SARS-CoV-2 exacerbates proinflammatory responses in myeloid cells through C-type lectin receptors and Tweety family member 2.

Despite mounting evidence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) engagement with immune cells, most express little, if any, of the canonical receptor of SARS-CoV-2, angiotensin-converting enzyme 2 (ACE2). Here, using a myeloid cell receptor-focused ectopic expression screen, we identified several C-type lectins (DC-SIGN, L-SIGN, LSECtin, ASGR1, and CLEC10A) and Tweety family member 2 (TTYH2) as glycan-dependent binding partners of the SARS-CoV-2 spike. Except for TTYH2, these molecules primarily interacted with spike via regions outside of the receptor-binding domain. Single-cell RNA sequencing analysis of pulmonary cells from individuals with coronavirus disease 2019 (COVID-19) indicated predominant expression of these molecules on myeloid cells. Although these receptors do not support active replication of SARS-CoV-2, their engagement with the virus induced robust proinflammatory responses in myeloid cells that correlated with COVID-19 severity. We also generated a bispecific anti-spike nanobody that not only blocked ACE2-mediated infection but also the myeloid receptor-mediated proinflammatory responses. Our findings suggest that SARS-CoV-2-myeloid receptor interactions promote immune hyperactivation, which represents potential targets for COVID-19 therapy.

A pre-classification strategy based on UPLC-Triple-TOF/MS for metabolic screening and identification of Radix glehniae in rats.

Traditional Chinese Medicines (TCMs) have gained increasing popularity in modern society. However, the profiles of TCMs in vivo are still unclear owing to their complexity and low level in vivo. In this study, UPLC-Triple-TOF techniques were employed for data acquiring, and a novel pre-classification strategy was developed to rapidly and systematically screen and identify the absorbed constituents and metabolites of TCMs in vivo using Radix glehniae as the research object. In this strategy, pre-classification for absorbed constituents was first performed according to the similarity of their structures. Then representative constituents were elected from every class and analyzed separately to screen non-target absorbed constituents and metabolites in biosamples. This pre-classification strategy is basing on target (known) constituents to screen non-target (unknown) constituents from the massive data acquired by mass spectrometry. Finally, the screened candidate compounds were interpreted and identified based on a predicted metabolic pathway, well - studied fragmentation rules, a predicted metabolic pathway, polarity and retention time of the compounds, and some related literature. With this method, a total of 111 absorbed constituents and metabolites of Radix glehniae in rats' urine, plasma, and bile samples were screened and identified or tentatively characterized successfully. This strategy provides an idea for the screening and identification of the metabolites of other TCMs.

Simultaneous determination of nine coumarins in rat plasma by HPLC-MS/MS for pharmacokinetics studies following oral administration of Fraxini Cortex extract.

A high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method was developed for the simultaneous determination of nine coumarins including aesculin, aesculetin, fraxin, fraxetin, scopoletin, isoscopoletin, 6-hydroxy-7,8-dimethoxy coumarin, 8-hydroxy-6,7-dimethoxy coumarin and umbelliferone in rat plasma using nodakenin as the internal standard (IS). The plasma samples were pretreated by a one-step direct protein precipitation with methanol. The chromatographic separation was carried out on a C18 column with a gradient mobile phase consisting of methanol and water (containing 0.05% acetic acid). All analytes and IS were quantitated through electrospray ionization in negative ion multiple reaction monitoring (MRM) mode. This method was fully validated in terms of the sensitivity, specificity, accuracy, precision (intra- and inter-day), matrix effect, recovery as well as the stability of the analyte under various conditions, and the results satisfied the requirements of biological sample measurement. The validated method was successfully applied to pharmacokinetic study of the nine coumarins in rat plasma after oral administration of Fraxini Cortex aqueous extract, among which the pharmacokinetics of four coumarins including fraxetin, isoscopoletin, 6-hydroxy-7,8-dimethoxy coumarin and 8-hydroxy-6,7-dimethoxy coumarin were studied for the first time.

[Gender-related differences in metabolism of the enantiomers of trans tramadol and trans O-demethyltramadol in rat liver microsomes].

AIM: To investigate the gender-related differences in the metabolism of trans tramadol (trans T) enantiomers and the glucuronidation of trans O-demethyltramadol (M1) enantiomers. METHODS: In vitro, trans T or M1 were separately incubated with liver microsomes of male or female rats. The concentrations of the enantiomers of trans T and M1 were determined by an HPCE method. RESULTS: Compared with (+)-enantiomers, (-)-trans T was preferentially metabolized, and (-)-M1 was produced faster in rat liver microsomes. (+)-M1 and (-)-M1 were preferentially glucuronidated in the liver microsomes of male and female rats, respectively. Compared with those in male rat liver microsomes, the enantiomeric ratios of CLint for M1 formation and M1 glucuronidation were more deviated from 1 in female rat liver microsomes. CONCLUSION: In vitro, trans T metabolism, M1 formation and M1 glucuronidation were found to be stereoselective in rat liver microsomes. There were gender-related differences in the stereoselectivity in M1 formation and M1 glucuronidation, with a larger extent in female rat liver microsomes.

Gender-related differences in pharmacokinetics of enantiomers of trans-tramadol and its active metabolite, trans-O-demethyltramadol, in rats.

AIM: To compare the pharmacokinetics of the enantiomers of trans-tramadol (trans-T) and its active metabolite, trans-O-demethyltramadol (M1), in male and female rats. METHODS: Following a single oral dose of 10 mg/kg trans-T hydrochloride to rats, (+)-trans-T, (-)-trans-T, (+)-M1, and (-)-M1 in plasma were determined by a high performance capillary electrophoresis method. RESULTS: The females showed higher plasma concentrations of (+)-trans-T, (-)-trans-T, and (+)-M1 than the males. The enantiomers of trans-T were absorbed and eliminated more slowly in the females than in the males. (+)-M1 was eliminated more slowly in the females than in the males. All pharmacokinetic parameters but Tmax of the two enantiomers of trans-T were significantly different in both sex rats. The (+)/(-)-enantiomeric ratios of the pharmacokinetic parameters for trans-T in the males were similar to those in the females. The values of Cmax, AUC(0-infinity) of the two enantiomers of M1 were significantly different in both sex rats. The (+)/(-)-enantiomeric ratios of Cmax, AUC(0-infinity) for M1 were lower than 1 in the males, larger than 1 in the females. CONCLUSIONS: Systemic exposure of (+)-trans-T, (-)-trans-T, and (+)-M1 was higher in female rats than in male rats. The stereoselectivity in pharmacokinetics of trans-T was similar, and that of M1 was different in male and female rats.