Synthesis of heparan sulfate tetrasaccharide as a substrate for human heparanase.

Regiospecifically sulfated heparan sulfate tetrasaccharide, GlcAβ-GlcN(NS6S)α-GlcAβ-GlcN(NS6S)α was first synthesized as an octyl glycoside. Total synthesis was achieved effectively by coupling the corresponding disaccharide units in short steps.

Syntheses of mono- and dinuclear silylplatinum complexes bearing a diphosphino ligand via stepwise bond activation of unsymmetric disilanes.

Zero-valence platinum complex [Pt(dppe)(eta(2)-C(2)H(4))] (1, dppe = 1,2-bis(diphenylphosphino)ethane) treated with disilanes HR(1)R(2)SiSiMe(3) (a, R(1) = R(2) = Me; b, R(1) = R(2) = Ph; c, R(1) = H, R(2) = Ph) afforded the corresponding disilanylplatinum hydrides [Pt(dppe)(H)(SiR(1)R(2)SiMe(3))] (2a-c) by oxidative addition of the Si-H bond to the platinum center. The 1,2-silyl migration in 2a,b led to the formation of bis(silyl)platinum complexes [Pt(dppe)(SiHR(1)R(2))(SiMe(3))] (3a,b) with a first-order rate constant of 7.2(2) x 10(-4) s(-1) at 25 degrees C for 2a and 3.

Cellular FLIP inhibits beta-catenin ubiquitylation and enhances Wnt signaling.

Cellular FLIP (cFLIP) is a close homologue of caspase 8 without caspase activity that inhibits Fas signaling. The cFLIP protein is often expressed in human tumors and is believed to suppress antitumor immune responses involving the Fas system. Here, we report that a long form of cFLIP (cFLIP-L) inhibits beta-catenin ubiquitylation and increases endogenous cytosolic beta-catenin, which results in translocation of beta-catenin into nuclei and induction of beta-catenin-dependent gene expression in cFLIP-L-expressing cells.

Mouse primary osteoblasts express vitamin D3 25-hydroxylase mRNA and convert 1 alpha-hydroxyvitamin D3 into 1 alpha,25-dihydroxyvitamin D3.

We examined whether 1 alpha-hydroxyvitamin D3 (1 alpha(OH)D3) is metabolized into 1 alpha,25-dihydroxyvitamin D3 (1 alpha,25(OH)2D3) in bone. Northern blot analysis indicated that the expression of vitamin D3 25-hydroxylase mRNA was highest in the liver, followed by the duodenum, calvaria, lung, kidney, skin and long bone, and lowest in the spleen. Of the bone cell fractions isolated from fetal mouse calvaria by a sequential enzymatic digestion, fraction 3, which consisted of mostly osteoblastic cells, showed the highest expression of vitamin D3 25-hydroxylase mRNA.

Effect of 1,25-dihydroxyvitamin D3 and its analogs on human immunodeficiency virus infection in monocytes/macrophages.

We have investigated the effects of 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] and several potent vitamin D3 analogs [1,25(OH)2-16-ene-23-yne-D3; 1,25(OH)2-16-ene-23-yne-26,27-F6-D3] on productive infection by human immunodeficiency virus (HIV) in human macrophages. Macrophages derived from the peripheral blood were either pretreated with the vitamin D3 analogs, washed, and exposed to HIV (pre-infection treatment) or were infected with HIV, washed, and cultured with the vitamin D3 compounds (post-infection treatment). After three days of HIV-infection, levels of p24 antigen were measured.