Faculty Opinions recommendation of Expression and function of rat urothelial P2Y receptors.

Prolonged vasoconstrictor-stimulated phospholipase C activity can induce arterial constriction, hypertension, and smooth muscle hypertrophy/hyperplasia. Arrestin proteins are recruited by agonist-occupied G protein-coupled receptors to terminate signaling and counteract changes in vascular tone. Here we determine whether the development of hypertension affects arrestin expression in resistance arteries and how such changes alter arterial contractile signaling and function. Arrestin2/3 expression was increased in mesenteric arteries of 12-wk-old spontaneously hypertensive rats (SHR) compared with normotensive Wistar-Kyoto (WKY) controls, while no differences in arrestin expression were observed between 6-wk-old SHR and WKY animals. In mesenteric artery myography experiments, high extracellular K+-stimulated contractions were increased in both 6- and 12-wk-old SHR animals. Concentration-response experiments for uridine 5′-triphosphate (UTP) acting through P2Y receptors displayed a leftward shift in 12-wk, but not 6-wk-old animals. Desensitization of UTP-stimulated vessel contractions was increased in 12-wk-old (but not 6-wk-old) SHR animals. Dual IP3/Ca2+ imaging in mesenteric arterial cells showed that desensitization of UTP and endothelin-1 (ET1) responses was enhanced in 12-wk-old (but not 6-wk-old) SHR compared with WKY rats. siRNA-mediated depletion of arrestin2 for UTP and arrestin3 for ET1, reversed the desensitization of PLC signaling. In conclusion, arrestin2 and 3 expression is elevated in resistance arteries during the emergence of the early hypertensive phenotype, which underlies an enhanced ability to desensitize vasoconstrictor signaling and vessel contraction. Such regulatory changes may act to compensate for increased vasoconstrictor-induced vessel contraction.

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P2Y receptors mediate Ca2+ signaling in duodenocytes and contribute to duodenal mucosal bicarbonate secretion

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.90314.2008 ◽

2009 ◽

Vol 296 (2) ◽

pp. G424-G432 ◽

Cited By ~ 22

Author(s):

Xiao Dong ◽

Eric James Smoll ◽

Kwang Hyun Ko ◽

Jonathan Lee ◽

Jimmy Yip Chow ◽

...

Keyword(s):

Short Circuit ◽

Short Circuit Current ◽

P2y Receptors ◽

Epithelial Cell Line ◽

Initial Increase ◽

Bicarbonate Secretion ◽

Duodenal Epithelium ◽

And Function

Since little is known about the role of P2Y receptors (purinoceptors) in duodenal mucosal bicarbonate secretion (DMBS), we sought to investigate the expression and function of these receptors in duodenal epithelium. Expression of P2Y2 receptors was detected by RT-PCR in mouse duodenal epithelium and SCBN cells, a duodenal epithelial cell line. UTP, a P2Y2-receptor agonist, but not ADP (10 μM), significantly induced murine duodenal short-circuit current and DMBS in vitro; these responses were abolished by suramin (300 μM), a P2Y-receptor antagonist, or 2-aminoethoxydiphenyl borate (2-APB; 100 μM), a store-operated channel blocker. Mucosal or serosal addition of UTP induced a comparable DMBS in wild-type mice, but markedly impaired response occurred in P2Y2 knockout mice. Acid-stimulated DMBS in vivo was significantly inhibited by suramin (1 mM) or PPADS (30 μM). Both ATP and UTP, but not ADP (1 μM), raised cytoplasmic-free Ca2+ concentrations ([Ca2+]cyt) with similar potencies in SCBN cells. ATP-induced [Ca2+]cyt was attenuated by U-73122 (10 μM), La3+ (30 μM), or 2-APB (10 μM), but was not significantly affected by nifedipine (10 μM). UTP (1 μM) induced a [Ca2+]cyt transient in Ca2+-free solutions, and restoration of external Ca2+ (2 mM) raised [Ca2+]cyt due to capacitative Ca2+ entry. La3+ (30 μM), SK&F96365 (30 μM), and 2-APB (10 μM) inhibited UTP-induced Ca2+ entry by 92, 87, and 94%, respectively. Taken together, our results imply that activation of P2Y2 receptors enhances DMBS via elevation of [Ca2+]cyt that likely results from an initial increase in intracellular Ca2+ release followed by extracellular Ca2+ entry via store-operated channel.

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P2Y Receptors: Structure and Function

Purinergic and Pyrimidinergic Signalling I ◽

10.1007/978-3-662-09604-8_4 ◽

2001 ◽

pp. 65-88 ◽

Cited By ~ 9

Author(s):

M. R. Boarder ◽

T. E. Webb

Keyword(s):

P2y Receptors ◽

Structure And Function ◽

And Function

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Expression and function of rat urothelial P2Y receptors

AJP Renal Physiology ◽

10.1152/ajprenal.00321.2006 ◽

2008 ◽

Vol 294 (4) ◽

pp. F821-F829 ◽

Cited By ~ 44

Author(s):

Bikramjit Chopra ◽

Joel Gever ◽

Stacey R. Barrick ◽

Ann T. Hanna-Mitchell ◽

Jonathan M. Beckel ◽

...

Keyword(s):

Purinergic Signaling ◽

Rank Order ◽

Atp Release ◽

P2y Receptors ◽

Urothelial Cells ◽

Paracrine Signaling ◽

Rat Urinary Bladder ◽

Afferent Fibers ◽

And Function ◽

Lower Urinary

The control and regulation of the lower urinary tract are partly mediated by purinergic signaling. This study investigated the distribution and function of P2Y receptors in the rat urinary bladder. Application of P2Y agonists to rat urothelial cells evoked increases in intracellular calcium; the rank order of agonist potency (pEC50 ± SE) was ATP (5.10 ± 0.07) > UTP (4.91 ± 0.14) > UTPγS (4.61 ± 0.16) = ATPγS (4.70 ± 0.05) > 2-methylthio adenosine 5′-diphosphate = 5′-( N-ethylcarboxamido)adenosine = ADP (<3.5). The rank order potency for these agonists indicates that urothelial cells functionally express P2Y2/P2Y4 receptors, with a relative lack of contribution from other P2Y or adenosine receptors. Real-time PCR, Western blotting, and immunocytochemistry confirmed the expression of P2Y2 and to a lesser extent P2Y4 in the urothelium. Immunocytochemical studies revealed expression of P2Y2 staining in all layers of the urothelium, with relative absence of P2Y4. P2Y2 staining was also present in suburothelial nerve bundles and underlying detrusor smooth muscle. Addition of UTP and UTPγS was found to evoke ATP release from cultured rat urothelial cells. These findings indicate that cultured rat urothelial cells functionally express P2Y2/P2Y4 receptors. Activation of these receptors could have a role in autocrine and paracrine signaling throughout the urothelium. This could lead to the release of bioactive mediators such as additional ATP, nitric oxide, and acetylcholine, which can modulate the micturition reflex by acting on suburothelial myofibroblasts and/or pelvic afferent fibers.

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Nucleotides Acting at P2Y Receptors: Connecting Structure and Function

Molecular Pharmacology ◽

10.1124/mol.114.095711 ◽

2015 ◽

Vol 88 (2) ◽

pp. 220-230 ◽

Cited By ~ 59

Author(s):

Kenneth A. Jacobson ◽

Silvia Paoletta ◽

Vsevolod Katritch ◽

Beili Wu ◽

Zhan-Guo Gao ◽

...

Keyword(s):

P2y Receptors ◽

Structure And Function ◽

And Function

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Polarized expression and function of P2Y ATP receptors in rat bile duct epithelia

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.2001.281.4.g1059 ◽

2001 ◽

Vol 281 (4) ◽

pp. G1059-G1067 ◽

Cited By ~ 70

Author(s):

Jonathan A. Dranoff ◽

Anatoly I. Masyuk ◽

Emma A. Kruglov ◽

Nicholas F. LaRusso ◽

Michael H. Nathanson

Keyword(s):

Bile Duct ◽

Intrahepatic Bile Duct ◽

P2y Receptors ◽

Bile Secretion ◽

Extracellular Nucleotides ◽

Apical Plasma Membrane ◽

Receptor Subtypes ◽

P2y Receptor ◽

Atp Receptors ◽

And Function

Extracellular nucleotides may be important regulators of bile ductular secretion, because cholangiocytes express P2Y ATP receptors and nucleotides are found in bile. However, the expression, distribution, and function of specific P2Y receptor subtypes in cholangiocytes are unknown. Thus our aim was to determine the subtypes, distribution, and role in secretion of P2Y receptors expressed by cholangiocytes. The molecular subtypes of P2Y receptors were determined by RT-PCR. Functional studies measuring cytosolic Ca2+ (Ca[Formula: see text]) signals and bile ductular pH were performed in isolated, microperfused intrahepatic bile duct units (IBDUs). PCR products corresponding to P2Y1, P2Y2, P2Y4, P2Y6, and P2X4 receptor subtypes were identified. Luminal perfusion of ATP into IBDUs induced increases in Ca[Formula: see text] that were inhibited by apyrase and suramin. Luminal ATP, ADP, 2-methylthioadenosine 5′-triphosphate, UTP, and UDP each increased Ca[Formula: see text]. Basolateral addition of adenosine 5′- O-(3-thiotriphosphate) (ATP-γ-S), but not ATP, to the perifusing bath increased Ca[Formula: see text]. IBDU perfusion with ATP-γ-S induced net bile ductular alkalization. Cholangiocytes express multiple P2Y receptor subtypes that are expressed at the apical plasma membrane domain. P2Y receptors are also expressed on the basolateral domain, but their activation is attenuated by nucleotide hydrolysis. Activation of ductular P2Y receptors induces net ductular alkalization, suggesting that nucleotide signaling may be an important regulator of bile secretion by the liver.

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Increased Purinergic Responses Dependent on P2Y2 Receptors in Hepatocytes from CCl4-Treated Fibrotic Mice

International Journal of Molecular Sciences ◽

10.3390/ijms21072305 ◽

2020 ◽

Vol 21 (7) ◽

pp. 2305 ◽

Cited By ~ 1

Author(s):

Erandi Velázquez-Miranda ◽

Christian Molina-Aguilar ◽

Adriana González-Gallardo ◽

Olivia Vázquez-Martínez ◽

Mauricio Díaz-Muñoz ◽

...

Keyword(s):

Purinergic Signaling ◽

P2y Receptors ◽

Transcriptional Analysis ◽

Zonal Distribution ◽

P2y2 Receptors ◽

Action Mechanisms ◽

Ccl4 Administration ◽

Enhanced Expression ◽

And Function

Inflammatory and wound healing responses take place during liver damage, primarily in the parenchymal tissue. It is known that cellular injury elicits an activation of the purinergic signaling, mainly by the P2X7 receptor; however, the role of P2Y receptors in the onset of liver pathology such as fibrosis has not been explored. Hence, we used mice treated with the hepatotoxin CCl4 to implement a reversible model of liver fibrosis to evaluate the expression and function of the P2Y2 receptor (P2Y2R). Fibrotic livers showed an enhanced expression of P2Y2R that eliminated its zonal distribution. Hepatocytes from CCl4-treated mice showed an exacerbated ERK-phosphorylated response to the P2Y2R-specific agonist, UTP. Cell proliferation was also enhanced in the fibrotic livers. Hepatic transcriptional analysis by microarrays, upon CCl4 administration, showed that P2Y2 activation regulated diverse pathways, revealing complex action mechanisms. In conclusion, our data indicate that P2Y2R activation is involved in the onset of the fibrotic damage associated with the reversible phase of the hepatic damage promoted by CCl4.

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β-arrestin-1 participates in thrombosis and regulates integrin αIIbβ3 signalling without affecting P2Y receptors desensitisation and function

Thrombosis and Haemostasis ◽

10.1160/th11-06-0430 ◽

2012 ◽

Vol 107 (04) ◽

pp. 735-748 ◽

Cited By ~ 14

Author(s):

Mathieu Schaff ◽

Nicolas Receveur ◽

Catherine Bourdon ◽

Philippe Ohlmann ◽

François Lanza ◽

...

Keyword(s):

Platelet Activation ◽

Thrombus Formation ◽

P2y Receptors ◽

Integrin Αiibβ3 ◽

Akt Phosphorylation ◽

Fibrinogen Binding ◽

And Function ◽

G Protein Coupled ◽

Receptor Desensitisation

Summaryβ-arrestin-1 (β-arr1) and β-arrestin-2 (β-arr2) are cytosolic proteins well-known to participate in G protein-coupled receptor desensitisation and signalling. We used genetically-inactivated mice to evaluate the role of β-arr1 or β-arr2 in platelet function, P2Y receptor desensitisation, haemostasis and thrombosis. Platelet aggregation, soluble fibrinogen binding and P-selectin exposure induced by various agonists were near normal in β-arr1−/− and β-arr2−/− platelets. In addition, deficiency in β-arr1 or β-arr2 was not critical for P2Y receptors desensitisation. A functional redundancy between β-arr1 and β-arr2 may explain these unchanged platelet responses. Interestingly, β-arr1−/− but not β-arr2−/− mice were protected against laser- and FeCl3-induced thrombosis. The tail bleeding times, number of rebleeds and volume of blood loss were unchanged in β-arr1−/− and β-arr2−/− mice, suggesting no defect in haemostasis. β-arr1−/− platelet activation upon adhesion to immobilised fibrinogen was inhibited, as attested by a 37 ± 5% (n = 3, p<0.0001) decrease in filopodia extension, suggesting defective signalling through integrin αIIbβ3. β-arr1 appeared to be located downstream of Src family kinases and to regulate αIIbβ3 signalling by increasing Akt phosphorylation. Overall, this study supports a role for β-arr1 in promoting thrombus formation, in part through its participation in αIIbβ3 signalling, and no role of β-arr1 and β-arr2 in agonist-induced platelet activation and P2Y receptors desensitisation.

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