-
Signal Transduction and Targeted Therapy Jun 2023Repurposing existing drugs to inhibit SARS-CoV-2 infection in airway epithelial cells (AECs) is a quick way to find novel treatments for COVID-19. Computational...
Repurposing existing drugs to inhibit SARS-CoV-2 infection in airway epithelial cells (AECs) is a quick way to find novel treatments for COVID-19. Computational screening has found dicoumarol (DCM), a natural anticoagulant, to be a potential SARS-CoV-2 inhibitor, but its inhibitory effects and possible working mechanisms remain unknown. Using air-liquid interface culture of primary human AECs, we demonstrated that DCM has potent antiviral activity against the infection of multiple Omicron variants (including BA.1, BQ.1 and XBB.1). Time-of-addition and drug withdrawal assays revealed that early treatment (continuously incubated after viral absorption) of DCM could markedly inhibit Omicron replication in AECs, but DCM did not affect the absorption, exocytosis and spread of viruses or directly eliminate viruses. Mechanistically, we performed single-cell sequencing analysis (a database of 77,969 cells from different airway locations from 10 healthy volunteers) and immunofluorescence staining, and showed that the expression of NAD(P)H quinone oxidoreductase 1 (NQO1), one of the known DCM targets, was predominantly localised in ciliated AECs. We further found that the NQO1 expression level was positively correlated with both the disease severity of COVID-19 patients and virus copy levels in cultured AECs. In addition, DCM treatment downregulated NQO1 expression and disrupted signalling pathways associated with SARS-CoV-2 disease outcomes (e.g., Endocytosis and COVID-19 signalling pathways) in cultured AECs. Collectively, we demonstrated that DCM is an effective post-exposure prophylactic for SARS-CoV-2 infection in the human AECs, and these findings could help physicians formulate novel treatment strategies for COVID-19.
Topics: Humans; Dicumarol; SARS-CoV-2; COVID-19; Epithelium
PubMed: 37301869
DOI: 10.1038/s41392-023-01511-7 -
Journal of Clinical Biochemistry and... Jul 2023NAD(P)H-dependent quinone oxidoreductase (NQO) is an essential enzyme in living organisms and cells protecting them from oxidative stress. NQO reduces coenzyme Q (CoQ)...
NAD(P)H-dependent quinone oxidoreductase (NQO) is an essential enzyme in living organisms and cells protecting them from oxidative stress. NQO reduces coenzyme Q (CoQ) using NAD(P)H as an electron donor. In the present study, we searched for coenzyme Q10 reducing activity from fractions of gel filtration-fractionated rat liver homogenate. In addition to the large-molecular-weight fraction containing NQO, CoQ10 reducing activity was also detected in a low-molecular-weight fraction. Furthermore, dicumarol, a conventional inhibitor of NQO1 (DT diaphorase), did not inhibit the reduction but quercetin did, suggesting that the activity was not due to NQO1. After further purification, the NADH-dependent CoQ10-reducing compound was identified as riboflavin. Riboflavin is an active substituent of other flavin compounds such as FAD and FMN. These flavin compounds also reduced not only CoQ homologues but also vitamin K homologues in the presence of NADH. The mechanism was speculated to work as follows: NADH reduces flavin compounds to the corresponding reduced forms, and subsequently, the reduced flavin compounds immediately reduce bio-quinones. Furthermore, the flavin-NADH system reduces CoQ10 bound with saposin B, which is believed to function as a CoQ transfer protein . This flavin-dependent CoQ10 reduction, therefore, may function in aqueous phases such as the cell cytosol and bodily fluids.
PubMed: 37534093
DOI: 10.3164/jcbn.22-140 -
Molecular Medicine Reports Jun 2024Knee osteoarthritis (KOA) is a major cause of disability in elderly individuals. Dicoumarol is a coumarin‑like compound derived from sweet clover [ (L.) Pall]. It has...
Knee osteoarthritis (KOA) is a major cause of disability in elderly individuals. Dicoumarol is a coumarin‑like compound derived from sweet clover [ (L.) Pall]. It has been suggested that dicoumarol exhibits various types of pharmacological activities, including anticoagulant, antitumor and antibacterial effects. Due to its various biological activities, dicoumarol has a potential protective effect against OA. Therefore, the present study aimed to assess the effects of dicoumarol on knee osteoarthritis. In the present study, dicoumarol was found to protect rat synoviocytes from lipopolysaccharide (LPS)‑induced cell apoptosis. Western blot analysis showed that dicoumarol significantly reduced the protein expression levels of fibrosis‑related markers and inflammatory cytokines (, , , and ). The inhibitory rates of these proteins were all >50% (P<0.01) compared with those in the LPS and ATP‑induced group. Consistently, the mRNA expression levels of these markers and cytokines were decreased to normal levels by dicoumarol after the treatment of rat synovial fibroblasts with LPS and ATP. Mechanistic studies demonstrated that dicoumarol did not affect NF‑κB signaling, but it did directly interact with NOD‑like receptor protein 3 (NLRP3) to promote its protein degradation, which could be reversed by MG132, but not NH4Cl. The protein half‑life of NLRP3 was accelerated from 26.1 to 4.3 h by dicoumarol. Subsequently, dicoumarol could alleviate KOA ; knee joint diameter was decreased from 11.03 to 9.93 mm. Furthermore, the inflammation and fibrosis of the knee joints were inhibited in rats. In conclusion, the present findings demonstrated that dicoumarol could impede the progression of KOA by inhibiting NLRP3 activation, providing a potential treatment strategy for KOA.
Topics: Animals; Rats; Adenosine Triphosphate; Cytokines; Dicumarol; Fibrosis; Inflammasomes; Inflammation; Lipopolysaccharides; NLR Family, Pyrin Domain-Containing 3 Protein; NLR Proteins; Osteoarthritis, Knee
PubMed: 38639180
DOI: 10.3892/mmr.2024.13224