Filamin A Binds to CCR2B and Regulates Its Internalization

The chemokine (C-C motif) receptor 2B (CCR2B) is one of the two isoforms of the receptor for monocyte chemoattractant protein-1 (CCL2), the major chemoattractant for monocytes, involved in an array of chronic inflammatory diseases. Employing the yeast two-hybrid system, we identified the actin-binding protein filamin A (FLNa) as a protein that associates with the carboxyl-terminal tail of CCR2B. Co-immunoprecipitation experiments and in vitro pull down assays demonstrated that FLNa binds constitutively to CCR2B. The colocalization of endogenous CCR2B and filamin A was detected at the surface and in internalized vesicles of THP-1 cells. In addition, CCR2B and FLNa were colocalized in lamellipodia structures of CCR2B-expressing A7 cells. Expression of the receptor in filamin-deficient M2 cells together with siRNA experiments knocking down FLNa in HEK293 cells, demonstrated that lack of FLNa delays the internalization of the receptor. Furthermore, depletion of FLNa in THP-1 monocytes by RNA interference reduced the migration of cells in response to MCP-1. Therefore, FLNa emerges as an important protein for controlling the internalization and spatial localization of the CCR2B receptor in different dynamic membrane structures

A short history of the 5-HT2C receptor: from the choroid plexus to depression, obesity and addiction treatment

This paper is a personal account on the discovery and characterization of the 5-HT2C receptor (first known as the 5- HT1C receptor) over 30 years ago and how it translated into a number of unsuspected features for a G protein-coupled receptor (GPCR) and a diversity of clinical applications. The 5-HT2C receptor is one of the most intriguing members of the GPCR superfamily. Initially referred to as 5-HT1CR, the 5-HT2CR was discovered while studying the pharmacological features and the distribution of [3H]mesulergine-labelled sites, primarily in the brain using radioligand binding and slice autoradiography. Mesulergine (SDZ CU-085), was, at the time, best defined as a ligand with serotonergic and dopaminergic properties. Autoradiographic studies showed remarkably strong [3H]mesulergine-labelling to the rat choroid plexus. [3H]mesulergine-labelled sites had pharmacological properties different from, at the time, known or purported 5-HT receptors. In spite of similarities with 5-HT2 binding, the new binding site was called 5-HT1C because of its very high affinity for 5-HT itself. Within the following 10 years, the 5-HT1CR (later named 5- HT2C) was extensively characterised pharmacologically, anatomically and functionally: it was one of the first 5-HT receptors to be sequenced and cloned. The 5-HT2CR is a GPCR, with a very complex gene structure. It constitutes a rarity in theGPCR family: many 5-HT2CR variants exist, especially in humans, due to RNA editing, in addition to a few 5-HT2CR splice variants. Intense research led to therapeutically active 5-HT2C receptor ligands, both antagonists (or inverse agonists) and agonists: keeping in mind that a number of antidepressants and antipsychotics are 5- HT2CR antagonists/inverse agonists. Agomelatine, a 5-HT2CR antagonist is registered for the treatment of major depression. The agonist Lorcaserin is registered for the treatment of aspects of obesity and has further potential in addiction, especially nicotine/ smoking. There is good evidence that the 5-HT2CR is involved in spinal cord injury-induced spasms of the lower limbs, which can be treated with 5-HT2CR antagonists/inverse agonists such as cyproheptadine or SB206553. The 5-HT2CR may play a role in schizophrenia and epilepsy. Vabicaserin, a 5-HT2CR agonist has been in development for the treatment of schizophrenia and obesity, but was stopped. As is common, there is potential for further indications for 5-HT2CR ligands, as suggested by a number of preclinical and/or genome-wide association studies (GWAS) on depression, suicide, sexual dysfunction, addictions and obesity. The 5-HT2CR is clearly affected by a number of established antidepressants/antipsychotics and may be one of the culprits in antipsychotic-induced weight gain

First operation of a 72-k element hybrid silicon micropattern pixel detector array

none57We have constructed and tested silicon pixel detector arrays of 96 × 378 (36 288) sensor elements with 75 μm × 500 μm area. The low-noise signal processing circuit associated with each element occupies an identical area on a bump-bonded readout chip. The pixel cell response for ionizing particles is binary with an adjustable threshold between 4000 e− and 15 000 e−. Single chips, the array of 6 ladders and a double array have been characterized in particle test beams and in the Omega experiment WA97 at CERN. The two arrays together, staggered by ∼ 4 mm cover hermetically a 53 mm × 55 mm area with 72 576 pixels. The proportion of properly functioning pixels was 98% in the first 36 k pixel array and 80% in the second one. The ∼ 1% “always-on” pixels could be masked electronically. After masking the rate of “spurious noise hits” was 99% was measured. Tracks were reconstructed with a precision of 22 μm. The proportion of double hits (∼ 11%) depends only slightly on threshold and detector bias voltage, and for these double hits a precision of 10 μm on the particle position was obtained.E.H.M. HEIJNE; F. ANTINORI; R. ARNOLD; D. BARBERIS; H. BEKER; W. BEUSCH; P. BURGER; M. CAMPBELL; M.G. CATANESI; E. CHESI; G. DARBO; C. DA VIA; D. DI BARI; S. DI LIBERTO; D. ELIA; C.C. ENZ; M. GLASER; J.L. GUYONNET; T. GYS; H. HELSTRUP; J. HEUSER; R. HURST; A. JACHOLKOWSKI; P. JARRON; S. KERSTEN; F. KRUMMENACHER; R. LEITNER; F. LEMEILLEUR; V. LENTI; M. LETHEREN; M. LOKAJICEK; L. LOPEZ; M. LO VETERE; G. MAGGI; P. MARTINENGO; G. MEDDELER; F. MEDDI; A. MENETREY; P. MIDDELKAMP; M. MORANDO; A. MUNNS; P. MUSICO; C. NEYER; M. PALLAVICINI; F. PELLEGRINI; F. PENGG; S. POSPISIL; E. QUERCIGH; J. RIDKY; L. ROSSI; K. SAFARIK; G. SEGATO; S. SIMONE; P. TEMPESTA; H. VERWEIJ; G.M. VIERTEL; V. VRBAE. H. M., Heijne; F., Antinori; R., Arnold; Barberis, Dario; H., Beker; W., Beusch; P., Burger; M., Campbell; M. G., Catanesi; E., Chesi; G., Darbo; C., DA VIA; D., DI BARI; S., DI LIBERTO; D., Elia; C. C., Enz; M., Glaser; J. L., Guyonnet; T., Gys; H., Helstrup; J., Heuser; R., Hurst; A., Jacholkowski; P., Jarron; S., Kersten; F., Krummenacher; R., Leitner; F., Lemeilleur; V., Lenti; M., Letheren; M., Lokajicek; L., Lopez; LO VETERE, Maurizio; G., Maggi; P., Martinengo; G., Meddeler; F., Meddi; A., Menetrey; P., Middelkamp; M., Morando; A., Munns; P., Musico; C., Neyer; Pallavicini, Marco; F., Pellegrini; F., Pengg; S., Pospisil; E., Quercigh; J., Ridky; L., Rossi; K., Safarik; G., Segato; S., Simone; P., Tempesta; H., Verweij; G. M., Viertel; V., Vrb