Substantial evidence has shown that the oxidative damage to hippocampal neurons is associated with the cognitive impairment induced by adverse stimuli during gestation named prenatal stress (PS). Taurine, a conditionally essential amino acid, possesses multiple roles in the brain as a neuromodulator or antioxidant. In this study, to explore the roles of taurine in PS-induced learning and memory impairment, prenatal restraint stress was set up and Morris water maze (MWM) was employed for testing the cognitive function in the one-month-old rat offspring. The mitochondrial reactive oxygen species (ROS) level, mitochondrial membrane potential (MMP), ATP and cytochrome c oxidase (CcO) activity and apoptosis-related proteins in the hippocampus were detected. The activity of the Akt-cyclic AMP response element-binding protein (CREB)peroxisome proliferator-activated receptor-gamma coactivator-1 alpha (PGC1 alpha) pathway in the hippocampus was measured. The results showed that high dosage of taurine administration in the early postnatal period attenuated impairment of spatial learning and memory induced by PS. Meanwhile, taurine administration diminished the increase in mitochondrial ROS, and recovered the reduction of MMP, ATP level and the activities of CcO, superoxide dismutase 2 (SOD2) and catalase induced by PS in the hippocampus. In addition, taurine administration recovered PS-suppressed SOD2 expression level. Taurine administration blocked PS-induced decrease in the ratio of Bcl-2/Bax and increase in the ratio of cleaved caspase-3/full-length caspase-3. Notably, taurine inhibited PS-decreased phosphorylation of Akt (pAkt) and phosphorylation of CREB (pCREB), which consequently enhanced the mRNA and protein levels of PGC1a. Taken together, these results suggest that high dosage of taurine administration during the early postnatal period can significantly improve the cognitive function in prenatally stressed juvenile rats via activating the Akt-CREB-PGC1 alpha pathway. Therefore, taurine has therapeutic potential for prenatal stressed offspring rats in future.
Chemical doping with nitrogen, phosphorus or halogens can effectively favor the room temperature phosphorescence (RTP) appearing of carbon dots (CDs) through facilitating their intersystem crossing (ISC) process. Here we raised a facile microwave strategy to synthesize nitrogen and phosphorus co-doped carbon dots (P-CDs), while triethanolamine served as the carbon source with phosphoric acid being the dopant. Meanwhile, the P-CDs showed both the bright-blue fluorescent emission and the green-RTP emission. Additionally, the filter paper functioned as the matrix to stabilize the triplet excitons of P-CDs, thus achieving their RTP emission by suppressing the non-radiative transitions. Significantly, an innovative painting technology of employing P-CDs as RTP-ink has been developed toward the confidential information encryption. Moreover, we applied the proposed P-CDs to respectively assay pH ranging from 9.15 to 13.55 and 2.29 to 13.55 by virtue of their pH-responsible fluorescence and RTP. Again, we further explored the fluorescent and phosphorescent sensing mechanism of P-CDs by the deprotonation of P-O bonds and the precipitation of P-CDs. (C) 2019 Elsevier Ltd. All rights reserved.