IL-10 Prevents apoptosis of brain endothelium during bacteremia

IL-10-deficient mice infected with the relapsing fever bacterium Borrelia turicatae rapidly succumb to a brain hemorrhage if they are unable to clear peak bacteremia. In this study, we investigated the protective role of IL-10 during relapsing-remitting bacteremia and explored the molecular events involved in the protection of brain endothelium by IL-10. Brain endothelial injury was measured with cytotoxicity and diverse apoptotic assays, whereas the signaling pathway analysis was done by quantitative PCR array. The results showed that severe endothelial cell injury leading to hemorrhage in the brain and other organs occurred in IL-10-deficient mice during relapsing-remitting infection. Human brain microvascular endothelial cells (HBMEC) produced abundant proinflammatory mediators upon exposure to whole bacteria or purified bacterial lipoprotein but did not produce any detectable IL-10. Whole bacteria and purified outer membrane lipoprotein rapidly killed HBMEC by apoptosis in a time- and concentration-dependent manner. Exogenous IL-10 protected HBMEC from apoptosis. HBMEC apoptosis during exposure to a low number of bacteria was associated with downregulation of TNF and TNFAIP3 and upregulation of BAX. In contrast, HBMEC apoptosis during exposure to high concentrations of purified outer membrane lipoprotein was associated with marked upregulation of FAS, FAS ligand, and the adaptor molecules RIPK1 and CFLAR. Exogenous IL-10 reversed all the apoptotic signaling changes induced by whole bacteria or its purified lipoprotein. The results indicate that prominent brain endothelial cell apoptosis occurs during relapsing-remitting bacteremia in the absence of IL-10 and point to a prominent role for bacterial lipoprotein-mediated activation of FAS and caspase-3 in this process.     

Analysis of brain metabolism by proton magnetic resonance spectroscopy (1H-MRS) in attention-deficit/hyperactivity disorder suggests a generalized differential ontogenic pattern from controls

Attention-deficit/hyperactivity disorder (ADHD) is the most common behavioral disorder of childhood. Preliminary studies with proton magnetic resonance spectroscopy (¹H-MRS) of the brain have reported differences in brain metabolite concentration-to-Cr ratios between individuals with ADHD and unaffected controls in several frontal brain regions including anterior cingulate cortex. Using multivoxel ¹H-MRS, we compared 14 individuals affected with ADHD to 20 individuals without ADHD from the same genetic isolate. After controlling by sex, age, and multiple testing, we found significant differences at the right posterior cingulate of the Glx/Cr ratio density distribution function between ADHD cases and controls (P?<?0.05). Furthermore, we found several interactions of metabolite concentration-to-Cr ratio, age, and ADHD status: Ins/Cr and Glx/Cr ratios at the left posterior cingulate, and NAA/Cr at the splenius, right posterior cingulate, and at the left posterior cingulate. We also found a differential metabolite ratio interaction between ADHD cases and controls for Ins/Cr and NAA/Cr at the right striatum. These results show that: (1) NAA/Cr, Glx/Cr, and Ins/Cr ratios, as reported in other studies, exhibit significant differences between ADHD cases and controls; (2) differences of these metabolite ratios between ADHD cases and controls evolve in specific and recognizable patterns throughout age, a finding that replicates previous results obtained by structural MRI, where is demonstrated that brain ontogeny follows a different program in ADHD cases and controls; (3) Ins/Cr and NAA/Cr ratios, at the right striatum, interact in a differential way between ADHD cases and controls. As a whole, these results replicate previous 1H-MRS findings and add new intriguing differential metabolic and ontogeny patterns between ADHD cases and controls that warrant further pursue.     

Physiological Low Doses of Leptin and Cholecystokinin Induces Body Weight-Loss in Juvenile and Lean, but not in Adult-Obese Rats

Leptin and cholecystokinin (CCK) are two hormones involved in body weight regulation and feeding behavior. Leptin, an adiposity-derived signal, and CCK, a gut-satiety signal, interact in a synergistic manner and their concomitant treatment causes more weight loss than any hormone administered alone. The synergistic interaction between CCK and leptin has been widely characterized in lean rats, but there are a few studies performed in obese rats. Herein, in the same individual, we compared the sensitivity to CCK, leptin and the combined treatment, leptin + CCK, on body weight and food intake in two experiments one performed in juvenile-lean rats, and in a second experiment comparing adult Chow-fed versus adult-high fat diet (HFD) rats. We found that only the combined treatment had a long-term effect on food intake and caused a substantial and synergistic body weight loss, in juvenile rats. However, the same combined treatment failed to induce weight loss in both Chow-fed and HFD rats. We thus conclude that the sensitivity to leptin + CCK was age dependent, and at the doses used ineffective in adult and obese rats.     

An acidic phospholipase A₂ with antibacterial activity from Porthidium nasutum snake venom

Snake venoms are complex mixtures of proteins among which both basic and acidic phospholipases A₂ (PLA₂s) can be found. Basic PLA₂s are usually responsible for major toxic effects induced by snake venoms, while acidic PLA₂s tend to have a lower toxicity. A novel PLA₂, here named PnPLA₂, was purified from the venom of Porthidium nasutum by means of RP-HPLC on a C18 column. PnPLA₂ is an acidic protein with a pI of 4.6, which migrates as a single band under both non-reducing and reducing conditions in SDS-PAGE. PnPLA₂ had a molecular mass of 15,802.6 Da, determined by ESI-MS. Three tryptic peptides of this protein were characterized by HPLC-nESI-MS/MS, and N-terminal sequencing by direct Edman degradation showing homology to other acidic PLA₂s from viperid venoms. PnPLA₂ displayed indirect hemolytic activity in agarose erythrocyte-egg yolk gels and bactericidal activity against Staphylococcus aureus in a dose-dependent manner, with a MIC and MBC of 32 μg/mL. In addition, PnPLA₂ showed a potent inhibitory effect on platelet aggregation with doses up to 40 μg/mL. This acidic PLA₂, in contrast to basic enzymes isolated from other viperid snake venoms, was not cytotoxic to murine skeletal muscle myoblasts C₂C₁₂. This is the first report on a bactericidal protein of Porthidium nasutum venom.     

Polychaetes of the mangrove-fouling community at the Colombian Archipelago of San Andres and Old Providence,Western Caribbean

This study records the polychaetes found on the submerged roots of Rhizophora mangl on San Andres and Providence Islands, ColombianCaribbean. Sampling was done in 1998 during the rainy (July) and dry(November) seasons; each season, 17 roots were collected in threedifferent stations with different kinds of human impact, two in San Andresand one in Providence. At the same time temperature, salinity anddissolved oxygen were measured in situ. Aromatic hydrocarbons weremeasured in the laboratory. The polychaetes were removed from the rootsand identified. The available root area for the organisms was alsomeasured.Five genera and 11 species were newly recorded for the ColombianCaribbean. The most abundant families were Terebellidae in Old ProvidenceMc Bean Lagoon, Syllidae in Honda Bay and Nereididae in Hooker Bayon the San Andres Island. Thelepus `setosus' (Terebellidae) and Amblyosyllis sp. (Syllidae) were highly abundant in less polluted samplingstations such as Old Providence Mc Bean Lagoon and Honda Bay. On theother hand, Neanthes `succinea' (Nereididae) were abundant inHooker Bay which was the most polluted station. Salinity seemed to be the mostimportant parameter for the polychaete populations. The populations ofpolychaetes, as a total group, seemed to be related to the root areaavailable on both islands, independent of the season. However, during therainy season, the populations were independent of root area availability,while during the dry season, the populations were dependent on it.     

Circulating Glycated Albumin and Glomerular Anionic Charges

Aiming to discern the mechanisms by which circulating glycated albumin alters the glomerular filtration properties that lead to glomerular dysfunction in diabetes, the authors studied the distribution and densities of anionic charges through the rat glomerular wall upon intravascular infusion of Amadori products, as well as in various conditions of increased glomerular permselectivity. Polylysine-gold was used as the probe to reveal the anionic charges. The study was carried on renal tissue sections of bovine serum albumin (BSA)- and glycated BSA–injected, normoglycemic animals. Results were generated through morphometrical evaluations of the gold labeling. Changes in glomerular anionic distribution were corroborated on renal tissue sections of short- and long-term diabetic rats and of normal newborn rats, situations known for abnormal glomerular filtration. Altered renal function in these conditions was clearly associated with changes in glomerular anionic charges. On the other hand, the infusion of glycated albumin in the circulation of normal rats, though altering glomerular filtration properties, did not modify the distribution and density of the polylysine-gold labeling through the glomerular basement membrane. Thus, anionic charges seem not to be the factor involved in the early changes of glomerular permeability induced by circulating glycated albumin.     

Arbuscular mycorrhizal fungi in the growth and extraction of trace elements by Chrysopogon zizanioides (vetiver) in a substrate containing coal mine wastes

Vetiver (Chrysopogon zizanioides) is a fast-growing, high biomass producing plant employed for environmental rehabilitation. The study evaluated the effects of arbuscular mycorrhizal fungi (AMF) on the growth and trace element phytoextracting capabilities of vetiver in a substrate containing coalmine wastes in Southern Brazil. AMF included Acaulospora colombiana, Acaulospora morrowiae, Acaulospora scrobiculata, Dentiscutata heterogama, Gigaspora margarita, and Rhizophagus clarus. Among those, A. colombiana, G. margarita, and R. clarus promoted higher growth. AMF stimulated average increments in the accumulated P of 82% (roots), 194% (shoots first harvest—90 days) and 300% (shoots second harvest—165 days) and affected the phytoextraction of trace elements by vetiver, with larger concentrations in the roots. Plants inoculated with A. colombiana, A. morrowiae, and A. scrobiculata, in addition to the control, presented the highest levels of Cu and Zn in the roots. Overall, G. margarita stimulated the highest production of biomass, and, therefore, showed the most significant levels of trace elements in the plants. This work shows the benefits of certain AMF (especially A. morrowiae, G. margarita, and R. clarus) for the production of biomass and P uptake by vetiver, demonstrating the potential of those species for the rehabilitation of coal-mine-degraded soils.     

Synthesis, structure and biological activities of cobalt(II) and zinc(II) coordination compounds with 2-benzimidazole derivatives

In this work we present the synthesis, structural and spectroscopic characterisation of a series of cobalt(II) and zinc(II) coordination compounds with benzimidazole (bz) and its 2-benzimidazole derivatives: 2-aminobenzimidazole (2ab), albendazole (abz) and tris(2-benzimidazolylmethyl)amine (ntb). The compounds were evaluated for their in vitro antimicrobial activity against Staphylococcus aureus, Micrococcus luteus, Salmonella typhi, Pseudomonas aeruginosa, Escherichia coli and Proteus vulgaris. Their cytotoxic activity was also evaluated using human cancer lines, HeLa, HCT-15 and SKLU-1. The halide tetrahedral compounds [Co(bz)₂Br₂] 3, [Zn(2ab)₂Cl₂] · 0.5H₂O 11, [Co(abz)Cl₂(H₂O)] · 3H₂O 14, [Co(abz)Br₂(H₂O)] 15, [Zn(abz)Cl₂(H₂O)] · 3H₂O 17 and [Zn(abz)Br₂(H₂O)] · H₂O 18 displayed similar minimal inhibition concentration (MIC) values against Micrococcus luteus and Escherichia coli, comparable to those of amoxicillin and chloramphenicol. Additionally, 11 showed a wide range of activity towards Gram(+) and Gram(−) microorganisms. The tetradentate ntb and its trigonal bipyramidal cobalt(II) and zinc(II) compounds were active, regardless of the anion present in the complex. Compound [Co(abz)Cl₂(H₂O)] · 3H₂O 14 showed promising activity in HeLa cells, while [Co(ntb)Br]Br · H₂O 21 inhibited Hela and HCT-15 cell lines.     

Differences in telomere length between homologous chromosomes in humans

Telomeres are important structures for DNA replication and chromosome stability during cell growth. Telomere length has been correlated with the division potential of human cells and has been found to decrease with age in healthy individuals. Nevertheless, telomere lengths within the same cell are heterogeneous and certain chromosome arms typically have either short or long telomeres. Both the origin and the physiological consequences of this heterogeneity in telomere length remain unknown. In this study we used quantitative telomeric FISH combined with a method to identify the parental origin of chromosomes to show that significant differences in relative telomere intensities are frequently observed between chromosomal homologs in short-term stimulated cultures of peripheral blood lymphocytes. These differences appear to be stable for at least 4 months in vivo, but disappear after prolonged proliferation in vitro. The telomere length differences are also stable during in vitro growth of telomerase-negative fibroblast cells but can be abolished by exogenous telomerase expression in these cells. These findings suggest the existence of a mechanism maintaining differences in telomere length between chromosome homologs that is independent of telomere length itself.     

Methods for the differential integrative omic analysis of plasma from a transgenic disease animal model

Multitiered quantitative analysis of biological systems is rapidly becoming the desired approach to study hierarchical functional interactions between proteins and metabolites. We describe here a novel systematic approach to analyze organisms with complex metabolic regulatory networks. By using precise analytical methods to measure biochemical constituents and their relative abundance in whole plasma of transgenic ApoE*3-Leiden mice and an isogenic wild-type control group, simultaneous snapshots of metabolic and protein states were obtained. Novel data processing and multivariate analysis tools such as Impurity Resolution Software (IMPRESS) and Windows-based linear fit program (WINLIN) were used to compare protein and metabolic profiles in parallel. Canonical correlations of the resulting data show quantitative relationships between heterogeneous components in the TG animals. These results, obtained solely from whole plasma analysis allowed us, in a rapid manner, to corroborate previous findings as well as find new events pertaining to dominant and peripheral events in lipoprotein metabolism of a genetically modified mammalian organism in relation to ApoE3, a key mediator of lipoprotein metabolism.