Design Of Fluorescent Probe With AIE Activity For Detection Of SIRT1 Activity And Its Application In Discovery Of Bioactive Compounds From Traditional Chinese Medicine

Sirtuin 1 (SIRT1) is nicotinamide adenine dinucleotide (NAD+) dependent histone deacetylase 1, regulating the acetylated levels and activities of substrates by deacetylating a variety of histone and non-histone substrates. Therefore, SIRT1 participates in the regulation of gene expression, apoptosis, differentiation, and many other physiological processes. It has been reported that SIRT1 activators have potential application in treating cardiovascular disease, diabetes and other metabolic syndrome, whilst SIRT1 inhibitors currently are available for the treatment of tumors. Nowadays, resveratrol, as representative of natural SIRT1 activators has aroused people’s greatest attention. However, to rhe best of our knowledge, appropriate assays to screen bioactive compound with SIRT1 moderatory effects from traditional Chinese medicine have rarely been reported.Based on the pricinple of aggregation induced emission (AIE), we designed a novel fluorescent probes for the detection of SIRT1 activity. The probe could be applied to monitor SIRT1 activity in living cell as well as discovery of both activators and inhibitors from traditional Chinese medicine.The main contents of the thesis includes:1. We designed a fluorescent probe with aggregation induced emission characteristics for detection of SIRT1 activity. The probes contains carboxyl tetraphenylethylene (TPE) derivatives as fluorescent chromophores and LKB-based peptide Gly-Lys(Ac)-Try-Asp-Asp as substrtrate. Turn on property of fluorescent probe for SIRT1 protein activity detection were studied. The results showed that the fluorescent probe TPE-GK (Ac) YDD with satisfied sensitivity, linearity and specificity can be used to specifically detect SIRTl activity.2. SIRT1 modulators were screened by fluorescent probes both in vitro and in living cells. Meanwhile, we also applied the established approach for discovery of bioactive compounds from traditional Chinese medicine, and subsequently validated the dose-effect relationship of SIRT1 activators. The results showed that the fluorescent probes can achieve dual screening of SIRT1 inhibitors and activators in vitro and SIRT1 modulators screening based on live cell imaging. A sum of 19 SIRT1 activators, mostly from Panax ginseng and Ophiopogon japonicas from tonifying herb, Schisandra chinensis from astringent herb were identified.3. The activate effects of ginsenosides Rb2, ginsenosides Rc, ginsenoside F1 and schisandrin A were validated by intracellular SIRT1 activity test and surface plasmon resonance (SPR) technology. We also studied the cardio-protection mechanisms of 4 SIRT1 activators. The results indicated that found 4 SIRT1 activators, ginsenoside Rb2, ginsenoside Rc, ginsenoside F1 and schisandrin A exert cardio-protection against oxidative stress through activation of SIRT1 and regulation of mitochondrial energy metabolism.