Mutant and Overexpression Analysis of a C2H2 Single Zinc Finger Gene of Arabidopsis

The goal of this work was to characterize an Arabidopsis C2H2 single zinc finger gene, named AtZFP11, that is similar to SUPERMAN (SUP) and RABBIT EARS (RBE). No altered phenotype was observed in mutants analyzed that were derived through TILLING nor a T-DNA insertion into the exon of AtZFP11. Plants derived by intercrossing AtZFP11 to SUP and RBE alleles did not display any phenotype that could be attributed to AtZFP11. Transgenic plants constitutively overexpressing the AtZFP11 protein displayed severe abnormalities. Phenotypically normal transgenic plants that contained an ecdysone-inducible promoter system fused to the AtZFP11 gene were recovered. These transgenic plants displayed similar abnormalities once induced with methoxyfenozide. Microarray and RT-PCR analysis of gene expression in plants overexpressing AtZFP11 after induction revealed changes in gene expression of a number of genes involved in auxin, jasmonic acid, and stress responses. These results suggest that AtZFP11 plays a role in regulation of gene expression and may be functionally redundant or that conditions needed to observe phenotypic differences in the mutant plants were not provided in the course of these experiments.     

Ameliorating Effect of Fish Oil on Acrylamide Induced Oxidative Stress and Neuronal Apoptosis in Cerebral Cortex

Acrylamide (ACR) is a known industrial toxic chemical that produce neurotoxicity characterized by progressive neuronal degeneration. This study was designed to investigate the protective effect of fish oil on ACR-induced neuronal damage in Wistar rats. ACR enhances the production of reactive oxygen species and potentially affects brain. ACR administered rats showed increased levels of lipid peroxidative product, protein carbonyl content, hydroxyl radical and hydroperoxide which were significantly modulated by the supplementation of fish oil. The activities of enzymic antioxidants and levels of reduced glutathione were markedly lowered in ACR-induced rats; fish oil treatment augmented these antioxidant levels in cortex. Free radicals generated during ACR administration reduced the activities of membrane adenosine triphosphatases and acetylcholine esterase. Fish oil enhanced the activities of these enzymes near normal level. Histological observation represented the protective role of fish oil in ACR-induced neuronal damage. Fish oil reduced the ACR-induced apoptosis through the modulation in expressions of B-cell lymphoma 2 (Bcl2)-associated X protein and Bcl2-associated death promoter. Further, fish oil increases the expression of heat shock protein 27 (Hsp27) in ACR-induced rats. This study provides evidence for the neuroprotective effect of fish oil on ACR-induced neurotoxicity by reducing oxidative stress and apoptosis with modulation in the expression of Hsp27.     

Characterization of temperature inducible promoters from a novel rolling circle replicating plasmid of Enterococcus faecium DJ1

Limited studies have been performed on the characterization of small size plasmids of Enterococcus faecium with the intention of evaluating the strength of their promoters in Escherichia coli. The complete nucleotide sequence (3.825 Kb) and structural organization of E. faecium DJ1 cryptic plasmid pNJAKD is presented. Seven promoter sequences from the pNJAKD plasmid of E. faecium have been identified. The regions coding for the putative promoters were either amplified using PCR based techniques or chemically synthesized as oligonucleotides of different sizes. These were subsequently cloned in the pEGFP vector at the Pvu II site. The efficiency of putative promoter fragments were measured using the intensity of eGFP fluorescence in E. coli JM101, DH5α and BL21(DE3), among which AKD3 exhibited moderate to strongest promoter activity at temperatures of 30, 37, and 42°C.     

Synthesis and evaluation of novel 2-pyridone derivatives as inhibitors of phosphodiesterase3 (PDE3): A target for heart failure and platelet aggregation

Twenty-six 2-pyridone derivatives (8a-8z), which are structurally analogous to amrinone and milrinone two important cardiotonic drugs, are synthesized and characterized. The synthesis of 2-pyridone derivatives involves addition, followed by cyclization between Baylis-Hillman acetates (7a-7k) and enamino esters or nitriles (3a-3e). Thus synthesized pyridones were subjected to PDE3 inhibitory activity, 14 pyridones were found to be hits out of 26 pyridones synthesized and out of 14 hits, there are 5 pyridones found to be lead compounds having excellent PDE3 inhibitory activity. Further we have carried out computational analysis to understand protein/enzyme and 2-pyridone derivative interactions to identify amino acid residues involved in the vicinity of binding and compared with milrinone drug.     

EGFR and c-Met Cross Talk in Glioblastoma and Its Regulation by Human Cord Blood Stem Cells

Receptor tyrosine kinases (RTK) and their ligands control critical biologic processes, such as cell proliferation, migration, and differentiation. Aberrant expression of these receptor kinases in tumor cells alters multiple downstream signaling cascades that ultimately drive the malignant phenotype by enhancing tumor cell proliferation, invasion, metastasis, and angiogenesis. As observed in human glioblastoma (hGBM) and other cancers, this dysregulation of RTK networks correlates with poor patient survival. Epidermal growth factor receptor (EGFR) and c-Met, two well-known receptor kinases, are coexpressed in multiple cancers including hGBM, corroborating that their downstream signaling pathways enhance a malignant phenotype. The integration of c-Met and EGFR signaling in cancer cells indicates that treatment regimens designed to target both receptor pathways simultaneously could prove effective, though resistance to tyrosine kinase inhibitors continues to be a substantial obstacle. In the present study, we analyzed the antitumor efficacy of EGFR inhibitors erlotinib and gefitinib and c-Met inhibitor PHA-665752, along with their respective small hairpin RNAs (shRNAs) alone or in combination with human umbilical cord blood stem cells (hUCBSCs), in glioma cell lines and in animal xenograft models. We also measured the effect of dual inhibition of EGFR/c-Met pathways on invasion and wound healing. Combination treatments of hUCBSC with tyrosine kinase inhibitors significantly inhibited invasion and wound healing in U251 and 5310 cell lines, thereby indicating the role of hUCBSC in inhibition of RTK-driven cell behavior. Further, the EGFR and c-Met localization in glioma cells and hGBM clinical specimens indicated that a possible cross talk exists between EGFR and c-Met signaling pathway.     

Recombinant D. radiodurans cells for bioremediation of heavy metals from acidic/neutral aqueous wastes

The stability and superior metal bioremediation ability of genetically engineered Deinococcus radiodurans cells, expressing a non-specific acid phosphatase, PhoN in high radiation environment has already been established. The lyophilized recombinant DrPhoN cells retained PhoN activity and uranium precipitation ability. Such cells also displayed an extended shelf life of 6 months during storage at room temperature and showed surface associated precipitation of uranium as well as other metals like cadmium. Lyophilized cells, immobilized in polyacrylamide gels could be used for uranium bioprecipitation in a flow through system resulting in 70% removal from 1mM input uranium solution and a loading of 1 g uranium/g dry weight cells. Compared with a batch process which achieved a loading of 5.7 g uranium/g biomass, the efficiency of the column process was low due to clogging of the column by the precipitate.