Differential expression of thrombospondin,collagen, and thyroglobulin by thyroid-stimulating hormone and tumor-promoting phorbol ester in cultured porcine thyroid cells

In the present study, we have investigated the potential regulation of thyroglobulin (Tg) and extracellular matrix components synthesis by thyroid-stimulating hormone (TSH) and tetradecanoyl phorbol-13-acetate (TPA) on thyroid cells. Porcine thyroid cells isolated by trypsin-EGTA digestion of thyroid glands were maintained in serum containing medium on poly (L-lysine)-coated dishes. Cells differentiated into follicular or vesicular-like structures were distinguished by their ability to organify Na[¹²⁵l] and to respond to TSH stimulation. After an incubation of the cells with radiolabeled proline or methionine, two major proteins were identified, p450–480 and p290 (so named because of their molecular masses). Tg (p290) synthesis was demonstrated by the synthesis of [¹³¹l]-labeled polypeptides with electrophoretic properties identical to those of authentic Tg molecules. P450–480 resolved to Mr 190,000 under reducing sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) conditions. It was identified as thrombospondin by its reactivity with a monoclonal anti-human thrombospondin and by peptide sequencing of some of its tryptic fragments that displayed identity to thrombospondin l. Collagen synthesis was demonstrated by the formation of radioactive hydroxyproline and by the synthesis of pepsin-resistant polypeptides ranging from Mrs 120,000 to 200,000. When the cells were cultured in the presence of 100 nM TPA, the culture medium contents of thrombospondin and collagen were increased by 2.7 and 1.6-fold, respectively, whereas Tg content was decreased by a factor 3.9. In contrast, the acute treatment of control cells with TPA induced a decrease in both Tg and collagen content by factors 3.0 and 1.5, respectively, and an increase in thrombospondin content by a factor 2.5. In the presence of 100 nM TPA, TSH (1 mU/ml) did not counteract the stimulating effect of TPA on extracellular matrix components synthesis. In contrast, when cells were cultured in the presence of TSH alone at concentrations higher than 0.1 mU/ml, collagen and thrombospondin in the medium were decreased by a factor 2.0 and 1.9, respectively, and TSH preferentially activated Tg synthesis. However, no acute response to TSH was observed in cells incubated for 2 days without effectors (control cells). On TSH differentiated cells, TPA decreased both collagen and Tg accumulation by factor 1.2 and 1.8, respectively, whereas it increased the one of thrombospondin by a factor 2. These results, together with the stimulating effect of TPA on TSH mediated cell proliferation, argue for a role of thrombospondin in cell adhesion and migration events within the thyroid epithelium. © 1994 Wiley-Liss, Inc.     

Fungal post-treatment of pulp mill effluents for the removal of recalcitrant pollutants

The objective of this work was to evaluate the post-treatment of an anaerobic recalcitrant effluent (anaerobically-treated weak black liquor, AnE) in an aerobic, upflow reactor packed with “biocubes” of Trametes versicolor immobilized onto small cubes of holm oak wood. The treated effluent (named anaerobic effluent; AnE) from an anaerobic fluidized bed reactor was fed to an up-flow aerobic fungal packed bed reactor (PBR). Two HRT were tested in this unit, namely 5 and 2.5 days; the PBR operated 60 days at 5-day HRT and 35 days at 2.5-day HRT. The aerobic packed bench scale reactor was a glass column 1.5 L total geometric volume containing 0.75 L biocubes of T. versicolor immobilized onto holm oak wood small cubes of 5 mm side. The reactor was operated at 25 °C. The pH of the AnE was adjusted to 4.5 before feeding; no carbohydrates or other soluble carbon source was supplemented. The fungal packed bed bioreactor averaged organic matter removals of 30% and 32% COD basis, during an experimental run of 60 days at 5-day HRT and 35 days at 2.5-day HRT, respectively. Colour and ligninoids contents were removed at higher percentages (69% and 54% respectively, average of both HRT). There was no significant difference between reactor performance at 5- and 2.5-day HRT, so, operation at 2.5-day HRT is recommended since reactor throughput is double. Activity of manganese peroxidase and laccase was found during the entire operation of the fungal PBR whereas lignin peroxidase activity practically disappeared in the second operation period. In general, enzyme activities were higher in the first period of operation (5-day HRT) than at 2.5-day HRT. To the best of our knowledge, this is one of the few works that demonstrated extended performance (3 months) of a fungal bioreactor for the treatment of a recalcitrant wastewater with no supplementation of glucose or other expensive, soluble carbohydrate.     

Molecular taxonomic identification in the absence of a ‘barcoding gap’: a test with the endemic flora of the Canarian oceanic hotspot

We use a comprehensive subset of Canarian angiosperms corresponding to 23 families, 35 genera and 60 Canarian endemic taxa to test whether this flora is suitable to taxonomic identification with the two proposed plant DNA barcode sequences and whether these sequences may reveal the existence of cryptic species overlooked by morphology. The rate of discrimination success between the insular congeneric samples using the rbcL+matK combination and a ‘character‐based’ approach (where we use only the combination of nucleotide positions in an alignment that allows unambiguous species identification) is higher (82.29%) than that obtained with the ‘distance‐based’ approach (80.20%) used by the CBOL Plant Working Group in 2009 and also when compared with tests conducted in other floras. This suggests that the molecular identification of the Canarian endemic flora can be achieved as successfully as in other floras where the incidence of radiation is not as relevant. The facts that (i) a distance‐based criterion was unable to discriminate between congeneric and conspecific comparisons and (ii) only the character‐based discrimination criterion resolved cases that the distance‐based criterion did not, further support the use of a character discrimination approach for a more efficient DNA barcoding of floras from oceanic islands like the Canaries. Thus, a barcoding gap seems not to be necessary for the correct molecular characterization of the Canarian flora. DNA barcodes also suggest the possible existence of cryptic taxa to be further investigated by morphology and that the current taxonomic status of some of the taxa analysed may need revision.     

Cerebral Circulation Time is Prolonged and Not Correlated with EDSS in Multiple Sclerosis Patients: A Study Using Digital Subtracted Angiography

Literature has suggested that changes in brain flow circulation occur in patients with multiple sclerosis. In this study, digital subtraction angiography (DSA) was used to measure the absolute CCT value in MS patients and to correlate its value to age at disease onset and duration, and to expand disability status scale (EDSS). DSA assessment was performed on eighty MS patients and on a control group of forty-four age-matched patients. CCT in MS and control groups was calculated by analyzing the angiographic images. Lesion and brain volumes were calculated in a representative group of MS patients. Statistical correlations among CCT and disease duration, age at disease onset, lesion load, brain volumes and EDSS were considered. A significant difference between CCT in MS patients (mean = 4.9s; sd = 1.27s) and control group (mean = 2.8s; sd = 0.51s) was demonstrated. No significant statistical correlation was found between CCT and the other parameters in all MS patients. Significantly increased CCT value in MS patients suggests the presence of microvascular dysfunctions, which do not depend on clinical and MRI findings. Hemodynamic changes may not be exclusively the result of a late chronic inflammatory process.     

The Human Pathogen Streptococcus pyogenes Releases Lipoproteins as Lipoprotein-rich Membrane Vesicles

Bacterial lipoproteins are attractive vaccine candidates because they represent a major class of cell surface-exposed proteins in many bacteria and are considered as potential pathogen-associated molecular patterns sensed by Toll-like receptors with built-in adjuvanticity. Although Gram-negative lipoproteins have been extensively characterized, little is known about Gram-positive lipoproteins. We isolated from Streptococcus pyogenes a large amount of lipoproteins organized in vesicles. These vesicles were obtained by weakening the bacterial cell wall with a sublethal concentration of penicillin. Lipid and proteomic analysis of the vesicles revealed that they were enriched in phosphatidylglycerol and almost exclusively composed of lipoproteins. In association with lipoproteins, a few hypothetical proteins, penicillin-binding proteins, and several members of the ExPortal, a membrane microdomain responsible for the maturation of secreted proteins, were identified. The typical lipidic moiety was apparently not necessary for lipoprotein insertion in the vesicle bilayer because they were also recovered from the isogenic diacylglyceryl transferase deletion mutant. The vesicles were not able to activate specific Toll-like receptor 2, indicating that lipoproteins organized in these vesicular structures do not act as pathogen-associated molecular patterns. In light of these findings, we propose to name these new structures Lipoprotein-rich Membrane Vesicles.Bacterial lipoproteins (Lpps)¹ are a subset of membrane proteins that are covalently modified with a lipidic moiety at their N-terminal cysteine residue. It is commonly reported that Lpps of Gram-positive bacteria are processed by two key enzymes; the prolipoprotein diacylglyceryl transferase (Lgt) and the lipoprotein signal peptidase (Lsp). The Lgt enzyme recognizes a so-called lipobox motif in the C-terminal region of the signal peptide of a premature lipoprotein and transfers a diacylglyceryl moiety to the cysteine residue of the lipobox (1), (2). Subsequently, the Lsp enzyme cleaves the signal peptide resulting in a mature Lpp (3), (4). Nevertheless, recent reports have suggested that N-acylation occurs in bacteria that lack the Gram-negative homologous apolipoprotein N-acyltransferase (Lnt) gene responsible for this modification (5, 6), and that Lpp N-terminal could also be modified with an acetyl group in some Gram-positive (7).Lpps have been described as virulence factors because they play critical roles in membrane stabilization, nutrient uptake, antibiotic resistance, bacterial adhesion to host cells, protein maturation and secretion and many of them still have unknown function (8). Several studies have suggested that bacterial Lpps are pathogen-associated molecular patterns (PAMPs) sensed by the mammalian host through Toll-like receptor 2 (TLR2) heterodimerized with TLR1 or TLR6 to induce innate immunity activation and to control adaptive immunity (9–12). TLR2 plays a critical role in the host response to the Gram-positive bacteria Staphylococcus aureus (13) and Streptococcus agalactiae (14). Although TLR2 has been considered a receptor for various structurally unrelated PAMPs, recent studies have suggested that, via their lipid moiety, bacterial Lpps function as the major, if not the sole, ligand molecules responsible for TLR2 activation (15). Although Gram-negative Lpps have been widely studied, little information is available for Gram-positive Lpps (16) and the ways they are released into the bacterial extracellular compartment and reach the host immune system remain unclear.We focused our attention on Lpps release by Streptococcus pyogenes. This Gram-positive bacterium is an important human pathogen that causes a wide range of diseases from superficial and self-limiting infection, e.g. pharyngitis and impetigo, to more systemic or invasive diseases like necrotizing fasciitis and septicemia (17). Understanding the role of bacterial Lpps in mediating innate and acquired immunity can be instrumental for the therapy and prophylaxis of human S. pyogenes infections. In this study, we showed that in S. pyogenes Lpps are released into the growth medium within vesicle-like structures in minute amounts. Conditions weakening the bacterial cell wall, such as the addition of sublethal concentrations of penicillin to the bacterial growth medium enhanced this phenomenon and allowed the recovery of sufficient material to enable an in-depth characterization. Proteomic analysis of the vesicles revealed that they were almost exclusively constituted of Lpps. A total of 28 Lpps were identified, representing more than 72% of the Lpps predicted from the genome of the strain under investigation. In addition, multiple transmembrane domain proteins were not found in abundance associated to the vesicles, indicating that vesicles were not representative of the bacterial membrane. We defined these vesicles as Lipoprotein-rich Membrane Vesicles (LMVs).Common characteristics are shared between the LMVs and the ExPortal described for the first time by Rosch and Caparon (18). This asymmetric and distinct membrane microdomain has been reported to be enriched in anionic phospholipids and acts in promoting the biogenesis of secreted proteins by coordinating interactions between nascent unfolded secretory proteins and the accessory factors required for their maturation (19–21). An association between ExPortal and peptidoglycan synthesis has also been reported (22). Similarly, LMVs are enriched in anionic phosphatidylglycerol, enzymes involved in protein maturation/secretion and cell wall biogenesis, suggesting that LMVs might derive from the ExPortal. Finally, we showed that LMVs do not induce TLR2 activation, indicating that the Lpps did not act as PAMPs when integrated into the LMVs.     

Integration Analysis of Three Omics Data Using Penalized Regression Methods: An Application to Bladder Cancer

Omics data integration is becoming necessary to investigate the genomic mechanisms involved in complex diseases. During the integration process, many challenges arise such as data heterogeneity, the smaller number of individuals in comparison to the number of parameters, multicollinearity, and interpretation and validation of results due to their complexity and lack of knowledge about biological processes. To overcome some of these issues, innovative statistical approaches are being developed. In this work, we propose a permutation-based method to concomitantly assess significance and correct by multiple testing with the MaxT algorithm. This was applied with penalized regression methods (LASSO and ENET) when exploring relationships between common genetic variants, DNA methylation and gene expression measured in bladder tumor samples. The overall analysis flow consisted of three steps: (1) SNPs/CpGs were selected per each gene probe within 1Mb window upstream and downstream the gene; (2) LASSO and ENET were applied to assess the association between each expression probe and the selected SNPs/CpGs in three multivariable models (SNP, CPG, and Global models, the latter integrating SNPs and CPGs); and (3) the significance of each model was assessed using the permutation-based MaxT method. We identified 48 genes whose expression levels were significantly associated with both SNPs and CPGs. Importantly, 36 (75%) of them were replicated in an independent data set (TCGA) and the performance of the proposed method was checked with a simulation study. We further support our results with a biological interpretation based on an enrichment analysis. The approach we propose allows reducing computational time and is flexible and easy to implement when analyzing several types of omics data. Our results highlight the importance of integrating omics data by applying appropriate statistical strategies to discover new insights into the complex genetic mechanisms involved in disease conditions.     

Verbascoside down‐regulates some pro‐inflammatory signal transduction pathways by increasing the activity of tyrosine phosphatase SHP‐1 in the U937 cell line

Polyphenols are the major components of many traditional herbal remedies, which exhibit several beneficial effects including anti‐inflammation and antioxidant properties. Src homology region 2 domain‐containing phosphatase‐1 (SHP‐1) is a redox sensitive protein tyrosine phosphatase that negatively influences downstream signalling molecules, such as mitogen‐activated protein kinases, thereby inhibiting inflammatory signalling induced by lipopolysaccharide (LPS). Because a role of transforming growth factor β‐activated kinase‐1 (TAK1) in the upstream regulation of JNK molecule has been well demonstrated, we conjectured that SHP‐1 could mediate the anti‐inflammatory effect of verbascoside through the regulation of TAK‐1/JNK/AP‐1 signalling in the U937 cell line. Our results demonstrate that verbascoside increased the phosphorylation of SHP‐1, by attenuating the activation of TAK‐1/JNK/AP‐1 signalling. This leads to a reduction in the expression and activity of both COX and NOS. Moreover, SHP‐1 depletion deletes verbascoside inhibitory effects on pro‐inflammatory molecules induced by LPS. Our data confirm that SHP‐1 plays a critical role in restoring the physiological mechanisms of inducible proteins such as COX2 and iNOS, and that the down‐regulation of TAK‐1/JNK/AP‐1 signalling by targeting SHP‐1 should be considered as a new therapeutic strategy for the treatment of inflammatory diseases.