Tin-n Chu

Effects of oral consumption of the green tea polyphenol EGCG in a murine model for human Sjogren's syndrome, an autoimmune disease.

SIGNIFICANCE Protection of glandular cells from autoimmune-induced damage would be of significant clinical benefit to Sjogrens syndrome (SS) patients. Epigallocatechin-3-gallate (EGCG) possesses anti-apoptotic, anti-inflammatory, and autoantigen-inhibitory properties. AIMS To investigate if EGCG protects against certain autoimmune-induced pathological changes in the salivary glands of the non-obese diabetic (NOD) mouse model for SS. MAIN METHODS Animals were provided with either water or water containing 0.2% EGCG. At the age of 8, 16 and 22 weeks, submandibular salivary gland tissue and serum samples were collected for pathological and serological analysis. KEY FINDINGS Significant lymphocyte infiltration was observed in the salivary glands of the water-fed group at the age of 16 weeks, while the EGCG group showed reduced lymphocyte infiltration. By 22 weeks of age, water-fed animals demonstrated elevated levels of apoptotic activity within the lymphocytic infiltrates, and high levels of serum total anti-nuclear antibody, compared to EGCG-fed animals. Remarkably, proliferating cell nuclear antigen (PCNA) and Ki-67 levels in the salivary glands of water-fed NOD mice were significantly elevated in comparison to BALB/c control mice; in contrast, PCNA and Ki-67 levels in EGCG-fed NOD animals were similar to BALB/c mice. These results indicate that EGCG protects the NOD mouse submandibular glands from autoimmune-induced inflammation, and reduces serum autoantibody levels. Abnormal proliferation, rather than apoptosis, appears to be a characteristic of the NOD mouse gland that is normalized by EGCG. The evidence suggests that EGCG could be useful in delaying or managing SS-like autoimmune disorders.

Antiviral activity of theaflavin digallate against herpes simplex virus type 1

Abstract Tea is the second most consumed drink in the world. The beneficial effects of tea have been mostly attributed to its catechin content. Black tea is derived from the leaves of Camellia sinensis plant, and it is rich in theaflavin polyphenols, in particular theaflavin (TF1), theaflavin-3-monogallate (TF2A), theaflavin-3′-monogallate (TF2B), and theaflavin-3,3′-digallate (TF3). Vero and A549 cells were used to evaluate the effect of purified individual black tea theaflavins as anti-herpes simplex virus 1 agents. With the rise of HSV resistant strains, there is a critical need to develop novel antiherpesviral treatments. Results of the cytotoxicity assay tested by MTS [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxy-phenyl)-2-(4-sulfophenyl)-2H-tetrazolium] showed that TF1, TF2, and TF3 are not toxic to Vero and A549 cells at a concentration up to 75μM. The antiviral activity of the individual theaflavins was tested by plaque reduction assay, MTS assay, flow cytometric analysis and confocal microscopy observations. The results showed that TF1, TF2, and TF3 exhibit potent, dose-dependent anti-HSV-1 effect, with TF3 being the most efficient in both Vero and A549 cells. A concentration of 50μM TF3 and above was sufficient to inhibit >99% of the production of HSV-1 viral particles. The anti-HSV-1 effect of TF3 is due to a direct effect on the virions, and treating Vero or A549 cells with TF3 for 1h prior to infection, or treating the cells at different times post infection does not inhibit HSV-1 production. TF3 is stable at vaginal pH, indicating its potential to be a promising natural and affordable remedy against herpes simplex viral infections.

Induction of temperate cyanophage AS-1 by heavy metal – copper

BackgroundIt has been reported that some marine cyanophage are temperate and can be induced from a lysogenic phase to a lytic phase by different agents such as heavy metals. However, to date no significant reports have focused on the temperate nature of freshwater cyanophage/cyanobacteria. Previous experiments with cyanophage AS-1 and cyanobacteria Anacystis nidulans have provided some evidence that AS-1 may have a lysogenic life cycle in addition to the characterized lytic cycle.ResultsIn this study, the possible temperate A. nidulans was treated with different concentrations of heavy metal-copper. CuSO4 with concentrations of 3.1 × 10-3 M, 3.1 × 10-4 M, 3.1 × 10-5 M and 3.1 × 10-6 M were used to detect the induction of AS-1 from A. nidulans. The population of the host, unicellular cyanobacteria Anacystis nidulans, was monitored by direct count and turbidity while the amount of virus produced was derived from plaque forming units (PFU) by a direct plating method. The ratio of AS-1 release from A. nidulans was also determined. From these results it appears that AS-1 lysogenic phage can be induced by copper at concentrations from 3.1 × 10-6 M to 3.1 × 10-4 M. Maximal phage induction occurred at 6 hours after addition of copper, with an optimal concentration of 3.1 × 10-6 M.ConclusionCu2+ is a significant inducer for lysogenic cyanobacterial cells and consequently would be a potential control agent in the cyanobacteria population in fresh water ecosystems.

Temperature-induced activation of freshwater Cyanophage AS-1 prophage

Synechococcus sp. IU 625 is one of the freshwater cyanobacteria responsible for harmful algal blooms (HAB). Cyanophages can serve as natural control agents and may be responsible for algal bloom prevention and disappearance. Cyanophage AS-1, which infects Synechococcus sp. IU 625 (Anacystis nidulans) and Synechococcus cedrorum, plays an important role in the environment, significantly altering the numbers of its hosts. Since seasonal (temperature-dependent) lytic induction of cyanobacterial prophage has been proposed to affect seawater algal blooms, we investigated if the AS-1 lytic cycle could be induced by a shift to high temperature. Our hypothesis was confirmed, as more phages were released at 35°C than at 24°C, with maximal induction observed with a shift from 24 to 35°C. Furthermore, transmission electron microscopy (TEM) images provide direct evidence of lysogenic to lytic conversion with temperature shift. Thus, temperature is an important inducer for AS-1 conversion from lysogenic to lytic cycle and could have applications in terms of modulating cyanobacterial populations in freshwater aquatic environments. The study gives insight into the effect of climate change on the interaction between cyanophage and cyanobacteria in freshwater ecosystems.

Adaption of Synechococcus sp. IU 625 to growth in the presence of mercuric chloride

Resistance to heavy metals is important for the survival of bacteria in contaminated environments. In this study, we show that the unicellular cyanobacterial species Synechococcus sp. IU 625 adapts to growth in the presence of mercuric chloride, recovering from pigmentation and morphological defects. Cells accumulate mercury within 2 h of growth and by 3 days, the total mercury concentration is significantly reduced, with all remaining mercury associated with the cells. This suggests that Synechococcus sp. IU 625 can convert mercury to a volatile form.

Protamine-like Proteins in 12 Sequenced Species of Drosophila

The current study was aimed at analyzing putative protein sequences of the protamine-like proteins of 12 Drosophila species based on the reference sequences of two protamine-like proteins (Mst35Ba and Mst35Bb) found in Drosophila melanogaster sperm nuclei. Protamine-like proteins belong to a larger group of proteins that are involved in DNAbinding known as sperm nuclear basic proteins (SNBPs). SNBPs play a role in chromatin condensation during the postmeiotic stage of spermatogenesis, termed spermiogenesis. During spermiogenesis, nuclear transformation occurs where histones are exchanged for SNBPs, the chromatin condenses, and the nucleus transforms into a needle-like shape in Drosophila. Our goal was to search the 12 sequenced Drosophila genomes for protamine-like proteins based on the known sequences for D. melanogaster. Searches were performed on genomic DNA, mRNA transcripts and amino acid sequences using NCBI basic local alignment search tool (BLAST). Sequence alignments and analysis of amino acid content indicate that homologs for Mst35Ba and Mst35Bb are present in all 12 species of flies analyzed in this study. Functional analyses of a conserved region found within the proteins indicate the presence of a DNA-binding domain, possibly a high mobility group DNA- binding box. This study represents the first large-scale, single-genus dataset for protamine-like proteins and provides the basis for a fine-grained analysis of their evolution.

Bloom-Forming Cyanobacteria and Other Phytoplankton in Northern New Jersey Freshwater Bodies

Diatoms are a type of phytoplankton that possess several unique contours due to a cell wall composed of silicon dioxide (SiO2) [2, 3]. The diatoms, or Bacillariophyta, have distinct structures and thus are easily identifiable in a water sample. Diatoms can be found in a large range of pH and dissolved oxygen values as well as in ecosystems with a wide concentra‐ tion of solutes, nutrients, contaminants, and across a large range of water temperatures due to their durable cell walls [2].

Bioinformatic analysis of the metal-binding protein families and heavy metal resistance amongst cyanobacteria

Cyanobacteria are often used as an indicator of the presence and level of pollutants in the environment. They have been especially recognized for their ability to identify contamination of heavy metals. Class II metallothioneins (MTs), usually found in cyanobacteria, are low molecular weight metal-binding proteins and may be required for heavy metal tolerance. It would be important to examine the phylogenetic pattern as well as prokaryotic evolution of metal-binding protein families among cyanobacteria. All the available protein sequences of cyanobacteria metallothioneins from GenBank, PDB and Pfam have been aligned and the phylogenetic tree was constructed by utilizing four multiple sequence alignment software ClustalW, T-Coffee, POA and GCG-PileUp. Eight cyanobacteria included in this study were Synechococcus sp. PCC 7942, Synechococcus sp. WH 8102, Thermosynechococcus vulcanus, Thermosynechococcus elongates BP-1, Nostoc sp. PCC 7120, Gloeobacter violaceus PCC 7421, Oscillatoria brevis, and Magnetospirillum magnetotacticum. 22 reported heavy metal resistant sequences from these 8 species of cyanobacteria were aligned. A phyletic pattern search tool provided by Cluster of Orthologous Groups (COGs) database, a collection of COGs from 63 sequenced prokaryotes and 3 unicellular eukaryotic genomes was also used to select a desired pattern of presence-absence of species. Cn3D 4.1 program was used for structural alignment. The results indicated that the tree was composed by five clusters. Most Synechococcus and Thermosynechococcus were clustered into 2 clades while others had relatively far genetic distance with Synechococcus but closely linked to each other. Structure alignment of metallothionein among cyanobacteria indicated that a major portion of their structure are not identical but with similar properties such as polarity. The results clearly showed several conserved C-X-C motifs near N-and C-terminus of Class II metallothioneins.

Characterization of zinc stress response in Cyanobacterium Synechococcus sp. IU 625

The ability of cyanobacteria to survive many environmental stress factors is a testament to their resilience in nature. Of these environmental stress factors, overexposure to zinc is important to study since excessive zinc intake can be a severe hazard. Zinc toxicity in freshwater has been demonstrated to affects organisms such as invertebrates, algae and cyanobacteria. Cyanobacteria which possess increased resistance to zinc have been isolated. It is therefore important to elucidate the mechanism of survival and response to determine what factors allow their survival; as well as any remediation implications they may have. To characterize the effects of zinc in freshwater cyanobacteria, we investigated the response of Synechococcus sp. IU 625 (S. IU 625) over 29days to various concentrations (10, 25, and 50mg/L) of ZnCl2. S. IU 625 was shown to be tolerant up to 25mg/L ZnCl2 exposure, with 10mg/L ZnCl2 having no outward physiological change and 50mg/L ZnCl2 proving lethal to the cells. To determine a potential mechanism Inductive Coupled Plasma-Mass Spectrometry (ICP-MS) and RNA-seq analysis were performed on zinc exposed cells. Analysis performed on days 4 and 7 indicated that response is dose-dependent, with 10mg/L ZnCl2 exhibiting nearly all zinc extracellular, corresponding with upregulation of cation transport response. Whereas the 25mg/L ZnCl2 exhibited half of total zinc sequestered by the cells, which corresponds with the upregulation of sequestering proteins such as metallothionein and the downregulation of genes involved with ATP synthesis and phycobilisome assembly. These analyses were combined with growth monitoring, microscopy, quantitative polymerase chain reaction (qPCR) and flow cytometry to present a full spectrum of mechanisms behind zinc response in S. IU 625.

Genomic and expression analysis of transition proteins in Drosophila

The current study was aimed at analyzing putative protein sequences of the transition protein-like proteins in 12 Drosophila species based on the reference sequences of transition protein-like protein (Tpl94D) expressed in Drosophila melanogaster sperm nuclei. Transition proteins aid in transforming chromatin from a histone-based nucleosome structure to a protamine-based structure during spermiogenesis - the post-meiotic stage of spermatogenesis. Sequences were obtained from NCBI Ref-Seq database using NCBI ORF-Finder (PSI-BLAST). Sequence alignments and analysis of the amino acid content indicate that orthologs for Tpl94D are present in the melanogaster species subgroup (D. simulans, D. sechellia, D. erecta, and D. yakuba), D. ananassae, and D. pseudoobscura, but absent in D. persmilis, D. willistoni, D. mojavensis, D. virilis, and D. grimshawi. Transcriptome next generation sequence (RNA-Seq) data for testes and ovaries was used to conduct differential gene expression analysis for Tpl94D in D. melanogaster, D. simulans, D. yakuba, D. ananassae, and D. pseudoobscura. The identified Tpl94D orthologs show high expression in the testes as compared to the ovaries. Additionally, 2 isoforms of Tpl94D were detected in D. melanogaster with isoform A being much more highly expressed than isoform B. Functional analyses of the conserved region revealed that the same high mobility group (HMG) box/DNA binding region is conserved for both Drosophila Tpl94D and Drosophila protamine-like proteins (MST35Ba and MST35Bb). Based on the rigorous bioinformatic approach and the conservation of the HMG box reported in this work, we suggest that the Drosophila Tpl94D orthologs should be classified as their own transition protein group.