Current drug therapies for ulcerative colitis (UC) are not completely effective in managing moderate-to-severe UC and approximately 20% of patients with severe UC require surgical interventions. Heparins, polydisperse mixtures of non-anticoagulant and anticoagulant oligosaccharides, are widely used as anticoagulants. However, heparins are also reported to have anti-inflammatory properties. Unfractionated heparin was initially used in patients with UC for the treatment of rectal microthrombi. Surprisingly, it was found to be effective in reducing UC-associated symptoms. Since then, several pre-clinical and clinical studies have reported promising outcomes of heparins in UC. In contrast, some controlled clinical trials demonstrated no or only limited benefits, thus the potential of heparins for the treatment of UC remains uncertain. This review discusses potential mechanisms of action of heparins, as well as proposed reasons for their contradictory clinical effectiveness in the treatment of UC.
The effects of the anticoagulant sodium heparin and time of centrifugation on 20 biochemical analytes in the blood of Malaysian flying foxes (Pteropus vampyrus) were evaluated. Paired plasma and serum samples were centrifuged at 1 hr and 6 hr postcollection. Heparinization and time of centrifugation did not significantly affect albumin, cholesterol, triglycerides, amylase, blood urea nitrogen, creatinine, alanine aminotransferase, aspartate aminotransaminase, alkaline phosphatase, calcium, sodium, and total carbon dioxide levels. Plasma was associated with higher globulin and lower potassium values. Glucose and chloride levels decreased significantly over time, whereas phosphorus levels increased. Serum creatine kinase activity at 6 hr postcollection was significantly higher than the other creatine kinase means. Sodium levels were not significantly affected by sodium heparin as used as an anticoagulant in this study.
Decellularized native extracellular matrix (ECM) biomaterials are widely used in tissue engineering and have reached clinical application as biomesh implants. To enhance their regenerative properties and postimplantation performance, ECM biomaterials could be functionalized via immobilization of bioactive molecules. To facilitate ECM functionalization, we developed a metabolic glycan labeling approach using physiologic pathways to covalently incorporate click-reactive azide ligands into the native ECM of a wide variety of rodent tissues and organs in vivo, and into the ECM of isolated rodent and porcine lungs cultured ex vivo. The incorporated azides within the ECM were preserved after decellularization and served as chemoselective ligands for subsequent bioconjugation via click chemistry. As proof of principle, we generated alkyne-modified heparin, immobilized it onto azide-incorporated acellular lungs, and demonstrated its bioactivity by Antithrombin III immobilization and Factor Xa inhibition. The herein reported metabolic glycan labeling approach represents a novel platform technology for manufacturing click-reactive native ECM biomaterials, thereby enabling efficient and chemoselective functionalization of these materials to facilitate tissue regeneration and repair.
Zika virus (ZIKV) is an arthropod-borne flavivirus that causes newborn microcephaly and Guillian-Barré syndrome in adults. No therapeutics are available to treat ZIKV infection or other flaviviruses. In this study, we explored the inhibitory effect of glycosaminoglycans and analogues against ZIKV infection. Highly sulfated heparin, dextran sulfate and suramin significantly inhibited ZIKV infection in Vero cells. De-sulfated heparin analogues lose inhibitory effect, implying that sulfonate groups are critical for viral inhibition. Suramin, an FDA-approved anti-parasitic drug, inhibits ZIKV infection with 3-5 log10 PFU viral reduction with IC50value of ∼2.5-5 μg/ml (1.93 μM-3.85 μM). A time-of-drug-addition study revealed that suramin remains potent even when administrated at 1-24 hpi. Suramin inhibits ZIKV infection by preventing viral adsorption, entry and replication. Molecular dynamics simulation revealed stronger interaction of suramin with ZIKV NS3 helicase than with the envelope protein. Suramin warrants further investigation as a potential antiviral candidate for ZIKV infection. Heparan sulfate (HS) is a cellular attachment receptor for multiple flaviviruses. However, no direct ZIKV-heparin interaction was observed in heparin-binding analysis, and downregulate or removal of cellular HS with sodium chlorate or heparinase I/III did not inhibit ZIKV infection. This indicates that cell surface HS is not utilized by ZIKV as an attachment receptor.