Amide-to-chloroalkene substitution for overcoming intramolecular acyl transfer challenges in hexapeptidic neuromedin U receptor 2 agonists.

CPN-116 is a peptidic agonist that activates human neuromedin U receptor type 2 (NMUR2) but suffers from chemical instability due to inherent backbone isomerization on the Dap residue. To address this, a Leu-Dap-type (Z)-chloroalkene dipeptide isostere was synthesized diastereoselectively as a surrogate of the Leu-Dap peptide bond to develop a (Z)-chloroalkene analogue of CPN-116. The synthesized CPN-116 analogue is stable in 1.0 M phosphate buffer (pH 7.4) without backbone isomerization and can activate NMUR2 with similar potency to CPN-116 at nM concentrations (EC50 = 1.0 nM).

Transvenous Radiofrequency Catheter Ablation for an Aldosterone-Producing Tumor of the Left Adrenal Gland: A First in Human Case Report.

PURPOSE: To describe a novel technique of transvenous radiofrequency catheter ablation of an aldosterone-producing adenoma (APA) of the left adrenal gland using the GOS System (Japan Lifeline, Tokyo, Japan). Using the GOS system, a flexible radiofrequency tip catheter can be inserted into the adrenal central and tributary veins, the drainers for functional tumors. MATERIALS AND METHODS: An APA at the left adrenal gland, which was diagnosed by segmental adrenal venous sampling following administration of 0.25 mg cosyntropin, was ablated using the GOS catheter inserted into adrenal tributary veins via a right femoral vein 7-Fr sheath. The effect of radiofrequency ablation on APA was assessed using the international consensus on surgical outcomes for unilateral primary aldosteronism (PA). RESULTS: No device-related complications were observed. The patient was deeply sedated under blood pressure and heart rate control with continuous administration of ß-blockers. Then, the tumor and surrounding adrenal gland were cauterized at 7000 J two times each in sequence. The output time was 7-11 min for each ablation and 80 min in total. For blood pressure and pulse rate control, esmolol hydrochloride and phentolamine mesylate were used. The contrast enhancement of APA disappeared on dynamic CT immediately after the procedure. PA was biochemically cured until 12 months after the procedure. CONCLUSION: Using the radiofrequency device with the GOS catheter and system is a method for cauterizing adrenal tumors from blood vessels. This approach resulted in a marked reduction in aldosterone concentrations and a complete biochemical cure of PA over the observation period.

Transvenous Radiofrequency Ablation of Adrenal Gland: Experimental Study.

PURPOSE: The aim was to evaluate a flexible device for transvenous adrenal gland radiofrequency ablation in vitro and in an in vivo animal model. MATERIALS AND METHODS: A flexible radiofrequency-tip catheter with an inner-cooling mechanism and a guidewire lumen was made. Then, using a polyvinyl alcohol gel model, the ablation diameter was evaluated and how much energy to deliver in vivo was determined. Finally, transvenous radiofrequency ablation of the left adrenal glands of two pigs was performed, delivering 5000 or 7000 J in a single dose to each. The ablation effects were also assessed by histological examination of hematoxylin-eosin-stained sections. RESULTS: The mean ablation diameters in the gel model were 20.2 and 21.9 mm in the short axis and 15 and 20 mm in the long axis for 5000 or 7000 J, respectively. The device was inserted into porcine left adrenal vein with no complications. The mean ablation diameters were 10 mm in the shorter axis (whole thickness of porcine left adrenal gland) in the porcine model for 7000 J. Transient increases in blood pressure and heart rate occurred during ablation. Histologically, the adrenal gland showed severe necrosis at ablated area. There was venous congestion upstream in a non-ablated area, and thermal damage to surrounding organs was not observed. CONCLUSIONS: A flexible radiofrequency-tip catheter could be inserted successfully into the left adrenal vein. The left adrenal gland was entirely ablated without any thermal damage to surrounding organs. We suggest transvenous adrenal ablation has potential as a therapeutic option for primary aldosteronism.

Comparison of physiological functions between neuromedin U-related peptide and neuromedin S-related peptide in the rat central nervous system.

Two novel peptides, neuromedin U precursor-related peptide (NURP) and neuromedin S precursor-related peptide (NSRP), are produced from neuromedin U (NMU) and neuromedin S (NMS) precursors, respectively, as these precursors have multiple consensus sequences for proteolytic processing. Our group has shown previously that one of these two novel peptides, NURP, stimulates body temperature and locomotor activity, but not food intake. However, the physiological function of the other peptide, NSRP, has remained unclear. Therefore, the aim of this study was to characterize differences in the regions of the rat brain targeted by the NMU/NMS peptide family, including NURP and NSRP, and their physiological functions. First, we explored the regions of c-Fos expression after intracerebroventricular (i.c.v.) injection of NURP and NSRP and found that these were fewer than after i.c.v. injection of NMU and NMS in the hypothalamus, possibly because NURP and NSRP cannot activate NMU/NMS receptors. In the ventral subiculum, which is one region of the hippocampus, c-Fos expression was evident only after i.c.v. injection of NURP. We also examined the effects of NSRP on food intake, body temperature and locomotor activity. Like NURP, NSRP increased both body temperature and locomotor activity, but not food intake, indicating that NSRP is also a functional peptide. However, these effects of NSRP were distinctly weaker than those of NURP. These findings suggest differences in the affinity of NURP and/or NSRP for specific receptors, or in their respective biological activities.

Neuromedin U suppresses prolactin secretion via dopamine neurons of the arcuate nucleus.

Neuromedin U (NMU) has a precursor that contains one additional peptide consisting of 33 or 36 amino acid residues. Recently, we identified this second peptide from rat brain and designated it neuromedin U precursor-related peptide (NURP), showing it to stimulate prolactin release from the pituitary when injected via the intracerebroventricular (icv) route. Here, we examined whether NMU, like NURP, also stimulates prolactin release. Unlike NURP, icv injection of NMU significantly decreased the secretion of prolactin from the pituitary. This suppression of prolactin release by NMU was observed in hyper-prolactin states such as lactation, stress, pseudopregnancy, domperidone (dopamine antagonist) administration, and icv injection of NURP. Immunohistochemical analysis revealed that icv injection of NMU induced cFos expression in dopaminergic neurons of the arcuate nucleus, but not the substantia nigra. Mice with double knockout of NMU and neuromedin S (NMS), the latter also binding to NMU receptors, showed a significant increase of the plasma prolactin level after domperidone treatment relative to wild-type mice. These results suggest that NMU and NURP may play important reciprocal roles in physiological prolactin secretion.

Transnasal Delivery of the Peptide Agonist Specific to Neuromedin-U Receptor 2 to the Brain for the Treatment of Obesity.

Obesity and metabolic syndrome are threats to the health of large population worldwide as they are associated with high mortality, mainly linked to cardiovascular diseases. Recently, CPN-116 (CPN), which is an agonist peptide specific to neuromedin-U receptor 2 (NMUR2) that is expressed predominantly in the brain, has been developed as a new therapeutic candidate for the treatment of obesity and metabolic syndrome. However, treatment with CPN poses a challenge due to the limited delivery of CPN to the brain. Recent studies have clarified that the direct anatomical connection of the nasal cavity with brain allows delivery of several drugs to the brain. In this study, we confirm the nasal cavity as a promising CPN delivery route to the brain for the treatment of obesity and metabolic syndrome. According to the pharmacokinetic study, the clearance of CPN from the blood was very rapid with a half-life of 3 min. In vitro study on its stability in the serum and cerebrospinal fluid (CSF) indicates that CPN was more stable in the CSF than in the blood. The concentration of CPN in the brain was higher after nasal administration, despite its lower concentrations in the plasma than that after intravenous administration. The study on its pharmacological potency suggests the effective suppression of increased body weight in mice in a dose-dependent manner due to the direct activation of NMUR2 by CPN. This results from the higher concentration of corticosterone in blood after nasal administration of CPN as compared to nasal application of saline. In conclusion, the above findings indicate that the nasal cavity is a promising CPN delivery route to the brain to treat obesity and metabolic syndrome.

Discovery of a Human Neuromedin U Receptor 1-Selective Hexapeptide Agonist with Enhanced Serum Stability.

Neuromedin U (NMU) activates two NMU receptors (NMUR1 and NMUR2) and is a useful antiobesity drug lead. We report discovery of a hexapeptide agonist, 2-thienylacetyl-Trp1-Phe(4-F)2-Arg3-Pro4-Arg5-Asn6-NH2 (4). However, the NMUR1 selectivity and serum stability of this agonist were unsatisfactory. Through a structure-activity relationship study focused on residue 2 of agonist 4, serum stability, and pharmacokinetic properties, we report here the discovery of a novel NMUR1 selective hexapeptide agonist 7b that suppresses body weight gain in mice.

Purification and characterization of bioactive peptides RYamide and CCHamide in the kuruma shrimp Marsupenaeus japonicus.

To understand the regulation systems of appetite, bioactive peptides from the kuruma shrimp Marsupenaeus japonicus (Mj) were isolated and purified by reverse pharmacological assays using CHO cells expressing the Drosophila melanogaster G-protein-coupled receptors (GPCRs) CG5811 (a RYamide receptor) or CG14593 (a CCHamide-2 receptor). Four peptides having binding activity to GPCRs were obtained and named Mj RYamide-1, Mj RYamide-2, Mj RYamide-3, and Mj CCHamide. Genes encoding the prepropeptides of these peptides were identified using kuruma shrimp transcriptome databases. The Mj prepro-RYamide gene encodes a 130-amino acid polypeptide containing Mj RYamide-1, Mj RYamide-2, and Mj RYamide-3, whereas the Mj prepro-CCHamide gene encodes a 119-amino acid polypeptide containing a single Mj CCHamide peptide. The expression of these genes was confirmed in various neuronal organs including the brain and ventral nerve cord. In addition, prepro-RYamide gene expression is significantly reduced in the brain after starvation. RYamides may thus be associated with regulation of feeding or digestion. Changes in kayak (the c-fos ortholog in invertebrates) gene expression after administration of synthetic peptides were also investigated. Mj kayak expression levels are upregulated in hepatopancreas after treatment with Mj RYamide-3 or CCHamide. Thus, the peptides isolated in this study may have some regulatory effect on cellular metabolism in aquacultured invertebrates.

Synthesis of RCAI-172 (C6 epimer of RCAI-147) and its biological activity.

RCAI-147 is one of the hydroxylated analogues of KRN7000 which is known as a ligand for the activation of CD1d mediated invariant natural killer T cells (iNKT cells) and releases both T helper 1 (Th1) cytokines such as IFN-γ and T helper 2 (Th2) cytokines such as IL-4. KRN7000 has been anticipated as an antitumor drug or an adjuvant for viral infection such as influenza, because of its strong secretion of IFN-γ. In an interesting twist, it has been obvious in our previous paper that RCAI-147 induces much more Th2 cytokines (IL-4) than Th1 cytokines (IFN-γ) from iNKT cells compared to KRN7000, and shows fairly good result in the experimental autoimmune encephalomyelitis (EAE) test. Therefore, synthesis of RCAI-172 (C6-OH epimer of RCAI-147) was attempted to examine the biological activity. As a result, RCAI-172 was synthesized and its biological activity biased to Th2 response largely compared to that of KRN7000. However, this level decreased to approximately 61% compared to that of RCAI-147. And the clinical score of RCAI-172 for EAE suppression was disappointing. There exist seven chiral centers in the aglycon part of RCAI-172, and even though the change of configuration is just one position (C6-OH), the effect on both Th1/Th2 response and EAE test is fairly large.

RCAI-61 and related 6'-modified analogs of KRN7000: their synthesis and bioactivity for mouse lymphocytes to produce interferon-γ in vivo.

We synthesized ten new analogs of 6'-modified KRN7000 (A): RCAI-58, 61, 64, 83, 85-87, 113, 119, and 125. They could be synthesized by α-selective galactosylation of ceramide 9 with the 6-modified D-galactopyranosyl fluorides (8a-8f) or L-arabinopyranosyl fluoride (17), or by etherification of the known alcohol 19. Bioassay of the ten analogs demonstrated that RCAI-61 (1, 6'-O-methylated analog of A) was the most potent immunostimulant among them, and could induce the production of a large amount of IFN-γ even at a low concentration in mice in vivo.

Synthesis and biological activity of hydroxylated analogues of KRN7000 (α-galactosylceramide).

KRN7000 is one of the α-galactosylceramides, which has a 2-hexacosanoylamino-3,4-dihydroxyoctadecyl group. This compound, known as a ligand for the activation of CD1d mediated invariant natural killer T cells (iNKT cells) which release both T helper 1 (Th1) cytokines such as IFNγ and Th2 cytokines such as IL-4, has been anticipated as an antitumor drug, because of its strong secretion of IFNγ. This time, we focused on the hydroxylated analogues of KRN7000 which could be thought of as increasing hydrophilicity and showing bias to Th2 cytokine (IL-4) secretion. Therefore, they may become the drugs for autoimmune diseases for the following reasons: (i) compound OCH, one of the α-galactosylceramide analogues with a shorter sphingosine chain than KRN7000, increases hydrophilicity relative to KRN7000; and (ii) OCH is known to induce much more Th2 cytokines (IL-4) than Th1 cytokines from iNKT cells compared to KRN7000. Naturally, OCH has become one of the candidate drugs for autoimmune diseases. The more hydroxylated derivatives of KRN7000 are anticipated to induce Th2 bias. Therefore, eight analogues with 1-4 excess hydroxyl groups on the lipid chain of KRN7000 were synthesized to examine if they behave in the same way as OCH. As a result, three out of eight compounds biased largely to IL-4 secretion, and their effectiveness for experimental autoimmune encephalomyelitis (EAE) was examined. It was recognized that two compounds (†)RCAI-147/-160 showed good suppression of EAE symptoms.

Effective treatment of a 13-year-old boy with steroid-dependent ocular myasthenia gravis using tacrolimus.

Over the past several years, tacrolimus has attracted attention as a new therapeutic drug for myasthenia gravis (MG), but few reports have considered its use for MG in pediatric patients, and most of these have focused on severe systemic MG. In this case report, we used tacrolimus to successfully treat a 13-year-old boy with ocular MG who had suffered from severe steroid complications, including a failure of thrive and osteoporosis. He first showed symptoms of ocular MG at age 2 years 3 months. At age 13 years, he was receiving PSL (3.75 mg/day), but the symptoms of ocular MG recurred. We increased the dosage of oral PSL up to 30 mg/day, and three courses of mPSL pulse therapy were applied, but these therapies had only limited effect, and his symptoms worsened. Tacrolimus was started at 0.4 mg/day (0.011 mg/kg/day), and every 2 weeks the dose was gradually increased by 0.2 mg/day. His symptoms of MG began to improve 3 weeks after the initial administration of tacrolimus. Approximately 3 months after the start of tacrolimus administration, PSL was discontinued. Currently, at 1 year and 4 months after the start of tacrolimus administration, while slight ptosis is observed in the evening, it does not influence his daily life, and his condition remains comparable to that when he stopped taking PSL. No adverse effects of tacrolimus have been recognized. In pediatric patients with steroid-dependent ocular MG without thymectomy, tacrolimus may be a safe and effective alternative to steroid and thymectomy.

Decreased benzodiazepine receptor and increased GABA level in cortical tubers in tuberous sclerosis complex.

PURPOSE: To elucidate the functional characteristics of cortical tubers that might be responsible for epilepsy in tuberous sclerosis complex (TSC), proton magnetic resonance spectroscopy ((1)H-MRS) and [123I] iomazenil (123I-IMZ) single photon emission computed tomography (SPECT) were performed. METHODS: (1)H-MRS using a clinical 3-tesla magnetic resonance imager was performed in four children with TSC and 10 age-and sex-matched healthy control subjects. A single voxel was set on the right parietal lobe in control subjects. In patients with TSC, a single voxel was set on the epileptogenic tuber in the parietal or temporal lobe, and another voxel was set on the contralateral normal-appearing brain region. N-Acetylaspartate (NAA), myo-Inositol (mIns) and Glutamate (Glu) were analyzed using a conventional STEAM (Stimulated Echo Acquisition Mode) method. The concentration of gamma-aminobutyric acid (GABA) was quantified using MEGA-Point Resolved Spectroscopy (PRESS). Interictal 123I-IMZ SPECT was examined in all four patients with TSC. RESULTS: A significant decrease in the NAA concentration and significant increases in the mIns and GABA concentrations were detected in the cortical tubers of all 4 patients. No significant difference was observed in Glu concentrations. In all of the cortical tubers detected by magnetic resonance imaging, 123I-IMZ binding was significantly decreased. CONCLUSION: Epileptogenesis in TSC might be caused by decreased inhibition secondary to the decrease in GABA receptors in dysplastic neurons of cortical tubers. An increase in the GABA concentration may compensate for decreased inhibition.

Synthesis and biological activity of ester and ether analogues of alpha-galactosylceramide (KRN7000).

Alpha-Galactosylceramide (alphaGalCer, KRN7000) has been identified as a modulator of immunological processes through its capacity to bind iNKT cells mediated by CD1d molecules. Some analogues in while the amide group in alphaGalCer is replaced with ester or ether groups were synthesized from d-arabinitol or l-ribose to evaluate their ability to activate iNKT cells. Ester analogues 30a, 31a, and 61 showed activity for IFNgamma and IL-4 production of iNKT cells, while ether (31b) and 4-methoxy ester (76) analogues of alpha-galactosylceramide were not active for iNKT cells.

Alternative splicing of the pituitary adenylate cyclase-activating polypetide (PACAP) receptor contributes to function of PACAP-27.

Pituitary adenylate cyclase-activating polypeptide (PACAP)-27 and PACAP-38 are neuropeptides performing a variety of physiological functions. The PACAP-specific receptor PAC1 has several variants that result mainly from alternative splicing in the mRNA region encoding the first extracellular (EC1) domain and the third intracellular cytoplasmic (IC3) loop. To characterize the molecular forms of alternative splicing variants of PAC1, we examined the binding affinity and activation of two major second messenger pathways (cAMP production and changes in [Ca(2+)]( i )) by PACAP-27. Activation of cAMP was influenced by the variant in both of the EC1 domain and IC3 loops. In the N form in the EC1 domain, the suppressive effect of the HOP1 form in the IC3 loop was enhanced. Regarding the intracellular calcium mobilization assay, the rank order of the potency of PACAP-27 for the different PAC1 isoforms was S/HOP1>>N/R~S/R>>N/HOP1. In particular, PACAP-27 exhibited remarkable potency of calcium mobilization in the S/HOP1-expressing cells at sub-picomolar concentrations even though the affinities of PACAP-27 to the four PAC1 isoforms were not significantly different. This suggests the specific functions of PACAP-27 due to PACAP-27 preferring PAC1 activation, and leads in clarification of the pleiotoropic function of PACAP.

Induction of Th1-biased cytokine production by alpha-carba-GalCer, a neoglycolipid ligand for NKT cells.

NKT cells are characterized by their production of both T(h)1 and T(h)2 cytokines immediately after stimulation with alpha-galactosylceramide (alpha-GalCer), which is composed of alpha-galactopyranose linked to ceramide (itself composed of sphingosine and fatty-acyl chains); the chain length of the ceramide varies and this affects the ability of alpha-GalCer to stimulate cytokine production. However, the contribution of its galactopyranose sugar moiety remains unclear. We synthesized alpha-carba-GalCer, which has an alpha-linked carba-galactosyl moiety; here, the 5a'-oxygen atom of the D-galactopyranose ring of alpha-GalCer is replaced by a methylene group. The alpha-carba-GalCer was more stable and showed higher affinity to the NKT receptor. It thus enhanced and prolonged production of IL-12 and IFN-gamma compared with alpha-GalCer, resulting in augmented NKT cell-mediated adjuvant effects in vivo. The alpha-carba-GalCer, which has an ether linkage, was more resistant to degradation by liver microsomes than was alpha-GalCer, which has an acetal bond. Modulation of the sugar moiety in glycolipids might therefore provide optimal therapeutic reagents for protective immune responses against tumor or pathogens.

Generation of functional NKT cells in vitro from embryonic stem cells bearing rearranged invariant Valpha14-Jalpha18 TCRalpha gene.

Establishment of a system with efficient generation of natural killer T (NKT) cells from embryonic stem (ES) cells would enable us to identify the cells with NKT-cell potential and obtain NKT cells with desired function. Here, using cloned ES (NKT-ES) cells generated by the transfer of nuclei from mature NKT cells, we have established a culture system that preferentially developed functional NKT cells and also identified early NKT progenitors, which first appeared on day 11 as a c-kit(+) population in the cocultures on OP9 cells with expression of Notch ligand, delta-like1 (OP9/Dll-1) and became c-kit(lo/-) on day 14. Interestingly, in the presence of Notch signals, NKT-ES cells differentiated only to thymic CD44(lo) CD24(hi) NKT cells producing mainly interleukin-4 (IL-4), whereas NKT cells resembling CD44(hi) CD24(lo) liver NKT cells producing mainly interferon gamma (IFN-gamma) and exhibiting strong adjuvant activity in vivo were developed in the switch culture starting at day 14 in the absence of Notch. The cloned ES culture system offers a new opportunity for the elucidation of the molecular events on NKT-cell development and for the establishment of NKT-cell therapy.

[Incidence of taste disorder associated with cancer patients undergoing chemotherapy on an ambulatory basis].

Taste disorders are a common complaint among cancer patients undergoing chemotherapy on an ambulatory basis. We conducted a survey on the incidence of such disorders among 74 patients, and 45.95% (34 of 74 patients) developed taste disorders. When stratified by medication into a regimen including 5-FU and one including taxanes, taste disorders were found in 59.0% (23 of 39 patients) of the former and 60.0% (9 of 15) of the latter. The survey also included the effects of taste disorders on patients appetites. Both regimens led to reduced appetite in a number of these patients (39.1% and 44.4%, respectively). Among patients on the 5-FU-containing regimen, the FOLFOX/FOLFIRI therapy was found to be responsible for loss of appetite. Regarding change in tastes, many patients stated that the medication dulled their taste sensation except for bitterness; their capacity to sense intensity of taste remained unchanged. It was found that acute taste disorders develop frequently among patients on a high dosage of 5-FU or a taxane-containing regimen.

First synthesis of (+/-)-basidifferquinone C, an inducer for fruiting-body formation in Polyporus arcularius.

Basidifferquinones, isolated from Streptomyces sp., are potent inducers of fruiting-body formation in the basidiomycete, Polyporus arcularius. The first synthesis of (+/-)-basidifferquinone C was accomplished by starting from 3,5-dihydroxy-2-naphthoic acid.

High gamma-aminobutyric acid level in cortical tubers in epileptic infants with tuberous sclerosis complex measured with the MEGA-editing J-difference method and a three-Tesla clinical MRI Instrument.

The purpose of this study was to estimate the gamma-aminobutyric acid (GABA) and glutamate plus glutamine (Glx) concentrations in the cortical tubers of patients with tuberous sclerosis complex (TSC) using the MEGA-editing J-difference method and a stimulated echo-acquisition mode with a short echo time, and to determine which abnormality was more dominant between GABA and Glx in patients with TSC with epilepsy. This study included six patients with TSC (mean age, 4.3 years) and seven control subjects (mean age, 4.8 years). Measurements were obtained with a three-Tesla apparatus and postprocessing was conducted with an LCModel. The GABA level in the cortical gray matter (cgGABA) was calculated as a result of segmentation in voxels and from the literature values for gray and white matter ratios for GABA. Increased GABA and myo-inositol (mI) concentrations and a decreased N-acetyl aspartate (NAA) concentration were observed in the cortical tubers. The cgGABA level, and cgGABA/NAA and cgGABA/Glx ratios were also higher in patients with TSC than in control subjects. No significant difference was found in Glx concentration between patients with TSC and control subjects. Although the number of patients with TSC in this study was small, the increase in GABA and no significant change in Glx were consistent with previous neurochemical studies and support the hypothesis that brain GABA plays a key role in the pathophysiology of epilepsy during the process of neuronal development.