Induction of antigen-specific immunity by pH-sensitive carbonate apatite as a potent vaccine carrier.

The ability of carbonate apatite (CO(3)Ap) to enhance antigen-specific immunity was examined in vitro and in vivo to investigate its utility as a vaccine carrier. Murine bone marrow-derived dendritic cells took up ovalbumin (OVA) containing CO(3)Ap more effectively than free OVA. Interestingly, mice immunized with OVA-containing CO(3)Ap produced OVA-specific antibodies more effectively than mice immunized with free OVA.

Cardiac differentiation of embryonic stem cells by substrate immobilization of insulin-like growth factor binding protein 4 with elastin-like polypeptides.

The establishment of cardiomyocyte differentiation of embryonic stem cells (ESCs) is a useful strategy for cardiovascular regenerative medicine. Here, we report a strategy for cardiomyocyte differentiation of ESCs using substrate immobilization of insulin-like growth factor binding protein 4 (IGFBP4) with elastin-like polypeptides. Recently, IGFBP4 was reported to promote cardiomyocyte differentiation of ESCs through inhibition of the Wnt/β-catenin signaling.

Regulation by mitochondrial superoxide and NADPH oxidase of cellular formation of nitrated cyclic GMP: potential implications for ROS signalling.

8-Nitro-cGMP (8-nitroguanosine 3',5'-cyclic monophosphate) is a nitrated derivative of cGMP, which can function as a unique electrophilic second messenger involved in regulation of an antioxidant adaptive response in cells. In the present study, we investigated chemical and biochemical regulatory mechanisms involved in 8-nitro-cGMP formation, with particular focus on the roles of ROS (reactive oxygen species). Chemical analyses demonstrated that peroxynitrite-dependent oxidation and myeloperoxidase-dependent oxidation of nitrite in the presence of H2O2 were two major pathways for guanine nucleotide nitration.

Detoxification of methylmercury by hydrogen sulfide-producing enzyme in Mammalian cells.

Methylmercury (MeHg) covalently modifies cellular proteins through their SH groups, resulting in cytotoxicity. We report that cystathionine β-synthase (CBS), which catalyzes the production of hydrogen sulfide, contributes to cellular protection against MeHg. Pretreatment with NaHS or overexpression of CBS reduced MeHg cytotoxicity, whereas transfection with CBS small interfering RNA enhanced MeHg toxicity in human neuroblastoma SH-SY5Y cells.

Modulation of cytochrome P450 gene expression in primary hepatocytes on various artificial extracellular matrices.

We studied effect of artificial extracellular matrices (ECMs), such as collagen I, poly (N-p-vinylbenzyl-4-O-β-D-galactopyranosyl-D-gluconamide)(PVLA) and E-cadherin-IgG Fc (E-cad-Fc) on hepatic metabolism to identify the mechanism of in vivo hepatocellular functional and metabolic integrity. mRNA expression of liver function marker, cytochrome P450 (CYP) and transporter genes in hepatocytes were compared among used ECMs using real-time RT-PCR. mRNA expressions of Cyp2c29 and Cyp2d22 among CYP genes in hepatocytes on PVLA were recovered after 3days due to enhanced liver-specific function by the spheroid formation of hepatocytes whereas mRNA expressions of CYP genes in hepatocytes on collagen and E-cad-Fc drastically decreased with time.

Targeting N-acetylglucosamine-bearing polymer-coated liposomes to vascular smooth muscle cells.

The targeted delivery of anti-inflammatory agents has great therapeutic potential for treating restenosis following percutaneous coronary intervention. To develop a drug delivery system targeted to injured blood vessels, we examined whether N-acetylglucosamine (GlcNAc)-bearing polymer-coated liposomes (GlcNAc-Ls) are specifically taken up by vascular smooth muscle cells (VSMCs). Flow cytometric analysis revealed that GlcNAc-Ls were taken up by VSMCs in vitro.

Cellular uptake mechanisms and responses to NO transferred from mono- and poly-S-nitrosated human serum albumin.

Endogenous S-nitrosated human serum albumin (E-Mono-SNO-HSA) is a large molecular weight nitric oxide (NO) carrier in human plasma, which has shown many beneficial effects in different animal models. To construct more efficient SNO-HSA preparations, SNO-HSA with many conjugated SNO groups has been prepared using chemical modification (CM-Poly-SNO-HSA). We have compared the properties of such a preparation to those of E-Mono-SNO-HSA.

Methodological proof of immunochemistry for specific identification of 8-nitroguanosine 3',5'-cyclic monophosphate formed in glia cells.

The biological significance of nitrated guanine derivatives, especially 8-nitroguanosine 3',5'-cyclic monophosphate (8-nitro-cGMP), has become evident. Therefore it is important to determine the presence and relative abundance of 8-nitro-cGMP formed in cells and tissues. In the present study, we performed immunocytochemistry with monoclonal antibodies specific for 8-nitroguanine (clone NO2-52) and 8-nitro-cGMP (clone 1G6) in rat C6 glioma cells and rat primary cultured astrocytes.

[A case where the tracheotomy tube was burned during Nd-YAG laser cautery treatment for tracheal neoplasm].

For the treatment of the residual tumor above the incision site, laser cautery was scheduled. Artificial ventilation was carried out using a tracheotomy tube, and a laser fiber was inserted orally for tumor ablation. During the procedure, white smoke appeared in the oral cavity.

Antioxidant effect of a nitrated cyclic nucleotide functioning as an endogenous electrophile.

We describe here physiological formation of a unique nitrated cyclic nucleotide, 8-nitroguanosine 3',5'-cyclic monophosphate (8-nitro-cGMP) and its potent antioxidant activity. Our earlier studies revealed the NO-dependent guanine nitration in several types of cells. In fact, we identified physiological formation and functions of 8-nitro-cGMP, which is the first demonstration of a new second messenger derived from cGMP in mammals since the discovery of cGMP more than 40 years ago.

Gene delivery system based on highly specific recognition of surface-vimentin with N-acetylglucosamine immobilized polyethylenimine.

Gene and drug-delivery systems that use immobilization of carbohydrates are useful for the specific targeting of lectin-expressing tissues. Here, we report that N-acetylglucosamine (GlcNAc) with polyethylenimine (GlcNAc-PEI) specifically interacted with vimentin-expressing cells such as 293FT and HeLa cells. Recently, the intermediate filaments vimentin and desmin have been reported to have GlcNAc-binding lectin-like properties on the cell surface.

Nucleotides function as endogenous chemical sensors for oxidative stress signaling.

Oxidized and nitrated nucleotides including 8-oxogunanine and 8-nitroguanine derivatives such as 8-nitroguanosine 3',5'-cyclic monophosphate were generated by reactive nitrogen oxides and reactive oxygen species in cultured cells and in tissues. 8-oxoguanine and 8-nitroguanine in DNA and RNA are potentially mutagenic, and the former also induces cell death. Some derivative, 8-nitroguanosine 3',5'-cyclic monophosphate a major nitrated guanine nucleotide, was identified as a novel second messenger.

Vascular responses to 8-nitro-cyclic GMP in non-diabetic and diabetic mice.

Background And Purpose: 8-Nitroguanosine 3',5'-cyclic monophosphate (8-nitro-cGMP), formed nitric oxide (NO)-dependently, is a physiological second messenger, yet little is known about its role in the pathophysiology of vascular diseases. To study the pharmacological activity of 8-nitro-cGMP in diabetic mice, we compared its effects on vascular reactivity of aortas from non-diabetic and diabetic mice.

Experimental Approach: Vascular tension recording was performed in thoracic aortic rings from wild-type (C57BL/6), non-diabetic db/+ and obese/diabetic db/db mice.

The effect of recombinant E-cadherin substratum on the differentiation of endoderm-derived hepatocyte-like cells from embryonic stem cells.

Generation of specific lineages of cells from embryonic stem (ES) cells is pre-requisite to use these cells in pre-clinical applications. Here, we developed a recombinant E-cadherin substratum for generation of hepatic progenitor populations at single cell level. This artificial acellular feeder layer supports the stepwise differentiation of ES cells to cells with characteristics of definitive endoderm, hepatic progenitor cells, and finally cells with phenotypic and functional characteristics of hepatocytes.

Self-organization of the compositional gradient structure in hyaluronic acid and poly(N-isopropylacrylamide) blend film.

A compositional gradient structure in hyaluronic acid (HA) and poly(N-isopropylacrylamide) (PIPAAm) blend film was self-organized from a homogeneous aqueous solution in a plasma-treated polystyrene dish (PTPSD), and the formation mechanisms of the gradient structure were studied by casting the same solution on PTPSD and a non-treated polystyrene dish (NTPSD) under ambient and vacuum conditions. The formation of a compositional gradient structure in HA/PIPAAm blend film was confirmed by scanning electron microscopy, energy dispersive X-ray (EDX) mapping analysis and step-scan photoacoustic Fourier transformed infrared spectroscopy (PAS-FT-IR) measurements. The EDX mapping measurements for Na element revealed that the HA component gradually decreases from the dish-side to the air-side of the film cast on PTPSD, while for the film cast on NTPSD no such obvious change was observed on the cross-section.

Nuclear localization and antisense effect of PNA internalized by ASGP-R-mediated endocytosis with protein/DNA conjugates.

In order for peptide nucleic acids (PNAs) to be effective as therapeutic agents, methods for cellular delivery must be developed. Here we demonstrate spontaneous nuclear localization and antisense effects of peptide nucleic acids (PNAs) delivered to hepatic cells through asialoglycoprotein receptor-mediated endocytosis. Asialofetuin conjugates with DNA oligonucleotides (AF/DNA) complementary to the PNA of interest were designed as cell-specific delivery vectors.

Current approaches for drug delivery to central nervous system.

Brain, the center of the nervous system in all vertebrate, plays the most vital role in every function of human body. However, many neurodegenerative diseases, cancer and infections of the brain become more prevalent as populations become older. In spite of the major advances in neuroscience, many potential therapeutics are still unable to reach the central nervous system (CNS) due to the blood-brain barrier (BBB) which is formed by the tight junctions within the capillary endothelium of the vertebrate brain.

Midbrain dopaminergic neurons utilize nitric oxide/cyclic GMP signaling to recruit ERK that links retinoic acid receptor stimulation to up-regulation of BDNF.

Stimulation of retinoic acid receptors (RARs) protects midbrain dopaminergic neurons, presumably via up-regulation of brain-derived neurotrophic factor (BDNF) expression. The present study was focused on unexplored signaling mechanisms linking RAR stimulation to BDNF expression. Rat midbrain slice cultures treated with an RAR agonist Am80 showed increased tissue levels of BDNF mRNA and protein as compared to cultures without treatment.

Carbonate apatite-facilitated intracellularly delivered siRNA for efficient knockdown of functional genes.

Gene therapy through intracellular delivery of a functional gene or a gene-silencing element is a promising approach to treat critical diseases. Elucidation of the genetic basis of human diseases with complete sequencing of human genome revealed many vital genes as possible targets in gene therapy programs. RNA interference (RNAi), a powerful tool in functional genomics to selectively silence messenger RNA (mRNA) expression, can be harnessed to rapidly develop novel drugs against any disease target.

Cell signaling mediated by nitrated cyclic guanine nucleotide.

We recently clarified the physiological formation of 8-nitroguanosine 3',5'-cyclic monophosphate (8-nitro-cGMP) and its critical roles in nitric oxide (NO) signal transductions. This discovery of 8-nitro-cGMP is the first demonstration of a nitrated cyclic nucleotide functioning as a new second messenger in mammals since the identification of cGMP more than 40 years ago. By means of chemical analyses, e.

Culture of human pluripotent stem cells using completely defined conditions on a recombinant E-cadherin substratum.

Background: To maintain pluripotency of human embryonic stem (huES) cells in feeder-free culture it has been necessary to provide a Matrigel substratum, which is a complex of poorly defined extracellular matrices and growth factors derived from mouse Engelbreth-Holm-Swarm sarcoma cells. Culture of stem cells under ill-defined conditions can inhibit the effectiveness of maintaining cells in a pluripotent state and reduce reproducibility of differentiation protocols. Moreover recent batches of Matrigel have been found to be contaminated with the single stranded RNA virus, Lactate Dehydrogenase Elevating Virus (LDEV), raising concerns regarding the safety of using stem cells that have been cultured on Matrigel in a therapeutic setting.

The critical role of nitric oxide signaling, via protein S-guanylation and nitrated cyclic GMP, in the antioxidant adaptive response.

A nitrated guanine nucleotide, 8-nitroguanosine 3',5'-cyclic monophosphate (8-nitro-cGMP), is formed via nitric oxide (NO) and causes protein S-guanylation. However, intracellular 8-nitro-cGMP levels and mechanisms of formation of 8-nitro-cGMP and S-guanylation are yet to be identified. In this study, we precisely quantified NO-dependent formation of 8-nitro-cGMP in C6 glioma cells via liquid chromatography-tandem mass spectrometry.