Stem cell factor is localized in, released from, and cleaved by human mast cells.

Stem cell factor (SCF) is the most important cytokine regulating human mast cell growth and functions. The immunogold technique showed SCF in the secretory granules of skin mast cells and in lung parenchymal mast cells (HLMC). Immunoreactive SCF (iSCF) was detected in cell lysates of HLMC, but not in basophils; iSCF and histamine were detected in supernatants of HLMC 3 min after challenge with anti-FcepsilonRI or anti-IgE, and iSCF in supernatants rapidly declined after 30 min, whereas histamine remained unchanged for 120 min. HPLC and electrospray mass spectrometry (ES/MS) analysis of recombinant human SCF1-166 (18,656. 9 +/- 0.9 Da) treated with chymase showed a polypeptide of 17,977.1 +/- 0.6 Da and a minor component of 697.4 +/- 0.1 Da generated by specific cleavage at Phe159. SCF1-166 and SCF1-159 similarly activated HLMC, potentiated anti-IgE-induced activation of these cells, and stimulated HLMC chemotaxis. SCF159-166 had no effect on mast cells. Western blot analysis of supernatants of anti-IgE-activated HLMC incubated with recombinant human SCF1-166 showed that SCF1-166 was rapidly cleaved to SCF1-159 and SCF1-144. Experiments with supernatants of anti-IgE-activated HLMC incubated with SCF1-166 yielded similar results. In conclusion, SCF is stored in mast cell secretory granules and is immunologically released by human mast cells. SCF1-166 is rapidly and specifically cleaved to SCF1-159 by chymase, which retains its biological effect on mast cells. SCF is also cleaved by other proteases to several SCF species whose possible biological activities remain to be established.     

Long- and short-term phosphate deprivation in bean roots: plasma membrane lipid alterations and transient stimulation of phospholipases

In a long-term experiment bean (Phaseolus vulgaris L.) seedlings were grown for 18 days in hydroponics in either phosphate-sufficient (+P) or phosphate-deficient (-P) nutrient solutions. Phosphate deprivation halved the phosphorous content of roots. In plasma membrane (PM) fractions isolated from -P roots the phospholipid (PL) level was reduced from 35 to 21 mol%, while PL composition and degree of unsaturation were hardly altered. Digalactosyldiacylglycerol (DGDG) accumulated up to 26% of total PM lipids, replacing PL to a large extent. Molecular species and fatty acid compositions of DGDG in root PM were different compared to DGDG present in the -P plastids. In a short-term study, bean seedlings were grown for 18 days in hydroponics with a complete nutrient solution containing phosphate and then incubated in a -P medium for increasing time ranging from 1 up to 96 h. At the end of the starvation period phosphorous content of -P roots was reduced by 30% compared to +P ones. An activation of phospholipase D and phospholipase C was observed after 1 and 2h of phosphate deprivation, respectively. Maximal phosphatidic acid accumulation was detected after 4h of phosphate deprivation, when also DGDG started to accumulate in PM of bean roots. The fatty acid composition of PLD-derived phosphatidylbutanol resembled that of phosphatidylcholine.     

3-[6-(2-Dimethylamino-1-imidazol-1-yl-butyl)-naphthalen-2-yloxy]-2,2-dimethyl-propionic acid as a highly potent and selective retinoic acid metabolic blocking agent

3-[6-(2-Dimethylamino-1-imidazol-1-yl-butyl)-naphthalen-2-yloxy]-2,2-dimethyl-propionic acid and analogs were designed and synthesized as highly potent and selective CYP26 inhibitors, serving as retinoic acid metabolic blocking agents (RAMBAs), with demonstrated in vivo efficacy to increase the half-life of exogenous atRA.     

Genetic variation and population structure of two species of neo-tropical mud-mussels (Mytella spp)

Mytella guyanensis Lamarck (1819) and Mytella charruana d'Orbigny (1846) are widespread euryhaline bivalves that have become commercially important in Brazil. Despite their importance, however, no genetic information that would be useful to orient governmental policies is available for these species. We analyzed, through allozyme electrophoresis, populations of M. guyanensis and M. charruana along 3,500 km of Brazilian coast. Pairwise comparisons among gene frequencies in M. guyanensis resulted in high levels of pairwise gene identity (I = 0.976 to 0.998). Conversely, significant levels of population structure were found in both M. guyanensis (FST = 0.089) and M. charruana (FST = 0.102). Heterozygosity levels for both species were high (H(e) = 0.090 to 0.134 in M. guyanensis and H(e) = 0.191 to 0.228 in M. charruana). The larger population size of M. charruana could explain, at least partially, the higher levels of genetic variability for this species. These levels of genetic variability yield an effective population size estimate of about 300,000 for M. guyanensis, and 540,000 for M. charruana, based on neutralist expectations. Remarkably, these numbers are much smaller than the estimated actual population sizes. This distortion might be explained by unstable population sizes and it suggests that long-term genetic variability studies are crucial to prevent artifactual viability analysis data for these commercially exploited species.     

Cell death evaluation in benzo[a]pyrene-transformed human breast epithelial cells after microcell-mediated transfer of chromosomes 11 and 17

The incidence of apoptosis and nuclear instability, including the incidence of catastrophic death, were investigated in benzo[a]pyrene (BP)-transformed human breast epithelial cells (BP1-E cell line) after microcell-mediated transfer of chromosomes 11 and 17. Since the introduction of normal chromosomes 11 and 17 into tumorigenic human breast BP1-E cells reverts some of these cells' characteristics (especially those affected by microsatellite instabilities and loss of heterozygosity) to those of parental non-transformed MCF-10F cells, it was expected that the cell death rates would also be affected by this treatment. The transfer of the mentioned chromosomes, especially chromosome 17, to tumorigenic BP1-E cells increased the apoptotic ratios and decreased the nuclear instability ratios, thus showing that the microsatellite instability and loss of heterozygosity induced by BP in these chromosomes of MCF-10F cells affect the control of cell death mechanisms.     

Emerging Insights into Noncanonical Inflammasome Recognition of Microbes

Inflammasomes are cytosolic multi-molecular complexes that sense intracellular microbial danger signals and metabolic perturbations. Inflammasome activation leads to the activation of caspase-1 and the release of pro-inflammatory cytokines IL-1β and IL-18 accompanied by cell death. An inflammasome-based surveillance machinery for Gram-negative bacterial infections has been recently discovered. This noncanonical inflammasome relies on sensing the cytosolic presence of lipopolysaccharide of Gram-negative bacteria via inflammatory caspases such as caspase-4, -5, and -11. This review discusses the recent findings related to the mechanism of activation of the noncanonical inflammasome and its biological functions.     

Targeting autophagy as a novel strategy for facilitating the therapeutic action of potentiators on ΔF508 cystic fibrosis transmembrane conductance regulator

Channel activators (potentiators) of cystic fibrosis (CF) transmembrane conductance regulator (CFTR), can be used for the treatment of the small subset of CF patients that carry plasma membrane-resident CFTR mutants. However, approximately 90% of CF patients carry the misfolded ΔF508-CFTR and are poorly responsive to potentiators, because ΔF508-CFTR is intrinsically unstable at the plasma membrane (PM) even if rescued by pharmacological correctors. We have demonstrated that human and mouse CF airways are autophagy deficient due to functional sequestration of BECN1 and that the tissue transglutaminase-2 inhibitor, cystamine, or antioxidants restore BECN1-dependent autophagy and reduce SQSTM1/p62 levels, thus favoring ΔF508-CFTR trafficking to the epithelial surface. Here, we investigated whether these treatments could facilitate the beneficial action of potentiators on ΔF508-CFTR homozygous airways. Cystamine or the superoxide dismutase (SOD)/catalase-mimetic EUK-134 stabilized ΔF508-CFTR at the plasma membrane of airway epithelial cells and sustained the expression of CFTR at the epithelial surface well beyond drug withdrawal, overexpressing BECN1 and depleting SQSTM1. This facilitates the beneficial action of potentiators in controlling inflammation in ex vivo ΔF508-CFTR homozygous human nasal biopsies and in vivo in mouse ΔF508-CFTR lungs. Direct depletion of Sqstm1 by shRNAs in vivo in ΔF508-CFTR mice synergized with potentiators in sustaining surface CFTR expression and suppressing inflammation. Cystamine pre-treatment restored ΔF508-CFTR response to the CFTR potentiators genistein, Vrx-532 or Vrx-770 in freshly isolated brushed nasal epithelial cells from ΔF508-CFTR homozygous patients. These findings delineate a novel therapeutic strategy for the treatment of CF patients with the ΔF508-CFTR mutation in which patients are first treated with cystamine and subsequently pulsed with CFTR potentiators.     

Miocene ostracodes of cold seep settings from northern Apennines (Italy)

The Miocene Termina Formation of the northern Apennines (Italy) contains thin marly limestone or marly sandstone bodies rich in macrofauna mainly consisting of large lucinid clams. Modern representatives of this fauna occur in cold seep settings where they house chemosymbiotic bacteria. Moreover, these rocks record a δ¹³C-depletion confirming their origin influenced by a cold seep. The Miocene sections of Sasso delle Streghe and Sarsetta (near Modena) represent classic examples of cold seeps. These sections consist of marls and marly sandstones, respectively, with lucinids (Sasso delle Streghe) or bioclastic sands with lucinids (Sarsetta); both sections are capped by the Sandstones of Montebaranzone. They yield ostracodes that are mainly represented by deep-water filter-feeder species (Platycopa, i.e. Cytherella sp.) and numerous deposit-feeders (Podocopa: i.e. Neonesidea and Krithe), together with species frequently occurring in shallow water environments. These assemblages are able to colonize disaerobic environments such as cold seeps. Although some authors consider the filter-feeders as dominant taxa in disaerobic settings, our data do not provide evidence of significant differences in the ostracode assemblage composition between the deposits originated in seafloors with or without seepage influence. However, the number of specimens is greater in seafloors devoid of seepage influence.     

An African bat in Europe,Plecotus gaisleri: Biogeographic and ecological insights from molecular taxonomy and Species Distribution Models

Because of the high risk of going unnoticed, cryptic species represent a major challenge to biodiversity assessments, and this is particularly true for taxa that include many such species, for example, bats. Long‐eared bats from the genus Plecotus comprise numerous cryptic species occurring in the Mediterranean Region and present complex phylogenetic relationships and often unclear distributions, particularly at the edge of their known ranges and on islands. Here, we combine Species Distribution Models (SDMs), field surveys and molecular analyses to shed light on the presence of a cryptic long‐eared bat species from North Africa, Plecotus gaisleri, on the islands of the Sicily Channel, providing strong evidence that this species also occurs in Europe, at least on the islands of the Western Mediterranean Sea that act as a crossroad between the Old Continent and Africa. Species Distribution Models built using African records of P. gaisleri and projected to the Sicily Channel Islands showed that all these islands are potentially suitable for the species. Molecular identification of Plecotus captured on Pantelleria, and recent data from Malta and Gozo, confirmed the species' presence on two of the islands in question. Besides confirming that P. gaisleri occurs on Pantelleria, haplotype network reconstructions highlighted moderate structuring between insular and continental populations of this species. Our results remark the role of Italy as a bat diversity hotspot in the Mediterranean and also highlight the need to include P. gaisleri in European faunal checklists and conservation directives, confirming the usefulness of combining different approaches to explore the presence of cryptic species outside their known ranges—a fundamental step to informing conservation.