Diuretic Hormone Research Articles

The involvement of Rhopr-CRF/DH in feeding and reproduction in the blood-gorging insect Rhodnius prolixus

Rhodnius prolixus is a blood-gorging insect and a vector for human Chagas disease. The insect transmits the disease following feeding, when it excretes urine and feces contaminated with the Trypanosoma cruzi parasite. A corticotropin-releasing factor-like peptide acts as a diuretic hormone in R. prolixus (Rhopr-CRF/DH); however, its distribution throughout the insect’s central nervous system (CNS) and the expression of its receptor in feeding-related tissue as well as the female reproductive system suggests a multifaceted role for the hormone beyond that of diuresis. Here we investigate the involvement of Rhopr-CRF/DH in feeding and reproduction in R. prolixus. Immunohistochemistry of the CNS showed diminished CRF-like staining in neurosecretory cells (NSCs) of the mesothoracic ganglionic mass (MTGM) immediately following feeding, and partial restocking of those same cells two hours later, indicating Rhopr-CRF/DH stores in this regions are involved in feeding. The results of the temporal qPCR analysis were consistent with the immunohistochemical findings, showing an increase in Rhopr-CRF/DH transcript expression in the MTGM immediately after feeding, presumably capturing the restocking of Rhopr-CRF/DH in the lateral NSCs following release of the peptide during feeding. Elevating haemolymph Rhopr-CRF/DH titres by injection of Rhopr-CRF/DH prior to feeding resulted in the intake of a significantly smaller blood meal in 5th instars and adults without an apparent effect on the rate of short-term diuresis. When adult females were injected with Rhopr-CRF/DH, they also produced and laid significantly fewer eggs. Finally, in vitro oviduct contraction assays illustrate that Rhopr-CRF/DH inhibits the amplitude of contractions of the lateral oviducts, highlighting a potential mechanism via which the hormone diminishes reproductive capacity. To conclude, the study of the Rhopr-CRF/DH pathway, its components and mechanisms of action, has implications for vector control by highlighting targets to alter feeding, diuresis, and reproduction of this disease vector.

A Peptidergic Circuit Links the Circadian Clock to Locomotor Activity

The mechanisms by which clock neurons in the Drosophila brain confer an ∼24-hr rhythm onto locomotor activity are unclear, but involve the neuropeptide diuretic hormone 44 (DH44), an ortholog of corticotropin-releasing factor. Here we identified DH44 receptor 1 as the relevant receptor for rest:activity rhythms and mapped its site of action to hugin-expressing neurons in the subesophageal zone (SEZ). We traced a circuit that extends from Dh44-expressing neurons in the pars intercerebralis (PI) through hugin+ SEZ neurons to the ventral nerve cord. Hugin neuropeptide, a neuromedin U ortholog, also regulates behavioral rhythms. The DH44 PI-Hugin SEZ circuit controls circadian locomotor activity in a daily cycle but has minimal effect on feeding rhythms, suggesting that the circadian drive to feed can be separated from circadian locomotion. These findings define a linear peptidergic circuit that links the clock to motor outputs to modulate circadian control of locomotor activity.

Peptidergic Modulation in the Lobster Cardiac Neuromuscular System: A Transcriptomic Analysis of Peptides and Peptide Receptors in Cardiac Ganglion and Muscle

Central pattern generator (CPG)‐effector systems can produce flexible rhythmic motor output via modulation by both intrinsically‐ and extrinsically‐derived neuropeptides. In the lobster, Homarus americanus, the cardiac neuromuscular system, which consists of the cardiac ganglion (CG) and cardiac muscle (CM), controls the rhythmic motor output of the heart. This is a well‐studied, but simple, CPG‐effector system that has been used extensively for investigating peptidergic control of rhythmic behavior. Here, transcriptomes were generated for the two components that comprise the cardiac neuromuscular system, the cardiac ganglion (CG) and cardiac muscle (CM). Transcripts encoding precursor proteins for approximately ten peptide families, including allatostatin‐C (AST‐C), diuretic hormone 31 (DH31), diuretic hormone 44, myosuppressin, and proctolin, were identified from the CG transcriptome, suggesting that these peptide groups may be produced by neurons in the CG. Transcripts encoding receptors for many of the peptides identified from the CG, including those for all four of the above‐mentioned peptide families, were also identified from the CG and/or CM transcriptomes, suggesting that these peptides serve as intrinsic modulators of the cardiac neuromuscular system. To investigate hormonal modulation in the cardiac neuromuscular system, the transcriptomes were mined for the receptors of peptides known to be present in the sinus gland and/or pericardial organs, two neuroendocrine organs. Receptors for seven peptide families were identified, with some receptors restricted either to the CG (crustacean cardioactive peptide, red pigment concentrating hormone, and tachykinin‐related peptide) or CM (pigment dispersing hormone), and others found in both tissues (AST‐C, myosuppressin, and proctolin). These data suggest that some peptides may have different sites of action within the cardiac neuromuscular system. Immunohistochemistry confirmed that DH31 is produced by the motor neurons of the CG, and suggested that AST‐C is present in the CG. Immunohistochemical confirmation of the other putative intrinsic CG modulators is ongoing.Support or Funding InformationNSF (IOS‐1353023, IOS‐1354567, OCE‐1459235), NIH (8P20GM103423‐12), Cades Fdn., University of Hawaii at Manoa's Undergrad Res. Opp. Prog., APS Undergrad Res. Fellowship, Doherty Fdn./Bowdoin College

MP31-05 IMPACT OF BRAIN-TYPE NATRIURETIC PEPTIDE, A REPRESENTATIVE BIOMARKER FOR CARDIAC LOAD, ON NOCTURIA IN MEN.

You have accessJournal of UrologyUrodynamics/Lower Urinary Tract Dysfunction/Female Pelvic Medicine: Non-neurogenic Voiding Dysfunction I1 Apr 2017MP31-05 IMPACT OF BRAIN-TYPE NATRIURETIC PEPTIDE, A REPRESENTATIVE BIOMARKER FOR CARDIAC LOAD, ON NOCTURIA IN MEN. Keita Izumi, Masaya Ito, Masaharu Inoue, Toshiki Kijima, Soichiro Yoshida, Minato Yokoyama, Junichiro Ishioka, Yoh Matsuoka, Kazutaka Saito, Kazunori Kihara, and Yasuhisa Fujii Keita IzumiKeita Izumi More articles by this author , Masaya ItoMasaya Ito More articles by this author , Masaharu InoueMasaharu Inoue More articles by this author , Toshiki KijimaToshiki Kijima More articles by this author , Soichiro YoshidaSoichiro Yoshida More articles by this author , Minato YokoyamaMinato Yokoyama More articles by this author , Junichiro IshiokaJunichiro Ishioka More articles by this author , Yoh MatsuokaYoh Matsuoka More articles by this author , Kazutaka SaitoKazutaka Saito More articles by this author , Kazunori KiharaKazunori Kihara More articles by this author , and Yasuhisa FujiiYasuhisa Fujii More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2017.02.959AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Congestive heart failure (CHF) has been assumed to be one of the causes of nocturia. The relationship between nocturia and the extent of cardiac load, however, has not been fully examined. Brain-type natriuretic peptide (BNP) is a diuretic and vasodilatory hormone that is secreted in response to the left ventricular load and reported to be associated with the severity of CHF. Moreover, BNP can reflect the cardiac load before cardiac symptoms develop (Adnan Nadir et al., J Am Coll Cardiol HF 2015). In this study, we aimed to investigate the influence of the cardiac load evaluated by BNP on nocturia. METHODS This retrospective study included 431 men whose BNP levels were evaluated before prostate biopsy between 2014 and 2016. We assessed the frequency of nocturnal voiding by International Prostate Symptom Score (IPSS). Nocturia was defined as voiding at night two or more times. The association of BNP and other clinical variables with nocturia was examined using multivariate logistic regression analyses. The other variables were age, prostate-specific antigen (PSA), prostate volume, body mass index, the presence of prostate cancer, estimated glomerular ?ltration rate (eGFR), hypertension, diabetes, sleep disorder, and the use of any a-blocker or muscarinic antagonist. We also assessed the correlation between BNP and each item in the IPSS subgroups. RESULTS Median age, BNP, and PSA were 69 years, 19.8 pg/ml and 8.7 ng/ml, respectively. Median time of nocturnal voiding was 1 and nocturia was observed in 191 men (44.3%). Presence or absence of prostate cancer was not associated with nocturia or BNP levels. Median BNP in men with nocturia was 26.5 pg/ml whereas that in men without nocturia was 13.7 pg/ml (p < 0.01). Median BNP in each frequency group of nocturnal voiding was 13.1 ng/ml in 0 times (n = 65), 14.2 ng/ml in 1 time (n = 175), 23.9 ng/ml in 2 times (n = 118), 37.1 ng/ml in 3 times (n = 52), and 37.9 ng/ml in 4 or more times (n = 21) (p < 0.01). Univariate analyses demonstrated that age, PSA, prostate volume, eGFR, use of any a-blocker, hypertension, diabetes, sleep disorder, and BNP were correlated with nocturia. In multivariate analyses, BNP (p < 0.01) was an independent risk factor of nocturia, as well as age (p < 0.01), prostate volume (p < 0.01), and diabetes (p = 0.04). There were no correlations between BNP and each item in the IPSS subgroups other than nocturia. CONCLUSIONS BNP, a representative biomarker for cardiac load, is associated with nocturia in men. © 2017FiguresReferencesRelatedDetails Volume 197Issue 4SApril 2017Page: e400 Advertisement Copyright & Permissions© 2017MetricsAuthor Information Keita Izumi More articles by this author Masaya Ito More articles by this author Masaharu Inoue More articles by this author Toshiki Kijima More articles by this author Soichiro Yoshida More articles by this author Minato Yokoyama More articles by this author Junichiro Ishioka More articles by this author Yoh Matsuoka More articles by this author Kazutaka Saito More articles by this author Kazunori Kihara More articles by this author Yasuhisa Fujii More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

VASOPRESSIN RECEPTOR ANTAGONISTS IN HYPONATREMIA: AN UPDATE

Vasopressin also known as Anti Diuretic hormone acting through V2 receptor is the primary physiologic determinant of the rate of free water excretion. In the last decade, knowledge of vasopressin receptors has increased significantly. Multiple vasopressin receptor antagonists have been developed with differences in their specificity to V2:V1 receptors. These agents have applications in conditions of hypervolemic and euvolemic hyponatremia like the syndrome of inappropriate antidiuretic hormone secretion, congestive heart failure, cirrhosis and perhaps in brain edema following traumatic brain injury. Although V2 receptor antagonist may have a proven role in certain condition, only few drugs are currently available and its use still remains limited.

A case report of severe hyponatraemia secondary to enalapril and olanzapine

AbstractBackgroundOlanzapine is a commonly used atypical antipsychotic in the management of schizophrenia. Its well‐known adverse effects include sedation, weight gain and metabolic adverse effects. Enalapril is widely used as an antihypertensive with the known adverse drug effect of hyperkalaemia.AimsTo report a very rare adverse effect of enalapril and olanzapine induced severe hyponatraemia.Clinical detailsA 56‐year‐old lady was admitted to the hospital suffering from severe lethargy, decreased oral intake, and a decreased level of consciousness. She had been taking olanzapine 10 mg once at night for the past one and a half years and enalapril 5 mg twice daily for the past three years. Laboratory investigations revealed a plasma sodium level of 110 mmol/L, blood osmolality of 244 mosm/kg and urine osmolality of 512 mosm/kg. A diagnosis of SIADH (syndrome of inappropriate diuretic hormone) was made. Enalapril and olanzapine were suspected as causative agents as there was no other apparent cause of SIADH identified.OutcomePatient was treated with normal saline in the ward and her plasma sodium level rose to 130 mmol/L.ConclusionEnalapril or olanzapine induced hyponatraemia is extremely rare. However, healthcare professionals should be aware that patients being treated with enalapril or olanzapine alone or in combination can develop hyponatraemia in addition to their known metabolic adverse effects. Sodium level monitoring is necessary if patient develop symptoms suggestive of hyponatraemia.

Drosophila DH31 Neuropeptide and PDF Receptor Regulate Night-Onset Temperature Preference.

Body temperature rhythm (BTR) is fundamental for the maintenance of functions essential for homeostasis, such as generating metabolic energy and sleep. One major unsolved question is how body temperature decreases dramatically during the night. Previously, we demonstrated that a BTR-like mechanism, referred to as temperature preference rhythm (TPR), exists in Drosophila Here, we demonstrate that the diuretic hormone 31 (DH31) neuropeptide and pigment-dispersing factor receptor (PDFR) regulate preferred temperature decreases at night-onset via dorsal neurons 2. This is the first in vivo evidence that DH31 could function as a ligand of PDFR. Although both DH31 and PDF are ligands of PDFR, we show that DH31 regulates night-onset TPR, but PDF does not, suggesting that night-onset TPR and locomotor activity rhythms are controlled by different neuropeptides via different clock cells.

Prediction of a neuropeptidome for the eyestalk ganglia of the lobster Homarus americanus using a tissue-specific de novo assembled transcriptome

In silico transcriptome mining is a powerful tool for crustacean peptidome prediction. Using homology-based BLAST searches and a simple bioinformatics workflow, large peptidomes have recently been predicted for a variety of crustaceans, including the lobster, Homarus americanus. Interestingly, no in silico studies have been conducted on the eyestalk ganglia (lamina ganglionaris, medulla externa, medulla interna and medulla terminalis) of the lobster, although the eyestalk is the location of a major neuroendocrine complex, i.e., the X-organ-sinus gland system. Here, an H. americanus eyestalk ganglia-specific transcriptome was produced using the de novo assembler Trinity. This transcriptome was generated from 130,973,220 Illumina reads and consists of 147,542 unique contigs. Eighty-nine neuropeptide-encoding transcripts were identified from this dataset, allowing for the deduction of 62 distinct pre/preprohormones. Two hundred sixty-two neuropeptides were predicted from this set of precursors; the peptides include members of the adipokinetic hormone-corazonin-like peptide, allatostatin A, allatostatin B, allatostatin C, bursicon α, CCHamide, corazonin, crustacean cardioactive peptide, crustacean hyperglycemic hormone (CHH), CHH precursor-related peptide, diuretic hormone 31, diuretic hormone 44, eclosion hormone, elevenin, FMRFamide-like peptide, glycoprotein hormone α2, glycoprotein hormone β5, GSEFLamide, intocin, leucokinin, molt-inhibiting hormone, myosuppressin, neuroparsin, neuropeptide F, orcokinin, orcomyotropin, pigment dispersing hormone, proctolin, pyrokinin, red pigment concentrating hormone, RYamide, short neuropeptide F, SIFamide, sulfakinin, tachykinin-related peptide and trissin families. The predicted peptides expand the H. americanus eyestalk ganglia neuropeptidome approximately 7-fold, and include 78 peptides new to the lobster. The transcriptome and predicted neuropeptidome described here provide new resources for investigating peptidergic signaling within/from the lobster eyestalk ganglia.

Prediction of a peptidome for the western tarnished plant bug Lygus hesperus

Many strategies for controlling insect pests require an understanding of their hormonal signaling agents, peptides being the largest and most diverse single class of these molecules. Lygus hesperus is a pest species of particular concern, as it is responsible for significant damage to a wide variety of commercially important plant crops. At present, little is known about the peptide hormones of L. hesperus. Here, transcriptomic data were used to predict a peptidome for L. hesperus. Fifty-three L. hesperus transcripts encoding peptide precursors were identified, with a subset amplified by PCR for sequence verification. The proteins deduced from these transcripts allowed for the prediction of a 119-sequence peptidome for L. hesperus. The predicted peptides include isoforms of allatostatin A, allatostatin B (AST-B), allatostatin C, allatotropin, bursicon, CCHamide, corazonin, crustacean cardioactive peptide, crustacean hyperglycemic hormone/ion transport peptide, diuretic hormone 31, GSEFLamide, insulin-like peptide, myosuppressin, neuroparsin, neuropeptide F, orcokinin, orcomyotropin, pyrokinin, short neuropeptide F, SIFamide, sulfakinin and tachykinin-related peptide. Of note were several isoforms of AST-B that possess –WX7Wamide carboxyl-termini rather than the stereotypical –WX6Wamide (e.g., KWQDMQNPGWamide), an allatotropin ending in –SARGFamide rather than –TARGFamide (GLKNGPLNSARGFamide), a GSEFLamide ending in –GTEFLamide (TVGTEFLamide), several orcokinins with PMDEIDR– rather than NFDEIDR– amino-termini (e.g., PMDEIDRAGFTHFV), and an eight rather than 12 amino acid long isoform of SIFamide (PPFNGSIFamide). Collectively, the L. hesperus peptidome predicted here provides a resource for initiating physiological investigations of peptidergic signaling in this species, including studies directed at the biological control of this agricultural pest.

Peptidergic signaling in the crab Cancer borealis: Tapping the power of transcriptomics for neuropeptidome expansion

The crab Cancer borealis has long been used as a model for understanding neural control of rhythmic behavior. One significant discovery made through its use is that even numerically simple neural circuits are capable of producing an essentially infinite array of distinct motor outputs via the actions of locally released and circulating neuromodulators, the largest class being peptides. While much work has focused on elucidating the peptidome of C. borealis, no investigation has used in silico transcriptome mining for peptide discovery in this species, a strategy proven highly effective for identifying neuropeptides in other crustaceans. Here, we mined a C. borealis neural transcriptome for putative peptide-encoding transcripts, and predicted 200 distinct mature neuropeptides from the proteins deduced from these sequences. The identified peptides include isoforms of allatostatin A, allatostatin B, allatostatin C, CCHamide, crustacean cardioactive peptide, crustacean hyperglycemic hormone, diuretic hormone 31 (DH31), diuretic hormone 44 (DH44), FMRFamide-like peptide, GSEFLamide, HIGSLYRamide, insulin-like peptide (ILP), intocin, leucokinin, neuroparsin, pigment dispersing hormone, pyrokinin, red pigment concentrating hormone, short neuropeptide F and SIFamide. While some of the predicted peptides were known previously from C. borealis, most (159) are new discoveries for the species, e.g., the isoforms of CCHamide, DH31, DH44, GSEFLamide, ILP, intocin and neuroparsin, which are the first members of these peptide families identified from C. borealis. Collectively, the peptides predicted here approximately double the peptidome known for C. borealis, and in so doing provide an expanded platform from which to launch new investigations of peptidergic neuromodulation in this species.

Calcitonin-like peptide hormone (CT/DH) in the frontal ganglia as a feeding regulatory peptide of the silkworm, Bombyx mori

The frontal ganglion (FrG) in insects contributes to the modulation of feeding behavior via the regulation of foregut contraction and other neural networks. Profiling the peptides of the FrG is important to understand endocrine regulation of feeding behavior in insects. High-resolution spiral matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) identified an ion peak, corresponding to calcitonin-like diuretic hormone 31 (CT/DH) in the FrG of silkworm Bombyx mori larvae. RT-PCR confirmed that CT/DH is expressed in the FrG, as are other peptide hormones, including allatoregulatory peptides. A feeding latency assay using synthetic CT/DH revealed that it increases the time to the initiation of feeding in a dose-dependent manner. These data indicate that CT/DH is a candidate regulatory peptide that modulates the feeding behavior of B. mori.

Postoperative persistent hyponatremia: A case with metastatic lung cancer

Introduction: Hyponatremia is most commonly encountered electrolyte disorder in clinical practice. syndrome of inappropriate anti- diuretic hormone secretion (sIADH), most frequent cause of euvolemic hyponatremia, is an important element that increases risk for morbidity and mortality and indicates severity of primary disease. sIADH can be seen in many clinical conditions or as multifactorial. case report: A 64-years old male presented to our facility emergency department with the complaints of shortness of breath and abdominal pain. According to the assessment, Morgagni hernia was in the thoracic and abdominal computed tomography (ct). the patient was hospitalized in the general surgery service and taken to the operation for hernia repair. On day-2 after operation, he had low serum Na+ value (124 mEq/L (124 mmol/L)). serum Na+ value decreased

Evaluation of Diuretic Activity of aqueous extract of Ipomoea batatas (L)

A diuretic is any substance that promotes the production of urine. This includes forced diuresis. There are several categories of diuretics. All diuretics increase the excretion of water from bodies, although each class does so in a distinct way. Alternatively, an ant diuretic such as vasopressin, or ant diuretic hormone, is an agent or drug which reduces the excretion of water in urine. In medicine, diuretics are used to treat heart failure, liver cirrhosis, hypertension, influenza, water poisoning, and certain kidney diseases. Some diuretics, such as acetazolamide, help to make the urine more alkaline and are helpful in increasing excretion of substances such as aspirin in cases of overdose or poisoning. Diuretics are often abused by those with eating disorders, especially bulimics, in attempts to lose weight. The antihypertensive actions of some diuretics (thiazides and loop diuretics in particular) are independent of their diuretic effect. That is, the reduction in blood pressure is not due to decreased blood volume resulting from increased urine production, but occurs through other mechanisms and at lower doses than that required to produce diuresis. Indapamide was specifically designed with this in mind, and has a larger therapeutic window for hypertension (without pronounced diuresis) than most other diuretics. The main objective of the present research work is to isolate the bioactive molecules and evaluate the diuretic activity of aqueous extract of Ipomoea batatas the phytochemical analysis of aqueous extract of Ipomoea batatas root showed the presence of various phytochemical constituents such as flavonoids, carbohydrates, tannins, phenol. The effect of aqueous extract of root of Ipomoea batatas on rats with reference to biochemical changes in serum. The group-II (Standard Hydrochlorothiazide 10 ml/kg, p. o) animals showed significant (P<0.01) increase in total urine volume ml/100 gm/hr (10.44 ml). Whereas animals received AEIB significantly (P<0.01) increase in total urine volume ml/100 gm/hr (4.44 and 8.06 ml) and significantly (P<0.05) increased total 200 & 400 mg/kg doses respectively. The results of most several clinical investigations showed the efficacy and safety of carbohydrate, flavonoids are using diuretic activity give a fine action comparative standard drugs. The phytochemical studies revealed the presence of Carbohydrate, flavonoids, Tannins in the AEIB these may be responsible for its pharmacological activities.

Isolation and characterization of the corticotropin-releasing factor-related diuretic hormone receptor in Rhodnius prolixus

Rhodnius prolixus, the vector of human Chagas disease, is a hemipteran insect that undergoes rapid post-feeding diuresis following ingestion of a blood meal that can be up to 10 times its initial body weight. Corticotropin-releasing factor-related diuretic hormone (Rhopr-CRF/DH) and serotonin are neurohormones that are synergistic in increasing rates of fluid secretion by Malpighian tubules during this rapid post-feeding diuresis. A Rhopr-CRF/DH receptor transcript has now been isolated and characterized from fifth instar R. prolixus. The receptor is a family B1 (secretin) G protein-coupled receptor (GPCR) and was deorphaned in a heterologous cellular system using Chinese hamster ovary (CHO) cells stably expressing a promiscuous G-protein (Gα16). This assay was also used to demonstrate the presence of Rhopr-CRF/DH in the haemolymph of R. prolixus in response to blood-gorging. Two additional cell lines were used in this heterologous assay to verify that the cyclic adenosine monophosphate (cAMP) pathway and not the inositol triphosphate (IP3) pathway was stimulated upon activation of the receptor. Lastly, quantitative PCR demonstrated strong receptor expression in digestive tissues, upper Malpighian tubules and reproductive tissues. Identification of the Rhopr-CRF/DH receptor now provides tools for a more detailed understanding into the precise coordination of diuresis and other physiological processes in R. prolixus.

Expansion of the neuropeptidome of the globally invasive marine crab Carcinus maenas

Carcinus maenas is widely recognized as one of the world’s most successful marine invasive species; its success as an invader is due largely to its ability to thrive under varied environmental conditions. The physiological/behavioral control systems that allow C. maenas to adapt to new environments are undoubtedly under hormonal control, the largest single class of hormones being peptides. While numerous studies have focused on identifying native C. maenas peptides, none has taken advantage of mining transcriptome shotgun assembly (TSA) sequence data, a strategy proven highly successful for peptide discovery in other crustaceans. Here, a C. maenas peptidome was predicted via in silico transcriptome mining. Thirty-seven peptide families were searched for in the extant TSA database, with transcripts encoding precursors for 29 groups identified. The pre/preprohormones deduced from the identified sequences allowed for the prediction of 263 distinct mature peptides, 193 of which are new discoveries for C. maenas. The predicted peptides include isoforms of adipokinetic hormone-corazonin-like peptide, allatostatin A, allatostatin B, allatostatin C, bursicon, CCHamide, corazonin, crustacean cardioactive peptide, crustacean hyperglycemic hormone, diuretic hormone 31, diuretic hormone 44, eclosion hormone, FMRFamide-like peptide, HIGSLYRamide, intocin, leucokinin, myosuppressin, neuroparsin, neuropeptide F, orcokinin, pigment dispersing hormone, proctolin, pyrokinin, red pigment concentrating hormone, RYamide, short neuropeptide F, SIFamide, and tachykinin-related peptide. This peptidome is the largest predicted from any single crustacean using the in silico approach, and provides a platform for investigating peptidergic signaling in C. maenas, including control of the processes that allow for its success as a global marine invader.

Prediction of Scylla olivacea (Crustacea; Brachyura) peptide hormones using publicly accessible transcriptome shotgun assembly (TSA) sequences

The aquaculture of crabs from the genus Scylla is of increasing economic importance for many Southeast Asian countries. Expansion of Scylla farming has led to increased efforts to understand the physiology and behavior of these crabs, and as such, there are growing molecular resources for them. Here, publicly accessible Scylla olivacea transcriptomic data were mined for putative peptide-encoding transcripts; the proteins deduced from the identified sequences were then used to predict the structures of mature peptide hormones. Forty-nine pre/preprohormone-encoding transcripts were identified, allowing for the prediction of 187 distinct mature peptides. The identified peptides included isoforms of adipokinetic hormone-corazonin-like peptide, allatostatin A, allatostatin B, allatostatin C, bursicon β, CCHamide, corazonin, crustacean cardioactive peptide, crustacean hyperglycemic hormone/molt-inhibiting hormone, diuretic hormone 31, eclosion hormone, FMRFamide-like peptide, HIGSLYRamide, insulin-like peptide, intocin, leucokinin, myosuppressin, neuroparsin, neuropeptide F, orcokinin, pigment dispersing hormone, pyrokinin, red pigment concentrating hormone, RYamide, short neuropeptide F, SIFamide and tachykinin-related peptide, all well-known neuropeptide families. Surprisingly, the tissue used to generate the transcriptome mined here is reported to be testis. Whether or not the testis samples had neural contamination is unknown. However, if the peptides are truly produced by this reproductive organ, it could have far reaching consequences for the study of crustacean endocrinology, particularly in the area of reproductive control. Regardless, this peptidome is the largest thus far predicted for any brachyuran (true crab) species, and will serve as a foundation for future studies of peptidergic control in members of the commercially important genus Scylla.

The corticotropin-releasing factor-like diuretic hormone 44 (DH44) and kinin neuropeptides modulate desiccation and starvation tolerance in Drosophila melanogaster

Malpighian tubules are critical organs for epithelial fluid transport and stress tolerance in insects, and are under neuroendocrine control by multiple neuropeptides secreted by identified neurons. Here, we demonstrate roles for CRF-like diuretic hormone 44 (DH44) and Drosophila melanogaster kinin (Drome-kinin, DK) in desiccation and starvation tolerance.Gene expression and labelled DH44 ligand binding data, as well as highly selective knockdowns and/or neuronal ablations of DH44 in neurons of the pars intercerebralis and DH44 receptor (DH44-R2) in Malpighian tubule principal cells, indicate that suppression of DH44 signalling improves desiccation tolerance of the intact fly.Drome-kinin receptor, encoded by the leucokinin receptor gene, LKR, is expressed in DH44 neurons as well as in stellate cells of the Malpighian tubules. LKR knockdown in DH44-expressing neurons reduces Malpighian tubule-specific LKR, suggesting interactions between DH44 and LK signalling pathways.Finally, although a role for DK in desiccation tolerance was not defined, we demonstrate a novel role for Malpighian tubule cell-specific LKR in starvation tolerance. Starvation increases gene expression of epithelial LKR. Also, Malpighian tubule stellate cell-specific knockdown of LKR significantly reduced starvation tolerance, demonstrating a role for neuropeptide signalling during starvation stress.

Angiotensin II and Anti Diuretic Hormone Exert Synergistic Effects on Thick Ascending Limb Transport in Spontaneously Hypertensive Rats

Background: Sodium reabsorption is increased in the thick ascending limb (TAL) of Henle in several hypertensive models. In this segment, while transport is increased by ADH via cAMP, sodium reabsorption results from Ang II-induced superoxide (O₂^-) production. Surprisingly, it is unknown whether these mechanisms overlap in hypertension. We hypothesized that Ang II and ADH have accumulative effects on TAL's transport during hypertension. Methods: The effect of ADH/Ang II in TALs from spontaneously hypertensive rats (SHR) on oxygen consumption (QO₂), cAMP and O₂^- was measured. Results: Basal QO₂ was 113.3 ± 14.2 nmol O₂/min/mg protein. Addition of ADH (1 n<smlcap>M</smlcap>) increased QO₂ by 198%. In the presence of ADH, Ang II (1 n<smlcap>M</smlcap>) elicited a QO₂ transient response and then rose to 321.5 ± 28.3 (p = 0.003 vs. ADH). These accumulative effects could be due to nitric oxide synthase (NOS) uncoupling, lower Ang II ability to decrease cAMP or increased O₂^-. We first measured QO₂ using a NOS inhibitor. Pretreatment with <smlcap>L</smlcap>-NAME did not block the observed interaction (p = 0.001 Ang II vs. ADH). Also, Ang II blocked the ADH-stimulated cAMP accumulation in TAL of SHRs. In the presence of ADH, Ang II increased O₂^- production in TALs from SHR by 309% (p = 0.015 vs. basal). The O₂^- scavenger tempol blocked the Ang II effects on QO₂. In the presence of the NADPH oxidase inhibitor apocynin, the accumulative effects of ADH and Ang II were abolished. We conclude that (1) in SHR, Ang II has accumulative effects on ADH-stimulated transport; (2) this effect is mediated by AT1 receptors, and increased O₂^- production.

Molecular cloning, expression and identification of the promoter regulatory region for the neuropeptide trissin in the nervous system of the silkmoth Bombyx mori.

Trissin has recently been identified as a conserved insect neuropeptide, but its cellular expression and function is unknown. We detected the presence of this neuropeptide in the silkworm Bombyx mori using in silico search and molecular cloning. In situ hybridisation was used to examine trissin expression in the entire central nervous system (CNS) and gut of larvae, pupae and adults. Surprisingly, its expression is restricted to only two pairs of small protocerebral interneurons and four to five large neurons in the frontal ganglion (FG). These neurons were further characterised by subsequent multiple staining with selected antibodies against insect neuropeptides. The brain interneurons innervate edges of the mushroom bodies and co-express trissin with myoinhibitory peptides (MIP) and CRF-like diuretic hormones (CRF-DH). In the FG, one pair of neurons co-express trissin with calcitonin-like diuretic hormone (CT-DH), short neuropeptide F (sNPF) and MIP. These neurons innervate the brain tritocerebrum and musculature of the anterior midgut. The other pair of trissin neurons in the FG co-express sNPF and project axons to the tritocerebrum and midgut. We also used the baculovirus expression system to identify the promoter regulatory region of the trissin gene for targeted expression of various molecular markers in these neurons. Dominant expression of trissin in the FG indicates its possible role in the regulation of foregut-midgut contractions and food intake.

Neuropeptidergic Signaling in the American Lobster Homarus americanus: New Insights from High-Throughput Nucleotide Sequencing.

Peptides are the largest and most diverse class of molecules used for neurochemical communication, playing key roles in the control of essentially all aspects of physiology and behavior. The American lobster, Homarus americanus, is a crustacean of commercial and biomedical importance; lobster growth and reproduction are under neuropeptidergic control, and portions of the lobster nervous system serve as models for understanding the general principles underlying rhythmic motor behavior (including peptidergic neuromodulation). While a number of neuropeptides have been identified from H. americanus, and the effects of some have been investigated at the cellular/systems levels, little is currently known about the molecular components of neuropeptidergic signaling in the lobster. Here, a H. americanus neural transcriptome was generated and mined for sequences encoding putative peptide precursors and receptors; 35 precursor- and 41 receptor-encoding transcripts were identified. We predicted 194 distinct neuropeptides from the deduced precursor proteins, including members of the adipokinetic hormone-corazonin-like peptide, allatostatin A, allatostatin C, bursicon, CCHamide, corazonin, crustacean cardioactive peptide, crustacean hyperglycemic hormone (CHH), CHH precursor-related peptide, diuretic hormone 31, diuretic hormone 44, eclosion hormone, FLRFamide, GSEFLamide, insulin-like peptide, intocin, leucokinin, myosuppressin, neuroparsin, neuropeptide F, orcokinin, pigment dispersing hormone, proctolin, pyrokinin, SIFamide, sulfakinin and tachykinin-related peptide families. While some of the predicted peptides are known H. americanus isoforms, most are novel identifications, more than doubling the extant lobster neuropeptidome. The deduced receptor proteins are the first descriptions of H. americanus neuropeptide receptors, and include ones for most of the peptide groups mentioned earlier, as well as those for ecdysis-triggering hormone, red pigment concentrating hormone and short neuropeptide F. Multiple receptors were identified for most peptide families. These data represent the most complete description of the molecular underpinnings of peptidergic signaling in H. americanus, and will serve as a foundation for future gene-based studies of neuropeptidergic control in the lobster.