Comparison of the efficiency of evolutionary change-based and side chain orientation-based fold recognition potentials

The present article describes residue level knowledge based potential SORDIS. SORDIS incorporates the information on side-chain orientation in relation to hydrophobic core centres, distance of residue from the globule centre and secondary structure. SORDIS has been tested and compared with widespread evolutionary change-based substitution matrices (BLOSUM, PAM, GONNET, Johnson-Overington, BLAJ, HSDM, and STROMA) in fold recognition experiments within the zone of weak sequence similarity (<16%). The obtained results show that the lower is the amino acid similarity between homologous pairs the higher is the performance of SORDIS in comparison with the potentials, based on the information about the evolutionary changes. Therefore, we propose that the employment of SORDIS in fold recognition can be useful.     

Pepsin as a catalyst for peptide synthesis: formation of peptide bonds not typical for pepsin substrate specificity.

Porcine pepsin in water solutions containing 15-28% of dimethylformamide at pH 5 and 20-37 degrees C catalysed the formation of peptide bonds between Z-Ala-Ala-Phe-OH and various amino acid or peptide derivatives. Substrate binding subsite S1' of pepsin demonstrated broad specificity in these reactions but revealed a certain preference for hydrophobic amino acid residues, including non-proteinous homophenylalanine, p-nitrophenylalanine, S-methylcysteine, as well as for those that contained, in addition to the hydrophobic elements, a group capable of donating a hydrogen bond, e.g. o-nitrotyrosine. This observation increases the range of peptides that might be prepared by pepsin-catalysed synthesis.     

Heat shock protein 90 associates with monarch-1 and regulates its ability to promote degradation of NF-kappaB-inducing kinase

Monarch-1/NLRP12 is expressed in myeloid cells and functions as a negative regulator of inflammation by inducing proteasome-mediated degradation of NF-kappaB-inducing kinase. Monarch-1 is a member of the CATERPILLER gene family, also known as the nucleotide-binding domain leucine-rich repeat gene family. This family shares strong structural homology to major immune regulators expressed in lower organisms, including plants. In plants, these disease-resistance proteins (R proteins) sense pathogenic insult and initiate a protective response to limit pathogen growth. To perform this role, many R proteins require the highly conserved chaperone molecule, heat shock protein (Hsp) 90. Using a two-dimensional gel/mass spectrometry system, we detected the association of the nucleotide-binding domain leucine-rich repeat protein Monarch-1 with heat shock proteins. Further analysis indicates that analogous to plant R proteins, Hsp90 is required for Monarch-1 activity. In human monocytes, Monarch-1 associates with Hsp90, and these complexes are sensitive to treatment with specific Hsp90 inhibitors. Disruption of these complexes results in rapid degradation of Monarch-1 via the proteasome and prevents Monarch-1-induced proteolysis of NF-kappaB-inducing kinase. This demonstrates that Hsp90 is a critical regulator of Monarch-1 anti-inflammatory activity.     

HLA transgenic mice provide evidence for a direct and dominant role of HLA class II variation in modulating the severity of streptococcal sepsis

Our epidemiologic studies on invasive Group A Streptococci (GAS) infections identified specific HLA class II haplotypes/alleles conferring high-risk or protection from streptococcal toxic shock syndrome with a strong protection conferred by the DRB1*15/DQB1*06 haplotype. We used HLA-transgenic mice to provide an in vitro and in vivo validation for the direct role of HLA class II allelic variation in streptococcal toxic shock syndrome. When splenocytes from mice expressing the protective HLA-DQB1*06 (DQ6) allele were stimulated with a mixture of streptococcal superantigens (SAgs), secreted by the prevalent M1T1 strain, both proliferative and cytokine responses were significantly lower than those of splenocytes from mice expressing the neutral DRB1*0402/DQB1*0302 (DR4/DQ8) alleles (p < 0.001). In crisscross experiments, the presentation of SAgs to pure T cells from either the DQ6 or the DR4/DQ8 mice resulted in significantly different levels of response depending on the HLA type expressed on the APCs. Presentation by HLA-DQ6 APCs elicited significantly lower responses than the presentation by HLA-DR4/DQ8 APCs. Our in vitro data were supported by in vivo findings, as the DQ6 mice showed significantly longer survival post-i.v. infection with live M1T1 GAS (p < 0.001) and lower inflammatory cytokine responses as compared with the DR4/DQ8 mice (p < 0.01). The data presented here provide evidence for a direct role of HLA class II molecules in modulating responses to GAS SAgs and underscore the dominant role of HLA class II allelic variation in potentiating the severity of GAS systemic infections.     

Health Reporting in Print Media in Lebanon: Evidence,Quality and Role in Informing Policymaking

Background

Media plays a vital role in shaping public policies and opinions through disseminating health-related information. This study aims at exploring the role of media in informing health policies in Lebanon, identifying the factors influencing health reporting and investigating the role of evidence in health journalism and the quality of health reporting. It also identifies strategies to enhance the use of evidence in health journalism and improve the quality of health reporting.

Methods

Media analysis was conducted to assess the way media reports on health-related issues and the quality of reporting using a quality assessment tool. Semi-structured interviews were also conducted with 27 journalists, researchers and policymakers to explore their perception on the role of media in health policymaking and the factors influencing health reporting. In addition, a validation workshop was conducted.

Results

Out of 1,279 health-related news articles identified, 318 articles used certain type of evidence to report health issues 39.8% of which relied on experts’ opinions as their source of evidence while only 5.9% referenced peer-reviewed research studies. The quality of health reporting was judged to be low based on a quality assessment tool consisting of a set of ten criteria. Journalists raised concerns about issues impeding them from referring to evidence. Journalists also reported difficulties with the investigative health journalism. Policymakers and researchers viewed media as an important tool for evidence-informed health policies, however, serious concerns were voiced in terms of the current practice and capacities.

Conclusion

Our study provides a structured reflection on the role of media and the factors that influence health reporting including context-specific strategies that would enhance the quality and promote the use of evidence in health reporting. In the light of the political changes in many Middle Eastern countries, findings from this study can contribute to redefining the role of media in strengthening health systems.     

Angiotensin II‐induced redox‐sensitive SGLT1 and 2 expression promotes high glucose‐induced endothelial cell senescence

High glucose (HG)‐induced endothelial senescence and dysfunction contribute to the increased cardiovascular risk in diabetes. Empagliflozin, a selective sodium glucose co‐transporter2 (SGLT2) inhibitor, reduced the risk of cardiovascular mortality in type 2 diabetic patients but the protective mechanism remains unclear. This study examines the role of SGLT2 in HG‐induced endothelial senescence and dysfunction. Porcine coronary artery cultured endothelial cells (ECs) or segments were exposed to HG (25 mmol/L) before determination of senescence‐associated beta‐galactosidase activity, protein level by Western blot and immunofluorescence staining, mRNA by RT‐PCR, nitric oxide (NO) by electron paramagnetic resonance, oxidative stress using dihydroethidium and glucose uptake using 2‐NBD‐glucose. HG increased ECs senescence markers and oxidative stress, down‐regulated eNOS expression and NO formation, and induced the expression of VCAM‐1, tissue factor, and the local angiotensin system, all these effects were prevented by empagliflozin. Empagliflozin and LX‐4211 (dual SGLT1/2 inhibitor) reduced glucose uptake stimulated by HG and H₂O₂ in ECs. HG increased SGLT1 and 2 protein levels in cultured ECs and native endothelium. Inhibition of the angiotensin system prevented HG‐induced ECs senescence and SGLT1 and 2 expression. Thus, HG‐induced ECs ageing is driven by the local angiotensin system via the redox‐sensitive up‐regulation of SGLT1 and 2, and, in turn, enhanced glucotoxicity.     

Significance of neutrophil microparticles in ischaemia‐reperfusion: Pro‐inflammatory effectors of endothelial senescence and vascular dysfunction

Endothelial senescence is an emerging cause of vascular dysfunction. Because microparticles are effectors of endothelial inflammation and vascular injury after ischaemia‐reperfusion, we examined leucocyte‐derived microparticles of spleen origin as possible contributors. Microparticles were generated from primary rat splenocytes by either lipopolysaccharide or phorbol‐myristate‐acetate/calcium ionophore, under conditions mimicking innate and adaptive immune responses. Incubation of primary porcine coronary endothelial cells with either type of microparticles, but not with those from unstimulated splenocytes, leads to a similar threefold raise in senescence‐associated β‐galactosidase activity within 48 hours, indicating accelerated senescence, to endothelial oxidative stress, and a fivefold and threefold increase in p21 and p16 senescence markers after 24 hours. After 12‐hour incubation, the endothelial‐dependent relaxation of coronary artery rings was reduced by 50%, at distinct optimal microparticle concentration. In vitro, microparticles were pro‐thrombotic by up‐regulating the local angiotensin system, by prompting tissue factor activity and a secondary generation of pro‐coagulant endothelial microparticles. They initiated an early pro‐inflammatory response by inducing phosphorylation of NF‐κB, MAP kinases and Akt after 1 hour, and up‐regulated VCAM‐1 and ICAM‐1 at 24 hours. Accordingly, VCAM‐1 and COX‐2 were also up‐regulated in the coronary artery endothelium and eNOS down‐regulated. Lipopolysaccharide specifically favoured the shedding of neutrophil‐ and monocyte‐derived microparticles. A 80% immuno‐depletion of neutrophil microparticles reduced endothelial senescence by 55%, indicating a key role. Altogether, data suggest that microparticles from activated splenocytes prompt early pro‐inflammatory, pro‐coagulant and pro‐senescent responses in endothelial cells through redox‐sensitive pathways. The control of neutrophil shedding could preserve the endothelium at site of ischaemia‐reperfusion–driven inflammation and delay its dysfunction.     

Plant Growth Promoting Characterization of Indigenous Azotobacteria Isolated from Soils in Iran

It has been well known that the bacteria of the genus Azotobacter, in addition to the beneficial N₂-fixing activity, are able to improve plant growth by a number of direct and indirect mechanisms. To identify this potential in indigenous azotobacteria, the efficiency of 17 isolates of Azotobacter from the rhizosphere of wheat and barley plants cultivated in salt- and/or drought-affected soils in Iran were evaluated for their ability to dissolve inorganic and organic phosphates, siderophore secretion, indole acetic acid (IAA) production; and protease, chitinase, and ACC deaminase (ACCD) activities. First, they were biochemically characterized and one isolate (strain) was identified by 16S rDNA sequencing. Eight isolates were designated as Azotobacter vinelandii and the remaining isolates were identified as A. chroococcum. All isolates hydrolyzed the organic and inorganic phosphate compounds and effectively produced IAA. Fifteen isolates produced siderophore, but only one isolate showed protease activity which is being reported for the first time in relation to Azotobacter. None of the 17 isolates was capable of producing ACCD or chitinase. However, polymerase chain reaction amplification of the ACCD coding genes, by the use of the gene-specific primers, indicated that not all contain the ACCD gene. The standard screening methods with slight modifications, especially in the case of ACCD assay, were applied. The results showed that the use of specific screening methods, modified according to bacterial nutritional requirements, are the efficient methods for precise evaluation of the plant growth promoting rhizobacteria activity.