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Introduction
My current research focuses on Systems Neuroscience and Neuroendocrinology, in particular the brain circuits that control reproduction and metabolism and the neural pathways through which they respond to peripheral information.
Publications
Publications (366)
While hypothalamic kisspeptin (KP) neurons play well-established roles in the estrogen-dependent regulation of reproduction, little is known about extrahypothalamic KP-producing (KP LS ) neurons of the lateral septum. As established previously, Kiss1 expression in this region is low and regulated by estrogen receptor- and GABA B receptor-dependent...
The use of incretin agonists for managing metabolic dysfunction-associated steatohepatitis (MASH) is currently experiencing considerable interest. However, whether these compounds have a direct action on MASH is still under debate. This study aims to investigate whether GLP-1R/GIPR agonists act directly in hepatocytes and hepatic stellate cells (HS...
While liraglutide effectively treats type 2 diabetes (T2D) and obesity, its mechanism of action across disease progression remains poorly understood. Liraglutide selectively enhances GSIS in islets from glucose-intolerant donors and in islets exposed to prediabetic conditions, but not in normoglycemic or T2D islets. In healthy mice, liraglutide's i...
The hypothalamic arcuate nucleus (ARH) contains neurons vital for maintaining energy homeostasis that sense and respond to changes in blood-borne metabolic hormones. Despite its juxtaposition to the median eminence (ME), a circumventricular organ lacking a blood-brain barrier and thus exposed to circulating molecules, only a few ventral ARH neurons...
Hypothalamic gonadotropin-releasing hormone (GnRH) neurons regulate fertility and integrate hormonal status with environmental cues to ensure reproductive success. Here we show that GnRH neurons in the olfactory bulb (GnRHOB) of adult mice can mediate social recognition. Specifically, we show that GnRHOB neurons extend neurites into the vomeronasal...
Prader-Willi syndrome (PWS) is a multigenic disorder caused by the loss of seven contiguous paternally expressed genes. Mouse models with inactivation of all PWS genes are lethal. Knockout (KO) mouse models for each candidate gene were generated, but they lack the functional interactions between PWS genes. Here, we revealed an interplay between Nec...
Complications of diabetes are often attributed to glucose and reactive dicarbonyl metabolites derived from glycolysis or gluconeogenesis, such as methylglyoxal. However, in the CNS, neurons and endothelial cells use lactate as energy source in addition to glucose, which does not lead to the formation of methylglyoxal and has previously been conside...
Prolonged lactation: Preventing obesity since infancy
Dr Vincent Prevot and Professors Markus Schwaninger and Ruben Nogueiras explain the significance of the perinatal maternal lifestyle, specifically prolonged lactation, in shielding offspring from chronic disease. In recent years, the escalating prevalence of obesity and its associated diseases h...
Objectives
In Western society, high-caloric diets rich in fats and sugars have fueled the obesity epidemic and its related disorders. Disruption of the body-brain communication, crucial for maintaining glucose and energy homeostasis, arises from both obesogenic and genetic factors, leading to metabolic disorders. Here, we investigate the role of hy...
Background and Aims
Mitochondrial antiviral signaling protein (MAVS) is a critical regulator that activates the host’s innate immunity against RNA viruses, and its signaling pathway has been linked to the secretion of proinflammatory cytokines. However, the actions of MAVS on inflammatory pathways during the development of metabolic dysfunction–ass...
Objective
Low-density lipoprotein receptor-related protein-1 (LRP1) regulates energy homeostasis, blood–brain barrier integrity, and metabolic signaling in the brain. Deficiency of LRP1 in inhibitory gamma-aminobutyric acid (GABA)ergic neurons causes severe obesity in mice. However, the impact of LRP1 in inhibitory neurons on memory function and co...
Bridging brain barriers for gene therapy
Reflecting on the challenges in treating brain diseases, this article explores ways to transduce the blood-brain barrier as well as the critical role of tanycytes as a target for gene therapy vectors. It is vital that the precious central nervous system is protected from exogenous harmful factors that can da...
In humans, the first 1000 days of life are pivotal for brain and organism development. Shortly after birth, gonadotropin‐releasing hormone (GnRH) neurons in the hypothalamus are activated, a phenomenon known as minipuberty. This phenomenon, observed in all mammals studied, influences the postnatal development of the hypothalamic–pituitary–gonadal (...
Empirical evidence suggests that heat exposure reduces food intake. However, the neurocircuit architecture and the signalling mechanisms that form an associative interface between sensory and metabolic modalities remain unknown, despite primary thermoceptive neurons in the pontine parabrachial nucleus becoming well characterized¹. Tanycytes are a s...
Alzheimer disease has a sex bias, with women twice as likely as men to be affected. Studies have linked elevated follicle-stimulating hormone (FSH) levels to worsened Alzheimer disease pathology and cognitive decline in mice. FSH interacts with APOE4, uncovering new aspects of Alzheimer disease. The therapeutic potential of FSH and gonadotropin-rel...
The p63 protein has pleiotropic functions and, in the liver, participates in the progression of nonalcoholic fatty liver disease (NAFLD). However, its functions in hepatic stellate cells (HSCs) have not yet been explored. TAp63 is induced in HSCs from animal models and patients with liver fibrosis and its levels positively correlate with NAFLD acti...
Gonadotropin-releasing hormone is implicated in cognitive functions, and its loss is a factor in pathological brain ageing. There are similarities between these processes and the neurological and cognitive deficits observed in patients with long COVID. Here, we explore the hypothesis that neuroanatomical and transcriptomic alterations associated wi...
Background:
Tanycytes are specialized glial cells within the mediobasal hypothalamus that have multiple functions, including hormone sensing and regulation of hypophysiotropic hormone secretion. There are ongoing discussions about the role of tanycytes in regulating the supply of hypothalamic thyroid hormones (THs) through the expression of TH tra...
An individual's nutritional status has a powerful effect on sexual maturation. Puberty onset is delayed in response to chronic energy insufficiency and is advanced under energy abundance. The consequences of altered pubertal timing for human health are profound. Late puberty increases the chances of cardiometabolic, musculoskeletal and neurocogniti...
Background
Polycystic ovary syndrome (PCOS) is the most common endocrine disorder leading to anovulatory infertility. Abnormalities in the central neuroendocrine system governed by gonadotropin-releasing hormone (GnRH) neurons might be related to ovarian dysfunction in PCOS, although the link in this disordered brain-to-ovary communication remains...
Disclosure: E.G. Mills: None. M. Swedrowska: None. V. Delli: None. K. Chachlaki: None. M. Silva: None. L. Decoster: None. G. Ternier: None. L. Thurston: None. M. Phylactou: None. B. Patel: None. L. Yang: None. S.A. Clarke: None. B. Muzi: None. E.C. Alexander: None. M. Choudhury: None. P. Bech: None. A. Abbara: None. B. Forbes: None. P. Giacobini: N...
Background
We have recently demonstrated a causal link between loss of gonadotropin-releasing hormone (GnRH), the master molecule regulating reproduction, and cognitive deficits during pathological aging, including Down syndrome and Alzheimer's disease. Olfactory and cognitive alterations, which persist in some COVID-19 patients, and long-term hypo...
Here, we present a protocol for tanycyte-neuron paired whole-cell patch-clamp recording in living mouse brain slices. We describe steps for mice generation, solution preparation, and dissection. We then detail realization of slices and patch-clamp recordings. While we use, as an example, tanycytes of the arcuate nucleus of the hypothalamus and pro-...
Neddylation is a post-translational mechanism that adds a ubiquitin-like protein, namely neural precursor cell expressed developmentally downregulated protein 8 (NEDD8). Here, we show that neddylation in mouse liver is modulated by nutrient availability. Inhibition of neddylation in mouse liver reduces gluconeogenic capacity and the hyperglycemic a...
Older age is one of the strongest risk factors for severe COVID-19. In this study, we determined whether age-associated cellular senescence contributes to the severity of experimental COVID-19. Aged golden hamsters accumulate senescent cells in the lungs, and the senolytic drug ABT-263, a BCL-2 inhibitor, depletes these cells at baseline and during...
Adipocyte-derived leptin enters the brain to exert its anorexigenic action, yet its transport mechanism is poorly understood. Here we report that LRP1 (low density lipoprotein receptor-related protein-1) mediates the transport of leptin across the blood-CSF barrier in Foxj1 expressing cells highly enriched at the choroid plexus (ChP), coupled with...
Objective:
O-GlcNAcylation is a post-translational modification that directly couples the processes of nutrient sensing, metabolism, and signal transduction, affecting protein function and localization, since the O-linked N-acetylglucosamine moiety comes directly from the metabolism of glucose, lipids, and amino acids. The addition and removal of...
Hypothalamic gonadotropin-releasing hormones (GnRH) neurons are central regulators of fertility and integrate endogenous hormonal status with environmental cues to ensure reproductive success. Here, we found that a novel population of extra-hypothalamic GnRH neurons in the olfactory bulb of adult mice and humans (GnRH OB ) can mediate social recogn...
Pulsatile secretion of gonadotropin-releasing hormone (GnRH) is essential for activating and maintaining the function of the hypothalamic-pituitary-gonadal (HPG) axis, which controls the onset of puberty and fertility. Two recent studies suggest that, in addition to controlling reproduction, the neurons in the brain that produce GnRH are also invol...
Background:
Polycystic ovary syndrome (PCOS) is the most common reproductive-endocrine disorder affecting between 5 and 18% of women worldwide. An elevated frequency of pulsatile luteinizing hormone (LH) secretion and higher serum levels of anti-Müllerian hormone (AMH) are frequently observed in women with PCOS. The origin of these abnormalities i...
The median eminence (ME) is a circumventricular organ at the base of the brain that controls body homeostasis. Tanycytes are its specialized glial cells that constitute the ventricular walls and regulate different physiological states, however individual signaling pathways in these cells are incompletely understood. Here, we identify a functional t...
Objective:
p63 is a transcription factor within the p53 protein family that has key roles in development, differentiation and prevention of senescence, but its metabolic actions remain largely unknown. Herein, we investigated the physiological role of p63 in glucose metabolism.
Design:
We used cell lines and mouse models to genetically manipulat...
The third ventricle (3V) wall of the tuberal hypothalamus is composed of two types of cells, specialized ependymoglial cells called tanycytes located ventrally and ependymocytes dorsally, which control the exchanges between the cerebrospinal fluid and the hypothalamic parenchyma. By regulating the dialogue between the brain and the periphery, tanyc...
The WATCH project: Tanycytes in health and disease
In our aging societies, maintaining health and limiting age-related metabolic or cognitive disorders are of primordial importance not only for the well-being of the individual but also from the economic and societal points of view. The Synergy project Well-Aging and the Tanycytic Control of Health...
Food odour recognition is involved in the food anticipatory response. A study in Nature Metabolism describes how the olfactory system differentially regulates metabolic adaptations depending on energy availability. These effects are mediated by a brain circuit involving the melanocortin system that controls systemic lipid utilization via the sympat...
Background
The maturation of the hypothalamic-pituitary-gonadal (HPG) axis is crucial for the establishment of reproductive function. In female mice, neuronal nitric oxide synthase (nNOS) activity appears to be key for the first postnatal activation of the neural network promoting the release of gonadotropin-releasing hormone (GnRH), i.e. minipuber...
Therapies based on glucagon-like peptide-1 (GLP-1) long-acting analogs and insulin are often used in the treatment of metabolic diseases. Both insulin and GLP-1 receptors are expressed in metabolically relevant brain regions, suggesting a cooperative action. However, the mechanisms underlying the synergistic actions of insulin and GLP-1R agonists r...
The nitric oxide (NO) signaling pathway in hypothalamic neurons plays a key role in the regulation of the secretion of gonadotropin-releasing hormone (GnRH), which is crucial for reproduction. We hypothesized that a disruption of neuronal NO synthase (NOS1) activity underlies some forms of hypogonadotropic hypogonadism. Whole-exome sequencing was p...
Objectif
Étudier l’efficacité à un et trois mois d’un traitement en première intention par lanréotide 120 mg sur la réduction du volume tumoral (VT) et l’amélioration des atteintes ophtalmologiques chez des patients nouvellement diagnostiqués d’acromégalie.
Patients et méthodes
Dans cette étude monocentrique, 21 patients atteints d’acromégalie de...
Objectif
Nous avons d’abord cherché à établir l’intervalle de référence pour les concentrations sériques d’AMH chez des hommes adultes. Deuxièmement, nous avons étudié la relation entre les concentrations sériques d’AMH et les gonadotrophines, la testostérone totale ainsi que les paramètres spermatiques.
Patients et méthodes
Au total, 578 hommes a...
At the present time, no viable treatment exists for cognitive and olfactory deficits in Down syndrome (DS). We show in a DS model (Ts65Dn mice) that these progressive nonreproductive neurological symptoms closely parallel a postpubertal decrease in hypothalamic as well as extrahypothalamic expression of a master molecule that controls reproduction-...
Narcolepsy type 1 (NT1) is a rare neurological sleep disorder triggered by postnatal loss of the orexin/hypocretin neuropeptides. Overweight/obesity and precocious puberty are highly prevalent comorbidities of NT1, with a close temporal correlation with disease onset, suggesting a common origin. However, the underlying mechanisms remain unknown and...
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes a multi-organ damage that includes hepatic dysfunction, which has been observed in over 50% of COVID-19 patients. Liver injury in COVID-19 could be attributed to the cytopathic effects, exacerbated immune responses or treatment-associated drug toxicity. Herein we demonstrate that h...
Kiss1 neurons, producing kisspeptins, are essential for puberty and fertility, but their molecular regulatory mechanisms remain unfolded. Here, we report that congenital ablation of the microRNA-synthesizing enzyme, Dicer, in Kiss1 cells, causes late-onset hypogonadotropic hypogonadism in both sexes, but is compatible with pubertal initiation and p...
Women with polycystic ovary syndrome (PCOS) frequently experience decreased sexual arousal, desire, and sexual satisfaction. While the hypothalamus is known to regulate sexual behavior, the specific neuronal pathways affected in patients with PCOS are not known. To dissect the underlying neural circuitry, we capitalized on a robust preclinical anim...
COVID-19 is a complex disease with short- and long-term respiratory, inflammatory and neurological symptoms that are triggered by the infection with SARS-CoV-2. Invasion of the brain by SARS-CoV-2 has been observed in humans and is postulated to be involved in post-COVID state. Brain infection is particularly pronounced in the K18-hACE2 mouse model...
Early-life determinants are thought to be a major factor in the rapid increase of obesity. However, while maternal nutrition has been extensively studied, the effects of breastfeeding by the infant on the reprogramming of energy balance in childhood and throughout adulthood remain largely unknown. Here we show that delayed weaning in rat pups prote...
Communication between the periphery and the brain is key for maintaining energy homeostasis. To do so, peripheral signals from the circulation reach the brain via the circumventricular organs (CVOs), which are characterized by fenestrated vessels lacking the protective blood–brain barrier (BBB). Glial cells, by virtue of their plasticity and their...
Liraglutide, an anti-diabetic drug and agonist of the glucagon-like peptide one receptor (GLP1R), has recently been approved to treat obesity in individuals with or without type 2 diabetes. Despite its extensive metabolic benefits, the mechanism and site of action of liraglutide remain unclear. Here, we demonstrate that liraglutide is shuttled to t...
Introduction: Few studies have attempted to evaluate the early efficacy of first-generation somatostatin analogs in somatotroph macroadenomas.
Objective: To investigate the short-term efficacy of primary therapy with lanreotide 120 mg at one and three months on tumor shrinkage and ophthalmologic symptoms in newly diagnosed patients with acromegaly....
The accumulation of pathological Tau in the brain and cerebrospinal fluid (CSF) and its eventual increase in the blood are hallmarks of Alzheimer’s disease (AD). However, the mechanisms of Tau clearance from the brain to the periphery are not clear. We show here, using animal and cellular models as well as patient blood samples and post mortem brai...
Abstract
Background: Few studies to date have attempted to measure serum anti-Müllerian hormone (AMH) levels in adult men, and solid references ranges have not yet been defined on a large cohort.
Objective: In this study, we aimed to first establish the reference ranges for serum AMH and AMH-to-total testosterone ratio (AMH/tT) in adult males. Sec...