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Biomedical subjects

Hoon Han

Publications and source records attributed to Hoon Han.

36 records · Page 2Linked to original sources
PubMed2003

Amyloid beta peptide (Abeta42) activates PLC-delta1 promoter through the NF-kappaB binding site.

The abnormal deposition of amyloid beta peptide (Abeta) is a hallmark of Alzheimer's disease (AD). Phospholipase C-delta1 (PLC-delta1) is also known to abnormally accumulate in the brains of AD patients, but no report has addressed the relationship between these two events. This study investigated the effect of Abeta42 on the PLC-delta1 expression in human neuroblastoma cell lines. The PLC-delta1 mRNA level was increased by treatment with Abeta42 in a RT-PCR analysis. In the reporter assay, Abeta42 was found to activate the PLC-delta1 promoter activity in a dose-dependent manner. A novel NF-kappaB binding site in the PLC-delta1 promoter appeared to be responsible for the Abeta42 activity. First, the dominant negative forms of the NF-kappaB activating molecules, dominant negative TGF-beta activated kinase 1 (dnTAK1) and dnNIK (dominant negative NF-kappaB-inducing kinase), abolished the Abeta42 activity in the reporter assay. Second, the Abeta42 augmented a factor binding on the NF-kappaB site in the electrophoretic mobility shift assay (EMSA), which was abolished by a molar excess of the unlabeled consensus NF-kappaB oligonucleotide. These results suggest that the PLC-delta1 promoter is under the control of NF-kappaB, which mediates the expression of PLC-delta due to the Abeta42 treatment.

Amyloid beta-Peptides↗
PubMed2003

Ru-catalyzed hydroamidation of alkenes and cooperative aminocarboxylation procedure with chelating formamide.

[reaction: see text] A strategy of chelation-assisted activation of formamide was employed to achieve hydroamidation of alkenes to generate one-carbon-elongated amides in moderate to good selectivity and yields. Also reported is the two-metal-catalyzed cooperative aminocarboxylation of aryl iodides, in which Ru is presumed to catalyze decarbonylation of formamide to release carbon monoxide and amine for the subsequent Pd-catalyzed aminocarboxylation routes, thus enabling the net transformation to be performed in the absence of external CO pressure.

Journal Article↗
PubMed2003

TNFB polymorphism may be associated with schizophrenia in the Korean population.

This study was conducted to test the association between the tumor necrosis factor (TNF)-beta gene (B) polymorphism and schizophrenia in the Korean population. 127 patients with schizophrenia according to the DSM-IV criteria and 202 healthy controls were enrolled in this study. Patients and controls were biologically unrelated age and sex-matched native Koreans. Genotyping for the TNFB polymorphism was performed by polymerase chain reaction-restriction fragment length polymorphism. Genotype and allele distributions of the TNFB polymorphism in patients with schizophrenia were significantly different from those of the controls. Subjects with the TNFB*2 allele had an increased risk for schizophrenia (Odds Ratio=1.76, 95% CI=1.27-2.45). The present study suggests that the TNFB polymorphism may confer susceptibility to schizophrenia in the Korean population.

Adult↗
PubMed2003

Tumor necrosis factor-beta gene polymorphism may not be associated with major depressive disorder in the Korean population.

Tumor necrosis factor (TNF)-beta has been implicated in the regulation of immune system. Alterations of the immune system in patients with major depressive disorder (MDD) have been also proposed to date. The present study was undertaken to investigate whether TNF-beta gene polymorphism is associated with MDD in the Korean population. Ninety-five patients with MDD who met the criteria of DSM-IV and 202 gender- and age-matched unrelated volunteers participated in the study. Genotyping for TNF-beta gene was performed by a polymerase chain reaction-restriction fragment length polymorphism method. The genotype and allele distribution in patients with MDD was similar to that of the controls. This study suggests that the TNF-beta gene polymorphism does not confer a susceptibility to MDD in the Korean population. A larger scaled study to examine different races is necessary to determine a role in the pathogenesis of MDD.

Adult↗
PubMed2003

Interleukin-10 gene promoter polymorphism is not associated with schizophrenia in the Korean population.

The present study was aimed at examining the interleukin (IL)-10 gene promoter region polymorphic variants in patients with schizophrenia in the Korean population. Two hundred and thirty-three Korean patients diagnosed to have schizophrenia on the basis of Diagnostic and Statistical Manual of Mental Disorders (4th edn; DSM-IV) and 181 normal healthy controls participated in the present study. The DNA was extracted from whole blood using proteinase K and the IL-10 gene promoter region was amplified by polymerase chain reaction. Gene typing was performed by restriction fragment length polymorphism and single-strand conformation polymorphism. Distribution of the alleles and haplotypes in patients with schizophrenia was not significantly different from those of controls. The present study suggests that IL-10 gene promoter polymorphism is not associated with the development of schizophrenia in the Korean population.

Genetic Predisposition to Disease↗
PubMed2003

Polymorphisms of interleukin-4 promoter and receptor gene for schizophrenia in the Korean population.

The purpose of the present paper was to investigate the interleukin (IL)-4 promoter gene -590 and receptor alpha (Ralpha) gene 1902 polymorphism in Korean schizophrenic patients. A total of 222 Korean patients diagnosed with schizophrenia according to Diagnostic and Statistical Manual of Mental Disorders (4th edn; DSM-IV) and 165 normal healthy controls participated in the present study. The DNA was extracted from whole blood using proteinase K, and the IL-4 promoter and receptor gene were amplified by polymerase chain reaction. The genotype was determined using single-strand conformation polymorphism (SSCP) analysis. The distribution of the alleles and genotypes in patients with schizophrenia was not significantly different from those of controls. In conclusion, these results suggest that the polymorphisms in IL-4 promoter gene -590 and IL-4 Ralpha gene 1902 are not involved in the pathophysiology of schizophrenia in the Korean population.

Adult↗
PubMed2003

Tumor necrosis factor-alpha gene polymorphism at position -308 and schizophrenia in the Korean population.

The purpose of the present study was to examine the association between the tumor necrosis factor (TNF)-alpha gene (A) polymorphism and schizophrenia in a Korean sample of schizophrenic patients and control subjects. Genotyping for the TNFA polymorphism was performed by polymerase chain reaction-restriction fragment length polymorphism. Genotype and allele distributions of the TNFA polymorphism between schizophrenic patients and controls were not significantly different. In the light of these results, the TNFA polymorphism seems not to confer susceptibility to the pathogenesis of schizophrenia, at least in the Korean population.

Adult↗
PubMed2003

Associations of Moyamoya patients with HLA class I and class II alleles in the Korean population.

Moyamoya disease is characterized by progressive cerebrovascular occlusion at the peripheral internal carotid artery and development of abnormal collateral circulation at the cerebral basal region. Although abnormal thrombogenesis, inflammation and autoimmune process might be involved in the etiology, the genetic pathogenesis of Moyamoya disease is still unknown. To evaluate the association of Moyamoya disease with HLA alleles in the Korean population, we investigated HLA class I and class II alleles in 28 Moyamoya patients and 198 unrelated healthy controls. The frequency of HLA-B35 allele was significantly increased in the patients compared to the controls (32.1% vs. 10.1%, RR=4.2, p<0.008). Further analysis of HLA-B35 on onset age and sex showed that this allele was significantly increased compared to the controls in both late-onset and female group. Especially, HLA-B35 was the most significantly increased in female of late-onset group compared to the controls. These results suggest that HLA-B35 may be an useful genetic marker for Moyamoya disease, and particularly in females of late onset group in the Korean population.

Adolescent↗
PubMed2002

Inhibition of ras-mediated activator protein 1 activity and cell growth by merlin.

The neurofibromatosis type2 (NF2) gene encodes an intracellular-associated protein that is referred to as either merlin or schwannomin. Merlin/Schwannomin is a tumor suppressor protein that has been reported to block the Ras-mediated cell proliferation and -anchorage-independent cell growth. However, its inhibitory mechanism is uncertain. In this report, merlin was demonstrated to be effective in suppressing Ras-induced foci-formation and its associated AP-1 activity in NIH3T3cells. In addition, merlin blocked Ras-induced Rb phosphorylation, and inhibited the increase of cyclin D1 levels. It also blocked E2F-1-dependent transcription. These results suggest that merlin inhibits abnormal cell proliferation which is activated via Ras by repressing Rb phosphorylation, blocking the increase of the cyclin D1 protein level, and inhibiting the activation of AP-1- and E2F-1-dependent transcription in NIH3T3 cells.

3T3 Cells↗
PubMed2002

Identification of the elements regulating the expression of the phospholipase C delta1.

Recently we cloned the phospholipase C deltal (PLC-delta1) promoter region and found that PLC-delta1 is selectively expressed in several tissues. In order to establish the common and cell-type specific transcriptional elements, 1.8 kilobase of the 5'-flanking region of PLC-delta1 was characterized in several cell lines. A transient transfection assay of the -1787-Luc construct in several cell lines demonstrated the potential transcriptional enhancement of reporter activities in the neuroblastoma cell [SK-N-BE(2)C] and kidney cell lines (Cos-7), but not in liver cell lines (Chang liver cell). Transient transfection assays of a series of 5' --> 3' deletion constructs of the PLC-delta1 promoter and electronic mobility shift assays suggested that the E-box and HFH3 binding sites are cell-type specific elements, and that Sp-1 is a major transcriptional activator of a majority of cell lines. Our findings, therefore, indicate that the combination of several elements within the 5'-flanking region of the PLC-delta1 gene dictates its restricted expression in several cell lines.

5' Flanking Region↗
PubMed2002

TAK1 mediates lipopolysaccharide-induced RANTES promoter activation in BV-2 microglial cells.

Lipopolysaccharide (LPS), a part of the outer membrane of gram-negative bacteria activates the expression of the regulated upon activation, normal T cell expressed and secreted (RANTES), which plays an important role in the chemo-attraction of leukocytes during the inflammatory response. Recently, we found that LPS-induced RANTES production is mediated by the activation of NF-kappaB, but, the upstream regulatory mechanism involved in mediating this NF-kappaB activation was unclear. In this study, we investigated signal transducing molecules that mediate LPS-induced RANTES promoter activation and found the followings. First, LPS activates the RANTES gene promoter through NF-kappaB binding sites. Second, the expression of dominant negative mutants of TGF-beta-activated kinasel (TAK1) and NF-kappaB-inducing kinase (NIK), blocked the LPS-induced transcriptional activation of RANTES promoter. Moreover, the overexpression of TAK1 along with TAK1-binding protein 1 (TAB1), or NIK stimulated the transcriptional activation of RANTES in the absence of external stimuli. Third, we showed that endogenous TAK1 is phosphorylated by LPS stimulation, and that the association between TAK1 and tumour necrosis factor receptor-associated factor 6 (TRAF6) is constitutive and not induced by LPS treatment. These results indicate that NF-kappaB mediates LPS-triggered RANTES induction and that TAK1 as well as NIK, as NF-kappaB activators participates in LPS-triggered RANTES induction.

Animals↗
PubMed2002

Polymorphism of CTLA-4 gene at position 49 of exon 1 may be associated with schizophrenia in the Korean population.

This study was carried out to investigate the association of a polymorphism of the CTLA-4 gene, at position 49 of exon 1, with schizophrenia in the Korean population. Among Korean patients diagnosed with schizophrenia according to DSM-IV, 116 patients who met the selection criteria were recruited for the study. One hundred and forty-nine normal healthy Koreans from the Catholic Hemopoietic Stem Cell Information Bank, were used as a normal control group. DNA was extracted from whole blood using proteinase K and the CTLA-4 gene region was amplified by polymerase chain reaction. Geneo typing was performed by single strand conformation polymorphism (SSCP). The genotype and allele distribution in patients with schizophrenia was significantly different from that seen in the control group. This study suggests a putative role of the CTLA-4 gene polymorphism at position 49 of exon 1 for schizophrenia in the Korean population, although the detailed mechanisms remained to be elucidated.

Abatacept↗
PubMed2002

The clinical implications of mixed lymphocyte reaction with leukemic cells.

To evaluate the clinical implications of a mixed lymphocyte reaction between leukemic cells and lymphocytes from HLA-matched sibling donors, we attempted to generate donor-derived, graft-versus-leukemia-effective cells and to define their characteristics. We studied 8 patients with chronic myelogenous leukemia (CML), including 5 patients in the chronic phase (CP), 3 patients in the accelerated phase (AP), and 2 patients with acute myelogenous leukemia (AML) in their first complete remission. Cells from these patients were used as stimulators in a mixed lymphocyte reaction.The effects of natural killer (NK) cells and cytotoxic T-lymphocytes (CTLs) were separated by observing tests for cytotoxicity to target cells, including K562 cells, the patient's leukemic cells, and phytohemagglutinin (PHA) blasts. Donor-derived antileukemic CTLs againstthe patient's own leukemic cells are productive in vitro. The efficacy of generating CTLs against leukemic target cells was (in decreasing order) AML, CML-CP, and CML-AP. Cytotoxic activity against leukemic targets was prominent in 4 cases--2 CML-CP and the 2 AML cases. On the contrary, the 3 cases of CML-AP showed low CTL activity. In cases showing 1 positive result among 3 targets (K562 cells, the patient's leukemic cells, and PHA blasts), the relapse rate was significantly lower (P = .022) on follow-up (median, 33 months; 7-40 months) after hematopoietic stem cell transplantation. By a combined analysis of the cytotoxicity effects for all 3 target cells, we were able to demonstrate a correlation between leukemic relapse and the variable degree of the cytotoxicity test results. Although the total sample numbers for this study were low, we speculate that these results may come from differences in the individual characteristics of the leukemic cells that are in line with their clinical disease status.

Cytotoxicity, Immunologic↗
PubMed2002

Report on IL-10 gene polymorphism at position -819 for major depression and schizophrenia in Korean population.

The present study was carried out to examine the relationship of interleukin (IL)-10 gene polymorphism at position -819 for major depression and schizophrenia in the Korean population. DNA was extracted from 92 Korean patients with major depression, 141 Korean patients with schizophrenia, and 146 ethnically matched controls. DNA was amplified by a polymerase chain reaction-based method and digested by MaeIII, and the restriction fragment length polymorphism of two alleles, IL-10*C and IL-10*T, were assessed. There were no significant differences in genotype frequencies of IL-10*T/T, IL-10*T/C, and IL-10*C/C as well as allelic frequencies of IL-10*T and IL-10*C between patients with major depression and controls in the Korean population. Comparison of genotype and allelic frequencies of IL-10 gene between patients with schizophrenia and controls were also not significant. The present study suggests that IL-10 gene polymorphism at position -819 does not confer susceptibility to major depression and schizophrenia, at least in the Korean population. Further systematic studies including various clinical variables would be required.

DNA↗
PubMed2002

Human leukocyte antigen alleles in patients with bipolar disorder in the Korean population.

We performed an association study between human leukocyte antigen (HLA) alleles and bipolar disorder to evaluate the potentiality of HLA as a genetic marker in bipolar disorder. HLA class I and class II allele frequencies were assessed in 87 bipolar patients and were compared with those of 206 normal controls in the Korean population. HLA class I typing was performed using the microlymphocytotoxicity method, whereas class II (DRB1 and DQB1) genotyping was performed with polymerase chain reaction-sequence specific oligonucleotide probes. When the allele frequency of HLA in bipolar patients was compared with that in normal controls, there were some significant differences. Bipolar patients showed statistically significant increased allele frequencies of HLA-A29 and B54. Allele frequencies of HLA-B51 and DRB1*02 were significantly higher in normal controls. However, these results were no longer significant after correcting for the number of alleles. The results of the present study suggest that HLA alleles may not confer susceptibility to bipolar disorder in the Korean population. To clarify the genetic influence of HLA on bipolar disorder, we should conduct a consecutive study with a larger cohort of subjects.

Adolescent↗
PubMed2001

Generation of Cytotoxic T Lymphocytes Specific for Human Cytomegalovirus Using Dendritic Cells In Vitro.

SUMMARY: For the adoptive immunotherapy in immunodeficient bone marrow transplant recipients to prevent and treat human cytomegalovirus (HCMV)-associated diseases, HCMV-pulsed dendritic cells (DCs) were used as antigen-presenting cells for the induction of cytotoxic T lymphocytes (CTLs) specific to HCMV antigens in vitro. The antiviral CTL responses induced by HCMV-pulsed DCs were as highly efficient as those induced by HCMV-infected dermal fibroblasts, and endogenous viral gene expression was not required to induce virus-specific T-cell lines. The strong cytotoxic activity against HCMV-pp65, known as HCMV major antigen, was identified using autologous B lymphoblastoid cell line expressing pp65 antigen. The cytotoxic activity toward HCMV-infected target cells was found to be mediated primarily by CD8+ T cells, although both CD8+ cells and CD4+ cells were able to lyse autologous virus-infected target cells. The CTLs contained a mixture of effector cells that recognized virus peptides in the context of major histocompatibility complex. This system may be useful for defining the cellular immune response to HCMV and for the treatment of HCMV infection in immunocompromised patients.

Journal Article↗
PubMed1985

A Human case of thelaziasis in Korea.

A case of thelaziasis in 36 year-old Korean woman who suffered from foreign body sensation of both eyes and itching of conjuctiva, was reported in August 1984. Four thread-like white worms was removed from cojunctival fornix of both eyes. This is the 12th case of thelaziasis in Korea(summarized from text).

Journal Article↗