Purinergic P2Y Receptor Antagonists ; Consensus ; Cardiovascular System ; Cardiology ; Asia

Acute Coronary Syndrome/drug therapy* ; Aged ; Clopidogrel/therapeutic use* ; Humans ; Percutaneous Coronary Intervention ; Platelet Aggregation Inhibitors/therapeutic use* ; Purinergic P2Y Receptor Antagonists/therapeutic use* ; Ticagrelor/therapeutic use* ; Treatment Outcome

OBJECTIVE: Dual antiplatelet therapy (DAPT) with aspirin and a P2Y12 receptor inhibitor is the cornerstone of treatment in patients with acute coronary syndromes (ACS) and in those undergoing percutaneous coronary intervention (PCI). In current clinical situation, availability of different oral P2Y12 inhibitors (clopidogrel, prasugrel, and ticagrelor) has enabled physicians to switch among therapies owing to specific clinical scenarios. Although optimum time, loading dose and interval of transition between P2Y12 inhibitors is still controversial and needs further evidence, switching between oral inhibitors frequently occurs in clinical practice for several reasons. DATA SOURCES: This review was based on data in articles published in PubMed up to June 2018, with the following keywords "antiplatelet therapy", "ACS", "PCI", "ticagrelor", and "clopidogrel". STUDY SELECTION: Original articles and critical reviews on de-escalation strategy in ACS patients after PCI were selected. References of the retrieved articles were also screened to search for potentially relevant papers. RESULTS: Safety concerns associated with switching between antiplatelet agents, has prompted the use of clopidogrel for patients with ACS especially after PCI as a de-escalation strategy. Practical considerations for de-escalating therapies in patients with ACS such as reducing dose of P2Y12 inhibitors or shortening duration of DAPT (followed by aspirin or P2Y12 receptor inhibitor monotherapy) as potential options are yet to be standardized and validated. CONCLUSIONS Current review will provide an overview of the pharmacology of common P2Y12 inhibitors, definitions of de-escalation and different de-escalating strategies and its outcomes, along with possible direction to be explored in de-escalation.
Acute Coronary Syndrome ; drug therapy ; therapy ; Aspirin ; therapeutic use ; Diamines ; therapeutic use ; Humans ; Percutaneous Coronary Intervention ; Platelet Aggregation Inhibitors ; therapeutic use ; Purinergic P2Y Receptor Antagonists ; therapeutic use ; Thiazoles ; therapeutic use

To investigate the protective effects of P2X7 receptor (P2X7R) inhibitor against cerebral ischemia/reperfusion (I/R) injury in rats and the possible mechanisms.
 Methods: The neurological deficit of rats was evaluated by Longa score. The infarct volume was examined by 2, 3, 5-triphenyltetrazolium chloride (TTC) staining. The expression levels of extracellular signal-regulated kinase (ERK), phosphorylation extracellular signal-regulated kinas p-ERK), connexin 43 (Cx43), Bax, Bcl-2 and cleaved caspase-3 were detected by Western blot.
 Results: Compared with sham group, the neurobehavioral score (P<0.05) and cerebral infarct volume (P<0.01) of rats in I/R group was increased. Compared with I/R group, brilliant blue G (BBG, the antagonist of P2X7R) or PD98059 (the inhibitor of EKR kinase) could reduce the neurobehavioral score (P<0.01) and cerebral infarct volume significantly (P<0.05). The neurobehavioral score and cerebral infarct volume was further decreased (P<0.05) when rats were treated with both BBG and PD98059. Compared with I/R group, the expression levels of p-ERK, Cx43, cleaved caspase-3 and the ratio of Bax/Bcl-2 were decreased by BBG or PD98059 pretreatment, and the protective effects were further enhanced when rats were treated with both BBG and PD98059 (P<0.05).
 Conclusion: Inhibition of P2X7R reduces the cerebral I/R injury of rats. ERK inhibition is probably involved in the protective effects of P2X7R inhibitor against cerebral I/R injury, which may be related to the reduction of Cx43 and cleaved caspase-3, and the ratio of Bax/Bcl-2.
Animals ; Brain Ischemia ; drug therapy ; prevention & control ; Gene Expression Regulation ; drug effects ; Phosphorylation ; drug effects ; Purinergic P2X Receptor Antagonists ; pharmacology ; therapeutic use ; Rats ; Receptors, Purinergic P2X7 ; Reperfusion Injury ; drug therapy ; prevention & control

OBJECTIVE: To study the diagnostic value of P2X7 receptor for rheumatoid arthritis (RA) and its role in the inflammatory response. METHODS: With the synovial tissues from 25 patients with bone and joint replacement as the control,the synovial tissues of 25 RA patients were examined for the relative expression of P2X7 receptor mRNA using qRT-PCR.In an immortalized RA synovial cell line (MH7A),the effect of P2X7 receptor knockdown via a small interfering RNA were examined on the productions of the inflammatory cytokines including interleukin-1β(IL-1β),IL-6,and IL-8 using ELISA. RESULTS: The RA patients showed significantly higher levels of P2X7 receptor mRNA expression in the synovial tissue than the control patients.P2X7 receptor had a good diagnostic value for RA.The expression levels of IL-1β,IL-6,and IL-8 were positively correlated with the levels of P2X7 receptor in the synovial tissues of RA patients (<0.001).In MH7A cells,P2X7 receptor knockdown obviously reduced the secretion of IL-1β and IL-6. CONCLUSIONS RA patients show elevated P2X7 receptor level in the synovial tissue, which has a good diagnostic value for RA.Blocking P2X7 receptor can inhibit inflammatory factor secretion and suppress inflammatory reactions.
Arthritis, Rheumatoid ; diagnosis ; physiopathology ; Case-Control Studies ; Cell Line ; Gene Knockdown Techniques ; Humans ; Inflammation ; metabolism ; Interleukin-1beta ; metabolism ; Interleukin-6 ; metabolism ; Interleukin-8 ; metabolism ; Purinergic P2X Receptor Antagonists ; RNA, Messenger ; metabolism ; Receptors, Purinergic P2X7 ; physiology ; Synovial Membrane ; metabolism

OBJECTIVE: To explore the inhibitory effect of PSB0739 on the formation of semen-derived amyloid fibrils. METHODS: PAP248-286 (440 μmol/L) was incubated with PSB0739 at different concentrations, and at different time points of incubation, aliquots were taken from each sample for Congo red staining to detect the formation of amyloid fibers. The morphology of amyloid fibrils incubated in the presence or absence of PSB0739 was visualized using transmission electron microscope. The effect of PSB0739 on amyloid fibril formation was determined using virus infection assays at different time points, and the surface charges of amyloid fibril incubated with PSB0739 were calculated using a Zeta potentiometer. The cytotoxicity of PSB0739 in Hela cells was determined using MTT assay. The antiviral effect of PSB0738 against HIV- 1 was evaluated by infection assay. RESULTS: PSB0739 inhibited SEVI fibril formation in a dose-dependent manner . At 48 h of incubation, 220 μmol/L of PSB0739 obviously inhibited the formation of amyloid fibrils in 440 μmol/L of SEVI. Transmission electron microscopy revealed that 220 μmol/L PSB0739 prevented PAP248- 286 (440 μmol/L) from forming amyloid fibrils. PSB0739 antagonized SEVI-mediated enhancement of HIV-1 infection, and 1760 μmol/L of PSB0739 completely reversed the positive charge of SEVI ( < 0.05). PSB0739 below the concentration of 62.5 μmol/L showed no obvious cytotoxicity in Hela cells (>0.05). PSB0739 showed a direct anti-HIV activity with an IC of 21.77±5.15 μmol/L. CONCLUSIONS PSB0739 can inhibit the formation of semen-derived amyloid fibrils .
Amyloid ; chemistry ; drug effects ; Anti-HIV Agents ; pharmacology ; Dose-Response Relationship, Drug ; HIV Infections ; drug therapy ; HIV-1 ; drug effects ; HeLa Cells ; Humans ; In Vitro Techniques ; Microscopy, Electron, Transmission ; Purinergic P2Y Receptor Antagonists ; pharmacology ; Semen ; chemistry

BACKGROUND/AIMS: Platelet counts and characteristics can influence platelet reactivity during antiplatelet therapy. We compared the effects of both platelet count and indices on platelet reactivity between patients who were treated with either clopodogrel or ticagrelor. METHODS: Patients with coronary artery disease who underwent percutaneous coronary intervention were randomly assigned to either the clopidogrel (n = 63) or ticagrelor (n = 65) groups. Platelet count, platelet indices (including mean platelet volume, platelet distribution width, platelet large cell ratio, and immature platelet fraction), and platelet reactivity were measured before intervention, and 48 hours and 30 days post-intervention. High on-treatment platelet reactivity (HPR) was defined as ≥ 47 unit as assessed by multiple electrode platelet aggregometry. RESULTS: Baseline platelet reactivity was similar between the two groups; however, at 48 hours and 30 days, platelet reactivity was significantly lower in the ticagrelor group than in the clopidogrel group. Platelet count, mean platelet volume, platelet distribution width, platelet large cell ratio, and immature platelet fraction were significantly correlated with platelet reactivity in the clopidogrel group; however, these correlations were attenuated in the ticagrelor group. The use of clopodogrel (hazard ratio [HR] 4.1, 95% confidence interval [CI] 1.4–11.9; p = 0.010) and platelet count (HR 9.7, 95% CI 2.9–32.7; p = 0.001) were independent predictors for 30 day HPR. Platelet count was an independent predictor of HPR in the clopidogrel group but not in the ticagrelor group. CONCLUSIONS: Platelet count and indices are significantly correlated with platelet reactivity. However, antiplatelet treatment with ticagrelor could overcome these associations.
Blood Platelets* ; Coronary Artery Disease ; Electrodes ; Humans ; Mean Platelet Volume ; Percutaneous Coronary Intervention ; Platelet Count* ; Platelet Function Tests ; Purinergic P2Y Receptor Antagonists

PURPOSE: To simultaneously monitor electrical discharges in various bladder regions and the external urethral sphincter (EUS) during voiding contractions, and to assess the functional role of myogenic modulation of the lower urinary tract (LUT) by ionotropic purinergic receptors containing the P2X3 subunit. METHODS: Female Sprague-Dawley rats were anesthetized with urethane, and implanted with a suprapubic catheter for open cystometry. Flexible microelectrodes were placed ventrally in the bladder dome, upper bladder, lower bladder, and bladder base, along with the middle section of the exposed EUS. Intravesical P2X3-containing receptors were blocked with AF-323, a specific P2X3-P2X2/3 receptor antagonist. A digital electrophysiology amplifier was used to record electrical and cystometric signals throughout the LUT. RESULTS: Electrical activity in the LUT started before effective voiding contractions. Bladder pressure and electrical waveforms showed consistent out-of-phase activity when compared with the recordings made at the EUS. This pattern was also observed during voiding contractions in the presence of AF-353, supporting the hypothesis that during bladder distension, activation of P2X3-containing receptors is required for voiding contractions. Furthermore, the inhibition of P2X3-containing receptors significantly decreased the amplitude of electrical signals in the urinary bladder, but not the base or EUS. CONCLUSIONS: Our results provide novel information about the regulation of the micturition process by P2X3-containing receptors located in the inner layers of the bladder.
Animals ; Catheters ; Electrophysiology ; Female* ; Humans ; Lower Urinary Tract Symptoms ; Microelectrodes ; Purinergic P2X Receptor Antagonists ; Rats* ; Rats, Sprague-Dawley ; Receptors, Purinergic ; Urethane ; Urethra ; Urinary Bladder* ; Urinary Tract ; Urination*

No abstract available.
Korea* ; Myocardial Infarction* ; Purinergic P2Y Receptor Antagonists*

OBJECTIVETo explore the expression of purinergic p2X4 receptor (P2X4R) in trigeminal ganglion of rats after occlusal interference. Investigation of peripheral receptor mechanism of occlusal interference-induced masticatory muscle pain will aid the development of drug intervention against this condition.

METHODSExperimental occlusal interference was established by application of 0.4 mm metal crown to the upper right first molar of male Sprague-Dawley rats. Real-time PCR assay was used to investigate P2X4R mRNA level in trigeminal ganglion in rats with occlusal interference for 3, 7, 10 and 14 days and in control rats without occlusal interference (n=5 in each). Retrograde labelling combining immunofluorescence was performed to evaluate the percentage of P2X4R-positive cells in masseter afferent neurons (n=5 in each group). Graded concentrations of P2XR antagonist TNP-ATP (0.1, 10, 125, 250, 500 μmol/L) or saline (n=5 in each group) was administrated in right masseter and the mechanical sensitivity of bilateral masseters was measured before occlusal interference application, before the injection, and 30 min as well as 60 min after the injection.

RESULTSCompared with control rats (P2X4R mRNA: right side: 1.00±0.26, left side: 0.94± 0.21; percentage of P2X4R-positive masseter afferents: right side: [64.3±6.3]%, left side: [67.7±5.8]%), the level of P2X4R mRNA in bilateral trigeminal ganglia (right side: 5.98±3.56; left side: 5.06±2.88) of rats with occlusal interference for 7 days up-regulated (P<0.01) and the percentage of P2X4R-positive masseter afferent neurons(right side: [81.7±1.5]%; left side: [82.9±2.3]%) increased (P<0.05). Local administration of 10, 125, 250, 500 μmol/L TNP-ATP increased the mechanical withdrawal threshold in masseter 30 min after injection, compared with those before injection (P<0.05).

CONCLUSIONSIncreased expression of trigeminal P2X4R involves in the development of occlusal interference-induced masseter hyperalgesia.

Adenosine Triphosphate ; administration & dosage ; analogs & derivatives ; pharmacology ; Animals ; Dental Occlusion ; Hyperalgesia ; etiology ; Male ; Masseter Muscle ; drug effects ; Masticatory Muscles ; Purinergic P2X Receptor Antagonists ; administration & dosage ; pharmacology ; RNA, Messenger ; metabolism ; Rats ; Rats, Sprague-Dawley ; Real-Time Polymerase Chain Reaction ; Receptors, Purinergic P2X4 ; genetics ; metabolism ; Time Factors ; Trigeminal Ganglion ; metabolism