Disturbances in purinergic [Ca2+]i signaling pathways in a transformed rat thyroid cell line

It was previously shown that in rat thyroid PC-Cl3 cell line, a purinergic P2Y receptor increases the concentration of free cytosolic Ca(2+) ([Ca(2+)](i)) via phospholipase C activation. We here studied whether in a transformed cell line (PC-E1Araf) derived from parental PC-Cl3 cells, ATP is still able to transduce the [Ca(2+)](i)-based intracellular signal.We demonstrate the expression of mRNA for P2Y2 in both PC-Cl3 and PC-E1Araf cells; mRNAs for P2Y1, P2Y4, P2Y6 and P2Y11 were absent. In both cell lines activation of P2Y2 receptor provokes a transient increase in [Ca(2+)](i) followed by a lower sustained phase persisting for over 5min in PC-Cl3 and only 1.5 min in PC-E1Araf cells. In both cell lines the [Ca(2+)](i) reached a plateau level significantly higher than the basal [Ca(2+)](i) level persisting for over 10 min. Removal of extracellular Ca(2+) reduced the initial transient response to ATP in PC-Cl3, but not in PC-E1Araf cells, and completely abolished the plateau phase in both cell lines.In the presence of extracellular Ca(2+) thapsigargin (TG) caused a rise in [Ca(2+)](i) significantly higher in PC-Cl3 than transformed PC-E1Araf cells, while in Ca(2+)-free medium the effect of TG was similar in both cell lines. The capacitative Ca(2+)-entry in PC-Cl3 resulted significantly higher than in PC-E1Araf cells.Further studies were performed in order to investigate whether the different effects of ATP on [Ca(2+)](i) was due to variation in divalent cation plasma membrane permeability. PC-E1Araf cells showed a much lower permeability to Ca(2+), Ba(2+), Sr(2+), Mn(2+), and Co(2+) that may be responsible for the differences in purinergic Ca(2+) signaling pathway with respect to parental PC-Cl3 cells.     

Interactions of Cultures and Top People of Wikipedia from Ranking of 24 Language Editions

Wikipedia is a huge global repository of human knowledge that can be leveraged to investigate interwinements between cultures. With this aim, we apply methods of Markov chains and Google matrix for the analysis of the hyperlink networks of 24 Wikipedia language editions, and rank all their articles by PageRank, 2DRank and CheiRank algorithms. Using automatic extraction of people names, we obtain the top 100 historical figures, for each edition and for each algorithm. We investigate their spatial, temporal, and gender distributions in dependence of their cultural origins. Our study demonstrates not only the existence of skewness with local figures, mainly recognized only in their own cultures, but also the existence of global historical figures appearing in a large number of editions. By determining the birth time and place of these persons, we perform an analysis of the evolution of such figures through 35 centuries of human history for each language, thus recovering interactions and entanglement of cultures over time. We also obtain the distributions of historical figures over world countries, highlighting geographical aspects of cross-cultural links. Considering historical figures who appear in multiple editions as interactions between cultures, we construct a network of cultures and identify the most influential cultures according to this network.     

Beneficial Bacteria Isolated from Grapevine Inner Tissues Shape Arabidopsis thaliana Roots

We investigated the potential plant growth-promoting traits of 377 culturable endophytic bacteria, isolated from Vitis vinifera cv. Glera, as good biofertilizer candidates in vineyard management. Endophyte ability in promoting plant growth was assessed in vitro by testing ammonia production, phosphate solubilization, indole-3-acetic acid (IAA) and IAA-like molecule biosynthesis, siderophore and lytic enzyme secretion. Many of the isolates were able to mobilize phosphate (33%), release ammonium (39%), secrete siderophores (38%) and a limited part of them synthetized IAA and IAA-like molecules (5%). Effects of each of the 377 grapevine beneficial bacteria on Arabidopsis thaliana root development were also analyzed to discern plant growth-promoting abilities (PGP) of the different strains, that often exhibit more than one PGP trait. A supervised model-based clustering analysis highlighted six different classes of PGP effects on root architecture. A. thaliana DR5::GUS plantlets, inoculated with IAA-producing endophytes, resulted in altered root growth and enhanced auxin response. Overall, the results indicate that the Glera PGP endospheric culturable microbiome could contribute, by structural root changes, to obtain water and nutrients increasing plant adaptation and survival. From the complete cultivable collection, twelve promising endophytes mainly belonging to the Bacillus but also to Micrococcus and Pantoea genera, were selected for further investigations in the grapevine host plants towards future application in sustainable management of vineyards.     

Antibiotic resistance in long-term care facilities

Long-term-care facilities (LTCFs) comprise a heterogeneous group of institutions that provide a wide variety of services to diverse groups of patients, most of whom are elderly. Infections are common in LTCFs and these are complicated by antimicrobial-resistant pathogens. The residents in LTCFs have a high frequency of colonization with antimicrobial-resistant organisms, including methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci, penicillin-resistant pneumococci, extended spectrum P-lactamase-producing gram-negative organisms, and fluoroquinolone-resistant gram-negative organisms. Although several control programs have been published, up to now there still is a long way to go in this area of health care. This review will briefly touch upon the clinical relevance of antimicrobial resistance in LTCFs.     

Metabolic phenotyping of the Crohn's disease-like IBD etiopathology in the TNF(ΔARE/WT) mouse model

The underlying biochemical consequences of inflammatory bowel disease (IBD) on the systemic and gastrointestinal metabolism have not yet been fully elucidated but could help to better understand the disease pathogenesis and to identify tissue-specific markers associated with the different disease stages. Here, we applied a metabonomic approach to monitor metabolic events associated with the gradual development of Crohn's disease (CD)-like ileitis in the TNF(ΔARE/WT) mouse model. Metabolic profiles of different intestinal compartments from the age of 4 up to 24 weeks were generated by combining proton nuclear magnetic resonance ((1)H NMR) spectroscopy and liquid chromatography-mass spectrometry (LC-MS). From 8 weeks onward, mice developed CD similar to the immune and tissue-related phenotype of human CD with ileal involvement, including ileal histological abnormalities, reduced fat mass and body weight, as well as hallmarks of malabsorption with higher energy wasting. The metabonomic approach highlighted shifts in the intestinal lipid metabolism concomitant to the histological onset of inflammation. Moreover, the advanced disease status was characterized by a significantly altered metabolism of cholesterol, triglycerides, phospholipids, plasmalogens, and sphingomyelins in the inflamed tissue (ileum) and the adjacent intestinal parts (proximal colon). These results describe different biological processes associated with the disease onset, including modifications of the general cell membrane composition, alteration of energy homeostasis, and finally the generation of inflammatory lipid mediators. Taken together, this provides novel insights into IBD-related alterations of specific lipid-dependant processes during inflammatory states.     

Experimental demonstration that mammalian oocytes are not selective towards X- or Y-bearing sperm

Mammalian oocytes are thought to be neutral as for X- or Y-bearing sperm selection is concerned, and penetration of an oocyte by an X- or a Y-bearing sperm is considered a random event. This assumption is mainly based on a posteriori evidences of a nearly equal sex ratio at birth, but it has never been experimentally demonstrated. We have designed a simple experiment, which allowed the penetration of an oocyte by more than one sperm and the further sexing by PCR of each single pronucleus present within the ooplasm. For the first time, we provide experimental evidence that mammalian oocytes do not play a selecting role since a single oocyte may be simultaneously fertilised by both X- and Y-bearing sperm.     

Adaptor protein ARH is recruited to the plasma membrane by low density lipoprotein (LDL) binding and modulates endocytosis of the LDL/LDL receptor complex in hepatocytes

ARH is a newly discovered adaptor protein required for the efficient activity of low density lipoprotein receptor (LDLR) in selected tissues. Individuals lacking ARH have severe hypercholesterolemia due to an impaired hepatic clearance of LDL. It has been demonstrated that ARH is required for the efficient internalization of the LDL-LDLR complex and to stabilize the association of the receptor with LDL in Epstein-Barr virus-immortalized B lymphocytes. However, little information is available on the role of ARH in liver cells. Here we provide evidence that ARH is codistributed with LDLR on the basolateral area in confluent HepG2-polarized cells. This distribution is not modified by the overexpression of LDLR. Conversely, the activation of the LDLR-mediated endocytosis, but not the binding of LDL to LDLR, promotes a significant colocalization of ARH with LDL-LDLR complex that peaked at 2 min at 37 degrees C. To further assess the role of ARH in LDL-LDLR complex internalization, we depleted ARH protein using the RNA interference technique. Twenty-four hours after transfection with ARH-specific RNA interference, ARH protein was depleted in HepG2 cells by more than 70%. Quantitative immunofluorescence analysis revealed that the depletion of ARH caused about 80% reduction in LDL internalization. Moreover, our findings indicate that ARH is associated with other proteins of the endocytic machinery. We suggest that ARH is an endocytic sorting adaptor that actively participates in the internalization of the LDL-LDLR complex, possibly enhancing the efficiency of its packaging into the endocytic vesicles.     

The dependence of leaf hydraulic conductance on irradiance during HPFM measurements: any role for stomatal response?

This paper examines the dependence of whole leaf hydraulic conductance to liquid water (K(L)) on irradiance when measured with a high pressure flowmeter (HPFM). During HPFM measurements, water is perfused into leaves faster than it evaporates hence water infiltrates leaf air spaces and must pass through stomates in the liquid state. Since stomates open and close under high versus low irradiance, respectively, the possibility exists that K(L) might change with irradiance if stomates close tightly enough to restrict water movement. However, the dependence of K(L) on irradiance could be due to a direct effect of irradiance on the hydraulic properties of other tissues in the leaf. In the present study, K(L) increased with irradiance for 6 of the 11 species tested. Whole leaf conductance to water vapour, g(L), was used as a proxy for stomatal aperture and the time-course of changes in K(L) and g(L) was studied during the transition from low to high irradiance and from high to low irradiance. Experiments showed that in some species K(L) changes were not paralleled by g(L) changes. Measurements were also done after perfusion of leaves with ABA which inhibited the g(L) response to irradiance. These leaves showed the same K(L) response to irradiance as control leaves. These experimental results and theoretical calculations suggest that the irradiance dependence of K(L) is more consistent with an effect on extravascular (and/or vascular) tissues rather than stomatal aperture. Irradiance-mediated stimulation of aquaporins or hydrogel effects in leaf tracheids may be involved.