Potent Anti-Inflammatory Activity of Novel Microtubule-Modulating Brominated Noscapine Analogs

Noscapine, a plant-derived, non-toxic, over-the-counter antitussive alkaloid has tubulin-binding properties. Based upon the structural resemblance of noscapine to colchicine, a tubulin-binding anti-inflammatory drug, noscapine and its semi-synthetic brominated analogs were examined for in vitro anti-inflammatory activity. Brominated noscapine analogs were found to inhibit cytokine and chemokine release from macrophage cell lines but did not affect cell viability. Brominated noscapine analogs demonstrated anti-inflammatory properties in both TLR- and non-TLR induced in vitro innate immune pathway inflammation models, mimicking septic and sterile infection respectively. In addition, electron microscopy and immunoblotting data indicated that these analogs induced robust autophagy in human macrophages. This study is the first report to identify brominated noscapines as innate immune pathway anti-inflammatory molecules

Metabolomics Profiling of Vitamin D Status in Relation to Dyslipidemia.

Vitamin D deficiency is a global disorder associated with several chronic illnesses including dyslipidemia and metabolic syndrome. The impact of this association with both dyslipidemia and vitamin D deficiency on metabolomics profile is not yet fully understood. This study analyses the metabolomics and lipidomic signatures in relation to vitamin D status and dyslipidemia. Metabolomics data were collected from Qatar Biobank database and categorized into four groups based on vitamin D and dyslipidemia status. Metabolomics multivariate analysis was performed using the orthogonal partial least square discriminate analysis (OPLS-DA) whilst linear models were used to assess the per-metabolite association with each of the four dyslipidemia/vitamin D combination groups. Our results indicate a high prevalence of vitamin D deficiency among the younger age group, while dyslipidemia was more prominent in the older group. A significant alteration of metabolomics profile was observed among the dyslipidemic and vitamin D deficient individuals in comparison with control groups. These modifications reflected changes in some key pathways including ceramides, diacylglycerols, hemosylceramides, lysophospholipids, phosphatidylcholines, phosphatidylethanol amines, and sphingomyelins. Vitamin D deficiency and dyslipidemia have a deep impact on sphingomyelins profile. The modifications were noted at the level of ceramides and are likely to propagate through downstream pathways

Staphylococcus aureus histone deacteylase-like enzyme is a potential target for adjuvant antibiotic discovery

Background: The rise in antibiotic resistance requires prompt action to reduce the burden of untreatable bacterial diseases1. Staphylococcus aureus is a human commensal and opportunistic pathogen that causes a broad range of diseases, from mild skin infections to infective endocarditis. The World Health Organization has placed S. aureus on the high-priority pathogen list due to its multidrug-resisting nature2. The study aims to identify molecular targets for antibiotic adjuvants to restore antibiotic activity. Methods: Extensive blast search and computational analysis were employed to search published S. aureus genomes. The effect of suggested adjuvants was tested on sensitive and resistant S. aureus strains in-vitro. Bacteria were incubated in the presence of either an HDAC inhibitor (TSA) or an antibiotic (Cefixime), or a combination of both. Results: A gene that encodes a histone deacetylase-like enzyme (SA-HDAC) and shares high 3D-homology to human HDAC2 and HDAC8 was identified3. Using computational modeling, it was found that the SA-HDAC protein has an active catalytic pocket containing the highly conserved zinc-binding constellation, suggesting an HDAC-like activity. I-TASSER analysis revealed that HDAC inhibitors such as TSA, CRI, LLX, NHB, and B3N can bind to the catalytic core. From the growth curves generated using the in-vitro study, it was observed that while Cefixime alone had no effect, TSA had an inhibitory effect, and the combination showed an additive effect on both strains. Further, the effect was more evident in the sensitive strain as compared to MRSA. An extensive bioinformatics blast search showed that this gene is absent in most gut microbiota species but found in many pathogens that carry and spread multidrug resistance in healthcare settings as well as in community-acquired infections. Conclusion: SA-HDAC enzyme, which is absent in most gut microbiota, is a highly druggable target that can be utilized for novel adjuvant antibiotic discovery.qscienc

The Human Host Defense Peptide LL-37 Interacts with Neisseria meningitidis Capsular Polysaccharides and Inhibits Inflammatory Mediators Release

Capsular polysaccharides (CPS) are a major virulence factor in meningococcal infections and form the basis for serogroup designation and protective vaccines. Our work has identified meningococcal CPS as a pro-inflammatory ligand that functions through TLR2 and TLR4-MD2-dependent activation. We hypothesized that human cationic host defense peptides interact with CPS and influence its biologic activity. Accordingly, the interaction of meningococcal CPS with the human-derived cationic peptide LL-37, which is expressed by phagocytic and epithelial cells that interface with meningococci during infection, was investigated. LL-37 neutralized the pro-inflammatory activity of endotoxin-free CPS as assessed by TLR2 and TLR4-MD-2-dependent release of TNFα, IL-6 and IL-8 from human and murine macrophages. The cationic and hydrophobic properties of LL-37 were crucial for this inhibition, which was due to binding of LL-37 to CPS. LL-37 also inhibited the ability of meningococcal CPS to induce nitric oxide release, as well as TNFα and CXCL10 (IP-10) release from TLR4-sufficient and TLR4-deficient murine macrophages. Truncated LL-37 analogs, especially those that retained the antibacterial domain, inhibited vaccine grade CPS and meningococcal CPS prepared from the major serogroups (A, B C, Y and W135). Thus, LL-37 interaction with CPS was independent of specific glucan structure. We conclude that the capacity of meningococcal CPS to activate macrophages via TLR2 and TLR4-MD-2 can be inhibited by the human cationic host defense peptide LL-37 and propose that this impacts CPS-based vaccine responses

Editorial: Role of Iron in Bacterial Pathogenesis

The collection of articles published in this eBook represent different facets of the interactions between pathogens and their host concerning the battle for iron. Pathogens have developed different strategies to acquire iron from their host. These include the production of siderophores, heme acquisition and ferrous iron uptake

Highly Sensitive Detection and Differentiation of Endotoxins Derived from Bacterial Pathogens by Surface-Enhanced Raman Scattering.

Bacterial endotoxins, as major components of Gram-negative bacterial outer membrane leaflets and a well-characterized TLR4-MD-2 ligand, are lipopolysaccharides (LPSs) that are constantly shed from bacteria during growth and infection. For the first time, we report that unique surface-enhanced Raman scattering (SERS) spectra of enteric LPSs from , , , , species . CE3, and . NGR, as well as endotoxin structures, LPSs, lipid A, and KDO2-lipid A can be obtained. The characteristic peaks of the SERS spectra reveal that most of the tested LPS structures are from lipids and saccharides, i.e., the major components of LPSs, and these spectra can be successfully used to differentiate between endotoxins with principal components analysis. In addition, all the LPS samples here are measured at a concentration of 10 nmole/mL, which corresponds to their relevant pathophysiological concentrations in clinical infections. This study demonstrates that LPSs can be used as biomarkers for the highly sensitive detection of bacteria using SERS-based methods.R21-AI096364/NH/NIH HHS/United States NPRP12S-0224-190144/Qatar National Research Fund CBET-1064228/National Science Foundatio

RamanNet: A generalized neural network architecture for Raman Spectrum Analysis

Raman spectroscopy provides a vibrational profile of the molecules and thus can be used to uniquely identify different kind of materials. This sort of fingerprinting molecules has thus led to widespread application of Raman spectrum in various fields like medical dignostics, forensics, mineralogy, bacteriology and virology etc. Despite the recent rise in Raman spectra data volume, there has not been any significant effort in developing generalized machine learning methods for Raman spectra analysis. We examine, experiment and evaluate existing methods and conjecture that neither current sequential models nor traditional machine learning models are satisfactorily sufficient to analyze Raman spectra. Both has their perks and pitfalls, therefore we attempt to mix the best of both worlds and propose a novel network architecture RamanNet. RamanNet is immune to invariance property in CNN and at the same time better than traditional machine learning models for the inclusion of sparse connectivity. Our experiments on 4 public datasets demonstrate superior performance over the much complex state-of-the-art methods and thus RamanNet has the potential to become the defacto standard in Raman spectra data analysi

Rapid detection of bacterial infections using nanotechnology-based point-of-care sensor with Raman spectroscopy

Background: Mass gathering is a risk factor for infectious diseases transmission. Therefore, rapid detection of infections is highly desirable. The current gold standard approach to detect bacterial infections in clinical samples (biological fluids) requires three days of bacterial culture to obtain the diagnosis and antibiotic sensitivity results1. This approach, although very accurate results in considerable delay in initiating proper treatment which increases the transmission of infection, mainly hospital-acquired infections. Therefore, rapid detection of infection would lead to rapid clinical interventions, which mitigate the spread of infection and support antibiotic stewardship consequently reducing the burden of hospital-acquired infections. The goal of this research is to develop a highly innovative sensor (point-of-care device) for rapid detection of bacterial infections in biological fluids. This project will also focus on identifying unique SERS spectra of bacterial infections commonly associated with mass gathering and early detection of antibiotic resistant bacteria. Methods: The proposed biosensor is a culture-free diagnostic method utilizing nanotechnology-based fabricated silver nanorod arrays (AgNR) as a substrate for the Surface Enhanced Raman Spectroscopy. Results: We reported the proof-of-concept study using this novel SERS-based diagnostic where we showed that rapid detection of bacterial biomarkers in sputum and exhaled breath condensates (EBC) from patients with cystic fibrosis2,3. We further identified unique SERS spectra of various bacterial siderophores and small molecule metabolites. Conclusion: This method is highly sensitive, fast, cheap, and can be implemented at the bedside using a portable (hand-held) Raman spectroscope.qscienc