Genomic analysis reveals a cryptic pangolin species.

Eight extant species of pangolins are currently recognized. Recent studies found that two mitochondrial haplotypes identified in confiscations in Hong Kong could not be assigned to any known pangolin species, implying the existence of a species. Here, we report that two additional mitochondrial haplotypes identified in independent confiscations from Yunnan align with the putative species haplotypes supporting the existence of this mysterious species/population.

Vicagrel enhances aspirin-induced inhibition of both platelet aggregation and thrombus formation in rodents due to its decreased metabolic inactivation.

Both aspirin and vicagrel are effective antiplatelet drugs, with the potential for concomitant use as another dual-antiplatelet therapy for the prevention of recurrent thrombotic or ischemic events. Because they both are the substrates of carboxylesterase 2 (CES2), aspirin attenuated the metabolic activation of and platelet response to vicagrel in mice treated with the two drugs concomitantly. In this study, we sought to clarify whether vicagrel could affect platelet responses to aspirin and their underlying mechanisms.

Enhanced responsiveness of platelets to vicagrel in IL-10-deficient mice through STAT3-dependent up-regulation of the hydrolase arylacetamide deacetylase in the intestine.

Background And Purpose: Vicagrel is a novel promising antiplatelet drug designed for overcoming clopidogrel resistance. There is limited evidence indicating that exogenous IL-10 suppresses CYP3A4 activity in healthy subjects and that IL-10 knockout (KO) mice exhibit increased clopidogrel bioactivation compared with wild-type (WT) mice. In this study, we sought to determine whether IL-10 could play an important role in the metabolism of and platelet response to vicagrel in mice.

Aspirin Attenuates the Bioactivation of and Platelet Response to Vicagrel in Mice.

Vicagrel, a novel acetate analogue of clopidogrel, exerts more potent antiplatelet effect than clopidogrel in rodents. Relevant evidence indicated that aspirin and vicagrel are the drug substrate for carboxylesterase 2. Accordingly, it is deduced that concomitant use of aspirin could attenuate the bioactivation of and platelet response to vicagrel.

Human UGT2B7 is the major isoform responsible for the glucuronidation of clopidogrel carboxylate.

Clopidogrel is predominantly hydrolyzed to clopidogrel carboxylic acid (CCA) by carboxylesterase 1, and subsequently CCA is glucuronidated to clopidogrel acyl glucuronide (CAG) by uridine diphosphate-glucuronosyltransferases (UGTs); however, the UGT isoenzymes glucuronidating CCA remain unidentified to date. In this study, the glucuronidation of CCA was screened with pooled human liver microsomes (HLMs) and 7 human recombinant UGT (rUGT) isoforms. Results indicated that rUGT2B7 exhibited the highest catalytical activity for the CCA glucuronidation as measured with a mean V value of 120.

Mrp3 Transports Clopidogrel Acyl Glucuronide from the Hepatocytes into Blood.

Clopidogrel acyl glucuronide (CLP-G) is a major phase II metabolite of clopidogrel generated in the liver for further excretion into urine; however, it is unclear whether CLP-G transports from hepatocytes into blood. Because multidrug resistance-associated protein 3 (MRP3) is predominantly expressed in the sinusoidal side of hepatocytes and preferentially transports glucuronide conjugates of drug metabolites from hepatocytes into bloodstream, we hypothesized that MRP3 could be such an efflux transporter for CLP-G. In this study, we compared the liver-to-plasma ratios of clopidogrel and its metabolites (including CLP-G) between (ATP-binding cassette, subfamily C, member 3) knockout (KO) and wild-type (WT) mice.