Related Experiment Video
Updated: Jul 14, 2026
06:04
LC-MS Analysis of Human Platelets as a Platform for Studying Mitochondrial Metabolism
Published on: April 4, 2016
The leptin receptor system of human platelets
G Giandomenico1, C Dellas, R-P Czekay
1Department of Cell Biology, The Scripps Research Institute, La Jolla, CA 92037, USA.
Journal of Thrombosis and Haemostasis : JTH
|May 5, 2005
Summary
Obesity-linked leptin can activate human platelets, increasing thrombosis risk. This effect depends on individual platelet leptin receptor levels, suggesting varying thrombosis susceptibility in obese individuals.
Area of Science:
- Cardiovascular Biology
- Endocrinology
- Hematology
Background:
- Obesity is linked to higher blood leptin levels.
- Elevated leptin is a human thrombosis risk factor.
- Leptin promotes platelet activation and thrombosis in mice.
Purpose of the Study:
- Investigate leptin's effect on human platelets.
- Characterize the leptin receptor on human platelets.
Main Methods:
- Platelet aggregation assays with ADP, collagen, and epinephrine.
- Western blotting and RT-PCR for leptin receptor expression.
- Ligand-binding assays to determine receptor affinity.
Main Results:
- Leptin potentiated platelet aggregation in approximately 40% of donors (responders).
- Responder platelets expressed higher levels of the signaling leptin receptor than non-responders.
- Specific leptin binding occurred in both responder and non-responder platelets.
Conclusions:
- Human platelet leptin response varies among individuals.
- Differences in leptin receptor expression/affinity may explain variable responses.
- Leptin-responsive individuals may face higher obesity-associated thrombosis risk.
Related Concept Videos
01:38Receptor-mediated Endocytosis
Overview
01:17Intracellular Signaling Affects Focal Adhesions
Integrins act both as extracellular input receivers and as intracellular processing activators. As their name suggests, integrins are entirely integrated into the membrane structure. Their hydrophobic membrane-spanning regions interact with the phospholipid bilayer's hydrophobic region. These membrane receptors provide extracellular attachment sites for effectors like hormones and growth factors. They activate intracellular response cascades when their effectors are bound and active.
Some...
Some...
01:27Transducer Mechanism: Enzyme-Linked Receptors
Enzyme-linked receptors are cell-surface receptors acting as an enzyme or associating with an enzyme intracellularly. They make excellent drug targets. Drugs can bind to the extracellular ligand-binding domain or directly affect their enzymatic domain and alter their activity.
Major types that are helpful drug targets include:
Major types that are helpful drug targets include:
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...
01:28Insulin: The Receptor and Signaling Pathways
Insulin action is mediated through a receptor tyrosine kinase, akin to the IGF-1 receptor. The number of receptors per cell varies significantly, from 40 on erythrocytes to 300,000 on adipocytes and hepatocytes. The insulin receptor consists of linked α/β subunit dimers, forming a heterotetramer glycoprotein with two extracellular α subunits and two β subunits spanning the membrane. The α subunits inhibit the inherent tyrosine kinase activity of the β subunits, but this inhibition is released...