Project description:Recent technological advances have made transcriptome sequencing (RNA-seq) possible in cells with low RNA copy number including platelets. Resulting studies have used RNA-seq in platelets isolated from healthy individuals to characterize the platelet transcriptome. However, platelets, possibly through gene expression changes, contribute to the etiology of and response to cardiovascular disease and events. To address this, we performed the largest human platelet RNA-seq analysis to date in 34 platelet samples: 16 ST-segment elevation myocardial infarction (STEMI), 16 non-STEMI (NSTEMI), and 2 controls. RNA-seq of platelet samples from 34 individuals: 16 with ST-elevation myocardial infarction (STEMI), 16 with non-STEMI, and 2 non-myocardial infarction controls
Project description:Despite the abundance of data demonstrating the critical role of platelets in myocardial infarction (MI), few studies have characterized the MI-platelet transcriptome in the acute or chronic setting. The association between MI subtype and platelet transcriptomic signature have not been explored. We report that transcripts associated with actin cytoskeleton and Rho family GTPase signaling, mitochondrial dysfunction, and inflammatory signaling are enriched in platelets from MI patients in the acute setting (n=40 MI, n=38 controls), and do not significantly change over time. We identified 79 platelet genes chronically altered post-MI that are also associated with future cardiovascular events in independent cardiovascular disease validationcohort (n=135). Compared to patients with MI with non-obstructive coronary arteries (MINOCA), platelets from patients with MI due to obstructive coronary artery disease (MI-CAD) were enriched in neutrophil activation and proinflammatory signaling pathways driven by increased TNFα signaling. Hierarchical clustering identified three MI transcriptomic subgroups with disinctive pathways and MI correlates, including a group with MI-CAD, and a group that was predominantly MINOCA. Our data demonstrate that platelets from MI patients are phenotypically different from MI-naïve patients, in the acute and chronic setting, and reveal a transcriptomic signature with distinct clinical features.
Project description:Acute myocardial infarction (AMI) is primarily due to coronary atherosclerotic plaque rupture and subsequent thrombus formation. Platelets play a key role in the genesis and progression of both atherosclerosis and thrombosis. Since platelets are anuclear cells that inherit their mRNA from megakaryocyte precursors and maintain it unchanged during their life span, gene expression (GE) profiling at the time of an AMI provides information concerning the platelet GE preceding the coronary event. In ST-segment elevation myocardial infarction (STEMI), a gene-by-gene analysis of the platelet GE identified five differentially expressed genes (DEGs): FKBP5, S100P, SAMSN1, CLEC4E and S100A12. The logistic regression model used to combine the GE in a STEMI vs healthy donors score showed an AUC of 0.95. The same five DEGs were externally validated using platelet GE data from patients with coronary atherosclerosis but without thrombosis. Early signals of an imminent AMI are likely to be found by platelet GE profiling before the infarction occurs.
Project description:Recent technological advances have made transcriptome sequencing (RNA-seq) possible in cells with low RNA copy number including platelets. Resulting studies have used RNA-seq in platelets isolated from healthy individuals to characterize the platelet transcriptome. However, platelets, possibly through gene expression changes, contribute to the etiology of and response to cardiovascular disease and events. To address this, we performed the largest human platelet RNA-seq analysis to date in 34 platelet samples: 16 ST-segment elevation myocardial infarction (STEMI), 16 non-STEMI (NSTEMI), and 2 controls.
Project description:Despite a substantial progress in diagnosis and therapy, acute myocardial infarction (MI) is a major cause of mortality in the general population. A novel insight into the pathophysiology of myocardial infarction obtained by studying gene expression should help to discover novel biomarkers of MI and to suggest novel strategies of therapy. The aim of our study was to establish gene expression patterns in leukocytes from acute myocardial infarction patients. ST-segment elevation myocardial infarction alters expression of several groups of genes. On admission, several genes and pathways that could be directly or indirectly linked with lipid/glucose metabolism, platelet function and atherosclerotic plaque stability were affected (signaling of PPAR, IL-10, IL-6). Analysis at discharge highlighted specific immune response (upregulation of immunoglobulins). Highly significant and substantial upregulation of SOCS3 and FAM20 genes expression in the first 4-6 days of myocardial infarction in all patients is the most robust observation of our work Twenty-eight patients with ST-segment elevation myocardial infarction (STEMI) were included. The blood was collected on the 1st day of myocardial infarction, after 4-6 days, and after 6 months. Control group comprised 14 patients with stable coronary artery disease (CAD), without history of myocardial infarction. Gene expression analysis was performed with Affymetrix GeneChipM-BM-. Human Gene 1.0 ST microarrays and GCS3000 TG system.
Project description:Affymetrix microarray analysis of molecular changes after myocardial infarction. Samples of heart tissue were analyzed after myocardial infarction from WT and reg3beta knock-out mice. Samples from scar tissue and samples adjacent to the scar were analyzed. In the experiment we primarily compared infarction zone of wild-type to infarction zone of knock-out animals, and remote zone of wild-type to remote zone of knock-outs.
Project description:Despite a substantial progress in diagnosis and therapy, acute myocardial infarction (MI) is a major cause of mortality in the general population. A novel insight into the pathophysiology of myocardial infarction obtained by studying gene expression should help to discover novel biomarkers of MI and to suggest novel strategies of therapy. The aim of our study was to establish gene expression patterns in leukocytes from acute myocardial infarction patients. ST-segment elevation myocardial infarction alters expression of several groups of genes. On admission, several genes and pathways that could be directly or indirectly linked with lipid/glucose metabolism, platelet function and atherosclerotic plaque stability were affected (signaling of PPAR, IL-10, IL-6). Analysis at discharge highlighted specific immune response (upregulation of immunoglobulins). Highly significant and substantial upregulation of SOCS3 and FAM20 genes expression in the first 4-6 days of myocardial infarction in all patients is the most robust observation of our work
Project description:Platelets are central to the pathophysiology of myocardial infarction (MI). How the platelet proteome is altered during MI is unknown. We sought to describe changes in the platelet proteome at the time of MI and identify potential mechanisms. Platelets from patients experiencing ST-elevation myocardial infarction (STEMI) before and 3 days after treatment (n= 30), and a matched cohort of patients with severe stable coronary artery disease (CAD) prior to and 3 days after coronary artery bypass grafting (CABG, n=25) underwent quantitative proteomic analysis. Elevations of the alarmins S100A8 and S100A9 were detected at the time of STEMI compared with stable CAD (S100A8, FC = 2.00, FDR = 0.05; S100A9, FC = 2.28, FDR = 0.005). During STEMI, S100A8 mRNA and protein levels were correlated in platelets (R = 0.46, p = 0.012). To determine if protein synthesis occurs, activated platelets were incubated with 13C-labelled amino acids for 24 hours and analyzed by mass spectrometry. No incorporation was detected, consistent with the notion that protein synthesis in platelets is not a major contributor to the platelet proteome. Platelet abundance of S100A8 and A9 was strongly correlated with neutrophil abundance at the time of STEMI. When isolated platelets and neutrophils were co-incubated under quiescent and TRAP-6 activated conditions, release of S100A8 from neutrophils resulted in uptake of S100A8 by platelets. Leukocyte-to-platelet protein transfer, rather than protein synthesis, may occur in a thromboinflammatory environment such as STEMI, representing a potential new contributor in the innate immune pathogenesis of STEMI.
Project description:Platelets are central to the pathophysiology of myocardial infarction (MI). How the platelet proteome is altered during MI is unknown. We sought to describe changes in the platelet proteome at the time of MI and identify potential mechanisms. Platelets from patients experiencing ST-elevation myocardial infarction (STEMI) before and 3 days after treatment (n= 30), and a matched cohort of patients with severe stable coronary artery disease(CAD) prior to and 3 days after coronary artery bypass grafting (CABG, n=25) underwent quantitative proteomic analysis. Elevations of the alarmins S100A8 and S100A9 were detected at the time of STEMI compared with stable CAD (S100A8, FC = 2.00, FDR = 0.05; S100A9, FC = 2.28, FDR = 0.005). During STEMI, S100A8 mRNA and protein levels were correlated in platelets (R = 0.46, p = 0.012). To determine if protein synthesis occurs, activated platelets were incubated with 13C-labelled amino acids for 24 hours and analyzed by mass spectrometry. No incorporation was detected, consistent with the notion that protein synthesis in platelets is not a major contributor to the platelet proteome. Platelet abundance of S100A8 and A9 was strongly correlated with neutrophil abundance at the time of STEMI. When isolated platelets and neutrophils were co-incubated under quiescent and TRAP-6 activated conditions, release of S100A8 from neutrophils resulted in uptake of S100A8 by platelets. Leukocyte-to-platelet protein transfer, rather than protein synthesis, may occur in a thromboinflammatory environment such as STEMI, representing a potential new contributor in the innate immune pathogenesis of STEMI.