NK3R signalling in the posterodorsal medial amygdala is involved in stress-induced suppression of pulsatile LH secretion in female mice

This is the final version. Available on open access from Wiley via the DOI in this recordData availability statement: The data that support the findings of this study are available from the corresponding author upon reasonable request.Psychosocial stress negatively impacts reproductive function by inhibiting pulsatile luteinizing hormone (LH) secretion. The posterodorsal medial amygdala (MePD) is responsible in part for processing stress and modulating the reproductive axis. Activation of the neurokinin 3 receptor (NK3R) suppresses the gonadotropin-releasing hormone (GnRH) pulse generator, under hypoestrogenic conditions, and NK3R activity in the amygdala has been documented to play a role in stress and anxiety. We investigate whether NK3R activation in the MePD is involved in mediating the inhibitory effect of psychosocial stress on LH pulsatility in ovariectomised female mice. First, we administered senktide, an NK3R agonist, into the MePD and monitored the effect on pulsatile LH secretion. We then delivered SB222200, a selective NK3R antagonist, intra-MePD in the presence of predator odour, 2,4,5-trimethylthiazole (TMT) and examined the effect on LH pulses. Senktide administration into the MePD dose-dependently suppresses pulsatile LH secretion. Moreover, NK3R signalling in the MePD mediates TMT-induced suppression of the GnRH pulse generator, which we verified using a mathematical model. The model verifies our experimental findings: (i) predator odour exposure inhibits LH pulses, (ii) activation of NK3R in the MePD inhibits LH pulses and (iii) NK3R antagonism in the MePD blocks stressor-induced inhibition of LH pulse frequency in the absence of ovarian steroids. These results demonstrate for the first time that NK3R neurons in the MePD mediate psychosocial stress-induced suppression of the GnRH pulse generator.Biotechnology and Biological Sciences Research Council (BBSRC)Medical Research Council (MRC

Mathematical models in GnRH research

This is the final version. Available on open access from Wiley via the DOI in this recordMathematical modelling is an indispensable tool in modern biosciences, enabling quantitative analysis and integration of biological data, transparent formulation of our understanding of complex biological systems, and efficient experimental design based on model predictions. This review article provides an overview of the impact that mathematical models had on GnRH research. Indeed, over the last 20 years mathematical modelling has been used to describe and explore the physiology of the GnRH neuron, the mechanisms underlying GnRH pulsatile secretion, and GnRH signalling to the pituitary. Importantly, these models have contributed to GnRH research via novel hypotheses and predictions regarding the bursting behaviour of the GnRH neuron, the role of kisspeptin neurons in the emergence of pulsatile GnRH dynamics, and the decoding of GnRH signals by biochemical signalling networks. We envisage that with the advent of novel experimental technologies, mathematical modelling will have an even greater role to play in our endeavour to understand the complex spatiotemporal dynamics underlying the reproductive neuroendocrine system.Biotechnology & Biological Sciences Research Council (BBSRC)Kings College Londo

PIK3CA Mutations Frequently Coexist with RAS and BRAF Mutations in Patients with Advanced Cancers

Oncogenic mutations of PIK3CA, RAS (KRAS, NRAS), and BRAF have been identified in various malignancies, and activate the PI3K/AKT/mTOR and RAS/RAF/MEK pathways, respectively. Both pathways are critical drivers of tumorigenesis.Tumor tissues from 504 patients with diverse cancers referred to the Clinical Center for Targeted Therapy at MD Anderson Cancer Center starting in October 2008 were analyzed for PIK3CA, RAS (KRAS, NRAS), and BRAF mutations using polymerase chain reaction-based DNA sequencing.PIK3CA mutations were found in 54 (11%) of 504 patients tested; KRAS in 69 (19%) of 367; NRAS in 19 (8%) of 225; and BRAF in 31 (9%) of 361 patients. PIK3CA mutations were most frequent in squamous cervical (5/14, 36%), uterine (7/28, 25%), breast (6/29, 21%), and colorectal cancers (18/105, 17%); KRAS in pancreatic (5/9, 56%), colorectal (49/97, 51%), and uterine cancers (3/20, 15%); NRAS in melanoma (12/40, 30%), and uterine cancer (2/11, 18%); BRAF in melanoma (23/52, 44%), and colorectal cancer (5/88, 6%). Regardless of histology, KRAS mutations were found in 38% of patients with PIK3CA mutations compared to 16% of patients with wild-type (wt)PIK3CA (p = 0.001). In total, RAS (KRAS, NRAS) or BRAF mutations were found in 47% of patients with PIK3CA mutations vs. 24% of patients wtPIK3CA (p = 0.001). PIK3CA mutations were found in 28% of patients with KRAS mutations compared to 10% with wtKRAS (p = 0.001) and in 20% of patients with RAS (KRAS, NRAS) or BRAF mutations compared to 8% with wtRAS (KRAS, NRAS) or wtBRAF (p = 0.001).PIK3CA, RAS (KRAS, NRAS), and BRAF mutations are frequent in diverse tumors. In a wide variety of tumors, PIK3CA mutations coexist with RAS (KRAS, NRAS) and BRAF mutations

Allergen-specific immunotherapy provides immediate, long-term and preventive clinical effects in children and adults: the effects of immunotherapy can be categorised by level of benefit -the centenary of allergen specific subcutaneous immunotherapy

Allergen Specific Immunotherapy (SIT) for respiratory allergic diseases is able to significantly improve symptoms as well as reduce the need for symptomatic medication, but SIT also has the capacity for long-term clinical effects and plays a protective role against the development of further allergies and symptoms. The treatment acts on basic immunological mechanisms, and has the potential to change the pathological allergic immune response. In this paper we discuss some of the most important achievements in the documentation of the benefits of immunotherapy, over the last 2 decades, which have marked a period of extensive research on the clinical effects and immunological background of the mechanisms involved. The outcome of immunotherapy is described as different levels of benefit from early reduction in symptoms over progressive clinical effects during treatment to long-term effects after discontinuation of the treatment and prevention of asthma. The efficacy of SIT increases the longer it is continued and immunological changes lead to potential long-term benefits. SIT alone and not the symptomatic treatment nor other avoidance measures has so far been documented as the therapy with long-term or preventive potential. The allergic condition is driven by a subset of T-helper lymphocytes (Th2), which are characterised by the production of cytokines like IL-4, and IL-5. Immunological changes following SIT lead to potential curative effects. One mechanism whereby immunotherapy suppresses the allergic response is through increased production of IgG4 antibodies. Induction of specific IgG4 is able to influence the allergic response in different ways and is related to immunological effector mechanisms, also responsible for the reduced late phase hyperreactivity and ongoing allergic inflammation. SIT is the only treatment which interferes with the basic pathophysiological mechanisms of the allergic disease, thereby creating the potential for changes in the long-term prognosis of respiratory allergy. SIT should not only be recognised as first-line therapeutic treatment for allergic rhinoconjunctivitis but also as secondary preventive treatment for respiratory allergic diseases

Kisspeptin as a behavioral hormone

Successful reproduction is dependent not only on hormonal endocrine responses but also on suitable partner selection, copulatory acts, as well as associated emotional, behavioral, and cognitive processes many of which are supported by the limbic system. The reproductive hormone kisspeptin (encoded by the KISS1/kiss1 gene) is now recognized as the key orchestrator of the reproductive axis. In addition to the hypothalamus, prominent kisspeptin neuronal populations have been identified throughout limbic and paralimbic brain regions across an assortment of species. In this review, we detail the emerging roles of kisspeptin signaling in the broader aspects of behavioral, emotional, and cognitive control. Recent studies from zebrafish through humans have provided new molecular and neural insights into the complex role of kisspeptin in interpreting olfactory and auditory cues to govern sexual partner preference, in regulating copulatory behaviors and in influencing mood and emotions. Furthermore, emerging roles for kisspeptin in facilitating memory and learning are also discussed. To this end, these findings shed new light onto the importance of kisspeptin signaling, while informing the pharmacological development of kisspeptin as a potential therapeutic strategy for individuals suffering from associated reproductive, emotional, and cognitive disorders

The roles of the amygdala kisspeptin system

The hypothalamic hormone kisspeptin (encoded by the KISS1/kiss1 gene) is the master regulator of the reproductive axis with its role in controlling gonadotrophin hormone secretion now well characterized. However, identification of kisspeptin and its cognate receptor expression within the amygdala, a key limbic brain region whose functions contribute to a broad range of physiological and behavioral processes, has heightened interest concerning kisspeptins' role in the broader aspects of reproductive physiology. In this review, we detail the important developments and key studies examining the emerging functions of this kisspeptin population. These studies provide novel advances in our understanding of the mechanisms controlling reproductive neuroendocrinology by defining the crucial role of the amygdala kisspeptin system in modulating pubertal timing, reproductive hormone secretion, and pulsatility, as well as its influence in governing-related behaviors. To this end, the role of the amygdala kisspeptin system in integrating reproductive hormone secretion with behavior sheds new light onto the potential use of kisspeptin-based therapeutics for reproductive and related psychosexual disorders

Calcitonin gene-related peptide-induced suppression of luteinizing hormone pulses in the rat: the role of endogenous opioid peptides

Calcitonin gene-related peptide (CGRP) is involved in a variety of stress responses in the rat. Central administration of CGRP activates the hypothalamo–pituitary–adrenal axis resulting in increased corticosterone secretion. We have previously shown that central CGRP suppresses the gonadotrophin-releasing hormone (GnRH) pulse generator, specifically LH pulses. Endogenous opioid peptides (EOPs) have been shown to play an important role in stress-induced suppression of the reproductive axis. The aim of the present study was to test the hypothesis that EOPs mediate CGRP-induced suppression of pulsatile LH secretion. Ovariectomized rats were implanted with intracerebroventricular (i.c.v.) and i.v. cannulae. Intravenous administration of the opioid antagonist naloxone (250 μg) completely blocked the suppression of LH pulses induced by 1.5 μg i.c.v. CGRP and significantly attenuated the suppression of pulsatile LH secretion induced by 5 μg i.c.v. CGRP. Furthermore, intravenous administration of naloxone was found to immediately restore normal LH pulse frequency in animals treated 90 min earlier with 1.5 μg i.c.v. CGRP. Co-administration (i.c.v.) of CGRP (1.5 μg) with the μ and κ opioid receptor-specific antagonists naloxone (10 μg) and norbinaltorphimine (5 μg), respectively, blocked the CGRP-induced suppression of LH pulses, whilst i.c.v. co-administration of CGRP (1.5 μg) with the δ opioid receptor-specific antagonist naltrindole (5 μg) did not. These data provide evidence that EOPs play a pivotal role in mediating the inhibitory effects of CGRP on pulsatile LH secretion in the rat. They also suggest that the μ and κ, but not the δ, opioid receptors may be responsible for mediating the effects of CGRP on LH pulses

Kisspeptin neurones in the posterodorsal medial amygdala modulate sexual partner preference and anxiety in male mice.

The posterodorsal medial amygdala (MePD) is a neural site in the limbic brain involved in regulating emotional and sexual behaviours. There is however limited information on the specific neuronal cell type in the MePD functionally mediating these behaviours in rodents. The recent discovery of a significant kisspeptin neurone population in the MePD has raised interest in the possible role of kisspeptin and its cognate receptor in sexual behaviour. This study therefore tested the hypothesis that the MePD kisspeptin neurone population is involved in regulating attraction towards opposite sex conspecifics, sexual behaviour, social interaction and anxiety response by selectively stimulating these neurones using the novel pharmacosynthetic DREADDs (designer receptors exclusively activated by designer drugs) technique. Adult male Kiss-Cre mice received bilateral stereotaxic injections of a stimulatory DREADD viral construct (AAV-hSyn-DIO-hM3D(Gq)-mCherry) targeted to the MePD which were activated by intraperitoneal (i.p.) injection of clozapine-N-oxide (CNO). Socio-sexual behaviours were assessed in a counter-balanced fashion after i.p. injection of either saline or CNO (5mg/kg). Selective activation of MePD kisspeptin neurones by CNO significantly increased the time spent by male mice in investigating an oestrous female as well as duration of social interaction. Additionally, after CNO injection the mice appeared less anxious; evidenced by longer exploratory time in the open arms of the elevated plus maze. However, levels of copulatory behaviour were comparable between CNO and saline treated controls. These data indicate that DREADD-induced activation of MePD kisspeptin neurones enhances sexual partner preference in males and social interaction and decreases anxiety, suggesting a key role played by MePD kisspeptin in sexual motivation and social behaviour. This article is protected by copyright. All rights reserved.This work was supported by the Medical Research Council, UK. DAA is a Commonwealth Scholar funded by the UK Government