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Trp
Terms modified by Trp Selected AbstractsThe calcium-conducting ion channel transient receptor potential canonical 6 is involved in macrophage inflammatory protein-2-induced migration of mouse neutrophils,ACTA PHYSIOLOGICA, Issue 1 2009N. Damann Abstract Aim:, The role of the calcium-conducting ion channel transient receptor potential canonical 6 (TRPC6) in macrophage inflammatory protein-2 (MIP-2) induced migration of mouse neutrophils was investigated. Methods:, Neutrophil granulocytes isolated from murine bone marrow of wild-type (TRPC6+/+) and TRPC6 knockout (TRPC6,/,) mice were tested for the presence of TRPC6 channel expression using quantitative real-time polymerase chain reactions and immunocytochemistry. The effect of different stimuli (e.g. MIP-2, 1-oleoyl-2-acetyl-sn-glycerol, formyl-methionyl-leucyl-phenylalanin) on migration of isolated neutrophils was tested by two-dimensional (2D) migration assays, phalloidin staining and intracellular calcium imaging. Results:, We found that neutrophil granulocytes express TRPC6 channels. MIP-2 induced fast cell migration of isolated neutrophils in a 2D cell-tracking system. Strikingly, MIP-2 was less potent in neutrophils derived from TRPC6,/, mice. These cells showed less phalloidin-coupled fluorescence and the pattern of cytosolic calcium transients was altered. Conclusions:, We describe in this paper for the first time a role for transient receptor potential (TRP) channels in migration of native lymphocytes as a new paradigm for the universal functional role of TRPs. Our data give strong evidence that TRPC6 operates downstream to CXC-type Gq -protein-coupled chemokine receptors upon stimulation with MIP-2 and is crucial for the arrangement of filamentous actin in migrating neutrophils. This is a novel cell function of TRP channel beyond their well-recognized role as universal cell sensors. [source] Transient concentration of a ,-tubulin-related protein with a pericentrin-related protein in the formation of basal bodies and flagella during the differentiation of Naegleria gruberiCYTOSKELETON, Issue 2 2002Mi Ra Suh Abstract The distribution of two proteins in Naegleria gruberi, N-,TRP (Naegleria ,-tubulin-related protein) and N-PRP (Naegleria pericentrin-related protein), was examined during the de novo formation of basal bodies and flagella that occurs during the differentiation of N. gruberi. After the initiation of differentiation, N-,TRP and N-PRP began to concentrate at the same site within cells. The percentage of cells with a concentrated region of N-,TRP and N-PRP was maximal (68%) at 40 min when the synthesis of tubulin had just started but no assembled microtubules were visible. When concentrated tubulin became visible (60 min), the region of concentrated N-,TRP and N-PRP was co-localized with the tubulin spot and then flagella began to elongate from the region of concentrated tubulin. When cells had elongated flagella, the concentrated N-,TRP and N-PRP were translocated to the opposite end of the flagellated cells and disappeared. The transient concentration of N-,TRP coincided with the transient formation of an F-actin spot at which N-,TRP and ,-tubulin mRNA were co-localized. The concentration of N-,TRP and formation of the F-actin spot occurred without the formation of microtubules but were inhibited by cytochalasin D. These observations suggest that the regional concentration of N-,TRP and N-PRP is mediated by actin filaments and might provide a site of microtubule nucleation for the assembly of newly synthesized tubulins into basal bodies and flagella. Cell Motil. Cytoskeleton 52:66,81, 2002. © 2002 Wiley-Liss, Inc. [source] Altered Tryptophan Metabolism in the Brain of Cystatin B -Deficient Mice: A Model System for Progressive Myoclonus EpilepsyEPILEPSIA, Issue 10 2006Annika Vaarmann Summary:,Purpose: Progressive myoclonus epilepsy of the Unverricht,Lundborg type (EPM1) is a rare neurologic disorder, associated with mutations in the Cystatin B (Cstb) gene. Mice lacking Cstb, a cysteine protease inhibitor of the cathepsine family of proteases, provide a mammalian model for EPM1 by displaying similarly progressive ataxia, myoclonic seizures, and neurodegeneration. However, the linkage of Cstb deficit on the molecular level to pathologic features like myoclonic jerks or tonic,clonic seizures has remained unclear. We examined the tryptophan (TRP) metabolism, along the serotonin (5HT) and kynurenine (KYN) pathway in the brain of Cstb -deficient mice, in relation to their possible involvement in the seizure phenotype. Methods: TRP and its metabolites, along the 5HT and KYN pathways, were assayed in brain tissue by high-pressure liquid chromatography (HPLC) with electrochemical detection. The inverted wire grid and mild handling tests were used for evaluation of ataxia and myoclonic activity. Results: The Cstb -deficient mice had constitutively increased TRP, 5HT, and 5-hydroxyindole acetic acid (5HIAA) levels in the cerebral cortex and cerebellum and increased levels of KYN in the cerebellum. These neurochemical changes were accompanied with ataxia and an apparent myoclonic phenotype among the Cstb -deficient mice. Conclusions: Our findings suggest that secondary processes (i.e., overstimulation of serotoninergic transmission) on the cellular level, initiated by Cstb deficiency in specific brain regions, may be responsible for the myoclonic/seizure phenotype in EPM1. [source] Transient receptor potential A1 mediates acetaldehyde-evoked pain sensationEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 9 2007Sangsu Bang Abstract Six transient receptor potential (TRP) ion channels expressed in the sensory afferents play an important role as body thermosensors and also as peripheral pain detectors. It is known that a number of natural compounds specifically activate those sensory neuronal TRP channels, and a well-known example is cinnamaldehyde for TRPA1. Here we show that human and mouse TRPA1 are activated by acetaldehyde, an intermediate substance of ethanol metabolism, in the HEK293T cell heterologous expression system and in cultured mouse trigeminal neurons. Acetaldehyde failed to activate other temperature-sensitive TRP channels expressed in sensory neurons. TRPA1 antagonists camphor and gadolinium, and a general TRP blocker ruthenium red inhibited TRPA1 activation by acetaldehyde. Camphor, gadolinium and ruthenium red also suppressed the acute nociceptive behaviors induced by the intradermal administration of acetaldehyde into the mouse footpads. Intradermal co-application of prostaglandin E2 and acetaldehyde greatly potentiated the acetaldehyde-induced nociceptive responses, and this effect was reversed by treatment with the TRPA1 antagonist camphor. These results suggest that acetaldehyde causes nociception via TRPA1 activation. Our data may also help elucidate the mechanisms underlying acetaldehyde-related pathological symptoms such as hangover pain. [source] Inherent flammability parameters,Room corner test applicationFIRE AND MATERIALS, Issue 8 2009J. G. Quintiere Abstract It has been hypothesized that four parameters are solely responsible for a material's performance in a flammability scenario. This excludes effects of material physical integrity, i.e. melting, delamination, etc. They are (1) the critical heat flux below which piloted ignition cannot occur (CHF), (2) the ratio of heat of combustion to heat of gasification (HRP), (3) the thermal response parameter related to the thermal inertia and the ignition temperature (TRP), and (4) the available energy per unit area (AEP). The fire scenario controls the process by its initial heat flux and region of ignition. The hypothesis is applied to 54 tests of the ISO Room Corner Test to assess its validity. It is shown that these four parameters give good correlations in predicting the time to flashover and whether it occurs. In principle, different correlations could be developed for other scenarios of tests and fire configurations. Copyright © 2009 John Wiley & Sons, Ltd. [source] Loudness dependence of evoked dipole source activity during acute serotonin challenge in femalesHUMAN PSYCHOPHARMACOLOGY: CLINICAL AND EXPERIMENTAL, Issue 1 2008Christine Norra Abstract Objectives Direct challenge of cortical serotonergic (5-hydroxytryptamine, 5-HT) availability by tryptophan depletion test (TDT) was used to assess the hypothesized inverse relationship between central 5-HT function and loudness dependence of auditory evoked potentials (LDAEPs). Gender must be taken into particular account here, since there are gender differences in 5-HT brain synthesis, with women reacting more strongly to TDT. Methods In a double-blind, controlled cross-over study, 16 healthy females were ingested two highly concentrated amino acid mixtures with (+TRP) or without TRP (,TRP). While monitoring TRP levels and mood states, the AEP of different loudness stimuli were recorded, followed by dipole source analysis. Results Under the ,TRP condition, free plasma TRP levels decreased by 81.10% (±5.14). Most of the loudness change rates of the relevant N1/P2 tangential dipole activities were significantly increased under ,TRP, but calculated LDAEP did not differ significantly between treatments. LDAEP and states of mood were not correlated. Conclusions Despite strong TRP depletion, the results did not reach sufficient evidence that LDAEP is a valid biological marker of central 5-HT activity in females when using TDT. This agrees with the literature and supports the view that LDAEP indicates predominantly biological vulnerability in predisposed individuals. Copyright © 2007 John Wiley & Sons, Ltd. [source] Effects of dietary l -tryptophan and lighting conditions on growth performance of European sea bass (Dicentrarchus labrax) juveniles reared in a recirculating water systemJOURNAL OF APPLIED ICHTHYOLOGY, Issue 6 2005S. E. Papoutsoglou Summary The aim of the present study was to investigate possible stressful effects on European sea bass Dicentrarchus labrax reared under constant darkness (0L-24D) and to examine the possible anti-stressful effect of dietary tryptophan (TRP) supplementation. Juvenile European sea bass (initial body weight 4.23 ± 0.032 g) were reared for 10 weeks under 0L-24D and 12L-12D and fed either a commercial diet (0.47% TRP) or the same diet supplemented with L-TRP (2.47% TRP). Results showed that lighting conditions had no significant effect on fish growth, while a depressive effect by the TRP supplementation was obvious. All fish populations reared under 0L-24D exhibited reduced body protein, lipid and ash content and increased food consumption. Reduced body lipids, food consumption and nutrient utilization were observed in TRP-supplemented fed fish, along with lower liver lipids. Dietary TRP enrichment significantly lowered liver saturated and monounsaturated acids and increased poly- and highly-unsaturated fatty acids, especially in combination with 0L-24D. These changes were also considerably reflected in carcass fatty acid composition. [source] Differentiation dependent expression of TRPA1 and TRPM8 channels in IMR-32 human neuroblastoma cellsJOURNAL OF CELLULAR PHYSIOLOGY, Issue 1 2009Lauri M. Louhivuori TRPA1 and TRPM8 are transient receptor potential (TRP) channels involved in sensory perception. TRPA1 is a non-selective calcium permeable channel activated by irritants and proalgesic agents. TRPM8 reacts to chemical cooling agents such as menthol. The human neuroblastoma cell line IMR-32 undergoes a remarkable differentiation in response to treatment with 5-bromo-2-deoxyuridine. The cells acquire a neuronal morphology with increased expression of N-type voltage gated calcium channels and neurotransmitters. Here we show using RT-PCR, that mRNA for TRPA1 and TRPM8 are strongly upregulated in differentiating IMR-32 cells. Using whole cell patch clamp recordings, we demonstrate that activators of these channels, wasabi, allyl-isothiocyanate (AITC) and menthol activate membrane currents in differentiated cells. Calcium imaging experiments demonstrated that AITC mediated elevation of intracellular calcium levels were attenuated by ruthenium red, spermine, and HC-030031 as well as by siRNA directed against the channel. This indicates that the detected mRNA level correlate with the presence of functional channels of both types in the membrane of differentiated cells. Although the differentiated IMR-32 cells responded to cooling many of the cells showing this response did not respond to TRPA1/TRPM8 channel activators (60% and 90% for AITC and menthol respectively). Conversely many of the cells responding to these activators did not respond to cooling (30%). This suggests that these channels have also other functions than cold perception in these cells. Furthermore, our results suggest that IMR-32 cells have sensory characteristics and can be used to study native TRPA1 and TRPM8 channel function as well as developmental expression. J. Cell. Physiol. 221: 67,74, 2009. © 2009 Wiley-Liss, Inc [source] Identification, physiological actions, and distribution of TPSGFLGMRamide: a novel tachykinin-related peptide from the midgut and stomatogastric nervous system of Cancer crabsJOURNAL OF NEUROCHEMISTRY, Issue 5 2007Elizabeth A. Stemmler Abstract In most invertebrates, multiple species-specific isoforms of tachykinin-related peptide (TRP) are common. In contrast, only a single conserved TRP isoform, APSGFLGMRamide, has been documented in decapod crustaceans, leading to the hypothesis that it is the sole TRP present in this arthropod order. Previous studies of crustacean TRPs have focused on neuronal tissue, but the recent demonstration of TRPs in midgut epithelial cells in Cancer species led us to question whether other TRPs are present in the gut, as is the case in insects. Using direct tissue matrix assisted laser desorption/ionization Fourier transform mass spectrometry, in combination with sustained off-resonance irradiation collision-induced dissociation, we found that at least one additional TRP is present in Cancer irroratus, Cancer borealis, Cancer magister, and Cancer productus. The novel TRP isoform, TPSGFLGMRamide, was present not only in the midgut, but also in the stomatogastric nervous system (STNS). In addition, we identified an unprocessed TRP precursor APSGFLGMRG, which was detected in midgut tissues only. TRP immunohistochemistry, in combination with preadsorption studies, suggests that APSGFLGMRamide and TPSGFLGMRamide are co-localized in the stomatogastric ganglion (STG), which is contained within the STNS. Exogenous application of TPSGFLGMRamide to the STG elicited a pyloric motor pattern that was identical to that elicited by APSGFLGMRamide, whereas APSGFLGMRG did not alter the pyloric motor pattern. [source] Ethanol inhibits cold-menthol receptor TRPM8 by modulating its interaction with membrane phosphatidylinositol 4,5-bisphosphateJOURNAL OF NEUROCHEMISTRY, Issue 1 2007Jan Benedikt Abstract Ethanol has opposite effects on two members of the transient receptor potential (TRP) family of ion channels: it inhibits the cold-menthol receptor TRPM8, whereas it potentiates the activity of the heat- and capsaicin-gated vanilloid receptor TRPV1. Both thermosensitive cation channels are critically regulated by the membrane lipid, phosphatidylinositol 4,5-bisphosphate (PIP2). The effects of this phospholipid on TRPM8 and TRPV1 are also functionally opposite: PIP2 is necessary for the activation of TRPM8 but it constitutively inhibits TRPV1. This parallel led us to investigate the possible role of PIP2 in the ethanol-induced modulation of rat TRPM8, heterologously expressed in HEK293T cells. In this study, we characterize the effects of ethanol (0.1,10%) on whole-cell currents produced by menthol and by low temperature (< 17°C). We show that the inclusion of PIP2 in the intracellular solution results in a strong reduction in the ethanol-induced inhibition of menthol-evoked responses. Conversely, intracellular dialysis with anti-PIP2 antibody or with the PIP2 scavenger, poly l -lysine, enhanced the ethanol-induced inhibition of TRPM8. A 20 min pre-incubation with wortmannin caused a modest decrease in inhibition produced by 1% ethanol, indicating that the ethanol-induced inhibition is not mediated by lipid kinases. These findings suggest that ethanol inhibits TRPM8 by weakening the PIP2,TRPM8 channel interaction; a similar mechanism may contribute to the ethanol-mediated modulation of some other PIP2 -sensitive TRP channels. [source] Inhibitory effects of 5-chloroacetyl-2-piperidino-1,3-selenazole, a novel selenium-containing compound, on skin melanin biosynthesisJOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 3 2010Eunjoo H. Lee Abstract Objectives Increased production and accumulation of melanin leads to many hyperpigmentation disorders such as melasma, freckles and geriatric pigment spots. Thus, there is a need for the development of depigmenting agents. Based on our previous reports, selenium derivatives as anti-melanogenic lead compounds could be very important. The aim of this study was to investigate the depigmenting effect of novel selenium-containing compounds. Methods The inhibitory effects of 5-chloroacetyl-2-piperidino-1,3-selenazole (CS1), a novel selenium-containing compound, on melanogenesis were investigated in B16F10 melanoma cells and cultured brownish guinea pig skin tissue with ,-melanocyte-stimulating hormone stimulation. Key findings We found that CS1 inhibited melanin production in B16F10 cells by suppressing tyrosinase activity and its protein expression. In addition, Western blotting analysis revealed that CS1 suppressed the expression of tyrosinase-related protein (TRP)-1 and TRP-2. Therefore, the depigmenting effect of CS1 might have been due to inhibition of tyrosinase activity and expression of melanogenic enzymes. Furthermore, CS1 had inhibitory effects on melanin biosynthesis of primary cultured skin of brownish guinea pig. Conclusions The results suggested that CS1 could be a useful candidate for the treatment of skin hyperpigmentation. [source] Phosphate-solubilizing potential of the nematophagous fungus Arthrobotrys oligosporaJOURNAL OF PLANT NUTRITION AND SOIL SCIENCE, Issue 2 2006Robin Duponnois Abstract The nematophagous fungus Arthrobotrys oligospora was tested in vitro and in vivo for its ability to solubilize rock phosphate. Three types of rock phosphate (RP) from Burkina Faso (KRP), Senegal (TRP), and Mali (TIRP) were used at four concentrations for the in-vitro experiment. All three types of RP were solubilized by the fungus. The maximum quantity of P recovered in solution was obtained with TRP, 12.5% for an application of 1 g L,1. The effect of TRP and A. oligospora applied separately or in combination was tested in vivo on the growth of A. holosericea. In a P-deficient soil without addition of RP, P solubilization was increased by addition of A. oligospora. The P uptake by plants growing in soil amended with TRP and inoculated with A. oligospora was significantly higher compared to noninoculated controls, thus demonstrating the ability of the fungus to solubilize additional phosphate from RP in vivo. [source] Sensor Mechanism and Afferent Signal Transduction of the Urinary Bladder: Special Focus on transient receptor potential Ion ChannelsLUTS, Issue 2 2010Masayuki TAKEDA In the urine storage phase, mechanical stretch stimulates bladder afferents. These urinary bladder afferent sensory nerves consist of small diameter A, - and C-fibers running in the hypogastic and pelvic nerves. Neuroanatomical studies have revealed a complex neuronal network within the bladder wall. The exact mechanisms that underline mechano-sensory transduction in bladder afferent terminals remain ambiguous; however, a wide range of ion channels (e.g. TTX-resistant Na+ channels, Kv channels and hyperpolarization-activated cyclic nucleotidegated cation channels, degenerin/epithelial Na+ channel), and receptors (e.g. TRPV1, TRPM8, TRPA1, P2X2/3, etc.) have been identified at bladder afferent terminals and have implicated in the generation and modulation of afferent signals, which are elcited by a wide range of bladder stimulations including physiological bladder filling, noxious distension, cold, chemical irritation and inflammation. The mammalian transient receptor potential (TRP) family consists of 28 channels that can be subdivided into six different classes: TRPV (Vanilloid), TRPC (Canonical), TRPM (Melastatin), TRPP (Polycystin), TRPML (Mucolipin), and TRPA (Ankyrin). TRP channels are activated by a diversity of physical (voltage, heat, cold, mechanical stress) or chemical (pH, osmolality) stimuli and by binding of specific ligands, enabling them to act as multifunctional sensors at the cellular level. TRPV1, TRPV2, TRPV4, TRPM8, and TRPA1 have been described in different parts of the urogenital tract. Although only TRPV1 among TRPs has been extensively studied so far, more evidence is slowly accumulating about the role of other TRP channels, ion channels, and receptors in the pathophysiology of the urogenital tract, and may provide a new strategy for the treatment of bladder dysfunction. [source] TRP channels as therapeutic targets: hot property, or time to cool down?NEUROGASTROENTEROLOGY & MOTILITY, Issue 8 2006G. A. Hicks Abstract,Transient receptor potential (TRP) channels are involved in a wide range of processes ranging from osmoregulation, thermal, chemical and sensory signalling, and potentially in the pathophysiology associated with several diseases. Patents for TRPV1 antagonists alone span diseases ranging across chronic pain, neuropathies, headache, bladder disorders, irritable bowel syndrome (IBS), gastro-oesophageal reflux disease (GORD), and cough amongst others. Most research is currently focused around those TRP channels involved in sensory processes, with the neurogastroenterology and motility field playing a major role, for example, through recent discoveries of differential roles for TRPV receptor subtypes in chemosensitivity and mechanosensitivity of visceral afferents. At this time, however, the understanding of the role of even TRPV1, let alone most of the other TRP channels in disease pathophysiology is only just beginning, and although enthusiasm around the therapeutic potential for modulators of these channels is understandable, based largely upon the experience of the effects of natural ligands, such as capsaicin, the sheer size and complexity of the TRP family as a whole must serve as a warning against expecting too much too soon from drug discovery efforts. [source] GDNF Expression in Terminal Schwann Cells Associated With the Periodontal Ruffini Endings of the Rat Incisors During Nerve RegenerationTHE ANATOMICAL RECORD : ADVANCES IN INTEGRATIVE ANATOMY AND EVOLUTIONARY BIOLOGY, Issue 8 2009Megumi Ohishi Abstract The terminal Schwann cells (TSCs) which play crucial roles in regeneration of the periodontal Ruffini endings (RE) exhibit immunoreaction for glial cell line-derived neurotrophic factor (GDNF). However, no information is available regarding the role of GDNF in the periodontal RE during nerve regeneration. This study was undertaken to examine the changes in GDNF expression in the rat periodontal RE following transection of the inferior alveolar nerve (IAN) using immunohistochemistry for GDNF and S-100 protein, a marker for the TSCs. We additionally investigated the changes in expression of GDNF in the trigeminal ganglion (TG) at protein and mRNA levels. A transection to IAN induced a disappearance of the TSCs from the alveolus-related part (ARP), followed by a migration of spindle-shaped cells with S-100 but without GDNF immunoreactions into the tooth-related part (TRP) by postoperative (PO) week 2. At PO week 2, GDNF immunoreacted cellular elements increased in number in the ARP although the spindle-shaped cells without GDNF reaction remained in the TRP. After PO week 4, many GDNF-positive TSCs appeared in the ARP though the spindle-shaped cells vanished from the TRP. A real time RT-PCR analysis demonstrated the highest elevation of GDNF mRNA in the TG at PO week 2. These findings suggested the involvement of this molecule in the maturation and maintenance of the periodontal RE during regeneration. Taken together with our previous and current studies, it appears that the regeneration of the periodontal RE is controlled by multiple neurotrophins in a stage-specific manner. Anat Rec, 2009. © 2009 Wiley-Liss, Inc. [source] Multiple regulation by calcium of murine homologues of transient receptor potential proteins TRPC6 and TRPC7 expressed in HEK293 cellsTHE JOURNAL OF PHYSIOLOGY, Issue 2 2004Juan Shi We investigated, by using the patch clamp technique, Ca2+ -mediated regulation of heterologously expressed TRPC6 and TRPC7 proteins in HEK293 cells, two closely related homologues of the transient receptor potential (TRP) family and molecular candidates for native receptor-operated Ca2+ entry channels. With nystatin-perforated recording, the magnitude and time courses of activation and inactivation of carbachol (CCh; 100 ,m)-activated TRPC6 currents (ITRPC6) were enhanced and accelerated, respectively, by extracellular Ca2+ (Ca2o+) whether it was continuously present or applied after receptor stimulation. In contrast, Ca2o+ solely inhibited TRPC7 currents (ITRPC7). Vigorous buffering of intracellular Ca2+ (Ca2i+) under conventional whole-cell clamp abolished the slow potentiating (i.e. accelerated activation) and inactivating effects of Ca2o+, disclosing fast potentiation (EC50: ,0.4 mm) and inhibition (IC50: ,4 mm) of ITRPC6 and fast inhibition (IC50: ,0.4 mm) of ITRPC7. This inhibition of ITRPC6 and ITRPC7 seems to be associated with voltage-dependent reductions of unitary conductance and open probability at the single channel level, whereas the potentiation of ITRPC6 showed little voltage dependence and was mimicked by Sr2+ but not Ba2+. The activation process of ITRPC6 or its acceleration by Ca2o+ probably involves phosphorylation by calmodulin (CaM)-dependent kinase II (CaMKII), as pretreatment with calmidazolium (3 ,m), coexpression of Ca2+ -insesentive mutant CaM, and intracellular perfusion of the non-hydrolysable ATP analogue AMP-PNP and a CaMKII-specific inhibitory peptide all effectively prevented channel activation. However, this was not observed for TRPC7. Instead, single CCh-activated TRPC7 channel activity was concentration-dependently suppressed by nanomolar Ca2i+ via CaM and conversely enhanced by IP3. In addition, the inactivation time course of ITRPC6 was significantly retarded by pharmacological inhibition of protein kinase C (PKC). These results collectively suggest that TRPC6 and 7 channels are multiply regulated by Ca2+ from both sides of the membrane through differential Ca2+,CaM-dependent and -independent mechanisms. [source] Gene Transfer of TRPC6DN (Dominant Negative) Restores Erectile Function in Diabetic RatsTHE JOURNAL OF SEXUAL MEDICINE, Issue 3 2010Jae Hun Jung MD ABSTRACT Introduction., Transient receptor potential (TRP) channels play an important role in modulating intracellular Ca2+ ([Ca2+]i) levels. Aim., We examined the hypothesis that overexpression of TRPC6DN (dominant negative) may contribute to decreased [Ca2+]i levels in corporal smooth muscle (CSM). We also investigated whether gene transfer of TRPC6DN could restore erectile function in diabetic rats. Methods., For the in vitro study, the KCa, KATP, and TRPC6DN channel genes were transferred using cDNA, into cultured human CSM cells and human embryonic kidney cells. For the in vivo study, young adult rats were divided into three groups: normal controls; diabetic controls transfected with vector only; and a diabetic group transfected with pcDNA of the TRPC6DN gene. Main Outcome Measures., After gene transfer, the effects of reducing [Ca2+]i levels were assessed by Fura-2-based imaging analysis. The intracavernosal pressure (ICP) response to cavernosal nerve stimulation was assessed after intracorporal injection of TRPC6DN pcDNA. The transgene expression of the TRPC6DN was examined by reverse transcription polymerase chain reaction (RT-PCR) in rats transfected with TRPC6DN pcDNA. Results., Gene transfer of ion channels effectively reduced [Ca2+]i. Among these channels, transfer of the TRPC6DN gene resulted in the greatest reduction of [Ca2+]i in human CSM. The mean (±standard error of the mean) ratio of ICP to mean arterial pressure (BP) in the gene-transfer rats was 79.4 ± 2.4% (N = 8). This was significantly higher than that in control rats (55.6 ± 3.7% [N = 8]), and similar to that in the young control rats (83 ± 2.2% [N = 12]). The RT-PCR showed expression of TRPC6DN genes in the transfected rats. Conclusion., Gene transfer of TRPC6DN not only reduced [Ca2+]i in human CSM but also restored erectile function in diabetic rats. These results suggest that pcDNA transfer of TRPC6DN may represent a promising new form of therapy for the treatment of male erectile dysfunction in the future. Jung JH, Kim BJ, Chae MR, Kam SC, Jeon J-H, So I, Chung KH, and Lee SW. Gene transfer of TRPC6DN (dominant negative) restores erectile function in diabetic rats. J Sex Med 2010;7:1126,1138. [source] A possible role of central serotonin in L-tryptophan-induced GH secretion in cattleANIMAL SCIENCE JOURNAL, Issue 3 2010Etsuko KASUYA ABSTRACT To clarify the role of serotonin (5-HT) in the regulatory mechanism of L-tryptophan (TRP)-induced growth hormone (GH) secretion in cattle, changes in 5-HT concentrations in the cerebrospinal fluid (CSF) in the third ventricle (3V) and GH in plasma before and after the peripheral infusion of TRP were determined simultaneously. The direct effect of TRP on GH release from the dispersed anterior pituitary cells was also assessed. A chronic cannula was placed in 3V by stereotaxic surgery, then CSF and blood were withdrawn under physiological conditions. TRP (38.5 mg/kg BW) was infused through an intravenous catheter from 12.00 to 14.00 hours and CSF and blood sampling were performed from 11.00 to 18.00 hours at 1-h intervals. The concentration of 5-HT in CSF was determined by high-performance liquid chromatography with electrochemical detection. GH, melatonin (MEL), and cortisol (CORT) concentrations were measured by radio-immunoassay and enzyme-immunoassay. Concentrations of 5-HT were increased by TRP infusion. The TRP infusion significantly increased GH release. On the other hand, TRP did not stimulate GH release from the bovine pituitary cells. MEL and CORT concentrations were not altered by TRP infusion. These results suggest that TRP induced GH release via the activation of serotonergic neurons in cattle. [source] Synthesis and Antidepressant Evaluation of Five Novel Heterocyclic Tryptophan-Hybrid DerivativesARCHIV DER PHARMAZIE, Issue 5 2010Gamal A. Elmegeed Abstract This study aimed at evaluating the reactivity of L -Tryptophan (TRP) 1 towards various chemical reagents to produce new bi- and tri-heterocyclic systems providing basic pharmacological activities. Indol-3-yl hydroxyoxazol-2-yl acetonitrile derivatives 5 and 6, indol-3-yl-hydroxyoxazol-2-yl-1,2,4-triazine derivatives 8 and 9, indol-3-yl-hydroxyoxazol-2-yl-aminopyrazole derivatives 11a, b, and indol-3-yl-hydroxyoxazol-2-yl-aminoisoxazole derivative 12 were synthesized via straightforward and efficient methods. The structures were characterized by spectral data (IR, 1H-NMR, 13C-NMR, and MS) and the purity was ascertained by microanalysis. Also, this work was extended to study the potential role of the novel synthesized TRP derivatives 5, 6, 9, 11a, and 12 as antidepressant and sedative agents in comparison with TRP. All compounds showed significant antidepressant activity in the forced-swimming test at two doses (50 or 100 mg/kg). Also, all tested compounds (at 50 or 100 mg/kg) produced a significant decrease in locomotor activity of mice during a 30 min observation period. The most potent antidepressant and sedative effect was produced by the tri-heterocyclic compounds 9 and 12, followed by 11a and TRP. [source] TRPM1: The endpoint of the mGluR6 signal transduction cascade in retinal ON-bipolar cellsBIOESSAYS, Issue 7 2010Catherine W. Morgans Abstract For almost 30 years the ion channel that initiates the ON visual pathway in vertebrate vision has remained elusive. Recent findings now indicate that the pathway, which begins with unbinding of glutamate from the metabotropic glutamate receptor 6 (mGluR6), ends with the opening of the transient receptor potential (TRP)M1 cation channel. As a component of the mGluR6 signal transduction pathway, mutations in TRPM1 would be expected to cause congenital stationary night blindness (CSNB), and several such mutations have already been identified in CSNB families. Furthermore, expression of TRPM1 in both the retina and skin raises the possibility that a genetic link exists between certain types of visual and skin disorders. [source] Maternal cardiac function and uterine artery Doppler at 11,14 weeks in the prediction of pre-eclampsia in nulliparous womenBJOG : AN INTERNATIONAL JOURNAL OF OBSTETRICS & GYNAECOLOGY, Issue 3 2008A Khaw Objective, To assess maternal cardiac function in nulliparous women in the first trimester of pregnancy and evaluate its potential role for predicting pre-eclampsia and small for gestational age (SGA). Design, Prospective, observational, cross-sectional study. Setting, Maternity unit of a teaching hospital. Population, Nulliparous women with singleton pregnancies presenting consecutively for routine antenatal care (n= 534). Methods, Two-dimensional and M-mode echocardiography and uterine artery Dopplers were carried out at 11-14 weeks. Main outcome measures, Cardiac output (CO), stroke volume (SV), mean arterial pressure (MAP), total vascular resistance and uterine artery pulsatility index (UAPI) were compared in four outcome groups according to the development of pre-eclampsia and/or SGA. Results, Compared with the normal outcome group (n= 457), in those with pre-eclampsia but not SGA (n = 8), CO and MAP were increased; in the group with pre-eclampsia and SGA (n= 19) MAP, TRP and UAPI were increased and in the group with SGA but no pre-eclampsia (n= 50) total peripheral resistance and UAPI were increased. Independent predictors of pre-eclampsia were MAP, SV and UAPI and of SGA SV and UAPI. Conclusions, Alterations in maternal cardiac function and UAPI are observed in the first trimester of pregnancy in nulliparous women that subsequently develop pre-eclampsia and/or SGA. [source] Inhibition of TRPM2 function by PARP inhibitors protects cells from oxidative stress-induced deathBRITISH JOURNAL OF PHARMACOLOGY, Issue 5 2004Barbara A Miller TRPM2 is a member of the transient receptor potential (TRP) protein superfamily of calcium-permeable, voltage-independent ion channels expressed in nonexcitable cells. Activation of TRPM2 by oxidative stress results in calcium influx and susceptibility to cell death, whereas inhibition of TRPM2 function enhances cell survival. In the present edition of this journal, Fonfria et al. demonstrate a role for poly(ADP ribose) polymerase (PARP) as a mediator between oxidative stress and TRPM2 activation. They present evidence that inhibition of either PARP or TRPM2 protects cells from plasma membrane damage and cell death. The therapeutic implications of this important observation are discussed. British Journal of Pharmacology (2004) 143, 515,516. doi:10.1038/sj.bjp.0705923 [source] 3133: Planar patch-clamping in human corneal endothelial cells: a new tool for clinical application?ACTA OPHTHALMOLOGICA, Issue 2010S MERGLER Purpose Identification of apoptotic or damaged human corneal endothelial cells (HCECs) is limited to morphological evaluation such as phase contrast microscopy and vital staining. The molecular mechanisms of corneal endothelial cell loss are not fully understood. Special investigations in cellular signalling and ion channel research are necessary to elucidate the mechanisms of corneal cell loss. In this context, it is known that this cell loss is often caused by apoptosis in oxidative stress. Methods Automated planar patch-clamp has become common in drug development and safety programs because it enables efficient and systematic testing of compounds against ion channels during voltage-clamp. A particularly successful automated approach is based on planar patch-clamp chips and this is the basis for the technology used here. Routine intracellular or extracellular perfusion opens possibilities for studying the regulation and pharmacology of ion channels. Previously, these studies were available only to highly skilled and dedicated experimenters. Results Notable, definite ion channel activities could be demonstrated by conventional as well as by planar patch-clamp in HCECs for the first time. In particular, temperature-sensing transient receptor potential (TRP)-like non-selective cation channel currents as well as capsaicin-sensitive ion channel currents could be detected. The expression of TRPV1-3 ion channels in HCEC could also be confirmed by RT-PCR, Western blot analysis and fluorescence cell imaging. Conclusion The administration of this novel measuring technology opens new perspectives in the investigation of the physiology of HCEC. The findings may have direct clinical implication (eye banking procedures, keratoplasty). [source] 4,-PDD induces Ca2+ influx in human corneal epithelial cells by activating TRPV4 channelsACTA OPHTHALMOLOGICA, Issue 2007S MERGLER Purpose: Transient receptor potential (TRP) isoform expression is evident in human corneal epithelial cells (HCEC-SV40). However, their role in maintaining corneal epithelial homeostasis is not fully understood. We probed for gene and protein expression as well as functional activity of the vanilloid subtype, TRPV4, in immortalized HCEC-SV40 since they elicit Ca2+ dependent regulatory volume decrease (RVD) responses during exposure to a hypotonic challenge. Methods: RT-PCR and Western blotting analyses identified TRPV4 gene and protein expression. Functional activity was assessed based on determining whether the TRPV4 selective agonist, 4,-PDD, induced transients increases in intracellular Ca2+ concentration. Results: Single cell fluorescence imaging results showed that 4,-PDD (3 ,M) increased intracellular Ca2+ concentration. The fura2 fluorescence ratio (f340/f380) was 0.39 ± 0.03578 in the resting state (n = 5). After application of 4,-PDD it increased to 0.904 ± 0.14363 (n = 5; p = 5.72077×10-5). This increase was abolished by the TRP channel blocker ruthenium red or by Ca2+-free Ringer's medium. Conclusions: In conclusion, there is functional TRPV4 expression in HCEC-SV40. TRPV4 expression may provide an osmosensor role to induce RVD behavior during exposure to a hypotonic challenge since this response is mediated through intracellular Ca2+ transients. Supported in part DFG Pl 150/14-1 and NIH, EY04795. CR: none [source] Spectroscopic Study on Interaction of , -Cyclodextrin with Triprolidine HydrochlorideCHINESE JOURNAL OF CHEMISTRY, Issue 5 2006Syed Mashhood Ali Abstract The complexation of triprolidine hydrochloride (TRP) and , -cyclodextrin (, -CD) in deuterium oxide was investigated by 400 MHz 1H NMR spectroscopy. The 800 MHz 2D ROESY data revealed that two 1:1 and one 2:1 , -CD-TRP inclusion complexes were formed. Both aromatic moieties (p -tolyl and pyridyl ring) has entered into the , -CD cavity, confirming the existence of two different equilibria for 1:1 inclusion complexes in which p -tolyl ring of the guest is more tightly held by the host cavity. The ROE intermolecular interactions provided the plausible structures of these 1:1 and 2:1 stoichiometric inclusion complexes of , -CD-triprolidine hydrochloride in solution. [source] Myofascial Trigger Points, Neck Mobility, and Forward Head Posture in Episodic Tension-Type HeadacheHEADACHE, Issue 5 2007César Fernández-de-las-Peñas PT Objective.,To assess the differences in the presence of trigger points (TrPs) in head and neck muscles, forward head posture (FHP) and neck mobility between episodic tension-type headache (ETTH) subjects and healthy controls. In addition, we assess the relationship between these muscle TrPs, FHP, neck mobility, and several clinical variables concerning the intensity and the temporal profile of headache. Background.,TTH is a headache in which musculoskeletal disorders of the craniocervical region might play an important role in its pathogenesis. Design.,A blinded, controlled pilot study. Methods.,Fifteen ETTH subjects and 15 matched controls without headache were studied. TrPs in both upper trapezius, both sternocleidomastoids, and both temporalis muscles were identified according to Simons and Gerwin diagnostic criteria (tenderness in a hypersensible spot within a palpable taut band, local twitch response elicited by snapping palpation, and elicited referred pain with palpation). Side-view pictures of each subject were taken in both sitting and standing positions, in order to assess FHP by measuring the craniovertebral angle. A cervical goniometer was employed to measure neck mobility. All measures were taken by a blinded assessor. A headache diary was kept for 4 weeks in order to assess headache intensity, frequency, and duration. Results.,The mean number of TrPs for each ETTH subject was 3.7 (SD: 1.3), of which 1.9 (SD: 0.9) were active, and 1.8 (SD: 0.9) were latent. Control subjects only had latent TrPs (mean: 1.5; SD: 1). TrP occurrence between the 2 groups was significantly different for active TrPs (P < .001), but not for latent TrPs (P > .05). Differences in the distribution of TrPs were significant for the right upper trapezius muscles (P= .04), the left sternocleidomastoid (P= .03), and both temporalis muscles (P < .001). Within the ETTH group, headache intensity, frequency, and duration outcomes did not differ depending on TrP activity, whether the TrP was active or latent. The craniovertebral angle was smaller, ie, there was a greater FHP, in ETTH patients than in healthy controls for both sitting and standing positions (P < .05). ETTH subjects with active TrPs in the analyzed muscles had a greater FHP than those with latent TrPs in both sitting and standing positions, though differences were only significant for certain muscles. Finally, ETTH patients also showed lesser neck mobility than healthy controls in the total range of motion as well as in half-cycles (except for cervical extension), although neck mobility did not seem to influence headache parameters. Conclusions.,Active TrPs in the upper trapezius, sternocleidomastoid, and temporalis muscles were more common in ETTH subjects than in healthy controls, although TrP activity was not related to any clinical variable concerning the intensity and the temporal profile of headache. ETTH patients showed greater FHP and lesser neck mobility than healthy controls, although both disorders were not correlated with headache parameters. [source] Improved Voltammetric Response of L -Tyrosine on Multiwalled Carbon Nanotubes-Ionic Liquid Composite Coated Glassy Electrodes in the Presence of Cupric IonELECTROANALYSIS, Issue 19 2008Liqin Liu Abstract L -Tyrosine can exhibit a small anodic peak on multiwalled carbon nanotubes (MWCNTs) coated glassy carbon electrodes (GCE). At pH,5.5 its peak potential is 0.70,V (vs. SCE). When an ionic liquid (i.e., 1-octyl-3-methylimidazolium hexafluorophosphate, [omim][PF6]) is introduced on the MWCNT coat, the peak becomes bigger. Furthermore, in the presence of Cu2+ ion the anodic peak of L -tyrosine increases further due to the formation of Cu2+ - L -tyrosine complex, while the peak potential keeps unchanged. Therefore, a sensitive voltammetry based on the oxidation of Cu2+ - L -tyrosine complex on MWCNTs-[omim][PF6] composite coated electrode is developed for L -tyrosine. Under the optimized conditions, the anodic peak current is linear to L -tyrosine concentration in the range of 1×10,8,5×10,6 M, and the detection limit is 8×10,9 M. The modified electrode shows good reproducibility and stability. In addition, the voltammetric behavior of other amino acids is explored. It is found that among them tryptophan (Trp) and histidine (His) can also produce sensitive anodic peak under same experimental conditions, and their detection limits are 4×10,9 M and 4×10,6 M, respectively. [source] Preparation of Novel Arrays Silver Nanoparticles Modified Polyrutin Coat-Paraffin-Impregnated Graphite Electrode for Tyrosine and Tryptophan's OxidationELECTROANALYSIS, Issue 8 2008Guan-Ping Jin Abstract A novel array silver nanoparticles and Rutin complex film modified paraffin-impregnated graphite electrode was proposed in this work (denoted as Ag/Rutin/WGE). The characteristics were investigated by the field emission scanning electron microscopy (FE-SEM), infrared spectra (IR), UV-visible (UV), X-ray photoelectron spectroscopy (XPS) and electrochemical techniques. Silver ions were gradually chelated by polyrutin film at 4,-oxo-5,-OH and 5-OH-4-oxo sites accompanying adsorption, then. Silver nanoparticles were highly-dispersed electrodeposited on polyrutin film. The electrochemical behaviors of tyrosine (Tyr) and tryptophan (Trp) were studied by cyclic voltammetry (CV) and differential pulse voltammetry (DPV) techniques. The Ag/Rutin/WGE electrode shows overlapping catalysis for the oxidation of Tyr and Trp. The linear response of Tyr and Trp were 0.3,10.0 and 0.7,70.0,,M with detection limit of 0.07 and 0.1,,M in a signal-to-noise ratio of 3. [source] Simultaneous and Direct Determination of Tryptophan and Tyrosine at Boron-Doped Diamond ElectrodeELECTROANALYSIS, Issue 8 2006Guohua Zhao Abstract A facile method for the simultaneous measurement of tryptophan (Trp) and tyrosine (Tyr) was firstly exploited at unmodified boron-doped diamond (BDD) electrode. The experimental results indicated that by using differential pulse voltammetry, the oxidative peaks of these two kinds of amino acids could be completely separated at BDD electrode. The peak separation of Trp and Tyr was developed to be 0.64,V when Na2PO4/NaOH buffer solution with the optimized pH,11.2 was employed. The detection limit of Trp was obtained to be 1×10,5,M, while that of Tyr was achieved to be 1×10,6,M. The present method was also evidenced to be available to the determination of real samples of amino acids. [source] Multifunctional host defense peptides: intracellular-targeting antimicrobial peptidesFEBS JOURNAL, Issue 22 2009Pierre Nicolas There is widespread acceptance that cationic antimicrobial peptides, apart from their membrane-permeabilizing/disrupting properties, also operate through interactions with intracellular targets, or disruption of key cellular processes. Examples of intracellular activity include inhibition of DNA and protein synthesis, inhibition of chaperone-assisted protein folding and enzymatic activity, and inhibition of cytoplasmic membrane septum formation and cell wall synthesis. The purpose of this minireview is to question some widely held views about intracellular-targeting antimicrobial peptides. In particular, I focus on the relative contributions of intracellular targeting and membrane disruption to the overall killing strategy of antimicrobial peptides, as well as on mechanisms whereby some peptides are able to translocate spontaneously across the plasma membrane. Currently, there are no more than three peptides that have been convincingly demonstrated to enter microbial cells without the involvement of stereospecific interactions with a receptor/docking molecule and, once in the cell, to interfere with cellular functions. From the limited data currently available, it seems unlikely that this property, which is isolated in particular peptide families, is also shared by the hundreds of naturally occurring antimicrobial peptides that differ in length, amino acid composition, sequence, hydrophobicity, amphipathicity, and membrane-bound conformation. Microbial cell entry and/or membrane damage associated with membrane phase/transient pore or long-lived transitions could be a feature common to intracellular-targeting antimicrobial peptides and mammalian cell-penetrating peptides that have an overrepresentation of one or two amino acids, i.e. Trp and Pro, His, or Arg. Differences in membrane lipid composition, as well as differential lipid recruitment by peptides, may provide a basis for microbial cell killing on one hand, and mammalian cell passage on the other. [source] | ||||||||||||||||||||||||||||||||||||||||