Comparison and analysis of soil microbial communities in organic and conventional paddy fields by farming season.

Interest in soil health and biodiversity conservation has become increasingly important. Consequently, studies comparing the chemical and biological characteristics of organic and traditional paddy soils have been increasing. Soil microorganisms are essential in nutrient cycling; however, their diversity is challenging to ascertain because of their environmental sensitivity and complex interactions. Particularly, in domestic rice cultivation, the soil undergoes multiple irrigation and drainage processes during crop growth, providing a diverse ecological environment for soil microorganisms. The objective of this study is to compare the microbial community and diversity between paddy soils in two agricultural systems. We selected organic and conventional paddy fields in Yangpyeong, Gyeonggi Province, and collected monthly samples from August to November 2022 for analysis. Bacteria and fungi were amplified from the 16S rRNA V3V4 region, ITS 3-4 region respectively, For the comparison of microbial diversity, Alpha diversity indices (Chao1, Shannon, Gini-Simpson indices) were analyzed. The results indicated genus-level differences in microbial communities, with the genera Mucor and Sirastachys exclusively present in organic paddy soils, while the genus Ustilaginoidea was exclusively found in conventional paddy soils. Among them, Ustilaginoidea is reported to be a fungus causing false smut disease, causing damage to crop growth and quality. Additionally, the comparison of microbial diversity between the two farming showed no significant differences (p>0.05). In conclusion, When the microbial communities present in both farming systems were examined, organic farming appeared to be more advantageous than conventional farming regarding crop disease and health. This study provides essential soil chemical and microbiological data for understanding the fundamental characteristics of paddy soils in South Korea.

Ursodeoxycholic acid inhibits epithelial-mesenchymal transition, suppressing invasiveness of bile duct cancer cells: An in vitro study.

Epithelial-mesenchymal transition (EMT) features are associated with pathological severity in the progression and metastasis of various cancer types, including bile duct cancer (BDC). Our previous study demonstrated that ursodeoxycholic acid (UDCA) blocked the EGFR-MAPK signaling pathway and inhibited the invasion of BDC cells. The present study was performed to determine whether UDCA inhibits EMT and promotes the expression of E-cadherin to inhibit the invasion and aggressiveness of BDC. In addition, the present study aimed to confirm that the primary mechanism of inhibition of EMT by UDCA is related to the EGFR axis. Human extrahepatic BDC cells were cultured. The effect of UDCA on cell proliferation was evaluated using MTT assays. A cell death ELISA kit was used to measure apoptosis, and western blot assays or immunofluorescence staining assays measured the expression levels of various target proteins. The mRNA expression of Slug and ZEB1 was evaluated via reverse transcription-quantitative PCR. The invasiveness of BDC cells was estimated by invasion assays and western blot assays for focal adhesion kinase (FAK). UDCA inhibited the proliferation of BDC cells as effectively as gefitinib (an EGFR inhibitor), and the combination of UDCA and gefitinib revealed an additive effect on the proliferation of cells. UDCA and gefitinib induced apoptosis, and the combination of UDCA and gefitinib demonstrated an additive effect on apoptosis in BDC cells. UDCA restored the E-cadherin expression inhibited by EGF and suppressed N-cadherin expression increased by EGF as effectively as gefitinib. UDCA suppressed the Slug and ZEB1 mRNA expression induced by EGF in BDC cells. UDCA suppressed the invasiveness of BDC cells and FAK expression linked to the invasiveness of BDC. In conclusion, UDCA enhanced E-cadherin expression and suppressed N-cadherin expression through inhibition of the EGF-EGFR axis, contributing to the inhibition of EMT and invasiveness in BDC cells. Therefore, UDCA may be applied as an adjuvant or palliative antineoplastic agent and as a therapeutic option to enhance the effect of other chemotherapeutics.

Review: An integrated framework for understanding ecological drought and drought resistance.

Droughts are a frequent natural phenomenon that has amplified globally in the 21st century and are projected to become more common and extreme in the future. Consequently, this affects the progress of drought indices and frameworks to categorize drought conditions. Several drought-related indices and variables are required to capture different features of complex drought conditions. Therefore, we explained the signs of progress of ecological drought that were ecologically expressive to promote the integration between the research on and identification of water scarcity situations and analyzed different frameworks to synthesize the drought effects on species and ecosystems. Notably, we present an inclusive review of an integrated framework for an ecological drought. The ecological drought framework affords the advantage of improved methodologies for assessing ecological drought. This is supported by research on water-limited ecosystems that incorporated several drought-related elements and indicators to produce an integrated drought framework. In this framework, we combined multiple studies on drought recovery, early warning signs, and the effects of land management interferences, along with a schematic representation of a new extension of the framework into ecological systems, to contribute to the success and long-term sustainability of ecological drought adaptation, as well as on-the-ground examples of climate-informed ecological drought management in action for an integrated framework for ecological drought. This study provides an integrated approach to the understanding of ecological drought in line with accelerated scientific advancement to promote persistence and plan for a future that irretrievably exceeds the ecosystem thresholds and new multivariate drought indices.

Physicochemical properties and freeze-thaw stability of rice flour blends among rice cultivars with different amylose contents.

The effectiveness of the rice flour blends (RFB) for improving the processing suitability of Dodamssal rice flour (DD), a functional rice variety with a relatively high amylose and resistance starch content, was investigated. Physicochemical properties and freeze-thaw stability of RFB composed of DD and four rice flour (RF) samples with different amylose contents were measured at different DD ratios. DD, which has low swelling power and low pasting viscosity properties, has improved some quality in terms of physicochemical properties by blending with other RF. Especially, non-additive behavior was observed in the blend with Geonyang No.2 RF (GY), a medium waxy variety, due to water competition caused by the difference in pasting temperature. The syneresis of DD was reduced by blending with 75% Hanareum No. 4 RF, with a gradual reduction effect observed following a repeated freeze-thaw cycle. GY significantly improved the low freeze-thaw stability of DD with only a 25% blend. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s10068-021-00989-7.

Ursodeoxycholic acid shows antineoplastic effects in bile duct cancer cells via apoptosis induction; p53 activation; and EGFR-ERK, COX-2, and PI3K-AKT pathway inhibition.

Unlike in normal cells, ursodeoxycholic acid (UDCA) causes apoptosis rather than protection in cancer cells. Aim of this study was to demonstrate whether UDCA actually inhibits proliferation and induces apoptosis in bile duct cancer cells; the effect of UDCA on the expression of COX-2, PI3K/AKT, ERK, and EGFR; how UDCA affects cancer cell invasiveness and metastasis, since these effects are not established in bile duct cancer cells. SNU-245 cells (human extrahepatic bile duct cancer cells) were cultured. MTT assays were performed to evaluate the effect of UDCA on the cell proliferation. A cell death detection enzyme-linked immunosorbent assay and a caspase-3 activity assay were used to determine apoptosis. Western blot analysis measured expression levels of various proteins. The invasiveness of the cancer cells was evaluated by invasion assay. In cultured bile duct cancer cells, UDCA suppressed cell proliferation in bile duct cancer cells by inducing apoptosis and p53 activation, blocking deoxycholic acid (DCA)-induced activated EGFR-ERK signaling and COX-2, inhibiting DCA-induced activated PI3K-AKT signaling, and suppressing the invasiveness of bile duct cancer cells. In addition, a MEK inhibitor impaired UDCA-induced apoptosis in bile duct cancer cells. UDCA has antineoplastic and apoptotic effects in bile duct cancer cells. Thus, UDCA could be a chemopreventive agent in patients with a high risk of cancer, and/or a therapeutic option that enhances other chemotherapeutics.

Atorvastatin Induces FXR and CYP7A1 Activation as a Result of the Sequential Action of PPARγ/PGC-1α/HNF-4α in Hep3B Cells.

Backgrounds/Aims: PPARγ, farnesoid X receptor (FXR) and CYP7A1 are associated with solubility of bile. This study was performed to understand a mechanism and interactions of statin-induced PPARγ, PGC-1α and HNF-4α related to the statin-induced activation of FXR and CYP7A1, and verify whether the mevalonate pathway is involved in the mechanism. Methods: MTT assays were performed using cultured human Hep3B cells to determine the effect of atorvastatin on the cell proliferation. Expression levels of indicated proteins were measured using Western blotting assays by inhibiting the protein expression or not. Results: Atorvastatin increased expression of PPARγ, PGC-1α, HNF-4α, FXR, and CYP7A1 in Hep3B cells. PPARγ ligand of troglitazone upregulated the expression of PGC-1α, HNF-4α, FXR, and CYP7A1 in Hep3B cells. Silencing of PPARγ, PGC1α, and HNF4α using respective siRNA demonstrated that atorvastatin-induced FXR and CYP7A1 activation required sequential action of PPARγ /PGC-1α/HNF-4α. The silencing of PPARγ completely inhibited atorvastatin-induced PGC-1α expression, and the PGC1α silencing partially inhibited atorvastatin-induced PPARγ expression. The inhibition of HNF4α did not affect atorvastatin-induced PPARγ expression, but partially inhibited atorvastatin-induced PGC-1α expression. Besides, mevalonate completely reversed the effect of atorvastatin on PPARγ, PGC-1α, HNF-4α, FXR, and CYP7A1. Conclusions: Atorvastatin induces FXR and CYP7A1 activation as a result of sequential action of PPARγ/PGC-1α/HNF-4α in human hepatocytes. We propose that atorvastatin enhances solubility of cholesterol in bile by simultaneously activating of FXR and CYP7A1.

The Protective Effect of 5-Aminosalicylic Acid Against Non-Steroidal Anti-Inflammatory Drug-Induced Injury Through Free Radical Scavenging in Small Intestinal Epithelial Cells.

Background and objectives: Non-steroidal anti-inflammatory drugs (NSAIDs) have been among the major causes of small intestinal injury in clinical practice. As such, the current study investigated the protective effect of 5-aminosalicylic acid (5-ASA) against an NSAID-induced small intestinal injury. Materials and Methods: IEC-6 cells were treated with various concentrations of indomethacin with or without 5-ASA in a serum-free medium, after which an 3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Dromide (MTT) assay, a cell apoptosis assay, a caspase-3 activity assay, a reactive oxygen species (ROS) content and Superoxide dismutase 2 (SOD2) activity measurement, a Western blotting for occludin and zonula occludens-1 (ZO-1) and a wound healing assay were conducted. Results: 5-ASA ameliorated indomethacin-induced cell apoptosis and an increase in the intracellular ROS content while augmenting the indomethacin-induced suppression of SOD2 activity in IEC-6 cells. Moreover, 5-ASA reversed the indomethacin-induced attenuation of occludin and ZO-1 expression and promoted faster wound healing effects in IEC-6 cells following an indomethacin-induced injury. Conclusion: Our results suggested that 5-ASA protects small intestinal cells against an NSAID-induced small intestinal injury by scavenging free radicals. Therefore, 5-ASA could be a potential treatment for an NSAID-induced small intestinal injury.

Stereoisomer-specific ginsenoside 20(S)-Rg3 reverses replicative senescence of human diploid fibroblasts via Akt-mTOR-Sirtuin signaling.

BACKGROUND: The replicative senescence of human dermal fibroblasts (HDFs) is accompanied by growth arrest. In our previous study, the treatment of senescent HDFs with Rg3(S) lowered the intrinsic reactive oxygen species (ROS) levels and reversed cellular senescence by inducing peroxiredoxin-3, an antioxidant enzyme. However, the signaling pathways involved in Rg3(S)-induced senescence reversal in HDFs and the relatedness of the stereoisomer Rg3(R) in corresponding signaling pathways are not known yet. METHODS: We performed senescence-associated ß-galactosidase and cell cycle assays in Rg3(S)-treated senescent HDFs. The levels of ROS, adenosine triphosphate (ATP), and cyclic adenosine monophosphate (cAMP) as well as the mitochondrial DNA copy number, nicotinamide adenine dinucleotide (NAD)+/1,4-dihydronicotinamide adenine dinucleotide (NADH) ratio, and NAD-dependent sirtuins expression were measured and compared among young, old, and Rg3(S)-pretreated old HDFs. Major signaling pathways of phosphatidylinositol 3-kinase/Akt, 5' adenosine monophosphate-activated protein kinase (AMPK), and sirtuin 1/3, including cell cycle regulatory proteins, were examined by immunoblot analysis. RESULTS: Ginsenoside Rg3(S) reversed the replicative senescence of HDFs by restoring the ATP level and NAD+/NADH ratio in downregulated senescent HDFs. Rg3(S) recovered directly the cellular levels of ROS and the NAD+/NADH ratio in young HDFs inactivated by rotenone. Rg3(S) mainly downregulated phosphatidylinositol 3-kinase/Akt through the inhibition of mTOR by cell cycle regulators like p53/p21 in senescent HDFs, whereas Rg3(R) did not alter the corresponding signaling pathways. Rg3(S)-activated sirtuin 3/PGC1α to stimulate mitochondrial biogenesis. CONCLUSION: Cellular molecular analysis suggests that Rg3(S) specifically reverses the replicative senescence of HDFs by modulating Akt-mTOR-sirtuin signaling to promote the biogenesis of mitochondria.

Metformin Induces Apoptosis and Inhibits Proliferation through the AMP-Activated Protein Kinase and Insulin-like Growth Factor 1 Receptor Pathways in the Bile Duct Cancer Cells.

Background/Aims: Metformin has been found to have antineoplastic activity in some cancer cells. This study was performed to determine whether metformin inhibits the proliferation of bile duct cancer cells by inducing apoptosis and its effects on the expression of gene-related proteins involved in cancer growth. Methods: Human extrahepatic bile duct cancer cells (SNU-245 and SNU-1196) were cultured. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assays were performed to determine the effect of metformin on the cell proliferation. Apoptosis was measured by a cell death detection enzyme-linked immunosorbent assay and a caspase-3 activity assay. Expression levels of various proteins, with or without specific small interfering ribonucleic acid-induced gene disruption, were measured by Western blot analysis. The migratory activity of the cancer cells was evaluated by wound healing assay. Results: Metformin suppressed cell proliferation in bile duct cancer cells by inducing apoptosis. Metformin inhibited mammalian target of rapamycin (mTOR) by activation of tuberous sclerosis complex 2 (TSC-2) through phosphorylation of adenosine monophosphate-activated protein kinase at threonine-172 (AMPKThr172). Hyperglycemia impaired metformin-induced AMPKThr172 activation and enhanced phosphorylation of AMPK at serine-485 (AMPKSer485). Metformin blocked the inhibitory effect of insulin-like growth factor 1 receptor (IGF-1R)/insulin receptor substrate 1 (IRS-1) pathway on TSC-2, and hyperglycemia impaired metformin-induced inhibition of IGF-1R/IRS-1 pathway and modulated the invasiveness of bile duct cancer cells; however, this effect was impaired by hyperglycemia. Conclusions: Metformin has antineoplastic effects in bile duct cancer, and hyperglycemic environment interrupts the effect of metformin. In addition, AMPK and IGF-1R play a key role in the proliferation of bile duct cancer cells.

Development and evaluation of the bacterial fate and transport module for the Agricultural Policy/Environmental eXtender (APEX) model.

The Agricultural Policy/Environmental eXtender (APEX) is a watershed-scale water quality model that includes detailed representation of agricultural management. The objective of this work was to develop a process-based model for simulating the fate and transport of manure-borne bacteria on land and in streams with the APEX model. The bacteria model utilizes manure erosion rates to estimate the amount of edge-of-field bacteria export. Bacteria survival in manure is simulated as a two-stage process separately for each manure application event. In-stream microbial fate and transport processes include bacteria release from streambeds due to sediment resuspension during high flow events, active release from the streambed sediment during low flow periods, bacteria settling with sediment, and survival. Default parameter values were selected from published databases and evaluated based on field observations. The APEX model with the newly developed microbial fate and transport module was applied to simulate fate and transport of the fecal indicator bacterium Escherichia coli in the Toenepi watershed, New Zealand that was monitored for seven years. The stream network of the watershed ran through grazing lands with daily bovine waste deposition. Results show that the APEX with the bacteria module reproduced well the monitored pattern of E. coli concentrations at the watershed outlet. The APEX with the microbial fate and transport module will be utilized for predicting microbial quality of water as affected by various agricultural practices, evaluating monitoring protocols, and supporting the selection of management practices based on regulations that rely on fecal indicator bacteria concentrations.

Release from Streambed to Water Column during Baseflow Periods: A Modeling Study.

Streambed sediments can harbor large populations that are released into the water column during high-flow events. Few studies have been conducted on the rates of transfer from streambed sediment to water column in low-flow conditions in natural streams. The aim of this work was to apply the watershed-scale model SWAT (Soil and Water Assessment Tool) to a natural stream to evaluate the need to account for the release from streambed sediments during baseflow periods and to compare the results of simulating such a release by assuming predominantly passive transport, driven by groundwater influx, against simulations assuming predominantly active transport of random or chemotaxis-driven bacteria movement. concentrations in water during baseflow periods were substantially underestimated when release from the streambed was attributed only to streambed sediment resuspension. When considered in addition to the release due to sediment resuspension at high flows, the active and passive release assumptions provided 42 and 4% improvement, respectively, in the RMSE of logarithms of concentrations. Estimated fluxes to water column during the baseflow periods from June to November ranged from 3.3 × 10 colony-forming units (CFU) m d in the game land area to 1.4 × 10 CFU m d in the mixed pasture and cropland. Results demonstrate that release of from streambed sediments during baseflow periods is substantial and that water column concentrations are dependent on not only land management practices but also on in-stream processes.

Modeling the interannual variability of microbial quality metrics of irrigation water in a Pennsylvania stream.

Knowledge of the microbial quality of irrigation waters is extremely limited. For this reason, the US FDA has promulgated the Produce Rule, mandating the testing of irrigation water sources for many farms. The rule requires the collection and analysis of at least 20 water samples over two to four years to adequately evaluate the quality of water intended for produce irrigation. The objective of this work was to evaluate the effect of interannual weather variability on surface water microbial quality. We used the Soil and Water Assessment Tool model to simulate E. coli concentrations in the Little Cove Creek; this is a perennial creek located in an agricultural watershed in south-eastern Pennsylvania. The model performance was evaluated using the US FDA regulatory microbial water quality metrics of geometric mean (GM) and the statistical threshold value (STV). Using the 90-year time series of weather observations, we simulated and randomly sampled the time series of E. coli concentrations. We found that weather conditions of a specific year may strongly affect the evaluation of microbial quality and that the long-term assessment of microbial water quality may be quite different from the evaluation based on short-term observations. The variations in microbial concentrations and water quality metrics were affected by location, wetness of the hydrological years, and seasonality, with 15.7-70.1% of samples exceeding the regulatory threshold. The results of this work demonstrate the value of using modeling to design and evaluate monitoring protocols to assess the microbial quality of water used for produce irrigation.

Simvastatin induces heme oxygenase-1 via NF-E2-related factor 2 (Nrf2) activation through ERK and PI3K/Akt pathway in colon cancer.

Statin has been known not only as their cholesterol-lowering action but also on their pleiotropic effects including anti-inflammatory and anti-oxidant as well as anti-cancer effect. Nrf2 (NF-E2-related factor 2) is a transcription factor to activate cellular antioxidant response to oxidative stress. There are little known whether statins affect activation of Nrf2 and Nrf2 signaling pathway in colon cancer cells. We investigated whether simvastatin stimulates the expression of Nrf2 and nuclear translocation of Nrf2 and which signal pathway is involved in the expression of Nrf2 and antioxidant enzymes. We investigated the effect of simvastatin on the expression of Nrf2 and nuclear translocation of Nrf2 in two human colon cancer cell lines, HT-29 and HCT 116 through cell proliferation assay, Western blotting and immunocytochemical analysis. We evaluated which signal pathway such as ERK or PI3K pathway affect Nrf2 activation and whether simvastatin induces antioxidant enzymes (heme oxygenase-1 (HO-1), NAD(P)H: quinine oxidoreductase 1 (NQO1), γ-glutamate-cysteine ligase catalytic subunit (GCLC)). We demonstrated simvastatin-induced dose-dependent up-regulation of Nrf2 expression and stimulated Nrf2 nuclear translocation in colon cancer cells. We also demonstrated that simvastatin-induced anti-oxidant enzymes (HO-1, NQO1, and GCLC) in HT-29 and HCT 116 cells. PI3K/Akt inhibitor (LY294002) and ERK inhibitor (PD98059) suppressed simvastatin-induced Nrf2 and HO-1 expression in both HT-29 and HCT 116 cells. This study shows that simvastatin induces the activation and nuclear translocation of Nrf2 and the expression of various anti-oxidant enzymes via ERK and PI3K/Akt pathway in colon cancer cells.

Statin induces apoptosis of human colon cancer cells and downregulation of insulin-like growth factor 1 receptor via proapoptotic ERK activation.

Insulin-like growth factor 1 (IGF-1) and IGF-1 receptor (IGF-1R) signaling plays an important role in tumor progression in patients with certain gastrointestinal tract cancers. In addition to lowering cholesterol in serum, statins have pleiotropic effects, including anti-oxidative, anti-inflammatory or anti-neoplastic effects. Therefore, the present study investigated whether statins could induce the apoptosis of colon cancer cells and regulate the expression of IGF-1R and its associated signaling pathways in the present study. It was demonstrated that simvastatin and pravastatin suppressed cell proliferation and induced cell death in human HT-29 cells, but simvastatin was more potent than pravastatin. Simvastatin induced apoptosis in a concentration-dependent manner. In addition, simvastatin suppressed the expression of IGF-1R and inhibited the activity of phosphorylated-extracellular signal-regulated kinase (ERK)1/2 and phosphorylated-Akt activated by IGF-1. Simvastatin and IGF-1 each stimulated the activity of phosphorylated ERK1/2. However, simvastatin inhibited cell proliferation and IGF-1 stimulated cell proliferation. Mevalonic acid and PD98059 reversed the ERK activation and apoptosis induced by treatment with simvastatin. It was concluded that simvastatin induces the apoptosis of human colon cancer cells and inhibits IGF-1-induced ERK and Akt expression via the downregulation of IGF-1R expression and proapoptotic ERK activation. Simvastatin may be beneficial for the treatment of colon cancer. The present study suggested that statin may possess therapeutic potential for the treatment of colon cancer.

Synergistic Effects of Simvastatin and Irinotecan against Colon Cancer Cells with or without Irinotecan Resistance.

Aims. We here investigated whether the combination of simvastatin and irinotecan could induce the synergistic effect on colon cancer cells with or without resistance to irinotecan. Methods. We investigated cell proliferation assay and assessed cell death detection ELISA and caspase-3 activity assay of various concentrations of simvastatin and irinotecan to evaluate the efficacy of drug combination on colon cancer cells with or without irinotecan resistance. Results. The IC50 values of simvastatin alone and irinotecan alone were 115.4 ± 0.14 µM (r = 0.98) and 62.5 ± 0.18 µM (r = 0.98) in HT-29 cells without resistance to irinotecan. The IC50 values of these two drugs were 221.9 ± 0.22 µM (r = 0.98) and 195.9 ± 0.16 µM (r = 0.99), respectively, in HT-29 cell with resistance to irinotecan. The results of combinations of the various concentrations of two drugs showed that combined treatment with irinotecan and simvastatin more efficiently suppressed cell proliferation of HT-29 cells even with resistance to irinotecan as well as without resistance. Furthermore, the combination of simvastatin and irinotecan at 2 : 1 molar ratio showed the best synergistic interaction. Conclusion. Simvastatin could act synergistically with irinotecan to overcome irinotecan resistance of colon cancer.

Simvastatin Induces Apoptosis and Suppresses Insulin-Like Growth Factor 1 Receptor in Bile Duct Cancer Cells.

BACKGROUND/AIMS: Statins act as antineoplastic agents through the inhibition of cell proliferation. This study sought to demonstrate the effects of statins on extrahepatic bile duct cancer cell apoptosis and to document the changes in protein expression involved in tumor growth and suppression. METHODS: Human extrahepatic bile duct cancer cells were cultured. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays were performed to determine the effect of statins on cell proliferation. Apoptosis was measured by a cell death detection enzyme-linked immunosorbent assay and caspase-3 activity assay, and flow cytometry was used to determine the percentage of cells in each phase of the cell cycle. The protein expression of Bax, Bcl-2, insulin-like growth factor 1 (IGF-1) receptor, extracellular signal-regulated kinase 1/2 (ERK1/2), and Akt was measured by Western blot analysis. RESULTS: Simvastatin suppressed cell proliferation by inducing G1 phase cell cycle arrest in bile duct cancer cells. Furthermore, it induced apoptosis via caspase-3 activation, downregulated the expression of the Bcl-2 protein, and enhanced the expression of the Bax protein. Moreover, simvastatin suppressed the expression of the IGF-1 receptor and IGF-1-induced ERK/Akt activation. CONCLUSIONS: Simvastatin induces apoptosis in bile duct cancer cells, which suggests that it could be an antineoplastic agent for bile duct cancer.

Selective modulation of charge-carrier transport of a photoanode in a photoelectrochemical cell by a graphitized fullerene interfacial layer.

We show that a graphitic carbon interfacial layer, derived from C70 by annealing at 500 °C, results in a significant increase in the attainable photocurrent of a photoelectrochemical cell that contains a WO3 -functionalized fluorine-doped tin oxide (FTO) photoanode. Time-resolved photoluminescence spectroscopy, photoconductive atomic force microscopy, Hall measurements, and electrochemical impedance spectroscopy show that the increase in photocurrent is the result of fast and selective electron transport from optically excited WO3 through the graphitic carbon interfacial layer to the FTO-coated glass electrode. Thus the energy efficiency of perspective solar-to-fuel devices can be improved by modification of the interface of semiconductors and conducting substrate electrodes by using graphitized fullerene derivatives.

Pravastatin activates the expression of farnesoid X receptor and liver X receptor alpha in Hep3B cells.

BACKGROUND: Statins are suggested to preserve gallbladder function by suppressing pro-inflammatory cytokines and preventing cholesterol accumulation in gallbladder epithelial cells. They also affect cross-talk among the nuclear hormone receptors that regulate cholesterol-bile acid metabolism in the nuclei of hepatocytes. However, there is controversy over whether or how statins change the expression of peroxisome proliferator-activated receptor (PPAR)alpha, PPARgamma, liver X receptor alpha (LXRalpha), farnesoid X receptor (FXR), ABCG5, ABCG8, and 7alpha-hydroxylase (CYP7A1) which are directly involved in the cholesterol saturation index in bile. METHODS: Human Hep3B cells were cultured on dishes. MTT assays were performed to determine the appropriate concentrations of reagents to be used. The protein expression of PPARalpha and PPARgamma was measured by Western blotting analysis, and the mRNA expression of LXRalpha, FXR, ABCG5, ABCG8 and CYP7A1 was estimated by RT-PCR. RESULTS: In cultured Hep3B cells, pravastatin activated PPARalpha and PPARgamma protein expression, induced stronger expression of PPARgamma than that of PPARalpha, increased LXRalpha mRNA expression, activated ABCG5 and ABCG8 mRNA expression mediated by FXR as well as LXRalpha, enhanced FXR mRNA expression, and increased CYP7A1 mRNA expression mediated by the PPARgamma and LXRalpha pathways, together or independently. CONCLUSION: Our data suggested that pravastatin prevents cholesterol gallstone diseases via the increase of FXR, LXRalpha and CYP7A1 in human hepatocytes.

HMG-CoA reductase inhibitors (statins) activate expression of PPARalpha/PPARgamma and ABCA1 in cultured gallbladder epithelial cells.

In gallbladder epithelial cells (GBEC), PPARalpha and PPARgamma ligands modulate inflammation by suppression of TNFalpha production and prevent excessive accumulation of cholesterol by ABCA1 activation. Recently, HMG-CoA reductase inhibitors (statins) were shown to activate PPARalpha and PPARgamma in various cells but no studies of their effects in GBEC have been conducted. The objective of this study was, therefore, to determine the effects of statins on PPAR and ABCA1 expression and the anti-inflammatory effect of statins in GBEC. Canine GBEC were cultured on Petri dishes. Expression of the proteins PPARalpha, PPARgamma, and ABCA1 was measured by western blotting analysis after treatment with simvastatin, pravastatin, NO-pravastatin, PPARalpha ligand, or PPARgamma ligand in the culture media. Expression of ABCA1 and LXRalpha mRNAs was estimated by RT-PCR. Expression of TNFalpha mRNA was measured by RT-PCR after 24 h pre-treatment with the statins, preceding 1 h of lipopolysaccharide (LPS) loading. Simvastatin, pravastatin, and NO-pravastatin increased expression of the proteins PPARalpha, PPARgamma, and ABCA1, and expression of the mRNA of ABCA1 and LXRalpha in GBEC. Pre-treatment with simvastatin, pravastatin, and NO-pravastatin suppressed the production of TNFalpha mRNA induced by LPS. In conclusion, statins probably contribute to the preservation of GBEC function by activation of PPARalpha and PPARgamma, which have anti-inflammatory effects by suppression of pro-inflammatory cytokines, and ABCA1 activation mediated by LXRalpha, which prevents the accumulation of cholesterol in GBEC.

The effect of PPARalpha and PPARgamma ligands on inflammation and ABCA1 expression in cultured gallbladder epithelial cells.

The preservation of gallbladder function by control of inflammation and elimination of cholesterol accumulation in gallbladder epithelial cells (GBEC) could contribute to the prevention of gallstone formation and cholecystitis. Peroxisome proliferator-activated receptors (PPARs) modulate inflammation and lipid metabolism in various cells and GBEC efflux of excessive amounts of absorbed cholesterol through the ATP-binding cassette transporter A1 (ABCA1)-mediated pathway. The aim of this study was to determine whether ligands of PPARalpha and PPARgamma modulate inflammation and have an effect on ABCA1 expression in GBEC. Canine GBEC were cultured on dishes coated with collagen matrix. We performed Western blot analysis for the expression of specific protein and/or RT-PCR for the expression of specific mRNA. PPARalpha and PPARgamma expression was observed and increased in GBEC treated with WY-14643 (PPARalpha ligand), troglitazone (PPARgamma ligand), and lipopolysaccharide (LPS) compared to the no-treatment control and PPARalpha( antagonist (GW-9662) treatment group. WY-14643, troglitazone, and LPS also induced an increase in the expression of ABCA1 protein and mRNA in cultured GBEC. LPS-induced TNFalpha mRNA expression was suppressed by pretreatment with WY-14643 and troglitazone preceding LPS treatment in GBEC. PPAR ligands, especially PPARgamma, may preserve gallbladder function by suppression of inflammatory reaction and prevention of cholesterol accumulation in GBEC, contributing to the prevention of gallstone formation and progression to cholecystitis.