Project description:The purpose of this study was to identify changes in platelet mRNA that result from exposure to antiplatelet therapy. A total of 84 healthy volunteers were recruited into a longitudinal study of various antiplatelet exposures with 58 completing all study visits. This was a 5 visit study where each visit was separated by ~ 4 weeks. At each Visit purified platelets using a CD45 negative selection protocol was performed in addition to platelet function testing using light transmittance aggregometry (ADP, EPI, and Collagen) and PFA100 (Col/EPI). After the baseline visit (V1), participants were randomized to receive 81mg/day or 325mg/day aspirin x 4 weeks followed by Visit 2. Participants then crossed over to the alternative dose of aspirin for 4 weeks followed by Visit 3. Between Visits 3 and 4 participants washed out their aspirin for 4 weeks. The final exposure was ticagrelor 90mg twice daily x 4 weeks until Visit 5.
Project description:MicroRNAs (miRNAs) regulate cell physiology by altering protein expression, but the biology of platelet miRNAs is largely unexplored. We tested whether platelet miRNA levels were associated with platelet reactivity by genome-wide profiling using platelet RNA from 19 healthy subjects. We found that human platelets express 284 miRNAs. Unsupervised hierarchical clustering of miRNA profiles resulted in 2 groups of subjects that appeared to cluster by platelet aggregation phenotypes. Seventy-four miRNAs were differentially expressed (DE) between subjects grouped according to platelet aggregation to epinephrine, a subset of which predicted the platelet reactivity response. Using whole genome mRNA expression data on these same subjects, we computationally generated a high-priority list of miRNA-mRNA pairs in which the DE platelet miRNAs had binding sites in 3'UTRs of DE mRNAs, and the levels were negatively correlated. Three miRNA-mRNA pairs (miR-200b:PRKAR2B, miR-495:KLHL5 and miR-107:CLOCK) were selected from this list and all 3 miRNAs knocked down protein expression from the target mRNA. Reduced activation from platelets lacking PRKAR2B supported these findings. In summary, (1) platelet miRNAs are able to repress expression of platelet proteins, (2) miRNA profiles are associated with and may predict platelet reactivity, and (3) bioinformatic approaches can successfully identify functional miRNAs in platelets. Total RNA from the platelets of 19 donors was harvested and labeled with Hy3. Reference RNA (a pool of all samples) was labeled with Hy5. This submission represents the miRNA expression component of the study.
Project description:MicroRNAs (miRNAs) regulate cell physiology by altering protein expression, but the biology of platelet miRNAs is largely unexplored. We tested whether platelet miRNA levels were associated with platelet reactivity by genome-wide profiling using platelet RNA from 19 healthy subjects. We found that human platelets express 284 miRNAs. Unsupervised hierarchical clustering of miRNA profiles resulted in 2 groups of subjects that appeared to cluster by platelet aggregation phenotypes. Seventy-four miRNAs were differentially expressed (DE) between subjects grouped according to platelet aggregation to epinephrine, a subset of which predicted the platelet reactivity response. Using whole genome mRNA expression data on these same subjects, we computationally generated a high-priority list of miRNA-mRNA pairs in which the DE platelet miRNAs had binding sites in 3'UTRs of DE mRNAs, and the levels were negatively correlated. Three miRNA-mRNA pairs (miR-200b:PRKAR2B, miR-495:KLHL5 and miR-107:CLOCK) were selected from this list and all 3 miRNAs knocked down protein expression from the target mRNA. Reduced activation from platelets lacking PRKAR2B supported these findings. In summary, (1) platelet miRNAs are able to repress expression of platelet proteins, (2) miRNA profiles are associated with and may predict platelet reactivity, and (3) bioinformatic approaches can successfully identify functional miRNAs in platelets.
Project description:Platelets play an important role in primary hemostasis, inflammation , (tumor) angiogenesis and cancer metastasis. Platelets are produced by megakaryocytes in the bone marrow and contain numerous bioactive proteins (e.g. growth factors, chemokine’s and proteases). These proteins inside platelets are either synthesized by the parental megakaryocytes or absorbed from the (micro)circulation. Therefore, it was postulated that changes in platelet protein content might indicate the presence or recurrence of a malignant tumor. We followed up the notion that both cancer and cancer therapy affect the platelet proteome. The aim of the current study was 1) to identify a pan-cancer proteome signature that could be used to discriminate patients with cancer from healthy individuals, and 2) to investigate the effect of cancer therapy on the platelet proteome. In this study, we included patients with cancer and healthy controls. Using global protein profiling by mass spectrometry-based proteomics we determined that the platelet proteome is affected by both cancer presence and antitumor therapy.
Project description:RNA-sequencing analysis of human platelet polyA-mRNA from a normal male. The goal of this experiment was to identify genes expressed in unstimulated circulating platelets.
Project description:Antiplatelet therapy is the most important treatment to reduce the risk of developing recurrent thrombosis, and to prevent progression to a complete occlusion of coronary arterial disease (CAD) patients after percutaneous coronary intervention Aim of study was to investigate the relationship between response to antiplatelet drugs and global mRNA gene expression in peripheral blood cells (PBC) in patients with coronary arterial disease (CAD) All patients were treated crhonically with acetylsalicylic acid (ASA) (100 mg/day) and clopidogrel (75 mg/day). Blood samples were drown before PCI to evaluate platelet reactivity by VerifyNow® ASA and P2Y12 assays and mRNA expression was measured by Affymetrix GeneChip Human Exon 1.0 ST array.
Project description:For the anucleate platelet it has been unclear how well platelet transcriptomes correlate among different donors or across different RNA profiling platforms, and what the transcriptomes’ relationship is with the platelet proteome. We generated RNA-seq pro-files of the long RNA transcriptomes from the platelets of 10 healthy young males (5 white and 5 black) with median age of 24.5 years, no notable clinical history, and no pre-vious history of thrombosis or bleeding. We also profiled the subjects’ messenger RNAs using the Affymetrix microarray gene expression system. We found that the abundance of platelet mRNA transcripts was highly correlated across the 10 individuals, inde-pendently of race and of the employed technology. Our RNA-seq data also showed that these high inter-individual correlations extend beyond mRNAs to several categories of non-coding RNAs. Pseudogenes represented a notable exception to this by exhibiting a clear difference in expression by race. Comparison of our mRNA signatures with the only publicly available quantitative platelet proteome data showed that most (87.5%) identified platelet proteins had a detectable corresponding mRNA. However, a high number of mRNAs that were present in the transcriptomes of all 10 individuals had no representa-tion in the proteome. The Spearman correlation of the relative abundances for those platelet genes that were represented by both an mRNA and a protein showed a weak (~0.3) yet statistically significant (P=5.0E-16) connection. Further analysis of the overlap-ping and non-overlapping platelet mRNAs and proteins identified gene groups corre-sponding to distinct cellular processes, a finding that provides novel insights for platelet biology. This represents the Affymetrix GeneChip component of the study only 10 Resting Human Platelet samples
Project description:Double anti-platelet therapy (DAPT) has wide inter-individual variabilities in coronary heart disease (CHD) patients’ responses, which undermines the prognosis effect in clinical practice. Noncoding RNAs are present in platelets, albeit their potential roles in platelet responses to DAPT largely remains in the realm of the unknown. This study aims to screen differential noncoding RNAs responsible for low residual platelet reactivities under DAPT. We enrolled 144 CHD patients that received DAPT and assigned them to high platelet reactivity (HPR) group and baseline group according to their residual platelet reactivities. Through microarray analysis, we detected a total of 22,424 kinds of co-expressed lncRNAs in three pairs of the patients between the HPR and baseline groups.
Project description:For the anucleate platelet it has been unclear how well platelet transcriptomes correlate among different donors or across different RNA profiling platforms, and what the transcriptomes’ relationship is with the platelet proteome. We generated RNA-seq pro-files of the long RNA transcriptomes from the platelets of 10 healthy young males (5 white and 5 black) with median age of 24.5 years, no notable clinical history, and no pre-vious history of thrombosis or bleeding. We also profiled the subjects’ messenger RNAs using the Affymetrix microarray gene expression system. We found that the abundance of platelet mRNA transcripts was highly correlated across the 10 individuals, inde-pendently of race and of the employed technology. Our RNA-seq data also showed that these high inter-individual correlations extend beyond mRNAs to several categories of non-coding RNAs. Pseudogenes represented a notable exception to this by exhibiting a clear difference in expression by race. Comparison of our mRNA signatures with the only publicly available quantitative platelet proteome data showed that most (87.5%) identified platelet proteins had a detectable corresponding mRNA. However, a high number of mRNAs that were present in the transcriptomes of all 10 individuals had no representa-tion in the proteome. The Spearman correlation of the relative abundances for those platelet genes that were represented by both an mRNA and a protein showed a weak (~0.3) yet statistically significant (P=5.0E-16) connection. Further analysis of the overlap-ping and non-overlapping platelet mRNAs and proteins identified gene groups corre-sponding to distinct cellular processes, a finding that provides novel insights for platelet biology. This represents the Affymetrix GeneChip component of the study only
Project description:We conducted an unbiased genome-wide assessment of genomic factors that may influence response to low-dose aspirin in pregnant women at high risk of pre-eclampsia in two pregnancy cohorts: Liverpool (n=91) and Dublin (n=91). We applied UK Axiom microarray technology for GWAS investigations. We specified tight phenotyping with COX-selective urinary 11-dehydrothromboxane B2 (pg/mg creatinine) and accounted for adherence/platelet exposure to aspirin by detection of aspirin’s principal urinary metabolite, SUA, with nuclear magnetic resonance (NMR).