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American Journal of Physiology. Renal... Jan 2024Tolvaptan, a vasopressin antagonist selective for the V2-subtype vasopressin receptor (V2R), is widely used in the treatment of hyponatremia and autosomal-dominant...
Tolvaptan, a vasopressin antagonist selective for the V2-subtype vasopressin receptor (V2R), is widely used in the treatment of hyponatremia and autosomal-dominant polycystic kidney disease (ADPKD). Its effects on signaling in collecting duct cells have not been fully characterized. Here, we perform RNA-seq in a collecting duct cell line (mpkCCD). The data show that tolvaptan inhibits the expression of mRNAs that were previously shown to be increased in response to vasopressin including aquaporin-2, but also reveals mRNA changes that were not readily predictable and suggest off-target actions of tolvaptan. One such action is activation of the MAPK kinase (ERK1/ERK2) pathway. Prior studies have shown that ERK1/ERK2 activation is essential in the regulation of a variety of cellular and physiological processes and can be associated with cell proliferation. In immunoblotting experiments, we demonstrated that ERK1/ERK2 phosphorylation in mpkCCD cells was significantly reduced by vasopressin, in contrast to the increases seen in non-collecting-duct cells overexpressing V2R in prior studies. We also found that tolvaptan has a strong effect to increase ERK1/ERK2 phosphorylation in the presence of vasopressin and that tolvaptan's effect to increase ERK1/ERK2 phosphorylation is absent in mpkCCD cells in which both protein kinase A (PKA)-catalytic subunits have been deleted. Thus, it appears that the tolvaptan effect to increase ERK activation is PKA-dependent and is not due to an off-target effect of tolvaptan. We conclude that in cells expressing V2R at endogenous levels: ) vasopressin decreases ERK1/ERK2 activation; ) in the presence of vasopressin, tolvaptan increases ERK1/ERK2 activation; and ) these effects are PKA-dependent. Vasopressin is a key hormone that regulates the function of the collecting duct of the kidney. ERK1 and ERK2 are enzymes that play key roles in physiological regulation in all cells. The authors used collecting duct cell cultures to investigate the effects of vasopressin and the vasopressin receptor antagonist tolvaptan on ERK1 and ERK2 phosphorylation and activation.
Topics: Tolvaptan; Receptors, Vasopressin; Phosphorylation; MAP Kinase Signaling System; Kidney; Antidiuretic Hormone Receptor Antagonists; Vasopressins
PubMed: 37916285
DOI: 10.1152/ajprenal.00124.2023 -
Case Reports in Nephrology and Dialysis 2023Congenital nephrogenic diabetes insipidus (CNDI), a rare hereditary disorder, is characterized by the inability of the kidneys to concentrate urine in response to the...
Congenital nephrogenic diabetes insipidus (CNDI), a rare hereditary disorder, is characterized by the inability of the kidneys to concentrate urine in response to the antidiuretic hormone arginine vasopressin (AVP); as a result, large volumes of unconcentrated urine are excreted. In addition to the clinical manifestations of CNDI, such as dehydration and electrolyte disturbances (hypernatremia and hyperchloremia), developmental delay can result without prompt treatment. In approximately 90% of cases, CNDI is an X-linked disease caused by mutations in the arginine vasopressin receptor 2 () gene. In approximately 9% of cases, CNDI is an autosomal recessive disease caused by mutations in the water channel protein aquaporin 2 (), and 1% of cases are autosomal dominant. We report a case of CNDI caused by a novel nonsense mutation, c.520C>T (p.Q174X), and cases of siblings in another family who had a different nonsense mutation, c.852G>A (p.W284X). Both cases responded well to treatment with hydrochlorothiazide and spironolactone. If CNDI is suspected, especially in carriers and neonates, aggressive genetic testing and early treatment may alleviate growth disorders and prevent irreversible central nervous system disorders and developmental delay.
PubMed: 37900924
DOI: 10.1159/000533895 -
International Journal of Molecular... Oct 2023In patients with heart failure (HF), the neuroendocrine systems of the sympathetic nervous system (SNS), the renin-angiotensin-aldosterone system (RAAS) and the arginine... (Review)
Review
In patients with heart failure (HF), the neuroendocrine systems of the sympathetic nervous system (SNS), the renin-angiotensin-aldosterone system (RAAS) and the arginine vasopressin (AVP) system, are activated to various degrees producing often-observed tachycardia and concomitant increased systemic vascular resistance. Furthermore, sustained neurohormonal activation plays a key role in the progression of HF and may be responsible for the pathogenetic mechanisms leading to the perpetuation of the pathophysiology and worsening of the HF signs and symptoms. There are biomarkers of activation of these neurohormonal pathways, such as the natriuretic peptides, catecholamine levels and neprilysin and various newer ones, which may be employed to better understand the mechanisms of HF drugs and also aid in defining the subgroups of patients who might benefit from specific therapies, irrespective of the degree of left ventricular dysfunction. These therapies are directed against these neurohumoral systems (neurohumoral antagonists) and classically comprise beta blockers, angiotensin-converting enzyme (ACE) inhibitors/angiotensin receptor blockers and vaptans. Recently, the RAAS blockade has been refined by the introduction of the angiotensin receptor-neprilysin inhibitor (ARNI) sacubitril/valsartan, which combines the RAAS inhibition and neprilysin blocking, enhancing the actions of natriuretic peptides. All these issues relating to the neurohumoral activation in HF are herein reviewed, and the underlying mechanisms are pictorially illustrated.
Topics: Humans; Neprilysin; Tetrazoles; Angiotensin Receptor Antagonists; Heart Failure; Angiotensin-Converting Enzyme Inhibitors; Drug Combinations; Renin-Angiotensin System; Natriuretic Peptides; Aminobutyrates; Biphenyl Compounds
PubMed: 37895150
DOI: 10.3390/ijms242015472 -
Biomedicines Sep 2023Autism spectrum disorder (ASD) is rather common, presenting with prevalent early problems in social communication and accompanied by repetitive behavior. As vasopressin... (Review)
Review
Autism spectrum disorder (ASD) is rather common, presenting with prevalent early problems in social communication and accompanied by repetitive behavior. As vasopressin was implicated not only in salt-water homeostasis and stress-axis regulation, but also in social behavior, its role in the development of ASD might be suggested. In this review, we summarized a wide range of problems associated with ASD to which vasopressin might contribute, from social skills to communication, motor function problems, autonomous nervous system alterations as well as sleep disturbances, and altered sensory information processing. Beside functional connections between vasopressin and ASD, we draw attention to the anatomical background, highlighting several brain areas, including the paraventricular nucleus of the hypothalamus, medial preoptic area, lateral septum, bed nucleus of stria terminalis, amygdala, hippocampus, olfactory bulb and even the cerebellum, either producing vasopressin or containing vasopressinergic receptors (presumably V). Sex differences in the vasopressinergic system might underline the male prevalence of ASD. Moreover, vasopressin might contribute to the effectiveness of available off-label therapies as well as serve as a possible target for intervention. In this sense, vasopressin, but paradoxically also V receptor antagonist, were found to be effective in some clinical trials. We concluded that although vasopressin might be an effective candidate for ASD treatment, we might assume that only a subgroup (e.g., with stress-axis disturbances), a certain sex (most probably males) and a certain brain area (targeting by means of virus vectors) would benefit from this therapy.
PubMed: 37892977
DOI: 10.3390/biomedicines11102603 -
Toxics Oct 2023(1) Introduction: Epigenetic changes have been proposed as a biologic link between in-utero exposure to maternal smoking and health outcomes. Therefore, we examined if...
(1) Introduction: Epigenetic changes have been proposed as a biologic link between in-utero exposure to maternal smoking and health outcomes. Therefore, we examined if in-utero exposure to maternal smoking was associated with infant DNA methylation (DNAm) of cytosine-phosphate-guanine dinucleotides (CpG sites) in the arginine vasopressin receptor 1A gene. The gene encodes a receptor that interacts with the arginine vasopressin hormone and may influence physiological stress regulation, blood pressure, and child development. (2) Methods: Fifty-two infants were included in this cohort study. Multivariable linear models were used to examine the effect of in-utero exposure to maternal smoking on the mean DNAm of CpG sites located at (3) Results: After adjusting the model for substance use, infants with in-utero exposure to maternal smoking had a reduction in DNAm at CpG sites by -0.02 (95% CI -0.03, -0.01) at one month of age. In conclusion, in-utero exposure to tobacco smoke can lead to differential patterns of DNAm of among infants. Conclusions: Future studies are needed to identify how gene expression in response to early environmental exposures contributes to health outcomes.
PubMed: 37888705
DOI: 10.3390/toxics11100855 -
Current Issues in Molecular Biology Oct 2023Autism spectrum disorder (ASD) is a complex neurodevelopmental disorder that affects social interactions, communication, and behavior. Although the predominant genetic...
Autism spectrum disorder (ASD) is a complex neurodevelopmental disorder that affects social interactions, communication, and behavior. Although the predominant genetic predisposition to ASD seems beyond doubt, its exact nature remains unclear. In the context of social cognition disorders and the basis of ASD, the oxytocinergic and vasopresynergic systems arouse great interest among researchers. The aim of the present study was to analyze gene expression levels for oxytocin and vasopressin receptors, as well as CD38 protein and oxytocinase, in the context of the clinical picture of autism spectrum disorders. The study included 90 people, of whom 63 were diagnosed with ASD based on anamnesis, mental status testing, and the ADOS-2 protocol. The results obtained in the presented study indicate that the balance between the levels of expression of the CD38 gene and the oxytocinase gene plays a key role in the risk and clinical presentation of ASD. In a hypothetical scenario, an imbalance in the expression of CD38 and LNPEP could potentially lead to alterations in the concentrations of oxytocin and vasopressin. At the same time, the most frequently studied genes-AVPR1a and OXTR-seem to be at best of marginal importance for the risk of ASD.
PubMed: 37886970
DOI: 10.3390/cimb45100527 -
Gastroenterology Insights Dec 2023Hepatorenal syndrome stands as one of several potential triggers of acute kidney injury in individuals grappling with either acute or persistent liver ailments. The...
Hepatorenal syndrome stands as one of several potential triggers of acute kidney injury in individuals grappling with either acute or persistent liver ailments. The nature of the decline in kidney function has led to the identification of two variants of hepatorenal syndrome. In cases where terlipressin therapy is accessible, the initial approach involves administering terlipressin alongside albumin. Terlipressin, a synthetic analog of vasopressin, boasts double the preference for vasopressin V1 receptors compared to V2 receptors. The FDA granted approval to terlipressin in September 2022, demonstrating its intrinsic activity, although a significant portion of its function arises from its transformation into lysine vasopressin. This article provides a comprehensive examination of terlipressin's various pharmacodynamic and pharmacokinetic facets, as well as its clinical utility, aiming to keep the scientific community well informed about its safe and efficient utilization.
PubMed: 37873544
DOI: 10.3390/gastroent14040031 -
Journal of Medicinal Chemistry Nov 2023Oxytocin (OT) and vasopressin (VP) are related neuropeptides that regulate many biological processes. In humans, OT and VP act via four G protein-coupled receptors, OTR,...
Oxytocin (OT) and vasopressin (VP) are related neuropeptides that regulate many biological processes. In humans, OT and VP act via four G protein-coupled receptors, OTR, VR, VR, and VR (VPRs), which are associated with several disorders. To investigate the therapeutic potential of these receptors, particularly in the receptor-dense areas of the brain, molecular probes with a high temporal and spatial resolution are required. Such a spatiotemporal resolution can be achieved by incorporating photochromic moieties into OT and VP. Here, we report the design, synthesis, and (photo)pharmacological characterization of 12 OT- and VP-derived photoprobes using different modification strategies. Despite OT's and VP's sensitivity toward structural changes, we identified two photoprobes with good potency and photoswitch window for investigating the OTR and VR. These photoprobes should be of high value for producing cutting-edge photocontrollable peptide probes for the study of dynamic and kinetic receptor activation processes in specific regions of the brain.
Topics: Humans; Oxytocin; Receptors, Oxytocin; Vasopressins; Receptors, G-Protein-Coupled; Neuropeptides
PubMed: 37857356
DOI: 10.1021/acs.jmedchem.3c01415 -
ELife Oct 2023The vasopressin type 2 receptor (VR) is an essential G protein-coupled receptor (GPCR) in renal regulation of water homeostasis. Upon stimulation, the VR activates Gα...
The vasopressin type 2 receptor (VR) is an essential G protein-coupled receptor (GPCR) in renal regulation of water homeostasis. Upon stimulation, the VR activates Gα and Gα, which is followed by robust recruitment of β-arrestins and receptor internalization into endosomes. Unlike canonical GPCR signaling, the β-arrestin association with the VR does not terminate Gα activation, and thus, Gα-mediated signaling is sustained while the receptor is internalized. Here, we demonstrate that this VR ability to co-interact with G protein/β-arrestin and promote endosomal G protein signaling is not restricted to Gα, but also involves Gα. Furthermore, our data imply that β-arrestins potentiate Gα/Gα activation at endosomes rather than terminating their signaling. Surprisingly, we found that the VR internalizes and promote endosomal G protein activation independent of β-arrestins to a minor degree. These new observations challenge the current model of endosomal GPCR signaling and suggest that this event can occur in both β-arrestin-dependent and -independent manners.
Topics: beta-Arrestins; Receptors, Vasopressin; Arrestins; beta-Arrestin 1; Endosomes; GTP-Binding Proteins; Vasopressins
PubMed: 37855711
DOI: 10.7554/eLife.87754 -
Frontiers in Endocrinology 2023
PubMed: 37854180
DOI: 10.3389/fendo.2023.1279895