Caspase-activated ROCK-1 allows erythroblast terminal maturation independently of cytokine-induced Rho signaling

Stem cell factor (SCF) and erythropoietin are strictly required for preventing apoptosis and stimulating proliferation, allowing the differentiation of erythroid precursors from colony-forming unit-E to the polychromatophilic stage. In contrast, terminal maturation to generate reticulocytes occurs independently of cytokine signaling by a mechanism not fully understood. Terminal differentiation is characterized by a sequence of morphological changes including a progressive decrease in cell size, chromatin condensation in the nucleus and disappearance of organelles, which requires transient caspase activation. These events are followed by nucleus extrusion as a consequence of plasma membrane and cytoskeleton reorganization. Here, we show that in early step, SCF stimulates the Rho/ROCK pathway until the basophilic stage. Thereafter, ROCK-1 is activated independently of Rho signaling by caspase-3-mediated cleavage, allowing terminal maturation at least in part through phosphorylation of the light chain of myosin II. Therefore, in this differentiation system, final maturation occurs independently of SCF signaling through caspase-induced ROCK-1 kinase activation.     

Erythropoietin preserves the endothelial differentiation capacity of cardiac progenitor cells and reduces heart failure during anticancer therapies

Anticancer therapies, such as targeting of STAT3 or the use of anthracyclins (doxorubicin), can induce cardiomyopathy. In mice prone to developing heart failure as a result of reduced cardiac STAT3 expression (cardiomyocyte-restricted deficiency of STAT3) or treatment with doxorubicin, we observed impaired endothelial differentiation capacity of Sca-1(+) cardiac progenitor cells (CPCs) in conjunction with attenuated CCL2/CCR2 activation. Mice in both models also displayed reduced erythropoietin (EPO) levels in the cardiac microenvironment. EPO binds to CPCs and seems to be responsible for maintaining an active CCL2/CCR2 system. Supplementation with the EPO derivative CERA in a hematocrit-inactive low dose was sufficient to upregulate CCL2, restore endothelial differentiation of CPCs, and preserve the cardiac microvasculature and cardiac function in both mouse models. Thus, low-dose EPO treatment could potentially be exploited as a therapeutic strategy to reduce the risk of heart failure in certain treatment regimens.     

Population genetic structure of Tunisian <Emphasis Type="Italic">Hypericum humifusum</Emphasis> assessed by RAPD markers

The genetic variation within and among seven Tunisian natural Hypericum humifusum L. populations belonging to three bioclimatic zones (sub-humid, upper semi-arid, and lower semi-arid) was assessed using random amplified polymorphic DNA markers. Eight selected primers produced a total of 166 bands, of which 153 were polymorphic. The genetic diversity within a population, based on Shannon’s index and percentage of polymorphic loci, was relatively high. The level of variation among populations did not differ significantly. However, the variation among populations grouped according to their bioclimates was significant.     

Cerebral rheumatoid vasculitis: a case report

ABSTRACT: INTRODUCTION: Central nervous system involvement in rheumatoid arthritis is infrequent. The most frequent neurological manifestations of rheumatoid arthritis are peripheral neuropathy and cervical spinal cord compression due to subluxation of the cervical vertebrae. Cerebral rheumatoid vasculitis is an uncommon and serious complication which can be life-threatening. CASE PRESENTATION: A 52-year-old North African Tunisian Caucasian woman presented with a six-week history of headache. She had suffered seropositive and destructive rheumatoid arthritis for nine years without any extra-articular complications. Magnetic resonance imaging of the brain with the T2 sequence showed high-intensity signal images at the frontal and parietal corticosubcortical junction suggesting hemispheric vasculitis. CONCLUSIONS: Cerebral vasculitis is an infrequent complication in rheumatoid arthritis which is associated with high morbidity and in some cases can be life-threatening. Early assessment and a high index of suspicion to recognize such complications are essential in managing these patients.     

Application of municipal solid waste compost reduces the negative effects of saline water in Hordeum maritimum L

The efficiency of composted municipal solid wastes (MSW) to reduce the adverse effects of salinity was investigated in Hordeum maritimum under greenhouse conditions. Plants were cultivated in pots filled with soil added with 0 and 40tha(-1) of MSW compost, and irrigated twice a week with tap water at two salinities (0 and 4gl(-1) NaCl). Harvests were achieved at 70 (shoots) and 130 (shoots and roots) days after sowing. At each cutting, dry weight (DW), NPK nutrition, chlorophyll, leaf protein content, Rubisco (ribulose-bisphosphate carboxylase/oxygenase) capacity, and contents of potential toxic elements were determined. Results showed that compost supply increased significantly the biomass production of non salt-treated plants (+80%). This was associated with higher N and P uptake in both shoots (+61% and +80%, respectively) and roots (+48% and +25%, respectively), while lesser impact was observed for K+. In addition, chlorophyll and protein contents as well as Rubisco capacity were significantly improved by the organic amendment. MSW compost mitigated the deleterious effect of salt stress on the plant growth, partly due to improved chlorophyll and protein contents and Rubisco capacity (-15%, -27% and -14%, respectively, in combined treatment, against -45%, -84% and -25%, respectively, in salt-stressed plants without compost addition), which presumably favoured photosynthesis and alleviated salt affect on biomass production by 21%. In addition, plants grown on amended soil showed a general improvement in their heavy metals contents Cu2+, Pb2+, Cd2+, and Zn2+ (in combined treatment: 190%, 53%, 168% and 174% in shoots and 183%, 42%, 42% and 114% in roots, respectively) but remained lower than phytotoxic values. Taken together, these findings suggest that municipal waste compost may be safely applied to salt-affected soils without adverse effects on plant physiology.     

Variation of volatiles in Tunisian populations of Teucrium polium L. (Lamiaceae)

Volatiles from wild Tunisian diploid (2n=2x=26) and tetraploid (2n=4x=52) Teucrium polium L. populations from five bioclimatic zones were assessed by GC and GC/MS. Thirty-eight compounds were identified. Main volatiles at the species level were myrcene (6; 15.3%), germacrene D (27; 9.0%), alpha-pinene (6.6%), beta-pinene (3; 5.8%), and alpha-cadinol (38; 5.1%). A significant variation among populations was observed. The tetraploid populations belonging to the sub humid and lower semi arid bioclimates showed a high amount of myrcene (6; 24.2-43.8%), those from the upper arid contain high percentages of alpha-cadinol (38; 50.6%). The dominant compounds in diploid populations, mainly located in the semi arid zone, are alpha-pinene (1) and germacrene D (27). Population chemical structure, assessed by a principal component analysis (PCA) using all identified compounds, is concordant with bioclimate and ploidy level. In situ conservation of populations should be made appropriately according to these two factors.     

Essential Oils of Myrtaceae Species Growing Wild in Tunisia: Chemical Variability and Antifungal Activity Against Biscogniauxia mediterranea,the Causative Agent of Charcoal Canker

The chemical composition of five Eucalyptus species and five Myrtus communis L. populations was investigated using GC/MS and GC‐FID. For Eucalyptus essential oils, 32 compounds, representing 88.56 – 96.83% of the total oil according to species, were identified. The main compounds were 1,8‐cineole, α‐pinene, p‐cymene, γ‐gurjunene, α‐aromadendrene, and β‐phellandrene. For Myrtle essential oils, 26 compounds, representing 93.13 – 98.91% of the total oil were identified. α‐Pinene, 1,8‐cineole, linalool, and myrtenyl acetate were found to be the major compounds. Principal component analysis (PCA) showed chemical differentiation between Eucalyptus species and between Myrtle populations. Biscogniauxia mediterranea, the causative agent of charcoal canker, was identified according to its morphological and molecular characteristics. Essential oils of the investigated Eucalyptus species and Myrtle populations were tested for their antifungal capacity against this fungus. The antifungal activity varied according to the essential oil composition. Biscogniauxia mediterranea exhibited powerful resistance to some essential oils including them of Eucalyptus lehmannii and Eucalyptus sideroxylon but it was very sensitive to Eucalyptus camaldulensis oil (IC₅₀ = 3.83 mg/ml) and M. communis oil from Zaghouan (IC₅₀ = 1 mg/ml). This sensitivity was found to be correlated to some essential oil compounds such as p‐cymene, carvacrol, cuminaldehyde, and linalool.     

Semi-automatic Method for Low-Grade Gliomas Segmentation in Magnetic Resonance Imaging

Background: Analyzing MR scans of low-grade glioma, with highly accurate segmentation will have an enormous potential in neurosurgery for diagnosis and therapy planning. Low-grade gliomas are mainly distinguished by their infiltrating character and irregular contours, which make the analysis, and therefore the segmentation task, more difficult. Moreover, MRI images show some constraints such as intensity variation and the presence of noise.Methods: To tackle these issues, a novel segmentation method built from the local properties of image is presented in this paper. Phase-based edge detection is estimated locally by the monogenic signal using quadrature filters. This way of detecting edges is, from a theoretical point of view, intensity invariant and responds well to the MR images. To strengthen the tumor detection process, a region-based term is designated locally in order to achieve a local maximum likelihood segmentation of the region of interest. A Gaussian probability distribution is considered to model local images intensities.Results: The proposed model is evaluated using a set of real subjects and synthetic images derived from the Brain Tumor Segmentation challenge –BraTS 2015. In addition, the obtained results are compared to the manual segmentation performed by two experts. Quantitative evaluations are performed using the proposed approach with regard to four related existing methods.Conclusion: The comparison of the proposed method, shows more accurate results than the four existing methods.     

Two Panels of Plasma MicroRNAs as Non-Invasive Biomarkers for Prediction of Recurrence in Resectable NSCLC

The diagnosis of non-small cell lung carcinoma (NSCLC) at an early stage, as well as better prediction of outcome remains clinically challenging due to the lack of specific and robust non-invasive markers. The discovery of microRNAs (miRNAs), particularly those found in the bloodstream, has opened up new perspectives for tumor diagnosis and prognosis. The aim of our study was to determine whether expression profiles of specific miRNAs in plasma could accurately discriminate between NSCLC patients and controls, and whether they are able to predict the prognosis of resectable NSCLC patients. We therefore evaluated a series of seventeen NSCLC-related miRNAs by quantitative real-time (qRT)-PCR in plasma from 52 patients with I-IIIA stages NSCLC, 10 patients with chronic obstructive pulmonary disease (COPD) and 20-age, sex and smoking status-matched healthy individuals. We identified an eleven-plasma miRNA panel that could distinguish NSCLC patients from healthy subjects (AUC = 0.879). A six-plasma miRNA panel was able to discriminate between NSCLC patients and COPD patients (AUC = 0.944). Furthermore, we identified a three-miRNA plasma signature (high miR-155-5p, high miR-223-3p, and low miR-126-3p) that significantly associated with a higher risk for progression in adenocarcinoma patients. In addition, a three-miRNA plasma panel (high miR-20a-5p, low miR-152-3p, and low miR-199a-5p) significantly predicted survival of squamous cell carcinoma patients. In conclusion, we identified two plasma miRNA expression profiles that may be useful for predicting the outcome of patients with resectable NSCLC.