Berberine inhibits human hepatoma cell invasion without cytotoxicity in healthy hepatocytes

Conventional chemotherapy fails to cure metastatic hepatoma mainly due to its high hepatotoxicity. Many plant-derived agents have been accepted to effectively inhibit hepatoma cell invasion. However, the investigation that whether effectual plant-derived agents against invasive hepatoma cells exert unexpected cytotoxicity in healthy hepatocytes has been ignored. This study demonstrated that berberine exhibited significant cytotoxicity in HepG2 cells mainly through upregulation of reactive oxygen species (ROS) production but was ineffective in normal Chang liver cells. Berberine exerted anti-invasive effect on HepG2 cells through suppression of matrix metalloproteinase-9 (MMP-9) expression. Moreover, berberine could significantly inhibit the activity of PI3K-AKT and ERK pathways. Combination treatment of ERK pathway inhibitor PD98059 or AKT pathway inhibitor LY294002 and berberine could result in a synergistic reduction on MMP-9 expression along with an inhibition of cell invasion. Enhancement of ROS production by berberine had no influence on its suppressive effects on the activity of PI3K-AKT and ERK pathways, as well as MMP-9 expression and HepG2 cell invasion. In conclusion, our results suggest that berberine may be a potential alternative against invasive hepatoma cells through PI3K-AKT and ERK pathways-dependent downregulation of MMP-9 expression. This study also provides a previously neglected insight into the investigation of plant-derived agents-based therapy against tumor invasion with the consideration of damage to healthy cells.     

Resveratrol Inhibits the Growth of Gastric Cancer by Inducing G1 Phase Arrest and Senescence in a Sirt1-Dependent Manner

Resveratrol, a naturally occurring polyphenolic compound, has been reported to exert anticancer activity by affecting diverse molecular targets. In this study, we examined the effects and the underlying mechanisms of resveratrol on gastric cancer. We found that resveratrol inhibited the proliferation of gastric cancer cells in a dose-dependent manner. At the concentration of 25 and 50 µM, resveratrol inhibited the cell viability and diminished the clonogenic potential of gastric cancer cells. Resveratrol treatment arrested gastric cancer cells in the G1 phase and led to senescence instead of apoptosis. Regulators of the cell cycle and senescence pathways, including cyclin D1, cyclin-dependent kinase (CDK4 and 6), p21 and p16, were dysregulated by resveratrol treatment. The inhibitory effects of resveratrol on gastric cancer were also verified in vivo using a nude mice xenograft model. Resveratrol (40 mg/kg/d) exerted inhibitory activities on gastric cancer development and significantly decreased the fractions of Ki67-positive cells in the tumor specimens from the nude mice. After resveratrol treatment, the induction of senescence and the changes in the expression of the regulators involved in the cell cycle and senescence pathways were similar to what we observed in vitro. However, the depletion of Sirtuin (Sirt)1 reversed the above-described effects of resveratrol both in vitro and in vivo. Our data suggest that resveratrol inhibits gastric cancer in a Sirt1-dependent manner and provide detailed evidence for the possibility of applying resveratrol in gastric cancer prevention and therapy.     

Investigation on the removal of Mo(VI) from Mo-Re containing wastewater by chemically modified persimmon residua

Persimmon waste was chemically modified by crosslinking with concentrated sulfuric acid to obtain a novel kind of adsorption gel, which was termed as crosslinked persimmon tannin (CPT), hereinafter. The adsorption behaviors of Mo(VI) with other coexisting metal ions onto the CPT gel were investigated. The gel exhibited selectivity only for Mo(VI) ions evidenced by the high value of separation factor of molybdenum and rhenium (β_Mo/Re = 164.37), and the adsorption mechanism of Mo(VI) as a multispecies was studied. The molybdenum adsorption behavior conforms to the Langmuir model with a remarkably high adsorption capacity of 0.56 mol/kg. A kinetic study for the adsorption of molybdenum at various temperatures confirmed that the endothermic adsorption process followed pseudo-second order kinetics. Moreover, its excellent adsorption properties and applicability for Mo(VI) were demonstrated by the removal and separation of Mo(VI) from different Mo-Re containing industrial wastewaters.     

Purification and characterization of a novel NADH-dependent carbonyl reductase from Pichia stipitis involved in biosynthesis of optically pure ethyl (S)-4-chloro-3-hydroxybutanoate

A novel NADH-dependent dehydrogenases/reductases (SDRs) superfamily reductase (PsCRII) was isolated from Pichia stipitis. It produced ethyl (S)-4-chloro-3-hydroxybutanoate [(S)-CHBE] in greater than 99% enantiomeric excess. This enzyme was purified to homogeneity by ammonium sulfate precipitation followed by Q-Sepharose chromatography. Compared to similar known reductases producing (S)-CHBE, PsCR II was more suitable for production since the purified PsCRII preferred the inexpensive cofactor NADH to NADPH as the electron donor. Furthermore, the Km of PsCRII for ethyl 4-chloro-3-oxobutanoate (COBE) was 3.3 mM, and the corresponding Vmax was 224 μmol/mg protein/min. The catalytic efficiency is the highest value ever reported for NADH-dependent reductases from yeasts that produce CHBE with high enantioselectivity. In addition, this enzyme exhibited broad substrate specificity for several β-keto esters using NADH as the coenzyme. The properties of PsCRII with those of other carbonyl reductases from yeasts were also compared in this study.     

辐射诱变技术在农业育种中的应用与探析

辐射诱变育种是在人工控制的条件下,利用中子、质子或者射线等物理辐射诱变因素对种子进行辐照,诱发其染色体的数量、结构和行为变异,从而得到可供利用的突变体,并在此基础上进一步培育出新的种质资源的一种新兴的育种技术.本文以水稻、小麦、大豆、花卉和林木等材料所做的辐照试验为依托,综述了国内外在辐射诱变育种方面所取得的成就,分析了该技术的作用机理、特点、优势、适用范围及其发展历程,并对其发展方向和应用前景做出了展望.其主旨在于提高人们对辐射诱变育种技术在农业生产中应用的价值、意义及其前景的认识,并为该技术的进一步发展和应用提供参考与借鉴,以期促进现代化物理农业工程的发展和应用,提高人民的生活水平与质量.     

Phytoplankton patchiness in Winam Gulf,Lake Victoria: a study using principal component analysis of in situ fluorescent excitation spectra

1. In order to characterise phytoplankton patchiness at fine scales, a profiling multiwavelength fluorometer was cast at numerous locations throughout Winam Gulf in Lake Victoria to measure fluorescent excitation spectra, which are indicators of both phytoplankton diversity and coloured dissolved organic matter (CDOM). 2. Processing the spectral data with principal component analysis (PCA) revealed that linear combinations of four fundamental ‘base’ spectra could explain almost all of the variation in spectral measurements. Three of the base spectra were associated with spatially distinct patches of phytoplankton containing different species assemblages, while the fourth base spectrum was due to CDOM fluorescence. 3. The locations of the phytoplankton patches were traced to the south‐east of Winam Gulf, the western end of the Rusinga Channel and the open waters of Lake Victoria adjacent to Winam Gulf, respectively. The high CDOM fluorescence was traced mainly to relatively deep water in the Rusinga Channel. 4. The phytoplankton and CDOM patchiness were interpreted in the context of physical and chemical gradients that were measured at the site at the same scale as the spectral data. Strong relationships were found between the gradients in spectral data and other environmental variables, which suggested several underlying explanations for the phytoplankton and CDOM patchiness.     

Effects of Decitabine on the proliferation of K562 cells and the expression of DR4 gene

Objective

To investigate the role of DR4 gene in the occurrence, development and prognosis of acute myeloid leukemia (AML), find a new regulatory gene of Decitabine for the treatment of AML, namely DR4 gene, and explore the molecular mechanism of AML in the treatment of AML.

TGF-β-mediated upregulation of Sox9 in fibroblast promotes renal fibrosis

TGF-β signaling plays a principal role in renal fibrosis, but the precise mechanisms and the downstream factors are still largely unknown. Sox9 exhibits diverse roles in regulating the production of extracellular matrix proteins. Here we found that Sox9 was induced by TGF-β in the kidney fibroblast and acted as an important downstream mediator of TGF-β signaling in promoting renal fibrosis. TGF-β/Smad signaling mediated the upregulation of Sox9 in kidney fibroblast by binding to a conserved enhancer. In different mouse models of renal fibrosis, as well as in the kidney biopsy tissue from patients with renal fibrosis, Sox9 expression significantly increased. Immunostaining confirmed the upregulation of Sox9 in the kidney fibroblast during renal fibrosis. Delivery of Sox9 knockdown plasmid to the kidney by ultrasound microbubble–mediated gene transfer suppressed the unilateral ureteral obstruction (UUO) or folic acid-induced mouse renal fibrosis, whereas ectopic expression of Sox9 aggravated renal fibrosis. In addition, we identified Sox9 as a direct target of miR-30. Notably, miR-30 expression was significantly inhibited by TGF-β1 in the kidney fibroblast and the downregulation of miR-30 was observed in renal fibrosis. Mechanistically, inhibition of miR-30 independently strengthened the effect of TGF-β/Smad signaling on Sox9 upregulation. Adenovirus-mediated ectopic expression of miR-30 in kidney fibroblast greatly reduced UUO-induced renal fibrosis by targeting Sox9. These findings link Sox9 to intrinsic mechanisms of TGF-β signaling in renal fibrosis and may have therapeutic potential for tissue fibrosis.