A Comparative Analysis of Gene Expression Patterns and Cell Phenotypes between Cervical and Peripheral Blood Mononuclear Cells

Studies of the immunological environment in the female genital tract (FGT) are critical for the development of vaccines or microbicides to halt the spread of sexually transmitted infections. Challenges arise due to the difficulties of sampling from this site, and the majority of studies have been conducted utilising peripheral blood mononuclear cells. Identifying functional differences between immune cells of the FGT and peripheral blood would aid in our understanding of mucosal immunology. We compared the gene expression profile of mononuclear cells at these two sites. Messenger RNA expression analysis was performed using gene expression arrays on matched cervical mononuclear cells and peripheral blood mononuclear cells. Further cellular phenotyping was done by 10 colour flow cytometry. Of the 22,185 genes expressed by these samples, 5345 genes were significantly differentially expressed between the cell populations. Most differences can be explained by significantly lower levels of T and B cells and higher levels of macrophages and dendritic cells in the FGT compared with peripheral blood. Several immunologically relevant pathways such as apoptosis and innate immune signalling, and a variety of cytokines and cytokine receptors were differentially expressed. This study highlights the importance of the unique immunological environment of the FGT and identifies important differences between systemic and mucosal immune compartments.     

Towards efficient hydrogen production: the impact of antenna size and external factors on electron transport dynamics in <Emphasis Type="Italic">Synechocystis</Emphasis> PCC 6803

Three Synechocystis PCC 6803 strains with different levels of phycobilisome antenna-deficiency have been investigated for their impact on photosynthetic electron transport and response to environmental factors (i.e. light-quality, -quantity and composition of growth media). Oxygen yield and P₇₀₀ reduction kinetic measurements showed enhanced linear electron transport rates—especially under photoautotrophic conditions—with impaired antenna-size, starting from wild type (WT) (full antenna) over ΔapcE- (phycobilisomes functionally dissociated) and Olive (lacking phycocyanin) up to the PAL mutant (lacking the whole phycobilisome). In contrast to mixotrophic conditions (up to 80% contribution), cyclic electron transport plays only a minor role (below 10%) under photoautotrophic conditions for all the strains, while linear electron transport increased up to 5.5-fold from WT to PAL mutant. The minor contribution of the cyclic electron transport was proportionally increased with the linear one in the ΔapcE and Olive mutant, but was not altered in the PAL mutant, indicating that upregulation of the linear route does not have to be correlated with downregulation of the cyclic electron transport. Antenna-deficiency involves higher linear electron transport rates by tuning the PS2/PS1 ratio from 1:5 in WT up to 1:1 in the PAL mutant. While state transitions were observed only in the WT and Olive mutant, a further ~30% increase in the PS2/PS1 ratio was achieved in all the strains by long-term adaptation to far red light (720 nm). These results are discussed in the context of using these cells for future H₂ production in direct combination with the photosynthetic electron transport and suggest both Olive and PAL as potential candidates for future manipulations toward this goal. In conclusion, the highest rates can be expected if mutants deficient in phycobilisome antennas are grown under photoautotrophic conditions in combination with uncoupling of electron transport and an illumination which excites preferably PS1.     

The response to oestrogen deprivation of the cartilage collagen degradation marker, CTX-II, is unique compared with other markers of collagen turnover

Introduction  

The urinary level of the type II collagen degradation marker CTX-II is increased in postmenopausal women and in ovariectomised rats, suggesting that oestrogen deprivation induces cartilage breakdown. Here we investigate whether this response to oestrogen is also true for other type II collagen turnover markers known to be affected in osteoarthritis, and whether it relates to its presence in specific areas of cartilage tissue.     

Pravastatin: A tool for investigating the availability of mevalonate metabolites for primary and secondary metabolism in Catharanthus roseus cell suspensions

In the C20 strain of Catharanthus roseus , 2,4-dichlorophenoxyacetic acid (2,4-D) reduces alkaloid accumulation by inhibiting the synthesis of precursors of alkaloid terpenoids. However, the presence of this growth regulator is necessary to promote growth, as measured in terms of dry weight and sterol content. The terpenoid metabolism implicated in the accumulation of alkaloids would therefore be the target of 2,4-D inhibition and not the metabolism leading to sterol biosynthesis. The specific inhibition by pravastatin of 3-hydroxy-3-methylglutaryl CoA reductase (EC 1.1.1.34), the enzyme that catalyses mevalonate synthesis, enables the limitation of mevalonate on sterol content and on alkaloid accumulation to be studied. In presence of pravastatin cells are supplied with labelled mevalonate. Under these conditions the mevalonate is incorporated into sterols but not into alkaloids accumulated in the absence of 2,4-D. The inhibition of sterol biosynthesis induced by pravastatin is not overcome by zeatin or a cytokinin-like compound, whereas the inhibition of alkaloid accumulation can be partially overcome. The use of pravastatin shows that the availability of mevalonate for primary and secondary metabolism is differently regulated in Catharanthus roseus cells.     

Low temporal dynamics of mycosporine‐like amino acids in benthic cyanobacteria from an alpine lake

1. Cyanobacteria are one of the oldest organisms on Earth and they originated at a time when damaging ultraviolet (UV) C radiation still reached the surface. Their long evolution led to several adaptations to avoid deleterious effects caused by exposure to solar UV radiation. Synthesis of sunscreen substances, such as mycosporine‐like amino acids (MAAs), allows them to photosynthesise with reduced risk of cell damage. The interplay of solar UV radiation and MAAs is well documented for cyanobacteria in the plankton realm, but little is known for those in the benthic realm, particularly of clear alpine lakes.
2. Here, we assessed the temporal dynamics of MAAs in the benthic algal community of one clear alpine lake dominated by cyanobacteria during the ice‐free season and along a depth gradient using state‐of‐the‐art analytical methods (high‐performance liquid chromatography, nuclear magnetic resonance, liquid chromatography–mass spectrometry). We differentiated between the epilithic cyanobacterial community and the overlying loosely attached filamentous cyanobacteria, as we expected they will have an important shielding/shading effect on the former. We hypothesised that in contrast to the case of phytoplankton, benthic cyanobacteria will show less pronounced temporal changes in MAAs concentration in response to changes in solar UV exposure.
3. Three UV‐absorbing substances were present in both types of communities, whereby all were unknown. The chemical structure of the dominant unknown substance (maximum absorption at 334 nm) resulted in the identification of a novel MAA that we named aplysiapalythine‐D for its similarity to the previously described aplysiapalythine‐C.
4. Chlorophyll‐a‐specific MAA concentrations for epilithic and filamentous cyanobacteria showed a significant decrease with depth, although only traces were found in the former community. The temporal dynamics in MAA concentrations of filamentous cyanobacteria showed no significant variations during the ice‐free season.
5. Our result on the low temporal MAA dynamics agrees with the reduced growth rates of benthic cyanobacteria reported for cold ecosystems. The permanent presence of this community, which is adapted to the high UV levels characteristic of clear alpine lakes, probably represents the most important primary producers of these ecosystems.

     

Identifying genetic traces of historical expansions: Phoenician footprints in the Mediterranean

The Phoenicians were the dominant traders in the Mediterranean Sea two thousand to three thousand years ago and expanded from their homeland in the Levant to establish colonies and trading posts throughout the Mediterranean, but then they disappeared from history. We wished to identify their male genetic traces in modern populations. Therefore, we chose Phoenician-influenced sites on the basis of well-documented historical records and collected new Y-chromosomal data from 1330 men from six such sites, as well as comparative data from the literature. We then developed an analytical strategy to distinguish between lineages specifically associated with the Phoenicians and those spread by geographically similar but historically distinct events, such as the Neolithic, Greek, and Jewish expansions. This involved comparing historically documented Phoenician sites with neighboring non-Phoenician sites for the identification of weak but systematic signatures shared by the Phoenician sites that could not readily be explained by chance or by other expansions. From these comparisons, we found that haplogroup J2, in general, and six Y-STR haplotypes, in particular, exhibited a Phoenician signature that contributed > 6% to the modern Phoenician-influenced populations examined. Our methodology can be applied to any historically documented expansion in which contact and noncontact sites can be identified.     

Interaction with dopamine D2 receptor enhances expression of transient receptor potential channel 1 at the cell surface

Receptor signaling is mediated by direct protein interaction with various types of cytoskeletal, adapter, effector, and additional receptor molecules. In brain tissue and in cultured neurons, activation of dopamine D2 receptors (D2Rs) has been found to impact cellular calcium signaling. Using a yeast two-hybrid approach, we have uncovered a direct physical interaction between the D2R and the transient receptor potential channel (TRPC) subtypes 1, 4 and 5. The TRPC/D2R interaction was further validated by GST-pulldown assays and coimmunoprecipitation from mammalian brain. Ultrastructural analysis of TRPC1 and D2R expression indicates colocalization of the two proteins within the cell body and dendrites of cortical neurons. In cultured cells, expression of D2Rs was found to increase expression of TRPC1 at the cell surface by 50%. These findings shed new light on the constituents of the D2R signalplex, and support the involvement of D2Rs in cellular calcium signaling pathways via a novel link to TRPC channels.     

Are Obesity and Physical Activity Clustered? A Spatial Analysis Linked to Residential Density

The aim of this study was to examine spatial clustering of obesity and/or moderate physical activity and their relationship to a neighborhood's built environment. Data on levels of obesity and moderate physical activity were derived from the results of a telephone survey conducted in 2006, with 1,863 survey respondents in the study sample. This sample was spread across eight suburban neighborhoods in Metro Vancouver. These areas were selected to contrast residential density and income and do not constitute a random sample, but within each area, respondents were selected randomly. Obesity and moderate physical activity were mapped to determine levels of global and local spatial autocorrelation within the neighborhoods. Clustering was measured using Moran's I at the global level, Anselin's Local Moran's I at the local level, and geographically weighted regression (GWR). The global‐level spatial analysis reveals no significant clustering for the attributes of obesity or moderate physical activity. Within individual neighborhoods, there is moderate clustering of obesity and/or physical activity but these clusters do not achieve statistical significance. In some neighborhoods, local clustering is restricted to a single pair of respondents with moderate physical activity. In other neighborhoods, any moderate local clustering is offset by negative local spatial autocorrelation. Importantly, there is no evidence of significant clustering for the attribute of obesity at either the global or local level of analysis. The GWR analysis fails to improve significantly upon the global model—thus reinforcing the negative results. Overall, the study indicates that the relationship between the urban environment and obesity is not direct.