Cytotoxic nortriterpenoids from the barks of Juglans cathayensis.

A chemical study of 90% ethanol extract of the barks of Juglans cathayensis resulted in the isolation of three new nortriterpenoids, jugcathenoids A-C (1-3). The structures of the new compounds were elucidated by spectroscopic analysis (NMR, IR, UV, and MS). The isolated nortriterpenoids were tested in vitro for cytotoxic activities against 6 pancreatic cell lines. As a result, compounds 1-3 exhibited some cytotoxic activities against all the tested tumor cell lines with IC50 values less than 50 µM.

Mesoscale Analysis of the Effect of Interfacial Transition Zone on the Compressive Damage of Concrete Based on Discrete Element Method.

The coarse aggregate-mortar interface transition zone (ITZ) has a great influence on the mechanical properties of concrete, which cannot be easily studied using laboratory tests in the mesoscale. In this paper, a series of axial compression tests were conducted using the discrete element method (DEM) on concrete specimens for four phases: coarse aggregates, mortars, aggregate-mortar interface transition zones, and voids. The effects of ITZ strength on macroscopic stress and microscopic cracks under different strength reduction factors were investigated through axial compression testing. With the increase in interface transition strength, the compressive strength of the concrete becomes stronger; moreover, the number of cracks decreases, and the anisotropy of contact orientation becomes weaker. Meanwhile, the direction of crack development and the damage mode of compressed concrete specimens were also dependent on the coarse aggregate-mortar interface strength coefficient.

Optimal bounds for Neuman-Sándor mean in terms of the convex combination of the logarithmic and the second Seiffert means.

In the article, we prove that the double inequality [Formula: see text] holds for [Formula: see text] with [Formula: see text] if and only if [Formula: see text] and [Formula: see text], where [Formula: see text], [Formula: see text] and [Formula: see text] denote the Neuman-Sándor, logarithmic and second Seiffert means of two positive numbers a and b, respectively.

Vitamin C down-regulate apo(a) expression via Tet2-dependent DNA demethylation in HepG2 cells.

Lipoprotein(a)[Lp(a)] is a risk factor for coronary heart diseases. However, the metabolism of this protein remains poorly understood. Efficient and specific drugs that can decrease high plasma levels of Lp(a) have not been developed yet. Vitamin C is responsible for maintaining the catalytic activity of a group of iron and 2-oxoglutarate (2OG)-dependent dioxygenases and induces the generation of 5-hydroxymethylcytosine (5hmC) via Ten-eleven translocation (Tet) dioxygenases. In addition, It has been reported vitamin C deficiency induces atherosclerosis and increases Lp(a) and apo(a) plasma levels in Lp(a)+ mice. However, the mechanism is still unclear. In this study, we investigated the effects of vitamin C on apo(a) expression and the possible molecular mechanism of vitamin C that influences apolipoprotein(a) [apo(a)] biosynthesis in HepG2 cells. Results showed that vitamin C significantly inhibited the expression and secretion levels of apo(a). Vitamin C can also increase ELK1 expression and hydroxymethylation of ELK1 promoter and the globle DNA in HepG2 cells. In addition, the effects of vitamin C inhibiting the apo(a) expression were attenuated by ELK1siRNA and Tet2siRNA. These results suggested vitamin C down-regulate apo(a) expression via Tet2-dependent DNA demethylation in HepG2 cells.

H2 S inhibits apo(a) expression and secretion through PKCα/FXR and Akt/HNF4α pathways in HepG2 cells.

Lipoprotein(a) [Lp(a)] is a strong genetic risk factor for coronary heart diseases. However, the metabolism of this protein remains poorly understood. Efficient and specific drugs that can decrease high plasma levels of Lp(a) have not been developed yet. Hydrogen sulfide (H2 S), a member of the gas transmitter family, performs important biological actions, including protection against cardiovascular diseases and maintenance of the lipid metabolism equilibrium in hepatocytes and adipocytes. In this study, we investigated the possible molecular mechanism of H2 S that influences apolipoprotein(a) [apo(a)] biosynthesis. We also determined the effects of H2 S on apo(a) expression and secretion in HepG2 cells as well as the underlying mechanisms. Results showed that H2 S significantly inhibited the expression and secretion levels of apo(a). These effects were attenuated by the PKCα inhibitor and FXR siRNA. H2 S also reduced HNF4α expression and enhanced FXR expression. The Akt inhibitor partially reversed H2 S-induced inhibition of apo(a) and HNF4α expression and apo(a) secretion. This study reveals that H2 S suppressed apo(a) expression and secretion via the PKCα-FXR and PI3K/Akt-HNF4α pathways.

Ox-Lp(a) transiently induces HUVEC autophagy via an ROS-dependent PAPR-1-LKB1-AMPK-mTOR pathway.

Oxidised lipoprotein(a) [oxLp(a)] is considered as a more potent arteriosclerotic factor than native Lp(a). However, the molecular mechanisms underlying this potency remain unclear. Reactive oxygen species (ROS) possibly act as intracellular second messengers that participate in autophagy stimulation. In this study, the effect of oxLp(a) on endothelial cell autophagy was determined. The mechanism and effect of autophagy on endothelial cells were also investigated. Results showed that oxLp(a) could induce autophagy depending on the generation of cellular ROS. Superoxide dismutase, an antioxidant, could inhibit oxLp(a)-induced autophagy in human umbilical vascular endothelial cells. Furthermore, poly(adenosine diphosphate-ribose) polymerase-1 (PARP-1)-liver kinase B1 (LKB1)-adenosine monophosphate-activated protein kinase (AMPK)-mammalian target of rapamycin (mTOR) and LKB1-AMPK-mTOR pathways are involved in oxLp(a)-induced autophagy. These pathways are also dependent on ROS. Thus, oxLp(a) induced autophagy via LKB1-AMPK-mTOR and PAPR-1-LKB1-AMPK-mTOR pathways, which are dependent on ROS generation.

Characterization of a new male sterility-related gene Camf1 in Capsicum annum L.

For the sake of screening novel genes related to the male sterility in chili pepper for studying the molecular mechanism of plant male sterility, the gene differential expression analysis was performed by cDNA-amplified fragment length polymorphism (cDNA-AFLP) in the genic male sterile-fertile line 114AB of Capsicum annum L., and a variety of differentially expressed cDNA fragments were detected in fertile or sterility material. Camf1, a transcript-derived fragment (TDF) accumulated in fertile line flower buds was further investigated. The Camf1 has 1,854 bp in length with no introns containing a 1,707-bp open reading frame (ORF). The deduced amino acid sequence of Camf1 shares higher similarity to some members from a glyoxal oxidase-related protein family, and has a glyoxal oxidase conserved domain at the N-terminus and a domain of unknown function (DUF1929) at C-terminal end. Expression analysis showed that Camf1 expressed only in stage 3-7 flower buds of male fertile of C. annum L. 114AB, and no detection in all organs of male sterility. The peak of expression level of Camf1 appeared at stage 4 flower buds of fertile line. Furthermore, expression analysis of different organs revealed that Camf1 expressed only in anthers of male fertile material and there were no expression in sepals, petals, pistils, roots, stems, leaves and open flowers. These results suggested that Camf1 was an anther-specific gene and might be essential for the fertility of C. annum L.

[Application of kanamycin in transgenic mustard(Brassica juncea Coss.)].

In order to find the best screening kanamycin concentration in the genetic transformation of mustard (Brassica juncea Coss.), the seedling cotyledons of mustard were placed on bud-induced media supplemented with different kanamycin concentrations. The bud differentiation of explants was totally inhibited when the kanamycin concentration was greater than 30 mg/L. The seeds of mustard were placed on germination media supplemented with different concentrations of kanamycin. All the seedlings were white when kanamycin concentration was higher than 200 mg/L. The leaves of mustard in field were smeared with the solutions including different concentrations of kanamycin. The treated leaves showed white when kanamycin concentration was over 200 mg/L. To study the segregation of the alien gene in transgenic mustard offspring, the transgenic mustard seeds and the leaves of the transgenic mustard offspring using npt-gene as assistant selection-marker were treated with 200 mg/L kanamycin, and the results were analyzed by chi-square test. The segregation ratio in the offspring of 4 transgenic lines with single copy of transgene agreed with a ratio of 3:1. The segregation ratio in offspring of the one transgenic line with double copies was agreed with a ratio of 3:1, and the segregation ratio in offspring of the other transgenic line with double copies was agreed with ratios of 3:1 and 15:1 simultaneously. It is indispensable to thoroughly study the insert of the double copies of transgenes in transgenic mustard. PCR technology was used to confirm the above detection methods. It is concluded that applying kanamycin to screen transgenic mustard offspring is feasible.

[Cloning a gene related to resistance to TuMV in cabbage].

A cDNA library was constructed from cabbage 84075 which resists TuMV. The degenerate primers was designed with the disease resistance gene conservative domain (NBS-LRR). The fragments of 513 bp were amplified by RT-PCR and genomic DNA PCR from resistant material 84075, then cloned and sequenced. Two recombinants which are highly homologous with the resistance genes cloned in other plants were used as probes, (named as Bor1, Bor2), the cDNA library was screened. A positive clone was obtained, named as TuR2, whose length was 762 bp, which encodes 226 amino acids, contains a long 681 bp open reading frame (ORF), and has different homology score of amino acid compared with the cloned resistance disease genes of other plants. TuR2 was used as probe. Southern blotting hybridization with genomic DNA shows that TuR2 is probably present in single copy; No. rthern blotting hybridization with RNA shows that the gene expression is constitutive and not differential in every part of the resistance plant 84075, the result of separating detection in F2 population shows that TuR2 gene is probably related to resistance to TuMV in cabbage.