Related Experiment Video
Updated: Jul 28, 2026
05:49
Procoagulant Platelet Characterization by Measuring Phosphatidylserine Exposure and Microvesicle Release from Human Purified Platelets
Published on: November 29, 2024
Decreased expression of phospholipase C-beta 2 isozyme in human platelets with impaired function
1Laboratory of Cell Signaling, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892-0340, USA.
Blood
|September 1, 1996
Summary
A specific deficiency in phospholipase C-beta 2 (PLC-beta 2) in human platelets is linked to inherited bleeding disorders. This finding identifies a key enzyme in platelet function and aggregation.
Area of Science:
- Hematology
- Biochemistry
- Molecular Biology
Background:
- Platelet dysfunction in inherited bleeding disorders can stem from signaling pathway defects.
- Phospholipase C (PLC) activation is crucial for platelet aggregation and secretion.
- Identifying specific PLC isozyme roles in platelets is essential for understanding hemostasis.
Observation:
- Patient platelets exhibited reduced inositol 1,4,5-trisphosphate generation and intracellular calcium mobilization.
- Analysis revealed a significant deficiency in PLC-beta 2 levels in the patient's platelets.
- Conversely, PLC-beta 4 levels were found to be threefold higher in the patient's platelets compared to normal.
Findings:
- A novel method quantified platelet PLC isozymes using high-performance liquid chromatography and immunoblot analysis.
- Seven PLC isoforms were detected, with PLC-gamma 2 and PLC-beta 2 being most abundant in normal platelets.
- The patient's platelets showed a marked reduction in PLC-beta 2 and an increase in PLC-beta 4, suggesting a specific isozyme deficiency.
Implications:
- This study is the first to document a specific PLC isozyme deficiency in human platelets.
- The findings implicate PLC-beta 2 deficiency as the cause of impaired platelet function in this patient.
- This research provides a unique model for investigating the distinct roles of PLC isozymes in platelet biology and hemostasis.
Related Concept Videos
01:42Phosphoinositides and PIPs
Phosphoinositides are a group of phospholipids containing a glycerol backbone with two fatty acid chains and a phosphate attached to a myoinositol sugar ring. The inositol head group extends into the cytoplasm, where it is modified by adding phosphate groups to form phosphatidylinositol phosphates or PIPs.
Different phosphoinositides are synthesized and recruited on the cytosolic face of the plasma membrane. The localization of specific phosphoinositides concentrated in separate membrane...
Different phosphoinositides are synthesized and recruited on the cytosolic face of the plasma membrane. The localization of specific phosphoinositides concentrated in separate membrane...
01:30Anticoagulant Drugs: Low-Molecular-Weight Heparins
Hemostasis is a crucial process that prevents excessive blood loss from damaged blood vessels. It involves various mechanisms such as vasoconstriction, platelet adhesion and activation, and fibrin formation. The importance of each mechanism depends on the type of vessel injury. In contrast, thrombosis is the abnormal formation of a blood clot within the blood vessels, leading to potential complications if the clot obstructs blood flow. Thrombosis can be caused by increased coagulability of the...
01:18Structure 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...
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...
01:22Formation 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...
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...
01:24Disorders of Hemostasis
Hemostasis, the process that stops bleeding after a blood vessel injury, is crucial for maintaining the integrity of the circulatory system. However, disorders of hemostasis can disrupt this delicate balance, leading to either excessive clotting or bleeding. These disorders can be broadly classified into thromboembolic disorders and bleeding disorders.
Thromboembolic Disorders
Two factors primarily cause thromboembolic conditions.
Thromboembolic Disorders
Two factors primarily cause thromboembolic conditions.