Amphiphilic α-Peptoid-deoxynojirimycin Conjugate-based Multivalent Glycosidase Inhibitor for Hypoglycemic Effect and Fluorescence Imaging.

Multivalent glycosidase inhibitors based on 1-deoxynojirimycin derivatives against α-glucosidases have been rapidly developed. Nonetheless, the mechanism based on self-assembled multivalent glucosidase inhibitors in living systems needs to be further studied. It remains to be determined whether the self-assembly possesses sufficient stability to endure transit through the small intestine and subsequently bind to the glycosidases located therein. In this paper, two amphiphilic compounds, 1-deoxynojirimycin and α-peptoid conjugates (LP-4DNJ-3C and LP-4DNJ-6C), were designed. Their self-assembling behaviors, multivalent α-glucosidase inhibition effect, and fluorescence imaging on living organs were studied. LP-4DNJ-6C exhibited better multivalent α-glucosidase inhibition activities in vitro. Moreover, the self-assembly of LP-4DNJ-6C could effectively form a complex with Nile red. The complex showed fluorescence quenching effect upon binding with α-glucosidases and exhibited potent fluorescence imaging in the small intestine. This result suggests that a multivalent hypoglycemic effect achieved through self-assembly in the intestine is a viable approach, enabling the rational design of multivalent hypoglycemic drugs.

Nucleolus imaging based on naphthalimide derivatives.

Nucleolus was an important cellular organelle. The abnormal morphology and number of the nucleolus have been considered as diagnostic biomarkers for some human diseases. However, the imaging agent based on nucleolus was limited. In this manuscript, a series of nucleolar fluorescent probes based on naphthalimide derivatives (NI-1 âˆ¼ NI-5) had been designed and synthesized. NI-1 âˆ¼ NI-5 could penetrate cell membranes and nuclear membranes, achieve clear nucleolar staining in living cells. These results suggested that the presence of amino groups on the side chains of naphthalimide backbone could enhance the targeting to the cell nucleolus. In addition, the molecular docking results showed that NI-1 âˆ¼ NI-5 formed hydrogen bonds and hydrophobic interactions with RNA, and exhibited enhanced fluorescence upon binding with RNA. These results will provide favorable support for the diagnosis and treatment of nucleolus-related diseases in the future.

[Inhibition of the Wnt signaling pathway contributes to the cardiac protection of exercise training in spontaneously hypertensive rats].

The objective of this study was to investigate the cardiac protective effect of low-to-moderate intensity exercise training and the role of the Wnt signaling pathway in spontaneously hypertensive rats (SHR). SHR and Wistar-Kyoto (WKY) rats were randomly divided into 5 groups, namely hypertensive control (SHR-S), hypertensive plus exercise training (SHR-E), normal blood pressure control (WKY-S), normal blood pressure plus exercise training (WKY-E) and SHR-E plus Wnt agonist (SHR-E-Wnt). The rats in SHR-E and WKY-E groups underwent low-to-moderate intensity swimming for 16 weeks, and the rats in SHR-E-Wnt group were injected with Wnt agonist 1 through tail vein 4 weeks before the end of swimming. The blood pressure of rats was measured every week. After exercise training, the left ventricular wall thickness and ejection function were measured by ultrasound cardiogram, myocardial structure and collagen fiber changes were observed by HE staining and Masson staining, and the expression levels of ß-catenin and Dishevelled-1 (DVL-1) mRNA and protein in left ventricular myocardium were detected by real-time fluorescence quantitative PCR and Western blot, respectively. The results showed that the body weight was decreased (P < 0.05), blood pressure was increased (P < 0.01), heart weight and ventricular wall thickness were increased (P < 0.01), and the left ventricular ejection function was decreased (P < 0.05) in SHR-S group compared with those in WKY-S group. In addition, the heart structure was damaged, collagen fibers were significantly increased, and the mRNA and protein expressions of ß-catenin and DVL-1 in the left ventricle were significantly up-regulated in SHR-S group compared with those in WKY-S group (P < 0.01). Compared with those in SHR-S group, the body weight of SHR-E group did not change significantly (P > 0.05), but the blood pressure was decreased (P < 0.01), heart weight and ventricular wall thickness were diminished, ejection function was increased (P < 0.01), myocardial structure injury was significantly improved, collagen fibers were significantly reduced, and mRNA and protein expression levels of ß-catenin and DVL-1 in the left ventricle were significantly down-regulated (P < 0.01) in SHR-E group. Importantly, exercise-induced antihypertensive and cardioprotective effects in SHR were blunted by Wnt agonist. These results suggest that low-to-moderate intensity exercise training exerts cardioprotective effects in SHR, possibly through inhibiting the Wnt signaling pathway.