bluuebunny/crossref_metadata_2025 huggingface dataset:
Inhibitory Mechanism of Omega‐3 Fatty Acids in Pancreatic Inflammation and Apoptosis
Authors: Park Kyung Suk , Lim Joo Weon , Kim Hyeyoung
Published: August 2009

Oxidative stress is regarded as a major pathogenic factor in acute pancreatitis. Inflammation and apoptosis linked to oxidative stress has been implicated in cerulein‐induced pancreatitis as an experimental model of acute pancreatitis. Recently, we found that reactive oxygen species mediate inflammatory cytokine expression and apoptosis of pancreatic acinar cells stimulated with cerulein. Omega‐3 fatty acids show antioxidant action in various cells and tissues. In the present study, we investigated whether omega‐3 fatty acids inhibit cytokine expression in cerulein‐stimulated pancreatic acinar cells and whether omega‐3 fatty acids suppress apoptotic cell death in pancreatic acinar cells exposed to hydrogen peroxide. We found that omega‐3 fatty acids, such as docosahexaenoic acid (DHA) and α‐linolenic acid (ALA), suppressed the expression of inflammatory cytokines (IL‐1β, IL‐6) and inhibited the activation of transcription factor activator protein‐1 in cerulein‐stimulated pancreatic acinar cells. DHA and ALA inhibited DNA fragmentation, inhibited the decrease in cell viability, and inhibited the expression of apoptotic genes (p53, Bax, apoptosis‐inducing factor) induced by hydrogen peroxide in pancreatic acinar cells. In conclusion, omega‐3 fatty acids may be beneficial for preventing oxidative stress‐induced pancreatic inflammation and apoptosis by inhibiting inflammatory cytokine and apoptotic gene expression of pancreatic acinar cells.
Celecoxib Potentiates the Anticancer Effect of Cisplatin on Vulvar Cancer Cells Independently of Cyclooxygenase
Authors: Kim Su‐Hyeon , Kim Su‐Hyeong , Song Yoo‐Choel , Song Yong‐Sang
Published: August 2009

Cyclooxygenase‐2 (COX‐2) has been found to be associated with the development and progression of various cancers. Our previous study showed a high expression rate of COX‐2 in paraffin‐embedded tissue specimens from patients with vulvar cancer. In this study, we evaluated the efficacy of celecoxib, a selective COX‐2 inhibitor, as a chemosensitizing agent with cisplatin in vulvar cancer cells A431 and SW962. COX‐2 was expressed in both A431 and SW962 vulvar cancer cell lines. COX‐1 was expressed in A431 but not in SW962. MTT [3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazoliumbromide] assay showed that treatment with 30 μmol/L celecoxib had no effect on cell growth in A431 cells for 72 h. However, combined treatment with celecoxib and cisplatin induced a significant reduction in cell growth compared to single treatment with cisplatin. Interestingly, single treatment with celecoxib or cisplatin and combined treatment of 10 μmol/L celecoxib with 10 μmol/L cisplatin increased COX‐2 expression. However, the combination of 30 μmol/L celecoxib and 30 μmol/L cisplatin reduced COX‐2 expression to the control state. Inhibition of cell growth by celecoxib alone and in combination with cisplatin was independent of the expression level of COX‐2 induced by these agents. While treatment with 10 μmol/L celecoxib or 10 μmol/L piroxicam significantly suppressed the activity of COX enzymes, neither agent affected the growth of A431 and SW962 cells at this concentration. Taken together, celecoxib could be used as a chemosensitizing agent in vulva cancer cells; the anticancer activity of celecoxib seemed to be independent of COX.
Neuroprotective Activity of Viola mandshurica Extracts on Hydrogen Peroxide‐Induced DNA Damage and Cell Death in PC12 Cells
Authors: Jeon Gyeong‐Im , Yoon Mi‐Young , Park Hae‐Ryoung , Lee Seung‐Cheol , Park Eunju
Published: August 2009

This study was conducted to examine the neuroprotective effects of acetone extracts from Viola mandshurica (VME). The effect of VME on hydrogen peroxide (H2O2)‐induced DNA damage in PC12 cells was evaluated by the comet assay where VME (100 and 250 μg/mL) was a dose‐dependent inhibitor of DNA damage induced by 500 μmol/L of H2O2. The protective effect of VME against H2O2‐induced oxidative damage on PC12 cells was investigated by an MTT [3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyl tetrazolium bromide] reduction assay and lactate dehydrogenase (LDH) release assays. After 3 h of cell exposure to 500 μmol/L of H2O2, a marked reduction in cell survival was observed. However, the reduction was significantly prevented by 100 and 250 μg/mL of VME. H2O2 also induced severe apoptosis of the PC12 cells, which was indicated by Hoechst 33342 staining. Interestingly, the H2O2‐stressed PC12 cells that were incubated with 100 and 250 μg/mL of VME had greatly suppressed apoptosis. The results suggest that VME could be a new antioxidant candidate against neuronal diseases.
Gene Expression Profiling Related to Anti‐inflammatory Properties of Curcumin in K562 Leukemia Cells
Authors: Teiten Marie‐Helene , Eifes Serge , Reuter Simone , Duvoix Annelyse , Dicato Mario , Diederich Marc
Published: August 2009

A strong relationship exists between inflammation and carcinogenesis. To bring insights into the anti‐inflammatory mechanisms by which chemopreventive agents, such as curcumin, are able to counteract the action of inflammation mediators, such as tumor necrosis factor‐α (TNF‐α), we compared gene expression profiles in K562 cells treated with curcumin‐TNF‐α versus TNF‐α alone. Microarray data analysis revealed that, among the 376 differentially expressed genes by curcumin treatment, genes belonging to the cell cycle and the Janus kinase‐signal transducer and activator of transcription signaling pathways were downregulated. This study also indicated that the upregulation of the heat shock family genes is highly implicated in the anti‐inflammatory effect of curcumin.
Expression of Vascular Endothelial Growth Factor and Hypoxia Inducible Factor‐1α in Cervical Neoplasia
Authors: No Jae Hong , Jo Hoenil , Kim Su‐Hyeong , Park In‐Ae , Kang Daehee , Han Seung‐Su , Kim Jae Weon , Park Noh‐Hyun , Kang Soon‐Beom , Song Yong‐Sang
Published: August 2009

Altered angiogenesis is an important phenotype of high‐grade cervical lesions and invasive cervical carcinomas. Many researchers, including us, have shown that oncoproteins of human papillomavirus could enhance the vascular endothelial growth factor (VEGF) expression. We investigated the change in VEGF and hypoxia‐inducible factor‐1α (HIF‐1α) expression patterns that occur during the carcinogenesis and progression of cervical cancer. Expressions of HIF‐1α and VEGF were evaluated by immunohistochemistry using paraffin‐embedded specimens obtained from 41 patients with a normal cervix, 39 patients with cervical intraepithelial neoplasia (CIN 1, 10; CIN 2/3, 29), and 36 patients with cervical cancer. The VEGF and HIF‐1α expressions were higher in CIN and invasive cancer than in normal cervix (P= 0.021, P < 0.001, respectively). It is interesting to note that there was no significant difference in VEGF and HIF‐1α overexpressions between CIN 2/3 and cervical cancer and between nonmetastatic and metastatic cancers. In addition, there was a significant correlation between the immunohistochemical score of HIF‐1α and that of VEGF expression (Spearman's correlation coefficient 0.275, P= 0.003, n= 116). Taken together, the results of our study suggest that expressions of VEGF and HIF‐1α could be involved in cervical carcinogenesis. In addition, the weak correlation between VEGF and HIF‐1α expressions suggests that regulatory mechanisms other than HIF‐1α may be involved in the expression of VEGF during cervical carcinogenesis.
Differentiation and Apoptosis in UVA‐Irradiated Cells Treated with Furocoumarin Derivatives
Authors: Viola Giampietro , Salvador Alessia , Vedaldi Daniela , Dall’Acqua Francesco , Bianchi Nicoletta , Zuccato Cristina , Borgatti Monica , Lampronti Ilaria , Gambari Roberto
Published: August 2009

In this review we summarize the structure and biological effects of linear and angular psoralens. These compounds exhibit interesting biological effects on the cell cycle, apoptosis and differentiation. These molecules should be considered promising drugs in the therapy of several diseases, including psoriasis, mycosis fungoides and cancer. Also, preclinical data demonstrate a possible use of these molecules for the treatment of β‐thalassemia and other hematological disorders.
Chlorella Methanol Extract Reduces Lipid Accumulation in and Increases the Number of Apoptotic 3T3‐L1 Cells
Authors: Chon Jeong‐Woo , Sung Ju‐Hyun , Hwang Eun‐Joo , Park Yoo‐Kyoung
Published: August 2009

Obesity is a fast‐growing problem that is reaching pandemic proportions. Chlorella has many biological merits for promoting health, including detoxification, boosting the immune system, and even reversing cancer. In this study, we found that methanol extract of Chlorella reduces lipid accumulation in 3T3‐L1 adipocytes. It has been postulated that these antiobesity effects could be a result of reducing adipogenesis. First, the MTT assay indicated that Chlorella significantly inhibited cell growth of 3T3‐L1 preadipocytes. The accumulation of triacylglycerol in 3T3‐L1 adipocytes decreased in cells treated with Chlorella versus those in untreated cells by Oil Red O staining. In parallel, Chlorella showed a significant dose‐dependent increase in lactate dehydrogenase activity in culture medium of differentiated 3T3‐L1 adipocytes. Second, we investigated the effects of Chlorella on the induction of apoptosis by fluorescence‐activated cell sorting analysis. Chlorella showed that apoptotic cells increased in a time‐ and dose‐dependent manner in cell apoptosis analysis by propidium iodide (PI) staining. Treatment with Chlorella decreased the number of normal cells and increased the number of apoptotic cells in a dose‐dependent manner in annexin V–fluorescein isothiocyanate/PI double staining. Therefore, Chlorella is expected to efficiently reduce adipogenesis in 3T3‐L1 adipocytes and to induce apoptosis in 3T3‐L1 preadipocytes.
Intracellular Prooxidant Activity of Melatonin Induces a Survival Pathway Involving NF‐κB Activation
Authors: Cristofanon Silvia , Uguccioni Francesco , Cerella Claudia , Radogna Flavia , Dicato Mario , Ghibelli Lina , Diederich Marc
Published: August 2009

We have shown that melatonin exerts a prooxidant activity in U937 cells, a tumor human promonocytic cell line.1 Here we show that melatonin induces a strong canonical activation of NF‐κB, inducing IκBα degradation and the consequential nuclear translocation of p50/p65 subunits. The timing of NF‐κB activation overlaps with the timing of reactive oxygen species (ROS) production due to melatonin. Overexpression of dominant‐negative IκB, which prevents a possible NF‐κB activation, transformed melatonin in a proapoptotic molecule. These data indicate for the first time that melatonin can trigger NF‐κB activation and might suggest a possible role for ROS induced by melatonin. Results indicate a possible involvement in the survival pathway of melatonin‐generated ROS as secondary messengers.
Growth‐Inhibitory and Proapoptotic Effects of Alpha‐Linolenic Acid on Estrogen‐Positive Breast Cancer Cells
Authors: Kim Ji‐Yoon , Park Han Deuk , Park Eunju , Chon Jeong‐Woo , Park Yoo Kyoung
Published: August 2009

We tested the anticarcinogenic effect of alpha‐linolenic acid (ALA) as a single compound. To test the role of ALA in breast cancer cells (MCF‐7), we analyzed the antiproliferative pathway and the proapoptotic pathway. ALA exhibited growth inhibition on MCF‐7 cells dose‐dependently of ALA in 24, 48, and 72 h, without possible cytotoxicity per se. ALA enhanced the cell growth–inhibitory activity in a dose‐dependent manner. Second, the proapoptotic pathway showed a sub‐G1 accumulation with concomitant upregulation of proapoptotic Bax expression, as well as a downregulation of antiapoptotic Bcl‐2 expression dose‐dependently, causing the Bcl‐2/Bax ratio to decrease by about 50%. Subsequent cytochrome c release and proteolytic activation of caspase‐3 followed by proteolytic cleavage of poly(ADP‐ribose) polymerase all suggest ensuing progression to apoptosis. This finding suggests that ALA alone might also be responsible for growth‐inhibitory and proapoptotic effects on estrogen‐positive breast cancer cells.
Genistein Inhibits Cell Growth by Modulating Various Mitogen‐Activated Protein Kinases and AKT in Cervical Cancer Cells
Authors: Kim Su‐Hyeon , Kim Su‐Hyeong , Kim Yong‐Beom , Jeon Yong‐Tark , Lee Sang‐Chul , Song Yong‐Sang
Published: August 2009

Genistein, a soy‐derived isoflavone, inhibits growth of tumor cells from various malignancies. Here we investigated the effect of genistein on the growth of cervical cancer cells (HeLa and CaSki) and its possible mechanism. Genistein significantly suppressed cell growth of HeLa and CaSki cells at concentrations of 20 and 60 μmol/L, respectively, for 24 h. Western blotting analysis showed that genistein reduced phosphorylation of AKT and extracellular signal–regulated kinase (ERK)‐1/2 and induced phosphorylation of p38 mitogen‐activated protein kinase (MAPK) and c‐Jun N‐terminal kinase (JNK). Moreover, inhibition of ERK1/2 activity enhanced cell growth inhibition by genistein, whereas inhibition of p38 MAPK activity rescued from genistein‐mediated growth inhibition. Interestingly, inhibition of AKT activity recovered genistein‐induced growth inhibition in CaSki cells but did not in HeLa cells. However, inhibition of JNK activity seemed to have little effect on cell growth inhibition by genistein. Taken together, these results suggest that genistein could inhibit cell growth by inhibiting ERK1/2 activity and activating p38 MAPK.
Neuroprotection by Melatonin on Astrocytoma Cell Death
Authors: Radogna Flavia , Nuccitelli Silvia , Mengoni Fabio , Ghibelli Lina
Published: August 2009

Glial cells play an active role in the homeostatic regulation of the central nervous system (CNS). Astrocytes, the most abundant glial cell types in the brain, provide mechanical and metabolic support for neurons. The regulation of astrocyte apoptosis, therefore, is important for physiological and pathological processes in the CNS. Melatonin is a neurohormone that regulates target cells via binding to specific high‐affinity plasma membrane receptors, MT1/MT2. In addition to regulating circadian rhythms, melatonin has recently attracted much interest for its potential regulation of cell apoptosis. We recently showed that melatonin antagonizes apoptosis on U937 cells via intersecting signal transduction events involving binding to MT1/MT2 and activation of lipoxygenase. Here we describe the neuroprotective potential of melatonin, showing that melatonin significantly reduces damage‐induced apoptosis in astrocytoma cells. The mechanism of protection is different from that shown in U937 cells, because it does not involve MT1/MT2 or lipoxygenase; likewise, Ca2+influx is not involved. Intriguingly, inhibition of phospholipase C (PLC) with neomycin reverses melatonin protection, suggesting that a PLC‐dependent signal transduction, different from that triggered by MT1/MT2, is involved in the antiapoptotic pathway of melatonin.
Multiple Mechanisms for Hydrogen Peroxide–Induced Apoptosis
Authors: Cerella Claudia , Coppola Simona , Maresca Vittoria , De Nicola Milena , Radogna Flavia , Ghibelli Lina
Published: August 2009

The mechanisms of cell killing by oxidative stress, in particular by hydrogen peroxide, are not yet well clarified. Here, we show that during recovery after H2O2 treatment, apoptosis occurs in two different waves, peaking at 8 h (early) and 18 h (late) of recovery from oxidative stress. The two peaks are differentially modulated by a set of inhibitors of metabolic processes, which suggests that the first peak depends on DNA break formation, whereas the second may be correlated with H2O2‐induced mitochondrial alterations.
Roscovitine Triggers Apoptosis in B‐Cell Chronic Lymphocytic Leukemia Cells with Similar Efficiency as Combinations of Conventional Purine Analogs with Cyclophosphamide
Authors: Zolnierczyk Jolanta D. , Błoński Jerzy Z. , Robak Tadeusz , Kiliańska Zofia M. , Węsierska‐Gadek Józefa
Published: August 2009

B‐cell chronic lymphocytic leukemia (CLL) is characterized by an accumulation in peripheral blood of many long‐lived lymphocytes that do not die because of the deregulation of apoptosis. Most CLL cells are quiescent, and therefore the leukemic lymphocytes are resistant to conventional chemotherapy. The aim of this study was to evaluatein vitrothe chemosensitivity of CLL cells to cladribine or fludarabine used alone or in combinations with mafosfamide (Mf; the active form of cyclophosphamide) as well as to roscovitine, a potent inhibitor of cyclin‐dependent kinases with proapoptotic potential. The results of flow cytometry revealed that tested agents differentially reduced the viability of leukemic cells. Interestingly, roscovitine exerts a similar cytotoxic effect as the combinations of the used purine analogs with Mf, but with other kinetics. Roscovitine kills leukemic cells after a much shorter exposure time. Immunoblotting analysis showed that the reduction of the number of living cells coincides with marked changes of the balance between pro‐ and antiapoptotic factors. The latter were markedly reduced. The activation of proapoptotic proteins became evident especially after exposure of cells to roscovitine alone or to combinations of purine analogs and Mf. Furthermore, exposure of CLL cells to tested drugs degraded p27KIP1protein. Our findings demonstrate that roscovitine alone significantly reduces the number of viable CLL cells by inducing them to undergo apoptosis, and it acts earlier than clinically applied combinations of purine analogs with Mf/cyclophosphamide. These results confirm the high efficacy of roscovitine against CLL cells.
Evaluation of Anti‐inflammatory and Analgesic Activity of a Novel Rigid 3, 4‐Dihydroxy Chalcone in Mice
Authors: Heidari M. R. , Foroumadi A. , Amirabadi A. , Samzadeh‐Kermani A. , Azimzadeh B. S. , Eskandarizadeh A.
Published: August 2009

There have been many reports indicating the analgesic and anti‐inflammatory effects of 3,4‐dihydroxychalcones. We have designed and synthesized a rigid 3,4‐dihydroxychalcone (RDHC) as a possible drug effecting inflammation and nociception. The analgesic and anti‐inflammatory effects were evaluated by formalin and hot‐plate tests, respectively. The results showed that RDHC induced significant antinociceptive and anti‐inflammatory effects (P < 0.01). Maximum analgesia (63.7%) was observed at 37.5 mg/kg in the first phase of the formalin test. The effect of RDHC was higher in the chronic phase (inflammation phase) of the formalin test (86.4%, P < 0.01). In addition, a significant analgesia (maximum possible effect; MPE = 30.1%) was observed in the hot plate test 45 min after injection of 37.5 mg/kg RDHC (P < 0.01). As a result of our findings, this new RDHC could be suggested for further pharmacological studies.
Apoptosis of Human Primary Osteoclasts Treated with Molecules Targeting Nuclear Factor‐κB
Authors: Piva Roberta , Penolazzi Letizia , Borgatti Monica , Lampronti Ilaria , Lambertini Elisabetta , Torreggiani Elena , Gambari Roberto
Published: August 2009

Osteoclasts (OCs) are involved in several pathologies associated with bone loss, including rheumatoid arthritis, osteoporosis, bone metastasis of myeloma, osteosarcoma, and breast cancer. In this review we determined the effects of natural compounds, including extracts from medicinal plants, on differentiation and survival of human primary OCs obtained from peripheral blood. We found that OCs from umbilical cord blood and peripheral blood behave differently in response to molecules inducing apoptosis in this experimental system. Apoptosis induced by decoy oligonucleotides was reproducibly obtained in OCs from peripheral blood but not in OCs derived from cord blood. With respect to effects of medicinal plants, we found that crude extracts of Emblica officinalis are able to induce specifically programmed cell death of mature OCs without altering the process of osteoclastogenesis. E. officinalis specifically increased the expression levels of Fas, a critical member of the apoptotic pathway. Gel shift experiments BioPharmaNet demonstrate that E. officinalis extracts specifically compete with the binding of a transcription factor involved in osteoclastogenesis NF‐κB to its specific target DNA sequences. This might explain the observed effects of E. officinalis on the expression levels of IL‐6, an NF‐κB‐specific target gene. We suggest the application of natural products as an alternative tool for therapy applied to bone diseases.
Changes in Antioxidant Status, Blood Pressure, and Lymphocyte DNA Damage from Grape Juice Supplementation
Authors: Park Yoo Kyoung , Lee Sun Hee , Park Eunju , Kim Jung‐shin , Kang Myung‐Hee
Published: August 2009

In a placebo‐controlled double‐blinded study, the effect of 8 weeks of grape juice was compared to the effect of isocaloric placebo juice. Volunteers with a systolic blood pressure > 130 mmHg and diastolic blood pressure > 90 mmHg were recruited. A total of 40 healthy subjects were randomized to receive isocaloric juices for 8 weeks. Twenty‐one subjects were instructed to consume 5.5 mL/kg daily of grape juice (GJ), and 19 subjects consumed placebo juice (PJ). Plasma antioxidant vitamin C, total radical trapping antioxidant capacity, blood pressure, and lymphocyte DNA damage were assessed pre‐ and postsupplementation. Plasma total radical‐trapping antioxidant potential showed an increase at the level of 1.31 ± 0.01 (postsupplementation) versus 1.33 ± 0.01 (presupplementation) (P < 0.1). Grape juice consumption resulted in a 26% decrease in lymphocyte DNA (both hydrogen peroxide treated or spontaneous) in the grape juice group, while no difference was found in the PJ group. Consuming moderate amounts of daily grape juice may favorably affect antioxidant defense systems and lymphocyte DNA damage in hypertensive individuals.
eEF1A2 as a Putative Oncogene
Authors: Lee Mee‐Hyun , Surh Young‐Joon
Published: August 2009

The first evidence for the role of the protein elongation factor eEF1A2 in tumorigenesis was reported by Anand and colleagues who demonstrated that eEF1A2 is overexpressed in about 30% of ovarian tumors and some established ovarian cancer cells. This abnormal expression correlates with a poor prognosis. Since this discovery, there have been several reports suggesting eEF1A2 as a diagnostic marker in various cancers. This review highlights the oncogenic potential of eEF1A2.
Signal Transducer and Activator of Transcription‐3, Inflammation, and Cancer
Authors: Aggarwal Bharat B. , Kunnumakkara Ajaikumar B. , Harikumar Kuzhuvelil B. , Gupta Shan R. , Tharakan Sheeja T. , Koca Cemile , Dey Sanjit , Sung Bokyung
Published: August 2009

Signal transducer and activator of transcription‐3 (STAT‐3) is one of six members of a family of transcription factors. It was discovered almost 15 years ago as an acute‐phase response factor. This factor has now been associated with inflammation, cellular transformation, survival, proliferation, invasion, angiogenesis, and metastasis of cancer. Various types of carcinogens, radiation, viruses, growth factors, oncogenes, and inflammatory cytokines have been found to activate STAT‐3. STAT‐3 is constitutively active in most tumor cells but not in normal cells. Phosphorylation of STAT‐3 at tyrosine 705 leads to its dimerization, nuclear translocation, DNA binding, and gene transcription. The phosphorylation of STAT‐3 at serine 727 may regulate its activity negatively or positively. STAT‐3 regulates the expression of genes that mediate survival (survivin, bcl‐xl, mcl‐1, cellular FLICE‐like inhibitory protein), proliferation (c‐fos, c‐myc, cyclin D1), invasion (matrix metalloproteinase‐2), and angiogenesis (vascular endothelial growth factor). STAT‐3 activation has also been associated with both chemoresistance and radioresistance. STAT‐3 mediates these effects through its collaboration with various other transcription factors, including nuclear factor‐κB, hypoxia‐inducible factor‐1, and peroxisome proliferator activated receptor‐γ. Because of its critical role in tumorigenesis, inhibitors of this factor's activation are being sought for both prevention and therapy of cancer. This has led to identification of small peptides, oligonucleotides, and small molecules as potential STAT‐3 inhibitors. Several of these small molecules are chemopreventive agents derived from plants. This review discusses the intimate relationship between STAT‐3, inflammation, and cancer in more detail.
Effects of 15‐Deoxy‐Δ12,14‐prostaglandin J2 on the Expression of p53 in MCF‐7 Cells
Authors: Kim Do‐Hee , Kim Eun‐Hee , Na Hye‐Kyung , Surh Young‐Joon
Published: August 2009

Cyclopentenone prostaglandins (cyPGs) exert diverse cellular functions, such as anti‐inflammatory and cytoprotective effects, via multiple mechanisms. CyPGs, especially those of the A and J series, are characterized by the presence of a chemically reactive α,β‐unsaturated carbonyl group. 15‐Deoxy‐Δ12,14‐prostaglandin J2 (15d‐PGJ2), a representative cyPG of the J series, has been reported to directly inhibit the activity of redox‐sensitive transcription factors, such as activator protein‐1 and nuclear factor‐κB. In the present study, we examined the effects of 15d‐PGJ2 on activation of p53 tumor suppressor in human breast cancer (MCF‐7) cells. MCF‐7 cells treated with 15d‐PGJ2 exhibited elevated p53 protein expression in time‐ and concentration‐related manners, whereas prostaglandin A2 (PGA2) and the nonprostaglandin derivative 2‐cyclopenten‐1‐one exerted an effect to a lesser extent than did 15d‐PGJ2. In addition, MCF‐7 cells exposed to 15d‐PGJ2 significantly accumulated p53 in both cytosolic and nuclear fractions. Despite the elevated levels of p53, its DNA‐binding activity was reduced in 15d‐PGJ2‐treated MCF‐7 cells. Moreover, isolated MCF‐7 nuclear extracts directly treated with 15d‐PGJ2 exhibite diminished DNA‐binding ability of p53, while the same concentration of PGA2 or 2‐cyclopenten‐1‐one was much less inhibitory. Thus, the electrophilic carbon center located in the α,β‐unsaturated carbonyl moiety of the cyclopentenone ring might be critical for the control of DNA‐binding activity as well as cellular levels of p53 by 15d‐PGJ2.
Effects of Exercise on Cyclooxygenase‐2 Expression and Nuclear Factor‐κB DNA Binding in Human Peripheral Blood Mononuclear Cells
Authors: Kim Si‐Young , Jun Tae‐Won , Lee Young‐Soo , Na Hye‐Kyung , Surh Young‐Joon , Song Wook
Published: August 2009

There are multiple lines of compelling evidence supporting the beneficial effect of exercise on the prevention and/or improvement of certain chronic diseases. However, exhaustive or intense exercise causes oxygen free radical generation and oxidative stress, which can lead to injuries and chronic fatigue as well as inflammation. Abnormal upregulation of cyclooxygenase‐2 (COX‐2), a rate‐limiting enzyme in prostaglandin biosynthesis, has been implicated in many inflammation‐associated chronic disorders. Nuclear factor‐κB (NF‐κB) is a major transcription factor involved in regulation of COX‐2 gene expression. To determine whether inflammation induction is dependent on intensity of exercise, COX‐2 expression and NF‐κB activation were adopted as the main targets. Thirteen volunteers who participated in the exercise program were subject to four exercise intensities [40, 60, 80, and 100% of heart rate reserve (HRR)] on a treadmill and to resting conditions. Isolated human peripheral blood mononuclear cells (PBMCs) were collected during the resting state and immediately after exercise and subjected to the electrophoretic mobility gel shift assay and Western blot analysis. As exercise intensity increased, both COX‐2 expression and NF‐κB DNA‐binding activity were enhanced. The expression of IκB kinase α (IKKα) and IκBα were not significantly altered. However, exhaustive/vigorous exercise (100% HRR) could induce the phosphorylation of both IKKα and IκBα. In conclusion, a single bout of exercise induced COX‐2 expression and DNA‐binding activity of NF‐κB in human PBMCs, and both COX‐2 expression and DNA‐binding activity of NF‐κB were dependent on exercise intensity.
Involvement of Reactive Oxygen Species in Apoptosis Induced by Pharmacological Inhibition of Protein Kinase CK2
Authors: Hanif Ismail M. , Ahmad Kashif A. , Ahmed Khalil , Pervaiz Shazib
Published: August 2009

It has been reported that inhibition of protein kinase CK2 (CK2) with antisense oligodeoxynucleotides (ODN) is a potent inducer of apoptosis in cancer cells but not in normal cells. In this regard, the apoptotic‐inducing effect is attributed to the catalytic activity of the enzyme, which phosphorylates proapoptotic proteins to inhibit their functions. In this study we investigate the role of intracellular redox status in the proapoptotic activity of CK2 inhibition in human leukemia Cem cells. We provide evidence that inhibition of CK2 activity induces apoptotic cell death as evident by activation of caspase 3, DNA fragmentation, and phosphatidylserine externalization. Inhibition of CK2 resulted in a significant increase in intracellular hydrogen peroxide production, which we show as a critical mediator of apoptosis. To that end, apoptotic hallmarks, like DNA fragmentation and phosphatidylserine externalization, were blocked with the specific hydrogen peroxide scavenger catalase. We also show that inhibition of CK2 reduces cytosolic intracellular superoxide, a precursor of hydrogen peroxide. In summary, decreasing CK2 activity increases intracellular hydrogen peroxide, creating an intracellular environment conducive for death execution. Taken together, these data provide information on novel pathways involved in CK2 biology with implications for effective tools against drug‐resistant tumors.
Study of Antiseizure Effects of Matricaria recutita Extract in Mice
Authors: Heidari M. R. , Dadollahi Z. , Mehrabani M. , Mehrabi H. , Pourzadeh‐Hosseini M. , Behravan E. , Etemad L.
Published: August 2009

Matricaria recutita L. is a well‐known medicinal plant that is suggested as being carminative, analgesic, and anticonvulsant in traditional medicine. In the present investigation the effect of hydro‐methanolic percolated extract of this plant on seizure induced by picrotoxin was studied in male mice. This study was performed on animals pretreated with doses of 100, 200, and 300 mg/kg of extract or 40 mg/kg phenobarbital as the reference drug via intraperitoneal injection. After 20 min each animal received 12 mg/kg picrotoxin for induction of seizure. Latency of onset time of seizure, duration of seizure, death latency, and death rate were determined in experimental and control groups. The results showed that latency of the beginning time of seizure was increased in groups that were pretreated with different doses of extract. The most effective dose was 200 mg/kg (P < 0.05). In addition, this dose delayed the time of death in mice (P < 0.01). The extract had no effect on the death rate. The results indicate that the extract of M. recutita possesses suitable effects on seizure induced by picrotoxin, and more experiments are needed in this field.
Antioxidant and Apoptotic Effects of Korean White Ginseng Extracted with the Same Ratio of Protopanaxadiol and Protopanaxatriol Saponins in Human Hepatoma HepG2 Cells
Authors: Lee Myoungsook , Sorn Sungbin , Baek Seungyong , Jang Soojung , Kim Sungsoo
Published: August 2009

To investigate the antioxidative effects of ginsenosides [protopanaxadiol derivatives (PD):protopanaxatriol derivatives (PT) = 1:1] from the roots of Korean ginseng, cell viability, malondialdehyde (MDA) production, antioxidant enzyme activities, and expressions of apoptosis were analyzed after pretreatment of human hepatoma HepG2 cells with H2O2. Cell death was increased through H2O2 treatment dose dependently, and a dose of ginseng extract (PD:PT = 1:1) of 18.6 μg/mL was enough to derive it in reverse. MDA production was reduced through the administration of ginseng extracts even with more intensive H2O2 treatments. Through the use of even low levels of ginseng extract (e.g., 1.86 μg/mL), catalase (CAT) activity was easily reduced from the plateau induced by H2O2. The glutathione peroxidase activity was no better than that of CAT. We assume that ginseng extract acts as an antioxidant even when effective levels of ginseng differ. A ginseng extract dose of 18.6 μg/mL increased the apoptotic expression of oxidative stressed signals, such as c‐Jun‐N‐terminal kinase and stress‐activated protein kinase expressions, and mitochondrial cytochrome c released caspase‐3 activation; however, these expressions changed with higher doses of ginseng.
Synovial Inflammation in Patients with Osteonecrosis of the Femoral Head
Authors: Rabquer Bradley J. , Tan Giselle J. , Shaheen Philip J. , Haines III G. Kenneth , Urquhart Andrew G. , Koch Alisa E.
Published: August 2009

Much of the work aimed at elucidating the pathogenesis of osteonecrosis (ON) of the femoral head has focused on bone blood supply, with little attention to the surrounding synovial tissue (ST). We hypothesized that patients with ON exhibit synovial inflammation. Using immunohistological techniques, we found that a large population of patients with ON had synovial inflammation. Moreover, a population of ON patients had inflamed ST without having an inflammatory disease co‐morbidity. The inflammatory infiltrate in these patients comprised primarily CD4+ T cells and CD68+ macrophages, the latter of which expressed increased levels of cellular adhesion molecules. Our results suggest the presence of a previously unrecognized population of ON patients without a diagnosed inflammatory co‐morbidity and a highly inflammed synovium consisting primarily of a macrophage and CD4+ T‐cell infi ltrate.
Retinol‐Binding Protein in Serum and Urine of Hyperthyroid Cats before and after Treatment with Radioiodine
Authors: Van Hoek I. , Meyer E. , Duchateau L. , Peremans K. , Smets P. , Daminet S.
Published: August 2009

Background:Retinol‐binding protein (RBP) is suggested as a clinically useful marker of renal function in cats.

Hypothesis:Serum and urinary RBP concentrations in hyperthyroid (HT) cats differ from those in healthy (H) cats; radioiodine (131I) treatment influences serum and urinary RBP concentrations in HT cats.

Animals:Ten HT and 8 H cats.

Methods:RBP concentration was evaluated in feline serum and urine samples from a prospective study.

Results:There was a significant (P= .003) difference in the urinary RBP/creatinine (uRBP/c) ratios of H (−) and untreated HT (1.4 ± 1.5 × 10−2 μg/mg) cats. Serum total thyroxine concentration (1.8 ± 1.9 μg/dL, 24 weeks) and uRBP/c (0.6 ± 1.0 × 10−2 μg/mg, 24 weeks) decreased significantly (P< .001) in HT cats at all time points after treatment with131I, and these variables were significantly correlated with one another (r= 0.42,P= .007). Serum RBP concentrations from HT cats (199 ± 86 μg/L) did not differ significantly (P= .98) from those of H cats (174 ± 60) and did not change after treatment with131I (182 ± 124 μg/L,P= .80).

Conclusion and Clinical Importance:The presence of urinary RBP in HT cats is a potential marker of tubular dysfunction that is correlated to thyroid status, although it is independent of circulating RBP concentrations. The decreased uRBP/c combined with the absence of changes in serum RBP after treatment suggests that the suspected tubular dysfunction was partly reversible with treatment of131I.
The changes in neuromuscular excitability with normobaric hyperoxia in humans
Authors: Brerro‐Saby Christelle , Delliaux Stéphane , Steinberg Jean Guillaume , Jammes Yves
Published: August 2009

Based on previous observations in hyperbaric hyperoxia, we hypothesized that normobaric hyperoxia, often used during general anaesthesia and resuscitation, might also induce a neuromuscular excitability. In heathy volunteers, we studied the consequences of a 50 min period of pure oxygen breathing on the neuromuscular conduction time (CT), the amplitude of the compound evoked muscle potential (M‐wave), the latency and amplitude of the Hoffman reflex (H reflex) and the electromyographic tonic vibratory response (TVR) of the flexor digitorum superficialis muscle to explore the proprioceptive reflex loop. Hyperoxia‐induced oxidative stress was measured by the changes in blood markers of lipid peroxidation (thiobarbituric acid reactive substances, TBARS) and antioxidant response (reduced ascorbic acid, RAA). During hyperoxia, the M‐wave amplitude increased, both CT and H reflex latency were shortened, and the H reflex amplitude increased. By contrast, TVR significantly decreased. Concomitantly, an oxidative stress was assessed by increased TBARS and decreased RAA levels. This study shows the existence of dual effects of hyperoxia, which facilitates the muscle membrane excitability, nerve conduction and spinal reflexes, but reduces the gain of the proprioceptive reflex loop. The activation of the group IV muscle afferents by hyperoxia and the resulting oxidative stress might explain the TVR depression.
Longitudinal Study of
Escherichia coli
O157:H7 in a Beef Cattle Feedlot and Role of High-Level Shedders in Hide Contamination
Authors: Arthur Terrance M. , Keen James E. , Bosilevac Joseph M. , Brichta-Harhay Dayna M. , Kalchayanand Norasak , Shackelford Steven D. , Wheeler Tommy L. , Nou Xiangwu , Koohmaraie Mohammad
Published: August 2009

The objectives of the study described here were (i) to investigate the dynamics of
Escherichia coli
O157:H7 fecal and hide prevalence over a 9-month period in a feedlot setting and (ii) to determine how animals shedding
E. coli
O157:H7 at high levels affect the prevalence and levels of
E. coli
O157:H7 on the hides of other animals in the same pen. Cattle (
n
= 319) were distributed in 10 adjacent pens, and fecal and hide levels of
E. coli
O157:H7 were monitored. When the fecal pen prevalence exceeded 20%, the hide pen prevalence was usually (25 of 27 pens) greater than 80%. Sixteen of 19 (84.2%) supershedder (>10
4
CFU/g) pens had a fecal prevalence greater than 20%. Significant associations with hide and high-level hide (≥40 CFU/100 cm
2
) contamination were identified for (i) a fecal prevalence greater than 20%, (ii) the presence of one or more high-density shedders (≥200 CFU/g) in a pen, and (iii) the presence of one or more supershedders in a pen. The results presented here suggest that the
E. coli
O157:H7 fecal prevalence should be reduced below 20% and the levels of shedding should be kept below 200 CFU/g to minimize the contamination of cattle hides. Also, large and unpredictable fluctuations within and between pens in both fecal and hide prevalence of
E. coli
O157:H7 were detected and should be used as a guide when preharvest studies, particularly preharvest intervention studies, are designed.
Investigation of Associations of
Yarrowia lipolytica
,
Staphylococcus xylosus
, and
Lactococcus lactis
in Culture as a First Step in Microbial Interaction Analysis
Authors: Mansour S. , Bailly J. , Landaud S. , Monnet C. , Sarthou A. S. , Cocaign-Bousquet M. , Leroy S. , Irlinger F. , Bonnarme P.
Published: August 2009

The interactions that may occur between microorganisms in different ecosystems have not been adequately studied yet. We investigated yeast-bacterium interactions in a synthetic medium using different culture associations involving the yeast
Yarrowia lipolytica
1E07 and two bacteria,
Staphylococcus xylosus
C2a and
Lactococcus lactis
LD61. The growth and biochemical characteristics of each microorganism in the different culture associations were studied. The expression of genes related to glucose, lactate, and amino acid catabolism was analyzed by reverse transcription followed by quantitative PCR. Our results show that the growth of
Y. lipolytica
1E07 is dramatically reduced by the presence of
S. xylosus
C2a. As a result of a low amino acid concentration in the medium, the expression of
Y. lipolytica
genes involved in amino acid catabolism was downregulated in the presence of
S. xylosus
C2a, even when
L. lactis
was present in the culture. Furthermore, the production of lactate by both bacteria had an impact on the lactate dehydrogenase gene expression of the yeast, which increased up to 30-fold in the three-species culture compared to the
Y. lipolytica
1E07 pure culture.
S. xylosus
C2a growth dramatically decreased in the presence of
Y. lipolytica
1E07. The growth of lactic acid bacteria was not affected by the presence of
S. xylosus
C2a or
Y. lipolytica
1E07, although the study of gene expression showed significant variations.
Multiplex PCR for Detection of Botulinum Neurotoxin-Producing Clostridia in Clinical, Food, and Environmental Samples
Authors: De Medici Dario , Anniballi Fabrizio , Wyatt Gary M. , Lindström Miia , Messelhäußer Ute , Aldus Clare F. , Delibato Elisabetta , Korkeala Hannu , Peck Michael W. , Fenicia Lucia
Published: August 2009

Botulinum neurotoxin (BoNT), the most toxic substance known, is produced by the spore-forming bacteriumClostridium botulinumand, in rare cases, also by some strains ofClostridium butyricumandClostridium baratii. The standard procedure for definitive detection of BoNT-producing clostridia is a culture method combined with neurotoxin detection using a standard mouse bioassay (SMB). The SMB is highly sensitive and specific, but it is expensive and time-consuming and there are ethical concerns due to use of laboratory animals. PCR provides a rapid alternative for initial screening for BoNT-producing clostridia. In this study, a previously described multiplex PCR assay was modified to detect all type A, B, E, and F neurotoxin genes in isolated strains and in clinical, food, environmental samples. This assay includes an internal amplification control. The effectiveness of the multiplex PCR method for detecting clostridia possessing type A, B, E, and F neurotoxin genes was evaluated by direct comparison with the SMB. This method showed 100% inclusivity and 100% exclusivity when 182 BoNT-producing clostridia and 21 other bacterial strains were used. The relative accuracy of the multiplex PCR and SMB was evaluated using 532 clinical, food, and environmental samples and was estimated to be 99.2%. The multiplex PCR was also used to investigate 110 freshly collected food and environmental samples, and 4 of the 110 samples (3.6%) were positive for BoNT-encoding genes.
Virulence Genes and Molecular Typing of Different Groups of
Escherichia coli
O157 Strains in Cattle
Authors: Tóth István , Schmidt Herbert , Kardos Gábor , Lancz Zsuzsanna , Creuzburg Kristina , Damjanova Ivelina , Pászti Judit , Beutin Lothar , Nagy Béla
Published: August 2009

Characterization of an
Escherichia coli
O157 strain collection (
n
= 42) derived from healthy Hungarian cattle revealed the existence of diverse pathotypes. Enteropathogenic
E. coli
(EPEC;
eae
positive) appeared to be the most frequent pathotype (
n
= 22 strains), 11 O157 strains were typical enterohemorrhagic
E. coli
(EHEC;
stx
and
eae
positive), and 9 O157 strains were atypical, with none of the key
stx
and
eae
virulence genes detected. EHEC and EPEC O157 strains all carried
eae-
gamma,
tir-
gamma,
tccP
, and
paa
. Other virulence genes located on the pO157 virulence plasmid and different O islands (O island 43 [OI-43] and OI-122), as well as
espJ
and
espM
, also characterized the EPEC and EHEC O157 strains with similar frequencies. However, none of these virulence genes were detected by PCR in atypical O157 strains. Interestingly, five of nine atypical O157 strains produced cytolethal distending toxin V (CDT-V) and carried genes encoding long polar fimbriae. Macro-restriction fragment enzyme analysis (pulsed-field gel electrophoresis) revealed that these
E. coli
O157 strains belong to four main clusters. Multilocus sequence typing analysis revealed that five housekeeping genes were identical in EHEC and EPEC O157 strains but were different in the atypical O157 strains. These results suggest that the Hungarian bovine
E. coli
O157 strains represent at least two main clones: EHEC/EPEC O157:H7/NM (nonmotile) and atypical CDT-V-producing O157 strains with H antigens different from H7. The CDT-V-producing O157 strains represent a novel genogroup. The pathogenic potential of these strains remains to be elucidated.
Little Heterogeneity among Genes Encoding Heat-Labile and Heat-Stable Toxins of Enterotoxigenic
Escherichia coli
Strains Isolated from Diarrheal Pigs
Authors: Zhang Chengxian , Rausch Dana , Zhang Weiping
Published: August 2009

To examine whether the heat-labile enterotoxin gene in porcine enterotoxigenic
Escherichia coli
(ETEC) strains is as divergent as in human ETEC strains, we sequenced the heat-labile and heat-stable toxin genes from 52 and 33 porcine ETEC strains, respectively. We found that the STa gene is identical, that the LT gene has only two mutations in 4 (of 52) strains, and that both mutations cause a reduction in GM1 binding and toxicity.
Zif, the Zoocin A Immunity Factor, Is a FemABX-Like Immunity Protein with a Novel Mode of Action
Authors: Gargis Shaw R. , Gargis Amy S. , Heath Harry E. , Heath Lucie S. , LeBlanc Paul A. , Senn Maria M. , Berger-Bächi Brigitte , Simmonds Robin S. , Sloan Gary L.
Published: August 2009

Producer cell immunity to the streptococcolytic enzyme zoocin A, which is a
d
-alanyl-
l
-alanine endopeptidase, is due to Zif, the zoocin A immunity factor. Zif has high degrees of similarity to MurM and MurN (members of the FemABX family of proteins), which are responsible for the addition of amino acids to cross bridges during peptidoglycan synthesis in streptococci. In this study, purified peptidoglycans from strains with and without
zif
were compared to determine how Zif modifies the peptidoglycan layer to cause resistance to zoocin A. The peptidoglycan from each strain was hydrolyzed using the streptococcolytic phage lysin B30, and the resulting muropeptides were separated by reverse-phase high-pressure liquid chromatography, labeled with 4-sulfophenyl isothiocyanate, and analyzed by tandem mass spectrometry in the negative-ion mode. It was determined that Zif alters the peptidoglycan by increasing the proportion of cross bridges containing three
l
-alanines instead of two. This modification decreased binding of the recombinant target recognition domain of zoocin A to peptidoglycan. Zif-modified peptidoglycan also was less susceptible to hydrolysis by the recombinant catalytic domain of zoocin A. Thus, Zif is a novel FemABX-like immunity factor because it provides resistance to a bacteriolytic endopeptidase by lengthening the peptidoglycan cross bridge rather than by causing an amino acid substitution.