Overcharging and reentrant condensation of thermoresponsive ionic microgels

We investigated the complexation of thermoresponsive anionic poly(N-isopropylacrylamide) (PNiPAM) microgels and cationic $\epsilon$-polylysine ($\epsilon$-PLL) chains. By combining electrophoresis, light scattering, transmission electron microscopy (TEM) and dielectric spectroscopy (DS) we studied the adsorption of $\epsilon$-PLL onto the microgel networks and its effect on the stability of the suspensions. We show that the volume phase transition (VPT) of the microgels triggers a large polyion adsorption. Two interesting phenomena with unique features occur: a temperature-dependent microgel overcharging and a complex reentrant condensation. The latter may occur at fixed polyion concentration, when temperature is raised above the VPT of microgels, or by increasing the number density of polycations at fixed temperature. TEM and DS measurements unambiguously show that short PLL chains adsorb onto microgels and act as electrostatic glue above the VPT. By performing thermal cycles, we further show that polyion-induced clustering is a quasi-reversible process: within the time of our experiments large clusters form above the VPT and partially re-dissolve as the mixtures are cooled down. Finally we give a proof that the observed phenomenology is purely electrostatic in nature: an increase of the ionic strength gives rise to the polyion desorption from the microgel outer shell.Comment: 15 Figure

Water quality evaluation in Mediterranean Lagoons using the Multimetric Phytoplankton Index (MPI): study cases from Sardinia

1 - Water quality in four Sardinian lagoons (western Mediterranean Sea) was assessed using the Multimetric Phytoplankton Index (MPI), which is consistent with the EU Water Framework Directive. The index was developed using data on phytoplankton abundances, species structure and chlorophyll a concentrations in Venice Lagoon, Italy. 2 - The aim of this study was to test the MPI on a larger geographical scale and across a range of lagoon types. Therefore, it was applied to assess water quality in the Cabras, S’Ena Arrubia, Santa Giusta and Calich lagoons in Sardinia. These lagoons are all “choked”, but exhibit a range of sizes and morphometric features. They are directly affected by human activity within the lagoons themselves, such as fisheries, aquaculture and the construction of dams and canals, and are indirectly affected by anthropogenic activities in their catchments, including intensive agriculture, industrial activity and urban development. 3 - The data used in the present study were collected monthly over a period of 4 years (Calich, Santa Giusta and S’Ena Arrubia) to 7 years (Cabras). Samples were collected at three stations at each of the Cabras, Santa Giusta and Calich lagoons, and at two stations at the S’Ena Arrubia Lagoon, providing a total of 220 samples. 4 - The water quality in three of the four lagoons investigated (Cabras, S’Ena Arrubia and Calich) was classified as bad using the MPI. Among these three, water in Cabras Lagoon exhibited the worst condition. Water quality in Santa Giusta Lagoon was classified as poor using the MPI. 5 - Although we present preliminary results that require further verification, the index appears to be a useful tool for assessing the ecological status of typical Mediterranean lagoons

Histone modifications underlie monocyte dysregulation in patients with systemic sclerosis, underlining the treatment potential of epigenetic targeting.

Background and objective S ystemic sclerosis (SSc) is a severe autoimmune disease, in which the pathogenesis is dependent on both genetic and epigenetic factors. Altered gene expression in SSc monocytes, particularly of interferon (IFN)-responsive genes, suggests their involvement in SSc development. We investigated the correlation between epigenetic histone marks and gene expression in SSc monocytes. Methods C hromatin immunoprecipitation followed by sequencing (ChIPseq) for histone marks H3K4me3 and H3K27ac was performed on monocytes of nine healthy controls and 14 patients with SSc. RNA sequencing was performed in parallel to identify aberrantly expressed genes and their correlation with the levels of H3K4me3 and H3K27ac located nearby their transcription start sites. ChIP-qPCR assays were used to verify the role of bromodomain proteins, H3K27ac and STATs on IFNresponsive gene expression. Results 1046 and 534 genomic loci showed aberrant H3K4me3 and H3K27ac marks, respectively, in SSc monocytes. The expression of 381 genes was directly and significantly proportional to the levels of such chromatin marks present near their transcription start site. Genes correlated to altered histone marks were enriched for immune, IFN and antiviral pathways and presented with recurrent binding sites for IRF and STAT transcription factors at their promoters. IFN\u3b1 induced the binding of STAT1 and STAT2 at the promoter of two of these genes, while blocking acetylation readers using the bromodomain BET family inhibitor JQ1 suppressed their expression. Conclusion SS c monocytes have altered chromatin marks correlating with their IFN signature. Enzymes modulating these reversible marks may provide interesting therapeutic targets to restore monocyte homeostasis to treat or even prevent SSc

Acromegaly is associated with increased cancer risk: A survey in Italy

It is debated if acromegalic patients have an increased risk to develop malignancies. The aim of the present study was to assess the standardized incidence ratios (SIRs) of different types of cancer in acromegaly on a large series of acromegalic patients managed in the somatostatin analogs era. It was evaluated the incidence of cancer in an Italian nationwide multicenter cohort study of 1512 acromegalic patients, 624 men and 888 women, mean age at diagnosis 45 \uc2\ub1 13 years, followed up for a mean of 10 years (12573 person-years) in respect to the general Italian population. Cancer was diagnosed in 124 patients, 72 women and 52 men. The SIRs for all cancers was significantly increased compared to the general Italian population (expected: 88, SIR 1.41; 95% CI, 1.18-1.68, P < 0.001). In the whole series, we found a significantly increased incidence of colorectal cancer (SIR 1.67; 95% CI, 1.07-2.58, P = 0.022), kidney cancer (SIR 2.87; 95% CI, 1.55-5.34, P < 0.001) and thyroid cancer (SIR 3.99; 95% CI, 2.32-6.87, P < 0.001). The exclusion of 11 cancers occurring before diagnosis of acromegaly (all in women) did not change remarkably the study outcome. In multivariate analysis, the factors significantly associated with an increased risk of malignancy were age and family history of cancer, with a non-significant trend for the estimated duration of acromegaly before diagnosis. In conclusion, we found evidence that acromegaly in Italy is associated with a moderate increase in cancer risk

Same place, different time, head up: multiple antipredator responses to a recolonizing apex predator

Prey adjust their antipredator behavioral tactics to minimize the risk of an encounter with predators. Spatio-temporal responses of prey to predators have been reported, but antipredator response is not ubiquitous, and it is the object of increasing interest, especially considering the recent recovery of large carnivores in Europe, and the potential for behavioral antipredator responses to elicit consequences at the ecosystem level. We have tested multiple antipredator responses by fallow deer Dama dama to wolf Canis lupus, in a Mediterranean protected area recently recolonized by this apex predator. Through intensive camera trapping, we tested for temporal and spatial association between predator and prey, and we have also studied deer vigilance in forest habitats where focal observations are usually impossible. Wolf detection rates were spatially associated with those of fallow deer. Accordingly, no evidence was found for fallow deer avoiding sites with higher predator detection rates. Temporal activity patterns were significantly different between the two species, with the wolf being mainly nocturnal whereas fallow deer was active especially during daylight. A comparison with a preliminary study strongly suggests an increase in diurnal activity of fallow deer along with the stabilization of wolf presence in the area. Both the rate and the duration of vigilance of female fallow deer increased with the local frequency of wolf activity. We suggest an antipredator response based on temporal – rather than spatial – avoidance, as well as increased vigilance

Valproic Acid Inhibits Proliferation and Reduces Invasiveness in Glioma Stem Cells Through Wnt/\u3b2 Catenin Signalling Activation

Glioblastoma is the most common malignant brain tumour in adults. The failure of current therapies can be ascribed to glioma stem cells (GSCs), which can rapidly repopulate the tumour following the initial treatment. The study of histone deacetylase inhibitors, such as valproic acid (VPA), is becoming an attractive field in cancer research. However, the exact mechanisms underlying its anti-cancer effect remain to be elucidated due to its pleiotropic effects on several cell-signalling pathways. Ingenuity Pathway Analysis (IPA) bioinformatics analysis was performed on genome-wide data regarding GSCs methylome to identify the signalling pathways mainly affected by methylation changes induced by VPA. Real time PCR and luciferase reporter assay were used to better investigate VPA effects on Wnt/\u3b2-catenin signalling pathway. VPA effect on GSC proliferation was evaluated by 3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide (MTT) and Trypan blue assays. Finally, VPA impact on GSC motility was demonstrated by Boyden chamber assay and further confirmed evaluating the expression levels or localisation, through western blot or immunofluorescence, of Twist1, Snail1, E-Cadherin and N-Cadherin. The bioinformatics analyses performed on GSCs methylome highlighted that Wnt/\u3b2-catenin signalling was affected by the methylation changes induced by VPA, which could influence its activation status. In particular, we pointed out a general activation of this pathway after VPA exposure, which was accompanied by an inhibitory potential on GSCs proliferation. Finally, we also proved VPA's ability to inhibit GSCs invasion through Snail1 and Twist1 downregulation and E-Cadherin relocalisation. VPA treatment may represent a new, interesting therapeutic approach to affect GSC proliferation and motility, but further investigations are certainly needed

Utilizzo del fitoplancton per la valutazione della qualità ambientale della Laguna di Cabras (Sardegna occidentale, Italia)

I dati di abbondanza e composizione fitoplanctonica e di clorofilla a della Laguna di Cabras (Sardegna occidentale), raccolti con cadenza da quindicinale a mensile dal 1999 al 2009 in tre stazioni collocate lungo un gradiente salino, sono stati utilizzati per valutare la qualità ambientale attraverso l’applicazione di un indice multimetrico sviluppato da FACCA et al. (2011). I risultati hanno indicato una condizione della laguna complessivamente scadente (poor), principalmente dovuta ad un importante arricchimento in nutrienti, e hanno inoltre evidenziato che non esistono significative differenze tra le stazioni considerate. The multimetric index developed by FACCA et al. (2011) was applied to valuate the ecological quality of the Cabras Lagoon (western Sardinia, Italy). The database was composed by data collected from 1999 to 2009, at intervals from fortnightly to monthly, on phytoplankton abundances and species composition, and chlorophyll a in three stations sited along a salinity gradient. The preliminary results showed an overall poor condition of the lagoon, mainly due to nutrient enrichment; moreover, no significant differences were noticed among stations

Identification of a STAT3-miRNA Axis in T-LGL Leukemia

Introduction T large granular lymphocytes leukemia (T-LGLL) is a rare disease characterized by the abnormal expansion of T-large granular lymphocytes (T-LGLs) in the peripheral blood. The etiology of this disease is still largely unknown. LGL proliferation is maintained through an impairment of the apoptotic machinery due to the activation of many survival signals. Among these, JAK/STAT signaling represents one of the most important deregulated pathways in T-LGLL. In particular, leukemic LGLs are equipped with STAT3 constitutively over-expressed and over-activated. Moreover, in 30-40% of patients, STAT3 has been demonstrated carrying hot-spot mutations, likely resulting in STAT3 activation. Although STAT3 is an inducer of transcription of a large number of oncogenes, its relationship with microRNAs (miRNAs) has not yet been extensively evaluated in T-LGLL patients. As a matter of fact, several miRNAs contribute to normal hematopoietic processes and many miRNAs act both as tumor suppressors and oncogenes in the pathology of hematological malignancies, including acute and chronic leukemias and lymphomas, where they contribute to lymphomagenesis acting in various cellular functions, such as the regulation of cell survival and proliferation. Aims We investigated whether STAT3 could carry out its pathogenetic role in T-LGLL through an altered expression of miRNAs. A high throughput quantitative and qualitative analysis of the miRNA expression profile in leukemic LGLs compared to healthy controls was performed with the aim to investigate whether STAT3 activation and/or mutation were correlated to some miRNAs in leukemic LGLs. Methods Six patients (3 characterized by STAT3 mutations and 3 with wild type STAT3) and three healthy controls were enrolled in a pilot study. STAT3 mRNA expression and protein activation levels were analyzed by Real Time-PCR and Western Blot, respectively. The expression level of 756 mature miRNAs was assessed by using a TaqMan-based Low Density Array on purified LGLs. Experimental data were analyzed by ViiA7 RUO software and the relative miRNA expression values were calculated using U6 as endogenous control. miRNA array data underwent hierarchical cluster analysis (HCL) by using MEV. miRNAs with a 2 or 0.5 fold change and p value < 0.05 in samples as compared to controls were considered as differentially expressed. Results of this pilot study were validated on additional 12 T-LGLL and 3 healthy controls subjects. Results Two clusters were identified by HCL analysis: cluster A included healthy controls and LGL patients characterized by comparably low levels of STAT3 activation (S3low) and absence of STAT3 mutations. Cluster B included four patients characterized by high levels of STAT3 activation (S3high). Remarkably, three out of four LGL patients in cluster B shared STAT3 mutation. Comparative analysis of the miRNAs expressed identified 33 miRNAs upregulated and 9 miRNAs downregulated in S3high as compared to S3low. Interestingly, the level of expression of these selected miRNAs correlated with the level of STAT3 expression/activation in LGL. Among these, three miRNAs, miR-484, miR-501 and miR-1249, have been validated and confirmed in the validation cohort. Conclusions These data firstly describe the miRNA pattern in T-LGLL, providing evidence that a series of miRNAs are correlated with relevant key factors in T-LGLL pathogenesis, including STAT3 activation/expression and mutations. Our results suggest the hypothesis that STAT3 could mediate its role through some defined miRNAs