Light signaling genes and their manipulation towards modulation of phytonutrient content in tomato fruits

Due to its economic importance, ease of genetic manipulation, cultivation and processing, the tomato plant has been a target for increasing and diversifying content of fruit phytonutrients by transgenic and non-transgenic approaches. The tomato high pigment (hp) mutations exemplify the latter alternative and due to their positive effect on fruit lycopene content, they were introgressed into elite tomato germplasm for cost effective extraction of this important carotenoid. Interestingly, hp mutant fruits are also characterized by higher fruit levels of other functional metabolites, phenotypes caused by mutations in central genes regulating light signal-transduction. This gene identification suggests that modulation of light signaling machinery in plants may be highly effective towards manipulation of fruit phytonutrients but has never been thoroughly reviewed. This review therefore summarizes the progress which has been made on this valuable approach, emphasizing the consequences of transgenic modulation of light signaling components on the functional properties of the tomato fruit.     

Gender difference in C-reactive protein concentrations in individuals with atherothrombotic risk factors and apparently healthy ones.

Recent studies have shown that C-reactive proteins have a pathogenetic role in atherothrombosis and concentrations of these substances could be used as a marker for future vascular events. The objective of this study was to determine gender differences in highly sensitive C-reactive protein (hs-CRP) in individuals with atherothrombotic risk factors and apparently healthy ones. We have presently matched 469 females and 469 males having the same age and body mass index (BMI). Of these, 210 men and 210 women had no atherothrombotic risk factors. In this group the hs-CRP concentrations were 1.6+/-3.4 mg l(-1) in women and 1.0+/-2.7 mg l(-1) in men (p<0.0005). These values were 2.1+/-3.4 mg l(-1) and 1.5+/-2.8 mg l(-1), respectively, in the entire cohort (p<0.0005), which included also individuals with atherothrombotic risk factors. We conclude that significant gender differences exist in hs-CRP concentrations despite perfect matching for age and BMI. These differences should be reflected in guidelines that suggest hs-CRP cut-off points for the stratification of vascular risk.     

Feedback-Based,System-Level Properties of Vertebrate-Microbial Interactions

Background

Improved characterization of infectious disease dynamics is required. To that end, three-dimensional (3D) data analysis of feedback-like processes may be considered.

Methods

To detect infectious disease data patterns, a systems biology (SB) and evolutionary biology (EB) approach was evaluated, which utilizes leukocyte data structures designed to diminish data variability and enhance discrimination. Using data collected from one avian and two mammalian (human and bovine) species infected with viral, parasite, or bacterial agents (both sensitive and resistant to antimicrobials), four data structures were explored: (i) counts or percentages of a single leukocyte type, such as lymphocytes, neutrophils, or macrophages (the classic approach), and three levels of the SB/EB approach, which assessed (ii) 2D, (iii) 3D, and (iv) multi-dimensional (rotating 3D) host-microbial interactions.

Results

In all studies, no classic data structure discriminated disease-positive (D+, or observations in which a microbe was isolated) from disease-negative (D–, or microbial-negative) groups: D+ and D– data distributions overlapped. In contrast, multi-dimensional analysis of indicators designed to possess desirable features, such as a single line of observations, displayed a continuous, circular data structure, whose abrupt inflections facilitated partitioning into subsets statistically significantly different from one another. In all studies, the 3D, SB/EB approach distinguished three (steady, positive, and negative) feedback phases, in which D– data characterized the steady state phase, and D+ data were found in the positive and negative phases. In humans, spatial patterns revealed false-negative observations and three malaria-positive data classes. In both humans and bovines, methicillin-resistant Staphylococcus aureus (MRSA) infections were discriminated from non-MRSA infections.

Conclusions

More information can be extracted, from the same data, provided that data are structured, their 3D relationships are considered, and well-conserved (feedback-like) functions are estimated. Patterns emerging from such structures may distinguish well-conserved from recently developed host-microbial interactions. Applications include diagnosis, error detection, and modeling.     

Jointly They Edit: Examining the Impact of Community Identification on Political Interaction in Wikipedia

Background

In their 2005 study, Adamic and Glance coined the memorable phrase ‘divided they blog’, referring to a trend of cyberbalkanization in the political blogosphere, with liberal and conservative blogs tending to link to other blogs with a similar political slant, and not to one another. As political discussion and activity increasingly moves online, the power of framing political discourses is shifting from mass media to social media.

Methodology/Principal Findings

Continued examination of political interactions online is critical, and we extend this line of research by examining the activities of political users within the Wikipedia community. First, we examined how users in Wikipedia choose to display their political affiliation. Next, we analyzed the patterns of cross-party interaction and community participation among those users proclaiming a political affiliation. In contrast to previous analyses of other social media, we did not find strong trends indicating a preference to interact with members of the same political party within the Wikipedia community.

Conclusions/Significance

Our results indicate that users who proclaim their political affiliation within the community tend to proclaim their identity as a ‘Wikipedian’ even more loudly. It seems that the shared identity of ‘being Wikipedian’ may be strong enough to triumph over other potentially divisive facets of personal identity, such as political affiliation.     

Knockdown of heme oxygenase-2 impairs corneal epithelial cell wound healing

Heme oxygenase (HO) represents an intrinsic cytoprotective system based on its anti‐oxidative and anti‐inflammatory properties mediated via its products biliverdin/bilirubin and carbon monoxide (CO). We showed that deletion of HO‐2 results in impaired corneal wound healing with associated chronic inflammatory complications. This study was undertaken to examine the role of HO activity and the contribution of HO‐1 and HO‐2 to corneal wound healing in an in vitro epithelial scratch injury model. A scratch wound model was established using human corneal epithelial (HCE) cells. These cells expressed both HO‐1 and HO‐2 proteins. Injury elicited a rapid and transient increase in HO‐1 and HO activity; HO‐2 expression was unchanged. Treatment with biliverdin or CORM‐A1, a CO donor, accelerated wound closure by 10% at 24 h. Inhibition of HO activity impaired wound closure by more than 50%. However, addition of biliverdin or CORM‐A1 reversed the effect of HO inhibition on wound healing. Moreover, knockdown of HO‐2 expression, but not HO‐1, significantly impaired wound healing. These results indicate that HO activity is required for corneal epithelial cell migration. Inhibition of HO activity impairs wound healing while amplification of its activity restores and accelerates healing. Importantly, HO‐2, which is highly expressed in the corneal epithelium, appears to be critical for the wound healing process in the cornea. The mechanisms by which it contributes to cell migration in response to injury may reside in the cytoprotective properties of CO and biliverdin. J. Cell. Physiol. 226: 1732–1740, 2011. © 2010 Wiley‐Liss, Inc.     

Adhesion and biofilm formation of <Emphasis Type="Italic">Mycoplasma pneumoniae</Emphasis> on an abiotic surface

We demonstrated that when M. pneumoniae was grown on an abiotic surface of either glass or polystyrene with a serum-containing medium, the bacteria adhered to the surface and formed highly differentiated volcano-like biofilm structures. As adherence to the surface and/or biofilm formation was totally inhibited by anti-P1 polyclonal monospecific antibodies, we suggest that the adherence of M. pneumoniae to the abiotic surface and/or biofilm formation is associated with P1, the major tip organelle protein of this organism. Furthermore, adherence and/or biofilm formation was markedly inhibited by treating the serum component of the growth medium with neuraminidase or by growing the bacteria in the presence of sialyllactose, suggesting that the initial step in the adherence to and/or biofilm formation by M. pneumoniae on an abiotic surface is the interaction of the bacterium through its tip organelle with sialic acid residues of serum glycoproteins.     

The role of 20-HETE in androgen-mediated hypertension

Androgen plays an important role in blood pressure regulation. Epidemiological studies have shown that men have a higher prevalence for developing hypertension than aged-matched, premenopausal women. Interestingly, postmenopausal women and women with polycystic ovary syndrome, both of which have increased endogenous androgen production, have elevated risks for hypertension suggesting that androgen may contribute to its development. Studies from our laboratory and others have provided substantial evidence that 20-hydroxyeicosatetraenoic acid (20-HETE) mediates the hypertension seen in rodents treated with androgen. 20-HETE is the cytochrome P450 (CYP)-derived ω-hydroxylated metabolite of arachidonic acid. 20-HETE plays a complex role in blood pressure regulation. In the kidney tubules, 20-HETE decreases blood pressure by promoting natriuresis, while in the microvasculature it has a pressor effect. In the microcirculation, 20-HETE participates in the regulation of vascular tone by sensitizing the smooth muscle cells to constrictor stimuli and contributes to myogenic, mitogenic and angiogenic responses. In addition, 20-HETE acts on the endothelium to promote endothelial dysfunction and endothelial activation. Recently, we have demonstrated that 20-HETE induces endothelial ACE thus setting forth a potential feed forward mechanism through activation of the renin-angiotensin-aldosterone system. In this review, we will discuss the pro-hypertensive effects of 20-HETE and its role in androgen-induced vascular dysfunction and hypertension.     

Oleic acid and adipokines synergize in inducing proliferation and inflammatory signalling in human vascular smooth muscle cells

In the context of obesity, perivascular fat produces various adipokines and releases free fatty acids, which may induce inflammation and proliferation in the vascular wall. In this study we investigated how adipokines, oleic acid (OA) and the combined treatment regulate human vascular smooth muscle cell (hVSMC) proliferation and migration and the underlying signalling pathways. Adipocyte‐conditioned media (CM) generated from human adipocytes induces a prominent proliferation and migration of hVSMC. Autocrine action of adiponectin totally abolishes CM‐induced proliferation. Furthermore, OA but not palmitic acid induces proliferation of hVSMC. CM itself does not contain fatty acids, but CM in combination with OA markedly enhances proliferation of hVSMC in a synergistic way. Both the nuclear factor (NF)‐κB and the mammalian target of rapamycin (mTOR) pathway were synergistically activated under these conditions and found to be essential for hVSMC proliferation. Expression of iNOS and production of nitric oxide was only enhanced by combined treatment inducing a marked release of VEGF. Combination of OA and VEGF induces an additive increase of hVSMC proliferation. We could show that the combination of CM and OA led to a synergistic proliferation of hVSMC. Expression of iNOS and production of nitric oxide were only enhanced under these conditions and were paralleled by a marked release of VEGF. These results suggest that the combined elevated release of fatty acids and adipokines by adipose tissue in obesity might be critically related to hVSMC dysfunction, vascular inflammation and the development of atherosclerosis.