ABSTRACT
[Display omitted] • Tb-MOF as a potential sensing material for chloroquine phosphate recovered for multiple cycles. • The quenching mechanisms between Tb-MOF and chloroquine phosphate from many aspects investigated. • The sensor used for the visual detection of chloroquine phosphate in serum. A novel three-dimensional (3D) anionic anhydrous metal − organic framework (MOF), {[NH 2 (CH 3) 2 ]·[Tb(pdca) 2 ]} n (Tb-MOF ;H 2 pdca = 2,5-pyridinedicarboxylic acid) has been triumphantly fabricated and structurally characterized. The obtained Tb-MOF displays good stability in some common solvent systems and high temperature environments. The luminescence properties of Tb-MOF are investigated by fluorescence spectra, and the results exhibit superb characteristic emission of Tb3+ ions, which lay a foundation for exploring the fluorescence sensing application of the material. More importantly, based on competitive absorption and dynamic quenching, Tb-MOF can be applied to detect chloroquine phosphate (CQ) used for the treatment of COVID-19 and malaria, showing high sensitivity and fast response speed in the sensing process. Notably, the specific quenching effect between Tb-MOF and CQ in the serum system without interference from other components, demonstrating the practical application potential of Tb-MOF. [ FROM AUTHOR] Copyright of Microchemical Journal is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full . (Copyright applies to all s.)
ABSTRACT
BACKGROUND: Recent numerous epidemiology and clinical association studies reported that ApoE polymorphism might be associated with the risk and severity of coronavirus disease 2019 (COVID-19), and yielded inconsistent results. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection relies on its spike protein binding to angiotensin-converting enzyme 2 (ACE2) receptor expressed on host cell membranes. METHODS: A meta-analysis was conducted to clarify the association between ApoE polymorphism and the risk and severity of COVID-19. Multiple protein interaction assays were utilized to investigate the potential molecular link between ApoE and the SARS-CoV-2 primary receptor ACE2, ApoE and spike protein. Immunoblotting and immunofluorescence staining methods were used to access the regulatory effect of different ApoE isoform on ACE2 protein expression. RESULTS: ApoE gene polymorphism (ε4 carrier genotypes VS non-ε4 carrier genotypes) is associated with the increased risk (P = 0.0003, OR = 1.44, 95% CI 1.18-1.76) and progression (P < 0.00001, OR = 1.85, 95% CI 1.50-2.28) of COVID-19. ApoE interacts with both ACE2 and the spike protein but did not show isoform-dependent binding effects. ApoE4 significantly downregulates ACE2 protein expression in vitro and in vivo and subsequently decreases the conversion of Ang II to Ang 1-7. CONCLUSIONS: ApoE4 increases SARS-CoV-2 infectivity in a manner that may not depend on differential interactions with the spike protein or ACE2. Instead, ApoE4 downregulates ACE2 protein expression and subsequently the dysregulation of renin-angiotensin system (RAS) may provide explanation by which ApoE4 exacerbates COVID-19 disease.