title: Peripheral injection of bombesin induces c-Fos in NUCB2/nesfatin-1 neurons.
abstract: As anorexigenic hormones bombesin and nucleobindin2 (NUCB2)/nesfatin-1 decrease food intake in rodents. Both hormones have been described in brain nuclei that play a role in the modulation of hunger and satiety, like the paraventricular nucleus of the hypothalamus (PVN) and the nucleus of the solitary tract (NTS). However, the direct interaction of the two hormones is unknown so far. The aim of study was to elucidate whether bombesin directly interacts with NUCB2/nesfatin-1 neurons in the PVN and NTS. Therefore, we injected bombesin intraperitoneally (ip) at two doses (26 and 32nmol/kg body weight) and assessed c-Fos activation in the PVN, arcuate nucleus (ARC) and NTS compared to vehicle treated rats (0.15M NaCl). We also performed co-localization studies with oxytocin or tyrosine hydroxylase. Bombesin at both doses increased the number of c-Fos positive neurons in the PVN (p<0.05) and NTS (p<0.05) compared to vehicle, while in the ARC no modulation was observed (p>0.05). In the PVN and NTS the number of c-Fos positive neurons colocalized with NUCB2/nesfatin-1 increased after bombesin injection compared to vehicle treatment (p<0.05). Moreover, an increase of activated NUCB2/nesfatin-1 immunoreactive neurons that co-expressed oxytocin in the PVN (p<0.05) or tyrosine hydroxylase in the NTS (p<0.05) was observed compared to vehicle. Our results show that peripherally injected bombesin activates NUCB2/nesfatin-1 neurons in the PVN and NTS giving rise to a possible interaction between bombesin and NUCB2/nesfatin-1 in the modulation of food intake.
authors.affiliation: Charité Center for Internal Medicine and Dermatology, Department of Psychosomatic Medicine, Charité - Universitätsmedizin Berlin, Germany.
authors.forename: Kim-Marie
authors.initials: KM
authors.lastname: Engster
authors.affiliation: Charité Center for Internal Medicine and Dermatology, Department of Psychosomatic Medicine, Charité - Universitätsmedizin Berlin, Germany.
authors.forename: Arthur L
authors.initials: AL
authors.lastname: Kroczek
authors.affiliation: Charité Center for Internal Medicine and Dermatology, Department of Psychosomatic Medicine, Charité - Universitätsmedizin Berlin, Germany.
authors.forename: Matthias
authors.initials: M
authors.lastname: Rose
authors.affiliation: Charité Center for Internal Medicine and Dermatology, Department of Psychosomatic Medicine, Charité - Universitätsmedizin Berlin, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Stengel
authors.affiliation: Charité Center for Internal Medicine and Dermatology, Department of Psychosomatic Medicine, Charité - Universitätsmedizin Berlin, Germany. Electronic address: peter.kobelt@charite.de.
authors.forename: Peter
authors.initials: P
authors.lastname: Kobelt
mesh_terms: D000818:Animals; D001111:Arcuate Nucleus of Hypothalamus / Q000378:metabolism; D001839:Bombesin / Q000378:metabolism* / Q000502:physiology; D002135:Calcium-Binding Proteins / Q000378:metabolism* / Q000502:physiology; D004268:DNA-Binding Proteins / Q000378:metabolism* / Q000502:physiology; D004435:Eating / Q000502:physiology*; D007031:Hypothalamus / Q000378:metabolism; D008297:Male; D009419:Nerve Tissue Proteins / Q000378:metabolism* / Q000502:physiology; D009474:Neurons / Q000378:metabolism; D000080866:Nucleobindins; D010121:Oxytocin; D010286:Paraventricular Hypothalamic Nucleus / Q000378:metabolism; D016760:Proto-Oncogene Proteins c-fos / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D017552:Solitary Nucleus / Q000378:metabolism; D014446:Tyrosine 3-Monooxygenase
chemical_list: D002135:Calcium-Binding Proteins; D004268:DNA-Binding Proteins; D009419:Nerve Tissue Proteins; C000630652:Nucb1 protein, rat; D000080866:Nucleobindins; D016760:Proto-Oncogene Proteins c-fos; D010121:Oxytocin; D014446:Tyrosine 3-Monooxygenase; D001839:Bombesin
keywords: Brain-gut-axis, food intake, hypothalamus, nucleus of the solitary tract; Paraventricular nucleus; Rat