Extremely low frequency magnetic field induces human neuronal differentiation through NMDA receptor activation

Magnetic fields with different frequency and intensity parameters exhibit a wide range of effects on different biological models. Extremely low frequency magnetic field (ELF MF) exposure is known to augment or even initiate neuronal differentiation in several in vitro and in vivo models. This effect holds potential for clinical translation into treatment of neurodegenerative conditions such as autism, Parkinson's disease and dementia by promoting neurogenesis, non-invasively. However, the lack of information on underlying mechanisms hinders further investigation into this phenomenon. Here, we examine involvement of glutamatergic Ca2+ channel, N-methyl-D-aspartate (NMDA) receptors in the process of human neuronal differentiation under ELF MF exposure. We show that human neural progenitor cells (hNPCs) differentiate more efficiently under ELF MF exposure in vitro, as demonstrated by the abundance of neuronal markers. Furthermore, they exhibit higher intracellular Ca2+ levels as evidenced by c-fos expression and more elongated mature neurites. We were able to neutralize these effects by blocking NMDA receptors with memantine. As a result, we hypothesize that the effects of ELF MF exposure on neuronal differentiation originate from the effects on NMDA receptors, which sequentially triggers Ca2+-dependent cascades that lead to differentiation. Our findings identify NMDA receptors as a new key player in this field that will aid further research in the pursuit of effect mechanisms of ELF MFs.European Molecular Biology Organization Short Term Fellowships, ASTF 7502. This work was partially supported by TUBITAK Projects under Grant No. 117Z864, Bogazici University Research Fund by Grant Number 6701. A.J. Salgado and A. Marote acknowledge the financial support from: Prémios Santa Casa Neurociências–Prize Melo e Castro for Spinal Cord Injury Research (MC-04/17); Portuguese Foundation for Science and Technology Pre–Doctoral fellowship to A. Marote PDE/BDE/113598/2015 and IF Development Grant to A. J. Salgado. This work is funded by national funds through FCT under the scope of grant reference TUBITAK/0007/2014. This article has been developed under the scope of the projects NORTE-01-0145-FEDER-000023, supported by the Northern Portugal Regional Operational Programme (NORTE 2020), under the Portugal 2020 Partnership Agreement, through the European Regional Development Fund (FEDER). This work has been funded by FEDER funds, through the Competitiveness Factors Operational Programme (COMPETE), and by National funds, through the Foundation for Science and Technology (FCT), under the scope of the project POCI-01-0145-FEDER-007038 and POCI-01-0145-FEDER-02920

Dietary suppression of MHC-II expression in intestinal stem cells enhances intestinal tumorigenesis

Little is known about how interactions between diet, immune recognition, and intestinal stem cells (ISCs) impact the early steps of intestinal tumorigenesis. Here, we show that a high fat diet (HFD) reduces the expression of the major histocompatibility complex II (MHC-II) genes in ISCs. This decline in ISC MHC-II expression in a HFD correlates with an altered intestinal microbiome composition and is recapitulated in antibiotic treated and germ-free mice on a control diet. Mechanistically, pattern recognition receptor and IFNg signaling regulate MHC-II expression in ISCs. Although MHC-II expression on ISCs is dispensable for stem cell function in organoid cultures in vitro, upon loss of the tumor suppressor gene Apc in a HFD, MHC-II- ISCs harbor greater in vivo tumor-initiating capacity than their MHC-II+ counterparts, thus implicating a role for epithelial MHC-II in suppressing tumorigenesis. Finally, ISC-specific genetic ablation of MHC-II in engineered Apc-mediated intestinal tumor models increases tumor burden in a cell autonomous manner. These findings highlight how a HFD alters the immune recognition properties of ISCs through the regulation of MHC-II expression in a manner that could contribute to intestinal tumorigenesis

Cytotoxicity of multifunctional surfactant containing capped mesoporous silica nanoparticles

This paper reports the synthesis of silica capped surfactant (cetyltrimethylammonium bromide; CTAB) and dye (Rose Bengal; RB) containing mesoporous silica nanoparticles (MSNs). Capping the pores of the surfactant containing MSNs with a thin silica layer decreased the immediate surfactant originated cytotoxicity of these particles without affecting their long term (3 days) cytotoxicity. Also, the silica capping process almost completely prevented the hemolytic activity of the surfactant containing MSNs. In addition, improved uptake of silica capped MSNs compared to the uncapped particles by cancer cells was demonstrated. The delayed cytotoxicity, low hemolytic activity, and better cellular uptake of the silica capped MSNs make them promising for the development of safe (i.e. with fewer side effects) yet efficient theranostic agents. These nanocarriers may release the loaded cytotoxic molecules (CTAB) mostly after being accumulated in the tumor site and cause so minimal damage to the normal tissues and blood components. In addition, the nanoscale confinement of RB molecules inside the pores of MSNs makes the particles brightly fluorescent. Furthermore, it was demonstrated that due to the singlet oxygen generation capability of the RB dye the silica capped MSNs can be also used for photodynamic therapy of cancer. © 2016 The Royal Society of Chemistry

Nonporous monosize polymeric sorbents: Dye and metal chelate affinity separation of lysozyme

Garipcan, Bora/0000-0002-1773-5607WOS: 000085582800001Lysozyme adsorption onto dye-attached nonporous monosize poly(2-hydroxyethyl-methacrylate-methylmethacrylate) [poly(HEMA-MMA)] microspheres was investigated. Poly(HEMA-MNA) microspheres were prepared by dispersion polymerization. The monochloro-triazine dye, Cibacron Blue F3GA, was immobilized covalently as dye-ligand. These dye-affinity microspheres were used in the lysozyme adsorption-desorption studies. The effect of initial concentration of lysozyme and medium pH on the adsorption efficiency of dye-attached and metal-chelated microspheres were studied in a batch reactor. Effect of Cu(II) chelation on lysozyme adsorption was also studied. The nonspecific adsorption of lysozyme on the poly(HEMA-MMA) microspheres was 3.6 mg/g. Cibacron Blue F3GA attachment significantly increased the lysozyme adsorption up to 247.8 mg/g. Lysozyme adsorption capacity of the Cu(II) incorporated microspheres (318.9 mg/g) was greater than that of the Cibacron Blue F3GA-attached microspheres. Significant amount of the adsorbed lysozyme (up to 97%) was desorbed in 1 h in the desorption medium containing 1.0M NaSCN at pH 8.0 and 25 mM EDTA at pH 4.9. In order to examine the effects of separation conditions on possible conformational changes of lysozyme structure, fluorescence spectrophotometry was employed. We conclude that dye-attached and metal-chelate affinity chromatography with poly(HEMA-MMA) microspheres can be applied for lysozyme separation without causing any significant changes and denaturation. Repeated adsorption/desorption processes showed that these novel dye-attached monosize microspheres are suitable for lysozyme adsorption. (C) 2000 John Wiley & Sons, Inc

Synthesis of poly[(hydroxyethyl methacrylate)-co-(methacrylamidoalanine)] membranes and their utilization as an affinity sorbent for lysozyme adsorption

Garipcan, Bora/0000-0002-1773-5607;WOS: 000172273200002Various adsorbent materials have been reported in the literature for protein separation. We have developed a novel and new approach to obtain high protein-adsorption capacity utilizing a 2-methacrylamidoalamne-containing membrane. An amino acid ligand 2-methacrylamidoalanine (MAAL) was synthesized from methacrylochloride and alanine. Then, poly[(2-hydro-xyethel methacrylate)-co-(2-methacrylamidoalanine)] [p(HEMA-co-MAAL)] membranes were prepared by UV-initiated photopolymerization of HEMA and MAAL. The synthesized MAAL monomer was characterized by NMR spectrometry. p(HEMA-co-MAAL) membranes were characterized by swelling studies, porosimeter, scanning electron microscopy,FT-IR spectroscopy and elemental analysis. These membranes have large pores; the micropore dimensions are around 5-10 mum. p(HEMA-co-MAAL) affinity membranes with a swelling ration of 198.9%, and containing 23.9 (mmol MAAL).m(-2) were used in the adsorption of lysozyme (0.1-3.0 mg.ml(-1)) and at different pH values (4.0-8.0). The effect of Cu(II) incorporation on lysozyme adsorption was also studied. The non-specific adsorption of lysozyme on the pHEMA membranes was 0.9 mug-cm(-2). Incorporation of MAAL molecules into the polymeric structure significantly increased the lysozyme adsorption up to 2.96 mg.cm(-2). The lysozyme-adsorption capacity of the membranes incorporated with Cu(III) (9.98 mg.cm(-2)) was greater than that of the p(HEMA-co-MAAL) membranes. More than 85% of the adsorbed lysozyme was desorbed in 1 h in the desorption medium containing 1.0 M NaCl. The p(HEMA-co-MAAL) membranes are suitable for repeated use for more than 5 cycles without noticable loss of capacity. These features make p(HEMA-co-MAAL) membrane a very good candidate for bioaffinity adsorption. Adsorption rates of lysozyme: MAAL loading: 23.9 mmol.m(-2); pH: 7.0; temperature: 20 degreesC; total external membrane surface area in each batch: 100 cm(2).l(-1); Each point is the average of five parallel studies

Poly(hydroxyethyl methacrylate-co-methacrylamidoalanine) membranes and their utilization as metal-chelate affinity adsorbents for lysozyme adsorption

Garipcan, Bora/0000-0002-1773-5607;WOS: 000177648400005PubMed: 12182559Different adsorbents have been reported in the literature for protein purification. The authors have developed a novel and new approach to obtain high protein adsorption capacity utilizing a 2-methacrylamidoalanine-containing membrane. Amino acid ligand 2-methacrylamidoalanine (MAAL) monomer was synthesized using methacryloyl chloride and alanine. Poly(2-hydroxyethylmethacrylate-co-2-methacrylamidoalanine) [p(HEMA-co-MAAL)] membranes were then prepared by UV-initiated photopolymerization of HEMA and MAAL in the presence of an initiator (azobisisobutyronitrile, AIBN). The synthesized MAAL monomer was characterized by NMR. p(HEMA-co-MAAL) membranes were characterized by swelling studies, porosimeter, SEM, FTIR, and elemental analysis. These membranes have macropores in the size range of 5-10 mum. Cu(II) ions (25.9 mmol/m(2)) were chelated on these membranes. p(HEMA-co-MAAL) membranes were used to study the adsorption of lysozyme from aqueous media containing different amounts of lysozyme (0.1-3.0 mg/l) and at different pH values (4.0-8.0). The non-specific adsorption of lysozyme on the pHEMA membranes was negligible (0.9 mug/cm(2)). Incorporation of MAAL increased the lysozyme adsorption significantly up to 2.96 mg/cm(2). The lysozyme adsorption capacity of the Cu(II) incorporated membranes (9.98 mg/cm(2)) was greater than that of the p(HEMA-co-MAAL) membranes. More than 90% of the adsorbed lysozyme was desorbed in I h in the desorption medium containing 1.0 M NaCl and 0.025 M EDTA. The metal-chelate affinity membranes are suitable for repeated use for more than ten cycles without a noticeable loss of capacity

Design, Synthesis, And Antitumor Evaluation Of Novel Methylene Moiety-Tethered Tetrahydroquinoline Derivatives

Novel methylene-tethered tetrahydroquinolines (THQs) and cyclopenta[b]pyridines were synthesized by one-pot multicomponent reactions of Mannich bases, enolizable ketones, and NH4 OAc in water by an environmentally friendly K-10 montmorillonite clay-catalyzed reaction. The cytotoxic activities of 1-(2-methyl-8-methylene-5,6,7,8-tetrahydroquinolin-3-yl)ethanone (9a), ethyl 2-methyl-8-methylene-5,6,7,8-tetrahydroquinoline-3 carboxylate (9b), and 1-(2-methyl-7-methylene-6,7-dihydro-5 H-cyclopenta[b]pyridin-3-yl)ethanone (11a) were tested against rat glioblastoma (C6), human breast cancer (MCF-7), prostate cancer (PC3), neuroblastoma (SH-SY5Y), and mouse fibroblast (L929) cell lines in a concentration-dependent (50-300 mu M) and time-dependent (24-72 h) manner and expressed as IC50 values. The results showed that compound 9a induced the lowest IC50 values in all cell lines ranging from 111 +/- 1.1 mu M to 128 +/- 1.3 mu M when compared to 9b and 11a after 72 h. As an evaluation of antibacterial properties, a swarming motility assay was performed with the Pseudomonas aeruginosa PA01 strain and compound 9a showed higher inhibition of swarming motility.WoSScopu

Bioinspired hydrogel surfaces to augment corneal endothelial cell monolayer formation

Abstract Corneal endothelial cells (CECs) have limited proliferation ability leading to corneal endothelium (CE) dysfunction and eventually vision loss when cell number decreases below a critical level. Although transplantation is the main treatment method, donor shortage problem is a major bottleneck. The transplantation of in vitro developed endothelial cells with desirable density is a promising idea. Designing cell substrates that mimic the native CE microenvironment is a substantial step to achieve this goal. In the presented study, we prepared polyacrylamide (PA) cell substrates that have a microfabricated topography inspired by the dimensions of CECs. Hydrogel surfaces were prepared via two different designs with small and large patterns. Small patterned hydrogels have physiologically relevant hexagon densities (∼2000 hexagons/mm²), whereas large patterned hydrogels have sparsely populated hexagons (∼400 hexagons/mm²). These substrates have similar elastic modulus of native Descemet’s membrane (DM; ∼50 kPa) and were modified with Collagen IV (Col IV) to have biochemical content similar to native DM. The behavior of bovine corneal endothelial cells on these substrates was investigated and results show that cell proliferation on small patterned substrates was significantly (p = 0.0004) higher than the large patterned substrates. Small patterned substrates enabled a more densely populated cell monolayer compared to other groups (p = 0.001 vs. flat and p < 0.0001 vs. large patterned substrates). These results suggest that generating bioinspired surface topographies augments the formation of CE monolayers with the desired cell density, addressing the in vitro development of CE layers