Review

Authors: Akihiro Onishi, Kalib St Ange, Jonathan S Dordick...

Heparin, a sulfated polysaccharide, has been used as a clinical anticoagulant for over 90 years. Newer anticoagulants, introduced for certain specialized applications, have not significantly displaced heparin and newer heparin-based anticoagulants in most medical procedures. This chapter, while reviewing anticoagulation and these newer anticoagulants, focuses on heparin-based anticoagulants, including unfractionated heparin, low molecular weight heparins and ultra-low molecular weight heparins. Heparin's structures and its biological and therapeutic roles are discussed. Particular emphasis is placed on heparin's therapeutic application and its adverse effects. The future prospects are excellent for new heparins and new heparin-based therapeutics with improved properties.

Topics: Anticoagulants; Blood Coagulation; Disseminated Intravascular Coagulation; Extracorporeal Circulation; Heparin; Humans; Venous Thromboembolism

PubMed: 27100512
DOI: 10.2741/4462

Review

Authors: John Hogwood, Barbara Mulloy, Rebeca Lever...

Heparin has been used extensively as an antithrombotic and anticoagulant for close to 100 years. This anticoagulant activity is attributed mainly to the pentasaccharide sequence, which potentiates the inhibitory action of antithrombin, a major inhibitor of the coagulation cascade. More recently it has been elucidated that heparin exhibits anti-inflammatory effect via interference of the formation of neutrophil extracellular traps and this may also contribute to heparin's antithrombotic activity. This illustrates that heparin interacts with a broad range of biomolecules, exerting both anticoagulant and nonanticoagulant actions. Since our previous review, there has been an increased interest in these nonanticoagulant effects of heparin, with the beneficial role in patients infected with SARS2-coronavirus a highly topical example. This article provides an update on our previous review with more recent developments and observations made for these novel uses of heparin and an overview of the development status of heparin-based drugs. SIGNIFICANCE STATEMENT: This state-of-the-art review covers recent developments in the use of heparin and heparin-like materials as anticoagulant, now including immunothrombosis observations, and as nonanticoagulant including a role in the treatment of SARS-coronavirus and inflammatory conditions.

Topics: Humans; Anticoagulants; COVID-19; Fibrinolytic Agents; Heparin; Heparin, Low-Molecular-Weight

PubMed: 36792365
DOI: 10.1124/pharmrev.122.000684

Review

Authors: Maureen A Smythe, Jennifer Priziola, Paul P Dobesh...

Venous thromboembolism (VTE) is a serious and often fatal medical condition with an increasing incidence. Despite the changing landscape of VTE treatment with the introduction of the new direct oral anticoagulants many uncertainties remain regarding the optimal use of traditional parenteral agents. This manuscript, initiated by the Anticoagulation Forum, provides clinical guidance based on existing guidelines and consensus expert opinion where guidelines are lacking. This specific chapter addresses the practical management of heparins including low molecular weight heparins and fondaparinux. For each anticoagulant a list of the most common practice related questions were created. Each question was addressed using a brief focused literature review followed by a multidisciplinary consensus guidance recommendation. Issues addressed included initial anticoagulant dosing recommendations, recommended baseline laboratory monitoring, managing dose adjustments, evidence to support a relationship between laboratory tests and meaningful clinical outcomes, special patient populations including extremes of weight and renal impairment, duration of necessary parenteral therapy during the transition to oral therapy, candidates for outpatient treatment where appropriate and management of over-anticoagulation and adverse effects including bleeding and heparin induced thrombocytopenia. This article concludes with a concise table of clinical management questions and guidance recommendations to provide a quick reference for the practical management of heparin, low molecular weight heparin and fondaparinux.

Topics: Anticoagulants; Heparin; Humans; Practice Guidelines as Topic; Venous Thromboembolism

PubMed: 26780745
DOI: 10.1007/s11239-015-1315-2

Review

Authors: Keshavmurthy A Adya, Arun C Inamadar, Aparna Palit...

Anticoagulants are the cornerstone of treatment of venous thromboembolism associated with various medical conditions and surgical procedures. They act on different steps of the coagulation pathway and are broadly categorized into heparins, vitamin K antagonists, and inhibitors of thrombin and factor Xa. The classification is evolving as newer and better oral and parenteral anticoagulants are being added. Anticoagulants in dermatology are important not only for their therapeutic application in cutaneous thrombotic dermatoses such as livedoid vasculitis, purpura fulminans, superficial and deep venous thrombosis and others but also for their use in non-thrombotic dermatoses such as lichen planus, recurrent oral aphthosis, chronic urticaria and several others. Further, the use of anticoagulants for any indication is associated with various adverse effects with dermatologic manifestations including specific reactions such as warfarin-induced skin necrosis, heparin-induced thrombocytopenia and anticoagulant-associated cholesterol embolization syndrome.

Topics: Anticoagulants; Dermatology; Heparin; Humans; Skin Diseases; Thromboembolism; Venous Thrombosis; Warfarin

PubMed: 27320765
DOI: 10.4103/0378-6323.184199

Review

Authors: L B Jaques

Protamine is used for titration of heparin in vitro for diagnosis of hemorrhagic states and for neutralization of heparin in vivo to terminate heparinization. The protamine equivalent varies with the heparin preparation, conditions of testing and, in vivo, with the amount of heparin present in the circulation. The latter depends on time after administration and the hemodynamic and metabolic state of the patient. Protamine, when injected rapidly, will release histamine and agglutinate platelets. Bleeding (spontaneous hemorrhage) demonstrates a multiple breakdown of hemostatic mechanisms due to surgical stress, drugs, exposure of the blood to foreign surfaces, etc. Simple rules for the amount of protamine required for an individual patient based on clinical judgement will be satisfactory in most cases. When hemostasis is not achieved, it must be appreciated that heparin and protamine are only part of a complex deteriorating situation.

Topics: Hemorrhage; Hemostasis; Heparin; Heparin Antagonists; Histamine Release; Humans; Hypotension; In Vitro Techniques; Neutralization Tests; Protamines; Thrombocytopenia

PubMed: 4122234
DOI: No ID Found

Review

Authors: Svenja Nicolin Bolten, Ursula Rinas, Thomas Scheper...

Heparin is a highly sulfated polysaccharide which belongs to the family of glycosaminoglycans. It is involved in various important biological activities. The major biological purpose is the inhibition of the coagulation cascade to maintain the blood flow in the vasculature. These properties are employed in several therapeutic drugs. Heparin's activities are associated with its interaction to various proteins. To date, the structural heparin-protein interactions are not completely understood. This review gives a general overview of specific patterns and functional groups which are involved in the heparin-protein binding. An understanding of the heparin-protein interactions at the molecular level is not only advantageous in the therapeutic application but also in biotechnological application of heparin for downstreaming. This review focuses on the heparin affinity chromatography. Diverse recombinant proteins can be successfully purified by this method. While effective, it is disadvantageous that heparin is an animal-derived material. Animal-based components carry the risk of contamination. Therefore, they are liable to strict quality controls and the validation of effective good manufacturing practice (GMP) implementation. Hence, adequate alternatives to animal-derived components are needed. This review examines strategies to avoid these disadvantages. Thereby, alternatives for the provision of heparin such as chemical synthesized heparin, chemoenzymatic heparin, and bioengineered heparin are discussed. Moreover, the usage of other chromatographic systems mimetic the heparin effect is reviewed.

Topics: Animals; Chromatography, Affinity; Heparin; Humans; Proteins

PubMed: 30094590
DOI: 10.1007/s00253-018-9263-3

Review

Authors: Pierpaolo Di Micco, Egidio Imbalzano, Vincenzo Russo...

Low molecular weight heparin, enoxaparin, has been one of most used drugs to fight the SARS-CoV-2 pandemic. Pharmacological properties of heparin recognize its specific ability, as with other oligosaccharides and glycosaminoglycan, to bind several types of viruses during their pass through the extracellular matrix of the respiratory tract, as well as its anticoagulant activity to prevent venous thromboembolism. Antithrombotic actions of enoxaparin have been testified both for inpatients with COVID-19 in regular ward and for inpatients in Intensive Care Units (ICUs). Prophylactic doses seem to be able to prevent venous thromboembolism (VTE) in inpatients in the regular ward, while intermediate or therapeutic doses have been frequently adopted for inpatients with COVID-19 in ICU. On the other hand, although we reported several useful actions of heparin for inpatients with COVID-19, an increased rate of bleeding has been recorded, and it may be related to several conditions such as underlying diseases with increased risks of bleeding, increased doses or prolonged administration of heparin, personal trend to bleed, and so on.

Topics: Anticoagulants; COVID-19; Enoxaparin; Fondaparinux; Hemorrhage; Heparin; Heparin, Low-Molecular-Weight; Humans; Inpatients; Intensive Care Units; Pandemics; SARS-CoV-2; Venous Thromboembolism

PubMed: 34960754
DOI: 10.3390/v13122486

Review

Authors: Sai-Nan Ma, Zhi-Xiang Mao, Yang Wu...

Heparin, including unfractionated heparin (UFH), low-molecular-weight heparin (LMWH) and heparin derivatives, are commonly used in venous thromboembolism treatment and reportedly have beneficial effects on cancer survival. Heparin can affect the proliferation, adhesion, angiogenesis, migration and invasion of cancer cells via multiple mechanisms. The main mechanisms involve inhibition of heparanase, P-/L-selectin, angiogenesis, and interference with the CXCL12-CXCR4 axis. Here we summarize the current experimental evidence regarding the anti-cancer role of heparin and its derivatives, and conclude that there is evidence to support heparin's role in inhibiting cancer progression, making it a promising anti-cancer agent.

Topics: Angiogenesis Inhibitors; Animals; Antineoplastic Agents; Glucuronidase; Heparin; Humans; Lymphatic Vessels; Neoplastic Stem Cells

PubMed: 32538273
DOI: 10.1080/19336918.2020.1767489

Authors: Caroline Kardeby, Alice Evans, Joana Campos...

BACKGROUND

Platelet endothelial aggregation receptor 1 (PEAR1) is a single-transmembrane orphan receptor primarily expressed on platelets and endothelial cells. Genetic variants of PEAR1 have repeatedly and independently been identified to be associated with cardiovascular diseases, including coronary artery disease.

OBJECTIVES

We have identified sulfated fucoidans and their mimetics as ligands for PEAR1 and proposed that its endogenous ligand is a sulfated proteoglycan. The aim of this study was to test this hypothesis.

METHODS

A heparin proteoglycan-mimetic (HPGM) was created by linking unfractionated heparin (UFH) to albumin. The ability of the HPGM, UFH and selectively desulfated heparins to stimulate platelet aggregation and protein phosphorylation was investigated. Nanobodies against the 12th to 13th epidermal growth factor-like repeat of PEAR1 and phosphoinositide 3-kinase (PI3K) isoform-selective inhibitors were tested for the inhibition of platelet activation.

RESULTS

We show that HPGM, heparin conjugated to an albumin protein core, stimulates aggregation and phosphorylation of PEAR1 in washed platelets. Platelet aggregation was abolished by an anti-PEAR1 nanobody, Nb138. UFH stimulated platelet aggregation in washed platelets, but desulfated UFH did not. Furthermore, HPGM, but not UFH, stimulated maximal aggregation in platelet-rich plasma. However, both HPGM and UFH increased integrin αIIbβ3 activation in whole blood. By using PI3K isoform-selective inhibitors, we show that PEAR1 activates PI3Kβ, leading to Akt phosphorylation.

CONCLUSION

Our findings reveal that PEAR1 is a receptor for heparin and HPGM and that PI3Kβ is a key signaling molecule downstream of PEAR1 in platelets. These findings may have important implications for our understanding of the role of PEAR1 in cardiovascular disease.

Topics: Humans; Heparin; Phosphatidylinositol 3-Kinases; Endothelial Cells; Receptors, Cell Surface; Blood Platelets; Platelet Aggregation; Proteoglycans; Platelet Glycoprotein GPIIb-IIIa Complex; Ligands; Albumins

PubMed: 36695374
DOI: 10.1016/j.jtha.2022.10.008