Related Experiment Video

Updated: Jul 7, 2026

Comprehensive Analysis of Procoagulant Platelets Exhibiting Features of Necrosis, Apoptosis and Platelet Activation
04:37

Comprehensive Analysis of Procoagulant Platelets Exhibiting Features of Necrosis, Apoptosis and Platelet Activation

Published on: May 23, 2025

Platelet microparticles contain active caspase 3

Anita N Böing1, Chi M Hau, Auguste Sturk

  • 1Department of Clinical Chemistry, Academic Medical Center, Amsterdam, The Netherlands. A.N.Boing@amc.nl

Platelets
|February 26, 2008
PubMed

Insights

Platelet-derived microparticles (PMP) contain active caspase 3 during storage and in human plasma. These PMP can induce apoptosis in macrophages, suggesting a role in cell death signaling.

Area of Science:

  • Hematology
  • Cell Biology
  • Biochemistry

Background:

  • Platelets undergo apoptosis-like changes during storage, including microparticle release.
  • Endothelial microparticles have been shown to contain caspase 3, an apoptosis-executing enzyme.

Purpose of the Study:

  • To determine if platelet-derived microparticles (PMP) contain caspase 3 in vitro and ex vivo.
  • To investigate the mechanism of caspase 3 formation in PMP.
  • To assess the ability of PMP to induce apoptosis in human macrophages.

Main Methods:

  • Western blot and flow cytometry to detect caspase 3 antigen.
  • Enzyme activity assays (Ac-DEVD-pNA, ROCK I cleavage) to measure caspase 3 activity.
  • Incubation of THP-1 cells with PMP to assess apoptosis induction.

Main Results:

  • PMP numbers increased during platelet storage.
  • Procaspase 3 was present in PMP from day one of storage; active caspase 3 appeared after 5-7 days.
  • PMP contained caspase 9, and its formation correlated with procaspase 3 processing and caspase 3 appearance.
  • Caspase 3 was also detected in PMP from human plasma.
  • PMP induced apoptosis in THP-1 macrophages.

Conclusions:

  • Platelet-derived microparticles contain caspase 3 in vitro and ex vivo.
  • Caspase 9 likely processes procaspase 3 within PMP during storage.
  • PMP can induce macrophage apoptosis, though the direct role of transferred caspase 3 requires further investigation.

More Related Videos

Caspase-3 Activity in the Rat Amygdala Measured by Spectrofluorometry After Myocardial Infarction08:41

Caspase-3 Activity in the Rat Amygdala Measured by Spectrofluorometry After Myocardial Infarction

Published on: January 12, 2016

Visualization of Inflammatory Caspases Induced Proximity in Human Monocyte-Derived Macrophages08:41

Visualization of Inflammatory Caspases Induced Proximity in Human Monocyte-Derived Macrophages

Published on: April 6, 2022

Related Concept Videos

Caspases01:24

Caspases

Caspase, a family of cysteine proteases, serve as effectors in apoptosis. The ced3 gene in C.elegans was first identified to be involved in apoptosis. This gene encodes the ced-3 caspase that is similar to the interleukin-1-beta converting enzyme or ICE in mammals. In addition to apoptosis, caspases also function in the inflammatory response. Inflammatory caspases are essential in activating pro-inflammatory cytokines that recruit immune cells and block the replication of pathogens inside cells.
Structure and Function of Platelets01:18

Structure and Function of Platelets

The cell fragments known as platelets are disc-shaped, with an average diameter of about 3 μm and a thickness of roughly 1 μm. They play a crucial role in the body's vascular clotting system, which also involves plasma proteins, blood cells, and blood vessel tissues.
Platelets are continually replenished, circulating in the bloodstream for 9-12 days before being removed by phagocytes, primarily in the spleen. A microliter of circulating blood contains between 150,000 and 450,000 platelets, with...
The Extrinsic Apoptotic Pathway01:17

The Extrinsic Apoptotic Pathway

The extrinsic apoptotic pathway is initiated when extracellular death-inducing signals, such as specific cytokines, activate the death receptors expressed on the cell surface. The immune cells involved in this pathway are natural killer cells (NK cells) and cytotoxic T-lymphocytes. NK cells are critical in innate immune response, while cytotoxic T-lymphocytes are associated with adaptive immune response. These cells recognize specific receptors expressed on the altered cells and activate...
Formation of the Platelet Plug01:22

Formation of the Platelet Plug

The platelet phase, the second stage of hemostasis, commences around 15-20 seconds after an injury. It follows and overlaps with the vascular phase, during which blood vessels constrict to minimize blood loss.
As the injured blood vessel contracts, endothelial cells undergo contraction, revealing collagen fibers in the basement membrane and underlying connective tissue. Furthermore, the plasma membrane of endothelial cells becomes adhesive, preparing the site for platelet adhesion. Platelets...
The Intrinsic Apoptotic Pathway01:31

The Intrinsic Apoptotic Pathway

Internal cellular stress, such as cellular injury or hypoxia, triggers intrinsic apoptosis. The B-cell lymphoma 2 (Bcl-2) family of proteins are the primary regulators of the intrinsic apoptotic pathway. For example, during DNA damage, checkpoint proteins, such as Ataxia Telangiectasia Mutated (ATM protein) and Checkpoints Factor-2 (Chk2) proteins, are activated. These proteins phosphorylate p53 which further activates pro-apoptotic proteins, such as Bax, Bak, PUMA, and Noxa, and inhibits...
Phagocytosis of Apoptotic Cells01:17

Phagocytosis of Apoptotic Cells

Cells undergoing apoptosis form apoptotic bodies that must be removed immediately to prevent inflammation, autoimmune diseases, and necrosis. Phagocytosis is carried out by professional phagocytes such as macrophages or  immature dendritic cells. Non-professional phagocytes such as  epithelial cells and fibroblasts also take part in this process; however, they are not as effective as professional phagocytes. 
Normal cells contain receptors that prevent them from being recognized by phagocytes.