ZHOU WAN

and 8 more

Aims: Olanzapine, a second-generation antipsychotic, can cause dose-adverse drug reactions. Its steady-state concentration can vary due to several factors. This study explores how physiological factors, smoking, inflammation, concomitant medications, and metabolic enzyme single nucleotide polymorphisms (SNPs) influence its metabolic levels, aiming to guide personalized dosing. Methods: This study analyzed data from 310 olanzapine-treated patients at Beijing Anding Hospital. Liquid chromatography-mass spectrometry (LC-MS/MS) quantified 1002 serum concentrations. Eleven SNPs from CYP1A2, CYP3A5, UGT1A4, and FMO1/3 were identified through real-time fluorescence quantitative polymerase chain reaction (q-PCR). A Bayesian network was applied to elucidate causal relationships between variables, followed by g-computation to quantify the effect of individual factors on the dose-adjusted concentration (C/D ratio) of olanzapine. The Wilcoxon signed-rank test assessed the intra-individual variations in the steady-state C/D ratio. Results: The Bayesian network suggested causality between smoking, sex, sertraline, Danggui-Longhui, valproic acid, and the olanzapine C/D ratio. None of the SNPs reached significance levels. The Wilcoxon signed-rank test confirmed that both polypharmacy and inflammation increased the C/D ratio within individuals. G-computation showed that the log ratio of olanzapine C/D decreased by 0.392 ± 0.037 in males and 0.004 ± 0.001 with smoking. Danggui-Longhui, sertraline, and valproic acid reduced the ratio by 0.652 ± 0.131, 0.398 ± 0.127, and 0.328 ± 0.039, respectively. Conclusion: Our study confirms that sex, age, smoking, inflammation, and co-prescription with sertraline, Danggui-Longhui, and valproic acid contributed to variability in olanzapine’s steady-state concentration. Considering these factors in clinical practice may help to personalize olanzapine treatment in Asian patients.

Jiangman Song

and 7 more

Purpose: To study the antiplatelet mechanisms of ticagrelor. Experimental design: Platelets underwent activation with 20 μM ADP for 30 seconds followed by inhibition with 2 nM ticagrelor for another 30 seconds. Mass-spectrometry-based phosphoproteomic technique was applied to obtain phosphorylation spectra in platelets. Results: We successfully quantified 2285 phosphopeptides with high confidence in 1189 phosphoproteins. Compared with intact platelets, ADP-activated platelets showed significant upregulation of PDE5ASer102 and downregulation of 178 phosphopeptides in 154 proteins. Gene Ontology analysis showed that downregulated phosphoproteins were enriched in molecular functions and pathways associated with RNA processing and surveillance. After ticagrelor treatment, we identified 53 significantly regulated phosphopeptides, including 17 upregulated and 36 downregulated, in 45 phosphoproteins. Eight phosphopeptides in STIM1, DENND4C, TNIK, BCL9L, DBN1, DOCK10, FRMD4B, and PRKAR2B were significantly downregulated after ADP stimulation and significantly upregulated after adding ticagrelor. They were mainly implicated in regulation of Ca2+ flow, Wnt/β-catenin signaling, and cytoskeleton remodeling, suggesting their potential role as mediators in ticagrelor-related signaling pathways. Conclusions and clinical relevance: By sequential activation and inhibition of platelets using mutual competitive inhibitors, ADP and ticagrelor, we demonstrated alternations in phosphorylation status of phosphoproteins, which could help to interpret the mechanism of bleeding complications associated with ticagrelor.