Sleeve gastrectomy ameliorated high-fat diet (HFD)-induced non-alcoholic fatty liver disease and upregulated the nicotinamide adenine dinucleotide +/ Sirtuin-1 pathway in mice.

BACKGROUND: /Objective: Non-alcoholic fatty liver disease (NAFLD) is the most prevalent chronic liver disease, and effective treatments are lacking. Bariatric surgery, including sleeve gastrectomy (SG), is a potential therapeutic strategy for NAFLD, but the molecular mechanisms underlying its effects are not fully understood. In this study, the effects of SG and the underlying mechanisms were evaluated in a mouse model of high-fat diet (HFD)-induced NAFLD. METHODS: C57BL/6 mice were randomly divided into three groups: normal diet with sham operation (NC-Sham group), HFD with sham operation (HFD-Sham group), and HFD with sleeve gastrectomy (HFD-SG group). Glucose metabolism and fat accumulation in the body and liver were analyzed before and after SG. Lipid metabolism and inflammation in the liver were evaluated. Nicotinamide adenine dinucleotide (NAD+) levels as well as nicotinamide riboside kinase (NRK1) and Sirtuin-1 (SIRT1) expression levels were evaluated. RESULTS: SG attenuated the HFD-induced increases in glucose and insulin levels, fat accumulation, and lipid droplet accumulation. Fatty acid biosynthesis, the expression of the metabolism-related genes ACC1, FASN, SCD1, and DGAT1, and the levels of inflammatory factors were higher in HFD mice than in NC mice and decreased after SG. NAD + concentrations were 54.9 ± 13.4 µmol/mg in NC-Sham mice, 37.6 ± 8.1 µmol/mg in HFD-Sham mice, and 79.9 ± 13.0 µmol/mg in HFD-SG mice (p < 0.05). NRK1 and SIRT1 expression increased dramatically after SG at both the RNA and protein levels. CONCLUSION: SG significantly alleviated NAFLD in HFD-induced obese mice with increasing the hepatic NAD + levels and upregulating the NRK1/NAD+/SIRT1 pathway.

Cyclodextrin-Based Peptide Self-Assemblies (Spds) That Enhance Peptide-Based Fluorescence Imaging and Antimicrobial Efficacy.

As a result of their high specificity for their corresponding biological targets, peptides have shown significant potential in a range of diagnostic and therapeutic applications. However, their widespread use has been limited by their minimal cell permeability and stability in biological milieus. We describe here a hepta-dicyanomethylene-4H-pyran appended ß-cyclodextrin (DCM7-ß-CD) that acts as a delivery enhancing "host" for 1-bromonaphthalene-modified peptides, as demonstrated with peptide probes P1-P4. Interaction between the fluorescent peptides P1-P3 and DCM7-ß-CD results in the hierarchical formation of unique supramolecular architectures, which we term supramolecular-peptide-dots (Spds). Each Spd (Spd-1, Spd-2, and Spd-3) was found to facilitate the intracellular delivery of the constituent fluorescent probes (P1-P3), thus allowing spatiotemporal imaging of an apoptosis biomarker (caspase-3) and mitosis. Spd-4, incorporating the antimicrobial peptide P4, was found to provide an enhanced therapeutic benefit against both Gram-positive and Gram-negative bacteria relative to P4 alone. In addition, a fluorescent Spd-4 was prepared, which revealed greater bacterial cellular uptake compared to the peptide alone (P4-FITC) in E. coli. (ATCC 25922) and S. aureus (ATCC 25923). This latter observation supports the suggestion that the Spd platform reported here has the ability to facilitate the delivery of a therapeutic peptide and provides an easy-to-implement strategy for enhancing the antimicrobial efficacy of known therapeutic peptides. The present findings thus serve to highlight a new and effective supramolecular delivery approach that is potentially generalizable to overcome limitations associated with functional peptides.