Comparison of Estetrol Exposure between Women and Mice to Model Preclinical Experiments and Anticipate Human Treatment.

peer reviewedEstetrol (E4) is a natural estrogen with promising therapeutic applications in humans. The European Medicines Agency and the Food and Drug Administration have approved the use of 15 mg E4/3 mg drospirenone for contraceptive indication. Phase III clinical trials with 15-20 mg E4 for the relief of climacteric complaints are currently running. Relevant data from preclinical animal models are needed to characterize the molecular mechanisms and the pharmacological effects of E4 and possibly to reveal new therapeutic applications and to anticipate potential adverse effects. Therefore, it is important to design experimental procedures in rodents that closely mimic or anticipate human E4 exposure. In this study, we compared the effects of E4 exposure after acute or chronic administration in women and mice. Women who received chronic E4 treatment per os at a dose of 15 mg once daily reached a steady state within 6 to 8 days, with a mean plasma concentration of 3.20 ng/mL. Importantly, with subcutaneous, intraperitoneal or oral administration of E4 in mice, a stable concentration over time that would mimic human pharmacokinetics could not be achieved. The use of osmotic minipumps continuously releasing E4 for several weeks provided an exposure profile mimicking chronic oral administration in women. Measurements of the circulating concentration of E4 in mice revealed that the mouse equivalent dose necessary to mimic human treatment does not fit with the allometric prediction. In conclusion, this study highlights the importance of precise definition of the most appropriate dose and route of administration to utilize when developing predictive preclinical animal models to mimic or anticipate specific human treatment

Microfluidics contribution to pharmaceutical sciences: From drug discovery to post marketing product management

Drug discovery and development is a long-lasting process in which many challenges have to be addressed at every stage, from the discovery of the target biomolecule to the commercialization of the discovered drugs and its quality control. From thousands of hits identified during early drug discovery only one drug is eventually efficient and safe enough to be commercialized. This high rejection rate, especially during preclinical and clinical studies have led to an exponential increase of costs to develop new medicines thereby strongly impacting healthcare systems. In this context, miniaturized devices have the potency to significantly reduce the cost and the time needed to develop new therapeutics by streamlining drug development and rejecting drug candidates earlier in the process prior to costly animal and human trials. In this review, we present recent advances involving miniaturized technologies in the field of drug discovery such as target discovery, drug screening, drug synthesis and formulation, in-vitro and in-vivo testing and quality control. We discuss opportunities enabled by miniaturized devices but also their limitations and challenges that need to be resolved in order to spread their use in the pharmaceutical industries. © 2018 Elsevier B.V

Metabolomic and proteomic biomarker quantification in the context of personalized medicin

Présentation de résultats concernant l'étude de biomarqueurs protéiques dans le cadre des affections rhumatologiques

Multidimensional performance assessment of micro pillar array column chromatography combined to ion mobility-mass spectrometry for proteome research

peer reviewedMicro pillar arrays columns (mPAC) are recent nanoflow liquid chromatographic (LC) systems featuring highly ordered pillars containing an outer porous shell grafted with C18 groups. This format limits backpressure and allows the use of extremely long separation channel (up to 2 m). In this study, we evaluated the use of mPAC in combination with ion mobility mass spectrometry (IM-MS). In IM-MS, ions are separated in gas-phase based on their size and charge. mPAC was compared to two other nanoflow systems and a state-of-the-art ultra-high-pressure liquid chromatograph (UHPLC). Performances in the four dimensions of information (LC, IM, MS and intensity) were calculated to assess the multidimensional efficiency of each tested system. mPAC proved to be superior to other nanoflow systems by producing more efficient peaks regardless of the gradient time employed which resulted in higher peak capacities (386 after 240 min gradient). In combination with IM, 3 times more peaks could be separated without loss of analysis time. Although UHPLC-ESI was superior from a chromatographic point of view, its sensitivity was rather limited compared to nanoflow LCs. On average, peaks in mPAC were 45-times more intense. Finally, mPAC combined to IM prove to enhance the proteome coverage by identifying two times more peptides than nanoflow LCs and ten times more than UHPLC. As a conclusion, mPAC combined to IM seems to be a suitable platform for discovery proteomics due to its high separation capacities

Volumetric absorptive microsampling for targeted metabolomics of whole blood

Volumetric absorptive microsampling (VAMS) enables the collection of small and accurate quantities of biological fluids. Therefore, this sampling technique is of great interest for volume-limited samples or serial collection of samples. Here, we present and discuss the potential of VAMS for targeted mass spectrometry (MS)-based metabolomics. In total, 24 amino acids and 12 organic acids were selected as target metabolites. Two ultra-high performance liquid chromatography (UHPLC) methods coupled to tandem MS have been developed and optimized for the separation and quantitation of these metabolites. A reversed-phase UHPLC-MS/MS method was used to analyze organic acids, whereas hydrophilic interaction chromatography (HILIC)-MS/MS was selected for the determination of amino acids. VAMS devices were used to collect 10 µL of whole blood via a simple finger prick. After collection, the samples were dried for two hours before sample preparation. A design of experiments was conducted to find an extraction solvent providing the maximum recovery of the target analytes from the dried VAMS samples. Overall, the optimum extraction solvent was acetonitrile-water in a proportion of 60:40 (v/v), resulting in the detection of all target metabolites in whole blood with good repeatability. Furthermore, the stability of the analytes in dried whole blood supported on VAMS devices was investigated. We showed that the amino and organic acids were stable for at least 4 days when stored at room temperature. This is in contrast to the instability of these compounds in blood, thereby showing great possibilities of VAMS in metabolomics studies

Effect of cyclo-oxygenase inhibition on embryonic microglia and the sexual differentiation of the brain and behavior of Japanese quail (Coturnix japonica)

peer reviewedEnduring sex differences in the brain are established during a developmental process known as brain sexual differentiation and are mainly driven by estrogens during a critical period. In rodents, the masculinization of the preoptic area by estrogens derived from the central aromatization of testosterone depends in part on the interaction between microglia and prostaglandin E2 (PGE2), a pro-inflammatory hormone of the prostanoid subclass. In contrast, in birds, estrogens produced by females induce a demasculinization, but whether an interaction with the neuro-immune system is involved in this process is unknown. This study addressed this question by testing the effects of blockade of cyclo-oxygenases (COX), the rate-limiting enzymes for prostanoid synthesis, on embryonic microglia and the sexual differentiation of brain and behavior using the Japanese quail as an animal model. The results show that COX inhibition does not affect the behavior of females, but impairs male sexual behavior and suppresses the sex difference in microglial profiles at embryonic day 12 (E12) in the medial preoptic nucleus by increasing the number of microglia in males only. However, neither prostanoid concentrations nor PGE2 receptors differed between sexes in the hypothalamus and preoptic area (HPOA) during development. Overall, these results uncovered a potential role of prostanoids in the demasculinization of Japanese quail. Moreover, the parallel effect of COX inhibition on behavior and microglia suggests an interaction between prostanoids and microglia in brain demasculinization, thus fueling the hypothesis of a conserved role of the neuroimmune system in the organization of the brain by estrogens