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The precise control of the shape, size and microstructure of nanomaterials is of high interest in chemistry and material sciences. However, living lateral growth of cylinders is still very challenging. Herein, we propose a crystallization-driven fusion-induced particle assembly (CD-FIPA) strategy to prepare cylinders with growing diameters by the controlled fusion of spherical micelles self-assembled from an amphiphilic homopolymer. The spherical micelles are heated upon glass transition temperature (Tg) to break the metastable state to induce the aggregation and fusion of the amorphous micelles to form crystalline cylinders. With the addition of extra spherical micelles, these micelles can attach onto and fuse with the cylinders, showing the living character of the lateral growth of cylinders. Computer simulations and mathematical calculations are preformed to reveal the total energy changes of the nanostructures during the self-assembly and CD-FIPA process. Overall, we demonstrated a CD-FIPA concept for preparing cylinders with growing diameters. Precise control of the microstructure of nanomaterials is of interest but living lateral growth of cylinders is still very challenging. Here, the authors propose a crystallization-driven fusion-induced particle assembly strategy to prepare cylinders with growing diameters by controlled fusion of spherical micelles self-assembled from an amphiphilic homopolymer. [ABSTRACT FROM AUTHOR]

Aim:Defects in fatty acid metabolism contribute to the pathogenesis of insulin resistance and obesity. In this study, we investigated the effects of a novel compound yhhu981 on fatty acid metabolism in vitro and in vivo.Methods:The capacity to stimulate fatty acid oxidation was assessed in C2C12 myotubes. The fatty acid synthesis was studied in HepG2 cells using isotope tracing. The phosphorylation of AMPK and acetyl-CoA carboxylase (ACC) was examined with Western blot analysis. For in vivo experiments, ob/ob mice were orally treated with yhhu981 acutely (300 mg/kg) or chronically (150 or 300 mg·kg−1·d−1 for 22 d). On the last day of treatment, serum and tissue samples were collected for analysis.Results:Yhhu981 (12.5-25 μmol/L) significantly increased fatty acid oxidation and the expression of related genes (Sirt1, Pgc1α and Mcad) in C2C12 myotubes, and inhibited fatty acid synthesis in HepG2 cells. Furthermore, yhhu981 dose-dependently increased the phosphorylation of AMPK and ACC in both C2C12 myotubes and HepG2 cells. Compound C, an AMPK inhibitor, blocked fatty acid oxidation in yhhu981-treated C2C12 myotubes and fatty acid synthesis decrease in yhhu981-treated HepG2 cells. Acute administration of yhhu981 decreased the respiratory exchange ratio in ob/ob mice, whereas chronic treatment with yhhu981 ameliorated the lipid abnormalities and ectopic lipid deposition in skeletal muscle and liver of ob/ob mice.Conclusion:Yhhu981 is a potent compound that stimulates fatty acid oxidation, and exerts pleiotropic effects on lipid metabolism by activating AMPK. [ABSTRACT FROM AUTHOR]

Aim:The sodium glucose cotransporter 2 (SGLT2) plays an important role in renal glucose reabsorption, thus serves as a new target for the treatment of diabetes. The purpose of this study was to evaluate SHR3824 as a novel selective SGLT2 inhibitor and to characterize its in vivo effects on glucose homeostasis. The effects of chronic administration of SHR3824 on peripheral insulin sensitivity and pancreatic β-cell function were also investigated.Methods:The in vitro potency and selectivity of SHR3824 were assessed in HEK293 cells transfected with human SGLT2 or SGLT1. Acute and multi-dose studies were performed on ICR mice, GK rats and db/db mice to assess the ability of SHR3824 to enhance urinary glucose excretion and improve blood glucose levels. 2-Deoxyglucose uptake and insulin immunohistochemical staining were performed in the soleus muscle and pancreas, respectively, of db/db mice. A selective SGLT2 inhibitor BMS512148 (dapagliflozin) was taken as positive control.Results:SHR3824 potently inhibited human SGLT2 in vitro, but exerted much weak inhibition on human SGLT1 (the IC50 values of SHR3824 against human SGLT2 and SGLT1 were 2.38 and 4324 nmol/L, respectively). Acute oral administration of SHR3824 (0.3, 1.0, 3.0 mg/kg) dose-dependently improved glucose tolerance in ICR mice, and reduced hyperglycemia by increasing urinary glucose excretion in GK rats and db/db mice. Chronic oral administration of SHR3824 (0.3, 1.0, 3.0 mg·kg−1·d−1) dose-dependently reduced blood glucose and HbA1c levels in GK rats and db/db mice, and significantly increased insulin-stimulated glucose uptake in the soleus muscles and enhanced insulin staining in the islet cells of db/db mice.Conclusion:SHR3824 is a potent and selective SGLT2 inhibitor and exhibits antidiabetic efficacy in several rodent models, suggesting its potential as a new therapeutic agent for the treatment of type 2 diabetes. [ABSTRACT FROM AUTHOR]

Aim:Emodin (1,3,8-trihydroxy-6-methylanthraquinone) is a potent and selective inhibitor of 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) with the ability to ameliorate metabolic disorders in diet-induced obese mice. In the present study, we investigated the effects of emodin on adipocyte function and the underlying mechanisms in vitro, and its anti-diabetic effects in ob/ob mice.Methods:3T3-L1 adipocytes were used for in vitro studies. 11β-HSD1A activity was evaluated with a scintillation proximity assay. The adipogenesis, glucose uptake, lipolysis and adiponectin secretion were investigated in 3T3-L1 adipocytes treated with emodin in the presence of active (corticosterone) or inactive glucocorticoid (11-dehydrocorticosterone). For in vivo studies, ob/ob mice were administered emodin (25 and 50 mg·kg−1·d−1, ip) for 26 d. On the last day of administration, the serum was collected and the mesenteric and perirenal fat were dissected for analyses.Results:Emodin inhibited the 11β-HSD1 activity in 3T3-L1 adipocytes in concentration- and time-dependent manners (the IC50 values were 7.237 and 4.204 μmol/L, respectively, after 1 and 24 h treatment. In 3T3-L1 adipocytes, emodin (30 μmol/L) suppressed 11-dehydrocorticosterone-induced adipogenesis without affecting corticosterone-induced adipogenesis; emodin (3 μmol/L) reduced 11-dehydrocorticosterone-stimulated lipolysis, but had no effect on corticosterone-induced lipolysis. Moreover, emodin (3 μmol/L) partly reversed the impaired insulin-stimulated glucose uptake and adiponectin secretion induced by 11-dehydrocorticosterone but not those induced by corticosterone. In ob/ob mice, long-term emodin administration decreased 11β-HSD1 activity in mesenteric adipose tissues, lowered non-fasting and fasting blood glucose levels, and improved glucose tolerance.Conclusion:Emodin improves the inactive glucocorticoid-induced adipose tissue dysfunction by selective inhibition on 11β-HSD1 in adipocyte in vitro and improves glycemic control in ob/ob mice. [ABSTRACT FROM AUTHOR]

Aim:Dipeptidyl deptidase-4 (DPP-4) inhibitors are a new class of anti-diabetic agents. The purpose of this study was to assess the acute and chronic effects of SHR117887, a novel DPP-4 inhibitor, on metabolic control and pancreatic β-cell function in normal or diabetic rodent models.Methods:In the acute experiments, ICR mice, diet-induced obese (DIO) rats and ob/ob mice were subjected to an oral glucose tolerance test (OGTT) following a single oral administration of SHR117887 (0.1, 0.3, 1 or 3 mg/kg). Blood samples were collected to measure glucose, insulin, DPP-4 activity and active GLP-1 level. In the chronic experiments, ob/ob mice was administered SHR117887 (3, 10 or 30 mg/kg) twice daily for 33 d to assess the effects on metabolic control and pancreatic β-cell function. Vildagliptin (LAF237) was used as a positive control in all the experiments.Results:Acute oral administration of SHR117887 dose-dependently decreased the serum DPP-4 activity and improved glucose tolerance in ICR mice, DIO rats and ob/ob mice. This was accompanied by significant increases in the serum active GLP-1 and insulin levels. Chronic administration of SHR117887 significantly decreased fasting blood glucose level and improved the lipid profiles in ob/ob mice by reducing the serum triglyceride and free fatty acid levels, and its efficacy was comparable with that of vildagliptin at the same molarity. Moreover, chronic administration of SHR117887 increased the insulin staining of islet cells, which is suggestive of improved β-cell function.Conclusion:SHR117887 is a potent DPP-4 inhibitor that improves metabolic control and β-cell function in diabetic rodent models, suggesting that it could be a new therapeutic agent for the treatment of type 2 diabetes. [ABSTRACT FROM AUTHOR]

Mesenchymal epithelial transition factor (c-Met) is an attractive target for cancer therapy. Three-dimensional pharmacophore hypotheses were built based on a set of known structurally diverse c-Met inhibitors. The best pharmacophore model, which identified inhibitors with an associated correlation coefficient of 0.983 between their experimental and estimated IC values, consisted of two hydrogen-bond acceptors, one hydrophobic, and one ring aromatic feature. The highly predictive power of the model was rigorously validated by test set prediction and Fischer's randomization method. The high values of enrichment factor and receiver operating characteristic (ROC) score indicated the model performed fairly well at distinguishing active from inactive compounds. The model was then applied to screen compound database for potential c-Met inhibitors. A filtering protocol, including druggability and molecular docking, were also applied in hits selection. The final 38 molecules, which exhibited good estimated activities, desired binding mode and favorable drug likeness were identified as potential c-Met inhibitors. Their novel backbone structures could be served as scaffolds for further study, which may facilitate the discovery and rational design of potent c-Met kinase inhibitors. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

The phosphatidylinositol-3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) signaling pathway plays a critical role in the regulation of cellular growth, survival and proliferation. mTOR and PI3K have attracted particular attention as cancer targets. These kinases belong to the phosphatidylinositol-3-kinase-related kinase (PIKK) family and therefore have considerable homology in their active sites. To accelerate the discovery of inhibitors with selective activity against mTOR and PI3K as cancer targets, in this work, a homology model of mTOR was developed to identify the structural divergence in the active sites between mTOR and PI3Kα. Furthermore, two highly predictive comparative molecular similarity index analyses (CoMSIA) models were built based on 304 selective inhibitors docked into mTOR and PI3Kα, respectively (mTOR: q = 0.658, r = 0.839; PI3Kα: q = 0.540, r = 0.719). The results showed that steric and electrostatic fields have an important influence on selectivity towards mTOR and PI3Kα-a finding consistent with the structural divergence between the active sites. The findings may be helpful in investigating selective mTOR/PI3Kα inhibitors. [ABSTRACT FROM AUTHOR]

Two new 16-nor limonoids, harperspinoids A and B (1 and 2), with a unique 7/5/5/6/5 ring system, have been isolated from the plant Harrisonia perforate together with a known one, Harperforin G (3). Their structures were elucidated by NMR spectroscopy, X-ray diffraction analysis and computational modelling. Compound 1 exists as polymorphic crystals. Conformations of 1 in solution were further discussed based on the computational results. These compounds exhibited notable inhibitory activity against the 11β-HSD1 enzyme. Compound 3 had potencies for the inhibition of human 11β-HSD1 with high selectivity against 11β-HSD2 (IC50 0.58 μM, SI > 174). Molecular docking and quantitative structure-activity relationship studies revealed a mixed regulatory mechanism. [ABSTRACT FROM AUTHOR]