The anti-apoptotic effect of fluid mechanics preconditioning by cells membrane and mitochondria in rats brain microvascular endothelial cells.

Exercise preconditioning is a simple and effective way to prevent ischemia. This paper further provided the mechanism in hemodynamic aspects at the cellular level. To study the anti-apoptotic effects of fluid mechanics preconditioning, Cultured rats brain microvascular endothelial cells were given fluid intervention in a parallel plate flow chamber before oxygen glucose deprivation. It showed that fluid mechanics preconditioning could inhibit the apoptosis of endothelial cells, and this process might be mediated by the shear stress activation of Tie-2 on cells membrane surface and Bcl-2 on the mitochondria surface.

Simultaneous Determination of Bosentan, Glimepiride, HYBOS and M1 in Rat Plasma by UPLC-MS-MS and its Application to Pharmacokinetic Study.

A rapid and sensitive ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS-MS) method for the simultaneous determination of bosentan (BOS), glimepiride (GLP), hydroxyl bosentan (HYBOS) and hydroxyl glimepiride (M1) in rat plasma using one-step protein precipitation was developed and validated. After addition of ambrisentan as an internal standard (IS), protein precipitation by acetonitrile was used in sample preparation. Chromatographic separation was achieved on a Waters ACQUITY UPLC BEH C18 column (2.1 mm × 100 mm, 1.7 µm particle size, Waters Corp., Milford, MA, USA) and inline 0.2 µm stainless steel frit filter (Waters Corp.) with acetonitrile-0.1% formic acid as the mobile phase at a flow rate of 0.4 mL/min with gradient elution. The column temperature was maintained at 40°C. Only 4 min was needed for an analytical run. The retention times were ∼3.29 min for BOS, 3.56 min for GLP, 1.42 min for HYBOS, 1.53 min for M1 and 3.22 min for IS. Electrospray ionization source was employed and operated in positive-ion mode; multiple reaction monitoring mode was applied to target fragment ions m/z 552 → 202, m/z 568 → 202, m/z 491 → 352, m/z 507 → 352 and m/z 379 → 347 for BOS, HYBOS, GLP, M1 and IS, respectively. The assay was validated over concentration ranges of 25-5,000 ng/mL (r(2) = 0.9984) for BOS, 1-200 ng/mL (r(2) = 0.9999) for GLP, 0.5-100 ng/mL (r(2) = 0.9999) for HYBOS and 0.1-20 ng/mL (r(2) = 0.9984) for M1. Intra- and interday precision values for replicate quality control samples were within 14.2% for all analytes during the assay validation. Mean quality control accuracy values were within -3.3 to 14.4% of nominal values for all analytes. The mean recoveries of BOS, GLP, HYBOS, M1 and ambrisentan from the plasma exceeded 90.4%. The analytes were stable in rat plasma for at least 2 h at room temperature, 30 days at -40°C and following at least three freeze-thaw cycles (-40°C to room temperature). This method was successfully applied to a pharmacokinetic study of coadministeration of BOS and GLP in rats.

Effects of 22 CYP2D6 Genetic Variations Newly Identified in Chinese Population on Olanzapine Metabolism in vitro.

The objective of this study was to assess the catalytic activity of 22 novel CYP2D6 allelic variants (2D6*87-*98, R25Q, F164L, E215K, F219S, V327M, D336N, V342M, R344Q, R440C and R497C) to olanzapine in vitro. Their protein products expressed in Spodoptera frugiperda 21 (Sf21) insect cells were incubated with olanzapine 100-2,000 µmol/l for 30 min. The kinetic parameters of Km, Vmax and intrinsic clearance were determined by 2-hydroxymethylolanzapine, the metabolite of olanzapine mediated by CYP2D6, using ultra-performance liquid chromatography tandem mass spectrometry. Results showed that the kinetic parameters of 2 alleles, CYP2D6*92 and 2D6*96, could not be detected; 17 allelic variants, CYP2D6*87-*88, 2D6*90-*91, 2D6*93-*95, 2D6*97, R25Q, F164L, E215K, F219S, V327M, V342M, R344Q, R440C and R497C, significantly reduced the intrinsic clearance of olanzapine; 2 variants, CYP2D6*89 and 2D6*98, increased the intrinsic clearance of olanzapine; no difference was found in intrinsic clearance of D336N. Furthermore, 6 alleles, CYP2D6*87, 2D6*88, 2D6*91, 2D6*93, 2D6*97 and R497C, exhibited higher Km values in a range of 120.80-217.56% relative to wild-type CYP2D6*1. The research demonstrated the metabolic phenotype of the 22 novel CYP2D6 variants for olanzapine that were different from probe drugs we used previously and might provide beneficial information to the personalized medicine of olanzapine.

Morphology, differentiation and adhesion molecule expression changes of bone marrow mesenchymal stem cells from acute myeloid leukemia patients.

Bone marrow mesenchymal stem cells (BMSCs) have been identified as an important component of the hematopoietic stem cell (HSC) niche, which is essential for the maintenance of HSCs. HSC niche alternation has been considered to be the main cause of acute myeloid leukemia (AML). However, little is known with regard to BMSC alteration in AML patients. BMSCs were collected from 10 AML patients and 13 controls in order to examine the morphology, differentiation and adhesion molecule expression changes. It was observed that primary BMSCs from AML patients exhibited aberrant morphologies compared with those from the controls. Prior to adipogenic differentiation, the mRNA and protein levels of the lipid marker gene lipoprotein lipase, from the BMSCs of AML patients, were significantly higher. lipid drops were present early during differentiation in the BMSCs of AML patients and exhibited greater numbers later. Following adipogenic differentiation, the mRNA level of E-cadherin in the BMSCs of AML patients was significantly lower than that identified in the BMSCs of the control groups. Following osteogenic induction, the mRNA level of E-cadherin in the BMSCs of AML patients was significantly higher than in the controls. Therefore BMSCs from the AML patients exhibited irregular morphology, tendency to pre-differentiate to adipocytes and different adhesion molecule expression following differentiation. These differences may further our understanding of the HSC niche in the pathological condition.