ABSTRACT
Cortical spreading depression (CSD) is a slow wave of cortical depolarization closely associated with migraines with an aura. Previously, it was thought that CSD depolarization was mainly driven by neurons, with characteristic changes in neuronal swelling and increased extracellular potassium (K+) and glutamate. However, the role of astrocytes, a member of the neurovascular unit, in migraine with CSD has recently received increasing attention. In the early stages of CSD, astrocytes provide neurons with energy support and clear K+ and glutamate from synaptic gaps. However, in the late stages of CSD, astrocytes release large amounts of lactic acid to exacerbate hypoxia when the energy demand exceeds the astrocytes' compensatory capacity. Astrocyte endfoot swelling is a characteristic of CSD, and neurons are not similarly altered. It is primarily due to K+ influx and abnormally active calcium (Ca2+) signaling. Aquaporin 4 (AQP-4) only mediates K+ influx and has little role as an aquaporin. Astrocytes endfoot swelling causes perivascular space closure, slowing the glymphatic system flow and exacerbating neuroinflammation, leading to persistent CSD. Astrocytes are double-edged swords in migraine with CSD and may be potential targets for CSD interventions.
ABSTRACT
Two novel vanadium(III) complexes: V(dipic)(Hbdc)(H2O)2 (1) and [V2(dipic)2(H2btec)(H2O)4]·2H2O (2) (H2dipic = 2,6-pyridinedicarboxylic acid, H2bdc = 1,3-benzene-dicarboxylic acid, H4btec = 1,2,4,5-benzenetetracarboxylic acid) are synthesized by the reaction of V2(SO4)3, 2,6-pyridinedicarboxylic acid and 1,3-benzene-dicarboxylic acid (for 1) or 1,2,4,5-benzenetetracarboxylic acid (for 2) under hydrothermal condition at 120 °C for 3 days. They were characterized by elemental analysis, IR, UV-Vis, single crystal X-ray diffraction analysis and thermogravimetric analyses (TG). Structural analyses show that the vanadium atoms in the complexes 1 and 2 are both in a pentagonal-bipyramidal coordination environment with the NO6 donor set, and there is intermolecular hydrogen bonding in each complex. Research results found that the complexes exhibited bromination catalytic activity in the single-pot reaction of the conversion of phenol red to bromophenol blue in the mixed solution of H2O-DMF at the constant temperature of 30 ± 0.5 °C with pH = 5.8, and catalytic C-H bond cleavage activity for the peroxidative oxidation (with hydrogen peroxide) of cyclohexane to cyclohexanol and cyclohexanone (the maximum total turnover number is 395) under the mild conditions.
