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BACKGROUND Patients with major depressive disorder (MDD) frequently retain cognitive disturbances after recovery from mood symptoms. We investigated the relationship between early response of mood symptoms and/or remission, and residual cognitive disturbances after 6 months of antidepressant treatment. METHODS 518 patients with MDD were followed up for 6 months after antidepressant treatment initiation (first-line or switch from a previous drug). Subjective and objective cognitive disturbances were assessed by the Perceived Deficits Questionnaire - Depression (PDQ-D) and digit symbol substitution test (DSST), respectively. Depressive symptoms, as well as remission and early response to treatment, were assessed using the Montgomery-Asberg Depression Rating Scale (MADRS). Multivariable linear and logistic regression models were used to adjust for confounders. RESULTS Early response of depressive mood (≥50% reduction in MADRS score at month 1) was related with fewer residual subjective cognitive symptoms, as evaluated by the PDQ-D at month 6 (p

The effects of 7β-hydroxycholesterol (7βOH) and 25-hydroxycholesterol (25OH) on the phase behavior and the structural properties of the multilamellar vesicles of dipalmitoylphosphatidylcholine (DPPC) bilayers were investigated with comparing to the effects of cholesterol (Chol). Differential scanning calorimetry (DSC) measurements showed these three sterols have slightly but distinctly different effects on the thermal behavior of DPPC bilayers. X-ray diffraction data analysis on DPPC bilayers containing 30 mol% sterols with the aid of molecular volume data estimated by the neutral buoyancy method indicated that the order of apparent occupied surface area per molecule is DPPC/7βOH > DPPC/25OH > DPPC/Chol at both 25 ℃ and 50 ℃, suggesting that the strength of the condensation effect of these sterols follows inversely this order. Based on the findings in this study, we inferred the molecular orientations of Chol, 7βOH, and 25OH in DPPC bilayers.

The precise control for the micropatterning of nonparenchymal cells (endothelial cells; ECs and hepatic stellate cells; HSCs) is useful for regenerative medicine, artificial organs, and cell-based biodevice. The adhesion and alignment of nonparenchymal cells on a micro-patterned surface fabricated by two-step plasma polymerization process were investigated. The first functionalization step involves the deposition of a nitrogen-rich plasma-polymerized film to render the entire surface a cell-adherent region. Following this, a hydrophobic plasma-polymerized film is formed through a grid metal mask (hundred-micrometer-sized openings) to renders these areas cell repellent. Imaging ellipsometry showed that groove and ridge patterns 100 μm wide and steps with heights on the scale of tens of nanometers were obtained. EC and HSC culture experiments were conducted on the patterned surfaces. EC rapidly adhered and aligned along the cell-adherent groove of the patterned surface, while it did not adhere to the cell-repellent ridge. HSC patterning succeeded only when the height of the cell-repellent ridge was 20 nm, whereas the patterning failed when the ridge height was 10 nm. This indicates that EC patterning is possible with only a chemical effect, whereas HSC patterning required both a chemical effect and the topological constraints of the patterned surface.

An electrochemical enzyme biosensor with electronically type-sorted (metallic and semiconducting) single-walled carbon nanotubes (SWNTs) for use in aqueous media is presented. This research investigates how the electronic types of SWNTs influence the amperometric response of enzyme biosensors. To conduct a clear evaluation, a simple layer-by-layer process based on a plasma-polymerized nano thin film (PPF) was adopted because a PPF is an inactive matrix that can form a well-defined nanostructure composed of SWNTs and enzyme. For a biosensor with the glucose oxidase (GOx) enzyme in the presence of oxygen, the response of a metallic SWNT-GOx electrode was 2 times larger than that of a semiconducting SWNT-GOx electrode. In contrast, in the absence of oxygen, the response of the semiconducting SWNT-GOx electrode was retained, whereas that of the metallic SWNT-GOx electrode was significantly reduced. This indicates that direct electron transfer occurred with the semiconducting SWNT-GOx electrode, whereas the metallic SWNT-GOx electrode was dominated by a hydrogen peroxide pathway caused by an enzymatic reaction. For a biosensor with the glucose dehydrogenase (GDH; oxygen-independent catalysis) enzyme, the response of the semiconducting SWNT-GDH electrode was 4 times larger than that of the metallic SWNT-GDH electrode. Electrochemical impedance spectroscopy was used to show that the semiconducting SWNT network has less resistance for electron transfer than the metallic SWNT network. Therefore, it was concluded that semiconducting SWNTs are more suitable than metallic SWNTs for electrochemical enzyme biosensors in terms of direct electron transfer as a detection mechanism. This study makes a valuable contribution toward the development of electrochemical biosensors that employ sorted SWNTs and various enzymes.

The encapsulation of emulsion oil droplets by amorphous sugar matrices, formed by freeze-drying, was investigated, with a focus on the influence of the type of sugar. An oil-in-water emulsion, comprised of linoleic acid methyl ester (LME) and sucrose monolaurate (SML) as an oil phase and surfactant, respectively, were freeze-dried in the presence of different types of sugars. LME-droplet encapsulation during and after freeze-drying were evaluated by FTIR analysis. The loss of LME largely occurred in the early stage of freeze-drying. The size distribution of the encapsulated LME droplets remained unchanged before and after freeze-drying in most cases. The encapsulated fractions of LME droplets could be correlated with the glass transition temperature of the sugars in the fully hydrated state ( T g *), and the existence of an optimum T g * value for the sugar matrix was predicted. The encapsulation ability of an amorphous sugar matrix was maximized when mono- and polysaccharide were combined so as to give a value for T g * of approximately − 50 °C, although, individually, mono- and polysaccharides were quite poor for oil droplet encapsulation. These findings suggest that the structural flexibility of the amorphous sugar matrix is a major determinant in oil droplet encapsulation by an amorphous sugar matrix during freeze-drying.

We report on a novel fabrication approach of amperometric biosensor based on multilayer films containing carbon nanotubes (CNT), a nano-thin plasma-polymerized film (PPF), electron transfer mediator phenothiazine (PT), and enzyme glucose dehydrogenase (GDH). The configuration of the electrochemical electrode is sequentially composed of sputtered gold, acetonitrile PPF, PT, GDH, and acetonitrile PPF (denoted as PPF/GDH/PT/CNT/PPF/Au). First PPF deposited on Au acts as a permselective membrane and as a scaffold for CNT layer formation. Second PPF directly deposited on GDH acts as a matrix for enzyme immobilization. To facilitate the electrochemical communication between the CNT layer and GDH, CNT was treated with nitrogen plasma. The electron transfer mediator PT plays a role as the mediator in which the electron caused by enzymatic reaction transports to the electrode. The synergy between the mediator and CNT provides benefits in terms of lowering the operational potential and enhancing the sensitivity (current). The optimized glucose biosensor revealed a sensitivity of 5.1 ± 0.9 μA mM− 1 cm− 2 at + 0.2 V vs. Ag/AgCl, linear dynamic range of 4.9–19 mM, and a response time of 5 ± 1 s. Unlike conventional wet-chemical processes that are incompatible with mass production techniques, this dry-chemistry procedure has great potential for enabling high-throughput production of bioelectronic devices. Furthermore, those devices can be applied and expands for the cell biological functional field as a useful, helpful, or indispensable tool.

Amyloid-β peptide (Aβ), which is generated by the β- and γ-secretase-mediated proteolysis of β-amyloid precursor protein (APP), plays an important role in the pathogenesis of Alzheimer's disease (AD). We recently reported that prostaglandin E(2) (PGE(2) ) stimulates the production of Aβ through both EP(2) and EP(4) receptors and that activation of the EP(4) receptor stimulates Aβ production through endocytosis and activation of γ-secretase. We here found that transgenic mice expressing mutant APP (APP23) mice showed a greater or lesser apparent cognitive deficit when they were crossed with mice lacking EP(2) or EP(4) receptors, respectively. Mice lacking the EP(4) receptor also displayed lower levels of Aβ plaque deposition and less neuronal and synaptic loss than control mice. Oral administration of a specific EP(4) receptor antagonist, AE3-208 to APP23 mice, improved their cognitive performance, as well as decreasing brain levels of Aβ and suppressing endocytosis and activation of γ-secretase. Taken together, these results suggest that inhibition of the EP(4) receptor improves the cognitive function of APP23 mice by suppressing Aβ production and reducing neuronal and synaptic loss. We therefore propose that EP(4) receptor antagonists, such as AE3-208, could be therapeutically beneficial for the prevention and treatment of AD.

We report a novel approach to fabrication of an amperometric biosensor with an enzyme, a plasma-polymerized film (PPF), and carbon nanotubes (CNTs). The CNTs were grown directly on an island-patterned Co/Ti/Cr layer on a glass substrate by microwave plasma enhanced chemical vapor deposition. The as-grown CNTs were subsequently treated by nitrogen plasma, which changed the surface from hydrophobic to hydrophilic in order to obtain an electrochemical contact between the CNTs and enzymes. A glucose oxidase (GOx) enzyme was then adsorbed onto the CNT surface and directly treated with acetonitrile plasma to overcoat the GOx layer with a PPF. This fabrication process provides a robust design of CNT-based enzyme biosensor, because of all processes are dry except the procedure for enzyme immobilization. The main novelty of the present methodology lies in the PPF and/or plasma processes. The optimized glucose biosensor revealed a high sensitivity of 38 μA mM(-1) cm(-2), a broad linear dynamic range of 0.25-19 mM (correlation coefficient of 0.994), selectivity toward an interferent (ascorbic acid), and a fast response time of 7 s. The background current was much smaller in magnitude than the current due to 10 mM glucose response. The low limit of detection was 34 μM (S/N = 3). All results strongly suggest that a plasma-polymerized process can provide a new platform for CNT-based biosensor design.

It is now believed that cancer stem cells (CSCs) that are resistant to chemotherapy due to their undifferentiated nature drive tumor growth, metastasis and relapse, so development of drugs that induce differentiation of CSCs should have a profound impact on cancer eradication. In this study, we screened medicines that are already in clinical use for drugs that induce differentiation of CSCs. We used MDA-MB-231, a human breast cancer cell line that contains cancer stem cell-like cells. We found that acetaminophen, an anti-inflammatory, antipyretic and analgesic drug, induces differentiation of MDA-MB-231 cells. Differentiation was assessed by observing alterations in cell shape and expression of differentiated and undifferentiated cell markers, a decrease in cell invasion activity and an increase in susceptibility to anti-tumor drugs. This increased susceptibility seems to involve suppression of expression of multidrug efflux pumps. We also suggest that this induction of differentiation is mediated by inhibition of a Wnt/β-catenin canonical signaling pathway. Treatment of MDA-MB-231 cells with acetaminophen in vitro resulted in the loss of their tumorigenic ability in nude mice. Furthermore, administration of acetaminophen inhibited the growth of tumor xenografts of MDA-MB-231 cells in both the presence and absence of simultaneous administration of doxorubicine, a typical anti-tumor drug for breast cancer. Analysis with various acetaminophen derivatives revealed that o-acetamidophenol has a similar differentiation-inducing activity and a similar inhibitory effect on tumor xenograft growth. These results suggest that acetaminophen may be beneficial for breast cancer chemotherapy by inducing the differentiation of CSCs.

Measurement of multichannel continuous-wave near-infrared spectroscopy (CW-NIRS) is dependent on the modified Beer-Lambert law, which includes optical path length (PL) as an essential parameter. PLs are known to differ across different head regions and between individuals, but the distribution of PLs for the whole head has not been evaluated so far. Thus, using time-resolved near-infrared spectroscopy (TR-NIRS), we measured the optical characteristics, including PL, scattering coefficients (μls), and absorption coefficients (μa) at three wavelengths (760, 800, and 830 nm). We then constructed maps of these parameters on the surface of the subject′s head. While the PLs in nearby channels are similar, they differ depending on the regions of the head. The PLs in the region above the Sylvian fissure tended to be shorter than those in the other regions at all of the wavelengths. The difference in the distribution of PLs may be attributed to differences in tissue absorption and scattering properties. The current study suggests the importance of considering PL differences in interpreting functional data obtained by CW-NIRS.

Background Early detection of vasospasm is essential for the treatment of delayed ischemic neurological deficits in subarachnoid hemorrhage (SAH). We evaluated cerebral blood oxygenation (CBO) changes after SAH employing quantitative time-resolved near-infrared spectroscopy (TR-NIRS) for this purpose. Methods We investigated 11 age-matched controls and 14 aneurysmal SAH patients, including 10 patients with WFNS grade V and 4 patients with grade II. Employing TR-NIRS, we measured the cortical oxygen saturation (CoSO2) and baseline hemoglobin concentrations in the middle cerebral artery territory. Measurements of TR-NIRS and transcranial Doppler sonography (TCD) were performed repeatedly after SAH. Results In six patients, the CoSO2 and hemoglobin concentrations remained stable after SAH; digital subtraction angiography (DSA) did not reveal vasospasm in these patients. In eight patients, however, CoSO2 and total hemoglobin decreased abruptly between 5 and 9 days after SAH. DSA revealed diffuse vasospasms in six of eight patients. The reduction of CoSO2 predicted occurrence of vasospasm at a cutoff value of 3.9%-6.4% with 100% of sensitivity and 85.7% of specificity. TCD failed to detect the vasospasm in four cases, which TR-NIRS could detect. Finally, TR-NIRS performed on Day 1 after SAH revealed significantly higher CoSO2 than that of controls (p = .048), but there was no significant difference in total hemoglobin. Conclusion TR-NIRS detected vasospasm by evaluating the CBO in the cortex and may be more sensitive than TCD, which assesses the blood flow velocity in the M1 portion. The cerebral oxygen metabolism in SAH might be reduced by brain damage due to aneurysmal rupture.

Skin hyperpigmentation disorders due to abnormal melanin production induced by ultraviolet (UV) irradiation are both a clinical and cosmetic problem. UV irradiation stimulates melanin production in melanocytes by increasing intracellular cAMP. Expression of heat shock proteins (HSPs), especially HSP70, is induced by various stressors, including UV irradiation, to provide cellular resistance to such stressors. In this study we examined the effect of expression of HSP70 on melanin production both in vitro and in vivo. 3-Isobutyl-1-methylxanthine (IBMX), a cAMP-elevating agent, stimulated melanin production in cultured mouse melanoma cells, and this stimulation was suppressed in cells overexpressing HSP70. IBMX-dependent transcriptional activation of the tyrosinase gene was also suppressed in HSP70-overexpressing cells. Expression of microphthalmia-associated transcription factor (MITF), which positively regulates transcription of the tyrosinase gene, was up-regulated by IBMX; however, this up-regulation was not suppressed in HSP70-overexpressing cells. On the other hand, immunoprecipitation and immunostaining analyses revealed a physical interaction between and co-localization of MITF and HSP70, respectively. Furthermore, the transcription of tyrosinase gene in nuclear extract was inhibited by HSP70. In vivo, UV irradiation of wild-type mice increased the amount of melanin in the basal layer of the epidermis, and this increase was suppressed in transgenic mice expressing HSP70. This study provides the first evidence of an inhibitory effect of HSP70 on melanin production both in vitro and in vivo. This effect seems to be mediated by modulation of MITF activity through a direct interaction between HSP70 and MITF.

Irradiation with UV light, especially UVB, causes epidermal damage via the induction of apoptosis, inflammatory responses, and DNA damage. Various stressors, including UV light, induce heat shock proteins (HSPs) and the induction, particularly that of HSP70, provides cellular resistance to such stressors. The anti-inflammatory activity of HSP70, such as its inhibition of nuclear factor kappa B (NF-kappaB), was recently revealed. These in vitro results suggest that HSP70 protects against UVB-induced epidermal damage. Here we tested this idea by using transgenic mice expressing HSP70 and cultured keratinocytes. Irradiation of wild-type mice with UVB caused epidermal damage such as induction of apoptosis, which was suppressed in transgenic mice expressing HSP70. UVB-induced apoptosis in cultured keratinocytes was suppressed by overexpression of HSP70. Irradiation of wild-type mice with UVB decreased the cutaneous level of IkappaB-alpha (an inhibitor of NF-kappaB) and increased the infiltration of leukocytes and levels of pro-inflammatory cytokines and chemokines in the epidermis. These inflammatory responses were suppressed in transgenic mice expressing HSP70. In vitro, the overexpression of HSP70 suppressed the expression of pro-inflammatory cytokines and chemokines and increased the level of IkappaB-alpha in keratinocytes irradiated with UVB. UVB induced an increase in cutaneous levels of cyclobutane pyrimidine dimers and 8-hydroxy-2'-deoxyguanosine, both of which were suppressed in transgenic mice expressing HSP70. This study provides genetic evidence that HSP70 protects the epidermis from UVB-induced radiation damage. The findings here also suggest that the protective action of HSP70 is mediated by anti-apoptotic, anti-inflammatory, and anti-DNA damage effects.

Although recent reports suggest that the endoplasmic reticulum (ER) stress response is induced in association with the development of inflammatory bowel disease, its role in the pathogenesis of inflammatory bowel disease remains unclear. The CCAAT/enhancer-binding protein (C/EBP) homologous protein (CHOP) is a transcription factor that is involved in the ER stress response, especially ER stress-induced apoptosis. In this study, we found that experimental colitis was ameliorated in CHOP-null mice, suggesting that CHOP exacerbates the development of colitis. The mRNA expression of Mac-1 (CD11b, a positive regulator of macrophage infiltration), Ero-1alpha, and Caspase-11 (a positive regulator of interleukin-1beta production) in the intestine was induced with the development of colitis, and this induction was suppressed in CHOP-null mice. ERO-1alpha is involved in the production of reactive oxygen species (ROS); an increase in ROS production, which is associated with the development of colitis in the intestine, was suppressed in CHOP-null mice. A greater number of apoptotic cells in the intestinal mucosa of wild-type mice were observed to accompany the development of colitis compared with CHOP-null mice, suggesting that up-regulation of CHOP expression exacerbates the development of colitis. Furthermore, this CHOP activity appears to involve various stimulatory mechanisms, such as macrophage infiltration via the induction of Mac-1, ROS production via the induction of ERO-1alpha, interleukin-1beta production via the induction of Caspase-11, and intestinal mucosal cell apoptosis.

Alteration in the expression of claudins, consisting of tight junctions (TJs), has been reported in various clinically isolated tumors. Claudins play an important role not only in the intercellular barrier function of TJs but also in migration and invasiveness of cancer cells. However, the use of different types of cells and different claudins in these studies has complicated the picture. In this study, we systematically examined the effect of claudin (claudin-1, -2, -3, -4 and -15) overexpression on the paracellular permeability, migration and invasiveness of Caco-2 colonic cancer cells. Overexpression of claudin-4 or claudin-2 increased or decreased, respectively, paracellular permeability. Overexpression of claudin-4 specifically stimulated the invasive activity of the Caco-2 cells. Furthermore, activation of matrix metalloproteinase (MMP)-2 and MMP-9 were observed in the claudin-4-overexpressing cells, suggesting that the invasive activity was stimulated through an increase in MMP activity. Overexpression of claudin-2 or claudin-3 and -4 stimulated or inhibited, respectively, the migration activity of the Caco-2 cells. Immunostaining analysis revealed that each of the overexpressed claudins localized at TJs under the conditions used to evaluate paracellular permeability. In contrast, they localized mainly in intracellular compartments under experimental conditions designed to assess cell invasion and migration. Overall, the results of this study show that the effect exerted by the claudins on the intercellular barrier function of TJs, as well as on cell migration and invasive activity, differs depending on the particular claudin species. Furthermore, the subcellular localization of the claudins varies according to the culture conditions.

Amyloid-beta peptides (Abeta), generated by proteolysis of the beta-amyloid precursor protein (APP) by beta- and gamma-secretases, play an important role in the pathogenesis of Alzheimer disease (AD). Inflammation is also believed to be integral to the pathogenesis of AD. Here we show that prostaglandin E(2) (PGE(2)), a strong inducer of inflammation, stimulates the production of Abeta in cultured human embryonic kidney (HEK) 293 or human neuroblastoma (SH-SY5Y) cells, both of which express a mutant type of APP. We have demonstrated using subtype-specific agonists that, of the four main subtypes of PGE(2) receptors (EP(1-4)), EP(4) receptors alone or EP(2) and EP(4) receptors together are responsible for this PGE(2)-stimulated production of Abeta in HEK293 or SH-SY5Y cells, respectively. An EP(4) receptor antagonist suppressed the PGE(2)-stimulated production of Abeta in HEK293 cells. This stimulation was accompanied by an increase in cellular cAMP levels, and an analogue of cAMP stimulated the production of Abeta, demonstrating that increases in the cellular level of cAMP are responsible for the PGE(2)-stimulated production of Abeta. Immunoblotting experiments and direct measurement of gamma-secretase activity suggested that PGE(2)-stimulated production of Abeta is mediated by activation ofgamma-secretase but not of beta-secretase. Transgenic mice expressing the mutant type of APP showed lower levels of Abeta in the brain, when they were crossed with mice lacking either EP(2) or EP(4) receptors, suggesting that PGE(2)-mediated activation of EP(2) and EP(4) receptors is involved in the production of Abeta in vivo and in the pathogenesis of AD.

NSAIDs such as celecoxib induce apoptosis in cancer cells. Although this apoptotic effect is involved in the anti-tumor activity associated with such drugs, the mechanism by which this occurs is not fully understood. We report here that various NSAIDs, including celecoxib, up-regulate PUMA, a Bcl-2 family protein with potent apoptosis-inducing activity, in human gastric carcinoma cell line, accompanying the induction of apoptosis. Experiments using siRNA and an intracellular Ca(2+) chelator revealed that Ca(2+)-dependent up-regulation of ATF4 and CHOP is involved in this up-regulation of PUMA. The siRNA for PUMA inhibited the celecoxib-induced activation and translocation of Bax, release of cytochrome c into the cytosol and induction of apoptosis, suggesting that PUMA plays an important role in celecoxib-induced mitochondrial dysfunction and the resulting apoptosis.

Abeta (amyloid-beta peptides) generated by proteolysis of APP (beta-amyloid precursor protein), play an important role in the pathogenesis of AD (Alzheimer's disease). ER (endoplasmic reticulum) chaperones, such as GRP78 (glucose-regulated protein 78), make a major contribution to protein quality control in the ER. In the present study, we examined the effect of overexpression of various ER chaperones on the production of Abeta in cultured cells, which produce a mutant type of APP (APPsw). Overexpression of GRP78 or inhibition of its basal expression, decreased and increased respectively the level of Abeta40 and Abeta42 in conditioned medium. Co-expression of GRP78's co-chaperones ERdj3 or ERdj4 stimulated this inhibitory effect of GRP78. In the case of the other ER chaperones, overexpression of some (150 kDa oxygen-regulated protein and calnexin) but not others (GRP94 and calreticulin) suppressed the production of Abeta. These results indicate that certain ER chaperones are effective suppressors of Abeta production and that non-toxic inducers of ER chaperones may be therapeutically beneficial for AD treatment. GRP78 was co-immunoprecipitated with APP and overexpression of GRP78 inhibited the maturation of APP, suggesting that GRP78 binds directly to APP and inhibits its maturation, resulting in suppression of the proteolysis of APP. On the other hand, overproduction of APPsw or addition of synthetic Abeta42 caused up-regulation of the mRNA of various ER chaperones in cells. Furthermore, in the cortex and hippocampus of transgenic mice expressing APPsw, the mRNA of some ER chaperones was up-regulated in comparison with wild-type mice. We consider that this up-regulation is a cellular protective response against Abeta.

Pancreatic cancer is one of the most difficult malignancies to treat owing to the rapid acquisition of resistance to chemotherapy. Gemcitabine, a first-line treatment for pancreatic cancer, prolongs patient survival by several months, and combination treatment with gemcitabine and other anti-cancer drugs in the clinic do not show any significant effects on overall survival. Thus, identification of a drug that resensitizes gemcitabine-resistant pancreatic cancer to gemcitabine and a better understanding of the molecular mechanisms of gemcitabine resistance are critical to develop new therapeutic options for pancreatic cancer. Here, we report that zidovudine resensitizes gemcitabine-resistant pancreatic cancer to gemcitabine as shown by screening a compound library, including clinical medicine, using gemcitabine-resistant cells. In analyzing the molecular mechanisms of zidovudine effects, we found that the epithelial-to-mesenchymal transition (EMT)-like phenotype and downregulation of human equilibrative nucleoside transporter 1 (hENT1) are essential for the acquisition of gemcitabine resistance, and zidovudine restored these changes. The chemical biology investigations also revealed that activation of the Akt-GSK3β-Snail1 pathway in resistant cells is a key signaling event for gemcitabine resistance, and zidovudine resensitized resistant cells to gemcitabine by inhibiting this activated pathway. Moreover, our in vivo study demonstrated that co-administration of zidovudine and gemcitabine strongly suppressed the formation of tumors by gemcitabine-resistant pancreatic cancer and prevented gemcitabine-sensitive pancreatic tumors from acquiring gemcitabine-resistant properties, inducing an EMT-like phenotype and downregulating hENT1 expression. These results suggested that co-treatment with zidovudine and gemcitabine may become a novel therapeutic strategy for pancreatic cancer by inhibiting chemoresistance-specific signaling.

Gastric lesions result from an imbalance between aggressive and defensive factors. Indirect lines of evidence suggest that heat shock proteins (HSPs) induced by various aggressive factors provide a major protective mechanism. In this study, we compared gastric ulcerogenic response in wild-type mice and in those lacking heat shock factor 1 (HSF1), a transcription factor for hsp genes. The severity of gastric lesions induced by ethanol or hydrochloric acid was worsened in HSF1-null mice. Immunoblotting, real-time reverse transcription-polymerase chain reaction, immunohistochemical analysis, and terminal deoxynucleotidyl transferase dUTP nick-end labeling assay revealed that the ethanol administration up-regulated gastric mucosal HSPs, in particular HSP70, in an HSF1-dependent manner, and more apoptotic cells were observed in the gastric mucosa of HSF1-null mice than in wild-type mice. In contrast, other parameters governing the gastric ulcerogenic response, including gastric acid secretion, gastric mucosal blood flow, and prostaglandin E(2) levels, were not significantly affected by the absence of the hsf1 gene. Geranylgeranylacetone (GGA), a clinically used antiulcer drug with HSP-inducing activity, suppressed ethanol-induced gastric lesions in wild-type mice but not in heat shock factor 1 (HSF1)-null mice. The results suggest that the aggravation of irritant-induced gastric lesions in HSF1-null mice is due to their inability to up-regulate HSPs, leading to apoptosis. It is also suggested that the HSP-inducing activity of GGA contributes to the drug's antiulcer activity. This study provides direct genetic evidence that HSPs, after their HSF1-dependent up-regulation, confer gastric protection against the irritant-induced lesions.

Gastric mucosal cell death by non-steroidal anti-inflammatory drugs (NSAIDs) is suggested to be involved in NSAID-induced gastric lesions. Therefore, cellular factors that suppress this cell death are important for protection of the gastric mucosa from NSAIDs. Heme oxygenase-1 (HO-1) is up-regulated by various stressors and protects cells against stressors. Here, we have examined up-regulation of HO-1 by NSAIDs and the contribution of HO-1 to the protection of gastric mucosal cells against NSAIDs both in vitro and in vivo. In cultured gastric mucosal cells, all NSAIDs tested up-regulated HO-1. In rats, orally administered indomethacin up-regulated HO-1, induced apoptosis, and produced lesions at gastric mucosa. An inhibitor of HO-stimulated NSAID-induced apoptosis in vitro and in vivo and also stimulated NSAID-produced gastric lesions, suggesting that NSAID-induced up-regulation of HO-1 protects the gastric mucosa from NSAID-induced gastric lesions by inhibiting NSAID-induced apoptosis. Indomethacin activated the HO-1 promoter and caused nuclear accumulation of NF-E2-related factor 2 (Nrf2), a transcription factor for the HO-1 gene. Examination of phosphorylation of p38 mitogen-activated protein kinase (MAPK) and experiments with its inhibitor strongly suggest that the nuclear accumulation of Nrf2 and resulting up-regulation of HO-1 by NSAIDs is mediated through NSAID-dependent activation (phosphorylation) of p38 MAPK. This is the first report showing the protective role of HO-1 against irritant-induced gastric lesions.

Background and Purpose— To evaluate the mechanisms of failure of blood oxygenation level–dependent (BOLD) imaging in stroke, we compared the evoked cerebral blood oxygenation (CBO) responses and activation volumes (AVs) of BOLD functional MRI (fMRI) in chronic stroke patients with moderate and severe cerebral ischemia. Methods— We measured the evoked CBO responses in the primary sensorimotor cortex (PSMC) by means of near-infrared spectroscopy during contralateral motor tasks. We compared the AV of BOLD-functional MRI in the PSMC on the nonlesion and lesion sides. Single-photon emission computed tomography was used to classify ischemic status as moderate (slight reduction of regional cerebral blood flow and cerebrovascular reserve capacity [CVRC]) or severe (marked reduction of regional cerebral blood flow and CVRC; ie, misery perfusion). Results— In age-matched controls, deoxyhemoglobin concentration decreased with concomitant increases in oxyhemoglobin and total hemoglobin concentrations during activation. The PSMC on the nonlesion side exhibited a normal CBO response pattern. On the lesion side, moderate cerebral ischemia did not affect the CBO response pattern, but severe cerebral ischemia caused an increase of deoxyhemoglobin during the task, associated with increases of oxyhemoglobin and total hemoglobin. Moderate cerebral ischemia induced only a slight reduction of the AV on the lesion side; however, severe cerebral ischemia markedly reduced the AV on the lesion side. The BOLD signal did not change in some areas of the PSMC on the lesion side in severe cerebral ischemia, whereas it tended to decrease in other areas during the tasks. Conclusions— Misery perfusion caused a marked reduction of the AV on BOLD imaging, associated with an increase of deoxyhemoglobin concentration during activation. BOLD-fMRI investigations of stroke patients should be performed while giving consideration to baseline circulatory status. Functional near-infrared spectroscopy could be an alternative means to assess the CVRC.

We recently reported that nonsteroidal anti-inflammatory drug (NSAID)-induced gastric lesions involve NSAID-induced apoptosis of gastric mucosal cells, which in turn involves the endoplasmic reticulum stress response, in particular the up-regulation of CCAAT/enhancer-binding protein homologous transcription factor (CHOP). In this study, we have examined the molecular mechanism governing this NSAID-induced apoptosis in primary cultures of gastric mucosal cells. Various NSAIDs showed membrane permeabilization activity that correlated with their apoptosis-inducing activity. Various NSAIDs, particularly celecoxib, also increased intracellular Ca2+ levels. This increase was accompanied by K+ efflux from cells and was virtually absent when extracellular Ca2+ had been depleted. These data indicate that the increase in intracellular Ca2+ levels that is observed in the presence of NSAIDs is due to the stimulation of Ca2+ influx across the cytoplasmic membrane, which results from their membrane permeabilization activity. An intracellular Ca2+ chelator partially inhibited celecoxib-induced release of cytochrome c from mitochondria, reduced the magnitude of the celecoxib-induced decrease in mitochondrial membrane potential and inhibited celecoxib-induced apoptotic cell death. It is therefore likely that an increase in intracellular Ca2+ levels is involved in celecoxib-induced mitochondrial dysfunction and the resulting apoptosis. An inhibitor of calpain, a Ca2+-dependent cysteine protease, partially suppressed mitochondrial dysfunction and apoptosis in the presence of celecoxib. Celecoxib-dependent CHOP-induction was partially inhibited by the intracellular Ca2+ chelator but not by the calpain inhibitor. These results suggest that Ca2+-stimulated calpain activity and CHOP expression play important roles in celecoxib-induced apoptosis in gastric mucosal cells.

Background Cortical stimulation via a subdural grid electrode (SGE) is one of the most reliable methods for identifying eloquent areas before surgery. However, the physiological conditions of the cortex during stimulation cannot be monitored electrophysiologically because of electrical artifacts. In the present case, we tested whether or not multichannel near-infrared spectroscopy (NIRS) topography, a noninvasive optical imaging technique, is applicable for monitoring the physiological conditions of the stimulated cortex. Case description The patient (a 27-year-old right-handed man) suffered from glioma in the left frontal lobe. For preoperative cortical mapping, SGEs were implanted over the left motor cortex before tumor resection. Employing NIRS topography, we undertook 2 dimensional imaging of the changes in oxyhemoglobin (Oxy-Hb) and deoxyhemoglobin (Deoxy-Hb) concentration during electrical stimulation. Five-hertz stimulation with 5 mA at the left-hand area produced a localized increase in Oxy-Hb and a decrease in Deoxy-Hb, associated with slight twitching of the right hand. In contrast, 50-Hz stimulation produced significant increases in both Oxy-Hb and Deoxy-Hb at the stimulation site, and the area with such cerebral blood oxygenation (CBO) changes propagated beyond the hand area associated with prominent muscle contractions of the right upper extremity, suggesting that 50-Hz stimulation caused epileptic discharge. Conclusion Near-infrared spectroscopy topography may represent a useful tool for imaging the degree and extent of the physiological effects of electrical stimulation on the cortex, and permits safe and accurate cortical mapping.

We investigated whether an acyclic polyisoprenoid antiulcer drug, geranylgeranylacetone (GGA), induces the expression of HSP70 in the rat cochlea. Immunoblotting revealed upregulation of HSP70 in the cochlea at 12 h after transtympanic (local) or oral (systemic) administration of GGA, and this increased at 24 h after administration. Positive immunohistochemical staining of HSP70 was observed in the hair cells, the spiral ganglion, the stria vascularis, the spiral ligament, and the perivascular portion of modiolar vessels. We therefore subsequently studied the effects of GGA as an HSP-inducer on inner ear trauma due to inflammation. Damage to the lateral wall due to inflammation induced by lipopolysaccharide inoculation was protected against by pretreatment with GGA, as assessed physiologically by measurement of cochlear blood flow and morphologically by electron microscopy. The results of the present study suggest that GGA can protect the cochlea against other injuries including those induced by noise, ototoxic drugs, and ischemia by upregulating HSP70.

Prostaglandin E(2) (PGE(2)) has a strong protective effect on the gastric mucosa in vivo; however, the molecular mechanism of a direct cytoprotective effect of PGE(2) on gastric mucosal cells has yet to be elucidated. Although we reported previously that PGE(2) inhibited gastric irritant-induced apoptotic DNA fragmentation in primary cultures of guinea pig gastric mucosal cells, we show here that PGE(2) inhibits the ethanol-dependent release of cytochrome c from mitochondria. Of the four main subtypes of PGE(2) receptors, we also demonstrated, using subtype-specific agonists, that EP(2) and EP(4) receptors are involved in the PGE(2)-mediated protection of gastric mucosal cells from ethanol-induced apoptosis. Activation of EP(2) and EP(4) receptors is coupled with an increase in cAMP, for which a cAMP analogue was found here to inhibit the ethanol-induced apoptosis. The increase in cAMP is known to activate both protein kinase A (PKA) and phosphatidylinositol 3-kinase pathways. An inhibitor of PKA but not of phosphatidylinositol 3-kinase blocked the PGE(2)-mediated protection of cells from ethanol-induced apoptosis, suggesting that a PKA pathway is mainly responsible for the PGE(2)-mediated inhibition of apoptosis. Based on these results, we considered that PGE(2) inhibited gastric irritant-induced apoptosis in gastric mucosal cells via induction of an increase in cAMP and activation of PKA, and that this effect was involved in the PGE(2)-mediated protection of the gastric mucosa from gastric irritants in vivo.

A novel fabrication approach for electrochemical sensing of nicotinamide adenine dinucleotide (NADH) using neutral red (NR) functinalized carbon nanotube/plasma-polymerized film (PPF) composite electrode is reported. The configuration of sensing electrode was NR-functionalized CNTs sandwiched between two acetonitrile PPFs on sputtered gold thin film. The NR as an electron transfer mediator shuttles the electron from CNT to gold electrode. Due to the synergistic effect between NR and CNT, the resulting electrode showed the lower detection potential and the larger sensitivity (current) than that with NR or CNT alone. As a result, the electrode showed the selectivity against the interference ascorbic acid.

Amyloid-β peptide (Aβ), especially its oligomeric form, is believed to play an important role in the pathogenesis of Alzheimer's disease (AD). To this end, the binding of Aβ oligomer to cellular prion protein (PrP(C)) plays an important role in synaptic dysfunction in a mouse model of AD. Here, we have screened for compounds that inhibit Aβ oligomer binding to PrP(C) from medicines already used clinically (Mizushima Approved Medicine Library 1), and identified dextran sulfate sodium (DSS) as a candidate. In a cell-free assay, DSS inhibited Aβ oligomer binding to PrP(C) but not to ephrin receptor B2, another endogenous receptor for Aβ oligomers, suggesting that the drug's action is specific to the binding of Aβ oligomer to PrP(C) . Dextran on the other hand did not affect this binding. DSS also suppressed Aβ oligomer binding to cells expressing PrP(C) but not to control cells. Furthermore, while incubation of mouse hippocampal slices with Aβ oligomers inhibited the induction of long-term potentiation, simultaneous treatment with DSS restored the long-term potentiation. As DSS has already been approved for use in patients with hypertriglyceridemia, and its safety in humans has been confirmed, we propose further analysis of this drug as a candidate for AD treatment. Amyloid-β peptide (Aβ) oligomer-binding to cellular prion protein (PrP(C) ) is important in synaptic dysfunction in Alzheimer's disease (AD). We found here that dextran sulfate sodium (DSS) inhibits Aβ oligomer binding to PrP(C) . Simultaneous treatment of hippocampal slices with DSS restored long-term potentiation (LTP) in the presence of Aβ oligomers. Since DSS has already been approved for clinical use, we propose this drug is a candidate drug for AD treatment.

In this study, we established a system of high concentration serum-dependent spontaneous apoptosis of guinea pig gastric pit cells in primary culture, which seems to mimic the spontaneous apoptosis of matured gastric pit cells at gastric surface in vivo. In addition to induction of the spontaneous apoptosis, cell growth was inhibited in the presence of 10% serum compared with 0.5% serum. Transforming growth factor-β1 (TGF-β1), which is known to cause both apoptosis and growth inhibition in mammalian cells, was present in serum of both fetal calf and guinea pig. The addition of recombinant TGF-β1 to the culture medium containing 0.5% fetal calf serum caused both induction of apoptosis and inhibition of cell growth. On the other hand, immunodepletion of TGF-β1 from fetal calf serum caused inability to induce both the spontaneous apoptosis and inhibition of cell growth. These data suggest that TGF-β1 is involved in the spontaneous apoptosis of guinea pig gastric pit cells in primary culture.

Various stressors induce apoptosis in gastric mucosal cells, which may cause gastric mucosal lesions in vivo. We recently reproduced gastric stressor-induced apoptosis in vitro, using primary cultures of guinea pig gastric mucosal cells. Geranylgeranylacetone is an antiulcer drug with heat-shock protein-inducing properties. The purpose of this study is to examine the effect of geranylgeranylacetone on gastric stressor-induced apoptosis in vitro. Ethanol, hydrogen peroxide, and hydrochloric acid all induced, in a dose-dependent manner, apoptotic DNA fragmentation. Pretreatment of cells with geranylgeranylacetone inhibited the apoptotic DNA fragmentation caused by each of these gastric stressors. Pretreatment of cells with a low concentration of ethanol, a procedure that is also known to induce heat-shock proteins, made cells resistant to the apoptotic DNA fragmentation. These results suggest that heat-shock proteins could be at least partly involved in the inhibitory effect of geranylgeranylacetone against apoptosis of gastric mucosal cells caused by these gastric stressors.

Guinea pig gastric pit cells in primary culture undergo serum-dependent cell maturation, which mimics their maturation in vivo. In this study we compared the sensitivities of these cells, as a function of early- and late-stage cell maturation, to various gastric stressors. Gastric pit cells in the early stage of maturation (two days of culture) were more resistant to apoptotic cell death induced by exposure to hydrogen peroxide than those cells in late-stage maturation (three days of culture). This maturation-associated difference was not observed for the sensitivities of cells to necrotic cell death induced by hydrogen peroxide, nor for necrotic and apoptotic cell death induced by other gastric stressors (ethanol and hydrochloric acid). The activities of catalase and glutathione peroxidase were specifically decreased in cells at the late stage of maturation compared to those at the early stage. The relative gastric pit cell phenotype sensitivity to hydrogen peroxide at the late stage of maturation may be due to a decrease in the activities of catalase and glutathione peroxidase, which are antioxidants for hydrogen peroxide.

Prostaglandins have cytoprotective effects on gastric mucosa via the influence of various mechanisms. The purpose of this study is to examine the effects of prostaglandins on maturation-dependent spontaneous apoptosis in gastric mucosal cells in vitro, which mimics the apoptosis of gastric mucosal cells related with a rapid cell turnover rate in vivo. Both prostaglandin E1 and E2 inhibited spontaneous apoptosis in a dose-dependent manner and increased the viability of gastric mucosal cells in culture. A number of antiulcer drugs presently in clinical use were shown to increase the concentrations of prostaglandins in cells. All of the drugs tested clearly inhibited the spontaneous apoptosis in a dose-dependent manner. Based on these results, we propose that the cytoprotective effects of prostaglandins on gastric mucosa in vivo can be partially explained by an increase in the number of gastric mucosal cells present as a result of the inhibition of maturation-dependent spontaneous apoptosis.

We previously reported that various gastric irritants induced both apoptosis and necrosis in cultured gastric mucosal cells. In a continuation of this work, the present study has examined the effects of prostaglandin E2 (PGE2), a cytoprotective factor for gastric mucosa in vivo, on gastric irritant-induced apoptosis and necrosis in vitro. PGE2 inhibited ethanol-induced apoptosis and increased cell viability in a dose-dependent manner in primary cultures of guinea pig gastric mucosal cells. PGE2 also inhibited hydrogen peroxide-induced apoptosis. In contrast, PGE2 showed no cytoprotective effects against ethanol-induced necrosis. Based on these results, we consider that the cytoprotective effects of PGE2 on gastric mucosa in vivo can be partially explained by its inhibitory effect on gastric irritant-induced apoptosis.

Background The expression of heat shock proteins (HSPs), particularly HSP70, is receiving considerable attention in the field of cosmetics, particularly given our recent report that ultraviolet-induced melanin production, skin damage and wrinkle formation were all suppressed in transgenic mice expressing HSP70. Objective In the present study, we searched for HSP70-inducers from a library of herbal extracts that have already been approved as quasi-pharmaceutical products in Japan. We selected an ethanol extract of Arnica montana ( A. montana ), based on its high HSP70-inducing activity and low cytotoxicity. Methods Cell viability was determined by MTT method and expression of HPS70 was monitored by immunoblotting analysis. Results From the extract, we purified and identified eight sesquiterpene lactones (AM1–8) as HSP70-inducers, among which AM-2 (helenalin 2-methylbutyrate) was selected due to its good HSP70-inducing properties and low cytotoxicity. Treatment of cultured mouse melanoma cells with AM-2 or A. montana extract up-regulated the expression of HSP70 in a dose-dependent manner. This treatment also activated heat shock factor-1, a transcription factor for hsp genes. Furthermore, pre-treatment of cells with AM-2 or A. montana extract decreased melanin production and expression and activity of tyrosinase. Conclusion These results suggest that AM-2 and A. montana extract could be beneficial for use in hypopigmenting cosmetics as a consequence of their stimulatory effects on HSP70 expression.

Skin hyperpigmentation disorders as a result of abnormal melanin production induced by ultraviolet (UV) irradiation are both a clinical and a cosmetic problem. This melanin production is mediated by tyrosinase whose expression is positively regulated by microphthalmia-associated transcription factor (MITF). We recently found that expression of heat shock protein 70 (HSP70) inhibits melanin production. In this study, we searched for HSP70 inducers from Chinese herbs and selected an ethanol extract of Eupatorium lindleyanum (E. lindleyanum). Not only melanin production but also the activity and expression of tyrosinase were significantly suppressed in cells treated with E. lindleyanum extract as well as in HSP70-overexpressing cells. The expression of MITF was clearly suppressed in cells treated with E. lindleyanum extract but not in HSP70-overexpressing cells. These results suggest that E. lindleyanum extract suppresses the expression of tyrosinase and melanin production through both HSP70-dependent and HSP70-independent mechanisms.