kiss1-protein--human and Primary-Ovarian-Insufficiency

In recent years, it has been found that kisspeptin plays some key roles in the physiological processes of the brain, such as gender differentiation, positive and negative feedback of sex hormones, onset of puberty, and transduction of energy signals in the body, which suggests that kisspeptin may be a key molecule for the maturation and regulation of female reproductive function. In addition to the systemic roles of the kisspeptin, its local roles in reproductive organs are constantly being discovered. With the discovery that kisspeptin is involved in the pathological process of reproductive endocrine diseases such as isolated hypogonadotropic hypogonadism (IHH), polycystic ovary syndrome (PCOS), premature ovarian failure (POF) and pathological hyperprolactinemia, exogenous application of kisspeptin to solve reproductive problems has become a new hot topic. The review focuses on the research progress of kisspeptin in the female reproductive system, especially on its application in assisted reproduction.

Topics: Female; Gonadal Steroid Hormones; Humans; Hyperprolactinemia; Hypogonadism; Kisspeptins; Polycystic Ovary Syndrome; Pregnancy; Primary Ovarian Insufficiency; Reproductive Techniques, Assisted

Topics: Animals; Cadmium; Female; Humans; Kisspeptins; Ovarian Follicle; Polycystic Ovary Syndrome; Primary Ovarian Insufficiency; Rats

Premature ovarian failure (POF) affects 1% of women in reproductive age, but its etiology remains uncertain. Whereas kisspeptins, the products of Kiss1 that act via Kiss1r (aka, Gpr54), are known to operate at the hypothalamus to control GnRH/gonadotropin secretion, additional actions at other reproductive organs, including the ovary, have been proposed. Yet, their physiological relevance is still unclear. We present here a series of studies in Kiss1r haplo-insufficient and null mice suggesting a direct role of kisspeptin signaling in the ovary, the defect of which precipitates a state of primary POF. Kiss1r hypomorph mice displayed a premature decline in ovulatory rate, followed by progressive loss of antral follicles, oocyte loss, and a reduction in all categories of preantral follicles. These alterations were accompanied by reduced fertility. Because of this precocious ovarian ageing, mice more than 48 weeks of age showed atrophic ovaries, lacking growing follicles and corpora lutea. This phenomenon was associated with a drop in ovarian Kiss1r mRNA expression, but took place in the absence of a decrease in circulating gonadotropins. In fact, FSH levels increased in aged hypomorph animals, reflecting loss of follicular function. In turn, Kiss1r-null mice, which do not spontaneously ovulate and have arrested follicular development, failed to show normal ovulatory responses to standard gonadotropin priming and required GnRH prestimulation during 1 week in order to display gonadotropin-induced ovulation. Yet, the magnitude of such ovulatory responses was approximately half of that seen in control immature wild-type animals. Altogether, our data are the first to demonstrate that Kiss1r haplo-insufficiency induces a state of POF, which is not attributable to defective gonadotropin secretion. We also show that the failure of follicular development and ovulation linked to the absence of Kiss1r cannot be fully rescued by (even extended) gonadotropin replacement. These findings suggest a direct ovarian role of kisspeptin signaling, the perturbation of which may contribute to the pathogenesis of POF.

Topics: Animals; Female; Gonadotropins; Hypogonadism; Kisspeptins; Male; Mice; Mice, Inbred C57BL; Mice, Transgenic; Ovary; Ovulation; Phenotype; Primary Ovarian Insufficiency; Receptors, G-Protein-Coupled; Receptors, Kisspeptin-1

Topics: Animals; Female; Kisspeptins; Male; Membrane Glycoproteins; Oocytes; Ovary; Ovulation; Primary Ovarian Insufficiency; Protein-Tyrosine Kinases; Receptors, G-Protein-Coupled; Receptors, Kisspeptin-1

Spontaneously hypertensive (SH) rats, extensively used as experimental models of essential human hypertension, display important alterations in the neuroendocrine reproductive axis, which manifest as markedly delayed puberty onset in females but whose basis remains largely unknown. We analyze herein in female SH rats: 1) possible alterations in the expression and function of KiSS-1/GPR54 and GnRH/GnRH-receptor systems, 2) the integrity of feedback mechanisms governing the hypothalamic-pituitary-ovarian axis, and 3) the control of ovarian function by gonadotropins. Our data demonstrate that, despite overtly delayed puberty, no significant decrease in hypothalamic KiSS-1, GPR54, or GnRH mRNA levels was detected in this strain. Likewise, in vivo gonadotropin responses to ovariectomy and systemic kisspeptin-10 or GnRH administration, as well as in vitro gonadotropin responses to GnRH, were fully preserved in SH rats. Moreover, circulating LH levels were grossly conserved during prepubertal maturation, whereas FSH levels were even enhanced from d 20 postpartum onwards. In striking contrast, ovarian weight and hormone (progesterone and testosterone) responses to human chorionic gonadotropin (CG) in vitro were profoundly decreased in SH rats, with impaired follicular development and delayed ovulation at puberty. Such reduced hormonal responses to human CG could not be attributed to changes in LH/CG or FSH-receptor mRNA expression but might be linked to blunted P450scc, 3beta-hydroxy steroid dehydrogenase, and aromatase mRNA levels in ovaries from SH rats. In conclusion, our results indicate that the expression and function of KiSS-1/GPR54 and GnRH/GnRH-receptor systems is normal in SH rats, whereas ovarian development, steroidogenesis, and responsiveness to gonadotropins are strongly compromised.

Topics: Animals; Chorionic Gonadotropin; Disease Models, Animal; Female; Follicle Stimulating Hormone; Gonadotropin-Releasing Hormone; Hypertension; Hypothalamus; Kisspeptins; Luteinizing Hormone; Male; Ovariectomy; Ovary; Primary Ovarian Insufficiency; Proteins; Puberty, Delayed; Rats; Rats, Inbred SHR; Rats, Inbred WKY; Receptors, G-Protein-Coupled; Receptors, Kisspeptin-1; RNA, Messenger; Signal Transduction