Biomedical subjects

Tohru Sugimoto

Publications and source records attributed to Tohru Sugimoto.

At least 19 recordsLinked to original sources

PubMed2006

Murine neocortical histogenesis is perturbed by prenatal exposure to low doses of Bisphenol A.

Bisphenol A (BPA) has been shown to disrupt thyroid hormone function. We therefore studied whether prenatal exposure to low-doses of BPA affects the morphology and the expression of some genes related to brain development in the murine fetal neocortex. Pregnant mice were injected subcutaneously with 20 microg/kg of BPA daily from embryonic day 0 (E0). Control animals received vehicle alone. For evaluating cell proliferation, neuronal differentiation and migration, bromodeoxyuridine (BrdU) was injected intraperitoneally into pregnant mice with various regimens and the brains were processed for immunohistochemistry. The total RNA was extracted from the embryonic telencephalon at various embryonic stages. The BrdU-labeled cells examined 1 hour after BrdU injection showed no differences between the BPA-treated and control groups (n = 10, each), which indicated that the proliferation of precursor cells was not affected. The BrdU-labeled cells, analysed 2 days after BrdU injection, were decreased in the ventricular zone of BPA-treated mice at E14.5 and E16.5, whereas they were increased in the cortical plate at E14.5 as compared with those in control mice (n = 10, each). Furthermore, the expression of Math3, Ngn2, Hes1, LICAM, and THRalpha was significantly upregulated at E14.5 in the BPA-treated group. These results suggested that BPA might disrupt normal neocortical development by accelerating neuronal differentiation/migration.

Animals↗

PubMed2006

UT-B1 urea transporter plays a noble role as active water transporter in C6 glial cells.

Since our experimental results suggest that UT-B1 functions as active water transporter against osmotic gradient in C6 glial cells, we report here for the first time the evidence for the active water transport. Exposure of C6 cells to a hyperosmotic solution containing glycerol or sucrose produced cell shrinkage due to water efflux according to osmotic gradient for water movement. On the other hand, C6 cells show cell swelling against osmotic gradient for water movement just after exposure to a hyperosmotic solution containing urea, indicating that water influx against osmotic gradient for water movement is accelerated by urea; i.e., urea performs active water transport. A specific inhibitor of UT-B, pCMBS, blocked the urea-induced swelling. The urea-induced cell swelling was significantly suppressed in the siRNA-induced UT-B1-knockdown C6 cells. Taken together, these observations indicate that UT-B1 acts as an active water transporter, providing a new model on active water transport.

Animals↗

PubMed2006

High serum values of soluble CD154, IL-2 receptor, RANKL and osteoprotegerin in Langerhans cell histiocytosis.

BACKGROUND: To determine useful biochemical markers in Langerhans cell histiocytosis (LCH), we analyzed the serum levels of soluble CD154 (sCD154), IL2 receptor (sIL2-R), receptor activator of NF-kappaB ligand (sRANKL), and osteoprotegerin (OPG). PROCEDURE: Our study included 46 newly diagnosed LCH patients (single-system multi-site (SM type): n = 20, and multi-system multi-site (MM type): n = 26) who were treated with the JLSG-02 protocol between 2002 and 2004. The median age of the patients was 3.8 years old (range 0-18). sCD154, sIL2-R, sRANKL, and OPG were measured by ELISA at diagnosis (n = 46) and after 6-weeks of induction therapy (n = 14). RESULTS: The values of sCD154, sIL-2R, sRANKL, and OPG, and the sRANKL/OPG ratio in sera were significantly higher in patients with LCH compared with controls (1.83 +/- 1.38 vs. 0.22 +/- 0.16 ng/ml, P < 0.001; 1,600 +/- 1,060 vs. 420 +/- 160 pg/ml, P < 0.001; 1.72 +/- 1.20 vs. 1.04 +/- 1.09 pmol/L, P = 0.019; 6.34 +/- 2.94 vs. 3.71 +/- 2.03 pmol/L, P < 0.001; and 0.40 +/- 0.45 vs. 0.16 +/- 0.17, P = 0.023, respectively). Serum levels of sIL-2R were significantly elevated in the MM type compared with the SM type (2,050 +/- 1,060 vs. 870 +/- 340 pg/ml, P < 0.001). Serum OPG levels were also significantly elevated in the MM type compared with the SM type (7.58 +/- 2.72 vs. 5.13 +/- 2.69 pmol/L, P = 0.008) and negatively correlated with the number of bone lesions (r = -0.56, P = 0.007). In contrast, the sRANKL/OPG ratios were significantly higher in the SM type than the MM type (0.57 +/- 0.54 vs. 0.19 +/- 0.14, P = 0.002) and positively correlated with the number of bone lesions (r = 0.34, P = 0.040). In patients who responded to the induction therapy, serum levels of sIL-2R, sRANKL, and OPG, and the sRANKL/OPG ratio decreased significantly after the therapy (1,170 +/- 600 vs. 730 +/- 290 pg/ml, P = 0.029; 2.19 +/- 1.06 vs. 1.24 +/- 0.66 pmol/L, P < 0.001; 6.13 +/- 2.40 vs. 4.72 +/- 2.03 pmol/L, P = 0.040; and 0.57 +/- 0.52 vs. 0.41 +/- 0.37, P = 0.02, respectively). In the three patients who did not respond to the induction therapy, the serum levels of sCD154 increased significantly after the therapy (1.3 +/- 1.1 vs. 2.7 +/- 1.2, P = 0.004). CONCLUSIONS: Serum levels of sIL-2R and sCD154 could be useful as indicators of inflammation and sRANKL/OPG ratios as markers of osteolytic activity in LCH patients.

Adolescent↗

PubMed2006

Irinotecan for children with relapsed solid tumors.

Irinotecan is expected to become a new drug for childhood solid tumors. Sixteen children with relapsed solid tumors received irinotecan 180 mg/m2/day for 3 consecutive days, repeated once after 25 days off. Their original tumors were neuroblastoma in 7, rhabdomyosarcoma in 3, nephroblastoma and undifferentiated sarcoma in 2 each, and primitive neuroectodermal tumor and leiomyosarcoma in 1 each. The average age at trials was 6 years. Partial response was achieved in 5 (31.3%) (neuro-blastoma, rhabdomyosarcoma, nephroblastoma, undifferentiated sarcoma, and leiomyosarcoma), and decrease in tumor marker in the other 2. Irinotecan appears promising, and could become included in the first-line treatment.

Camptothecin↗

PubMed2006

Features and prognoses of infantile patients with atopic dermatitis hospitalized for severe complications.

Although atopic dermatitis (AD) itself is regarded as a non-life threatening disease, childhood AD may be rarely accompanied by some serious complications. Six infantile AD patients who were hospitalized because of severe systemic complications, in addition to severe dermatitis on almost the entire body surface, are described. They were complicated by hypoproteinemia, hypovolemia, thrombocytosis, reduced serum immunoglobulin G, elevated serum liver enzymes and growth retardation. They had not been treated with topical corticosteroid before hospitalization. They were treated with topical corticosteroid and their eruption remarkably improved within 20 days (median) of hospitalization. Most of the abnormal clinical data including platelet numbers, serum levels of total protein, and liver enzymes had become normal at the day of discharge. After 30 +/- 4 months of follow up, their skin condition was fair with daily application of moisturizer and occasional use of topical corticosteroid, without any systemic problems. Although severe infantile AD may be accompanied by potentially life-threatening systemic complications, their prognoses concerning AD are favorable if they are treated adequately from the beginning of their infancy.

Administration, Cutaneous↗

PubMed2006

SCN1A mutation mosaicism in a family with severe myoclonic epilepsy in infancy.

PURPOSE: To investigate the genetic background of familial severe myoclonic epilepsy in infancy (SMEI) cases. METHODS: We performed mutation analyses of the sodium-channel gene SCN1A in two Japanese brothers with clinical features of SMEI and their parents, who had no history of febrile and epileptic seizures. RESULTS: Each patient showed nucleotide changes (c.[730G>T; 735G>T; 736A>T]) in the coding exon 6 of SCN1A that led to a truncation of the channel protein. Their father showed no mutations, but their mother showed the same mutation in a subpopulation of lymphocytes. CONCLUSIONS: The maternal mosaicism explains the identical SCN1A mutations in the two brothers. This highlights the importance of investigating parental mosaicism even in sporadic SMEI cases.

Child, Preschool↗

PubMed2006

A novel perforin gene mutation in a Japanese family with hemophagocytic lymphohistiocytosis.

A 4-month-old girl with clinical features of hemophagocytic lymphohistiocytosis (HLH) was successfully treated with immunochemotherapy but died at the age of 1 year and 3 months, before hematopoietic stem cell transplantation could be performed. Her family history showed death during infancy of the eldest sister, suggesting a diagnosis of familial HLH (FHL). Direct sequencing of the DNA extracted from the patient's spleen tissue obtained at autopsy revealed a novel perforin gene mutation: a homozygous 1289G insertion (Asp430 frameshift and termination at amino acid residue 457), which has not previously been reported in FHL patients.

DNA Mutational Analysis↗

PubMed2006

A novel synthetic drug, LB-18, closely related to lembehyne-A derived from a marine sponge, induces caspase-independent cell death to human neuroblastoma cells.

Neuroblastoma is a common solid tumor of children that arises from the sympathetic nervous system. Much work has consequently focused on the possibility of inducing marked cell death in neuroblastoma, and the new effective drugs are required. We have newly synthesized LB-18, closely related to lembehyne A (LB-A), a polyacetylene derived from a kind of marine sponge. LB-A has been shown to induce p21/WAF1 and causes G1 phase arrest in mouse neuroblastoma Neuro2A cells; however, we show here that LB-18 causes cell death in human neuroblastoma KP-N-TK cells in a dose-dependent manner. TUNEL assay and flow cytometric analysis showed that the cell death caused by LB-18 was associated with the DNA damage but the pan-caspase inhibitor, zVAD-fmk, could not prevent the cell death. Western blot analysis and cleavage of the caspase-3 or -7 substrate assay showed that LB-18 could not activate caspases 3, 7, 8 and 9. These results suggest that LB-18 causes caspase-independent cell death in human neuroblastoma cells. In the future, LB-18 may be useful for cancer therapeutics, especially for neuroblastoma.

Alkynes↗

PubMed2005

Methylation-associated silencing of the nuclear receptor 1I2 gene in advanced-type neuroblastomas, identified by bacterial artificial chromosome array-based methylated CpG island amplification.

To identify genes whose expression patterns are altered by methylation of DNA, we established a method for scanning human genomes for methylated DNA sequences, namely bacterial artificial chromosome array-based methylated CpG island amplification (BAMCA). In the course of a program using BAMCA to screen neuroblastoma cell lines for aberrant DNA methylation compared with stage I primary neuroblastoma tumors, we identified CpG methylation-dependent silencing of the nuclear receptor 1I2 (NR1I2) gene. NR1I2 was methylated in a subset of neuroblastoma cell lines and also in advanced-stage primary tumors with amplification of MYCN. Its methylation status was inversely associated with gene expression. Treatment with the demethylating agent 5-aza-2'-deoxycytidine restored NR1I2 transcription in neuroblastoma cell lines lacking endogenous expression of this gene. A CpG island located around exon 3 of NR1I2 showed promoter activity, and its methylation status was clearly and inversely correlated with NR1I2 expression status. The gene product, NR1I2, has a known function in regulating response to xenobiotic agents but it also suppressed growth of neuroblastoma cells in our experiments. We identified some possible transcriptional targets of NR1I2 by expression array analysis. The high prevalence of NR1I2 silencing by methylation in aggressive neuroblastomas, together with the growth-suppressive activity of NR1I2, suggests that this molecule could serve as a diagnostic marker to predict prognosis for neuroblastomas.

Cell Line, Tumor↗

PubMed2005

Quercetin and NPPB-induced diminution of aldosterone action on Na+ absorption and ENaC expression in renal epithelium.

In renal epithelial A6 cells, aldosterone applied for 24 h increased the transepithelial Cl- secretion over 30-fold due to activation of the Na+/K+/2Cl- cotransporter and stimulated the transepithelial Na+ absorption, activity of epithelial Na+ channel (ENaC), and alpha-ENaC mRNA expression. The stimulatory action of aldosterone on the transepithelial Na+ absorption, ENaC activity, and alpha-ENaC mRNA expression was diminished by 24h-pretreatment with quercetin (an activator of Na+/K+/2Cl- cotransporter participating in Cl- entry into the cytosolic space) or 5-nitro 2-(3-phenylpropylamino)benzoate (NPPB) (a blocker of Cl- channel participating in Cl- release from the cytosolic space), while 24h-pretreatment with bumetanide (a blocker of Na+/K+/2Cl- cotransporter) enhanced the stimulatory action of aldosterone on transepithelial Na+ absorption. On the other hand, under the basal (aldosterone-unstimulated) condition, quercetin, NPPB or bumetanide had no effect on transepithelial Na+ absorption, activity of ENaC or alpha-ENaC mRNA expression. These observations suggest that although aldosterone shows overall its stimulatory action on ENaC (transepithelial Na+ transport), aldosterone has an inhibitory action on ENaC (transepithelial Na+ transport) via activation of the Na+/K+/2Cl- cotransporter, and that modification of activity of Cl- transporter/channel participating in the transepithelial Cl- secretion influences the aldosterone-stimulated ENaC (transepithelial Na+ transport).

Absorption↗

PubMed2005

Diversity in neuroblastomas and discrimination of the risk to progress.

The clinical diversity of Neuroblastomas (NBs) was discriminated into three groups with high sensitivity and specificity to patient's outcome. The 'high risk' NB is defined with any of following conditions, MYCN amplification or unfavorable histology of International Neuroblastoma Pathological Classification (INPC) or low Ha-ras/trk A expression. The 'low risk' NB is defined with all following conditions, single copy of MYCN and INPC favorable histology and high Ha-ras/trk A expression and localized tumor. The remaining NBs were classified into 'intermediate risk' ones. According to these criteria, the diversity of the 248 mass-screening NBs was shown with variety progressive risk; 40% were classified in low risk group, 25% were in high risk group and 35% were in intermediate risk group.

Disease Progression↗

PubMed2005

Prediction of MYCN amplification in neuroblastoma using serum DNA and real-time quantitative polymerase chain reaction.

PURPOSE: MYCN amplification (MNA) indicates a poor prognosis in neuroblastoma (NB) and is routinely assayed for therapy stratification. We aimed to develop a diagnostic tool to predict MYCN status using serum DNA, which, in cancer patients, predominantly originates from tumor-released DNA. PATIENTS AND METHODS: Using DNA-based real-time quantitative polymerase chain reaction, we simultaneously quantified MYCN (2p24) and a reference gene, NAGK (2p12), and evaluated MYCN copy number as an MYCN/NAGK (M/N) ratio in 87 NB patients whose MYCN status had been determined by Southern blotting. Of these patients, 17 had MYCN-amplified NB, and 70 had nonamplified NB. RESULTS: The serum M/N ratio in the MNA group (median, 199.32; range, 17.1 to 901.6; 99% CI, 107.0 to 528.7) was significantly (P < .001) higher than the ratio in the non-MNA group (median, 0.87; range, 0.25 to 4.6; 99% CI, 0.82 to 1.26; Mann-Whitney U test). The sensitivity and specificity of the serum M/N ratio as a diagnostic test were both 100% when the serum M/N ratio cutoff was set at 10.0. Among six MNA patients whose clinical courses were followed, the serum ratios decreased to the normal range in the patients in remission (n = 3), whereas the ratios increased to high levels in the patients who relapsed (n = 2) or failed to achieve remission (n = 1). CONCLUSION: Measurement of the serum M/N ratio seems to be a promising method for accurately assessing MYCN status in NB, although a larger set of patients needs to be examined to confirm this result.

Adolescent↗

PubMed2005

Imaging analysis of mineralocorticoid receptor and importins in single living cells by using GFP color variants.

Mineralocorticoid receptor (MR) is a ligand-dependent transcription factor involved in gene regulation in association with another corticosteroid receptor, glucocorticoid receptor. In the absence of ligand, MR resides both in the cytoplasm and in the nucleus. Agonists increase the number of MRs residing in the nucleus. Importins are docking proteins for karyopherin-mediated binding of substrate in a nuclear import pathway. To investigate the interactions between MR and importins, we analyzed the subcellular distribution of MR and importins in response to ligand in living COS-1 cells, which do not express endogenous MR, by using fusion proteins labeled with different spectral variants of green fluorescent protein. In the cells coexpressing fluorescent protein-tagged (FP)-MR and FP-importin alpha, the proteins simultaneously moved into the nucleus from the cytoplasm upon activation with ligand treatment. In the cells coexpressing FP-MR and FP-importin beta, FP-MR moved into the nucleus from the cytoplasm, but the distribution of FP-importin beta was little changed upon ligand treatment. Analysis of a mutant of MR, in which nuclear localization signal (NLS) is inactivated, demonstrated that the intact NLS is necessary for the trafficking of MR related to importin alpha. This is the first visual evidence of the nuclear import of MR in association with importin alpha in single living cells.

Active Transport, Cell Nucleus↗

PubMed2005

Establishment of a cell line from a malignant rhabdoid tumor of the liver lacking the function of two tumor suppressor genes, hSNF5/INI1 and p16.

Malignant rhabdoid tumors (MRT) of the liver are rare. A few liver MRT cell lines have been established but none has been characterized in detail. Here we describe a new MRT cell line from the liver, which is designated MP-MRT-AN, and describe it in detail. Immunohistochemical assays detected the expression of vimentin and cytokeratin but they were negative for neurofilament, desmin, alpha-smooth muscle actin, alpha-sarcomeric actin, and smooth muscle myosin heavy chains SM1 and SM2. RT-PCR assays revealed that this cell line did not express smooth muscle myosin heavy chain isoforms or MyoD1. No aberration was identified in 22q by G-banded analysis; however, the hSNF5/INI1 gene, a suppressor gene of MRT that maps to 22q11.2, was homozygously deleted from exons 1 to 5 in this cell line. Furthermore, the expression of another tumor suppressor gene, p16 (CDKN2A), was not detected by RT-PCR. This raises the possibility that the aggressive phenotype of malignant rhabdoid tumors is caused by the loss of two or more tumor suppressor genes.

Animals↗

PubMed2005

Shared and distinct roles mediated through C-terminal subdomains of acute myeloid leukemia/Runt-related transcription factor molecules in murine development.

AML1/Runx1 is a frequent target of human leukemia-associated gene aberration and encodes a transcription factor with nonredundant biologic functions in initial development of definitive hematopoiesis, T-cell development, and steady-state platelet production. AML1/Runx1 and 2 closely related family genes, AML2/Runx3 and AML3/Runx2/Cbfa1, present in mammals, comprise the Runt-domain transcription factor family. Although they have similar structural and biochemical properties, gene-targeting experiments have identified distinct biologic roles. To directly determine the presence of functional overlap among runt-related transcription factor (Runx) family molecules, we replaced the C-terminal portion of acute myeloid leukemia 1 (AML1) with that derived from its family members, which are variable in contrast to conserved Runt domain, using the gene knock-in method. We found that C-terminal portions of either AML2 or AML3 could functionally replace that of AML1 for myeloid development in culture and within the entire mouse. However, while AML2 substituted for AML1 could effectively rescue lymphoid lineages, AML3 could not, resulting in a smaller thymus and lymphoid deficiency in peripheral blood. Substitution by the C-terminal portion of AML3 also led to high infantile mortality and growth retardation, suggesting that AML1 has as yet unidentified effects on these phenotypes. Thus, the C-terminal portions of Runx family members have both similar and distinct biologic functions.

Animals↗

PubMed2005

Infantile bilateral striatal necrosis associated with human herpes virus-6 (HHV-6) infection.

A 1-year-old female with acute bilateral striatal necrosis secondary to exanthema subitum associated with human herpesvirus 6 (HHV-6) infection is reported. The patient was previously healthy. She presented with progressive neurologic signs of oral dyskinesia and involuntary movements, after suffering from exanthema subitum. Initial magnetic resonance imaging (MRI) demonstrated abnormal signals in the bilateral striatal regions. In addition, the serum HHV-6 IgM class antibody level was significantly increased. The patient is thought to be the first case of HHV-6 infection related infantile bilateral striatal necrosis (IBSN).

Basal Ganglia Diseases↗

PubMed2005

Effects of fukutin deficiency in the developing mouse brain.

The major pathological change in Fukuyama-type congenital muscular dystrophy brain is polymicrogyria. Pathological studies of Fukuyama-type congenital muscular dystrophy brain indicated that protrusion of neurons into the subarachnoid space through breaches in the glia limitans-basal lamina complex is a cardinal pathogenic process in this condition. It remains undetermined, however, whether the defect causing this abnormal migration resides in the migrating neurons or in the glia limitans-basal lamina complex. To elucidate the pathogenesis of brain abnormalities in Fukuyama-type congenital muscular dystrophy, we analyzed histologically and immunohistochemically the developing forebrain in fukutin-deficient chimeric mice and compared it with that in controls (n=4 in each group). In chimeric embryos, ectopia became apparent as early as embryonic day 14, and laminar organization became progressively distorted. The basal lamina of the cortical surface in chimeras showed defects at E14, coinciding with the earliest time point at which ectopia were detected. Immunohistochemical analysis of glycosylated alpha-dystroglycan showed progressive defects coincidental with the disruption of the basal lamina. Neuronal migration was not affected in chimeras, as determined by detection of bromodeoxyuridine-labeled neurons. Extension of radial glial fibers was intact in chimeras. Taken together, disruption of the basal lamina, caused by the loss of interaction between hypoglycosylated alpha-dystroglycan and its ligands, plays a key role in the pathogenesis of cortical dysplasia in Fukuyama-type congenital muscular dystrophy.

Animals↗

PubMed2005

Cerebral thrombotic complications in adolescent leukemia/lymphoma patients treated with L-asparaginase-containing chemotherapy.

We described the cerebral thrombotic complications developed in 2 adolescent patients treated with L-asparaginase-containing regimens. For determining risk factors, we retrospectively analysed hemostatic markers in 19 pediatric patients with leukemia or lymphoma who were treated with either 1 of the 2 L-asparaginase-containing regimens; 11 were treated with VLP1 and the remaining 8 were treated with the VLAD protocol. The data indicated that low coagulation factors in association with increased plasma D-dimer levels during or post-L-asparaginase administration combined with fresh frozen plasma infusion might have activated coagulation processes in these patients. Careful management is required to prevent such episodes in patients with markedly decreased coagulation factors and increased D-dimer levels following L-asparaginase administration.

Adolescent↗