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In all of the clinical trials for COVID-19 conducted thus far and among those ongoing involving chloroquine or hydroxychloroquine, the drug substance used has invariably been chloroquine (CQ) diphosphate or hydroxychloroquine (HCQ) sulfate, i.e., the phosphoric or sulfuric acid salt of a racemic mixture of R- and S-enantiomer (50/50), respectively. As a result, the clinical outcome from previous CQ or HCQ trials were, in fact, the collective manifestation of both R and S- enantiomers with inherent different pharmacodynamic and pharmacokinetic properties, and toxicity liabilities. Our data for the first time demonstrated the stereoselective difference of CQ and HCQ against live SARS-CoV-2 virus in a Biosafety Level 3 laboratory. S-chloroquine (S-CQ) and S-hydroxychloroquine (S-HCQ) significantly more active against SARS-CoV-2, as compared to R-CQ and R-HCQ, respectively. In addition, Mpro, as one of the critical enzymes for viral transcription and replication, also exhibited an enantioselective binding affinity toward the S-enantiomers. The most significant finding from this study is the pronounced difference of the two enantiomers of CQ and HCQ observed in hERG inhibition assay. The IC50 value of S-HCQ was higher than 20 M against hERG channel, which was much less active over all tested CQ and HCQ compounds. Moreover, S-HCQ alone did not prolong QT interval in guinea pigs after 3 days and 6 days of administration, indicating a much lower cardiac toxicity potential. With these and previous findings on the enantio-differentiated metabolism, we recommend that future clinical studies should employ S-HCQ, substantially free of the R-enantiomer, to potentially improve the therapeutic index for the treatment of COVID-19 over the racemic CQ and HCQ.
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Objective To investigate the effects of interferon alpha?2b(IFNα?2b)on serum Hepcidin in hepatitis C patients and its mechanism. Methods Hepatitis C patients were divided evenly into treatment group and control group according to whether they had received treatment with IFNα?2b in the past 3 months. The serum hepci?din was compared between the two groups. HepG2 cells and LO2 cells were treated for 24 hours at varied levels of IFNα?2b(0,50,100,200,400μL)and real?time PCR was used to detect the hepcidin,interleukin?6(IL?6)and signal transduction and transcription activator 3(STAT3)mRNA expression of cells. The protein levels of STAT3 and phosphorylated STAT3(pSTAT3)were measured by Western blot. The changes of these indexes were observed with the gradual increase of IFNα?2b levels. Results Serum Hepcidin level in the treatment group was significantly lower than the control(P<0.05). IFNα?2b inhibited the Hepcidin mRNA in HepG2 cells and LO2 cells. pSTAT3 was significantly decreased with the increased levels of IFNα?2b(P<0.05),and the expression of IL?6 and STAT3 had no significant changes with the increase of IFNα?2b. Conclusion The serum Hepcidin levels can be decreased because IFNα?2b suppresses the expression of Hepcidin,and its mechanism may be related with inhibited STAT3 pathway activation.
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Objective To investigate the influence of miR-106b on Wnt/β-catenin pathway in HCC cells. Methods QGY-7703 and HepG2 cells were transfected with miRNA mimics or inhibitors. TOP/FOP luciferase ratio assay was used to test the Wnt/β-catenin pathway activity. The expression of downstream targeted genes of Wnt/β-catenin pathway were examined by Real-time PCR. The accumulation of β-catenin in nuclears were measured by Western blotting. Results Ectopic expression of miR-106b dramatically increased the average TOP/FOP ratio and the mRNA expression of downstream targeted genes in QGY-7703 and HepG2 cells. Compared with that in control cells , miR-106b over-expression promoted the nuclear β-catenin accumulation in QGY-7703 cells. Clonclusion MiR-106b activated Wnt/β-catenin pathway in HCC cells.
