Grid1 regulates the onset of puberty in female rats.

The study aimed to investigate the effect of Grid1, encoding the glutamate ionotropic receptor delta type subunit 1 (GluD1), on puberty onset in female rats. Grid1 mRNA and protein expression was detected in the hypothalamus of female rats at prepuberty and puberty. The levels of Grid1 mRNA in the hypothalamus, the fluorescence intensity in the arcuate nucleus and paraventricular nucleus of the prepubertal rats was significantly lower than pubertal. Additionally, the expression of Grid1 was suppressed in primary hypothalamus cells and prepubertal rat. Finally, investigated the effect of Grid1 knockdown on puberty onset and reproductive performance. Treatment of hypothalamic neurons with LV-Grid1 decreased the level of Grid1 and Rfrp-3 (encoding RFamide-related peptide 3) mRNA expression, but increased the Gnrh (encoding gonadotropin-releasing hormone) mRNA levels. After an ICV injection, the time for the rat vaginal opening occurred earlier. Moreover, Gnrh mRNA expression was increased, whereas Rfrp-3 mRNA expression was decreased in the hypothalamus. The concentration of progesterone (P4) in the serum was significantly decreased compare with control group. Ovary hematoxylin-eosin staining revealed that the LV-Grid1 group mainly contained primary and secondary follicles. The reproductive performance of the rats was not affected by the Grid1 knockdown. Therefore, Grid1 may affect the onset of puberty in female rats by regulating the levels of Gnrh, and Rfrp-3 in the hypothalamus, as well as the concentrations of P4, but not reproduction performance.

Integrative proteomic and phosphoproteomic analysis in the female goat hypothalamus to study the onset of puberty.

BACKGROUND: Puberty marks the end of childhood and achieve sexual maturation and fertility. The role of hypothalamic proteins in regulating puberty onset is unclear. We performed a comprehensive differential proteomics and phosphoproteomics analysis in prepubertal and pubertal goats to determine the roles of hypothalamic proteins and phosphoproteins during the onset of puberty. RESULTS: We used peptide and posttranslational modifications peptide quantification and statistical analyses, and identified 69 differentially expressed proteins from 5,057 proteins and 576 differentially expressed phosphopeptides from 1574 phosphorylated proteins. Combined proteomic and phosphoproteomics, 759 correlated proteins were identified, of which 5 were differentially expressed only at the protein level, and 201 were only differentially expressed at the phosphoprotein level. Pathway enrichment analyses revealed that the majority of correlated proteins were associated with glycolysis/gluconeogenesis, Fc gamma R-mediated phagocytosis, focal adhesion, GABAergic synapse, and Rap1 signaling pathway. These pathways are related to cell proliferation, neurocyte migration, and promoting the release of gonadotropin-releasing hormone in the hypothalamus. CTNNB1 occupied important locations in the protein-protein interaction network and is involved in focal adhesion. CONCLUSION: The results demonstrate that the proteins differentially expression only at the protein level or only differentially expressed at the phosphoprotein level and their related signalling pathways are crucial in regulating puberty in goats. These differentially expressed proteins and phosphorylated proteins may constitute the proteomic backgrounds between the two different stages.

Knockdown of lncRNA Meg3 delays the onset of puberty in female rats.

This study investigated how lncRNA Meg3 affects the onset of puberty in female rats. We determined Meg3 expression in the hypothalamus-pituitary-ovary axis of female rats at the infancy, prepubertal, pubertal, and adult life stages, using quantitative reverse transcription polymerase chain reaction (qRT-PCR). We also assessed the effects of Meg3 knockdown on the expression levels of puberty-related genes and Wnt/ß-catenin proteins in the hypothalamus, time of puberty onset, levels of reproductive genes and hormones, and ovarian morphology in female rats. Meg3 expression in the ovary varied significantly between prepuberty and puberty (P < 0.01). Meg3 knockdown decreased the expression of Gnrh, and Kiss1 mRNA (P < 0.05) and increased the expression of Wnt (P < 0.01) and ß-catenin proteins (P < 0.05) in the hypothalamic cells. Onset of puberty in Meg3 knockdown rats was delayed compared to the control group (P < 0.05). Meg3 knockdown decreased Gnrh mRNA levels (P < 0.05) and increased Rfrp-3 mRNA levels (P < 0.05) in the hypothalamus. The serum concentrations of progesterone (P4) and estradiol (E2) of Meg3 knockdown rats were lower than those in the control animals (P < 0.05). Higher longitudinal diameter and ovary weight were found in Meg3 knockdown rats (P < 0.05). These findings suggest that Meg3 regulates the expression of Gnrh, Kiss-1 mRNA and Wnt/ß-catenin proteins in the hypothalamic cells, and Gnrh, Rfrp-3 mRNA of the hypothalamus and the serum concentration of P4 and E2, and its knockdown delays the onset of puberty in female rats.