A comparative assessment of phenotypic and molecular diversity in Doum (Hyphaene thebaica L.)

Doum palm (Hyphaene thebaica L.) has been reported as one of the most beneficial species worldwide. Its fruits are a good source of fibers, antioxidants, B-complex vitamins, essential minerals, monosaccharides, essential oil and flavonoids. Fruit extract shows anti-inflammatory, antioxidant, antimicrobial, anticancer and pharmacological potential. However, there is a lack of investigations dealing with its genetic diversity. Therefore, a collection of twelve mature female palm landraces grown in the botanical garden of Aswan, “Egypt” were used for genetic diversity assessment based on phenotypic and molecular levels. 18 vegetal and chemical traits were evaluated. Fifteen of them showed highly significant variation among the tested landraces. Euclidian-based-dendrogram discriminated the tested landraces based on their phenotypic similarities to three main clusters showing a high level of variability. Molecular analysis using inter simple sequence repeats (ISSR) vis-à-vis start codon targeted (SCoT) polymorphism markers displayed the relationships among the tested landraces molecularly. Both markers showed a reasonable degree of polymorphism, however SCoT was more effective than the ISSR by showing a higher percentage of polymorphism, polymorphism information content, resolving power and diversity index. Cluster analysis based on molecular data showed a clear relationship among the doum landraces. However, ISSR- and SCoT-based dendrograms were slightly different, and completely unlike that based on phenotypic data. Nevertheless, phenotypic and molecular evaluations might complement each other, and by data of both an excellent overview was obtained from principle coordinate analysis. The information herein is valuable and considered as a keystone for further proximate studies on doum genetic diversity to help in improvement and breeding approaches.

     

The ability of freeze-dried bull spermatozoa to induce calcium oscillations and resumption of meiosis

The objective was to investigate the ability of freeze-dried (FD) bull spermatozoa to induce calcium oscillations in mouse oocytes and meiosis resumption in in vitro-matured bovine oocytes after intracytoplasmic sperm injection (ICSI). Bull spermatozoa were freeze-dried and stored for 1 y at +25, +4, or -196 degrees C. In the first experiment, rehydrated sperm heads were microinseminated into hybrid mouse oocytes loaded with fluo-3/AM, and the kinetics of intracellular calcium concentration was monitored for 1h. Repetitive increases of intracellular calcium concentration were recorded in the majority of injected oocytes, with exception of a few oocytes injected with FD sperm heads stored at +4 degrees C (11%) and +25 degrees C (8%) that exhibited a single increase or no response (non-oscillated). The proportion of oocytes that oscillated with high frequency (>or=10 spikes/h) was higher in the non-dried control group (79%; P<0.05) than in the FD groups (58, 55, and 54% for storage at -196, +4, and +25 degrees C, respectively). In the second experiment, control and FD spermatozoa were microinseminated into in vitro-matured, denuded bovine oocytes. The oocytes were fixed and stained 12h after ICSI. A higher proportion of bovine oocytes injected with control spermatozoa (70%; P<0.05) resumed meiosis than those injected with +25, +4 and -196 degrees C stored FD spermatozoa (53, 48, and 57%, respectively). The proportion of ICSI oocytes that developed to the pronuclear stage (complete activation) was higher in the control group (64%; P<0.05) than those in all the FD groups (34, 27, and 28% for storage at -196, +4, and +25 degrees C, respectively). Thus, the ability of bull spermatozoa to induce frequent intracellular calcium spikes in mouse oocytes was impaired by the process of freeze-drying, without differences among storage at +25, +4 or -196 degrees C, probably resulting in a lower proportion of bovine oocytes that resumed meiosis and/or developed to the pronuclear stage.     

Regiospecific Reduction of 4,6-Dinitrobenzimidazoles: Synthesis,Characterization, and Biological Evaluation

The regiospecific reduction of 4,6-dinitrobenzimidazole derivatives leading to the corresponding 4-amino-6-nitrobenzimidazoles was studied. The identification of the formed product structures was accomplished by spectroscopic and X-ray diffraction data. The anticancer and antiparasitic activities of the synthesized compounds were examined, and promising activities against Toxoplasma gondii and Leishmania major parasites were discovered for certain 4,6-dinitrobenzimidazoles in addition to moderate anticancer activities of the 4-amino-6-nitrobenzimidazole derivatives against T. gondii cells. However, the tumor cell experiments revealed a promising sensitivity of p53-negative colon cancer cells to these compounds.     

Functional expression of an Arabidopsis cDNA clone encoding a flavonol 3'-O-methyltransferase and characterization of the gene product

We report that the cDNA clone (Accession No. U70424), previously isolated from Arabidopsis thaliana as encoding a caffeic acid/5-hydroxyferulic acid O-methyltransferase (OMT) (1), has now been overexpressed in Escherichia coli BL21 and its recombinant protein identified as a novel flavonol 3'-OMT. It is, therefore, renamed AtOMT1. This cDNA clone has previously been identified on the basis of its 88% amino acid sequence similarity and 80% identity to the aspen bispecific lignin OMT (2), the type member of the group involved in lignin biosynthesis. Our data indicate that this novel OMT uses the flavonol quercetin as the preferred substrate, but neither of the hydroxycinnamic acids, caffeic or 5-hydroxyferulic, to any significant extent. This indicates that the high sequence similarity/identity of AtOMT1 to that of the aspen lignin OMT (2) is not sufficient to assign the function of this gene product.     

Chemoprevention of rat liver toxicity and carcinogenesis by Spirulina

Spirulina platensis (SP) is a filamentous cyanobacterium microalgae with potent dietary phyto-antioxidant, anti-inflammatory and anti-cancerous properties. The present study aimed to investigate the chemopreventive effect of SP against rat liver toxicity and carcinogenesis induced by dibutyl nitrosamine (DBN) precursors, and further characterized its underlying mechanisms of action in HepG2 cell line. Investigation by light and electron microscopy showed that DBN treatment induced severe liver injury and histopathological abnormalities, which were prevented by SP supplementation. The incidence of liver tumors was significantly reduced from 80 to 20% by SP. Immunohistochemical results indicated that both PCNA and p53 were highly expressed in the liver of DBN-treated rats, but were significantly reduced by SP supplementation. Molecular analysis indicated that SP treatment inhibited cell proliferation, which was accompanied by increased p21 and decreased Rb expression levels at 48hrs post-treatment. In addition, SP increased Bax and decreased Bcl-2 expression, indicating induction of apoptosis by 48hrs. This is the first report of the in vivo chemopreventive effect of SP against DBN-induced rat liver cytotoxicity and carcinogenesis, suggesting its potential use in chemoprevention of cancer.     

Correlation between PDZK1, Cdc37, Akt and Breast Cancer Malignancy: The Role of PDZK1 in Cell Growth through Akt Stabilization by Increasing and Interacting with Cdc37

PDZ domain containing 1 (PDZK1) is a scaffold protein that plays a role in the fate of several proteins. Estrogen can induce PDZK1 gene expression; however, our recent report showed that PDZK1 expression in the breast cancer cell line MCF-7 is indirect and involves insulin-like growth factor (IGF)-1 receptor function. Such a relationship was established in cell culture systems and human breast cancer tissues. Here we show that overexpression of PDZK1 promoted an increase in cyclin D1 and enhanced anchorage-independent growth of MCF-7 cells in the absence of 17β-estradiol, suggesting that PDZK1 harbors oncogenic activity. Indeed, PDKZ1 overexpression enhanced epidermal growth factor receptor (EGFR)-stimulated MEK/ERK1/2 signaling and IGF-induced Akt phosphorylation. PDZK1 appeared to play this role, in part, by stabilizing the integrity of the growth promoting factors Akt, human epidermal growth factor receptor 2 (Her2/Neu) and EGFR. Increased Akt levels occurred via a decrease in the ubiquitination of the kinase. PDZK1 overexpression was associated with resistance to paclitaxel/5-fluorouracil/etoposide only at low concentrations. Although the increased stability of Akt was sensitive to heat shock protein 90 (HSP90) inhibition, increased levels of the cochaperone cell division cycle 37 (Cdc37), as well as its ability to bind PDZK1, appear to play a larger role in kinase stability. Using human tissue microarrays, we show strong positive correlation between PDZK1, Akt and Cdc37 protein levels, and all correlated with human breast malignancy. There were no positive correlations between PDZK1 and Cdc37 at the mRNA levels, confirming our in vitro studies. These results demonstrate a relationship between PDZK1, Akt and Cdc37, and potentially Her2/Neu and EGFR, in breast cancer, representing a new axis that can be targeted therapeutically to reduce the burden of human breast cancer.     

Growth of Candida albicans in the presence of hydrocarbons: a correlation between sterol concentration and hydrocarbon uptake

Summary Candida albicans KTCC 89062 grown on n-alkanes showed higher levels of sterol content as compared to glucose-grown cells. Certain sterols, such as lanosterol, were significantly reduced in cells grown on n-alkanes, while others, such as ergosterol, increased in these cells. Sterol fractions declined as the chain length of the n-alkanes increased. Ergosterol supplementation of the chemically defined medium showed an increase in the uptake of dodecane (C₁₂) by cells grown on such medium. Increase in the concentration of ergosterol supplementation resulted in an increase in C₁₂ uptake. The uptake of C₁₂ was not stimulated by ergosterol supplementation in the case of non-viable yeast cells.     

Synergistic plant–microbe interactions between endophytic bacterial communities and the medicinal plant <Emphasis Type="Italic">Glycyrrhiza uralensis</Emphasis> F.

Little is known about the composition, diversity, and geographical distribution of bacterial communities associated with medicinal plants in arid lands. To address this, a collection of 116 endophytic bacteria were isolated from wild populations of the herb Glycyrrhiza uralensis Fisch (licorice) in Xinyuan, Gongliu, and Tekesi of Xinjiang Province, China, and identified based on their 16S rRNA gene sequences. The endophytes were highly diverse, including 20 genera and 35 species. The number of distinct bacterial genera obtained from root tissues was higher (n?=?14) compared to stem (n?=?9) and leaf (n?=?6) tissue. Geographically, the diversity of culturable endophytic genera was higher at the Tekesi (n?=?14) and Xinyuan (n?=?12) sites than the Gongliu site (n?=?4), reflecting the extremely low organic carbon content, high salinity, and low nutrient status of Gongliu soils. The endophytic bacteria exhibited a number of plant growth-promoting activities ex situ, including diazotrophy, phosphate and potassium solubilization, siderophore production, auxin synthesis, and production of hydrolytic enzymes. Twelve endophytes were selected based on their ex situ plant growth-promoting activities for growth chamber assays to test for their ability to promote growth of G. uralensis F. and Triticum aestivum (wheat) plants. Several strains belonging to the genera Bacillus (n?=?6) and Achromobacter (n?=?1) stimulated total biomass production in both G. uralensis and T. aestivum under low-nutrient conditions. This work is the first report on the isolation and characterization of endophytes associated with G. uralensis F. in arid lands. The results demonstrate the broad diversity of endophytes associated with wild licorice and suggest that some Bacillus strains may be promising candidates for biofertilizers to promote enhanced survival and growth of licorice and other valuable crops in arid environments.     

P21 Activated Kinase-1 (Pak1) Promotes Prostate Tumor Growth and Microinvasion via Inhibition of Transforming Growth Factor β Expression and Enhanced Matrix Metalloproteinase 9 Secretion

P21-activated kinases (Paks) are major effectors downstream of the small Rho family of GTPases. Among the six isoforms, Pak1 is the most ubiquitous and the best characterized member. Previous studies have shown that inhibition of Pak6, which is predominantly present in the prostate compared with other tissues, inhibits prostate tumor growth in vivo. Even though Pak1 has been identified in normal prostatic epithelial cells and cancer cells, its specific role in the development of prostate cancer remains unclear. We report here that highly invasive prostate cancer cells express significantly higher levels of Pak1 protein compared with non-invasive prostate cancer cells. Furthermore, prostate tumor tissues and prostate cancer metastasized to lungs showed a higher expression of Pak1 compared with normal tissues. Interestingly, Pak6 protein expression levels did not change with the invasive/metastatic potential of the cancer cells or tumors. Although inhibition of Pak1, and not Pak6, resulted in impaired PC3 cell migration, the effects of Pak1 knockdown on transendothelial migration (microinvasion), tumor growth, and tumor angiogenesis was higher compared with Pak6 knockdown. Finally, gene array data revealed reduced expression of matrix metalloproteinase 9 with the ablation of either Pak1 or Pak6 gene expression in PC3 cells, whereas protein levels of TGFβ was elevated significantly with specific modulation of Pak1 activity or ablation of the Pak1 gene. Our observations suggest that although some level of functional redundancy exists between Pak1 and Pak6 in prostate cancer cells, targeting Pak1 is a potential option for the management of prostate tumor growth, microinvasion, and metastasis.     

Secondary Metabolites Generated from Saussurea lappa and Ligusticum sinensis Essential Oils by Microwave-Assisted Hydrodistillation: in Silico Molecular Docking and in Vitro Antibacterial Efficacy

In the current study, both the essential oil composition and biological activity of Saussurea lappa and Ligusticum sinensis were investigated by means of microwave-assisted hydrodistillation (MAHD) and characterized by Gas chromatography/mass spectrometry (GC/MS), whereas the antimicrobial efficiency of MAHD essential oils was examined against four pathogens: Staphylococcus aureus, Escherichia coli, Aspergillus niger, and Candida albicans responsible for microbial infections. The goal was to spot synergy and a favorable method that gives essential oils to possibly use as alternatives to common antimicrobial agents for the treatment of bacterial infections using a microdilution assay. S. lappa's 21 compounds were characterized by MAHD extraction. Sesquiterpene lactones (39.7 % MAHD) represented the major components, followed by sesquiterpene dialdehyde (25.50 % MAHD), while L. sinensis's 14 compounds were identified by MAHD extraction. Tetrahydroisobenzofurans (72.94 % MAHD) was the predominant compound class. S. lappa essential oil collection showed the strongest antimicrobial activity with MIC values of 16 μg/ml against all pathogens tested, while L. sinensis showed strong antibacterial activity and moderate antifungal activity with MIC values of 32 μg/ml and 500 μg/ml, respectively. The principal components of both oils, (velleral, eremanthin and neocnidilide), were docked into the bacterial histidine kinase (HK) and the fungal heat shock protein 90 (Hsp90).