Effects of Poly-L-Lactic Acid on Adipogenesis and Collagen Gene Expression in Cultured Adipocytes Irradiated with Ultraviolet B Rays

BACKGROUND

Poly-L-lactic acid (PLLA), a synthetic, biocompatible, and biodegradable polymer, has been safely used in several clinical applications. Recently, PLLA has been widely used in the field of dermatology to treat wrinkles in aging skin. Reportedly, PLLA directly acts on dermal fibroblasts causing a significant increase in the expression of type I collagen. However, little is known about the effect of PLLA on adipocytes.

OBJECTIVE

This study aimed to analyze the effect of PLLA on adipocytes and examine its potential in treating deep wrinkles engendered by the loss of subcutaneous fat because of aging and photoaging.

METHODS

To elucidate the effect of PLLA on skin photoaging, cultured 3T3-L1 adipocytes were irradiated with ultraviolet B (UVB) rays. Oil red O staining was used to detect lipid accumulation in the adipocytes. Real-time quantitative polymerase chain reaction and Western blotting were performed to detect types IV and VI collagen mRNA and protein levels, respectively, under different conditions.

RESULTS

The differentiation of 3T3-L1 cells enhanced adipogenesis and the expression of types IV and VI collagens, both of which were inhibited by UVB irradiation. Following this irradiation, PLLA stimulated adipogenesis and the expression of types IV and VI collagens.

CONCLUSION

PLLA may provide the beneficial effect on adipocytes from the aspect of adipogenesis and collagen expression in the subcutaneous adipose tissues.

Diagnostic Role of Bile Pigment Components in Biliary Tract Cancer

Bile pigment, bilirubin, and biliverdin concentrations may change as a results of biliary tract cancer (BTC) altering the mechanisms of radical oxidation and heme breakdown. We explored whether changes in bile pigment components could help distinguish BTC from benign biliary illness by evaluating alterations in patients with BTC. We collected bile fluid from 15 patients with a common bile duct stone (CBD group) and 63 individuals with BTC (BTC group). We examined the bile fluid's bilirubin, biliverdin reductase (BVR), heme oxygenase (HO-1), and bacterial taxonomic abundance. Serum bilirubin levels had no impact on the amounts of bile HO-1, BVR, or bilirubin. In comparison to the control group, the BTC group had considerably higher amounts of HO-1, BVR, and bilirubin in the bile. The areas under the curve for the receiver operating characteristic curve analyses of the BVR and HO-1 were 0.832 (p<0.001) and 0.891 (p<0.001), respectively. Firmicutes was the most prevalent phylum in both CBD and BTC, according to a taxonomic abundance analysis, however the Firmicutes/Bacteroidetes ratio was substantially greater in the BTC group than in the CBD group. The findings of this study showed that, regardless of the existence of obstructive jaundice, biliary carcinogenesis impacts heme degradation and bile pigmentation, and that the bile pigment components HO-1, BVR, and bilirubin in bile fluid have a diagnostic significance in BTC. In tissue biopsies for the diagnosis of BTC, particularly for distinguishing BTC from benign biliary strictures, bile pigment components can be used as additional biomarkers.

Resistance of hypervirulent Klebsiella pneumoniae to cathepsin B-mediated pyroptosis in murine macrophages

Introduction

Hypervirulent Klebsiella pneumoniae (hvKp) has emerged as a clinically significant global pathogen in the last decade. However, the host immune responses of the macrophages during hvKp infection are largely unknown. In the present study, we aimed to compare the cytotoxic effects of hvKp and classical K. pneumoniae (cKp) in murine macrophages.

Results

We found that the activation of caspase-1 -dependent pyroptosis was higher in cKp-infected macrophages compared with that in hvKp-infected macrophages. In Caspase-1 deficiency macrophages, pyroptosis diminished during infection. Both hvKp and cKp strains led to nucleotide-binding and oligomerization domain-like receptor protein 3 (NLRP3) inflammasome formation and lysosomal cathepsin B activation, thus resulting in pyroptosis. Compared with the cKp strain, the hvKp strain inhibited these phenomena in murine macrophages.

Conclusion

HvKp infection resulted in different levels of pyroptosis via the activation of cathepsin B-NLRP3-caspase-1 in murine macrophages. Therefore, the manipulation of pyroptotic cell death is a potential target for host response during hvKp infection in macrophages.

Circulating microRNAs as biomarkers in bile-derived exosomes of cholangiocarcinoma

Purpose

In this pilot study, using next-generation sequencing and integrated messenger RNA (mRNA) sequencing, we investigated circulating microRNA (miRNA) expression profiling from bile-derived exosomes to identify dysregulated miRNA signatures and oncogenic pathways and determine their effects on targeted mRNAs in cholangiocarcinoma (CCA). Moreover, we explored the possibility that genetic analysis using bile-derived exosomes may replace gene analysis using tissue.

Methods

Bile was collected from a patient with perihilar CCA before curative resection. As a control, bile was collected from a patient with a common bile duct stone. Exosomes were isolated from the bile, and we performed next-generation miRNA sequencing using isolated exosomes. To evaluate miRNA-mRNA interactions, mRNA sequencing was performed using bile fluid in both patients.

Results

We identified 22 differentially expressed miRNAs. More than 65% of the predicted mRNA targets of those miRNAs were actually differentially expressed between control and CCA bile samples. In functional pathway analysis, targets of 22 miRNAs were primarily enriched in mitogen-activated protein kinase, platelet derived growth factor, vascular endothelial growth factor, epidermal growth factor receptor, and p53 signaling. In particular, in the functional assessment of miRNA-mRNA interactions, RAS pathways, including downstream pathways (PI3K-AKT-mTOR and RAS-RAF-MEK-ERK), were determined to be enriched.

Conclusion

Circulating miRNAs in bile-derived exosomes provide new information for the development of miRNA analysis in CCA. These miRNAs may represent the oncogenic characteristics of CCA tissue, enabling them to be used instead of tissue samples for the diagnosis of CCA. Further research investigating circulating miRNAs in bile exosomes may lead to more rational, targeted approaches to treatment.

Liquid Biopsy from Bile-Circulating Tumor DNA in Patients with Biliary Tract Cancer

Simple Summary

Utilization of cell free DNA for diagnosing and monitoring patients with biliary tract cancers is emerging and promising. The strength of the present study is in its description of a novel approach using bile rather than blood or tissue samples, which is particularly relevant in biliary tract cancers. This paper largely serves as a proof of concept that ctDNA from bile is potentially feasible.

Abstract

Although liquid biopsy of blood is useful for cancer diagnosis and prediction of prognosis, diagnostic and prognostic value of ctDNA in bile fluid for BTCs are not clear yet. To determine whether liquid biopsy for circulating tumor DNA (ctDNA) can replace tissue biopsy when assessing somatic mutations in biliary tract cancers (BTCs). Bile samples were obtained from 42 patients with BTC. Matched formalin-fixed paraffin-embedded (FFPE) samples were obtained from 20 of these patients and matched plasma samples from 16 of them. Droplet digital PCR (ddPCR) was used for detection KRAS somatic mutation. KRAS mutations were identified in the bile ctDNA of 20 of 42 (48%) patients. Patients with mutant KRAS showed significantly worse survival than those with wild-type KRAS (2-year survival rates: 0% vs. 55.5%, respectively; p = 0.018). There was 80.0% mutational concordance between the paired bile ctDNA and FFPE samples, and 42.9% between the plasma and FFPE samples. On transcriptomic sequencing of one set of paired bile and FFPE samples, expression level of KRAS-associated signaling oncogenes in the bile and tissue samples showed a strong positive correlation (r = 0.991, p < 0.001). Liquid biopsy of bile reliably detect mutational variants within the bile ctDNA of BTC patients. These results suggest that bile is an effective biopsy fluid for ctDNA analysis.

Miconazole induces autophagic death in glioblastoma cells via reactive oxygen species-mediated endoplasmic reticulum stress

Miconazole is an antifungal agent that is used for the treatment of superficial mycosis. However, recent studies have indicated that miconazole also exhibits potent anticancer effects in various types of cancer via the activation of apoptosis. The main aim of the present study was to observe the effect of miconazole on autophagic cell death of cancer cells. Cytotoxicity was measured by viable cell counting after miconazole treatment in glioblastoma cell lines (U343MG, U87MG and U251MG). Induction of autophagy was analyzed by examining microtubule-associated protein light chain 3 (LC3)-II expression levels using western blotting and by detecting GFP-LC3 translocation using a fluorescence microscope. Intracellular ROS production was measured using a fluorescent probe, 2',7'-dichlorodihydrofluorescein diacetate. It was found that miconazole induced autophagic cell death in the U251MG glioblastoma cell line via the generation of reactive oxygen species (ROS) and endoplasmic reticulum (ER) stress response. An association between miconazole-induced ROS production and autophagy was also identified; in particular, pretreatment of the cells with a ROS scavenger resulted in a reduction in the levels of LC3-II. Miconazole-induced ER stress was associated with increases in binding immunoglobulin protein (BiP), inositol-requiring enzyme 1α (IRE1α) and CHOP expression, and phospho-eIF2α levels. The inhibition of ER stress via treatment with 4-phenylbutyric acid or BiP knockdown reduced miconazole-induced autophagy and cell death. These findings suggest that miconazole induces autophagic cell death by inducing an ROS-dependent ER stress response in U251MG glioma cancer cells and provide new insights into the potential antiproliferative effects of miconazole.

Usefulness of bile as a biomarker via ferroptosis and cysteine prenylation in cholangiocarcinoma; role of diagnosis and differentiation from benign biliary disease

BACKGROUND

Cholangiocarcinoma (CCA) is a malignant cancer of the biliary tract with a poor prognosis. Herein, we investigated possible mechanism of extrahepatic CCA (eCCA) by dysregulated iron metabolism and post-translational modifications (PTMs). Further, we evaluated potential biomarkers in the bile fluid for diagnosis of eCCA and differentiation between eCCA and benign biliary disease.

METHODS

From August 2018 to April 2019, we obtained bile fluids from 46 patients; 28 patients with eCCA (eCCA group) and 18 patients with common bile duct stone (Control group) via percutaneous transhepatic biliary drainage. We examined the levels of reduced glutathione (GSH), peroxide, ferrous iron [Fe⁺²], glutathione peroxidase (GP_X) and farnesyl transferase/geranylgeranyl transferase type-1 subunit alpha (FNTA) concentration in bile fluids to clarify the mechanism of ferroptosis and prenylation.

RESULTS

The remarkable difference of PTMs was that FNTA which means prenylated cysteine as regulator was significantly decreased in eCCA than that of control. In addition, level of GSH, peroxide, GP_X and ferrous iron [Fe⁺²] were significantly depleted in eCCA than control. These results demonstrate that PTM, dysregulated iron metabolism and GP_X-regulated ferroptosis with GSH depletion through cysteine modification in bile are possible mechanisms of eCCA. Liquid Chromatography (LC)-Mass Spectrometry (MS) analysis, several oncogenic pathways including MYC target, apoptosis, fatty acid metabolism, P53 and mTORC1 were enriched in eCCA.

CONCLUSIONS

In conclusion, redox-dependent modification of cysteine and ferroptosis in bile fluids are possible mechanisms of eCCA. Several protein and oncogenic pathways related to PTM which are seen in eCCA tissues were also enriched in bile fluids. It suggests that bile fluid represents the oncogenic characteristics of eCCA tissues. Therefore, bile fluids have a role of a biomarker for diagnosis in eCCA, especially, differentiation of eCCA from benign biliary stricture.

Juglone induces cell death of Acanthamoeba through increased production of reactive oxygen species

Juglone (5-hydroxy-1,4-naphthoquinone) is a major chemical constituent of Juglans mandshruica Maxim. Recent studies have demonstrated that juglone exhibits anti-cancer, anti-bacterial, anti-viral, and anti-parasitic properties. However, its effect against Acanthamoeba has not been defined yet. The aim of this study was to investigate the effect of juglone on Acanthamoeba. We demonstrate that juglone significantly inhibits the growth of Acanthamoeba castellanii at 3-5 μM concentrations. Juglone increased the production of reactive oxygen species (ROS) and caused cell death of A. castellanii. Inhibition of ROS by antioxidant N-acetyl-l-cysteine (NAC) restored the cell viability. Furthermore, our results show that juglone increased the uptake of mitochondrial specific dye. Collectively, these results indicate that ROS played a significant role in the juglone-induced cell death of Acanthamoeba.

Biofilm Formation and Colistin Susceptibility of Acinetobacter baumannii Isolated from Korean Nosocomial Samples

Biofilm formation, a virulence factor of Acinetobacter baumannii, is associated with long-term survival in hospital environments and provides resistance to antibiotics. Standard tests for antibiotic susceptibility involve analyzing bacteria in the planktonic state. However, the biofilm formation ability can influence antibiotic susceptibility. Therefore, here, the biofilm formation ability of A. baumannii clinical isolates from Korea was investigated and the susceptibility of biofilm and planktonic bacteria to colistin was compared. Of the 100 clinical isolates examined, 77% exhibited enhanced biofilm formation capacity relative to a standard A. baumannii strain (ATCC 19606). Differences between the minimal inhibitory concentrations and minimal biofilm-inhibitory concentrations of colistin were significantly greater in the group of A. baumannii that exhibited enhanced biofilm formation than the group that exhibited less ability for biofilm formation. Thus, the ability to form a biofilm may affect antibiotic susceptibility and clinical failure, even when the dose administered is in the susceptible range.

Genome-wide association study of medication adherence in chronic diseases in the korean population

Medication adherence is generally defined as the extent of voluntary cooperation of a patient in taking medicine as prescribed. Adherence to long-term treatment with chronic disease is essential for reducing disease comorbidity and mortality. However, medication non-adherence in chronic disease averages 50%. This study was conducted a genome-wide association study to identify the genetic basis of medication adherence. A total of 235 medication non-adherents and 1,067 medication adherents with hypertension or diabetes were used from the Korean Association Resource project data according to the self-reported treatment status of each chronic disease, respectively. We identified four single nucleotide polymorphisms with suggestive genome-wide association. The most significant single nucleotide polymorphism was rs6978712 (chromosome 7, p = 4.87 × 10^-7), which is located proximal to the GCC1 gene, which was previously implicated in decision-making capability in drug abusers. Two suggestive single nucleotide polymorphisms were in strong linkage disequilibrium (r² > 0.8) with rs6978712. Thus, in the aspect of decision-making in adherence behavior, the association between medication adherence and three loci proximal to the GCC1 gene seems worthy of further research. However, to overcome a few limitations in this study, defining the standardized phenotype criteria for self-reported adherence should be performed before replicating association studies.

Translational suppression of HIF-1α by miconazole through the mTOR signaling pathway

BACKGROUND

Miconazole is an imidazole antifungal agent that has amply been used in the treatment of superficial mycosis. Preliminary data indicate that miconazole may also induce anticancer effects. As yet, however, little is known about the therapeutic efficacy of miconazole on cancer and the putative mechanism(s) involved. Here, we show that miconazole suppresses hypoxia inducible factor-1α (HIF-1α) protein translation in different cancer-derived cells.

METHODS

The effect of miconazole on HIF-1α expression was examined by Western blotting and reverse transcriptase polymerase chain reaction assays in human U87MG and MCF-7 glioma and breast cancer-derived cell lines, respectively. The transcriptional activity of the HIF-1 complex was confirmed using a luciferase assay. To assess whether angiogenic factors are increased under hypoxic conditions in these cells, vascular endothelial growth factor (VEGF) levels were measured by ELISA. Metabolic labeling was performed to examine HIF-1α protein translation and global protein synthesis. The role of the mammalian target of rapamycin (mTOR) signaling pathway was examined to determine translation regulation of HIF-1α after miconazole treatment.

RESULTS

Miconazole was found to suppress HIF-1α protein expression through post-transcriptional regulation in U87MG and MCF-7 cells. The suppressive effect of HIF-1α protein synthesis was found to be due to inhibition of mTOR. Miconazole significantly inhibited the transcriptional activity of the HIF-1 complex and the expression of its target VEGF. Moreover, miconazole was found to suppress global protein synthesis by inducing phosphorylation of the translation initiation factor 2α (eIF2α).

CONCLUSION

Our data indicate that miconazole plays a role in translational suppression of HIF-1α. We suggest that miconazole may represent a novel therapeutic option for the treatment of cancer.

Pentamidine reduces expression of hypoxia-inducible factor-1α in DU145 and MDA-MB-231 cancer cells

Pentamidine is an aromatic diamine used for the treatment of human protozoa infections. Recently, pentamidine has been reported to exhibit anticancer properties. In this study, we report that pentamidine inhibits expression of hypoxia-inducible factor (HIF)-1α in cancer cells. Pentamidine decreased HIF-1α protein translation and enhanced its protein degradation in DU145 prostate cancer and MDA-MB-231 breast cancer cells. In parallel with reduction of de novo synthesis of HIF-1α, pentamidine was able to suppress global protein translation, an effect accompanied by the reduction of eIF4F complex formation and also the induction of eIF2α phosphorylation. These results show that pentamidine is a potential inhibitor of HIF-1α and its potential as a cancer therapeutic reagent warrants further study.

Melatonin down-regulates HIF-1 alpha expression through inhibition of protein translation in prostate cancer cells

Melatonin, the main secretory product of the pineal gland, has been shown to exert an oncostatic activity in cancer cells. Recently, several studies have shown that melatonin has antiangiogenic properties. However, the mechanism by which melatonin exerts antiangiogenenic effects is not understood. Hypoxia inducible factor (HIF)-1 is a transcription factor which mediates adaptive response to changes in tissue oxygenation. HIF-1 is a heterodimer formed by the association of a constitutively expressed HIF-1 beta subunit and a HIF-1 alpha subunit, the expression of which is highly regulated. In this study, pharmacologic concentrations of melatonin was found to inhibit expression of HIF-1 alpha protein under both normoxic and hypoxic conditions in DU145, PC-3, and LNCaP prostate cancer cells without affecting HIF-1 alpha mRNA levels. Consistent with the reduction in HIF-1 alpha protein levels, melatonin inhibited HIF-1 transcriptional activity and the release of vascular endothelial growth factor. We found that the suppression of HIF-1 alpha expression by melatonin correlated with dephosphorylation of p70S6K and its direct target RPS6, a pathway known to regulate HIF-1 alpha expression at the translational level. Metabolic labeling assays indicated that melatonin inhibits de novo synthesis of HIF-1 alpha protein. Taken together, these results suggest that the pharmacologic concentration of melatonin inhibits HIF-1 alpha expression through the suppression of protein translation in prostate cancer cells.

Cytokine array after cyclosporine treatment in rats

OBJECTIVES

Long-term treatment with cyclosporine (CsA) results in chronic nephrotoxicity, which is known to be mediated by several cytokines including transforming growth factor-betal. Cytokines are known to play an important role in innate immunity, apoptosis, angiogenesis, cell growth, and differentiation. They are known to be involved in most disease processes, including cancer, cardiac disease, and nephrotoxicity. To evaluate changes of cytokines in a rat model of CsA-induced chronic nephrotoxicity, we performed a cytokine array.

METHODS

Experiments were performed on two groups of rats; normal control group and CsA-treated group. Cytokine array in rat serum was performed using Cytokine Antibody Array I kit from RayBiotech.

RESULTS

Serum creatinine, urine creatinine, and creatinine clearance increased in the CsA-treated group. Among the several cytokines, the expressions of the lipopolysaccharide-induced CXC chemokine (LIX), monocyte chemoattractant protein 1 (MCP-1), nerve growth factor (beta-NGF), and tissue inhibitor of metalloproteinase-1 (TIMP-1) in the CsA-treated group were increased above that of cytokines in the control group. The density of the LIX in controls was 0.62, and in the CsA-treated group was 1.24. The density of the MCP-1 in controls was 0.68, and in CsA-treated, 1.43. The density of the beta-NGF in controls was 0.62, and that in CsA-treated, 1.24. The density of the TIMP-1 in controls 1.13, and in CsA-treated, 1.40.

CONCLUSIONS

Our data suggested that among several cytokines elevated levels of the LIX, MCP-1, beta-NGF, and TIMP-1 are the contributing factors to CsA-induced nephropathy.

The production of reactive oxygen species in tacrolimus-treated glial cells

OBJECTIVE

After organ transplantation, some patients suffer from mild neurological symptoms, such as tremor, to severe complications, including seizures and encephalopathy. These neurological side effects can be caused by immunosuppressants such as tacrolimus. However, the mechanism of encephalopathy by tacrolimus is not fully understood.

METHODS

We measured the production of reactive oxygen species (ROS) in glioma cells after tacrolimus treatment. Tacrolimus added to glioma cells was incubated for 60 minutes at 37 degrees C. The production of ROS was evaluated by measuring the fluorescent product from the oxidation of an oxidant-sensitive 2',7'-dichlorofluorescin using VICTOR3TM multilabel counter.

RESULTS

Tacrolimus resulted in the production of the ROS in glioma cells. The production of the ROS was increased in time-dependent fashion.

CONCLUSIONS

These findings indicated that the tacrolimus may contribute the neurological side effects by ROS production.

Cadmium specifically induces MKP-1 expression via the glutathione depletion-mediated p38 MAPK activation in C6 glioma cells

Cadmium is a toxic heavy metal and an environmental pollutant. Mitogen-activated protein kinase (MAPK) phosphatase-1 (MKP-1) is a negative regulator of the family of MAPK. In this study, we investigated the effect of heavy metals on MKP-1 expression in C6 rat glioma cells. Cadmium treatment induced MKP-1 at both protein and mRNA levels while cobalt or manganese treatment did not, suggesting the specificity. Cadmium treatment also depleted intracellular GSH and activated p38 MAPK, JNKs, and AKT. Profoundly, pretreatment with thiol-containing compounds NAC or GSH, but not vitamin E, blocked GSH depletion, 38 MAPK activation and MKP-1 expression by cadmium. Moreover, pharmacological inhibition of p38 MAPK by SB203580 suppressed the cadmium-induced MKP-1. Collectively, these results demonstrate that cadmium specifically induces MKP-1 by transcriptional up-regulation in C6 cells in a mechanism associated with the glutathione depletion-dependent p38 MAPK activation.

The significance of gastric juice analysis for a positive challenge by a standard oral challenge test in typical cow's milk protein-induced enterocolitis

This study was performed to investigate the significance of gastric juice analysis (GJA) as a diagnostic criterion of a positive challenge in a standard oral cow's milk challenge (OCC) to confirm typical cow's milk protein-induced enterocolitis (CMPIE). Data from 16 CMPIE patients (aged 14 to 44 days) were analyzed. A standard OCC was openly executed using 0.15 g/kg of protein. Three symptoms (vomiting, lethargy, and bloody or pus-like stool), and four laboratory findings (GJA [3 hr], changes in peripheral blood absolute neutrophil count [ANC] [6 hr], C-reactive protein [6 hr], and stool smear test for occult blood or leukocytes) were observed after OCC. Before OCC, baseline studies were conducted; a stool smear test, blood sampling, and GJA. Positive OCC results were; vomiting (87.5%) (observed 1-3 hr after OCC), lethargy (62.5%) (1-3 hr), bloody or pus-like stool (43.8%) (6-10 hr), abnormal GJA (93.8%), an ANC rise >3,500 cells/microL (93.8%), and an abnormal stool smear test (75.0%). A single GJA test after a standard OCC is a sensitive diagnostic criterion of a positive challenge, and may provide an early confirmatory diagnosis of CMPIE. An investigation of positive OCC outcomes helps to find out a diagnostic algorithm of criteria of a positive challenge in CMPIE.

Protective effects of several components of Gastrodia elata on lipid peroxidation in gerbil brain homogenates

Gastrodia elata (GE) Blume, a traditional herbal agent, has been used mainly in anticonvulsive treatment in Asia. Recently, extracts of GE were evaluated for their potential as neuroprotectives and antioxidants. This study was designed to examine the antioxidant effect of the ether fraction of the methanol extract (EFME) of GE along with its major constituents vanillin, vanillyl alcohol, hydroxybenzaldehyde and hydroxybenzyl alcohol. In experiment 1, gerbils were treated with EFME of GE at a dosage of 500 mg/kg/day for 2 weeks. Oxidative stress was induced with H(2)O(2) or ferrous ion, and lipid peroxidation was measured. In experiment 2, oxidative stress was induced with various concentrations of H(2)O(2) or ferrous ammonium sulfate, and lipid peroxidation was measured. To compare the antioxidant potency, the inhibitory concentration 50% (IC(50)) was determined. EFME of GE reduced auto-peroxidation and H(2)O(2)-induced lipid peroxidation. However, it did not significantly reduce ferrous ammonium sulfate-induced lipid peroxidation. The order of antioxidation potency was as follows: hydroxybenzyl alcohol > vanillyl alcohol > vanillin > hydroxybenzaldehyde. In the case of hydroxybenzaldehyde, its antioxidant effect was more potent than that of melatonin. The excellent antioxidant effects of GE and its main constituents may have potential in the treatment of lipid peroxidation-associated neurological disease.

12-O-tetradecanoyl phorbol 13-acetate induces the expression of B7-DC, -H1, -H2, and -H3 in K562 cells

Induction of the B7 family molecules by 12-O-tetradecanoyl phorbol 13-acetate (TPA) has been reported, however, the mechanism by which TPA up-regulates these molecules remains poorly understood. In this study, the expression of B7-DC, -H1, -H2, and -H3 in response to TPA was markedly induced in K562 cells. TPA also induced activation of ERK, p38 mitogen-activated protein kinase (MAPK), JNK, phosphatidylinositol-3-kinase (PI-3K), or nuclear factor (NF)-kappaB. Pre-treatments with protein kinase C (PKC) inhibitors significantly inhibited TPA-induced expression of B7-DC, -H1, -H2, and -H3 mRNA as well as TPA-induced phosphorylation of ERK, p38 MAPK, JNK, and PI-3K. TPA-induced expression of B7-DC, -H1, -H2, and -H3 mRNA was abrogated by pre-treatments with inhibitors of ERK and p38 MAPK. However, inhibition of PI-3K and JNK only caused decrease of TPA-induced B7-DC mRNA and B7-H3 mRNA, respectively. TPA-induced degradation of IkappaB-alpha was markedly abrogated by treatments with PKC inhibitors, but not by treatments with inhibitors of ERK, p38 MAPK, JNK, or PI-3K. NF-kappaB inhibitors significantly attenuated the expression of B7-DC, -H1, -H2, and -H3 mRNA in response to TPA. These results suggest that TPA induces the expression of B7-DC, -H1, -H2, and -H3 mRNA in K562 cells via activation of PKC, ERK, p38 MAPK, and NF-kappaB. Distinctly, the expression of B7-DC mRNA and -H3 mRNA in response to TPA is also PI-3K- and JNK-dependent, respectively.

Dexamethasone suppresses interleukin-1beta-induced human beta-defensin 2 mRNA expression: involvement of p38 MAPK, JNK, MKP-1, and NF-kappaB transcriptional factor in A549 cells

Human beta-defensin (HBD)-2 is an inducible antimicrobial peptide that plays an important role in innate immunity. Glucocorticoids, on the other hand, exert immunosuppressive and anti-inflammatory actions. We have previously reported that interleukin (IL)-1beta induces HBD-2 mRNA expression through the activation of nuclear factor-kappaB (NF-kappaB) transcriptional factor, as well as p38 mitogen-activated protein kinase (MAPK), c-Jun N-terminal kinase (JNK), or phosphatidylinositol-3-kinase/AKT in A549 cells. In this study, we further investigated whether dexamethasone (Dex) controls IL-1beta-induced HBD-2 mRNA expression in A549 cells and the molecular mechanism associated with it. Dex suppressed IL-1beta-induced HBD-2 mRNA expression, which is mediated by a glucocorticoid receptor, at the transcriptional level. Interestingly, Dex attenuated IL-1beta-mediated activation of p38 MAPK and JNK, but not of AKT. Dex increased the expression of MAPK phosphatase (MKP)-1, which dephosphorylated p38 MAPK, but not JNK, by IL-1beta. However, although Dex did not inhibit the nuclear translocation of p65 NF-kappaB in response to IL-1beta, it profoundly inhibited NF-kappaB promoter- and HBD-2 promoter-driven luciferase activities. These results suggest that Dex acts to inhibit IL-1beta-induced HBD-2 mRNA expression through blockage of the nuclear transcriptional activation of p65 NF-kappaB as well as through inactivation of p38 MAPK and JNK. Specifically, Dex-induced MKP-1 expression is responsible for the inactivation of p38 MAPK, but not JNK, in response to IL-1beta in A549 cells.

Glucosamine hydrochloride specifically inhibits COX-2 by preventing COX-2 N-glycosylation and by increasing COX-2 protein turnover in a proteasome-dependent manner

COX-2 and its products, including prostaglandin E(2), are involved in many inflammatory processes. Glucosamine (GS) is an amino monosaccharide and has been widely used for alternative regimen of (osteo) arthritis. However, the mechanism of action of GS on COX-2 expression remains unclear. Here we describe a new action mechanism of glucosamine hydrochloride (GS-HCl) to tackle endogenous and agonist-driven COX-2 at protein level. GS-HCl (but not GS sulfate, N-acetyl GS, or galactosamine HCl) resulted in a shift in the molecular mass of COX-2 from 72-74 to 66-70 kDa and concomitant inhibition of prostaglandin E(2) production in a concentration-dependent manner in interleukin (IL)-1beta-treated A549 human lung epithelial cells. Remarkably, GS-HCl-mediated decrease in COX-2 molecular mass was associated with inhibition of COX-2 N-glycosylation during translation, as assessed by the effect of tunicamycin, the protein N-glycosylation inhibitor, or of cycloheximide, the translation inhibitor, on COX-2 modification. Specifically, the effect of low concentration of GS-HCl (1 mM) or of tunicamycin (0.1 microg/ml) to produce the aglycosylated COX-2 was rescued by the proteasomal inhibitor MG132 but not by the lysosomal or caspase inhibitors. However, the proteasomal inhibitors did not show an effect at 5 mM GS-HCl, which produced the aglycosylated or completely deglycosylated form of COX-2. Notably, GS-HCl (5 mM) also facilitated degradation of the higher molecular species of COX-2 in IL-1beta-treated A549 cells that was retarded by MG132. GS-HCl (5 mM) was also able to decrease the molecular mass of endogenous and IL-1beta- or tumor necrosis factor-alpha-driven COX-2 in different human cell lines, including Hep2 (bronchial) and H292 (laryngeal). However, GS-HCl did not affect COX-1 protein expression. These results demonstrate for the first time that GS-HCl inhibits COX-2 activity by preventing COX-2 co-translational N-glycosylation and by facilitating COX-2 protein turnover during translation in a proteasome-dependent manner.

D-glucosamine inhibits proliferation of human cancer cells through inhibition of p70S6K

Although D-glucosamine has been reported as an inhibitor of tumor growth both in vivo and in vitro, the mechanism for the anticancer effect of D-glucosamine is still unclear. Since there are several reports suggesting D-glucosamine inhibits protein synthesis, we examined whether D-glucosamine affects p70S6K activity, an important signaling molecule involved in protein translation. In the present study, we found D-glucosamine inhibited the activity of p70S6K and the proliferation of DU145 prostate cancer cells and MDA-MB-231 breast cancer cells. D-glucosamine decreased phosphorylation of p70S6K, and its downstream substrates RPS6, and eIF-4B, but not mTOR and 4EBP1 in DU145 cells, suggesting that D-glucosamine induced inhibition of p70S6K is not through the inhibition of mTOR. In addition, D-glucosamine enhanced the growth inhibitory effects of rapamycin, a specific inhibitor of mTOR. These findings suggest that D-glucosamine can inhibit growth of cancer cells through dephosphorylation of p70S6K.

Triptolide suppresses interleukin-1beta-induced human beta-defensin-2 mRNA expression through inhibition of transcriptional activation of NF-kappaB in A549 cells

The immunosuppressive effect of triptolide has been associated with suppression of T-cell activation. However, the immunosuppressive effects of triptolide on innate immunity in the epithelial barrier remain to be elucidated. Human beta-defensin (HBD)-2 is an inducible antimicrobial peptide and plays an important role in the innate immunity. We have previously demonstrated that IL-1beta induced HBD-2 mRNA expression in A549 cells through activation of nuclear factor-kappaB (NF-kappaB) transcriptional factor as well as p38 mitogen-activated protein kinase (MAPK), c-Jun N-terminal kinase (JNK), or phosphatidylinositol-3-kinase (PI3K). In this study, we investigated effects of triptolide on IL-1beta-induced HBD-2 mRNA expression in A549 cells. Triptolide inhibited IL-1beta-induced HBD-2 mRNA expression in a dose-dependent manner. Addition of triptolide did not suppress activation of p38 MAPK, JNK, or PI3K in response to IL-1beta. Triptolide inhibited IL-1beta-induced MAPK phosphatase-1 expression at the transcriptional level and resulted in sustained phosphorylation of JNK or p38 MAPK, explaining the little effect of triptolide on IL-1beta-induced phosphorylation of these kinases. Although triptolide partially suppressed IL-1beta-mediated degradation of IkappaB-alpha and nuclear translocation of p65 NF-kappaB, triptolide potently inhibited NF-kappaB promoter-driven luciferase activity in A549 cells. These results collectively suggest that the inhibitory effect of triptolide on IL-1beta-induced HBD-2 mRNA expression in A549 cells seems to be at least in part mediated through nuclear inhibition of NF-kappaB transcriptional activity, but not inhibition of p38 MAPK, JNK, or PI3K. This inhibition may explain the ability of triptolide to diminish innate immune response.

Advanced criteria for clinicopathological diagnosis of food protein-induced proctocolitis

The clinicopathological findings in previous studies concerning food protein-induced proctocolitis (FPIPC) are quite diverse in terms of results and conclusions. The aim of this study was to suggest advanced clinicopathological diagnostic criteria that facilitate the early confirmation of FPIPC. Data of 38 FPIPC patients, who had received sigmoidoscopy and biopsy, was analyzed. Microscopic findings were compared with observations of previous studies. Feeding at onset of bleeding was exclusively breast-fed (94.7%) and formula-fed or mixed-fed (5.3%). Endoscopic abnormalities were observed in all patients; nodular hyperplasias with circumscribed and/or central pit-like erosions in 94.7% and erythema in 5.3%. Histopathological findings were; lymphoid aggregates in 94.7%, eosinophils in lamina propria of >or=60 cells/10 HPF in 97.4% and of >20 cells/HPF in 63.2%, epithelial or muscularis mucosa eosinophil infiltration in 97.4%, and crypt abscess in 2.6%. The majority of FPIPC patients are exclusively breast-fed and nodular hyperplasias with erosions may be a disease specific endoscopic finding. Histologic diagnosis of FPIPC is compatible with eosinophils in the lamina propria of >or=60 cells/10 high power fields; however, >20 cells/HPF is not an appropriate diagnostic criterion.

Effect of tacrolimus on the production of oxygen free radicals in hepatic mitochondria

OBJECTIVES

Cyclosporine (CsA) causes side effects that occur mainly in the kidney but also in the liver. Several reports have strongly suggested that the production of oxygen free radicals (OFRs) is a common mechanism of CsA toxicity. However, tacrolimus is believed to suppress the production of OFRs.

METHODS

We obtained the mitochondrial fraction with 96% purity from rat liver using a sucrose density gradient solution. Zero to 100 micromol/L tacrolimus was incubated with the mitochondrial fraction for 6 hours at 37 degrees C. OFRs were evaluated by measuring the fluorescent product from the oxidation of an oxidant-sensitive 2,7-dichlorefluorescein using a VICTOR3 multilabel counter.

RESULTS

The fluorescence units for OFR production were increased as the time of exposure to tacrolimus passed from 1 to 6 hours. The fluorescence units in 0.1 micromol/L tacrolimus were 6.0 x 10(5) at 1 hour, 7.8 x 10(5) at 2 hours, 9.0 x 10(5) at 3 hours, 10.0 x 10(5) at 4 hours, 11.1 x 10(5) at 5 hours, and 11.4 x 10(5) at 6 hours. However, the fluorescence units were similar although the tacrolimus concentration increases from 0.1 to 100 micromol/L.

CONCLUSIONS

The results in this experiment suggested that tacrolimus induced the production of OFRs depending on the exposure time.

Effects of cyclosporine and tacrolimus on the oxidative stress in cultured mesangial cells

OBJECTIVES

Cyclosporine (CsA) and tacrolimus (Tac) are two primary immunosuppressive agents used for the prevention of graft rejection. However, their use is associated with significant side effects, most notably nephrotoxicity. The mechanisms of this toxicity are not fully understood, but they seem to be associated with increases in the production of oxygen free radicals (OFRs). This present work examined the effect of CsA and Tac on the production of OFRs in cultured rat renal mesangial cells (RMCs).

METHODS

Varying concentrations of CsA and Tac (0 to 40 micromol/L) were added to RMCs and incubated for 60 minutes at 37 degrees C. The production of OFRs was evaluated by measuring the fluorescent product from the oxidation of an oxidant-sensitive 2', 7'-dichlorofluorescin.

RESULTS

At 60 minutes, the relative fluorescence units (RFU) for OFRs production in RMCs exposure to CsA were increased by 2.5%, 11.5%, 22.5%, 57.2%, and 174% at 2.5, 5, 10, 20, and 40 micromol/L, respectively. Tac increased the RFU by 15.9%, 13.6%, 14.8%, 13.2%, 21.4%, 13.2%, and 28.1% at 0.1, 1, 2.5, 5, 10, 20, and 40 micromol/L, respectively. In RMCs, the RFU produced by CsA was higher than that by Tac.

CONCLUSIONS

The results of this experiment suggest that CsA and Tac induced renal injury by OFRs.

Leptomycin B, a metabolite of Streptomyces, inhibits the expression of inducible nitric oxide synthase in BV2 microglial cells

Overexpression of inducible nitric oxide synthase (iNOS) and the resultant overproduction of NO has been implicated in neuronal inflammatory diseases. Leptomycin B (LMB), a metabolite of Streptomyces, has been identified as a specific inhibitor of CRM1 nuclear export receptor. In this study, we evaluated the effect of LMB on lipopolysaccharide (LPS)-induced iNOS expression in BV2 cells, a murine microglial cells and the associated mechanisms. LMB strongly inhibited LPS-induced iNOS protein and mRNA expressions in BV2 cells in which 10 ng/ml of LMB (18 nM) was sufficient to greatly down-regulate iNOS by LPS, suggesting the potency of LMB to inhibit iNOS. The data of iNOS promoter-driven luciferase assay further suggested that the LMB inhibitory effect was in part due to inhibition of iNOS transcription. However, LPS-induced activation of various intracellular signaling proteins, such as nuclear factor-kappaB (NF-kappaB), extracellular signal-regulated kinases (ERKs), p38s, and c-Jun N-terminal kinases (JNKs), whose activations are known to be important for iNOS expression by LPS in BV2 cells, were not affected in the presence of LMB. Together, these results suggest that LMB inhibits iNOS expression in response to LPS in BV2 microglia, and the inhibition seems to be associated with blockage of CRM1-mediated iNOS mRNA nuclear export and also in part transcriptional down-regulation of iNOS, but not through modulation of NF-kappaB and the mitogen-activated protein kinase signaling pathways.

Phase contrast radiography of Lewy bodies in Parkinson disease

Parkinson's disease (PD), defined as a neurodegenerative disorder, is characterized by the loss of dopaminergic neurons and the presence of Lewy bodies in neurons. Morphological study of Lewy bodies is important to identify the causes and the processes of PD. Here, we investigate a possibility of phase contrast radiography using coherent synchrotron X-rays to explore the microscopic details of Lewy bodies in thick (approximately 3 mm) midbrain tissues. Autopsied midbrain tissues of a PD patient were sliced in 3 mm thickness and then examined using synchrotron X-rays from the 7B2 beamline of the Pohang Light Source. Refraction-enhanced phase contrast radiography and microtomography were adopted to identify dark core and dim edge of Lewy bodies in neurons. The morphology of Lewy bodies was clearly revealed by the phase contrast radiography in very thick (3 mm) midbrain tissues without any staining treatment. Three-dimensional volume rendered microtomography of the autopsied midbrain tissues demonstrates striking evidence that several Lewy bodies are agglomerated by dim edges in a neuron. We suggest that the phase contrast radiography could be a useful tool to morphologically investigate the causes or the processes in PD.

Mutational analysis of the NF2 gene in sporadic meningiomas by denaturing high-performance liquid chromatography

The NF2 tumor suppressor gene, located in chromosome 22q12, is involved in the development of sporadic meningiomas of the nervous system. In order to evaluate the role of the NF2 gene in sporadic meningiomas, we analyzed the entire coding regions of the NF2 gene in a group of 42 sporadic meningiomas: 17 meningothelial, 11 transitional, 11 fibrous, one secretory, one atypical, and one malignant subtype, using denaturing high-performance liquid chromatography (DHPLC) and sequence analysis. Twenty-one mutations were identified in 20 patients with an overall mutation detection rate of 47.6%. The mutations included nine deletions (exons 1, 2, 5, 10, and 12), resulting in a frameshift, four non-sense mutations (exons 1, 2, and 7), four splice errors (exons 4, 5, 7, and 12), two missense mutations (exon 5) and two silent mutations (exon 11). Among these, 14 novel mutations were also identified in the present study. All mutations were noted in the first 12 exons, the region of homology with the ezrin-moesin-radixin protein. Furthermore, an association between NF2 mutations and histologic subtypes were observed; NF2 mutations were more frequent in fibrous meningiomas (8/11, 73%) and transitional meningiomas (6/11, 55%), than in meningothelial variant (5/17, 29%). These results provide evidence that mutations in the NF2 gene play an important role in the development of sporadic meningiomas as well as indicating a different tumorigenesis of these meningioma variants.

Simultaneous Bilateral Carotid Stenting under the Circumstance of Neuroprotection Device. A Retrospective Analysis

SUMMARY

In this study, in order to evaluate the feasibility and outcomes of simultaneous bilateral carotid artery stenting (CAS) with the use of neuroprotection in symptomatic patients, we conducted a retrospective analysis of 27 patients (19 men, eight women; median age, 69.2 years), all of whom had been scheduled to undergo bilateral CAS in a single setting. All patients presented with severe atherosclerotic bilateral carotid stenosis (> 50% for symptomatic side, > 80% for asymptomatic side), exhibiting symptoms of either a cerebrovascular accident or of a transient ischemic attack on at least one side. 48 arteries were treated with self-expandable stents. Neuroprotection devices were utilized for bilateral CAS in 11 patients, and in 16 unilateral CAS patients. We did not perform the second procedure in six patients, in cases in which a patient exhibited (a) hemodynamic instability, (b) a new neurological impairment, or (c) restlessness after a prolonged time for the first CAS. The second procedure was postponed in a staged manner. We achieved a mean residual stenosis of 8.1 +/- 5.0 % in the treated lesions. The mean procedural time for bilateral CAS was three hours and 18 minutes. 17 patients (63%) developed transient bradycardia during the balloon dilatation of one or both of the relevant arteries. Three patients (11%) exhibited persistent bradycardia and hypotension, which required the administration of intravenous vasopressors for several days (2~7 days). None of the patients ultimately required pacemakers, or any further therapy. Two of the patients (7%) developed transient ischemic attack during the periprocedural period, but recovered completely. One patient developed a new minor stroke after the first procedure, and the second procedure was delayed in a staged manner.We observed no periprocedural deaths, major strokes, or myocardial infarctions, nor did we detect any cases of hyperperfusion syndrome within 30 days. In summary, simultaneous bilateral CAS with neuroprotection can be performed in a single setting without increased concerns with regard to hyperperfusion syndrome, hemodynamic instability, thrombo-embolism, or procedure time, when the first CAS has been safely completed with no evidence of complications in a wellmanaged procedure time.

Manganese induces inducible nitric oxide synthase (iNOS) expression via activation of both MAP kinase and PI3K/Akt pathways in BV2 microglial cells

It is well documented that manganese neurotoxicity induces clinical symptoms similar to those of idiopathic Parkinson's disease. Although microglial cytotoxic mediator-induced neurotoxicity is suggested, the mechanism by which manganese up-regulates cytotoxic mediator, such as nitric oxide (NO), remains poorly understood. Therefore, in this study, we investigated the mechanism of manganese on induction of iNOS in microglial cells. iNOS promoter/luciferase assay revealed that manganese (500 (M) regulated the iNOS expression at the transcriptional level. Immunoblot analysis also revealed that phosphorylation levels of ERK, JNK MAPKs and Akt (PKB, PI 3-kinase downstream effector), were increased. Both protein and mRNA levels of iNOS expression were abrogated by specific inhibitors, SP600125 (JNK inhibitor, 20 microM), PD98059 (ERKs inhibitor, 50 microM), or LY294002 (PI 3-kinase inhibitor, 20 microM), but not by SB203580 (20 microM), a p38 specific inhibitor. These data lead to the conclusion that manganese regulates the iNOS expression at the transcriptional level in BV2 microglial cells and the increased iNOS protein expression is mediated via both JNK-ERK MAPK and PI3K/Akt signaling pathways, but not via p38 MAPK pathway. Increased iNOS protein level was also found in RAW264.7 murine macrophage cells.

Differential inhibitory effects of baicalein and baicalin on LPS-induced cyclooxygenase-2 expression through inhibition of C/EBPbeta DNA-binding activity

To evaluate the possible mechanisms responsible for the anti-inflammatory effects of baicalein or baicalin, lipopolysaccharide (LPS)-induced inflammatory responses in cultured Raw 264.7 cells were studied. In the present study, baicalein and baicalin, a flavonoid present in the root of Scutellaria baicalensis Georgi, were examined for their effects on LPS-induced cyclooxygenase-2 (COX-2) gene expression in Raw 264.7 macrophages. Baicalein, but not baicalin, inhibited COX-2 gene expression in LPS-induced Raw 264.7 cells. However, both polyphenolic compounds inhibited LPS-induced inducible nitric oxide synthase (iNOS) protein expression, iNOS mRNA expression, and NO production in a dose-dependent manner. To investigate the mechanism by which baicalein inhibits COX-2 gene expression, we examined activation of mitogen-activated protein kinases (MAPKs) in Raw 264.7 cells. We did not observe any significant change in the phosphorylation of MAPKs between baicalein- and baicalin-treated cells. Baicalein and baicalin had no effect on LPS-induced nuclear factor-kappaB (NF-kappaB) and cAMP response element binding protein (CREB) DNA binding activity. Baicalein, but not baicalin, significantly inhibited the DNA binding activity of CCAAT/enhancer binding protein beta (C/EBPbeta) These results indicated that differential effects of baicalein and baicalin on COX-2 gene expression in LPS-induced Raw 264.7 cells were mediated through inhibition of C/EBPbeta DNA binding activity. Taken together, these results suggest that baicalein acts to inhibit inflammation through inhibition of COX-2 gene expression through blockade of C/EBPbeta DNA binding activity.

Inhibitory effects of glucosamine on lipopolysaccharide‐induced activation in microglial cells

The aim of the present study was to investigate the effects of glucosamine on lipopolysaccharide (LPS)-induced cellular activation in microglia and to evaluate the inhibitory mechanisms involved. Lipopolysaccharide (100 ng/mL) was used for the activation of primary cultured rat microglial or BV2 microglial cells. Changes in intracellular Ca2+ levels and outward K+ currents were measured using fura-2/AM and whole-cell patch-clamp methods, respectively. Lipopolysaccharide-induced expression of tumour necrosis factor (TNF)-alpha mRNA was analysed by reverse transcription-polymerase chain reaction. Lipopolysaccharide transformed cell morphology into an amoeboid shape in vitro and induced microglial activation in vivo, as measured by immunohistochemical staining, but glucosamine inhibited this activation. Glucosamine also inhibited LPS-induced Ca2+ influx, outward K+ currents and TNF-alpha mRNA expression, which are typically representative of microglial activation. 4. The results suggest that the inhibitory mechanisms of glucosamine on LPS-induced microglial activation include inhibition of Ca2+ influx and outward K+ currents, as well as downregulation of the microglial activator gene TNF-alpha.

Interferon regulatory factor-1 is prerequisite to the constitutive expression and IFN-gamma-induced upregulation of B7-H1 (CD274)

Majority of cancer cells upregulate co-inhibitory molecule B7-H1 which confers resistance to anti-tumor immunity, allowing cancers to escape from host immune surveillance. We addressed the molecular mechanism underlying the regulation of cancer-associated B7-H1 expression in response to interferon-gamma (IFN-gamma). Using promoter constructs in luciferase assay, the region between 202 and 320 bp from the translational start site is responsible for B7-H1 expression. Electrophoretic mobility shift assay, site-directed mutagenesis and knockdown experiment using siRNA revealed that interferon regulatory factor-1 (IRF-1) is primarily responsible for the constitutive B7-H1 expression as well as for the IFN-gamma-mediated B7-H1 upregulation in a human lung cancer cell line A549. Additionally, AG490, a Janus activated kinase/signal transducer and activator of transcription inhibitor, greatly abolished the responsiveness of A549 cells to IFN-gamma by reducing the IRF-1 transcription. Our findings support a critical role of IRF-1 in the regulation of constitutive and IFN-gamma-induced expression of B7-H1 in cancer cells.

Thimerosal induces apoptosis and G2/M phase arrest in human leukemia cells

Thimerosal is an organomercury compound with sulfhydryl-reactive properties. The ability of thimerosal to act as a sulfhydryl group is related to the presence of mercury. Due to its antibacterial effect, thimerosal is widely used as preservatives and has been reported to cause chemically mediated side effects. In the present study, we showed that the molecular mechanism of thimerosal induced apoptosis in U937 cells. Thimerosal was shown to be responsible for the inhibition of U937 cells growth by inducing apoptosis. Treatment with 2.5-5 microM thimerosal but not thiosalicylic acid (structural analog of thimerosal devoid of mercury) for 12 h produced apoptosis, G(2)/M phase arrest, and DNA fragmentation in a dose-dependent manner. Treatment with caspase inhibitor significantly reduced thimerosal-induced caspase 3 activation. In addition, thimerosal-induced apoptosis was attenuated by antioxidant Mn (III) meso-tetrakis (4-benzoic acid) porphyrin (Mn-TBAP). These data indicate that the cytotoxic effect of thimerosal on U937 cells is attributable to the induced apoptosis and that thimerosal-induced apoptosis is mediated by reactive oxygen species generation and caspase-3 activation.

Rapid blockade of telomerase activity and tumor cell growth by the DPL lipofection of ribbon antisense to hTR

Ribbon antisense (RiAS) to the hTR RNA, a component of the telomerase complex, was employed to inhibit telomerase activity and cancer cell growth. The antisense molecule, hTR-RiAS, combined with enhanced cellular uptake was shown to effectively inhibit telomerase activity and cause rapid cell death in various cancer cell lines. When cancer cells were treated with hTR-RiAS, the level of hTR RNA was reduced by more than 90% accompanied with reduction in telomerase activity. When checked for cancer cell viability, cancer cell lines treated with hTR-RiAS using DNA+Peptide+Lipid complex showed 70-80% growth inhibition in 3 days. The reduced cell viability was due to apoptosis as the percentage of cells exhibiting the sub-G0 arrest and DNA fragmentation increased after antisense treatment. Further, when subcutaneous tumors of a colon cancer cell line (SW480) were treated intratumorally with hTR-RiAS, tumor growth was markedly suppressed with almost total ablation of hTR RNA in the tumor tissue. Cells in the tumor tissue were also found to undergo apoptosis after hTR-RiAS treatment. These results suggest that hTR-RiAS is an effective anticancer reagent, with a potential for broad efficacy to diverse malignant tumors.

Down-regulation of peroxisome proliferator-activated receptor gamma in human cervical carcinoma

OBJECTIVE

Peroxisome proliferator-activated receptor gamma (PPARgamma) is a member of the nuclear hormone receptor superfamily. Treatment of PPARgamma ligands has been shown to inhibit the growth of various human cancer cells. However, it has not been reported whether human cervical carcinoma cells express PPARgamma. In this study, we investigated the expression of PPARgamma in human normal cervix and cervical carcinoma tissues, and as well as the effect of PPARgamma ligands on cervical cancer cells survival.

METHODS

Fresh cervical tissues from a study group of 10 study patients diagnosed with cervical carcinoma were analyzed for the expression of PPARgamma using real-time RT-PCR and Western blot analysis. Immunohistochemical staining for PPARgamma was also performed on the serial sections of 40 cervical carcinomas. In addition, we evaluated the feasibility of PPARgamma ligands, as a potential therapeutic drug against cervical cancer cells using MTT assay and FACS analysis.

RESULTS

We found that there were lower expression levels of PPARgamma mRNA and protein in cervical carcinoma tissues than in normal cervical tissues. The extent and intensity of immunoreactive PPARgamma in normal cervix tissues were statistically much greater than those of carcinoma tissues. In order to study effects of PPAR ligand on cell proliferation, we chose ciglitizone that showed very potent growth inhibitory effects on the proliferation of two human cervical cancer cell lines (C-33-A and C-4II). C-4II cells express high expression of PPARgamma, while C-33A cells express low level of PPARgamma. Treatment with ciglitizone inhibited the growth of C-4II cells in a dose-dependent manner, while the growth inhibitory effect of ciglitizone was much less in C-33A cells. In order to test whether ciglitizone-induced growth suppressive effects on cervical cancer cell lines is PPAR-dependent, we treated cervical cancer cells with ciglitizone and/or GW9662 (a PPARgamma antagonist). No significant difference in cell survival was found in cells treated with ciglitizone alone vs. co-treated with ciglitizone and GW9662. GW9662 alone did not induce any cell growth arrest in the cells that we used (data not shown). Thus, we concluded that growth suppressive effects by ciglitizone may not be dependent upon status of PPAR expression. To clarify the mechanism by which ciglitizone inhibits the growth of cervical carcinoma cells, flow cytometry and Western blotting assay were performed. As results, we demonstrated that a large portion of C-4II cells (but not in C-33A) after ciglitizone treatment were arrest at G1 phase with the induction of p21(Cip1/Waf1) and p27(kip1) protein.

CONCLUSIONS

These results suggest that PPARgamma is down-regulated in multiple human cervical cancer tissues and cell lines. Ciglitizone may suppress human cervical cancer cells in PPAR-independent manner.

Curcumin decreases cell proliferation rates through BTG2-mediated cyclin D1 down-regulation in U937 cells

Curcumin is a promising chemopreventive agent due to its multiple properties including anti-inflammation, induction of apoptosis and inhibition of signal cascades involving cell proliferation. It has been reported that curcumin-treated cells show decreased expression of cyclin D1, ultimately resulting in decreased cell growth rate. Thus, modulation of cell cycle regulatory proteins by curcumin has been suggested as one of the important mechanisms underlying its chemopreventive effects. However, the precise molecular mechanisms involving down-regulation of cyclin D1 by curcumin are not largely understood. In this study we investigated the mechanisms of cyclin D1 down-regulation by curcumin in U937 cells. Expressions of cyclin D1, particularly at protein and mRNA levels, were clearly decreased in curcumin-treated cells. The stability of cyclin D1 mRNA was not affected by curcumin treatment. Treatment of curcumin increased expression of BTG2 mRNA, a member of anti-proliferative gene family and a negative transcriptional regulator of cyclin D1. Furthermore, overexpression of BTG2 led to down-regulation of cyclin D1 mRNA expression in U937 cells. Nuclear translocation of p65 NF-kappaB is involved in the expression of cyclin D1 mRNA. Treatment of curcumin inhibited nuclear translocation of p65 NF-kappaB. Moreover, the expression of cyclin D1 mRNA was dramatically decreased after co-treatment curcumin with NF-kappaB inhibitors. The data presented here indicate that curcumin-induced down-regulation of cyclin D1 mRNA is mediated by induction of BTG2 as well as inhibition of nuclear translocation of NF-kappaB.

Curcumin inhibits the expression of COX-2 in UVB-irradiated human keratinocytes (HaCaT) by inhibiting activation of AP-1: p38 MAP kinase and JNK as potential upstream targets

Ultraviolet B (UVB) irradiation of skin induces an acute inflammation. Cyclooxygenase-2 (COX-2) protein plays key roles in acute inflammation in UVB-irradiated keratinocyte cell line HaCaT. Recently, curcumin has been regarded as a promising anti-inflammatory agent due to its ability to inhibit COX-2 expression. However, it remains largely unknown whether curcumin inhibits the UVB-induced COX-2 expression in HaCaT cells. This study was undertaken to clarify the effect of curcumin on the expression of COX-2 in UVB- irradiated HaCaT cells and further determined the molecular mechanisms associated with this process. In this study, we have found that the expression of COX-2 mRNA and protein were up-regulated in UVB-irradiated HaCaT cells in a dose- and time-dependent manner. Interestingly, treatment with curcumin strongly inhibited COX-2 mRNA and protein expressions in UVB-irradiated HaCaT cells. Notably, there was effective inhibition by curcumin on UVB-induced activations of p38 MAPK and JNK in HaCaT cells. The DNA binding activity of AP-1 transcription factor was also markedly decreased with curcumin treatment in UVB-irradiated HaCaT cells. These results collectively suggest that curcumin may inhibit COX- 2 expression by suppressing p38 MAPK and JNK activities in UVB-irradiated HaCaT cells. We propose that curcumin may be applied as an effective and novel sunscreen drug for the protection of photoinflammation.

Catalase induced expression of inflammatory mediators via activation of NF-κB, PI3K/AKT, p70S6K, and JNKs in BV2 microglia

Catalase induces COX-2 or iNOS expression in some type of cells, but the mechanism remains unclear. Here we investigated the effect of catalase on COX-2 and iNOS expression in BV2 microglia and the inductive mechanism associated. Exposure of catalase to BV2 microglia induced expression of COX-2 and iNOS that was related with transcriptional up-regulation. Importantly, catalase-induced COX-2 and iNOS expression needed activations of NF-kappaB, PI3K/AKT, and JNKs, which were important for the transcriptional up-regulation of COX-2 and iNOS. Notably, rapamycin inhibition of p70S6K led to down-regulation of COX-2 and iNOS protein expression, but not steady-state mRNA expression and transcription, induced by catalase, suggesting that p70S6K is involved in increased COX-2 and iNOS mRNA translation by catalase. Interestingly, there was PI3K-dependent activation of AKT, p70S6K, JNKs, and NF-kappaB in response to catalase. These data collectively suggest catalase-induced COX-2 and iNOS expression in BV2 microglia is, in part at least, mediated through activation of multiple signaling proteins.

Effects of polyhemoglobin-antioxidant enzyme complex on ischemia-reperfusion in kidney

INTRODUCTION

The kidney suffers ischemia-reperfusion (I/R) injury during transplantation. The purpose of the present study was to investigate the therapeutic effect of artificials cells on renal I/R injury through biochemical assays and histological examination.

METHODS

We prepared artificial cells using cross-linked hemoglobin (Hb), superoxide dismutase (SOD), and catalase. Normal male Sprague-Dawley rats were divided into 6 groups: the sham-operated control group, the group treated with polyHb,and the group treated with polyHb-SOD-catalase (PSC) (per groups were subjected to ischemia for 1 hour or 2 hours). After reperfusion for 4 hours, kidney and blood samples were obtained.

RESULTS

The levels of SOD and catalase in the PSC group were 15 and 50 times higher than those of the control group, respectively. In the polyHb group, the levels of blood urea nitrogen (BUN), serum creatinine, renal hydrogen peroxide, and renal malondialdehyde were increased. However, their levels were significantly decreased by PSC administration. Renal SOD activity did not show any significant changes in the polyHb group, but renal catalase activity was decreased by polyHb treatment in comparison with the control group. The activities of renal SOD and catalase were increased using PSC treatment. In the histological findings, the PSC group showed no evidence of acute tubular necrosis in proximal convoluted tubules; their microvilli and cytoplasmic microorganelles were relatively well preserved.

CONCLUSIONS

These results show that PSC effectively reduces renal damage via diminished oxygen free radical-mediated injury after I/R.