title: ADP-induced bladder contractility is mediated by P2Y12 receptor and temporally regulated by ectonucleotidases and adenosine signaling.
abstract: Purinergic signaling comprises one key pathway in modulating bladder smooth muscle (BSM) contractility, disorders of which become highly prevalent with aging. ADP was first observed to modulate BSM contractility >40 yr ago, yet the underlying molecular mechanism still remains unclear. Here, we demonstrate, using myography, that ADP and ADPβS dose-dependently induce mouse BSM contraction, and ADP-induced BSM contraction is blocked by a selective P2Y12 receptor (P2Y12R) antagonist, PSB 0739 (25 μM), but is unaffected by P2Y1 and P2Y13 receptor antagonists. P2Y12R in BSM exhibits distinct pharmacological properties that are different from P2Y12R in platelets. After an immediate contraction, prolonged exposure to ADP causes BSM to become refractory to further ADP-mediated contraction. However, in mice lacking ectonucleotidases Entpd1 (ATP→ADP→AMP) or Nt5e (AMP→adenosine), or by inhibiting adenosine signaling, the refractory response was altered, resulting in repeated BSM contractions in response to repeated ADP (0.1-1 mM) stimulation. Our data indicate that P2Y12R undergoes slow desensitization; ADP-P2Y12 signaling is tightly regulated by Entpd1/Nt5e activity and adenosine receptors; and ADP-adenosine signaling play an important role in modulating P2X-mediated BSM contraction. The identification of P2Y12R in BSM, and the current clinical availability of P2Y12R inhibitors, such as clopidogrel, offers potentially novel treatment strategies for bladder contractility disorders.
authors.affiliation: Laboratory of Voiding Dysfunction, Division of Nephrology, and wyu2@bidmc.harvard.edu.
authors.forename: Weiqun
authors.initials: W
authors.lastname: Yu
authors.affiliation: Division of Gastroenterology, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, USA.
authors.forename: Xiaofeng
authors.initials: X
authors.lastname: Sun
authors.affiliation: Division of Gastroenterology, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, USA.
authors.forename: Simon C
authors.initials: SC
authors.lastname: Robson
authors.affiliation: Laboratory of Voiding Dysfunction, Division of Nephrology, and.
authors.forename: Warren G
authors.initials: WG
authors.lastname: Hill
mesh_terms: D000241:Adenosine / Q000378:metabolism*; D000244:Adenosine Diphosphate / Q000494:pharmacology*; D000251:Adenosine Triphosphatases / Q000378:metabolism*; D000818:Animals; D004558:Electric Stimulation; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009119:Muscle Contraction / Q000187:drug effects; D058925:Receptors, Purinergic P2Y12 / Q000502:physiology*; D015398:Signal Transduction; D001743:Urinary Bladder / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology
chemical_list: C548577:P2ry12 protein, mouse; D058925:Receptors, Purinergic P2Y12; D000244:Adenosine Diphosphate; D000251:Adenosine Triphosphatases; C027201:ectoATPase; D000241:Adenosine
keywords: detrusor; mechanotransduction; micturition; myography; urinary tract