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Receptor B (receptor + b)
Selected AbstractsEndothelin System in Human Persistent and Paroxysmal Atrial FibrillationJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 7 2001BIANCA J.J.M. BRUNDEL Ph.D. Endothelin System in Atrial Fibrillation. Introduction: Activation of the endothelin system is an important compensatory mechanism that is activated during left ventricular dysfunction. Whether this system plays a role at the atrial level during atrial fibrillation (AF) has not been examined in detail. The purpose of this study was to investigate mRNA and protein expression levels of the endothelin system in AF patients with and without concomitant underlying valve disease. Methods and Results: Right atrial appendages of 36 patients with either paroxysmal or persistent AF were compared with 36 controls in sinus rhythm. The mRNA amounts of pro-endothelin-1 (pro-ET-1), endothelin receptor A (ET-A), and endothelin receptor B (ET-B) were studied by semiquantitative polymerase chain reaction. Protein amounts of the receptors were investigated by slot-blot analysis. mRNA amounts of pro-ET-1 were increased (+ 40%; P = 0.002) only in AF patients with underlying valve disease. ET-A and ET-B receptor protein amounts were significantly reduced in patients with paroxysmal AF (,39% and ,47%, respectively) and persistent AF with underlying valve disease (, 28% and , 30%, respectively) and in persistent AF without valve disease (,20% and ,40%, respectively). ET-A mRNA expression was unaltered in paroxysmal and persistent AF, whereas ET-B mRNA was reduced by 30% in persistent AF with (P < 0.001) or without (P = 0.04) valve disease, but unchanged in paroxysmal AF. Conclusion: Substantial changes in gene expression of the endothelin system were observed in human atria during AF, especially in the presence of underlying valve disease. Alterations in endothelin expression associated with AF could play a role in the pathophysiology of AF and the progression of underlying heart disease. [source] Expression of Interleukin-8 Receptor A Predicts Poor Outcome in Patients With Nasopharyngeal Carcinoma,THE LARYNGOSCOPE, Issue 1 2005Toshiyuki Horikawa MD Abstract Objectives/Hypothesis: The authors recently demonstrated that interleukin-8 (IL-8) is induced by Epstein-Barr virus encoding latent membrane protein 1 and that IL-8 is overexpressed in tumor cells and correlates significantly with angiogenesis in nasopharyngeal carcinoma. The present objective was to investigate the expressions and the roles of IL-8 receptors in nasopharyngeal carcinoma. Study Design: Retrospective patient file review and immunohistochemical study of tissues of patients with nasopharyngeal carcinoma. Methods: The authors examined the expressions of two high-affinity IL-8 receptors, IL-8 receptor A (IL8RA) and IL-8 receptor B (IL8RB), in 30 patients with nasopharyngeal carcinoma by immunohistochemical analysis. Results: As expected, both IL-8 receptors were expressed on microvessels in tumor nests and surrounding stroma. Interestingly, they were also abundantly expressed on tumor cells. The expressions of IL8RA and IL8RB had no associations with gender, metastasis, or clinical stage. However, the expression of IL8RA in tumors significantly correlated with a shorter overall survival rate (P = .0045). Although the estimated 5-year overall survival rate for IL8RA-negative patients was 68.2%, that in IL8RA-positive patients was only 33.3%. Conclusion: The study results suggest that the expression of IL8RA in tumor cells becomes an important indicator of poor prognosis in nasopharyngeal carcinoma. [source] Endothelin receptor B2 (EDNRB2) is associated with the panda plumage colour mutation in Japanese quailANIMAL GENETICS, Issue 2 2007M. Miwa Summary The panda mutant in Japanese quail (Coturnix japonica) displays spots of wild-type plumage on a white background and is controlled by an autosomal recessive allele (s). The dotted white is controlled by a third allele (sdw) of the s locus with sdw/sdw quail having less pigmentation than s/s quail. We mapped the s locus to the Japanese quail chromosome 4 (CJA04) in a previous study. The orthologous region of the chicken (Gallus gallus) genome includes endothelin receptor B2 (EDNRB2), an avian-specific paralog of endothelin receptor B (EDNRB). EDNRB mutations in mammals retard the migration of neural crest cells (NCCs), which results in a spotted coat colour and an enteric nervous defect. In the present study, we investigated the association between the s locus and EDNRB2 in Japanese quail. Sequence comparison among transcripts from livers of wild-type, panda and dotted white quail revealed a nucleotide substitution (c.995G>A) leading to a p.R332H amino acid change that was specific to panda, whereas no amino acid substitution was found in dotted white birds. The amino acid position 332 is located in the sixth transmembrane domain and is highly conserved in both avian and mammalian endothelin receptors. The A allele at nucleotide position 995 was specific to panda (s/s) birds among 10 strains, and was mapped to the same chromosomal region as the s locus. Quantitative RT-PCR revealed that EDNRB2 transcripts were reduced in both panda and dotted white mutants compared with wild-type. However, there was no difference between the early embryos of wild-type and panda with respect to the migration of NCCs. The genetic association of EDNRB2 with plumage colour in birds was found for the first time in this study. [source] Human B cells express the orphan chemokine receptor CRAM-A/B in a maturation-stage-dependent and CCL5-modulated mannerIMMUNOLOGY, Issue 2 2008Tanja N. Hartmann Summary Chemokines orchestrate the organization of leucocyte recruitment during inflammation and homeostasis. Despite growing knowledge of chemokine receptors, some orphan chemokine receptors are still not characterized. The gene CCRL2 encodes such a receptor that exists in two splice variants, CRAM-A and CRAM-B. Here, we report that CRAM is expressed by human peripheral blood and bone marrow B cells, and by different B-cell lines dependent on the B-cell maturation stage. Intriguingly, CRAM surface expression on the pre-B-cell lines Nalm6 and G2 is specifically upregulated in response to the inflammatory chemokine CCL5 (RANTES), a chemokine that is well known to play an important role in modulating immune responses. Although Nalm6 cells do not express any of the known CCL5 binding receptors, extracellular signal-regulated kinases 1 and 2 (ERK1/2) are phosphorylated upon CCL5 stimulation, suggesting a direct effect of CCL5 through the CRAM receptor. However, no calcium mobilization or migratory responses upon CCL5 stimulation are induced in B-cell lines or in transfected cells. Also, ERK1/2 phosphorylation cannot be inhibited by pertussis toxin, suggesting that CRAM does not couple to Gi proteins. Our results describe the expression of a novel, non-classical chemokine receptor on B cells that is potentially involved in immunomodulatory functions together with CCL5. [source] | ||||||||||