori adhesion. Gene ontology analysis showed that up-regulated genes were categorized into endolipidase activity (17 genes), receptor binding (17 genes), integrin binding (4 genes), and two down-regulated genes into GTP binding category. The expression levels of 20 up- and 5 down-regulated genes were quantified by real-time RT-PCR. Sixteen genes involving cytokine activity (IL8, IL1B, TNF), hydrolase activity (PTP4A1, ERCC1, CASP8, CASP7, ACIN1), VIP receptor activity (VIPR2), and neuropeptide Y receptor activity (GPR83) were confirmed to be up-regulated. Five genes, namely, ARF3, M17S2, DDB2, AWP1, and WTAP were confirmed to be down-regulated. CONCLUSIONS: Host genes are significantly changed by H. pylori adhesion, which might explain the gastroduodenal pathogenesis induced by H. pylori infection.

Leptina e seu papel nas funções reprodutivas / Leptin and its role in reproductive functions

A leptina é um hormônio protéico produzido pelos adipócitos. É responsável pela modulação dos processos fisiológicos como regulação do consumo de alimentos, matabolismo energético e termogênese. O gene responsável por sua produção é o gene ob/ob, que foi identificado em 1994 em camundongos. Atua, primariamente, no Sistema Nervoso Central, mais especificamente no núcleo arqueado do hipotálamo; além disso, tem mostrado diversos efeitos periféricos, pois seus receptores também estão presentes em outros tecidos. Estudos recentes têm confirmado a importância da leptina no coportamento sexual, reprodução, desenvolvimento do embrião e início da puberdade

Estudo do gene do receptor do neuropeptídeo Y-Y1 (NPY-Y1R) em pacientes com hipogonadismo hipogonadotrófico e puberdade precoce dependente de gonadotrofinas idiopáticos / Molecular analysis of the neuropeptide Y-Y1 receptor gene (NPY-Y1R) in patients with hypogonadism and gonadotropin-dependent precocious puberty

Para avaliar se mutações no gene do receptor do neuropeptídeo Y –Y1 (NPY-Y1R) estão associadas com variações na idade do início da puberdade humana, nós sequenciamos a região codificadora do NPY-Y1R em 55 pacientes com distúrbios puberais idiopáticos. Identificamos uma substituição do aminoácido lisina por treonina na posição 374 do NPY-Y1R em uma paciente com puberdade precoce dependente de gonadotrofinas familial. A introdução da mutação K374T em um vetor de expressão contendo o NPY-Y1R humano causou uma modesta redução da expressão do receptor na superfície celular e uma redução parcial do efeito inibitório do NPY na produção de AMPc. Em conclusão, nós identificamos uma mutação que inativa parcialmente o NPY-Y1R, podendo ter contribuído para a puberdade precoce humana / In order to establish if mutations in the neuropeptide Y-Y1 receptor gene (NPY-Y1R) could be responsible for alterations in the timing of human puberty, we investigated the entire coding region of the NPY-Y1R in 55 patients with idiopathic pubertal disorders. We identified a substitution of lysine by threonine at position 374 of the NPY-Y1R in one girl with familial gonadotropin-dependent precocious puberty. The introduction of the K374T mutation into an expression vector containing the human NPY-Y1R led to a modest decrease in cell surface expression of NPY-Y1R and it caused a partial reduction of the inhibitory effect of NPY on cAMP production in transfected cells. In conclusion, we have identified a mild inactivating mutation of the NPY-Y1R that may have contributed to human precocious puberty...

Antisense mRNA for NPY-Y1 receptor in the medial preoptic area increases prolactin secretion

We investigated the participation of neuropeptide Y-Y1 receptors within the medial preoptic area in luteinizing hormone, follicle-stimulating hormone and prolactin release. Four bilateral microinjections of sense (control) or antisense 18-base oligonucleotides of messenger ribonucleic acid (mRNA) (250 ng) corresponding to the NH2-terminus of the neuropeptide Y1 receptor were performed at 12-h intervals for two days into the medial preoptic area of ovariectomized Wistar rats (N = 16), weighing 180 to 200 g, treated with estrogen (50 µg) and progesterone (25 mg) two days before the experiments between 8.00 and 10:00 a.m. Blockade of Y1 receptor synthesis in the medial preoptic area by the antisense mRNA did not change plasma luteinizing hormone or follicle-stimulating hormone but did increase prolactin from 19.6 + or - 5.9 ng/ml in the sense group to 52.9 + or - 9.6 ng/ml in the antisense group. The plasma hormones were measured by radioimmunoassay and the values are reported as mean + or - SEM. These data suggest that endogenous neuropeptide Y in the medial preoptic area has an inhibitory action on prolactin secretion through Y1 receptors

Neuropéptide Y e psiquiatria / Neuropeptide Y and psychiatry

O mais abundante dos peptídeos neurotransmissores no encéfalo dos mamíferos, o neuropéptide Y, ou neuropéptide tirosina, foi identificado apenas em 1982. Constituído de 36 aminoácidos, apresenta poderosos e variaods efeitos centraise periféricos, incluindo açöes nas emoçöes, no comportamento ingestivo, na memória, em convulsöes, em respostas so estresse, na pressäo arterial, na contratilidade cardíaca, nas secreçöes intestinais e outras ainda. É particularmente relevante no controle da alimentaçäo, sendo a mais poderosa substância orexígena conhecida. Além de açäo direta, possui atividade de interaçäo com outros neurotransmissores, particularmente com a noradrenalina, com a somatostatina, com o óxido nítrico, com o glutamato e com a galanina. Até o momento, foram identificados 5 tipos de receptores para o neuropéptide Y. Drogas agonistas e antagonistas desses receptores poderiam ter lugar no tratamento de epilepsias, alteraçöes da memória e doença de Alzheimer, ansiedade, estresse e depressäo, drogadicçä e transtornos alimentares

Quantitative receptor radioautography in the study of receptor-receptor interactions in the nucleus tractus solitarii

The nucleus tractus solitarii (NTS) in the dorsomedial medulla comprises a wide range of neuropeptides and biogenic amines. Several of them are related to mechanism of central blood pressure control. Angiotensin II (Ang II), neuropeptide Y (NPY) and noradrenaline (NA) are found in the NTS cells, as well as their receptors. Based on this observation we have evaluated the modulatory effect of these peptide receptors on alpha2-adrenoceptors in the NTS. Using quantitative recptor radioautography, we observed that NPY and Ang II receptors decreased the affinity of alpha1-adrenoceptors for their agonists in the NTS of the rat. Cardiovascular experiments agreed with the in vitro data. Coinjection of a threshold dose of Ang II of the NPY agonists together with an ED50 dose of adrenergic agonists such as NA, adrenaline and clonidine counteracted the depressor effect produced by the alpha2-agonist in the NTS. The results provide evidence for the existence of an antagonistic interaction between Ang II AT1 receptors and NPY receptor subtypes with the alpha2-adrenoceptors in the NTS. This receptor interaction may reduce the transduction over the alpha2-adrenoceptors which can be important in central cardiovascular regulation and in the development of hypertension.

Lack of interaction of angiotensin converting enzyme inhibitors with muscarinic and neuropeptide Y receptors

In studies conducted in patients undergoing cardiac catheterizations, some hemodynamic changes were observed after the acute sublingual administration of the angiotensin converting enzyme inhibitors (ACEI) captopril, enalapril, and lisinopril. These changes consisted of an increase in pulmonary artery pressure, pulmonary vascular resistance (PVR) and induction of hypoxia. The pressure changes were transitory and disappeared after 25 min. The possible mechanisms involved in these changes may relate to interactions of the ACEI with peripheral receptor systems for hormones and neurotransmitters. We have thus undertaken the task of evaluating the potential effect of ACEI on biological receptor molecules. We have begun with studies on muscarinic receptors, and the recently characterized neuropeptide Y (NPY) receptors of endothelial cells. Equilibrium binding assays with 3H-QNB have been conducted for muscarinic receptors using rat brain synaptosomes, due to its expression of multiple muscarinic receptors subtypes. In addition 125BH-NPY binding assays were conducted on intact adrenal medullary endothelial cells. Enalapril and captopril, 10(-7) to 10(-3) M, were not able to produce significant inhibition of either muscarinic or NPY receptor probes. The paradoxical changes elicited by sublingual ACEI seems not to involve interaction with muscarinic or NPY receptors