Project description:Gene expression profile of platelets have been explored due to their stability and abundance in plasma. In this study, we try to address the knowledge gap regarding liquid biopsy markers for early detection of non-small cell lung cancer (NSCLC). For that blood samples were collected in two time points, in the presence and absence of NSCLC. Platelets were isolated and miRNA expression evaluated by microarray technique.
Project description:To explore the diverse platelet microRNA (miRNA) expression between high platelet reactivity (HPR) and low platelet reactivity (LPR) patients with acute coronary syndromes (ACS), we enrolled a cohort of ACS patients and performed miRNA expression profiling of platelets from four HPR and four LPR patients using human miRNA microarray system. VerifyNow P2Y12 assay was applied to indentify HPR and LPR. Venous blood was drawn from the patients and was centrifuged to prepare platelets. Among the candidate differentially expressed miRNAs, miR-15b expression was further confirmed to be lower in platelets of 22 HPR patients than 17 LPR by quantitative reverse-transcription polymerase chain reaction (RT-qPCR). We enrolled a consecutive cohort of 290 ACS patients and assessed the platelet reactivity using VerifyNow P2Y12 assay. In this study, HPR was defined as M-bM-^IM-%300 platelet reactivity unit (PRU) while LPR <170 PRU. miRNA microarray analysis was performed in platelets of four HPR and four LPR patients with ACS.
Project description:To explore the diverse platelet microRNA (miRNA) expression between high platelet reactivity (HPR) and low platelet reactivity (LPR) patients with acute coronary syndromes (ACS), we enrolled a cohort of ACS patients and performed miRNA expression profiling of platelets from four HPR and four LPR patients using human miRNA microarray system. VerifyNow P2Y12 assay was applied to indentify HPR and LPR. Venous blood was drawn from the patients and was centrifuged to prepare platelets. Among the candidate differentially expressed miRNAs, miR-15b expression was further confirmed to be lower in platelets of 22 HPR patients than 17 LPR by quantitative reverse-transcription polymerase chain reaction (RT-qPCR).
Project description:Results Platelets in non-diabetic patients demonstrated miRNA expression profiles comparable to previously published data. The miRNA expression profiles of platelets in diabetics were similar. Statistical analysis unveiled only three miRNAs (miR-377-5p, miR-628-3p, miR-3137) with high reselection probabilities in resampling techniques, corresponding to signatures with only modest discriminatory performance. Functional annotation of predicted targets for these miRNAs pointed towards an influence of diabetes mellitus on mRNA processing. Conclusions/interpretation We did not find any major differences in platelet miRNA profiles between diabetics and non-diabetics. Minor differences pertained to miRNAs associated with mRNA processing. Thus, previously described differences in plasma miRNAs between diabetic and nondiabetic patients cannot be explained by plain changes in the platelet miRNA profile. Platelet miRNA profiles were assessed in clinically stable diabetic and nondiabetic patients (each n=30). Platelet miRNA was isolated from leucocyte-depleted platelet-rich plasma, and miRNA profiling was performed using LNA micro-array technology (miRBase 18.0, containing 1,917 human miRNAs). Effects of diabetes mellitus were explored by univariate statistical tests for each miRNA, adjusted for potential confounders, and by developing a multivariable signature, which was evaluated by resampling techniques. Platelet phenotype was assessed by light transmission aggregometry and impedance aggregometry.
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.