Estudo de associação entre variantes dos genes BCHE,APOE,SLITRK3, MME e GHRL e perfil das proteínas Apoe : as colinesterases BCHE/ACHE e a doença de Alzheimer

Orientador : Prof. Dr. Ricardo L. R. de SouzaTese (doutorado) - Universidade Federal do Paraná, Setor de Ciências Biológicas, Programa de Pós-Graduação em Genética. Defesa: Curitiba, 30/06/2014Inclui referênciasÁrea de concentração : GenéticaResumo: Na doenca de Alzheimer (DA) os padroes colinergicos sao alterados, ocorrendo reducao da acetilcolinesterase (AChE) e um aumento da butirilcolinesterase (BChE) nas regioes encefalicas. A K (539T) e a variante mais comum do gene BCHE e varios estudos demonstraram associacao entre essa variante e a DA. A associacao e controversa, enquanto alguns trabalhos sugerem um efeito protetor da K, outros associam como fator de risco para a DA. Ou ainda, como um fator de risco dependente da sinergia entre BCHE-K e APOE4. Para melhor compreender a dinamica colinergica na DA e importante avaliar as variantes geneticas, proteicas e enzimaticas atuantes no organismo como um todo, pois, muitos trabalhos tem considerado apenas os niveis encefalicos e nao o plasmatico para essas variantes. Considerando essa discussao, o presente trabalho teve por objetivo avaliar o perfil proteico, em plasma, para BChE, AChE e ApoE em 112 pacientes com DA e 118 controles idosos e a associacao com as variantes genotipicas: K, -116A e 1914G do gene BCHE, a variante L72M do gene GHRL, variante APOEƒÃ4 do gene APOE, dois SNPs para o gene SLITRK3 (rs3828419 e rs17449213) e dois polimorfismos do gene MME (rs1086740 e rs2016846). Estes genes, SLITRK3 e MME, estao a jusante do gene BCHE. Os niveis de ApoE, AChE e BChE proteica e enzimaticas foram mensurados por ELISA sanduiche, no Instituto Karolinska (Estocolmo . SE), com otimizacao de um novo protocolo para mensuracao do perfil proteico para BChE, e adaptacao para avaliacao em plasma para ApoE e AChE. Os genotipos foram obtidos com uso do kit de genotipagem por TaqManR (Applied Biosystems). Ocorreu um decrescimo da atividade da BChE em pacientes com doenca de Alzheimer, no entanto, essa reducao parece ser devido ao curso da patologia. A variante K, por si so, nao foi suficiente para diminuir a atividade da BChE, mas em conjunto com a variante 1914G do gene BCHE. Estas variantes, 1914G e K, estao em desequilibrio de ligacao e, eventualmente, este fato contribui para controversia e nao compreensao do papel desta variante (K) na DA. Dos genes a jusante da BCHE, as variantes analisadas para SLITRK3 nao foram associacao com a DA. Contudo, ambas as variantes do gene MME foram associadas a alteracoes no padrao enzimatico e proteico da BChE. O rs1086740 foi associado a diminuicao da atividade da BChE, inclusive conferindo decrescimo na atividade da BChE-K, porem sem associacao direta com a DA. O SNP rs2016846, em homozigose para o genotipo usual (TT), foi associado ao aumento da atividade da BChE e esteve associado a DA nos estagios moderado e grave (CDR2 e CDR3), sendo a variante rs2016846, no presente trabalho, um fator protetivo contra DA. A variante APOE4, como esperado, foi associada a presenca da DA e, representou diminuição da concentração da proteína ApoE. O aumento da concentração da ApoE foi correlacionado com aumento do déficit cognitivo. Nossos resultados foram condizentes com um processo sinérgico entre ApoE e BChE, com atuação da atividade da BChE sobre a concentração da ApoE, principalmente na presença da variante -116A do gene BCHE. A atividade da AChE está aumentada em DA, e mais ainda na presença da -116A do gene BCHE. Assim sendo, consideramos que o padrão colinérgico, ao nível plasmático, é modulado por uma gama de variáveis, e que variantes como a BCHE-K dependem de uma série de interações, genéticas e ambientais, e não devem ser avaliados isoladamente como fator de proteção ou risco para a doença de Alzheimer. Este trabalho demostra ainda, que o padrão de atividade da AChE e BChE periférico é o oposto ao padrão encefálico, apontando a necessidade de avaliar a direção desta regulação e o papel da variante -116A, do gene BCHE, neste processo, visando também otimizar o uso dos inibidores colinérgicos na DA. Destacamos também o potencial das variantes do gene MME na modulação da atividade da BChE e ação protetora da variante rs2016846 do gene MME contra DA. Palavras-chave: MME, rs2016846; variante K, perfil colinérgico plasmático, Apolipoproteína E.Abstract: In Alzheimer's disease (AD) cholinergic patterns are changed, became of a reduction in Acetylcholinesterase (AChE) and an increase in butyrylcholinesterase (BChE) activity in brain regions. The K (539T) is the most common variant of the BCHE gene and several studies reported an association between this variant and AD. The association is controversial, while some suggest a protective effect, others suggest K as risk factor for AD. Or yet, as risk factor dependent of synergy between BCHE-K and APOE4. To better understand the cholinergic dynamic in AD, is important to evaluate the genetic, proteic and enzyme variants working in the body as a whole, as many studies have considered only the brain levels and no plasmatic to evaluate these variants. Considering this discussion, this work aimed to evaluate the protein profile in plasma for BChE, AChE and ApoE in 112 AD patients and 118 elderly controls and the association with the genotypic variants: K, -116A and -1914 of BCHE gene, the L72M variant of GHRL, APOEå4 of APOE gene, two SNPs for SLITRK3 gene (rs3828419 and rs17449213) and two polymorphisms for MME (rs1086740 and rs2016846). These genes, SLITRK3 and MME, are downstream of the BCHE gene. ApoE, AChE and BChE levels in plasma were measured by sandwich ELISA in the Karolinska Institute, Department of Neurobiology (Stockholm, SE) with optimization of a new protocol for BChE protein profile measurement, and protocol adaptation for ApoE and AChE in plasma evaluation. The genotyping was performed with the kit TaqMan® genotyping assays (Applied Biosystems). A decrease in the BChE activity was observed in patients, however this reduction seems to be due to progress of the AD pathology. The variant K, alone, was not sufficient to account for a decrease in BChE activity, unless together with the 1914G variant BCHE gene. These variants, 1914G and K, are in linkage disequilibrium and, eventually, this fact contributes to controversy about the role of this variant (K) in AD. Of the genes downstream of BCHE evaluated, SLITRK3 variants were not association with AD. However, both MME gene variants were associated with alterations in the BChE enzymatic and protein standard. The rs1086740 was associated with decreased in BChE activity, even conferring decrease in BChE-K activity, but not straight associated with AD. The SNP rs2016846, in the homozygote genotype for the usual form (TT), was associated with increased in BChE activity and was associated with AD in the moderate and severe stages (CDR2 and CDR3). This variant, rs2016846, in the present work, conferred protection against AD. The ApoE4 variant, as expected, was associated with the presence of AD and partnered for lowering of the ApoE protein concentration. The higher concentrations of ApoE were correlated with increased cognitive deficit. Our results were consistent with a synergistic process between ApoE and BChE, with ApoE concentration modulated by the BChE activity, especially in the presence of the -116A variant of BCHE gene. The AChE activity is increased in AD, and even more in the presence of -116A of BCHE gene. Therefore, we consider that the cholinergic profile, in plasma level, is modulated by a set of variables, and variants such as BCHE-K, are dependent on a series of genetic and environmental interactions, and should not be evaluated singly as a protective factor or increased risk of Alzheimer's disease. This work also demonstrates that the peripheral pattern of AChE and BChE activity is the opposite of the brain pattern. This finding indicates the requirement to evaluate the direction of this regulation and the role of variant -116A of BCHE gene in this process, aiming also optimize the use of cholinergic inhibitors in AD. We also emphasize the potential of the MME gene variants in modulating the activity of BChE and protective action of the gene variant rs2016846 MME against AD. Keywords: MME, rs2016846, K variant, cholinergic plasma profile, apolipoprotein E

Synthesis of Nanostructure In_xGa_1−xN Bulk Alloys and Thin Films for LED Devices

In this study, we investigated an innovative method for the fabrication of nanostructure bulk alloys and thin films of indium gallium nitride (InxGa1−xN) as active, thin films for light-emitting diode (LED) devices using both crystal growth and thermal vacuum evaporation techniques, respectively. These methods resulted in some tangible improvements upon the usual techniques of InxGa1−xN systems. A cheap glass substrate was used for the fabrication of the LED devices instead of sapphire. Indium (In) and Gallium (Ga) metals, and ammonia (NH3) were the precursors for the alloy formation. The alloys were prepared at different growth temperatures with compositions ranging from 0.1 ≤ x ≤ 0.9. InxGa1−xN alloys at 0.1 ≤ x ≤ 0.9 had different crystallinities with respect to X-Ray diffraction (XRD) patterns where the energy bandgap that was measured by photoluminescence (PL) fell in the range between 1.3 and 2.5 eV. The bulk alloys were utilized to deposit the thin films onto the glass substrate using thermal vacuum evaporation (TVE). The XRD thin films that were prepared by TVE showed high crystallinity of cubic and hexagonal structures with high homogeneity. Using TVE, the InxGa1−xN phase separation of 0.1 ≤ x ≤ 0.9 was eliminated and highly detected by XRD and FESEM. Also, the Raman spectroscopy confirmed the structure that was detected by XRD. The FESEM showed a variance in the grain size of both alloys and thin films. The InxGa1−xN LED device with the structure of glass/GaN/n-In0.1Ga0.9N:n/In0.1Ga0.9N/p-In0.1Ga0.9N:Mg was checked by the light emitted by electroluminescence (EL). White light generation is a promising new direction for the fabrication of such devices based on InxGa1−xN LED devices with simple and low-cost techniques

Preparation and characterization of DC sputtered molybdenum thin films

Molybdenum (Mo) thin films have been deposited on soda-lime glass substrates using a DC magnetron sputtering system. Their electrical resistivity, and their morphological, structural and adhesive properties have been examined with respect to the deposition power, deposition time and substrate temperature. The electrical resistivity of the Mo films could be reduced by increasing any of the above parameters. Within the range of the investigated deposition parameters, the films showed a mono-crystalline nature with a preferred orientation along the (1 1 0) plane. The Mo films adhesion to the soda-lime glass could be improved by increasing the substrate temperature. At a deposition power of 200 W, deposition time of 20 min and substrate temperature of 450 °C, Mo thin film exhibiting mono-crystalline structure with thickness equal to 450 nm and electrical resistivity equal to 1.85 × 10−4 Ω cm was obtained

Bacterial nanocellulose from agro-industrial wastes: low-cost and enhanced production by Komagataeibacter saccharivorans MD1

Bacterial nanocellulose (BNC) has been drawing enormous attention because of its versatile properties. Herein, we shed light on the BNC production by a novel bacterial isolate (MD1) utilizing various agro-industrial wastes. Using 16S rRNA nucleotide sequences, the isolate was identified as Komagataeibacter saccharivorans MD1. For the first time, BNC synthesis by K. saccharivorans MD1 was investigated utilizing wastes of palm date, fig, and sugarcane molasses along with glucose on the Hestrin-Schramm (HS) medium as a control. After incubation for 168 h, the highest BNC yield was perceived on the molasses medium recording 3.9 g/L with an initial concentration of (v/v) 10%. The physicochemical characteristics of the BNC sheets were inspected adopting field-emission scanning electron microscope (FESEM), atomic force microscopy (AFM), X-ray diffraction (XRD), and Fourier transform infrared (FTIR) analysis. The FESEM characterization revealed no impact of the wastes on either fiber diameter or the branching scheme, whereas the AFM depicted a BNC film with minimal roughness was generated using date wastes. Furthermore, a high crystallinity index was estimated by XRD up to 94% for the date wastes-derived BNC, while the FTIR analyses exhibited very similar profiles for all BNC films. Additionally, mechanical characteristics and water holding capacity of the produced BNCs were studied. Our findings substantiated that expensive substrates could be exchanged by agro-industrial wastes for BNC production conserving its remarkable physical and microstructural properties.Te authors would like to express their grateful thanks to the City of Scientifc Research and Technological Applications (SRTA-City), New Borg El-Arab City, Alexandria, Egypt for its support in implementing this study.Peer reviewe

Novel slag/natural rubber composite as flexible material for protecting workers against radiation hazards

Abstract This work is an attempt to employ the electric arc furnace (EAF) slag as a by-product material to develop an alternative and environmentally friendly material for gamma-radiation protection applications such as in medical and industrial areas. For this purpose, different concentrations of micro-sized EAF slag (0, 20, 40, 60, 80, 100, 500, and 800 phr) were incorporated as fillers in the natural rubber (NR) matrix to produce the shielding composites. In addition, nano-sized EAF slag particles were prepared by using a high-energy ball milling technique to investigate the effect of particle size on the gamma-radiation shielding properties. The synthesized micro and nano EAF/NR composites were tested as protective materials against gamma-radiation by employing NaI(Tl) scintillation detector and standard radioactive point sources (152Eu, 137Cs, 133Ba, and 60Co). Different shielding parameters such as linear and mass attenuation coefficient, half value layer (HVL), tenth value layer, mean free path, effective atomic number (Zeff), and effective electron density (Neff) were determined to assess the radiation shielding capability of the EAF/NR composites. Furthermore, equivalent atomic number (Zeq) and the exposure buildup factor values for photon energy in the range from 0.015 to 15 MeV were also computed by Geometric Progression method. The experimental results of micro EAF/NR composites showed that at 121.78 keV, EAF0 composite (without EAF slag content) had the lowest μ value of 0.1695 cm−1, while the EAF800 composite (which was loaded with 800 phr of micro EAF slag) had the highest μ value of 0.2939 cm−1 at the same energy, which in turn decreases the HVL from 4.09 to 2.36 cm, respectively. Therefore, increasing the filler weight fractions of EAF slag in the NR matrix, increases the shielding properties of the composites. Moreover, the NR composite reinforced with 800 phr of nano EAF slag has better gamma-radiation shielding efficiency compared to that filled with 800 phr of micro EAF slag. The success of this work was to prepare a flexible, lightweight, low-cost, and lead-free material with better shielding capability