Synthetic pro-peptide design to enhance the secretion of heterologous proteins by Saccharomyces cerevisiae.

Heterologous protein production in Saccharomyces cerevisiae is a useful and effective strategy with many advantages, including the secretion of proteins that require posttranslational processing. However, heterologous proteins in S. cerevisiae are often secreted at comparatively low levels. To improve the production of the heterologous protein, human granulocyte colony-stimulating factor (hG-CSF) in S. cerevisiae, a secretion-enhancing peptide cassette including an hIL-1ß-derived pro-peptide, was added and used as a secretion enhancer to alleviate specific bottlenecks in the yeast secretory pathway. The effects of three key parameters-N-glycosylation, net negative charge balance, and glycine-rich flexible linker-were investigated in batch cultures of S. cerevisiae. Using a three-stage design involving screening, selection, and optimization, the production and secretion of hG-CSF by S. cerevisiae were significantly increased. The amount of extracellular mature hG-CSF produced by the optimized pro-peptide after the final stage increased by 190% compared to that of the original pro-peptide. Although hG-CSF was used as the model protein in the current study, this strategy is applicable to the enhanced production of other heterologous proteins, using S. cerevisiae as the host.

Spatial immune heterogeneity of hypoxia-induced exhausted features in high-grade glioma.

The tumor immune microenvironment (TIME) in high-grade glioma (HGG) exhibits high spatial heterogeneity. Though the tumor core and peripheral regions have different biological features, the cause of this spatial heterogeneity has not been clearly elucidated. Here, we examined the spatial heterogeneity of HGG using core and peripheral regions obtained separately from the patients with HGG. We analyzed infiltrating immune cells by flow cytometry from 34 patients with HGG and the transcriptomes by RNA-seq analysis from 18 patients with HGG. Peripheral region-infiltrating immune cells were in vitro cultured in hypoxic conditions and their immunophenotypes analyzed. We analyzed whether the frequencies of exhausted CD8+ T cells and immunosuppressive cells in the core or peripheral regions are associated with the survival of patients with HGG. We found that terminally exhausted CD8+ T cells and immunosuppressive cells, including regulatory T (TREG) cells and M2 tumor-associated macrophages (TAMs), are more enriched in the core regions than the peripheral regions. Terminally exhausted and immunosuppressive profiles in the core region significantly correlated with the hypoxia signature, which was enriched in the core region. Importantly, in vitro culture of peripheral region-infiltrating immune cells in hypoxic conditions resulted in an increase in terminally exhausted CD8+ T cells, CTLA-4+ TREG cells, and M2 TAMs. Finally, we found that a high frequency of PD-1+CTLA-4+CD8+ T cells in the core regions was significantly associated with decreased progression-free survival of patients with HGG. The hypoxic condition in the core region of HGG directly induces an immunosuppressive TIME, which is associated with patient survival.

(-)-Loliolide Isolated from Sargassum horneri Suppressed Oxidative Stress and Inflammation by Activating Nrf2/HO-1 Signaling in IFN-γ/TNF-α-Stimulated HaCaT Keratinocytes.

The present study evaluated the effects of (-)-loliolide isolated from Sargassum horneri (S. horneri) against oxidative stress and inflammation, and its biological mechanism in interferon (IFN)-γ/tumor necrosis factor (TNF)-α-stimulated HaCaT keratinocytes. The results showed that (-)-loliolide improved the cell viability by reducing the production of intracellular reactive oxygen species (ROS) in IFN-γ/TNF-α-stimulated HaCaT keratinocytes. In addition, (-)-loliolide effectively decreased the expression of inflammatory cytokines (interleukin (IL)-4 IL-6, IL-13, IFN-γ and TNF-α) and chemokines (CCL11 (Eotaxin), macrophage-derived chemokine (MDC), regulated on activation, normal T cell expressed and secreted (RANTES), and thymus and activation-regulated chemokine (TARC)), by downregulating the expression of epidermal-derived initial cytokines (IL-25, IL-33 and thymic stromal lymphopoietin (TSLP)). Furthermore, (-)-loliolide suppressed the activation of mitogen-activated protein kinase (MAPK) and nuclear factor-κB (NF-κB) signaling, whereas it activated nuclear factor erythroid 2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) signaling. Interestingly, the cytoprotective effects of (-)-loliolide against IFN-γ/TNF-α stimulation were significantly blocked upon inhibition of HO-1. Taken together, these results suggest that (-)-loliolide effectively suppressed the oxidative stress and inflammation by activating the Nrf2/HO-1 signaling in IFN-γ/TNF-α-stimulated HaCaT keratinocytes.

Z-ajoene from Crushed Garlic Alleviates Cancer-Induced Skeletal Muscle Atrophy.

Skeletal muscle atrophy is one of the major symptoms of cancer cachexia. Garlic (Allium sativum), one of the world's most commonly used and versatile herbs, has been employed for the prevention and treatment of diverse diseases for centuries. In the present study, we found that ajoene, a sulfur compound found in crushed garlic, exhibits protective effects against muscle atrophy. Using CT26 tumor-bearing BALB/c mice, we demonstrate in vivo that ajoene extract alleviated muscle degradation by decreasing not only myokines secretion but also janus kinase/signal transducer and activator of transcription 3 (JAK/STAT3) and SMADs/forkhead box (FoxO) signaling pathways, thereby suppressing muscle-specific E3 ligases. In mouse skeletal myoblasts, Z-ajoene enhanced myogenesis as evidenced by increased expression of myogenic markers via p38 mitogen-activated protein kinase (MAPK) activation. In mature myotubes, Z-ajoene protected against muscle protein degradation induced by conditioned media from CT26 colon carcinoma cells, by suppressing expression of muscle specific E3 ligases and nuclear transcription factor kappa B (NF-κB) phosphorylation which contribute to muscle atrophy. Moreover, Z-ajoene treatment improved myofiber formation via stimulation of muscle protein synthesis. These findings suggest that ajoene extract and Z-ajoene can attenuate skeletal muscle atrophy induced by cancer cachexia through suppressing inflammatory responses and the muscle wasting as well as by promoting muscle protein synthesis.

Dietary fat intake and age modulate the composition of the gut microbiota and colonic inflammation in C57BL/6J mice.

BACKGROUND: More than half of the adult population worldwide is overweight or obese, while excess adiposity has been linked to chronic low-grade inflammation, contributing to the development of chronic diseases. Recent studies have showed that diet-induced alterations to the gut microbiota composition play a pivotal role in the development of obesity. However, the cause-effect relationship between obesity and gut microbiota composition is not yet fully understood. In this study, we investigated the short-term responses of gut microbiota composition to diets with different fat contents and their associations with inflammatory biomarkers. RESULTS: Sixty male C57BL/6 J mice were fed a normal diet (ND; 15% fat) or a high-fat diet (HFD; 45% fat) for 10 or 20 weeks. The relative proportion of the phylum Actinobacteria was elevated by the HFD and was positively associated with body weight and proinflammatory cytokines including TNF-α, IL-1ß, and IL-6. The proportion of the phylum Firmicutes increased with aging and was also positively correlated with proinflammatory cytokines. The proportions of Actinobacteria and Firmicutes were inversely associated with tight junction proteins claudin-1 and E-cadherin, respectively. The proportions of the class Clostridia and the family Ruminococcaceae within the phylum Firmicutes were affected by both diet and age. In addition, the proportions of the phylum Bacteroidetes, the family Bacteroidaceae, and the genus Bacteroides decreased with aging and were inversely correlated with colonic proinflammatory cytokines representing a positive association with tight junction proteins. CONCLUSIONS: Host age and dietary fat intake are important elements that induce proportional changes in gut microbiota, and these changes are also associated with systemic inflammation. This study provides evidence that diet affects the gut microbiota composition within a short period of time.

Suppressor of Variegation 3-9 Homolog 2, a Novel Binding Protein of Translationally Controlled Tumor Protein, Regulates Cancer Cell Proliferation.

Suppressor of Variegation 3-9 Homolog 2 (SUV39H2) methylates the lysine 9 residue of histone H3 and induces heterochromatin formation, resulting in transcriptional repression or silencing of target genes. SUV39H1 and SUV39H2 have a role in embryonic development, and SUV39H1 was shown to suppress cell cycle progression associated with Rb. However, the function of human SUV39H2 has not been extensively studied. We observed that forced expression of SUV39H2 decreased cell proliferation by inducing G1 cell cycle arrest. In addition, SUV39H2 was degraded through the ubiquitin-proteasomal pathway. Using yeast two-hybrid screening to address the degradation mechanism and function of SUV39H2, we identified translationally controlled tumor protein (TCTP) as an SUV39H2-interacting molecule. Mapping of the interacting regions indicated that the N-terminal 60 amino acids (aa) of full-length SUV39H2 and the C-terminus of TCTP (120-172 aa) were critical for binding. The interaction of SUV39H2 and TCTP was further confirmed by co-immunoprecipitation and immunofluorescence staining for colocalization. Moreover, depletion of TCTP by RNAi led to up-regulation of SUV39H2 protein, while TCTP overexpression reduced SUV39H2 protein level. The half-life of SUV39H2 protein was significantly extended upon TCTP depletion. These results clearly indicate that TCTP negatively regulates the expression of SUV39H2 post-translationally. Furthermore, SUV39H2 induced apoptotic cell death in TCTP-knockdown cells. Taken together, we identified SUV39H2, as a novel target protein of TCTP and demonstrated that SUV39H2 regulates cell proliferation of lung cancer cells.

Asxl1 exerts an antiproliferative effect on mouse lung maturation via epigenetic repression of the E2f1-Nmyc axis.

Although additional sex combs-like 1 (ASXL1) has been extensively described in hematologic malignancies, little is known about the molecular role of ASXL1 in organ development. Here, we show that Asxl1 ablation in mice results in postnatal lethality due to cyanosis, a respiratory failure. This lung defect is likely caused by higher proliferative potential and reduced expression of surfactant proteins, leading to reduced air space and defective lung maturation. By microarray analysis, we identified E2F1-responsive genes, including Nmyc, as targets repressed by Asxl1. Nmyc and Asxl1 are reciprocally expressed during the fetal development of normal mouse lungs, whereas Nmyc downregulation is impaired in Asxl1-deficient lungs. Together with E2F1 and ASXL1, host cell factor 1 (HCF-1), purified as an Asxl1-bound protein, is recruited to the E2F1-binding site of the Nmyc promoter. The interaction occurs between the C-terminal region of Asxl1 and the N-terminal Kelch domain of HCF-1. Trimethylation (me3) of histone H3 lysine 27 (H3K27) is enriched in the Nmyc promoter upon Asxl1 overexpression, whereas it is downregulated in Asxl1-deleted lung and -depleted A549 cells, similar to H3K9me3, another repressive histone marker. Overall, these findings suggest that Asxl1 modulates proliferation of lung epithelial cells via the epigenetic repression of Nmyc expression, deficiency of which may cause hyperplasia, leading to dyspnea.

Health behaviors and illness according to marital status in middle-aged Koreans.

Background: Marital status influences health and this association might differ by time and/or country. Divorce rates have increased abruptly in Korea. We investigated relationships between marital status and health behaviors and illness among middle-aged Koreans. Methods: Data from the fifth Korean National Health and Nutrition Examination Survey 2010-12 was used. Participants were middle-aged (40-65 years) Koreans (3015 male and 4498 female) who had been married. Health behaviors and physical and mental health status were evaluated separately for each gender according to marital status (currently married versus separated, divorced or widowed) using logistic regression analyses adjusted for age, income level and region. Results: About 5.4% of men and 13.0% of women lived without their spouses. Odd ratios (ORs) for smoking, binge drinking, inadequate sleep, hypertriglyceridemia and depression were significantly higher in participants not living with their spouses. ORs for non-participation in regular health examinations and cancer screenings, anemia, elevated alanine aminotransferase and suicidal ideation were significantly higher in men not living with their spouses. Conclusions: Health behaviors and illness were significantly worse in middle-aged Koreans not living with their spouses. Men were more susceptible to poor health screening, nutritional deficiencies and mental illness. Preventive services are necessary to improve their health status.

Phenolic acid and flavonoid-rich fraction of Sasa quelpaertensis Nakai leaves prevent alcohol induced fatty liver through AMPK activation.

ETHNOPHARMACOLOGICAL RELEVANCE: Sasa quelpaertensis Nakai is an edible dwarf bamboo cultivated mainly in Jeju Island, South Korea and its leaf displays various health-promoting properties including antioxidant scavenging. AIM OF THE STUDY: In this study, we aimed at elucidating its hepatoprotective effect against alcohol-induced fatty liver. METHODS: In in vitro study, we evaluated the cytotoxicity and hepatoprotective effect of different solvent fractions (aqua, butanol, chloroform, ethyl acetate and hexane) of 80% EtOH extract of S. quelpaertensis Nakai leaf. In vivo experiment performed using binge alcohol consumption model. RESULTS: Although all five fractions (0-1000 µg/mL) were non-cytotoxic to HepG2 cells, only ethyl acetate fraction (SQEA), rich in phenolic acids such as p-coumaric acid and flavonoids particularly myristin, showed hepatoprotective effect against EtOH (400 mM) in HepG2 cells. Furthermore, SQEA significantly decreased the ethanol induced cell death and enhanced the cell proliferation. In in vivo experiment using binge consumption model (5 g of EtOH/kg body weight in every 12 h for 3 times), SQEA treatment (10, 50 and 100 mg/kg) markedly reduced the alcohol induced histopathological changes and serum EtOH content, and reversed the reduction of glutathione level in ethanol challenged livers. Further, it suppressed the expression of cytochrome P450 2E1 (CYP2E1). In particular, SQEA activated AMP activated protein kinase (AMPK) pathway, and decreased the expression of tumor necrosis factor receptor-1 (TNFR1), which attenuated lipogenesis via decreased expression of fatty acid synthase (FAS). Inhibited lipogenesis due to SQEA treatment directed towards decreased perilipin-2 expression. These results indicate that SQEA has hypolipidemic effect which is mediated by decreased oxidative stress, increased fatty acid oxidation response and decreased lipogenesis. CONCLUSION: Our results suggest the possibility of developing SQEA as a natural hepatoprotective agent potent in attenuating alcohol-induced fatty liver.

Sasa quelpaertensis leaves ameliorate alcohol-induced liver injury by attenuating oxidative stress in HepG2 cells and mice.

Oxidative stress plays a crucial role in the progression of alcoholic liver diseases and substances of antioxidant property are of special interest for therapeutic purposes. We investigated the hepatoprotective effect of leaf extracts of Sasa quelpaertensis, an edible bamboo mainly cultivated in Jeju Island, South Korea. We examined the cytotoxicity of different extracts (distilled water, 20-80% EtOH) of S. quelpaertensis on HepG2 cells and their hepatoprotective effect on HepG2 cells stimulated by ethanol (800 mM, 24 h). Furthermore, we measured reactive oxygen species (ROS) production, ethanol toxicity induced cell death, and the activity of antioxidant enzymes. In in vivo experiments, liver damage was induced by oral administration of 5 g/kg ethanol with or without potent ethanol extract of S. quelpaertensis (10 or 100 mg/kg) 12 h interval for a total of 3 doses. Only 80% ethanol extract of S. quelpaertensis (SQEE80) exhibited cytoprotective effect on HepG2 cells against alcohol-induced toxicity. SQEE80 treatment (250, 500 µg/mL) in ethanol exposed HepG2 cells showed significant attenuation of ROS production and ethanol toxicity induced cell death. Furthermore, SQEE80 markedly increased the activity of antioxidant enzyme glutathione peroxidase 1 in ethanol exposed HepG2 cells compared to ethanol stimulated cells. In in vivo experiments, SQEE80 treatment evidently suppressed the alcohol-induced histopathological changes in liver, serum ethanol content, and expression of cytochrome P450 2E1. Furthermore, SQEE80 significantly reversed the reduction of glutathione level in the ethanol challenged liver. Taken together, we suggest the possibility of developing SQEE80 as a natural hepatoprotective substance in attenuating alcohol-induced oxidative stress.

Immunostimulatory effect of pepsin enzymatic extract from Porphyra yezoensis on murine splenocytes.

BACKGROUND: Porphyra yezoensis is a red alga consumed mainly in Korea, Japan, and China for food. This study researches the immunological effect of pepsin extract of P. yezoensis (PPEE) on murine splenocytes. RESULTS: PPEE was not toxic on murine splenocytes and dramatically increased the proliferation of splenocytes compared with untreated control. Flow cytometry assay performed to sum up the effect of PPEE (31.3 and 62.5 µg mL-1 ) on major immune cells revealed that PPEE had no effect on the function of CD3e+ CD4+ T-helper cells, CD3e+ CD8+ T-cytotoxic cells, or CD44+ CD62L- effector T cells in splenocytes compared with untreated control. More importantly, CD45+ CD11b+ macrophage and dendritic cell populations and Ly-6C+ Ly-6G+ macrophages/monocytes in splenocytes were activated by PPEE treatment compared with untreated control. Further experiments showed that PPEE treatment increased the secretion of macrophage-derived cytokines such as interleukin-1ß, tumor necrosis factor-α, and interleukin-12, and macrophage-activating cytokines interferon-γ and interleukin-10 compared with untreated control. CONCLUSION: Taken together, these results suggest that PPEE has an immune stimulatory effect on macrophages, dendritic cells, and memory T cells. This property signifies the potential medicinal value of PPEE in clinical implications for immune-compromised diseases. © 2017 Society of Chemical Industry.

Estimating the economic value of counselling services using the contingent valuation method.

This study aimed to justify the use of the contingent valuation method to elicit the willingness to pay (WTP) for counselling services and to analyse the socio-demographic and psychological factors that influence WTP (through an increase in insurance premiums) for counselling services in South Korea. Regarding WTP for counselling services, the researchers asked 561 participants double-bounded dichotomous choice questions, which is one of the major estimation methods. Two survival analysis models were set up with their corresponding variables to investigate the factors affecting the WTP for an increase in insurance premiums to cover counselling services. The results indicate that a person in South Korea who makes KRW 2,500,000 (USD 2223.21) per month and pays KRW 66,625 (USD 59.25) per month in insurance premiums is willing to pay a roughly 1% premium to receive additional counselling services. The first regression analysis model for WTP showed that pocket money and counselling experience had significant positive effects while gender had a significant negative effect. The second model included four additional psychological factors and the significant effects of gender and counselling experience that had been found in the first model disappeared while only pocket money showed a significant effect on WTP.

Geraniin Promotes Recovery of Hematopoietic Cells after Radiation Injury.

Cells of the hematopoietic system are uniquely radiosensitive due to their rapid proliferation. Consequently, immune suppression readily and undesirably results from irradiation. Our previous studies demonstrated that geraniin isolated from Nymphaea tetragona var. angusta (water lily) had a protective effect on the splenocytes and intestinal tract of irradiated mice. This study was designed to assess the effectiveness of geraniin, an ellagitannin isolated from the water lily, in decreasing gamma ray irradiation-induced destruction of the hematopoietic system in mice. Geraniin treatment improved the survival time of bone marrow cells and maintained bone marrow integrity and also up-regulated the expression of stem cell receptors and the extent of cell mitosis. Geraniin also enhanced the proliferation and differentiation of immune cells that had been suppressed by irradiation. These results suggest geraniin is a promising agent for reconstituting hematopoietic cells after exposure to irradiation.

Beetroot (Beta vulgaris) rescues mice from γ-ray irradiation by accelerating hematopoiesis and curtailing immunosuppression.

CONTEXT: Beetroot [Beta vulgaris Linné (Chenopodiaceae)], a vegetable usually consumed as a food or a medicinal plant in Europe, has been reported to have antioxidant and anti-inflammatory properties. Since the lymphohematopoietic system is the most sensitive tissue to ionizing radiation, protecting it from radiation damage is one of the best ways to decrease detrimental effects from radiation exposure. OBJECTIVE: In this study, we evaluated the radio-protective effects of beetroot in hematopoietic stem cells (HSCs) and progenitor cells. MATERIALS AND METHODS: Beetroot extract was administered at a dose of 400 mg/mouse per os (p.o.) three times into C57BL/6 mice and, at day 10 after γ-ray irradiation, diverse molecular presentations were measured and compared against non-irradiated and irradiated mice with PBS treatments. Survival of beetroot-fed and unfed irradiated animal was also compared. RESULTS: Beetroot not only stimulated cell proliferation, but also minimized DNA damage of splenocytes. Beetroot also repopulated S-phase cells and increased Ki-67 or c-Kit positive cells in bone marrow. Moreover, beetroot-treated mice showed notable boosting of differentiation of HSCs into burst-forming units-erythroid along with increased production of IL-3. Also, beetroot-treated mice displayed enhancement in the level of hematocrit and hemoglobin as well as the number of red blood cell in peripheral blood. Beetroot diet improved survival rate of lethally exposed mice with a dose reduction factor (DRF) of 1.1. DISCUSSION AND CONCLUSION: These results suggest that beetroot has the potency to preserve bone marrow integrity and stimulate the differentiation of HSCs against ionizing radiation.

6,6'-Bieckol suppresses inflammatory responses by down-regulating nuclear factor-κB activation via Akt, JNK, and p38 MAPK in LPS-stimulated microglial cells.

OBJECTIVE: Microglial activation has been implicated in many neurological disorders for its inflammatory and neurotrophic effects. In this study, we investigated the pharmaceutical properties of 6,6'-bieckol on the regulation of nuclear factor-κB (NF-κB) activation responsible to the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX)-2 using lipopolysaccharide (LPS)-stimulated BV2 and murine primary microglial cells. Meterials and methods: The levels of nitric oxide (NO), prostaglandin E2 (PGE)2, and pro-inflammatory cytokines were measured by Griess assay and enzyme-linked immunosorbent assay. The levels of iNOS, COX-2, mitogen-activated protein kinases (MAPKs), and Akt were measured using Western blot. Nuclear translocation and transcriptional activation of NF-κB were determined by immunofluorescence and reporter gene assay, respectively. RESULTS: We found that 6,6'-bieckol decreased the expression of iNOS and COX-2 as well as pro-inflammatory cytokines in LPS-stimulated BV2 and primary microglial cells in a dose-dependent manner. 6,6'-Bieckol inhibited activation of NF-κB by preventing the degradation of inhibitor κB (IκB)-α and led to prevent the nuclear translocation of NF-κB/p65 subunit. Moreover, 6,6'-bieckol inhibited the phosphorylation of Akt, JNK, and p38 MAPK. DISCUSSION AND CONCLUSION: These results indicate that the anti-inflammatory effect of 6,6'-bieckol on LPS-stimulated microglial cells is mainly regulated by the inhibition of IκB-α/NF-κB and JNK/p38 MAPK/Akt pathways, supporting biochemical characteristics of the compound for therapeutic agent against neuroinflammatory diseases caused by microglial activation.

Emodin induces apoptosis of concanavalin A-stimulated murine splenocytes.

Emodin, one of the major compounds in the herb Reynoutria elliptica, is known to maintain immunosuppressive, anti-allergic, anti-cancer, and anti-inflammatory effects. In this study, we assessed the possibility of using emodin to induce apoptosis in stimulated immune cells in vitro. After treatment with emodin and concanavalin A (Con A), we observed DNA damage-induced apoptosis in splenocytes. Moreover, treatment with emodin and Con A increased the number of apoptotic splenocytes compared with untreated controls. Emodin also diminished the size of CD45R/B220+ cells, CD19+CD69+ cells, and cDC populations. These results indicate that emodin-induced apoptosis was involved in attenuating the immune activity promoted by DNA damage and in decreasing the number of CD45R/B220+ B cells and CD19+CD69+ activating B cells. This demonstration of emodin inducing apoptosis of Con A-stimulated immune cells indicates its potential utility as a therapy for diseases caused by abnormally activated immune cells.

Esculetin induces apoptosis in human colon cancer cells by inducing endoplasmic reticulum stress.

Colorectal cancer has become more common in many regions of the world. Recently, we showed that esculetin, a natural coumarin, induces apoptosis in HT-29 colon cancer cells via the reactive oxygen species-mediated mitochondrial pathway. The present study examined whether esculetin induces apoptosis in HT-29 colon cancer cells by inducing endoplasmic reticulum (ER) stress. We found that esculetin induced characteristic signs of ER stress, confirmed by ER staining, mitochondrial calcium overload and expression of ER stress-related proteins (i.e. glucose regulated protein 78, phosphorylated ribonucleic acid-dependent protein kinase-like ER kinase, phosphorylated inositol requiring enzyme 1, phosphorylated eukaryotic initiation factor-2α, spliced X-box binding protein 1 and cleaved activating transcription factor 6). Esculetin also induced the expression of the CCAAT/enhancer-binding protein-homologous protein (CHOP) and pro-apoptotic factors caspase-12. Moreover, transfection of colon cancer cells with a small interfering ribonucleic acid targeting CHOP attenuated esculetin-induced apoptosis. Taken together, these results suggest that the ER stress response plays an important role in esculetin-induced apoptosis in human colon cancer cells.

Involvement of glutathione and glutathione metabolizing enzymes in human colorectal cancer cell lines and tissues.

Reduced glutathione (GSH) is an abundant tripeptide present in the majority of cell types. GSH is highly reactive and is often conjugated to other molecules, via its sulfhydryl moiety. GSH is synthesized from glutamic acid, cysteine, and glycine via two sequential ATP­consuming steps, which are catalyzed by glutamate cysteine ligase (GCL) and GSH synthetase (GSS). However, the role of GSH in cancer remains to be elucidated. The present study aimed to determine the levels of GSH and GSH synthetic enzymes in human colorectal cancer. The mRNA and protein expression levels of GSH, the catalytic subunit of GCL (GCLC) and GSS were significantly higher in the following five colon cancer cell lines: Caco­2, SNU­407, SNU­1033, HCT­116, and HT­29, as compared with the normal colon cell line, FHC. Similarly, in 9 out of 15 patients with colon cancer, GSH expression levels were higher in tumor tissue, as compared with adjacent normal tissue. In addition, the protein expression levels of GCLC and GSS were higher in the tumor tissue of 8 out of 15, and 10 out of 15 patients with colon cancer respectively, as compared with adjacent normal tissue. Immunohistochemical analyses confirmed that GCLC and GSS were expressed at higher levels in colon cancer tissue, as compared with normal mucosa. Since GSH and GSH metabolizing enzymes are present at elevated levels in colonic tumors, they may serve as clinically useful biomarkers of colon cancer, and/or targets for anti-colon cancer drugs.

Esculetin induces death of human colon cancer cells via the reactive oxygen species-mediated mitochondrial apoptosis pathway.

The present study investigated the apoptotic effects of esculetin, a coumarin derivative, on the human colon cancer cell line HT-29. Esculetin had cytotoxic effects on HT-29 cells in a dose- and time-dependent manner; treatment with 55 µg/mL esculetin reduced cell viability by 50%. Esculetin induced apoptosis, as evidenced by apoptotic body formation, an increased percentage of cells in sub-G1 phase, and DNA fragmentation. Moreover, esculetin increased mitochondrial membrane depolarization, released cytochrome c into cytosol, and modulated the expression of apoptosis-associated proteins, resulting in reduced expression of B cell lymphoma-2, increased expression of Bcl-2-associated X protein, and activation of caspase-9 and caspase-3. Esculetin induced the formation of reactive oxygen species; however, treatment with an antioxidant reduced the apoptotic cell death induced by esculetin treatment. In addition, esculetin activated mitogen-activated protein kinases and specific inhibitors of these kinases abrogated the reduction in cell viability induced by esculetin treatment.

Pharmacokinetics and pharmacodynamics of ticagrelor and prasugrel in healthy male Korean volunteers.

PURPOSE: A combination of clopidogrel and aspirin is the standard treatment for patients with acute coronary syndrome and those undergoing percutaneous coronary intervention. Two novel antiplatelet agents, ticagrelor and prasugrel, have been shown to rapidly and more effectively inhibit the P2Y12 receptor compared with clopidogrel. The aim of this study was to evaluate and compare the pharmacokinetics (PK) and pharmacodynamics (PD) of ticagrelor and prasugrel in healthy male Korean volunteers. METHODS: Two separate studies were conducted. One study was performed by using a single-sequence, open-label, crossover design in 12 volunteers who received a single oral dose of ticagrelor (180 mg) and then a single oral dose of prasugrel (60 mg for 4 volunteers and 30 mg for 8 volunteers) with a 7-day washout period. The other study was a randomized, open-label, parallel-group investigation in which 8 volunteers received a single oral dose of prasugrel (10 mg for 4 volunteers and 30 mg for 4 volunteers). In each study, blood samples for PK and platelet aggregation inhibition analysis were serially collected after the administration of each dose. Plasma concentrations of ticagrelor, AR-C124910XX (the active metabolite of ticagrelor), R-95913 (the inactive metabolite of prasugrel), and R-138727 (the active metabolite of prasugrel) were measured by using a validated LC-MS/MS method. PK was analyzed by using a noncompartmental method. Maximal platelet aggregations were assessed with light transmission aggregometry after induction with 20 µmol/L of adenosine diphosphate. FINDINGS: Twenty healthy male Korean volunteers participated in the 2 studies. Plasma concentrations of ticagrelor and AR-C124910XX were obtained from 12 subjects, R-95913 from 20 subjects, and R-138727 from 8 subjects. Both ticagrelor and prasugrel were rapidly absorbed, with the shortest median Tmax of 2.0 and 2.25 hours for ticagrelor and AR-C124910XX, respectively, and a Tmax of 0.5 hour for both R-95913 and R-138727. Strong inhibition of platelet aggregation was shown after administration of both ticagrelor and prasugrel, with slightly stronger and more rapid inhibition with prasugrel in the tested doses. Inhibitory activities of prasugrel lasted longer than those of ticagrelor, reflecting the difference in binding kinetics between the 2 drugs. IMPLICATIONS: Prasugrel 30 and 60 mg exhibited slightly stronger, more rapid, and sustainable platelet inhibitory effects compared with ticagrelor 180 mg. These differing effects should be considered when determining the efficacy and adverse effects of ticagrelor and prasugrel. ClinicalTrials.gov identifier: NCT01876797 and NCT02075268.