Correlation with larval body size of mRNA levels of growth hormone, growth hormone receptor I and insulin-like growth factor I in larval torafugu Takifugu rubripes

The full-length of insulin-like growth factor (IGF) complementary (c)DNAs encoded by igf-I and igf-II from torafugu pufferfish Takifugu rubripes were cloned in the present study. The deduced amino acid sequences of the two genes showed c. 80% identity each with those of Igf-I and Igf-II from other teleosts, respectively. Two growth hormone (GH) receptors, ghr1 and ghr2, were also cloned in silico using the T. rubripes Fugu genome database. The transcripts of T. rubripes igf-I were detected in slow muscle, heart, skin, gill, liver and intestine but not in fast muscle, spleen and testis of adult fish, whereas those of igf-II were found in all tissues examined. Subsequently, the accumulated messenger (m)RNA levels of igf-I and igf-II were investigated in an F(2) population derived from a male of an apparent fast-growing T. rubripes strain and a wild female T. rubripes together with those of other growth-related genes encoding Gh, Ghr1 and Ghr2, and with those of prolactin (Prl) and leptin (Lep) previously reported. The accumulated mRNA levels of igf-I, gh and ghr1 were significantly correlated to growth rate at larval stages in the population, but not for those of igf-II, prl, ghr2 and lep. Although it is unclear whether or not this phenotype is directly related to the heredity of the fast-growing strain, the findings suggest that the expression of igf-I, gh and ghr1 is involved in the regulation of growth rate at larval stages in T. rubripes.

ATM-dependent nuclear accumulation of IKK-α plays an important role in the regulation of p73-mediated apoptosis in response to cisplatin

I kappa B kinase (IKK) complex plays an important role in the regulation of signaling pathway that activates nuclear factor-kappa-B (NF-kappaB). Recently, we reported that cisplatin (CDDP) treatment causes a remarkable nuclear accumulation of IKK-alpha in association with stabilization and activation of p73. However, underlying mechanisms of CDDP-induced nuclear accumulation of IKK-alpha are elusive. Here, we found that ataxia-telangiectasia mutated (ATM) is one of upstream mediators of IKK-alpha during CDDP-induced apoptosis. In response to CDDP, ATM was phosphorylated at Ser-1981, which was accompanied with nuclear accumulation of IKK-alpha in HepG2 cells, whereas CDDP treatment had undetectable effects on IKK-alpha in ATM-deficient cells. Indirect immunofluorescence experiments demonstrated that phosphorylated form of ATM colocalizes with nuclear IKK-alpha in response to CDDP. In vitro kinase assay indicated that ATM phosphorylates IKK-alpha at Ser-473. Moreover, IKK-alpha-deficient MEFs displayed CDDP-resistant phenotype as compared with wild-type MEFs. Taken together, our present results suggest that ATM-mediated phosphorylation of nuclear IKK-alpha, which stabilizes p73, is one of the main apoptotic pathways in response to CDDP.

TAp63-dependent induction of growth differentiation factor 15 (GDF15) plays a critical role in the regulation of keratinocyte differentiation

Since p63-deficient mice display severe defects in formation of epidermis, p63 has been considered to be a multi-isoform p53 family member essential for epidermal development. However, it is still unclear how p63 could contribute to keratinocyte differentiation. In the present study, we have found that TAp63alpha is induced in association with the upregulation and a secretion of growth differentiation factor 15 (GDF15) during the keratinocyte differentiation of HaCaT cells bearing p53 mutation. Short interference RNA-mediated knockdown of the endogenous TAp63 resulted in a remarkable reduction of GDF15. Luciferase reporter assay and reverse transcription-PCR analysis demonstrated that enforced expression of TAp63alpha significantly increases the luciferase activity driven by GDF15 promoter and the expression of GDF15. Consistent with these results, the proximal p53/p63-binding site within the GDF15 promoter region was required for the TAp63alpha-mediated transcriptional activation of GDF15, and TAp63alpha was recruited onto this site. Furthermore, siRNA-mediated knockdown of the endogenous GDF15 permitted cell growth and inhibited the expression of the differentiation markers such as keratin 10 and involucrin in response to differentiation stimuli. Taken together, our present results provide a novel insight into understanding the molecular mechanisms behind TAp63alpha-mediated keratinocyte differentiation.

DFF45/ICAD restores cisplatin-induced nuclear fragmentation but not DNA cleavage in DFF45-deficient neuroblastoma cells

We have previously defined a homozygously deleted region at chromosome 1p36.2-p36.3 in human neuroblastoma cell lines, NB-1 and NB-C201, and identified six genes including DFF45/ICAD within this region. In this study, we found that NB-C201 cells are much more resistant to various genotoxic stresses such as cisplatin (CDDP) than CHP134 and SH-SY5Y cells that do not have the homozygous deletion. To examine a role(s) of DFF45 in the regulation of apoptosis in response to CDDP, we have established stably DFF45-expressing NB-C201 cell clones (DFF45-1 and DFF45-3) and a control cell clone (NB-C201-C) using a retrovirus-mediated gene transfer. In contrast to NB-C201-C cells, DFF45-3 cells displayed apoptotic nuclear fragmentation in response to CDDP. Although CDDP-induced proteolytic cleavage of procaspase-3 and DFF45 in DFF45-3 cells, we could not detect a typical apoptotic DNA fragmentation. Additionally, deletion analysis revealed that C-terminal region of DFF45 is required for inducing nuclear fragmentation. Unexpectedly, (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays demonstrated that DFF45 has undetectable effect on CDDP sensitivity of NB-C201 cells. Taken together, our present results suggest that DFF45/DFF40 system may be sufficient for CDDP-induced nuclear fragmentation but not DNA cleavage.

324 EFFECT OF AGING ON AMOUNTS OF DNA METHYLTRANSFERASE mRNA IN MOUSE SPERMATOZOA

The spermatozoon is a specially differentiated cell designed to carry a haploid male genome into an oocyte at fertilization. It recently was reported that a matured spermatozoon contains several kinds of mRNAs and these are delivered into the oocyte at fertilization (Ostermeier et al. 2004 Nature 429, 154). The physiological role of paternally derived mRNAs is not clear; however, there is a report that the DNA methyltransferase (Dnmt) mRNA level in spermatozoa from male rats exposed to ethanol was significantly reduced (Bielawski et al. 2002 Alcohl. Clin. Res. 26, 347–351). The reduction of mRNA levels of Dnmt in spermatozoa would lead to altered epigenetic modification of the genome. Because factors such as age may affect spermatozoa mRNA levels, this study evaluated the effect of individual aging on the expression levels of Dnmts during spermatogenesis. This was accomplished by determining expression levels of Dnmts in the whole testis and in spermatozoa from young and aged mice by quantitative reverse-transcription-PCR. Seven- (young) and 68- (aged) week-old C57BL/6N male mice (n = 3/group) were sacrificed by cervical dislocation and whole testes and matured spermatozoa were collected. Total RNA was extracted and purified from each sample. In this study, 5 Dnmts (Dnmt1s, Dnmt1p, Dnmt3a, Dnmt3b, and Dnmt3l) and glyceraldehyde-3-phosphate dehydrogenase (GAPDH), a reference gene, were examined for expression levels in whole testis and spermatozoa using SYBR Premix Ex Taq (Takara Bio, Inc., Otsu, Shiga, Japan) and the 7300 Real-Time PCR System (Applied Biosystems, Foster City, CA, USA). Real-Time PCR runs for each Dnmt and GAPDH were repeated 3 times using different RNA batches from different individuals. The GAPDH expression level was used to normalize the expression levels of each Dnmt. Data were analyzed by Student's t-test. Relative expression levels of each Dnmt in testis from aged males compared to that of young males were 0.94, 1.15, 0.91, 1.15, and 1.14 (Dnmt1s, Dnmt1p, Dnmt3a, Dnmt3b, and Dnmt3l, respectively). There was no difference in the expression levels of the 5 Dnmts examined between testes from aged and young males. On the other hand, the relative amounts of each Dnmt mRNA in spermatozoa from aged males compared to that of young males were 0.87, 0.01, 0.54, 1.07, and 1.75 (Dnmt1s, Dnmt1p, Dnmt3a, Dnmt3b, and Dnmt3l, respectively). There was a significant reduction (P < 0.05) in the amount of Dnmt1p mRNA. The reason why the amount of Dnmt1p mRNA in spermatozoa from aged male mice showed such reduction is not clear. There was no difference in the relative expression levels of Dnmt1p in testis irrespective of male age. Dnmt1p is only translated in the spermatocyte during the pachytene stage in meiosis and its physiological role is not clear. To elucidate this male, age-related reduction of the amount of Dnmt1p mRNA in spermatozoa would clarify part of physiological role of Dnmt1p. This work was supported by Wakayama Prefecture Collaboration of Regional Entities for the Advanced of Technological Excellence, Japan, and by a Grant-in-Aid for the 21st Century Center of Excellence Program of the MEXT, Japan.

Estrogenic activity of 37 components of commercial sunscreen lotions evaluated by in vitro assays

Thirty-seven chemical components of commercial sunscreen lotions were evaluated for estrogen agonistic and/or antagonistic activity using two in vitro assays, (1) an ELISA-based estrogen receptor competitive binding assay (ER-ELISA) and (2) a modified yeast two-hybrid estrogen assay, with and without addition of a rat liver preparation, S9 mix. Eleven compounds, most of which were benzophenone derivatives and parabens, showed binding affinity to ER by ER-ELISA without S9 mix. Although the activities of almost all of the compounds were attenuated by addition of S9 mix, 4-octylphenylsalicylate and 2,2'-dihydroxy-4,4'-dimethoxybenzophenone acquired estrogenic activity, suggesting metabolic activation of these compounds. Two benzophenones showed agonistic activity in the yeast two-hybrid assay without S9 mix. The activity of one of these was reduced by S9 treatment and a further two benzophenones was activated. Eight parabens were active in this assay without S9 exposure, but their activities were eliminated by S9 treatment. Benzophenones with para-phenolic hydroxyl groups and parabens with branched and/or longer linear chains were generally more potent in both bioassays. In addition, weak antagonistic activity of 4-t-butylphenyl-salicylate, 2-ethylhexyl 4-dimethylaminobenzoate and (+/-)-alpha-tocopherolacetate was observed with S9 treatment. In vivo testing of the compounds reported here to have estrogen agonistic and antagonistic activities is required to confirm their effects at an organismal level.

Monitoring of the generation of non-mutagenic benzoic acid compounds during the manufacture of erythrosine

The generation of 2-(2',4'-dihydroxybenzoyl) benzoic acid (DHBBA) and 2-(2',4'-dihydroxy-3',5'-diiodobenzoyl) benzoic acid (DHDIBBA) during the manufacture of erythrosine (Food Red No. 3) was examined. DHBBA is formed as an intermediate during the synthesis of fluorescein, and as fluorescein is produced, it is gradually consumed. However, under inappropriate reaction conditions, it remains in the resulting fluorescein at the termination of synthesis. DHDIBBA is easily obtained by the iodination of DHBBA. These compounds are also found when erythrosine is heated in excessive alkali. The results of the Ames test using DHBBA and DHDIBBA showed they did not possess mutagenic activity. The results clearly demonstrated that establishment of an upper limit for DHBBA and DHDIBBA is important in the quality control of fluorescein and erythrosine.

A thirteen-week oral toxicity study of annatto extract (norbixin), a natural food color extracted from the seed coat of annatto (Bixa orellana L.), in Sprague-Dawley rats

A subchronic oral toxicity study of annatto extract (norbixin), a natural food color, was conducted. Groups of 10 male and 10 female Sprague-Dawley rats were fed annatto extract at dietary levels of 0, 0.1, 0.3 and 0.9% for 13 weeks. There were no treatment-related adverse effects on body weight, food and water consumption, ophthalmology and hematology data. Blood biochemical analysis revealed changes in rats of both sexes confined to the 0.9% and 0.3% groups, including increased alkaline phosphatase, phospholipid, total protein, albumin and albumin/globulin ratio. Marked elevation in absolute and relative liver weights was also found in both sexes of the 0.9% and 0.3% groups, but not the 0.1% group. Hepatocyte hypertrophy was evident and an additional electron microscopic examination demonstrated this to be linked to abundant mitochondria after exposure to a dietary level of 0.9% annatto extract for 2 weeks. Thus, the No-Observed-Adverse-Effect-Level (NOAEL) was judged to be a dietary level of 0.1% (69 mg/kg body weight/day for males, 76 mg/kg body weight/day for females) of annatto extract (norbixin) under the present experimental conditions.

Identification of rabaptin-5, rabex-5, and GM130 as putative effectors of rab33b, a regulator of retrograde traffic between the Golgi apparatus and ER

The role of rab33b, a Golgi-specific rab protein, was investigated. Microinjection of rab33b mutants stabilised in the GTP-specific state resulted in a marked inhibition of anterograde transport within the Golgi and in the recycling of glycosyltransferases from the Golgi to the ER, respectively. A GST-rab33b fusion protein stabilised in its GTP form was found to interact by Western blotting or mass spectroscopy with Golgi protein GM130 and rabaptin-5 and rabex-5, two rab effector molecules thought to function exclusively in the endocytic pathway. A similar binding was seen to rab1 but not to rab6, both Golgi rabs. In contrast, rab5 was as expected, shown to bind rabaptin-5 and rabex-5 as well as the endosomal effector protein EEA1 but not GM130. No binding of EEA1 was seen to any of the Golgi rabs.

Antidepressant drug treatments induce glial cell line-derived neurotrophic factor (GDNF) synthesis and release in rat C6 glioblastoma cells

Modulation of neurotrophic factors to protect neurons from damage is proposed as a novel mechanism for the action of antidepressants. However, the effect of antidepressants on modulation of glial cell line-derived neurotrophic factor (GDNF), which has potent and widespread effects, remains unknown. Here, we demonstrated that long-term use of antidepressant treatment significantly increased GDNF mRNA expression and GDNF release in time- and concentration-dependent manners in rat C6 glioblastoma cells. Amitriptyline treatment also increased GDNF mRNA expression in rat astrocytes. GDNF release continued for 24 h following withdrawal of amitriptyline. Furthermore, following treatment with antidepressants belonging to several different classes (amitriptyline, clomipramine, mianserin, fluoxetine and paroxetine) significantly increased GDNF release, but which did not occur after treatment with non-antidepressant psychotropic drugs (haloperidol, diazepam and diphenhydramine). Amitriptyline-induced GDNF release was inhibited by U0126 (10 microM), a mitogen-activated protein kinase (MAPK)-extracellular signal-related kinase (ERK) kinase (MEK) inhibitor, but was not inhibited by H-89 (1 microM), a protein kinase A inhibitor, calphostin C (100 nM), a protein kinase C inhibitor and PD 169316 (10 microM), a p38 mitogen-activated protein kinase inhibitor. These results suggested that amitriptyline-induced GDNF synthesis and release occurred at the transcriptional level, and may be regulated by MEK/MAPK signalling. The enhanced and prolonged induction of GDNF by antidepressants could promote neuronal survival, and protect neurons from the damaging effects of stress. This may contribute to explain therapeutic action of antidepressants and suggest new strategies of pharmacological intervention.

Th1 cytokine-conditioned bone marrow-derived dendritic cells can bypass the requirement for Th functions during the generation of CD8+ CTL

Bone marrow-derived dendritic cell (BMDC) subsets have distinct immunoregulatory functions. Th1 cytokine-induced BMDC (BMDC1), compared with Th2 cytokine-induced BMDC2, have superior activities for the differentiation and expansion of CTL. To evaluate the cellular interactions between dendritic cells and CD8+ T cells for the induction of CTL, BALB/c-derived BMDC subsets were cocultured with purified CD8+ T cells from C57BL/6 mice. Our results demonstrate that BMDC1 support the generation of allogeneic CD8+ CTL in the absence of CD4+ Th cells. In contrast, BMDC0 (GM-CSF- plus IL-3-induced BMDC) and BMDC2 failed to promote the differentiation of CD8+ CTL. Using Ab-blocking experiments and studies with gene knockout mice, IL-2 and LFA-1 are demonstrated to be critical for BMDC1-induced CTL differentiation. Unexpectedly, BMDC1 were able to induce CTL from CD8+ T cells isolated from IFN-gamma-/- and IFN-gamma receptor-/- mice. However, BMDC1 produced higher levels of IFN-beta than other BMDC subsets, and anti-IFN-beta mAb blocked BMDC1-dependent CTL generation. These results indicated an indispensable role of IFN-beta, but not IFN-gamma, during BMDC1-induced CTL differentiation. We conclude that Th1-cytokine-conditioned BMDC1 can bypass Th cell function for the differentiation of naive CD8+ T cells into CTL.

Pronounced inhibition by a natural anthocyanin, purple corn color, of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP)-associated colorectal carcinogenesis in male F344 rats pretreated with 1,2-dimethylhydrazine

The potential of purple corn color (PCC), a natural anthocyanin, to modify colorectal carcinogenesis was investigated in male F344/DuCrj rats, initially treated with 1,2-dimethylhydrazine (DMH), receiving 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) in the diet. After DMH initiation, PCC was given at a dietary level of 5.0% in combination with 0.02% PhIP until week 36. No PCC-treatment-related changes in clinical signs, body weight and food consumption were found. Incidences and multiplicities of colorectal adenomas and carcinomas in rats initiated with DMH were clearly increased by PhIP. In contrast, lesion development was suppressed by PCC administration. Furthermore, in the non-DMH initiation groups, induction of aberrant crypt foci by PhIP tended to be decreased by the PCC supplementation. The results thus demonstrate that while PhIP clearly exerts promoting effects on DMH-induced colorectal carcinogenesis, these can be reduced by 5.0% PCC in the diet, under the present experimental conditions.

Cloning, chromosomal mapping, and characteristic 5'-UTR sequence of murine cytosolic sialidase

We have totally sequenced a cytosolic sialidase [EC 3.2.1.18] by RT-PCR from the murine thymus (murine thymic sialidase, MTS) which has a 1844-base length (encoding 385 amino acids including two sialidase motifs) and is the longest cytosolic sialidase ever reported. MTS has high and relatively low homologies with those of mammalian cytosolic sialidases from the mouse brain (99%), rat (91%), and human skeletal muscle (75%), and those of the mouse lysosomal (47%) and membrane-bound (51%) sialidases, respectively. Chromosomal mapping, being the first report of mouse cytosolic sialidase gene, showed that the MTS gene is localized to the distal part of mouse chromosome 1D and to rat chromosome 9q36. RT-PCR with the site-specific primers revealed that the coding region was expressed in all organs tested, but expressions including the 5'-UTR were barely detectable except for in the upper-thymic fraction. Also, soluble sialidase activity in the thymus was the highest of these organs. There were mRNA instability signals and AT-rich regions in 143 bp of MTS 5'-end.

A critical role for mouse CXC chemokine(s) in pulmonary neutrophilia during Th type 1-dependent airway inflammation

Ag-specific Th1 and Th2 cells have been demonstrated to play a critical role in the induction of allergic diseases. Here we have investigated the precise mechanisms of Th1-induced airway inflammation. Airway inflammation was induced in BALB/c mice by transfer of freshly induced OVA-specific Th1 or Th2 cells followed by OVA inhalation. In this model, both Th1 and Th2 cells induced airway inflammation. The former induced neutrophilia in airways, whereas the latter induced eosinophilia. Moreover, we found that Th1 cells induced more severe airway hyperresponsiveness (AHR) than Th2 cells. The eosinophilia induced by Th2 cell infusion was almost completely blocked by administration of anti-IL-5 mAb, but not anti-IL-4 mAb. In contrast, Th1-induced AHR and pulmonary neutrophilia were inhibited by the administration of anti-human IL-8R Ab, which blocks the function of mouse CXC chemokine(s). These findings reveal a critical role of mouse CXC chemokine(s) in Th1-dependent pulmonary neutrophilia and AHR.

Effect of fudosteine, a cysteine derivative, on blood flow of tracheal microvasculature increased by airway inflammation

We examined the effect of fudosteine, a cysteine derivative, on blood flow of tracheal microvasculature increased by airway inflammation. Airway inflammation was elicited by sulfur dioxide (SO(2)) exposure for 2 weeks in rabbits. Each drug (500 mg/kg, p.o.) or 0.5% carboxymethylcellulose-Na (control group) was daily administered just before SO(2) exposure. After final SO(2) exposure was finished, blood flow of tracheal microvasculature was measured by blood perfusion monitor. Fudosteine or S-carboxymethylcysteine (S-CMC) significantly suppressed blood flow of tracheal microvasculature increased by SO(2) exposure. However, no effect of fudosteine was observed on the pharmacological microvascular response in trachea of SO(2)-exposed rabbits. On the other hand, fudosteine or S-CMC scavenged superoxide anion generated from rat neutrophils, and enzymatically generated from xanthine oxidase-acetaldehyde reaction. The results suggest that suppressive action in increased tracheal blood flow of fudosteine is due to anti-inflammatory activity, at least in part, via scavenging of superoxide anion.

Effect of fudosteine, a new cysteine derivative, on mucociliary transport

We examined the effect of fudosteine ((-)-(R)-2-amino-3-(3-hydroxypropylthio)propionic acid) on the mucociliary transport (MCT) rate in quails. The MCT rate was estimated by ash transport velocity on the tracheal mucosa of quails. Fudosteine (500 mg kg(-1), p.o.) did not affect the normal MCT rate. However, topical application of fudosteine to the tracheal mucosa dose-dependently protected the impairment of the MCT rate caused by exposure to cigarette smoke. The results suggest that fudosteine may participate in the defence mechanism in the respiratory tract against irritant gases.

Preliminary study of fortnightly irinotecan hydrochloride plus cisplatin therapy in patients with advanced gastric and colorectal cancer

PURPOSE

Irinotecan hydrochloride shows a strong activity against gastric cancer and colorectal cancer, while combined therapy with irinotecan and cisplatin is useful for gastric cancer. However, myelosuppression and diarrhea are still dose-limiting factors. To reduce such toxicities to enable therapy to be performed on an outpatient basis, we tested the effect of divided administration of cisplatin.

METHODS

Irinotecan (60 mg/m2) plus cisplatin (30 mg/m2) were administered on days 1 and 15 every 4 weeks to 13 patients with advanced gastric cancer and 13 with advanced colorectal cancer. Treatment was continued if a leukocyte count > or = 3000/mm3, a platelet count > or = 100,000/mm3, and grade 0 diarrhea were confirmed. Doses were reduced if grade 3-4 hematological toxicity and grade 2 or higher nonhematological toxicity occurred.

RESULTS

The major toxicity was leukopenia (neutropenia), but grade 3-4 nonhematological toxicity was not observed. The response rate was 41.7% for gastric cancer (5/12 evaluable patients) and 36.7% for colorectal cancer (4/11 evaluable patients). The median survival time was 313 days (range 29-920 days) for gastric cancer patients and 490 days (range 83-1184 + days) for colorectal cancer patients.

CONCLUSION

Fortnightly administration of irinotecan and cisplatin (with a divided cisplatin dose) seems to be a useful regimen for gastrointestinal cancer. It reduces toxicity while maintaining a good antitumor effect.

Potentiation of antitumor effect of NKT cell ligand, alpha-galactosylceramide by combination with IL-12 on lung metastasis of malignant melanoma cells

The combined therapeutic effect of natural killer T (NKT) cell ligand alpha-galactosylceramide (alpha-GalCer) and IL-12 against highly metastatic B16-BL6-HM melanoma cells was investigated. In comparison with a single administration of alpha-GalCer or IL-12, the combined treatment of tumor-bearing mice with alpha-GalCer plus IL-12 caused a super-induction of serum IFN-gamma levels, though alpha-GalCer-induced IL-4 production was rather inhibited. In parallel with the augmented IFN-gamma production, the natural killing activity against YAC-1 cells and syngeneic B16-BL6-HM melanoma was greatly augmented by the combined therapy. The major effector cells responsible for natural killing activity induced by alpha-GalCer plus IL-12 were enriched in both NK1.1+ TCRalphabeta+ NKT cells and NK1.1+ TCRalphabeta- NK cells. The preventing effect of alpha-GalCer or IL-12 alone against lung metastasis of B16-BL6-HM was also enhanced by the combination therapy. The antitumor activity of alpha-GalCer was totally abolished in NKT-deficient mice. However, IL-12-induced antitumor activity was not eliminated in NKT-deficient mice though it was inhibited by anti-asialo GM1 Ab treatment. These findings suggested that alpha-GalCer synergistically act with IL-12 to activate both NKT cells and NK cells, which may play a critical role in the strong prevention of distant tumor metastasis at early stages of tumor-bearing. These data will provide a novel tool for the prevention of tumor metastasis using NKT-specific ligands alpha-GalCer and IL-12.

Analytical method for Buddleja colorants in foods

Buddleja yellow colorant derived from Buddleja officinalis Maxim. has recently been approved for use as a new kind of natural colorant for food additives in China. In order to distinguish Buddleja yellow colorant from other yellow colorants, two known phenylpropanoid glycosides, acteoside (= verbascoside) and poliumoside, were isolated from the colorant as marker substances for Buddleja yellow colorant. Poliumoside has not been detected in B. officinalis Maxim. previously. These phenylpropanoid glycosides were not detected in the fruits of Gardenia jasminoides Ellis or in the stamens of the flowers of Crocus sativus L., which also contain crocetin derivatives as coloring components, using a photodiode array and mass chromatograms. Thus, an analytical HPLC method was developed to distinguish foods that have been colored with yellow colorants containing crocetin derivatives, using phenylpropanoid glycosides as markers.

[Effects of fudosteine, a new cysteine derivative, on airway secretion in rabbits and rats]

We examined the effects of fudosteine [(-)-(R)-2-amino-3-(3-hydroxypropylthio) propionic acid], a new cysteine derivative, on airway secretion in rabbits and rats. Indirect measurement of airway secretion in rabbits, which was expressed by the amount of dye excreted into the respiratory tract, was carried out according to the Sakuno's method, with some modifications. Fudosteine (500 mg/kg, p.o.) significantly increased the amount of dye excreted into the respiratory tract. As a direct method of measurement of airway secretion, the modified Perry and Boyd's method was used to collect respiratory tract fluid (RTF) in rabbits. Fudosteine (500 mg/kg, p.o.) significantly augmented the output volume of RTF, but there was no difference from the control in protein and phosphatidylcholine (PC) contents into RTF. On the other hand, fudosteine increased chloride ion concentration in broncho-alveolar lavage of rats. Fudosteine did not stimulate PC secretion in a primary culture of rat type II pneumocytes, and it did not have a mucolytic effect against gastric mucin in vitro. From the results described above, it was concluded that fudosteine may be a new cysteine derivative which offers a serous secretion.

Features of IgA nephropathy in preschool children

AIM

The aim of this study is to clarify the age-related characteristics of pediatric IgA nephropathy.

PATIENTS AND METHODS

Five cases in preschool children less than 6 years old were analyzed and compared to 38 cases in older children from 6 to 15 years old.

RESULTS

The group of younger children had higher incidences of gross hematuria, hypertension, proteinuria, and hypoproteinemia. Renal biopsy specimens in this group showed more intracapillary lesions including mesangial cell proliferation and endocapillary proliferation ofglomeruli, but less segmental lesions, global sclerosis, and interstitial changes.

CONCLUSION

IgA nephritis in preschool children demonstrated more symptoms of acute onset and less chronic renal injury.

The critical role of Th1-dominant immunity in tumor immunology

To investigate the precise role of antigen-specific Th1 and Th2 cells in tumor immunity, we developed a novel adoptive tumor-immunotherapy model using OVA-specific Th1 and Th2 cells and an OVA gene-transfected tumor. This therapeutic model demonstrated that both antigen-specific Th1 and Th2 cells had strong antitumor activity in vivo with distinct mechanisms. However, immunological memory suitable for the generation of tumor-specific cytotoxic T lymphocytes was induced only when tumor-bearing mice received Th1 cell therapy, but not Th2 cell therapy. Thus it was strongly suggested that Th1-dominant immunity is critically important for the induction of antitumor cellular immunity in vivo. We also proposed that several immunomodulating protocols using interleukin (IL)-12, IL-12 gene, the natural killer T cell ligand alpha-galactosylceramide, or Th1 cytokine-conditioned dendritic cells might be useful strategies for the induction of Th1-dominant immunity essential for the development of tumor-specific immunotherapy.

Indispensable role for TNF-alpha and IFN-gamma at the effector phase of liver injury mediated by Th1 cells specific to hepatitis B virus surface antigen

We report the development and characterization of a novel model of severe hepatitis induced against hepatitis B virus surface Ag (HBsAg). HBsAg was successfully targeted into the liver in soluble form. Using this unique property of HBsAg, we established a liver injury model induced by HBsAg-specific Th1 cells. Severe liver injury was induced in C57BL/6 mice by injection of HBsAg together with HBsAg-specific Th1 cells. Histochemical examination demonstrated extensive necroinflammatory hepatic lesions in these animals. Application of this liver injury model to mutant or gene knockout mice enabled us to define the effector mechanisms of Th1 cells in fulminant hepatitis. When Fas-deficient lpr mice were used as recipients, a similar degree of liver injury was induced as in wild-type mice. Moreover, HBsAg-specific Th1 cells obtained from perforin-/- mice could induce severe liver injury in both wild-type and lpr mice. These results indicated that neither Fas ligand nor perforin are essential for Th1-mediated liver injury in this model. Pretreatment with anti-TNF-alpha mAb prevented liver injury, whereas severe liver injury was induced in TNF-alpha-/- mice. Moreover, IFN-gamma receptor-deficient mice were resistant to Th1-mediated liver injury. Therefore, TNF-alpha and IFN-gamma, which were produced by HBsAg-specific Th1 cells during the effector phase, appeared to be indispensable in the pathogenesis of fulminant hepatitis.

The interface between innate and acquired immunity: glycolipid antigen presentation by CD1d-expressing dendritic cells to NKT cells induces the differentiation of antigen-specific cytotoxic T lymphocytes

In vivo administration of NKT cell ligand, alpha-galactosylceramide (alpha-GalCer), caused the activation of NKT cells to induce a strong NK activity and cytokine production by CD1d-restricted mechanisms. Surprisingly, we also found that alpha-GalCer induced the activation of immunoregulatory cells involved in acquired immunity. Specifically, in vivo administration of alpha-GalCer resulted in the induction of the early activation marker CD69 on CD4(+) T cells, CD8(+) T cells and B cells in addition to macrophages and NKT cells. However, no significant induction of CD69 was observed on cells from CD1d- or V(alpha)14 NKT-deficient mice, indicating an essential role for the interaction between NKT cells and CD1d-expressing dendritic cells (DC) in the activation of acquired immunity in response to alpha-GalCer. Indeed, in vivo injection of alpha-GalCer resulted not only in the activation of NKT cells but also in the generation of CD69(+)CD8(+) T cells possessing both cytotoxic T lymphocyte (CTL) activity and IFN-gamma-producing ability. Tumor-specific CTL generation was also accelerated by alpha-GalCer. The critical role of CD40-CD40 ligand (CD40L)-mediated NKT-DC interaction during the development of CD69(+)CD8(+) CTL by alpha-GalCer was demonstrated by blocking experiments using anti-CD40L mAb. These findings provide direct evidence for a critical role of CD1d-restricted NKT cells and DC in bridging innate and acquired immunity.

Interleukin-4-dependent induction of preproenkephalin in antigen-specific T helper-type 2 (Th2) cells

Naive Th cells obtained from OVA(323-339)-specific DO11.10 TCR-Tg mice did not express preproenkephalin (PPE) mRNA. However, culture of naive Th cells with OVA(323-339) peptide (OVA-pep) plus IL-2 under Th2-inducing conditions for 7 days resulted in an induction of PPE mRNA. The PPE mRNA was also induced by culturing with OVA-pep plus IL-2 (neutral condition). However, PPE mRNA induction under neutral conditions was totally abrogated by addition of anti-IL-4 mAb. The existence of methionine-enkephalin was also demonstrated in peptidase-digested peptides derived from Th2 cell lysate. These results demonstrate that IL-4 is a critical factor for the induction of PPE mRNA in freshly expanded antigen-specific Th2 cells.

Functional heterogeneity among bone marrow-derived dendritic cells conditioned by T(h)1- and T(h)2-biasing cytokines for the generation of allogeneic cytotoxic T lymphocytes

Three distinct bone marrow (BM)-derived dendritic cells (BMDC) were expanded from BALB/c BM cells by culture with (i) granulocyte macrophage colony stimulating factor (GM-CSF) plus IL-3, (ii) GM-CSF, IL-3 plus T(h)1-biasing cytokines (IL-12 and IFN-gamma) or (iii) GM-CSF, IL-3 plus T(h)2-biasing cytokines (IL-4). All of these cells expressed the DC-specific marker CD11c, and were designated as BMDC0, BMDC1 and BMDC2 cells respectively. BMDC1 cells exhibited superior T cell-stimulating activity in allogeneic mixed lymphocyte culture (MLC), while BMDC2 showed inferior stimulating activity. Specifically, BMDC1, as compared with BMDC2, induced a higher frequency of IFN-gamma-producing CD8(+) T cells in MLC. Moreover, BMDC1, but not BMDC2, were strong inducers of H-2(d)-specific cytotoxic T lymphocytes (CTL) in MLC. BMDC0 always showed intermediate stimulatory activity; however, when BMDC0 were cultured with IFN-gamma, they differentiated into BMDC1-like stimulator cells concomitant with the up-regulation of both MHC antigens and co-stimulatory molecules. In contrast, BMDC2 were refractory to differentiation into superior stimulator cells by treatment with IFN-gamma, although this treatment enhanced MHC expression. These findings indicate that T(h)1- and T(h)2-biasing cytokines, in addition to their effect on T(h) cell differentiation, may play a critical role in the functional skewing of DC. These findings have important implications for the development of DC-based immunotherapies.

alpha-galactosylceramide induces early B-cell activation through IL-4 production by NKT cells

alpha-Galactosylceramide (alpha-GalCer), a glycolipid antigen, specifically activates natural killer T (NKT) cells by a CD1d-restricted mechanism. In this work, we found that in vivo administration of alpha-GalCer resulted in the activation of B cells in addition to NKT cells, namely, alpha-GalCer administration caused upregulation of the early activation marker, CD69, on both NKT and B cells. In addition, expression of B7.2 and I-A(b) on B cells was greatly upregulated by alpha-GalCer. However, serum levels of IgE, IgG1, and IgG2a were not significantly changed within 48 h. In the present experiments, it was also demonstrated that the upregulation of CD69 expression by alpha-GalCer was strongly blocked by anti-IL-4 monoclonal antibody. Moreover, B-cell activation by alpha-GalCer was not observed in NKT-deficient mice. These results suggested that antigen-stimulated NKT cells might play a critical role not only in early defense mechanisms but also in early B-cell activation through IL-4 production.

Two proline-rich nuclear localization signals in the amino- and carboxyl-terminal regions of the Borna disease virus phosphoprotein

Borna disease virus (BDV) uses a unique strategy of replication and transcription which takes place in the nucleus, unlike other known, nonsegmented, negative-stranded RNA viruses of animal origin. In this process, viral constituents necessary for replication must be transported to the nucleus from the cytoplasm. We report here the evidence that BDV P protein, which may play an important role in viral replication and transcription, is transported into the nucleus in the absence of other viral constituents. This transportation is accomplished by its own nuclear localization signals (NLSs), which are present in both N-terminal (29PRPRKIPR36) and C-terminal (181PPRIYPQLPSAPT193) regions of the protein. These two NLSs can function independently and both have several Pro residues as key amino acids.

Cloning of the mouse gene for D-dopachrome tautomerase

D-Dopachrome tautomerase converts 2-carboxy-2,3-dihydroindole-5, 6-quinone (D-dopachrome) into 5,6-dihydroxyindole. The amino acid sequence of this protein is 27% identical with that of macrophage migration inhibitory factor, which is known as a cytokine, pituitary hormone, and glucocorticoid-induced immunomodulator. In this study, we isolated and sequenced a 3490 bp-long genomic DNA of mouse D-dopachrome tautomerase that consists of three exons and two introns. By two procedures, 5' rapid amplification of cDNA ends and cap site labeling, we determined the transcription initiation site, which is located 46 bp upstream of the translation initiation site. The possible polyadenylation sequence (AATAAA) is located 180 bp downstream of the termination codon. Computer-assisted analysis of the nucleotide sequence revealed a number of regulatory motifs, including multiple sites for Sp1, C/EBP, NF-Y, and USF. Although the precise pathophysiological functions of D-dopachrome tautomerase remain to be elucidated, the present results will contribute not only to elucidation of the mechanism of gene expression, but also to understanding of the molecular function of this protein.

Long-term follow-up of a patient with hepatocellular carcinoma associated with triple hepatitis virus (HBV, HDV, HCV) infection

A 69-year-old Japanese man with hepatocellular carcinoma (HCC) associated with triple hepatitis viruses [hepatitis B virus (HBV), hepatitis C virus (HCV), and hepatitis D virus (HDV)] infection is reported. The patient had a past history of intravenous drug abuse and a tattoo on his back. A liver biopsy, performed in November 1989, showed HCC associated with cirrhosis. HBsAg and anti-HD antibody had been detected repeatedly starting in August 1984 and anti-HCV antibody was detected in 1990. By indirect immunoperoxidase staining the HD antigen was detected in the nuclei of hepatocytes of biopsy specimens and noncancerous liver cells obtained from autopsy specimens. Liver cirrhosis associated with triple hepatitis virus infection developed to hepatocellular carcinoma, and transcatheter arterial embolization treatment for HCC was effective. Despite having HCC and cirrhosis, the patient lived well beyond the expected time.

Stimulation of bone formation in vivo by insulin-like growth factor-II in rats

Insulin-like growth factor-II (IGF-II) plays an important role in skeletal remodeling, however, little is known about its effect on bone formation in vivo. In our study of the stimulation of bone formation in vivo by IGF II we injected recombinant human IGF-II into the parietal bones of neonatal rats once a day for 12 days. The bone mineral density measured by dual energy X-ray absorptiometry and the thickness of IGF-II-injected parietal bones increased in a dose-dependent manner. The layers of osteoblasts were observed along the IGF-II-injected side.

A novel Rab GTPase, Rab33B, is ubiquitously expressed and localized to the medial Golgi cisternae

Small GTP-binding proteins of the Rab family play important roles at defined steps of vesicular transport in protein secretion and the endocytosis pathway. In mammals, more than 30 proteins belonging to the Rab family have been reported to date. We report here the molecular cloning and characterization of a novel Rab protein, Rab33B. The amino acid sequence of Rab33B shows 55.3% identity to the Rab33A protein (previously called S10), and these two proteins share unique amino acid sequences at the effector domain. The genomic organization of rab33B was the same as rab33A: it consists of two exons. Thus, these two proteins make a subclass within the Rab family. Northern blot analysis showed that rab33B is expressed ubiquitously in mouse tissues, in contrast to rab33A whose expression is restricted to the brain and the immune system. A 26 kDa protein was detected by western blotting using a Rab33B-specific monoclonal antibody. Using immunofluorescence studies, Rab33B was shown to co-localize with (alpha)-mannosidase II, a Golgi-specific marker. Immunoelectron microscopy analysis further defined the localization of Rab33B to the medial Golgi cisternae. These results suggest Rab33B plays a role in intra-Golgi transport.

Nuclear targeting activity associated with the amino terminal region of the Borna disease virus nucleoprotein

The Borna disease virus (BDV) replicates in the nucleus. The viral p40 protein (N), which is found abundantly in the nucleus in BDV-infected cells, may play an important role in virus replication. To analyze the amino acid residues involved in the nuclear targeting of BDV N, a series of eukaryotic expression plasmids encoding deletion mutants of N was constructed and transfected into COS-7 cells. In indirect immunofluorescence assays with a rabbit anti-BDV N antiserum, wild-type N was located in the nucleus of transfected cells in the absence of other viral constituents. In contrast, mutants lacking the 13 NH2-terminal amino acid residues 1MPPKRRLVDDADA13 in common gave a cytoplasmic localization pattern. Similarly, a mutant with substitution of 4KRR6 by 4NSG6 was retained in the cytoplasm. Furthermore, a nonapeptide, 3PKRRLVDDA11, derived from the NH2-terminal region of N conferred nuclear targeting activity to beta-galactosidase, which normally resides in the cytoplasm. Thus, we have identified the nuclear targeting signal of the BDV N and narrowed it to the NH2-terminal region where 4KRR6 basic amino acid residues are located.

Scanning near-field optical images of ordered polystyrene particle layers in transmission and luminescence excitation modes

Scanning near-field optical images of hexagonally close-packed layers of polystyrene spherical particles with a diameter of 1.0 microm have been investigated. The layers were composed of particles that were doped either totally or partially with an organic fluorescent dye. Observations were made in the transmission and luminescence excitation modes with a scanning near-field optical microscope (SNOM) with a spatial resolution shorter than the wavelength of light. The patterns observed in the SNOM images are significantly dependent on the microstructures of layers, that is, the layers are either single or double layered, and the particles are either totally or partially doped. These results are discussed in terms of specific modes of electromagnetic waves transmitting across and along the layers after the local excitation at the tip end of the scanning microprobe.

Structure and expression of the mouse S10 gene

We previously reported the cloning of a human S10 cDNA which encodes a small GTP-binding protein belonging to the Rab subfamily. Here we describe a mouse S10 cDNA and its genomic structure. Mouse S10 is 92.3% homologous at the nucleotide level and 98.3% identical at the amino acid level compared to human S10. The mouse S10 gene is comprised of two exons and a single intron. Northern blotting of tissue RNAs indicates that the S10 gene is predominantly expressed in brain.

Amplification of a full-length Borna disease virus (BDV) cDNA from total RNA of cells persistently infected with BDV

We have developed a novel reverse transcriptase-polymerase chain reaction (RT-PCR) to amplify the full-length 8.9 kilobase (kbp) cDNA of the Borna disease virus (BDV) RNA genome from the total cellular RNA of MDCK cells persistently infected with BDV (MDCK/BDV). Antigenomic BDV cDNA was reverse transcribed using a 53-mer oligonucleotide primer, corresponding to the 5'-terminus of a putative 3'-leader sequence of the BDV RNA genome, for 2 hr at 42 C followed by 30 min at 55 C. PCR was performed in the presence of this 53-mer antigenomic primer and a 25-mer primer, corresponding to the 3'-terminus of the BDV antigenomic cDNA, by use of an rTth DNA polymerase with proof-reading activity. The amplified full-length BDV cDNA was detected in as little as 20 ng of total cellular RNA of MDCK/BDV. This RT-PCR method should be a useful technique to study the molecular quasispecies of BDV.

Hepatitis C transmission between spouses

To examine inter-spouse transmission as one of the potential routes of infection for hepatitis C virus (HCV), 121 patients with HCV-related chronic liver disease who tested positive for antibodies to HCV (anti-HCV) and their spouses were studied. Of these, 21 (17.4%) patients had spouses with anti-HCV. In 12 couples, the HCV genotype matched (type II: 10 couples, type III: two couples). The genotype differed in six couples. One patient was positive for anti-HCV, but negative for HCV-RNA, while the spouse was positive for both. The remaining two couples were only positive for anti-HCV. Genetic heterogeneity in the hypervariable region 1 of HCV was analysed in 11 couples with matched genotypes. In two couples, no mutation was recognized in the putative E2/NS1 genes using the heteroduplex method. The present study provides evidence to verify household transmission of HCV between patients and their spouses. These results suggest that inter-spouse transmission may be a potential route of transmission of HCV infection. However, other environmental factors (e.g. the duration of the marriage) cannot be ignored.

17 beta-estradiol increases the receptor number and modulates the action of 1,25-dihydroxyvitamin D3 in human osteosarcoma-derived osteoblast-like cells

It is well known that 17 beta-estradiol (E2) and 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) have important roles in bone metabolism. This study was undertaken to examine E2 regulation of 1,25(OH)2D3 receptor (VDR) expression and the biological action of 1,25(OH)2D3 in human osteoblast-like cells. When human osteosarcoma-derived osteoblast-like cells were treated with varying concentrations of E2, the VDR levels increased by up to 100% in a dose-dependent manner. VDR levels significantly increased at 10 nM E2 and this increase plateaued at 100 nM E2. E2-dependent increase of VDR was time dependent, plateauing at 24 hours and was maintained for at least 48 hours in human osteoblast-like cells. Scatchard analysis showed that E2 increased the number of VDR (12.3 +/- 0.4 versus 26.5 +/- 0.3 fmol/mg protein; mean +/- SE of three independent experiments) rather than the Kd (0.15 +/- 0.02 versus 0.16 +/- 0.01 nM; mean +/- SE of three independent experiments). Tamoxifen (50 nM), a specific competitor with E2, completely abolished the E2-induced increase of VDR. The levels of VDR mRNA (4.5 kb) from the cells increased in a dose-dependent manner after E2 treatment. With regard to the biological effects, E2 increased by 10-25% the inhibitory effect of 1,25(OH)2D3 on cell growth. However, E2 did not increase the stimulation of alkaline phosphatase activity by 1,25(OH)2D3. The present study suggests that E2 modulates the biological action of 1,25(OH)2D3 through VDR levels in bone cells.

Pyrolysis-gas chromatography of carbonate apatites used for sintering

Gas chromatography was employed to quasi-continuously determine the amount of carbon dioxide that evolved from carbonate apatite specimens during sintering. Assuming that the carbonate in the specimens decomposed to carbon dioxide on a mole-for-mole basis, the determination of the carbon dioxide evolved allowed for the determination of the amount of carbonate that remained in the specimens during different stages of sintering. Previously, this measurement could be carried out only after sintering was completed. Comparison of data obtained from specimens compacted isostatically at 600 MPa for sintering with powder specimens indicated that the amount of carbonate remaining in the sintered apatite mass strongly depended on heating rates, heating temperatures, and holding-time intervals.