Trichostatin A-mediated upregulation of p21(WAF1) contributes to osteoclast apoptosis

Histone deacetylase inhibitors (HDIs), a new class of anti-cancer agents, have been reported to suppress formation of osteoclast precursors and their fusion into multinucleated cells. However, little is known about the effect of HDIs on mature osteoclasts, which may have significance for their therapeutic use. Here, we demonstrate a novel action of HDIs on osteoclast apoptosis. Primary multinucleated mature osteoclasts were prepared from mouse bone marrow cells. Treatment of osteoclasts with the HDI trichostatin A (TSA) caused apoptosis, as confirmed by annexin V staining and caspase activation. TSA caused the upregulation of p21WAF1 in osteoclasts. To understand the role of p21(WAF1) upregulation in TSA-treated osteoclasts, shRNA against p21(WAF1)-containing lentivirus was introduced into osteoclasts. The suppression of p21(WAF1) decreased TSA-directed osteoclast apoptosis. Collectively, our results provide evidence that TSA causes osteoclast apoptosis, which involves, in part, TSA-induced upregulation of p21(WAF1), and strongly supports HDIs as potential therapeutic agents for excessive bone resorption.     

Schiff Base Functionalized 1,2,4-Triazole and Pyrene Derivative for Selective and Sensitive Detection of Cu2+ ion in the Mixed Organic- Aqueous Media

We have prepared Schiff base functionalized 1,2,4-triazole and pyrene derivative for selective, sensitive, and naked eye colorimetric detection of Cu²⁺ in the mixed organic- aqueous media. Amongst the 18 different metal ions studied for absorption and fluorescence titration, only Cu²⁺ ion encourages the modification in spectral properties of Schiff base functionalized 1,2,4-Triazole and Pyrene Probe. The stoichiometric ratio of the TP-Cu²⁺ complex was determined to be 2:1 according to Job’s plot. The lower detection limit estimated for Cu²⁺ is 0.234 nM which shows excellent sensitivity and selectivity of the present analytical method towards detection of Cu²⁺ ion in the mixed organic-aqueous media. The present approach has been successfully utilized for the quantitative determination of Cu²⁺ ion from environmental aqueous solution.

     

NADPH oxidase activation contributes to native low-density lipoprotein-induced proliferation of human aortic smooth muscle cells

Elevated plasma concentration of native low-density lipoprotein (nLDL) is associated with vascular smooth muscle cell (VSMC) activation and cardiovascular disease. We investigated the mechanisms of superoxide generation and its contribution to pathophysiological cell proliferation in response to nLDL stimulation. Lucigenin-induced chemiluminescence was used to measure nLDL-induced superoxide production in human aortic smooth muscle cells (hAoSMCs). Superoxide production was increased by nicotinamide adenine dinucleotide phosphate (NADPH) and decreased by NADPH oxidase inhibitors in nLDL-stimulated hAoSMC and hAoSMC homogenates, as well as in prepared membrane fractions. Extracellular signal-regulated kinase 1/2 (Erk1/2), protein kinase C-θ (PKCθ) and protein kinase C-β (PKCβ) were phosphorylated and maximally activated within 3 min of nLDL stimulation. Phosphorylated Erk1/2 mitogen-activated protein kinase, PKCθ and PKCβ stimulated interactions between p47phox and p22phox; these interactions were prevented by MEK and PKC inhibitors (PD98059 and calphostin C, respectively). These inhibitors decreased nLDL-dependent superoxide production and blocked translocation of p47phox to the membrane, as shown by epifluorescence imaging and cellular fractionation experiments. Proliferation assays showed that a small interfering RNA against p47phox, as well as superoxide scavenger and NADPH oxidase inhibitors, blocked nLDL-induced hAoSMC proliferation. The nLDL stimulation in deendothelialized aortic rings from C57BL/6J mice increased dihydroethidine fluorescence and induced p47phox translocation that was blocked by PD98059 or calphostin C. Isolated aortic SMCs from p47phox^−/− mice (mAoSMCs) did not respond to nLDL stimulation. Furthermore, NADPH oxidase 1 (Nox1) was responsible for superoxide generation and cell proliferation in nLDL-stimulated hAoSMCs. These data demonstrated that NADPH oxidase activation contributed to cell proliferation in nLDL-stimulated hAoSMCs.     

Effect of geometry on impedance of cell suspended media in electrically mediated molecule uptake using a microstructure

A systematic design and miniaturization of conventional clinical and diagnostic tools are emerging in many nanobiotechnology and nanobioscience fields. Recently, the pharmaceutical and biotechnological industries have continuously accelerated novel drug discovery for cellular therapeutics of hard-to-cure diseases. Electroporation is a promising candidate in gene transfection methods for future cellular therapeutics. Here, we report our initial study on the effect of geometry on impedance of cell suspended media in electroporation using a microchannel. A full understanding of the electroporation environment and conditions enabled us to optimize protocols of electroporation for various cell lines efficiently. Furthermore, this study will open up a new vista of future electroporation devices using microstructures.     

Synthesis of ordered and disordered silicas with uniform pores on the border between micropore and mesopore regions using short double-chain surfactants.

Silica molecular sieves with uniform pores on the borderline between micropore (diameter <2 nm) and mesopore (from 2 to 50 nm) ranges were synthesized by a novel method using judiciously chosen mixtures of short double-chain alkylammonium surfactants. These silicas were characterized using X-ray diffraction (XRD), thermogravimetry, and nitrogen and argon adsorption. The calcined materials exhibited either 2-dimensional (2-D) hexagonal or disordered structures with XRD interplanar spacing from 2.51 to 2.93 nm, including the value of as small as 2.69 nm for highly ordered 2-D hexagonal silica. The dependence of the pore size and surfactant content on the surfactant chain length provided strong evidence for supramolecular templating being operative in the formation of small-pore silicas, even for the surfactant chain length of six carbon atoms. Both hexagonally ordered and disordered calcined samples were shown to exhibit narrow pore size distributions with maxima in the range from 1.96 to 2.61 nm (reliably evaluated on the basis of the unit-cell dimension and pore volume for 2-D hexagonal materials, and calculated using a properly calibrated procedure), tailored by the surfactant chain length. The samples exhibited primary pore volumes from 0.28 to 0.54 cm(3) g(-1) and specific surface areas from 730 to 930 m(2) g(-1). Because of their small yet uniform pore size and large specific surface area, the silicas reported herein promise to be useful in applications in adsorption and catalysis. Adsorption studies of these materials provided a unique new insight into the pore-filling mechanism for small-pore materials. Moreover, the approach proposed herein is expected to facilitate the synthesis of not only small-pore silicas but also materials with other framework compositions, thus largely contributing to bridging the gap in attainable pore sizes between micropore and mesopore ranges.     

Preparation of a high performance liquid chromatography column based on N-(3,5-dinitrobenzoyl)-aminoundecyl silica for the resolution of liquid crystal mixtures

A bonded silica stationary phase (SP 1) was prepared by connecting N-(3,5-dinitrobenzoyl) aminoundecylsilane to silica gel. The stationary phase was applied in resolving a liquid crystal mixture with a reversed phase high performance liquid chromatography (HPLC) mode and the chromatographic resolution results were compared with those on an octadecylsilane (ODS) column. From the comparison of the resolution results on SP 1 and the ODS column, we found the new stationary phase was better than the ODS column in resolving a liquid crystal mixture and the elution orders of some liquid crystal were changed. The better resolution and the change in the elution orders on the new column might be originated from additional π–π interaction between the π-acidic 3,5-dinitrobenzoyl group of the stationary phase and the π-basic aromatic group of liquid crystals.     

Structure of the zeros ofq-Bernoulli polynomials

In this paper we observe the structure of the roots ofq-Bernoulli polynomials,β _n (w, h|q), using numerical investigation. By numerical experiments, we demonstrate a remarkably regular structure of the real roots ofβ _n (w, h|q) forq=?1/5, ?1/2. Finally, we give a table for numbers of real and complex zeros ofβ _n (w, h|q).