scholarly journals Anxiogenic and Stressor Effects of the Hypothalamic Neuropeptide RFRP-3 Are Overcome by the NPFFR Antagonist GJ14

Endocrinology ◽  
2015 ◽  
Vol 156 (11) ◽  
pp. 4152-4162 ◽  
Author(s):  
Joon S. Kim ◽  
Phil W. Brownjohn ◽  
Blake S. Dyer ◽  
Massimiliano Beltramo ◽  
Christopher S. Walker ◽  
...  

RFamide-related peptide-3 (RFRP-3) is a recently discovered neuropeptide that has been proposed to play a role in the stress response. We aimed to elucidate the role of RFRP-3 and its receptor, neuropeptide FF (NPFF1R), in modulation of stress and anxiety responses. To achieve this, we characterized a new NPFF1R antagonist because our results showed that the only commercially available putative antagonist, RF9, is in fact an agonist at both NPFF1R and the kisspeptin receptor (KISS1R). We report here the identification and pharmacological characterization of GJ14, a true NPFFR antagonist. In in vivo tests of hypothalamic-pituitary-adrenal (HPA) axis function, GJ14 completely blocked RFRP-3-induced corticosterone release and neuronal activation in CRH neurons. Furthermore, chronic infusion of GJ14 led to anxiolytic-like behavior, whereas RFRP-3 infusion had anxiogenic effects. Mice receiving chronic RFRP-3 infusion also had higher basal circulating corticosterone levels. These results indicate a stimulatory action of RFRP-3 on the HPA axis, consistent with the dense expression of NPFF1R in the vicinity of CRH neurons. Importantly, coinfusion of RFRP-3 and GJ14 completely reversed the anxiogenic and HPA axis-stimulatory effects of RFRP-3. Here we have established the role of RFRP-3 as a regulator of stress and anxiety. We also show that GJ14 can reverse the effects of RFRP-3 both in vitro and in vivo. Infusion of GJ14 causes anxiolysis, revealing a novel potential target for treating anxiety disorders.

Open Biology ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 200172
Author(s):  
Ya Zhang ◽  
Luis Alfonso Yañez Guerra ◽  
Michaela Egertová ◽  
Cleidiane G. Zampronio ◽  
Alexandra M. Jones ◽  
...  

Somatostatin (SS) and allatostatin-C (ASTC) are structurally and evolutionarily related neuropeptides that act as inhibitory regulators of physiological processes in mammals and insects, respectively. Here, we report the first molecular and functional characterization of SS/ASTC-type signalling in a deuterostome invertebrate—the starfish Asterias rubens (phylum Echinodermata). Two SS/ASTC-type precursors were identified in A. rubens (ArSSP1 and ArSSP2) and the structures of neuropeptides derived from these proteins (ArSS1 and ArSS2) were analysed using mass spectrometry. Pharmacological characterization of three cloned A. rubens SS/ASTC-type receptors (ArSSR1–3) revealed that ArSS2, but not ArSS1, acts as a ligand for all three receptors. Analysis of ArSS2 expression in A. rubens using mRNA in situ hybridization and immunohistochemistry revealed stained cells/fibres in the central nervous system, the digestive system (e.g. cardiac stomach) and the body wall and its appendages (e.g. tube feet). Furthermore, in vitro pharmacological tests revealed that ArSS2 causes dose-dependent relaxation of tube foot and cardiac stomach preparations, while injection of ArSS2 in vivo causes partial eversion of the cardiac stomach. Our findings provide new insights into the molecular evolution of SS/ASTC-type signalling in the animal kingdom and reveal an ancient role of SS-type neuropeptides as inhibitory regulators of muscle contractility.


2016 ◽  
Vol 791 ◽  
pp. 115-123 ◽  
Author(s):  
Alessandra Porcu ◽  
Carla Lobina ◽  
Daniela Giunta ◽  
Maurizio Solinas ◽  
Claudia Mugnaini ◽  
...  

2019 ◽  
Vol 476 (10) ◽  
pp. 1521-1537 ◽  
Author(s):  
Emma J. Goldberg ◽  
Katherine A. Buddo ◽  
Kelsey L. McLaughlin ◽  
Regina F. Fernandez ◽  
Andrea S. Pereyra ◽  
...  

Abstract Alterations to branched-chain keto acid (BCKA) oxidation have been implicated in a wide variety of human diseases, ranging from diabetes to cancer. Although global shifts in BCKA metabolism—evident by gene transcription, metabolite profiling, and in vivo flux analyses have been documented across various pathological conditions, the underlying biochemical mechanism(s) within the mitochondrion remain largely unknown. In vitro experiments using isolated mitochondria represent a powerful biochemical tool for elucidating the role of the mitochondrion in driving disease. Such analyses have routinely been utilized across disciplines to shed valuable insight into mitochondrial-linked pathologies. That said, few studies have attempted to model in vitro BCKA oxidation in isolated organelles. The impetus for the present study stemmed from the knowledge that complete oxidation of each of the three BCKAs involves a reaction dependent upon bicarbonate and ATP, both of which are not typically included in respiration experiments. Based on this, it was hypothesized that the inclusion of exogenous bicarbonate and stimulation of respiration using physiological shifts in ATP-free energy, rather than excess ADP, would allow for maximal BCKA-supported respiratory flux in isolated mitochondria. This hypothesis was confirmed in mitochondria from several mouse tissues, including heart, liver and skeletal muscle. What follows is a thorough characterization and validation of a novel biochemical tool for investigating BCKA metabolism in isolated mitochondria.


Pituitary ◽  
2010 ◽  
Vol 14 (2) ◽  
pp. 141-147 ◽  
Author(s):  
Federico Gatto ◽  
Federica Barbieri ◽  
Lara Castelletti ◽  
Marica Arvigo ◽  
Alessandra Pattarozzi ◽  
...  

2010 ◽  
Vol 78 (6) ◽  
pp. 2370-2376 ◽  
Author(s):  
Louise M. Temple ◽  
David M. Miyamoto ◽  
Manju Mehta ◽  
Christian M. Capitini ◽  
Stephen Von Stetina ◽  
...  

ABSTRACT Bordetella avium causes bordetellosis in birds, a disease similar to whooping cough caused by Bordetella pertussis in children. B. avium agglutinates guinea pig erythrocytes via an unknown mechanism. Loss of hemagglutination ability results in attenuation. We report the use of transposon mutagenesis to identify two genes required for hemagglutination. The genes (hagA and hagB) were adjacent and divergently oriented and had no orthologs in the genomes of other Bordetella species. Construction of in-frame, unmarked mutations in each gene allowed examination of the role of each in conferring erythrocyte agglutination, explanted tracheal cell adherence, and turkey poult tracheal colonization. In all of the in vitro and in vivo assays, the requirement for the trans-acting products of hagA and hagB (HagA and HagB) was readily shown. Western blotting, using antibodies to purified HagA and HagB, revealed proteins of the predicted sizes of HagA and HagB in an outer membrane-enriched fraction. Antiserum to HagB, but not HagA, blocked B. avium erythrocyte agglutination and explanted turkey tracheal ring binding. Bioinformatic analysis indicated the similarity of HagA and HagB to several two-component secretory apparatuses in which one product facilitates the exposition of the other. HagB has the potential to serve as a useful immunogen to protect turkeys against colonization and subsequent disease.


2006 ◽  
Vol 20 (4) ◽  
Author(s):  
Johannes Rajarao ◽  
Lisa Potestio ◽  
Jessica Malberg ◽  
Corey Bender ◽  
Bart Nieuwenhuijsen ◽  
...  

2019 ◽  
Author(s):  
Alexandre Mariotte ◽  
Aurore Decauwer ◽  
Chrystelle Po ◽  
Cherine Abou-Faycal ◽  
Angelique Pichot ◽  
...  

The role of Monosodium Urate (MSU) crystals in gout pathophysiology is well described, as is the major impact of IL-1b in the inflammatory reaction that constitutes the hallmark of the disease. However, despite the discovery of the NLRP3 inflammasome and its role as a Pattern Recognition Receptor linking the detection of a danger signal (MSU) to IL-1b; secretion in vitro, the precise mechanisms leading to joint inflammation in gout patients are still poorly understood. Here, we provide an extensive clinical, biological and molecular characterization of the acute uratic inflammation mouse model induced by subcutaneous injection of MSU crystals, which accurately mimics human gout. Our work reveals several key features of MSU-dependent inflammation and identifies novel therapeutic opportunities, among which the use of topical application of imiquimod to promote interferon-dependent anti-inflammatory action maybe relevant.


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