Targeting KNDy neurons to control GnRH pulses

Estradiol Reverses Ovariectomy-Induced Disruption of Hypothalamic Gene Expression and Behavior via Modulation of Gonadotropin Releasing Hormone and Calcium Signaling Pathways

Estrogen plays a crucial role in regulating reproductive and neuroendocrine functions, yet the molecular mechanisms underlying its effects on the hypothalamus remain incompletely understood. This study investigates the transcriptional and behavioral changes induced by ovariectomy (OVX) and estradiol (E2) supplementation in female C57BL/6J mice. RNA sequencing was performed to identify differentially expressed genes (DEGs) across control (CK), E2, OVX, and OVX+E2 groups, followed by functional enrichment and pathway analyses. Behavioral assessments, including open field, Y-maze, and elevated plus maze tests, were conducted to evaluate anxiety-like and cognitive behaviors. Results revealed significant alterations in GnRH signaling, neurotransmission, and inflammatory pathways, with key genes such as Elk1, Prkcb, and Camk2a differentially expressed in response to estrogen modulation. OVX-induced neuroendocrine disruptions were partially reversed by E2 treatment, as evidenced by transcriptomic and behavioral outcomes. Pearson correlation analysis further linked gene expression patterns with phenotypic traits, providing insights into estrogen's regulatory mechanisms in the hypothalamus. These findings enhance our understanding of estrogen-mediated neuroendocrine regulation and may have implications for hormone replacement therapies in postmenopausal disorders.

What is known and unknown about the role of neuroendocrine genes Ptprn and Ptprn2

The protein tyrosine phosphatase receptors N and N2 are encoded by the Ptprn and Ptprn2 genes expressed in neuroendocrine cells of the hypothalamus, pituitary gland, and diffuse neuroendocrine system, including the pancreas, lung, and intestine. Unlike other members of the protein tyrosine phosphatase receptor family, PTPRN and PTPRN2 lack protein tyrosine phosphatase activity due to mutation of two residues in their intracellular catalytic domains. However, during evolution these proteins acquired new cellular roles beyond tyrosine dephosphorylation in the centralized and diffuse neuroendocrine systems. Here we discuss the current understanding and lack of information about the actions of these proteins, focusing on neuroendocrine cells of the hypothalamus, pituitary, and pancreas.

Kisspeptin and Endometriosis-Is There a Link?

This article presents a narrative review that explores the potential link between kisspeptin-a key regulator of the hypothalamic-pituitary-gonadal axis-and the pathogenesis of endometriosis. Kisspeptin plays a significant role in regulating reproductive functions by modulating the release of gonadotropin-releasing hormone (GnRH), which in turn stimulates the secretion of luteinizing hormone (LH) and follicle-stimulating hormone (FSH). Recent studies suggest that kisspeptin may also impact peripheral reproductive tissues and influence inflammatory processes involved in the development of endometriosis. Altered kisspeptin signaling has been associated with the abnormal hormonal environment observed in endometriosis, which affects menstrual cycles and ovarian function. Research indicates that women with endometriosis exhibit altered levels of kisspeptin and its receptor, KISS1R, in both eutopic and ectopic endometrial tissues, suggesting a role in disease progression, particularly in tissue invasion and lesion formation. Kisspeptin's role in regulating matrix metalloproteinases (MMPs), enzymes essential for tissue remodeling, further supports its potential contribution to the pathophysiology of endometriosis. Moreover, kisspeptin-based therapeutic strategies are currently under investigation, with the aim of providing targeted treatments that reduce the side effects commonly associated with existing therapies. Despite promising findings, further research is needed to fully understand the mechanisms by which kisspeptin influences endometriosis.

Genistein early in life Modifies the arcuate nucleus of the hypothalamus morphology differentially in male and female rats

In the present work we analyzed the effects of postnatal exposure to two doses of genistein (10 μg/g or 50 μg/g) from postnatal (P) day 6 to P13, on the morphology of the arcuate nucleus (Arc). The analyses of Arc coronal brain sections at 90 days showed that the ArcMP had higher values in volume, Nissl-stained neurons and GPER-ir neurons in males than in females and the treatment with genistein abolished these sex differences in most of the parameters studied. Moreover, in males, but not in females, the GPER-ir neurons decreased in the ArcMP but increased in the ArcL with both doses of genistein. In the ArcLP, GPER-ir population increased with the lowest doses and decreased with the highest one in males. Our results confirm that the Arc subdivisions have differential vulnerability to the effects of genistein during development, depending on which neuromorphological parameters, dose and sex are analyzed.