Transport and signaling through the phosphate-binding site of the yeast Pho84 phosphate transceptor

A novel concept in eukaryotic signal transduction is the use of nutrient transporters and closely related proteins as nutrient sensors. The action mechanism of these “transceptors” is unclear. The Pho84 phosphate transceptor in yeast transports phosphate and mediates rapid phosphate activation of the protein kinase A (PKA) pathway during growth induction. We have now identified several phosphate-containing compounds that act as nontransported signaling agonists of Pho84. This indicates that signaling does not require complete transport of the substrate. For the nontransported agonist glycerol-3-phosphate (Gly3P), we show that it is transported by two other carriers, Git1 and Pho91, without triggering signaling. Gly3P is a competitive inhibitor of transport through Pho84, indicating direct interaction with its phosphate-binding site. We also identified phosphonoacetic acid as a competitive inhibitor of transport without agonist function for signaling. This indicates that binding of a compound into the phosphate-binding site of Pho84 is not enough to trigger signaling. Apparently, signaling requires a specific conformational change that may be part of, but does not require, the complete transport cycle. Using Substituted Cysteine Accessibility Method (SCAM) we identified Phe¹⁶⁰ in TMD IV and Val³⁹² in TMD VIII as residues exposed with their side chain into the phosphate-binding site of Pho84. Inhibition of both transport and signaling by covalent modification of Pho84^F160C or Pho84^V392C showed that the same binding site is used for transport of phosphate and for signaling with both phosphate and Gly3P. Our results provide to the best of our knowledge the first insight into the molecular mechanism of a phosphate transceptor.     

A combined histologic and molecular approach identifies three groups of gastric cancer with different prognosis

The limited prognostic value of currently used histologic classifications of gastric cancer and their failure to account for the complexity of the disease as revealed by more recent investigations prompted a combined reinvestigation of histologic, molecular, and clinicopathologic patterns in 294 extensively sampled, invasive gastric cancers representing all main histotypes and stages of the disease and followed for a median of 150 months. Among histologic parameters tested, only cellular atypia, angio-lympho- or neuroinvasion, Ki67 proliferation index, expansile/infiltrative type growth, and T8 cell-rich high lymphoid intra-/peritumor response (HLR) proved to be stage-independent predictors of patient survival. Among molecular tests, p53 gene exon 7 (loop 3) and 8 (loop-sheet-helix motif and S-10 band), but not p53 protein overexpression, TP53 LOH or 18qLOH, were found to worsen prognosis. Microsatellite DNA instability was a favorable prognostic factor when coupled with HLR. Patient survival analysis of the main histotypes and their subtypes confirmed the favorable prognosis of HLR, well-differentiated tubular, muconodular, and low grade diffuse desmoplastic cancers, and highlighted the worse prognosis of anaplastic and infiltrative-lymphoinvasive mucinous cancers compared to ordinary cohesive and diffuse cancers. Distinct roles of individual morphologic and molecular factors in tumor progression of the different histotypes have been recognized. The combination of survival-predictive histotypes and individual histologic or molecular parameters allowed us to develop a classification of all gastric cancers into three grades of increasing malignancy which proved to be of high prognostic value.     

Dissociation between time reproduction of actions and of intervals in patients with Parkinson’s disease

Alterations in temporal estimation have been observed in patients with Parkinson’s disease (PD) and have been associated to dopaminergic dysfunction. Nevertheless, levodopa treatment and deep brain stimulation of the subthalamic nucleus (DBS-STN) have been shown to improve motor deficits and temporal estimation skills in such patients. So far, temporal estimation tasks in PD patients have evaluated the ability to reproduce intervals of time, but never the duration of an action. Here we investigated: (1) the ability of PD patients to reproduce the duration of their previous actions as compared to their ability to reproduce intervals of time and (2) the effect that DBS-STN has on both skills. Nineteen PD patients with DBS-STN and 19 controls were requested to reproduce the duration of an action and that of an interval of time. The patients were tested in the following treatment conditions: on stimulation/off medication, off stimulation/off medication and off stimulation/on medication. The results demonstrated that patients in the off stimulation/off medication condition under-reproduced the duration of their actions while accurately reproducing the duration of time intervals. The accuracy of the performance improved significantly in both treatment regimens. Our results indicate that in PD patients the ability to reproduce motor acts can be dissociated from that of reproducing time intervals and that it can be improved by the administration of medical or surgical treatment.     

The tight relationship between papillary thyroid cancer,autoimmunity and inflammation: clinical and molecular studies

Objective The recent concept that oncogenes responsible for thyroid neoplastic transformation are able to elicit an inflammatory protumourigenic microenvironment raises interest in further studies on papillary thyroid cancer (PTC) associated with thyroid autoimmunity. Patients The clinical and molecular features, and the expression of inflammation‐related genes, were investigated in a large series of PTCs with and without associated thyroiditis (groups A, n = 128 and B, n = 215). Results The two groups did not show significant differences in clinical and prognostic features, whereas they harboured a significantly different genetic background (P = 0·001), with RET/PTC1 being more represented in PTCs associated with autoimmunity, and BRAF^V600E in patients with PTC alone. A RET/PTC rearrangement was also found in 41% of non‐neoplastic thyroiditis tissues, contralateral to tumours harbouring either RET/PTC or BRAF mutations. The expression of genes encoding CCL20, CXCL8 and l ‐selectin was significantly higher in PTC specimens (either with RET/PTC, BRAF^V600E or unknown genetic lesion) compared with normal thyroid samples. On the contrary, thyroiditis showed l ‐selectin expression levels even higher than PTCs, but CCL20 and CXCL8 levels comparable with normal tissues. Conclusions The present data extend the knowledge about the tight relationships among oncogenes, thyroiditis and thyroid cancer. A different genetic background among PTCs with and without associated autoimmunity has been firstly demonstrated. The strong association between RET/PTC1 and thyroiditis points to a critical role of this oncoprotein in the modulation of the autoimmune response. Moreover, preliminary expression studies, indicating enhanced expression of inflammatory molecules in PTCs, suggest a proinflammatory, nonautoimmune relationship between thyroiditis and thyroid cancer.     

Characterization of salivaricin CRL 1328, a two-peptide bacteriocin produced by Lactobacillus salivarius CRL 1328 isolated from the human vagina

Salivaricin CRL 1328 is a heat-stable bacteriocin produced by Lactobacillus salivarius CRL 1328, a strain isolated from healthy human vagina, with potential applications for preventing urogenital infections. The objective of this study was to characterize the locus responsible for salivaricin CRL 1328 production and its mechanism of action against Enterococcus faecalis MP97 as the sensitive strain. Oligonucleotides were designed based on sequences of antimicrobial peptides previously described in the literature. The salivaricin CRL 1328 cluster was identified, sequenced and analyzed. This cluster was similar to the previously described ABP118 which codified for a two-peptide bacteriocin. The putative mature peptides of salivaricin CRL 1328, Salα and Salβ were chemically synthesized. These peptides did not show bacteriocin activity when assayed individually. Both peptides exhibited optimal antimicrobial activity at an equimolar ratio. Spectroscopic fluorescence assays were carried out using the synthetic peptides to study the effect of salivaricin on proton motive force. This bacteriocin was shown to dissipate membrane potential and the transmembrane proton gradient, both components of proton motive force. E. faecalis MP97 cells treated with salivaricin CRL 1328 peptides were observed in transmission electron microscopy which revealed ultrastructural modifications of the cell wall.     

Reproductive Immunology: a Focus on the Role of Female Sex Hormones and Other Gender-Related Factors

Reproductive immunology has attracted the attention of researchers interested in fertility and pregnancy as well as those interested in immunity and autoimmunity. Over the past couple of decades, a wealth of data on the immune-reproductive interactions has been generated. This issue of the Journal will examine several topics including the role of immune factors in the induction of anti-Ro antibody-mediated autoimmunity in neonates and the immunological effects of gender and sex hormones. The possible implications of the research reviewed here for the development of novel therapeutic approaches are also addressed.     

Primeros 3 casos en España de gestación a término tras tratamiento de miomas mediante cirugía no invasiva MRgFUS

Magnetic resonance-guided focused ultrasound surgery (MRgFUS) is a non-invasive surgical technique based on thermal coagulative necrosis of tissue by focused ultrasound guided by magnetic resonance. This fairly recent technique was approved by the American Food and Drug Administration in 2004 and by the European Union in 2006 for the treatment of uterine fibroids. In 2010 MRgFUS was approved by the European Union (CE label) for the treatment of adenomyosis and is being developed for the non-invasive treatment of other tumoral diseases, mainly in oncology. We present the first three cases of pregnancy achieved at the Instituto Cartuja, the only site in Spain with MRgFUS technology. We conclude that MRgFUS is a safe, reliable and effective technique for the treatment of uterine fibroids, even in women with a desire to preserve fertility.