Heparin and heparan sulfate glycosaminoglycans (Heparin/HS)

Heparin and heparan sulfate (HS) are complex, linear polysaccharides belonging to the glycosaminoglycan (GAG) family, consisting of repeating disaccharide units of uronic acid and glucosamine (NCBI, 2023). While heparin is a highly sulfated molecule primarily stored in mast cells and used clinically as a potent anticoagulant, heparan sulfate is ubiquitously expressed on cell surfaces and within the extracellular matrix as part of proteoglycans (PubMed, 2012). These molecules regulate critical physiological processes by interacting with hundreds of proteins, most notably activating antithrombin III to inhibit blood coagulation and sequestering growth factors like FGF and VEGF to modulate cell signaling (Nature Reviews, 2007). In various pathologies, HS chains are exploited by viruses (such as SARS-CoV-2 and HSV) for initial cell attachment and are utilized by cancer cells to facilitate metastasis and angiogenesis (PubMed, 2014). Pharmacological targeting of these chains includes the use of heparin and low-molecular-weight heparins (LMWHs) for thromboembolic disorders, as well as the development of HS mimetics and heparinase inhibitors for oncology and infectious diseases (NIH, 2021). Clinical management of these targets requires vigilance for safety concerns such as heparin-induced thrombocytopenia and significant bleeding risks (StatPearls, 2023).

Other names

HeparinHeparan sulfateHSHeparin-like glycosaminoglycansHLGSsHeparan sulfate proteoglycan chains

Potentiation of antithrombin III to accelerate the inhibition of Factor Xa and thrombin; competitive inhibition of ligand binding (growth factors, cytokines, or viral proteins) to endogenous cell surface heparan sulfate proteoglycans; neutralization of heparin activity via ionic binding (e.g., protamine sulfate).