Browsing by Author "Chen, Lingye"

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Open Access
Combining Heparin and a FX/Xa Aptamer to Reduce Thrombin Generation in Cardiopulmonary Bypass and COVID-19.
(Nucleic acid therapeutics, 2022-01-12) Chabata, Charlene V; Frederiksen, James W; Olson, Lyra B; Naqvi, Ibtehaj A; Hall, Sharon E; Gunaratne, Ruwan; Kraft, Bryan D; Que, Loretta G; Chen, Lingye; Sullenger, Bruce A
Known limitations of unfractionated heparin (UFH) have encouraged the evaluation of anticoagulant aptamers as alternatives to UFH in highly procoagulant settings such as cardiopulmonary bypass (CPB). Despite progress, these efforts have not been totally successful. We take a different approach and explore whether properties of an anticoagulant aptamer can complement UFH, rather than replace it, to address shortcomings with UFH use. Combining RNA aptamer 11F7t, which targets factor X/Xa, with UFH (or low molecular weight heparin) yields a significantly enhanced anticoagulant cocktail effective in normal and COVID-19 patient blood. This aptamer-UFH combination (1) supports continuous circulation of human blood through an ex vivo membrane oxygenation circuit, as is required for patients undergoing CPB and COVID-19 patients requiring extracorporeal membrane oxygenation, (2) allows for a reduced level of UFH to be employed, (3) more effectively limits thrombin generation compared to UFH alone, and (4) is rapidly reversed by the administration of protamine sulfate, the standard treatment for reversing UFH clinically following CPB. Thus, the combination of factor X/Xa aptamer and UFH has significantly improved anticoagulant properties compared to UFH alone and underscores the potential of RNA aptamers to improve medical management of acute care patients requiring potent yet rapidly reversible anticoagulation.
Open Access
DAMPs/PAMPs induce monocytic TLR activation and tolerance in COVID-19 patients; nucleic acid binding scavengers can counteract such TLR agonists.
(Biomaterials, 2022-04) Naqvi, Ibtehaj; Giroux, Nicholas; Olson, Lyra; Morrison, Sarah Ahn; Llanga, Telmo; Akinade, Tolu O; Zhu, Yuefei; Zhong, Yiling; Bose, Shree; Arvai, Stephanie; Abramson, Karen; Chen, Lingye; Que, Loretta; Kraft, Bryan; Shen, Xiling; Lee, Jaewoo; Leong, Kam W; Nair, Smita K; Sullenger, Bruce
Millions of COVID-19 patients have succumbed to respiratory and systemic inflammation. Hyperstimulation of toll-like receptor (TLR) signaling is a key driver of immunopathology following infection by viruses. We found that severely ill COVID-19 patients in the Intensive Care Unit (ICU) display hallmarks of such hyper-stimulation with abundant agonists of nucleic acid-sensing TLRs present in their blood and lungs. These nucleic acid-containing Damage and Pathogen Associated Molecular Patterns (DAMPs/PAMPs) can be depleted using nucleic acid-binding microfibers to limit the patient samples' ability to hyperactivate such innate immune receptors. Single-cell RNA-sequencing revealed that CD16⁺ monocytes from deceased but not recovered ICU patients exhibit a TLR-tolerant phenotype and a deficient anti-viral response after ex vivo TLR stimulation. Plasma proteomics confirmed such myeloid hyperactivation and revealed DAMP/PAMP carrier consumption in deceased patients. Treatment of these COVID-19 patient samples with MnO nanoparticles effectively neutralizes TLR activation by the abundant nucleic acid-containing DAMPs/PAMPs present in their lungs and blood. Finally, MnO nanoscavenger treatment limits the ability of DAMPs/PAMPs to induce TLR tolerance in monocytes. Thus, treatment with microfiber- or nanoparticle-based DAMP/PAMP scavengers may prove useful for limiting SARS-CoV-2 induced hyperinflammation, preventing monocytic TLR tolerance, and improving outcomes in severely ill COVID-19 patients.
Open Access
Key Pathogenic Factors in Coronavirus Disease 2019-Associated Coagulopathy and Acute Lung Injury Highlighted in a Patient With Copresentation of Acute Myelocytic Leukemia: A Case Report.
(A&A practice, 2021-03-30) Olson, Lyra B; Naqvi, Ibtehaj A; Turner, Daniel J; Morrison, Sarah A; Kraft, Bryan D; Chen, Lingye; Sullenger, Bruce A; Nair, Smita K; Que, Loretta G; Levy, Jerrold H
The role of concurrent illness in coronavirus disease 2019 (COVID-19) is unknown. Patients with leukemia may display altered thromboinflammatory responses. We report a 53-year-old man presenting with acute leukemia and COVID-19 who developed thrombotic complications and acute respiratory distress syndrome. Multiple analyses, including rotational thromboelastometry and flow cytometry on blood and bronchoalveolar lavage, are reported to characterize coagulation and immune profiles. The patient developed chemotherapy-induced neutropenia that may have protected his lungs from granulocyte-driven hyperinflammatory acute lung injury. However, neutropenia also alters viral clearing, potentially enabling ongoing viral propagation. This case depicts a precarious equilibrium between leukemia and COVID-19.