Synthesis of oligodeoxyribonucleotide bearing 2'-S-alkyl residue and its effect on the duplex stability

2'-Deoxy-2'-S-hexyluridine derivative was synthesized from 2,2'-anhydrouridine and 1-hexanethiol and incorporated into an oligodeoxyribonucleotide. The thermal stability of the duplexes formed by the 2'-S-hexyl modified ODN with either the complementary DNA or RNA strand was decreased compared to the unmodified counterparts.

[Multiple cavities in myocardium of left ventricle after irradiation therapy for breast cancer: a case report]

A 68-year-old woman was admitted to our hospital with congestive heart failure. She had been diagnosed with hypertrophic cardiomyopathy 12 years ago in another hospital. She had received irradiation therapy for left breast cancer 33 years ago after resection of her left breast. Echocardiography revealed left ventricular hypertrophy and wall motion hypokinesis, and multiple cavities in the myocardium of the left ventricle, interventricular septum, and anterior wall. Some cavities were observed to connect to the left ventricular cavity and Doppler echocardiography showed slow velocity flows in them different from that of the coronary artery. The pathologic diagnosis was severe sclerosis of the left coronary artery, especially the left descending artery and its branch, which was the area with irradiation. Histopathology revealed sclerotic changes of the coronary artery causing acute and chronic myocardial infarction, and incomplete regeneration and hypertrophy of cardiac cells. There was no sign of hypertrophic cardiomyopathy. Myocardial degeneration and deciduation were present next to the cavities connected to left ventricle-like fistulas.

Severe osteopetrosis, defective interleukin-1 signalling and lymph node organogenesis in TRAF6-deficient mice

BACKGROUND

TRAF6, a member of the tumour necrosis factor receptor-associated factor family, was first identified as a transducer of CD40 and interleukin-1 receptor (IL-1R) signals based on the interaction of TRAF6 with the cytoplasmic tail of CD40 and with the IL-1R associated kinase in vitro. However, the functions of TRAF6 in vivo remain unidentified.

RESULTS

We show that TRAF6-/- mice exhibit severe osteopetrosis and are defective in osteoclast formation. In vitro culture experiments revealed that osteoclast precursor cells derived from TRAF6-/- mice are unable to differentiate to functional osteoclasts in response to osteoclast differentiation factor (ODF). In bone marrow of TRAF6-/- mice, the number of sIgM+B220+ immature B cells is markedly reduced while the ratio of proB to preB cells is not affected. In contrast, development of thymocytes is not affected. Furthermore, TRAF6-/- mice are defective in lymph node organogenesis and IL-1 signalling in thymocytes.

CONCLUSIONS

The results identify TRAF6 as an essential component of ODF signalling pathway, and also show that TRAF6 plays pivotal roles in immune and inflammatory systems in vivo.

Two differently regulated nuclear factor kappaB activation pathways triggered by the cytoplasmic tail of CD40

CD40 signaling modulates the immune response at least in part by activation of nuclear factor kappaB (NFkappaB). It has been shown that two distinct domains in the CD40 cytoplasmic tail (cyt), namely cyt-N and cyt-C, independently activate NFkappaB. Although four members of the tumor necrosis factor receptor-associated factor (TRAF) family, including TRAF2, TRAF3, TRAF5, and TRAF6, bind to the CD40 cyt, how each TRAF protein contributes to the NFkappaB activation by CD40 is not clear. Here we report that TRAF2, TRAF3, and TRAF5 bind cyt-C, whereas TRAF6 binds cyt-N. cyt-N is conserved poorly between human and mouse CD40, while cyt-C is highly conserved. However, single aa substitution of Glu-235 in cyt-N of human CD40 with Ala abolishes the binding of TRAF6 to cyt-N and NFkappaB activation by cyt-N. Conservation of this Glu between mouse and human CD40 strongly suggests that TRAF6 could link cyt-N to signals essential for CD40-mediated immune response. Furthermore, NFkappaB activation by cyt-C is inhibited by a kinase-negative form of NFkappaB-inducing kinase more efficiently than that by cyt-N, consistent with the result that NFkappaB activation by TRAF2 and TRAF5 is inhibited by a kinase-negative form of NFkappaB-inducing kinase more efficiently than that by TRAF6. These results indicate that NFkappaB activating signals emanating from cyt-N and cyt-C are mediated by the different members of the TRAF family and could be regulated in a distinct manner.

Synthesis and biological evaluation of 1alpha,24-dihydroxy-25-nitrovitamin D3

1Alpha,24(R)Dihydroxy-25-nitrovitamin D3 1 and 1alpha,24(S)-dihydroxy-25-nitrovitamin D3 2 were synthesized using the palladium-catalyzed alkylative enyne cyclization reaction. Their biological properties were studied based on VDR binding affinity and HL-60 cell differentiation activity.

Endothelin ET(B) receptor-mediated action on systemic and renal hemodynamics and urine formation in deoxycorticosterone acetate-salt-induced hypertensive rats

The pathophysiological role of endothelin ET(B) receptor-mediated action on systemic and renal hemodynamics and urine formation in deoxYcorticosterone acetate (DOCA)-salt hypertensive rats was investigated. An intravenous bolus injection of a selective ET(B) receptor antagonist, BQ788 (1 mg/kg), produced a significant increase in mean arterial pressure (MAP) of DOCA-salt treated rats, whereas the agent-induced increase in MAP was less marked in normotensive sham rats. Administration of BQ788 caused a significant and sustained reduction in renal blood flow both in DOCA-salt and sham rats. No marked effects were observed on urine formation in both groups. Alternatively, a selective ET(A) receptor antagonist, FR139317 (10 mg/kg), produced a potent hypotensive effect, accompanied by significant renal vasodilation in DOCA-salt hypertensive rats, but these effects were partially reversed by the subsequent administration of BQ788. When renal perfusion pressure was protected from FR139317-induced hypotension by an aortic clamp, significant diuresis and natriuresis were observed, events partially reversed by the subsequent administration of BQ788. Our results indicate that the ET(B) receptor-mediated action tonically functions as a hypotensive and a renal vasodilatory factor and that these effects seem to be up-regulated in DOCA-salt hypertension. We also suggest that the ET(A) receptor blockade in DOCA-salt hypertensive rats unmasks the ET(B) receptor-mediated action which partially contributes to the antihypertensive effect induced by FR139317.

Cloning and characterization of a cDNA encoding the human homolog of tumor necrosis factor receptor-associated factor 5 (TRAF5)

A cDNA encoding the human homolog of the tumor necrosis factor receptor-associated factor 5 (TRAF5) protein has been molecularly cloned from a cDNA library of Human Daudi B cell line. The sequence analysis revealed that the cDNA encoded a protein of 557 aa residues with a calculated molecular weight of 64,236. The encoded protein has typical structural characteristics shown in the TRAF family of proteins and binds to the cytoplasmic region of lymphotoxin-beta receptor more efficiently than to that of CD40 and CD30. The TRAF5 gene was mapped to the human chromosome 1q32.3-q41.1. Overexpression of human TRAF5 activates NF kappa B transcription factor in human 293T kidney cells. These results suggest that the human TRAF5 protein could be involved in the signal triggered by various members of the tumor necrosis factor receptor (TNFR) superfamily including CD40, CD30 and lymphotoxin-beta receptor.

Developmental fate of single embryonic stem cells microinjected into 8-cell-stage mouse embryos

Embryonic stem (ES) cells are pluripotent and capable of differentiating into somatic as well as germ cell lineages when conjoined with blastomeres of early mouse embryos. However, the developmental potential of single ES cells has not been fully investigated. We injected single murine ES cells (A3-1 cell line) of 129 origin into 8-cell mouse embryos (B6xBDF1) and examined the patterns of distribution of ES-cell-derived cells in the blastocysts as well as in the fully grown chimeric mice. The ES cells underwent 1-2 cycles of mitosis between the 8-cell and the blastocyst stage when they were introduced as single cells, whereas those introduced as groups of 2-5 cells did not proliferate during the same period of development. The ES cells and their daughter cells were predominantly incorporated into the ICM. From the 63 8-cell embryos which received single ES cells microinjected into the perivitelline space, 24 newborns were obtained, and 4 (2 fertile males, 1 sterile female and 1 hermaphrodite) of them (16.6%) were chimeric. The test breeding studies revealed that all the progeny of the two chimeric males were derived from spermatozoa of 129 genotype. The relative contribution of the host-derived and the ES-cell-derived cells in different tissues of the chimeric mice was assessed by PCR analyses of the microsatellite polymorphism of genomic DNA extracted from the tissues. In two male germ line chimeras, the testes, the kidneys and the dorsal skeletal muscles exhibited exceptionally high 129 contents. Our results demonstrated that single ES cells which maintain totipotency or pluripotency of high degree are present in a colony of ES cells, and that single ES cells conjoined with the blastomeres of 8-cell-stage embryos may colonize, if the circumstances allow, almost exclusively the germ cells and concomitantly the urogenital cell lineages. Possible correlation between the allocation of the germ line and the urogenital lineages is discussed.

Highly sensitive mutation assay for mutagenicity monitoring of indoor air using Salmonella typhimurium YG1041 and a microsuspension method

A highly sensitive mutation assay for indoor mutagenicity monitoring was investigated by a combination of Salmonella typhimurium YG strains and the microsuspension method. Tester strains were YG1024, YG1029, YG1041 and YG1042. YG1041 gave the highest sensitivity in the mutagenicity test for the extracts of airborne particulates. The sensitivity of the microsuspension assay using S.typhimurium YG1041 in the absence of S9 mix was approximately 200 times higher than that of the preincubation assay using strain TA98, which has been widely used for mutagenicity monitoring of airborne particulates outdoors. Furthermore, a significant correlation was observed between mutagenicities determined by the microsuspension assay using S.typhimurium YG1041 and TA98, where mutagenicity assay was carried out for airborne particulates collected by a high volume sampler for 24 h every 12 days for 1 year. This new method was also useful for indoor mutagenicity monitoring in which a small amount of airborne particulates was collected by a low noise sampler for 12 h each of 6 consecutive days. The monitoring showed that mutagenicity in the daytime is generally higher than that in the night and that smoking is an important factor in increasing mutagenicity in indoor air.

Vitamin B12 enhances GABA content but reduces glutamate content in the rat suprachiasmatic nucleus

The present study attempted to elucidate effects of vitamin B12 (VB12) on the rat suprachiasmatic nucleus (SCN), which is the locus of the circadian clock in mammals, by evaluating the contents of its major neurotransmitters, gamma-aminobutyric acid (GABA) and glutamate (Glu). First, contents of these amino acids were analyzed from tissue samples prepared at three different circadian times (CTs) in free-running rats under constant dim illumination. The content of GABA was highest in the middle of the resting phase (CT 6), intermediate early in the active phase (CT 14), and lowest late in the active phase (CT 20), whereas Glu content indicated inverse circadian variations. Subsequently, effects of intracerebroventricularly infused VB12 were assayed at CT 20. Compared with the saline-infused control, the infusion of VB12 (30 nmol/30 microliters) at CT 12-15 significantly increased GABA content but decreased Glu content. The quantitative balance of these amino acids after VB12 infusion was similar to that at CT 6 in noninfused rats. These results suggest that infusion of VB12 to active rats shifts the ratio of SCN neurotransmitters toward that observed in resting rats.

A role for macrophage scavenger receptors in atherosclerosis and susceptibility to infection

Macrophage type-I and type-II class-A scavenger receptors (MSR-A) are implicated in the pathological deposition of cholesterol during atherogenesis as a result of receptor-mediated uptake of modified low-density lipoproteins (mLDL). MSR-A can bind an extraordinarily wide range of ligands, including bacterial pathogens, and also mediates cation-independent macrophage adhesion in vitro. Here we show that targeted disruption of the MSR-A gene in mice results in a reduction in the size of atherosclerotic lesions in an animal deficient in apolipoprotein E. Macrophages from MSR-A-deficient mice show a marked decrease in mLDL uptake in vitro, whereas mLDL clearance from plasma occurs at a normal rate, indicating that there may be alternative mechanisms for removing mLDL from the circulation. In addition, MSR-A-knockout mice show an increased susceptibility to infection with Listeria monocytogenes or herpes simplex virus type-1, indicating that MSR-A may play a part in host defence against pathogens.

Germ-line contribution of embryonic stem cells in chimeric mice: influence of karyotype and in vitro differentiation ability

The effect of the karyotype and the ability to differentiate in vitro upon germ-line transmission by A3-1 embryonic stem (ES) cells in chimeric mice were examined. Germ-line transmission was confirmed in ES cells exhibiting 38% and more of the normal karyotype, but no chimeric mice and/or germ-line transmitters were observed regardless of the karyotype when the cystic embryoid body (CEB) was formed on day 8 and later in the suspension culture. Germ-line transmission of the ES cells was not significantly influenced by formation of the simple embryoid body (SEB). Germ-line transmitters were preferentially observed in chimeras when the ES cell contribution to coat color was markedly increased, but this contribution to coat color varied regardless of the karyotype or in vitro differentiation ability. These results suggest that A3-1 ES cells which exhibit CEB at 7 days after suspension culture and approximately 40% of normal karyotype are capable of germ-line transmission in chimeric mice.

Identification of TRAF6, a novel tumor necrosis factor receptor-associated factor protein that mediates signaling from an amino-terminal domain of the CD40 cytoplasmic region

CD40 signalings play crucial roles in B-cell function. To identify molecules which transduce CD40 signalings, we have utilized the yeast two-hybrid system to clone cDNAs encoding proteins that bind the cytoplasmic tail of CD40. A cDNA encoding a putative signal transducer, designated TRAF6, has been molecularly cloned. TRAF6 has a tumor necrosis factor receptor (TNFR)-associated factor (TRAF) domain in its carboxyl terminus and has a RING finger domain, a cluster of zinc fingers and a coiled-coil domain, which are also present in other TRAF family proteins. TRAF6 does not associate with the cytoplasmic tails of TNFR2, CD30, lymphotoxin-beta receptor, and LMP1 of Epstein-Barr virus. Deletion analysis showed that residues 246-269 of CD40 which are required for its association with TRAF2, TRAF3, and TRAF5 are dispensable for its interaction with TRAF6, whereas residues 230-245 were required. Overexpression of TRAF6 activates transcription factor NFkappaB, and its TRAF-C domain suppresses NFkappaB activation triggered by CD40 lacking residues 246-277. These results suggest that TRAF6 could mediate the CD40 signal that is transduced by the amino-terminal domain (230-245) of the CD40 cytoplasmic region and appears to be independent of other known TRAF family proteins.

Effects of phosphate on in vitro 2-cell block of AKR/N mouse embryos based on changes in cdc2 kinase activity and phosphorylation states

This study demonstrated the effects of phosphate on the 2-cell block of AKR/N mouse embryos at the molecular level and focused on changes in the kinase activity and the phosphorylation state of cdc2, which is shown to regulate the cell division cycle. Removal of phosphate from the culture medium dramatically increased developmental rates to the 4-cell (91.8%) and blastocyst (42.6%) stages compared with those of embryos cultured in 1.17 mM phosphate (3.3% and 0%, respectively). The rate of development to the 4-cell stage was significantly inhibited by 0.001 mM phosphate (p < 0.05), and no morula formation was observed at 1.0 mM. The patterns of cdc2 kinase activity during the first cell cycle in AKR/N embryos were similar to those of control MCH embryos, showing the highest activity at M phase and low activity during the interphase. The phosphorylated form of cdc2 increased during the interphase, indicating that the synthesis of cyclin B and accumulation of inactive pre-maturation-promoting factor (pre-MPF) as well as abrupt dephosphorylation of cdc2 at the first cleavage correlated with the activation of cdc2 kinase. When phosphate was absent, the activation pattern of cdc2 kinase during the second cell cycle in AKR/N embryos was similar to that in the first cell cycle. On the other hand, no dephosphorylation of cdc2 was observed and the kinase activity remained at a low level until 56 h after insemination in the presence of phosphate, although an increase in phosphorylated cdc2 was observed as in the phosphate-free group. Treatment of AKR/N embryos arrested at the 2-cell stage with okadaic acid resulted in the dephosphorylation and activation of cdc2, confirming the presence of a sufficient amount of pre-MPF. These results show that phosphate has a deteriorative effect on the in vitro development of AKR/N embryos and suggest that this effect was not on the synthesis of cyclin B but on the dephosphorylation of phosphorylated cdc2.

State-dependent changes of extracellular glutamate in the medial preoptic area in freely behaving rats

Microdialysis technique was applied to the medial preoptic area (mPOA) of the hypothalamus, a crucial site for the regulation of sleep, in order to analyze the interrelationship between the extracellular level of glutamate (Glu) and the vigilance states. Dialysates from the mPOA were sampled at 5-min intervals for 2-h diurnal period with a perfusion rate of 2.0 microliters/min in freely moving rats, whose sleep-waking behaviors were polysomnographically monitored. Extracellular Glu increased during wakefulness, exhibiting a peak at the transition period from wakefulness to non-rapid-eye-movement sleep (NREMS) (18.0% above the average), whereas it decreased during NREMS (9.2% below the average). It is likely that Glu in the mPOA is dynamically involved in the alterations of the vigilance states.

Maintenance of pluripotency in mouse embryonic stem cells persistently infected with murine coronavirus

A persistently coronavirus-infected embryonic stem (ES) cell line A3/MHV was established by infecting an ES cell line, A3-1, with mouse hepatitis virus type-2. Although almost all A3/MHV cells were found infected, both A3/MHV and A3-1 cells expressed comparable levels of cell surface differentiation markers. In addition, A3/MHV cells retained the ability to form embryoid bodies. These results suggest that persistent coronavirus infection does not affect the differentiation of ES cells.

Gene transfer and expression in mouse preimplantation embryos by recombinant adenovirus vector

Replication-defective recombinant adenovirus, Adex4SRLacZL, was used as a vector for transferring exogenous genes in mouse zona pellucida-free eggs at the pronuclear stage. The vector contained the E. coli LacZ reporter gene under the control of the SR alpha promoter (SV40 early promoter-fused HTLV-I LTR), and the expression of the reporter gene was examined during preimplantation development in culture. Histochemical staining of the embryos for beta-galactosidase activity showed that the exogenous LacZ gene as expressed in 98% of the embryos at the morula-blastocyst stages. As in the microinjection method, the exogenous genes could be pursued from the 2-cell stage. Neither apparent morphological changes nor cytotoxic effects were observed. Both the percentages of embryos expressing reporter genes and the rate of development to the blastocyst stage were higher in the adenovirus vector-treated embryos than in the microinjected ones. These results suggest that the adenovirus vector system is a useful tool in investigating the genetic control of early mammalian development.

Mice deficient for the IL-3/GM-CSF/IL-5 beta c receptor exhibit lung pathology and impaired immune response, while beta IL3 receptor-deficient mice are normal

The receptors for IL-3, GM-CSF, and IL-5 share a common beta subunit (beta c), and mice have an additional IL-3 beta subunit (beta IL3). We have independently generated mice carrying null mutations of each molecule. beta c mutant bone marrow showed no response to GM-CSF or IL-5, whereas IL-3 stimulation of beta c or beta IL3 mutant bone marrow was normal. beta c mutant mice showed lung pathology consisting of lymphocytic infiltration and areas resembling alveolar proteinosis, and also exhibited low basal numbers of eosinophils. Infection of beta c mutant mice by Nippostrongylus brasiliensis resulted in the absence of blood and lung eosinophilia. Animals repopulated with beta c mutant bone marrow cells showed slower leukocyte recovery and reduced eosinophil numbers. These data define the role of beta c in vivo, and show a phenotype that is likely to be the cumulative effect of loss of GM-CSF and IL-5 stimulation.

Sperm from mice carrying a targeted mutation of the acrosin gene can penetrate the oocyte zona pellucida and effect fertilization

The physiological function of mammalian sperm acrosin has long been believed to be involved in the limited proteolysis of the oocyte zona pellucida, thus enabling the sperm to penetrate this extracellular matrix and to gain access to the oocyte plasma membrane. Here we show that male mice homozygous for a targeted mutation in the mouse acrosin gene are still fertile in spite of the complete absence of acrosin protease activity in the sperm. In vitro fertilization assays verified that sperm from the homozygous mutant mice penetrate the zona pellucida and effect fertilization. Therefore, acrosin is not essential for both sperm penetration of the zona pellucida and fertilization.

[Immunological effects of locoregional immunochemotherapy for liver metastases of gastric cancer]

Nine gastric cancer patients with simultaneous liver metastases were given intermittent transarterial administration of chemotherapeutics (adriamycin, mitomycin C or 5-fluorouracil) and biological response modifiers (BRM; OK-432 and interleukin (IL) -2) after gastrectomy. In terms of direct antitumor effect on liver metastases, a partial response was observed in 4 of 9 cases (44%). In addition, the concentration of 3 kinds of cytokines such as IL-6, tumor necrosis factor (TNF) -alpha and interferon (IFN) -gamma in the peripheral blood sera was measured immediately before and after transarterial administration of agents. While the concentration of IL-6 increased by BRM, chemotherapeutics could not alter the level of IL-6. As for TNF-alpha and IFN-gamma, no particular changing pattern was observed after transarterial administration. Furthermore, natural killer (NK) activity of peripheral blood mononuclear cells was measured. Administration of either BRM or BRM in combination with chemotherapeutics caused a decrease in NK activity, whereas chemotherapeutics did not. Flow cytometric analysis using 3 kinds of monoclonal antibodies (Anti-CD16, CD56 and CD57) revealed that the proportion of subset of both highly activated NK cells (CD16+.CD56+.CD57-) and moderately activated NK cells (CD16+.CD56+.CD57+) reduced after administration of BRM.

PCR sexing and developmental rate differences in preimplantation mouse embryos fertilized and cultured in vitro

A two-step polymerase chain reaction (PCR) assay was used to determine the sex of mouse preimplantation embryos obtained from oocytes fertilized and cultured in vitro, to investigate the differences in the developmental rates of mouse embryos according to the sex. All the in vitro developed embryos could be analyzed by this method. When the embryos were classified according to the time of morula to blastocyst transition as fast-intermediate- and slow-growing embryos, a significantly high percentage (78.0%) of the fast-developing embryos were identified as males; while a significantly lower percentage (42.5%) of slow-developing embryos were identified as males. The intermediate-developing embryos presented a sex ratio not significantly different from the total (57.5%). The deviation of sex ratio was further confirmed by embryo transfer experiment, where fast- and slow-developing embryos gave 76.2% and 25.7% male fetuses, respectively. We concluded that male mouse embryos fertilized and cultured in vitro develop faster than female embryos.