Immunolocalisation of P2X and P2Y nucleotide receptors in the rat nasal mucosa

Gayle, Shimona; Burnstock, Geoffrey

doi:10.1007/s00441-004-0979-2

Cited by 43 publications

(31 citation statements)

References 46 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Most relevant to this study, purinergic nucleotides have been found to reduce odor responsiveness in cultured mouse OSNs (25). In addition, the expression of the purinergic receptor subtypes P2Y 1 R and P2Y 2 R has previously been characterized in olfactory epithelium (25,50) consistent with our findings in the current study. Thus, the present data, taken together with previous findings, suggest that purinergic receptors in vivo may associate with certain ORs, such as M71, to promote OR surface expression and regulate OR functionality.…”

Section: Discussionsupporting

confidence: 91%

Specificity of Olfactory Receptor Interactions with Other G Protein-coupled Receptors

Bush

Jones

Lyle

et al. 2007

Journal of Biological Chemistry

View full text Add to dashboard Cite

Studies on olfactory receptor (OR) pharmacology have been hindered by the poor plasma membrane localization of most ORs in heterologous cells. We previously reported that association with the ␤ 2 -adrenergic receptor (␤ 2 -AR) facilitates functional expression of the OR M71 at the plasma membrane of HEK-293 cells. In the present study, we examined the specificity of M71 interactions with other G protein-coupled receptors (GPCRs). M71 was co-expressed in HEK-293 cells with 42 distinct GPCRs, and the vast majority of these receptors had no significant effect on M71 surface expression. However, co-expression with three subtypes of purinergic receptor (P2Y 1 R, P2Y 2 R, and A 2A R) resulted in markedly enhanced plasma membrane localization of M71. Agonist stimulation of M71 co-expressed with P2Y 1 R and P2Y 2 R activated the mitogen-activated protein kinase pathway via coupling of M71 to G␣ o . We also examined the ability of ␤ 2 -AR, P2Y 1 R, P2Y 2 R, and A 2A R to interact with and regulate ORs beyond M71. We found that coexpression of ␤ 2 -AR or the purinergic receptors enhanced the surface expression for an M71 subfamily member but not for several other ORs from different subfamilies. In addition, through chimeric receptor studies, we determined that the second transmembrane domain of ␤ 2 -AR is necessary for ␤ 2 -AR facilitation of M71 plasma membrane localization. These studies shed light on the specificity of OR interactions with other GPCRs and the mechanisms governing olfactory receptor trafficking.

show abstract

Section: Discussionsupporting

confidence: 91%

Specificity of Olfactory Receptor Interactions with Other G Protein-coupled Receptors

Bush

Jones

Lyle

et al. 2007

Journal of Biological Chemistry

View full text Add to dashboard Cite

show abstract

“…Model simulations accurately predicted the predominant role of the low affinity group in the regulation of high ATP concentrations (Ͼ1 M) (43)(44)(45)(46), as demonstrated on HBE cultures using selective inhibitors of NSAP (10 mM levamisole) (13) and NTPDase 3 (10 M NF-279) (53). Therapies inhibiting these ectoenzymes could potentially accentuate airway epithelial apoptosis (65,66) and inflammatory responses (45) because of increased ATP-mediated activation of P2X 7 receptors, which are up-regulated in lung diseases (67). In addition, these enzymes are likely responsible for the rapid elimination of aerosolized nucleotides (1-100 M) used to diagnose asthma and chronic obstructive pulmonary disease (ATP and AMP) (47,48), for the treatment of CF and primary ciliary dyskinesia (UTP) (49 -52) and in animal studies (48,68,69).…”

Section: Discussionmentioning

confidence: 99%

Mathematical Model of Nucleotide Regulation on Airway Epithelia

Zuo¹,

Picher²,

Okada³

et al. 2008

Journal of Biological Chemistry

View full text Add to dashboard Cite

In the airways, adenine nucleotides support a complex signaling network mediating host defenses. Released by the epithelium into the airway surface liquid (ASL) layer, they regulate mucus clearance through P2 (ATP) receptors, and following surface metabolism through P1 (adenosine; Ado) receptors. The complexity of ASL nucleotide regulation provides an ideal subject for biochemical network modeling. A mathematical model was developed to integrate nucleotide release, the ectoenzymes supporting the dephosphorylation of ATP into Ado, Ado deamination into inosine (Ino), and nucleoside uptake. The model also includes ecto-adenylate kinase activity and feed-forward inhibition of Ado production by ATP and ADP. The parameters were optimized by fitting the model to experimental data for the steady-state and transient concentration profiles generated by adding ATP to polarized primary cultures of human bronchial epithelial (HBE) cells. The model captures major aspects of ATP and Ado regulation, including their >4-fold increase in concentration induced by mechanical stress mimicking normal breathing. The model also confirmed the independence of steady-state nucleotide concentrations on the ASL volume, an important regulator of airway clearance. An interactive approach between simulations and assays revealed that feedforward inhibition is mediated by selective inhibition of ecto-5-nucleotidase. Importantly, the model identifies ecto-adenylate kinase as a key regulator of ASL ATP and proposes novel strategies for the treatment of airway diseases characterized by impaired nucleotide-mediated clearance. These new insights into the biochemical processes supporting ASL nucleotide regulation illustrate the potential of this mathematical model for fundamental and clinical research. Mucociliary clearance (MCC)4 constitutes the first line of defense against airway infection (1). Inhaled pathogens are trapped by a mucus layer, positioned above ciliated epithelia by a periciliary (PCL) layer. Together, mucus and PCL form the ASL layer, which is continuously transported cephalad by coordinated ciliary beating. Through their interactions with P2 receptors, adenine nucleotides regulate all major epithelial functions supporting MCC, including Cl Ϫ /liquid secretion via the Ca 2ϩ -activated Cl Ϫ channel and the cystic fibrosis transmembrane regulator (CFTR) (2), mucin secretion (3, 4), and ciliary beat activity (5, 6). Nucleotides are released by the epithelium into the ASL layer under basal conditions (7,8), and their release rate increases in response to mechanical stress imparted by tidal breathing (8 -12). Nucleotide-mediated epithelial responses are modified by surface enzymes (ectonucleotidases) that convert a fraction of the ATP into Ado (13-15). This nucleoside activates airway epithelial signaling pathways through P1 receptors, typically the A 2B receptor, which stimulates ciliary beat activity (16) and Cl Ϫ /liquid secretion by CFTR (17). In healthy airways, the purinergic regulation of MCC is mediated by both P1 and P2 receptor-m...

show abstract

“…RT-PCR studies of human nasal epithelial cells showed expression of mRNA for P2X3, P2X4, P2X7, P2Y 1 , P2Y 2 , P2Y 4 , P2Y 6 , P2Y 11 , and P2Y 12 , and functional studies showed that luminal membranes express P2Y 2 , P2Y 6 , and probably P2Y 11 receptors, whereas basolateral membranes express P2Y 2 receptors; P2X3, P2X4, P2X7, P2Y 4 , and P2Y 12 did not seem to be functional in normal epithelial cells (Kim et al, 2004). Immunohistochemical studies of P2 receptor proteins showed P2X3 receptors on neurons of the rat nasal mucosa, P2X5 and P2X7 receptors on respiratory epithelial cells, P2Y 1 receptors on respiratory epithelial cells and submucosal glands, and P2Y 2 receptors on mucous secretory cells (Gayle and Burnstock, 2005). Zinc increased ciliary beat frequency in a calcium-dependent way in mouse nasal septal epithelial cultures through activation of P2X receptors and may thus be a useful agent for stimulating mucociliary clearance (Woodworth et al, 2010).…”

Section: Nasal Mucosamentioning

confidence: 94%