Mutations in KCNK4 that Affect Gating Cause a Recognizable Neurodevelopmental Syndrome

Aberrant activation or inhibition of potassium (K+) currents across the plasma membrane of cells has been causally linked to altered neurotransmission, cardiac arrhythmias, endocrine dysfunction, and (more rarely) perturbed developmental processes. The K+ channel subfamily K member 4 (KCNK4), also known as TRAAK (TWIK-related arachidonic acid-stimulated K+ channel), belongs to the mechano-gated ion channels of the TRAAK/TREK subfamily of two-pore-domain (K2P) K+ channels. While K2P channels are well known to contribute to the resting membrane potential and cellular excitability, their involvement in pathophysiological processes remains largely uncharacterized. We report that de novo missense mutations in KCNK4 cause a recognizable syndrome with a distinctive facial gestalt, for which we propose the acronym FHEIG (facial dysmorphism, hypertrichosis, epilepsy, intellectual disability/developmental delay, and gingival overgrowth). Patch-clamp analyses documented a significant gain of function of the identified KCNK4 channel mutants basally and impaired sensitivity to mechanical stimulation and arachidonic acid. Co-expression experiments indicated a dominant behavior of the disease-causing mutations. Molecular dynamics simulations consistently indicated that mutations favor sealing of the lateral intramembrane fenestration that has been proposed to negatively control K+ flow by allowing lipid access to the central cavity of the channel. Overall, our findings illustrate the pleiotropic effect of dysregulated KCNK4 function and provide support to the hypothesis of a gating mechanism based on the lateral fenestrations of K2P channels

Specific Recognition of the Viral Protein UL18 by CD85j/LIR-1/ILT2 on CD8+ T Cells Mediates the Non-MHC-Restricted Lysis of Human Cytomegalovirus-Infected Cells

Abstract Immune evasion mechanisms of human CMV are known; however, the immune control of infection remains poorly elucidated. We show that interaction between the viral protein UL18 on infected cells and the invariant receptor CD85j/LIR-1/ILT2 expressed on CTL is relevant for the control of infection. Resting and activated CD8+ T cells lysed UL18 expressing cells, whereas cells infected with CMV defective for UL18 were not killed. Lysis was not dependent on CD8+ T cell Ag specificity, MHC-unrestricted and specifically blocked by anti-CD85j and anti-UL18 mAb. Moreover, soluble recombinant UL18Fc immunoprecipitated CD85j from T cells. Activation is mediated by CD85j and its pathway is unrelated to CD3/TCR engagement. UL18 is detected in immunocompromised patients with productive infection and the mechanism used in vivo by human CMV to ensure survival of the immunocompetent host may be mediated by activation signals delivered by infected cells to T lymphocytes via UL18/CD85j interactions

Pontine tegmental cap dysplasia: developmental and cognitive outcome in three adolescent patients

Pontine Tegmental Cap Dysplasia (PTCD) is a recently described, rare disorder characterized by a peculiar cerebellar and brainstem malformation. Nineteen patients have been reported to date, of which only one in the adolescent age, and data on the clinical, cognitive and behavioural outcome of this syndrome are scarce

Receptor Heteromerization Expands the Repertoire of Cannabinoid Signaling in Rodent Neurons

A fundamental question in G protein coupled receptor biology is how a single ligand acting at a specific receptor is able to induce a range of signaling that results in a variety of physiological responses. We focused on Type 1 cannabinoid receptor (CB1R) as a model GPCR involved in a variety of processes spanning from analgesia and euphoria to neuronal development, survival and differentiation. We examined receptor dimerization as a possible mechanism underlying expanded signaling responses by a single ligand and focused on interactions between CB1R and delta opioid receptor (DOR). Using co-immunoprecipitation assays as well as analysis of changes in receptor subcellular localization upon co-expression, we show that CB1R and DOR form receptor heteromers. We find that heteromerization affects receptor signaling since the potency of the CB1R ligand to stimulate G-protein activity is increased in the absence of DOR, suggesting that the decrease in CB1R activity in the presence of DOR could, at least in part, be due to heteromerization. We also find that the decrease in activity is associated with enhanced PLC-dependent recruitment of arrestin3 to the CB1R-DOR complex, suggesting that interaction with DOR enhances arrestin-mediated CB1R desensitization. Additionally, presence of DOR facilitates signaling via a new CB1R-mediated anti-apoptotic pathway leading to enhanced neuronal survival. Taken together, these results support a role for CB1R-DOR heteromerization in diversification of endocannabinoid signaling and highlight the importance of heteromer-directed signal trafficking in enhancing the repertoire of GPCR signaling

Natural history of KBG syndrome in a large European cohort

KBG syndrome (KBGS) is characterized by distinctive facial gestalt, short stature and variable clinical findings. With ageing, some features become more recognizable, allowing a differential diagnosis. We aimed to better characterize natural history of KBGS. In the context of a European collaborative study, we collected the largest cohort of KBGS patients (49). A combined array- based Comparative Genomic Hybridization and next generation sequencing (NGS) approach investigated both genomic Copy Number Variants and SNVs. Intellectual disability (ID) (82%) ranged from mild to moderate with severe ID identified in two patients. Epilepsy was present in 26.5%. Short stature was consistent over time, while occipitofrontal circumference (median value: -0.88 SD at birth) normalized over years. Cerebral anomalies, were identified in 56% of patients and thus represented the second most relevant clinical feature reinforcing clinical suspicion in the paediatric age when short stature and vertebral/dental anomalies are vague. Macrodontia, oligodontia and dental agenesis (53%) were almost as frequent as skeletal anomalies, such as brachydactyly, short fifth finger, fifth finger clinodactyly, pectus excavatum/carinatum, delayed bone age. In 28.5% of individuals, prenatal ultrasound anomalies were reported. Except for three splicing variants, leading to a premature termination, variants were almost all frameshift. Our results, broadening the spectrum of KBGS phenotype progression, provide useful tools to facilitate differential diagnosis and improve clinical management. We suggest to consider a wider range of dental anomalies before excluding diagnosis and to perform a careful odontoiatric/ear-nose-throat (ENT) evaluation in order to look for even submucosal palate cleft given the high percentage of palate abnormalities. NGS approaches, following evidence of antenatal ultrasound anomalies, should include ANKRD11.</p

Global Administrative Law: An Italian perspective

This Policy Paper collects a set of contributions given and discussed at the Conference on “Global Administrative Law: an Italian Perspective”, European University Institute, Global Governance Programme, 24 February 2012. The purpose of the conference was to present the work of a group of Italian scholars who have, to date, written more than a hundred articles or books on Global Administrative Law (GAL), and have been or are engaged in around ten collective enterprises on the subject. After a brief introduction by Sabino Cassese, in which the main features of GAL and its significance are examined, nine contributions deal with a high number of legal issues raised by globalization and global governance. All of them adopt a GAL approach in order to tame and frame relevant topics such as the role of administrative law beyond the State (Stefano Battini), courts acting as global regulators (Elisa D’Alterio), the global governance after the financial crisis (Giulio Napolitano), the global financial regulation (Maurizia De Bellis), global rules of public procurement (Hilde Caroli Casavola) and procurement regimes of international organizations (Elisabetta Morlino), global sports law (Lorenzo Casini), the relationships between GAL and EU administrative law (Edoardo Chiti) the transgovernmental power at the European and global level (Mario Savino). This Policy Paper aims at contributing to one of the most significant intellectual enterprise of 21st century, i.e. framing, understanding and explaining the legal implications of globalization. From this perspective, works here presented clearly show that public and administrative law can be very useful, but they must be studied solely in their usual paradigms. These latter were developed in national contexts as a set of values, principles, and rules necessary to the proper functioning of domestic institutions: they cannot be transposed mechanically to the global legal space and they must be adapted to such a different endeavor.-- What is Global Administrative Law and why study it?, Sabino Cassese 1 -- Administrative Law Beyond the State, Stefano Battini 11 -- Courts as Global Regulators? The Judicial Regulation in the GAL Perspective, Elisa D’Alterio 19 -- The ‘puzzle’ of global governance after the financial crisis, Giulio Napolitano 31 -- Global Financial Regulation. The Challenges Ahead and GAL, Maurizia De Bellis 41 -- Global Rules on Public Procurement, Hilde Caroli Casavola 51 -- Procurement Regimes of International Organizations, Elisabetta Morlino 59 -- Towards global administrative systems? The case of sport, Lorenzo Casini 69 -- GAL and EU administrative law. A research agenda, Edoardo Chiti 81 -- The Transgovernmental Power in the EU and Beyond: A Dangerous Branch?, Mario Savino 8

Inhibitory Receptors CD85j, LAIR-1, and CD152 Down-Regulate Immunoglobulin and Cytokine Production by Human B Lymphocytes

Class switching consists in the substitution of the heavy-chain constant region of immunoglobulin M (IgM) with that of IgG, IgA, or IgE. This enables antibodies to acquire new effector functions that are crucial to combat invading pathogens. Class switching usually requires engagement of CD40 on B cells by CD40 ligand (CD40L) on antigen-activated CD4(+) T cells and the production of cytokines. The process must be regulated tightly because abnormal IgG and IgA production favors the onset of autoimmunity, whereas increased switching to IgE leads to atopy. These inflammatory disorders can be triggered or exacerbated by costimulatory signals. Although thoroughly investigated on T cells, the roles of the inhibitory receptors CD85j, LAIR-1, and CD152 on B-cell functions have not been fully elucidated. In this study we show that cross-linking of the B-cell inhibitory receptors by specific monoclonal antibodies inhibits IgG and IgE production, reduces the percentage of IgG- and IgE-expressing B cells, and down-regulates interleukin 8 (IL-8), IL-10, and tumor necrosis factor alpha production. These effects were demonstrated using different B-cell stimulatory pathways (recall antigens, CD40L-transfected cells plus IL-4, and lipopolysaccharide plus IL-4). It thus appears that CD85j, LAIR-1, and CD152 play a central role for the control of IL-4-driven isotype switching