Age-associated characteristics of murine hematopoietic stem cells

Little is known of age-associated functional changes in hematopoietic stem cells (HSCs). We studied aging HSCs at the clonal level by isolating CD34(-/low)c-Kit(+)Sca-1(+) lineage marker-negative (CD34(-)KSL) cells from the bone marrow of C57BL/6 mice. A population of CD34(-)KSL cells gradually expanded as age increased. Regardless of age, these cells formed in vitro colonies with stem cell factor and interleukin (IL)-3 but not with IL-3 alone. They did not form day 12 colony-forming unit (CFU)-S, indicating that they are primitive cells with myeloid differentiation potential. An in vivo limiting dilution assay revealed that numbers of multilineage repopulating cells increased twofold from 2 to 18 mo of age within a population of CD34(-)KSL cells as well as among unseparated bone marrow cells. In addition, we detected another compartment of repopulating cells, which differed from HSCs, among CD34(-)KSL cells of 18-mo-old mice. These repopulating cells showed less differentiation potential toward lymphoid cells but retained self-renewal potential, as suggested by secondary transplantation. We propose that HSCs gradually accumulate with age, accompanied by cells with less lymphoid differentiation potential, as a result of repeated self-renewal of HSCs.

Oocyte apoptosis is suppressed by disruption of the acid sphingomyelinase gene or by sphingosine-1-phosphate therapy

The time at which ovarian failure (menopause) occurs in females is determined by the size of the oocyte reserve provided at birth, as well as by the rate at which this endowment is depleted throughout post-natal life. Here we show that disruption of the gene for acid sphingomyelinase in female mice suppressed the normal apoptotic deletion of fetal oocytes, leading to neonatal ovarian hyperplasia. Ex vivo, oocytes lacking the gene for acid sphingomyelinase or wild-type oocytes treated with sphingosine-1-phosphate resisted developmental apoptosis and apoptosis induced by anti-cancer therapy, confirming cell autonomy of the death defect. Moreover, radiation-induced oocyte loss in adult wild-type female mice, the event that drives premature ovarian failure and infertility in female cancer patients, was completely prevented by in vivo therapy with sphingosine-1-phosphate. Thus, the sphingomyelin pathway regulates developmental death of oocytes, and sphingosine-1-phosphate provides a new approach to preserve ovarian function in vivo.

NorM, a putative multidrug efflux protein, of Vibrio parahaemolyticus and its homolog in Escherichia coli

We found that cells of Vibrio parahaemolyticus possess an energy-dependent efflux system for norfloxacin. We cloned a gene for a putative norfloxacin efflux protein from the chromosomal DNA of V. parahaemolyticus by using an Escherichia coli mutant lacking the major multidrug efflux system AcrAB as the host and sequenced the gene (norM). Cells of E. coli transformed with a plasmid carrying the norM gene showed elevated energy-dependent efflux of norfloxacin. The transformants showed elevated resistance not only to norfloxacin and ciprofloxacin but also to the structurally unrelated compounds ethidium, kanamycin, and streptomycin. These results suggest that this is a multidrug efflux system. The hydropathy pattern of the deduced amino acid sequence of NorM suggested the presence of 12 transmembrane domains. The deduced primary structure of NorM showed 57% identity and 88% similarity with that of a hypothetical E. coli membrane protein, YdhE. No reported drug efflux protein in the sequence databases showed significant sequence similarity with NorM. Thus, NorM seems to be a novel type of multidrug efflux protein. We cloned the ydhE gene from E. coli. Cells of E. coli transformed with the cloned ydhE gene showed elevated resistance to norfloxacin, ciprofloxacin, acriflavine, and tetraphenylphosphonium ion, but not to ethidium, when MICs were measured. Thus, it seems that NorM and YdhE differ somehow in substrate specificity.

Oocyte apoptosis: like sand through an hourglass

Although the study of germ cell death is arguably still in its infancy as a field, several recent breakthroughs have provided the fodder for a story, replete with episodes of apparent mass cellular suicide if not murder, that will undoubtedly serve as a research base for many laboratories over the next several years. Death is known to strike the male and female germlines with roughly equal intensity, but the innate feature of male germ cells being self-renewing while those of the female are not places the death of oocytes in a completely different light. Indeed, the functional life span of the female gonads is defined in most species, including humans, by the size and rate of depletion of the precious endowment of oocytes enclosed within follicles in the ovaries at birth. This continuous loss of oocytes throughout life, referred to by many as the female biological clock, appears to be driven by a genetic program of cell death that is composed of players and pathways conserved from worms to humans. It is on this genetic pathway, and the role of its constituent molecules in regulating female germ cell fate, that this review will focus. Emphasis will be placed on those studies using genetic-null or transgenic models to explore the functional requirement of proteins, such as Bcl-2 family members, Apaf-1, and caspases in vertebrates to CED-9, CED-4, and CED-3 in Caenorhabditis elegans, in oocyte survival and death. Furthermore, hypotheses regarding the potential impact of translating what is now known of the oocyte death pathway into new approaches for the clinical diagnosis and management of female infertility and the menopause will be offered as a means to stimulate further research in this new and exciting field.

MDR1 genotype-related pharmacokinetics of digoxin after single oral administration in healthy Japanese subjects

PURPOSE

To evaluate the MDR1 genotype frequency in the Japanese population and to study the relationship between the MDR1 genotype and the pharmacokinetics of digoxin after single oral administration in healthy subjects.

METHODS

The MDR1 genotype at exon 26 was determined in 114 healthy volunteers by polymerase chain reaction-restriction fragment length polymorphism. The serum concentration-time profile of digoxin was examined after single oral administration at a dose of 0.25 mg.

RESULTS

It was found that 35.1 % (40/114) of subjects were homozygous for the wild-type allele (C/C). 52.6% (60/114) were compound heterozygotes with a mutant T-allele (C3435T) (C/T), and 12.3% (14/114) were homozygous for the mutant allele (T/T). There was no effect of gender or age on the distribution. The serum concentration of digoxin after a single oral administration increased rapidly, attaining a steady state in all subjects; however, it was lower in the subjects harboring the T-allele. AUC0-4 h values (+/-SD) were 4.11 +/- 0.57, 3.20 +/- 0.49. and 3.27 +/- 0.58 ng h/ml, respectively, with a significant difference between C/C and C/T or T/T.

CONCLUSIONS

The serum concentration of digoxin after single oral administration was lower in the subjects harboring a mutant allele (C3435T) at exon 26 of the MDR1 gene.

CD14+,CD16+ blood monocytes and joint inflammation in rheumatoid arthritis

OBJECTIVE

CD14+,CD16+ monocytes, identified as a minor population of monocytes in human peripheral blood (PB), have been implicated in several inflammatory diseases. We undertook this study to investigate the relevance of this phenotype to joint inflammation in rheumatoid arthritis (RA).

METHODS

The expression of CD14, CD16, CC chemokine receptor 1 (CCR1), CCR5, and intercellular adhesion molecule 1 (ICAM-1) on monocytes was measured by flow cytometric analysis. Concentrations of the cytokines known to induce CD16 (including transforming growth factor beta1 [TGFbeta1], macrophage colony-stimulating factor [M-CSF], and interleukin-10 [IL-10]) and concentrations of the soluble form of CD14 (sCD14) in plasma and synovial fluid (SF) samples were measured by enzyme-linked immunosorbent assay. The induction of CD16 on RA blood monocytes cultured for 18 hours with 1 or with all 3 cytokines was determined.

RESULTS

The mean +/- SD frequency of CD14+,CD16+ blood monocytes was significantly increased in RA patients (11.7 +/- 5.6%; n = 105) compared with healthy controls (9.5 +/- 2.2%; n = 15) (P < 0.01), and the patient group with an increased frequency of CD16+ monocytes (> or =13.9%) had active disease, as defined by increased counts of tender and swollen joints, levels of acute-phase reactants, and titers of rheumatoid factor. The response to drug therapy correlated with changes in the frequency of this phenotype. The expression of CD16 on SF monocytes from RA patients was markedly elevated compared with the expression on PB monocytes. CD16 expression on RA blood monocytes was augmented in vitro by IL-10, M-CSF, and TGFbeta1. Plasma concentrations of these cytokines and of sCD14 were significantly higher in RA patients with high CD16+ monocyte frequencies than in those with low CD16+ monocyte frequencies or in healthy controls. CD14+,CD16+ monocytes expressed higher levels of CCR1, CCR5, and ICAM-1 than did regular CD14++,CD16- monocytes, particularly in active RA.

CONCLUSION

These results indicate that the maturation of blood monocytes into tissue-infiltrative CD16+ cells before entry into the joint, induced by cytokine spillover from the inflamed joint, may contribute to the persistent joint inflammation of RA.

Inducible expression of a Th2-type CC chemokine thymus- and activation-regulated chemokine by human bronchial epithelial cells

CCR4 is now known to be selectively expressed in Th2 cells. Since the bronchial epithelium is recognized as an important source of mediators fundamental to the manifestation of respiratory allergic inflammation, we studied the expression of two functional ligands for CCR4, i.e., macrophage-derived chemokine (MDC) and thymus- and activation-regulated chemokine (TARC), in bronchial epithelial cells. The bronchial epithelium of asthmatics and normal subjects expressed TARC protein, and the asthmatics showed more intense expression than the normal subjects. On the other hand, MDC expression was only weakly detected in the asthmatics, but the intensity was not significantly different from that of normal subjects. Combination of TNF-alpha and IL-4 induced expression of TARC protein and mRNA in bronchial epithelial A549 cells, which was slightly up-regulated by IFN-gamma. The enhancement by IFN-gamma was more pronounced in bronchial epithelial BEAS-2B cells, and a maximum production occurred with combination of TNF-alpha, IL-4, and IFN-gamma. On the other hand, MDC was essentially not expressed in any of the cultures. Furthermore, expressions of TARC protein and mRNA were almost completely inhibited by glucocorticoids. These results indicate that the airway epithelium represents an important source of TARC, which potentially plays a role via a paracrine mechanism in the development of allergic respiratory diseases. Furthermore, the beneficial effect of inhaled glucocorticoids on asthma may be at least in part due to their direct inhibitory effect on TARC generation by the bronchial epithelium.

Accelerated apoptosis of lymphocytes by augmented induction of Bax in SSI-1 (STAT-induced STAT inhibitor-1) deficient mice

Growth, differentiation, and programmed cell death (apoptosis) are mainly controlled by cytokines. The Janus kinase-signal transducers and activators of transcription (JAK-STAT) signal pathway is an important component of cytokine signaling. We have previously shown that STAT3 induces a molecule designated as SSI-1, which inhibits STAT3 functions. To clarify the physiological roles of SSI-1 in vivo, we generated, here, mice lacking SSI-1. These SSI-1-/- mice displayed growth retardation and died within 3 weeks after birth. Lymphocytes in the thymus and spleen of the SSI-1-/- mice exhibited accelerated apoptosis with aging, and their number was 20-25% of that in SSI-1+/+ mice at 10 days of age. However, the differentiation of lymphocytes lacking SSI-1 appeared to be normal. Among various pro- and anti-apoptotic molecules examined, an up-regulation of Bax was found in lymphocytes of the spleen and thymus of SSI-1-/- mice. These findings suggest that SSI-1 prevents apoptosis by inhibiting the expression of Bax.

A detailed linkage map of medaka, Oryzias latipes: comparative genomics and genome evolution

We mapped 633 markers (488 AFLPs, 28 RAPDs, 34 IRSs, 75 ESTs, 4 STSs, and 4 phenotypic markers) for the Medaka Oryzias latipes, a teleost fish of the order Beloniformes. Linkage was determined using a reference typing DNA panel from 39 cell lines derived from backcross progeny. This panel provided unlimited DNA for the accumulation of mapping data. The total map length of Medaka was 1354.5 cM and 24 linkage groups were detected, corresponding to the haploid chromosome number of the organism. Thirteen to 49 markers for each linkage group were obtained. Conserved synteny between Medaka and zebrafish was observed for 2 independent linkage groups. Unlike zebrafish, however, the Medaka linkage map showed obvious restriction of recombination on the linkage group containing the male-determining region (Y) locus compared to the autosomal chromosomes.

Direct serotyping of human rotavirus in stools by an enzyme-linked immunosorbent assay using serotype 1-, 2-, 3-, and 4-specific monoclonal antibodies to VP7

Four serotypes of human rotaviruses that can be differentiated by neutralization tests have been described so far. We prepared serotype 1-, 2-, 3-, and 4-specific, neutralizing monoclonal antibodies to human rotaviruses. All were directed to VP7, a glycoprotein that carries a major serotype specificity. An enzyme-linked immunosorbent assay using these monoclonal antibodies has been developed for serotyping human rotavirus isolates. The sensitivity and specificity of this method were verified by using various strains of human rotavirus that were adapted to cell culture. Furthermore, it was shown that the method was applicable to serotyping human rotaviruses directly in stool specimens.

Three distinct domains of SSI-1/SOCS-1/JAB protein are required for its suppression of interleukin 6 signaling

Cytokine-inducible protein SSI-1 [signal transducers and activators of transcription (STAT)-induced STAT inhibitor 1, also referred to as SOCS-1 (suppressor of cytokine signaling 1) or JAB (Janus kinase-binding protein)] negatively regulates cytokine receptor signaling by inhibition of JAK kinases. The SSI family of proteins includes eight members that are structurally characterized by an SH2 domain and a C-terminal conserved region that we have called the SC-motif. In this study, we investigated the roles of these domains in the function of SSI-1. Results of reporter assays demonstrated that the pre-SH2 domain (24 aa in front of the SH2 domain) and the SH2 domain of SSI-1 were required for the suppression by SSI-1 of interleukin 6 signaling. Coexpression studies of COS7 cells revealed that these domains also were required for inhibition of three JAKs (JAK1, JAK2, and TYK2). Furthermore, deletion of the SH2 domain, but not the pre-SH2 domain, resulted in loss of association of SSI-1 with TYK2. Thus, SSI-1 associates with JAK family kinase via its SH2 domain, and the pre-SH2 domain is required for the function of SSI-1. Deletion of the SC-motif markedly reduced expression of SSI-1 protein in M1 cells, and this reduction was reversed by treatment with proteasome inhibitors, suggesting that this motif is required to protect the SSI-1 molecule from proteolytic degradation. Based on these findings, we concluded that three distinct domains of SSI-1 (the pre-SH2 domain, the SH2 domain, and the SC-motif) cooperate in the suppression of interleukin 6 signaling.

Expression in Escherichia coli of a new multidrug efflux pump, MexXY, from Pseudomonas aeruginosa

Two new genes (mexXY) similar to mexAB, mexCD, and mexEF and mediating multidrug resistance were cloned from the chromosome of Pseudomonas aeruginosa. Elevated ethidium extrusion was observed with Escherichia coli cells harboring the plasmid carrying mexXY. This MexXY system confers higher resistance to fluoroquinolones than the MexAB and MexCD systems, and E. coli ToIC or P. aeruginosa OprM is necessary for the function of the MexXY system.

Alpha-CGRP and beta-CGRP mRNAs are differentially regulated in the rat spinal cord and dorsal root ganglion

We found an increase in calcitonin gene-related peptide (CGRP)-like immunoreactivity in motoneurons of rat spinal cord after peripheral axotomy. By means of in situ hybridization histochemistry and Northern blotting, we further demonstrated that this increase was the result of increased levels of alpha-CGRP mRNA, not beta-CGRP mRNA. The increased level of alpha-CGRP mRNA was maintained for at least 5 weeks, and was present on both sides. In addition, alpha-CGRP and beta-CGRP mRNAs had different distributions from each other in the dorsal root ganglia and levels of both were decreased after axotomy. These results indicate that alpha-CGRP and beta-CGRP are regulated independently and have different roles in the motor and sensory systems of the spinal cord.

The synovial expression and serum levels of interleukin-6, interleukin-11, leukemia inhibitory factor, and oncostatin M in rheumatoid arthritis

OBJECTIVE

To determine the expression of interleukin-6 (IL-6), IL-11, leukemia inhibitory factor (LIF), and oncostatin M (OSM) and their major cellular sources in the joints of rheumatoid arthritis (RA) patients, as well as the correlation of circulating levels of these IL-6-type cytokines and C-reactive protein (CRP).

METHODS

Messenger RNA (mRNA) and protein levels for IL-6, IL-11, LIF, and OSM were determined by using reverse transcription-polymerase chain reaction and enzyme-linked immunosorbent assay, respectively.

RESULTS

Cells isolated from the synovium of RA patients expressed mRNA for IL-6, IL-11, LIF, and OSM at higher levels than did synovial cells from osteoarthritis (OA) patients, and spontaneously released greater quantities of these proteins in culture. Fibroblast cell lines derived from RA synovium were able to produce IL-6, IL-11, and LIF, but not OSM, when stimulated with IL-1 and tumor necrosis factor alpha. OSM was found to be produced spontaneously by synovial tissue macrophages. IL-6, IL-11, LIF, and OSM were present in synovial fluid from the RA patients; levels of IL-6, LIF, and OSM were present in significantly greater quantities in RA patients than in OA patients. However, only IL-6 was significantly elevated in the serum of RA patients and correlated with the serum CRP level, while other IL-6-type cytokines were not detected.

CONCLUSION

IL-6, IL-11, LIF, and OSM are all produced in large amounts at the site of disease activity, but IL-6 derived from synovial fibroblasts may be the major hormone-like mediator that induces the hepatic synthesis of acute-phase proteins in RA.

Allergenic activity of heated and ovomucoid-depleted egg white

BACKGROUND

No egg white products have been clearly proven to be hypoallergenic. The role of egg white proteins in allergic reactions to eggs is still debatable.

OBJECTIVE

This study was designed to determine the importance of ovomucoid, an egg white protein, in the development of allergies to egg white.

METHODS

We performed a double-blind, placebo-controlled food challenge in subjects with high levels of IgE antibodies for egg white to compare the allergenicities of heated and ovomucoid-depleted egg white, freeze-dried egg white, and heated egg white. Levels of IgE antibodies for egg white, ovomucoid, ovalbumin, ovotransferrin, and lysozyme were measured in serum by RAST.

RESULTS

Twenty-one of 38 subjects with positive challenge responses to freeze-dried egg white had negative challenge responses to heated egg white, whereas 16 of 17 subjects (94.1%) with positive responses to heated egg white did not respond to the heated and ovomucoid-depleted egg white challenge. The subjects with positive challenge responses to freeze-dried egg white tended to have higher IgE antibody values to ovomucoid than those with negative responses. IgE antibody levels to ovomucoid were significantly higher in subjects with positive responses to a challenge with heated egg white than in those with no response. There were no significant differences in the levels of IgE antibodies to the other proteins, except ovomucoid, in the negative-response and positive-response groups in challenge tests with freeze-dried and heated egg white.

CONCLUSION

The heated and ovomucoid-depleted egg white preparation was less allergenic than heated or freeze-dried preparations. Ovomucoid has a more important role in the pathogenesis of allergic reactions to egg white than other proteins in egg white.

Protective effect of naturally acquired homotypic and heterotypic rotavirus antibodies

To assess serotype specificity of immune resistance to rotavirus gastroenteritis, the relation between pre-existing neutralising antibodies to homotypic and heterotypic rotaviruses and protection against infection or clinical illness was investigated. The subjects were 44 orphans exposed once or twice to consecutive outbreaks of gastroenteritis due to type 3 rotavirus in an orphanage in Sapporo. Sera were collected throughout these outbreaks and the serum levels of neutralising antibodies against four different serotypes of group A human rotavirus were measured before and after the outbreaks. Protection against rotavirus gastroenteritis seemed to be serotype specific and to be related to levels of antibody against homotypic virus. A neutralising antibody level of 1/128 or greater seemed to be protective. The protective effect was of short duration, which was probably the explanation for recurrent attacks of gastroenteritis due to a rotavirus of the same serotype. Seroconversions or concomitant antibody responses to type 1 or 4 rotavirus in most children with type 3 rotavirus infection suggested that immunity to heterotypic virus can be induced by a rotavirus vaccine.

Extrinsic and intrinsic fiber connections of the telencephalon in a teleost, Sebastiscus marmoratus

Extrinsic and intrinsic fiber connections of the telencephalic subdivisions of Nieuwenhuys ('62) in a teleost, Sebastiscus marmoratus, were studied by means of horseradish peroxidase (HRP) and Fink-Heimer methods. The olfactory bulb projects bilaterally to area dorsalis pars posterior, area ventralis pars ventralis, pars lateralis, pars posterior, pars intermedia, and the nucleus posterior tuberis of Peter et al. ('75) and receives fibers from ipsilateral area dorsalis pars centralis, pars posterior, area ventralis pars dorsalis, and pars supracommissuralis. Area dorsalis pars posterior sends numerous fibers to the ipsilateral ventral region of area dorsalis pars medialis, from which fibers of the medial forebrain bundle arise and terminate in the inferior lobe and nucleus posterior tuberis. Area dorsalis pars lateralis, pars dorsalis, and the dorsal region of pars medialis are the main targets of extratelencephalic ascending afferents. Area dorsalis pars lateralis receives fibers from the ipsilateral nucleus prethalamicus of Meader ('34), where tectal projections terminate massively. Area dorsalis pars dorsalis and the dorsal region of pars medialis receive afferents from the ipsilateral nucleus preglomerulosus of Schnitzlein ('62), nucleus posterior tuberis, area preoptica pars medialis of Crosby and Showers ('69), and nucleus entopeduncularis of Sheldon ('12). Raphe nuclei and locus ceruleus project bilaterally to area dorsalis pars centralis, pars dorsalis, pars lateralis, and the dorsal region of pars medialis. Area dorsalis pars centralis, pars dorsalis, and the dorsal region of pars medialis are important sources of extratelencephalic efferents. These subdivisions give rise to the lateral forebrain bundle and project to the ipsilateral nucleus prethalamicus, nucleus preglomerulosus, inferior lobe, nucleus paracommissuralis of Ito et al. ('82), optic tectum, torus semicircularis, and the bilateral mesencephalic tegmentum. Within the telencephalon, most of the ventral subdivisions project to ipsilateral area dorsalis pars centralis, pars dorsalis, pars lateralis, and the dorsal region of pars medialis. Area dorsalis pars centralis has reciprocal connections with ipsilateral area dorsalis pars lateralis, pars dorsalis, pars posterior, and the dorsal region of pars medialis. A dorsal part of the anterior commissure is composed of axons of the ventral region of area dorsalis pars medialis destined to the contralateral ventral region of area dorsalis pars medialis. A ventral part of the anterior commissure contains axons of area dorsalis pars centralis destined to contralateral area dorsalis pars lateralis.

Dendritic cells genetically engineered to express IL-4 inhibit murine collagen-induced arthritis

Dendritic cells (DCs) are specialized antigen-presenting cells that migrate from the periphery to lymphoid tissues, where they activate and regulate T cells. Genetic modification of DCs to express immunoregulatory molecules would provide a new immunotherapeutic strategy for autoimmune and other diseases. We have engineered bone marrow-derived DCs that express IL-4 and tested the ability of these cells to control murine collagen-induced arthritis (CIA), a model for rheumatoid arthritis in which Th1 cells play a critical role. IL-4-transduced DCs inhibited Th1 responses to collagen type II in vitro. A single injection of IL-4-transduced DCs reduced the incidence and severity of CIA and suppressed established Th1 responses and associated humoral responses, despite only transient persistence of injected DCs in the spleen. In contrast, control DCs and IL-4-transduced T cells or fibroblastic cells failed to alter the course of the disease. The functional effects correlated well with the differential efficiency of DC migration from various sites of injection to lymphoid organs, especially the spleen. The ability of splenic T cells to produce IL-4 in response to anti-CD3 was enhanced after the administration of IL-4-transduced DCS: These results support the feasibility of using genetically modified DCs for the treatment of autoimmune disease.

Signals transducers and activators of transcription (STAT)-induced STAT inhibitor-1 (SSI-1)/suppressor of cytokine signaling-1 (SOCS-1) suppresses tumor necrosis factor alpha-induced cell death in fibroblasts

Signal transducers and activators of transcription (STAT)-induced STAT inhibitor-1 [SSI-1; also known as suppressor of cytokine signaling-1 (SOCS-1)] was identified as a negative feedback regulator of Janus kinase-STAT signaling. We previously generated mice lacking the SSI-1 gene (SSI-1 -/-) and showed that thymocytes and splenocytes in SSI-1 -/- mice underwent accelerated apoptosis. In this paper, we show that murine embryonic fibroblasts lacking the SSI-1 gene are more sensitive than their littermate controls to tumor necrosis factor-alpha (TNF-alpha)-induced cell death. In addition, L929 cells forced to express SSI-1 (L929/SSI-1), but not SSI-3 or SOCS-5, are resistant to TNF-alpha-induced cell death. Furthermore L929/SSI-1 cells treated with TNF-alpha sustain the activation of p38 mitogen-activated protein (MAP) kinase. In contrast, SSI-1 -/- murine embryonic fibroblasts treated with TNF-alpha show hardly any activation of p38 MAP kinase. These findings suggest that SSI-1 suppresses TNF-alpha-induced cell death, which is mediated by p38 MAP kinase signaling.

A noxious stimulus induces the preprotachykinin-A gene expression in the rat dorsal root ganglion: a quantitative study using in situ hybridization histochemistry

Using in situ hybridization histochemistry, we examined the biosynthesis of the preprotachykinin-A (PPTA) mRNAs, which code for substance P (SP) and also a related peptide, substance K (SK), in the rat dorsal root ganglion (DRG). The animals were injected with a small amount of formalin in the right hindpaw for nociceptive chemical stimulation. Analysis of hybridization signals in the emulsion autoradiography showed that the lumbar-5 DRG neurons expressing PPTA mRNAs were significantly increased in number and signal intensity on the formalin-injected side. Such elevation of the PPTA mRNA expression in the DRG was observed as early as 3 h after formalin injection. These results show that the expression of the PPTA gene is activated by chemogenic noxious stimuli.

SOCS-1/SSI-1-deficient NKT cells participate in severe hepatitis through dysregulated cross-talk inhibition of IFN-gamma and IL-4 signaling in vivo

Suppressor of cytokine signaling-1 (SOCS-1), also known as STAT-induced STAT inhibitor-1 (SSI-1), is a negative feedback molecule for cytokine signaling, and its in vivo deletion induces fulminant hepatitis. However, elimination of the STAT1 or STAT6 gene or deletion of NKT cells substantially prevented severe hepatitis in SOCS-1-deficient mice, while administration of IFN-gamma and IL-4 accelerated its development. SOCS-1 deficiency not only sustained IFN-gamma/IL-4 signaling but also eliminated the cross-inhibitory action of IFN-gamma on IL-4 signaling. These results suggest that SOCS-1 deficiency-induced persistent activation of STAT1 and STAT6, which would be inhibited by SOCS-1 under normal conditions, may induce abnormal activation of NKT cells, thus leading to lethal pathological changes in SOCS-1-deficient mice.

Prospective trial of combined transcatheter arterial chemoembolization and three-dimensional conformal radiotherapy for portal vein tumor thrombus in patients with unresectable hepatocellular carcinoma

PURPOSE

We conducted a prospective trial of combined transarterial chemoembolization (TACE) and three-dimensional conformal radiotherapy (3D-CRT) for portal vein tumor thrombus (PVTT) in unresectable hepatocellular carcinoma (HCC). The aim of the present study was to investigate the efficacy and toxicity of this trial regime.

METHODS AND MATERIALS

Patients with unresectable HCC complicated with tumor thrombus in the first branch of portal vein were selected as eligible for this study. TACE was performed using Lipiodol, epirubicin hydrochloride, and mitomycin, followed by gelatin sponge cubes. The 3D-CRT was performed targeting the clinical target volume (CTV) defined as PVTT only to a total dose of 60 Gy using 10-MV accelerator.

RESULTS

A total of 19 patients were enrolled in this study. Survival rates at 1 and 2 years were 40.6% and 10.2%, respectively. The median survival time was 7.0 months. An objective response was observed in 11 of 19 cases (57.9%). Recanalization of the first portal branches was not observed; however, the protrusion of PVTT into the main portal trunk decreased in all cases. Growth of intrahepatic metastasis outside the 3D-CRT field was observed in 12 cases (63%). Deterioration of the Child-Pugh Score was observed in 5 of 6 cases with the percent volume of the total liver receiving a dose exceeding 30 Gy (V(30)) > or =40%, vs. 2 of 13 cases with a V(30) <40% (p < 0.01).

CONCLUSION

This combined therapy was feasible. Our results indicate that V(30) was a predictive test for deterioration of liver function. Further investigation of treatment modalities is needed to prevent the growth of intrahepatic metastasis.

Detoxification of cadmium in tobacco plants: formation and active excretion of crystals containing cadmium and calcium through trichomes

In tobacco (Nicotiana tabacum L.), long and short trichomes can be distinguished morphologically. The established function of long trichomes is to exude a sticky gum containing diterpenes, whereas that of short trichomes is not known. When tobacco seedlings were exposed to toxic levels of cadmium (Cd), growth was retarded, but trichome number was increased up to 2-fold in comparison with untreated samples. Observation by variable-pressure scanning electron microscopy (VP-SEM) indicated that large crystals of 150 microm in size were formed on head cells of both short and long trichomes. An energy-dispersive X-ray analysis system fitted with VP-SEM revealed the crystals to contain amounts of Cd and calcium (Ca) at much higher concentrations than in the head cells themselves. Transmission electron microscopy demonstrated crystal formation in amorphous osmiophilic deposits in vacuoles. When seedlings were treated with Cd in the presence of Ca, tolerance was increased in proportion to the increase in Ca concentration. These results indicate that tobacco plants actively exclude toxic Cd by forming and excreting Cd/Ca-containing crystals through the head cells of trichomes.

Production of interleukin-7 and interleukin-15 by fibroblast-like synoviocytes from patients with rheumatoid arthritis

OBJECTIVE

To examine the ability of fibroblast-like synoviocytes in rheumatoid arthritis (RA) to produce interleukin-7 (IL-7) and IL-15, and the ability of these cytokines to induce the proliferation of synovium-infiltrating T cells.

METHODS

Messenger RNA (mRNA) and protein levels of IL-7 and IL-15 in synovial tissue cells and fibroblast cell lines were determined by reverse transcriptase-polymerase chain reaction and enzyme-linked immunosorbent assay, respectively. T cell-enriched populations from RA synovial tissues were isolated by deleting adherent cells after a 14-hour incubation in plastic dishes or by expanding T cells during a 14-day incubation of tissue cells with IL-2 alone, and their proliferative responses to IL-7, IL-15, and IL-2 were measured by 3H-thymidine incorporation.

RESULTS

Freshly isolated cells from RA synovial tissues more strongly expressed mRNA for both IL-7 and IL-15 compared with the cells from osteoarthritis tissues, and could spontaneously release greater amounts of these cytokine proteins in culture. Fibroblast cell lines prepared from RA patients were able to produce large amounts of IL-15 and small amounts of IL-7 at both the transcriptional and protein levels, and their cytokine production was significantly elevated when stimulated with IL-1 and tumor necrosis factor alpha. Purified synovial tissue macrophages spontaneously released IL-15 but not IL-7, and synovial T cells did not produce either cytokine. IL-7 and IL-15, similar to IL-2, stimulated the proliferation of synovial tissue T cells from RA patients; IL-7 was less potent than IL-15 or IL-2.

CONCLUSION

These results indicated that fibroblast-like synoviocytes are an important source of the cytokines with IL-2-like activity, IL-15 and IL-7, in RA joints, and that IL-15 may be mainly responsible for local T cell activation and expansion in the presence of deficient IL-2 production by T cells.