Precocious Puberty and the Lin28/Let7 Pathway: The Therapeutic Effect of the Nourishing "Yin" and Purging "Fire" Traditional Chinese Medicine Mixture in a Rat Model

Therapeutic effects of melatonin in female mice with central precocious puberty by regulating the hypothalamic Kiss-1/Kiss1R system

In recent years, central precocious puberty (CPP) in children is becoming more common, which seriously affects their physical and psychological health and requires finding a safe and effective treatment method. The aim of this study was to investigate the therapeutic effect of melatonin on CPP. A CPP model was established by subcutaneous injection of 300 micrograms of danazol into 5-day-old female mice, followed by treatment with melatonin and leuprolide. The vaginal opening was checked daily. Mice were weighed, gonads were weighed, gonadal index was calculated, and gonadal development was observed by hematoxylin and eosin (HE) staining. Serum follicle stimulating hormone (FSH), luteinizing hormone (LH) and estradiol (E2) levels were measured by ELISA. By using RT-PCR and Western blotting, the mRNA and protein expression of the hypothalamus Kiss-1, Kiss-1 receptor (Kiss1R), gonadotropin-releasing hormone (GnRH), and pituitary GnRH receptor (GnRHR) were identified. The results showed that melatonin delayed vaginal opening time and reduced body weight, gonadal weight and indices in female CPP mice. Melatonin treatment prevents uterine wall thickening and ovarian luteinization in female CPP mice. Melatonin treatment reduces serum concentrations of FSH, LH, and E2 in female CPP mice. Melatonin suppressed the expressions of Kiss-1, Kiss1R and GnRH in the hypothalamus, and the expression of GnRHR in the pituitary of the female CPP mice. Our results suggest that melatonin can inhibit the hypothalamic-pituitary-gonadal (HPG) axis by down-regulating the Kiss-1/Kiss1R system, thereby treating CPP in female mice.

Effect of nourishing and purging fire Chinese herbal mixture on delaying light-induced premature puberty in rats

OBJECTIVE

To elucidate the mechanism of the nourishing Yin and purging fire Chinese herbal mixture (NYPF) in delaying light-induced premature puberty in rats.

METHODS

Twenty-one days old female Sprague-Dawley rats were randomly assigned to normal group (N), long light exposure group (L), NYPF and normal saline group (NS). Rats in the L, NYPF and NS groups were exposed to 16 h: 350 lux light/8 h: dark, while rats in the N group were exposed to 12 h: 50 lux light/12 h: dark. NYPF and normal saline was administered to the rats in the NYPF group or NS group, respectively, from day 21. Five rats in every group were sacrificed at 9 p.m. on day 28 (P28), on the day when rat's vulva opened in the L group (L-VO), on the day when the first estrous interphase occurred in rats of L group (L-E1), and on the day when the second estrous interphase occurred in rats of L group (L-E2), respectively.

RESULITS

On day 34, all rats in the L group, 80% of rats in the NS group, 40% of rats in the N group, and 20% of rats in the NYPF group showed complete opening of the vulva. At P28, mRNA level of hypothalamic kisspeptin (Kiss-1) in the L group was significantly higher than that in the N group (P < 0.05). The rats in the L and NS groups had significantly lower hypothalamic arginine-phenylalanine-amide (RFamide)-related peptide 3 (RFRP-3) mRNA levels than those in the N group (P < 0.05), whereas RFRP-3 mRNA level was significantly higher in the NYPF group than that in the L group (P < 0.05). At L-VO, the ovarian index of the L and NS groups was significantly higher than that of the N group (P < 0.05) and estradiol (E2) level of the NYPF group was significantly lower than that of the N and NS groups (P < 0.05); hypothalamic Kiss-1 mRNA level in the L and NS groups was significantly higher than that in the N and NYPF groups (P < 0.05), whereas hypothalamic RFRP-3 mRNA level in the L, NYPF, and NS groups was significantly lower than that in the N group (P < 0.05). At L-E1, E2 level of the L and NS groups was significantly higher than that of the N group (P < 0.01), whereas it was significantly lower in the NYPF group than that of the N, L, and NS groups (P < 0.01), and serum luteinizing hormone level of the L and NS groups was significantly higher than that of the N group (P < 0.05); levels of serum melatonin and ovarian melatonin receptor 1 (MT-1) mRNA in the L, NYPF, and NS groups were significantly lower than those in the N group (P < 0.05). At L-E2, the uterine organ index of the NYPF group was significantly lower than that of the L group (P < 0.05); and ovarian MT-1 mRNA level of the L and NS groups was significantly lower than that in the N group (P < 0.05).

CONCLUSIONS

NYPF can delay puberty onset in rats exposed to strong light for a prolonged duration, and regulation of the gene expression of Kiss-1 and RFRP-3 in the hypothalamus has been suggested as one of the mechanisms.

A Novel Loss-of-Function MKRN3 Variant in a Chinese Patient With Familial Precocious Puberty: A Case Report and Functional Study

Background: Central precocious puberty (CPP) is one of the most common and complex problems in clinical pediatric endocrinology practice. Mutation of the MKRN3 gene can cause familial CPP. Methods and Results: Here we reported a Chinese patient bearing a novel MKRN3 mutation (c.G277A/p.Gly93Ser) and showing the CPP phenotype. Functional studies found that this mutation of MKRN3 attenuated its autoubiquitination, degradation, and inhibition on the transcriptional activity of GNRH1, KISS1, and TAC3 promoters. Conclusion: MKRN3 (Gly93Ser) is a loss-of-function mutation, which attenuates the inhibition on GnRH1-related signaling, suggesting that this mutant can lead to central precocious puberty.

The Traditional Chinese Medicine Fuyou Formula Alleviates Precocious Puberty by Inhibiting GPR54/GnRH in the Hypothalamus

The purpose of this study was to explore the effect of the traditional Chinese medicine Fuyou formula on precocious puberty (PP). The Fy formula may exert an effect in female rats with PP and GT-7 cells through the GPR54/GnRH signaling pathway. To confirm the effect of the Fy formula on PP through the GPR54/GnRH signaling pathway, we first treated GT1-7 cells with the Fy formula and observed changes in the expression of related genes and proteins and in GnRH secretion. Then, we randomly divided young female Sprague-Dawley rats into the control group, model group, leuprorelin group and the Fy formula group. A PP model was established by injection of danazol on postnatal day 5, and the Fy formula was administered on PND15. The time of vaginal opening, the wet weights of the ovary and uterus, serum hormone levels and the expression of hypothalamic-related genes were observed. We found that the Fy formula delayed vaginal opening, decreased the wet weights and coefficients of the ovary and uterus, decreased the levels of serum hormones (E2, follicle-stimulating hormone and luteinizing hormone) and the cellular GnRH level, and downregulated the gene expression of Kiss1, GPR54 and GnRH in the hypothalamus and the gene and protein expression of GPR54 and GnRH in GT1-7 cells. In conclusion, the Fy formula may alleviate PP via the GPR54/GnRH signaling pathway.

The Therapeutic Effect of Shugan Xiehuo Formula in the Female Rat Model with Central Precocious Puberty

Central precocious puberty (CPP) severely affects children's physical and mental health and needs to be treated promptly and effectively. This article aimed to research the therapeutic effect of Shugan Xiehuo Formula (SXF) on CPP. A female CPP rat model was established and then treated with leuprolide and different doses of SXF. Sex organ volume and index were measured. Ovaries and uteri were visualized by hematoxylin-eosin staining. The concentrations of follicle-stimulating hormone (FSH), luteinizing hormone (LH), prolactin (PRL), and estradiol (E2) in peripheral blood were determined. The expression levels of gonadotropin-releasing hormone (GnRH), gonadotropin-releasing hormone receptor (GnRHR), estrogen receptor alpha (ERα), and G protein-coupled receptor 30 (GPR30) in the hypophysis were investigated by Real-Time Quantitative Reverse Transcription PCR and western blot. GnRH expression in the hypothalamus and GnRHR expression in the ovary were detected by immunohistochemistry. SXF reduced the volume of the bilateral ovaries, as well as the volumes of the uterus, hypothalamus, and hypophysis in the female CPP rats and diminished the index of the ovary, uterus, hypothalamus, and hypophysis in the female CPP rats (P < 0.05 or P < 0.01). SXF treatment inhibited follicle maturation and uterine wall thickening in the female CPP rats. SXF decreased the concentrations of FSH, LH, PRL, and E2 in the peripheral blood in the female CPP rats (P < 0.01 or P < 0.001). SXF suppressed the expressions of GnRH, GnRHR, ERα, and GPR30 in the hypophysis (P < 0.05), the expression of GnRH in the hypothalamus (P < 0.01), and the expression of GnRHR in the ovaries (P < 0.001) of the female CPP rats. Overall, our study revealed that SXF had therapeutic effects on CPP in female rats. This is worthy of promoting clinically.

Effects of estrogen inhibition formula herbal mixture for danazol-induced precocious puberty in female rats: an experimental study with network pharmacology

Background

This study aimed at determining the effect of the herbal mixture estrogen inhibition formula (EIF) and its possible mechanisms by precocious puberty animal models and network pharmacology-based analysis.

Methods

Precocious puberty animal models were established by a single injection of 300 μg danazol, then female rats were administered EIF, vaginal openings were monitored, uterus and pituitary indices were determined. The levels of ALP, E2, LH, and FSH were measured using ELISA kits. Real-time PCR was performed to evaluate the mRNA expression of GnRH, UNC5C, and netrin-1 in hypothalamic tissues. We applied network pharmacological analysis to predict potential targets and pathways of EIF.

Results

EIF delayed danazol-induced early vaginal opening. In the onset model, EIF reduced the increased levels of serum ALP, E2, LH, and FSH; as well as mRNA expressions of GnRH, Netrin-1, and UNC5C. Moreover, long-term administration of EIF not only diminished all impaired factors but also had no effect on the normal development of the animals. The gene set enrichment analysis showed that the targets of EIF are mainly associated with the GnRH signaling and ovarian steroidogenesis pathways.

Conclusion

EIF could be used in preclinical research for the treatment of precocious puberty by the inhibition of HPGA pre-maturation.