par4 ap platelet agonist  (MedChemExpress)

Journal: JCI Insight

Article Title: Platelets impair the resolution of inflammation in atherosclerotic plaques in insulin-resistant mice after lipid lowering

doi: 10.1172/jci.insight.193593

Figure Lengend Snippet: ( A ) Study design. Eight-week-old Ldlr –/– male mice fed a high-fat, high-cholesterol (HFHC) diet for the whole duration of the study (23 weeks). After the atherosclerosis progression period (obese baseline, Ob), mice were injected with ApoB ASO to lower lipids (lipid-lowering period). All lipid-lowered mice were split into 2 groups, injected either with isotype control antibody (IgG) or platelet depletion antibody (αCD42b) every 3 days for a total of 3 weeks. ( B ) Platelet counts in circulating blood of Ob, IgG, and αCD42b 3 days before harvest. ( C ) Blood glucose measurements (lean n = 16, Ob n = 47) and ( D ) area of curve (AOC) quantification of glucose tolerance tests (GTTs) from lean, Ob, IgG, and αCD42b mice after 16 weeks of HFHC diet during atherosclerosis progression. ( E ) Blood glucose measurements (Ob n = 3, IgG n = 4, αCD42b n = 4) and ( F ) AOC quantification of GTTs from Ob, IgG, and αCD42b mice after 22 weeks of HFHC diet during atherosclerosis resolution. Mean fluorescent intensity (MFI) of platelet ( G ) JonA and ( H ) P-selectin in nonstimulated (NS) samples and upon 100 μM PAR4-AP agonist stimulation of lean and Ob circulating blood samples. ( I ) Mean platelet volume (MPV) from circulating blood of lean, Ob, and IgG-treated mice, 3 days before harvest. In C and E , error bars represent SD. Data were analyzed by Kruskal-Wallis with Dunn’s post hoc test ( B and F ), unpaired Mann-Whitney test ( C , D , and H ), unpaired Student’s t test ( G ), or ordinary 1-way ANOVA with Tukey’s multiple-comparison test ( I ). P values are shown in graphs.

Article Snippet: The whole blood was stained with anti–mouse JonA-PE (M023-2, Emfret Analytics) and anti–mouse P-selectin Alexa Fluor 647 (563674, BD Biosciences) and then treated with PAR4-AP platelet agonist (100 μM; MedChemExpress) for 15 minutes at room temperature.

Techniques: Injection, Control, MANN-WHITNEY, Comparison

Journal: Frontiers in Pharmacology

Article Title: Role of albumin in regulating platelet function

doi: 10.3389/fphar.2026.1734694

Figure Lengend Snippet: Hypoproteinemia was found to promote platelet activation. (A–E) Wash platelet aggregation in WT, ADR and ADR Albumin mice induced by thrombin (A) , U46619 (B) , PAR4-AP (C) , collagen (D) and ADP (E) (n = 5 independent experimental animals). (F–H) Thrombin (F) , U46619 (G) and PAR4-AP (H) induced integrin αIIbβ3 activation in washed platelets from mice (n = 5 independent experimental animals). (I–K) Thrombin (I) , U46619 (J) and PAR4-AP (K) induced P-selectin release from washed platelets from mice (n = 5 independent experimental animals). (L–O) ATP release from washed platelets in mice was induced by thrombin (L) , U46619 (M) , PAR4-AP (N) and collagen (O) (n = 5 independent experimental animals). (P–R) Wash platelet spreading in mice induced by U46619 (P) , mean spreading area of individual platelets (Q) , and proportion of spreading platelets to total platelets in the field of view (R) (n = 3 independent experimental animals). Differences between groups were assessed by one-way ANOVA followed by Dunnett’s post hoc test. Statistics are presented as mean ± SEM. * P < 0.05, ** P < 0.01 and *** P < 0.001.

Article Snippet: Rabbit antibodies against phospho-PKC substrate (2261), phospho-Akt (Ser473) (11E7), Akt (pan) (11E7), PKC alpha (2056), GAPDH (5174), cell lysate buffer (9803), and PAR4-AP (2328) were sourced from Cell Signaling Technology, Inc. (Beverly, MA, United States).

Techniques: Activation Assay

Journal: Immunity

Article Title: Inhibition of transcription factor NFAT activity in activated platelets enhances their aggregation and exacerbates gram-negative bacterial septicemia

doi: 10.1016/j.immuni.2021.12.002

Figure Lengend Snippet: (A) Western blot analysis of NFAT1, NFAT2, NFAT3, and NFAT4 was performed on lysates from murine platelets or the uterine tissue. One experiment representative of three experiments. (B) Phos-tag western blot analysis of mouse platelets pretreated, or not, with myristoylated VIVIT (MyrVIVIT) (10 μM) for 30 min and then stimulated with PAR4-AP (100 μM) for the indicated time points. One experiment representative of three experiments. (C) Murine platelets were pretreated, or not, with vehicle (DMSO), the myristoylated control peptide (MyrVEET), or MyrVIVIT (10 μM) for 10 min and then activated with PAR4-AP (75 μM). Aggregation was monitored for 5 min. Histograms represent the percentage of maximal aggregation and area under curve (AUC). Data represent mean ± SEM. n ≥ 3 independent experiments. (D) Human platelets were treated as in (C) and stimulated with TRAP (5 μM). Histograms represent the percentage of the maximal aggregation and AUC. Data represent mean ± SEM. n ≥ 3 independent experiments. (E) Platelet-rich plasma (PRP) from WT or Nfat1−/− mice was stimulated with PAR4-AP (150 μM). Histograms represent the percentage of maximal aggregation and AUC. Each dot represents an independent test and lines highlight measurements performed concomitantly. (F) PRP from WT or Nfat1−/− mice was stimulated with PAR4-AP (150 and 100 μM). Integrin αIIbβ3 activation was analyzed by cytofluorimetry. Bars represent the mean fluorescence intensity (MFI). Data represent mean ± SEM. n ≥ 3 independent experiments. (G) Representative phos-tag western blot analysis of murine platelets pretreated, or not, with 1 μM FK506 for 1 h and then stimulated with PAR4-AP (100 μM) for the indicated time. (H) Murine PRP was treated as in (G). Aggregation curves and histograms of maximal aggregation and AUC are shown. Each dot represents an independent test. (I) PRP was pretreated as in (G) and then stimulated with different concentration of PAR4-AP (150 and 100 μM). Integrin αIIbβ3 activation was analyzed by cytofluorimetry. Bars represent the MFI. Data represent mean ± SEM. n ≥ 3 independent experiments. (J) PRP from WT or Nfat1−/− mice was pretreated as in (G), and integrin αIIbβ3 activation was analyzed by cytofluorimetry. Data represent mean ± SEM. n ≥ 3 independent experiments. One-way ANOVA (C and D), unpaired two-tailed t test (E and H), or two-way ANOVA (F, I, and J) were used for statistics. n.s., not significant (p > 0.05), **p < 0.01, ***p < 0.001, and ****p < 0.0001. See also Figure S1.

Article Snippet: PAR4-AP , MedChemExpress , Cat# HY-P1309.

Techniques: Western Blot, Control, Activation Assay, Fluorescence, Concentration Assay, Two Tailed Test

Journal: Immunity

Article Title: Inhibition of transcription factor NFAT activity in activated platelets enhances their aggregation and exacerbates gram-negative bacterial septicemia

doi: 10.1016/j.immuni.2021.12.002

Figure Lengend Snippet: (A) PRP from mice treated, or not, with 4 mg/kg of FK506 for 14 days were stimulated with PAR4-AP (150 μM). Maximal aggregation and AUC are shown. Each dot represents an independent test and lines highlight measurements performed concomitantly. (B) Tail bleeding test was performed on mice treated, or not, with FK506 (left panel) or on WT and Nfat1−/− mice (right panel). Each dot represents a mouse (n = 29 for FK-treated mice, n = 16 for Nfat1−/− mice). (C) Mice treated, or not, with 4 mg/kg of FK506 for 14 days (left) or WT and Nfat1−/− mice (right) were intravenously injected with a mixture of collagen (500 μg/kg) and epinephrine (3 μg/kg) and were scored for a pathology index. Each dot represents a mouse (n = 9 for FK-treated mice, n = 5 for Nfat1−/− mice). (D) Tail bleeding test (left panel) and thromboembolism test (right panel) were performed on HPS mice treated, or not, with FK506. Each dot represents a mouse (n = 6). Unpaired two-tailed t test was used for statistics. *p < 0.05, **p < 0.01, and ***p < 0.001. See also Figure S3.

Article Snippet: PAR4-AP , MedChemExpress , Cat# HY-P1309.

Techniques: Injection, Two Tailed Test

Journal: Immunity

Article Title: Inhibition of transcription factor NFAT activity in activated platelets enhances their aggregation and exacerbates gram-negative bacterial septicemia

doi: 10.1016/j.immuni.2021.12.002

Figure Lengend Snippet: (A) Whole blood from mice treated, or not, with 4 mg/kg of FK506 for 14 days was stimulated, or not, with PAR4-AP (100 μM). The formation of complexes between platelets and neutrophils was analyzed by cytofluorimetry. Results show the MFI for the platelet marker CD41 on neutrophils, identified as Ly6G+CD11b+ cells. Data represent mean ± SEM. n ≥ 3 independent experiments. (B) Platelet-neutrophil complex formation was analyzed by ImageStream. Platelets treated, or not, with 1 μM FK506 for 1 h and identified with different fluorochromes, were washed, mixed with the blood from platelet-depleted mice, and stimulated (PAR4-AP), or not (Unstim), with PAR4-AP (25 μM). The percentage of neutrophils (identified as Ly6G+ cells in the whole blood) that did not bind any platelets (0), or that bound 1 or 2 platelets (1–2), or 3 or more platelets (>3) was measured for both platelets pretreated (FK-506) or not (NT) with FK506. Data represent mean ± SEM. n ≥ 3 independent experiments. (C) PRP was pretreated, or not, with 1 μM FK506 for 1 h and stimulated with PAR4-AP (150 μM) for 5 min. PAR4-AP-activated platelets were then used to induce NETosis. Histograms represent the percentage of neutrophils positive for the citrullinated histone H3 (left). Each dot represents an independent test. A representative image of NET released by neutrophils is shown (right). Scale bars, 10 μm. (D) Murine PRP was pretreated, or not, with 1 μM FK506 for 1 h and then stimulated with different concentration of PAR4-AP (150 and 100 μM). P-selectin exposure was analyzed by cytofluorimetry and P-selectin MFI is shown. Data represent mean ± SEM. n ≥ 3 independent experiments. (E) Neutrophils were stimulated as in (C) in the presence of the anti-P-selectin antibody or respective isotype control. Data represent mean ± SEM. n ≥ 3 independent experiments. One-way ANOVA (A, D, and E), two-way ANOVA (B), or unpaired two-tailed t test (C) were used for statistics. n.s., not significant (p > 0.05), *p < 0.05, **p < 0.01, and ****p < 0.0001. See also Figure S4.

Article Snippet: PAR4-AP , MedChemExpress , Cat# HY-P1309.

Techniques: Marker, Concentration Assay, Control, Two Tailed Test

Journal: Immunity

Article Title: Inhibition of transcription factor NFAT activity in activated platelets enhances their aggregation and exacerbates gram-negative bacterial septicemia

doi: 10.1016/j.immuni.2021.12.002

Figure Lengend Snippet: (A) PRP was pretreated, or not, with 1 μM FK506 for 1 h and incubated, or not, for 10 min with 3 μM ARC-66096 (ARC) then stimulated with different concentration of PAR4-AP (150 and 100 μM). Integrin αIIbβ3 activation and P-selectin exposure were analyzed by cytofluorimetry. Bars represent the MFI. Data represent mean ± SEM. n ≥ 3 independent experiments. (B) PRP was pretreated, or not, with 1 μM FK506 for 1 h and the release of ATP was measured upon stimulation with PAR4-AP (150 μM). Histogram represents maximal ATP release. Data represent mean ± SEM. n ≥ 3 independent experiments. (C and D) PRP was pretreated as in (B) and then stimulated with ADP (20 μM). Aggregation (C) and integrin αIIbβ3 activation and P-selectin exposure were analyzed (D). Data represent mean ± SEM. n ≥ 3 independent experiments. (E) PRP was pretreated as in (B) and then stimulated with PAR4-AP (150 μM) alone or in combination with ADP (10 nM). Integrin αIIbβ3 activation and P-selectin exposure were analyzed by cytofluorimetry. Data show mean ± SEM. n ≥ 3 independent experiments. Two-way ANOVA (A, D, and E) or unpaired two-tailed t test (B) were used for statistics. n.s., not significant (p > 0.05), *p < 0.05, **p < 0.01, and ****p < 0.0001. See also Figure S5.

Article Snippet: PAR4-AP , MedChemExpress , Cat# HY-P1309.

Techniques: Incubation, Concentration Assay, Activation Assay, Two Tailed Test

Journal: Immunity

Article Title: Inhibition of transcription factor NFAT activity in activated platelets enhances their aggregation and exacerbates gram-negative bacterial septicemia

doi: 10.1016/j.immuni.2021.12.002

Figure Lengend Snippet: (A) Schematic of the iNFATuation transgenic mouse model. (B) Blood from WT, littermates or iNFATuation-Pf4-cre mice was stained for the platelet marker CD41 and analyzed for expression of VIVIT-tdTomato signal. One experiment representative of three experiments. (C) PRP from littermates or iNFATuation-Pf4-cre mice was stimulated with PAR4-AP (150 μM). Aggregation was monitored for 5 min. Histograms of maximal aggregation and AUC are shown. Each dot represents an independent test. (D) PRP from littermates or iNFATuation-Pf4-cre mice was stimulated with PAR4-AP (150 μM). P-selectin exposure was analyzed by cytofluorimetry, and P-selectin MFI is shown. Data represent mean ± SEM. n ≥ 3 independent experiments. (E) Whole blood from littermates or iNFATuation-Pf4-cre mice was treated with PAR4-AP (100 μM). The formation of complexes between platelets and neutrophils was analyzed by cytofluorimetry. Results show the MFI for the platelet marker CD41 on neutrophils, identified as Ly6G+CD11b+ cells. Data represent mean ± SEM. n ≥ 3 independent experiments. (F) PRP from littermates or iNFATuation-Pf4-cre mice was stimulated with PAR4-AP (150 μM) for 5 min. PAR4-AP-activated platelets were then used to induce NETosis. Histograms represent the percentage of neutrophils positive for the citrullinated histone H3. Each dot represents an independent test. (G) Tail bleeding test (left panel) and thromboembolism test (right panel) were performed on littermates or iNFATuation-Pf4-cre mice. Each dot represents a mouse (n = 4 littermates, n = 6 iNFATuation-Pf4-cre). Data show mean ± SEM. Unpaired two-tailed t test (C, F, and G) and two-way ANOVA (D and E) were used for statistics. *p < 0.05, **p < 0.01, and ***p < 0.001. See also Figure S6.

Article Snippet: PAR4-AP , MedChemExpress , Cat# HY-P1309.

Techniques: Transgenic Assay, Staining, Marker, Expressing, Two Tailed Test

Journal: Immunity

Article Title: Inhibition of transcription factor NFAT activity in activated platelets enhances their aggregation and exacerbates gram-negative bacterial septicemia

doi: 10.1016/j.immuni.2021.12.002

Figure Lengend Snippet: KEY RESOURCES TABLE

Article Snippet: PAR4-AP , MedChemExpress , Cat# HY-P1309.

Techniques: Virus, Recombinant, Staining, Enzyme-linked Immunosorbent Assay, Software, Luminex

Journal: bioRxiv

Article Title: Sodium/Potassium ATPase Alpha 1 Subunit Fine-tunes Platelet GPCR Signaling Function and is Essential for Thrombosis

doi: 10.1101/2024.05.13.593923

Figure Lengend Snippet: A. COS-7 cells were transiently transfected with plasmids encoding mouse NKA α1 and WT or LGL>SFT mutated mouse P2Y12 for 36 hours and then cells were lysed and used for the IP-IB assay. B & C. Human platelet lysates prepared from two individuals were used for IP of α1 (with ab2872) and then IB for PAR4 and TP. The membranes were stripped and reblotted for α1 (ab76020). HRP-conjugated anti-rabbit IgG light chain antibody was used for the detection of PAR4, TP, and α1 (middle blot) signals. Due to the weak signal of α1 in the IP, the membranes were re-blotted using the HRP-conjugated anti-rabbit whole IgG, and then the α1 signal was visualized by DAB staining. D. COS-7 cells were transiently transfected with plasmids encoding human P2Y12 for 24 hours. The cells were then treated with LGL at the indicated concentrations for an additional 16 hours. Cells were lysed and used for the co-IP assay. GAPDH was blotted for loading control of input. E. COS-7 cells were transiently transfected with plasmids encoding mouse α1 and P2Y12, either WT or LGL(LGI)>SFT mutated genes, in different combinations and then cells were lysed and used for the IP-IB assay. Two dishes of cells transfected with mouse WT α1 and P2Y12 were treated with 100 µM Ouabain or 2 µM Digoxin, respectively, for 1 hour before being harvested for IP-IB assay. SB indicates sample buffer only was loaded in the corresponding lane.

Article Snippet: Antibodies to TP (27159-1-AP), P2Y1 (67654-1-AP), and PAR4 (25306-1-AP) were purchased from Proteintech Group, Inc (Rosemont, IL).

Techniques: Transfection, Staining, Co-Immunoprecipitation Assay, Control