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BioRxiv : the Preprint Server For... May 2024Oxytocin is a neuropeptide thought to play a central role in regulating social and emotional behavior. Current techniques for neuropeptide imaging are generally limited...
Oxytocin is a neuropeptide thought to play a central role in regulating social and emotional behavior. Current techniques for neuropeptide imaging are generally limited in spatial and temporal resolution, real-time imaging capacity, selectivity for oxytocin over vasopressin, and application in young and non-model organisms. To avoid the use of endogenous oxytocin receptors for oxytocin probe development, we employed a protocol to evolve purely synthetic molecular recognition on the surface of near-infrared fluorescent single-walled carbon nanotubes (SWCNT) using single-stranded DNA (ssDNA). This probe reversibly undergoes up to a 172% fluorescence increase in response to oxytocin with a K of 4.93 μM. Furthermore, this probe responds selectively to oxytocin over oxytocin analogs, receptor agonists and antagonists, and most other neurochemicals. Lastly, we show our probe can image synaptic evoked oxytocin release in live mouse brain slices. Optical probes with the specificity and resolution requisite to image endogenous oxytocin signaling can advance the study of oxytocin neurotransmission for its role in both health and disease.
PubMed: 38766215
DOI: 10.1101/2024.05.10.593556 -
PloS One 2024Loss-of-function mutations in the type 2 vasopressin receptor (V2R) are a major cause of congenital nephrogenic diabetes insipidus (cNDI). In the context of partial...
Loss-of-function mutations in the type 2 vasopressin receptor (V2R) are a major cause of congenital nephrogenic diabetes insipidus (cNDI). In the context of partial cNDI, the response to desmopressin (dDAVP) is partially, but not entirely, diminished. For those with the partial cNDI, restoration of V2R function would offer a prospective therapeutic approach. In this study, we revealed that OPC-51803 (OPC5) and its structurally related V2R agonists could functionally restore V2R mutants causing partial cNDI by inducing prolonged signal activation. The OPC5-related agonists exhibited functional selectivity by inducing signaling through the Gs-cAMP pathway while not recruiting β-arrestin1/2. We found that six cNDI-related V2R partial mutants (V882.53M, Y1283.41S, L1614.47P, T2736.37M, S3298.47R and S3338.51del) displayed varying degrees of plasma membrane expression levels and exhibited moderately impaired signaling function. Several OPC5-related agonists induced higher cAMP responses than AVP at V2R mutants after prolonged agonist stimulation, suggesting their potential effectiveness in compensating impaired V2R-mediated function. Furthermore, docking analysis revealed that the differential interaction of agonists with L3127.40 caused altered coordination of TM7, potentially contributing to the functional selectivity of signaling. These findings suggest that nonpeptide V2R agonists could hold promise as potential drug candidates for addressing partial cNDI.
Topics: Receptors, Vasopressin; Humans; HEK293 Cells; Diabetes Insipidus, Nephrogenic; Mutation; Signal Transduction; Cyclic AMP; Deamino Arginine Vasopressin; beta-Arrestins; Animals
PubMed: 38748623
DOI: 10.1371/journal.pone.0303507 -
Peptides Aug 2024Arginine vasotocin (AVT) is produced mainly in the hypothalamus and as a neurohypophyseal hormone peripherally regulates water-mineral balance in sub-mammals. In...
Intraperitoneal administration of arginine vasotocin (AVT) induces anorexigenic and anxiogenic actions via the brain V1a receptor-signaling pathway in the tiger puffer, Takifugu rubripes.
Arginine vasotocin (AVT) is produced mainly in the hypothalamus and as a neurohypophyseal hormone peripherally regulates water-mineral balance in sub-mammals. In addition, AVT-containing neurons innervate several areas of the brain, and AVT also acts centrally as both an anorexigenic and anxiogenic factor in goldfish. However, it is unclear whether these central effects operate in fish in general. In the present study, therefore, we investigated AVT-like immunoreactivity in the brain of the tiger puffer, a cultured fish with a high market value in Japan and also a representative marine teleost species, focusing particularly on whether AVT affects food intake and psychomotor activity. AVT-like immunoreactivity was distributed higher in the ventral region of the telencephalon, the hypothalamus and midbrain. Intraperitoneal (IP) administration of AVT at 100 pmol g body weight (BW) increased the immunoreactivity of phosphorylated ribosomal proteinS6 (RPS6), a neuronal activation marker, in the telencephalon and diencephalon, decreased food consumption and enhanced thigmotaxis. AVT-induced anorexigenic and anxiogenic actions were blocked by IP co-injection of a V1a receptor (V1aR) antagonist, Manning compound (MC) at 300 pmol g BW. These results suggest that AVT acts as an anorexigenic and anxiogenic factor via the V1aR-signaling pathway in the tiger puffer brain.
Topics: Animals; Vasotocin; Receptors, Vasopressin; Signal Transduction; Takifugu; Injections, Intraperitoneal; Brain; Eating; Anxiety; Telencephalon
PubMed: 38723948
DOI: 10.1016/j.peptides.2024.171239 -
BioRxiv : the Preprint Server For... Apr 2024The lateral septum (LS) is a midline, subcortical structure, which regulates social behaviors that are frequently impaired in neurodevelopmental disorders including...
The lateral septum (LS) is a midline, subcortical structure, which regulates social behaviors that are frequently impaired in neurodevelopmental disorders including schizophrenia and autism spectrum disorder. Mouse studies have identified neuronal populations within the LS that express a variety of molecular markers, including vasopressin receptor, oxytocin receptor, and corticotropin releasing hormone receptor, that control specific facets of social behavior. Despite its critical role in the regulation of social behavior and notable gene expression patterns, comprehensive molecular profiling of the human LS has not been performed. Here, we conducted single nucleus RNA-sequencing (snRNA-seq) to generate the first transcriptomic profiles of the human LS using postmortem human brain tissue samples from 3 neurotypical donors. Our analysis identified 4 transcriptionally distinct neuronal cell types within the human LS that are enriched for , the gene encoding Trp-related protein 4. Differential expression analysis revealed a distinct LS neuronal cell type that is enriched for , the gene encoding the μ-opioid receptor. Leveraging recently collected mouse LS snRNA-seq datasets, we also conducted a cross-species analysis. Our results demonstrate that enrichment in the LS is highly conserved between human and mouse, while which encodes FRAS1 related extracellular matrix protein 2, is enriched only in the human LS. Together, these results highlight transcriptional heterogeneity of the human LS, and identify robust marker genes for the human LS.
PubMed: 38712125
DOI: 10.1101/2024.04.22.590602 -
Proceedings of the National Academy of... May 2024One of the largest sex differences in brain neurochemistry is the expression of the neuropeptide arginine vasopressin (AVP) within the vertebrate brain, with males...
One of the largest sex differences in brain neurochemistry is the expression of the neuropeptide arginine vasopressin (AVP) within the vertebrate brain, with males having more AVP cells in the bed nucleus of the stria terminalis (BNST) than females. Despite the long-standing implication of AVP in social and anxiety-like behaviors, the circuitry underlying AVP's control of these behaviors is still not well defined. Using optogenetic approaches, we show that inhibiting AVP BNST cells reduces social investigation in males, but not in females, whereas stimulating these cells increases social investigation in both sexes, but more so in males. These cells may facilitate male social investigation through their projections to the lateral septum (LS), an area with the highest density of sexually differentiated AVP innervation in the brain, as optogenetic stimulation of BNST AVP → LS increased social investigation and anxiety-like behavior in males but not in females; the same stimulation also caused a biphasic response of LS cells ex vivo. Blocking the vasopressin 1a receptor (V1aR) in the LS eliminated all these responses. Together, these findings establish a sexually differentiated role for BNST AVP cells in the control of social investigation and anxiety-like behavior, likely mediated by their projections to the LS.
Topics: Animals; Female; Male; Mice; Anxiety; Arginine Vasopressin; Behavior, Animal; Mice, Inbred C57BL; Neurons; Optogenetics; Receptors, Vasopressin; Septal Nuclei; Social Behavior
PubMed: 38709918
DOI: 10.1073/pnas.2319641121 -
Scientific Reports Apr 2024Arginine-vasopressin (AVP), a cyclic peptide hormone composed of nine amino acids, regulates water reabsorption by increasing intracellular cyclic adenosine...
Arginine-vasopressin (AVP), a cyclic peptide hormone composed of nine amino acids, regulates water reabsorption by increasing intracellular cyclic adenosine monophosphate (cAMP) concentrations via the vasopressin V2 receptor (V2R). Plasma AVP is a valuable biomarker for the diagnosis of central diabetes insipidus (CDI) and is commonly measured using radioimmunoassay (RIA). However, RIA has several drawbacks, including a long hands-on time, complex procedures, and handling of radioisotopes with special equipment and facilities. In this study, we developed a bioassay to measure plasma AVP levels using HEK293 cells expressing an engineered V2R and a cAMP biosensor. To achieve high sensitivity, we screened V2R orthologs from 11 various mammalian species and found that the platypus V2R (pV2R) responded to AVP with approximately six-fold higher sensitivity than that observed by the human V2R. Furthermore, to reduce cross-reactivity with desmopressin (DDAVP), a V2R agonist used for CDI treatment, we introduced a previously described point mutation into pV2R, yielding an approximately 20-fold reduction of responsiveness to DDAVP while maintaining responsiveness to AVP. Finally, a comparison of plasma samples from 12 healthy individuals demonstrated a strong correlation (Pearson's correlation value: 0.90) between our bioassay and RIA. Overall, our assay offers a more rapid and convenient method for quantifying plasma AVP concentrations than existing techniques.
Topics: Humans; Arginine Vasopressin; HEK293 Cells; Cyclic AMP; Receptors, Vasopressin; Biosensing Techniques; Deamino Arginine Vasopressin; Animals; Biological Assay
PubMed: 38658606
DOI: 10.1038/s41598-024-60035-4 -
Journal of Cellular and Molecular... Apr 2024X-linked nephrogenic diabetes insipidus (X-NDI) is a rare congenital disease caused by inactivating mutations of the vasopressin type-2 receptor (AVPR2), characterized...
X-linked nephrogenic diabetes insipidus (X-NDI) is a rare congenital disease caused by inactivating mutations of the vasopressin type-2 receptor (AVPR2), characterized by impaired renal concentrating ability, dramatic polyuria, polydipsia and risk of dehydration. The disease, which still lacks a cure, could benefit from the pharmacologic stimulation of other GPCRs, activating the cAMP-intracellular pathway in the kidney cells expressing the AVPR2. On the basis of our previous studies, we here hypothesized that the β3-adrenergic receptor could be such an ideal candidate. We evaluated the effect of continuous 24 h stimulation of the β3-AR with the agonist BRL37344 and assessed the effects on urine output, urine osmolarity, water intake and the abundance and activation of the key renal water and electrolyte transporters, in the mouse model of X-NDI. Here we demonstrate that the β3-AR agonism exhibits a potent antidiuretic effect. The strong improvement in symptoms of X-NDI produced by a single i.p. injection of BRL37344 (1 mg/kg) was limited to 3 h but repeated administrations in the 24 h, mimicking the effect of a slow-release preparation, promoted a sustained antidiuretic effect, reducing the 24 h urine output by 27%, increasing urine osmolarity by 25% and reducing the water intake by 20%. At the molecular level, we show that BRL37344 acted by increasing the phosphorylation of NKCC2, NCC and AQP2 in the renal cell membrane, thereby increasing electrolytes and water reabsorption in the kidney tubule of X-NDI mice. Taken together, these data suggest that human β3-AR agonists might represent an effective possible treatment strategy for X-NDI.
Topics: Male; Animals; Mice, Inbred C57BL; Disease Models, Animal; Adrenergic beta-3 Receptor Agonists; Antidiuretic Agents; Kidney Concentrating Ability; Polydipsia
PubMed: 38652212
DOI: 10.1111/jcmm.18301 -
Molecular Genetics & Genomic Medicine Apr 2024Nephrogenic diabetes insipidus (NDI) is a rare genetic disease that causes water imbalance. The kidneys play a crucial role in regulating body fluids by controlling...
INTRODUCTION
Nephrogenic diabetes insipidus (NDI) is a rare genetic disease that causes water imbalance. The kidneys play a crucial role in regulating body fluids by controlling water balance through urine excretion. This highlights their essential function in managing the body's water levels, but individuals with NDI may have excess urine production (polyuria), that leads to excessive thirst (polydipsia). Untreated affected individuals may exhibit poor feeding and failure to thrive. This disease is caused by mutations in the AVPR2 and the AQP2 genes which have the X-linked and autosomal recessive/dominant inheritance, respectively. Both of these genes are expressed in the kidney.
METHODS
Twelve Iranian patients from 10 consanguineous families were studied in this project. DNA was extracted from the whole blood samples of the patients and their parents. All coding exons and exon-intron boundaries of the AVPR2 and AQP2 genes were sequenced in the affected individuals, and the identified variants were investigated in the parents. All variants were analyzed according to the ACMG (American College of Medical Genetics and Genomics) guidelines.
RESULTS
In this study, 6 different mutations were identified in the patients, including 5 in the AQP2 gene (c.439G>A, c.538G>A, c.140C>T, c.450T>A, and the novel c.668T>C) and 1 in the AVPR2 gene (c.337C>T) in the present study.
DISCUSSION
As expected, all the detected mutations in this study were missense. According to the ACMG guideline, the identified mutations were categorized as pathogenic or likely pathogenic. Unlike previous studies which showed more than 90% of mutations were in the AVPR2 gene, and only less than 10% of the mutations were in the AQP2 gene, it was found that more than 90% of our identified mutations located in the AQP2 gene, and only one mutation was observed in the AVPR2 gene, which seems it may be a result of the high rate of consanguineous marriages in the Iranian population. We observed genotype-phenotype correlation in some of our affected individuals, and some of the mutations were observed in unrelated families from same ethnicity which could be suggestive of a founder mutation.
Topics: Humans; Diabetes Insipidus, Nephrogenic; Aquaporin 2; Iran; Mutation; Water; Diabetes Mellitus
PubMed: 38622833
DOI: 10.1002/mgg3.2421 -
Peptides Jun 2024Glucagon is best known for its contribution to glucose regulation through activation of the glucagon receptor (GCGR), primarily located in the liver. However, glucagon's...
Glucagon is best known for its contribution to glucose regulation through activation of the glucagon receptor (GCGR), primarily located in the liver. However, glucagon's impact on other organs may also contribute to its potent effects in health and disease. Given that glucagon-based medicine is entering the arena of anti-obesity drugs, elucidating extrahepatic actions of glucagon are of increased importance. It has been reported that glucagon may stimulate secretion of arginine-vasopressin (AVP)/copeptin, growth hormone (GH) and adrenocorticotrophic hormone (ACTH) from the pituitary gland. Nevertheless, the mechanisms and whether GCGR is present in human pituitary are unknown. In this study we found that intravenous administration of 0.2 mg glucagon to 14 healthy subjects was not associated with increases in plasma concentrations of copeptin, GH, ACTH or cortisol over a 120-min period. GCGR immunoreactivity was present in the anterior pituitary but not in cells containing GH or ACTH. Collectively, glucagon may not directly stimulate secretion of GH, ACTH or AVP/copeptin in humans but may instead be involved in yet unidentified pituitary functions.
Topics: Humans; Glycopeptides; Glucagon; Adrenocorticotropic Hormone; Male; Adult; Female; Pituitary Gland; Hydrocortisone; Receptors, Glucagon; Human Growth Hormone; Growth Hormone; Middle Aged
PubMed: 38604379
DOI: 10.1016/j.peptides.2024.171213 -
Planta Medica May 2024The medicinal plant was previously shown to block oxytocin (OT)-induced signals in myometrial cells, consistent with its tocolytic effect observed in patients. OT...
The medicinal plant was previously shown to block oxytocin (OT)-induced signals in myometrial cells, consistent with its tocolytic effect observed in patients. OT activates not only OT receptors but also V receptors, two receptors with high receptor homology that are both expressed in the myometrium and play a crucial role in myometrial contraction signaling. We aimed to study the molecular pharmacology of herbal preparations using specific receptor ligands, the human myometrial cell line hTERT-C3, and cell lines expressing recombinant human OT and V receptors.We found that press juice from (BPJ) inhibits both OT- and vasopressin (AVP)-induced intracellular calcium increases in hTERT-C3 myometrial cells. In additional assays performed with cells expressing recombinant receptors, BPJ also inhibited OT and V receptor-mediated signals with a similar potency (IC about 0.5 mg/mL). We further studied endogenous OT- and AVP-sensitive receptors in hTERT-C3 cells and found that OT and AVP stimulated those receptors with similar potency (EC of ~ 1 nM), suggesting expression of both receptor subtypes. This interpretation was corroborated by the antagonist potencies of atosiban and relcovaptan that we found. However, using qPCR, we almost exclusively found expression of OT receptors suggesting a pharmacological difference between recombinant OT receptors and native receptors expressed in hTERT-C3 cells.In conclusion, we show that inhibits both OT and AVP signaling, which may point beyond its tocolytic effects to other indications involving a disbalance in the vasopressinergic system.
PubMed: 38599625
DOI: 10.1055/a-2303-9608