Endocrine Abstracts

Gonadotropin releasing hormone neurons are a small group of scattered hypothalamic neuroendocrine cells that control reproductive functions in all mammals and many vertebrates.Despite their position in the adult hypothalamus, during development they originate in the nasal placode and migrate along the vomeronasal nerve to reach the forebrain and attain their final position in the hypothalamus. Failure of GnRH neurons to migrate lead to Kallmann Syndrome,...

Objectives: Abnormal pubertal timing affects >4% of adolescents and is associated with adverse health outcomes. Up to 80% of variation in the timing of pubertal onset is genetically determined. Self-limited delayed puberty (DP) segregates in an autosomal dominant pattern, but in the majority the neuroendocrine pathophysiology and genetic regulation remain unclear. Mis-regulation of the embryonic migration of GnRH neurons has been implicated in the pathogenesis of DP (Howar...

During development, gonadotropin releasing hormone (GnRH) neurons are born in the nasal placode and migrate to the hypothalamus, where they position to regulate sexual reproduction by the pulsatile release of GnRH. Defective GnRH neuron development or action may lead to GnRH deficiency (GD) which is characterized by absent or delayed puberty (1). GD can also be present as a trait shared by several complex neurodevelopmental disorders (NDDs), such as cerebellar ataxia, developm...

Reproduction in mammals is centrally regulated by neuroendocrine neurons scattered in the hypothalamus and secreting the decapeptide GnRH (gonadotropin releasing hormone). During development, GnRH-secreting neurons originate in the olfactory placode – at least in rodents – and migrate along olfactory nerves (the vomeronasal and the terminalis) to gain access to the forebrain and reach their final destinations in the hypothalamus. Defects in the migration of these neu...

Leukemia inhibitory factor (LIF), a pleiotropic cytokine of the interleukine-6 superfamily, is involved in several functions including the control of reproduction at the embrionic-endometrial interface and the regulation of energy homeostasis. LIF activates a cell-surface receptor complex (LIF-Rs) composed of one ligand-specific low affinity LIF receptor β (LIFRβ) subunit and the gp130 subunit. Since little is known about the involvement of LIF in the modulation of t...

Background: Disturbances of pubertal timing affect >4% of the population and are associated with adverse health outcomes. Studies estimate 60–80% of variation in pubertal onset is genetically determined, but few genetic factors are known. We hypothesise that causal variants will be low-frequency, intermediate-impact variants and will be enriched in populations at the extremes of normal pubertal timing. Families with constitutional delay in growth and puberty (CDGP) ha...

Background: The initiation of puberty is heralded by increasing gonadotropin-releasing hormone (GnRH) secretion from the hypothalamus. During embryonic life the GnRH neuroendocrine network develops thanks to a coordinated migration of neurons from the nasal placode to the forebrain. Our group has previously demonstrated that dysregulation in GnRH neuronal migration leads to delayed pubertal onset. Late puberty affects up to 2% of the population and is associated with adverse h...

Background: Male hypogonadism is known to be associated with an increased incidence of cardiovascular (CV) events, although the underlying biochemical mechanisms are so far not fully understood. The clinical condition characterized by low levels of testosterone offers a unique model to unravel the possible role of lipoprotein-associated abnormalities in CV risk. In particular, the assessment of the functional capacities of high-density lipoproteins (HDL) may provide novel insi...

Idiopathic hypogonadotropic hypogonadism (IHH) is a rare and heterogeneous disease due to defects of GnRH secretion or action. IHH could be associated or not with anosmia respectively identifying the Kallmann’s syndrome (KS) or the normosmic IHH (nIHH). So far numerous causative genetic defects have been described, but very recent molecular genetic studies and animal models have opened novel perspectives. We are studying a series of 16 KS (14M,2F) and 18 nIHH (14M,4F). Al...

Background: Abnormal pubertal timing affects over 4% of adolescents and is associated with adverse health and psychosocial outcomes. Previous studies estimate that 60–80% of variation in the timing of pubertal onset is genetically determined. However, despite this strong heritability, little is known about the genetic control of human puberty. Self-limited delayed puberty (DP) segregates in an autosomal dominant pattern, but in the majority of patients the neuroendocrine ...