Metronidazole aryloxy,carboxy and azole derivatives: Synthesis,anti-tumor activity,QSAR, molecular docking and dynamics studies

A series of novel metronidazole aryloxy, carboxy and azole derivatives has been synthesized and their cytotoxic activities on three cancer cell lines were evaluated by MTT assay. Compounds 4m, 4l and 4d showed the most potent cytotoxic activity (IC₅₀s?less than?100?µg/mL). Apoptosis was also detected for these compounds by flow cytometry. Docking studies were performed in order to propose the probable target protein. In the next step, molecular dynamics simulation was carried out on the proposed target protein, focal adhesion kinase (FAK, PDB code: 2ETM), bound to compound 4m. As, 4m showed a potent cytotoxic activity and an acceptable apoptotic effect, it can be a potential anticancer candidate that may work through inhibition of FAK.     

An architecture for a shop-floor controller using colored Petri nets

In a dynamic and flexible manufacturing environment, a shop-floor controller must be designed so that it automatically (or with minimum human intervention) and quickly responds to the changes (e.g., in part type or part routing) in the system. Such a performance may be achieved provided that the controller is simple and sufficiently general in its scope of application. In this article, we present an architecture for such a shop-floor controller. The architecture is based on colored Petri nets with ordered colored sets and structured input and output functions.     

Exploring the generality of associations between plant functional traits: evidence within ecological groups along an altitudinal gradient in Hyrcanian forest

We hypothesized that associations among plant functional traits may differ within different ecological assemblages and plant communities. Association among plant traits including plant maximum height, seed weight, fruit type, pollination mode, mean leaf area, and leaf type were explored within life forms, plant strategy groups along with lowland and montane forest vegetation. In total, 83 sampling plots of 400 m² were placed along a 2400 m altitudinal gradient in Hyrcanian forest. Importance‐values of species within vegetation types were used for weighting data and trait associations were explored using categorical principal component analysis. A G‐test and Fisher's exact test of independence were used to retest significance of the correlations. Different paired trait associations (association lines) including height–leaf, height–seed, height–pollination, leaf–seed, seed–fruit and fruit–pollination were observed and their ecological or physiological basis was discussed. Life forms, strategy types and vegetation types differed based on association lines. Some of the well‐known trade‐offs appear by increasing scale from ecological groups to vegetation types in Hyrcanian forest. The observed patterns of trait associations in Hyrcanian forest and several other ecosystems of the world call the generality of previously accepted trait correlations into question.     

Sodium nitroprusside: its beneficial role in drought stress tolerance of “Mexican lime” (Citrus aurantifolia (Christ.) Swingle) under in vitro conditions

In Vitro Cellular & Developmental Biology - Plant - As a novel antioxidant, sodium nitroprusside (SNP) can be used to reduce the adverse effects of various abiotic stresses, especially drought...     

Tyrosyl-DNA Phosphodiesterase I Catalytic Mutants Reveal an Alternative Nucleophile That Can Catalyze Substrate Cleavage

Tyrosyl-DNA phosphodiesterase I (Tdp1) catalyzes the repair of 3′-DNA adducts, such as the 3′-phosphotyrosyl linkage of DNA topoisomerase I to DNA. Tdp1 contains two conserved catalytic histidines: a nucleophilic His (His^nuc) that attacks DNA adducts to form a covalent 3′-phosphohistidyl intermediate and a general acid/base His (His^gab), which resolves the Tdp1-DNA linkage. A His^nuc to Ala mutant protein is reportedly inactive, whereas the autosomal recessive neurodegenerative disease SCAN1 has been attributed to the enhanced stability of the Tdp1-DNA intermediate induced by mutation of His^gab to Arg. However, here we report that expression of the yeast His^nucAla (H182A) mutant actually induced topoisomerase I-dependent cytotoxicity and further enhanced the cytotoxicity of Tdp1 His^gab mutants, including H432N and the SCAN1-related H432R. Moreover, the His^nucAla mutant was catalytically active in vitro, albeit at levels 85-fold less than that observed with wild type Tdp1. In contrast, the His^nucPhe mutant was catalytically inactive and suppressed His^gab mutant-induced toxicity. These data suggest that the activity of another nucleophile when His^nuc is replaced with residues containing a small side chain (Ala, Asn, and Gln), but not with a bulky side chain. Indeed, genetic, biochemical, and mass spectrometry analyses show that a highly conserved His, immediately N-terminal to His^nuc, can act as a nucleophile to catalyze the formation of a covalent Tdp1-DNA intermediate. These findings suggest that the flexibility of Tdp1 active site residues may impair the resolution of mutant Tdp1 covalent phosphohistidyl intermediates and provide the rationale for developing chemotherapeutics that stabilize the covalent Tdp1-DNA intermediate.     

Axonal cytoskeletal changes after non-disruptive axonal injury

In animal models of human diffuse axonal injury, axonal swellings leading to secondary axotomy occur between 2 and 6 h after injury. But, analysis of cytoskeletal changes associated with secondary axotomy has not been undertaken. We have carried out a quantitative analysis of cytoskeletal changes in a model of diffuse axonal injury 4 h after stretch-injury to adult guinea-pig optic nerves. The major site of axonal damage was the middle portion of the nerve. There was a statistically significant increase in the proportion of small axons with a diameter of 0.5 μm and smaller in which there was compaction of neurofilaments. Axons with a diameter greater than 2.0 μm demonstrated an increased spacing between cytoskeletal elements throughout the length of the nerve. However, in the middle segment of the nerve these larger axons demonstrated two different types of response. Either, where periaxonal spaces occurred, there was a reduction in axonal calibre, compaction of neurofilaments but no change in their number, and a loss of microtubules. Or, where intramyelinic spaces occurred there was an increased spacing between neurofilaments and microtubules with a significant loss in the number of both. Longitudinal sections showed foci of compaction of neurofilaments interspersed between regions where axonal structure was apparently normal. Neurofilament compaction was correlated with disruption of the axolemma at these foci present some hours after injury. We suggest that the time course of these axonal cytoskeletal changes after stretch-injury to central axons is shorter than those changes documented to occur during Wallerian degeneration.     

Trends in the Design and Development of Specific Aptamers Against Peptides and Proteins

Aptamers are single stranded oligonucleotides, comparable to monoclonal antibodies (mAbs) in selectivity and affinity and have significant strategic properties in design, development and applications more than mAbs. Ease of design and development, simple chemical modification and the attachment of functional groups, easily handling and more adaptability with analytical methods, small size and adaptation with nanostructures are the valuable characteristics of aptamers in comparison to large protein based ligands. Among a broad range of targets that their specific aptamers developed, proteins and peptides have significant position according to the number of related studies performed so far. Since proteins control many of important physiological and pathological incidents in the living organisms, particularly human beings and because of the benefits of aptamers in clinical and analytical applications, aptamer related technologies in the field of proteins and peptides are under progress, exclusively. Currently, there is only one FDA approved therapeutic aptamer in the pharmaceutical market, which is specific to vascular endothelial growth factor and is prescribed for age related macular degenerative disease. Additionally, there are several aptamers in the different phases of clinical trials. Almost all of these aptamers are specific to clinically important peptide or protein targets. In addition, the application of protein specific aptamers in the design and development of targeted drug delivery systems and diagnostic biosensors is another intersting field of aptamer technology. In this review, significant efforts related to development and applications of aptamer technologies in proteins and peptides sciences were considered to emphasis on the importance of aptamers in medicinal and clinical applications.     

Prolonged cigarette smoke exposure alters mitochondrial structure and function in airway epithelial cells

Background

Cigarette smoking is the major risk factor for COPD, leading to chronic airway inflammation. We hypothesized that cigarette smoke induces structural and functional changes of airway epithelial mitochondria, with important implications for lung inflammation and COPD pathogenesis.

Methods

We studied changes in mitochondrial morphology and in expression of markers for mitochondrial capacity, damage/biogenesis and fission/fusion in the human bronchial epithelial cell line BEAS-2B upon 6-months from ex-smoking COPD GOLD stage IV patients to age-matched smoking and never-smoking controls.

Results

We observed that long-term CSE exposure induces robust changes in mitochondrial structure, including fragmentation, branching and quantity of cristae. The majority of these changes were persistent upon CSE depletion. Furthermore, long-term CSE exposure significantly increased the expression of specific fission/fusion markers (Fis1, Mfn1, Mfn2, Drp1 and Opa1), oxidative phosphorylation (OXPHOS) proteins (Complex II, III and V), and oxidative stress (Mn-SOD) markers. These changes were accompanied by increased levels of the pro-inflammatory mediators IL-6, IL-8, and IL-1β. Importantly, COPD primary bronchial epithelial cells (PBECs) displayed similar changes in mitochondrial morphology as observed in long-term CSE-exposure BEAS-2B cells. Moreover, expression of specific OXPHOS proteins was higher in PBECs from COPD patients than control smokers, as was the expression of mitochondrial stress marker PINK1.

Conclusion

The observed mitochondrial changes in COPD epithelium are potentially the consequence of long-term exposure to cigarette smoke, leading to impaired mitochondrial function and may play a role in the pathogenesis of COPD.     

Expression of anti human IL-4 and IL-6 scFvs in transgenic tobacco plants

The two murine single-chain Fv (scFv) genes against human interleukin IL-4 and IL-6 cytokines were cloned in a plant expression vector (pGEJAE1) and mobilized to Agrobacterium tumefaciens. Tobacco leaf discs were co-cultured with Agrobacterium and transferred to selective media for regeneration. The tobacco in vitro plants produced scFvs against human IL-4 and IL-6. Only 8% of transformed plants expressing anti-IL-4 scFv were obtained versus 76% of transformed plants expressing anti-IL-6 scFv. In addition, some plants producing anti-IL-4 and anti-IL-6 scFvs aged more rapidly in in vitro conditions and in greenhouse pots than did control plants. Western blot analysis showed that the transformed Nicotiana tabacum plants contained proteins with an apparent molecular mass on electrophoresis of ca. 32 kDa, corresponding to the predicted size of the scFvs. As entire plant root seemed to accumulate more scFv than did leaves, we decided to continue working with isolated roots. Anti-IL-6 scFvs were detected in cultivated roots and their culture media. Functional anti-IL-6 scFv accounted for 0.16–0.18% of total soluble proteins. The affinity of the anti-IL-6 scFv produced in plants and measured by Biacore was similar to that of scFv produced in Escherichia coli. The high levels of antibody accumulation in isolated roots and secretion into the medium demonstrate the potential for producing recombinant protein in bioreactor systems.these authors contributed equally to this workthese authors contributed equally to this work