Peptides (v.51, #C)
Gayle & Richard Olson prize pages (III-IV).
IFC (editorial board) (CO2).
Higher Orexin A levels in lumbar compared to ventricular CSF: A study in idiopathic normal pressure hydrocephalus by T. Kalamatianos; M. Markianos; K. Margetis; F. Bourlogiannis; G. Stranjalis (1-3).
Orexin A (ORX-A) is implicated in the regulation of various physiological processes, including sleep/wake cycles and reward/motivation. The hypothalamic ORX-A neurons project throughout the brain and spinal cord. In the present study we established and compared ORX-A levels in lumbar and ventricular cerebrospinal fluid (CSF) samples, drawn from idiopathic normal pressure hydrocephalus (INPH) patients, during respectively, lumbar puncture and shunt placement. Ventricular and lumbar CSF levels of total protein and of the dopamine, serotonin and norepinephrine metabolites HVA, 5-HIAA and MHPG respectively, were also estimated. ORX-A was quantified using a commercially available radioimmunoassay kit. Neurotransmitter metabolites were quantified by high performance liquid chromatography. Expectedly, HVA and 5-HIAA levels were significantly higher and total protein levels lower in ventricular compared to lumbar CSF while there were no differences in MHPG levels. However, in contrast to HVA and 5-HIAA and similar to total protein, lumbar ORX-A levels were significantly higher than ventricular levels. The higher lumbar compared to ventricular ORX-A levels may reflect elevated contributions from the spinal cord. The finding of a ventriculo-lumbar difference for ORX-A should be considered in studies utilizing its CSF levels in assessing Orexin system status.
Keywords: Orexin-A; Ventriculo-lumbar; Hydrocephalus; Cerebrospinal fluid;
Plasma copeptin levels are associated with prognosis of severe acute pancreatitis by Gao Sang; Jian-Min Du; Yong-Yi Chen; Yang-Bo Chen; Jun-Xian Chen; Yong-Can Chen (4-8).
Copeptin reflects the individual stress level, and is correlated with outcomes of critical illness. This study was designed to evaluate its relationship with disease severity, local complications, organ failure and mortality of severe acute pancreatitis (SAP). Seventy-eight SAP patients and 78 sex- and age-matched healthy individuals were recruited. Plasma samples were obtained on admission from SAP patients and at study entry from healthy individuals. Copeptin concentration was determined using enzyme-linked immunosorbent assay. Plasma copeptin level was obviously higher in patients than in healthy individuals, was identified as an independent predictor of local complications, organ failure and in-hospital mortality, was highly associated with traditional predictors of disease severity and mortality including the Acute Physiology and Chronic Health Care Evaluation II score, Ranson score, multiple organ dysfunction score, sequential organ failure assessment score, and predicted local complications, organ failure, and in-hospital mortality of SAP patients with high areas under receiver operating characteristic curve. Furthermore, its predictive value was similar to the traditional predictors’. However, it could not improve these traditional predictors’ predictive values. Therefore, increased plasma copeptin level is associated with disease severity and identified as a novel prognostic marker of local complications, organ failure and mortality after SAP.
Keywords: Copeptin; Severe acute pancreatitis; Prognosis; Biomarker;
Endogenous peptides as risk markers to assess the development of insulin resistance by Penghua Fang; Mingyi Shi; Mei Yu; Lili Guo; Ping Bo; Zhenwen Zhang (9-14).
Insulin resistance, the reciprocal of insulin sensitivity, is known to be a characteristic of type 2 diabetes mellitus, and is regarded as an important mechanism in the pathogenesis. The hallmark of insulin resistance is a gradual break-down of insulin-regulative glucose uptake by muscle and adipose tissues in subjects. Insulin resistance is increasingly estimated in various disease conditions to examine and assess their etiology, pathogenesis and consequences. Although our understanding of insulin resistance has tremendously been improved in recent years, certain aspects of its estimation and etiology still remain elusive to clinicians and researchers. There are numerous factors involved in pathogenesis and mechanisms of insulin resistance. Recent studies have provided compelling clues about some peptides and proteins, including galanin, galanin-like peptide, ghrelin, adiponectin, retinol binding protein 4 (RBP4) and CRP, which may be used to simplify and to improve the determination of insulin resistance. And alterations of these peptide levels may be recognized as risk markers of developing insulin resistance and type 2 diabetes mellitus. This review examines the updated information for these peptides, highlighting the relations between these peptide levels and insulin resistance. The plasma high ghrelin, RBP4 and CRP as well as low galanin, GALP and adiponectin levels may be taken as the markers of deteriorating insulin resistance. An increase in the knowledge of these marker proteins and peptides will help us correctly diagnose and alleviate insulin resistance in clinic and study.
Keywords: Peptides; Insulin resistance; Type 2 diabetes;
Involvement of multiple μ-opioid receptor subtypes on the presynaptic or postsynaptic inhibition of spinal pain transmission by Hirokazu Mizoguchi; Hirokazu Takagi; Chizuko Watanabe; Akihiko Yonezawa; Takumi Sato; Tsukasa Sakurada; Shinobu Sakurada (15-25).
The involvement of the μ-opioid receptor subtypes on the presynaptic or postsynaptic inhibition of spinal pain transmission was characterized in ddY mice using endomorphins. Intrathecal treatment with capsaicin, N-methyl-d-aspartate (NMDA) or substance P elicited characteristic nociceptive behaviors that consisted primarily of vigorous biting and/or licking with some scratching. Intrathecal co-administration of endogenous μ-opioid peptide endomorphin-1 or endomorphin-2 resulted in a potent antinociceptive effect against the nociceptive behaviors induced by capsaicin, NMDA or substance P, which was eliminated by i.t. co-administration of the μ-opioid receptor antagonist D-Phe-Cys-Tyr-D-Trp-Orn-Thr-Pen-Thr-NH2 (CTOP). The antinociceptive effect of endomorphin-1 was significantly suppressed by i.t.-co-administration of the μ2-opioid receptor antagonist Tyr-D-Pro-Trp-Phe-NH2 (D-Pro2-endomorphin-1) but not the μ1-opioid receptor antagonist Tyr-D-Pro-Phe-Phe-NH2 (D-Pro2-endomorphin-2) on capsaicin- or NMDA-elicited nociceptive behaviors. In contrast, the antinociceptive effect of endomorphin-2 was significantly suppressed by i.t.-co-administration of D-Pro2-endomorphin-2 but not D-Pro2-endomorphin-1 on capsaicin-, NMDA- or substance P-elicited nociceptive behaviors. Interestingly, regarding substance P-elicited nociceptive behaviors, the antinociceptive effect of endomorphin-1 was significantly suppressed by i.t.-co-administration of another μ2-opioid receptor antagonist, Tyr-D-Pro-Trp-Gly-NH2 (D-Pro2-Tyr-W-MIF-1), but not D-Pro2-endomorphin-1 or D-Pro2-endomorphin-2. The present results suggest that the multiple μ-opioid receptor subtypes are involved in the presynaptic or postsynaptic inhibition of spinal pain transmission.
Keywords: Endomorphins; Antinociception; μ-Opioid receptors; NMDA receptors; NK1 receptors; Nociceptive behaviors; Spinal cord;
Angiotensin 1–7 improves insulin sensitivity by increasing skeletal muscle glucose uptake in vivo by Omar Echeverría-Rodríguez; Leonardo Del Valle-Mondragón; Enrique Hong (26-30).
The renin–angiotensin system (RAS) regulates skeletal muscle insulin sensitivity through different mechanisms. The overactivation of the ACE (angiotensin-converting enzyme)/Ang (angiotensin) II/AT1R (Ang II type 1 receptor) axis has been associated with the development of insulin resistance, whereas the stimulation of the ACE2/Ang 1–7/MasR (Mas receptor) axis improves insulin sensitivity. The in vivo mechanisms by which this axis enhances skeletal muscle insulin sensitivity are scarcely known. In this work, we investigated whether rat soleus muscle expresses the ACE2/Ang 1–7/MasR axis and determined the effect of Ang 1–7 on rat skeletal muscle glucose uptake in vivo. Western blot analysis revealed the expression of ACE2 and MasR, while Ang 1–7 levels were detected in rat soleus muscle by capillary zone electrophoresis. The euglycemic clamp exhibited that Ang 1–7 by itself did not promote glucose transport, but it increased insulin-stimulated glucose disposal in the rat. In a similar manner, captopril (an ACE inhibitor) enhanced insulin-induced glucose uptake and this effect was blocked by the MasR antagonist A-779. Our results show for the first time that rat soleus muscle expresses the ACE2/Ang 1–7/MasR axis of the RAS, and Ang 1–7 improves insulin sensitivity by enhancing insulin-stimulated glucose uptake in rat skeletal muscle in vivo. Thus, endogenous (systemic and/or local) Ang 1–7 could regulate insulin-mediated glucose transport in vivo.
Keywords: Renin–angiotensin system (RAS); Angiotensin-converting enzyme 2 (ACE2); Angiotensin 1–7; Mas receptor; Skeletal muscle; Glucose uptake;
Individual plasma ghrelin changes in the same patients in hyperthyroid, hypothyroid and euthyroid state by Marek Ruchala; Edyta Gurgul; Adam Stangierski; Elzbieta Wrotkowska; Jerzy Moczko (31-34).
Ghrelin is a multifunctional peptide of widespread expression. Since it has been shown to influence energy homeostatis, its potential role in thyroid dysfunction may have clinical significance. In this study, plasma ghrelin changes have been analyzed in the same patients in three different thyroid states for the first time. The study group consisted of 16 patients who had been diagnosed with hyperthyroidism, were treated with radioiodine, developed hypothyroidism after treatment, and finally became euthyroid on l-thyroxine substitution. In the initial state of hyperthyroidism plasma ghrelin levels correlated negatively with fT3 and fT4. In hypothyroidism ghrelin concentration increased significantly (p < 0.05). Although the mean value of plasma ghrelin tended to decrease in the euthyroid state, the individual difference between hypothyroidism and euthyroidism was not significant. Plasma ghrelin in euthyroidism was still significantly higher than in hyperthyroidism (p < 0.05), and correlated positively with ghrelin levels in hyperthyroidism and hypothyroidism. In our opinion, plasma ghrelin fluctuations may reflect metabolic changes in patients with thyroid dysfunction. Moreover, it cannot be excluded that in thyroid disorders ghrelin acts as a compensatory factor, helping to balance metabolic disturbances.
Keywords: Ghrelin; Hyperthyroidism; Hypothyroidism; Thyroid dysfunction; Metabolism;
Scorpion venom peptides with no disulfide bridges: A review by Ammar Almaaytah; Qosay Albalas (35-45).
Scorpion venoms are rich sources of biologically active peptides that are classified into disulfide-bridged peptides (DBPs) and non-disulfide-bridged peptides (NDBPs). DBPs are the main scorpion venom components responsible for the neurotoxic effects observed during scorpion envenomation as they usually target membrane bound ion channels of excitable and non-excitable cells. Several hundred DBPs have been identified and functionally characterized in the past two decades. The NDBPs represent a novel group of molecules that have gained great interest only recently due to their high diversity both in their primary structures and bioactivities. This review provides an overview of scorpion NDBPs focusing on their therapeutic applications, modes of discovery, mechanisms of NDBPs genetic diversity and structural properties. It also provides a simple classification for NDBPs that could be adopted and applied to other NDBPs identified in future studies.
Keywords: Scorpion; Venom; Non-disulfide-bridged peptides; NDBPs; Antimicrobial; Anticancer; Structural properties; Classification;
Obesity and chronic stress are able to desynchronize the temporal pattern of serum levels of leptin and triglycerides by Carla de Oliveira; Vanessa Leal Scarabelot; Andressa de Souza; Cleverson Moraes de Oliveira; Liciane Fernandes Medeiros; Isabel Cristina de Macedo; Paulo Ricardo Marques Filho; Stefania Giotti Cioato; Wolnei Caumo; Iraci L.S. Torres (46-53).
Disruption of the circadian system can lead to metabolic dysfunction as a response to environmental alterations. This study assessed the effects of the association between obesity and chronic stress on the temporal pattern of serum levels of adipogenic markers and corticosterone in rats. We evaluated weekly weight, delta weight, Lee index, and weight fractions of adipose tissue (mesenteric, MAT; subcutaneous, SAT; and pericardial, PAT) to control for hypercaloric diet-induced obesity model efficacy. Wistar rats were divided into four groups: standard chow (C), hypercaloric diet (HD), stress plus standard chow (S), and stress plus hypercaloric diet (SHD), and analyzed at three time points: ZT0, ZT12, and ZT18. Stressed animals were subjected to chronic stress for 1 h per day, 5 days per week, during 80 days. The chronic exposure to a hypercaloric diet was an effective model for the induction of obesity and metabolic syndrome, increasing delta weight, Lee index, weight fractions of adipose tissue, and triglycerides and leptin levels. We confirmed the presence of a temporal pattern in the release of triglycerides, corticosterone, leptin, and adiponectin in naïve animals. Chronic stress reduced delta weight, MAT weight, and levels of triglycerides, total cholesterol, and leptin. There were interactions between chronic stress and obesity and serum total cholesterol levels, between time points and obesity and adiponectin and corticosterone levels, and between time points and chronic stress and serum leptin levels. In conclusion, both parameters were able to desynchronize the temporal pattern of leptin and triglyceride release, which could contribute to the development of metabolic diseases such as obesity and metabolic syndrome.
Keywords: Temporal pattern; Obesity; Metabolic syndrome; Hypercaloric diet; Chronic stress;
Enhanced levels of immunoreactive β-casomorphin-8 in milk of breastfeeding women with mastitis by Lennart Righard; Anna Carlsson-Jonsson; Fred Nyberg (54-58).
An incorrect, superficial suckling technique in breastfeeding frequently leads to milk congestion and sometimes mastitis. In the present study we have examined whether milk congestion may affect levels of the atypical opioid β-casomorphin-8 in milk and in plasma. We also investigated whether the rate of acute psychosis during the first half year after parturition has declined in Sweden over the years. Milk and plasma samples were collected for peptide analysis from 14 women with mastitis and 10 controls. We found that in a group of 14 late cases of mastitis (median 48 days post partum) the detected mean level of β-casomorphin-8 in milk was significantly higher and somewhat higher in plasma at the acute stage compared with 2–3 weeks later, after recovery when the symptoms had disappeared, as well as compared to the control subjects. Swedish official statistics show that the incidence of acute psychosis in the first month and in the first half year after birth has declined by a half during the last 30 years. A relationship between postpartum psychosis and elevated β-casomorphin-8 levels in CSF has been suggested from earlier studies. In this study, milk congestion led to enhanced levels of β-casomorphin-8 in milk, which may be related to postpartum psychosis and probably also to ‘the postnatal blues’.
Keywords: Atypical opioids; β-Casomorphins; Lactation; Radioimmunoassay; Mastitis; Postpartum psychosis;
Stimulation of corticotropin-releasing factor gene expression by FosB in rat hypothalamic 4B cells by Kazunori Kageyama; Keiichi Itoi; Yasumasa Iwasaki; Kanako Niioka; Yutaka Watanuki; Satoshi Yamagata; Yuki Nakada; Gopal Das; Toshihiro Suda; Makoto Daimon (59-64).
The Fos- and Jun family proteins are immediate-early gene products, and the Fos/Jun heterodimer, activator protein-1 (AP-1), may be involved in the regulation of corticotropin-releasing factor (CRF) gene expression. FosB is a member of the Fos family proteins that is expressed in the paraventricular nucleus of the hypothalamus upon stress exposure, but it has not been clear whether FosB participates in the regulation of CRF gene expression. This study aimed to explore the effect of the FosB and cJun proteins on CRF gene expression in rat hypothalamic 4B cells. The levels of FosB mRNA and cJun mRNA increased following treatment with forskolin, phorbol-12-myristate-13-acetate (PMA), or A23187 in the hypothalamic cells. Overexpression of FosB or cJun potently increased CRF mRNA levels. Furthermore, downregulation of FosB or cJun suppressed the CRF gene expression induced by forskolin, PMA, or A23187. In addition, the basal CRF mRNA levels were partially reduced by cJun downregulation. These findings suggest that FosB, together with cJun, may mediate CRF gene expression in the hypothalamic cells.
Keywords: Corticotropin-releasing factor; FosB; Jun; Hypothalamus; Stress;
An orally active angiotensin-(1–7) inclusion compound and exercise training produce similar cardiovascular effects in spontaneously hypertensive rats by Mariane Bertagnolli; Karina R. Casali; Frederico B. De Sousa; Katya Rigatto; Lenice Becker; Sergio H.S. Santos; Lucinara D. Dias; Graziela Pinto; Daniela R. Dartora; Beatriz D. Schaan; Ruben Dario Sinisterra Milan; Maria Claudia Irigoyen; Robson A.S. Santos (65-73).
Low angiotensin-(1–7) (Ang-(1–7)) concentration is observed in some cardiovascular diseases and exercise training seems to restore its concentration in the heart. Recently, a novel formulation of an orally active Ang-(1–7) included in hydroxy-propyl-beta-cyclodextrin (HPB-CD) was developed and chronically administered in experimental models of cardiovascular diseases. The present study examined whether chronic administration of HPB-CD/Ang-(1–7) produces beneficial cardiovascular effects in spontaneously hypertensive rats (SHR), as well as to compare the results obtained with those produced by exercise training. Male SHR (15-week old) were divided in control (tap water) or treated with HPB-CD/Ang-(1–7) (corresponding to 30 μg kg−1 day−1 of Ang-(1–7)) by gavage, concomitantly or not to exercise training (treadmill, 10 weeks). After chronic treatment, hemodynamic, morphometric and molecular analysis in the heart were performed. Chronic HPB-CD/Ang-(1–7) decreased arterial blood pressure (BP) and heart rate in SHR. The inclusion compound significantly improved left ventricular (LV) end-diastolic pressure, restored the maximum and minimum derivatives (dP/dT) and decreased cardiac hypertrophy index in SHR. Chronic treatment improved autonomic control by attenuating sympathetic modulation on heart and vessels and the SAP variability, as well as increasing parasympathetic modulation and HR variability. Overall results were similar to those obtained with exercise training. These results show that chronic treatment with the HPB-CD/Ang-(1–7) inclusion compound produced beneficial effects in SHR resembling the ones produced by exercise training. This observation reinforces the potential cardiovascular therapeutic effect of this novel peptide formulation.
Keywords: Hypertension; Renin–angiotensin system; Exercise training; Cardiac function; Autonomic control;
Stimulatory effect of ghrelin on food intake in bullfrog larvae by Shunsuke Shimizu; Hiroyuki Kaiya; Kouhei Matsuda (74-79).
Ghrelin is a potent orexigenic peptide implicated in appetite regulation in rodents. However, except for teleost fish, the involvement of ghrelin in the regulation of feeding in non-mammalian vertebrates has not been well studied. Anuran amphibian larvae feed and grow during the pre- and prometamorphic stages, but, thereafter they stop feeding as the metamorphic climax approaches. Therefore, orexigenic factors seem to play important roles in growing larvae. In the present study, we examined the effect of intraperitoneal (IP) or intracerebroventricular (ICV) administration of synthetic bullfrog ghrelin (n-octanoylated 28-amino acid form) on food intake in larvae at the prometamorphic stages. Cumulative food intake was significantly increased by IP (8 and 16 pmol/g body weight (BW)) or ICV (0.5 and 1 pmol/g BW) administration of ghrelin during a 15-min observation period. The orexigenic action of ghrelin at 8 pmol/g BW (IP) or at 0.5 pmol/g BW (ICV) was blocked by treatment with a growth hormone secretagogue-receptor antagonist, [D-Lys3]GHRP-6 at 80 pmol/g BW (IP) or at 5 pmol/g BW (ICV). We then investigated the effect of feeding status on expression levels of the ghrelin transcript in the hypothalamus and gastrointestinal tract. Ghrelin mRNA levels in both were decreased 15 and 60 min after feeding. These results indicate that ghrelin acts as an orexigenic factor in bullfrog larvae.
Keywords: Bullfrog; Prometamorphic larvae; Ghrelin; Ghrelin mRNA; Food intake; Orexigenic action; GHS receptor; GHS receptor antagonist;
Salivary adiponectin levels are associated with training intensity but not with bone mass or reproductive function in elite Rhythmic Gymnasts by Nikolaos D. Roupas; Laurent Maïmoun; Irene Mamali; Olivier Coste; Alexandra Tsouka; Krishna Kunal Mahadea; Thibault Mura; Pascal Philibert; Laura Gaspari; Denis Mariano-Goulart; Michel Leglise; Charles Sultan; Neoklis A. Georgopoulos (80-85).
Elite Rhythmic Gymnasts (RGs) constitute a unique metabolic model and they are prone to developing Anorexia Athletica. The aim of the present study was to evaluate the effect of training intensity on salivary adiponectin levels and assess a possible role of salivary adiponectin levels as a predictive factor of reproductive dysfunction and bone mass acquisition in elite RGs. The study included 80 elite female RGs participating in the World Rhythmic Gymnastics Championship tournament held in Montpellier, France on September 2011. Anthropometric values were assessed, training data and menstrual pattern were recorded, bone mass was measured with Broadband ultrasound attenuation (dB/Mhz) and baseline salivary adiponectin levels were determined. The athletes were classified as intensely and very intensely trained, considering the mean training intensity (40.84 h/week). Moreover, considering their reproductive status, they were divided into RG's with normal menstruation, primary amenorrhea and oligomenorrhea. All comparisons were adjusted to age, BMI and body fat percentage differences. Very intensely trained RGs showed higher salivary adiponectin levels (p = 0.05). Moreover, salivary adiponectin levels showed significant correlation with training intensity (r = 0.409, p = 0.003). On the other hand, no association of salivary adiponectin levels was documented with either reproductive function or bone mass acquisition. The results of the present study suggest that, in elite RGs, salivary adiponectin levels are associated with the intensity of training, possibly reflecting the deterioration of energy balance rather than the training stress. On the other hand, a predictive role of salivary adiponectin levels in reproductive dysfunction or bone mass acquisition could not be supported.
Keywords: Adiponectin; Saliva; Intense training; Gymnasts; Bone mass; Menstrual function;
Preoperative serum visfatin levels and prognosis of breast cancer among Chinese women by Xiao-Yang Li; Shao-Hua Tang; Xiao-Cong Zhou; Ying-Hai Ye; Xue-Qin Xu; Ri-Zeng Li (86-90).
Visfatin is identified a pro-inflammatory cytokine and its serum level is increased in various cancers. This study aimed to evaluate the prognostic value of preoperative serum visfatin level in breast cancers. Preoperative serum visfatin levels of 248 patients with breast cancer and serum visfatin levels of 100 healthy individuals and 100 benign women controls were determined using enzyme-linked immunosorbent assay. Unfavorable outcome was defined as first local recurrence, distant metastasis, second primary cancer of another organ, or death from any cause. Disease-free survival was defined as the time between surgery and the date of unfavorable outcome whichever appeared first. Overall survival was defined from surgery to death for any cause. The association of serum visfatin level with outcomes including mortality, unfavorable outcome, disease-free survival and overall survival was investigated by univariate and multivariate analyses. Preoperative serum visfatin level was substantially higher in patients than in healthy subjects and benign controls respectively. Elevated preoperative serum level of visfatin was identified an independent predictor of mortality, unfavorable outcome, disease-free survival and overall survival. Receiver operating characteristic curve analysis showed that serum level visfatin had high predictive value for mortality and unfavorable outcome. Thus, our results suggest that high preoperative serum visfatin level is associated with poor patient outcomes as well as may play a role as prognostic biomarker in breast cancer survival.
Keywords: Visfatin; Breast cancer; Prognosis; Biomarker;
Human BRS-3 receptor: Functions/role in cell signaling pathways and glucose metabolism in obese or diabetic myocytes by I. Ramos-Álvarez; Z. Moreno-Villegas; A. Martín-Duce; R. Sanz; C. Aparicio; S. Portal-Núñez; S.A. Mantey; R.T. Jensen; N. González (91-99).
Several studies showed that the orphan Bombesin Receptor Subtype-3 (BRS-3) – member of the bombesin receptor family – has an important role in glucose homeostasis (v.g.: BRS-3-KO mice developed mild obesity, and decreased levels of BRS-3 mRNA/protein have been described in muscle from obese (OB) and type 2 diabetic (T2D) patients). In this work, to gain insight into BRS-3 receptor cell signaling pathways, and its implication on glucose metabolism, primary cultured myocytes from normal subjects, OB or T2D patients were tested using high affinity ligand – [d-Tyr6,β-Ala11,Phe13,Nle14]bombesin6–14. In muscle cells from all metabolic conditions, the compound significantly increased not only MAPKs, p90RSK1, PKB and p70s6K phosphorylation levels, but also PI3K activity; moreover, it produced a dose–response stimulation of glycogen synthase a activity and glycogen synthesis. Myocytes from OB and T2D patients were more sensitive to the ligand than normal, and T2D cells even more than obese myocytes. These results widen the knowledge of human BRS-3 cell signaling pathways induced by a BRS-3 agonist, described its insulin-mimetic effects on glucose metabolism, showed the role of BRS-3 receptor in glucose homeostasis, and also propose the employing of BRS-3/ligand system, as participant in the obese and diabetic therapies.
Keywords: BRS-3 human muscle; Signaling; Glucose metabolism; Diabetes; Obesity;
Enhanced expression of neuropeptide S (NPS) receptor in eosinophils from severe asthmatics and subjects with total IgE above 100 IU/ml by Pinja Ilmarinen; Anna James; Eeva Moilanen; Ville Pulkkinen; Kameran Daham; Seppo Saarelainen; Tarja Laitinen; Sven-Erik Dahlén; Juha Kere; Barbro Dahlén; Hannu Kankaanranta (100-109).
Eosinophils are inflammatory cells of particular relevance to asthma exacerbations. Neuropeptide S (NPS) receptor was identified in a search for asthma susceptibility genes, where the risk haplotypes of the NPS receptor gene associated with total serum IgE above 100 IU/ml and asthma. The aim of the present study was to investigate and compare expression of NPS receptor in human peripheral blood eosinophils derived from subjects with total serum IgE above and below 100 IU/ml and patients with different phenotypes of asthma. Additionally, we aimed to study the function of NPS receptor in human eosinophils. We found higher NPS receptor protein expression in eosinophils derived from subjects with high IgE when compared to those from subjects with low IgE and the level of NPS receptor positively correlated with serum IgE. NPS receptor expression was also higher in eosinophils from patients with severe asthma than in cells from mild asthmatics or healthy controls. The receptor agonist NPS was a chemotactic agent for eosinophils. NPS also increased N-formyl-methionyl-leucyl-phenylalanine (fMLP)-stimulated CD11b integrin levels in eosinophils from subjects with high IgE. Furthermore, eosinophils from those subjects exhibited Ca2+ mobilization but not cAMP rise in response to NPS. Altogether, NPS receptor may have a pathological role in individuals with severe asthma and/or elevated serum IgE levels as eosinophils from these patients express higher levels of NPS receptor protein and respond to NPS by enhanced migration and adhesion molecule expression.
Keywords: NPS; NPS receptor; asthma; eosinophils; IgE; CD11b; chemotaxis; calcium; cAMP;
Peripheral oxytocin treatment affects the rat adreno-medullary catecholamine content modulating expression of vesicular monoamine transporter 2 by P. Jovanovic; N. Spasojevic; B. Stefanovic; N. Bozovic; N. Jasnic; J. Djordjevic; S. Dronjak (110-114).
The neuropeptide oxytocin has been shown to influence on neuroendocrine function. The aim of the present study was to investigate the effect of peripheral oxytocin treatment on the synthesis, uptake and content of adreno-medullary catecholamine. For this purpose oxytocin (3.6 μg/100 g body weight, s.c) was administrated to male rats once a day over 14 days. In order to assess the effect of peripheral oxytocin treatment on adreno-medullary catecholamine we measured epinephrine and norepinephrine content and gene expression of tyrosine hydroxylase (TH), norepinephrine transporter (NET) and vesicular monoamine transporter 2 (VMAT2) in the adrenal medulla. Our results show a significant increase of epinephrine (1.7-fold, p < 0.05) and norepinephrine (1.5-fold, p < 0.05) content in oxytocin treated animals compared to saline treated ones. Oxytocin treatment had no effect either on mRNA or protein level of TH and NET. Under oxytocin treatment the increase in VMAT2 mRNA level was not statistically significant, but it caused a significant increase in protein level of VMAT2 (3.7-fold, p < 0.001). These findings indicate that oxytocin treatment increases catecholamine content in the rat adrenal medulla modulating VMAT2 expression.
Keywords: Oxytocin; Adrenal-medulla; Epinephrine; Norepinephrine; Vesicular monoamine transporter 2;
Peripheral chemerin administration modulates hypothalamic control of feeding by Luigi Brunetti; Giustino Orlando; Claudio Ferrante; Lucia Recinella; Sheila Leone; Annalisa Chiavaroli; Chiara Di Nisio; Rugia Shohreh; Fabio Manippa; Adriana Ricciuti; Michele Vacca (115-121).
Chemerin is a recently identified adipokine that is involved in the regulation of adipogenesis, energy metabolism, and inflammation. The aim of the present study was to investigate the role of chemerin on food intake, body weight and hypothalamic peptidergic and aminergic modulators which play a pivotal role in feeding regulation in rats. Male adult Wistar rats were intraperitoneally injected, daily for 17 days at 9.00 am, with either vehicle (saline; N = 12) or chemerin (8 μg/kg; N = 12) and (16 μg/kg; N = 12). Food intake was recorded 24 h after each administration. Animals were sacrificed 24 h after the last injection. Total RNA was extracted from hypothalami and reverse transcribed to evaluate gene expression of agouti-related peptide (AgRP), neuropeptide Y (NPY), orexin-A, corticotrophin releasing hormone (CRH), pro-opiomelanocortin (POMC) and cocaine and amphetamine-regulated transcript (CART). Furthermore, we evaluated the effect of chemerin on dopamine, norepinephrine and serotonin steady state concentrations in rat hypothalamus homogenate, and monoamine release from rat hypothalamic synaptosomes. Chemerin administration (8 and 16 μg/kg) decreased both food intake and body weight compared to vehicle, possibly associated with a significant increase in serotonin synthesis and release, in the hypothalamus. On the other hand, the pattern of gene expression following chemerin administration indicates a minor role played by chemerin as a peripheral appetite-regulating signal.
Keywords: Agouti-related peptide; Chemerin; Feeding; Orexin A; Serotonin;
Peptide diversity in the venom of the social wasp Polybia paulista (Hymenoptera): A comparison of the intra- and inter-colony compositions by Nathalia Baptista Dias; Bibiana Monson de Souza; Paulo Cesar Gomes; Mario Sergio Palma (122-130).
The venoms of the social wasps evolved to be used as defensive tools to protect the colonies of these insects against the attacks of predators. Previous studies estimated the presence of a dozen peptide components in the venoms of each species of these insects, which altogether comprise up to 70% of the weight of freeze-dried venoms. In the present study, an optimized experimental protocol is reported that utilizes liquid chromatography coupled to electrospray ionization mass spectrometry for the detection of peptides in the venom of the social wasp Polybia paulista; peptide profiles for both intra- and inter-colonial comparisons were obtained using this protocol. The results of our study revealed a surprisingly high level of intra- and inter-colonial variability for the same wasp species. We detected 78–108 different peptides in the venom of different colonies of P. paulista in the molar mass range from 400 to 3000 Da; among those, only 36 and 44 common peptides were observed in the inter- and intra-colony comparisons, respectively.
Keywords: Polybia paulista; Venomics; Venom toxin; Peptide toxin; LC/MS;
Increased serum chemerin level promotes cellular invasiveness in gastric cancer: A clinical and experimental study by Chunhu Wang; William K.K. Wu; Xiaodong Liu; Kai-Fa To; Gong G. Chen; Jun Yu; Enders K.W. Ng (131-138).
This study sought to determine the serum levels of chemerin in gastric cancer patients and healthy subjects and to investigate the biological effect of chemerin on gastric cancer cells. Serum chemerin level of 36 gastric cancer patients and 40 healthy subjects was measured by enzyme-linked immunosorbent assay. AGS and MKN28 cells were treated with recombinant human chemerin, MAPKs phosphorylation was then measured. Chemerin were added to culture medium of AGS and MKN28 in the absence or presence of MAPK inhibitors, VEGF, MMP-7, IL-6 and cell invasiveness assay were then performed. Serum level of chemerin was significantly higher in gastric cancer patients than healthy subjects (P < 0.01). The elevation of serum chemerin level was associated with advanced clinical stages and nonintestinal type of gastric cancer. Chemerin increased invasiveness of gastric cancer cells. Chemerin induced phosphorylation of p38 and ERK1/2 MAPKs and upregulated VEGF, MMP-7 and IL-6. Inhibition of ERK1/2 phosphorylation abolished the upregulation of VEGF, MMP-7 and IL-6 and the pro-invasive effect of chemerin. This study demonstrates a novel action of chemerin in gastric carcinogenesis.
Keywords: Chemerin; Adipokine; Gastric cancer; Invasiveness; MAPK;
Urocortin1-induced anorexia is regulated by activation of the serotonin 2C receptor in the brain by Yumi Harada; Kiyoshige Takayama; Shoki Ro; Mitsuko Ochiai; Masamichi Noguchi; Seiichi Iizuka; Tomohisa Hattori; Koji Yakabi (139-144).
This study was conducted to determine the mechanisms by which serotonin (5-hydroxytryptamine, 5-HT) receptors are involved in the suppression of food intake in a rat stress model and to observe the degree of activation in the areas of the brain involved in feeding. In the stress model, male Sprague–Dawley rats (8 weeks old) were given intracerebroventricular injections of urocortin (UCN) 1. To determine the role of the 5-HT2c receptor (5-HT2cR) in the decreased food intake in UCN1-treated rats, specific 5-HT2cR or 5-HT2b receptor (5-HT2bR) antagonists were administered. Food intake was markedly reduced in UCN1-injected rats compared with phosphate buffered saline treated control rats. Intraperitoneal administration of a 5-HT2cR antagonist, but not a 5-HT2bR antagonist, significantly inhibited the decreased food intake. To assess the involvement of neural activation, we tracked the expression of c-fos mRNA as a neuronal activation marker. Expression of the c-fos mRNA in the arcuate nucleus, ventromedial hypothalamic nucleus (VMH) and rostral ventrolateral medulla (RVLM) in UNC1-injected rats showed significantly higher expression than in the PBS-injected rats. Increased c-fos mRNA was also observed in the paraventricular nucleus (PVN), the nucleus of the solitary tract (NTS), and the amygdala (AMG) after injection of UCN1. Increased 5-HT2cR protein expression was also observed in several areas. However, increased coexpression of 5-HT2cR and c-fos was observed in the PVN, VMH, NTS, RVLM and AMG. Whereas, pro-opiomelanocortin mRNA expression was not changed. In an UNC1-induced stress model, 5-HT2cR expression and activation was found in brain areas involved in feeding control.
Keywords: Stress; Anorexia; 5-HT2cR; Activation; CRF neuron; Food intake;
Intravenous infusion of gastrin-releasing peptide-27 and bombesin in rats reveals differential effects on meal size and intermeal interval length by Martha C. Washington; Sarah Salyer; Amnah H. Aglan; Ayman I. Sayegh (145-149).
We have previously shown that the intraperitoneal (i.p.) administration of gastrin-releasing peptide-27 (GRP-27) or bombesin (BN) (at 0.21, 0.41 and 1.03 nmol/kg) reduces meal size (MS) and prolongs the intermeal interval (IMI). Here, we hypothesized that the intravenous (i.v.) administration of the same doses of GRP-27 and BN will be as effective as the i.p. administration in evoking these feeding responses. To test this hypothesis, we administered GRP-27 and BN i.v. and measured first MS (10% sucrose), IMI, satiety ratio (SR, IMI/MS) and second MS in overnight food-deprived but not water-deprived male Sprague Dawley rats. We found that (1) only GRP-27 reduced the first MS, (2) BN prolonged the IMI, (3) GRP-27 and BN increased the SR and (4) only BN reduced the size of the second meal. Contrary to our hypothesis, the i.v. administration of GRP-27 and BN affected the MS and IMI differently than did the i.p. administration. In conclusion, this pharmacological study suggests that the MS and IMI are regulated at different sites.
Keywords: Gastrin-releasing peptide; GRP; Bombesin; Meal size; Intermeal interval; Gastrointestinal tract;