Phosphatidylinositol 4,5-bisphosphate,cholesterol, and fatty acids modulate the calcium-activated chloride channel TMEM16A (ANO1)

The TMEM16A-mediated Ca²⁺-activated Cl^? current drives several important physiological functions. Membrane lipids regulate ion channels and transporters but their influence on members of the TMEM16 family is poorly understood. Here we have studied the regulation of TMEM16A by phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2), cholesterol, and fatty acids using patch clamp, biochemistry and fluorescence microscopy. We found that depletion of membrane PI(4,5)P2 causes a decline in TMEM16A current that is independent of cytoskeleton, but is partially prevented by removing intracellular Ca²⁺. On the other hand, supplying PI(4,5)P2 to inside-out patches attenuated channel rundown and/or partially rescued activity after channel rundown. Also, depletion (with methyl-β-cyclodextrin M-βCD) or restoration (with M-βCD + cholesterol) of membrane cholesterol slows down the current decay observed after reduction of PI(4,5)P2. Neither depletion nor restoration of cholesterol change PI(4,5)P2 content. However, M-βCD alone transiently increases TMEM16A activity and dampens rundown whereas M-βCD + cholesterol increases channel rundown. Thus, PI(4,5)P2 is required for TMEM16A function while cholesterol directly and indirectly via a PI(4,5)P2-independent mechanism regulate channel function. Stearic, arachidonic, oleic, docosahexaenoic, and eicosapentaenoic fatty acids as well as methyl stearate inhibit TMEM16A in a dose- and voltage-dependent manner. Phosphatidylserine, a phospholipid whose hydrocarbon tails contain stearic and oleic acids also inhibits TMEM16A. Finally, we show that TMEM16A remains in the plasma membrane after treatment with M-βCD, M-βCD + cholesterol, oleic, or docosahexaenoic acids. Thus, we propose that lipids and fatty acids regulate TMEM16A channels through a membrane-delimited protein-lipid interaction.     

Evaluation of the interaction between proliferation,oxidant–antioxidant status,Wnt pathway,and apoptosis in zebrafish embryos exposed to silver nanoparticles used in textile industry

Antimicrobial textile products are developing rapidly as an important part of functional textiles. Silver nanoparticles (AgNPs) are nanotechnology products with antimicrobial properties. However, exposure to nanoparticles in daily life is an important issue for public health, still being updated. Aim was to evaluate the effects of AgNPs on the development of zebrafish embryos focusing on Wnt pathway, proliferation, oxidant–antioxidant status, and apoptosis. The expressions of ccnd1 and gsk3β were determined by RT‐PCR, whereas β‐catenin and proliferative cell antigen (PCNA) expressions were determined immunohistochemically. Lipid peroxidation, superoxide dismutase, and glutathione‐S‐transferase activities were determined spectrophotometrically. Apoptosis was determined using acridine orange staining. Oxidant status, apoptosis, immunohistochemical PCNA, and β catenin staining increased, whereas ccnd1 and antioxidant enzyme activities decreased in AgNPs‐exposed embryos in a dose‐dependent manner. Our results indicate the interaction of possible mechanisms that may be responsible for the toxic effects of AgNPs in zebrafish embryos.     

The effects of alpha1-adrenergic and muscarinic cholinergic stimulation on prostaglandin release by rabbit iris

We have investigated the effects of norepinephrine (NE) and acetylcholine (ACh) on prostaglandin (PGE₂ and 6 keto-PGF_1α) production by rabbit iris, measured by radioimmunoassay (RIA), and the type of phospholipase activated by NE in irides in which phosphatidylinositol (PI) was doubly prelabeled with [³H] myo-inositol and [1-¹⁴C] arachidonic acid (¹⁴C-AA), quantitated by radiometric and chromatographic methods. PGE₂ output in 60 min (3.6 μg/g tissue) was 2.6 times greater than 6 keto-PGF_1α. PG production is time-dependent and it is stimulated by NE and ACh in a dose-dependent manner. The Ne- and ACh-induced release of PGE₂, measured by RIA, is mediated through α₁-adrenergic and muscarinic cholinergic receptors, respectively, and it requeires Ca²⁺ for maximal stimulation. Studies on the mechanism of AA release PI in irides doubly prelabeled with ¹⁴C-AA and [³H] myo-inositol revelased the following: (a) Both Ne and ACh increased the breakdown of PI, and this was accompanied by a significant increase in the release of AA and consequently PGE₂. The stimulatory effects of NE and ACh are mediated through α₁-adrenergic and muscainic cholinergic receptors respectively. (b) The NE-induced formation of ³H-lyso PI and the NE-induced metabolism of ¹⁴C-1,2-diacyl-glycerol (DG) are time-dependent. Two pathways for AA release from PI are probably operaitve in the iris: (a) An indirect release by PI-specific phospholipase C which producers DG, followed by the actions of DG- and monoacylglycerol lipases on DG to release AA. (b) A direct release by phospholipase A₂. Whether lyso PI is a product of the polypholipids such as prosphatidylcholine and phosphatidylethanolamine could also serve as a source for AA in PG synthesis. In conclusion, the data presented provide evidence that in the iris the neurotransmitter-stimulated release of PG and AA, from phosphoinositides, for PG synthesis is coupled to the activation of α₁-adrenergic and muscarinic cholinergic receptors.     

Promising immunotherapy: Highlighting cytokine-induced killer cells

For many years, cancer therapy has appeared to be a challenging issue for researchers and physicians. By the introduction of novel methods in immunotherapy, the prospect of cancer therapy even more explained than before. Cytokine-induced killer (CIK) cell-based immunotherapy demonstrated to have potentiality in improving clinical outcomes and relieving major side effects of standard treatment options. In addition, given the distinctive features such as high safety, low toxicity effects on healthy cells, numerous clinical trials conducted on CIK cells. Due to the shortcomings that observed in CIK cell immunotherapy alone, arising a tendency to make modifications (combined modality therapy or combination therapy) including the addition of various types of cytokines, genetic engineering, combination with immune checkpoints, and so on. In this review, we have tried to bring forth the latest immunotherapy methods and their overview. We have discussed the combination therapies with CIK cells and the conducted clinical trials. This helps the future studies to use integrated therapies with CIK cells as a promising treatment of many types of cancers.     

Surfactant proteins A and D in the genital tract of mares

The presence of surface-active material in the lung alveolus has been known for several decades as being essential for normal lung function. Surfactant is essential for reducing the surface tension at the alveolar air-liquid interface. Pulmonary surfactant is composed of 90% lipids and 10% proteins. There are four non-serum proteins surfactant protein-A (SP-A), surfactant protein-B (SP-B), surfactant protein-C (SP-C) and surfactant protein-D (SP-D) named in chronologic order of discovery. Lung SP-A and SP-D belong to a family of collagen-containing C-type lectin family called collectins. The host defence and controlling inflammatory processes of the lung are the major functions of SP-A and SP-D. SP-A and SP-D were originally demonstrated in alveolar type II cells, but recent studies have shown extrapulmonary expression of SP-A and SP-D indicating systemic roles of these proteins. Present study describes the presence of SP-A and SP-D in the mare genital tract, vulva, vagina, ovarium, uterus and tuba uterina using immunohistochemistry and Western blotting. The aim of this study was to characterize surfactant proteins in terms of: (i) whether surfactant proteins were present in the various structures of the mare genital system, (ii) if so, identifying and locating the surfactant proteins and finally (iii) determining the differences from those previously characterized for the lung. Although beyond the scope of this report, it is recognized that there are also some potential implications for better defining the reproductive defence mechanisms in mare. Therefore, genital system organs and tissues from mares were examined. We were able to show that proteins reactive with surfactant-specific antibodies were present in the mare genital tract. Thus, surfactant proteins are present not in just lamellar bodies associated with lung, but also genital system of mare.     

A general approach for developing system-specific functions to score protein-ligand docked complexes using support vector inductive logic programming

Despite the increased recent use of protein-ligand and protein-protein docking in the drug discovery process due to the increases in computational power, the difficulty of accurately ranking the binding affinities of a series of ligands or a series of proteins docked to a protein receptor remains largely unsolved. This problem is of major concern in lead optimization procedures and has lead to the development of scoring functions tailored to rank the binding affinities of a series of ligands to a specific system. However, such methods can take a long time to develop and their transferability to other systems remains open to question. Here we demonstrate that given a suitable amount of background information a new approach using support vector inductive logic programming (SVILP) can be used to produce system-specific scoring functions. Inductive logic programming (ILP) learns logic-based rules for a given dataset that can be used to describe properties of each member of the set in a qualitative manner. By combining ILP with support vector machine regression, a quantitative set of rules can be obtained. SVILP has previously been used in a biological context to examine datasets containing a series of singular molecular structures and properties. Here we describe the use of SVILP to produce binding affinity predictions of a series of ligands to a particular protein. We also for the first time examine the applicability of SVILP techniques to datasets consisting of protein-ligand complexes. Our results show that SVILP performs comparably with other state-of-the-art methods on five protein-ligand systems as judged by similar cross-validated squares of their correlation coefficients. A McNemar test comparing SVILP to CoMFA and CoMSIA across the five systems indicates our method to be significantly better on one occasion. The ability to graphically display and understand the SVILP-produced rules is demonstrated and this feature of ILP can be used to derive hypothesis for future ligand design in lead optimization procedures. The approach can readily be extended to evaluate the binding affinities of a series of protein-protein complexes.     

Destruction of cyanide in gold mill effluents: biological versus chemical treatments

In gold mining, cyanide has been the preferred lixiviant worldwide since 1887. Although cyanide can be destroyed and recovered by several processes, it is still widely discussed and examined due to its potential toxicity and environmental impact. Biological treatment of cyanide is a well-established process and has been commercially used at gold mining operations in North America. Biological treatment processes facilitate growth of microorganisms that are essential for the treatment. The present review describes the advances in the use of biological treatment for the destruction of cyanide in gold mill effluents.     

MicroRNAs in breast cancer: Roles,functions, and mechanism of actions

Breast cancer is one of the most lethal malignancies in women in the world. Various factors are involved in the development and promotion of the malignancy; most of them involve changes in the expression of certain genes, such as microRNAs (miRNAs). MiRNAs can regulate signaling pathways negatively or positively, thereby affecting tumorigenesis and various aspects of cancer progression, particularly breast cancer. Besides, accumulating data demonstrated that miRNAs are a novel tool for prognosis and diagnosis of breast cancer patients. Herein, we will review the roles of these RNA molecules in several important signaling pathways, such as transforming growth factor, Wnt, Notch, nuclear factor-κ B, phosphoinositide-3-kinase/Akt, and extracellular-signal-regulated kinase/mitogen activated protein kinase signaling pathways in breast cancer.