Mechanisms for nickel(0)/N-heterocyclic carbene-catalyzed intramolecular alkene hydroacylation: insights from a DFT study

Journal of Molecular Modeling - Multi-furazan compounds bis[4-nitramino- furazanyl-3-azoxy]azofurazan (ADNAAF) and its derivatives were first synthesized by our research group, and their structures...     

miR24-2 accelerates progression of liver cancer cells by activating Pim1 through tri-methylation of Histone H3 on the ninth lysine

Several microRNAs are associated with carcinogenesis and tumour progression. Herein, our observations suggest both miR24-2 and Pim1 are up-regulated in human liver cancers, and miR24-2 accelerates growth of liver cancer cells in vitro and in vivo. Mechanistically, miR24-2 increases the expression of N6-adenosine-methyltransferase METTL3 and thereafter promotes the expression of miR6079 via RNA methylation modification. Furthermore, miR6079 targets JMJD2A and then increased the tri-methylation of histone H3 on the ninth lysine (H3K9me3). Therefore, miR24-2 inhibits JMJD2A by increasing miR6079 and then increases H3K9me3. Strikingly, miR24-2 increases the expression of Pim1 dependent on H3K9me3 and METTL3. Notably, our findings suggest that miR24-2 alters several related genes (pHistone H3, SUZ12, SUV39H1, Nanog, MEKK4, pTyr) and accelerates progression of liver cancer cells through Pim1 activation. In particular, Pim1 is required for the oncogenic action of miR24-2 in liver cancer. This study elucidates a novel mechanism for miR24-2 in liver cancer and suggests that miR24-2 may be used as novel therapeutic targets of liver cancer.     

Paclobutrazol and plant-growth promoting bacterial endophyte Pantoea sp. enhance copper tolerance of guinea grass (Panicum maximum) in hydroponic culture

As most gramineous plants, guinea grass (Panicum maximum) comprise cellulosic biomass, which may be used as a feedstock for bioenergy. In order to develop such potential energy plants on copper-polluted lands, the hydroponic experiments with Cu, Paclobutrazol (PP333, a kind of antigibberellin) and plant growth-promoting bacterial endophyte (PGPB) treatments were carried out in a greenhouse. The seedlings of two cultivars of guinea grass, GG1 (P. maximum var. Natsukomaki) and GG2 (P. maximum var. Natsukaze) in 3 weeks old were treated, respectively, with different Cu treatments [0(CK), 100, 200, 300, 400, 500 μM l⁻¹ Cu] for estimating Cu toxicity. The results showed that elevated Cu restrained plant growth and reduced biomass. According to the EC50 value [the Cu concentration when the relative gain in fresh weight ratio was 50% of control] of two tested cultivars, the concentration of Cu for further experiments was decided as 300 μM l⁻¹. Both pretreatments of PP333 (200, 400, 600 mg l⁻¹) and PGPB (Pantoea sp.) significantly alleviated the negative affect caused by stress of 300 μM l⁻¹ Cu. The pretreatment of 400 mg l⁻¹ PP333 promoted both two cultivars in biomass, compared to 300 μM l⁻¹ Cu treat. The inoculation of Pantoea sp. Jp3-3 increased shoot dry weight, compared to Cu treat. The results suggested that the main reason for both PP333 and Pantoea sp. Jp3-3 enhanced Cu tolerance in guinea grass was that their pretreatments significantly decreased Cu absorption and accumulation under excessive Cu stress. The present study has provided a new insight into the exploitation of energy plant in heavy metal polluted condition by the way of plant growth regulation for increasing heavy metal tolerance.     

Phenotypic and genetic dissection of cadmium accumulation in roots,nodes and grains of rice hybrids

Plant and Soil - Rice accumulates higher levels of cadmium (Cd) in grain than other cereals, and hybrid rice varieties cover around half of the total rice area in China. Therefore, understanding...     

碰伤富士苹果果实内源茉莉酸和主要保护酶活性的变化

以富士苹果为试验材料,采用自由落体将其从离地面40 cm和70 cm高处跌至大理石地面上,测定损伤后48 h内在室温贮藏条件下果实内源茉莉酸和主要保护酶活性的动态变化,探讨碰撞损伤对果实内源茉莉酸和主要保护酶活性的影响.结果显示:40 cm和70 cm高处摔伤两种处理的苹果果实的内源茉莉酸含量显著升高,乙烯释放速率、O(-)/(·)2产生速率和H2O2含量迅速增加,相应的保护酶(SOD、CAT、POD和PAL)活性也显著提高.研究表明,碰撞损伤后可以诱导富士苹果果实内源茉莉酸含量和乙烯释放速率迅速增加,以及主要保护酶活性提高,使活性氧代谢加强,并在一定程度上能引起苹果果实膜脂过氧化,进一步加重果实伤害.     

RNAi screening for fat regulatory genes with SRS microscopy

Identification of genes regulating fat accumulation is important for basic and medical research; genetic screening for those genes in Caenorhabditis elegans, a widely used model organism, requires in vivo quantification of lipids. We demonstrated RNA interference screening based on quantitative imaging of lipids with label-free stimulated Raman scattering (SRS) microscopy, which overcomes major limitations of coherent anti-Stokes Raman scattering microscopy. Our screening yielded eight new genetic regulators of fat storage.     

Hydrogen sulfide reduces mRNA and protein levels of β-site amyloid precursor protein cleaving enzyme 1 in PC12 cells

Hydrogen sulfide (H(2)S) is now identified as a new neuromodulator. Increasing evidence suggest that H(2)S may play an important role in the progression of Alzheimer's disease (AD). The aim of the present study is to investigate the effects of H(2)S on beta-site amyloid precursor protein cleaving enzyme 1 (BACE-1) expression and amyloid beta (Aβ) secretion in PC12 cells. The levels of BACE-1 mRNA were measured by quantitative polymerase chain reaction analysis. BACE-1 protein levels were assessed by Western blot. Cellular culture medium levels of Aβ1-42 were analyzed by ELISA. We found that sodium hydrosulfide (NaHS), a H(2)S donor, decreased BACE-1 mRNA and protein levels and Aβ1-42 release. Furthermore, NaHS promoted the phosphorylation of Akt and ERK but not JNK or p38 MAPK. However, the effects of NaHS on BACE-1 expression and Aβ1-42 secretion were abolished by inhibitors of phosphatidylinositol 3-kinase (PI3-K), but not of mitogen-activated protein kinase kinases (MEK). Our data indicate that H(2)S reduces BACE-1 expression in PC12 cells via activation of PI3-K/Akt signaling pathways. H(2)S releasing drugs may have therapeutic potential in AD patients.