C-Aryl 5a-carba-β-d-glucopyranosides as novel sodium glucose cotransporter 2 (SGLT2) inhibitors for the treatment of type 2 diabetes

C-Aryl 5a-carba-β-d-glucopyranose derivatives were synthesized and evaluated for inhibition activity against hSGLT1 and hSGLT2. Modifications to the substituents on the two benzene rings resulted in enhanced hSGLT2 inhibition activity and extremely high hSGLT2 selectivity versus SGLT1. Using the created superimposed model, the reason for the high hSGLT2 selectivity was speculated to be that additional substituents occupied a new space, in a different way than known inhibitors. Among the tested compounds, the ethoxy compound 5h with high hSGLT2 selectivity exhibited more potent and longer hypoglycemic action in db/db mice than our O-carbasugar compound (1) and sergliflozin (2), which could be explained by its improved PK profiles relative to those of the two compounds. These results indicated that 5h might be a promising drug candidate for the treatment of type 2 diabetes.     

A BAC-based integrated linkage map of the silkworm Bombyx mori

Background

In 2004, draft sequences of the model lepidopteran Bombyx mori were reported using whole-genome shotgun sequencing. Because of relatively shallow genome coverage, the silkworm genome remains fragmented, hampering annotation and comparative genome studies. For a more complete genome analysis, we developed extended scaffolds combining physical maps with improved genetic maps.

Results

We mapped 1,755 single nucleotide polymorphism (SNP) markers from bacterial artificial chromosome (BAC) end sequences onto 28 linkage groups using a recombining male backcross population, yielding an average inter-SNP distance of 0.81 cM (about 270 kilobases). We constructed 6,221 contigs by fingerprinting clones from three BAC libraries digested with different restriction enzymes, and assigned a total of 724 single copy genes to them by BLAST (basic local alignment search tool) search of the BAC end sequences and high-density BAC filter hybridization using expressed sequence tags as probes. We assigned 964 additional expressed sequence tags to linkage groups by restriction fragment length polymorphism analysis of a nonrecombining female backcross population. Altogether, 361.1 megabases of BAC contigs and singletons were integrated with a map containing 1,688 independent genes. A test of synteny using Oxford grid analysis with more than 500 silkworm genes revealed six versus 20 silkworm linkage groups containing eight or more orthologs of Apis versus Tribolium, respectively.

Conclusion

The integrated map contains approximately 10% of predicted silkworm genes and has an estimated 76% genome coverage by BACs. This provides a new resource for improved assembly of whole-genome shotgun data, gene annotation and positional cloning, and will serve as a platform for comparative genomics and gene discovery in Lepidoptera and other insects.     

Cell adhesion and proliferation on poly(N-vinylacetamide) hydrogels and double network approaches for changing cellular affinities

Poly(N-vinylacetamide) hydrogels (PNVA gels) were synthesized to investigate their basic characteristics for biomedical applications such as water contact angles, protein uptake, and mouse fibroblasts (L-929) cell adhesion. Because PNVA gels show hydrophilic features, double network (DN) hydrogels were prepared by the secondary polymerization of N-vinylacetamide (NVA) or acrylamide (AAm) in PNVA gels (NVA/NVA DN gels and NVA/AAm DN gels, respectively), in order to vary PNVA gel features for biocompatibility. Contact angles for both DN gels decreased to around 20 degrees, whereas both PNVA and PAAm gels were over 30 degrees. On the other hand, more protein tended to adsorb to DN gels than single network hydrogels. Compared to PNVA gel, cell adhesion and proliferation on NVA/NVA DN gel were improved with less swelling ratio and much protein uptake, while no significant difference was observed on NVA/AAm DN gel, probably due to more hydrophilic character, supported by lowest water contact angle. These complicated structure change in DN gels would provide a new methodology for tuning the biocompatibility of hydrogels and for controlling surface hydrophilic characteristics and network structures.     

M chromosome of the wild silkworm, Bombyx mandarina (n = 27), corresponds to two chromosomes in the domesticated silkworm, Bombyx mori (n = 28).

Chromosomes of Bombyx mori (n = 28) and of Bombyx mandarina (n = 27) were studied cytogenetically to resolve the origin of the large M chromosome in the Japaneses type of B. mandarina. In the F1 progeny from the reciprocal cross between B. mandarina and B. mori, the mitotic chromosome number was 2n = 55, and a chromosome configuration of 26 bivalents plus 1 trivalent was observed at metaphase I of germ cells. The trivalent chromosome consisted of the M chromosome from B. mandarina and two chromosomes from B. mori. When males of B. mori were mated to the F1 females, nuclei with two types of chromosome number (2n = 55 and 2n = 56) and two sets of chromosome pairs (26 bivalents plus 1 trivalent versus 28 bivalents) were observed in the metaphase I stage. Linkage analysis showed that the 14th chromosome of B. mori was involved in these two types of chromosome segregation. This result indicates that the M chromosome in B. mandarina arose from a fusion between a chromosome corresponding to the 14th linkage group and another, yet unidentified linkage group.     

Synthesis of 3',4'-epoxynoraristeromycin analogs for molecular labeling probe of S-adenosyl-l-homocysteine hydrolase

3',4'-epoxynoraristeromycin analogs were designed and synthesized. Their affinities with human and Plasmodium falciparum S-adenosyl-l-homo-cysteine hydrolase were investigated.     

PKN regulates phospholipase D1 through direct interaction

The association of phospholipase (PLD)-1 with protein kinase C-related protein kinases, PKNalpha and PKNbeta, was analyzed. PLD1 interacted with PKNalpha and PKNbeta in COS-7 cells transiently transfected with PLD1 and PKNalpha or PKNbeta expression constructs. The interactions between endogenous PLD1 and PKNalpha or PKNbeta were confirmed by co-immunoprecipitation from mammalian cells. In vitro binding studies using the deletion mutants of PLD1 indicated that PKNalpha directly bound to residues 228-598 of PLD1 and that PKNbeta interacted with residues 1-228 and 228-598 of PLD1. PKNalpha stimulated the activity of PLD1 in the presence of phosphatidylinositol 4,5-bisphosphate in vitro, whereas PKNbeta had a modest effect on the stimulation of PLD1 activity. The stimulation of PLD1 activity by PKNalpha was slightly enhanced by the addition of arachidonic acid. These results suggest that the PKN family functions as a novel intracellular player of PLD1 signaling pathway.