Molecular characterisation, expression and localisation of human neurokinin-3 receptor

AbstractThe complete amino acid sequence of the human neurokinin-3 receptor was deduced by DNA sequence analysis of human genomic fragments. Comparison of the predicted primary structure with those for the human neurokinin receptors 1 and 2 shows a highly conserved pattern of seven hydrophobic regions with maximum divergence occuring at the amino- and carboxy-termini. The position of intron-exon junctions are identical to those in other reported neurokinin genes. Using a chimeric genomic-cDNA gene, the human NK-3 receptor was expressed in Xenopus laevis oocytes where it mediates membrane conductance changes in response to its agonist, neurokinin B. More significantly, expression of the gene in mammalian cells resulted in detection of receptor binding as well as neurokinin-stimulated calcium mobilization and arachidonic acid release, all displaying the pharmacological characteristics expected of a neurokinin-3 receptor, By using the polymerase chain reaction we have shown that mRNA for the human neurokinin-3 receptor is expressed predominantly in the central nervous system

Serum IL-33, a new marker predicting response to rituximab in rheumatoid arthritis

Background. Recent works have suggested a possible link between IL-33 and B-cell biology. We aimed to study in different cohorts and with an accurate ELISA assay the possible association between serum IL-33 detection and response to rituximab (RTX) in rheumatoid arthritis (RA) patients. Method. Serum IL-33, rheumatoid factor (RF), anti-citrullinated cyclic peptide antibodies (anti-CCP), high serum IgG level were assessed in 111 RA patients receiving a first course of 2 grams RTX (cohort 1) in an observational study and in 74 RA patients treated with the same schedule in routine care (cohort 2). Uni and multivariate analyzes identified factors associated with a European League Against Rheumatism response at 24 weeks. Results. At week 24, 84/111 (76%) and 54/74 (73%) patients reached EULAR response in the cohorts 1 and 2, respectively. Serum IL-33 was detectable in only 33,5% of the patients. In the combined cohorts, presence of RF or anti-CCP (OR 3.27, 95%CI [1.13-9.46]; p=0.03), high serum IgG (OR 2.32, 95%CI [1.01-5.33]; p=0.048) and detectable serum IL-33 (OR 2.40, 95%CI [1.01-5.72]; p=0.047) were all associated with RTX response in multivariate analysis. Combination of these 3 factors increased the likelihood to response to RTX. When serum IL-33 detection was added to seropositivity and serum IgG level, 100% of the patients with the 3 risk factors (corresponding to 9% of the population) responded to RTX (OR versus patients with none of the 3 risk factors = 29.61; 95% CI [1.30-674.79] p=0.034) Conclusion. Detectable serum IL-33 may predict clinical response to RTX, independently of and synergistically with autoantibodies and serum IgG level

Gene structure and chromosomal localization of the human P2X7 receptor

The genomic organization for the human P2X7 receptor gene was determined to comprise 13 exons. Alignment of the exon-intron junctions with those for the rat P2X2 gene demonstrated a precise conservation of the boundaries for the first 10 introns. The human P2X7 receptor gene was localized by in situ hybridization to chromosome 12q24. Radiation hybrid mapping indicated that this is within 130 kb of the gene for the homologous P2X4 receptor

Characterization and chromosomal localization of a human P2X receptor from the urinary bladder

A cDNA encoding an ion channel (hP2X), gated by extracellular ATP, was isolated from the human urinary bladder. It encodes a 399 amino acid protein, composed of a cysteine-rich central domain, flanked by two hydrophobic regions. A comparison of the sequence with those of the corresponding rat and mouse proteins shows predominantly conservative substitutions of hydrophilic residues. Northern blot analysis demonstrated the presence of the mRNA in several human tissues and established that the distal untranslated portion of the mRNA includes an 'expressed sequence tag' for the differentiation of the hemopoetic cell line, HL60. By fluorescent in situ hybridization the hP2X gene was mapped to the short arm of human chromosome 17. Expressed in Xenopus oocytes, the receptor was sensitive to the purinergic agonists ATP and alpha,beta-methylene ATP