3,3-diphenylpentane skeleton as a steroid skeleton substitute: novel inhibitors of human 5alpha-reductase 1

We designed and synthesized novel type 1 5alpha-reductase inhibitors by using 3,3-diphenylpentane skeleton as a substitute for the usual steroid skeleton. 4-(3-(4-(N-Methylacetamido)phenyl)pentan-3-yl)phenyl dibenzylcarbamate (11k) is a competitive 5alpha-reductase inhibitor with the IC(50) value of 0.84 microM.     

Effects of dipeptides having a C-terminal lysine on the cholesterol 7alpha-hydroxylase mRNA level in HepG2 cells

Inducing expression of the cholesterol-catabolizing enzyme cholesterol 7alpha-hydroxylase (CYP7A1) in the liver can be an effective strategy in preventing hypercholesterolemia and atherosclerosis. We used HepG2 cells to investigate the effects of 1 mM dipeptides having a C-terminal lysine group on the CYP7A1 mRNA level. We found that the dipeptides Asp-Lys, Glu-Lys, and Trp-Lys significantly increased the CYP7A1 mRNA level.     

Crystallization and preliminary crystallographic study of DNA polymerase from Pyrococcus furiosus

A new member of archaeal DNA polymerase from Pyrococcus furiosus was crystallized. Diffraction data to 3.1 A of the selenomethionine-derivatized crystal were collected, and preliminary crystallographic study has been completed. The crystal belongs to the space group C2 with unit cell parameters of a = 93.2 A, b = 124.9 A, c = 87.7 A, alpha = 90 degrees , beta = 109.7 degrees , and gamma = 90 degrees . Assuming the presence of one molecule in the asymmetric unit, the solvent content of the crystal is estimated to be 54%, corresponding to a Matthews coefficient V(M) of 2.7A (3) Da(-1).     

Expression of Secretogranin III in Chicken Endocrine Cells: Its Relevance to the Secretory Granule Properties of Peptide Prohormone Processing and Bioactive Amine Content

The expression of secretogranin III (SgIII) in chicken endocrine cells has not been investigated. There is limited data available for the immunohistochemical localization of SgIII in the brain, pituitary, and pancreatic islets of humans and rodents. In the present study, we used immunoblotting to reveal the similarities between the expression patterns of SgIII in the common endocrine glands of chickens and rats. The protein–protein interactions between SgIII and chromogranin A (CgA) mediate the sorting of CgA/prohormone core aggregates to the secretory granule membrane. We examined these interactions using co-immunoprecipitation in chicken endocrine tissues. Using immunohistochemistry, we also examined the expression of SgIII in a wide range of chicken endocrine glands and gastrointestinal endocrine cells (GECs). SgIII was expressed in the pituitary, pineal, adrenal (medullary parts), parathyroid, and ultimobranchial glands, but not in the thyroid gland. It was also expressed in GECs of the stomach (proventriculus and gizzard), small and large intestines, and pancreatic islet cells. These SgIII-expressing cells co-expressed serotonin, somatostatin, gastric inhibitory polypeptide, glucagon-like peptide-1, glucagon, or insulin. These results suggest that SgIII is expressed in the endocrine cells that secrete peptide hormones, which mature via the intragranular enzymatic processing of prohormones and physiologically active amines in chickens.     

Regulation of Hyaluronan (HA) Metabolism Mediated by HYBID (Hyaluronan-binding Protein Involved in HA Depolymerization,KIAA1199) and HA Synthases in Growth Factor-stimulated Fibroblasts

Regulation of hyaluronan (HA) synthesis and degradation is essential to maintenance of extracellular matrix homeostasis. We recently reported that HYBID (HYaluronan-Binding protein Involved in hyaluronan Depolymerization), also called KIAA1199, plays a key role in HA depolymerization in skin and arthritic synovial fibroblasts. However, regulation of HA metabolism mediated by HYBID and HA synthases (HASs) under stimulation with growth factors remains obscure. Here we report that TGF-β1, basic FGF, EGF, and PDGF-BB commonly enhance total amount of HA in skin fibroblasts through up-regulation of HAS expression, but molecular size of newly produced HA is dependent on HYBID expression levels. Stimulation of HAS1/2 expression and suppression of HYBID expression by TGF-β1 were abrogated by blockade of the MAPK and/or Smad signaling and the PI3K-Akt signaling, respectively. In normal human skin, expression of the TGF-β1 receptors correlated positively with HAS2 expression and inversely with HYBID expression. On the other hand, TGF-β1 up-regulated HAS1/2 expression but exerted only a slight suppressive effect on HYBID expression in synovial fibroblasts from the patients with osteoarthritis or rheumatoid arthritis, resulting in the production of lower molecular weight HA compared with normal skin and synovial fibroblasts. These data demonstrate that although TGF-β1, basic FGF, EGF, and PDGF-BB enhance HA production in skin fibroblasts, TGF-β1 most efficiently contributes to production of high molecular weight HA by HAS up-regulation and HYBID down-regulation and suggests that inefficient down-regulation of HYBID by TGF-β1 in arthritic synovial fibroblasts may be linked to accumulation of depolymerized HA in synovial fluids in arthritis patients.     

5a-Carba-β-D-glucopyranose derivatives as novel sodium-dependent glucose cotransporter 2 (SGLT2) inhibitors for the treatment of type 2 diabetes

5a-Carba-β-D-glucopyranose derivatives were synthesized and identified as novel SGLT2-selective inhibitors. These inhibitors exhibited potent SGLT2 inhibition with high selectivity over SGLT1. Among the tested compounds, 6f indicated the most potent hSGLT2 inhibition and the highest selectivity over hSGLT1. Moreover, the pharmacokinetics data also showed that 6h, which had the same aglycon structure as sergliflozin-active (3-active), had a threefold longer half-life time (T(1/2)) than sergliflozin (3) with a high distribution volume in db/db mice. Subsequently, 6h lowered blood glucose levels as much as 3 and showed longer hypoglycemic action than 3 in db/db mice.     

Evaluating DNA barcoding criteria using African duiker antelope (Cephalophinae) as a test case

African duikers in the subfamily Cephalophinae (genera Cephalophus, Philantomba and Sylvicapra) constitute an important target for DNA barcoding efforts because of their importance to the bushmeat trade and protection under the Convention for International Trade in Endangered Species (CITES). Duikers also make a challenging test case of barcoding methods due to their recent diversification, substantial intra-specific genetic variation and high species richness. However, no study to date has evaluated how well DNA barcoding methods can be used to delineate all of the taxa within this group. To address this question, cytochrome c oxidase subunit 1 (COX1) sequences from all eighteen species within this subfamily and an outgroup taxon (genus Tragelaphus) were used to build a neighbor-joining tree, identify species-specific diagnostic synapomorphies, and determine whether species exceed a given pair-wise genetic distance threshold commonly employed in DNA barcoding studies. Tree-based analyses of the data indicate that several species within two clusters of closely related taxa consistently failed to form reciprocally monophyletic clades and similarly lack species-specific synapomorphies. Furthermore, one additional taxon failed to constitute a diagnosable clade and another occupied an unresolved position in the tree. Of the two genetic distance criteria evaluated, the 3% threshold was far more effective in delimiting species than a threshold level based on the ratio of inter- to intra-specific distances. However, neither approach could effectively delineate all sister species. While the taxonomy of this group might be open to question, the fact that barcodes consistently failed to differentiate several currently recognized sister taxa challenges the routine application of this approach in forensic studies of duiker species. Future barcoding work of this group should always include a complete taxonomic sampling and strive to include a broader geographic sampling of sequence diversity than has been carried out to date. Lastly, this work highlights the need to re-examine the taxonomy of this group, which may illuminate why some barcoding criteria fail to reliably differentiate species.