ABSTRACT
Objective:To observe the effect of Jiuwei Chushi Decoction on sex hormone level of serum and Kisspeptin protein expression in hypothalamus of Central Precocious Puberty (CPP) rats model.Methods:After sixty female rat were breeded from SD rats, they are randomly divided into six groups, which are normal control group, model group, Gonadorelin group, and high, medium and low dose group of Jiuwei Chushi Decoction, 10 in each group. In addition to the normal control group, the other groups were subcutaneously injected with N-methyl-DL-aspartic acid to establish CPP model. Gonadorelin group was subcutaneously injected with Gonadorelin 100 μg/(kg·d), and high, medium and low dose group of Jiuwei Chushi Decoction were intragastrated with Jiuwei Chushi Decoction extract at 5.75, 2.87 and 1.43 ml/(kg·d) respectively. The levels of Luteinizing Hormone (LH), Follicle Stimulating Hormone (FSH),Estradiol (E 2) were detected by ELISA, and the protein expressions of Gonadotropin-releasing Hormone (GnRH) and Kisspeptin in hypothalamus were detected by Western Blot. Results:Compared with the model group, the levels of LH and E 2 of the low, medium and high dose group of Jiuwei Chushi Decoction were significantly decreased ( P<0.05), while the FSH level was significantly increased ( P<0.05). The relative protein expression of GnRH (0.657±0.110, 0.536±0.152 vs. 0.912±0.219) and Kisspeptin (0.508±0.035,0.347±0.073 vs. 0.659±0.030) in the medium and high dose group of Jiuwei Chushi Decoction was lower than that of model group. Conclusion:Jiuwei Chushi Decoction could affect hypothalamic Kisspeptin protein expression, inhibite hypothalamic GnRH expression, and decrease LH and E 2 levels in the serum of CPP rats.
ABSTRACT
Central precocious puberty (CPP) is caused by the premature reactivation of the hypothalamic-pituitary-gonadal axis. Genetic, nutritional, and environmental factors play a crucial role in determining pubertal timing. Recently mutations in kisspeptin (KISS1), kisspeptin receptor (KISS1R), and makorin RING finger protein 3 (MKRN3) genes have been identified as genetic causes of CPP. In particular, the MKRN3 gene is known to affect pubertal initiation. The MKRN3 gene is located on chromosome 15q11-q13 in the Prader-Willi syndrome (PWS) critical region. MKRN3 deficiency, due to a loss of function mutation, leads to the withdrawal of hypothalamic inhibition and prompts pulsatile gonadotropin-releasing hormone secretion, resulting in precocious puberty. The exact functions of these genes associated with CPP are still not well understood. Larger studies are required to discover the mechanisms involved in pubertal development.
Subject(s)
Fingers , Gonadotropin-Releasing Hormone , Kisspeptins , Prader-Willi Syndrome , Puberty, PrecociousABSTRACT
Central precocious puberty (CPP) is caused by the premature reactivation of the hypothalamic-pituitary-gonadal axis. Genetic, nutritional, and environmental factors play a crucial role in determining pubertal timing. Recently mutations in kisspeptin (KISS1), kisspeptin receptor (KISS1R), and makorin RING finger protein 3 (MKRN3) genes have been identified as genetic causes of CPP. In particular, the MKRN3 gene is known to affect pubertal initiation. The MKRN3 gene is located on chromosome 15q11-q13 in the Prader-Willi syndrome (PWS) critical region. MKRN3 deficiency, due to a loss of function mutation, leads to the withdrawal of hypothalamic inhibition and prompts pulsatile gonadotropin-releasing hormone secretion, resulting in precocious puberty. The exact functions of these genes associated with CPP are still not well understood. Larger studies are required to discover the mechanisms involved in pubertal development.
Subject(s)
Fingers , Gonadotropin-Releasing Hormone , Kisspeptins , Prader-Willi Syndrome , Puberty, PrecociousABSTRACT
Kisspeptins are a group of peptide fragments encoded by the KISS1 gene in humans. They bind to kisspeptin receptors with equal efficacy. Kisspeptins and their receptors are expressed by neurons in the arcuate and anteroventral periventricular nuclei of the hypothalamus. Oestrogen mediates negative feedback of gonadotrophin-releasing hormone secretion via the arcuate nucleus. Conversely, it exerts positive feedback via the anteroventral periventricular nucleus. The sexual dimorphism of these nuclei accounts for the differential behaviour of the hypothalamic-pituitary-gonadal axis between genders. Kisspeptins are essential for reproductive function. Puberty is regulated by the maturation of kisspeptin neurons and by interactions between kisspeptins and leptin. Hence, kisspeptins have potential diagnostic and therapeutic applications. Kisspeptin agonists may be used to localise lesions in cases of hypothalamic-pituitary-gonadal axis dysfunction and evaluate the gonadotrophic potential of subfertile individuals. Kisspeptin antagonists may be useful as contraceptives in women, through the prevention of premature luteinisation during in vitro fertilisation, and in the treatment of sex steroid-dependent diseases and metastatic cancers.
Subject(s)
Animals , Female , Humans , Male , Mice , Rats , Arcuate Nucleus of Hypothalamus , Metabolism , Estrogens , Metabolism , Feedback, Physiological , Fertilization in Vitro , Gonadotropin-Releasing Hormone , Metabolism , Homeostasis , Kisspeptins , Physiology , Neoplasms , Metabolism , Neurons , Metabolism , Protein Binding , Reproduction , Sex Factors , Signal TransductionABSTRACT
Kisspeptin has recently emerged as a key regulator of the mammalian reproductive axis. It is known that kisspeptin, acting centrally via the kisspeptin receptor, stimulates secretion of gonadotrophin releasing hormone (GnRH). Loss of kisspeptin signaling causes hypogonadotrophic hypogonadism in humans and other mammals. Kisspeptin interacts with other neuropeptides such as neurokinin B and dynorphin, to regulate GnRH pulse generation. In addition, a growing body of evidence suggests that kisspeptin signaling be regulated by nutritional status and stress. Kisspeptin may also represent a novel potential therapeutic target in the treatment of fertility disorders. Early human studies suggest that peripheral exogenous kisspeptin administration stimulates gonadotrophin release in healthy adults and in patients with certain forms of infertility. This review aims to concisely summarize what is known about kisspeptin as a regulator of reproductive function, and provide an update on recent advances within this field.
Subject(s)
Adult , Humans , Dynorphins , Fertility , Gonadotropin-Releasing Hormone , Hypogonadism , Hypothalamus , Infertility , Kisspeptins , Mammals , Neurokinin B , Neuropeptides , Nutritional Status , Axis, Cervical VertebraABSTRACT
Kisspeptin/G-protein couple receptor-54 (GPR54) system plays a key role in the activation of the gonadotropic axis at puberty. Central precocious puberty (CPP) is caused by the premature activation of hypothalamic gonadotropin-releasing hormone secretion. This study was aimed to identify KISS1 gene variations and to investigate the associations between KISS1 gene variations and CPP in Korean girls. All coding exons of KISS1 gene were sequenced in Korean girls with CPP (n = 143) and their healthy controls (n = 101). Nine polymorphisms were identified in KISS1 gene. A novel single-nucleotide polymorphism (SNP), 55648176 T/G, was identified for the first time. SNP 55648184 C/G and 55648186 -/T were detected more frequently in CPP group than in control group. SNP 55648176 T/G was detected less frequently in CPP group than in control group. Haplotype GGGC-ACCC was detected less frequently in CPP group. The genetic variations of KISS1 gene can be contributing factors of development of CPP. The association between the gene variations and CPP should be validated by further evidence obtained from large-scaled and functional studies.
Subject(s)
Child , Female , Humans , Base Sequence , Genetic Markers/genetics , Genetic Predisposition to Disease/epidemiology , Kisspeptins/genetics , Molecular Sequence Data , Point Mutation/genetics , Polymorphism, Single Nucleotide/genetics , Prevalence , Puberty, Precocious/epidemiology , Reproducibility of Results , Republic of Korea/epidemiology , Risk Assessment , Sensitivity and SpecificityABSTRACT
Kisspeptin/G-protein couple receptor-54 (GPR54) system plays a key role in the activation of the gonadotropic axis at puberty. Central precocious puberty (CPP) is caused by the premature activation of hypothalamic gonadotropin-releasing hormone secretion. This study was aimed to identify KISS1 gene variations and to investigate the associations between KISS1 gene variations and CPP in Korean girls. All coding exons of KISS1 gene were sequenced in Korean girls with CPP (n = 143) and their healthy controls (n = 101). Nine polymorphisms were identified in KISS1 gene. A novel single-nucleotide polymorphism (SNP), 55648176 T/G, was identified for the first time. SNP 55648184 C/G and 55648186 -/T were detected more frequently in CPP group than in control group. SNP 55648176 T/G was detected less frequently in CPP group than in control group. Haplotype GGGC-ACCC was detected less frequently in CPP group. The genetic variations of KISS1 gene can be contributing factors of development of CPP. The association between the gene variations and CPP should be validated by further evidence obtained from large-scaled and functional studies.
Subject(s)
Child , Female , Humans , Base Sequence , Genetic Markers/genetics , Genetic Predisposition to Disease/epidemiology , Kisspeptins/genetics , Molecular Sequence Data , Point Mutation/genetics , Polymorphism, Single Nucleotide/genetics , Prevalence , Puberty, Precocious/epidemiology , Reproducibility of Results , Republic of Korea/epidemiology , Risk Assessment , Sensitivity and SpecificityABSTRACT
OBJECTIVE: Stress is known to be an inhibitor of the reproductive hypothalamic-pituitary-gonadal (HPG) axis. However, the neural and molecular connections between stress and reproduction are not yet understood. It is well established that in both humans and rodents, kisspeptin (encoded by the kiss1 gene) is a strong stimulator of the HPG axis. In the present study we hypothesized that endocannabinoids, an important neuromodulatory system in the brain, can act on the HPG axis at the level of kiss1 expression to inhibit reproductive function under stress. METHODS: Adult male Wistar rats were unilaterally implanted with an intracerebroventricular cannula. Afterwards, the animals were exposed to immobilization stress, with or without the presence of the cannabinoid CB1 receptor antagonist AM251 (1 microg/rat). Blood samples were collected through a retro-orbital plexus puncture before and after stress. Five hours after the stress, brain tissue was collected for reverse transcriptase-quantitative polymerase chain reaction measurements of kiss1 mRNA. RESULTS: Immobilization stress (1 hour) resulted in a decrease in the serum luteinizing hormone concentration. Additionally, kiss1 gene expression was decreased in key hypothalamic nuclei that regulate gonadotrophin secretion, the medial preoptic area (mPOA), and to some extent the arcuate nucleus (ARC). A single central administration of AM251 was effective in blocking these inhibitory responses. CONCLUSION: These findings suggest that endocannabinoids mediate, at least in part, immobilization stress-induced inhibition of the reproductive system. Our data suggest that the connection between immobilization stress and the HPG axis is kiss1 expression in the mPOA rather than the ARC.