NMR Metabolomics for Stem Cell type discrimination

Cell metabolism is a key determinant factor for the pluripotency and fate commitment of Stem Cells (SCs) during development, ageing, pathological onset and progression. We derived and cultured selected subpopulations of rodent fetal, postnatal, adult Neural SCs (NSCs) and postnatal glial progenitors, Olfactory Ensheathing Cells (OECs), respectively from the subventricular zone (SVZ) and the olfactory bulb (OB). Cell lysates were analyzed by proton Nuclear Magnetic Resonance (1H-NMR) spectroscopy leading to metabolites identification and quantitation. Subsequent multivariate analysis of NMR data by Principal Component Analysis (PCA), and Partial Least Square Discriminant Analysis (PLS-DA) allowed data reduction and cluster analysis. This strategy ensures the definition of specific features in the metabolic content of phenotypically similar SCs sharing a common developmental origin. The metabolic fingerprints for selective metabolites or for the whole spectra demonstrated enhanced peculiarities among cell types. The key result of our work is a neat divergence between OECs and the remaining NSC cells. We also show that statistically significant differences for selective metabolites characterizes NSCs of different ages. Finally, the retrived metabolome in cell cultures correlates to the physiological SC features, thus allowing an integrated bioengineering approach for biologic fingerprints able to dissect the (neural) SC molecular specificitie

Reaction rate of NaOCl in contact with bovine dentine: effect of activation, exposure time, concentration and pH

Abstract Macedo RG, Wesselink PR, Zaccheo F, Fanali D, van der Sluis LWM. Reaction rate of NaOCl in contact with bovine dentine: effect of activation, exposure time, concentration and pH. International Endodontic Journal. Aim To determine the influence of activation method (ultrasound or laser), concentration, pH and exposure time on the reaction rate (RR) of NaOCl when in contact with dentinal walls. Methodology The walls from standardized root canals in bovine incisors were exposed to a standardized volume of sodium hypochlorite (NaOCl) with different concentrations (2% and 10%), pH (5 and 12) and exposure times (1 and 4 min). Two irrigation protocols were tested: passive ultrasonic irrigation or laser activated irrigation with no activation as the control. The activation interval lasted 1 min followed by a rest interval of 3 min with no activation. The RR was determined by measuring the iodine concentration using an iodine/thiosulfate titration method. Results Exposure time, concentration and activation method influenced the reaction rate of NaOCl whereas pH did not. Conclusions Activation is a strong modulator of the reaction rate of NaOCl. During the rest interval of 3 min, the consumption of available chlorine increased significantly. This effect seems to be more pronounced after irrigant activation by laser. pH did not affect the reaction rate of 2% NaOCl

VEGF165b, an antiangiogenic VEGF-A isoform, binds and inhibits bevacizumab treatment in experimental colorectal carcinoma: balance of pro- and antiangiogenic VEGF-A isoforms has implications for therapy

Bevacizumab, an anti-vascular endothelial growth factor (VEGF-A) antibody, is used in metastatic colorectal carcinoma (CRC) treatment, but responses are unpredictable. Vascular endothelial growth factor is alternatively spliced to form proangiogenic VEGF165 and antiangiogenic VEGF165b. Using isoform-specific enzyme-linked immunosorbent assay and quantitative polymerase chain reaction, we found that over 90% of the VEGF in normal colonic tissue was VEGFxxxb, but there was a variable upregulation of VEGFxxx and downregulation of VEGFxxxb in paired human CRC samples. Furthermore, cultured colonic adenoma cells expressed predominantly VEGFxxxb, whereas colonic carcinoma cells expressed predominantly VEGFxxx. However, adenoma cells exposed to hypoxia switched their expression from predominantly VEGFxxxb to predominantly VEGFxxx. VEGF165b overexpression in LS174t colon cancer cells inhibited colon carcinoma growth in mouse xenograft models. Western blotting and surface plasmon resonance showed that VEGF165b bound to bevacizumab with similar affinity as VEGF165. However, although bevacizumab effectively inhibited the rapid growth of colon carcinomas expressing VEGF165, it did not affect the slower growth of tumours from colonic carcinoma cells expressing VEGF165b. Both bevacizumab and anti-VEGF165b-specific antibodies were cytotoxic to colonic epithelial cells, but less so to colonic carcinoma cells. These results show that the balance of antiangiogenic to proangiogenic isoforms switches to a variable extent in CRC, regulates tumour growth rates and affects the sensitivity of tumours to bevacizumab by competitive binding. Together with the identification of an autocrine cytoprotective role for VEGF165b in colonic epithelial cells, these results indicate that bevacizumab treatment of human CRC may depend upon this balance of VEGF isoforms

Degeneracija aksona i esteraza povezana s neuropatskim djelovanjem organofosfornih spojeva - pregled

This brief review summarises recent observations which suggest a possible mechanism for organophosphateinduced delayed neuropathy (OPIDN). Neuropathy target esterase (NTE) has been shown to deacylate endoplasmic reticulum (ER) membrane phosphatidylcholine (PtdCho). Raised levels of PtdCho are present in the brains of swiss cheese/NTE mutant Drosophila together with abnormal membrane structures, axonal and dendritic degeneration and neural cell loss. Similar vacuolated pathology is found in the brains of mice with brain-specific deletion of the NTE gene and, in old age, these mice show clinical and histopathological features of neuropathy resembling those in wild-type mice chronically dosed with tri-ortho-cresylphosphate. It is suggested that OPIDN results from the loss of NTE’s phospholipase activity which in turn causes ER malfunction and perturbation of axonal transport and glial-axonal interactions.Ovim se kratkim pregledom razmatraju nedavna opažanja koja upućuju na mogući mehanizam odgođene neuropatije uzrokovane organofosfatima (engl. organophosphate-induced delayed neuropathy, krat. OPIDN). Za esterazu povezanu s neuropatskim djelovanjem organofosfornih spojeva (engl. neuropathy target esterase, krat. NTE) dokazano je da deacilira fosfatidilkolin (PtdCho) membrane endoplazmatskog retikuluma (ER). Povišene razine PtdCho prisutne su u mozgu swiss cheese/NTE mutanta mušice Drosophila uz abnormalne membranske strukture, degeneraciju aksona i dendrita te gubitak neurona. Slična je vakuolarna patologija zamijećena u mozgu miševa u kojih je obrisan NTE gen u mozgu te koji u starijoj dobi pokazuju kliničke i histopatološke znakove neuropatije koja je slična onoj u običnih miševa kronično tretiranih tri-ortho-krezilfosfatom. Odgođena neuropatija uzrokovana organofosfatima mogla bi biti posljedicom prestanka djelovanja fosfolipaze NTE, što potom uzrokuje zatajenje endoplazmatskog retikuluma i smetnje u prijenosu signala putem aksona te interakcije između glija i aksona

New MACRO results on atmospheric neutrino oscillations

The final results of the MACRO experiment on atmospheric neutrino oscillations are presented and discussed. The data concern different event topologies with average neutrino energies of ~3 and ~50 GeV. Multiple Coulomb Scattering of the high energy muons in absorbers was used to estimate the neutrino energy of each event. The angular distributions, the L/E_nu distribution, the particle ratios and the absolute fluxes all favour nu_mu --> nu_tau oscillations with maximal mixing and Delta m^2 =0.0023 eV^2. A discussion is made on the Monte Carlos used for the atmospheric neutrino flux. Some results on neutrino astrophysics are also briefly discussed.Comment: Invited Paper at the NANP03 Int. Conf., Dubna, 200

Paper-based enzymatic microfluidic fuel cell: From a two-stream flow device to a single-stream lateral flow strip

This work presents a first approach towards the development of a cost-effective enzymatic paper-based glucose/O2 microfluidic fuel cell in which fluid transport is based on capillary action. A first fuel cell configuration consists of a Y-shaped paper device with the fuel and the oxidant flowing in parallel over carbon paper electrodes modified with bioelectrocatalytic enzymes. The anode consists of a ferrocenium-based polyethyleneimine polymer linked to glucose oxidase (GOx/Fc-C6-LPEI), while the cathode contains a mixture of laccase, anthracene-modified multiwall carbon nanotubes, and tetrabutylammonium bromide-modified Nafion (MWCNTs/laccase/TBAB-Nafion). Subsequently, the Y-shaped configuration is improved to use a single solution containing both, the anolyte and the catholyte. Thus, the electrolytes pHs of the fuel and the oxidant solutions are adapted to an intermediate pH of 5.5. Finally, the fuel cell is run with this single solution obtaining a maximum open circuit of 0.55 ± 0.04 V and a maximum current and power density of 225 ± 17 μA cm−2 and 24 ± 5 μW cm−2, respectively. Hence, a power source closer to a commercial application (similar to conventional lateral flow test strips) is developed and successfully operated. This system can be used to supply the energy required to power microelectronics demanding low power consumption.F. Javier del Campo acknowledges funding from the Spanish Ministry of Economy through the DADDi2 project (TEC2013-48506-C3). Juan Pablo Esquivel would like to thank the support from Marie Curie International Outgoing Fellowship (APPOCS-328144) within the 7th European Community Framework Programme. Shelley D. Minteer and Fabien Giroud would like to thank the National Science Foundation (CHE-1057597) for funding. Neus Sabaté acknowledges funding from the European H2020 Framework Programme (Grant Agreement 648518 - SUPERCELL - ERC 2014 CoG).Peer reviewe

A role for ubiquitin ligases and Spartin/SPG20 in lipid droplet turnover

HECT (homologous to the E6AP C terminus) ubiquitin ligases have diverse functions in eukaryotic cells. In screens for proteins that bind to the HECT ubiquitin ligase WWP1, we identified Spartin, which is also known as SPG20. This protein is truncated in a neurological disease, Troyer syndrome. In this study, we show that SPG20 associates with the surface of lipid droplets (LDs) and can regulate their size and number. SPG20 binds to another LD protein, TIP47, and both proteins compete with an additional LD protein, adipophilin/adipocyte differentiation-related protein, for occupancy of LDs. The mutant SPG20 present in Troyer syndrome does not possess these activities. Depletion of SPG20 using RNA interference increases the number and size of LDs when cells are fed with oleic acid. Binding of WWP1 to SPG20 and the consequent ubiquitin transfer remove SPG20 from LDs and reduce the levels of coexpressed SPG20. These experiments suggest functions for ubiquitin ligases and SPG20 in the regulation of LD turnover and potential pathological mechanisms in Troyer syndrome