Sex-specific hypothalamic expression of kisspeptin, gonadotropin releasing hormone, and kisspeptin receptor in progressive demyelination model.

Demyelinating diseases, such as multiple sclerosis, decrease the quality of life of patients and can affect reproduction. Assisted reproductive therapies are available, which although effective, aggravate motor symptoms. For this reason, it is important to determine how the control of the hypothalamus-pituitary-gonadal axis is affected in order to develop better strategies for these patients. One way to determine this is using animal models such as the taiep rat, which shows progressive demyelination of the central nervous system, and was used in the present study to characterize the expression of gonadotrophin-releasing hormone (GnRH), Kisspeptin, and kisspeptin receptor (Kiss1R) and luteinizing hormone (LH) secretion. The expression of kisspeptin, GnRH, and Kiss1R was determined at the hypothalamic level by immunofluorescence and serum LH levels were determined by ELISA. The expression of kisspeptin at the hypothalamic level showed sexual dimorphism, where there was an increase in males and a decrease in females during oestrus. There was no change in the expression of GnRH or kisspeptin receptor, regardless of sex. However, a decrease in serum LH concentration was observed in both sexes. The taiep rat showed changes in the expression of kisspeptin at the hypothalamic level. These changes are different from those reported in the literature with the use of animals with experimental allergic encephalomyelitis, this is because both animal models represent different degrees of progression of multiple sclerosis. Our results suggest that the effects on the hypothalamus-pituitary-gonadal axis depend on the differences between the demyelinating processes, their progression, and even individual factors, and it is thus important that fertility treatments are individualized to maximize therapeutic effects.

Escitalopram as a modulator of proopiomelanocortin, kisspeptin, Kiss1R and MCHR1 gene expressions in the male rat brain.

Neuropeptides are important, multifunctional regulatory factors of the nervous system, being considered as a novel, atypical sites of antidepressants action. It has already been proven that some of them, such as selective serotonin reuptake inhibitors (SSRI), are able to affect peptidergic pathways in various brain regions. Despite these reports, there is so far no reports regarding the effect of treatment with SSRIs on brain proopiomelanocortin (POMC), kisspeptin, Kiss1R and MCHR1 gene expression. In the current study we examined POMC, kisspeptin, Kiss1R and MCHR1 mRNA expression in the selected brain structures (hypothalamus, hippocampus, amygdala, striatum, cerebellum and brainstem) of rats chronically treated with a 10 mg/kg dose of escitalopram using quantitative Real-Time PCR. Long-term treatment with escitalopram led to the upregulation of MCHR1 expression in the rat amygdala. Kisspeptin mRNA level was also increased in the amygdala, but Kiss1R mRNA expressions were elevated in the hippocampus, hypothalamus and cerebellum. POMC mRNA expressions were in turn decreased in the hippocampus, amygdala, cerebellum and brainstem. These results may support the hypothesis that these neuropeptides may be involved in the site-dependent actions of SSRI antidepressants. This is the first report of the effects of escitalopram on POMC, kisspeptin, Kiss1R and MCHR1 in animal brain. Our findings shed a new light on the pharmacology of SSRIs and may contribute to a better understanding of the alternative, neuropeptide-dependent modes of antidepressant action.

Female infertility is associated with an altered expression of the neurokinin B/neurokinin B receptor and kisspeptin/kisspeptin receptor systems in ovarian granulosa and cumulus cells.

OBJECTIVE: To analyze and compare the expression profile of TAC3, TACR3, KISS1, and KISS1R in mural granulosa and cumulus cells from healthy oocyte donors and patients with different infertility etiologies, including advanced maternal age, endometriosis, and low ovarian response. DESIGN: Genetic association study. SETTING: Private fertility clinic and public research laboratory. PATIENT(S): Healthy oocyte donors and infertile women undergoing in vitro fertilization (IVF) treatment. INTERVENTION(S): IVF. MAIN OUTCOME MEASURE(S): Gene expression levels of KISS1, KISS1R, TAC3, and TACR3 in human mural granulosa and cumulus cells. RESULT(S): Infertile women showed statistically significantly altered expression levels of KISS1 (-2.57 ± 2.30 vs. -1.37 ± 2.11), TAC3 (-1.21 ± 1.40 vs. -1.49 ± 1.98), and TACR3 (-0.77 ± 1.36 vs. -0.03 ± 0.56) when compared with healthy oocyte donors. Advanced maternal age patients, endometriosis patients, and low responders showed specific and altered expression profiles in comparison with oocyte donors. CONCLUSION(S): Abnormal expression levels of KISS1/KISS1R and TAC3/TACR3 systems in granulosa cells might be involved in the decreased fertility associated to advanced maternal age, endometriosis, and low ovarian response.

Expression of Kisspeptin (KISS1) and its Receptor GPR54 (KISS1R) in Prostate Cancer.

BACKGROUND/AIM: Prostate cancer (PCa) is the second most commonly diagnosed cancer in men. In contrast to localized disease, metastatic PCa leads to increased mortality. Kisspeptin (KISS1) functions as a metastasis suppressor in various cancers. The aim of this study was to detect the expression of KISS1 and its receptor GPR54 (KISS1R) in prostate cancer. MATERIALS AND METHODS: The expression of KISS1 and KISS1R was examined in prostate cancer tissue specimens after radical prostatectomy. RESULTS: A higher expression of KISS1 and KISS1R was shown in patients with localized tumors (Stage ≤IIb) compared to patients with advanced (Stage ≥III) tumor. High Gleason score PCa and higher prognostic groups patients showed a lower expression rate of both KISS1 and KISS1R. CONCLUSION: A down-regulation of KISS1-KISS1R system was detected in advanced prostate cancer. KISS1as tumor suppressor might be useful in the future for the diagnosis, risk assessment of prostate cancer progression, as well as a therapeutic target for aggressive tumors.

The Impact of Morphine on Reproductive Activity in Male Rats Is Regulated by Rf-Amid-Related Peptide-3 and Substance P Adjusting Hypothalamic Kisspeptin Expression.

Obviously, opiates (e.g., morphine) are associated with the suppression and dysfunction of reproductive axis. It has been reported that substance P (SP) and RF-amid-related peptide-3 (RFRP-3) can exhibit anti-opioid effects in some regions of the nervous system. Moreover, SP and RFRP-3 are deemed as neuropeptides which exert modulatory and regulatory impacts on the function of the reproductive axis. The precise interactions of morphine with SP or RFRP-3 on the parameters of the reproductive activity, however, are not fully known. The present study was aimed to determine the impacts of the interaction of morphine either with SP or RFRP-3 on the hormonal and behavioral parameters of reproductive activity in male rats. In addition, it was aimed at determining whether the effects of these interactions rely on kisspeptin/G protein coupled receptor 54 (GPR54) pathway as the main upstream pulse generator and the mediator of the function of many inputs of gonadotropin-releasing hormone (GnRH)/luteinizing hormone (LH) system or not. Altogether, the resulted data from the sexual behavior tests, radioimmunoassay of LH/testosterone, and real-time quantitative PCR for the assessment of the expression of hypothalamic Kiss1, Gpr54, and Gnrh1 genes following concomitant administration of morphine with SP or RFRP-3 revealed that the suppressing effects of morphine on the parameters of reproductive axis activity can be affected by the administration of either RFRP-3 or SP. It is advocated that SP and RFRP-3, by the modulation of the expression of hypothalamic Kiss1, can possibly antagonize the effects of morphine on GnRH/LH system and sexual behavior.

Kisspeptin/kisspeptin receptor system in pseudopregnant rabbit corpora lutea: presence and function.

Kisspeptin (KiSS) and its related receptors (KiSS1R) have a critical role in the reproduction of mammals. The KiSS/KiSS1R system is expressed in numerous reproductive organs including the ovary. Here, we studied the expression of the KiSS/KiSS1R system and its functional role in rabbit corpora lutea (CL) at days 4 (early-), 9 (mid-), and 13 (late-stage) of pseudopregnancy. In vitro progesterone, prostaglandin (PG) F2α (PGF2α) and E2 (PGE2) productions and prostaglandin-endoperoxide synthase 1 (PTGS1) and 2 (PTGS2) activities were evaluated. Immune reactivity (IR) for KiSS and KiSS1R were detected in luteal cells at nuclear and cytoplasmic level at all luteal stage for KiSS and only at early- and mid-stage for KiSS1R; IR decreased from early- to later stages of pseudopregnancy. The KiSS-10 augmented progesterone and PGE2 and diminished PGF2α secretions by early- and mid-CL; KiSS-10 reduced PTGS2 activity at early- and mid-stages, but did not affect PTGS1 at any luteal stages. The antagonist KiSS-234 counteracted all KiSS-10 effects. This study shows that the KiSS/KiSS1R system is expressed in CL of pseudopregnant rabbits and exerts a luteotropic action by down-regulating PTGS2, which decreases PGF2α and increases PGE2 and progesterone.

Increased Expression of KISS1 and KISS1 Receptor in Human Granulosa Lutein Cells-Potential Pathogenesis of Polycystic Ovary Syndrome.

Kisspeptins are a family of neuropeptides that are essential for fertility. Recent experimental data suggest a putative role of kisspeptin signaling in the direct control of ovarian function. To explore the expression of KISS1 and KISS1 receptor (KISS1R) in human granulosa lutein cells and the potential role of KISS1/KISS1R system in the pathogenesis of polycystic ovary syndrome (PCOS), we measured the concentration of KISS1 in follicular fluid, the expression of KISS1 and KISS1R in granulosa lutein cells, and the circulating hormones. The expression levels of KISS1 and KISS1R were significantly upregulated in human granulosa lutein cells obtained from women with PCOS. The expression levels of KISS1 in human granulosa lutein cells highly correlated with those of KISS1R in non-PCOS patients, but not in patients with PCOS, most likely due to the divergent expression patterns in women with PCOS. Additionally, the expression levels of KISS1 highly correlated with the serum levels of anti-Müllerian hormone (AMH). The expression levels of KISS1 and KISS1R, as well as the follicular fluid levels of KISS1, were not significantly different between the pregnant and nonpregnant patients in both PCOS and non-PCOS groups. In conclusion, the increased expression of KISS1 and KISS1R in human granulosa lutein cells may contribute to the pathogenesis of PCOS. The expression levels of KISS1 highly correlated with the serum levels of AMH. The KISS1 and KISS1R system in the ovary may not have a remarkable role in predicting the in vitro fertilization (IVF) outcome.

A three-gene methylation marker panel for the nodal metastatic risk assessment of muscle-invasive bladder cancer.

PURPOSE: In this study, we aimed to identify a DNA methylation pattern suitable for prognosis assessment of muscle-invasive bladder cancer and to investigate metastasis-associated processes regulated by DNA methylation. METHODS: Genome-wide methylation analysis was performed on 23 muscle-invasive bladder tumors by microarray analysis. Validation was performed by the qAMP technique in two different patient cohorts (n = 32 and n = 100). mRNA expression was analyzed in 12 samples. Protein expression was determined using tissue microarrays of 291 patients. Bladder cancer cell lines T24 and 253JB-V were used for functional analyses. RESULTS: Microarray analyses revealed KISS1R, SEPT9 and CSAD as putative biomarkers with hypermethylation in node-positive tumors. The combination of the three genes predicted the metastatic risk with sensitivity of 73% and specificity of 71% in cohort 1, and sensitivity of 82% and specificity of 54% in cohort 2. mRNA expression differences were detected for KISS1R (p = 0.04). Protein expression of KISS1R was significantly reduced (p < 0.001). Knockdown of SEPT9v3 resulted in increased cell migration by 28% (p = 0.04) and increased invasion by 22% (p = 0.004). KISS1R overexpression resulted in decreased cell migration (25%, p = 0.1). CONCLUSIONS: We identified a methylation marker panel suitable to differentiate between patients with positive and negative lymph nodes at time of cystectomy. This enables a risk assessment for patients who potentially benefit from extended lymph node resection as well as from neoadjuvant chemotherapy and could improve the survival rates. Furthermore, we examined the impact of putative markers on tumor behavior. Hence, KISS1R and SEPT9 could represent a starting point for the development of novel therapy approaches.

KISS1 and KISS1R expression in primary and metastatic colorectal cancer.

PURPOSE: Kisspeptins are produced by the KISS1 gene and have tumor-suppressing and anti-metastatic properties. Our aim was to study the expression of KISS1 and its receptor, KISS1R, in colorectal cancer. METHODS: KISS1 and KISS1R expression was detected using immunohistochemistry in malignant tissue samples from 66 patients (34 men, 32 women) with colorectal adenocarcinoma. In total, 74 tumor samples were studied, 57 samples from primary tumors and 17 samples from liver metastases. KISS1 and KISS1R levels were associated with various clinicopathological parameters and survival data. RESULTS: KISS1 expression was higher in primary tumors with advanced stage (III or IV) and in those with infiltrated lymph nodes. KISS1R expression was higher in primary tumors with distant metastases. No significant differences were detected between primary and metastatic tumors regarding KISS1 and KISS1R levels. Furthermore, patients with high KISS1R levels had longer overall survival. CONCLUSIONS: KISS1 and KISS1R expression is higher in advanced colorectal cancers and high KISS1R levels are associated with better prognosis in colorectal cancer.

G protein-coupled KISS1 receptor is overexpressed in triple negative breast cancer and promotes drug resistance.

Triple-negative breast cancer (TNBC) lacks the expression of estrogen receptor α, progesterone receptor and human epidermal growth factor receptor 2 (HER2). TNBC patients lack targeted therapies, as they fail to respond to endocrine and anti-HER2 therapy. Prognosis for this aggressive cancer subtype is poor and survival is limited due to the development of resistance to available chemotherapies and resultant metastases. The mechanisms regulating tumor resistance are poorly understood. Here we demonstrate that the G protein-coupled kisspeptin receptor (KISS1R) promotes drug resistance in TNBC cells. KISS1R binds kisspeptins, peptide products of the KISS1 gene and in numerous cancers, this signaling pathway plays anti-metastatic roles. However, in TNBC, KISS1R promotes tumor invasion. We show that KISS1 and KISS1R mRNA and KISS1R protein are upregulated in TNBC tumors, compared to normal breast tissue. KISS1R signaling promotes drug resistance by increasing the expression of efflux drug transporter, breast cancer resistance protein (BCRP) and by inducing the activity and transcription of the receptor tyrosine kinase, AXL. BCRP and AXL transcripts are elevated in TNBC tumors, compared to normal breast, and TNBC tumors expressing KISS1R also express AXL and BCRP. Thus, KISS1R represents a potentially novel therapeutic target to restore drug sensitivity in TNBC patients.

Characterisation of Kiss1r (Gpr54)-Expressing Neurones in the Arcuate Nucleus of the Female Rat Hypothalamus.

Kisspeptin is essential in reproduction and acts by stimulating neurones expressing gonadotrophin-releasing hormone (GnRH). Recent studies suggest that kisspeptin has multiple roles in the modulation of neuronal circuits in systems outside the hypothalamic-pituitary-gonadal axis. Our recent research using in situ hybridisation (ISH) clarified the histological distribution of Kiss1r (Gpr54)-expressing neurones in the rat brain that were presumed to be putative targets of kisspeptin. The arcuate nucleus (ARN) of the hypothalamus is one of the brain regions in which Kiss1r expression in non-GnRH neurones is prominent. However, the characteristics of Kiss1r-expressing neurones in the ARN remain unclear. The present study aimed to determine the neurochemical characteristics of Kiss1r-expressing neurones in the ARN using ISH and immunofluorescence. We revealed that the majority (approximately 63%) of Kiss1r-expressing neurones in the ARN were pro-opiomelanocortin (POMC) neurones, which have an anorexic effect in mammals. Additionally, a few Kiss1r-expressing neurones in the dorsal ARN are tuberoinfundibular dopamine (TIDA) neurones, which control milk production by inhibiting prolactin secretion from the anterior pituitary. TIDA neurones showed a relatively weak Kiss1r ISH signal compared to POMC neurones, as well as low co-expression of Kiss1r (approximately 15%). We also examined the expression of Kiss1r in neuropeptide Y and kisspeptin neurones, which are reported to arise from POMC-expressing progenitor cells during development. However, the vast majority of neuropeptide Y and kisspeptin neurones in the ARN did not express Kiss1r. These results suggest that kisspeptin may directly regulate energy homeostasis and milk production by modulating the activity of POMC and TIDA neurones, respectively. Our results provide an insight into the wide variety of roles that kisspeptin plays in homeostatic and neuroendocrine functions.