Project description:The effects of phoenixin-14 on the hypothalamic-pituitary-gonadal (HPG) axis and spawning in green-spotted puffer (Dichotomyctere nigroviridis)
Project description:Pregnancy is a unique and critical period in a female’s life during which the whole organism is mobilized and focused on ensuring the successful survival and development of the embryo. The main regulatory system responsible for the reproductive functions during both the oestrous cycle and pregnancy is the hypothalamic-pituitary-gonadal (HPG) axis. Herein we verified hypothesis assuming the modulatory effect of visfatin on the anterior pituitary transcriptome during the peri-implantation period. We analyzed samples obtained from 5 individuals (n=5). After the enzymatic tissue digestion with the use collagenase V and pancreatin cells were divided for two groups: controls [without treatment] and visfatin (100 ng/mL) treated ones. In vitro cell cultures were conducted for 24 hours.
Project description:Ultraviolet (UV) light affects endocrinological and behavioral aspects of human sexuality via an unknown mechanism. Using a unique male-female comparative approach, we discovered that the sexual behavioral and hormonal features enhanced by UVB are mediated by the skin. In mice, UV exposure increases hypothalamus-pituitary-gonadal axis hormone levels, resulting in enhanced ovary size, extended estrus days, and anti-Mullerian hormone (AMH) expression. It likewise enhances the sexual responsiveness and attractiveness of females and male-female interactions of both males and females. Conditional knockout of p53 specifically in skin keratinocytes abolished UV’s effects. In humans, UV exposure enhanced romantic passion in both genders increased testosterone levels in men. Our data, revealing that UVB triggers a skin-brain-gonadal axis through skin p53 activation, offers therapeutic opportunities for sex-steroid-related dysfunctions. We speculate that during human furless skin evolution, the skin became the front-line regulator of the response to UVB.
Project description:Maternal stress during late pregnancy can lead to intrauterine hyperthermia affecting fetal hypothalamic-pituitary-adrenal axis development and function. This study aimed to characterize the impact of in utero heat stress on the postnatal offspring's adrenal gland transcriptome.
Project description:Enhanced nutrition during the early calfhood period has been shown to hasten the onset of puberty in heifer calves. The hypothalamic-pituitary-ovarian biochemical signalling axis regulates reproductive development in heifers, with the dynamics of gonadotropin pulsatility within the anterior pituitary gland, in particular, central to final sexual maturity. However, the precise molecular mechanisms regulating the influence of metabolic status on this signalling axis in heifer calves is yet to be fully elucidated. The objective of this study was to determine the effect of an enhanced plane of nutrition during early life, up to 21 weeks of age, on the anterior pituitary gland proteome of heifer calves. Heifer calves were offered either a high or moderate plane of nutrition. Pathway analysis of differentially abundant proteins highlighted an effect on both growth hormone and GnRH signalling pathways, as well as an effect towards reproductive system development and function
Project description:Recent genome-wide association studies (GWAS) identified Dusp8, a dual-specificity phosphatase targeting MAP kinases, as type 2 diabetes risk gene. Here, we unravel Dusp8 as gatekeeper in the hypothalamic control of glucose homeostasis in mice and humans. Male but not female Dusp8 loss-of-function mice, either with global or CRH neuron-specific deletion, had impaired systemic glucose tolerance and insulin sensitivity when exposed to high-fat diet (HFD). Mechanistically, we found impaired hypothalamic–pituitary–adrenal (HPA) axis feedback, blunted sympathetic responsiveness, and chronically elevated corticosterone levels driven by hypothalamic hyperactivation of Jnk signaling. Accordingly, global Jnk1 ablation, AAV-mediated Dusp8 overexpression in the mediobasal hypothalamus, or metyrapone-induced chemical adrenalectomy rescued the impaired glucose homeostasis of male Dusp8 KO mice, respectively. This sex-specific and rheostatic role of murine Dusp8 in governing hypothalamic Jnk signaling, insulin sensitivity and systemic glucose tolerance was consistent with fMRI data in human volunteers that revealed an association of the DUSP8 rs2334499 risk variant with hypothalamic insulin resistance in men. In summary, our findings suggest GWAS-identified gene Dusp8 as novel hypothalamic factor that plays a functional role in the etiology of type 2 diabetes.
Project description:Kisspeptin-expressing neurons in the rostral periventricular region of the third ventricle (RP3V) play an essential role in female reproduction. However, adult male mice were reported to have very few Kisspeptin-expressing neurons in the RP3V compared to females. This led to the hypothesis that Kiss1 RP3V neurons are responsible for the ability of females, but not males, to generate a surge of LH, triggering ovulation and steroid synthesis in the female. Using mouse genetics and cell type-specific gene expression analysis, we show that male mice harbor almost as many Kiss1 RP3V neurons as the female and that gene expression in these neurons is very similar. Specific activation of male Kiss1 RP3V neurons expressing viral-encoded hM3Dq caused a surge in serum testosterone levels. These results demonstrate that Kiss1 RP3V neurons are present in the adult male and fully capable of regulating the hypothalamic/pituitary/gonadal axis. We suggest that these neurons may continue to play a role in reproductive behavior in adult male mice.
Project description:Adiponectin is thought to be involved in the regulation of metabolic homeostasis and reproductive processes. Adiponectin controls carbohydrate and lipid metabolism by regulating the fatty acid oxidation process, increasing insulin sensitivity and decreasing plasma triglyceride levels. Adiponectin also plays an important role in the modulation of female reproductive functions, both directly and by influencing the secretory functions of the higher branches of the hypothalamic-pituitary-gonadal axis. The main aim of this study was to determine the effect of adiponectin on global gene expression and on differentially expressed genes (DE-genes) under the influence of the studied hormone in porcine anterior pituitary (AP) cells.
Project description:Fructose consumption has increased by over 25% since 1970, and excess consumption has deleterious metabolic effects. Additionally, fructose can alter hypothalamic pituitary adrenal axis function, potentially resulting in increased vulnerability to mood disorders. Adolescents are the greatest consumers of fructose and also at a critical period of development. Here, we examine the effects of consumption of a 55% fructose diet from weaning until adulthood on the hypothalamic transcriptome.