Human pluripotent stem cell-derived hepatocytes have the potential to provide in vitro model syst... more Human pluripotent stem cell-derived hepatocytes have the potential to provide in vitro model systems for drug discovery and hepatotoxicity testing. However, these cells are currently unsuitable for drug toxicity and efficacy testing because of their limited expression of genes encoding drug-metabolizing enzymes, especially cytochrome P450 (CYP) enzymes. Transcript levels of major CYP genes were much lower in human embryonic stem cell-derived hepatocytes (hESC-Hep) than in human primary hepatocytes (hPH). To verify the mechanism underlying this reduced expression of CYP genes, including CYP1A1, CYP1A2, CYP1B1, CYP2D6, and CYP2E1, we investigated their epigenetic regulation in terms of DNA methylation and histone modifications in hESC-Hep and hPH. CpG islands of CYP genes were hypermethylated in hESC-Hep, whereas they had an open chromatin structure, as represented by hypomethylation of CpG sites and permissive histone modifications, in hPH. Inhibition of DNA methyltransferases (DNMTs...
In our previous study, Hwang-Ryun-Hae-Dok-Tang, which contains berberine (BBR) as a main active i... more In our previous study, Hwang-Ryun-Hae-Dok-Tang, which contains berberine (BBR) as a main active ingredient, inhibited cytochrome P450 (CYP) 2D6 in a quasi-irreversible manner. However, no information is available on the detailed mechanism of BBR-induced CYP2D6 inhibition. Thus, the present study aimed to characterize the inhibition mode and kinetics of BBR and its analogues against CYP2D6 using pooled human liver microsomes (HLM). BBR exhibited selective quasi-irreversible inhibition of CYP2D6 with inactivation rate constant (kinact) of 0.025 min−1, inhibition constant (KI) of 4.29 µM, and kinact/KI of 5.83 mL/min/µmol. In pooled HLM, BBR was metabolized to thalifendine (TFD), demethyleneberberine (DMB), M1 (proposed as demethylene-TFD), and to a lesser extent berberrubine (BRB), showing moderate metabolic stability with a half-life of 35.4 min and a microsomal intrinsic clearance of 7.82 µL/min/mg protein. However, unlike BBR, those metabolites (i.e., TFD, DMB, and BRB) were neithe...
Background: Meperidine has proved a far more effective treatment for shivering after spinal anest... more Background: Meperidine has proved a far more effective treatment for shivering after spinal anesthesia than equianalgesic doses of opioid agonist. We performed this prospective, double-blinded, randomized study to compare the antishivering effect of fentanyl and meperidine when added to intrathecal hyperbaric bupivacaine during Cesarean delivery under spinal anesthesia.
Background: Meperidine has proved a far more effective treatment for shivering after spinal anest... more Background: Meperidine has proved a far more effective treatment for shivering after spinal anesthesia than equianalgesic doses of opioid agonist. We performed this prospective, double-blinded, randomized study to compare the antishivering effect of fentanyl and meperidine when added to intrathecal hyperbaric bupivacaine during Cesarean delivery under spinal anesthesia.
Diethylstilbestrol (DES), a synthetic estrogen, was examined for genotoxicity in mouse testicular... more Diethylstilbestrol (DES), a synthetic estrogen, was examined for genotoxicity in mouse testicular Sertoli TM4 cells using an in vitro micronucleus assay and microarray analysis to clarify the molecular mechanisms underlying the genotoxicity of estrogenic compounds on the male reproductive system. The micronucleus test showed that DES induced genotoxic effects on TM4 cells with S9 activation. Gene expression profiles were studied in DES-treated cells and positive controls, which were cyclophosphamide (CPA)-treated TM4 cells, as compared to the negative controls. In total, 349 and 328 genes were identified as being either up- or down-regulated, with over 2-fold changes, in DES- and CPA-treated TM4 cells, respectively. Biofunction and canonical pathways of differentially expressed genes were analyzed using Ingenuity Pathways Analysis, which were mainly categorized as cellular development and growth/proliferation. In addition, genes related to cell cycle regulation, such as Egr1, Far1, Cd44, Wint16, Sox6, Sox14, Dnmt3a, and Hdac11, were differentially expressed in DES-treated TM4 cells. A gene network analysis was also performed. Comprehensive gene expression profiling of DES-treated TM4 cells provides valuable information to better understand the genotoxic events of estrogenic chemicals in testicular Sertoli cells.
Diethylstilbestrol (DES), a synthetic estrogen, was examined for genotoxicity in mouse testicular... more Diethylstilbestrol (DES), a synthetic estrogen, was examined for genotoxicity in mouse testicular Sertoli TM4 cells using an in vitro micronucleus assay and microarray analysis to clarify the molecular mechanisms underlying the genotoxicity of estrogenic compounds on the male reproductive system. The micronucleus test showed that DES induced genotoxic effects on TM4 cells with S9 activation. Gene expression profiles were studied in DES-treated cells and positive controls, which were cyclophosphamide (CPA)-treated TM4 cells, as compared to the negative controls. In total, 349 and 328 genes were identified as being either up- or down-regulated, with over 2-fold changes, in DES- and CPA-treated TM4 cells, respectively. Biofunction and canonical pathways of differentially expressed genes were analyzed using Ingenuity Pathways Analysis, which were mainly categorized as cellular development and growth/proliferation. In addition, genes related to cell cycle regulation, such as Egr1, Far1, Cd44, Wint16, Sox6, Sox14, Dnmt3a, and Hdac11, were differentially expressed in DES-treated TM4 cells. A gene network analysis was also performed. Comprehensive gene expression profiling of DES-treated TM4 cells provides valuable information to better understand the genotoxic events of estrogenic chemicals in testicular Sertoli cells.
Toxicogenomic approaches have been applied to chemical-induced heptocarcinogenesis rodent models ... more Toxicogenomic approaches have been applied to chemical-induced heptocarcinogenesis rodent models for the identification of biomarkers of early-stage hepatocarcinogenesis and to help clarify the underlying carcinogenic mechanisms in the liver. In this study, we used toxiciogenomic methods to identify candidate biomarker genes associated with hepatocarcinogenesis in rasH2 mice. Blood chemical, histopathologic, and gene expression analyses of the livers of rasH2 mice were performed 7 and 91 days after the administration of the genotoxic hepatocarcinogens 2-acetylaminofluorene (AAF) and diethylnitrosoamine (DEN), the genotoxic carcinogen melphalan (Mel), and the nongenotoxic noncarcinogen 1-naphthylisothiocynate (ANIT). Histopathologic lesions and a rise in accompanying serum marker levels were found in the DEN-treated rasH2 mice, whereas no neoplastic lesions were observed in the rasH2 mice. However, biological functional analysis using Ingenuity Pathways Analysis (IPA) software revealed that genes with comparable molecular and cellular functions were similarly deregulated in the AAF- and DEN-treated rasH2 mice. We selected 68 significantly deregulated genes that represented a hepatocarcinogen-specific signature; these genes were commonly deregulated in both the AAF- and DEN-treated rasH2 mice on days 7 and 91. Hierarchical clustering analysis indicated that the expression patterns of the selected genes in the hepatocarcinogen (AAF and DEN) groups were distinctive from the patterns in the control, Mel, and ANIT groups. Biomarker filter analysis using IPA software suggested that 28 of the 68 signature genes represent promising candidate biomarkers of cancer. Quantitative real-time PCR analysis confirmed that the deregulated genes, which exhibited sustained up- and down-regulation up to day 91, are likely involved in early-stage hepatocarcinogenesis. In summary, the common and significant gene expression changes induced by AAF and DEN may reflect early molecular events associated with hepatocarcinogenesis, and these “signature” genes may be useful as biomarkers of hepatocarcinogenesis in mice.
Toxicogenomic approaches have been applied to chemical-induced heptocarcinogenesis rodent models ... more Toxicogenomic approaches have been applied to chemical-induced heptocarcinogenesis rodent models for the identification of biomarkers of early-stage hepatocarcinogenesis and to help clarify the underlying carcinogenic mechanisms in the liver. In this study, we used toxiciogenomic methods to identify candidate biomarker genes associated with hepatocarcinogenesis in rasH2 mice. Blood chemical, histopathologic, and gene expression analyses of the livers of rasH2 mice were performed 7 and 91 days after the administration of the genotoxic hepatocarcinogens 2-acetylaminofluorene (AAF) and diethylnitrosoamine (DEN), the genotoxic carcinogen melphalan (Mel), and the nongenotoxic noncarcinogen 1-naphthylisothiocynate (ANIT). Histopathologic lesions and a rise in accompanying serum marker levels were found in the DEN-treated rasH2 mice, whereas no neoplastic lesions were observed in the rasH2 mice. However, biological functional analysis using Ingenuity Pathways Analysis (IPA) software revealed that genes with comparable molecular and cellular functions were similarly deregulated in the AAF- and DEN-treated rasH2 mice. We selected 68 significantly deregulated genes that represented a hepatocarcinogen-specific signature; these genes were commonly deregulated in both the AAF- and DEN-treated rasH2 mice on days 7 and 91. Hierarchical clustering analysis indicated that the expression patterns of the selected genes in the hepatocarcinogen (AAF and DEN) groups were distinctive from the patterns in the control, Mel, and ANIT groups. Biomarker filter analysis using IPA software suggested that 28 of the 68 signature genes represent promising candidate biomarkers of cancer. Quantitative real-time PCR analysis confirmed that the deregulated genes, which exhibited sustained up- and down-regulation up to day 91, are likely involved in early-stage hepatocarcinogenesis. In summary, the common and significant gene expression changes induced by AAF and DEN may reflect early molecular events associated with hepatocarcinogenesis, and these “signature” genes may be useful as biomarkers of hepatocarcinogenesis in mice.
An attempt has been made to identify molecular markers of intrahepatic cholestasis in mice employ... more An attempt has been made to identify molecular markers of intrahepatic cholestasis in mice employing phalloidin as a cholestatic agent. Phalloidin was administered to BALB/c mice at three predetermined dose: 250 microg/kg, 500 microg/kg, and 1 mg/kg for 1, 3, and 7 days. Liver function was estimated to confirm cholestasis. Histopathological observations on liver were also made to confirm liver injury. Phalloidin at 1 mg/kg for 7 days was found to induce cholestasis. Therefore gene expression studies were confined to this group only. A total of 88 genes were found to be affected by phalloidin. These were the genes associated with cytoskeleton regulation as well as tight junction, focal adhesion, and ATP-binding cassette transporters. Such proteins obstruct the removal of bile components from hepatocytes to the bile canaliculus or blood. Phalloidin treatment did not affect the proteins responsible for cell maintenance or death. The authors show that phalloidin-induced intrahepatic cholestasis is manifested by disturbing the cytoskeleton. The set of genes up-regulated by phalloidin can be considered as molecular markers of intrahepatic cholestasis. The observations are further expected to be helpful in the management of cholestatic pharmaceuticals and associated problems of liver diseases in humans.
An attempt has been made to identify molecular markers of intrahepatic cholestasis in mice employ... more An attempt has been made to identify molecular markers of intrahepatic cholestasis in mice employing phalloidin as a cholestatic agent. Phalloidin was administered to BALB/c mice at three predetermined dose: 250 microg/kg, 500 microg/kg, and 1 mg/kg for 1, 3, and 7 days. Liver function was estimated to confirm cholestasis. Histopathological observations on liver were also made to confirm liver injury. Phalloidin at 1 mg/kg for 7 days was found to induce cholestasis. Therefore gene expression studies were confined to this group only. A total of 88 genes were found to be affected by phalloidin. These were the genes associated with cytoskeleton regulation as well as tight junction, focal adhesion, and ATP-binding cassette transporters. Such proteins obstruct the removal of bile components from hepatocytes to the bile canaliculus or blood. Phalloidin treatment did not affect the proteins responsible for cell maintenance or death. The authors show that phalloidin-induced intrahepatic cholestasis is manifested by disturbing the cytoskeleton. The set of genes up-regulated by phalloidin can be considered as molecular markers of intrahepatic cholestasis. The observations are further expected to be helpful in the management of cholestatic pharmaceuticals and associated problems of liver diseases in humans.
1,3-Dinitrobenzene (1,3-DNB) specifically injures Sertoli cells and induces testicular toxicity b... more 1,3-Dinitrobenzene (1,3-DNB) specifically injures Sertoli cells and induces testicular toxicity by disrupting the key function of these cells. To clarify the molecular mechanism underlying 1,3-DNB’s action on Sertoli cells, we analyzed gene expression profiles of TM4 mouse Sertoli cells after chemical treatment. In total, 1,203 genes were identified as either up- or down-regulated, with greater than 1.5-fold changes (P<0.05). Based on k-means clustering, genes that were differentially expressed in a time-dependent manner were identified; then biofunction and canonical pathways were analyzed using Ingenuity Pathways Analysis. Genes related to axonal guidance, Nrf2-mediated oxidative stress response, protein ubiquitination, and tight junction signaling pathways were identified in either time-specifically or time-dependently regulated groups. The transcription levels of genes related to tight junction signaling pathways (Mpp5, F11r, Prkcz, Magi2, and Tgfb2) and genes encoding junction proteins (Ocln, Tjp1, Tjp2, Gja1, and Gjd2) were validated in 1,3-DNB-treated and 2,5-hexanedione-treated TM4 cells by quantitative real-time polymerase chain reaction. Comprehensive gene expression profiling of 1,3-DNB-treated TM4 cells and subsequent canonical pathway analyses provided valuable information regarding the molecular mechanism of cell death and cell interaction in TM4 mouse Sertoli cells after 1,3-DNB exposure.
1,3-Dinitrobenzene (1,3-DNB) specifically injures Sertoli cells and induces testicular toxicity b... more 1,3-Dinitrobenzene (1,3-DNB) specifically injures Sertoli cells and induces testicular toxicity by disrupting the key function of these cells. To clarify the molecular mechanism underlying 1,3-DNB’s action on Sertoli cells, we analyzed gene expression profiles of TM4 mouse Sertoli cells after chemical treatment. In total, 1,203 genes were identified as either up- or down-regulated, with greater than 1.5-fold changes (P<0.05). Based on k-means clustering, genes that were differentially expressed in a time-dependent manner were identified; then biofunction and canonical pathways were analyzed using Ingenuity Pathways Analysis. Genes related to axonal guidance, Nrf2-mediated oxidative stress response, protein ubiquitination, and tight junction signaling pathways were identified in either time-specifically or time-dependently regulated groups. The transcription levels of genes related to tight junction signaling pathways (Mpp5, F11r, Prkcz, Magi2, and Tgfb2) and genes encoding junction proteins (Ocln, Tjp1, Tjp2, Gja1, and Gjd2) were validated in 1,3-DNB-treated and 2,5-hexanedione-treated TM4 cells by quantitative real-time polymerase chain reaction. Comprehensive gene expression profiling of 1,3-DNB-treated TM4 cells and subsequent canonical pathway analyses provided valuable information regarding the molecular mechanism of cell death and cell interaction in TM4 mouse Sertoli cells after 1,3-DNB exposure.
Several studies have shown that 1,3-dinitrobenzene (1,3-DNB) causes injury to Sertoli cells and i... more Several studies have shown that 1,3-dinitrobenzene (1,3-DNB) causes injury to Sertoli cells and induces apoptosis in the surrounding germinal cells in male laboratory rats; however, the mechanism by which 1,3-DNB functions is not well understood. In this study, we investigated whether 1,3-DNB induces apoptosis and which pathways are undertaken in TM4 cells. When cells were treated with 1,3-DNB, a dosedependent reduction in cell viability was observed by tetrazolium dye assay and LDH assay. The reduced cell viability by 1,3-DNB treatment appeared to involve necrosis as well as apoptosis, based on staining with annexin V-FITC and propidium iodide (PI) staining and Western blotting for PARP protein. 1,3-DNB treatment decreased total transcript and protein levels of the apoptosis inhibitory protein Bcl-2, and increased expression levels of the pro-apoptotic protein Bax. In addition, using FACS analysis we detected G2/M phase cell cycle arrest by 1,3-DNB, concurrent with a remarkable increase in p21 expression and decrease in cdc2 expression. Interestingly, we found that the phosphorylation of c-Jun N-terminal kinase (JNK), and extracellular signal-regulated kinase (ERK) was promoted by 1,3-DNB, furthermore, 1,3-DNBinduced cell death was significantly inhibited by the JNK inhibitor, but not by ERK inhibitor or the p38 inhibitor. Together, our results suggest that 1,3-DNB induces apoptotic cell death and G2/M phase cell cycle arrest, at least in part, via JNK signaling in TM4 mouse Sertoli cells.
Several studies have shown that 1,3-dinitrobenzene (1,3-DNB) causes injury to Sertoli cells and i... more Several studies have shown that 1,3-dinitrobenzene (1,3-DNB) causes injury to Sertoli cells and induces apoptosis in the surrounding germinal cells in male laboratory rats; however, the mechanism by which 1,3-DNB functions is not well understood. In this study, we investigated whether 1,3-DNB induces apoptosis and which pathways are undertaken in TM4 cells. When cells were treated with 1,3-DNB, a dosedependent reduction in cell viability was observed by tetrazolium dye assay and LDH assay. The reduced cell viability by 1,3-DNB treatment appeared to involve necrosis as well as apoptosis, based on staining with annexin V-FITC and propidium iodide (PI) staining and Western blotting for PARP protein. 1,3-DNB treatment decreased total transcript and protein levels of the apoptosis inhibitory protein Bcl-2, and increased expression levels of the pro-apoptotic protein Bax. In addition, using FACS analysis we detected G2/M phase cell cycle arrest by 1,3-DNB, concurrent with a remarkable increase in p21 expression and decrease in cdc2 expression. Interestingly, we found that the phosphorylation of c-Jun N-terminal kinase (JNK), and extracellular signal-regulated kinase (ERK) was promoted by 1,3-DNB, furthermore, 1,3-DNBinduced cell death was significantly inhibited by the JNK inhibitor, but not by ERK inhibitor or the p38 inhibitor. Together, our results suggest that 1,3-DNB induces apoptotic cell death and G2/M phase cell cycle arrest, at least in part, via JNK signaling in TM4 mouse Sertoli cells.
Repeated exposure to welding fumes promotes a reversible increase in pulmonary disease risk, but ... more Repeated exposure to welding fumes promotes a reversible increase in pulmonary disease risk, but the molecular mechanisms by which welding fumes induce lung injury and how the lung recovers from such insults are unclear. In the present study, pulmonary function and gene-expression profiles in the lung were analyzed by Affymetrix GeneChip microarray after 30 days of consecutive exposure to manual metal arc welding combined with stainless-steel (MMA-SS) welding fumes, and again after 30 days of recovery from MMA-SS fume exposure. In total, 577 genes were identified as being either up-regulated or down-regulated (over twofold changes, p &amp;amp;amp;amp;lt; 0.05) in the lungs of low-dose or high-dose groups. Differentially expressed genes were classified based on a k-means clustering algorithm and biological functions and molecular networks were further analyzed using Ingenuity Pathways Analysis. Among the genes affected by exposure to or recovery from MMA-SS fumes, the transcriptional changes of 13 genes that were highly altered by treatment were confirmed by quantitative real-time PCR. Notably, Mmp12, Cd5l, Ccl7, Cxcl5, and Spp1 related to the immune response were up-regulated only in the exposure group, whereas Trem2, IgG-2a, Igh-1a, and Igh were persistently up-regulated in both the exposure and recovery groups. In addition, several genes that might play a role in the repair process of the lung were up-regulated exclusively in the recovery group. Collectively, these data may help elucidate the molecular mechanism of the recovery process of the lung after welding fume exposure.
Repeated exposure to welding fumes promotes a reversible increase in pulmonary disease risk, but ... more Repeated exposure to welding fumes promotes a reversible increase in pulmonary disease risk, but the molecular mechanisms by which welding fumes induce lung injury and how the lung recovers from such insults are unclear. In the present study, pulmonary function and gene-expression profiles in the lung were analyzed by Affymetrix GeneChip microarray after 30 days of consecutive exposure to manual metal arc welding combined with stainless-steel (MMA-SS) welding fumes, and again after 30 days of recovery from MMA-SS fume exposure. In total, 577 genes were identified as being either up-regulated or down-regulated (over twofold changes, p &amp;amp;amp;amp;lt; 0.05) in the lungs of low-dose or high-dose groups. Differentially expressed genes were classified based on a k-means clustering algorithm and biological functions and molecular networks were further analyzed using Ingenuity Pathways Analysis. Among the genes affected by exposure to or recovery from MMA-SS fumes, the transcriptional changes of 13 genes that were highly altered by treatment were confirmed by quantitative real-time PCR. Notably, Mmp12, Cd5l, Ccl7, Cxcl5, and Spp1 related to the immune response were up-regulated only in the exposure group, whereas Trem2, IgG-2a, Igh-1a, and Igh were persistently up-regulated in both the exposure and recovery groups. In addition, several genes that might play a role in the repair process of the lung were up-regulated exclusively in the recovery group. Collectively, these data may help elucidate the molecular mechanism of the recovery process of the lung after welding fume exposure.
We investigated the effects of astemizole, a second-generation antihistamine, on the heart and pe... more We investigated the effects of astemizole, a second-generation antihistamine, on the heart and peripheral blood mononuclear cells (PBMCs) and identified the early markers of its cardiotoxicity using gene expression profiling. Astemizole causes torsades de pointes, which is a type of ventricular tachycardia. We administered astemizole (dosage: 20, 60 mg/kg) to male Sprague–Dawley rats, using an oral gavage. Cardiac tissue and PBMCs were collected from the rats 4 h after treatment. Gene expression profiles were obtained using an Affymetrix GeneChip. The most deregulated genes were associated with energy metabolism pathways and calcium ion homeostasis in the heart of astemizole-treated rats. The most altered genes in the PBMCs were those involved in developmental processes and cardiotoxicity. Genes related to the response to oxidative stress, reactive oxygen species, heat shock proteins, hypoxia, immunity, and inflammation were also deregulated in the heart and PBMCs. These data provide further insight into the genetic pathways affected by astemizole. In addition, the simultaneously deregulated genes identified herein may be further studied. It will be interesting to find out whether single genes or certain sets of these genes could finally serve as biomarkers for cardiotoxicity of astemizole or other similar antihistamine drugs.
We investigated the effects of astemizole, a second-generation antihistamine, on the heart and pe... more We investigated the effects of astemizole, a second-generation antihistamine, on the heart and peripheral blood mononuclear cells (PBMCs) and identified the early markers of its cardiotoxicity using gene expression profiling. Astemizole causes torsades de pointes, which is a type of ventricular tachycardia. We administered astemizole (dosage: 20, 60 mg/kg) to male Sprague–Dawley rats, using an oral gavage. Cardiac tissue and PBMCs were collected from the rats 4 h after treatment. Gene expression profiles were obtained using an Affymetrix GeneChip. The most deregulated genes were associated with energy metabolism pathways and calcium ion homeostasis in the heart of astemizole-treated rats. The most altered genes in the PBMCs were those involved in developmental processes and cardiotoxicity. Genes related to the response to oxidative stress, reactive oxygen species, heat shock proteins, hypoxia, immunity, and inflammation were also deregulated in the heart and PBMCs. These data provide further insight into the genetic pathways affected by astemizole. In addition, the simultaneously deregulated genes identified herein may be further studied. It will be interesting to find out whether single genes or certain sets of these genes could finally serve as biomarkers for cardiotoxicity of astemizole or other similar antihistamine drugs.
Human pluripotent stem cell-derived hepatocytes have the potential to provide in vitro model syst... more Human pluripotent stem cell-derived hepatocytes have the potential to provide in vitro model systems for drug discovery and hepatotoxicity testing. However, these cells are currently unsuitable for drug toxicity and efficacy testing because of their limited expression of genes encoding drug-metabolizing enzymes, especially cytochrome P450 (CYP) enzymes. Transcript levels of major CYP genes were much lower in human embryonic stem cell-derived hepatocytes (hESC-Hep) than in human primary hepatocytes (hPH). To verify the mechanism underlying this reduced expression of CYP genes, including CYP1A1, CYP1A2, CYP1B1, CYP2D6, and CYP2E1, we investigated their epigenetic regulation in terms of DNA methylation and histone modifications in hESC-Hep and hPH. CpG islands of CYP genes were hypermethylated in hESC-Hep, whereas they had an open chromatin structure, as represented by hypomethylation of CpG sites and permissive histone modifications, in hPH. Inhibition of DNA methyltransferases (DNMTs...
In our previous study, Hwang-Ryun-Hae-Dok-Tang, which contains berberine (BBR) as a main active i... more In our previous study, Hwang-Ryun-Hae-Dok-Tang, which contains berberine (BBR) as a main active ingredient, inhibited cytochrome P450 (CYP) 2D6 in a quasi-irreversible manner. However, no information is available on the detailed mechanism of BBR-induced CYP2D6 inhibition. Thus, the present study aimed to characterize the inhibition mode and kinetics of BBR and its analogues against CYP2D6 using pooled human liver microsomes (HLM). BBR exhibited selective quasi-irreversible inhibition of CYP2D6 with inactivation rate constant (kinact) of 0.025 min−1, inhibition constant (KI) of 4.29 µM, and kinact/KI of 5.83 mL/min/µmol. In pooled HLM, BBR was metabolized to thalifendine (TFD), demethyleneberberine (DMB), M1 (proposed as demethylene-TFD), and to a lesser extent berberrubine (BRB), showing moderate metabolic stability with a half-life of 35.4 min and a microsomal intrinsic clearance of 7.82 µL/min/mg protein. However, unlike BBR, those metabolites (i.e., TFD, DMB, and BRB) were neithe...
Background: Meperidine has proved a far more effective treatment for shivering after spinal anest... more Background: Meperidine has proved a far more effective treatment for shivering after spinal anesthesia than equianalgesic doses of opioid agonist. We performed this prospective, double-blinded, randomized study to compare the antishivering effect of fentanyl and meperidine when added to intrathecal hyperbaric bupivacaine during Cesarean delivery under spinal anesthesia.
Background: Meperidine has proved a far more effective treatment for shivering after spinal anest... more Background: Meperidine has proved a far more effective treatment for shivering after spinal anesthesia than equianalgesic doses of opioid agonist. We performed this prospective, double-blinded, randomized study to compare the antishivering effect of fentanyl and meperidine when added to intrathecal hyperbaric bupivacaine during Cesarean delivery under spinal anesthesia.
Diethylstilbestrol (DES), a synthetic estrogen, was examined for genotoxicity in mouse testicular... more Diethylstilbestrol (DES), a synthetic estrogen, was examined for genotoxicity in mouse testicular Sertoli TM4 cells using an in vitro micronucleus assay and microarray analysis to clarify the molecular mechanisms underlying the genotoxicity of estrogenic compounds on the male reproductive system. The micronucleus test showed that DES induced genotoxic effects on TM4 cells with S9 activation. Gene expression profiles were studied in DES-treated cells and positive controls, which were cyclophosphamide (CPA)-treated TM4 cells, as compared to the negative controls. In total, 349 and 328 genes were identified as being either up- or down-regulated, with over 2-fold changes, in DES- and CPA-treated TM4 cells, respectively. Biofunction and canonical pathways of differentially expressed genes were analyzed using Ingenuity Pathways Analysis, which were mainly categorized as cellular development and growth/proliferation. In addition, genes related to cell cycle regulation, such as Egr1, Far1, Cd44, Wint16, Sox6, Sox14, Dnmt3a, and Hdac11, were differentially expressed in DES-treated TM4 cells. A gene network analysis was also performed. Comprehensive gene expression profiling of DES-treated TM4 cells provides valuable information to better understand the genotoxic events of estrogenic chemicals in testicular Sertoli cells.
Diethylstilbestrol (DES), a synthetic estrogen, was examined for genotoxicity in mouse testicular... more Diethylstilbestrol (DES), a synthetic estrogen, was examined for genotoxicity in mouse testicular Sertoli TM4 cells using an in vitro micronucleus assay and microarray analysis to clarify the molecular mechanisms underlying the genotoxicity of estrogenic compounds on the male reproductive system. The micronucleus test showed that DES induced genotoxic effects on TM4 cells with S9 activation. Gene expression profiles were studied in DES-treated cells and positive controls, which were cyclophosphamide (CPA)-treated TM4 cells, as compared to the negative controls. In total, 349 and 328 genes were identified as being either up- or down-regulated, with over 2-fold changes, in DES- and CPA-treated TM4 cells, respectively. Biofunction and canonical pathways of differentially expressed genes were analyzed using Ingenuity Pathways Analysis, which were mainly categorized as cellular development and growth/proliferation. In addition, genes related to cell cycle regulation, such as Egr1, Far1, Cd44, Wint16, Sox6, Sox14, Dnmt3a, and Hdac11, were differentially expressed in DES-treated TM4 cells. A gene network analysis was also performed. Comprehensive gene expression profiling of DES-treated TM4 cells provides valuable information to better understand the genotoxic events of estrogenic chemicals in testicular Sertoli cells.
Toxicogenomic approaches have been applied to chemical-induced heptocarcinogenesis rodent models ... more Toxicogenomic approaches have been applied to chemical-induced heptocarcinogenesis rodent models for the identification of biomarkers of early-stage hepatocarcinogenesis and to help clarify the underlying carcinogenic mechanisms in the liver. In this study, we used toxiciogenomic methods to identify candidate biomarker genes associated with hepatocarcinogenesis in rasH2 mice. Blood chemical, histopathologic, and gene expression analyses of the livers of rasH2 mice were performed 7 and 91 days after the administration of the genotoxic hepatocarcinogens 2-acetylaminofluorene (AAF) and diethylnitrosoamine (DEN), the genotoxic carcinogen melphalan (Mel), and the nongenotoxic noncarcinogen 1-naphthylisothiocynate (ANIT). Histopathologic lesions and a rise in accompanying serum marker levels were found in the DEN-treated rasH2 mice, whereas no neoplastic lesions were observed in the rasH2 mice. However, biological functional analysis using Ingenuity Pathways Analysis (IPA) software revealed that genes with comparable molecular and cellular functions were similarly deregulated in the AAF- and DEN-treated rasH2 mice. We selected 68 significantly deregulated genes that represented a hepatocarcinogen-specific signature; these genes were commonly deregulated in both the AAF- and DEN-treated rasH2 mice on days 7 and 91. Hierarchical clustering analysis indicated that the expression patterns of the selected genes in the hepatocarcinogen (AAF and DEN) groups were distinctive from the patterns in the control, Mel, and ANIT groups. Biomarker filter analysis using IPA software suggested that 28 of the 68 signature genes represent promising candidate biomarkers of cancer. Quantitative real-time PCR analysis confirmed that the deregulated genes, which exhibited sustained up- and down-regulation up to day 91, are likely involved in early-stage hepatocarcinogenesis. In summary, the common and significant gene expression changes induced by AAF and DEN may reflect early molecular events associated with hepatocarcinogenesis, and these “signature” genes may be useful as biomarkers of hepatocarcinogenesis in mice.
Toxicogenomic approaches have been applied to chemical-induced heptocarcinogenesis rodent models ... more Toxicogenomic approaches have been applied to chemical-induced heptocarcinogenesis rodent models for the identification of biomarkers of early-stage hepatocarcinogenesis and to help clarify the underlying carcinogenic mechanisms in the liver. In this study, we used toxiciogenomic methods to identify candidate biomarker genes associated with hepatocarcinogenesis in rasH2 mice. Blood chemical, histopathologic, and gene expression analyses of the livers of rasH2 mice were performed 7 and 91 days after the administration of the genotoxic hepatocarcinogens 2-acetylaminofluorene (AAF) and diethylnitrosoamine (DEN), the genotoxic carcinogen melphalan (Mel), and the nongenotoxic noncarcinogen 1-naphthylisothiocynate (ANIT). Histopathologic lesions and a rise in accompanying serum marker levels were found in the DEN-treated rasH2 mice, whereas no neoplastic lesions were observed in the rasH2 mice. However, biological functional analysis using Ingenuity Pathways Analysis (IPA) software revealed that genes with comparable molecular and cellular functions were similarly deregulated in the AAF- and DEN-treated rasH2 mice. We selected 68 significantly deregulated genes that represented a hepatocarcinogen-specific signature; these genes were commonly deregulated in both the AAF- and DEN-treated rasH2 mice on days 7 and 91. Hierarchical clustering analysis indicated that the expression patterns of the selected genes in the hepatocarcinogen (AAF and DEN) groups were distinctive from the patterns in the control, Mel, and ANIT groups. Biomarker filter analysis using IPA software suggested that 28 of the 68 signature genes represent promising candidate biomarkers of cancer. Quantitative real-time PCR analysis confirmed that the deregulated genes, which exhibited sustained up- and down-regulation up to day 91, are likely involved in early-stage hepatocarcinogenesis. In summary, the common and significant gene expression changes induced by AAF and DEN may reflect early molecular events associated with hepatocarcinogenesis, and these “signature” genes may be useful as biomarkers of hepatocarcinogenesis in mice.
An attempt has been made to identify molecular markers of intrahepatic cholestasis in mice employ... more An attempt has been made to identify molecular markers of intrahepatic cholestasis in mice employing phalloidin as a cholestatic agent. Phalloidin was administered to BALB/c mice at three predetermined dose: 250 microg/kg, 500 microg/kg, and 1 mg/kg for 1, 3, and 7 days. Liver function was estimated to confirm cholestasis. Histopathological observations on liver were also made to confirm liver injury. Phalloidin at 1 mg/kg for 7 days was found to induce cholestasis. Therefore gene expression studies were confined to this group only. A total of 88 genes were found to be affected by phalloidin. These were the genes associated with cytoskeleton regulation as well as tight junction, focal adhesion, and ATP-binding cassette transporters. Such proteins obstruct the removal of bile components from hepatocytes to the bile canaliculus or blood. Phalloidin treatment did not affect the proteins responsible for cell maintenance or death. The authors show that phalloidin-induced intrahepatic cholestasis is manifested by disturbing the cytoskeleton. The set of genes up-regulated by phalloidin can be considered as molecular markers of intrahepatic cholestasis. The observations are further expected to be helpful in the management of cholestatic pharmaceuticals and associated problems of liver diseases in humans.
An attempt has been made to identify molecular markers of intrahepatic cholestasis in mice employ... more An attempt has been made to identify molecular markers of intrahepatic cholestasis in mice employing phalloidin as a cholestatic agent. Phalloidin was administered to BALB/c mice at three predetermined dose: 250 microg/kg, 500 microg/kg, and 1 mg/kg for 1, 3, and 7 days. Liver function was estimated to confirm cholestasis. Histopathological observations on liver were also made to confirm liver injury. Phalloidin at 1 mg/kg for 7 days was found to induce cholestasis. Therefore gene expression studies were confined to this group only. A total of 88 genes were found to be affected by phalloidin. These were the genes associated with cytoskeleton regulation as well as tight junction, focal adhesion, and ATP-binding cassette transporters. Such proteins obstruct the removal of bile components from hepatocytes to the bile canaliculus or blood. Phalloidin treatment did not affect the proteins responsible for cell maintenance or death. The authors show that phalloidin-induced intrahepatic cholestasis is manifested by disturbing the cytoskeleton. The set of genes up-regulated by phalloidin can be considered as molecular markers of intrahepatic cholestasis. The observations are further expected to be helpful in the management of cholestatic pharmaceuticals and associated problems of liver diseases in humans.
1,3-Dinitrobenzene (1,3-DNB) specifically injures Sertoli cells and induces testicular toxicity b... more 1,3-Dinitrobenzene (1,3-DNB) specifically injures Sertoli cells and induces testicular toxicity by disrupting the key function of these cells. To clarify the molecular mechanism underlying 1,3-DNB’s action on Sertoli cells, we analyzed gene expression profiles of TM4 mouse Sertoli cells after chemical treatment. In total, 1,203 genes were identified as either up- or down-regulated, with greater than 1.5-fold changes (P<0.05). Based on k-means clustering, genes that were differentially expressed in a time-dependent manner were identified; then biofunction and canonical pathways were analyzed using Ingenuity Pathways Analysis. Genes related to axonal guidance, Nrf2-mediated oxidative stress response, protein ubiquitination, and tight junction signaling pathways were identified in either time-specifically or time-dependently regulated groups. The transcription levels of genes related to tight junction signaling pathways (Mpp5, F11r, Prkcz, Magi2, and Tgfb2) and genes encoding junction proteins (Ocln, Tjp1, Tjp2, Gja1, and Gjd2) were validated in 1,3-DNB-treated and 2,5-hexanedione-treated TM4 cells by quantitative real-time polymerase chain reaction. Comprehensive gene expression profiling of 1,3-DNB-treated TM4 cells and subsequent canonical pathway analyses provided valuable information regarding the molecular mechanism of cell death and cell interaction in TM4 mouse Sertoli cells after 1,3-DNB exposure.
1,3-Dinitrobenzene (1,3-DNB) specifically injures Sertoli cells and induces testicular toxicity b... more 1,3-Dinitrobenzene (1,3-DNB) specifically injures Sertoli cells and induces testicular toxicity by disrupting the key function of these cells. To clarify the molecular mechanism underlying 1,3-DNB’s action on Sertoli cells, we analyzed gene expression profiles of TM4 mouse Sertoli cells after chemical treatment. In total, 1,203 genes were identified as either up- or down-regulated, with greater than 1.5-fold changes (P<0.05). Based on k-means clustering, genes that were differentially expressed in a time-dependent manner were identified; then biofunction and canonical pathways were analyzed using Ingenuity Pathways Analysis. Genes related to axonal guidance, Nrf2-mediated oxidative stress response, protein ubiquitination, and tight junction signaling pathways were identified in either time-specifically or time-dependently regulated groups. The transcription levels of genes related to tight junction signaling pathways (Mpp5, F11r, Prkcz, Magi2, and Tgfb2) and genes encoding junction proteins (Ocln, Tjp1, Tjp2, Gja1, and Gjd2) were validated in 1,3-DNB-treated and 2,5-hexanedione-treated TM4 cells by quantitative real-time polymerase chain reaction. Comprehensive gene expression profiling of 1,3-DNB-treated TM4 cells and subsequent canonical pathway analyses provided valuable information regarding the molecular mechanism of cell death and cell interaction in TM4 mouse Sertoli cells after 1,3-DNB exposure.
Several studies have shown that 1,3-dinitrobenzene (1,3-DNB) causes injury to Sertoli cells and i... more Several studies have shown that 1,3-dinitrobenzene (1,3-DNB) causes injury to Sertoli cells and induces apoptosis in the surrounding germinal cells in male laboratory rats; however, the mechanism by which 1,3-DNB functions is not well understood. In this study, we investigated whether 1,3-DNB induces apoptosis and which pathways are undertaken in TM4 cells. When cells were treated with 1,3-DNB, a dosedependent reduction in cell viability was observed by tetrazolium dye assay and LDH assay. The reduced cell viability by 1,3-DNB treatment appeared to involve necrosis as well as apoptosis, based on staining with annexin V-FITC and propidium iodide (PI) staining and Western blotting for PARP protein. 1,3-DNB treatment decreased total transcript and protein levels of the apoptosis inhibitory protein Bcl-2, and increased expression levels of the pro-apoptotic protein Bax. In addition, using FACS analysis we detected G2/M phase cell cycle arrest by 1,3-DNB, concurrent with a remarkable increase in p21 expression and decrease in cdc2 expression. Interestingly, we found that the phosphorylation of c-Jun N-terminal kinase (JNK), and extracellular signal-regulated kinase (ERK) was promoted by 1,3-DNB, furthermore, 1,3-DNBinduced cell death was significantly inhibited by the JNK inhibitor, but not by ERK inhibitor or the p38 inhibitor. Together, our results suggest that 1,3-DNB induces apoptotic cell death and G2/M phase cell cycle arrest, at least in part, via JNK signaling in TM4 mouse Sertoli cells.
Several studies have shown that 1,3-dinitrobenzene (1,3-DNB) causes injury to Sertoli cells and i... more Several studies have shown that 1,3-dinitrobenzene (1,3-DNB) causes injury to Sertoli cells and induces apoptosis in the surrounding germinal cells in male laboratory rats; however, the mechanism by which 1,3-DNB functions is not well understood. In this study, we investigated whether 1,3-DNB induces apoptosis and which pathways are undertaken in TM4 cells. When cells were treated with 1,3-DNB, a dosedependent reduction in cell viability was observed by tetrazolium dye assay and LDH assay. The reduced cell viability by 1,3-DNB treatment appeared to involve necrosis as well as apoptosis, based on staining with annexin V-FITC and propidium iodide (PI) staining and Western blotting for PARP protein. 1,3-DNB treatment decreased total transcript and protein levels of the apoptosis inhibitory protein Bcl-2, and increased expression levels of the pro-apoptotic protein Bax. In addition, using FACS analysis we detected G2/M phase cell cycle arrest by 1,3-DNB, concurrent with a remarkable increase in p21 expression and decrease in cdc2 expression. Interestingly, we found that the phosphorylation of c-Jun N-terminal kinase (JNK), and extracellular signal-regulated kinase (ERK) was promoted by 1,3-DNB, furthermore, 1,3-DNBinduced cell death was significantly inhibited by the JNK inhibitor, but not by ERK inhibitor or the p38 inhibitor. Together, our results suggest that 1,3-DNB induces apoptotic cell death and G2/M phase cell cycle arrest, at least in part, via JNK signaling in TM4 mouse Sertoli cells.
Repeated exposure to welding fumes promotes a reversible increase in pulmonary disease risk, but ... more Repeated exposure to welding fumes promotes a reversible increase in pulmonary disease risk, but the molecular mechanisms by which welding fumes induce lung injury and how the lung recovers from such insults are unclear. In the present study, pulmonary function and gene-expression profiles in the lung were analyzed by Affymetrix GeneChip microarray after 30 days of consecutive exposure to manual metal arc welding combined with stainless-steel (MMA-SS) welding fumes, and again after 30 days of recovery from MMA-SS fume exposure. In total, 577 genes were identified as being either up-regulated or down-regulated (over twofold changes, p &amp;amp;amp;amp;lt; 0.05) in the lungs of low-dose or high-dose groups. Differentially expressed genes were classified based on a k-means clustering algorithm and biological functions and molecular networks were further analyzed using Ingenuity Pathways Analysis. Among the genes affected by exposure to or recovery from MMA-SS fumes, the transcriptional changes of 13 genes that were highly altered by treatment were confirmed by quantitative real-time PCR. Notably, Mmp12, Cd5l, Ccl7, Cxcl5, and Spp1 related to the immune response were up-regulated only in the exposure group, whereas Trem2, IgG-2a, Igh-1a, and Igh were persistently up-regulated in both the exposure and recovery groups. In addition, several genes that might play a role in the repair process of the lung were up-regulated exclusively in the recovery group. Collectively, these data may help elucidate the molecular mechanism of the recovery process of the lung after welding fume exposure.
Repeated exposure to welding fumes promotes a reversible increase in pulmonary disease risk, but ... more Repeated exposure to welding fumes promotes a reversible increase in pulmonary disease risk, but the molecular mechanisms by which welding fumes induce lung injury and how the lung recovers from such insults are unclear. In the present study, pulmonary function and gene-expression profiles in the lung were analyzed by Affymetrix GeneChip microarray after 30 days of consecutive exposure to manual metal arc welding combined with stainless-steel (MMA-SS) welding fumes, and again after 30 days of recovery from MMA-SS fume exposure. In total, 577 genes were identified as being either up-regulated or down-regulated (over twofold changes, p &amp;amp;amp;amp;lt; 0.05) in the lungs of low-dose or high-dose groups. Differentially expressed genes were classified based on a k-means clustering algorithm and biological functions and molecular networks were further analyzed using Ingenuity Pathways Analysis. Among the genes affected by exposure to or recovery from MMA-SS fumes, the transcriptional changes of 13 genes that were highly altered by treatment were confirmed by quantitative real-time PCR. Notably, Mmp12, Cd5l, Ccl7, Cxcl5, and Spp1 related to the immune response were up-regulated only in the exposure group, whereas Trem2, IgG-2a, Igh-1a, and Igh were persistently up-regulated in both the exposure and recovery groups. In addition, several genes that might play a role in the repair process of the lung were up-regulated exclusively in the recovery group. Collectively, these data may help elucidate the molecular mechanism of the recovery process of the lung after welding fume exposure.
We investigated the effects of astemizole, a second-generation antihistamine, on the heart and pe... more We investigated the effects of astemizole, a second-generation antihistamine, on the heart and peripheral blood mononuclear cells (PBMCs) and identified the early markers of its cardiotoxicity using gene expression profiling. Astemizole causes torsades de pointes, which is a type of ventricular tachycardia. We administered astemizole (dosage: 20, 60 mg/kg) to male Sprague–Dawley rats, using an oral gavage. Cardiac tissue and PBMCs were collected from the rats 4 h after treatment. Gene expression profiles were obtained using an Affymetrix GeneChip. The most deregulated genes were associated with energy metabolism pathways and calcium ion homeostasis in the heart of astemizole-treated rats. The most altered genes in the PBMCs were those involved in developmental processes and cardiotoxicity. Genes related to the response to oxidative stress, reactive oxygen species, heat shock proteins, hypoxia, immunity, and inflammation were also deregulated in the heart and PBMCs. These data provide further insight into the genetic pathways affected by astemizole. In addition, the simultaneously deregulated genes identified herein may be further studied. It will be interesting to find out whether single genes or certain sets of these genes could finally serve as biomarkers for cardiotoxicity of astemizole or other similar antihistamine drugs.
We investigated the effects of astemizole, a second-generation antihistamine, on the heart and pe... more We investigated the effects of astemizole, a second-generation antihistamine, on the heart and peripheral blood mononuclear cells (PBMCs) and identified the early markers of its cardiotoxicity using gene expression profiling. Astemizole causes torsades de pointes, which is a type of ventricular tachycardia. We administered astemizole (dosage: 20, 60 mg/kg) to male Sprague–Dawley rats, using an oral gavage. Cardiac tissue and PBMCs were collected from the rats 4 h after treatment. Gene expression profiles were obtained using an Affymetrix GeneChip. The most deregulated genes were associated with energy metabolism pathways and calcium ion homeostasis in the heart of astemizole-treated rats. The most altered genes in the PBMCs were those involved in developmental processes and cardiotoxicity. Genes related to the response to oxidative stress, reactive oxygen species, heat shock proteins, hypoxia, immunity, and inflammation were also deregulated in the heart and PBMCs. These data provide further insight into the genetic pathways affected by astemizole. In addition, the simultaneously deregulated genes identified herein may be further studied. It will be interesting to find out whether single genes or certain sets of these genes could finally serve as biomarkers for cardiotoxicity of astemizole or other similar antihistamine drugs.
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