Chiral Biases in Solids by Effect of Shear Gradients: A Speculation on the Deterministic Origin of Biological Homochirality

We present an experimental approach to the study of the chirality of three CM2 meteorite solid samples by direct measurement of the optical activity (circular birefringence; CB). The measurements are based on transmission two modulator generalized ellipsometry in conjuction with microscope optics to map the CB of the samples. In spite of the complexity of such optical analysis, these first results indicate the presence of optically active areas in the meteorite solid matrix. In the case of the Murchison sample the statistics of the CB mapping shows a bimodal distribution with a bias to negative CB values. The composition of the active areas probably corresponds to serpentines and other poorly identified phyllosilicate phases. The results are compatible with the hypothesis that in a mineral-based scenario for the origin of life a CB sign bias in the chiral fractures originated by mechanical and flow shear gradients on clays could be later transferred to the reactions of the absorbed organic compounds.     

Prevalence of neutralizing antibodies to West Nile virus in Eleonora's Falcons in the Canary Islands

Birds are the major amplifying host for West Nile virus (WNV), a flavivirus that may affect humans and transmitted by bloodsucking vectors. Eleonora's Falcons (Falco eleonorae) migrate to the Canary Islands annually from WNV-endemic regions. To investigate the possible role of Eleonora's Falcons in the circulation of WNV, we measured WNV-specific antibodies in 81 falcons captured in 2006. None of the nestlings but 14.8% of the adults had WNV-neutralizing antibodies. RT-PCR did not detect flaviviruses in nonculicine ectoparasites (n=231) of the falcons. These findings suggest that WNV infection did not occur locally, but rather on the wintering grounds or during migration.     

Modulation of white adipose tissue proteome by aging and calorie restriction

Aging is associated with an accrual of body fat, progressive development of insulin resistance and other obesity comorbidities that contribute to decrease life span. Caloric restriction (CR), which primarily affects energy stores in adipose tissue, is known to extend life span and retard the aging process in animal models. In this study, a proteomic approach combining 2‐DE and MS was used to identify proteins modulated by aging and CR in rat white adipose tissue proteome. Proteomic analysis revealed 133 differentially expressed spots, 57 of which were unambiguously identified by MS. Although CR opposed part of the age‐associated protein expression patterns, many effects of CR were on proteins unaltered by age, suggesting that the effects of CR on adipose tissue are only weakly related to those of aging. Particularly, CR and aging altered glucose, intermediate and lipid metabolism, with CR enhancing the expression of enzymes involved in oxalacetate and NADPH production, lipid biosynthesis and lipolysis. Consistently, insulin‐β and β3‐adrenergic receptors were also increased by CR, which denotes improved sensitivity to lipogenic/lipolytic stimuli. Other beneficial outcomes of CR were an improvement in oxidative stress, preventing the age‐associated decrease in several antioxidant enzymes. Proteins involved in cytoskeleton, iron storage, energy metabolism and several proteins with novel or unknown functions in adipose tissue were also modulated by age and/or CR. Such orchestrated changes in expression of multiple proteins provide insights into the mechanism underlying CR effects, ultimately allowing the discovery of new markers of aging and targets for the development of CR‐mimetics.     

Globular Adiponectin as a Complete Mesoangioblast Regulator: Role in Proliferation,Survival, Motility,and Skeletal Muscle Differentiation

Mesoangioblasts are progenitor endowed with multipotent mesoderm differentiation ability. Despite the promising results obtained with mesoangioblast transplantation in muscle dystrophy, an improvement of their efficient engrafting and survival within damaged muscles, as well as their ex vivo activation/expansion and commitment toward myogenic lineage, is highly needed and should greatly increase their therapeutic potential. We show that globular adiponectin, an adipokine endowed with metabolic and differentiating functions for muscles, regulates vital cues of mesoangioblast cell biology. The adipokine drives mesoangioblasts to entry cell cycle and strongly counteracts the apoptotic process triggered by growth factor withdrawal, thereby serving as an activating and prosurvival stem cell factor. In addition, adiponectin provides a specific protection against anoikis, the apoptotic death due to lack of anchorage to extracellular matrix, suggesting a key protective role for these nonresident stem cells after systemic injection. Finally, adiponectin behaves as a chemoattractive factor toward mature myotubes and stimulates their differentiation toward the skeletal muscle lineage, serving as a positive regulator in mesoangioblast homing to injured or diseased muscles. We conclude that adiponectin exerts several advantageous effects on mesoangioblasts, potentially valuable to improve their efficacy in cell based therapies of diseased muscles.     

Intestinal and immunological effects of daily oral administration of Lactobacillus salivarius CECT5713 to healthy adults

There is an increasing interest in the intestinal and immunological effects of probiotics. The aim of the present study is to evaluate the tolerance and beneficial effects in healthy adults of the strain, Lactobacillus salivarius CECT5713 isolated from breast milk. A phase II, randomized, double-blinded, placebo-controlled human clinical trial was carried out in 40 healthy adults. The Probiotic group received a daily dose of 2 × 10⁸ CFU of L. salivarius CECT5713 in capsules during 4 weeks while volunteers of the control received only a placebo. Gastrointestinal and immunological parameters were analyzed. Results showed that L. salivarius CECT5713 was well tolerated and no adverse effects were detected. Consumption of the probiotic strain increased fecal lactobacilli counts (7.9 ± 0.1 vs. 7.05 ± 0.2 CFU/g feces, P = 0.001). Also, an improvement in the frequency of defecation (P = 0.04) was observed. Probiotic treatment induced significantly the percentage of NK cells and monocytes, as well as the plasmatic levels of immunoglobulins M, A and G, and the regulatory cytokine IL-10 (72.3 ± 11.7 in probiotic group vs. 27.3 ± 6.4 pg/mL in control group, P < 0.01). Thus, it can be concluded that daily administration of L. salivarius CECT5713 to healthy adults is safe and improve gut microbiota and different parameters related to immune response.     

Thermodynamic and structural study of the main phospholipid components comprising the mitochondrial inner membrane

Cardiolipin (CL) is a phospholipid found in the energy-transducing membranes of bacteria and mitochondria and it is thought to be involved in relevant biological processes as apoptosis. In this work, the mixing properties of CL and 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocoline (POPC) and 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoethanolamine (POPE) at the air-water interface, have been examined using the thermodynamic framework analysis of compression isotherms. Accordingly, the values of the Gibbs energy of mixing, the more stable monolayers assayed were: POPC:CL (0.6:0.4, mol:mol) and POPE:CL (0.8:0.2, mol:mol). The results reflect that attractive forces are the greatest contributors to the total interaction in these compositions. Supported planar bilayers (SPBs) with such compositions were examined using atomic force microscopy (AFM) at different temperatures. With the POPC:CL mixture, rounded and featureless SPBs were obtained at 4 °C and 24 °C. In contrast, the extension of the POPE:CL mixture revealed the existence of different lipid domains at 24 °C and 37 °C. Three lipid domains coexisted which can be distinguished by measuring the step height difference between the uncovered mica and the bilayer. While the low and intermediate domains were temperature dependent, the high domain was composition dependent. When cytochrome c (cyt c) was injected into the fluid cell, the protein showed a preferential adsorption onto the high domain of the POPC:CL. These results suggest that the high domain is mainly formed by CL.     

Watering, Fertilization, and Slurry Inoculation Promote Recovery of Biological Crust Function in Degraded Soils

Biological soil crusts are very sensitive to human-induced disturbances and are in a degraded state in many areas throughout their range. Given their importance in the functioning of arid and semiarid ecosystems, restoring these crusts may contribute to the recovery of ecosystem functionality in degraded areas. We conducted a factorial microcosm experiment to evaluate the effects of inoculation type (discrete fragments vs slurry), fertilization (control vs addition of composted sewage sludge), and watering frequency (two vs five times per week) on the cyanobacterial composition, nitrogen fixation, chlorophyll content, and net CO₂ exchange rate of biological soil crusts inoculated on a semiarid degraded soil from SE Spain. Six months after the inoculation, the highest rates of nitrogen fixation and chlorophyll a content were found when the biological crusts were inoculated as slurry, composted sewage sludge was added, and the microcosms were watered five times per week. Net CO₂ exchange rate increased when biological crusts were inoculated as slurry and the microcosms were watered five times per week. Denaturing gradient gel electrophoresis fingerprints and phylogenetic analyses indicated that most of the cyanobacterial species already present in the inoculated crust had the capability to spread and colonize the surface of the surrounding soil. These analyses showed that cyanobacterial communities were less diverse when the microcosms were watered five times per week, and that watering frequency (followed in importance by the addition of composted sewage sludge and inoculation type) was the treatment that most strongly influenced their composition. Our results suggest that the inoculation of biological soil crusts in the form of slurry combined with the addition of composted sewage sludge could be a suitable technique to accelerate the recovery of the composition and functioning of biological soil crusts in drylands.     

Considerations on the lactate consumption by CHO cells in the presence of galactose

A CHO cell line producing t-PA was cultured using glutamate and glucose or galactose to decrease the formation of metabolic end-products and therefore improving the process. In batch cultures using glutamate (6 mM) with glucose at two different levels (5 and 20 mM) or with glucose and galactose (5 and 20 mM, respectively) a remarkable difference in cell culture parameters was evidenced. For 20 mM glucose, a usual cell pattern was observed with lactate built-up in the medium. For 5 mM glucose, cell growth was arrested due to glucose depletion and only a limited use of the excreted lactate could be observed, not supporting cell growth sufficiently. However, when glucose 5 mM and galactose 20 mM were used together, cells consumed the glucose first and, interestingly, in a second phase they continued growing on galactose with the simultaneous consumption of the endogenous lactate. Under these conditions, cell growth was even improved with respect to growth on 20 mM glucose, used as a control. This metabolic behavior is further investigated by using metabolic flux analysis, suggesting that the lactate produced is not used in the oxidative metabolism through the TCA cycle. Metabolic fate of the lactate consumed is discussed.