ETS family of genes in leukemia and Down syndrome

The human ETS2 and ERG genes are members of the ETS gene family, with sequence homology to the viral ets gene of the avian erythroblastosis retrovirus, E26. These genes are located on chromosome 21 and molecular genetic analysis of Down syndrome (DS) patients with partial trisomy 21 suggested that ETS2 may be a gene within the minimal DS genetic region. We have, in fact, been able to confirm the presence of the ETS2 gene dosage in triplicate occurring in occult human 21 chromosome abnormalities. It is known that ERG and ETS2 gene translocations occur in certain specific leukemias associated with defined chromosome rearrangements [e.g., t(8;21)]. Moreover, it is known that DS individuals are at greater risk for leukemic disease than their normal familial cohorts, implying that trisomy of that region of human chromosome 21 may play a role in the development of this type of neoplasia. The human ETS genes, first identified in our laboratory, are highly conserved, being found from lower organisms, like Drosophila and sea urchin, to humans. In mammals, the ETS genes are structurally distinct, located on separate chromosomes; they are transcriptionally active and differentially regulated. The ETS2 protein is phosphorylated and turns over with a half-life of approximately 20 min. After activation with the tumor promoter, TPA, the level of ETS2 elevates 5- to 20-fold. The properties of the ETS2 protein, such as nuclear localization, phosphorylation, rapid turnover, and response to protein kinase C, indicate that this protein belongs to a group of oncogene proteins thought to have regulatory functions in the nucleus. In the mouse thymus ets-1 and ets-2 are 8-10-fold higher, respectively, in the CD4+ subset than in other subsets examined, suggesting a role in T-cell development for these genes. Cells transfected with the cellular ets-2 gene, expressing higher levels of ets-2 products, showed a stimulated proliferation response, abolished their serum requirement and formed colonies in soft agar that could induce tumors in nude mice. Collectively, these data suggest that this family of genes might play a role in controlling specific steps of the signaling transduction pathway. Thus, the ETS genes, as other genes with homology to viral oncogenes, might be instrumental in regulating cellular growth and differentiation, as well as organismal development.

Oligoclonal expansion of circulating and tissue-infiltrating CD8+ T cells with killer/effector phenotypes in juvenile dermatomyositis syndrome

Although triggering by infectious agents and abnormal immune responses may play some role in the pathogenesis of juvenile dermatomyositis syndrome (JDMS), the precise mechanism of muscle destruction and vascular damage is largely unknown. In this study, we tried to elucidate the role of cytotoxic T cells in two patients with JDMS, who were diagnosed based on the characteristic symptoms, laboratory data, MRI findings and electromyographic patterns. Peripheral blood T cell phenotypes were determined by flow cytometry, using mAbs against specific T cell receptor (TCR) Vbetas. Complementarity-determining region3 (CDR3) size analysis was performed by gene scanning of CDR3 polymerase chain reaction (PCR) amplification products specific for each Vbeta. Subsequently, CDR3 nucleotide sequences were obtained after cloning of the predominant products. The distribution of lymphocytes infiltrating the muscle tissue was analysed by immunohistochemistry. In both patients examined, a unique combination of TCR Vbeta repertoires was increased within the CD8+ T cells. These subpopulations expressed a characteristic phenotype, indicating that they are memory/effector T cells with killer functions. At the same time, immunohistological and molecular biological examinations of the biopsied muscle samples revealed that identical CD8+ T cell clones with identical phenotypes/TCR Vbeta infiltrated within the inflammatory tissue, in particular around vessels. These findings indicate that oligoclonal expansion of CD8+ T cells plays a central role in the pathogenesis of muscle injury in the juvenile form of dermatomyositis syndrome and may provide a useful clinical parameter of disease activity and responsiveness to anti-inflammatory therapy.

Lack of clinical utility of minimal residual disease detection in allogeneic stem cell recipients with childhood acute lymphoblastic leukemia: multi-institutional collaborative study in Japan

The clinical utility of minimal residual disease (MRD) measurements following allogeneic stem cell transplantation (SCT) in childhood ALL is controversial. We therefore performed a multi-institutional study of MRD in bone marrow samples taken before SCT and at 1, 3, 6 and 12 months after SCT. Case-specific clonal rearrangements of IgH and TCR genes and expression levels of Wilms' tumor 1 (WT1) mRNA were determined by PCR or RT-PCR methods. In total, 95 cases met all criteria for analysis of informative IgH/TCR markers and quantitative WT1 mRNA expression levels. During the 2-year (median 414 days) study period, 20 patients relapsed. Although the proportion of patients with a positive IgH/TCR result before SCT was significantly reduced at 1 month after treatment (P<0.001), attesting the efficacy of SCT, serial measurements of IgH/TCR rearrangements did not correlate with leukemic relapse. Clonal switch was demonstrated in 11 of the 14 patients with bone marrow relapse, indicating that the poor predictive power of the MRD assay most likely reflected the loss of PCR targets. WT1 expression was not related to either MRD detection by IgH/TCR assays or to clinical leukemic relapse. The clinical value of serial MRD monitoring would be limited in ALL patients undergoing SCT.

Mapping of the QTL (quantitative trait locus) conferring partial resistance to leaf blast in rice cultivar Chubu 32

The rice cultivar Chubu 32 possesses a high level of partial resistance to leaf blast. The number and chromosomal location of genes conferring this resistance were detected by restriction fragment length polymorphism (RFLP) linkage mapping and quantitative trait locus (QTL) analysis. For the mapping, 149 F(3) lines derived from the cross between rice cultivar Norin 29, with a low level of partial resistance, and Chubu 32 were used, and their partial resistance to leaf blast was assessed in upland nurseries. A linkage map covering six chromosomes and consisting of 36 RFLP markers was constructed. In the map, only one significant QTL (LOD>2.0) for partial resistance was detected on chromosome 11. This QTL explained 45.6% of the phenotypic variation. The segregation ratio of the F3 lines was 3:1 for partial resistance to susceptibility. These results suggest that the partial resistance in Chubu 32 is controlled by a major gene.

Two cases of mosaic RhD blood-group phenotypes and paternal isodisomy for chromosome 1

We encountered a 22-year-old man (case 1) and a 23-year-old woman (case 2), both unrelated and healthy. They were mosaic for the Rh blood group phenotype: one erythrocyte population was D-positive and the other was D-negative. Flow cytometric analysis of density profile of RhD antigen in their erythrocytes, and cytogenetic analysis including in situ hybridization using an RHD/RHCE-containing PAC clone, excluded a deletion of the RHD/RHCE gene complex, but suggested the presence of cells with uniparental disomy for chromosome 1 (UPD1). Microsatellite marker analysis was performed in both probands and their family members. In case 1, the analysis with markers spanning the chromosome 1 revealed both maternal and paternal alleles in his peripheral blood leukocytes (PBL), Epstein-Barr virus-transformed lymphoblastoid cells (EBL), and buccal mucosal cells. However, only paternal alleles were detected in all of 50 individual pieces of his hair or hair-roots and all of five monoclonal cell lines cloned from his established EBL. There was no direct evidence of heterozygous, biparental alleles in these two tissues. The presence of maternal isodisomy 1 was not absolutely ruled out in other tissues examined in case 1. Similar results were obtained in case 2, showing biparental, disomic patterns in her PBL and in 15 of 20 pieces of her hair roots, and showing monoallelic patterns in the remaining five pieces of hair roots. Analysis with markers for other autosomes confirmed their biparental inheritance. These findings indicated that both cases had at least two cell populations, one population having paternal UPD1 (isodisomy 1), and another heterozygous, biparental disomy 1. We emphasize that isodisomy for chromosome 1 is not infrequent and may cause unusual RhD phenotype, as seen in cases we described.

Cytoprotective role of heme oxygenase (HO)-1 in human kidney with various renal diseases

BACKGROUND

We previously reported that glomerular changes in the renal specimen of a human case with heme oxygenase-1 (HO-1) deficiency were mild, but tubulointerstitial injury advanced progressively. This study examined the patterns of HO-1 production in the kidney in various renal diseases. Furthermore, the critical cytoprotective roles of HO-1 were evaluated in the kidney by comparing HO-1 production and expressions of carboxymethyllysine (CML) and pentosidine, both of which are markers of oxidative stress.

METHODS

Renal biopsy or autopsy materials were obtained from a total of 74 patients. Degrees of hematuria and proteinuria and the levels of urinary N-acetyl-beta-D-glucosaminidase (NAG), beta2-microglobulin (beta2m), and creatinine were evaluated. Immunohistochemical studies for HO-1, CML, and pentosidine expressions were performed with their specific antiserum.

RESULTS

HO-1 staining was observed within tubular epithelial cells in all of the renal diseases, but was not detected within intrinsic glomerular cells. HO-1 staining tended to be more intense within distal tubuli than in proximal tubuli. Within distal tubuli, there was no significant correlation between intensity of HO-1 staining and degree of hematuria or presence of proteinuria. Within proximal tubuli, HO-1 staining tended to be more intense with greater degrees of hematuria, presence of proteinuria, and moderate tubulointerstitial damage. Intense staining of CML and pentosidine was observed within renal tubular epithelial cells only in HO-1-deficient patients.

CONCLUSIONS

HO-1 plays important roles in protecting renal tubuli from oxidative injuries, as these cells are constantly exposed to various oxidative stresses. It is suggested that renal tubular epithelia are more susceptible to oxidative stress due to the lack of this critical enzyme in HO-1 deficiency.

Differential cellular targets of Epstein-Barr virus (EBV) infection between acute EBV-associated hemophagocytic lymphohistiocytosis and chronic active EBV infection

Unusual Epstein-Barr virus (EBV) infection into T or natural killer cells plays a pivotal role in the pathogenesis of acute EBV-associated hemophagocytic lymphohistiocytosis (EBV-HLH) and chronic active EBV infection (CAEBV). The precise frequency and localization of EBV genome in lymphocyte subpopulations especially within T-cell subpopulations are unclear in these EBV-related disorders. This study analyzed the frequency of EBV-infected cells in circulating lymphocyte subpopulations from 4 patients with acute EBV-HLH and 4 with CAEBV. EBV- encoded small RNA-1 in situ hybridization examination of peripheral blood lymphocytes showed a significantly higher frequency of EBV-infected cells of 1.0% to 13.4% in EBV-HLH and 1.6% to 25.6% in CAEBV, respectively. The patterns of EBV infection in lymphocyte subpopulations were quite different between acute EBV-HLH and CAEBV. EBV infection was predominant in CD8(+) T cells in all EBV-HLH patients, whereas the dominant EBV-infected cell populations were non-CD8(+) lymphocyte subpopulations in CAEBV patients. Phenotypical analysis revealed that EBV-infected cell populations from both EBV-HLH and CAEBV were activated. There was no predominance of any EBV substrain of latent membrane protein-1, EBV-associated nuclear antigen (EBNA)-1, and EBNA-2 genes between the 2 abnormal EBV-associated disorders, and self-limited acute infectious mononucleosis. These results showing differential virus-cell interactions between acute EBV-HLH and CAEBV indicated different pathogenic mechanisms against EBV infection between the 2 EBV-associated diseases, which accounts for the difference in clinical manifestations between the 2 diseases.

Mechanisms underlying extracellular ATP-evoked interleukin-6 release in mouse microglial cell line, MG-5

Microglia play various important roles in the CNS via the synthesis of cytokines. The ATP-evoked production of interleukin-6 (IL-6) and its intracellular signals were examined using a mouse microglial cell line, MG-5. ATP, but not its metabolites, produced IL-6 in a concentration-dependent manner. Although ATP activated two mitogen-activated protein kinases, i.e. p38 and extracellular signal-regulated protein kinase, only p38 was involved in the IL-6 induction. However, the activation of p38 was not sufficient for the IL-6 induction because 2'- and 3'-O-(4-benzoylbenzoyl) ATP, an agonist to P2X7 receptors, failed to produce IL-6 despite the fact that it activated p38. Unlike in other cytokines in microglial cells, P2Y rather than P2X7 receptors seem to have a major role in the IL-6 production by the cells. The ATP-evoked IL-6 production was attenuated by Gö6976, an inhibitor of Ca(2+)-dependent protein kinase C (PKC). The P2Y receptor responsible for these responses was insensitive to pertussis toxin (PTX) and was linked to phospholipase C. Taken together, ATP acting on PTX-insensitive P2Y receptors activates p38 and Ca(2+)-dependent PKC, thereby resulting in the mRNA expression and release of IL-6 in MG-5. This is a novel pathway for the induction of cytokines in microglia.

Differences in survival-promoting effects and intracellular signaling properties of BDNF and IGF-1 in cultured cerebral cortical neurons

Brain-derived neurotrophic factor (BDNF) and insulin-like growth factor-1 (IGF-1) act on various neurons of the CNS as neurotrophic factors promoting neuronal differentiation and survival. We examined the survival-promoting effects of BDNF and IGF-1 on serum deprivation-induced death in cultured cerebral cortical neurons, and compared the intracellular signaling pathways stimulated by BDNF and IGF-1 in the neurons. We found that the survival-promoting effect of BDNF was much weaker than that of IGF-1 in serum deprivation-induced death of cultured cortical neurons. We found no differences in the levels of phosphatidylinositol 3-kinase (PtdIns3-K) activity or Akt (also called PKB) phosphorylation induced by BDNF and IGF-1 in the cultured cortical neurons, although many reports suggest that PtdIns3-K and Akt are involved in survival promotion. In addition, phosphorylation signals of mitogen-activated protein kinase (MAPK) and cAMP responsive element-binding protein (CREB), which have also been reported to be involved in survival promotion, were stimulated by BDNF much more potently than by IGF-1. These results show that there may be, as yet unidentified, intracellular signaling pathways other than the PtdIns3-K-Akt, MAPK and CREB signaling, to regulate survival promotion. These unidentified signaling pathways may be responsible for the distinct strengths of the survival-promoting effects of BDNF and IGF-1.

A novel single-nucleotide polymorphism in the 3'-untranslated region of the human dihydrofolate reductase gene with enhanced expression

A novel single-nucleotide polymorphism (SNP), 829C-->T in the 3'-untranslated region of the human dihydrofolate reductase (DHFR) gene transcript, was identified in the study population of 37 patients with childhood leukemias/lymphomas and 83 healthy Japanese children. Frequencies of the DHFR 829C/C, 829C/T, and 829T/T genotypes were 83.8, 10.8, and 5.4%, respectively, in the cases and 74.7, 19.3, and 6.0% in the controls, showing no significant difference in genotype frequencies between the cases and controls. When determined by real-time quantitative reverse transcription-PCR analysis, the highest expression of the DHFR transcript was demonstrated in the samples with a DHFR 829T/T polymorphism (P < 0.001). Direct association of the presence of the SNP with methotrexate-related adverse events in each patient was not demonstrated in this limited analysis. These data suggest that the novel DHFR 829 polymorphism is associated with a positive role in gene expression and provide evidence of a functional SNP in the 3' regulatory region of the gene.

Analysis of tyrosine phosphorylation-dependent protein-protein interactions in TrkB-mediated intracellular signaling using modified yeast two-hybrid system

Activated receptor tyrosine kinases induce a large number of tyrosine phosphorylation-dependent protein-protein interactions through which they mediate their various ligand-exerted functions including regulation of proliferation, differentiation and survival. TrkB receptor tyrosine kinase activated by binding of brain-derived neurotrophic factor (BDNF) also stimulates various protein interactions in a tyrosine phosphorylation-dependent manner in neuronal cells. To examine tyrosine phosphorylation-dependent interactions stimulated by active TrkB, we developed a modified yeast two-hybrid system, which we call the yeast two-and-a-half-hybrid system. In this system, yeast was engineered to express a tyrosine kinase domain of TrkB as an effector, in addition to two fusion proteins with GAL4 DNA-binding and GAL4 activation domains as bait and prey proteins, respectively. Using this system with Shp2 as the bait, we demonstrated that Shp2 interacts directly with BIT/SHPS-1 (also called SIRP) and Grb2 depending on tyrosine phosphorylation mediated by TrkB. Furthermore, we screened an adult human brain cDNA library with the yeast two-and-a-half-hybrid system in order to identify other Shp2-binding proteins in TrkB-stimulated tyrosine phosphorylation signaling. We found that fibroblast growth factor receptor substrate 2beta (FRS2beta), also called SNT2, interacts with Shp2 dependently on TrkB-mediated tyrosine phosphorylation of FRS2beta/SNT2. Therefore, we show that the two-and-a-half-hybrid system is a powerful tool for studying tyrosine phosphorylation-dependent protein-protein interactions in intracellular signaling pathways stimulated by TrkB receptor tyrosine kinase.

Abnormal illness behavior of patients with functional somatic symptoms: relation to psychiatric disorders

Functional somatic symptoms are highly associated with hypochondriasis, anxiety, and depressive disorders. Despite the absence of an organic disorder, underlying psychological distress of patients with functional somatic symptoms may result in abnormal illness behavior such as inadequate treatment seeking or overuse of medical services. Using the Illness Behavior Questionnaire (IBQ), we examined the illness behavior of Japanese patients visiting a general medicine clinic whose physical symptoms were considered functional. We used the General Health Questionnaire-30 to classify patients with functional somatic symptoms as those with and without psychological distress. Patients with distress (n=35) reported more physical complaints and higher IBQ scores than did patients without distress (n=22). The IBQ profile of patients with psychological distress was identical to that of patients diagnosed with either hypochondriasis or major depression. The illness behavior of patients without psychological distress was indistinguishable from that of patients whose physical symptoms were attributed to organic disease. These results further support the hypothesis that functional somatic symptoms may be associated with hypochondriasis and major depression, the pathology of which may contribute to the development of abnormal illness behavior.

[Systemic lupus erythematosus presenting as a brainstem infarction and hemorrhage during treating retroperitoneal abscess: a case report]

We report a case of a brainstem infarction and hemorrhage seen in a 21-year-old female with systemic lupus erythematosus (SLE) during treating retroperitoneal abscess. SLE has been treated with prednisolone and mizoribine for 4 years. The patient with right back and lower abdominal pain visited our hospital. Computed tomography (CT) revealed retroperitoneal abscess over surrounding right kidney, horizontal part of duodenum and in front of psoas muscle. Drainage was done with indwelled right single J catheter and penrose drain. Retroperitoneal abscess was much smaller, but, post drainage day 17, high fever, unconsciousness, down-blood pressure and down-beat nystagmus appeared suddenly. Brain CT scan revealed a brainstem wide infarction and hemorrhage spot. Pulse therapy with steroid was done, however unfortunately the patient was dead after 6 days.

Role of endogenous ATP at the incision area in a rat model of postoperative pain

The aim of the present study is to characterize the role of endogenous ATP leaked from damaged cells in a rat model of postoperative pain using behavioural and immunocytochemical approaches. We found that systemic (i.v.) and local (incision area) administration of a P2 receptor antagonist, pyridoxalphosphate-6-azophenyl-2',4'-disulphonic acid (PPADS) before surgery significantly attenuated mechanical allodynia caused by an incision of the plantar surface of the hindpaw. Furthermore, PPADS significantly reduced the incision-evoked c-Fos protein expression, a marker of neuronal activity, in the dorsal horn of the spinal cord. The present findings suggest that excitatory signaling by endogenous ATP leaked from damaged cells via PPADS-sensitive P2 receptors is necessary for the induction of the postoperative pain characterized by mechanical allodynia.

Ultraviolet emission from a diamond pn junction

We report the realization of an ultraviolet light-emitting diode with the use of a diamond pn junction. The pn junction was formed from a boron-doped p-type diamond layer and phosphorus-doped n-type diamond layer grown epitaxially on the 111 surface of single crystalline diamond. The pn junction exhibited good diode characteristics, and at forward bias of about 20 volts strong ultraviolet light emission at 235 nanometers was observed and was attributed to free exciton recombination.

Negative regulatory role of Sp1 in metal responsive element-mediated transcriptional activation

Transcription of mammalian metallothionein (MT) genes is activated by heavy metals via multiple copies of a cis-acting DNA element, the metal-responsive element (MRE). Our previous studies have shown that certain MREs of the human MT-IIA gene (MREb, MREc, MREd, and MREf) are less active than the others (MREa, MREe, and MREg). Gel shift analysis of HeLa cell nuclear proteins revealed that whereas the active MREs strongly bind the transcription factor MTF-1 essential for metal regulation, the less active MREs bind another distinct protein, MREb-BF. This protein recognizes the GC-rich region of MREb rather than the MRE core required for MTF-1 binding. All the MREs recognized by MREb-BF contain the CGCCC and/or CACCC motif, suggesting that the MREb-BF.MRE complex contains Sp1 or related proteins. Supershift analysis using antibodies against Sp1 family proteins as well as gel shift analysis using the recombinant Sp1 demonstrated that Sp1 represents the majority of MREb-BF activity. An MREb mutant with reduced affinity to Sp1 mediated zinc-inducible transcription much more actively than the wild-type MREb. Furthermore, when placed in the native promoter, this mutant MREb raised the overall promoter activity. These results strongly suggest that Sp1 acts as a negative regulator of transcription mediated by specific MREs.

[Experience of direct hemoperfusion using polymyxin B-immobilized fiber on patients with endotoxin shock from urosepsis]

We report the effects of direct hemoperfusion using polymyxin B-immobilized fiber (PMX treatment) on two patients with endotoxin shock from urosepsis. In both cases, urosepsis caused by pyelonephritis from a ureteral stone progressed to endotoxin shock and disseminating intravascular coagulation (DIC). Single J catheter was indwelt in the ureter for the purpose of drainage before PMX treatment. Drainage of the origin of infection, using effective antibiotics and PMX treatment improved shock state and DIC earlier than we expected.