RESUMO
Obesity is associated with hypogonadism in males, characterized by low testosterone and sperm number. Previous studies determined that these stem from dysregulation of hypothalamic circuitry that regulates reproduction, by unknown mechanisms. Herein, we used mice fed chronic high-fat diet, which mimics human obesity, to determine mechanisms of impairment at the level of the hypothalamus, in particular gonadotropin-releasing hormone (GnRH) neurons that regulate luteinizing hormone (LH), which then regulates testosterone. Consistent with obese humans, we demonstrated lower LH, and lower pulse frequency of LH secretion, but unchanged pituitary responsiveness to GnRH. LH pulse frequency is regulated by pulsatile GnRH secretion, which is controlled by kisspeptin. Peripheral and central kisspeptin injections, and DREADD-mediated activation of kisspeptin neurons, demonstrated that kisspeptin neurons were suppressed in obese mice. Thus, we investigated regulators of kisspeptin secretion. We determined that the LH response to NMDA was lower in obese mice, corresponding to fewer glutamate receptors in kisspeptin neurons, which may be critical for kisspeptin synchronization. Given that kisspeptin neurons also interact with anorexigenic POMC neurons, which are affected by obesity, we examined their cross talk, and determined that the LH response to either DREADD-mediated activation of POMC neurons or central injection of αMSH, a product of POMC, is abolished in obese mice. This was accompanied by diminished levels of αMSH receptor, MC4R, in kisspeptin neurons. Together, our studies determined that obesity leads to the downregulation of receptors that regulate kisspeptin neurons, which is associated with lower LH pulse frequency, leading to lower LH and hypogonadism.
Assuntos
Hormônio Liberador de Gonadotropina , Kisspeptinas , Hormônio Luteinizante , Camundongos Endogâmicos C57BL , Neurônios , Obesidade , Pró-Opiomelanocortina , Animais , Masculino , Kisspeptinas/metabolismo , Obesidade/metabolismo , Hormônio Luteinizante/metabolismo , Hormônio Luteinizante/sangue , Camundongos , Neurônios/metabolismo , Pró-Opiomelanocortina/metabolismo , Hormônio Liberador de Gonadotropina/metabolismo , Dieta Hiperlipídica/efeitos adversosRESUMO
Kisspeptin signaling regulates energy homeostasis. Adiposity is the principal source and receiver of peripheral Kisspeptin, and adipose Kiss1 metastasis suppressor (Kiss1) gene expression is stimulated by exercise. However, whether the adipose Kiss1 gene regulates energy homeostasis and plays a role in adaptive alterations during prolonged exercise remains unknown. Here, we investigated the role of Kiss1 role in mice and adipose tissues and the adaptive changes it induces after exercise, using adipose-specific Kiss1 knockout (Kiss1adipoq-/-) and adeno-associated virus-induced adipose tissue Kiss1-overexpressing (Kiss1adipoq over) mice. We found that adipose-derived kisspeptin signal regulates lipid and glucose homeostasis to maintain systemic energy homeostasis, but in a sex-dependent manner, with more pronounced metabolic changes in female mice. Kiss1 regulated adaptive alterations of genes and proteins in tricarboxylic acid (TCA) cycle and oxidative phosphorylation (OxPhos) pathways in female gWAT following prolonged aerobic exercise. We could further show that adipose Kiss1 deficiency leads to reduced peroxisome proliferator-activated receptor gamma co-activator 1 alpha (PGC-1α) protein content of soleus muscle and maximum oxygen uptake (VO2 max) of female mice after prolonged exercise. Therefore, adipose Kisspeptin may be a novel adipokine that increases organ sensitivity to glucose, lipids, and oxygen following exercise.
Assuntos
Tecido Adiposo , Metabolismo Energético , Homeostase , Kisspeptinas , Camundongos Knockout , Condicionamento Físico Animal , Animais , Kisspeptinas/metabolismo , Kisspeptinas/genética , Feminino , Camundongos , Condicionamento Físico Animal/fisiologia , Masculino , Tecido Adiposo/metabolismo , Camundongos Endogâmicos C57BL , Adaptação FisiológicaRESUMO
The pulsatile activity of gonadotropin-releasing hormone neurons (GnRH neurons) is a key factor in the regulation of reproductive hormones. This pulsatility is orchestrated by a network of neurons that release the neurotransmitters kisspeptin, neurokinin B, and dynorphin (KNDy neurons), and produce episodic bursts of activity driving the GnRH neurons. We show in this computational study that the features of coordinated KNDy neuron activity can be explained by a neural network in which connectivity among neurons is modular. That is, a network structure consisting of clusters of highly-connected neurons with sparse coupling among the clusters. This modular structure, with distinct parameters for intracluster and intercluster coupling, also yields predictions for the differential effects on synchronization of changes in the coupling strength within clusters versus between clusters.
Assuntos
Dinorfinas , Hormônio Liberador de Gonadotropina , Modelos Neurológicos , Rede Nervosa , Neurônios , Neurônios/fisiologia , Rede Nervosa/fisiologia , Animais , Dinorfinas/metabolismo , Dinorfinas/fisiologia , Hormônio Liberador de Gonadotropina/metabolismo , Kisspeptinas/metabolismo , Kisspeptinas/fisiologia , Neurocinina B/metabolismo , Neurocinina B/fisiologia , Biologia Computacional , Potenciais de Ação/fisiologia , Simulação por Computador , HumanosRESUMO
A hypothalamic pulse generator located in the arcuate nucleus controls episodic release of gonadotropin-releasing hormone (GnRH) and luteinizing hormone (LH) and is essential for reproduction. Recent evidence suggests this generator is composed of arcuate "KNDy" cells, the abbreviation based on coexpression of kisspeptin, neurokinin B, and dynorphin. However, direct visual evidence of KNDy neuron activity at a single-cell level during a pulse is lacking. Here, we use in vivo calcium imaging in freely moving female mice to show that individual KNDy neurons are synchronously activated in an episodic manner, and these synchronized episodes always precede LH pulses. Furthermore, synchronization among KNDy cells occurs in a temporal order, with some subsets of KNDy cells serving as "leaders" and others as "followers" during each synchronized episode. These results reveal an unsuspected temporal organization of activation and synchronization within the GnRH pulse generator, suggesting that different subsets of KNDy neurons are activated at pulse onset than afterward during maintenance and eventual termination of each pulse. Further studies to distinguish KNDy "leader" from "follower" cells is likely to have important clinical significance, since regulation of pulsatile GnRH secretion is essential for normal reproduction and disrupted in pathological conditions such as polycystic ovary syndrome and hypothalamic amenorrhea.
Assuntos
Hormônio Liberador de Gonadotropina/metabolismo , Neurônios/metabolismo , Animais , Núcleo Arqueado do Hipotálamo/metabolismo , Dinorfinas/metabolismo , Feminino , Kisspeptinas/metabolismo , Hormônio Luteinizante/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Neurocinina B/metabolismo , Reprodução/fisiologiaRESUMO
Kisspeptin neurons in the mediobasal hypothalamus (MBH) are critical targets of ovarian estrogen feedback regulating mammalian fertility. To reveal molecular mechanisms underlying this signaling, we thoroughly characterized the estrogen-regulated transcriptome of kisspeptin cells from ovariectomized transgenic mice substituted with 17ß-estradiol or vehicle. MBH kisspeptin neurons were harvested using laser-capture microdissection, pooled, and subjected to RNA sequencing. Estrogen treatment significantly (p.adj. < 0.05) up-regulated 1,190 and down-regulated 1,139 transcripts, including transcription factors, neuropeptides, ribosomal and mitochondrial proteins, ion channels, transporters, receptors, and regulatory RNAs. Reduced expression of the excitatory serotonin receptor-4 transcript (Htr4) diminished kisspeptin neuron responsiveness to serotonergic stimulation. Many estrogen-regulated transcripts have been implicated in puberty/fertility disorders. Patients (n = 337) with congenital hypogonadotropic hypogonadism (CHH) showed enrichment of rare variants in putative CHH-candidate genes (e.g., LRP1B, CACNA1G, FNDC3A). Comprehensive characterization of the estrogen-dependent kisspeptin neuron transcriptome sheds light on the molecular mechanisms of ovary-brain communication and informs genetic research on human fertility disorders.
Assuntos
Núcleo Arqueado do Hipotálamo , Estrogênios , Fertilidade , Kisspeptinas , Neurônios , Ovário , Animais , Núcleo Arqueado do Hipotálamo/metabolismo , Estrogênios/metabolismo , Feminino , Fertilidade/genética , Perfilação da Expressão Gênica , Humanos , Hipogonadismo/congênito , Hipogonadismo/genética , Kisspeptinas/genética , Kisspeptinas/metabolismo , Camundongos , Camundongos Transgênicos , Neurônios/metabolismo , Ovário/metabolismoRESUMO
Ovulation disorders are a serious problem for humans and livestock. In female rodents, kisspeptin neurons in the anteroventral periventricular nucleus (AVPV) are responsible for generating a luteinizing hormone (LH) surge and consequent ovulation. Here, we report that adenosine 5-triphosphate (ATP), a purinergic receptor ligand, is a possible neurotransmitter that stimulates AVPV kisspeptin neurons to induce an LH surge and consequent ovulation in rodents. Administration of an ATP receptor antagonist (PPADS) into the AVPV blocked the LH surge in ovariectomized (OVX) rats treated with a proestrous level of estrogen (OVX + high E2) and significantly reduced the ovulation rate in proestrous ovary-intact rats. AVPV ATP administration induced a surge-like LH increase in OVX + high E2 rats in the morning. Importantly, AVPV ATP administration could not induce the LH increase in Kiss1 KO rats. Furthermore, ATP significantly increased intracellular Ca2+ levels in immortalized kisspeptin neuronal cell line, and coadministration of PPADS blocked the ATP-induced Ca2+ increase. Histologic analysis revealed that the proestrous level of estrogen significantly increased the number of P2X2 receptor (an ATP receptor)-immunopositive AVPV kisspeptin neurons visualized by tdTomato in Kiss1-tdTomato rats. The proestrous level of estrogen significantly increased varicosity-like vesicular nucleotide transporter (a purinergic marker)-immunopositive fibers projecting to the vicinity of AVPV kisspeptin neurons. Furthermore, we found that some hindbrain vesicular nucleotide transporter-positive neurons projected to the AVPV and expressed estrogen receptor α, and the neurons were activated by the high E2 treatment. These results suggest that hindbrain ATP-purinergic signaling triggers ovulation via activation of AVPV kisspeptin neurons.SIGNIFICANCE STATEMENT Ovulation disorders, which cause infertility and low pregnancy rates, are a serious problem for humans and livestock. The present study provides evidence that adenosine 5-triphosphate, acting as a neurotransmitter in the brain, stimulates kisspeptin neurons in the anteroventral periventricular nucleus, known as the gonadotropin-releasing hormone surge generator, via purinergic receptors to induce the gonadotropin-releasing hormone/luteinizing hormone surge and ovulation in rats. In addition, histologic analyses indicate that adenosine 5-triphosphate is likely to be originated from the purinergic neurons in the A1 and A2 of the hindbrain. These findings may contribute to new therapeutic controls for hypothalamic ovulation disorders in humans and livestock.
Assuntos
Kisspeptinas , Receptores Purinérgicos P2 , Humanos , Ratos , Feminino , Animais , Kisspeptinas/metabolismo , Estradiol/farmacologia , Estradiol/metabolismo , Hormônio Luteinizante/metabolismo , Hipotálamo Anterior/metabolismo , Hormônio Liberador de Gonadotropina/metabolismo , Estrogênios/farmacologia , Estrogênios/metabolismo , Neurônios/metabolismo , Ovulação , Rombencéfalo/metabolismo , Trifosfato de Adenosina/metabolismo , Nucleotídeos/metabolismo , Nucleotídeos/farmacologia , Adenosina/metabolismoRESUMO
Airway remodeling is a cardinal feature of asthma, associated with increased airway smooth muscle (ASM) cell mass and upregulation of extracellular matrix deposition. Exaggerated ASM cell migration contributes to excessive ASM mass. Previously, we demonstrated the alleviating role of Kp (kisspeptin) receptor (KISS1R) activation by Kp-10 in mitogen (PDGF [platelet-derived growth factor])-induced human ASM cell proliferation in vitro and airway remodeling in vivo in a mouse model of asthma. Here, we examined the mechanisms by which KISS1R activation regulates mitogen-induced ASM cell migration. KISS1R activation using Kp-10 significantly inhibited PDGF-induced ASM cell migration, further confirmed using KISS1R shRNA. Furthermore, KISS1R activation modulated F/G actin dynamics and the expression of promigration proteins like CDC42 (cell division control protein 42) and cofilin. Mechanistically, we observed reduced ASM RhoA-GTPAse with KISS1R activation. The antimigratory effect of KISS1R was abolished by PKA (protein kinase A)-inhibitory peptide. Conversely, KISS1R activation significantly increased cAMP and phosphorylation of CREB (cAMP-response element binding protein) in PDGF-exposed ASM cells. Overall, these results highlight the alleviating properties of Kp-10 in the context of airway remodeling.
Assuntos
Movimento Celular , Kisspeptinas , Miócitos de Músculo Liso , Fator de Crescimento Derivado de Plaquetas , Receptores de Kisspeptina-1 , Transdução de Sinais , Proteína rhoA de Ligação ao GTP , Humanos , Movimento Celular/efeitos dos fármacos , Miócitos de Músculo Liso/metabolismo , Miócitos de Músculo Liso/efeitos dos fármacos , Kisspeptinas/metabolismo , Fator de Crescimento Derivado de Plaquetas/metabolismo , Fator de Crescimento Derivado de Plaquetas/farmacologia , Receptores de Kisspeptina-1/metabolismo , Receptores de Kisspeptina-1/genética , Proteína rhoA de Ligação ao GTP/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Proteína cdc42 de Ligação ao GTP/metabolismo , Remodelação das Vias Aéreas , AMP Cíclico/metabolismo , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Células Cultivadas , Fatores de Despolimerização de Actina/metabolismo , Actinas/metabolismo , Proliferação de CélulasRESUMO
The timing of puberty onset is reliant on increased gonadotropin-releasing hormone (GnRH). This elicits a corresponding increase in luteinizing hormone (LH) due to a lessening of sensitivity to the inhibitory actions of estradiol (E2). The mechanisms underlying the increase in GnRH release likely involve a subset of neurons within the arcuate (ARC) nucleus of the hypothalamus that contain kisspeptin, neurokinin B (NKB), and dynorphin (KNDy neurons). We aimed to determine if KNDy neurons in female sheep are critical for: timely puberty onset; the LH surge; and the response to an intravenous injection of the neurokinin-3 receptor (NK3R) agonist, senktide. Prepubertal ewes received injections aimed at the ARC containing blank-saporin (control, n = 5) or NK3-saporin (NK3-SAP, n = 6) to ablate neurons expressing NK3R. Blood samples taken 3/week for 65 days following surgery were assessed for progesterone to determine onset of puberty. Control ewes exhibited onset of puberty at 33.2 ± 3.9 days post sampling initiation, whereas 5/6 NK3-SAP treated ewes didn't display an increase in progesterone. After an artificial LH surge protocol, surge amplitude was lower in NK3-SAP ewes. Finally, ewes were treated with senktide to determine if an LH response was elicited. LH pulses were evident in both groups in the absence of injections, but the response to senktide vs saline was similar between groups. These results show that KNDy cells are necessary for timely puberty onset and for full expresson of the LH surge. The occurrence of LH pulses in NK3-SAP treated ewes may indicate a recovery from an apulsatile state.
Assuntos
Núcleo Arqueado do Hipotálamo , Hormônio Luteinizante , Fragmentos de Peptídeos , Substância P/análogos & derivados , Feminino , Animais , Ovinos , Hormônio Luteinizante/farmacologia , Núcleo Arqueado do Hipotálamo/metabolismo , Saporinas/farmacologia , Progesterona/farmacologia , Hormônio Liberador de Gonadotropina/farmacologia , Hormônio Liberador de Gonadotropina/metabolismo , Neurocinina B/metabolismo , Dinorfinas/farmacologia , Dinorfinas/metabolismo , Kisspeptinas/metabolismoRESUMO
Mammalian ovulation is induced by a luteinizing hormone surge, which is triggered by elevated plasma estrogen levels; however, chronic exposure to high levels of estradiol is known to inhibit luteinizing hormone secretion. In the present study, we hypothesized that the inhibition of the luteinizing hormone surge by chronic estradiol exposure is due to the downregulation of the estrogen receptor alpha in kisspeptin neurons at hypothalamic anteroventral periventricular nucleus, which is known as the gonadotropin-releasing hormone/luteinizing hormone surge generator. Animals exposed to estradiol for 2 days showed an luteinizing hormone surge, whereas those exposed for 14 days showed a significant suppression of luteinizing hormone. Chronic estradiol exposure did not affect the number of kisspeptin neurons and the percentage of kisspeptin neurons with estrogen receptor alpha or c-Fos in anteroventral periventricular nucleus, but it did affect the number of kisspeptin neurons in arcuate nucleus. Furthermore, chronic estradiol exposure did not affect gonadotropin-releasing hormone neurons. In the pituitary, 14-day estradiol exposure significantly reduced the expression of Lhb mRNA and LHß-immunoreactive areas. Gonadotropin-releasing hormone-induced luteinizing hormone release was also reduced significantly by 14-day estradiol exposure. We revealed that the suppression of an luteinizing hormone surge by chronic estradiol exposure was induced in association with the significant reduction in kisspeptin neurons in arcuate nucleus, luteinizing hormone expression in the pituitary, and pituitary responsiveness to gonadotropin-releasing hormone, and this was not caused by changes in the estrogen receptor alpha-expressing kisspeptin neurons in anteroventral periventricular nucleus and gonadotropin-releasing hormone neurons, which are responsible for estradiol positive feedback.
Assuntos
Estradiol , Hormônio Luteinizante , Feminino , Animais , Hormônio Luteinizante/metabolismo , Estradiol/farmacologia , Estradiol/metabolismo , Kisspeptinas/genética , Kisspeptinas/metabolismo , Receptor alfa de Estrogênio/genética , Receptor alfa de Estrogênio/metabolismo , Hormônio Liberador de Gonadotropina/metabolismo , Hipotálamo Anterior/metabolismo , Núcleo Arqueado do Hipotálamo/metabolismo , Neurônios/metabolismo , Mamíferos/metabolismoRESUMO
Nitric oxide (NO) is a gaseous molecule that regulates various reproductive functions. It is a well-recognized regulator of GnRH-FSH/LH-sex steroid secretion in vertebrates including fish. Kisspeptin is a recently discovered neuropeptide which also regulates GnRH secretion. Nitrergic and kisspeptin neurons are reported in close physical contact in the mammalian brain suggesting their interactive role in the release of GnRH. The existence of kisspeptin and NOS is also demonstrated in vertebrate gonads, but information on their reciprocal relation in gonads, if any, is obscure. Therefore, attempts were made to evaluate the functional reciprocal relation between nitric oxide and kisspeptin in the catfish gonads, if any, by administering the nitric oxide synthase (NOS) inhibitor, L-NAME {N(G)-nitro-L-arginine methyl ester}, which reduces NO production, and kisspeptin agonist (KP-10) and assessing their impacts on the expressions of kisspeptin1, different NOS isoforms, NO and steroid production in the gonadal tissue. The results revealed that L-NAME suppressed the expression of kiss1 in gonads of the catfish establishing the role of NO in kisspeptin expression. However, KP-10 increased the expression of all the isoforms of NOSs (iNOS, eNOS, nNOS) and concurrently NO and steroids in the ovary and testis. In vitro studies also indicate that kisspeptin stimulates the production of NO and estradiol and testosterone levels in the gonadal explants and medium. Thus, in vivo results clearly suggest a reciprocal interaction between kisspeptin and NO to regulate the gonadal activity of the catfish. The in vitro findings further substantiate our contention regarding the interactive role of kisspeptin and NO in gonadal steroidogenesis.
Assuntos
Peixes-Gato , Gametogênese , Kisspeptinas , NG-Nitroarginina Metil Éster , Óxido Nítrico , Animais , Óxido Nítrico/metabolismo , Peixes-Gato/metabolismo , Kisspeptinas/metabolismo , Masculino , NG-Nitroarginina Metil Éster/farmacologia , Feminino , Gametogênese/efeitos dos fármacos , Esteroides/biossíntese , Óxido Nítrico Sintase/metabolismo , Testículo/metabolismo , Testículo/efeitos dos fármacos , Gônadas/metabolismo , Gônadas/efeitos dos fármacos , Ovário/metabolismoRESUMO
Kisspeptin is an important hormone involved in the stimulation of the hypothalamo-pituitary gonadal (HPG) axis. The HPG axis can be suppressed in certain conditions such as stress, which gives rise to the activation of the hypothalamo-pituitary-adrenal (HPA) axis. However, the physiological role of kisspeptin in the interaction of HPG and HPA axis is not fully understood yet. This study was conducted to investigate the possible effects of central kisspeptin injection on HPG axis as well as HPA axis activity. Adult male Wistar rats were randomly divided into seven groups as followed: sham (control), kisspeptin (50 pmol), P234 (1 nmol), kisspeptin + p234, kisspeptin + antalarmin (0.1 µg), kisspeptin + astressin 2B (1 µg), and kisspeptin + atosiban (300 ng/rat) (n = 10 each group). At the end of the experiments, the hypothalamus, pituitary, and serum samples of the rats were collected. There was no significant difference in corticotropic-releasing hormone immunoreactivity in the paraventricular nucleus of the hypothalamus, serum adrenocorticotropic hormone, and corticosterone levels among all groups. Moreover, no significant difference was detected in pituitary oxytocin level. Serum follicle-stimulating hormone and luteinizing hormone levels of the kisspeptin, kisspeptin + antalarmin, and kisspeptin + astressin 2B groups were significantly higher than the control group. Serum testosterone levels were significantly higher in the kisspeptin kisspeptin + antalarmin, kisspeptin + astressin 2B, and kisspeptin + atosiban groups compared to the control group. Our findings suggest that central kisspeptin injection causes activation in the HPG axis, but not the HPA axis in male rats.
Assuntos
Sistema Hipotálamo-Hipofisário , Kisspeptinas , Sistema Hipófise-Suprarrenal , Ratos Wistar , Animais , Masculino , Kisspeptinas/administração & dosagem , Kisspeptinas/farmacologia , Kisspeptinas/metabolismo , Sistema Hipotálamo-Hipofisário/efeitos dos fármacos , Sistema Hipotálamo-Hipofisário/metabolismo , Sistema Hipófise-Suprarrenal/efeitos dos fármacos , Sistema Hipófise-Suprarrenal/metabolismo , Ratos , Fragmentos de Peptídeos/administração & dosagem , Hormônio Luteinizante/sangue , Hormônio Luteinizante/metabolismo , Corticosterona/sangue , Vasotocina/farmacologia , Vasotocina/administração & dosagem , Testosterona/sangue , Injeções Intraventriculares , Gônadas/metabolismo , Gônadas/efeitos dos fármacos , Hipófise/metabolismo , Hipófise/efeitos dos fármacos , Hormônio Liberador de Gonadotropina/metabolismo , Hormônio Adrenocorticotrópico/sangue , Hormônio Liberador da Corticotropina , OligopeptídeosRESUMO
In brief: The transcriptional profiles of Kiss1 neurons from the arcuate and the rostral periventricular region of the third ventricle of the hypothalamus have been directly compared in diestrous female mice. Differentially expressed genes provide molecular signatures for these two populations of Kiss1 neurons and insights into their physiology. Abstract: The neuropeptide kisspeptin is produced by Kiss1 neurons and is required for normal mammalian fertility. The two main populations of Kiss1 neurons are located in the arcuate (ARC) and the rostral periventricular area of the third ventricle (RP3V) of the hypothalamus. To define the molecular signature of these Kiss1 populations, transcriptomics profiling was performed using purified Kiss1 neurons from diestrous stage female mice. From a data set of 7026 genes, 332 differentially expressed transcripts were identified between the Kiss1ARC and Kiss1RP3V neurons. These data have uncovered novel transcripts and expanded the receptor expression, co-transmitter and transcription factor profiles of Kiss1 neurons. Validation by quantitative RT-PCR confirmed differential expression of Cartpt, Ddc, Gal, Gda, Npy2r, Penk, Rasp18, Rxfp3, Slc18a2, and Th in Kiss1RP3V neurons and Gpr83, Hctr2, Nhlh2, Nmn, Npr3, Nr4a2, Nr5a2, Olfm2, Tac2 and Tacr3 in Kiss1ARC neurons. Enriched pathways common to both Kiss1 populations included the NF-kB, mTor, endocannabinoid, GPCR, Wnt and oestrogen signalling while some pathways (e.g. cytomegalovirus infection, dopaminergic and serotonergic biosynthesis) were specific to Kiss1RP3V neurons. Our gene expression data set augments the existing data sets describing the transcriptional profiles of Kiss1 neuronal populations.
Assuntos
Kisspeptinas , Neurônios , Neuropeptídeos , Animais , Feminino , Camundongos , Núcleo Arqueado do Hipotálamo/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Hipotálamo/metabolismo , Kisspeptinas/genética , Kisspeptinas/metabolismo , Neurônios/metabolismo , Neuropeptídeos/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Transdução de Sinais , Perfilação da Expressão GênicaRESUMO
This study unravels the intricate interplay between photoperiod, melatonin, and kisspeptin to orchestrate the pubertal onset of Common carp. Female fingerlings exposed to long days (LD) exhibited a hormonal crescendo, with upregulated hypothalamic-pituitary-ovarian (HPO) axis genes (kiss1, kiss1r, kiss2, gnrh2, gnrh3) and their downstream targets (lhr, fshr, ar1, esr1). However, the expression of the melatonin receptor (mtnr1a) diminished in LD, suggesting a potential inhibitory role. This hormonal symphony was further amplified by increased activity of key transcriptional regulators (gata1, gata2, cdx1, sp1, n-myc, hoxc8, plc, tac3, tacr3) and decreased expression of delayed puberty genes (mkrn1, dlk1). In contrast, short days (SD) muted this hormonal chorus, with decreased gnrh gene and regulator expression, elevated mtnr1a, and suppressed gonadal development. In in-vitro, estradiol mimicked the LD effect, boosting gnrh and regulator genes while dampening mtnr1a and melatonin-responsive genes. Conversely, melatonin acted as a conductor, downregulating gnrh and regulator genes and amplifying mtnr1a. Our findings illuminate the crucial roles of melatonin and kisspeptin as opposing forces in regulating pubertal timing. LD-induced melatonin suppression allows the kisspeptin symphony to flourish, triggering GnRH release and, ultimately, gonadal maturation. This delicate dance between photoperiod, melatonin, and kisspeptin orchestrates common carp's transition from juvenile to reproductive life.
Assuntos
Carpas , Kisspeptinas , Melatonina , Fotoperíodo , Maturidade Sexual , Animais , Melatonina/metabolismo , Kisspeptinas/metabolismo , Kisspeptinas/genética , Feminino , Carpas/metabolismo , Carpas/genética , Carpas/crescimento & desenvolvimento , Carpas/fisiologia , Maturidade Sexual/fisiologia , Proteínas de Peixes/metabolismo , Proteínas de Peixes/genéticaRESUMO
Endometriosis and polycystic ovary syndrome (PCOS) are two common female reproductive disorders with a significant impact on the health and quality of life of women affected. A novel hypothesis by evolutionary biologists suggested that these two diseases are inversely related to one another, representing a pair of diametrical diseases in terms of opposite alterations in reproductive physiological processes but also contrasting phenotypic traits. However, to fully explain the phenotypic features observed in women with these conditions, we need to establish a potential nexus system between the reproductive system and general biological functions. The recent discovery of kisspeptin as pivotal mediator of internal and external inputs on the hypothalamic-pituitary-gonadal axis has led to a new understanding of the neuroendocrine upstream regulation of the human reproductive system. In this review, we summarize the current knowledge on the physiological roles of kisspeptin in human reproduction, as well as its involvement in complex biological functions such as metabolism, inflammation and pain sensitivity. Importantly, these functions are known to be dysregulated in both PCOS and endometriosis. Within the evolving scientific field of "kisspeptinology", we critically discuss the clinical relevance of these discoveries and their potential translational applications in endometriosis and PCOS. By exploring the possibilities of manipulating this complex signaling system, we aim to pave the way for novel targeted therapies in these reproductive diseases.
Assuntos
Endometriose , Síndrome do Ovário Policístico , Feminino , Humanos , Síndrome do Ovário Policístico/metabolismo , Kisspeptinas/metabolismo , Kisspeptinas/uso terapêutico , Qualidade de Vida , Reprodução/fisiologiaRESUMO
Early life adversity in the form of childhood maltreatment in humans or as modeled by maternal separation (MS) in rodents is often associated with an earlier emergence of puberty in females. Earlier pubertal initiation is an example of accelerated biological aging and predicts later risk for anxiety in women, especially in populations exposed to early life trauma. Here we investigated external pubertal markers as well as hypothalamic gene expression of pubertal regulators kisspeptin and gonadotropin-releasing hormone, to determine a biological substrate for MS-induced accelerated puberty. We further investigated a mechanism by which developmental stress might regulate pubertal timing. As kisspeptin and gonadotropin-releasing hormone secretion are typically inhibited by corticotropin releasing hormone at its receptor CRH-R1, we hypothesized that MS induces a downregulation of Crhr1 gene transcription in a cell-specific manner. Finally, we explored the association between pubertal timing and anxiety-like behavior in an acoustic startle paradigm, to drive future preclinical research linking accelerated puberty and anxiety. We replicated previous findings that MS leads to earlier puberty in females but not males, and found expression of kisspeptin and gonadotropin-releasing hormone mRNA to be prematurely increased in MS females. RNAscope confirmed increased expression of these genes, and further revealed that kisspeptin-expressing neurons in females were less likely to express Crhr1 after MS. Early puberty was associated with higher acoustic startle magnitude in females. Taken together, these findings indicate precocial maturation of central pubertal timing mechanisms after MS, as well as a potential role of CRH-R1 in these effects and an association with a translational measure of anxiety.
Assuntos
Experiências Adversas da Infância , Kisspeptinas , Humanos , Ratos , Feminino , Animais , Kisspeptinas/genética , Kisspeptinas/metabolismo , Privação Materna , Hipotálamo/metabolismo , Hormônio Liberador de Gonadotropina/metabolismo , Maturidade Sexual/fisiologiaRESUMO
INTRODUCTION: Postweaning social isolation (PWSI) in rodents is an advanced psychosocial stress model in early life. Some psychosocial stress, such as restrain and isolation, disrupts reproductive physiology in young and adult periods. Mechanisms of early-life stress effects on central regulation of reproduction need to be elucidated. We have investigated the effects of PWSI on function of arcuate kisspeptin (ARCKISS1) neurons by using electrophysiological techniques combining with monitoring of puberty onset and estrous cycle in male and female Kiss1-Cre mice. METHODS: Female mice were monitored for puberty onset with vaginal opening examination during social isolation. After isolation, the estrous cycle of female mice was monitored with vaginal cytology. Anxiety-like behavior of mice was determined by an elevated plus maze test. Effects of PWSI on electrophysiology of ARCKISS1 neurons were investigated by the patch clamp method after intracranial injection of AAV-GFP virus into arcuate nucleus of Kiss1-Cre mice after the isolation period. RESULTS: We found that both male and female isolated mice showed anxiety-like behavior. PWSI caused delay in vaginal opening and extension in estrous cycle length. Spontaneous-firing rates of ARCKISS1 neurons were significantly lower in the isolated male and female mice. The peak amplitude of inhibitory postsynaptic currents to ARCKISS1 neurons was higher in the isolated mice, while frequency of excitatory postsynaptic currents was higher in group-housed mice. CONCLUSION: These findings demonstrate that PWSI alters pre- and postpubertal reproductive physiology through metabolic and electrophysiological pathways.
Assuntos
Núcleo Arqueado do Hipotálamo , Ciclo Estral , Kisspeptinas , Neurônios , Maturidade Sexual , Isolamento Social , Animais , Kisspeptinas/metabolismo , Feminino , Núcleo Arqueado do Hipotálamo/metabolismo , Neurônios/fisiologia , Neurônios/metabolismo , Masculino , Maturidade Sexual/fisiologia , Camundongos , Ciclo Estral/fisiologia , Camundongos Transgênicos , Ansiedade/fisiopatologia , Estresse Psicológico/fisiopatologiaRESUMO
INTRODUCTION: Sodium-glucose cotransporter 2 inhibitors (SGLT2is) have shown neuroprotective effects in obese mice. However, whether SGLT2i can ameliorate high-fat diet (HFD)-related ovulation disorders remains unknown. The aim of this research was to investigate whether dapagliflozin improves HFD-induced ovulatory dysfunction by attenuating microglia-mediated hypothalamic inflammation. METHODS: C57BL/6J female mice fed HFD were treated with dapagliflozin (1 mg/kg) for 22 weeks. Plasma insulin, leptin, luteinizing hormone (LH), estradiol (E2), and IL-1ß levels were also tested. Microglial morphology, cell numbers, and SGLT2 expression were evaluated using immunofluorescence. The expression of IL-1ß, NLRP3, kisspeptin, gonadotropin-releasing hormone (GnRH), SGLT2, insulin, and leptin receptors in the hypothalamus was determined using immunohistochemical staining. We also examined the effects of dapagliflozin on glucose metabolism and the release of inflammatory factor in palmitic acid (PA)-treated HMC3 cells. RESULTS: As expected, dapagliflozin improved HFD-induced metabolic disturbances, peripheral versus central insulin and leptin resistance and also restored the regular estrous cycle. Furthermore, dapagliflozin blunted microglia activation, NLRP3 inflammasome priming, hypothalamic inflammation, and increased the expression of GnRH and kisspeptin at proestrus in the hypothalamus. Additionally, dapagliflozin markedly reduced IL-6 and NO release and fat accumulation, decreased lactic acid production and glucose consumption, and inhibited mammalian target of rapamycin (mTOR) and hexokinase 2 (HK2) expression in PA-treated HMC3 cells. These effects suggest that dapagliflozin reduced the mTOR/HK2-mediated aerobic glycolysis. CONCLUSIONS: Dapagliflozin improved HFD-related ovulation disorders by regulating glucose metabolism through mTOR/HK2 signaling and attenuating microglia-mediated hypothalamic inflammation. These results validate the novel role for the neuroprotection of SGLT2i in HFD-induced obesity and ovulation disorders.
Assuntos
Compostos Benzidrílicos , Dieta Hiperlipídica , Glucosídeos , Leptina , Camundongos , Feminino , Animais , Dieta Hiperlipídica/efeitos adversos , Leptina/metabolismo , Transportador 2 de Glucose-Sódio/metabolismo , Transportador 2 de Glucose-Sódio/farmacologia , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Kisspeptinas/metabolismo , Microglia , Camundongos Endogâmicos C57BL , Inflamação/tratamento farmacológico , Inflamação/metabolismo , Serina-Treonina Quinases TOR/metabolismo , Hipotálamo/metabolismo , Insulina/metabolismo , Glucose/metabolismo , Hormônio Liberador de Gonadotropina/metabolismo , Ovulação , Mamíferos/metabolismoRESUMO
Asthma is a multifactorial disease of origin characterized by airway hyperresponsiveness (AHR) and airway remodeling. Several pieces of evidence from other pathologies suggest that Kisspeptins (Kp) regulate cell proliferation, migration, and invasion, mechanisms that are highly relevant to asthma. Our recent in vitro studies show Kp-10 (active peptide of Kp), via its receptor, KISS1R, inhibits human airway smooth muscle cell proliferation. Here, we hypothesize a crucial role for Kp-10 in regulating AHR and airway remodeling in vivo. Utilizing C57BL/6J mice, we assessed the effect of chronic intranasal Kp-10 exposure on mixed allergen (MA)-induced mouse model of asthma. MA-challenged mice showed significant deterioration of lung function compared to those exposed to vehicle (DPBS); Kp-10 treatment significantly improved the MA-altered lung functions. Mice treated with Kp-10 alone did not show any notable changes in lung functions. MA-exposed mice showed a significant reduction in KISS1R expression as compared to vehicle alone. MA-challenged mice showed significant alterations in immune cell infiltration in the airways and remodeling changes. Proinflammatory cytokines were significantly increased upon MA exposure, an effect abrogated by Kp-10 treatment. Furthermore, biochemical and histological studies showed Kp-10 exposure significantly reduced MA-induced smooth muscle mass and soluble collagen in the lung. Overall, our findings highlight the effect of chronic Kp-10 exposure in regulating MA-induced AHR and remodeling. © 2023 The Pathological Society of Great Britain and Ireland.
Assuntos
Asma , Hipersensibilidade Respiratória , Animais , Camundongos , Remodelação das Vias Aéreas , Asma/metabolismo , Modelos Animais de Doenças , Kisspeptinas/efeitos adversos , Kisspeptinas/metabolismo , Pulmão/patologia , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Receptores de Kisspeptina-1/metabolismo , Hipersensibilidade Respiratória/metabolismoRESUMO
We attempted to clarify clinical value of KiSS-1 and MMP-2 levels in breast cancer (BC) tissue in evaluating prognosis of elderly BC patients after modified radical mastectomy (MCM). The data of 192 elderly female BC patients receiving MCM in our hospital from January 2018 to December 2022 were collected. According to prognosis, patients received division into poor prognosis group (n = 43) and good prognosis group (n = 149). The serum CEA level and KiSS-1 and MMP-2 levels in BC tissue received measurement in both groups. The predictive value of KiSS-1 and MMP-2 alone and jointly in adverse prognosis of elderly BC patients after MCM received assessment. Results showed that No statistical significance was exhibited between both groups in general data (P > 0.05). The serum CEA level and MMP-2 expression in BC tissue in poor prognosis group exhibited elevation relative to those in good prognosis group, and KiSS-1 expression in BC tissue in poor prognosis group exhibited depletion relative to that in good prognosis group, indicating statistical significance (P < 0.05). The high-level KiSS-1 might be a protective element for adverse prognosis of elderly BC patients after MCM, and high-level CEA and MMP-2 might be an independent risk element for adverse prognosis of elderly BC patients after MCM (P < 0.05). KiSS-1 and MMP-2 alone and jointly predicted AUC of adverse prognosis in elderly BC patients after MCM were 0.93, 0.802 and 0.958, with certain predictive values; when cutoff values of KiSS-1 and MMP-2 were 6.15 and 2.26, the predictive value was the best. In conclusion, KiSS-1 and MMP-2 levels in BC tissue possess relation to adverse prognosis of MCM. KiSS-1 and MMP-2 levels in elderly BC patients before surgery may be detected in the future to assist in prognosis evaluation of elderly BC patients after MCM.
Assuntos
Neoplasias da Mama , Kisspeptinas , Mastectomia Radical Modificada , Metaloproteinase 2 da Matriz , Humanos , Feminino , Metaloproteinase 2 da Matriz/metabolismo , Metaloproteinase 2 da Matriz/sangue , Neoplasias da Mama/cirurgia , Neoplasias da Mama/patologia , Neoplasias da Mama/metabolismo , Neoplasias da Mama/mortalidade , Idoso , Prognóstico , Kisspeptinas/metabolismo , Curva ROC , Biomarcadores Tumorais/metabolismo , Biomarcadores Tumorais/sangue , Idoso de 80 Anos ou maisRESUMO
The present study aims to analyze the effects of developmental exposure to phthalates at environmentally relevant doses on the neural control of male and female reproduction. For this purpose, C57Bl/6J mice were exposed to di-(2-ethylexyl) phthalate (DEHP) alone (5 or 50 µg/kg/d), or DEHP (5 µg/kg/d) in a phthalate mixture. Exposure through diet started 6 weeks before the first mating and lasted until weaning of litters from the second gestation (multiparous dams). Analyses of offspring born from multiparous dams exposed to DEHP alone or in a phthalate mixture showed that females experienced a delayed pubertal onset, and as adults they had prolonged estrous cyclicity and reduced Kiss1 expression in the preoptic area and mediobasal hypothalamus. Male littermates showed a reduced anogenital distance and delayed pubertal onset compared with controls. However, in adulthood the weight of androgen-sensitive organs and hypothalamic Kiss1 expression were unaffected, suggesting normal functioning of the male gonadotropic axis. Developmental exposure to DEHP alone or in a phthalate mixture reduced the ability of intact males and ovariectomized and hormonally primed females to attract a sexual partner and to express copulatory behaviors. In addition, females were unable to discriminate between male and female stimuli in the olfactory preference test. Social interaction was also impaired in females, while locomotor activity and anxiety-like behavior in both sexes were unaffected by the treatment. The sexual deficiencies were associated with reduced expression of the androgen receptor in the preoptic area and progesterone receptor in the mediobasal hypothalamus, the key regions involved in male and female sexual behavior, respectively. Thus, the neural structures controlling reproduction are vulnerable to developmental exposure to phthalates at environmentally relevant doses in male and female mice. Adult females had an impaired gonadotropic axis and showed more affected behaviors than adult males.