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Frontiers in Endocrinology 2024Gonadotropin-releasing hormone (GnRH) is a key stimulator for gonadotropin secretion in the pituitary and its pivotal role in reproduction is well conserved in...
Differential involvement of cAMP/PKA-, PLC/PKC- and Ca/calmodulin-dependent pathways in GnRH-induced prolactin secretion and gene expression in grass carp pituitary cells.
Gonadotropin-releasing hormone (GnRH) is a key stimulator for gonadotropin secretion in the pituitary and its pivotal role in reproduction is well conserved in vertebrates. In fish models, GnRH can also induce prolactin (PRL) release, but little is known for the corresponding effect on PRL gene expression as well as the post-receptor signalling involved. Using grass carp as a model, the functional role of GnRH and its underlying signal transduction for PRL regulation were examined at the pituitary level. Using laser capture microdissection coupled with RT-PCR, GnRH receptor expression could be located in carp lactotrophs. In primary cell culture prepared from grass carp pituitaries, the native forms of GnRH, GnRH2 and GnRH3, as well as the GnRH agonist [D-Arg, Pro, NEt]-sGnRH were all effective in elevating PRL secretion, PRL mRNA level, PRL cell content and total production. In pituitary cells prepared from the rostral pars distalis, the region in the carp pituitary enriched with lactotrophs, GnRH not only increased cAMP synthesis with parallel CREB phosphorylation and nuclear translocation but also induced a rapid rise in cytosolic Ca by Ca influx via L-type voltage-sensitive Ca channel (VSCC) with subsequent CaM expression and NFAT dephosphorylation. In carp pituitary cells prepared from whole pituitaries, GnRH-induced PRL secretion was reduced/negated by inhibiting cAMP/PKA, PLC/PKC and Ca/CaM/CaMK-II pathways but not the signalling events via IP and CaN/NFAT. The corresponding effect on PRL mRNA expression, however, was blocked by inhibiting cAMP/PKA/CREB/CBP and Ca/CaM/CaN/NFAT signalling but not PLC/IP/PKC pathway. At the pituitary cell level, activation of cAMP/PKA pathway could also induce CaM expression and Ca influx via VSCC with parallel rises in PRL release and gene expression in a Ca/CaM-dependent manner. These findings, as a whole, suggest that the cAMP/PKA-, PLC/PKC- and Ca/CaM-dependent cascades are differentially involved in GnRH-induced PRL secretion and PRL transcript expression in carp lactotrophs. During the process, a functional crosstalk between the cAMP/PKA- and Ca/CaM-dependent pathways may occur with PRL release linked with CaMK-II and PKC activation and PRL gene transcription caused by nuclear action of CREB/CBP and CaN/NFAT signalling.
Topics: Animals; Carps; Gonadotropin-Releasing Hormone; Prolactin; Pituitary Gland; Protein Kinase C; Cyclic AMP-Dependent Protein Kinases; Calcium; Type C Phospholipases; Cyclic AMP; Signal Transduction; Calmodulin; Cells, Cultured; Gene Expression
PubMed: 38894746
DOI: 10.3389/fendo.2024.1399274 -
Foods (Basel, Switzerland) May 2024Breast milk serves as the primary source of nourishment for newborns. In cases of low milk production, one approach to address this challenge involves the consumption of...
Breast milk serves as the primary source of nourishment for newborns. In cases of low milk production, one approach to address this challenge involves the consumption of lactagogues. Chicken-herb essence, a beverage rich in protein, amino acids, and minerals, presents itself as a viable option to supplement a lactating mother's diet, particularly in terms of protein intake. This study aimed to evaluate the effects of chicken-herb essence on prolactin and lactoferrin in lactating rats. Furthermore, the study also assessed the lactagogue effect on IgA in offspring. The experimental research method used a completely randomized design. The animal models in this study were female Sprague Dawley rats. The result showed that there was an increase in milk production, as seen from the results of the lactagogue effect. The highest increase in prolactin and lactoferrin was obtained in treatment group II (TG II). The increases in prolactin and lactoferrin of TG II were 214.18 ± 71.99 and 904.02 ± 435.35 pg/mL, respectively. The lactagogue test showed that TG II haspotency as a milk-booster. Testing the blood serum of offspring showed that the highest concentration of IgA was also found in TG II at 398.34 ± 214.85 pg/mL.
PubMed: 38890832
DOI: 10.3390/foods13111603 -
Cell Death Discovery Jun 2024As the mean age of first-time mothers increases in the industrialized world, inquiries into causes of human reproductive senescence have followed. Rates of ovulatory...
As the mean age of first-time mothers increases in the industrialized world, inquiries into causes of human reproductive senescence have followed. Rates of ovulatory dysfunction and oocyte aneuploidy parallel chronological age, but poor reproductive outcomes in women older than 35 years are also attributed to endometrial senescence. The current studies, using primary human endometrial stromal cell (ESC) cultures as an in vitro model for endometrial aging, characterize the proinflammatory cytokine, IL-1β-mediated and passage number-dependent effects on ESC phenotype. ESC senescence was accelerated by incubation with IL-1β, which was monitored by RNA sequencing, ELISA, immunocytochemistry and Western blotting. Senescence associated secreted phenotype (SASP) proteins, IL-1β, IL-6, IL-8, TNF-α, MMP3, CCL2, CCL5, and other senescence-associated biomarkers of DNA damage (p16, p21, HMGB1, phospho-γ-histone 2 A.X) were noted to increase directly in response to 0.1 nM IL-1β stimulation. Production of the corresponding SASP proteins increased further following extended cell passage. Using enzyme inhibitors and siRNA interference, these effects of IL-1β were found to be mediated via the c-Jun N-terminal kinase (JNK) signaling pathway. Hormone-induced ESC decidualization, classical morphological and biochemical endocrine responses to estradiol, progesterone and cAMP stimulation (prolactin, IGFBP-1, IL-11 and VEGF), were attenuated pari passu with prolonged ESC passaging. The kinetics of differentiation responses varied in a biomarker-specific manner, with IGFBP-1 and VEGF secretion showing the largest and smallest reductions, with respect to cell passage number. ESC hormone responsiveness was most robust when limited to the first six cell passages. Hence, investigation of ESC cultures as a decidualization model should respect this limitation of cell aging. The results support the hypotheses that "inflammaging" contributes to endometrial senescence, disruption of decidualization and impairment of fecundity. IL-1β and the JNK signaling pathway are pathogenetic targets amenable to pharmacological correction or mitigation with the potential to reduce endometrial stromal senescence and enhance uterine receptivity.
PubMed: 38879630
DOI: 10.1038/s41420-024-02048-6 -
International Journal of Surgery Case... Jul 2024Ectopic pituitary neuroendocrine tumor (EPNET) is a very rare entity, seldom with apoplexy evolution. Only three cases of intracranial ectropic pituitary neuroendocrine...
INTRODUCTION AND IMPORTANCE
Ectopic pituitary neuroendocrine tumor (EPNET) is a very rare entity, seldom with apoplexy evolution. Only three cases of intracranial ectropic pituitary neuroendocrine tumor apoplexy were reported in the literature.
CASE PRESENTATION
We report the case of a 45-year-old woman with a history of amenorrhea, and headaches. Neuroimaging showed a very aggressive giant mass within the clivus with the invasion of the sphenoidal sinus and encasement of internal carotid arteries with an empty sella. Endocrinology work-up revealed an exceedingly high level of prolactin surprisingly without galactorrhea. Immunohistochemical analysis after an endonasal biopsy confirmed the diagnosis of prolactinoma. One month after Cabergoline initiation, an apoplexy of the ectopic pituitary neuroendocrine tumor occurred. Conservational management with a decrease in cabergoline dose was performed.
DISCUSSION
This article highlights data from various cases reported in the literature in addition to our case to confirm the extreme rarity of apoplexy as a complication of EPNET.
CONCLUSION
Pituitary apoplexy in ectopic pituitary neuroendocrine tumor is extremely rare. Therefore, in case of unusual localization of pituitary neuroendocrine tumor, a thorough follow-up is necessary to detect complications and ensure early management.
PubMed: 38878728
DOI: 10.1016/j.ijscr.2024.109874 -
Neuropharmacology Jun 2024Kappa opioid receptors (KORs) are implicated in the pathophysiology of various psychiatric and neurological disorders creating interest in targeting the KOR system for...
Kappa opioid receptors (KORs) are implicated in the pathophysiology of various psychiatric and neurological disorders creating interest in targeting the KOR system for therapeutic purposes. Accordingly, navacaprant (NMRA-140) is a potent, selective KOR antagonist being evaluated as a treatment for major depressive disorder. In the present report, we have extended the pharmacological characterization of navacaprant by further demonstrating its selective KOR antagonist properties and confirming its lack of agonist activity at KORs and related targets involved in opioid-related abuse. Using CHO-K1 cells expressing human KOR, mu (MOR), or delta (DOR) opioid receptors, navacaprant demonstrated selective antagonist properties at KOR (IC = 0.029 μM) versus MOR (IC = 3.3 μM) and DOR (IC > 10 μM) in vitro. In vivo, navacaprant (10-30 mg/kg, i.p.) dose-dependently abolished KOR-agonist induced analgesia in the mouse tail-flick assay. Additionally, navacaprant (10, 30 mg/kg, p.o.) significantly reduced KOR agonist-stimulated prolactin release in mice and rats, confirming KOR antagonism in vivo. Navacaprant showed no agonist activity at any opioid receptor subtype (EC > 10 μM) in vitro and exhibited no analgesic effect in the tail-flick assays at doses ≤100 mg/kg, p.o. thereby confirming a lack of opioid receptor agonist activity in vivo. Importantly, navacaprant did not alter extracellular dopamine concentrations in the nucleus accumbens shell of freely-moving rats following doses ≤100 mg/kg, p.o., whereas morphine (10, 20 mg/kg, i.p.) significantly increased dopamine levels. These results demonstrate that navacaprant is a KOR-selective antagonist with no pharmacological properties implicated in opioid-related abuse.
PubMed: 38876309
DOI: 10.1016/j.neuropharm.2024.110037 -
Alternative Therapies in Health and... Jun 2024Polycystic ovary syndrome (PCOS) causes normogonadotrophic anovulation, where women experience abnormal and irregular ovulations due to dysfunctions in the...
BACKGROUND
Polycystic ovary syndrome (PCOS) causes normogonadotrophic anovulation, where women experience abnormal and irregular ovulations due to dysfunctions in the hypothalamic-pituitary that ensure normal levels of estradiol are maintained. This study aims to investigate the improvement of PCOS symptoms in obese patients after undergoing bariatric surgery.
METHODS
We conducted a retrospective study at The First Hospital of Hebei Medical University from 2020 to 2022. We recruited 65 females; the inclusion criteria involved patients who were obese and experiencing infertility issues due to PCOS, patients who consented to undergo bariatric surgery, patients who were aged 22 years to 40 years, and patients who had a post-surgical BMI of ≤ 35 kg/m2. We excluded patients with medical disorders and complications, aged 40 years and above, and patients who showed a post-surgical operation BMI of greater than 35 kg/m2.
RESULTS
The patients recorded an average pre-operating BMI of 44 kg/m2 with a mean age of 28 years. Most participants had an average menstrual cycle of 60 to 90 days, with 44% of patients reporting normal menstruation. At 6 months, post-surgery, the average level of prolactin was 11.39 ng/mL, progesterone was 0.4ng/dL, SHBG at 24 nmol/L, estradiol at 24.6 pg/mL, testosterone at 34 pg/mL, LH at 10.2 mIU/ml and FSH at 5.6 mIU/ml.
DISCUSSION
Bariatric surgery enhances a reduction in body weight due to lowering BMI levels of serum and total testosterone. The increased sensitivity to insulin reduces resistance to insulin and enhances regulation of hormones. Ovulation and menstrual cycle were restored in women with PCOS due to weight loss and positive regulation of hormones. Moreover, the effects of chronic low-grade inflammations were eliminated due to a significant reduction in the adipose mass and enhanced metabolic parameters.
CONCLUSION
We observed that bariatric surgery improved PCOS symptoms in obese women. Bariatric surgery combined with sustainable weight loss, shows promising improvements in menstrual regularity, hormonal balance, fertility and pregnancy rates for obese women with PCOS, potentially offering them a valuable option for achieving conception.
PubMed: 38870509
DOI: No ID Found