The Neuroprotective Peptide Poly-Arginine-12 (R12) Reduces Cell Surface Levels of NMDA NR2B Receptor Subunit in Cortical Neurons; Investigation into the Involvement of Endocytic Mechanisms

2016 ◽  
Vol 61 (2) ◽  
pp. 235-246 ◽  
Author(s):  
Gabriella MacDougall ◽  
Ryan S. Anderton ◽  
Adam B. Edwards ◽  
Neville W. Knuckey ◽  
Bruno P. Meloni
2004 ◽  
Vol 371 (1) ◽  
pp. 24-29 ◽  
Author(s):  
Ruth O’Donnell ◽  
Sylvain Molon-Noblot ◽  
Philippe Laroque ◽  
Michael Rigby ◽  
David Smith

2003 ◽  
Vol 89 (2) ◽  
pp. 822-832 ◽  
Author(s):  
Erik Harvey-Girard ◽  
Robert J. Dunn

The amino acid sequence of the N-methyl-d-aspartate (NMDA) receptor subunit NR2B from the brown ghost knife fish Apteronotus leptorhynchus has been determined and compared with the sequence of the murine NR2B. This comparison revealed high levels of sequence conservation throughout the ligand binding and membrane spanning segments. The functional properties of the NR1 and NR2B receptor complex were examined by coexpression in HEK cells. The recombinant AptNR1/NR2B receptors produced robust currents after stimulation with glutamate or NMDA in the presence of glycine. Measurements of the concentration dependencies for these agonists indicated that the agonist binding sites on the apteronotid receptor are highly conserved, with nearly identical agonist affinities to those of the murine NR1/NR2B receptor. The kinetic responses of the fish receptor were also highly conserved, with deactivation rates for the AptNR2B receptor matching those of the murine NR2B containing receptor. Evidently, most of the unique functional properties that reside in the NR2B receptor subunit have been well conserved in teleost NMDA receptors. On the other hand, the apteronitid receptor displayed a lowered sensitivity to voltage-dependent Mg2+ block and a reduced affinity for the NR2B-specific noncompetitive antagonist ifenprodil. We conclude that the functional properties that result from the incorporation of the NR2B receptor in the NMDA receptor complex have been maintained since the evolutionary divergence of teleost and mammalian organisms.


2006 ◽  
Vol 399 (1-2) ◽  
pp. 157-161 ◽  
Author(s):  
Paula I. Fuller ◽  
Courtney Reddrop ◽  
Jennifer Rodger ◽  
Mark C. Bellingham ◽  
Jacqueline K. Phillips

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Mukta Chakraborty ◽  
Liang-Fu Chen ◽  
Emma E. Fridel ◽  
Marguerita E. Klein ◽  
Rebecca A. Senft ◽  
...  

2004 ◽  
Vol 92 (4) ◽  
pp. 2610-2614 ◽  
Author(s):  
Leonardo Coutinho Faria ◽  
Istvan Mody

In the brain, spreading depression (SD) is characterized by a large extracellular DC shift, a massive failure of ion homeostasis and a transient cessation of neuronal function. Clinically, SD is believed to be involved in various neurological disorders including migraine and cerebrovascular diseases. The propagation of cortical SD requires the release of glutamate, and N-methyl-d-aspartate (NMDA) receptors play a crucial role in this process. Here, we have isolated the NMDA receptor-mediated component of extracellularly recorded field excitatory postsynaptic potentials (fEPSPs) in layers 2–3 of the entorhinal cortex of murine brain slices. In the absence of GABAA and AMPA receptor-mediated synaptic transmission, stimulation of layer 6 afferents every 15–90 s elicited spontaneous SD on average within 18.5 min after the start of the stimulation. In the presence of ifenprodil, an NR2B receptor subunit-selective NMDA receptor antagonist, the occurrence of SD was nearly abolished. Our results are consistent with an important role of NR2B subunits in triggering SD in the entorhinal cortex.


2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Renato Tozzoli

AbstractReceptor autoimmunity is one of the ways in which autoimmune diseases appear in humans. Graves’ disease, myasthenia gravis, idiopathic membranous nephropathy, and autoimmune acute encephalitis are the major autoimmune diseases belonging to this particular group. Receptor autoimmune disease are dependent on the presence of autoantibodies directed against cell-surface antigens, namely TSH receptor in thyrocytes, acetylcholine receptor in neuromuscular junction, phospholipase 2 receptor in podocytes, and NMDA receptor in cortical neurons. In this article we outline the distinctive features of receptor autoimmunity and the specific relationship between the autoimmunology laboratory and the presence/concentration of autoantibodies. Some immunological features distinguish receptor autoimmunity. Anti-receptor autoantibody pathologies are considered T cell-dependent, B-cell-mediated autoimmune disorders: the knowledge about the presence of circulating and/or localized autoantibodies to target organs and identification of autoantigens involved in the autoimmune reaction is of paramount importance. Due to the close correlation between the concentration of anti-receptor autoantibodies, the autoimmune target of some cell-surface receptors and the intensity of symptoms, the measurement of these immunoglobulins has become central to diagnose autoimmune diseases in all affected patients, not just in clinically dubious cases. The measurement of autoantibodies is also relevant for differential diagnosis of autoimmune and non-autoimmune forms with similar symptoms. From the methodological point of view, quantitative immunoassay methods of measurement should be preferred over semi-quantitative ones, for the capacity of the first class of methods to define precisely the reference ranges and decision levels overcoming the measurement uncertainty of semi-quantitative methods.


Sign in / Sign up

Export Citation Format

Share Document