Novel p53 target gene FUCA1 encodes a fucosidase and regulates growth and survival of cancer cells

The tumor suppressor p53 functions by inducing the transcription of a collection of target genes. We previously attempted to identify p53 target genes by microarray expression and ChIP‐sequencing analyses. In this study, we describe a novel p53 target gene, FUCA1, which encodes a fucosidase. Although fucosidase, α‐l‐1 (FUCA1) has been reported to be a lysosomal protein, we detected it outside of lysosomes and observed that its activity is highest at physiological pH. As there is a reported association between fucosylation and tumorigenesis, we investigated the potential role of FUCA1 in cancer. We found that overexpression of FUCA1, but not a mutant defective in enzyme activity, suppressed the growth of cancer cells and induced cell death. Furthermore, we showed that FUCA1 reduced fucosylation and activation of epidermal growth factor receptor, and concomitantly suppressed epidermal growth factor signaling pathways. FUCA1 loss‐of‐function mutations are found in several cancers, its expression is reduced in cancers of the large intestine, and low FUCA1 expression is associated with poorer prognosis in several cancers. These results show that protein defucosylation mediated by FUCA1 is involved in tumor suppression.

Brush biopsy of human oral mucosal epithelial cells as a quality control of the cell source for fabrication of transplantable epithelial cell sheets for regenerative medicine

Autologous oral mucosal epithelial cell sheets have been used for treating epithelial defects such as cornea and esophagus. The cell source of patients' oral mucosal epithelial cell sheet should be examined in normality because it has individual difference. In this study, oral mucosal epithelial cells were less invasively collected by brush biopsy from the buccal, gingival, labial, and palate mucosa of four healthy volunteer donors without anesthesia, and analyzed the keratin expressions by western blotting and the obtained results were compared with those by immunohistochemistry of each of the native tissues. All of the oral mucosal epithelial cells expressed keratin 4 (K4) and K13, which were mucosal stratified squamous epithelial cell markers. K1 and K10, keratinized epithelial cell markers, were also detected in keratinized tissues such as gingival and palate mucosa. The markers of epithelial basal cells such as p63 and K15 were not detected by brush biopsy-western blotting. Although this method does not include basal layers of oral mucosa, protein expressions of upper layer of lesion area are different from normal. Therefore, brush biopsy-western blotting was extremely less invasive and would contribute to quality control of the fabrication of autologous oral mucosal epithelial cell sheets.

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Cell sheet source of patient oral mucosal condition has individual difference.

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A new less invasive method for quality check of human oral mucosal epithelial cells.

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Keratin expressions were examined by brush biopsy western blot.

Prediction of bending set, wave efficacy, and hair damage using an extensional permanent waving treatment and the 20% index value

To predict "wave efficacy" as evaluated by hairdressers, an extensional permanent waving treatment was performed on human hair fibers using various wave lotions manufactured in Japan. Glass columns devised for the purpose were equipped with a tensile tester in order to increase the measurement accuracy. Notably, the observed set agreed with the theoretical set. In addition, the data for the extensional set exhibited good correlation with the bending set and the wave efficacy assessed in a beauty parlor, and hair damage was estimated by the characteristic change in the 20% index. The following facts were experimentally determined. First, the Young's modulus of the hair fibers after extensional permanent waving treatment continually decreased with an increase in the reduction of the fibers and then abruptly decreased at 80% reduction. Second, the reduction of hair treated with the ammonium salt of thioglycolic acid followed pseudo first-order kinetics only during the initial stage of the reaction, independent of the pH level. Third, the 20% index of the individual virgin hairs remained constant in water at 30°C and also correlated with the Young's modulus of the hair after extensional permanent waving treatment.

Surface characteristics determining the cell compatibility of ionically cross-linked alginate gels

In this study we investigated differences in the characteristics determining the suitability of five types of ion (Fe(3+), Al(3+), Ca(2+), Ba(2+) and Sr(2+))-cross-linked alginate films as culture substrates for cells. Human dermal fibroblasts were cultured on each alginate film to examine the cell affinity of the alginates. Since cell behavior on the surface of a material is dependent on the proteins adsorbed to it, we investigated the protein adsorption ability and surface features (wettability, morphology and charge) related to the protein adsorption abilities of alginate films. We observed that ferric, aluminum and barium ion-cross-linked alginate films supported better cell growth and adsorbed higher amounts of serum proteins than other types. Surface wettability analysis demonstrated that ferric and aluminum ion-cross-linked alginates had moderate hydrophilic surfaces, while other types showed highly hydrophilic surfaces. The roughness was exhibited only on barium ion-cross-linked alginate surface. Surface charge measurements revealed that alginate films had negatively charged surfaces, and showed little difference among the five types of gel. These results indicate that the critical factors of ionically cross-linked alginate films determining the protein adsorption ability required for their cell compatibility may be surface wettability and morphology.

The regulation of epithelial cell proliferation and growth by IL-1 receptor antagonist

We have performed clinical translation of epithelial cell sheets fabricated on temperature-responsive culture surfaces to treat cornea and esophagus. In the preclinical study using animal models, we found epithelial cell growth potential varied among species. Canine epithelial cell growth was prominent, while rat one was poor under 3T3 feeder layer-free condition. The aim of the present study was to identify growth-promoting factors for epithelial cells. Conditioned medium of canine cell culture harvested at different time points showed different growth promotive activity for rat epithelial cells. Time-dependent gene expression was quantitatively evaluated for forty growth factors, and compared with conditioned medium results. Statistically significant promotive activity was observed with IL-1RA, and significant inhibitory activity was observed with IL-1α. Furthermore, neutralizing anti-IL-1α antibody also showed significant promotive activity. Human epidermal keratinocytes were promoted to proliferate by IL-1RA and neutralizing anti-IL-1α antibody, and showed well differentiation to form transplantable, squamous stratified epithelial cell sheets. These findings would be useful to fabricate reproducible, transplantable epithelial cell sheets for regenerative medicine.

Cell sheet technology for regeneration of esophageal mucosa

The progress of tissue-engineering technology has realized development of new therapies to treat various disorders by using cultured cells. Cell- and tissue-based therapies have been successfully applied to human patients, and several tissue-engineered products have been approved by the regulatory agencies and are commercially available. In the review article, we describe our experience of development and clinical application of cell sheet-based regenerative medicine. Endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) have been shown to be useful for removal of gastrointestinal neoplasms with less invasiveness compared with open surgery, especially in esophageal surgery. However, postoperative inflammation and stenosis are major complications observed after intensive mucosal resection. Therefore, we have developed novel regenerative medicine to prevent such complications and promote wound healing of esophageal mucosa after EMR or ESD. Transplantable oral mucosal epithelial cell sheets were fabricated from patients’ own oral mucosa. Immediately after EMR or ESD, fabricated autologous cell sheets were endoscopically transplanted to the ulcer sites. We performed a preclinical study with a canine model. In human clinical settings, cell culture and cell sheet fabrication were performed in clean rooms according to good manufacturing practice guidelines, and pharmaceutical drugs were used as supplements to culture medium in place of research regents used in animal study. We believe that cell-based regenerative medicine would be useful to improve quality of life of patients after EMR or ESD.

Prevention of esophageal stricture after endoscopic submucosal dissection using tissue-engineered cell sheets

BACKGROUND & AIMS

The use of esophageal endoscopic submucosal dissection (ESD) to remove superficial esophageal neoplasms is gradually becoming more common in Japan. However, large-scale esophageal ESD often requires subsequent multiple balloon dilations to prevent postoperative esophageal stricture. We investigated the safety and efficacy of endoscopic transplantation of tissue-engineered autologous oral mucosal epithelial cell sheets in preventing formation of strictures after ESD.

METHODS

We performed an open-label, single-arm, single-institute study. We collected specimens of oral mucosal tissue from 9 patients with superficial esophageal neoplasms. Epithelial cell sheets were fabricated ex vivo by culturing isolated cells for 16 days on temperature-responsive cell culture surfaces. After a reduction in temperature, these sheets were endoscopically transplanted directly to the ulcer surfaces of patients who had just undergone ESD. All patients were monitored by endoscopy once a week until epithelialization was complete.

RESULTS

Autologous cell sheets were successfully transplanted to ulcer surfaces using an endoscope. Complete re-epithelialization occurred within a median time of 3.5 weeks. No patients experienced dysphagia, stricture, or other complications following the procedure, except for one patient who had a full circumferential ulceration that expanded to the esophagogastric junction.

CONCLUSIONS

Sutureless, endoscopic transplantation of carrier-free cell sheets composed of autologous oral mucosal epithelial cells safely and effectively promotes re-epithelialization of the esophagus after ESD. Patients in this study did not experience any serious complications. This procedure might be used to prevent stricture formation following ESD and improve patients' quality of life. Further study will be needed to show that stricture formation can be prevented.

Critical role of an antiviral stress granule containing RIG-I and PKR in viral detection and innate immunity

Retinoic acid inducible gene I (RIG-I)-like receptors (RLRs) function as cytoplasmic sensors for viral RNA to initiate antiviral responses including type I interferon (IFN) production. It has been unclear how RIG-I encounters and senses viral RNA. To address this issue, we examined intracellular localization of RIG-I in response to viral infection using newly generated anti-RIG-I antibody. Immunohistochemical analysis revealed that RLRs localized in virus-induced granules containing stress granule (SG) markers together with viral RNA and antiviral proteins. Because of similarity in morphology and components, we termed these aggregates antiviral stress granules (avSGs). Influenza A virus (IAV) deficient in non-structural protein 1 (NS1) efficiently generated avSGs as well as IFN, however IAV encoding NS1 produced little. Inhibition of avSGs formation by removal of either the SG component or double-stranded RNA (dsRNA)-dependent protein kinase (PKR) resulted in diminished IFN production and concomitant enhancement of viral replication. Furthermore, we observed that transfection of dsRNA resulted in IFN production in an avSGs-dependent manner. These results strongly suggest that the avSG is the locus for non-self RNA sensing and the orchestration of multiple proteins is critical in the triggering of antiviral responses.

Restraint of spreading-dependent activation of polymorphonuclear leukocyte NADPH oxidase in an acidified environment

Elucidation of the mechanisms by which environmental pH affects or regulates the functions of polymorphonuclear leukocytes (PMNs) is important because severe acidification of the microenvironment often prevails at sites of inflammation where they act in host defense. In the present study, we investigated the effect of an acidic environment on spreading-dependent activation of O2- -producing NADPH oxidase in PMNs. We found that PMNs underwent spreading spontaneously over type I collagen and plastic surfaces at both neutral and acidic pH, although spreading over fibrinogen surfaces, for which cellular stimulation with H2O2 is required, was inhibited by acidic pH. At acidic pH, however, PMNs were unable to undergo spreading-dependent production of O2-. Pharmacological experiments showed that p38 mitogen-activated protein kinase (MAPK) was involved in the signaling pathways mediating the spreading-dependent activation of NADPH oxidase, and that its spreading-dependent phosphorylation of Thr-180 and Tyr-182, a hallmark of activation, was impaired at acidic pH. Furthermore, the inhibition by acidic pH of O2- production as well as p38 MAPK phosphorylation subsequent to spreading induction was reversible; environmental neutralization and acidification after induction of spreading at acidic and neutral pH, respectively, up- and down-regulated the two phenomena. Acidic pH did not affect the O2- production activity of NADPH oxidase pre-activated by phorbol 12-myristate 13-acetate (PMA). These results suggest that, in PMNs, the p38 MAPK-mediated signaling pathway functions as a pH-sensing regulator of spreading-dependent NADPH oxidase activation.

Fabrication and validation of autologous human oral mucosal epithelial cell sheets to prevent stenosis after esophageal endoscopic submucosal dissection

OBJECTIVES

Human oral mucosal epithelial cells derived from 7 healthy volunteer donors were cultured in a clean room in a cell-processing center (CPC) according to good manufacturing practice guidelines. Cell culture and fabricated transplantable epithelial cell sheets were validated for treating ulcers after endoscopic mucosal dissection.

METHODS

The clonal growth and morphology of the human oral mucosal epithelial cells seeded on temperature-responsive surfaces were observed. During the cultivation, sterilization tests were performed to validate the environment in the CPC. To validate the purity and morphology of fabricated epithelial cell sheets, cell sheets harvested from temperature-responsive surfaces by temperature reduction were examined by histology and flow cytometry.

RESULTS

Human oral mucosal epithelial cells were successfully cultured and harvested as continuous cell sheets from temperature-responsive culture inserts without any animal-derived materials. During the cultivations, the sterile environment in the CPC was confirmed. The results of histological and flow cytometry analysis showed the high reproducibility of stratification and the purity of the fabricated human oral mucosal epithelial cell sheets.

CONCLUSIONS

The method for fabricating epithelial cell sheets shown in this study was suitable for the validation for clinical trials and suggested usability of the fabricated cell sheets.

Time-lapse imaging reveals symmetric neurogenic cell division of GFAP-expressing progenitors for expansion of postnatal dentate granule neurons

Granule cells in the hippocampus, a region critical for memory and learning, are generated mainly during the early postnatal period but neurogenesis continues in adulthood. Postnatal neuronal production is carried out by primary progenitors that express glial fibrillary acidic protein (GFAP) and they are assumed to function as stem cells. A central question regarding postnatal dentate neurogenesis is how astrocyte-like progenitors produce neurons. To reveal cell division patterns and the process of neuronal differentiation of astrocyte-like neural progenitors, we performed time-lapse imaging in cultured hippocampal slices from early postnatal transgenic mice with mouse GFAP promoter-controlled enhanced green fluorescent protein (mGFAP-eGFP Tg mice) in combination with a retrovirus carrying a red fluorescent protein gene. Our results showed that the majority of GFAP-eGFP+ progenitor cells that express GFAP, Sox2 and nestin divided symmetrically to produce pairs of GFAP+ cells (45%) or pairs of neuron-committed cells (45%), whereas a minority divided asymmetrically to generate GFAP+ cells and neuron-committed cells (10%). The present results suggest that a substantial number of GFAP-expressing progenitors functions as transient amplifying progenitors, at least in an early postnatal dentate gyrus, although a small population appears to be stem cell-like progenitors. From the present data, we discuss possible cell division patterns of adult GFAP+ progenitors.

The use of nanoimprinted scaffolds as 3D culture models to facilitate spontaneous tumor cell migration and well-regulated spheroid formation

Two-dimensional (2D) cell cultures are essential for drug development and tumor research. However, the limitations of 2D cultures are widely recognized, and a better technique is needed. Recent studies have indicated that a strong physical contact between cells and 2D substrates induces cellular characteristics that differ from those of tumors growing in vivo. 3D cell cultures using various substrates are then developing; nevertheless, conventional approaches have failed in maintenance of cellular proliferation and viability, uniformity, reproducibility, and/or simplicity of these assays. Here, we developed a 3D culture system with inorganic nanoscale scaffolding using nanoimprinting technology (nano-culture plates), which reproduced the characteristics of tumor cells growing in vivo. Diminished cell-to-substrate physical contact facilitated spontaneous tumor cell migration, intercellular adhesion, and multi-cellular 3D-spheroid formation while maintaining cellular proliferation and viability. The resulting multi-cellular spheroids formed hypoxic core regions similar to tumors growing in vivo. This technology allows creating uniform and highly-reproducible 3D cultures, which is easily applicable for microscopic and spectrophotometric assays, which can be used for high-throughput/high-content screening of anticancer drugs and should accelerate discovery of more effective anticancer therapies.

Estimation for diameter of superparamagnetic particles in Daphnia resting eggs

Ferromagnetic resonance (FMR) with an electron spin resonance (ESR) apparatus was investigated for super-paramagnetic particles within Daphnia resting eggs. High-field (HF) resonance lines near g=2 resulted from single superparamagnetic particles, were detected from ESR spectra of Daphnia resting eggs. The size of isolated superparamagnetic particles within Daphnia resting eggs was calculated to be approximately 13 nm in diameter by analysis of the temperature dependence of the HF line width. Small-angle X-ray scattering (SAXS) analysis of Daphnia resting eggs also showed that average size of superparamagnetic particles in diameter, equivalent to magnetite, was approximately 13 nm. The combination of FMR and SAXS measurement is very effective in estimating the size of superparamagnetic particles in biological organisms, with difficulties of preparing for samples for measurement by electron microscopy. However, Chlorella, with that Daphnia were raised, did not show FMR spectra, showing no magnetic particles within Daphnia resting eggs. Therefore, it suggested that superparamagnetic particles within Daphnia resting eggs, were mineralized in Daphnia as the result of biomineralization of Fe originated from Chlorella.

Fabrication of human oral mucosal epithelial cell sheets for treatment of esophageal ulceration by endoscopic submucosal dissection

BACKGROUND

Esophageal stenosis is one of the major complications of aggressive endoscopic resection. Tissue-engineered epithelial cell grafts have demonstrated effectiveness in promoting re-epithelialization and suppressing inflammation causing esophageal scarring and stenosis after endoscopic submucosal dissection (ESD) in an animal model.

OBJECTIVE

To confirm the reproducibility and efficacy of a human oral mucosal epithelial cell (hOMEC) sheet cultured on temperature-responsive surface in conformity with Good Manufacturing Practice guidelines.

DESIGN

A preclinical study.

SETTING

Good Manufacturing Practice grade cell-processing center, animal laboratory.

SUBJECTS

Canine esophageal ulcer models, which were made by ESD.

INTERVENTIONS

Oral mucosal specimens were obtained from 7 healthy volunteers.

MAIN OUTCOME MEASUREMENT

Fabricated and transplanted hOMEC sheets were subjected to histological analysis.

RESULTS

The reproducibility of the fabrication of hOMEC sheets was confirmed. In this method, animal-derived materials such as 3T3 feeder layer and fetal bovine serum were successfully excluded from the culture condition. Furthermore, the environment of the culture room and safety cabinet in the cell-processing center was maintained for obtaining sterility assurances during the fabrication. Transplanted hOMEC sheets after ESD were observed to graft onto canine esophageal ulcer surfaces.

LIMITATIONS

Small number of subjects, animal model.

CONCLUSIONS

Cultured hOMEC sheets were fabricated without animal-derived materials and demonstrated efficacy as a medical device that promotes re-epithelialization of an esophageal ulcer after ESD.

Oxidative stress-mediated bimodal regulation of polymorphonuclear leukocyte spreading by polyphenolic compounds

Pyrogallol-bearing polyphenolic compounds induce spreading of polymorphonuclear leukocytes (PMNL), although their optimal concentrations for induction of spreading are quite different (2000, 200, and 2 μM for pyrogallol, (-)-epigallocatechin gallate (EGCG), and tannic acid (TA), respectively), and TA tends to inhibit spreading at higher concentrations. In this study, we examined the involvement of oxidative stress in the regulation of PMNL spreading by these compounds. All three compounds in solution generated H(2)O(2) to a similar extent. Adsorption of the polyphenols to cell surfaces and their accumulation within cells were assessed by detection of the H(2)O(2) precursor O(2)(-) produced by the compounds through reduction of cytochrome c and p-nitro-blue tetrazolium, respectively. TA showed the highest degree of adsorption. EGCG adhered only to PMNL pre-fixed by paraformaldehyde, whereas pyrogallol did not adhere. None of the compounds caused intracellular O(2)(-) generation. A non-pyrogallic compound, 1,2,4-benzenetriol (BT), also produced H(2)O(2); it had no stimulatory effect on PMNL spreading, but inhibited spreading induced by other stimuli. BT did not adhere to PMNL but accumulated within them, and generated O(2)(-) in the presence of glycine. Thiol antioxidants abrogated all of the above spreading-regulatory effects of the polyphenolic compounds. We conclude that H(2)O(2)-generating polyphenols bimodally regulate the spreading of PMNL by subjecting them to oxidative stress. The ability of polyphenol to adhere to, or accumulate within, PMNL may govern the nature of the oxidative stress and determine the optimal concentration of each compound for induction of spreading, as well as whether spreading is promoted or inhibited.

Biphasic regulation of polymorphonuclear leukocyte spreading by polyphenolic compounds with pyrogallol moieties

Green tea polyphenols have been reported to have anti-inflammatory activities, although the molecular mechanisms responsible for this effect remain unclear. In the present study, we examined the effect of green tea extract and a variety of polyphenolic compounds on spreading of peripheral blood polymorphonuclear leukocytes (PMNs) over fibrinogen-coated surfaces. Green tea extract exerted a biphasic effect on PMN spreading; it induced or suppressed spreading at low and high concentrations, respectively. We also found that pyrogallol-bearing compounds have spreading induction activity. Among the compounds tested, tannic acid (TA) had the strongest activity; the concentrations required for induction of maximal spreading were 2 microM for TA, 200 microM for (-)-epigallocatechin gallate, and 2000 microM for the other active compounds. Furthermore, TA was the only compound showing a biphasic effect similar to that of green tea extract; TA at 20 or 200 microM suppressed spreading. The spreading-stimulatory signal was still latent during PMN exposure to TA at concentrations that inhibited spreading, because the pre-exposed PMNs underwent spreading when plated after removal of free TA by centrifugation. The spreading-inhibitory effect of TA at high concentrations overcame the induction of spreading by other stimuli, including phorbol 12-myristate 13-acetate, hydrogen peroxide, denatured fibrinogen surfaces, and naked plastic surfaces. These results suggest that TA as well as green tea extract is bi-functional, having pro-inflammatory and anti-inflammatory effects at low and high concentrations, respectively. Pharmacological use of TA may thus provide new strategies aimed at regulation of PMN spreading for control of inflammation.

Postnatal neurogenesis in hippocampal slice cultures: early in vitro labeling of neural precursor cells leads to efficient neuronal production

Neurogenesis continues throughout life in the hippocampus. To study postnatal neurogenesis in vitro, hippocampal slices from rats on postnatal day 5 (P5) were cultured on a porous membrane for 14 or 21 days. In the initial experiments, precursor cells were labeled with bromodeoxyuridine (BrdU) after 7 days in culture because hippocampal slices are generally used in experiments after 1-2 weeks in culture. Fourteen days after labeling, however, only about 10% of BrdU-labeled cells expressed neuronal markers, although in living rats, about 80% of cells labeled with BrdU on P5 had become neurons by P19. Next, rats were injected with BrdU 30 min before culture, after which hippocampal slices were cultured for 14 days to examine the capacity of in vivo-labeled neural precursors to differentiate into neurons in vitro. In this case, more than two-thirds of BrdU-labeled cells expressed neuronal markers, such as Hu, NeuN, and PSA-NCAM. Furthermore, precursor cells underwent early in vitro labeling by incubation with BrdU or a modified retrovirus vector carrying EGFP for 30 min from the beginning of the culture. This procedure resulted in a similar high rate of neuronal differentiation and normal development into granule cells. In addition, time-lapse imaging with retrovirus-EGFP revealed migration of neural precursors from the hilus to the granule cell layer. These results indicate that in vivo- and early in vitro-labeled cultures are readily available ex vivo models for studying postnatal neurogenesis and suggest that the capacity of neural precursors to differentiate into neurons is reduced during the culture period.

Grand Espoir: Robotics in Regenerative Medicine

Here, we overlook the brief history of regenerative medicine, and summarize the expectation to breakthroughs achieved by robotics in the field. One expected application of robotics is an automatic cell culture system, which can dramatically reduce the cost for manufacturing bioengineered tissues conventionally requiring GMP (Good Manufacturing Practice) facility for Cell Processing Center. The other is a robotic surgery system for less invasive transplantation of cells and fabricated tissues. To show the feasibility of robotic surgery-assisted transplantation, we have shown the success of cell sheet transplantation to luminal surface of living canine esophagus by endoscopy. Thus, the contribution of robotics to regenerative medicine has been wanted to realize the greatest success of tissue engineering and cell-based medicine.

Mechanism of membrane redistribution of protein kinase C by its ATP-competitive inhibitors

ATP-competitive inhibitors of PKC (protein kinase C) such as the bisindolylmaleimide GF 109203X, which interact with the ATP-binding site in the PKC molecule, have also been shown to affect several redistribution events of PKC. However, the reason why these inhibitors affect the redistribution is still controversial. In the present study, using immunoblot analysis and GFP (green fluorescent protein)-tagged PKC, we showed that, at commonly used concentrations, these ATP-competitive inhibitors alone induced redistribution of DAG (diacylglycerol)-sensitive PKCalpha, PKCbetaII, PKCdelta and PKCepsilon, but not atypical PKCzeta, to the endomembrane or the plasma membrane. Studies with deletion and point mutants showed that the DAG-sensitive C1 domain of PKC was required for membrane redistribution by these inhibitors. Furthermore, membrane redistribution was prevented by the aminosteroid PLC (phospholipase C) inhibitor U-73122, although an ATP-competitive inhibitor had no significant effect on acute DAG generation. Immunoblot analysis showed that an ATP-competitive inhibitor enhanced cell-permeable DAG analogue- or phorbol-ester-induced translocation of endogenous PKC. Furthermore, these inhibitors also enhanced [3H]phorbol 12,13-dibutyrate binding to the cytosolic fractions from PKCalpha-GFP-overexpressing cells. These results clearly demonstrate that ATP-competitive inhibitors cause redistribution of DAG-sensitive PKCs to membranes containing endogenous DAG by altering the DAG sensitivity of PKC and support the idea that the inhibitors destabilize the closed conformation of PKC and make the C1 domain accessible to DAG. Most importantly, our findings provide novel insights for the interpretation of studies using ATP-competitive inhibitors, and, especially, suggest caution about the interpretation of the relationship between the redistribution and kinase activity of PKC.

Viral infections activate types I and III interferon genes through a common mechanism

Viral infections trigger innate immune responses, including the production of type I interferons (IFN-alpha and -beta) and other proinflammatory cytokines. Novel antiviral cytokines IFN-lambda1, IFN-lambda2, and IFN-lambda3 are classified as type III IFNs and have evolved independently of type I IFNs. Type III IFN genes are regulated at the level of transcription and induced by viral infection. Although the regulatory mechanism of type I IFNs is well elucidated, the expression mechanism of IFN-lambdas is not well understood. Here, we analyzed the mechanism by which IFN-lambda gene expression is induced by viral infections. Loss- and gain-of-function experiments revealed the involvement of RIG-I (retinoic acid-inducible gene I), IPS-1, TBK1, and interferon regulatory factor-3, key regulators of the virus-induced activation of type I IFN genes. Consistent with this, a search for the cis-regulatory element of the human ifnlambda1 revealed a cluster of interferon regulatory factor-binding sites and a NF-kappaB-binding site. Functional analysis demonstrated that all of these sites are essential for gene activation by the virus. These results strongly suggest that types I and III IFN genes are regulated by a common mechanism.

Cytoplasmic pH-dependent spreading of polymorphonuclear leukocytes: Regulation by pH of PKC subcellular distribution and F-actin assembly

Cytoplasmic pH (pHi) plays an important role in the regulation of polymorphonuclear leukocyte (PMN) spreading, but the molecular mechanisms involved have long been obscure. In the present study, we investigated the pH-dependence of phorbol myristate acetate (PMA)-induced PMN spreading. A change in pHi alone did not induce spreading, but cytoplasmic alkalinization promoted the spreading induced by PMA, whereas acidification inhibited it. To further investigate the mechanism by which pHi affects cell spreading, we employed subcellular fractionation and immunoblot analyses to evaluate the effect of pH on the subcellular distribution of protein kinase C (PKC) and assembly of the actin cytoskeleton. We found that cytoplasmic alkalinization enhanced PKC membrane distribution and quantitatively up-regulated the actin cytoskeleton. On the other hand, cytoplasmic acidification was found to have effects on these signaling molecules that were opposite to those of cytoplasmic alkalinization. These results may provide a potential explanation for the pH-regulation of the PMA-induced PMN spreading.

Treatment of oesophageal ulcerations using endoscopic transplantation of tissue-engineered autologous oral mucosal epithelial cell sheets in a canine model

BACKGROUND

With the recent development of endoscopic submucosal dissection (ESD), large oesophageal cancers can be removed with a single procedure, with few limits on the resectable range. However, after aggressive ESD, a major complication that arises is postoperative inflammation and stenosis that can considerably affect the patient's quality of life.

AIMS

To examine a novel treatment combining ESD and the endoscopic transplantation of tissue-engineered cell sheets created using autologous oral mucosal epithelial cells, in a clinically relevant large animal model.

METHODS

Oral mucosal epithelial cells, harvested from beagle dogs, were cultured under normal conditions at 37 degrees C, on temperature-responsive dishes. After ESD (5 cm in length, 180 degrees in range), cell sheets were harvested by a simple reduction in temperature to 20 degrees C, and transplanted by endoscopy.

RESULTS

The transplanted cell sheets were able to adhere to and survive on the underlying muscle layers in the ulcer sites, providing an intact, stratified epithelium. Four weeks after surgery, complete wound healing, with no observable stenosis, was seen in the animals receiving autologous cell sheet transplantation. By contrast, noticeable fibrin mesh and host inflammation, consistent with the intermediate stages of wound healing, were observed in the control animals that received only ESD.

CONCLUSIONS

These findings in a clinically relevant canine model show the effectiveness of a novel combined endoscopic approach for the potential treatment of oesophageal cancers that can effectively enhance wound healing and possibly prevent postoperative oesophageal stenosis.

Magnetic characterization of Daphnia resting eggs

This study characterized the magnetic materials found within Daphnia resting eggs by measuring static magnetization with a superconducting quantum interference device (SQUID) magnetometer, after forming two types of conditions, each of which consists of zero-field cooling (ZFC) and field cooling (FC). Magnetic ions, such as Fe(3+), contained in Daphnia resting eggs existed as (1) paramagnetic and superparamagnetic particles, demonstrated by a magnetization and temperature dependence of the magnetic moments under an applied magnetic field after ZFC and FC, and (2) ferromagnetic particles with definite magnetic moments, the content of which was estimated to be very low, demonstrated by the Moskowitz test. Conventionally, biomagnets have been directly detected by transmission electron microscopes (TEM). As demonstrated in this study, it is possible to nondestructively detect small biomagnets by magnetization measurement, especially after two types of ZFC and FC. This nondestructive method can be applied in detecting biomagnets in complex biological organisms.

The effect of micropores in the surface of temperature-responsive culture inserts on the fabrication of transplantable canine oral mucosal epithelial cell sheets

Primary canine oral mucosal epithelial cells were cultured on temperature-responsive dishes and cell culture inserts to fabricate transplantable epithelial cell sheets. When 3T3 feeder layers and fetal bovine serum were eliminated from dish culture, the harvested cell sheets became significantly more fragile. In contrast, when epithelial cells were cultured on inserts having submicron-scale pores, cell sheet fragility was eliminated. Keratin expression profiles showed no differences among the harvested cell sheets, but the expression of p63, a putative stem/progenitor marker, was strongly dependent on the presence of 3T3 feeder layers and serum. These results suggest that the maintenance of stem/progenitor cells is influenced by the apical/basal supply of nutrients as well as culture supplements.

Fabrication of transplantable human oral mucosal epithelial cell sheets using temperature-responsive culture inserts without feeder layer cells

To exclude bacteria- or animal-derived factors from cultured fabrication of transplantable epithelial cell sheets, primary human oral mucosal epithelial cells were seeded on temperature-responsive culture inserts having submicron-scale pores. Supplying culture medium containing human autologous serum to both apical and basal sides of human epithelial cells allows these cells to grow to confluence. These proliferating cells created stratified epithelial layers even when 3T3 feeder layers and fetal bovine serum were eliminated from culture. Normal keratin expression profiles were obtained with these cells, and basal and midlayer cells expressed p63, a putative stem/progenitor marker. These results suggest that temperature-responsive culture inserts can be useful in clinical settings that require the exclusion of xenogeneic factors.

Cellular responses of the ciliate, Tetrahymena thermophila, to far infrared irradiation

Infrared rays from sunlight permeate the earth's atmosphere, yet little is known about their interactions with living organisms. To learn whether they affect cell structure and function, we tested the ciliated protozoan, Tetrahymena thermophila. These unicellular eukaryotes aggregate in swarms near the surface of freshwater habitats, where direct and diffuse solar radiation impinge upon the water-air interface. We report that populations irradiated in laboratory cultures grew and mated normally, but major changes occurred in cell physiology during the stationary phase. Early on, there were significant reductions in chromatin body size and the antibody reactivity of methyl groups on lysine residues 4 and 9 in histone H3. Later, when cells began to starve, messenger RNAs for key proteins related to chromatin structure, intermediary metabolism and cellular motility increased from two- to nearly nine-fold. Metabolic activity, swimming speed and linearity of motion also increased, and spindle shaped cells with a caudal cilium appeared. Our findings suggest that infrared radiation enhances differentiation towards a dispersal cell-like phenotype in saturated populations of Tetrahymena thermophila.

The fate of neural progenitor cells expressing astrocytic and radial glial markers in the postnatal rat dentate gyrus

In the dentate gyrus neurons continue to be generated from late embryonic to adult stage. Recent extensive studies have unveiled several key aspects of the adult neurogenesis, but only few attempts have so far been made on the analysis of the early postnatal neurogenenesis, a transition state between the embryonic and adult neurogenesis. Here, we focus on the early postnatal neurogenesis and examine the nature and development of neural progenitor cells in Wistar rats. Immunohistochemistry for Ki67, a cell cycle marker, and 5-bromo-2-deoxyuridine (BrdU) labelling show that cell proliferation occurs mainly in the hilus and partly in the subgranular zone. A majority of the proliferating cells express S100beta and astrocyte-specific glutamate transporter (GLAST) and the subpopulation are also positive for glial fibrillary acidic protein (GFAP) and nestin. Tracing with BrdU and our modified retrovirus vector carrying enhanced green fluorescent protein (GFP) indicate that a substantial population of the proliferating cells differentiate into proliferative neuroblasts and immature neurons in the hilus, which then migrate to the granule cell layer (66.8%), leaving a long axon-like process behind in the hilus, and the others mainly become star-shaped astrocytes (12.0%) and radial glia-like cells (4.7%) in the subgranular zone. These results suggest that the progenitors of the granule cells expressing astrocytic and radial glial markers, proliferate and differentiate into neurons mainly in the hilus during the early postnatal period.

Elemental Characterization of Daphnia Resting Eggs by X-ray Analytical Microscopy

Resting eggs of Daphnia, a key crustacean zooplankton of freshwater food chains, can remain viable for more than a century. These eggs are able to withstand freezing and drying, and can survive the harsh environment of a predator's digestive system. Until recently little was known about the chemical composition, microanatomy, and physical properties of the resting eggs. The current study utilized a physical technique, the X-ray analytical microscope, to identify and localize component elements of the Daphnia resting egg. The analysis demonstrated that phosphorus, sulfur, potassium, and calcium were detected as elemental components of the resting egg, and detection intensities of the four elements differed according to the position of the eggs. Phosphorus and calcium were mostly detected in regions of the eggshell that surrounded the two embryos. In addition, sulfur was distributed throughout the eggshell whereas potassium was localized to the areas that corresponded to where the embryos were encased. Through the use of X-ray analytical microscopy, the current study identifies elemental characteristics in relationship to the structure of the Daphnia resting eggs.

Comparison of nonmetal and metal hydrophilic photosensitizer, ATX-S10 (Na) and ATN-2, binding with human serum proteins using spectrophotometry

Intermolecular interactions of human serum proteins with a hydrophilic nonmetalloporphyrin, 13,17-bis(1-carboxypropionyl)carbomoylethyl-8-ethenyl-2-hydroxy-3-hydroxyiminoethylidene-2,7,12,18-tetramethylporphyrin sodium salt (ATX-S10 (Na)), or a hydrophilic gallium-metalloporphyrin, diethylenetriamine pentaacetic acid ester of 2-[1-(2-hydroxy-ethoxy)ethyl]-4-vinyl-deuteroporphyrin (IX) Ga complex (ATN-2), were investigated using spectrophotometry. ATX-S10 (Na) caused a bathochromic shift with albumin, high-density lipoprotein and low-density lipoprotein, but little or no shift was observed with hemopexin, transferrin and immunoglobulin G. In contrast, ATN-2 displayed a bathochromic shift only with hemopexin. These results suggest that the association energy of ATX-S10 (Na) with albumin might be slightly greater than that with lipoproteins and that of ATN-2 with hemopexin might be greater than that with other serum proteins.

Pervanadate-induced reverse translocation and tyrosine phosphorylation of phorbol ester-stimulated protein kinase C betaII are mediated by Src-family tyrosine kinases in porcine neutrophils

Protein kinase C (PKC), upon activation, translocates from the cytosol to the plasma membrane. Phorbol 12-myristate 13-acetate (PMA), a potent PKC activator, is known to induce irreversible translocation of PKC to the plasma membrane, in contrast to the reversible translocation resulting from physiological stimuli and subsequent rapid return to the cytosol (reverse translocation). However, we have previously shown that tyrosine phosphatase (PTPase) inhibitors induce reverse translocation of PMA-stimulated PKCbetaII in porcine polymorphonuclear leukocytes (PMNs). In the present study, we showed that pervanadate, a potent PTPase inhibitor, also induces tyrosine phosphorylation of PMA-stimulated PKCbetaII in porcine PMNs. Furthermore, PP2, a specific inhibitor of Src-family tyrosine kinases (PTKs), was found to inhibit both pervanadate-induced reverse translocation and tyrosine phosphorylation of PMA-stimulated PKCbetaII, suggesting that these two pervanadate-induced responses are mediated by Src-family PTKs. Our findings provide novel insight into the relationship between the subcellular localization and tyrosine phosphorylation of PKC.

[Serum hemopexin: suppressive effect on neutrophil functions and prospect of clinical application to autoimmune diseases]

Hemopexin is a serum glycoprotein with a high binding affinity for heme, and is known as a scavenger/transporter of heme. Recent studies indicated that purified hemopexin suppresses neutrophil adhesion and phagocytosis by a mechanism unrelated to heme-binding, suggesting a novel activity of hemopexin. Unidentified serum factor in combination with Ca2+ dampens the effect of hemopexin. So, hemopexin in peripheral blood may not act as an inhibitor of neutrophil function. However, because hemopexin is synthesized in injured peripheral nerves, it may be hypothesized that hemopexin has an anti-inflammatory role in nerve repair by suppressing phagocyte accumulation/phagocytosis. Further studies of hemopexin may provide new therapeutic strategies aimed at suppressing neutrophil functions to control inflammation and tissue injury, especially in autoimmune diseases such as rheumatoid arthritis.

Crystalline Calcium Phosphate and Magnetic Mineral Content ofDaphniaResting Eggs

Daphnia is a key crustacean zooplankton of freshwater food chains. One factor that ensures successful propagation is the Daphnia resting eggs, which are able to retain structural integrity under extreme conditions. Until recently little was known about the chemical composition, microanatomy, and physical properties of the egg itself. The current study demonstrates that the resting eggs: (1) have shells that are made up of crystalline calcium phosphate and include a honeycombed structure, and (2) contain magnetic material having properties consistent with magnetite. These properties of the resting eggs may ensure Daphnia survival in harsh environments.

Phenylarsine oxide and H2O2 plus vanadate induce reverse translocation of phorbol-ester-activated PKCbetaII

The intracellular localization of protein kinase C (PKC) is important for the regulation of its biological activity. Recently, it was reported that, whereas phorbol esters such as PMA induce prolonged translocation of PKC to the plasma membrane, with physiological stimuli, the translocation of PKC is transient and followed by rapid return to the cytoplasm. In addition, this membrane dissociation of PKC was shown to require both the kinase activity of PKC and the phosphorylation of its carboxyl terminus autophosphorylation sites. However, the detailed molecular mechanism of PKC reverse translocation remains obscure. We demonstrated that in porcine polymorphonuclear leucocytes (PMNs), phenylarsine oxide (PAO), a putative protein tyrosine phosphatase (PTPase) inhibitor, induced reverse translocation of PMA-stimulated PKCbetaII. Hydrogen peroxide (H(2)O(2)) in combination with vanadate, both of which are PTPase inhibitors, also induced reverse translocation of PKCbetaII. H(2)O(2) or vanadate alone had little effect on PMA-induced PKCbetaII translocation. Furthermore, genistein and ethanol, which are inhibitors of tyrosine kinase and phospholipase D, respectively, prevented the PKCbetaII reverse translocation induced by the PTPase inhibitors. These results indicate, for the first time, that the tyrosine phosphorylation/phospholipase D pathway may be involved in the process of membrane dissociation of PKC.

Rapid and sensitive detection method of a bacterium by using a GFP reporter phage

A rapid, sensitive, and convenient method for detecting a specific bacterium was developed by using a GFP phage. Here we describe a model system that utilizes the temperate Escherichia coli-restricted bacteriophage lambda, which was genetically modified to express a reporter gene for GFP to identify the colon bacillus E. coli in the specimen. E. coli infected with GFP phage was detected by GFP fluorescence after 4-6 hr of incubation. The results show that a few bacteria in a specimen can be detected under fluorescence microscopy equipped with a sensitive cooled CCD camera. When E. coli and Mycobacterium smegmatis were mixed in a solution containing GFP phage, only E. coli was infected, indicating the specificity of this method. The method has the following advantages: 1) Bacteria from biological samples need not be purified unless they contain fluorescent impurities; 2) The infection of GFP phage to bacteria is specific; 3) The fluorescence of GFP within infected bacteria enables highly sensitive detection; 4) Exogenous substrates and cofactors are not required for fluorescence. Therefore this method is suitable for any phage-bacterium system when bacteria-specific phages are available.

Inhibition of Mg2+-dependent Adhesion of Polymorphonuclear Leukocytes by Serum Hemopexin: Differences in Divalent-Cation Dependency of Cell Adhesion in the Presence and Absence of Serum

Circulating and nonadherent polymorphonuclear leukocytes (PMNs) become activated to attain adhesive state in an integrin-dependent manner by various stimuli, and perform a variety of microbicidal functions such as phagocytosis and superoxide production. We found that, in the absence of serum, a physiological concentration of hemopexin has a strong inhibitory action on Mg(2+)-dependent adhesion of PMA-activated PMNs to fibrinogen- and serum-coated surfaces. Under these conditions, Ca(2+) had no effect on Mg(2+)-dependent adhesion or the adhesion-inhibitory activity of hemopexin. In contrast, PMNs suspended in serum containing sufficient amounts of hemopexin to inhibit adhesion showed marked adherence, which was inhibited by EGTA. Next, we prepared a small-molecule fraction of serum by ultrafiltration followed by boiling. PMA-activated PMNs was found to adhere in the presence of both hemopexin and the small-molecule fraction, and the adhesion was enhanced by exogenous Ca(2+). EGTA abolished the effect of the small molecule fraction. The data suggest that serum contains adhesion-promoting factor(s) which allows PMNs to adhere despite the presence of hemopexin and that Ca(2+) is required for adhesion-promoting activity. Further study of hemopexin may provide clues for new therapeutic strategies aimed at interfering with PMN adhesion to control inflammation and tissue injury.

Comparison of Japanese general rules of prostatic cancer and Gleason grading system

BACKGROUND

We compared the prognostic efficacy between the Japanese General Rules of Prostatic Cancer (JGRPC) and the Gleason grading system (GGS) by applying them to a single set of patients and assessing the survival outcome.

METHODS

One hundred and seventy-six patients with previously untreated prostate cancer were studied. One experienced Japanese pathologist graded the slides with JGRPC. Another experienced American pathologist graded the same slides with the Gleason grading system. The JGRPC grades were correlated with the Gleason scores (GS) grouped into three (GS 2-4, 5-7 and 8-10) or four (GS 2-4, 5-6, 7 and 8-10) tiers.

RESULTS

The highest cancer death rates were seen in the higher grade groups in both systems. Comparison of JGRPC grade and three-tiered grouping of the GS showed identical grades in 81 of 176 cases (46.0%). The overall kappa value of agreement was only 0.151. The 96 cases of JGRPC moderately differentiated carcinoma group contained two nearly equal-sized groups by the Gleason grading system, those with GS 5-7 (47cases) and GS 8-10 (49 cases). There was a significant difference in survival rate between the GS 5-7 and GS 8-10 groups. No significant differences were noted in the reverse analysis of survival by JGRPC groups within patients with the same GS three-tiered groups. Similar trends were seen when JGRPC was compared with the four-tiered grouping of the GS.

CONCLUSION

Both JGRPC and the Gleason grading system are useful in estimating the prognosis of prostate cancer, but only a mild correlation was found between the two systems. The Gleason grading system may provide more prognostic information than JGRPC in the moderately differentiated group.

Hemopexins suppress phorbol ester-induced necrosis of polymorphonuclear leucocytes

It was recently reported that intravenous administration of phorbol 12-myristate 13-acetate (PMA) showed a therapeutic effect in myelocytic leukemia patients. However, we previously observed that, in serum-free conditions, polymorphonuclear leucocytes (PMNs) were killed rapidly by exposure to PMA, suggesting the possibility of serious side effects. In this study, we found that PMA-induced necrosis of PMNs was prevented by serum, suggesting the existence of a "necrosis-suppressing factor". Next we tried to identify the serum factor. The hemopexins we purified were found to suppress necrosis of PMNs in a dose-dependent fashion. Hemopexins alone could not suppress necrosis, however, as it required the coexistence of another macromolecule such as albumin. Albumin promoted the suppressive activity of hemopexins in a dose-dependent fashion. These results strongly suggest that serum hemopexins may rescue mature PMNs from necrosis in the PMA-administered leukemia patient as previously reported, resulting in avoidance of serious side effects.

Discrepancies between Gleason scores of needle biopsy and radical prostatectomy specimens

The purpose of this study was to determine the accuracy of Gleason scores in prostate needle biopsy diagnosis and to investigate factors affecting the accuracy of the tumor grade. A single pathologist reviewed 116 sets of prostate cancer biopsies and radical prostatectomy specimens. The following factors were examined to determine their effect on the accuracy of the biopsy Gleason scores: (i) relative tumor differentiation; (ii) pathological stage; (iii) amount of tissue in the biopsy specimen; (iv) amount of cancer tissue in the biopsy specimen; (v) tumor heterogeneity; (vi) clinical findings (prostate specific antigen value and digital rectal examination); and (vii) interobserver variability. In 53 cases the Gleason score of biopsy specimens was identical to the score of prostatectomy specimens (45.7%). Fifty-four cases (46.6%) of biopsy specimens were undergraded. The most common discrepancy was diagnosis of well-differentiated carcinoma in the biopsy but diagnosis of moderately differentiated tumor in the corresponding prostatectomy specimen. This discrepancy occurred when the amount of tumor in the biopsy was 3 mm or less. Biopsy and prostatectomy results showed less agreement when the original biopsy tumor grade rendered by nine different pathologists was used, suggesting that interobserver variability can adversely affect the accuracy of tumor grade. Clarifying the histologic criteria for distinguishing each grade, especially between Gleason grades 2 and 3, is important for accurate grading.

Induction of IRF-3/-7 kinase and NF-kappaB in response to double-stranded RNA and virus infection: common and unique pathways

BACKGROUND

Infection by virus or treatment with double-stranded RNA (dsRNA) results in the activation of transcription factors including IRF-3, IRF-7 and a pleiotropic regulator NF-kappaB by specific phosphorylation. These factors are important in triggering a cascade of antiviral responses. A protein kinase that is yet to be identified is responsible for the activation of these factors and plays a key role in the responses.

RESULTS

The signal cascade was analysed using sensitive assays for the activation of IRF-3 and NF-kappaB, and various inhibitors. We found that the activation of IRF-3 and NF-kappaB by dsRNA or virus involves a process that is sensitive to Geldanamycin. Although the induction of NF-kappaB by dsRNA/virus and TNF-alpha involves common downstream pathways including IKK activation, the upstream, Geldanamycin-sensitive process was unique to the dsRNA/virus-induced signal. By an in vitro assay using cell extract, we found an inducible protein kinase activity with physiological specificity of IRF-3 phosphorylation. Furthermore, the same extract specifically phosphorylated IRF-7 in a similar manner.

CONCLUSIONS

Double-stranded RNA or virus triggers a specific signal cascade that results in the activation of the IRF-3/-7 kinase we detected, which corresponds to the long-sought signalling machinery that is responsible for triggering the early phase of innate response. The signal branches to a common NF-kappaB activation cascade, thus resulting in the activation of a set of critical transcription factors for the response.

PACT, a double-stranded RNA binding protein acts as a positive regulator for type I interferon gene induced by Newcastle disease virus

Virus infection triggers innate responses to host cells including production of type I interferon (IFN). Since IFN production is also induced by treatment with poly(I:C), viral double-stranded (ds) RNA has been postulated to play a direct role in the process. In the present study, we investigated the effect of dsRNA binding proteins on virus-induced activation of the IFN-beta gene. We found that PACT, originally identified as protein activator for dsRNA-dependent protein kinase (PKR) and implicated in the regulation of translation, augmented IFN-beta gene activation induced by Newcastle disease virus. Concomitantly with the augmented activity of IFN-beta enhancer, increased activity of NF-kappaB and IRF-3 and IRF-7 was observed. For the observed effect, the dsRNA-binding activity of PACT was essential. We identified residues of PACT that interact with a presumptive target molecule to exert its function. Furthermore, PACT colocalized with viral replication complex in the infected cells. Thus the observed effect of PACT is novel and PACT is involved in the regulation of viral replication and results in a marked increase of cellular IFN-beta gene expression.