Investigations into tau-targeting diagnosis of Alzheimer's disease are currently underway, and the development of tau-selective molecular probes is urgently required. In this study, the donor-π-acceptor architecture of the previously reported tau-selective fluorescence probe was modified into thiophene-π-cyanoacetamides. While the fluorescence properties of the prepared probes were not influenced by the thiophene substituents, intense and tau-selective turn-on fluorescence in the near infrared region was observed only in the probes with unsubstituted phenyl or p-methylphenyl cyanoacetamides in the acceptor functionality. Compared with the parent compound, the newly identified probes showed 1.5 $ 4.1 times increase in tau-selectivity over Aβ fibrils and 3.5 $ 4.7 times increase in fluorescence intensity. The tau-selective fluorescence properties of the title probes were further demonstrated in the cellular milieu, and the green and red fluorescence emitted by GFP and tau-bound probes, respectively, were shown to be nicely colocalized in the SH-SY5Y cells stably expressing GFP-tagged tau.

(-)-Epigallocatechin gallate (EGCG) is one of the autophagy stimulators that have been reported to protect vascular endothelial cells from oxidative stress-induced damage. In this study, we attempted potentiation of the autophagy-stimulating activity of EGCG in human aortic epithelial cells (HAECs) by using the EGCG-phenylalanine conjugate, E10. Autophagy-stimulating activity of E10 was evaluated by LC3-II measurement in the absence and presence of the lysosomal blocker chloroquine, CTYO-ID staining, and reporter assay using tandem fluorescence-tagged LC3. These experiments revealed significantly enhanced autophagic flux stimulation in HAECs by E10 compared with EGCG. Further elaboration of E10 showed that activation of AMPK through phosphorylation as the major mechanism of its autophagy stimulation. Like other autophagy stimulators, E10 protected HAECs from lipotoxicity as well as accompanying endothelial senescence. Finally, stimulation of autophagy by E10 was shown to protect HAECs from oxidative stress-induced apoptosis. These findings collectively suggest potential clinical implications of E10 for various cardiovascular complications through stimulation of autophagy.