Inhibition of NADPH oxidase 4 activates apoptosis via the AKT/apoptosis signal-regulating kinase 1 pathway in pancreatic cancer PANC-1 cells.

Pancreatic adenocarcinoma is an aggressive human malignancy and is characterized by resistance to apoptosis. Recently, NADPH oxidase (Nox) 4-mediated generation of intracellular reactive oxygen species (ROS) was proposed to confer antiapoptotic activity and thus a growth advantage to pancreatic cancer cells. The signaling mechanism by which Nox4 transmits cell survival signals remains unclear. Here, we show that both a flavoprotein inhibitor, diphenylene iodonium (DPI), and small interfering RNAs designed to target Nox4 mRNA (siNox4RNAs) inhibited superoxide production in PANC-1 pancreatic cancer cells, and depletion of ROS by DPI or siNox4RNAs induced apoptosis. Parallely, DPI treatment and siNox4RNA transfection blocked activation of the cell survival kinase AKT by attenuating phosphorylation of AKT. Furthermore, AKT phosphorylation of apoptosis signal-regulating kinase 1 (ASK1) on Ser-83 was reduced by DPI and siNox4RNAs. When ASK1Ser83Ala (an AKT phosphorylation-defective ASK1 mutant) was introduced into PANC-1 cells, this mutant alone induced apoptosis. But, addition of DPI or co-transfection of siNox4RNA had no additive effect, indicating that the mutant can substitute for these reagents in apoptosis induction. Taken together, these findings suggest that ROS generated by Nox4, at least in part, transmit cell survival signals through the AKT-ASK1 pathway in pancreatic cancer cells and their depletion leads to apoptosis.

Crystallization and preliminary diffraction studies of recombinant human granulocyte-stimulating factor (KW2228).

Human granulocyte colony-stimulating factor (hG-CSF) specifically stimulates proliferation of neutrophils. Two crystal forms of a mutant of hG-CSF expressed in Escherichia coli have been obtained using the hanging drop vapour diffusion method. One form is triclinic, space group P1, with cell dimensions a = 37.3 A, b = 46.4 A, c = 47.7 A, alpha = 105.5 degrees, beta = 98.0 degrees and gamma = 109.4 degrees. The other is monoclinic, space group C2, with cell dimensions a = 82.0 A, b = 49.2 A, c = 49.4 A and beta = 113.9 degrees. Both crystal forms diffract beyond 2.0 A and are suitable for X-ray analysis.

Procyanidin oligomers selectively and intensively promote proliferation of mouse hair epithelial cells in vitro and activate hair follicle growth in vivo.

We have previously reported that proanthocyanidins extracted from grape seeds possess growth-promoting activity toward murine hair epithelial cells in vitro and stimulate anagen induction in hair cycle progression in vivo. This report constitutes a comparison of the growth-promoting activity of procyanidin oligomers and the target cells of procyanidins in the skin. Results show that procyanidin dimer and trimer exhibit higher growth-promoting activity than the monomer. The maximum growth-promoting activity for hair epithelial cells with procyanidin B-2, an epicatechin dimer, reached about 300% (30 microM) relative to controls (= 100%) in a 5 d culture. Optimum concentration of procyanidin C-1, an epicatechin trimer, was lower than that of procyanidin B-2; the maximum growth-promoting activity of procyanidin C-1 was about 220% (3 microM). No other flavonoid compounds examined exhibit higher proliferative activities than the procyanidins. In skin constituent cells, only epithelial cells such as hair keratinocytes or epidermal keratinocytes respond to procyanidin oligomers. Topical application of 1% procyanidin oligomers on shaven C3H mice in the telogen phase led to significant hair regeneration [procyanidin B-2, 69.6% +/- 21.8% (mean +/- SD); procyanidin B-3, 80.9% +/- 13.0%; procyanidin C-1, 78.3% +/- 7.6%] on the basis of the shaven area; application of vehicle only led to regeneration of 41.7% (SD = 16.3%). In this paper, we demonstrate the hair-growing activity of procyanidin oligomers both in vitro and in vivo, and their potential for use as agents to induce hair growth.

Structure of KW-2228, a tailored human granulocyte colony-stimulating factor with enhanced biological activity and stability.

KW-2228 is a tailored human granulocyte colony-stimulating factor (hG-CSF) which has more potent granulopoietic activity and is more stable than wild-type hG-CSF. Analysis of the 2.3 A resolution crystal structure of KW-2228 unambiguously revealed a four-alpha-helix bundle motif with up-up-down-down connectivity. The structures of long overhand loops connecting the helices and the N-terminus have been definitively determined. The present analysis has clearly revealed that substituted residues play important roles in fastening a long overhand loop to the N- and C-termini to fix the conformation. This conformation should be responsible for a substantial enhancement of the biological activity and stability.

Existence of associated, non-associated, and oligomeric forms of human chorionic gonadotropin subunits in placental extracts.

The molecular sizes of human chorionic gonadotropin (hCG) subunits in the native state in normal first trimester placental extracts were determined by gel filtration on Sephacryl S-300, followed by SDS-polyacrylamide gel electrophoresis, protein blotting, and immunobinding analysis using anti-alpha and - beta antibodies. Mature forms of hCG subunits in the extracts were only found in the same fraction as that which contained standard urinary hCG, indicating an alpha beta dimer. On the other hand, immature forms were detected with a wide range of molecular weights, which were higher than that of standard hCG, suggesting oligomerization of associated or non-associated immature subunits. In order to determine the associated state of these subunits, various forms of associated subunits (hCG alpha beta) in placental extracts were immunoprecipitated with anti-hCG antiserum, which only recognized hCG alpha beta, and Protein A-Sepharose. They were then analyzed by SDS-polyacrylamide gel electrophoresis under reducing and non-reducing conditions, followed by immunobinding assaying. It has been suggested that there are three kinds of hCG alpha beta S (one mature and two immature). To confirm the above results and to clarify the existence of free subunits, placental extracts were subjected to two-dimensional SDS-polyacrylamide gel electrophoresis. With this technique, high molecular weight forms of immature hCG subunits were found to be present in placental cells as an oligomer of not only the alpha beta dimer but of each subunit as well.

Modification of recombinant human granulocyte colony-stimulating factor (rhG-CSF) and its derivative ND 28 with polyethylene glycol.

Recombinant human granulocyte colony-stimulating factor (rhG-CSF) has been obtained from genetically engineered Escherichia coli as an unglycosylated protein. Both native glycosylated hG-CSF and rhG-CSF are rapidly cleared from the circulation, which may limit their effectiveness for clinical use. To improve this biological property, rhG-CSF and its derivative ND 28, which has a higher specific activity than does rhG-CSF, were modified with polyethylene glycol (PEG). Modified rhG-CSF and ND 28 in which 1 to 3 mol of PEG were bound, were purified by two-step chromatography and characterized by several methods. The results of their physicochemical characterization suggest that PEG-modification does not appreciably change the conformation of rhG-CSF and ND 28. As a result of the whole characterization, the PEG-modification of rhG-CSF and ND 28 enhanced the stability of rhG-CSF and ND 28 and decreased the plasma clearance rate, which led to more effective hemopoiesis.

Subcellular localization of intracellular forms of human chorionic gonadotropin in first trimester placenta.

To determine the subcellular sites for synthesis and processing of human chorionic gonadotropin subunits in cells, first trimester placental cells were fractionated subcellularly on sucrose density gradients. Analysis of the subcellular fractions by immunobinding techniques revealed that the rough endoplasmic reticulum-rich fraction contained only intermediates having high-mannose oligosaccharides, but the Golgi-rich fraction contained not only intermediates but also mature forms which were resistant to endoglycosidase H but sensitive to neuraminidase. These results show that human chorionic gonadotropin subunits are synthesized in the rough endoplasmic reticulum as forms containing high-mannose oligosaccharides, and their maturation occurs in the Golgi apparatus by trimming with endogenous glycosidases. They are then modified by addition of complex oligosaccharides and terminal sialic acid through glycosyltransferases.

Toxicological studies on procyanidin B-2 for external application as a hair growing agent.

Procyanidin B-2 [epicatechin-(4beta --> 8)-epicatechin] is one of condensed tannin that exists widely in plants. We have reported previously that procyanidin B-2 possesses hair epithelial cell growth-promoting activity and stimulates anagen induction in hair cycle progression. To evaluate the safety of topical procyanidin B-2 as a hair growing agent, we examined the mutagenicity, acute subcutaneous injection, primary irritation, skin sensitization, and eye irritation of this compound. Mutagenicity tests using bacteria showed procyanidin B-2 to be non-mutagenic. Chromosomal aberration tests using CHL cells indicated that procyanidin B-2 caused polyploidy but no structural aberrations. In micronucleus tests for mutagenicity using mice, procyanidin B-2 was negative. Acute subcutaneous injection study using rats revealed no symptoms of significant injury. The lethal dose of procyanidin B-2 is greater than 2000 mg/kg (subcutaneous injection). Primary irritation tests using rabbits indicated that procyanidin B-2 containing preparation shows no primary irritation. In the guinea pig maximization test, there was no evidence of sensitization to procyanidin B-2. In primary ocular irritation tests using rabbits, procyanidin B-2 containing preparation and vehicle showed slight irritation of conjunctivae which is assumed to be caused by ethanol. It is suggested that topical procyanidin B-2 is safe and acceptable from the series of toxicological tests.

Effect of divalent polyethylene glycol units, conjugated on human granulocyte colony-stimulating factor, on biological activities in vitro and in vivo.

New divalent (two-chain type) polyethylene glycol (PEG) conjugates of a derivative of human recombinant granulocyte colony-stimulating factor (rhG-CSF), ND28, were synthesized by a novel conjugation method using triazine ring and amino butyric acid, and separated into mono-, di- and tri-PEG2(two chains)-ND28 with high purity of more than 90%, to examine the effect of the number of PEG units on their biological properties. Three species of PEG2-ND28 conjugates showed reduced but clear in vitro bioactivity and receptor binding inhibitory activity, and an inverse correlation between the number of PEG units and the activity was seen. On the other hand, the in vivo granulopoietic effect of tri-PEG2-ND28 in mice was observed to be most potent and long-lasting for 6 days after only one administration, and was followed by di-PEG2-ND28 and mono-PEG2-ND28. The plasma concentration of tri-PEG2-ND28 was maintained at a high level for 3 days after administration, while that of PEG-unbound ND28 disappeared within 30 h. There was a positive correlation between the number of PEG units and both the granulopoietic effect and the plasma half-life. These results suggest that the number of PEG units attached to the rhG-CSF can increase their stability during circulation in the plasma of mice, in turn resulting in a long-lasting granulopoietic effect in vivo.

Antigenicity of group B Streptococcus strain "M9" and its prevalence in Japan.

Serological typing of group B streptococci is important for the epidemiological study of group B streptococcal infections. These days, non typable (NT) strains by conventional serotypes were on an increase. In 1984, strain "M9" was isolated from a pregnant woman in Meijo Hospital, Nagoya City; herein the antigenicity and prevalence of strains typed as "M9" were investigated and discussed. The results obtained were as follows: 1) It was confirmed that strain "M9" had a new polysaccharide antigen, different from conventional types, Ia, Ib, II, III, IV and V, type candidate NT6 and type candidate 7271, as found by precipitation and precipitation absorption reaction. This procedure, moreover, was useful for differentiation type candidate NT6 and 7271 from "M9" because of their provisionality. 2) Group B streptococci typed as "M9" were isolated not only from carriers but from patients who were newborn babies and suffered from sepsis. 3) Strain "M9" was not necessarily located in Nagoya City but in Chiba and in Kyoto, this type was isolated from clinical materials already in 1979. 4) It was observed that polysaccharide "M9" liked to combine with protein "R" and without other proteins, as our collection extends.

[Genetic difference in extinction of a conditioned behavior in mice (author's transl)].

The conditioned avoidance behavior from electric shock were examined in thirty male mice of inbred JCL: ICR and DDF with a newly-designed apparatus which had a wide square open field implanted shock-electrodes in floor and a fixed arc running path way where electric shock current could be delivered or not. Data were recorded on running traces and times from the start point to the goal and analysed statistically. 1. In acquisition training, both the JCL: ICR and the DDF acquired to run the way correctly and any difference between them could not be observed. While in extinction, the JCL: ICR were more rapid than the DDF. 2. After the 2nd acquisition training, all mice were trained to run of the field where electric shocks were delivered including the way. The DDF ran into the goal correctly along the way, while the JCL: ICR did not, but ran straight into the goal. The straight-trace of the JCL: ICR could not be changed by the following acquisition. 3. After a eight weeks' pause of acquisition, all mice were tested on retention without shock delivery. The both the JCL: ICR and the DDF ran correctly along the way, and showed a full score by a few trials of aquisition-training. 4. No change in behavior between the strains was found when high voltage shock were delivered during running the way. But in evaluation trials after the delivery only the JCL: ICR showed some changes in running trace and time. 5. Arguments on the difference in the process of extinctions between the strains were proved that may be associated with the genetic difference of a inhibitory mechanism.

Immunohistochemical study of the apoptosis process in epidermal epithelial cells of rats under a physiological condition.

Epidermal homeostasis is maintained by both epithelial proliferation in the stratum basale (SB) and the apoptosis of epithelial cells under physiological conditions. In this study, the induction and regulation mechanisms of epidermal apoptosis were immunohistochemically investigated in the epidermis from Wistar rat's palm and foot pad by using several apoptotic related proteins under a physiological condition. The results showed that Fas and Fas-L were expressed in cellular membranes of the stratum spinosum (SS), whereas TNF-R1 did not show any membranous expression in any epidermal layers. TNF-α was not observed in the epidermis. Caspase-10, cleaved caspase-3 and DNase-1 were found in the epithelial cytoplasms from the SS to stratum granulosum (SG), whereas caspase-8 was not detected in the epidermis. XIAP and Bak were found in the cytoplasm from the SS to SG, and the intensity of Bak-positivity was stronger in the SG than the SS, whereas Bid, Apaf-1 and cleaved caspase-9 were restricted in the SG. Homogenous cytoplasmic immunoreactivity of Bcl-2 was found in the SB and the intensity was gradually decreased from the SB to the SG. The granular-cytoplasmic immunopositivity of cytochrome C gradually altered into homogenous cytoplasmic expression in the upper half of the SG. Single-stranded DNA was rarely detected in the upper portion of the SG. These results suggest that epidermal apoptosis is induced by the interaction between Fas and Fas-L and the activation of caspase-10, and might initially proceed through a mitochondrial-independent pathway, and that a mitochondrial-dependent pathway finally accelerated under physiological conditions.