Project description:We performed microRNA sequencing (miRNA-seq) according to Illumina sequencing protocols. Platelet-rich plasma (PRP) has been obtained by centrifuging whole blood at 160 x g for 15 min at room temperature. Platelets have been activated with 3 different physiologic agonists, namely ADP (20uM), collagen (60ug/mL), or Thrombin Receptor Activating Peptide (TRAP 25uM) under continuous stirring. An aliquot of platelets has been obtained at 120 minutes following ADP, collagen and TRAP and then processed to determine miRNA expression profiles. Time 0, indicating samples before any agonist treatment, was used as baseline. Total RNA was extracted by using mirVana Paris kit (life technologies) and then was subjected to size selection library preparation and retrotranscribed. Obtained cDNA was sequenced with the Illumina HiSeq 1000 sequencer .
Project description:Ex vivo assays of platelet function critically inform mechanistic and clinical studies of hemostasis and thrombosis, where effects of divergent blood processing methods on platelet composition are apparent but remain unspecified. Parallel blood samples were collected from healthy human donors into sodium citrate, acid citrate dextrose, EDTA and heparin, and processed over an extended time course for physiological and biochemical experiments, including platelet proteome quantification with multiplexed tandem mass tag (TMT) labeling and high-resolution Tribrid mass spectrometry (MS). We evaluated how different blood anticoagulation options and processing times affect platelet protein content ex vivo. Following platelet isolation, TMT-MS quantified 3,358 proteins amongst all prepared platelet samples. Altogether, >400 proteins were differentially abundant in platelets isolated from blood processed at 24 h vs. 1 h post-phlebotomy, including sets of proteins pertinent to membrane trafficking and exocytosis.
Project description:Platelets are major players in the process of intravascular thrombus formation. Current therapeutic strategies still fail to prevent thrombotic coronary events in a substantial number of patients, indicating that the complex mechanisms modulating platelet response during activation are not fully elucidated. The evidence that platelets are capable of de novo protein synthesis has raised the issue of whether and how these resident mRNAs are regulated in circulating platelets. Among the several mechanisms potentially involved, mRNA splicing may be relevant. Purified platelet-rich plasmas from healthy volunteers were collected and in vitro activated with collagen or Thrombin Receptor Activating Peptide (TRAP). Transcriptome profiling by RNA-Seq and in silico intron representation analysis were applied to search for the presence of pre-mRNA molecules and splicing events affected by platelet activation. HiRIEF LC-MS allowed platelet proteome characterization at deep coverage to investigate a possible correlation between splicing events and protein levels. By comparing computational and wet-lab analyses it was possible to identify a set of transcripts influenced at both intron and protein level.
Project description:To compare immature and mature platelet transcriptome Methods: reticulated or immature platelets(RPs) were defined as the platelets with the highest thiazole orange staining intensity (15% highest, RNAhigh) according to previous experiences and mature platelets were defined as the platelet with the 30% lowest thiazole orange staining intensity (RNAlow) and sorted (supplemental Figure S1D). RPs have a prothrombotic transcriptomic profile
Project description:Transplantation with low numbers of hematopoietic stem cells (HSCs), found in many of the publically accessible cryopreserved umbilical cord blood (UCB) units, leads to delayed time to engraftment, high graft failure rates, and early mortality in many patients. A chemical screen in zebrafish identified the prostaglandin compound, 16,16 dimethyl prostaglandin E2 (dmPGE2), to be a critical regulator of hematopoietic stem cell homeostasis. We hypothesized that an ex vivo modulation with dmPGE2 prior to transplantation would lead to enhanced engraftment by increasing the “effective” dose of hematopoietic stem cells (HSCs) in cord blood. A phase I trial of reduced-intensity double UCB transplantation was performed to evaluate safety, rates of engraftment and fractional chimerism of dmPGE2 enhanced UCB units. To explore potential causes of the lack of enhanced efficacy in the first cohort, we characterized HSCs to determine whether the prostaglandin pathway was being activated under the ex vivo incubation conditions (4°C, 10µM dmPGE2, 60 minutes). Incubation conditions were identified (37°C, 10µM dmPGE2, 120 minutes) that maximize the activation of the prostaglandin pathway by dmPGE2 in human CD34+ cells. Isolated human CD34+ from umbilical cord blood were incubated ex vivo in Stem Span media with 10uM 16,16-dmPGE2 or DMSO. Two treatment conditions were evaluated (4 deg C for 1 hour, 37 deg C for 2 hours) with either 3 or 7 biological replicates at each condition. Total RNA was isolated post incubation and analyzed on Affymetrix microarrays for pathway activation.
Project description:Prospective, open labelled, multicenter trial to evaluate the feasibility of ex vivo culture 3D (chemogram obtaining) on biopsies in order to estimate the predictive value of this technique for treatment response in patients treated by two different chemotherapies (FOLFOX or FOLFIRI) for colorectal cancer.