Showing papers by "Rafal Pawlinski published in 2020"

Using heparin molecules to manage COVID-2019

Abstract: The coronavirus disease 2019 (COVID-19) pandemic is becoming one of the largest global public health crises in modern history. The race for an effective drug to prevent or treat the infection is the highest priority among health care providers, government officials, and the pharmaceutical industry. Recent evidence reports that the use of low-molecular-weight heparin reduces mortality in patients with severe coronavirus with coagulopathy. Although the full scope of the benefits from heparin for COVID-19 patients is unfolding, encouraging clinical data suggest that heparin-like molecules may represent a useful approach to treat or prevent severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. The intent of this article is to offer our opinions on the mechanism(s) by which heparin may attenuate the course of SARS-CoV-2 infection. Furthermore, we propose a novel strategy to treat or prevent SARS-CoV-2 infection using "designer" heparin molecules that are fabricated using a synthetic biology approach.

Design of anti-inflammatory heparan sulfate to protect against acetaminophen-induced acute liver failure

Abstract: Acetaminophen/paracetamol (APAP) overdose is the leading cause of drug-induced acute liver failure (ALF) in the United States and Europe. The progression of the disease is attributed to sterile inflammation induced by the release of high mobility group box 1 (HMGB1) and the interaction with receptor for advanced glycation end products (RAGE). A specific, effective, and safe approach to neutralize the proinflammatory activity of HMGB1 is highly desirable. Here, we found that a heparan sulfate (HS) octadecasaccharide (18-mer-HP or hepatoprotective 18-mer) displays potent hepatoprotection by targeting the HMGB1/RAGE axis. Endogenous HS proteoglycan, syndecan-1, is shed in response to APAP overdose in mice and humans. Furthermore, purified syndecan-1, but not syndecan-1 core protein, binds to HMGB1, suggesting that HMGB1 binds to HS polysaccharide side chains of syndecan-1. Last, we compared the protection effect between 18-mer-HP and N-acetyl cysteine, which is the standard of care to treat APAP overdose. We demonstrated that 18-mer-HP administered 3 hours after a lethal dose of APAP is fully protective; however, the treatment of N-acetyl cysteine loses protection. Therefore, 18-mer-HP may offer a potential therapeutic advantage over N-acetyl cysteine for late-presenting patients. Synthetic HS provides a potential approach for the treatment of APAP-induced ALF.

Development and application of global assays of hyper- and hypofibrinolysis.

Abstract: Numerous methods for evaluation of global fibrinolytic activity in whole blood or plasma have been proposed, with the majority based on tissue-type plasminogen activator (t-PA) addition to initiate fibrinolysis. We propose that such an approach is useful to reveal hypofibrinolysis, but t-PA concentrations should be kept to a minimum. In this paper, we describe a low-concentration t-PA plasma turbidity assay to evaluate several congenital factor deficiencies, including plasminogen activator inhibitor-1 (PAI-1) and plasminogen deficiency, as well as hemophilia A and B. In addition, we demonstrate a threshold dependency on endogenous PAI-1 levels. To assess endogenous hyperfibrinolysis, we suggest that assays that avoid t-PA addition are preferable, with assays based on euglobulin fractionation remaining a viable choice. We describe a euglobulin fraction clot lysis time (ECLT) assay with spectrophotometric readout and other modifications, and evaluate it as a tool to measure hyperfibrinolysis in inherited clotting factor deficiency states. We demonstrate that the ECLT is predominantly driven by residual amounts of PAI-1, t-PA, and α2-antiplasmin. These assays should be further evaluated for the detection of hypo- or hyperfibrinolysis in acquired thrombotic or hemorrhagic disorders.

Enzymatic Synthesis of Chondroitin Sulfate E to Attenuate Bacteria Lipopolysaccharide-Induced Organ Damage

Abstract: Chondroitin sulfate E (CS-E) is a sulfated polysaccharide that contains repeating disaccharides of 4,6-disulfated N-acetylgalactosamine and glucuronic acid residues Here, we report the enzymatic synthesis of three homogeneous CS-E oligosaccharides, including CS-E heptasaccharide (CS-E 7-mer), CS-E tridecasaccharide (CS-E13-mer), and CS-E nonadecasaccharide (CS-E 19-mer) The anti-inflammatory effect of CS-E 19-mer was investigated in this study CS-E 19-mer neutralizes the cytotoxic effect of histones in a cell-based assay and in mice We also demonstrate that CS-E 19-mer treatment improves survival and protects against organ damage in a mouse model of endotoxemia induced by bacterial lipopolysaccharide (LPS) CS-E19-mer directly interacts with circulating histones in the plasma from LPS-challenged mice CS-E 19-mer does not display anticoagulant activity nor react with heparin-induced thrombocytopenia antibodies isolated from patients The successful synthesis of CS-E oligosaccharides provides structurally defined carbohydrates for advancing CS-E research and offers a potential therapeutic agent to treat life-threatening systemic inflammation

Synthetic anticoagulant heparan sulfate attenuates liver ischemia reperfusion injury

Abstract: Heparan sulfate (HS) is a sulfated glycosaminoglycan abundant on the cell surface and in the extracellular matrix and has several biological activities including anticoagulation and anti-inflammation. Liver ischemia reperfusion injury is associated with coagulation and inflammatory responses. Here, we synthesized HS oligosaccharides with defined sulfation patterns and show that synthetic anticoagulant HS oligosaccharides limit liver ischemia reperfusion injury in a mouse model. Using a small targeted HS library, we demonstrate that an oligosaccharide that possesses both anticoagulant activity and binding affinity to HMGB1, the inflammatory target, decreases injury greater than oligosaccharides that only bind to HMGB1 or only have anticoagulant activity. HS oligosaccharides may represent a potential new therapeutic option for decreasing liver damage resulting from ischemia reperfusion injury.

Protease: Serpin complexes to assess contact system and intrinsic pathway activation.

Abstract: Mounting evidence suggests that a variety of disease states are pathophysiologically related to activation of the contact system in vivo The plasma contact system is composed of a cascade of serine proteases initiated by surface activation of factor XII, which can then proceed through a procoagulant pathway by activating the intrinsic coagulation factor XI, or a proinflammatory pathway by activating prekallikrein Serpins are the primary endogenous inhibitors of the contact system, which irreversibly inhibit their respective protease(s), forming a stable complex We modified an existing assay strategy for detecting these complexes in plasma using ELISAs and determined the effect of preanalytical variation caused by anticoagulant selection and processing time The assays were sensitive and specific to inherited deficiency of individual contact factors We conclude that these assays are robust and represent a relatively simple approach to the assessment of contact factor activation in plasma samples

Sulfated oligosaccharides having anti-inflammatory activity

Abstract: Provided herein are small molecule compounds, including non-anticoagulant heparan sulfate oligosaccharide molecules, having anti-inflammatory properties and capable of interacting with high mobility group box 1 (HMGB1) proteins in a manner sufficient to affect an interaction between the HMGB1 protein and a receptor for advanced glycation end products (RAGE) Also provided herein are methods of treating Paracetamol (APAP) overdose in subjects