Two heterologously expressed Planobispora rosea proteins cooperatively induce Streptomyces lividans thiostrepton uptake and storage from the extracellular medium

<p>Abstract</p> <p>Background</p> <p>A bacterial artificial chromosomal library of <it>Planobispora rosea</it>, a genetically intractable actinomycete strain, was constructed using <it>Escherichia coli</it>-<it>Streptomyces </it>artificial chromosome (ESAC) and screened for the presence of genes known to be involved in the biosynthesis of antibiotics.</p> <p>Results</p> <p>One clone with a 40 kb insert showed antimicrobial activity against Gram positive bacteria. Insert sequence analysis and subcloning experiments revealed that the bioactivity was due to a 3.5 kb DNA fragment containing two open reading frames. These <it>orfs </it>encode two proteins with high similarity to a putative membrane protein of <it>Streptomyces coelicolor </it>and to the nogalamycin resistance protein SnorO of <it>Streptomyces nogalater</it>, respectively. The role of these two Orfs is unknown in <it>Planobispora. </it>Disruption and complementation experiments revealed that both proteins are necessary for the antibacterial activity and chemical analysis demonstrated that the antibiotic activity was due to thiostrepton, antibiotic used as recombinant clone selection marker.</p> <p>Conclusion</p> <p>Two <it>Planobispora rosea orfs </it>are responsible for increasing intracellular amounts and storage of thiostrepton in <it>Streptomyces lividans</it>.</p

Are Toll-Like Receptors and Decoy Receptors Involved in the Immunopathogenesis of Systemic Lupus Erythematosus and Lupus-Like Syndromes?

In this paper we focus our attention on the role of two families of receptors, Toll-like receptors (TLR) and decoy receptors (DcR) involved in the generation of systemic lupus erythematosus (SLE) and lupus-like syndromes in human and mouse models. To date, these molecules were described in several autoimmune disorders such as rheumatoid arthritis, antiphospholipids syndrome, bowel inflammation, and SLE. Here, we summarize the findings of recent investigations on TLR and DcR and their role in the immunopathogenesis of the SLE

Stanja Jπ = 2+ i 0+, T = 0 8Be na energijama pobuđenja oko 20 MeV

The 7Li(d, αα)n reaction induced by deuterons of an incident energy of 7 MeV has been used to excite the 8Be nucleus in the region of excitation energy Ex of about 20 MeV. Each of the obtained αα coincidence spectra was fitted by an incoherent sum of the Jπ=2+ and 0+, T=0 8Be levels at Ex=20.1 and 20.2 MeV, respectively. The results show that the experimental data are well fitted when the G values deduced for these levels are 0.90 and 0.70 MeV, respectively.Reakcija 7Li (d, αα) n inducirana deuteronima energije 7 MeV je iskorištena za proučavanje jezgre 8Be na energijama pobuđenja Ex oko 20 MeV. Koincidentni αα spektri poravnani su nekoherentnim zbrojem stanja Jπ = 2 + na Ex = 20, 1 MeV i Jπ = 0+ na Ex = 20,2 MeV. Rezultati pokazuju da su eksperimentalni podaci najbolje opisani ako se za širine navedenih stanja uzmu vrijednosti 0,90 MeV odnosno 0, 70 Me V

Stanja Jπ = 2+ i 0+, T = 0 8Be na energijama pobuđenja oko 20 MeV

The 7Li(d, αα)n reaction induced by deuterons of an incident energy of 7 MeV has been used to excite the 8Be nucleus in the region of excitation energy Ex of about 20 MeV. Each of the obtained αα coincidence spectra was fitted by an incoherent sum of the Jπ=2+ and 0+, T=0 8Be levels at Ex=20.1 and 20.2 MeV, respectively. The results show that the experimental data are well fitted when the G values deduced for these levels are 0.90 and 0.70 MeV, respectively.Reakcija 7Li (d, αα) n inducirana deuteronima energije 7 MeV je iskorištena za proučavanje jezgre 8Be na energijama pobuđenja Ex oko 20 MeV. Koincidentni αα spektri poravnani su nekoherentnim zbrojem stanja Jπ = 2 + na Ex = 20, 1 MeV i Jπ = 0+ na Ex = 20,2 MeV. Rezultati pokazuju da su eksperimentalni podaci najbolje opisani ako se za širine navedenih stanja uzmu vrijednosti 0,90 MeV odnosno 0, 70 Me V

Elucidating the molecular physiology of lantibiotic NAI-107 production in <i>Microbispora </i>ATCC-PTA-5024

BACKGROUND: The filamentous actinomycete Microbispora ATCC-PTA-5024 produces the lantibiotic NAI-107, which is an antibiotic peptide effective against multidrug-resistant Gram-positive bacteria. In actinomycetes, antibiotic production is often associated with a physiological differentiation program controlled by a complex regulatory and metabolic network that may be elucidated by the integration of genomic, proteomic and bioinformatic tools. Accordingly, an extensive evaluation of the proteomic changes associated with NAI-107 production was performed on Microbispora ATCC-PTA-5024 by combining two-dimensional difference in gel electrophoresis, mass spectrometry and gene ontology approaches. RESULTS: Microbispora ATCC-PTA-5024 cultivations in a complex medium were characterized by stages of biomass accumulation (A) followed by biomass yield decline (D). NAI-107 production started at 90 h (A stage), reached a maximum at 140 h (D stage) and decreased thereafter. To reveal patterns of differentially represented proteins associated with NAI-107 production onset and maintenance, differential proteomic analyses were carried-out on biomass samples collected: i) before (66 h) and during (90 h) NAI-107 production at A stage; ii) during three time-points (117, 140, and 162 h) at D stage characterized by different profiles of NAI-107 yield accumulation (117 and 140 h) and decrement (162 h). Regulatory, metabolic and unknown-function proteins, were identified and functionally clustered, revealing that nutritional signals, regulatory cascades and primary metabolism shift-down trigger the accumulation of protein components involved in nitrogen and phosphate metabolism, cell wall biosynthesis/maturation, lipid metabolism, osmotic stress response, multi-drug resistance, and NAI-107 transport. The stimulating role on physiological differentiation of a TetR-like regulator, originally identified in this study, was confirmed by the construction of an over-expressing strain. Finally, the possible role of cellular response to membrane stability alterations and of multi-drug resistance ABC transporters as additional self-resistance mechanisms toward the lantibiotic was confirmed by proteomic and confocal microscopy experiments on a Microbispora ATCC-PTA-5024 lantibiotic-null producer strain which was exposed to an externally-added amount of NAI-107 during growth. CONCLUSION: This study provides a net contribution to the elucidation of the regulatory, metabolic and molecular patterns controlling physiological differentiation in Microbispora ATCC-PTA-5024, supporting the relevance of proteomics in revealing protein players of antibiotic biosynthesis in actinomycetes

Vertical foraging shifts in Hawaiian forest birds in response to invasive rat removal

Worldwide, native species increasingly contend with the interacting stressors of habitat fragmentation and invasive species, yet their combined effects have rarely been examined. Direct negative effects of invasive omnivores are well documented, but the indirect effects of resource competition or those caused by predator avoidance are unknown. Here we isolated and examined the independent and interactive effects of invasive omnivorous Black rats (Rattus rattus) and forest fragment size on the interactions between avian predators and their arthropod prey. Our study examines whether invasive omnivores and ecosystem fragment size impact: 1) the vertical distribution of arthropod species composition and abundance, and 2) the vertical profile of foraging behaviors of five native and two non-native bird species found in our study system. We predicted that the reduced edge effects and greater structural complexity and canopy height of larger fragments would limit the total and proportional habitat space frequented by rats and thus limit their impact on both arthropod biomass and birds’ foraging behavior. We experimentally removed invasive omnivorous Black rats across a 100-fold (0.1 to 12 ha) size gradient of forest fragments on Hawai‘i Island, and paired foraging observations of forest passerines with arthropod sampling in the 16 rat-removed and 18 control fragments. Rat removal was associated with shifts in the vertical distribution of arthropod biomass, irrespective of fragment size. Bird foraging behavior mirrored this shift, and the impact of rat removal was greater for birds that primarily eat fruit and insects compared with those that consume nectar. Evidence from this model study system indicates that invasive rats indirectly alter the feeding behavior of native birds, and consequently impact multiple trophic levels. This study suggests that native species can modify their foraging behavior in response to invasive species removal and presumably arrival through behavioral plasticity

Biological interactions of biocompatible and water-dispersed MoS2 nanosheets with bacteria and human cells

Two dimensional materials beyond graphene such as MoS2 and WS2 are novel and interesting class of materials whose unique physico-chemical properties can be exploited in applications ranging from leading edge nanoelectronics to the frontiers between biomedicine and biotechnology. To unravel the potential of TMD crystals in biomedicine, control over their production through green and scalable routes in biocompatible solvents is critically important. Furthermore, considering multiple applications of eco-friendly 2D dispersions and their potential impact onto live matter, their toxicity and antimicrobial activity still remain an open issue. Herein, we focus on the current demands of 2D TMDs and produce high-quality, few-layered and defect-free MoS2 nanosheets, exfoliated and dispersed in pure water, stabilized up to three weeks. Hence, we studied the impact of this material on human cells by investigating its interactions with three cell lines: two tumoral, MCF7 (breast cancer) and U937 (leukemia), and one normal, HaCaT (epithelium). We observed novel and intriguing results, exhibiting evident cytotoxic effect induced in the tumor cell lines, absent in the normal cells in the tested conditions. The antibacterial action of MoS2 nanosheets is then investigated against a very dangerous gram negative bacterium, such as two types of Salmonellas: ATCC 14028 and wild-type Salmonella typhimurium. Additionally, concentration and layer-dependent modulation of cytotoxic effect is found both on human cells and Salmonellas

A novel enzyme blend for efficient tissue dissociation and primary cells isolation

Tissue dissociation/primary cell isolation and cell harvesting are principal appli- cations for enzymes in tissue culture research and cell biology studies. The goal of a cell isolation procedure is to maximize the yield of functionally viable dissoci- ated cells. Among the parameters which affect the outcome of any particular dissociating procedure there are enzyme(s) used and related impurities presents in crude enzyme preparation. ABIEL srl recently produced the recombinant collagenase class I (Col G) and II (Col H) from Clostridium histolyticum (PCT WO 2011/073925 A9). The enzymes were produced in Escherichia coli and purified by affinity chromatography. The method of production adopted allows absolute control of the final composition of these enzymes, as well as their stability, purity, activity, absence of toxicity and higher reproducibility of batches. The two collagenases produced separately have been used in conjunction according to precise proportions to dissociate calvaria, liver, pancreas, retina of the BALB/c mouse; and bovine hoof. The analyses carried out on all isolated cell populations suggest that the cells maintain the structural and functional integrity of specific tissues/organs originating. Recombinant Col G and Col H enzymes produced by ABIEL are promising in the context of the tissue/cells dissociation, with the aim to make innovation in the fields of tissue engineering and transplantation medicine

Knowledge and attitudes towards clinical trials among women with ovarian cancer: results of the ACTO study

Background Despite several initiatives by research groups, regulatory authorities, and scientific associations to engage citizens/patients in clinical research, there are still obstacles to participation. Among the main discouraging aspects are incomplete understanding of the concepts related to a clinical trial, and the scant, sometimes confused, explanations given. This observational, cross-sectional multicenter study investigated knowledge, attitudes and trust in clinical research. We conducted a survey among women with ovarian cancer at their first follow-up visit or first therapy session, treated in centers belonging to the Mario Negri Gynecologic Oncology (MaNGO) and Multicenter Italian Trials in Ovarian Cancer (MITO) groups. A questionnaire on knowledge, attitudes and experience was assembled ad hoc after a literature review and a validation process involving patients of the Alliance against Ovarian Cancer (ACTO). Results From 25 centers 348 questionnaire were collected; 73.5% of responders were 56 years or older, 54.8% had a high level of education, more than 80% had no experience of trial participation. Among participants 59% knew what clinical trials were and 71% what informed consent was. However, more than half did not know the meaning of the term randomization. More than half (56%) were in favor of participating in a clinical trial, but 35% were not certain. Almost all responders acknowledged the doctor's importance in decision-making. Patients' associations were recognized as having a powerful role in the design and planning of clinical trials. Conclusions This study helps depict the knowledge and attitudes of women with ovarian cancer in relation to clinical trials, suggesting measures aimed at improving trial "culture", literacy and compliance, and fresh ways of communication between doctors and patients