Segmental vitiligo as the possible expression of cutaneous somatic mosaicism: implications for common non-segmental vitiligo

Clinical findings in vitiligo challenge the widely accepted organ specific autoimmune pathomechanisms. We draw the attention to the fact that the distribution of segmental vitiligo (SV) fits in at least a subset of patients a pattern usually associated with cutaneous mosaicism. The association of SV to non-segmental vitiligo (NSV) now confirmed by several observations indicates a continuum between the two subsets with shared predisposing genetic factors, including genes operating specifically in the skin. Some pedigrees associating SV and NSV further suggest a mechanism of loss of heterozygosity for a dominant gene controlling part of the cutaneous phenotype. The mosaic hypothesis applies only to SV and to the rare SV-NSV association, but suggests that predisposing genetic factors in common NSV should also be searched directly in the skin. SV would be a good candidate disease to explore as a proof of principle of a new gene discovery strategy useful for multigenic disorders with organ specificity, applicable in priority to chronic inflammatory skin disorders.     

Carbon metabolism in in vitro cultures of date palm: the role of carboxylases (PEPC and RubisCO)

While describing major trends of carbon metabolism during the initiation and expression of somatic embryogenesis in date palm (Phoenix dactylifera L., cv. Deglet Nour), we have investigated the role of two carboxylases, namely PEPC (Phosphoenolpyruvate carboxylase, EC 4.1.1.31) and RubisCO (Ribulose 1,5-bisphosphate carboxylase/oxygenase, EC 4.1.1.39), in embryogenic and non-embryogenic cultures. The detection of PEPC activity on polyacrylamide native gels after electrophoresis revealed the presence of 3 active isoforms in crude extracts from the embryogenic (E) callus strain, whereas only a single band was present in the non-embryogenic (NE) one. The level of PEPC specific capacity was of the same order (3.9 ± 1.2 μmol CO₂ h⁻¹ mg⁻¹ TSP) in both types of cultures. Further changes in carboxylase (PEPC and RubisCO) activities during the growth and development of somatic embryo–derived plantlets were also analysed. The PEPC/RubisCO ratio was found to progressively decrease (from 17.7 to 0.2) throughout the in vitro development of plantlets, due to a substantial depletion of PEPC activity, which decreased from 5.3 to 1.2 μmol CO₂ h⁻¹ mg⁻¹ TSP. Concomitantly, RubisCO assumed greater importance (from 0.3 to 5.3 μmol CO₂ h⁻¹ mg⁻¹ _TSP ) and became the main route for inorganic carbon fixation. Western blot analysis using polyclonal antibodies raised against PEPC and RubisCO purified from tobacco leaves confirmed this trend in terms of relative enzyme abundance. This revised version was published online in June 2006 with corrections to the Cover Date.     

Modulation of cell surface GABA(B) receptors by desensitization, trafficking and regulated degradation

Inhibitory neurotransmission ensures normal brain function by counteracting and integrating excitatory activity.-Aminobutyric acid (GABA) is the main inhibitory neurotransmitter in the mammalian central nervous system,and mediates its effects via two classes of receptors:the GABA A and GABA B receptors.GABA A receptors are heteropentameric GABA-gated chloride channels and responsible for fast inhibitory neurotransmission.GABA B receptors are heterodimeric G protein coupled receptors (GPCR) that mediate slow and prolonged inhibitory transmission.The extent of inhibitory neurotransmission is determined by a variety of factors,such as the degree of transmitter release and changes in receptor activity by posttranslational modifications (e.g.,phosphorylation),as well as by the number of receptors present in the plasma membrane available for signal transduction.The level of GABA B receptors at the cell surface critically depends on the residence time at the cell surface and finally the rates of endocytosis and degradation.In this review we focus primarily on recent advances in the understanding of trafficking mechanisms that determine the expression level of GABA B receptors in the plasma membrane,and thereby signaling strength.     

Future of an "Asymptomatic" T-cell Epitope-Based Therapeutic Herpes Simplex Vaccine

Considering the limited success of the recent herpes clinical vaccine trial [1], new vaccine strategies are needed. Infections with herpes simplex virus type 1 and type 2 (HSV-1 & HSV-2) in the majority of men and women are usually asymptomatic and results in lifelong viral latency in neurons of sensory ganglia (SG). However, in a minority of men and women HSV spontaneous reactivation can cause recurrent disease (i.e., symptomatic individuals). Our recent findings show that T cells from symptomatic and asymptomatic men and women (i.e. those with and without recurrences, respectively) recognize different herpes epitopes. This finding breaks new ground and opens new doors to assess a new vaccine strategy: mucosal immunization with HSV-1 & HSV-2 epitopes that induce strong in vitro CD4 and CD8 T cell responses from PBMC derived from asymptomatic men and women (designated here as "asymptomatic" protective epitopes") could boost local and systemic "natural" protective immunity, induced by wild-type infection. Here we highlight the rationale and the future of our emerging "asymptomatic" T cell epitope-based mucosal vaccine strategy to decrease recurrent herpetic disease.     

TMKP1 is a novel wheat stress responsive MAP kinase phosphatase localized in the nucleus

The regulation of plant signalling responses by Mitogen-Activated Protein Kinases (MAPKs)-mediated protein phosphorylation is well recognized. MAP kinase phosphatases (MKPs) are negative regulators of MAPKs in eukaryotes. We report here the identification and the characterization of TMKP1, the first wheat MKP (Triticum turgidum L. subsp. Durum). Expression profile analyses performed in two durum wheat cultivars showing a marked difference in salt and drought stress tolerance, revealed a differential regulation of TMKP1. Under salt and osmotic stress, TMKP1 is induced in the sensitive wheat variety and repressed in the tolerant one. A recombinant TMKP1 was shown to be an active phosphatase and capable to interact specifically with two wheat MAPKs (TMPK3 and TMPK6). In BY2 tobacco cells transiently expressing GFP::TMKP1, the fusion protein was localized into the nucleus. Interestingly, the deletion of the N-terminal non catalytic domain results in a strong accumulation of the truncated fusion protein in the cytoplasm. In addition, when expressed in BY2 cells, TMPK3 and TMPK6 fused to red fluorescent protein (RFP) were shown to be present predominantly in the nucleus. Surprisingly, when co-expressed with the N-terminal truncated TMKP1 fusion protein; both kinases are excluded from the nuclear compartment and accumulate in the cytoplasm. This strongly suggests that TMKP1 interacts in vivo with TMPK3 and TMPK6 and controls their subcellular localization. Taken together, our results show that the newly isolated wheat MKP might play an active role in modulating the plant cell responses to salt and osmotic stress responses.     

Improvement of nutritional quality of cultured sobaity sea bream,Sparidentex hasta (Valenciennes) muscle by preharvest feeding of finisher feeds

A 6‐month long study was conducted to improve the nutritional quality of the cultured sobaity bream, Sparidentex hasta by feeding them finisher feeds containing high docosahexaenoic acid (DHA) at the last two months of the grow‐out stage so that the muscle DHA level be increased at par to the wild. A grow‐out feed used from the beginning until the end of the trial was considered as the control (Diet 1). Experimental diets 2 and 3 were formulated to contain 9.0% DHA (e.g. 1.68 g DHA/100 g feed) and 10.5% DHA (2.20 g DHA/100 g feed), by incorporating high DHA tuna oil into a sea bream grow‐out diet. For comparison, a commercial finisher feed (Diet 4) from Skretting, Italy was also used. The results of this study demonstrated that fish fed DHA enriched finisher diets resulted in significantly (p < .05) better growth, feed utilization and higher muscle eicosapentaenoic acid (EPA) and DHA content compared to those fed grow‐out diet. The muscle DHA and EPA of fish fed finisher diets were also higher than those of the whole year average DHA and EPA content of wild sobaity. An organoleptic evaluation showed no significant (p > .05) differences between sensory attributes of muscle from cultured and wild sea bream. The results of the study demonstrated that feeding finisher feed enriched with DHA at the later part of the grow‐out operation, the n‐3 PUFA levels of cultured sobaity can cost‐effectively be increased at par to the wild.     

Morphology,ontogeny and molecular phylogeny of a new brackish water ciliate Bakuella subtropica sp. n. (Ciliophora,Hypotricha) from southern China

This paper investigates the morphology, ontogenesis and small subunit (SSU) rRNA gene-based phylogeny of a new urostylid ciliate, Bakuella subtropica sp. n., discovered from the estuary of the Pearl River in Guangzhou, southern China. The new species is diagnosed by its elongate body, one buccal and one parabuccal cirrus, midventral complex comprised of 9–23 midventral pairs and one or two midventral rows extending to four fifths of body length, yellow-brown to yellow-greenish cortical granules and an estuary habitat. Its main ontogenetic features are: (1) in the proter, the parental adoral zone of membranelles is completely renewed by new structures and old midventral pairs join the formation of frontal-midventral-transverse cirral anlagen (FVT-anlagen); (2) in the opisthe, the oral primordium originates apokinetally, FVT-anlagen are formed besides and some old midventral cirri join the formation; (3) the anlagen for marginal rows and dorsal kineties develop intrakinetally; and (4) the numerous macronuclear nodules fuse into a single mass before dividing. Based on the SSU rDNA sequences, phylogenetic analyses show a close relationship between Bakuella subtropica sp. n., Apobakuella and Neobakuella, forming a clade separated from the other genera in the family Bakuellidae. Available morphological and ontogenetic data challenge the monophyly of Bakuellidae.     

Effect of sub-inhibitory concentration of chlorhexidine on lipid and sterol composition of shape Candida albicans

The effect of a sub-inhibitory concentration of chlorhexidine on lipid and sterol composition of Candida albicans was investigated. The total lipid content of this yeast grown in the presence of chlorhexidine was reduced whilst the total sterol content was increased compared with control-grown cells. Lipids and sterol analyses of this yeast grown in the presence and absence of chlorhexidine are presented. Chlorhexidine-grown yeast had a higher level of phosphatidylethanolamine, phosphatidylcholine and monogalactosyldiacylglycerol. Lower proportions of phosphatidylinositol plus phosphatidylserine, phosphatidic acid and cardiolipin were found in C. albicans grown in the presence of the drug when compared with control-grown yeast. The major fatty acids in control-grown cells were C16 and C18. Drug grown-cells had higher proportions of palmitic acid (16 : 0) and stearic acid (18 : 0), but lower proportions of palmitoleic acid (16 : 1) and oleic acid (18 : 1). Chlorhexidine also decreased the unsaturated-to-saturated fatty acid ratio, while the C16/C18 ratios increased compared to control-grown cells. Differences in the fatty acid composition of major phospholipids and neutral lipids between drug and control-grown yeast were also detected. Sterol analysis of control-grown cells showed that the major sterol present was ergosterol (55.4% wt). A significant increase in ergosterol and obtusifoliol was observed in chlorhexidine-treated cells and a significant decrease in squalene and lanosterol. Our results suggested that chlorhexidine affected the lipid and sterol composition of C. albicans. This revised version was published online in August 2006 with corrections to the Cover Date.     

Amphiphilic and Nonamphiphilic Forms of Torpedo Cholinesterases: I. Solubility and Aggregation Properties

We report an analysis of the solubility and hydrophobic properties of the globular forms of acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) from various Torpedo tissues. We distinguish globular nonamphiphilic forms (Gna) from globular amphiphilic forms (Ga). The Ga forms bind micelles of detergent, as indicated by the following properties. They are converted by mild proteolysis into nonamphiphilic derivatives. Their Stokes radius in the presence of Triton X-100 is approximately 2 nm greater than that of their lytic derivatives. The G2a forms fall in two classes. Class I contains molecules that aggregate in the absence of detergent, when mixed with an AChE-depleted Triton X-100 extract from electric organ. AChE G2a forms from electric organs, nerves, skeletal muscle, and erythrocyte membranes correspond to this type, which is also detectable in detergent-soluble (DS) extracts of electric lobes and spinal cord. Class II forms never aggregate but only present a slight shift in sedimentation coefficient, in the presence or absence of detergent. This class contains the AChE G2a forms of plasma and of the low-salt-soluble (LSS) fractions from spinal cord and electric lobes. The heart possesses a BuChE G2a form of class II in LSS extracts, as well as a similar G1a form. G4a forms of AChE, which are solubilized only in the presence of detergent and aggregate in the absence of detergent, represent a large proportion of cholinesterase in DS extracts of nerves and spinal cord, together with a smaller component of G4a BuChE. These forms may be converted to nonamphiphilic derivatives by Pronase. Nonaggregating G4a forms exist at low levels in the plasma (BuChE) and in LSS extracts of nerves (BuChE) and spinal cord (AChE).     

Molecular dynamics simulation studies for DNA sequence recognition by reactive metabolites of anticancer compounds

The discovery of novel anticancer molecules 5F‐203 (NSC703786) and 5‐aminoflavone (5‐AMF, NSC686288) has addressed the issues of toxicity and reduced efficacy by targeting over expressed Cytochrome P450 1A1 (CYP1A1) in cancer cells. CYP1A1 metabolizes these compounds into their reactive metabolites, which are proven to mediate their anticancer effect through DNA adduct formation. However, the drug metabolite–DNA binding has not been explored so far. Hence, understanding the binding characteristics and molecular recognition for drug metabolites with DNA is of practical and fundamental interest. The present study is aimed to model binding preference shown by reactive metabolites of 5F‐203 and 5‐AMF with DNA in forming DNA adducts. To perform this, three different DNA crystal structures covering sequence diversity were selected, and 12 DNA‐reactive metabolite complexes were generated. Molecular dynamics simulations for all complexes were performed using AMBER 11 software after development of protocol for DNA‐reactive metabolite system. Furthermore, the MM‐PBSA/GBSA energy calculation, per‐nucleotide energy decomposition, and Molecular Electrostatic Surface Potential analysis were performed. The results obtained from present study clearly indicate that minor groove in DNA is preferable for binding of reactive metabolites of anticancer compounds. The binding preferences shown by reactive metabolites were also governed by specific nucleotide sequence and distribution of electrostatic charges in major and minor groove of DNA structure. Overall, our study provides useful insights into the initial step of mechanism of reactive metabolite binding to the DNA and the guidelines for designing of sequence specific DNA interacting anticancer agents. Copyright © 2014 John Wiley & Sons, Ltd.