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1.
Experimental & Molecular Medicine ; : e226-2016.
Article in English | WPRIM | ID: wpr-137224

ABSTRACT

Wnt10b, an endogenous inhibitor of adipogenesis, maintains preadipocytes in an undifferentiated state by suppressing adipogenic transcription factors. We have previously demonstrated that Wnt10b transcription during adipogenesis is negatively regulated by X-box-binding protein 1 (XBP1), an important transcription factor of the unfolded protein response. In this report, we demonstrate that XBP1s can directly induce the transcription of microRNA-148a, which in turn mediates the silencing of Wnt10b mRNA during adipogenic differentiation of 3T3-L1 cells. Stability of Wnt10b mRNA was found to be significantly increased by knockdown of XBP1s. Using computational algorithms, a set of microRNAs was predicted to bind Wnt10b mRNA, of which microRNA-148a was selected as a potential target for XBP1s. Our results revealed that microRNA-148a could bind to the 3′UTR of Wnt10b mRNA. Its ectopic expression significantly suppressed both Wnt10b expression and β-catenin activity. When we altered the expression of XBP1 in 3T3-L1 cells, microRNA-148a levels changed accordingly. A potential XBP1 response element was found in the promoter region of microRNA-148a, and XBP1s directly bound to this response element as shown by point mutation analysis and chromatin immunoprecipitation assay. In addition, a microRNA-148a mimic significantly restored adipogenic potential in XBP1-deficient 3T3-L1 cells. These findings provide the first evidence that XBP1s can regulate Wnt10b by a post-transcriptional mechanism through directly inducing microRNA-148a.


Subject(s)
3T3-L1 Cells , Adipogenesis , Chromatin Immunoprecipitation , Ectopic Gene Expression , MicroRNAs , Point Mutation , Promoter Regions, Genetic , Response Elements , RNA, Messenger , Transcription Factors , Unfolded Protein Response
2.
Experimental & Molecular Medicine ; : e226-2016.
Article in English | WPRIM | ID: wpr-137221

ABSTRACT

Wnt10b, an endogenous inhibitor of adipogenesis, maintains preadipocytes in an undifferentiated state by suppressing adipogenic transcription factors. We have previously demonstrated that Wnt10b transcription during adipogenesis is negatively regulated by X-box-binding protein 1 (XBP1), an important transcription factor of the unfolded protein response. In this report, we demonstrate that XBP1s can directly induce the transcription of microRNA-148a, which in turn mediates the silencing of Wnt10b mRNA during adipogenic differentiation of 3T3-L1 cells. Stability of Wnt10b mRNA was found to be significantly increased by knockdown of XBP1s. Using computational algorithms, a set of microRNAs was predicted to bind Wnt10b mRNA, of which microRNA-148a was selected as a potential target for XBP1s. Our results revealed that microRNA-148a could bind to the 3′UTR of Wnt10b mRNA. Its ectopic expression significantly suppressed both Wnt10b expression and β-catenin activity. When we altered the expression of XBP1 in 3T3-L1 cells, microRNA-148a levels changed accordingly. A potential XBP1 response element was found in the promoter region of microRNA-148a, and XBP1s directly bound to this response element as shown by point mutation analysis and chromatin immunoprecipitation assay. In addition, a microRNA-148a mimic significantly restored adipogenic potential in XBP1-deficient 3T3-L1 cells. These findings provide the first evidence that XBP1s can regulate Wnt10b by a post-transcriptional mechanism through directly inducing microRNA-148a.


Subject(s)
3T3-L1 Cells , Adipogenesis , Chromatin Immunoprecipitation , Ectopic Gene Expression , MicroRNAs , Point Mutation , Promoter Regions, Genetic , Response Elements , RNA, Messenger , Transcription Factors , Unfolded Protein Response
3.
Experimental & Molecular Medicine ; : 545-553, 2012.
Article in English | WPRIM | ID: wpr-211932

ABSTRACT

Brown adipose tissue is specialized to burn lipids for thermogenesis and energy expenditure. Second-generation antipsychotics (SGA) are the most commonly used drugs for schizophrenia with several advantages over first-line drugs, however, it can cause clinically-significant weight gain. To reveal the involvement of brown adipocytes in SGA-induced weight gain, we compared the effect of clozapine, quetiapine, and ziprasidone, SGA with different propensities to induce weight gain, on the differentiation and the expression of brown fat-specific markers, lipogenic genes and adipokines in a mouse brown preadipocyte cell line. On Oil Red-O staining, the differentiation was inhibited almost completely by clozapine (40 microM) and partially by quetiapine (30 microM). Clozapine significantly down-regulated the brown adipogenesis markers PRDM16, C/EBPbeta, PPARgamma2, UCP-1, PGC-1alpha, and Cidea in dose- and time-dependent manners, whereas quetiapine suppressed PRDM16, PPARgamma2, and UCP-1 much weakly than clozapine. Clozapine also significantly inhibited the mRNA expressions of lipogenic genes ACC, SCD1, GLUT4, aP2, and CD36 as well as adipokines such as resistin, leptin, and adiponectin. In contrast, quetiapine suppressed only resistin and leptin but not those of lipogenic genes and adiponectin. Ziprasidone (10 microM) did not alter the differentiation as well as the gene expression patterns. Our results suggest for the first time that the inhibition of brown adipogenesis may be a possible mechanism to explain weight gain induced by clozapine and quetiapine.


Subject(s)
Animals , Humans , Mice , Adipocytes, Brown/drug effects , Adipogenesis/drug effects , Adipokines/metabolism , Antipsychotic Agents/administration & dosage , Cell Differentiation/drug effects , Cell Line , Cell Survival/drug effects , Clozapine/administration & dosage , Dibenzothiazepines/administration & dosage , Gene Expression Regulation/drug effects , Piperazines/administration & dosage , Schizophrenia/drug therapy , Thiazoles/administration & dosage , Weight Gain/drug effects
4.
The Korean Journal of Pain ; : 126-129, 2012.
Article in English | WPRIM | ID: wpr-79403

ABSTRACT

Opioid analgesia is the primary pharmacologic intervention for managing pain. However, opioids can cause various adverse effects including pruritus, nausea, constipation, and sedation. Respiratory depression is the most fatal side effect. Therefore, cautious monitoring of respiratory status must be done after opioid administration. Here, we report a patient who suffered from respiratory depression with deep sedation and aspiration pneumonitis after intrathecal morphine administration.


Subject(s)
Humans , Analgesia , Analgesics, Opioid , Constipation , Deep Sedation , Morphine , Nausea , Pneumonia , Pruritus , Respiratory Insufficiency
5.
The Korean Journal of Physiology and Pharmacology ; : 149-156, 2011.
Article in English | WPRIM | ID: wpr-727888

ABSTRACT

Golgi SNAP receptor complex 1 (GS28) has been implicated in vesicular transport between intra-Golgi networks and between endoplasmic reticulum (ER) and Golgi. Additional role(s) of GS28 within cells have not been well characterized. We observed decreased expression of GS28 in rat ischemic hippocampus. In this study, we examined the role of GS28 and its molecular mechanisms in neuronal (SK-N-SH) cell death induced by hydrogen peroxide (H2O2). GS28 siRNA-transfected cells treated with H2O2 showed a significant increase in cytotoxicity under glutathione (GSH)-depleted conditions after pretreatment with buthionine sulfoximine, which corresponded to an increase of intracellular reactive oxygen species (ROS) in the cells. Pretreatment of GS28 siRNA-transfected cells with p38 chemical inhibitor significantly inhibited cytotoxicity; we also observed that p38 was activated in the cells by immunoblot analysis. We confirmed the role of p38 MAPK in cotransfected cells with GS28 siRNA and p38 siRNA in the cell viability assay, flow cytometry, and immunoblot. Involvement of apoptotic or autophagic processes in the cells was not shown in the cell viability, flow cytometry, and immunoblot analyses. However, pretreatment of the cells with necrostatin-1 completely inhibited H2O2-induced cytotoxicity, ROS generation, and p38 activation, indicating that the cell death is necroptotic. Collectively these data imply that H2O2 induces necroptotic cell death in the GS28 siRNA-transfected cells and that the necroptotic signals are mediated by sequential activations in RIP1/p38/ROS. Taken together, these results indicate that GS28 has a protective role in H2O2-induced necroptosis via inhibition of p38 MAPK in GSH-depleted neuronal cells.


Subject(s)
Animals , Rats , Buthionine Sulfoximine , Cell Death , Cell Survival , Endoplasmic Reticulum , Flow Cytometry , Glutathione , Hippocampus , Hydrogen , Hydrogen Peroxide , Imidazoles , Indoles , Methionine , Neurons , p38 Mitogen-Activated Protein Kinases , Reactive Oxygen Species , RNA, Small Interfering , SNARE Proteins
6.
Experimental & Molecular Medicine ; : 440-452, 2009.
Article in English | WPRIM | ID: wpr-196693

ABSTRACT

When we treated rat bone marrow stromal cells (rBMSCs) with neuronal differentiation induction media, typical unfolded protein response (UPR) was observed. BIP/GRP78 protein expression was time-dependently increased, and three branches of UPR were all activated. ATF6 increased the transcription of XBP1 which was successfully spliced by IRE1. PERK was phosphorylated and it was followed by eIF2alpha phosphorylation. Transcription of two downstream targets of eIF2alpha, ATF4 and CHOP/GADD153, were transiently up-regulated with the peak level at 24 h. Immunocytochemical study showed clear coexpression of BIP and ATF4 with NeuN and Map2, respectively. UPR was also observed during the neuronal differentiation of mouse embryonic stem (mES) cells. Finally, chemical endoplasmic reticulum (ER) stress inducers, thapsigargin, tunicamycin, and brefeldin A, dose-dependently increased both mRNA and protein expressions of NF-L, and, its expression was specific to BIP-positive rBMSCs. Our results showing the induction of UPR during neuronal differentiations of rBMSCs and mES cells as well as NF-L expression by ER stress inducers strongly suggest the potential role of UPR in neuronal differentiation.


Subject(s)
Animals , Mice , Rats , Activating Transcription Factor 4/genetics , Apoptosis/drug effects , Bone Marrow Cells/cytology , Cell Differentiation , Culture Media/pharmacology , Embryonic Stem Cells/cytology , Endoplasmic Reticulum/genetics , Gene Expression/drug effects , Heat-Shock Proteins/genetics , Microtubule-Associated Proteins/genetics , Molecular Chaperones/genetics , Nerve Tissue Proteins/genetics , Neurofilament Proteins/genetics , Neurons/cytology , Nuclear Proteins/genetics , Protein Folding , Stromal Cells
7.
The Korean Journal of Physiology and Pharmacology ; : 239-246, 2007.
Article in English | WPRIM | ID: wpr-728201

ABSTRACT

Expressions of endoplasmic reticulum stress response (ERSR) genes were examined during the neuronal differentiation of rat fetal cortical precursor cells (rCPC) and rat pheochromocytoma PC12 cells. When rCPC were differentiated into neuronal cells for 7 days, early stem cell marker, nestin, expression was decreased from day 4, and neuronal markers such as neurofilament-L, -M and Tuj1 were increased after day 4. In this condition, expressions of BIP, ATF6, and phosphorylated PERK as well as their down stream signaling molecules such as CHOP, ATF4, XBP1, GADD34, Nrf2 and p58IPK were significantly increased, suggesting the induction of ERSR during neuronal differentiation of rCPC. ERSR was also induced during the differentiation of PC12 cells for 9 days with NGF. Neurofilament-L transcript was time-dependently increased. Both mRNA and protein levels of Tuj1 were increased after the induction, and the significant increase in NeuN was observed at day 9. Similar to the expression patterns of neuronal markers, BIP/GRP78 and CHOP mRNAs were highly increased at day 9, and ATF4 mRNA was also increased from day 7. These results strongly suggest the induction and possible role of ERSR in neuronal differentiation process. Further study to identify targets responsible for neuronal induction will be necessary.


Subject(s)
Animals , Rats , Endoplasmic Reticulum Stress , Endoplasmic Reticulum , Nerve Growth Factor , Nestin , Neurons , PC12 Cells , Pheochromocytoma , Rivers , RNA, Messenger , Stem Cells
8.
Experimental & Molecular Medicine ; : 144-152, 2006.
Article in English | WPRIM | ID: wpr-15697

ABSTRACT

We have previously isolated a novel protein "B/K" that contains two C2-like domains. Here, we report the isolatioin and mRNA distribution of a human B/K isoform, and protein kinase A (PKA)-dependent phosphorylation of the B/K protein. The 1.5 kb human B/K cDNA clone exhibits 89% and 97% identities with rat B/K in the sequences of nucleotide and amino acid, respectively. Human B/K isoform encodes a 474 amino acid protein and shows structural features similar to the rat counterpart including two C2 domains, three consensus sequences for PKA, absence of a transmembrane region, and conservation of the N-terminal cysteine cluster. On Northern and dot blot analyses, a 3.0 kb B/K transcript was abundantly present in human brain, kidney, and prostate. Among the brain regions, strong signals were observed in the frontal and temporal lobes, the hippocampus, the hypothalamus, the amygdala, the substantia nigra, and the pituitary. Recombinant B/K proteins containing three consensus sites for PKA was very efficiently phosphorylated in vitro by PKA catalytic subunit. B/K protein which was overexpressed in LLC-PK1 cells was also strongly phosphorylated in vivo by vasopressin analog DDAVP, and PKA-specific inhibitor H89 as well as type 2 vasopressin receptor antagonist specifically suppressed DDAVP-induced B/K phosphorylation. These results suggest that B/K proteins play a role as potential substrates for PKA in the area where they are expressed.


Subject(s)
Rats , Mice , Male , Humans , Female , Animals , Adult , Sequence Homology, Amino Acid , Sequence Analysis, DNA , Protein Isoforms/genetics , Phosphorylation , Phosphoproteins/genetics , Molecular Sequence Data , Gene Expression Profiling , DNA, Complementary/chemistry , Cyclic AMP-Dependent Protein Kinases/physiology , Cloning, Molecular , Cell Line , Base Sequence , Amino Acid Sequence
9.
The Korean Journal of Physiology and Pharmacology ; : 275-282, 2005.
Article in English | WPRIM | ID: wpr-728719

ABSTRACT

By using differential display, we identified one of the genes encoding the multi-subunit complex protein V-ATPase, c subunit gene (ATP6L), and showed alterations of the gene expression by oxidative stresses. Expression of the ATP6L gene in Neuro-2A cells was increased by the treatment with H2O2 and incubation in hypoxic chamber, implying that the expression of the ATP6L gene is regulated by oxidative stresses. To examine mechanisms involved in the regulation of the gene expression by oxidative stresses, the transcriptional activity of the rat ATP6L promoter was studied. Transcription initiation site was determined by primer extension analysis and DNA sequencing, and promoter of the rat ATP6L and its deletion clones were constructed in reporter assay vector. Significant changes of the promoter activities in Neuro-2A cells were observed in two regions within the proximal 1 kbp promoter, and one containing a suppressor was in -195 to -220, which contains GC box that is activated by binding of Sp1 protein. The suppression of promoter activity was lost in mutants of the GC box. We confirmed by electrophoretic mobility shift and supershift assays that Sp1 protein specifically binds to the GC box. The promoter activity was not changed by the H2O2 treatment and incubation in hypoxic chamber, however, H2O2 increased the stability of ATP6L mRNA. These data suggest that the expression of the ATP6L gene by oxidative stresses is regulated at posttranscriptional level, whereas the GC box is important in basal activities of the promoter.


Subject(s)
Animals , Rats , Clone Cells , Gene Expression , Hydrogen Peroxide , Oxidative Stress , RNA, Messenger , Sequence Analysis, DNA , Transcription Initiation Site , Vacuolar Proton-Translocating ATPases
10.
The Korean Journal of Physiology and Pharmacology ; : 333-339, 2005.
Article in English | WPRIM | ID: wpr-728711

ABSTRACT

B/K protein is a novel protein containing double C2-like domains. We examined the specific signaling pathway that regulates the transcription of B/K in PC12 cells. When the cells were treated with forskolin (50microM), B/K mRNA and protein levels were time-dependently decreased, reaching the lowest level at 3 or 4 hr, and thereafter returning to the control level. Chemicals such as dibutyryl-cAMP, cell- permeable cyclic AMP (cAMP) analogue and CGS21680, adenosine receptor A2A agonist, also repressed the B/K transcription. However, 1, 9-dideoxyforskolin did not show inhibitory effect on B/K transcription, suggesting direct involvement of cAMP in the forskolin-induced inhibition of B/K transcription. Effect of forskolin, dibutyryl cAMP and CGS21680 was significantly reduced in PKA-deficient PC12 cell line (PC12-123.7). One cAMP-response element (CRE) -like sequence (B/K CLS) was found in the promoter region of B/K DNA, and electrophoretic mobility shift assay indicated its binding to CREM and CREB. Forskolin significantly suppressed the promoter activity in CHO-K1 cells transfected with the constructs containing B/K CLS, but not with the construct in which B/K CLS was mutated (AC: TG). Taken together, we suggest that the transcription of B/K gene in PC12 cells may be regulated by PKA-dependent mechanism.


Subject(s)
Animals , Colforsin , Cyclic AMP , Cyclic AMP-Dependent Protein Kinases , DNA , Electrophoretic Mobility Shift Assay , PC12 Cells , Promoter Regions, Genetic , Receptors, Purinergic P1 , RNA, Messenger
11.
Experimental & Molecular Medicine ; : 444-453, 2004.
Article in English | WPRIM | ID: wpr-76970

ABSTRACT

delta12-Prostaglandin (PG) J2 is known to elicit an anti-neoplastic effects via apoptosis induction. Previous study showed delta12-PGJ2-induced apoptosis utilized caspase cascade through cytochrome c-dependent pathways in HeLa cells. In this study, the cellular mechanism of delta12-PGJ2- induced apoptosis in HeLa cells, specifically, the role of two mitochondrial factors; bcl-2 and apoptosis-inducing factor (AIF) was investigated. Bcl-2 attenuated delta12-PGJ2-induced caspase activation, loss of mitochondrial transmembrane potential (delta psi m), nuclear fragmentation, DNA laddering, and growth curve inhibition for approximately 24 h, but not for longer time. AIF was not released from mitochondria, even if the delta psi m was dissipated. One of the earliest events observed in delta12-PGJ2-induced apoptotic events was dissipation of delta psi m, the process known to be inhibited by bcl-2. Pre-treatment of z-VAD- fmk, the pan-caspase inhibitor, resulted in the attenuation of delta psi m depolarization in delta12-PGJ2- induced apoptosis. Up-regulation of Sox-4 protein by delta12-PGJ2 was observed in HeLa and bcl-2 overexpressing HeLa B4 cell lines. Bcl-2 overexpression did not attenuate the expression of Sox-4 and its expression coincided with other apoptotic events. These results suggest that delta12-PGJ2 induced Sox-4 expression may activate another upstream caspases excluding the caspase 9-caspase 3 cascade of mitochondrial pathway. These and previous findings together suggest that delta12-PGJ2-induced apoptosis in HeLa cells is caspase-dependent, AIF-independent events which may be affected by Sox-4 protein expression up-regulated by delta12-PGJ2.


Subject(s)
Female , Humans , Amino Acid Chloromethyl Ketones/pharmacology , Antineoplastic Agents/pharmacology , Apoptosis/drug effects , Caspases/physiology , Cytochromes c/physiology , Flavoproteins/metabolism , HeLa Cells , High Mobility Group Proteins/physiology , Membrane Proteins/metabolism , Mitochondria/metabolism , Prostaglandin D2/pharmacology , Protein Transport/physiology , Proto-Oncogene Proteins c-bcl-2/biosynthesis , Transcriptional Activation , Trans-Activators/physiology
12.
The Korean Journal of Physiology and Pharmacology ; : 27-31, 2004.
Article in English | WPRIM | ID: wpr-728506

ABSTRACT

delta12-Prostaglandin J2 (delta12-PGJ2) is one of cyclopentenone prostaglandins. The delta12-PGJ2 is known to induce apoptosis of tumor cells, however, it's action mechanism is not clear. It has recently been reported that STAT3 is involved in tumorigenesis. In the present study, we investigated the role of STAT3-interacting protein (STIP1) in the cytotoxicity of delta12-PGJ2, since STIP1 was recently reported as a modulator of STAT3 activation by specifically binding to inactive (unphosphorylated) STAT3. The effect of delta12-PGJ2 was observed in stably overexpressing Neuro-2A cells transfected with full cDNA of STIP1, and cytotoxicity of delta12-PGJ2 in the transfected cells was increased, compared with the vector control cells. The cytotoxicity of delta12-PGJ2 treatment was significantly accentuated by pretreatment of the STIP1-transfected cells with protein kinase inhibitor, genistein, and less activation of STAT3 in STIP1-transfected cells was shown, compared with the vector control cells. Expression of bax was also increased in the STIP1-transfected cells. These data suggest that STIP1 inhibits cell growth via inhibition of STAT3 activation in delta12-PGJ2 treatment.


Subject(s)
Apoptosis , Carcinogenesis , Cell Death , DNA, Complementary , Genistein , Prostaglandins , Protein Kinases
13.
Experimental & Molecular Medicine ; : 293-300, 2003.
Article in English | WPRIM | ID: wpr-13853

ABSTRACT

Cyclopentenone prostaglandins (PGs) have antiproliferative activity on various tumor cell growth in vitro. Particularly, 9-deoxy-(9,12)-13,14-dihydro PGD2( delta12-PGJ2) was reported for its antineoplastic and apoptotic effects on various cancer cells, but its mechanism inducing apoptosis is still not clear. In this study, we have characterized apoptosis induced by delta12-PGJ2in HeLa cells. Treatment of delta12-PGJ2induced apoptosis as indicated by DNA fragmentation, chromatin condensation, and formation of apoptotic body. We also observed release of cytochrome c from mitochondria and activation of caspase cascade including caspase-3, -8, and -9. And the pan-caspase inhibitor z-Val-Ala-Asp (OMe) fluoromethyl-ketone (z-VAD-fmk) and Q-Val-Asp (OMe)-CH2-OPH (Q-VD (OMe)-OPH) prevented cell death induced by delta12-PGJ2 showing participation of caspases in this process. However, protein expression level of Bcl-2 family was not altered by delta12-PGJ2, seems to have no effect on HeLa cell apoptosis. And ZB4, an antagonistic Fas-antibody, exerted no effect on the activation of caspase 8 indicating that Fas receptor-ligand interaction was not involved in this pathway. Treatment of delta12-PGJ2 also leads to suppression of nuclear factor kappaB (NF-kappaB) as indicated by nuclear translocation of p65/RelA and c-Rel and its DNA binding ability analyzed by EMSA. Taken together, our results suggest that delta12-PGJ2-induced apoptosis in HeLa cell utilized caspase cascade without Fas receptor-ligand interaction and accompanied with NF-kappaB inactivation.


Subject(s)
Humans , fas Receptor/metabolism , Apoptosis/physiology , Caspases/metabolism , Cytochromes c/metabolism , HeLa Cells , NF-kappa B/metabolism , Prostaglandin D2/analogs & derivatives , Proto-Oncogene Proteins c-bcl-2/metabolism
14.
Experimental & Molecular Medicine ; : 243-249, 2002.
Article in English | WPRIM | ID: wpr-198787

ABSTRACT

We reported earlier that expression of Sox-4 was found to be elevated during prostaglandin (PG) A2 and delta(12)-PGJ(12) induced apoptosis in human hepatocarcinoma Hep3B cells. In this study, the role of Sox-4 was examined using human Hep3B and HepG2 cell lines. Sox-4 induction by several apoptotic inducer such as A23187 (Ca(2+) ionophore) and etoposide (topoisomerase II inhibitor) and Sox-4 transfection into the cells were able to induce apoptosis as observed by the cellular DNA fragmentation. Antisense oligonucleotide of Sox-4 inhibited the induction of Sox-4 expression and blocked the formation of DNA fragmentation by PGA(2) and delta(12)-PGJ(12) in Hep3B and HepG2 cells. Sox-4-induced apoptosis was accompanied with caspase-1 activation indicating that caspase cascade was involved in this apoptotic pathway. These results indicate that Sox-4 is involved in Hep3B and HepG2 cells apoptosis as an important apoptotic mediator.


Subject(s)
Humans , Apoptosis/drug effects , Blotting, Western , Calcimycin/pharmacology , Caspase 1/antagonists & inhibitors , Etoposide/pharmacology , Gene Expression Regulation, Neoplastic/drug effects , High Mobility Group Proteins/genetics , Liver Neoplasms/enzymology , Oligopeptides/pharmacology , Prostaglandin D2/analogs & derivatives , Prostaglandins A/pharmacology , Trans-Activators/genetics , Transfection , Tumor Cells, Cultured
15.
Experimental & Molecular Medicine ; : 284-292, 2001.
Article in English | WPRIM | ID: wpr-144630

ABSTRACT

3-Deazaadenosine (DZA), a cellular methylation blocker was reported to induce the caspase-3-like activities-dependent apoptosis in U-937 cells. In this study, we analyzed the activation pathway of the caspase cascade involved in the DZA-induced apoptosis using specific inhibitors of caspases. In the U-937 cells treated with DZA, cytochrome c release from mitochondria and subsequent activation of caspase-9, -8 and -3 were observed before the induction of apoptosis. zDEVD-Fmk, a specific inhibitor of caspase-3, and zLEHD-Fmk, a specific inhibitor of caspase-9, prevented the activation of caspase-8 but neither caspase-3 nor caspase-9, indicating that caspase-8 is downstream of both caspase-3 and caspase-9, which are activated by independent pathways. zVAD-Fmk, a universal inhibitor of caspases, kept the caspase-3 from being activated but not caspase-9. Moreover, ZB4, an antagonistic Fas-antibody, exerted no effect on the activation of caspase-8 and induction of apoptosis by DZA. In addition, zVAD-Fmk and mitochondrial permeability transition pore (MPTP) inhibitors such as cyclosporin A (CsA) and bongkrekic acid (BA) did not block the release of cytochrome c from mitochondria. Taken together, these results suggest that in the DZA-induced apoptosis, caspase-8 may serve as an executioner caspase and be activated downstream of both caspase-3 and caspase-9, independently of Fas receptor-ligand interaction. And caspase-3 seems to be activated by other caspses including IETDase-like enzyme and caspse-9 seems to be activated by cytochrome c released from mitochondria without the involvement of caspases and CsA- and BA- inhibitory MPTP.


Subject(s)
Humans , Amino Acid Chloromethyl Ketones/pharmacology , Apoptosis/drug effects , Bongkrekic Acid/pharmacology , Caspases/metabolism , Cell Line , Cyclosporine/pharmacology , Cytochromes c/drug effects , Enzyme Activation , Leukocytes, Mononuclear/cytology , Ligands , Membrane Glycoproteins/metabolism , Tubercidin/pharmacology , U937 Cells
16.
Experimental & Molecular Medicine ; : 284-292, 2001.
Article in English | WPRIM | ID: wpr-144618

ABSTRACT

3-Deazaadenosine (DZA), a cellular methylation blocker was reported to induce the caspase-3-like activities-dependent apoptosis in U-937 cells. In this study, we analyzed the activation pathway of the caspase cascade involved in the DZA-induced apoptosis using specific inhibitors of caspases. In the U-937 cells treated with DZA, cytochrome c release from mitochondria and subsequent activation of caspase-9, -8 and -3 were observed before the induction of apoptosis. zDEVD-Fmk, a specific inhibitor of caspase-3, and zLEHD-Fmk, a specific inhibitor of caspase-9, prevented the activation of caspase-8 but neither caspase-3 nor caspase-9, indicating that caspase-8 is downstream of both caspase-3 and caspase-9, which are activated by independent pathways. zVAD-Fmk, a universal inhibitor of caspases, kept the caspase-3 from being activated but not caspase-9. Moreover, ZB4, an antagonistic Fas-antibody, exerted no effect on the activation of caspase-8 and induction of apoptosis by DZA. In addition, zVAD-Fmk and mitochondrial permeability transition pore (MPTP) inhibitors such as cyclosporin A (CsA) and bongkrekic acid (BA) did not block the release of cytochrome c from mitochondria. Taken together, these results suggest that in the DZA-induced apoptosis, caspase-8 may serve as an executioner caspase and be activated downstream of both caspase-3 and caspase-9, independently of Fas receptor-ligand interaction. And caspase-3 seems to be activated by other caspses including IETDase-like enzyme and caspse-9 seems to be activated by cytochrome c released from mitochondria without the involvement of caspases and CsA- and BA- inhibitory MPTP.


Subject(s)
Humans , Amino Acid Chloromethyl Ketones/pharmacology , Apoptosis/drug effects , Bongkrekic Acid/pharmacology , Caspases/metabolism , Cell Line , Cyclosporine/pharmacology , Cytochromes c/drug effects , Enzyme Activation , Leukocytes, Mononuclear/cytology , Ligands , Membrane Glycoproteins/metabolism , Tubercidin/pharmacology , U937 Cells
17.
Experimental & Molecular Medicine ; : 197-203, 2000.
Article in English | WPRIM | ID: wpr-25123

ABSTRACT

3-Deazaadenosine (DZA), one of the potent inhibitors of S-adenosylhomocysteine hydrolase, is known to possess several biological properties including an induction of apoptosis. To evaluate a possibility that DZA may be utilized for the treatment of human leukemia, we studied molecular events of cell death induced by DZA in human leukemia HL-60 and U-937 cells. DZA induced a specific cleavage of poly ADP-ribose polymerase (PARP) and an activation of the cysteine protease caspase-3/CPP32 which is known to cleave PARP. DZA-mediated nuclear DNA-fragmentation was completely blocked in the presence of a universal inhibitor of caspases (z-VAD-fmk) or the specific inhibitor of caspase-3 (z-DEVD-fmk) unlike of cycloheximide (CHX). DNA fragmentation was preceded by the lowering of c-myc mRNA in the DZA treated cells. In addition, DZA-induced apoptosis was blocked by pretreatment with adenosine transporter inhibitors such as nitrobenzylthioinosine (NBTI) and dipyridamole (DPD). Taken together, these results demonstrate that DZA-induced apoptosis initiated through an active transport of DZA into human leukemia cells, is dependent on the caspase-3-like activity without de novo synthesis of proteins and possibly involves c-myc down-regulation.


Subject(s)
Humans , Adenosine/metabolism , Apoptosis , Biological Transport, Active , Carrier Proteins/metabolism , Caspases/metabolism , Down-Regulation , Enzyme Activation , Genes, myc , HL-60 Cells , Leukemia, Promyelocytic, Acute/drug therapy , Thioinosine/analogs & derivatives , Transcription Factors/genetics , Tubercidin/pharmacology , U937 Cells
18.
Tuberculosis and Respiratory Diseases ; : 1-10, 1995.
Article in Korean | WPRIM | ID: wpr-113090

ABSTRACT

BACKGROUND: It has been well known that bronchial asthma is a chronic inflammatory disorder. The "activation" of lymphocytes has a significant role in the pathogenesis of bronchial asthma. Among these lymphocytes, TH2-like rather than TH1-like lymphoytes are activated in the bronchial tissues from patients with atopic bronchial asthma. However, the difference of cytokines expression is not well documented between the atopic normal subjects and atopic asthmatics. METHODS: Bronchial tissues were obtained from the tweleve atopic and non-atpoic asthmatics and tweleve atopic and non-atopic healthy subjects for in stiu hybridizatin of IL-2, IL-4, IL-5, and INF-gamma. The probe of cytokines were tagged with digoxigenin by random priming method. RESULTS: The infiltration of many inflammatory cells on submucosa and denuded epithelium were observed in the bronchial tissue from patients with bronchial asthma. The RNase-treated bronchial tissues did not have the brown signal on the tissue, but, RNase-untreated bronchial tissues had the positive brown signal on the inflammatory cells under the basement membrane. The IL-2 positive signals were detected in 2 cases, IFN-gamma in 1 case, IL-4 in 2 cases, IL-5 in 2 cases among 6 non-atopic healthy subjects. The atopic healthy subjects showed 1 case of positive signal of IL-2 and IFN-gamma, but did not show any signals of IL-4 and IL-5. The positive signals of IL-2 were detected in 4 cases among 6 atopic and 6 non-atopic asthmatics, 2 cases and 1 case of IFN-gamma respectively, 4 cases and 3 cases of IL-4 respectively, 4 cases and 3 cases of IL-5 respectively. CONCLUSION: The lymphocytes were activated in the bronchus of asthmatics. Among lymphocytes, TH2-like lymphocytes may be involved in the pathogenesis of bronchial asthma. However, futher study with immunohistochemical stain may be necessary for defining the source of cytokines, because of TH2-like lymphocytes were also activated in some atopic healthy subjects.


Subject(s)
Humans , Asthma , Basement Membrane , Bronchi , Cytokines , Digoxigenin , Epithelium , Interleukin-2 , Interleukin-4 , Interleukin-5 , Lymphocytes
19.
Journal of the Korean Radiological Society ; : 751-756, 1995.
Article in Korean | WPRIM | ID: wpr-216188

ABSTRACT

PURPOSE: To observe sequential changes of acute and subacute hypersensitivity pneumonitis in high resolution CT and to correlate the findings with pulmonary function test and bronchoalveolar lavage. MATERIALS AND METHODS: This study includes 11 patients with pathologically (n=10) and clinically(n=1) proved acute and subacute hypersensitivity pneumonitis. The extent of ground glass attenuation and nodules on high resolution CT scan was correlated with pulmonary function test and bronchoalveolar lavage. We also evaluated serial changes of the lesion in high resolution CT scans. RESULTS: The extent of parenchymal abnormalities on high-resolution CT scans were significantly correlated with diffusing capacity (GGA & DLco:r=0.95, p<0.003, Nodule & DLco:r=-0.94, P<.005) and FEV1 (GGA & FEV1: r=-0.57, p<.05, Nodule & FEV1: r=-0.56, P<.05) on pulmonary function test and relatively correlated with total count of cells (GGA & total count of cells: r=0.86, P<.03, Nodule & total count of cells: r=0.71, p<0. 11) on bronchoalveolar lavage. The order in disappearance of abnormal findings were poorly defined centrilobular nodule, ground glass attenuation, and well defined small centrilobular nodule on sequential CT scans. CONCLUSION: The authors conclude that HRCT is useful for diagnosis and follow up evaluation of the acute and subacute hypersensitivity pneumonitis. Quantitative analysis of extent of disease on HRCT is useful for evaluation of clinical status.


Subject(s)
Humans , Alveolitis, Extrinsic Allergic , Bronchoalveolar Lavage , Diagnosis , Follow-Up Studies , Glass , Hypersensitivity , Respiratory Function Tests , Tomography, X-Ray Computed
20.
Korean Journal of Nephrology ; : 68-74, 1991.
Article in Korean | WPRIM | ID: wpr-50061

ABSTRACT

No abstract available.


Subject(s)
Histamine , Pruritus
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