Methylation-Based Age Estimation Model Construction and Its Effectiveness Evaluation / 法医学杂志

OBJECTIVES@#To screen the DNA methylation loci associated with the age of Han males in northern China and to construct an age estimation model.@*METHODS@#Twenty-one candidate methylation loci were screened. The DNA methylation levels of 476 blood samples from Chinese Han males were detected for 21 amplicons using EpiTYPER technology platform, and data on 153 DNA methylation loci were obtained.@*RESULTS@#After correlation analysis, 8 age-related DNA methylation loci were finally screened. CpG1, CpG2, CpG4, CpG7, CpG8 were located on TRIM59, RASSF5, Clorf132, CSNK1D, ELOVL2,CpG5, CpG6 on PDE4C, and CpG3 on chr17:21452808. Based on the 8 loci, 352 samples were used for model construction. A multivariate linear regression age estimation model was constructed （R2=0.93）, with mean absolute deviation （MAD） of 2.69 years old. When 109 samples were used for model validation, the MAD was 3.80 years old. The test was repeated 3 times in 15 new samples, with MADs of 4.08, 4.68 and 3.93 years old, respectively.@*CONCLUSIONS@#The age estimation model on Han males in northern China constructed in this study can be used to estimate the age of victims and suspects and to narrow the scope of investigation, and therefore has practical application value.

The protective effects of trace elements against side effects induced by ionizing radiation

Trace elements play crucial role in the maintenance of genome stability in the cells. Many endogenous defense enzymes are containing trace elements such as superoxide dismutase and metalloproteins. These enzymes are contributing in the detoxification of reactive oxidative species (ROS) induced by ionizing radiation in the cells. Zinc, copper, manganese, and selenium are main trace elements that have protective roles against radiation-induced DNA damages. Trace elements in the free salt forms have protective effect against cell toxicity induced by oxidative stress, metal-complex are more active in the attenuation of ROS particularly through superoxide dismutase mimetic activity. Manganese-complexes in protection of normal cell against radiation without any protective effect on cancer cells are more interesting compounds in this topic. The aim of this paper to review the role of trace elements in protection cells against genotoxicity and side effects induced by ionizing radiation.

Modificação de proteínas por produtos de oxidação do colesterol: mecanismos e implicações biológicas / Modification of proteins by oxidation products of cholesterol: mechanisms and biological implications

O colesterol é um importante componente das membranas celulares em eucariotos superiores, desempenhando papéis estruturais e funcionais. O colesterol possui uma insaturação em sua estrutura sendo, portanto, alvo de oxidação mediada por espécies reativas de oxigênio e/ou nitrogênio. A oxidação não enzimática do colesterol gera, como produtos primários, os hidroperóxidos de colesterol. Tais moléculas, por sua vez, são altamente reativas e podem reagir com metais livres e/ou metaloproteínas, trazendo consequências à celula. Neste sentido, o primeiro capítulo deste trabalho tem como objetivo estudar a reação dos hidroperóxidos de colesterol (ChOOH) com o citocromo c (citc), uma heme proteína envolvida no transporte de elétrons na mitocôndria. Análises de espectroscopia no UV-Vis mostraram que o ChOOH promove o bleaching da banda Soret do citc de uma maneira dose-dependente. Mais ainda, esta reação leva à formação de radicais centrados em carbono tanto na proteína como no lipídeo, sugerindo uma redução homolítica do ChOOH. Como consequências, pode-se observar a oligomerização do citc, um processo que pode influenciar no transporte de elétrons bem como na sinalização para a apoptose. A partir da reação do citc com ChOOH podem surgir, direta ou indiretamente, outras espécies reativas, como aldeídos, cetonas e epóxidos. Dentre estas, destacam-se os aldeídos de colesterol, em particular o colesterol secoaldeído (CSec) e o carboxialdeído (ChAld), uma vez que foram encontrados elevados em placas ateroscleróticas e em tecidos cerebrais de pacientes com doenças neurodegenerativas. Tais espécies podem reagir com resíduos de aminoácidos provocando alterações estruturais e funcionais em proteínas. Neste sentido, o segundo capítulo deste trabalho tem como objetivo estudar a reação do ChAld com citc. Usando modelos mimétivos de membrana e espectrometria de massas, foi mostrado que o ChAld modifica covalentemente o citc por um mecanismo consistente com a formação de bases de Schiff. Tal modificação ocorre preferencialmente em resíduos de lisina que interagem com a membrana. Estas modificações influenciam na afinidade do citc pela membrana, aumentando sua aderência, o que pode ter influência no transporte de elétrons e sinalização para a apoptose. No terceiro e último capítulo deste trabalho nós buscamos uma ferramente analítica que permitisse analisar modificação de proteínas promovidas por produtos de oxidação de colesterol e outros esteróis. Em um estudo realizado em colaboração com o grupo do professor Porter na Universidade de Vanderbilt, utilizamos ensaios baseados em click chemistry para buscar proteínas modificadas. Para isso, foram sintetizados derivados de colesterol e 7-deidrocolesterol (7-DHC, precursor imediato do colesterol) contendo um grupo alquinil na sua cadeia lateral. Este grupo pode ser ligado a um grupo azida por meio de uma reação de cicloadição, em um processo conhecido como click chemistry. Após a síntese e caracterização dos derivados lipídicos contendo o grupo alquinil na cadeia lateral, células Neuro2a foram tratadas com o alquinil-7-DHC e o alquinil-colesterol para averiguar seu metabolismo. Análises por HPLC-MS/MS mostraram que ambos derivados contendo o grupo alquinil foram metabolisados e convertdos nos respectivos ésteres. Usando um modelo celular para a doença conhecida como Sindrome de Smith-Lemli-Opitz (SLOS), doença caracterizada pela deficiência na enzima 7-deidrocolesterol redutase, foi mostrado que o acúmulo característico de 7-DHC nos pacientes pode levar a uma maior modificação de proteínas promovidas por seus derivados, o que pode contribuir para o desenvolvimento da doença

Cholesterol is an important component of eukaryotic cellular membranes, where it has an influence in the fluidity and stability. Due to the presence of a double bond in its structure, cholesterol can be oxidized by reactive oxygen and nitrogen species. This non-enzymatic oxidation generates, as primary products, cholesterol hydroperoxides. Such molecules, in turn, are highly reactive and can react with free metal ions and/or metalloproteins, affecting cell metabolism. Therefore, the first chapter of the present study aims to investigate the reaction of cholesterol hydroperoxides (ChOOH) with cytochrome c (cytc), a heme protein involved in the mitochondrial electron transport. Spectroscopic analyses in the UV-Vis region showed that ChOOH induces a dose-dependent bleaching of cytc's Soret band. In addition, this reaction leads to the formation of carbon-centered radicals on both protein and lipid, suggesting a homolytic reduction of ChOOH. As consequences, cytc undergoes oligomerization, a process that can influence electron transport and apoptosis signaling. The reaction of cytc and ChOOH can produce, directly or indirectly, reactive species such as epoxides, aldehydes and ketones. Among them, cholesterol aldehydes, such as cholesterol secoaldehyde (CSec) and cholesterol carboxyaldehyde (ChAld), are of particular interest, since they were previously found elevated in atherosclerotic plaques and brain tissue of patients bearing neurodegenerative diseases. These species can also react with amino acid residues leading to protein denaturation and malfunction. With that in mind, the second chapter of this study aims to investigate the reaction of ChAld and cytc. Using mimetic membrane models and mass spectrometry analyses, we showed that ChAld covalently modifies cytc through a mechanism consistent with the formation of Schiff base adducts. Such modification occurs mostly at lysine residues that are known to interact with the membrane. The modifications have an influence in the affinity of cytc to the membrane, where they increase its binding to the membrane, a process that could affect the electron transport and apoptosis signaling. In the last and third chapter of this study we wanted an analytical tool that allowed the investigation of protein adduction promoted by cholesterol and other sterols-derived oxidation products. In a study performed in collaboration with the Porter group from Vanderbilt University, we used analyses based on click chemistry to search for protein adduction. To address that, we first synthesized derivatives of cholesterol and 7-dehydrocholesterol (7-DHC, the immediate precursor of cholesterol) containing an alkynyl group in the side chain. The alkynyl group can be ligated to an azide group through a cycloaddition reaction, in a process known as click chemistry. After the synthesis and characterization of alkynyl derivatives, Neuro2a cells were treated with alkynyl-7-DHC and alkynyl-cholesterol to check their metabolism. HPLC-MS/MS analyses showed that both alkynyl derivatives are metabolized and converted into their respective esters. In addition, using a cell model for Smith-Lemli-Optiz Syndrome (SLOS), a disease characterized by the deficiency in the dehydrocholesterol reductase 7, we showed that the characteristic accumulation of 7-DHC in SLOS patients might be associated with protein adduction promoted by its oxidation products, which might contribute to the development of the disease

Clinical study of iron protein succinylate oral solution for preventing and treating anemia of prematurity / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To evaluate the efficacy and safety of iron protein succinylate (IPS) oral solution in preventing and treating anemia of prematurity (AOP).</p><p><b>METHODS</b>Sixty premature infants less than 35 weeks of gestation were randomly divided into IPS (n=30) and polysaccharide iron complex (PIC) groups(n=30). Treatment began at two weeks after birth. The infants received IPS or PIC in addition to recombinant human erythropoietin. On days 14, 28, 42, and 60 after treatment, hemoglobin (Hb), red blood cell count(RBC), hematocrit (HCT), percentage of reticulocytes, serum iron, and serum ferritin were determined. Liver and renal functions were evaluated before and after treatment.</p><p><b>RESULTS</b>There were significant differences in the changing trends of RBC and HCT between the two groups (P<0.05). In the IPS group, RBC and HCT gradually decreased after birth, but began to rise gradually on days 28 and 42 of treatment; in the PIC group, RBC and HCT kept decreasing from birth to day 60 of treatment. On day 60 of treatment, the IPS group had significantly higher levels of Hb, RBC, HCT, serum iron, and serum ferritin than the PIC group (P<0.05). No notable adverse events occurred in either group.</p><p><b>CONCLUSIONS</b>IPS oral solution has good efficacy and tolerability in preventing and treating AOP.</p>

Proteínas totales y factor de bioconcentración por exposición a metales en la Gambusia punctata (Poeciliidae) / Total proteins and bioconcentration factor by metal exposure in Gambusia punctata (Poeciliidae)

El objetivo del presente trabajo fue evaluar niveles de proteínas totales y el factor de bioconcentración por exposición a metales en la Gambusia punctata. La especie fue muestreada en el ecosistema Filé y luego trasladada hacia condiciones de laboratorio, donde fueron diseñados 3 tratamientos a 2 réplicas con 25 ejemplares. Se determinó la concentración letal media (CL-50) como parámetro de toxicidad durante 48 horas de bioensayo. Los metales analizados fueron plomo y cadmio, cuantificados por espectroscopia de plasma inductivamente acoplados con vista axial. Transcurrido el experimento, la CL-50 correspondió a 0,1, ensayándose las concentraciones 0,06 y 5,78 mg/L, además del control negativo. Posteriormente se cuantificó el nivel de proteínas totales y los metales en agua, tejido y su relación mediante el factor de bioconcentración. El menor valor de proteínas fue ante la exposición al cadmio, con 43,9 por ciento de inhibición (p< 0,05) en comparación con el control; en el caso del plomo se determinó 2,5 por ciento de estimulación. Las mayores concentraciones en agua y tejido correspondieron a este último, no así para el factor de bioconcentración. Se concluyó que los resultados mostraron sensibilidad en la respuesta del contenido de proteínas totales y alta capacidad bioacumulativa para ambos metales.

The aim of this study was to evaluate levels of total proteins and the bioconcentration factor by metal exposure in Gambusia punctata. The species was sampled in the ecosystem Filé and then transferred to the laboratory, where 3 treatments in 2 replications with 25 copies were designed. Mean lethal concentration (CL-50) was determined as a toxicity parameter for 48 hours of bioassay. The analyzed metals were lead and cadmium, quantified by plasma spectroscopy inductively coupled with axial view. After the experiment, the CL-50 corresponded to 0.1 and concentrations of 0.06 and 5.78 mg/L and the negative control were tested. Then the level of total proteins and metals in water, tissue and its relationship by means of the bioconcentration factor were quantified. The lower value of proteins was by exposure to cadmium with 43.9 percent of inhibition (p <0.05) compared with the control; for lead 2.5 percent of stimulation was determined. The highest concentrations in water and tissue corresponded to the latter, but not for the bioconcentration factor. It was concluded that the results showed sensitivity in the response of total protein content and a high bioaccumulative capacity for both metals.

Estudo da expressão imuno-histoquímica das MMps -2, -7, -9 e TIMPs -1 e -2 em adenomas pleomórficos e carcinomas adenóides císticos de glândulas salivares menores / Study of immunohistochemical expression of MMPs -2, -7, -9, and TIMPs -1 and -2 in pleomorphic adenomas and adenoid cystic carcinoma of minor salivary glands

0 balanço entre a expressão das metaloproteinases da matriz (MMPs) e seus inibidores teciduais (TIMPs) tem sido relacionado a vários processos fisiológicos e patológicos, incluindo a morfogênese de glândulas salivares e os processos de invasão e metástase tumoral. O adenoma pleomórfico (AP) e o carcinoma adenóide cístico (CAC) representam,respectivamente, neoplasias benignas e malignas de glândulas salivares que, embora compartilhem a mesma origem celular, apresentam comportamentos biológicos distintos. O propósito deste estudo foi comparar a expressão imuno-histoquímica das MMPs -2, -7, -9 e -26 e dos TIMPs -1 e -2 em casos de AP e CAC de glândulas salivares menores. Vinte casosde AP e vinte casos de CAC foram avaliados quanto à presença, intensidade e localização das MMPs e TIMPs no parênquima tumoral. A maioria dos APs e CACs apresentaram alta expressão das MMPs e dos TIMPs, predominantemente localizada nas células tumorais. Nãohouve diferença estatisticamente significativa na expressão das MMPs -2 (p=0,359), -7 (p=0,081) e -26 (p=0,553), bem como dos TIMPs -1 (p=0,657) e -2 (p=0,248), entre o parênquima dos APs e CACs. A MMP-9 demonstrou uma diferença significativa de expressão entre os dois tumores, apresentando o CAC uma marcação mais intensa para esta gelatinase(p=0,041). A forte expressão da MMP-9 observada no parênquima dos CACs sugere que esta gelatinase possa desempenhar um papel importante no comportamento biológico destes tumores. Por outro lado, apesar de não ocorrer uma diferença significativa entre as médias das MMPs -2, 7 e 26 nos tumores estudados, os dados quando analisados em conjunto sugeremque estas proteases podem estar participando de processos de remodelação tecidual em ambos os tumores, mas não apresentam uma relação direta com o padrão de agressividade do CAC...

Primary gastrointestinal diffuse large B-cell lymphoma: an immunohistochemical and prognostic study of 90 cases / 中华病理学杂志

<p><b>OBJECTIVE</b>To study the immunophenotype and prognostic significance of primary gastrointestinal diffuse large B-cell lymphoma, with reference to Hans, Choi and Tally algorithms.</p><p><b>METHODS</b>The clinicopathologic features and follow-up data in 90 cases of primary gastrointestinal diffuse large B-cell lymphoma were analyzed by Kaplan-Meier method, Log-rank test and Cox regression model. Immunohistochemistry was carried out using EliVision and EnVision methods for CD20, CD3ε, CD10, bcl-6, MUM-1, CD5, bcl-2, GCET1, FOXP1, LMO2, BLIMP1 and Ki-67.</p><p><b>RESULTS</b>The age of patients ranged from 27 to 83 years (mean = 58 years). The male-to-female ratio was 1.31:1. Amongst the 90 cases studied, 64.4% (58/90) involved the stomach and 35.6% (32/90) involved the intestine. The immunohistochemical findings were as follows: 100% positivity for CD20, 0% for CD3ε and CD5, 17.8% (16/90) for CD10, 75.6% (68/90) for bcl-6, 52.2% (47/90) for MUM-1 (cut off was 30%), 43.3% (39/90) for MUM-1 (cut off was 80%), 50.0% (45/90) for GCET1, 45.6% (41/90) for FOXP1, 23.3% (21/90) for LMO2, 42.2% (38/90) for bcl-2 and 8.9% (8/90) for BLIMP1. The Ki-67 index ranged from 20% to 95% (median = 80%). According to Hans algorithm, 51.1% of the cases belonged to germinal center B-cell (GCB) subtype and 48.9% belonged to non-GCB subtype. In contrast, Choi algorithm classified 55.6% cases as GCB subtype and 44.4% as activated B-cell (ABC) subtype. According to Tally algorithm, 34.4% were of GCB subtype and 65.6% of non-GCB subtype. Most of the patients (67.8%, 61/90) received chemotherapy and 68.9% (62/90) underwent surgical resection. The overall 2, 3 and 5-year survival rates were 58.5%, 52.8% and 49.8%, respectively. The overall 2, 3 and 5-year survival rates in the CHOP therapy group were 68.5%, 61.2% and 52.9%, respectively.</p><p><b>CONCLUSIONS</b>There is no significant difference in ratio between the GCB and non-GCB/ABC subtypes by Hans and Choi algorithms. The non-GCB subtype seems to be more prevalent according to Tally algorithm. Although there is no significant difference in survival between GCB and non-GCB/ABC subtypes by the 3 algorithms, GCB subtype tends to show a better survival. In univariate analysis, LDH level, international prognostic index, chemotherapy, surgical resection, B symptoms, number of involved sites and clinical stage are found to have prognostic significance. In multivariate analysis, Choi algorithm, Tally algorithm, chemotherapy, surgical resection, LDH level and clinical stage are independent prognostic factors.</p>

Engineering a zinc binding site into the de novo designed protein DS119 with a βαβ structure

Functional proteins designed de novo have potential application in chemical engineering, agriculture and healthcare. Metal binding sites are commonly used to incorporate functions. Based on a de novo designed protein DS119 with a βαβ structure, we have computationally engineered zinc binding sites into it using a home-made searching program. Seven out of the eight designed sequences tested were shown to bind Zn(2+) with micromolar affinity, and one of them bound Zn(2+) with 1:1 stoichiometry. This is the first time that metalloproteins with an α, β mixed structure have been designed from scratch.

Heavy metal absorption, transportation and accumulation mechanisms in hyperaccumulator Thlaspi caerulescens / 生物工程学报

Thlaspi caerulescens, the famous model plant of heavy-metal hyperaccumulator, can uptake and accumulate large amount of heavy metals in its above-ground part of the plants. However, the very low biomass in Thlaspi caerulescens makes this plant unfit for direct application in phytoremediation. In recent years, there are many reports about the physiological and molecular characterization of Thlaspi caerulescens under heavy metals stresses, including absorption, transport and intracellular detoxification processes (e.g., chelation and compartmentation). Research teams have conducted many studies of chelators in plants, such as organ acid, amino acid, phytochelatins, metallothioneins and nicotianamine, and so on. Several transport protein families, such as Zinc Regulated Protein, Cation Diffusion Facilitator, Natural Resistance and Macrophage Protein and Heavy Metal ATPase, play important role in short/long distance transport in the plant. In this review, we summarize the current knowledge of the physiological and molecular mechanisms of heavy metals accumulation in Thlaspi caerulescens, with particular emphasis on the roles of transporters and chelatins in modulating plant heave-metal-stress responses.

Hydrogen peroxide induces a specific DNA base change profile in the presence of the iron chelator 2, 2’ dipyridyl in Escherichia coli

Pretreatment of Escherichia coli cultures with the iron chelator 2,2’-dipyridyl (1 mM) protects against the lethal effects of low concentrations of hydrogen peroxide (<15 mM). However, at H2O2 concentrations equal to or greater than 15 mM, dipyridyl pretreatment increases lethality and mutagenesis, which is attributed to the formation of different types of DNA lesions. We show here that pretreatment with dipyridyl (1 mM) prior to challenge with high H2O2 concentrations (≥15 mM) induced mainly G:C→A:T transitions (more than 100X with 15 mM and more than 250X with 20 mM over the spontaneous mutagenesis rate) in E. coli. In contrast, high H2O2 concentrations in the absence of dipyridyl preferentially induced A:T→T:A transversions (more than 1800X and more than 300X over spontaneous mutagenesis for 15 and 20 mM, respectively). We also show that in the fpg nth double mutant, the rpoB gene mutation (RifS-RifR) induced by 20 mM H2O2 alone (20X higher) was increased in 20 mM H2O2 and dipyridyl-treated cultures (110X higher), suggesting additional and/or different lesions in cells treated with H2O2 under iron deprivation. It is suggested that, upon iron deprivation, cytosine may be the main damaged base and the origin of the pre-mutagenic lesions induced by H2O2.

Purification and characterization of extracellular lipase from a new strain: Pseudomonas aeruginosa SRT 9 / Purificação e caracterização de uma lipase extracelular produzida por uma nova cepa: Pseudomonas aeruginosa SRT9

An extra cellular lipase was isolated and purified from the culture broth of Pseudomonas aeruginosa SRT 9 to apparent homogeneity using ammonium sulfate precipitation followed by chromatographic techniques on phenyl Sepharose CL- 4B and Mono Q HR 5/5 column, resulting in a purification factor of 98 fold with specific activity of 12307.8 U/mg. The molecular weight of the purified lipase was estimated by SDS-PAGE to be 29 kDa with isoelectric point of 4.5. Maximum lipase activity was observed in a wide range of temperature and pH values with optimum temperature of 55ºC and pH 6.9. The lipase preferably acted on triacylglycerols of long chain (C14-C16) fatty acids. The lipase was inhibited strongly by EDTA suggesting the enzyme might be metalloprotein. SDS and metal ions such as Hg2+, Zn2+, Cu2+, Ag2+ and Fe2+ decreased the lipase activity remarkedly. Its marked stability and activity in organic solvents suggest that this lipase is highly suitable as a biotechnological tool with a variety of applications including organo synthetic reactions and preparation of enantiomerically pure pharmaceuticals. The Km and Vmax value of the purified enzyme for triolein hydrolysis were calculated to be 1.11 mmol/L and 0.05 mmol/L/minrespectively.

Uma lipase extracelular foi isolada e purificada a partir de um caldo de cultura de Pseudomonas aeruginosa SRT9 até homogeneidade visível empregando-se precipitação com sulfato de amônia, seguida de técnicas cromatográficas em colunas de fenil sefarose CL-4B e Mono Q HR 5/5, obtendo-se um fator de purificação de 98 vezes, e atividade especifica de 12307,8 U/mg. Por SDS_PAGE, estimou-se que o peso molecular da lipase purificada é 29kDa, com um ponto isoelétrico de 4,5. A lipase apresentou atividade máxima em uma ampla faixa de temperatura e pH, com ótimos a 55ºC e pH 6,9. A lípase foi mais ativa sobre triacilglicerois de cadeia longa (C14-C16). A lipase foi fortemente inibida por EDTA, o que sugere que a enzima pode ser uma metaloproteína. SDS e íons metálicos, como Hg2+, Zn2+,Cu2+, Ag2+ e Fe2+, diminuíram marcadamente a atividade da lipase. Sua grande estabilidade e atividade em solventes organicos sugerem que esta lípase pode ser uma excelente ferramenta tecnológica com várias aplicações como reações organosintéticas e preparação de produtos farmacêuticos enantiomericamente puros. Os valores de Km e Vmax para a enzima purificada na hidrólise de trioleina foram 1,11 mmol/L e 0,05 mmol/L/min, respectivamente.

Identification of interaction partners and function analysis of new splicing product of human LMO2 gene / 中华血液学杂志

<p><b>OBJECTIVE</b>To identify the interaction partners of a new splicing product of LMO2 gene (LMO2-C), and study its function in K562 cells.</p><p><b>METHODS</b>Maltose binding protein (MBP) pull down and mammalian two-hybrid assay (MTHA) were used to identify the interaction partners of LMO2-C in K562 cells. Semiquantitative RT-PCR was used to detect the expression of hematopoietic specific gene glycoprotein (GPA) in K562 cells.</p><p><b>RESULTS</b>MBP-LMO2-C fusion protein was expressed and purified in soluble form successfully. Endogenous GATA1 and LDB1 proteins were confirmed to bind to LMO2-C by MBP pull down analysis. The MTHA also showed that LMO2-C had comparable binding affinities to LDB1 with LMO2-L, and over expression of LMO2-C prevented LMO2-L from binding to LDB1, the inhibition rate being (81.13 +/- 0.68)%. RT-PCR results showed that the expression level of GPA was reduced [(51.00 +/- 1.58)%] in K562 cells while LMO2-C overexpressed.</p><p><b>CONCLUSION</b>LMO2-C can bind endogenous GATA1 and LDB1 protein in K562 cells and down regulates the expression of GPA.</p>

Effect of different tags on pulldown assays implemented by LMO2 fusion protein / 生物工程学报

Pulldown assay is an in vitro method for studies of protein-protein interactions, in which tagged proteins are usually expressed as the bait to enrich other proteins that could bind to them. In this technology, the GST tag is broadest used for its modest size and hydrophilic property. In most cases, the GST tag could increase the hydrophility of the fusion protein and help to avoid the formation of inclusion bodies. However, in the other few cases, the target protein may be strongly hydrophobic or have complicated structures that were hard to fold and assemble in correct conformations without champerons, and even the existence of GST tag could not make them soluble. These proteins were always expressed as inclusion bodies and had no functions. LMO2 was a small molecular weight and insoluble protein, in this study, GST system and MBP system were used to express GST-LMO2 and MBP-LMO2 fusion proteins, respectively. We found that GST-LMO2 fusion protein was expressed as inclusion bodies whereas MBP-LMO2 fusion protein was expressed in soluble form. Moreover, the production rate of MBP-LMO2 was also much higher than GST-LMO2. Then MBP-LMO2 fusion proteins and renatured GST-LMO2 fusion proteins were used as bait in pulldown assay to study the interaction between LMO2 and endogenous GATA1 in K562 cells. Western blot analyses showed that both of these proteins could bind to endogenous GATA1 in K562 cells, but recovered GATA1 protein by MBP-LMO2 fusion protein was much more than GST-LMO2 fusion protein. These results suggest that using of MBP system is a helpful attempt in the case of studying small molecular weight, strong hydrophobic proteins.

Contribuição à avaliação de pacientes com adednocarcinoma pulmonar avançado: estudo imunohistoquimico da espressão de fator 1 e de transcrição tireoidiano e da metaloproteínas 9 / Contribution to the prognostic assessment of patientes with advanced lunh adenovarcinoma; evaluation by immunohistochemical methods of thyroid transcription factor-1 and matrix metalloproteinase-9

O valor prognóstico da expressão do Fator 1 de Transcrição Tireoideano (TTF-1) e da metaloproteinase-9 (MMP-9) foi avaliado em 51 pacientes com adenocarcinoma pulmonar avançado. Foram fatores de mau prognóstico : baixa capacidade funcional (P=0,017), baixa expressão de TTF-1 (p=0,001) e alta expressão de MMP-9 (p=0,008). Identificaram-se três grupos de risco para mortalidade : baixo risco (TTF-140 por cento e MMP-9<80 por cento; sobrevida : 127,6 semanas), risco intermediário (TTF-1<40 por cento ou MMP-980 por cento; sobrevida : 39,0 semanas) e alto risco (TTF-1<40 por cento e MMP-980 por cento; sobrevida: 16,4 semanas). Com a detecção destes marcadores, podem-se identificar subgrupos com prognósticos clinicamente distintos / The prognostic value of Thyroid Transcription Factor-1 (TTF-1) and Matrix Metalloproteinase-9 (MMP-9) tumor expression was evaluated in 51 patients with advanced lung adenocarcinoma. Poor performance status (P=0,017), low TTF-1 (P=0.001), and high MMP-9(P=0.008) were independent prognostic factors. There were three risk group: low risk (TTF-140 per cent and MMP-9<80 per cent; median survival: 127.6 wk), intermediate risk (TTF-1<40 per cent or MMP-9>80 per cent; median survival: 39.0WK), and high risk (TTF-1<40 per cent and MMP-9 80 per cent; median survival: 16.4 wk). Evaluation of TTF-1 and MMP-9 may allow us to identify different, clinically meaningful, prognostic group of lung adenocarcinoma patients ...

Xinxibao for the treatment of chronic bacterial prostatitis / 中华男科学杂志

<p><b>OBJECTIVE</b>To study the effect of Xinxibao as a supplementary drug in the treatment of chronic bacterial prostatitis (CBP).</p><p><b>METHODS</b>Eighty-one cases of CBP were divided into two groups: Group A (n = 38), treated with Xinxibao combined with sensitive antibiotic, and Group B (n = 43), treated with sensitive antibiotic only. Contrast studies were made on the therapeutic effects in the two groups, and the results were analyzed.</p><p><b>RESULTS</b>The effectivity rate was significantly higher in Group A than in Group B.</p><p><b>CONCLUSION</b>Xinxibao can effectively relieve the symptoms of CBP.</p>

Expresión de biomarcadores de contaminación ambiental en organismos acuáticos bonaerenses / Biomarkers of contamination in coastal aquatic organisms of Río de La Plata (Argentina)

El desarrollo y aplicación de herramientas bioanalíticas en el diagnóstico ambiental ha cobrado un importante auge en la última década. De éstas, el grupo constituido por el conjunto de modificaciones a nivel celular y molecular que indican la presencia de contaminantes, ha recibido la denominación de "biomarcadores de contaminación". Estos se caracterizan por indicar en organismos centinelas la presencia subletal de xenobióticos de forma temprana. Entre los biomarcadores se destaca el estudio de la expresión de proteínas citosólicas como las metalotioneínas (o fitoquelatinas cuando de plantas se trata), y las proteínas de estrés ("Stress Proteins"), constituyendo ambos grupos descripciones complementarias, refiriendo sólo el primero respuesta específica a la exposición a metales. En esta presentación se exponen los resultados obtenidos en el desarrollo y optimización de biomarcadores en organismos representativos de la biota presente en la franja costera sur del Río de La Plata como Corbicula fluminea y Limnoperna fortunei (malacofauna regional) y Schoenoplectus californicus, Pistia stratiotes y Sagitaria montevidensis, plantas acuáticas de gran ubicuidad en la zona. Particularmente se analizan las cinéticas de captación de metales por parte de dichos organismos y su correlación con la expresión de proteínas citosólicas. La concentración de metales se determina por absorción atómica, mientras que el análisis de los perfiles proteicos se realiza mediante electroforesis SDS-PAGE (Tris-tricina)

Porphyrinosilica and metalloporphyrinosilica: hybrid organic-inorganic materials prepared by prepared by sol-gel processing

New materials porphyrinosilica and metalloporphyrinosilica template have been obtained by a sol-gel processing where functionalyzed porphyrins and metalloporphyrins "building blocks" were assembled into a three-dimensional silicate network. The optimized conditions for preparation of these materials are reviseed. The monomer precursors porphyrinopropylsilyl and metalloporphyrinopropylsilyl preparation reactions and subsequent one pot sol-gel processing with tetraethoxysilane are discussed. In the case of metalloporphyrins the nitrogen base coordinates to the central metal and acts as a template in the molecular imprinting technique. UV-visible absorption spectroscopy, thermogravimetric analysis, electron paramagnetic resonance, nuclear magnetic spectra, infrared spectra, luminescence spectra, surface area and electron spectroscopy imaging of the materials are used to characterize the prepared materials. The catalytic activities of these metalloporphyrinosilica-template are compared.

Serum butyrylcholinesterase of non-human primate shows amine sensitive aryl acyl amidase and metallopeptidase activities and characteristics similar to those of the human serum enzyme.

Butyrylcholinesterase (BChE) was purified from monkey serum and the catalytic activities were examined. The enzyme has a molecular mass of approximately equal to 74 kDa as seen by SDS-gel electrophoresis. Monkey serum BChE also exhibits an amine sensitive aryl acylamidase (AAA) and a metallocarboxypeptidase activity. The tyramine activation of the aryl acylamidase activity and the metal chelator inhibition of the peptidase activity were characteristics similar to those of the human enzyme. Studies on 65Zn2+ binding and zinc chelate Sepharose chromatography showed that monkey serum BChE and human serum BChE have similar characteristics. Limited alpha chymotrypsin digestion of monkey serum BChE followed by Sephadex gel chromatography cleaved the enzyme into a 36 kDa fragment exhibiting peptidase activity. However the 20 kDa fragment corresponding to cholinesterase and aryl acylamidase activity was not detectable possibly due to the unstable nature of the fragment. Immunological studies showed that a polyclonal antibody against human serum BChE cross reacted with monkey serum BChE. The identical nature of the catalytic activities of human serum BChE and monkey serum BChE supports the postulate that all three catalytic activities co-exist in the same enzyme. This is the first time that purification and characterisation of the monkey serum BChE which has the highest sequence identity and immunological identity with that of human serum BChE, is being reported.

Calcium- and zinc-binding proteins in intracellular transport

The complex mechanism of intracellular transport is regulated by free calcium in different manners. Calcium binding proteins regulate several aspects of the vesicle fusion mechanism mediated by NSF (N-ethylmaleimide sensitive fusion factor). At least in some regulated exocytosis, calcium-binding proteins are the trigger for fusion downstream of NSF, Still, calcium-binding proteins, such as annexins, may be part of a different fusion mechanism mediating some specific transport steps or working in parallel to the NSF-dependent fusion process. Calcium is not the only ion necessary for the function of factors involved in vesicular transport. A zinc requirement has been also proposed. One of the zinc-dependent factors is probably a protein with a cysteine-rich region that coordinates zinc and binds phorbol esters. Although protein kinase C is the more prominent family of proteins carrying this domain, the factor necessary for transport does not appear to function as a kinase.