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Medicina (Kaunas, Lithuania) Jun 2024Hyperprolactinemia, as a potential side-effect of some antipsychotic medications, is associated with decreased bone density and an increased risk of fractures. This...
Hyperprolactinemia, as a potential side-effect of some antipsychotic medications, is associated with decreased bone density and an increased risk of fractures. This study investigates whether calcium and vitamin D supplementation affects prolactin receptor ( gene expression in the duodenum, vertebrae, and kidneys of female rats with sulpiride-induced hyperprolactinemia. Twenty-one-week-old female Wistar rats were assigned to three groups: Group S consisted of ten rats who received sulpiride injections (10 mg/kg) twice daily for 6 weeks; Group D (10 rats) received daily supplementation of 50 mg calcium and 500 IU vitamin D along with sulpiride for the last 3 weeks; and Group C consisting of seven age-matched nulliparous rats serving as a control group. Real-time PCR was used to assess gene expression in the duodenum, vertebrae, and kidneys. In Group S, Prlr gene expression was notably decreased in the duodenum ( < 0.01) but elevated in the vertebrae and kidneys compared to Group C. Conversely, Group D exhibited significantly increased Prlr expression in the duodenum ( < 0.01) alongside elevated expression in the vertebrae and kidneys. In sulpiride-induced hyperprolactinemia, decreased Prlr gene expression in the duodenum may lead to reduced intestinal calcium absorption. Consequently, prolactin may draw calcium from the skeletal system to maintain calcium balance, facilitated by increased Prlr gene expression in the vertebrae. However, vitamin D supplementation in sulpiride-induced hyperprolactinemia notably enhances Prlr gene expression in the duodenum, potentially ameliorating intestinal calcium absorption and mitigating adverse effects on bone health.
Topics: Animals; Hyperprolactinemia; Sulpiride; Rats, Wistar; Female; Vitamin D; Rats; Calcium; Duodenum; Receptors, Prolactin; Gene Expression
PubMed: 38929559
DOI: 10.3390/medicina60060942 -
Animals : An Open Access Journal From... Jun 2024Yanshan Cashmere bucks are seasonal breeding animals and an important national genetic resource. This study aimed to investigate the involvement of prolactin (PRL) in...
Yanshan Cashmere bucks are seasonal breeding animals and an important national genetic resource. This study aimed to investigate the involvement of prolactin (PRL) in the epididymal function of bucks. Twenty eleven-month-old Cashmere bucks were randomly divided into a control (CON) group and a bromocriptine (BCR, a prolactin inhibitor, 0.06 mg/kg body weight (BW)) treatment group. The experiment was conducted from September to October 2020 in Qinhuangdao City, China, and lasted for 30 days. Blood was collected on the last day before the BCR treatment (day 0) and on the 15th and 30th days after the BCR treatment (days 15 and 30). On the 30th day, all bucks were transported to the local slaughterhouse, where epididymal samples were collected immediately after slaughter. The left epididymis was preserved in 4% paraformaldehyde for histological observation, and the right epididymis was immediately preserved in liquid nitrogen for RNA sequencing (RNA-seq). The results show that the PRL inhibitor reduced the serum PRL and estradiol (E2) concentrations ( < 0.05) and tended to decrease luteinizing hormone (LH) concentrations ( = 0.052) by the 30th day, but no differences ( > 0.05) occurred by either day 0 or 15. There were no differences ( > 0.05) observed in the follicle-stimulating hormone (FSH), testosterone (T), and dihydrotestosterone (DHT) concentrations between the two groups. The PRL receptor (PRLR) protein was mainly located in the cytoplasm and intercellular substance of the epididymal epithelial cells. The PRL inhibitor decreased ( < 0.05) the expression of the PRLR protein in the epididymis. In the BCR group, the height of the epididymal epithelium in the caput and cauda increased, as did the diameter of the epididymal duct in the caput ( < 0.05). However, the diameter of the cauda epididymal duct decreased ( < 0.05). Thereafter, a total of 358 differentially expressed genes (DEGs) were identified in the epididymal tissues, among which 191 were upregulated and 167 were downregulated. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses revealed that , , , , and were mainly enriched in the estrogen signaling pathway, steroid binding, calcium ion binding, the GnRH signaling pathway, the cAMP signaling pathway, and the chemical carcinogenesis-reactive oxygen species pathway, which are related to epididymal function. In conclusion, the inhibition of PRL may affect the structure of the epididymis by reducing the expression of the PRLR protein and the secretion of E2. , , , , and could be the key genes of PRL in its regulation of epididymal reproductive function.
PubMed: 38929397
DOI: 10.3390/ani14121778 -
Genome Biology and Evolution Jun 2024The European sprat is a small plankton-feeding clupeid present in the northeastern Atlantic Ocean, the Mediterranean Sea as well as in the brackish Baltic Sea and Black...
The European sprat is a small plankton-feeding clupeid present in the northeastern Atlantic Ocean, the Mediterranean Sea as well as in the brackish Baltic Sea and Black Sea. This species is the target of a major fishery and therefore an accurate characterization of its genetic population structure is crucial to delineate proper stock assessments that aid ensuring the fishery's sustainability. Here we present (i) a draft genome assembly, (ii) pooled whole genome sequencing of 19 population samples covering most of the species' distribution range, and (iii) the design and test of a SNP-chip resource and use this to validate the population structure inferred from pooled sequencing. These approaches revealed, using the populations sampled here, three major groups of European sprat: Oceanic, Coastal, and Brackish with limited differentiation within groups even over wide geographical stretches. Genetic structure is largely driven by six large putative inversions that differentiate Oceanic and Brackish sprats, while Coastal populations display intermediate frequencies of haplotypes at each locus. Interestingly, populations from the Baltic and the Black Seas share similar frequencies of haplotypes at these putative inversions despite their distant geographic location. The closely related clupeids European sprat and Atlantic herring both show genetic adaptation to the brackish Baltic Sea, providing an opportunity to explore the extent of genetic parallelism. This analysis revealed limited parallelism because out of 125 independent loci detected in the Atlantic herring, three showed sharp signals of selection that overlapped between the two species and contained single genes such as PRLRA, which encodes the receptor for prolactin, a freshwater-adapting hormone in euryhaline species, and THRB, a receptor for thyroid hormones, important both for metabolic regulation and the development of red cone photoreceptors.
PubMed: 38918882
DOI: 10.1093/gbe/evae133 -
Endocrine Journal Jun 2024Although growth hormone (GH) and prolactin (PRL) are usually recognized as pituitary hormones, their expression is not restricted to the adenohypophysis and can also be...
Although growth hormone (GH) and prolactin (PRL) are usually recognized as pituitary hormones, their expression is not restricted to the adenohypophysis and can also be found in extra-pituitary tissues including placenta. Furthermore, GH, PRL, and their receptors structurally belong to the cytokine family of proteins, and indeed they have remarkable pleiotropic effects. In this review, we analyzed the biological roles of GH/PRL from an evolutionary perspective. We have recognized that the biological significance of GH/PRL can be summarized as follows: cytokines (metabokines) that regulate the shift of nutrients and even of whole bodies to live in the most appropriate environment(s) for conducting growth and reproduction. In this sense, the common keyword of the two metabokines is "shift" for environmental adaptation. Considering that these metabokines flexibly changed their biological roles, GH/PRL may have played important roles during vertebrate evolution.
PubMed: 38910132
DOI: 10.1507/endocrj.EJ24-0118 -
Journal of Experimental & Clinical... Jun 2024Though tamoxifen achieves success in treating estrogen receptor α (ERα)-positive breast cancer, the followed development of tamoxifen resistance is a common challenge...
BACKGROUND
Though tamoxifen achieves success in treating estrogen receptor α (ERα)-positive breast cancer, the followed development of tamoxifen resistance is a common challenge in clinic. Signals downstream of prolactin receptor (PRLR) could synergize with ERα in breast cancer progression. However, the potential effect of targeting PRL-PRLR axis combined with tamoxifen has not been thoroughly investigated.
METHODS
High-throughput RNA-seq data obtained from TCGA, Metabric and GEO datasets were analyzed to explore PRLR expression in breast cancer cell and the association of PRLR expression with tamoxifen treatment. Exogenous or PRL overexpression cell models were employed to investigate the role of activated PRLR pathway in mediating tamoxifen insensitivity. Immunotoxin targeting PRLR (N8-PE24) was constructed with splicing-intein technique, and the efficacy of N8-PE24 against breast cancer was evaluated using in vitro and in vivo methods, including analysis of cells growth or apoptosis, 3D spheroids culture, and animal xenografts.
RESULTS
PRLR pathway activated by PRL could significantly decrease sensitivity of ERα-positive breast cancer cells to tamoxifen. Tamoxifen treatment upregulated transcription of PRLR and could induce significant accumulation of PRLR protein in breast cancer cells by alkalizing lysosomes. Meanwhile, tamoxifen-resistant MCF7 achieved by long-term tamoxifen pressure exhibited both upregulated transcription and protein level of PRLR. Immunotoxin N8-PE24 enhanced sensitivity of breast cancer cells to tamoxifen both in vitro and in vivo. In xenograft models, N8-PE24 significantly enhanced the efficacy of tamoxifen and paclitaxel when treating PRLR-positive triple-negative breast cancer.
CONCLUSIONS
PRL-PRLR axis potentially associates with tamoxifen insensitivity in ERα-positive breast cancer cells. N8-PE24 could inhibit cell growth of the breast cancers and promote drug sensitivity of PRLR-positive breast cancer cells to tamoxifen and paclitaxel. Our study provides a new perspective for targeting PRLR to treat breast cancer.
Topics: Tamoxifen; Humans; Female; Breast Neoplasms; Animals; Receptors, Prolactin; Mice; Immunotoxins; Xenograft Model Antitumor Assays; Cell Line, Tumor; Drug Resistance, Neoplasm; Cell Proliferation; Apoptosis
PubMed: 38898487
DOI: 10.1186/s13046-024-03099-4 -
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 -
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 -
Neuroscience and Biobehavioral Reviews Jun 2024The introduction of sex-as-a-biological-variable policies at funding agencies around the world has led to an explosion of very recent observations of sex differences in... (Review)
Review
The introduction of sex-as-a-biological-variable policies at funding agencies around the world has led to an explosion of very recent observations of sex differences in the biology underlying pain. This review considers evidence of sexually dimorphic mechanisms mediating pain hypersensitivity, derived from modern assays of persistent pain in rodent animal models. Three well-studied findings are described in detail: the male-specific role of spinal cord microglia, the female-specific role of calcitonin gene-related peptide (CGRP), and the female-specific role of prolactin and its receptor. Other findings of sex-specific molecular involvement in pain are subjected to pathway analyses and reveal at least one novel hypothesis: that females may preferentially use Th1 and males Th2 T cell activity to mediate chronic pain.
PubMed: 38838876
DOI: 10.1016/j.neubiorev.2024.105749 -
Cureus May 2024Hyperprolactinemia is an endocrinological disorder that might arise from various physiologic or pathologic conditions, as well as from pharmacologic sources. These...
Hyperprolactinemia is an endocrinological disorder that might arise from various physiologic or pathologic conditions, as well as from pharmacologic sources. These pharmacologic sources include antidepressants, antipsychotics, and dopamine receptor-blocking agents. Amitriptyline is classified as a tricyclic antidepressant. While it is FDA-approved primarily for the treatment of depression, amitriptyline also demonstrates efficacy in managing various other conditions, such as anxiety, post-traumatic stress disorder, insomnia, chronic and neuropathic pain, and migraine prevention. We present a case of a 10-year-old patient with a history of autism spectrum disorder (ASD), attention-deficit/hyperactivity disorder (ADHD), and migraine headaches who was incidentally found to have elevated prolactin levels while taking amitriptyline for migraine prophylaxis. While risperidone, an antipsychotic that can be used for ASD management, is commonly known to induce hyperprolactinemia, the association between amitriptyline and elevated prolactin is less frequently described in the literature. This case underscores the necessity for healthcare providers across various specialties to be aware of amitriptyline-induced hyperprolactinemia.
PubMed: 38826982
DOI: 10.7759/cureus.59604 -
Neurochemical Research Jul 2024Oxidative stress-induced death of neurons and astrocytes contributes to the pathogenesis of numerous neurodegenerative diseases. While significant progress has been made...
Oxidative stress-induced death of neurons and astrocytes contributes to the pathogenesis of numerous neurodegenerative diseases. While significant progress has been made in identifying neuroprotective molecules against neuronal oxidative damage, little is known about their counterparts for astrocytes. Prolactin (PRL), a hormone known to stimulate astroglial proliferation, viability, and cytokine expression, exhibits antioxidant effects in neurons. However, its role in protecting astrocytes from oxidative stress remains unexplored. Here, we investigated the effect of PRL against hydrogen peroxide (HO)-induced oxidative insult in primary cortical astrocyte cultures. Incubation of astrocytes with PRL led to increased enzymatic activity of superoxide dismutase (SOD) and glutathione peroxidase (GPX), resulting in higher total antioxidant capacity. Concomitantly, PRL prevented HO-induced cell death, reactive oxygen species accumulation, and protein and lipid oxidation. The protective effect of PRL upon HO-induced cell death can be explained by the activation of both signal transducer and activator of transcription 3 (STAT3) and NFE2 like bZIP transcription factor 2 (NRF2) transduction cascades. We demonstrated that PRL induced nuclear translocation and transcriptional upregulation of Nrf2, concurrently with the transcriptional upregulation of the NRF2-dependent genes heme oxygenase 1, Sod1, Sod2, and Gpx1. Pharmacological blockade of STAT3 suppressed PRL-induced transcriptional upregulation of Nrf2, Sod1 and Gpx1 mRNA, and SOD and GPX activities. Furthermore, genetic ablation of the PRL receptor increased astroglial susceptibility to HO-induced cell death and superoxide accumulation, while diminishing their intrinsic antioxidant capacity. Overall, these findings unveil PRL as a potent antioxidant hormone that protects astrocytes from oxidative insult, which may contribute to brain neuroprotection.
Topics: Astrocytes; Animals; NF-E2-Related Factor 2; Oxidative Stress; STAT3 Transcription Factor; Signal Transduction; Prolactin; Antioxidants; Cell Death; Hydrogen Peroxide; Cells, Cultured; Mice; Rats
PubMed: 38755517
DOI: 10.1007/s11064-024-04147-3