37 research outputs found
GPR139, an Orphan Receptor Highly Enriched in the Habenula and Septum, Is Activated by the Essential Amino Acids L-Tryptophan and L-Phenylalanine s
ABSTRACT GPR139 is an orphan G-protein-coupled receptor expressed in the central nervous system. To identify its physiologic ligand, we measured GPR139 receptor activity from recombinant cells after treatment with amino acids, orphan ligands, serum, and tissue extracts. GPR139 activity was measured using guanosine 59-O-(3-[ Sequence alignment revealed that GPR139 is highly conserved across species, and RNA sequencing studies of rat and human tissues indicated its exclusive expression in the brain and pituitary gland. Immunohistochemical analysis showed specific expression of the receptor in circumventricular regions of the habenula and septum in mice. Together, these findings suggest that L-Trp and L-Phe are candidate physiologic ligands for GPR139, and we hypothesize that this receptor may act as a sensor to detect dynamic changes of L-Trp and L-Phe in the brain
Nucleotide diversity maps reveal variation in diversity among wheat genomes and chromosomes
<p>Abstract</p> <p>Background</p> <p>A genome-wide assessment of nucleotide diversity in a polyploid species must minimize the inclusion of homoeologous sequences into diversity estimates and reliably allocate individual haplotypes into their respective genomes. The same requirements complicate the development and deployment of single nucleotide polymorphism (SNP) markers in polyploid species. We report here a strategy that satisfies these requirements and deploy it in the sequencing of genes in cultivated hexaploid wheat (<it>Triticum aestivum</it>, genomes AABBDD) and wild tetraploid wheat (<it>Triticum turgidum </it>ssp. <it>dicoccoides</it>, genomes AABB) from the putative site of wheat domestication in Turkey. Data are used to assess the distribution of diversity among and within wheat genomes and to develop a panel of SNP markers for polyploid wheat.</p> <p>Results</p> <p>Nucleotide diversity was estimated in 2114 wheat genes and was similar between the A and B genomes and reduced in the D genome. Within a genome, diversity was diminished on some chromosomes. Low diversity was always accompanied by an excess of rare alleles. A total of 5,471 SNPs was discovered in 1791 wheat genes. Totals of 1,271, 1,218, and 2,203 SNPs were discovered in 488, 463, and 641 genes of wheat putative diploid ancestors, <it>T. urartu</it>, <it>Aegilops speltoides</it>, and <it>Ae. tauschii</it>, respectively. A public database containing genome-specific primers, SNPs, and other information was constructed. A total of 987 genes with nucleotide diversity estimated in one or more of the wheat genomes was placed on an <it>Ae. tauschii </it>genetic map, and the map was superimposed on wheat deletion-bin maps. The agreement between the maps was assessed.</p> <p>Conclusions</p> <p>In a young polyploid, exemplified by <it>T. aestivum</it>, ancestral species are the primary source of genetic diversity. Low effective recombination due to self-pollination and a genetic mechanism precluding homoeologous chromosome pairing during polyploid meiosis can lead to the loss of diversity from large chromosomal regions. The net effect of these factors in <it>T. aestivum </it>is large variation in diversity among genomes and chromosomes, which impacts the development of SNP markers and their practical utility. Accumulation of new mutations in older polyploid species, such as wild emmer, results in increased diversity and its more uniform distribution across the genome.</p
Thoracic disc herniation in a patient with tethered cord and lumbar syringomyelia and diastematomyelia: magnetic resonance imaging and neurophysiological findings
STUDY DESIGN: Case report.
OBJECTIVE: To describe the diagnostic challenges in a patient suffering from thoracic disc herniation (TDH) and spina bifida complicated by multiple lumbar spinal cord abnormalities, i.e., tethered cord, lumbar syringomyelia, and diastematomyelia. SUMMARY OF BACKGROUND DATA: Advances in neuroimaging, i.e., magnetic resonance imaging, increase the sensitivity to disclose both clinically relevant but also other spine and spinal cord abnormalities. TDH accounts for less than 1% of all surgically treated disc herniations. Syringomyelia and diastematomyelia are comparably rare and present with varying degrees of spinal cord dysfunction. METHODS: A 54-year-old women presented with progressive pain and sensorimotor symptoms in the lower back and limbs. Neurologic examination revealed lower limb spastic motor deficits and spinal ataxia. Magnetic resonance imaging revealed a T6-T7 disc herniation, with spinal cord signal change in addition to a spina bifida with sacral tethered cord, lumbar syringomyelia, and diastematomyelia. Combined neurophysiological testing identified a neurologic lesion in the mid thoracic cord, with normal lower limb nerve conduction and reflex recordings, but pathologic somatosensory-evoked potential and T6 paravertebral electromyography. RESULTS: The patient was diagnosed with a clinically relevant T6-T7 disc herniation and underwent successful surgical decompression resulting in electrophysiological improvements. CONCLUSION: This unique case highlights the value of electrophysiology in the evaluation of a complex spinal disorder in a patient suffering from acquired TDH in the presence of extensive congenital spine and spinal cord abnormalities. Clinical symptoms and signs can be complemented by neurophysiological techniques to improve diagnostic accuracy and improve the basis for treatment recommendations. In cases involving multiple spinal abnormalities, a comprehensive neurophysiological assessment beyond paravertebral electromyography studies, including nerve conduction and somatosensory-evoked potential recordings, is recommended to assist in confirming the diagnosis
Rapid Synthesis of Di- and Triquinanes by Direct Reductive Fragmentation of Paterno−Büchi-Derived Oxetanes
Re-evaluation of Adrenocorticotropic Hormone and Melanocyte Stimulating Hormone Activation of GPR139 in Vitro
It is now well established that GPR139, a G-protein coupled receptor exclusively expressed in the brain and pituitary, is activated by the essential amino acids L-tryptophan (L-Trp) and L-phenylalanine (L-Phe) via Gαq-coupling. The in vitro affinity and potency values of L-Trp and L-Phe are within the physiological concentration ranges of L-Trp and L-Phe. A recent paper suggests that adrenocorticotropic hormone (ACTH), α and β melanocyte stimulating hormones (α-MSH and β-MSH) and derivatives α-MSH1-9/α-MSH1-10 can also activate GPR139 in vitro. We tested this hypothesis using guanosine 5′-O-(3-[35S]thio)-triphosphate binding (GTPγS), calcium mobilization and [3H]JNJ-63533054 radioligand binding assays. In the GTPγS binding assay, α-MSH, α-MSH1-9/α-MSH1-10, and β-MSH had no effect on [35S]GTPγS incorporation in cell membranes expressing GPR139 up to 30 μM in contrast to the concentration dependent activation produced by L-Trp, JNJ-63533054, and TC-09311 (two small molecule GPR139 agonists). ACTH slightly decreased the basal level of [35S]GTPγS incorporation at 30 μM. In the GPR139 radioligand binding assay, a moderate displacement of [3H]JNJ-63533054 binding by ACTH and β-MSH was observed at 30 μM (40 and 30%, respectively); α-MSH, α-MSH1-9/α-MSH1-10 did not displace any specific binding at 30 μM. In three different host cell lines stably expressing GPR139, α-MSH, and β-MSH did not stimulate calcium mobilization in contrast to L-Trp, JNJ-63533054, and TC-09311. ACTH, α-MSH1-9/α-MSH1-10 only weakly stimulated calcium mobilization at 30 μM (<50% of EC100). We then co-transfected GPR139 with the three melanocortin (MC) receptors (MC3R, MC4R, and MC5R) to test the hypothesis that ACTH, α-MSH, and β-MSH might stimulate calcium mobilization through a MCR/GPR139 interaction. All three MC peptides stimulated calcium response in cells co-transfected with GPR139 and MC3R, MC4R, or MC5R. The MC peptides did not stimulate calcium response in cells expressing MC3R or MC5R alone consistent with the Gs signaling transduction pathway of these receptors. In agreement with the previously reported multiple signaling pathways of MC4R, including Gq transduction pathway, the MC peptides produced a calcium response in cells expressing MC4R alone. Together, our findings do not support that GPR139 is activated by ACTH, α-MSH, and β-MSH at physiologically relevant concentration but we did unravel an in vitro interaction between GPR139 and the MCRs
Prognosis for Patients With Traumatic Cervical Spinal Cord Injury Combined With Cervical Radiculopathy
Myelin water and T(2) relaxation measurements in the healthy cervical spinal cord at 3.0T: repeatability and changes with age
Multiecho T(2) relaxation measurements offer specific information about myelin content through the myelin water fraction (MWF), as well as about the water environments through the intra- and extra-cellular (IE), and global, geometric mean T(2) (GMT(2)) times. While these measurements have yielded new insights into brain development and pathologies, they have yet to be thoroughly investigated in the spinal cord. The goals of this study were: (1) to apply a new 3D multiecho T(2) relaxation measurement in the cervical spine with sufficient axial resolution to distinguish grey and white matter; (2) to perform a pilot reliability assessment of the resulting MWF and GMT(2) measures in a target population; and (3) to detect differences in these measures between a younger cohort (20-30 years of age) and an older cohort (50-75 years of age) of healthy adults. The results demonstrated that the MWF in younger healthy adults follows the known pattern of lower myelin content in grey matter (mean (95% confidence interval)) (0.049 (0.030-0.067)) as compared to white matter (0.296 (0.275-0.317), p<0.001). The reliability coefficients were 0.65 and 0.82 for the MWF in the dorsal (DC) and lateral column (LC) white matter, respectively; 0.79 and 0.52 for the IE GMT(2); and 0.74 and 0.73 for the global GMT(2). Significantly lower MWF were found in the older adults than in the younger adults (DC p=0.014; LC p=0.012), as well as lower IE GMT(2) times (DC p=0.008; LC p=0.042), however, the global GMT(2) times did not show any differences. These changes in MWF and IE GMT(2) times, but not in global GMT(2) times, indicate that multiecho T(2) relaxation measures are sensitive to changes in myelin integrity and cell morphology that may not be apparent on conventional T(2) weighted images
Rehabilitation in spine and spinal cord trauma
STUDY DESIGN: Systematic review. OBJECTIVE: To define the optimal time for initiation of rehabilitation and review the most clinically relevant outcome measures of upper and lower limb motor function of the rehabilitating spinal cord injured patient, using a systematic review and expert opinion. SUMMARY OF BACKGROUND DATA: Comprehensive rehabilitation programs are required for patients after spinal cord injury (SCI) as early as feasible. In a dedicated SCI rehabilitation setting, effective treatment and proper monitoring of spontaneous and rehabilitation-based motor function improvements by means of appropriate, valid, reliable and internationally accepted clinical assessment tools is warranted. METHODS: Focused questions on key topics in rehabilitation of the spinal cord injured patient were defined by a panel of spine trauma surgeons. A keyword literature search for pertinent articles was conducted using multiple databases. Suitable articles were screened and the quality of evidence was graded and tabulated. Based on the evidence and expert opinion, recommendations were composed and rated as strong or weak. RESULTS: The outcome measures literature search yielded a total of 1251 abstracts. Out of these 86 articles were studied in detail. One high quality study was found with 3 articles referring to it. Furthermore, there were 19 moderate quality studies, 39 low quality studies, and 25 very low quality studies. The timing literature search yielded 508 abstracts of which 3 articles focused on the question and were all graded as low quality. CONCLUSION: For general motor function, assessing the American Spinal Injury Association motor score and the Spinal Cord Independence Measure III is strongly recommended. The American Spinal Injury Association motor score is also useful in assessing upper- and lower-extremity motor function. For ambulatory function, a timed walk test like the 10 m Walk test in combination with the Walking Index for SCI II is strongly recommended. Early rehabilitation, defined as within 30 days of injury, improves outcome and recovery for spinal cord trauma patients
The discovery and synthesis of JNJ 31020028, a small molecule antagonist of the Neuropeptide Y Y2 receptor
A series of small molecules based on a chemotype identified from our compound collection were synthesized and tested for binding affinity (IC50) at the human Neuropeptide Y Y2 receptor (NPY Y2). Six of the 23 analogs tested possessed an NPY Y2 IC50 ⩽ 15 nM. One member of this series, JNJ 31020028, is a selective, high affinity, receptor antagonist existing as a racemic mixture. As such a synthetic route to the desired enantiomer was designed starting from commercially available (S)-(+)-mandelic acid