The Multivalency of the glucocorticoid receptor ligand-binding domain explains its manifold physiological activities

The glucocorticoid receptor (GR) is a ubiquitously expressed transcription factor that controls metabolic and homeostatic processes essential for life. Although numerous crystal structures of the GR ligand-binding domain (GR-LBD) have been reported, the functional oligomeric state of the full-length receptor, which is essential for its transcriptional activity, remains disputed. Here we present five new crystal structures of agonist-bound GR-LBD, along with a thorough analysis of previous structural work. We identify four distinct homodimerization interfaces on the GR-LBD surface, which can associate into 20 topologically different homodimers. Biologically relevant homodimers were identified by studying a battery of GR point mutants including crosslinking assays in solution, quantitative fluorescence microscopy in living cells, and transcriptomic analyses. Our results highlight the relevance of non-canonical dimerization modes for GR, especially of contacts made by loop L1-3 residues such as Tyr545. Our work illustrates the unique flexibility of GR's LBD and suggests different dimeric conformations within cells. In addition, we unveil pathophysiologically relevant quaternary assemblies of the receptor with important implications for glucocorticoid action and drug design

Producing morphologically complex words: An ERP study with children and adults

A widely studied morphological phenomenon in psycholinguistic research is the plurals-inside-compounds effect in English, which is the avoidance of regular plural modifiers within compounds (e.g., *rats hunter). The current study employs event-related brain potentials (ERPs) to investigate the production of plurals-inside-compounds in children and adults. We specifically examined the ERP correlates of producing morphologically complex words in 8-year-olds, 12-year-olds and adults, by recording ERPs during the silent production of compounds with plural or singular modifiers. Results for both children and adults revealed a negativity in response to compounds produced from regular plural forms when compared to compounds formed from irregular plurals, indicating a highly specific brain response to a subtle linguistic contrast. Although children performed behaviourally with an adult-like pattern in the task, we found a broader distribution and a considerably later latency in children's brain potentials than in adults’, indicating that even in late childhood the brain networks involved in language processing are subject to subtle developmental changes

Functional oropharyngeal sensory disruption interferes with the cortical control of swallowing

<p>Abstract</p> <p>Background</p> <p>Sensory input is crucial to the initiation and modulation of swallowing. From a clinical point of view, oropharyngeal sensory deficits have been shown to be an important cause of dysphagia and aspiration in stroke patients. In the present study we therefore investigated effects of functional oropharyngeal disruption on the cortical control of swallowing. We employed whole-head MEG to study cortical activity during self-paced volitional swallowing with and without topical oropharyngeal anesthesia in ten healthy subjects. A simple swallowing screening-test confirmed that anesthesia caused swallowing difficulties with decreased swallowing speed and reduced volume per swallow in all subjects investigated. Data were analyzed by means of synthetic aperture magnetometry (SAM) and the group analysis of the individual SAM data was performed using a permutation test.</p> <p>Results</p> <p>The analysis of normal swallowing revealed bilateral activation of the mid-lateral primary sensorimotor cortex. Oropharyngeal anesthesia led to a pronounced decrease of both sensory and motor activation.</p> <p>Conclusion</p> <p>Our results suggest that a short-term decrease in oropharyngeal sensory input impedes the cortical control of swallowing. Apart from diminished sensory activity, a reduced activation of the primary motor cortex was found. These findings facilitate our understanding of the pathophysiology of dysphagia.</p

Antigen-Specific Blocking of CD4-Specific Immunological Synapse Formation Using BPI and Current Therapies for Autoimmune Diseases

This is the peer reviewed version of the following article: Manikwar, P., Kiptoo, P., Badawi, A. H., Büyüktimkin, B. and Siahaan, T. J. (2012), Antigen-specific blocking of CD4-Specific immunological synapse formation using BPI and current therapies for autoimmune diseases. Med Res Rev, 32: 727–764. doi:10.1002/med.20243, which has been published in final form at http://doi.org/10.1002/med.20243. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.In this review, we discuss T-cell activation, etiology, and the current therapies of autoimmune diseases (i.e., MS, T1D, and RA). T-cells are activated upon interaction with antigen-presenting cells (APC) followed by a “bull’s eye”-like formation of the immunological synapse (IS) at the T-cell–APC interface. Although the various disease-modifying therapies developed so far have been shown to modulate the IS and thus help in the management of these diseases, they are also known to present some undesirable side effects. In this study, we describe a novel and selective way to suppress autoimmunity by using a bifunctional peptide inhibitor (BPI). BPI uses an intercellular adhesion molecule-1 (ICAM-1)-binding peptide to target antigenic peptides (e.g., proteolipid peptide, glutamic acid decarboxylase, and type II collagen) to the APC and therefore modulate the immune response. The central hypothesis is that BPI blocks the IS formation by simultaneously binding to major histocompatibility complex-II and ICAM-1 on the APC and selectively alters the activation of T cells from TH1 to Treg and/or TH2 phenotypes, leading to tolerance

The multivalency of the glucocorticoid receptor ligand-binding domain explains its manifold physiological activities

20 páginas, 7 figurasThe glucocorticoid receptor (GR) is a ubiquitously expressed transcription factor that controls metabolic and homeostatic processes essential for life. Although numerous crystal structures of the GR ligand-binding domain (GR-LBD) have been reported, the functional oligomeric state of the full-length receptor, which is essential for its transcriptional activity, remains disputed. Here we present five new crystal structures of agonist-bound GR-LBD, along with a thorough analysis of previous structural work. We identify four distinct homodimerization interfaces on the GR-LBD surface, which can associate into 20 topologically different homodimers. Biologically relevant homodimers were identified by studying a battery of GR point mutants including crosslinking assays in solution, quantitative fluorescence microscopy in living cells, and transcriptomic analyses. Our results highlight the relevance of non-canonical dimerization modes for GR, especially of contacts made by loop L1-3 residues such as Tyr545. Our work illustrates the unique flexibility of GR's LBD and suggests different dimeric conformations within cells. In addition, we unveil pathophysiologically relevant quaternary assemblies of the receptor with important implications for glucocorticoid action and drug designE.E.-P. thanks the generosity of the Gemma E. Carretero Fund; MINECO [BFU2017-86906-R, SAF2017-71878-REDT, SAF2015-71878-REDT to E.E.-P., RTI2018-101500-B-I00 to P.F.-P., RTI2018-096735-B-100 to A.R.M., PID2019-110167RB-I00 to J.F.-R., SAF2017-89510-R to A.V.F. and C.C.]; G.L.H thanks the NIH Intramural Research Program; D.M.P was supported by CONICET. Funding for open access charge: Spanish Ministry of Science (MINECO).Peer reviewe

A922 Sequential measurement of 1 hour creatinine clearance (1-CRCL) in critically ill patients at risk of acute kidney injury (AKI)

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Demographic, clinical and antibody characteristics of patients with digital ulcers in systemic sclerosis: data from the DUO Registry

OBJECTIVES: The Digital Ulcers Outcome (DUO) Registry was designed to describe the clinical and antibody characteristics, disease course and outcomes of patients with digital ulcers associated with systemic sclerosis (SSc). METHODS: The DUO Registry is a European, prospective, multicentre, observational, registry of SSc patients with ongoing digital ulcer disease, irrespective of treatment regimen. Data collected included demographics, SSc duration, SSc subset, internal organ manifestations, autoantibodies, previous and ongoing interventions and complications related to digital ulcers. RESULTS: Up to 19 November 2010 a total of 2439 patients had enrolled into the registry. Most were classified as either limited cutaneous SSc (lcSSc; 52.2%) or diffuse cutaneous SSc (dcSSc; 36.9%). Digital ulcers developed earlier in patients with dcSSc compared with lcSSc. Almost all patients (95.7%) tested positive for antinuclear antibodies, 45.2% for anti-scleroderma-70 and 43.6% for anticentromere antibodies (ACA). The first digital ulcer in the anti-scleroderma-70-positive patient cohort occurred approximately 5 years earlier than the ACA-positive patient group. CONCLUSIONS: This study provides data from a large cohort of SSc patients with a history of digital ulcers. The early occurrence and high frequency of digital ulcer complications are especially seen in patients with dcSSc and/or anti-scleroderma-70 antibodies

Human gene therapy approaches for the treatment of Parkinson\u27s disease: An overview of current and completed clinical trials

Gene therapy has been employed in the human brain for a number of disorders in clinical trials and may serve as an avenue for the treatment of Parkinson\u27s disease (PD). Several gene therapy treatment strategies have been developed and evaluated in patients with PD. Three main strategies have been used-enhancement of dopamine synthesis, expression of trophic factors, and neuromodulation. Typically, genes are delivered via viral vectors and expressed within neurons in PD-relevant areas of the brain such as the striatum. These methods of gene delivery have the potential for long-term expression and may only need to be delivered once. Notably, current gene therapy strategies do not address the non-motor symptoms of PD and do not curtail α-synuclein aggregation/spread. Furthermore, many of the completed trials were open-label trials and are subject to placebo effects and bias. Clinical trials have, however, demonstrated safety and studies are ongoing. Here, we review the current landscape of the development of gene therapy for PD and discuss the future of this novel treatment strategy