| 1. |
- Bungart, D, et al.
(author)
-
Occurrence of analogues of the myotropic neuropeptide orcokinin in the shore crab, Carcinus maenas : evidence for a novel neuropeptide family.
- 1995
-
In: Peptides. - 0196-9781 .- 1873-5169. ; 16:1, s. 67-72
-
Journal article (peer-reviewed)abstract
- By use of an enzyme immunoassay that was developed for the determination of orcokinin, a myotropic neuropeptide of the sequence NFDEIDRSGFGFN from the crayfish, Orconectes limosus, immunoreactive material was detected in extracts of thoracic ganglia from the shore crab, Carcinus maenas. Isolation of the immunoreactive material was achieved by the following steps: 1) prepurification by gel filtration, 2) immunoaffinity chromatography on an anti-orcokinin IgG protein-A sepharose column, and 3) reversed-phase HPLC. The HPLC profile after affinity purification revealed three main immunoreactive peptides that were rechromatographed. None of these peptides was identical to orcokinin in terms of retention time. Automated gas-phase sequencing revealed these peptides to be analogues of orcokinin differing in one amino acid residue. They were named [Ser9]-, [Ala13]- and [Val13]orcokinin (NFDEIDRSSFGFN, Mr 1549.3; NFDEIDRSGFGFA, Mr 1475.3; NFDEIDRSGFGFV, Mr 1503.9). Carboxypeptidase A treatment of the peptides indicated a free C-terminus. Complete characterization of the three peptides was achieved from approximately 230 thoracic ganglia of Carcinus maenas.
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| 2. |
- Bungart, D, et al.
(author)
-
Quantitative determination and distribution of the myotropic neuropeptide orcokinin in the nervous system of astacidean crustaceans.
- 1994
-
In: Peptides. - : Elsevier BV. - 0196-9781 .- 1873-5169. ; 15:3, s. 393-400
-
Journal article (peer-reviewed)abstract
- For quantitative determinations of orcokinin, an indirect, noncompetitive sandwich ELISA was developed. This ELISA is highly specific for orcokinin and the detection limit is 1 fmol. In three astacidean species (Orconectes limosus, Homarus americanus, and Astacus astacus) orcokinin immunoreactivity (OK-IR) was measurable in all parts of the nervous system. Upon normalization to the protein content of the tissue (pmol/mg protein), concentrations were shown to be in the same range in all three species. The distribution of OK-IR in the nervous system is also very similar in the three species. In Orconectes limosus the following values were obtained (in pmol/mg protein): cerebral ganglion 215, optic ganglia in the eyestalk 38, subesophageal ganglion 182. The thoracic ganglia have lower concentrations (35-72) and the abdominal ganglia (AG) 1-5 even lower ones (11-17). In the AG 6 of Orconectes, from which the innervation of the hindgut arises, concentrations are approximately five times higher than in the other AG. In hindgut tissue, relatively high concentrations of 22 pmol/mg were measured, which is in agreement with the demonstrated function of orcokinin as a hindgut excitatory substance. Markedly elevated levels of orcokinin were observed in the AG 6 of Astacus, but not in Homarus. Orcokinin could also be measured consistently and reliably in the hemolymph, where its concentration is approximately 1 x 10(-11) M. These results show that orcokinin may be released into the hemolymph and may act as a hormone, in addition to its role as a locally acting neurotransmitter/modulator.
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| 3. |
- Dircksen, Heinrich, 1954-, et al.
(author)
-
Structure, distribution, and biological activity of novel members of the allatostatin family in the crayfish Orconectes limosus.
- 1999
-
In: Peptides. - 0196-9781 .- 1873-5169. ; 20:6, s. 695-712
-
Journal article (peer-reviewed)abstract
- In the central and peripheral nervous system of the crayfish, Orconectes limosus, neuropeptides immunoreactive to an antiserum against allatostatin I (= Dipstatin 7) of the cockroach Diploptera punctata have been detected by immunocytochemistry and a sensitive enzyme immunoassay. Abundant immunoreactivity occurs throughout the central nervous system in distinct interneurons and neurosecretory cells. The latter have terminals in well-known neurohemal organs, such as the sinus gland, the pericardial organs, and the perineural sheath of the ventral nerve cord. Nervous tissue extracts were separated by reverse-phase high-performance liquid chromatography and fractions were monitored in the enzyme immunoassay. Three of several immunopositive fractions have been purified and identified by mass spectroscopy and microsequencing as AGPYAFGL-NH2, SAGPYAFGL-NH2, and PRVYGFGL-NH2. The first peptide is identical to carcinustatin 8 previously identified in the crab Carcinus maenas. The others are novel and are designated orcostatin I and orcostatin II, respectively. All three peptides exert dramatic inhibitory effects on contractions of the crayfish hindgut. Carcinustatin 8 also inhibits induced contractions of the cockroach hindgut. Furthermore, this peptide reduces the cycle frequency of the pyloric rhythms generated by the stomatogastric nervous system of two decapod species in vitro. These crayfish allatostatin-like peptides are the first native crustacean peptides with demonstrated inhibitory actions on hindgut muscles and the pyloric rhythm of the stomatogastric ganglion.
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| 4. |
- Hallberg, Mathias, et al.
(author)
-
Anabolic-androgenic steroids affect the content of substance P and substance P(1-7) in the rat brain
- 2000
-
In: Peptides. - 0196-9781 .- 1873-5169. ; 21:6, s. 845-852
-
Journal article (peer-reviewed)abstract
- The effects of intramuscular (i.m.) injections of nandrolone decanoate (15 mg/kg/day), an anabolic-androgenic steroid, on the levels of substance P (SP) and on its N-terminal fragment SP(1-7) were examined in the male rat brain by radioimmunoassay. The results demonstrated that the SP immunoreactivity in amygdala, hypothalamus, striatum, and periaqueductal gray was significantly enhanced, whereas the concentration of the N-terminal fragment SP(1-7) was enhanced in the nucleus accumbens and in periaqueductal gray. In the striatum the steroid induced a decrease in the content of SP(1-7). The relevance of these peptides in connection with anabolic-androgenic steroid-induced aggression is discussed.
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| 5. |
- Koskinen, Lars-Owe D., Professor, 1955-
(author)
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Cerebral and peripheral blood flow effects of TRH in the rat : a role of vagal nerves
- 1989
-
In: Peptides. - : Elsevier BV. - 0196-9781 .- 1873-5169. ; 10:5, s. 933-938
-
Journal article (peer-reviewed)abstract
- The cardiovascular effects of the IV infusion of TRH were studied in the rat. TRH tended to increase the MAP and markedly increased the CBF(tot) in the control group, in vagotomized animals and in methylatropine-pretreated rats. A marked vasodilation was noted in the pancreas, gastric mucosa, duodenum and cardiac muscle. This effect was turned to vasoconstriction, the heart excluded, in vagotomized animals. Muscarinic blockade attenuated the vasodilating effect of TRH in the duodenum and gastric mucosa. The results indicate that TRH elicits cerebral vasodilation and a partly nonmuscarinic parasympathetically mediated vasodilation in several gastrointestinal organs in parallel with a vasoconstriction which is unmasked by vagotomy.
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| 6. |
- Koskinen, Lars-Owe D., Professor, 1955-
(author)
-
Naloxone and TRH affect regional blood flows in the anesthetized rabbit.
- 1991
-
In: Peptides. - : Elsevier BV. - 0196-9781 .- 1873-5169. ; 12:6, s. 1273-1277
-
Journal article (peer-reviewed)abstract
- The cardiovascular effects of IV naloxone and a subsequent administration of TRH IV were studied in the rabbit. Naloxone caused a vasodilation in the myocardium and adrenal glands. Naloxone elicited an increment in cerebral blood flow in several regions which attenuated the cerebrovasodilating effect of TRH in a few regions. The blockade of endogenous opioids with naloxone did not modify the peripheral vasoconstricting effect of TRH or affect the vascular effects of TRH mediated by the peripheral sympathetic nerves. The results indicate that naloxone has a vasodilating effect in the myocardium and CNS in anesthetized rabbits. The major part of the cardiovascular effect of TRH is not dependent on mechanisms sensitive to naloxone.
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| 7. |
- Koskinen, Lars-Owe D., Professor, 1955-, et al.
(author)
-
Nitric oxide inhibition by L-NAME but not 7-NI induces a transient increase in cortical cerebral blood flow and affects the cerebrovasodilation induced by TRH
- 2003
-
In: Peptides. - : Elsevier. - 0196-9781 .- 1873-5169. ; 24:4, s. 579-583
-
Journal article (peer-reviewed)abstract
- The tripeptide thyrotropin releasing hormone (TRH) has multiple interesting and complex physiological effects. One of these is the cerebrovasodilating effect, which has been described under several different conditions. The final mechanism for this effect is unknown. In the present study, we found an initial atropine-resistant cerebral vasodilation (24%) elicited by the NOS inhibitor L-NAME in the rat. D-NAME and 7-NI did not produce this effect. TRH (300 microg kg(-1), i.v.) induced an increase in cerebral blood flow by 62%. L-NAME reduced this effect significantly. The cerebrovasodilating mechanism of TRH, at least in part, is endothelial NO dependent as the neuronal 7-NI NOS inhibitor does not affect the TRH response.
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| 8. |
- Koskinen, Lars-Owe D., Professor, 1955-, et al.
(author)
-
The neuropeptide TRH has a minor effect on the enzymatic activity of acetylcholinesterase in vitro.
- 1998
-
In: Peptides. - : Elsevier BV. - 0196-9781 .- 1873-5169. ; 19:10, s. 1675-1677
-
Journal article (peer-reviewed)abstract
- The neuropeptide thyrotropin-releasing hormone (TRH) elicits a variety of physiological effects of which some are due to cholinergic mechanisms. TRH modulates in vivo the effects of compounds affecting acetylcholinesterase (AChE). In the present study the in vitro effects of TRH on the activity of AChE were explored. TRH has no effect at physiologically relevant concentrations. At unphysiologically high concentrations (>5 mM) a slight inhibition was found. This was noticed also when the enzyme was exposed to the amide-free tripeptide analog p-Glu-His-Pro. We conclude that any cholinergic effect of TRH observed in vivo is unlikely to be due to a direct interaction of the peptide with AChE.
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| 9. |
- Larsson, Jan, et al.
(author)
-
Effects of TRH and atropine on induction and duration of anesthesia with propofol in rats.
- 1996
-
In: Peptides. - : Elsevier BV. - 0196-9781 .- 1873-5169. ; 17:2, s. 293-297
-
Journal article (peer-reviewed)abstract
- The effects of IV TRH pretreatment on induction of anesthesia with propofol or pentobarbital were investigated in rats. The effects of IV TRH, administered after induction, on duration of propofol anesthesia and the interaction with atropine were also studied. The doses of propofol or pentobarbital were not influenced by TRH. TRH reduced duration of anesthesia after propofol, with higher brain concentrations of propofol at recovery. Atropine did not block this effect, but given alone prolonged duration of anesthesia. It is concluded that TRH shortens the duration of propofol anesthesia, probably due to a pharmacodynamic effect and not to a pharmacokinetic interaction.
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| 10. |
- Magnusson, B. M., et al.
(author)
-
Biological effects after percutaneous absorption of thyrotropin-releasing hormone and its analogue M-TRH
- 2001
-
In: Peptides. - : Elsevier. - 0196-9781 .- 1873-5169. ; 22:1, s. 73-79
-
Journal article (peer-reviewed)abstract
- Besides its well known endocrinological effects, thyrotropin-releasing hormone (TRH) has potential clinical value in the treatment of neurotrauma and various neurologic and psychiatric disorders. The aim of this study was to assess if transdermal delivery of TRH and its analogue, M-TRH, in the presence of enhancers, is an effective means for administration of the peptides. Using the in vitro diffusion cell method, the effect of ethanol and a terpene on the transdermal penetration of the peptides across full-thickness rat skin were studied. Steady-state permeability values for TRH and M-TRH were 8.7 +/- 2.2 and 6.7 +/- 1.4 microg/cm(2) h, respectively. The addition of 3 % terpene in combination with 47 % ethanol increased the penetration of TRH and M-TRH to 16.2 +/- 1.7 and 14.6 +/- 2.1 microg/cm(2) h, respectively. Rats were studied in vivo for release of thyroid-stimulating hormone (TSH) as a biologic effect after transdermally delivered peptide. Topical application of TRH and M-TRH induced an increase in TSH serum concentration from 0.32 +/- 0.09 ng/ml to 32.6 +/- 5.0 and 22.9 +/- 7.6 ng/ml, respectively, after 30 min. The addition of terpene and ethanol in combination with TRH or M-TRH, increased the TSH release to 43.0 +/- 3.8 and 48.4 +/- 4.0 ng/ml, respectively. It is concluded that, in the rat, peptides can be absorbed through the skin with retained biologic activity, and in amounts sufficient to elicit a physiological response.
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| 11. |
- Rugarn, Olof, et al.
(author)
-
Effects of estradiol, progesterone, and norethisterone on regional concentrations of galanin in the rat brain
- 1999
-
In: Peptides. - 0196-9781 .- 1873-5169. ; 20:6, s. 743-748
-
Journal article (peer-reviewed)abstract
- Concentrations of immunoreactive galanin were compared in eight gross brain regions of ovariectomized female rats treated with either estradiol, estradiol + progesterone, estradiol + norethisterone, or placebo. Higher concentrations with estradiol treatment compared with placebo were found in the pituitary (357%), frontal cortex (162%), occipital cortex (174%), hippocampus (170%), and median eminence (202%). A more profound difference with addition of progesterone or norethisterone was seen in the pituitary (529% and 467%, respectively). Sex steroids, particularly estradiol, modulate galanin concentrations not only in reproductive, but also in nonreproductive, brain regions.
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| 12. |
- Rugarn, Olof, et al.
(author)
-
Sex differences in neuropeptide distribution in the rat brain
- 1999
-
In: Peptides. - 0196-9781 .- 1873-5169. ; 20:1, s. 81-86
-
Journal article (peer-reviewed)abstract
- We have investigated possible sex differences in the regional concentrations of neuropeptides in the rat brain. Immunoreactive neurotensin (NT), neurokinin A (NKA), galanin (GAL), calcitonin gene-related peptide (CGRP), substance P (SP) and neuropeptide Y (NPY) were measured by radioimmunoassay in frontal cortex, occipital cortex, hippocampus, striatum, hypothalamus and pituitary in male and female pre- and postpubertal rats. Sex differences were found for NPY (p < 0.001), NT (p < 0.01) and GAL (p < 0.05), in particular in hippocampus, striatum, hypothalamus and pituitary, but not for CGRP, SP and NKA. Results from analysis of neuropeptides in one sex may not be entirely applicable to the other.
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| 13. |
- Sandin, Johan, et al.
(author)
-
Differential metabolism of dynorphins in substantia nigra, striatum and hippocampus
- 1997
-
In: Peptides. - 0196-9781 .- 1873-5169. ; 18:7, s. 949-956
-
Journal article (peer-reviewed)abstract
- To map the proteolytic enzymes metabolizing dynorphins in brain structures, size-exclusion chromatography linked to electrospray ionization mass spectrometry was used. Enzymes extracted from rat hippocampus, striatum, and substantia nigra were tested for their capability of converting dynorphin-related peptides. Dynorphin A was the most resistant to proteolytic conversion, whereas Big dynorphin and dynorphin B-29 were slowly converted to dynorphin A and dynorphins A and B, respectively. Dynorphin B and alpha-neoendorphin were the least resistant. Dynorphin B was rapidly converted to Leu-enkephalin in the striatum and hippocampus but to Leu-enkephalin-Arg6 in the substantia nigra. alpha-Neoendorphin was converted to Leu-enkephalin in all tissues investigated.
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| 14. |
- Silberring, Jerzy, et al.
(author)
-
Characterization of immunoreactive dynorphin B and beta-endorphin in human plasma
- 1998
-
In: Peptides. - 0196-9781 .- 1873-5169. ; 19:8, s. 1329-1337
-
Journal article (peer-reviewed)abstract
- Dynorphins and beta-endorphin in human plasma were characterized and studied quantitatively using radioimmunoassay, high-performance liquid chromatography (HPLC), and mass spectrometry. Most immunoreactive (ir) dynorphin B and beta-endorphin in human plasma coeluted with authentic peptides in analysis. Dynorphin A was not detected. Added to human plasma it was rapidly converted into Leu-enkephalin-Arg6 followed by elimination of the C-terminal arginine after prolonged incubation. The rate of dynorphin A conversion was estimated at 40 pmol/min/microl plasma. This process was inhibited by the thiol protease inhibitor, PHMB and by EDTA. Dynorphin B, alpha-neoendorphin and big dynorphin were virtually not metabolized by plasma proteases under the same conditions. beta-endorphin was processed into beta-endorphin(1-19) and the corresponding C-terminal counterpart beta-endorphin(20-31) at a rate of about 25 pmol/min/microl of plasma. Based on the above data, a reliable strategy was established to measure dynorphin B- and beta-endorphin-ir in human plasma samples. The basal levels in a male control group were 0.99 +/- 0.11 (n = 11) and 16.3 +/- 1.5 (n = 11) fmol/ml plasma, respectively.
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| 15. |
- Stangier, Joachim, et al.
(author)
-
Distribution of a novel cardioactive neuropeptide (CCAP) in the nervous system of the shore crab Carcinus maenas
- 1988
-
In: Peptides. - : Elsevier. - 0196-9781 .- 1873-5169. ; 9:4, s. 795-800
-
Journal article (peer-reviewed)abstract
- A radioimmunoassay (RIA) for the recently discovered crustacean cardioactive peptide (CCAP) has been developed and used to determine contents of CCAP in different parts of the nervous system of the shore crab Carcinus maenas. Immunoreactive material was detected throughout the nervous system. In contrast to the main ganglia which contained low levels of approximately 1.4 pmol CCAP/mg protein (brain and thoracic ganglion), a high concentration was found in a neurohemal structure, the pericardial organs (PO) (868 pmol/mg protein). A predominantly neurohormonal role of CCAP thus suggested is further supported by in vitro release studies. Incubation of POs in high (K+) saline showed that CCAP is secretable in considerable amounts by a Ca++-dependent release mechanism.
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| 16. |
- Stangier, J, et al.
(author)
-
Identification and immunocytochemical localization of proctolin in pericardial organs of the shore crab, Carcinus maenas.
- 1986
-
In: Peptides. - : Elsevier. - 0196-9781 .- 1873-5169. ; 7:1, s. 67-72
-
Journal article (peer-reviewed)abstract
- The occurrence of proctolin (Arg-Tyr-Leu-Pro-Thr) in crab neurohemal pericardial organs (POs) has been demonstrated by isolation of the pentapeptide by HPLC and manual microsequencing according to the DABITC-PITC double coupling technique. From one pair of POs approximately 5.4 pmol were obtained (= 45 pmol/mg protein). Immunocytochemically, an extensive system of positive structures was found in both whole mount preparations and semithin sections, consisting of numerous varicose fibres of varying diameter and many knoblike neurosecretory terminals abutting upon the epineurium of the PO trunks. The relatively high concentration in the POs as well as the pattern of proctolin-positive fibres and terminals clearly suggest a neurohormonal role of the pentapeptide in decapod crustaceans.
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| 17. |
- Ahrén, Bo
(author)
-
Glucagon-early breakthroughs and recent discoveries.
- 2015
-
In: Peptides. - : Elsevier BV. - 1873-5169 .- 0196-9781. ; 67, s. 74-81
-
Research review (peer-reviewed)abstract
- Glucagon was discovered in 1922 as a hyperglycemic factor in the pancreas. During its early history up to 1970, glucagon was shown to increase circulating glucose through stimulating glycogenolysis in the liver. It was also shown to be a constituent of islet non-ß cells and to signal through G protein coupled receptors and cyclic AMP. Furthermore, its chemical characteristics, including amino acid sequence, and its processing from the preproglucagon gene had been established. During the modern research during the last 40 years, glucagon has been established as a key hormone in the regulation of glucose homeostasis, including a key role for the glucose counterregulation to hypoglycemia and for development of type 2 diabetes, and today glucagon is a potential target for treatment of the disease. Glucagon has also been shown to be a key factor beyond glucose control and involved in many processes. For the coming, future research, studies will be focused on α-cell biology beyond glucagon, hyperglucagonemia in other conditions than diabetes, its involvement in the regulation of body weight and energy expenditure and the potential of glucagon as a target for other diseases than type 2 diabetes, such as type 1 diabetes and obesity. This review summarizes the more than 90 years history of this important hormone as well as discusses potential future research regarding glucagon.
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| 18. |
- Bankell, Elisabeth, et al.
(author)
-
LL-37-induced caspase-independent apoptosis is associated with plasma membrane permeabilization in human osteoblast-like cells
- 2021
-
In: Peptides. - : Elsevier BV. - 0196-9781 .- 1873-5169. ; 135
-
Journal article (peer-reviewed)abstract
- The host defense peptide LL-37 is active against both gram-positive and gram-negative bacteria, but it has also been shown to reduce human host cell viability. However, the mechanisms behind LL-37-induced human host cell cytotoxicity are not yet fully understood. Here, we assess if LL-37-evoked attenuation of human osteoblast-like MG63 cell viability is associated with apoptosis, and if the underlying mechanism may involve LL-37-induced plasma membrane permeabilization. MG63 cell viability and plasma membrane permeabilization were investigated by using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method and by measuring lactate dehydrogenase (LDH) release, respectively. Apoptosis was assessed by the terminal deoxynucleotidyl dUTP nick end labeling (TUNEL) assay and Annexin V flow cytometry, and caspase-3 and poly (ADP-ribose) polymerase (PARP) cleavage were determined by Western blot. LL-37 (4 and 10 μM) reduced both cell number and cell viability, and these effects were associated with a pro-apoptotic effect demonstrated by positive TUNEL staining and Annexin V flow cytometry. LL-37-induced apoptosis was not coupled to either caspase-3 or PARP cleavage, suggesting that LL-37 causes caspase-independent apoptosis in MG63 cells. Both LL-37 and the well-known plasma membrane permeabilizer Triton X-100 reduced cell viability and stimulated LDH release. Triton X-100-treated cells showed positive TUNEL staining, and the detergent accumulated cells in late apoptosis/necrosis. Similar to LL-37, Triton X-100 caused no PARP cleavage. We conclude that LL-37 promotes caspase-independent apoptosis, and that this effect seems coupled to plasma membrane permeabilization in human MG63 cells.
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| 19. |
- Bennet, Hedvig, et al.
(author)
-
Altered serotonin (5-HT) 1D and 2A receptor expression may contribute to defective insulin and glucagon secretion in human type 2 diabetes.
- 2015
-
In: Peptides. - : Elsevier BV. - 1873-5169 .- 0196-9781. ; 71, s. 113-120
-
Journal article (peer-reviewed)abstract
- Islet produced 5-hydroxy tryptamine (5-HT) is suggested to regulate islet hormone secretion in a paracrine and autocrine manner in rodents. Hitherto, no studies demonstrate a role for this amine in human islet function, nor is it known if 5-HT signaling is involved in the development of beta cell dysfunction in type 2 diabetes (T2D). To clarify this, we performed a complete transcriptional mapping of 5-HT receptors and processing enzymes in human islets and investigated differential expression of these genes in non-diabetic and T2D human islet donors. We show the expression of fourteen 5-HT receptors as well as processing enzymes involved in the biosynthesis of 5-HT at the mRNA level in human islets. Two 5-HT receptors (HTR1D and HTR2A) were over-expressed in T2D islet donors. Both receptors (5-HT1d and 5-HT2a) were localized to human alpha, beta and delta cells. 5-HT inhibited both insulin and glucagon secretion in non-diabetic islet donors. In islets isolated from T2D donors the amine significantly increased release of insulin in response to glucose. Our results suggest that 5-HT signaling participates in regulation of overall islet hormone secretion in non- diabetic individuals and over-expression of HTR1D and HTR2A may either contribute to islet dysfunction in T2D or arise as a consequence of an already dysfunctional islet.
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| 20. |
- Bivehed, Erik, et al.
(author)
-
Region-specific bioconversion of dynorphin neuropeptide detected by in situ histochemistry and MALDI imaging mass spectrometry
- 2017
-
In: Peptides. - : Elsevier BV. - 0196-9781 .- 1873-5169. ; 87, s. 20-27
-
Journal article (peer-reviewed)abstract
- Brain region-specific expression of proteolytic enzymes can control the biological activity of endogenous neuropeptides and has recently been targeted for the development of novel drugs, for neuropathic pain, cancer, and Parkinson's disease. Rapid and sensitive analytical methods to profile modulators of enzymatic activity are important for finding effective inhibitors with high therapeutic value. Combination of in situ enzyme histochemistry with MALDI imaging mass spectrometry allowed developing a highly sensitive method for analysis of brain-area specific neuropeptide conversion of synthetic and endogenous neuropeptides, and for selection of peptidase inhibitors that differentially target conversion enzymes at specific anatomical sites. Conversion and degradation products of Dynorphin B as model neuropeptide and effects of peptidase inhibitors applied to native brain tissue sections were analyzed at different brain locations. Synthetic dynorphin B (2 pmol) was found to be converted to the N-terminal fragments on brain sections whereas fewer C-terminal fragments were detected. N-ethylmaleimide (NEM), a non-selective inhibitor of cysteine peptidases, almost completely blocked the conversion of dynorphin B to dynorphin B(1-6; Leu-Enk-Arg), (1-9), (2-13), and (7-13). Proteinase inhibitor cocktail, and also incubation with acetic acid displayed similar results. Bioconversion of synthetic dynorphin B was region-specific producing dynorphin B(1-7) in the cortex and dynorphin B (2-13) in the striatum. Enzyme inhibitors showed region-and enzyme-specific inhibition of dynorphin bioconversion. Both phosphoramidon (inhibitor of the known dynorphin converting enzyme neprilysin) and opiorphin (inhibitor of neprilysin and aminopeptidase N) blocked cortical bioconversion to dynorphin B(1-7), wheras only opiorphin blocked striatal bioconversion to dynorphin B(2-13). This method may impact the development of novel therapies with aim to strengthen the effects of endogenous neuropeptides under pathological conditions such as chronic pain. Combining histochemistry and MALDI imaging MS is a powerful and sensitive tool for the study of inhibition of enzyme activity directly in native tissue sections. (C) 2016 The Authors. Published by Elsevier Inc.
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| 21. |
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| 22. |
- Björn, Camilla, et al.
(author)
-
Anti-infective efficacy of the lactoferrin-derived antimicrobial peptide HLR1r
- 2016
-
In: Peptides. - : Elsevier BV. - 0196-9781 .- 1873-5169. ; 81, s. 21-28
-
Journal article (peer-reviewed)abstract
- Antimicrobial peptides (AMPs) have emerged as a new class of drug candidates for the treatment of infectious diseases. Here we describe a novel AMP, HLR1r, which is structurally derived from the human milk protein lactoferrin and demonstrates a broad spectrum microbicidal action in vitro. The minimum concentration of HLR1r needed for killing >= 99% of microorganisms in vitro, was in the range of 3-50 mu g/ml for common Gram-negative and Gram-positive bacteria, including methicillin-resistant Staphylococcus aureus (MRSA), and for the yeast Candida albicans, when assessed in diluted brain-heart infusion medium. We found that HLR1r also possesses anti-inflammatory properties as evidenced by inhibition of tumor necrosis factor alpha (TNF-alpha) secretion from human monocyte-derived macrophages and by repression of interleukin-6 (IL-6) and plasminogen activator inhibitor-1 (PAI-1) secretion from human mesothelial cells, without any cytotoxic effect observed at the concentration range tested (up to 400 mu g/ml). HLR1r demonstrated pronounced anti-infectious effect in in vivo experimental models of cutaneous candidiasis in mice and of excision wounds infected with MRSA in rats as well as in an ex vivo model of pig skin infected with S. aureus. In conclusion, HLR1r may constitute a new therapeutic alternative for local treatment of skin infections. (C) 2016 Elsevier Inc. All rights reserved.
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| 23. |
- Blackshear, Alice, et al.
(author)
-
Intracerebroventricular administration of galanin or galanin receptor subtype 1 agonist M617 induces c-Fos activation in central amygdala and dorsomedial hypothalamus
- 2007
-
In: Peptides. - : Elsevier BV. - 0196-9781 .- 1873-5169. ; 28:5, s. 1120-1124
-
Journal article (peer-reviewed)abstract
- The neuropeptide galanin and galanin receptors are widespread throughout cortical, limbic and midbrain areas implicated in reward, learning/memory, pain, drinking and feeding. While many studies have shown that galanin produces a variety of presynaptic and postsynaptic responses, work studying the effects of galanin on neural activation is limited. The present study examined patterns of c-Fos immunoreactivity resulting from intracerebro-ventricular administration of galanin versus saline injection in awake rats. An initial comprehensive qualitative survey was conducted to identify regions of high c-Fos expression followed up with quantitative analysis. Galanin induced a significant increase in c-Fos levels relative to saline-treated controls in dorsomedial hypothalamus and in the central nucleus of the amygdala. This pattern of activation was also produced by galanin receptor type 1 agonist M617. The present findings confirm that galanin upregulates c-Fos activation in hypothalamic nuclei, and supports roles for galanin in central amygdala-mediated food intake, and Pavlovian conditioning.
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| 24. |
- Botros, Milad, et al.
(author)
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Endomorphins interact with the substance P (SP) aminoterminal SP (1-7) binding in the ventral tegmental area of the rat brain
- 2008
-
In: Peptides. - : Elsevier BV. - 0196-9781 .- 1873-5169. ; 29:10, s. 1820-1824
-
Journal article (peer-reviewed)abstract
- We have recently identified a specific binding site for the tachykinin peptide substance P (SP) fragment SP1-7 in the rat spinal cord. This site appeared very specific for SP1-7 as the binding affinity of this compound highly exceeded those of other SP fragments. We also observed that endomorphin-2 (EM-2) exhibited high potency in displacing SP1-7 from this site. In the present work using a [H-3]-labeled derivative of the heptapeptide we have identified and characterized [H-3]-SP1-7 binding in the rat ventral tegmental area (VTA). Similarly to the [H-3]-SP1-7 binding in the spinal cord the affinity of unlabeled SP1-7 to the specific site in VTA was significantly higher than those of other SP fragments. Further, the tachykinin receptor NK-1, NK-2 and NK-3 ligands showed no or negligible binding to the identified site. However, the mu-opioid peptide (MOP) receptor agonists DAMGO, EM-1 and EM-2 did, and significant difference was observed in the binding affinity between the two endomorphins. As recorded from displacement curves the affinity of EM-2 for the SP1-7 site was 4-5 times weaker than that for SP1-7 but about 5 times higher than that of EM-1. The opioid receptor antagonists naloxone and naloxonazine showed weak or negligible binding. it was concluded that the specific site identified for SP1-7 binding in the rat VTA is distinct from the MOP receptor although it exhibits high affinity for EM-2.
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| 25. |
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| 26. |
- Bukovics, Peter, et al.
(author)
-
Changes of PACAP level in cerebrospinal fluid and plasma of patients with severe traumatic brain injury
- 2014
-
In: Peptides. - : Elsevier. - 0196-9781 .- 1873-5169. ; 60, s. 18-22
-
Journal article (peer-reviewed)abstract
- PACAP has well-known neuroprotective potential including traumatic brain injury (TBI). Its level is up-regulated following various insults of the CNS in animal models. A few studies have documented alterations of PACAP levels in human serum. The time course of post-ictal PACAP levels, for example, show correlation with migraine severity. Very little is known about the course of PACAP levels following CNS injury in humans and the presence of PACAP has not yet been detected in cerebrospinal fluid (CSF) of subjects with severe TBI (sTBI). The aim of the present study was to determine whether PACAP occurs in the CSF and plasma (Pl) of patients that suffered sTBI and to establish a time course of PACAP levels in the CSF and Pl. Thirty eight subjects with sTBI were enrolled with a Glasgow Coma Scale ≤8 on admission. Samples were taken daily, until the time of death or for maximum 10 days. Our results demonstrated that PACAP was detectable in the CSF, with higher concentrations in patients with TBI. PACAP concentrations markedly increased in both Pl and CSF in the majority of patients 24-48h after the injury stayed high thereafter. In cases of surviving patients, Pl and CSF levels displayed parallel patterns, which may imply the damage of the blood-brain barrier. However, in patients, who died within the first week, Pl levels were markedly higher than CSF levels, possibly indicating the prognostic value of high Pl PACAP levels.
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| 27. |
- Carlini, Valeria P, et al.
(author)
-
Ghrelin and memory : differential effects on acquisition and retrieval
- 2010
-
In: Peptides. - : Elsevier BV. - 0196-9781 .- 1873-5169. ; 31:6, s. 1190-1193
-
Journal article (peer-reviewed)abstract
- In a previous paper we have demonstrated that the orexigenic peptide Ghrelin (Ghr), increases memory retention in rats and mice. In the present work we evaluated the Ghr effect when it was administered previous the training session or previous the test session (24h after training) on the memory performance, using step-down test. The results showed that the intra-hippocampal Ghr administration previous the training session improved the long-term memory in this task, but did not modify the short-term memory. Nevertheless, when the Ghr was administrated previous the test session, no changes were observed in the memory performance. Taking into account these results and other previously published by our group, we could hypothesizes that Ghr may modulate specific molecular intermediates involved in memory acquisition/consolidation but not in the retrieval.
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| 28. |
- Carlini, Valeria P., et al.
(author)
-
Melanin-concentrating hormone (MCH) reverts the behavioral effects induced by inescapable stress
- 2006
-
In: Peptides. - : Elsevier BV. - 0196-9781 .- 1873-5169. ; 27:9, s. 2300-2306
-
Journal article (peer-reviewed)abstract
- The aim of this work was to investigate if MCH modifies the feeding and freezing responses in rats exposed to stressful stimuli. We used a basic version of contextual fear, where one group of rats were placed in a novel environment and two different groups were exposed to footshock paradigms, one of them escapable and the other one inescapable. At the end of each treatment, freezing and feeding were measured. Only the animals exposed to inescapable footshock paradigm showed significant increase in the food intake and freezing behavior in comparison to the control animals. The MCH administration (intra-hippocampal or intra-amygdaline) reverted these effects elicited by inescapable footshock. Results presented in this paper lead us to the assumption that the anxiolytic effect of the peptide is responsible for the reversion of the IS effects.
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| 29. |
- Christ, Peter, et al.
(author)
-
Functional characterization of mosquito short neuropeptide F receptors
- 2018
-
In: Peptides. - : Elsevier BV. - 0196-9781 .- 1873-5169. ; 103, s. 31-39
-
Journal article (peer-reviewed)abstract
- Mosquito blood feeding transiently inhibits sugar-and host seeking through neuropeptide signaling. Short neuropeptide F (sNPF) is one of the neuromodulators involved in this regulation. Here, we identified the genes for the sNPF precursor and the sNPF receptor in the southern house mosquito, Culex quinquefasciatus. Comparative analyses are made with the genes of the sNPF precursor and receptor from two other important vectors, Aedes aegypti and Anopheles coluzzii. We functionally characterized the receptors in all three species using endogenous neuropeptides, and quantified their transcript expression following a blood meal and a sugar meal. Our analysis reveals several Cx. quinquefasciatus-specific duplications of the sNPF-3 isoform on the sNPF precursor, which are not reflected in the precursors of the other two species. In contrast, the structure of the sNPF receptors is highly conserved within mosquitoes, and a putative ligand binding region is proposed and discussed. Reflecting the high structural conservation, the sNPF receptor sensitivity to endogenous sNPF iso-forms is conserved across mosquito species. Using quantitative real time PCR, we demonstrate that transcript abundance of the sNPF receptor and precursor is regulated following feeding, only in Cx. quinquefasciatus. We discuss our findings in relation to previous work on sNPF signaling and its role in feeding regulation.
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| 30. |
- Christ, Peter, et al.
(author)
-
Functional characterization of the dual allatostatin-A receptors in mosquitoes
- 2018
-
In: Peptides. - : Elsevier BV. - 0196-9781 .- 1873-5169. ; 99, s. 44-55
-
Journal article (peer-reviewed)abstract
- The neuropeptide allatostatin-A (AstA) and its cognate receptors (AstARs) are involved in the modulation of feeding behavior, which in hematophagous insects includes the regulation of the disease vector-related behaviors, host seeking and blood feeding. In mosquitoes and other dipterans, there are two copies of AstAR, contrasting with the single copy found in other insects. In this study, we identified and cloned the dual AstAR system of two important disease vectors Aedes aegypti and Culex quinquefasciatus, and compared them with those previously described, including those in Anopheles coluzzii and Drosophila melanogaster. Phylogenetic analysis of the AstARs revealed that the mosquito AstAR1s has retained a similar amino acid sequence as the AstARs from non-dipteran insect species. Intron analysis revealed that the number of introns accumulated in the AstAR2s is similar to that in other insects, and that introns are conserved within the receptor types, but that only the final two introns are conserved across AstAR1s and 2s. We functionally characterized the dual AstARs in An. coluzzii, Ae. aegypti and Cx. quinquefasciatus by stably expressing the receptors in a Chinese hamster oocyte cell line (CHO) also stably expressing a promiscuous G-protein (G16), and challenged them with the endogenous isoforms of AstA from the three mosquito species. In the culicine mosquitoes, Ae. aegypti and Cx. quinquefasciatus, the AstARs demonstrated differential sensitivity to AstA, with the AstAR2s displaying a higher sensitivity than the AstAR1s, suggesting a divergence of functional roles for these AstARs. In contrast, both An. coluzzii AstARs demonstrated a similar sensitivity to the AstA ligands. We discuss our findings in the light of AstA acting as a regulator of blood feeding in mosquitoes. A better understanding of the regulation of host seeking and blood feeding in vector mosquitoes will lead to the rational development of novel approaches for vector control.
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| 31. |
- Dahl, Sara, et al.
(author)
-
The host defense peptide LL-37 triggers release of nucleic acids from human mast cells
- 2018
-
In: Peptides. - : Elsevier BV. - 0196-9781 .- 1873-5169. ; 109, s. 39-45
-
Journal article (peer-reviewed)abstract
- The human host defense peptide LL-37 possesses antimicrobial activity but also affects host cell function and viability. Mast cells are involved in innate immunity but no data have been presented on effects of LL-37 on human mast cell viability and export of nucleic acids. Here, we demonstrated by immunofluorescence microscopy that synthesized LL-37 was internalized by human LAD2 mast cells and detected both in cytoplasm and nucleus. Treatment with high (4 and 10 μM) but not low (1 μM) concentrations of LL-37 for 4 h reduced cell viability assessed by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Stimulation with 10 μM LL-37 for 4 h enhanced export of nucleic acids, total protein and lactate dehydrogenase (LDH), suggesting that both nuclear and plasma membranes are permeabilized by LL-37. Although LL-37 triggered release of nucleic acids, no extracellular trap-like structures were observed by laser scanning confocal microscopy of cells incubated with the plasma membrane impermeable nucleic acid fluorophore SYTOX-Green, indicating that LL-37 promotes export of nucleic acids but not formation of extracellular traps. On the other hand, phorbol-12-myristate-13-acetate (PMA), which is a well-known inducer of extracellular traps, stimulated export of nucleic acids and also formation of extracellular trap-like structures. However, PMA had no effect on export of either total protein or LDH. Hence, LL-37 and PMA seem to stimulate export of nucleic acids from LAD2 mast cells through different pathways. In conclusion, we demonstrate that LL-37 triggers release of nucleic acids from human mast cells but not the formation of extracellular trap-like structures.
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| 32. |
- Drott, Carl Johan, 1984-, et al.
(author)
-
CART decreases islet blood flow, but has no effect on total pancreatic blood flow and glucose tolerance in anesthetized rats
- 2021
-
In: Peptides. - : Elsevier BV. - 0196-9781 .- 1873-5169. ; 135
-
Journal article (peer-reviewed)abstract
- Cocaine- and amphetamine-regulated transcript (CART) is a neurotransmitter and hormone, involved in the regulation of e.g. food intake, body weight, reward and addiction, and stress response. CART has also been found to affect insulin secretion and beta cell morphology, both in vivo and in vitro. Furthermore, CART affects regulation of the cardiovascular system and helps to modulate vascular tone. The present study evaluated the local effect of CART on the pancreatic and islet circulation and function. CART (25 µg/h) or saline, combinations of CART and endothelin-A receptor antagonist (BQ123; 100 µg/kg), and glucose (2 g/kg) were intravenously infused in Sprague Dawley rats followed by blood flow measurements using a microsphere technique. Separately, CART-infused animals underwent an intravenous glucose tolerance test (ivGTT). The direct effect of CART on insulin release was investigated using isolated islets from Sprague Dawley rats. CART reduced islet blood flow, without reduction in total pancreatic blood flow. The normal glucose-induced islet blood flow increase was diminished by CART, albeit still present. Simultaneously, CART had no effect on systemic-, intestinal- or renal blood flow. The endothelin-A receptor antagonist BQ123 together with CART had no pancreatic vascular effects. We found that CART has pronounced vascular constrictive actions restricted to the pancreatic islet circulation but had no effect on insulin release neither in vivo nor in vitro. The mechanisms behind the vascular effects are still unknown, but may reflect a direct action on pancreatic blood vessels.
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| 33. |
- Ekblad, Eva
(author)
-
CART in the enteric nervous system.
- 2006
-
In: Peptides. - : Elsevier BV. - 1873-5169 .- 0196-9781. ; 27:8, s. 2024-2030
-
Research review (peer-reviewed)abstract
- The expression, distribution, origin, projections, chemical coding and functions of cocaine and amphetamine-regulated transcript (CART) in the gastro-intestinal tract are reviewed. CART is extensively expressed in the enteric nervous system. Except from being a possible modulator of NO induced intestinal relaxation CART does not seem to play any pivotal role in intestinal motility. Accumulating evidence suggest CART to be neuroprotective, involved in survival and maintenance of enteric neurons. CART expression increases in atrophic intestine thus suggesting a role of CART in intestinal adaptation. In rat antral mucosa CART is expressed in gastrin cells indicating a hormonal role of gastric CART.
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| 34. |
- Fuqua, Joshua L, et al.
(author)
-
Dynamic changes in dopamine neuron function after DNSP-11 treatment: Effects in vivo and increased ERK 1/2 phosphorylation in vitro.
- 2014
-
In: Peptides. - : Elsevier BV. - 1873-5169 .- 0196-9781. ; 54:Jan 7, s. 1-8
-
Journal article (peer-reviewed)abstract
- Glial cell-line derived neurotrophic factor (GDNF) has demonstrated robust effects on dopamine (DA) neuron function and survival. A post-translational processing model of the human GDNF proprotein theorizes the formation of smaller, amidated peptide(s) from the proregion that exhibit neurobiological function, including an 11-amino-acid peptide named dopamine neuron stimulating peptide-11 (DNSP-11). A single treatment of DNSP-11 was delivered to the substantia nigra in the rat to investigate effects on DA-neuron function. Four weeks after treatment, potassium (K+) and d-amphetamine evoked DA release were studied in the striatum using microdialysis. There were no significant changes in DA-release after DNSP-11 treatment determined by microdialysis. Dopamine release was further examined in discrete regions of the striatum using high-speed chronoamperometry at 1-, 2-, and 4-weeks after DNSP-11 treatment. Two weeks after DNSP-11 treatment, potassium-evoked DA release was increased in specific subregions of the striatum. However, spontaneous locomotor activity was unchanged by DNSP-11 treatment. In addition, we show that a single treatment of DNSP-11 in the MN9D dopaminergic neuronal cell line results in phosphorylation of ERK1/2, which suggests a novel cellular mechanism responsible for increases in DA function.
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| 35. |
- Gach, Katarzyna, et al.
(author)
-
Synthesis and biological evaluation of novel peripherally active morphiceptin analogs.
- 2010
-
In: Peptides. - Amsterdam : Elsevier BV. - 1873-5169 .- 0196-9781. ; 31:8, s. 1617-1624
-
Journal article (peer-reviewed)abstract
- Morphiceptin (Tyr-Pro-Phe-Pro-NH(2)), a tetrapeptide present in the enzymatic digest of bovine beta-casein, is a selective ligand of the mu-opioid receptor. In the present study, we describe the synthesis of a series of novel morphiceptin analogs modified in positions 1-3. Two of the obtained analogs, [Dmt(1), d-Ala(2), d-1-Nal(3)]morphiceptin and [Dmt(1), d-NMeAla(2), d-1-Nal(3)]morphiceptin (Dmt-2',6'-dimethyltyrosine and d-1-Nal-3-(1-naphthyl)-d-alanine)) displayed very high mu-receptor affinity, resistance to enzymatic degradation, and remarkable supraspinally mediated analgesia, as shown in the hot-plate test after intracerebroventricular but not intravenous administration, which indicated that they could not cross the blood-brain barrier. Therefore, these two analogs were further tested in vitro and in vivo towards their possible peripheral analgesic activity and inhibitory effect on gastrointestinal (GI) motility. We report that both peptides showed strong antinociceptive effect in the writhing test after intraperitoneal administration, inhibited smooth muscle contractility in vitro and GI motility in vivo. Taken together, these findings indicate that the novel morphiceptin analogs which induce peripheral, but not central antinociception, inhibit GI transit, and possess exceptional metabolic stability, may provide an interesting approach to the development of peripherally restricted agents for the treatment of GI motility disorders, such as diarrhea or diarrhea-predominant irritable bowel syndrome.
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| 36. |
- Ghazal, Ahmad, et al.
(author)
-
Venomous gland transcriptome and venom proteomic analysis of the scorpion Androctonus amoreuxi reveal new peptides with anti-SARS-CoV-2 activity
- 2024
-
In: Peptides. - : Elsevier. - 0196-9781 .- 1873-5169. ; 173
-
Journal article (peer-reviewed)abstract
- The recent COVID-19 pandemic shows the critical need for novel broad spectrum antiviral agents. Scorpion venoms are known to contain highly bioactive peptides, several of which have demonstrated strong antiviral activity against a range of viruses. We have generated the first annotated reference transcriptome for the Androctonus amoreuxi venom gland and used high performance liquid chromatography, transcriptome mining, circular dichroism and mass spectrometric analysis to purify and characterize twelve previously undescribed venom peptides. Selected peptides were tested for binding to the receptor-binding domain (RBD) of the SARSCoV-2 spike protein and inhibition of the spike RBD - human angiotensin-converting enzyme 2 (hACE2) interaction using surface plasmon resonance-based assays. Seven peptides showed dose-dependent inhibitory effects, albeit with IC50 in the high micromolar range (117-1202 mu M). The most active peptide was synthesized using solid phase peptide synthesis and tested for its antiviral activity against SARS-CoV-2 (Lineage B.1.1.7). On exposure to the synthetic peptide of a human lung cell line infected with replication-competent SARS-CoV-2, we observed an IC50 of 200 nM, which was nearly 600-fold lower than that observed in the RBD - hACE2 binding inhibition assay. Our results show that scorpion venom peptides can inhibit the SARS-CoV-2 replication although unlikely through inhibition of spike RBD - hACE2 interaction as the primary mode of action. Scorpion venom peptides represent excellent scaffolds for design of novel anti-SARS-CoV-2 constrained peptides. Future studies should fully explore their antiviral mode of action as well as the structural dynamics of inhibition of target virushost interactions.
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| 37. |
- Ghersi, Marisa Soledad, et al.
(author)
-
Ghrelin inhibited serotonin release from hippocampal slices
- 2011
-
In: Peptides. - : Elsevier BV. - 0196-9781 .- 1873-5169. ; 32:11, s. 2367-2371
-
Journal article (peer-reviewed)abstract
- Ghrelin (Ghr) is a peptide produced peripherally and centrally. It participates in the modulation of different biological processes. In our laboratory we have shown that (a) Ghr administration, either intracerebroventricular or directly into the hippocampus enhanced memory consolidation in a step down test in rats (b) the effect of Ghr upon memory decreases in animals pretreated with a serotonin (5-HT) reuptake inhibitor, Fluoxetine, suggesting that Ghr effects in the hippocampus could be related to the availability of 5-HT. It has been demonstrated that Ghr inhibits 5-HT release from rat hypothalamic synaptosomes. Taking in mint these evidences, we studied the release of radioactive 5-HT to the superfusion medium from hippocampal slices treated with two doses of Ghr (0.3 and 3 nm/mu l). Ghr inhibited significantly the 5-HT release in relation to those superfused with artificial cerebrospinal fluid (ACSF) (H = 9.48, df = 2, p <= 0.05). In another set of experiments. Ghr was infused into the CA1 area of hippocampus of the rats immediately after training in the step down test and the 5-HT release from slices was studied 24 h after Ghr injection showing that in this condition also the 5-HT release was inhibited (H = 11.72, df = 1, p < 0.05). In conclusion, results provide additional evidence about the neurobiological bases of Ghr action in hippocampus.
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| 38. |
- Gibbons, Catherine, et al.
(author)
-
Postprandial profiles of CCK after high fat and high carbohydrate meals and the relationship to satiety in humans
- 2016
-
In: Peptides. - : Elsevier BV. - 0196-9781 .- 1873-5169. ; 77, s. 3-8
-
Journal article (peer-reviewed)abstract
- CONTEXT: CCK is understood to play a major role in appetite regulation. Difficulties in measuring CCK have limited the potential to assess its profile in relation to food-induced satiety. Improvements in methodology and progress in theoretical understanding of satiety/satiation make it timely for this to be revisited.OBJECTIVE: First, examine how physiologically relevant postprandial CCK8/33(s) profiles are influenced by fat (HF) or carbohydrate (HCHO) meals. Second, to examine relationships between postprandial CCK and profiles of satiety (hunger/fullness) and satiation (meal size).PARTICIPANTS AND DESIGN: Sixteen overweight/obese adults (11 females/5 males) participated in a randomised-crossover study (46 years, 29.8kg/m(2)) in a university research centre. Plasma was collected preprandially and for 180min postprandially. Simultaneously, ratings of hunger/fullness were tracked for 180min before an ad libitum lunch was provided.RESULTS: CCK8/33(s) levels increased more rapidly and reached a higher peak following HF compared to HCHO breakfast (F(1,15)=14.737, p<0.01). Profiles of hunger/fullness did not differ between conditions (F(1,15)=0.505, p=0.488; F(1,15)=2.277, p=0.152). There was no difference in energy intake from the ad libitum meal (HF-3958 versus HCHO-3925kJ; t(14)=0.201, p=0.844). CCK8/33(s) profiles were not associated with subjective appetite during early and late phases of satiety; nor was there an association between CCK8/33(s) and meal size.CONCLUSIONS: These results demonstrate CCK levels were higher after HF meal compared to HCHO isocaloric meal. There was no association between CCK levels and intensity of satiety, or with meal size. Under these circumstances, CCK does not appear to play a unique independent role in satiety/satiation. CCK probably acts in conjunction with other peptides and the action of the stomach.
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| 39. |
- Gonzalez, Patricia Verónica, et al.
(author)
-
Interleukin-1 beta-induced anorexia is reversed by ghrelin
- 2006
-
In: Peptides. - : Elsevier BV. - 0196-9781 .- 1873-5169. ; 27:12, s. 3220-3225
-
Journal article (peer-reviewed)abstract
- Interleukins, in particular interleukin-1β (IL-1β), reduce food intake after peripheral and central administration, which suggests that they contribute to anorexia during various infectious, neoplastic, and autoimmune diseases. On the other hand, ghrelin stimulates food intake by acting on the central nervous system (CNS) and is considered an important regulator of food intake in both rodents and humans. In the present study, we investigated if ghrelin could reverse IL-1β-induced anorexia. Intracerebroventricular (i.c.v.) injection of 15, 30 or 45 ng/μl of IL-1β caused significant suppression of food intake in 20 h fasting animals. This effect lasted for a 24 h period. Ghrelin (0.15 nmol or 1.5 nmol/μl) produced a significant increase in cumulative food intake in normally fed animals. However, it did not alter food intake in 20 h fasting animals. Central administration of ghrelin reduced the anorexic effect of IL-1β (15 ng/μl). The effect was observed 30 min after injection and lasted for the next 24 h. This study provides evidence that ghrelin is an orexigenic peptide capable of antagonizing IL-1β-induced anorexia.
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| 40. |
- Hafizi, Sassan, et al.
(author)
-
Differential response of human cardiac fibroblasts to angiotensin I and angiotensin II
- 2004
-
In: Peptides. - : Elsevier BV. - 1873-5169 .- 0196-9781. ; 25:6, s. 1031-1033
-
Journal article (peer-reviewed)abstract
- The vasoactive peptide angiotensin II (Ang II) has been implicated as a mediator of myocardial fibrosis. We carried out a comparative investigation of the effects of Ang II and its precursor Ang I on collagen metabolism and proliferation in cultured human cardiac fibroblasts. Cardiac fibroblasts responded to both Ang I and Ang II with concentration-dependent increases in collagen synthesis but no proliferation. The stimulatory effect of Ang II was abolished by the AT, receptor antagonist losartan but not the AT(2) receptor antagonist PD123319. The response to Ang I was not affected by either antagonist, nor by the angiotensin-converting enzyme (ACE) inhibitor captopril. In conclusion, Both Ang I and Ang II stimulate collagen synthesis of human cardiac fibroblasts, the effect of Ang II occurring via the AT, receptor whilst Ang I appears to exert a direct effect through non-Ang II-dependent mechanisms. These results suggest distinct roles for angiotensin peptides in the development of cardiac fibrosis. (C) 2004 Elsevier Inc. All rights reserved.
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| 41. |
- Haitina, Tatjana, et al.
(author)
-
Further evidence for ancient role of ACTH peptides at melanocortin (MC) receptors; pharmacology of dogfish and lamprey peptides at dogfish MC receptors
- 2007
-
In: Peptides. - : Elsevier BV. - 0196-9781 .- 1873-5169. ; 28:4, s. 798-805
-
Journal article (peer-reviewed)abstract
- The cloning of melanocortin (MC) receptors in distant species has provided us tools to get insight in how the ligand–receptors interactions in the MC system have evolved. We have however lacked studies on pharmacology of native ancient melanocortin peptides at the ancient MC receptors. In this paper we synthesized melanocortin peptides from both the sea lamprey (Petromyzon marinus) and spiny dogfish (Squalus acanthias) and tested them on the MC3 and MC4 receptors from spiny dogfish. The results show that both the dogfish and lamprey ACTH peptides have similar or higher affinity than the dogfish α-, β- and γ-MSH peptides to the dogfish MC3 and MC4 receptors. Moreover, both the dogfish and lamprey ACTH peptides have more than 10-fold higher affinity than α-MSH to the dogfish MC4 receptor. We also show that dogfish δ-MSH is able to bind to MC receptors and its potency is higher than of dogfish β-MSH, which is considered to be its precursor. Our results provide the first evidence that native ACTH ligands from dogfish and lamprey have a preference above native MSH peptides to ancient version of the MC3 and MC4 receptors. This further strengthens the hypotheses that the ligand contributing to the first version of the melanocortin ligand-receptor system resembled ACTH.
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| 42. |
- Hallberg, Mathias, et al.
(author)
-
The impact of chronic nandrolone decanoate administration on the expression of the NK1 receptor density in rat brain as determined by autoradiography
- 2005
-
In: Peptides. - : Elsevier BV. - 0196-9781 .- 1873-5169. ; 26:7, s. 1228-1234
-
Journal article (peer-reviewed)abstract
- Adult male Sprague–Dawley rats were treated with the anabolic androgenic steroid nandrolone decanoate (15 mg/kg day) or oil vehicle (sterile arachidis oleum) during 14 days. The effect on the densities of the neurokinin NK1 receptor in brain was examined with autoradiography. An overall tendency of attenuation of NK1 receptor density was observed after completed treatment with nandrolone decanoate. The density of the NK1 receptor was found to be significantly lower compared to control animals in the nucleus accumbens core (37% density reduction), in dentate gyrus (26%), in basolateral amygdaloid nucleus (23%), in ventromedial hypothalamic nucleus (36%), in dorsomedial hypothalamic nucleus (43%) and finally in the periaqueductal gray (PAG) (24%). In the cortex region, no structures exhibited any significant reduction of NK1 receptor density. This result provides additional support to the hypothesis that substance P and the NK1 receptor may be involved as important components that participate in mediating physiological responses including the adverse behaviors often associated with chronically administrated anabolic androgenic steroids in human.
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| 43. |
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| 44. |
- Ingves, Simon, et al.
(author)
-
A randomized cross-over study of the effects of macronutrient composition and meal frequency on GLP-1, ghrelin and energy expenditure in humans
- 2017
-
In: Peptides. - : ELSEVIER SCIENCE INC. - 0196-9781 .- 1873-5169. ; 93, s. 20-26
-
Journal article (peer-reviewed)abstract
- Objective: Little is known about human postprandial increase of energy expenditure and satiety-associated hormones in relation to both meal frequency and macronutrient composition. Design: Randomized cross-over study with four conditions for each participant. Methods: Seven men and seven women (mean age 23 +/- 1.5 years) were randomly assigned to the order of intake of a 750 kcal drink with the same protein content while having either 20 energy-percent (E%) or 55 E% from carbohydrates and the remaining energy from fat. Participants were also randomized to consume the drinks as one large beverage or as five 150 kcal portions every 30 min, starting in the fasting state in the morning. Energy expenditure (EE) was determined every 30 min by indirect calorimetry. Hormonal responses and suppression of hunger (by visual-analogue scales) were also studied. A p amp;lt; 0.013 was considered statistically significant following Bonferroni-correction. Results: The area under the curve (AUC) for EE was higher during the 2.5 h after the high-carbohydrate drinks (p = 0.005 by Wilcoxon) and also after ingesting one drink compared with five (p = 0.004). AUC for serum active GLP-1 was higher after single drinks compared with five beverages (p = 0.002). Although GLP-1 levels remained particularly high at the end of the test during the low-carbohydrate meals, the AUC did not differ compared with the high-carbohydrate occasions (low-carbohydrate: 58.9 +/- 18 pg/ml/h, high-carbohydrate: 45.2 +/- 16 pg/ml/h, p = 0.028). Hunger sensations were suppressed more after single beverages compared with five small drinks (p = 0.009). Conclusions: We found higher EE during 2.5 h following one large drink compared with five smaller beverages. Since hunger was also suppressed more efficiently, and serum GLP-1 levels were higher after one compared with five smaller drinks, our findings do not support nibbling to avoid hunger or to keep up EE from morning to noon.
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| 45. |
- Jackson, Graham E, et al.
(author)
-
Solution conformations of an insect neuropeptide : crustacean cardioactive peptide (CCAP)
- 2009
-
In: Peptides. - : Elsevier BV. - 0196-9781 .- 1873-5169. ; 30:3, s. 557-564
-
Journal article (peer-reviewed)abstract
- The solution structure of crustacean cardioactive peptide (CCAP), a cyclic amidated nonapeptide neurohormone, was studied using molecular dynamics techniques, with constraints derived from NMR studies in water and water/dodecylphosphocholine micellar medium. This peptide, found in various invertebrates, has the primary sequence Pro(1) Phe(2) Cys(3) Asn(4) Ala(5) Phe(6) Thr(7) Gly(8) Cys(9) NH(2), with an intramolecular disulfide bridge between the two cysteine residues. In aqueous solution the peptide was found to have a type(IV) beta-turn between residues 5-8. In a water/decane biphasic medium a type(IV) beta-turn between residues 3 and 6 and two classic gamma-turns between residues 4-6 and 7-9, were found. Analysis of the (1)H and (13)C NMR chemical shifts data showed that the model free S(2) order parameter of the residues varied between 0.65 and 0.9. The molecular dynamic root mean square fluctuations of structural ensembles of the backbone varied between 0.5 and 2.2 with the central residues showing the least fluctuations.
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| 46. |
- Jansen-Olesen, I, et al.
(author)
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Peptidergic and non-peptidergic innervation and vasomotor responses of human lenticulostriate and posterior cerebral arteries
- 2004
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In: Peptides. - : Elsevier BV. - 1873-5169 .- 0196-9781. ; 25:12, s. 2105-2114
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Journal article (peer-reviewed)abstract
- The aim of the present study was to compare in man the innervation pattern and the functional responses to neuronal messengers in medium sized lenticulostriate and branches of the posterior cerebral arteries (PCA). The majority of the nerve fibers found were sympathetic and displayed specific immunoreactivity for tyrosine hydroxylase (TH) and neuropeptide Y (NPY). Only few nerve fibers displayed vasoactive intestinal polypeptide (VIP), calcitonin gene-related peptide (CGRP) and substance P (SP) immunoreactivity. In both arteries. the contractions induced by noradrenaline (NA), NPY and 5-hydroxytryptarnine (5-HT) and the relaxant responses induced by acetylcholine (ACh). VIP and pituitary adenylate cyclase activating peptide-27 (PACAP) as well as CGRP and SP were compared in vitro. In conclusion. there was no major difference in innervation pattern or vasomotor sensitivity (pEC(50) and pIC(50) values) between the two vessels'. However. the general pattern indicates stronger vasomotor responses (E-max and I-max) in the PCA branches as compared to the lenticulostriate arteries which may lend support for the clinical observation of a difference in stroke expression between the two vascular areas. (C) 2004 Elsevier Inc. All rights reserved.
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| 47. |
- Johansson, Andreas, et al.
(author)
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The relative impact of chronic food restriction and acute food deprivation on plasma hormone levels and hypothalamic neuropeptide expression
- 2008
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In: Peptides. - : Elsevier BV. - 0196-9781 .- 1873-5169. ; 29:9, s. 1588-1595
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Journal article (peer-reviewed)abstract
- Our understanding of the central regulation of food intake and body weight has increased tremendously through implication of a high number of neuropeptides. However, lack of all-embracing studies have made comparison difficult in the past. The objective of this study was to demonstrate the relative importance of the different neuropeptides in terms of involvement in appetite regulatory mechanisms. We quantified expression levels of 21 hypothalamic neuropeptides and circulating levels of leptin, insulin, corticosterone, adrenocorticotropic hormone, ghrelin and adiponectin in rats after acute food deprivation and chronic food restriction using validated quantitative real-time PCR and hormone measurements. Body weight, insulin and leptin were reduced whereas corticosterone was increased by both acute food deprivation and chronic food restriction. Our results confirmed the relative importance in body weight homeostasis of neuropeptide Y and proopiomelanocortin, which were increased and decreased as predicted. The expression of other neuropeptides previously attributed central roles in body weight homeostasis, e.g. melanin-concentrating hormone and orexin, appeared to be less affected by the treatments. Moreover, the expression of dynorphin, galanin-like peptide and neuropeptide B was dramatically reduced after both treatments. This suggests that the latter neuropeptides--although previously known to be involved in body weight homeostasis--may be of unexpected importance in states of negative energy balance.
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| 48. |
- Jönsson, Maria, 1980-, et al.
(author)
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Substance P and the neurokinin-1 receptor in relation to eosinophilia in ulcerative colitis
- 2005
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In: Peptides. - : Elsevier BV. - 0196-9781 .- 1873-5169. ; 26:5, s. 799-814
-
Journal article (peer-reviewed)abstract
- Substance P (SP) has been implicated in the pathophysiology of ulcerative colitis (UC) and it has been suggested that blocking of its effect would be advantageous in this disease. Eosinophils have also been implicated in the pathophysiology of UC. In the present study, specimens from the sigmoid colon of UC patients were investigated by the use of antisera against SP and the neurokinin-1 receptor (NK-1R) and staining for demonstration of eosinophils. The degrees of SP innervation and NK-1R immunoreaction, as well as the levels of eosinophil infiltration, varied between different patients. Interestingly, NK-1R immunoreaction in the epithelium was often seen to be the most marked where there were numerous eosinophils in the underlying mucosa and where the mucosa showed a marked morphologic derangement. The observations suggest that there are marked fluctuations in effects of SP and eosinophils during the disease. The infiltrating eosinophils may be involved in the destruction of the mucosal tissue. Furthermore, for the majority of cases where there is marked derangement of the mucosa, it is apparent that there is an upregulation of the NK-1 receptor in the epithelium in parallel with the infiltration of the eosinophils.
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| 49. |
- Larsson, Tomas A, et al.
(author)
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Characterization of NPY receptor subtypes Y2 and Y7 in rainbow trout Oncorhynchus mykiss
- 2006
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In: Peptides. - : Elsevier BV. - 0196-9781 .- 1873-5169. ; 27:6, s. 1320-1327
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Journal article (peer-reviewed)abstract
- We report the cloning and pharmacological characterization of two neuropeptide Y (NPY) receptor subtypes, Y2 and Y7, in rainbow trout (Oncorhynchus mykiss). These subtypes are approximately 50% identical to each other and belong to the Y2 subfamily of NPY receptors. The binding properties of the receptors were investigated after expression in human HEK-293 EBNA cells. Both receptors bound the three zebrafish peptides NPY, PYYa, and PYYb, as well as porcine NPY and PYY, with affinities in the nanomolar range that are similar to mammalian Y2. The affinity of the truncated porcine NPY fragments, NPY 13-36 and NPY 18-36 was markedly lower compared to mammalian and chicken Y2. This suggests that mammalian and chicken Y2 are unique among NPY receptors in their ability to bind truncated peptide fragments. The antagonist BIIE0246, developed for mammalian Y2, did not bind either of the two rainbow trout receptors. Our results support the proposed expansion of this gene family by duplications before the gnathostome radiation. They also reveal appreciable differences in the repertoire and characteristics of NPY receptors between fish and tetrapods stressing the importance of lineage-specific gene loss as well as sequence divergence after duplication.
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| 50. |
- Machado, Ivana, et al.
(author)
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α-Melanocyte-stimulating hormone (α-MSH) reverses impairment of memory reconsolidation induced by interleukin-1 beta (IL-1 beta) hippocampal infusions
- 2010
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In: Peptides. - : Elsevier BV. - 0196-9781 .- 1873-5169. ; 31:11, s. 2141-2144
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Journal article (peer-reviewed)abstract
- Interleukin-1 beta (IL-1β) significantly influences cognitive processes. Treatments which raise the level of IL-1β in the brain impair memory consolidation in contextual fear conditioning. However, the effect of IL-1β on memory reconsolidation has not yet been established. The melanocortin α-melanocyte-stimulating hormone (α-MSH) exerts potent anti-inflammatory actions by antagonizing the effect of proinflammatory cytokines. Five subtypes of melanocortin receptors (MC1R-MC5R) have been identified, of which MC3R and MC4R are predominant in the central nervous system. The present experiments show that the injection of IL-1β (5 ng/0.25 μl) in dorsal hippocampus up to 30 min after re-exposition to the context decreases freezing during the contextual fear test. Impairment of memory reconsolidation was reversed by treatment with α-MSH (0.05 μg/0.25 μl). Administration of the MC4 receptor antagonist HS014 (0.5 μg/0.25 μl) blocked the effect of α-MSH. These results suggest that IL-1β may influence memory reconsolidation and that activation of central MC4R could lead to improve cognitive performance.
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