Kiss1 Levels Research Articles

NAGK regulates the onset of puberty in female mice

This study examines the role of N-acetylglucosamine kinase (NAGK) in initiating puberty in female mice. We employed real-time quantitative reverse transcription polymerase chain reaction (RT-qPCR) and immunofluorescence to measure NAGK expression in the hypothalamic-pituitary-ovarian axis across various developmental stages: infant, prepuberty, puberty, and adult. We further investigated the impact of Nagk gene knockdown on puberty in female mice. This included assessing the expression of puberty-related genes both in vivo and in vitro, GT1-7 cells proliferation and apoptosis, concentrations of GnRH and Kisspeptin, puberty onset timing, serum levels of progesterone (P4) and estradiol (E2), and ovarian morphology. Results revealed that Nagk mRNA is present in the hypothalamus, pituitary, and ovaries throughout different developmental stages in female mice. In the hypothalamus, Nagk mRNA levels were comparable during infant and prepuberty, lowest during puberty, and highest in adult. In the pituitary, Nagk mRNA peaked in adult, with no significant variation between infant, prepuberty, and puberty. In the ovaries, Nagk mRNA levels increased during puberty and peaked in adult. NAGK is predominantly located in the arcuate nucleus (ARC), periventricular nucleus (PeN), dorsomedial hypothalamic nucleus (DMH), paraventricular nucleus (PVN), adenohypophysis, and in the ovarian oocytes, interstitium, and granulosa cells across all developmental stages in female mice. Nagk knockdown in GT1-7 cells decreased the transcriptional level of Gnrh, Kiss1, Gpr54, Igf1 and Mapk14 mRNA and cell proliferation but increased the level of β-catenin mRNA and cell apoptosis, while reducing GnRH secretion. Following ICV injection, Nagk gene knockdown mice exhibited delayed the timing of vaginal opening (VO) and reduced hypothalamic levels of Gnrh, Kiss1, Gpr54, Igf1, Mapk14, and β-catenin mRNA. Additionally, serum concentrations of E2 in Nagk gene knockdown mice were significantly lower compared to the control group. These findings indicate that Nagk regulates the expression of Gnrh and Kiss1 mRNA in GT1-7 cells, affects hypothalamus Gnrh mRNA levels and serum E2 concentration, and that its knockdown can delay puberty onset in female mice.

Kisspeptin expression levels in patients with placenta previa: A randomized trial.

This study aimed to explore the potential influence of kisspeptin (KISS1) levels on the etiology of placenta previa for early pregnancy diagnosis. The study included 20 pregnant women diagnosed with placenta previa and 20 pregnant woman with normal pregnancies between 2021 and 2022. Plasma KISS1 levels were determined through biochemical analysis, while genetic analysis assessed KISS1 and KISS1 receptor gene expression levels. Immunohistochemical methods were employed to determine placenta KISS1 levels. The evaluation of KISS1 concentration in serum revealed a significant decrease in the placenta previa group compared to the control group (P < .001). KISS1 gene expression level 0.043-fold decreased in the placenta previa group (P < .001). Furthermore, the KISS1 receptor gene expression level increased 170-fold in the placenta previa group. Results from biochemical, immunohistochemical, and genetic analyses consistently indicated significantly reduced KISS1 expression in patients with placenta previa. These findings suggest a potential link between diminished KISS1 levels and the occurrence of placenta previa. KISS1 may play a critical role in the etiology of placenta previa. Detailed studies on angiogenesis, cell migration and tissue modeling should be conducted to understand possible mechanisms.

Altered expression of kisspeptin, dynorphin, and related neuropeptides in polycystic ovary syndrome: A cross-sectional study.

Since kisspeptin (KISS1) in the hypothalamus is affected by the inhibitory effect of dynorphin, it raises questions about the controlled balance of these 2 neuropeptides in women with and without polycystic ovary syndrome (PCOS). This study compares the expression levels of KISS1, dynorphin, neurokinin-B, leptin, and neuropeptide-Y in women with and without PCOS. In this cross-sectional study, the peripheral blood samples of 20 women with PCOS and 20 women without PCOS who referred to Yamin Kencana Clinic, Cipto Mangunkusumo hospital, Jakarta, Indonesia were enrolled from August-December 2022. mRNA relative expression of genes related to the central factors associated with PCOS, such as leptin, neuropeptide-Y, KISS1, tachykinin-3, and prodynorphin (PDYN), in PCOS and non-PCOS populations were examined. Gene quantification was carried out by the quantitative polymerase chain reaction method. The KISS1/PDYN ratio was significantly higher in the PCOS group than in the control group (p = 0.02), and the PDYN was lower in the PCOS group than the control group (p 0.001). Moreover, the positive correlation between KISS1 and the KISS1/PDYN ratio was significantly stronger in the PCOS group than in the control group (R = 0.93; p 0.001 vs. R = 0.66, p 0.001). Our results suggest that an increased KISS1/PDYN ratio in PCOS women is related to diminished dynorphin expression. Low expression of the gene encoding dynorphin and a high KISS1/PDYN ratio is highly specific to PCOS.

Neurokinin B in the yellowtail kingfish (Seriola lalandi) and its potential role in controlling reproduction

The neurokinin B (NKB) system acts as a crucial modulator in the regulation of reproduction and feeding in mammals, however limited information is available in teleosts regarding its potential role in reproductive functions. Herein, we have identified its encoding gene, namely tachykinin 3 (tac3), in the yellowtail kingfish. The full-length tac3 cDNA sequence was 372 bp in size and encoded a 123-aa preprohormone, including two mature peptides, NKB and NKF. Tissue distribution analysis showed that tac3 was primarily expressed in the intestine of yellowtail kingfish. During embryonic development, the highest mRNA levels of tac3 were observed at stage 4 (16-cell) and stage 14 (newly-hatched larva). The peak of tac3 transcript levels was also noticed at 30 days post-hatching during early ontogeny. The physiological effects of NKB and NKF on expression of brain and pituitary genes along with plasma hormones levels were further analyzed by intraperitoneal injection. NKB exerted a stimulatory effect on gnrh1, gnrh2, gnih, and kiss2r mRNA levels, but suppressed kiss1r, gnihr, gal, gh, lhβ, and fshβ mRNA levels. An evident increase was observed on transcript levels of gnrh1, gnrh2, kiss1, kiss2, gnih, and gnihr after NKF treatment, whereas kiss1r, kiss2r, gh, lhβ, and fshβ mRNA levels were down-regulated. Moreover, NKF, but not NKB, reduced serum estradiol levels, and both of these two peptides suppressed serum 11-keto testosterone levels. Taken together, our results provide preliminary evidence that the NKB system participates in the control of reproduction in yellowtail kingfish via acting on brain, pituitary and gonadal hormones.

Metastasis suppressor kisspeptin (KISS1) in the blood serum of lung cancer patients

Aim. To conduct a comparative assessment of the content of kisspeptin (KISS1) metastasis suppressor in the blood serum of apparently healthy individuals and patients with lung cancer (LC) and to analyze the associations between the KISS1 level and clinical and pathological characteristics of the disease.Materials and methods. The study included 74 LC patients and 46 apparently healthy individuals. Stage I LC was diagnosed in 8 patients, stage II LC – in 7 patients, stage III LC – in 28 patients, and stage IV LC – in 31 patients. According to the histologic pattern, 32 tumors were characterized as adenocarcinoma, 29 – as squamous-cell carcinoma, 11 – as small-cell LC (SCLC), and 2 – as large-cell lung carcinoma. The pre-treatment KISS1 level in the blood serum was determined using the enzyme-linked immunosorbent assay kit (KISS1, CloudClone Corp., USA).Results. The median serum KISS1 level in LC patients was 213 (range 7.8–716) pg / ml and was significantly higher than in the control group – 83.4 (0–180) pg / ml (p &lt; 0.0001). The ROC analysis of the diagnostic value of serum KISS1 level demonstrated that the sensitivity of the test in relation to the healthy controls was 70% at a cutoff value of 152 pg / ml, and the specificity was 85% (AUC – 0.817; р &lt; 0.0001). In stage I–II LC, the sensitivity did not exceed 50%. The level of KISS1 in the blood serum did not depend on the histologic type of the tumor. No significant differences in the serum KISS1 levels were observed both between non-small cell lung cancer (NSCLC) on the whole and neuroendocrine SCLC and between the main histologic types of NSCLC. The level of KISS1 increased with the disease stage (p &lt; 0.05). However, none of the TNM staging system indices significantly influenced the level of the marker. No differences were found between serum KISS1 levels in patients with central or peripheral localization of the tumor.Conclusion. The KISS1 level was elevated in LC patients compared to healthy controls and was a stage-dependent marker. It has high diagnostic specificity but insufficient sensitivity, especially at early stages of the disease. Based on the results of this study and literature data on the role of KISS1in NSCLC, we conclude that clinical implications of KISS1 in this disease require further research.

Clinical value of KiSS-1 and MMP-2 expression levels in breast cancer tissue in evaluating prognosis of elderly breast cancer patients after modified radical mastectomy.

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.

Maternal oral exposure to low-dose BPA accelerates the onset of puberty by promoting prepubertal Kiss1 expression in the AVPV nucleus of female offspring

As the incidence of precocious puberty has risen in recent years and the age at puberty onset is younger, children may be at increased risk for health consequences associated with the early onset of puberty. Bisphenol A (BPA) is recognized as an endocrine disruptor chemical that is reported to induce precocious puberty. The effect of BPA exposure modes, times, and doses (especially low dose) were controversial. In the present study, we evaluated the potential effects of maternal exposure to low-dose BPA on the hypothalamus, particularly on the arcuate (ARC) nucleus and anteroventral periventricular (AVPV) nucleus during peri-puberty in offspring of BPA-treated rats. Pregnant rats were exposed to corn oil vehicle, 0.05 mg·kg−1·day−1 BPA, or 5 mg·kg−1·day−1 from gestation day 1 (GD1) to postnatal day 21 (PND21) by daily gavage. Body weight (BW), vaginal opening (VO), ovarian follicular luteinization, and relevant hormone concentrations were measured; hypothalamic Kiss1 and GnRH1 levels by western immunoblot analysis were also assessed as indices of puberty onset. During or after exposure, low-dose BPA restricted BW after birth (at PND1 and PND5), and subsequently accelerated puberty onset by promoting the expression of prepubertal Kiss1 and GnRH1 in the AVPV nucleus on PND30, leading to advanced VO, an elevation in LH and FSH concentrations (on PND30). We also noted increased BW on PND30 and PND35. Maternal oral exposure to low-dose BPA altered the BW curve during the neonatal and peripubertal periods, and subsequently accelerated puberty onset by promoting prepubertal Kiss1 expression in the AVPV nucleus.

Metabolic markers in male infertility: a pilot study

Male infertility is an emerging health problem and there is an urgent need to search for therapeutic options. Altered metabolic states such as obesity and metabolic syndrome have been linked with male infertility. Therefore, searching for metabolic biomarkers is vital. Present work aimed to study metabolic alterations in infertile males. The seminal levels of L-Carnitine (LC), Kisspeptin (Kiss1) and Ghrelin (GHRL) were evaluated in 14 infertile and 10 fertile males. Baseline semen analysis was performed for both cases and controls. The levels of LC and Kiss1 were found to be lower in infertile patients as compared to fertile controls and the difference was found to be statistically significant. There was no significant difference observed in GHRL levels between patients and controls. The study presents a preliminary data where LC and Kiss1 levels could possibly studied further for their association with male infertility. But to confirm their association with pathogenesis of male infertility, future studies need to be conducted in larger cohorts.

KISS-1 knockdown inhibits cell growth, migration, and invasion in HTR-8/SVneo cells by regulating the GRP54-mediated PI3K/AKT signaling pathway

Recurrent spontaneous abortions (RSA) affect reproductive health and increase the risk of subsequent abortions. To investigate the role of KISS-1/GPR-54 signaling in RSA progression. Villus tissue was collected from RSA patients, and human trophoblastic HTR-8/SVneo cells were used. KISS-1 and GRP54 levels were detected using RT-qPCR and immunohistochemistry. Western blotting was performed to analyze ZO-1 and ZEB1 levels. Cell proliferation was determined via CCK-8 and cell clone formation assays. Transwell assays were performed to assess cell migration and invasion abilities. KISS-1 was down-regulated in the villus tissues of RSA patients. KISS-1 overexpression dramatically inhibited trophoblast proliferation, migration, and invasion. Mechanistically, ZEB1 expression was down-regulated, whereas ZO-1 expression was up-regulated, after KISS-1 overexpression. GPR54 silencing neutralized the effect of KISS-1 in HTR-8/SVneo cells. Additionally, KISS-1 overexpression inactivated the PI3K/AKT signaling pathway through GRP54. The KISS-1/GPR-54 signaling axis regulates RSA progression by regulating the PI3K/AKT signaling pathway.

Postnatal feeding with high-fat combined with high-glucose diet induces precocious puberty in Sprague‒Dawley rat pups

With economic development and overnutrition, including high-fat diets (HFD) and high-glucose diets (HGD), the incidence of obesity in children is increasing, and thus, the incidence of precocious puberty is increasing. Therefore, it is of great importance to construct a suitable animal model of overnutrition-induced precocious puberty for further in-depth study. Here, we fed a HFD, HGD, or HFD combined with a HGD to pups after P-21 weaning, while weaned pups fed a normal diet served as the control group. The results showed that HFD combined with a HGD increased the body weight (BW) of weaned rat pups. In addition, a HFD, HGD, and HFD combined with a HGD lowered the age at which vaginal opening occurred and accelerated the vaginal cell cycle. Furthermore, a HFD combined with a HGD increased the weight of the uterus and ovaries of weaned rat pups. Additionally, a HFD combined with a HGD promoted the development of reproductive organs in weaned female rat pups. Ultimately, a HFD combined with a HGD was found to elevate the serum levels of gonadotropin-releasing hormone (GnRH), luteinizing hormone (LH), follicle stimulating hormone (FSH), leptin, adiponectin, and oestradiol (E2) and increase hypothalamic GnRH, Kiss-1, and GPR54 expression levels in weaned female rat pups. The current study found that overnutrition, such as that through a HFD combined with HGD, could induce precocious puberty in weaned female rat pups. In addition, a rat model of overnutrition-induced precocious puberty was established.

The interplay between kisspeptin and endocannabinoid systems modulates male hypothalamic and gonadic control of reproduction in vivo.

Male reproduction is under the control of the hypothalamus-pituitary-gonadal (HPG) axis. The endocannabinoid system (ECS) and the kisspeptin system (KS) are two major signaling systems in the central and peripheral control of reproduction, but their possible interaction has been poorly investigated in mammals. This manuscript analyzes their possible reciprocal modulation in the control of the HPG axis. Adolescent male rats were treated with kisspeptin-10 (Kp10) and endocannabinoid anandamide (AEA), the latter alone or in combination with the type 1 cannabinoid receptor (CB1) antagonist rimonabant (SR141716A). The hypothalamic KS system and GnRH expression, circulating sex steroids and kisspeptin (Kiss1) levels, and intratesticular KS and ECS were evaluated by immunohistochemical and molecular methods. Non-coding RNAs (i.e., miR145-5p, miR-132-3p, let7a-5p, let7b-5p) were also considered. Circulating hormonal values were not significantly affected by Kp10 or AEA; in the hypothalamus, Kp10 significantly increased GnRH mRNA and aromatase Cyp19, Kiss1, and Kiss1 receptor (Kiss1R) proteins. By contrast, AEA treatment affected the hypothalamic KS at the protein levels, with opposite effects on the ligand and receptor, and SR141716A was capable of attenuating the AEA effects. Among the considered non-coding RNA, only the expression of miR145-5p was positively affected by AEA but not by Kp10 treatment. Localization of Kiss1+/Kiss1R+ neurons in the arcuate nucleus revealed an increase of Kiss1R-expressing neurons in Kp10- and AEA-treated animals associated with enlargement of the lateral ventricles in Kp10-treated animals. In the brain and testis, the selected non-coding RNA was differently modulated by Kp10 or AEA. Lastly, in the testis, AEA treatment affected the KS at the protein levels, whereas Kp10 affected the intragonadal levels of CB1 and FAAH, the main modulator of the AEA tone. Changes in pubertal transition-related miRNAs and the intratesticular distribution of Kiss1, Kiss1R, CB1, and CB2 following KP and AEA treatment corroborate the KS-ECS crosstalk also showing that the CB1 receptor is involved in this interplay. For the first time in mammals, we report the modulation of the KS in both the hypothalamus and testis by AEA and revealed the KP-dependent modulation of CB1 and FAAH in the testis. KP involvement in the progression of spermatogenesis is also suggested.

SAT354 Molecular and Histological Characterization of a Guinea Pig Model of Mild Hyperandrogenemia

Abstract Disclosure: R.N. Tanori: None. J.E. Barboza Sagrero: None. K. Noll-Bader: None. S. Chandu: None. P.E. Chappell: None. C.V. Bishop: Consulting Fee; Self; Oviva, Oxford Pharmaceuticals Inc. There are several rodent models for polycystic ovarian syndrome (PCOS), but unlike primates, most rodents will not form a long-lived corpus luteum (CL) unless they experience cervico-vaginal stimulation/mating. Our research group has begun to determine if guinea pigs (Cavia porcellus), rodents with long-lived CL, are a suitable model for mild hyperandrogenemia, a risk factor for PCOS. The objective of this analysis was to determine the relative abundance of each follicle type within a cross-section of 20-week old guinea pig ovarian tissue from control and T-treated females after 3 months of androgen exposure. Ovarian tissues were collected from six guinea pigs treated with cholesterol implants (vehicle, n=4) or testosterone implants (n=3), which elevated androgen levels ∼2-fold above control females. Tissues were embedded in paraffin wax and cut into serial sections (5 μm) and placed onto glass slides (1 section/slide) for hematoxylin and eosin staining to identify follicle morphology within the ovarian tissue. Every fifth section was stained and analyzed using an ECHO Revolve microscope and follicles counted using ImageJ. Follicles of interest were primordial, primary, multi-layer, antral, and corpus luteum, and counts were normalized to ovarian area. All follicle types were found in all the ovaries imaged, as well as some corpora lutea. Multilayer follicles were significantly reduced by chronic exposure to mild hyperandrogenemia (p=0.01). These should provide needed baseline analyses for future experiments employing guinea pigs as a model of PCOS. In addition to histological analysis, we have begun quantifying gene expression changes for hormones and receptors throughout the reproductive axis. Preliminary studies using qPCR illustrate significantly elevated expression levels of hypothalamic kiss1, pituitary gnrhr, and ovarian fshr in T-treated females. No discernable differences were observed between treatment groups for kiss1r, gnrh, or fshb. Ongoing studies will explore differences in estrogen and androgen receptor expression throughout the reproductive axis, as well as any changes in metabolic regulators in liver and skeletal muscle that are associated with mild hyperandrogenemia in these animals. Presentation Date: Saturday, June 17, 2023

Effects of estradiol, progesterone and kisspeptin-1 concentrations at the time of insemination on conception rates in cattle

The present study aimed to investigate the effects of kisspeptin (Kiss-1), estradiol (E2), and progesterone (P4) levels at the time of artificial insemination (AI) on conception rates and also whether or not there is a relationship between Kiss-1 and E2 levels in cattle. Cows (n=100) raised on a semi-closed farm system and having corpus luteum were administered 25mg of prostaglandin F2a (Dinolytic®, Zoetis, Spain) and were evaluated following injection for signs of estrus. Just prior to AI, pre-ovulatory follicle diameters were assessed by ultrasonography (USG) and recorded. Then blood samples were collected. Blood serum samples were separated and stored until analyzed. Pregnancies were determined with rectal USG on day 30±2 following AI. The mean follicular diameters at the time of AI were similar in pregnant (17.9±0.01 mm) and non-pregnant (17.9±0.01 mm) cows. E2, P4, and Kiss-1 levels at the time of AI were determined from serum samples using the ELISA method. The Kiss-1 level at the time of AI in pregnant cows (80.58±4.4 pg/mL) was statistically higher than that in non-pregnant cows (66.68±2.48 pg/mL) (P=0.003). There were no statistically significant differences in E2 and P4 levels between pregnant and non-pregnant cows. Moreover, while a significant correlation was found between serum kiss-1 level and follicle diameter, no significant correlation was found between serum estrogen and progesterone levels. In conclusion, Kiss-1 levels at the time of AI may be used to predict the possibility of successful pregnancy in cattle, allowing different approaches to be developed to increase pregnancy rates in animals with low Kiss-1 levels at the time of AI.

Effects of 17α-ethinylestradiol on the neuroendocrine gonadotropic system and behavior of European sea bass larvae (Dicentrarchus labrax)

ABSTRACT The widespread use of 17α-ethinylestradiol (EE2), and other estrogenic endocrine disruptors, results in a continuous release of estrogenic compounds into aquatic environments. Xenoestrogens may interfere with the neuroendocrine system of aquatic organisms and may produce various adverse effects. The aim of the present study was to expose European sea bass larvae (Dicentrarchus labrax) to EE2 (0.5 and 50 nM) for 8 d and determine the expression levels of brain aromatase (cyp19a1b), gonadotropin-releasing hormones (gnrh1, gnrh2, gnrh3), kisspeptins (kiss1, kiss2) and estrogen receptors (esr1, esr2a, esr2b, gpera, gperb). Growth and behavior of larvae as evidenced by locomotor activity and anxiety-like behaviors were measured 8 d after EE2 treatment and a depuration period of 20 d. Exposure to 0.5 nM EE2 induced a significant increase in cyp19a1b expression levels, while upregulation of gnrh2, kiss1, and cyp19a1b expression was noted after 8 d at 50 nM EE2. Standard length at the end of the exposure phase was significantly lower in larvae exposed to 50 nM EE2 than in control; however, this effect was no longer observed after the depuration phase. The upregulation of gnrh2, kiss1, and cyp19a1b expression levels was found in conjunction with elevation in locomotor activity and anxiety-like behaviors in larvae. Behavioral alterations were still detected at the end of the depuration phase. Evidence indicates that the long-lasting effects of EE2 on behavior might impact normal development and subsequent fitness of exposed fish.

Investigation of irisin's role in pubertal onset physiology in female rats

ObjectiveThe timing of pubertal development is closely related to metabolic status and energy reserves. It is thought that irisin, which is involved in the regulation of energy metabolism and is shown to be present in the hypothalamo-pituitary-gonadal (HPG) axis, may play a role in this process. In our study, we aimed to investigate the effect of irisin administration on pubertal development and HPG axis in rats. Design-methods36 female rats were included in the study were divided into 3 groups: 100 ng/kg/day irisin treatment group (irisin-100), 50 ng/kg/day irisin treatment group (irisin-50), and control group. On the 38th day, serum samples were taken to determine levels of luteinizing hormone (LH) and follicle stimulating hormone (FSH), estradiol and irisin. Brain hypothalamus samples were taken to determine levels of pulsatile gonadotropin-releasing hormone (GnRH), kisspeptin, neurokinin-B, dynorphin (Dyn), and makorin ring finger protein-3 (MKRN3). ResultsVaginal opening and estrus were seen firstly in the irisin-100 group. At the end of the study, the highest rate of vaginal patency was found in the irisin-100 group. Hypothalamic protein expression levels of GnRH, NKB and Kiss1 in homogenates; serum FSH, LH, and estradiol levels were the highest in the irisin-100 group, followed by the irisin-50 and control groups, respectively. Ovarian sizes were significantly greater in the irisin-100 group compared to the other groups. The hypothalamic protein expression levels of MKRN3 and Dyn were the lowest in the irisin-100 group. ConclusionsIn this experimental study, irisin triggered the onset of puberty in a dose-dependent manner. Irisin administration caused the excitatory system to dominate in the hypothalamic GnRH pulse generator.

Kisspeptins, gonadotropins, and their receptors in the brain-pituitary-gonadal axis of Epinephelus akaara: Their relationship with oogonial proliferation and primary oocyte development

Previous studies have shown the regulation of follicle-stimulating hormone (Fshβ) and luteinizing hormone (Lhβ) during early ovarian differentiation and development from 30 to 160 days post-hatching (dph) in the red-spotted grouper. This study investigates the immunohistochemical identification of Fshβ and Lhβ in the pituitary and gene expression of kiss1, kiss2, gpr54, gnrh1, fshβ, lhβ, fshr, and lhr in the brain, pituitary, and ovary from 160 to 420 dph in this species. Fshβ and Lhβ immunohistochemical signals were primarily detected in the proximal pars distalis area at each stage, with few Fshβ or Lhβ signals detected in the pars intermedia area at 160, 200, 270, 300, 330, 360, and 390 dph. The expression levels of fshβ at 160 dph and fshr at 200 dph were significantly elevated, suggesting that increased fshr expression may reflect increased fshβ levels. Therefore, Fshβ may be more active than Lhβ during oogonial proliferation and new oocyte generation. While expression levels of kiss1 and kiss2 at 270 and 390 dph, gpr54 at 360 dph, gnrh1 at 270 dph, and lhβ at 300 dph were significantly elevated, they were not significantly altered in most stages between 240 and 420 dph. However, a comparison of Fshβ and Lhβ signal intensity indicated that Fshβ signals from 270 to 420 dph and Lhβ signals from 240 to 420 dph were consistently higher than in earlier stages. These results suggest that Fshβ/Lhβ may be active during primary oocyte development in the red-spotted grouper.

Annual changes in ovarian development stages of farmed female red‐spotted grouper, Epinephelus akaara, and inducing sexual maturity using photoperiod manipulation

AbstractThis study aimed to investigate the correlation between melatonin and the reproductive mechanism of farmed female red‐spotted groupers, Epinephelus akaara. Through the reproductive cycle experiment, the sexual maturity period was determined to be from June to July, following which the spawning season occurred in August. In addition, kiss1, kiss2, and GPR54 mRNA expression levels peaked in January, whereas that of sbGnRH mRNA remained at high levels from January to May and decreased during the sexual maturity and spawning seasons. During the day–night cycle, a nocturnal rhythm of AANAT2 mRNA expression was observed in the brain, and AANAT2 mRNA expression showed a seasonal pattern with increased expression during summer compared with that in winter. A correlation between melatonin and reproduction‐related genes could not be observed via melatonin administration, and sexual maturity was observed to be more induced under long photoperiod conditions compared with short photoperiod conditions. These results indicate that the reproductive mechanism of the farmed female red‐spotted grouper is related to changes in photoperiod and melatonin, and further research is needed to clarify the reproductive mechanism. Our findings provide basic information for identifying the reproductive mechanisms of farmed E. akaara.

The Kisspeptin and Kisspeptin receptor in follicular microenvironment: is that really necessary for oocyte maturation and fertilisation?

The aim of this study was to determine whether Kisspeptin and Kisspeptin receptor in the follicular microenvironment is necessary for human oocyte maturation and fertilisation. The cumulus cell (CC) and follicle fluids (FF) obtained from the first aspirated follicles (n = 52) from 32 patients were divided into three groups considering nuclear maturation and fertilisation results of oocytes: (1) Metaphase I or germinal vesicle stage oocytes (incomplete nuclear maturation, n = 10), (2) unfertilised metaphase II oocytes (incomplete cytoplasmic maturation, n = 16), and (3) fertilised metaphase II oocytes (completed nuclear-cytoplasmic maturation, n = 26). The gene expression levels were assessed by RT-PCR. The levels of Kisspeptin (KISS1) and Kisspeptin receptor (KISS1R) were measured by ELISA. There were no significant efficacy KISS1 and KISS1R gene expressions in cumulus cells in terms of oocyte nuclear maturation stage (Group 1, vs Group 2 + Group 3) (respectively p = .49; p = .45). In terms of the cytoplasmic maturation stage (Group 2, vs Group 3); KISS1 and KISS1R expressions in CCs were comparable (respectively p = .07; p = .08). In FFs, KISS1 and KISS1R concentrations were similar between all groups (respectively p = .86; p = .26). In conclusion, the relative KISS1 and KISS1R expressions in CC and also KISS1 and KISS1R level of FF were independent of oocytes nuclear and/or cytoplasmic maturation. Impact statement What is already known on this subject? It has been demonstrated that Kisspeptin is an essential regulator of reproductive function and plays a key role in the modulation of GnRH secretion and gonadotropin release. Still, no information is available about the link between gene expression or concentration in the follicular microenvironment and oocyte development. What do the results of this study add? The study has shown that the relative Kisspeptin (KISS1) and Kisspeptin receptor (KISS1R) and expressions in cumulus cell (CC) and also KISS1 and KISS1R levels of follicle fluids (FF) were independent of oocytes nuclear and/or cytoplasmic maturation. What are the implications of these findings for clinical practice and/or further research? Based on the findings, it is difficult to establish a concept that kisspeptin can directly induce oocyte maturation. Nevertheless, to confirm these findings, further studies with a larger sample size are needed.

Dicer ablation in Kiss1 neurons impairs puberty and fertility preferentially in female mice

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 preserved Kiss1 neuronal populations at the infantile/juvenile period. Yet, failure to complete puberty and attain fertility is observed only in females. Kiss1-specific ablation of Dicer evokes disparate changes of Kiss1-cell numbers and Kiss1/kisspeptin expression between hypothalamic subpopulations during the pubertal-transition, with a predominant decline in arcuate-nucleus Kiss1 levels, linked to enhanced expression of its repressors, Mkrn3, Cbx7 and Eap1. Our data unveil that miRNA-biosynthesis in Kiss1 neurons is essential for pubertal completion and fertility, especially in females, but dispensable for initial reproductive maturation and neuronal survival in both sexes. Our results disclose a predominant miRNA-mediated inhibitory program of repressive signals that is key for precise regulation of Kiss1 expression and, thereby, reproductive function.

Increased serum levels of KiSS1-derived peptides in non-small cell lung cancer patient liquid biopsies and biological relevance

BackgroundThe secreted products of the metastasis suppressor gene KiSS1 may represent useful biomarkers in non-small cell lung cancer (NSCLC) but their levels in patients have remained poorly investigated. We previously found that forced expression of KiSS1 decreased the invasive capability of NSCLC drug-resistant cells and a pro-apoptotic role for KiSS1 has been proposed in head and neck cancer. Thus, we designed a translational investigation including a pilot study to analyze KiSS1 levels in liquid biopsies, and in vitro experiments to explore the biological relevance of KiSS1 modulation.MethodsKiSS1-derived peptide levels in liquid biopsies from 60 NSCLC patients were assayed by ELISA. Preclinical experiments were carried out using quantitative real time polymerase chain reaction (qRT-PCR), ELISA, annexin V-binding and caspase activation assays.Results We compared KiSS1 release in 3 different matrices (serum, plasma and urine) and the highest levels were detectable in serum (range, 0–4.5 ng/mL). We observed increased levels of seric KiSS1 in NSCLC patients as compared to healthy donors. KiSS1 serum concentrations, after surgical procedure and/or adjuvant therapy. We observed differences among disease stages in urine samples. In preclinical models, KiSS1 mRNA levels were increased by short term exposure to azacytidine, enhanced KiSS1 release was induced by the combination of azacytidine and cisplatin and KiSS1-derived peptides enhanced cisplatin-induced apoptosis. KiSS1 increase was observed upon exposure neurons-enriched cultures to tumor cell conditioned medium.ConclusionsOur results showing a peculiar modulation of KiSS1 levels in liquid biopsies of NSCLC patients and a regulation of cisplatin-induced apoptosis by KiSS1-derived peptides support an involvement of KiSS1 in cell response to treatment and highlight its promising features as a potential biomarker in NSCLC.