The how and why of societal publications for citizen science projects and scientists

In the scientific community, the importance of communication to society is often underestimated. Scientists and scientific organisations often lack the skills to organise such communication effectively. The Dutch citizen science phenology network Nature’s Calendar has been successful in communicating to the general public via numerous newspaper articles, television appearances, presentations, websites and social media. We refer to these publications as societal publications. Due to active communication to mass media, we frequently reach millions of people. This communication helped us to involve thousands of volunteers in recording the timing of phenological events like the start of flowering, leaf unfolding and bird migration, but also several health-related events like hay fever symptoms and tick bites. In this paper, we analyse and present our experiences with the Nature’s Calendar project regarding societal publications. Based on this analysis, we explain the importance of societal publications for citizen science projects and scientists in general, and we show how scientists can increase the newsworthiness of scientific information and what factors and activities can increase the chances of media paying attention to this news. We show that societal publications help phenological networks by facilitating the recruitment, retention and instruction of observers. Furthermore, they stimulate the generation of new ideas and partners that lead to an increase in knowledge, awareness and behavioural change of the general public or specific stakeholders. They make projects, and scientists involved, better known to the public and increase their credibility and authority. Societal publications can catalyse the production of new publications, thereby enforcing the previous mentioned points.     

Functional claudication distance: a reliable and valid measurement to assess functional limitation in patients with intermittent claudication

Background

Pharmacological inhibition of endothelial arginase-II has been shown to improve endothelial nitric oxide synthase (eNOS) function and reduce atherogenesis in animal models. We investigated whether the endothelial arginase II is involved in inflammatory responses in endothelial cells.

Methods

Human endothelial cells were isolated from umbilical veins and stimulated with TNFα (10 ng/ml) for 4 hours. Endothelial expression of the inflammatory molecules i.e. vascular cell adhesion molecule-1 (VCAM-1), intercellular adhesion molecule-1 (ICAM-1), and E-selectin were assessed by immunoblotting.

Results

The induction of the expression of endothelial VCAM-1, ICAM-1 and E-selectin by TNFα was concentration-dependently reduced by incubation of the endothelial cells with the arginase inhibitor L-norvaline. However, inhibition of arginase by another arginase inhibitor S-(2-boronoethyl)-L-cysteine (BEC) had no effects. To confirm the role of arginase-II (the prominent isoform expressed in HUVECs) in the inflammatory responses, adenoviral mediated siRNA silencing of arginase-II knocked down the arginase II protein level, but did not inhibit the up-regulation of the adhesion molecules. Moreover, the inhibitory effect of L-norvaline was not reversed by the NOS inhibitor L-NAME and L-norvaline did not interfere with TNFα-induced activation of NF-κB, JNK, p38mapk, while it inhibited p70s6k (S6K1) activity. Silencing S6K1 prevented up-regulation of E-selectin, but not that of VCAM-1 or ICAM-1 induced by TNFα.

Conclusion

The arginase inhibitor L-norvaline exhibits anti-inflammatory effects independently of inhibition of arginase in human endothelial cells. The anti-inflammatory properties of L-norvaline are partially attributable to its ability to inhibit S6K1.     

A Disulfide Bond-Containing Alkaline Phosphatase Triggers a BdbC-Dependent Secretion Stress Response in Bacillus subtilis

The gram-positive bacterium Bacillus subtilis secretes high levels of proteins into its environment. Most of these secretory proteins are exported from the cytoplasm in an unfolded state and have to fold efficiently after membrane translocation. As previously shown for α-amylases of Bacillus species, inefficient posttranslocational protein folding is potentially detrimental and stressful. In B. subtilis, this so-called secretion stress is sensed and combated by the CssRS two-component system. Two known members of the CssRS regulon are the htrA and htrB genes, encoding potential extracytoplasmic chaperone proteases for protein quality control. In the present study, we investigated whether high-level production of a secretory protein with two disulfide bonds, PhoA of Escherichia coli, induces secretion stress in B. subtilis. Our results show that E. coli PhoA production triggers a relatively moderate CssRS-dependent secretion stress response in B. subtilis. The intensity of this response is significantly increased in the absence of BdbC, which is a major determinant for posttranslocational folding of disulfide bond-containing proteins in B. subtilis. Our findings show that BdbC is required to limit the PhoA-induced secretion stress. This conclusion focuses interest on the BdbC-dependent folding pathway for biotechnological production of proteins with disulfide bonds in B. subtilis and related bacilli.     

The major autolysin Acm2 from Lactobacillus plantarum undergoes cytoplasmic O-glycosylation

The major autolysin Acm2 from the probiotic strain Lactobacillus plantarum WCFS1 contains high proportions of alanine, serine, and threonine in its N-terminal so-called AST domain. It has been suggested that this extracellular protein might be glycosylated, but this has not been experimentally verified. We used high-resolution liquid chromatography-tandem mass spectrometry (LC-MS/MS) to study the possible occurrence of glycans on peptides generated from lactobacillary surface proteins by protease treatment. This approach yielded five glycopeptides in various glycoforms, all derived from the AST domain of Acm2. All five glycopeptides contained the hydroxy-amino acids serine and threonine, suggesting that Acm2 is O-glycosylated. By using lectin blotting with succinylated wheat germ agglutinin, and by comparing the wild-type strain with an Acm2-negative derivative (NZ3557), we found that the attached N-acetylhexosamines are most likely N-acetylglucosamines (GlcNAc). NZ3557 was further used as a genetic background to express an Acm2 variant lacking its secretion signal, resulting in intracellular expression of Acm2. We show that this intracellular version of Acm2 is also glycosylated, indicating that the GlcNAc modification is an intracellular process.     

The Impact of Lactobacillus plantarum WCFS1 Teichoic Acid D-Alanylation on the Generation of Effector and Regulatory T-cells in Healthy Mice

To date it remains unclear how probiotics affect the immune system. Bacterial envelope components may play an essential role, as these are the first to establish bacterial-host cell interactions. Teichoic acids (TAs), and especially lipoteichoic acids, are the most pro-inflammatory components of the gram-positive bacterial envelope. This effect is dependent on D-alanyl substitution of the TA backbone and interactions with TLR2 on host cells. Although the pro-inflammatory properties of TAs have been established in vitro, it remains unclear how TAs affect immunomodulation in vivo. In this study, we investigated the role of TA D-alanylation on L. plantarum–induced intestinal and systemic immunomodulation in vivo. For this, we compared the effect of L. plantarum WCFS1 and its TA D-Alanylation negative derivative (dltX-D) on the distribution of dendritic cell and T cell populations and responses in healthy mice. We demonstrated that the majority of the L. plantarum-induced in vivo immunomodulatory effects were dependent on D-alanylation (D-Ala), as some L. plantarum WCFS1-induced immune changes were not observed in the dltX-D-treated group and some were only observed after treatment with dltX-D. Strikingly, not only pro-inflammatory immune responses were abolished in the absence of D-Ala substitution, but also anti-inflammatory responses, such as the L. plantarum-induced generation of regulatory T cells in the spleen. With this study we provide insight in host-microbe interactions, by demonstrating the involvement of D-alanylation of TAs on the bacterial membrane in intestinal and systemic immunomodulation in healthy mice.     

A mouse model of in vivo chemical inhibition of retinal calcium-independent phospholipase A2 (iPLA2)

Numerous studies have reported the implication of calcium-independent phospholipase A2 (iPLA2) in various biological mechanisms. Most of these works have used in vitro models and only a few have been carried out in vivo on iPLA2^−/− mice. The functions of iPLA2 have been investigated in vivo in the heart, brain, pancreatic islets, and liver, but not in the retina despite its very high content in phospholipids. Phospholipids in the retina are known to be involved in several various key mechanisms such as visual transduction, inflammation or apoptosis. In order to investigate the implication of iPLA2 in these processes, this work was aimed to build an in vivo model of iPLA2 activity inhibition. After testing the efficacy of different chemical inhibitors of iPLA2, we have validated the use of bromoenol lactone (BEL) in vitro and in vivo for inhibiting the activity of iPLA2. Under in vivo conditions, a dose of 6 μg/g of body weight of BEL in mice displayed a 50%-inhibition of retinal iPLA2 activity 8–16 h after intraperitoneal administration. Delivering the same dose twice a day to animals was successful in producing a similar inhibition that was stable over one week. In summary, this novel mouse model exhibits a significant inhibition of retinal iPLA2 activity. This model of chemical inhibition of iPLA2 will be useful in future studies focusing on iPLA2 functions in the retina.     

Metabolic Syndrome Triggered by High-Fructose Diet Favors Choroidal Neovascularization and Impairs Retinal Light Sensitivity in the Rat

Diabetic retinopathy and age-related macular degeneration are the leading causes of blindness in Western populations. Although it is a matter of controversy, large-scale population-based studies have reported increased prevalence of age-related macular degeneration in patients with diabetes or diabetic retinopathy. We hypothesized that metabolic syndrome, one of the major risk factors for type 2 diabetes, would represent a favorable environment for the development of choroidal neovascularization, the main complication of age-related macular degeneration. The fructose-fed rat was used as a model for metabolic syndrome in which choroidal neovascularization was induced by laser photocoagulation. Male Brown Norway rats were fed for 1, 3, and 6 months with a standard equilibrated chow diet or a 60%-rich fructose diet (n = 24 per time point). The animals expectedly developed significant body adiposity (+17%), liver steatosis at 3 and 6 months, hyperleptinemia at 1 and 3 months (two-fold increase) and hyperinsulinemia at 3 and 6 months (up to two-fold increase), but remained normoglycemic and normolipemic. The fructose-fed animals exhibited partial loss of rod sensitivity to light stimulus and reduced amplitude of oscillatory potentials at 6 months. Fructose-fed rats developed significantly more choroidal neovascularization at 14 and 21 days post-laser photocoagulation after 1 and 3 months of diet compared to animals fed the control diet. These results were consistent with infiltration/activation of phagocytic cells and up-regulation of pro-angiogenic gene expression such as Vegf and Leptin in the retina. Our data therefore suggested that metabolic syndrome would exacerbate the development of choroidal neovascularization in our experimental model.