The pericytes (PCs) surrounding capillaries are vital regulators of capillary constriction. Persistent PC contraction results in the increased capillary constriction, therefore leading to the impaired cerebral blood flow (CBF) recovery after reperfusion and worsening the clinical outcomes in stroke patients. However, the potential determinants of PC functions during ischemia/reperfusion are poorly understood. Phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit Delta (PIK3CD/PI3Kδ) is a crucial factor involved with neuronflammation during ischemic stroke. PI3Kδ has shown the expression in PCs, while its effect on PC functions has not been explored yet. In this study, a rodent ischemia/reperfusion model was established in C57BL/6 mice via transient middle cerebral artery occlusion and reperfusion (MCAO/R). The PI3Kδ expression in ischemic penumbra was remarkably upregulated following MCAO/R induction. PI3Kδ inhibitor CAL-101 improved the CBF recovery, ischemic brain injury, and suppressed capillary constriction in MCAO/R mice. Besides, the production of tumor necrosis factor alpha (TNF-α), an inducer for tissue injury, and the expression of transient receptor potential vanilloid type 2 (TRPV2), a channel protein permitting calcium (Ca 2+ ) uptake, were significantly reduced in ischemic penumbra after CAL-101 treatment. In vitro, oxygen-glucose deprivation and reoxygenation (OGD/R) enhanced the expression of PI3Kδ and TRPV2 in primary mouse PCs. CAL-101 suppressed the TNF-α-induced TRPV2 expression in OGD/R-treated PCs, thus inhibiting the Ca 2+ uptake and PC contraction. Collectively, this study suggests that PI3Kδ is a critical regulator of PC function during ischemic stroke.
Parsaclisib is a novel, potent, highly selective, next-generation oral inhibitor of phosphatidylinositol 3-kinase δ (PI3Kδ) for patients with relapsed or refractory B-cell malignancies. However, there is no accurate and rapid method for the determination of parsaclisib. The aim of this study was to establish a rapid, specific and reliable ultra performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method for the determination of parsaclisib, and to investigate in vitro metabolic stability using rat liver microsomes (RLMs) and in vivo pharmacokinetics in rats. Parsaclisib was detected by gradient elution on an Acquity UPLC BEH C18 column (2.1 mm × 50 mm, 1.7 μm) using acetonitrile and 0.1% formic acid as mobile phases, and pilaralisib was used as an internal standard (IS). Selective reaction monitoring (SRM) was used for detection. The method showed acceptable intra- and inter-day precision (< 8.6%) and accuracy (2.0–14.9%). The stability of the test samples was reliable during the analysis. In addition, the recoveries and matrix effects of the samples were within acceptable limits and were stable during storage and determination in rat plasma. The pharmacokinetic trend of parsaclisib in rats was also investigated by this newly developed assay after gavage administration of 2.0 mg/kg parsaclisib. Finally, i n vitro results showed that parsaclisib had a slow intrinsic clearance (Clint) value of 2.4 µL/min/mg protein with a half-life (t 1/2 ) value of 571.3 min. These findings theoretically supported the potential metabolism of parsaclisib in vivo.
危险品化学品经营许可证（带存储）