Insights into laccase producing organisms,fermentation states,purification strategies,and biotechnological applications

Laccases are phenol oxidases belonging to the superfamily of multicopper oxidases and are found in bacteria, fungi, lichens, higher plants, and insects. Over the past few decades, laccases and laccase mediator systems (LMS) have found uses in a wide range of technological applications such as textile dye decolorization, industrial wastewater detoxification, pulp bleaching, chemical synthesis, and development of miniaturized biosensors. This has encouraged numerous studies to find and purify laccases with exploitable characteristics. The main aim of the present review is to summarize the rich literature data gained in recent years from the studies on laccases, focusing on the organisms that produce them, the methods used for screening, laccase activity assays, purification strategies, and the application of laccases as eco‐friendly biocatalysts. © 2015 American Institute of Chemical Engineers Biotechnol. Prog., 31:1443–1463, 2015     

Protective Effects of Caffeic Acid Phenethyl Ester on Cyclophosphamide‐Induced Hemorrhagic Cystitis in Rats

We investigated the protective effect of caffeic acid phenethyl ester (CAPE) on cyclophosphamide‐induced hemorrhagic cystitis in rats in comparison with 2‐mercaptoethane sulfonate (MESNA). Forty male rats were randomized into four groups: group 1 (control), group 2 (cyclophosphamide), group 3 (cyclophosphamide + MESNA), group 4 (cyclophosphamide + CAPE). Cyclophosphamide injection increased malondialdehyde levels indicating oxidative stress, whereas CAPE and MESNA ameliorated malondialdehyde levels in the bladder (p < 0.05). Only catalase activities were decreased significantly in both groups (cyclophosphamide + MESNA and cyclophosphamide + CAPE, p < 0.05). Pretreatment with CAPE (p < 0.01) resulted in a significant decrease in nitric oxide levels when compared with the cyclophosphamide group. When we consider the studies that show the critical importance of increased nitric oxide levels in pathogenesis of cyclophosphamide‐induced hemorrhagic cystitis, we suggest that it would be more beneficial to use MESNA with CAPE to prevent histological damage.     

Testing the Benefits of Neurofeedback on Selective Attention Measured Through Dichotic Listening

The electrophysiological changes after a single session of neurofeedback training (↑SMR/↓Theta) and its effects on executive attention during a dichotic listening test with forced attentional procedures were measured in a sample of 20 healthy women. A pre–post moment test double blind design, with the inclusion of a group receiving sham neurofeedback, allowed for minimization of alien influences. The interaction of Moment × Group was significant, indicating an enhancement of SMR band after the real neurofeedback. The dichotic listening scores were correlated with the amplitude of Beta band in baseline conditions. The performance on the forced left attentional condition in dichotic listening was significantly improved and correlated positively with the post-training enhancement of the SMR band. The sham neurofeedback group also improved DL scores, so a clear affirmation about the benefits of neurofeedback training over cognitive performance could not be unambiguously established. It is concluded that the protocol showed a good independence and acceptable trainability in modifying the EEG results, but there was limited interpretability regarding cognitive outcomes.     

Leukocyte Gene Expression and Plasma Concentration in Multiple Sclerosis: Alteration of Transforming Growth Factor-βs,Claudin-11, and Matrix Metalloproteinase-2

Multiple sclerosis is a neurodegenerative disease characterized by the present of leukocytes in the brain tissue and subsequently the formation of sclerotic plaques. Leukocytes penetration into the blood–brain barrier is related to several factors, such as, the conversion of leukocyte gene expression or plasma characteristics. In this frame, we explore alteration of matrix metalloproteinase-2 (MMP-2), transforming growth factor beta (TGF-β) family, and Claudin-11 (as a main myelin structural protein) in leukocytes and blood plasma of multiple sclerosis patients compared to the normal group. Blood samples were collected from thirteen men affected by MS and fifteen healthy men. Leukocyte gene expression was measured using real-time PCR and plasma parameters were examined by ELISA. The results of this study showed that the gene expression of Claudin-11 was significantly higher in MS group compared with normal. Interestingly, the MMP-2 pattern was similar to Claudin-11 and correlated positively with it. It was observed that, although the expressions of TGF-β1 and TGF-β2 are down-regulated in the leukocytes of subjects with MS, they showed higher levels of these cytokines in blood plasma. The plasma level of TGF-β3 in MS patients was higher than normal and correlated with Claudin-11 concentration. In conclusion, the aberrant pattern of Claudin-11, TGF-βs family, and MMP-2 expression in leukocytes of the MS patients was observed in this study. Moreover, the plasma levels of TGF-βs family increased in the MS group. The findings of this study provide clues for further investigations to assay MS pathogenesis.     

Using Isolated Mitochondria from Minimal Quantities of Mouse Skeletal Muscle for High throughput Microplate Respiratory Measurements

Skeletal muscle mitochondria play a specific role in many disease pathologies. As such, the measurement of oxygen consumption as an indicator of mitochondrial function in this tissue has become more prevalent. Although many technologies and assays exist that measure mitochondrial respiratory pathways in a variety of cells, tissue and species, there is currently a void in the literature in regards to the compilation of these assays using isolated mitochondria from mouse skeletal muscle for use in microplate based technologies. Importantly, the use of microplate based respirometric assays is growing among mitochondrial biologists as it allows for high throughput measurements using minimal quantities of isolated mitochondria. Therefore, a collection of microplate based respirometric assays were developed that are able to assess mechanistic changes/adaptations in oxygen consumption in a commonly used animal model. The methods presented herein provide step-by-step instructions to perform these assays with an optimal amount of mitochondrial protein and reagents, and high precision as evidenced by the minimal variance across the dynamic range of each assay.     

Electroactive centers in Euphorbia latex and lentil seedling amine oxidases

The electrochemical behavior of redox centers in the active site of amine oxidases from lentil seedlings and Euphorbia characias latex was investigated using a mercury film electrode. Tyrosine-derived 6-hydroxydopa quinone (TPQ) and copper ions in the active site are redox centers of these amine oxidases. The enzymes undergo two reduction processes at negative potentials related to the reduction of the TPQ cofactor to the corresponding hydroquinones and the reduction of copper ions, (Cu(II)-->Cu(I)). Copper depleted enzymes, prepared by reduction with dithionite followed by dialysis against cyanide, undergo only one reduction process. Nyquist diagrams, recorded at potentials corresponding to the reduction of cofactors as dc-offset, represent charge transfer impedance followed by a Warburg-type line at low frequencies, indicating the occurrence of a diffusion controlled process in the rate-limiting step of the reduction process.     

Receptor-like stereospecific binding of a pyrethroid insecticide to mouse brain membranes

A heterogeneous particulate fraction of mouse brain homogenates binds NRDC 157 (3-phenoxybenzyl [1$\text{R}$,$\text{cis}$]-3-(2,2-dibromovinyl)-2,2- dimethylcyclopropanecarboxylate), a potent pyrethroid insecticide, stereospecifically and with high affinity. Stereospecific binding is a minor component of total binding (2.8%); the remainder of observed binding is predominantly nonspecific and unsaturable. Stereospecific binding is half-saturated at 4×10^?8$\text{M}$ and fully saturated at concentrations in excess of 1×10^?7$\text{M}$. The stereospecific binding capacity of this preparation was 200–250 pmoles of NRDC 157 per gram equivalent of brain tissue (2.3–2.8 pmol/mg protein). This binding site may represent the neural receptor involved in the stereospecific toxic action of pyrethroids.     

Immunoresolvents in asthma and allergic diseases: Review and update

Asthma and allergic diseases are inflammatory conditions developed by excessive reaction of the immune system against normally harmless environmental substances. Although acute inflammation is necessary to eradicate the damaging agents, shifting to chronic inflammation can be potentially detrimental. Essential fatty-acids-derived immunoresolvents, namely, lipoxins, resolvins, protectins, and maresins, are anti-inflammatory compounds that are believed to have protective and beneficial effects in inflammatory disorders, including asthma and allergies. Accordingly, impaired biosynthesis and defective production of immunoresolvents could be involved in the development of chronic inflammation. In this review, recent evidence on the anti-inflam]matory effects of immunoresolvents, their enzymatic biosynthesis routes, as well as their receptors are discussed.