ABSTRACT
BACKGROUND: S-nitrosylation of mitochondrial enzymes involved in energy transfer under nitrosative stress may result in ATP deficiency. We investigated whether α-lipoic acid, a powerful antioxidant, could alleviate nitrosative stress by regulating S-nitrosylation, which could result in retaining the mitochondrial enzyme activity. METHODS: In this study, we have identified the S-nitrosylated forms of subunit 1 of dihydrolipoyllysine succinyltransferase (complex III), and subunit 2 of the α-ketoglutarate dehydrogenase complex by implementing a fluorescence-based differential quantitative proteomics method. RESULTS: We found that the activities of these two mitochondrial enzymes were partially but reversibly inhibited by S-nitrosylation in cultured endothelial cells, and that their activities were partially restored by supplementation of α-lipoic acid. We show that protein S-nitrosylation affects the activity of mitochondrial enzymes that are central to energy supply, and that α-lipoic acid protects mitochondrial enzymes by altering S-nitrosylation levels. CONCLUSIONS: Inhibiting protein S-nitrosylation with α-lipoic acid seems to be a protective mechanism against nitrosative stress. GENERAL SIGNIFICANCE: Identification and characterization of these new protein targets should contribute to expanding the therapeutic power of α-lipoic acid and to a better understanding of the underlying antioxidant mechanisms.
Subject(s)
Electron Transport Complex III/metabolism , Ketoglutarate Dehydrogenase Complex/metabolism , Nitric Oxide/metabolism , Oxidative Stress , Thioctic Acid/pharmacology , Adenosine Triphosphate/biosynthesis , Animals , Cells, Cultured , Mice , Mice, Inbred C57BL , Mitochondria/drug effects , Mitochondria/metabolismABSTRACT
D2C7-immunotoxin (IT), a dual-specific IT targeting wild-type epidermal growth factor receptor (EGFR) and mutant EGFR variant III (EGFRvIII) proteins, demonstrates encouraging survival outcomes in a subset of patients with glioblastoma. We hypothesized that immunosuppression in glioblastoma limits D2C7-IT efficacy. To improve the response rate and reverse immunosuppression, we combined D2C7-IT tumor cell killing with αCD40 costimulation of antigen-presenting cells. In murine glioma models, a single intratumoral injection of D2C7-IT+αCD40 treatment activated a proinflammatory phenotype in microglia and macrophages, promoted long-term tumor-specific CD8+ T cell immunity, and generated cures. D2C7-IT+αCD40 treatment increased intratumoral Slamf6+CD8+ T cells with a progenitor phenotype and decreased terminally exhausted CD8+ T cells. D2C7-IT+αCD40 treatment stimulated intratumoral CD8+ T cell proliferation and generated cures in glioma-bearing mice despite FTY720-induced peripheral T cell sequestration. Tumor transcriptome profiling established CD40 up-regulation, pattern recognition receptor, cell senescence, and immune response pathway activation as the drivers of D2C7-IT+αCD40 antitumor responses. To determine potential translation, immunohistochemistry staining confirmed CD40 expression in human GBM tissue sections. These promising preclinical data allowed us to initiate a phase 1 study with D2C7-IT+αhCD40 in patients with malignant glioma (NCT04547777) to further evaluate this treatment in humans.
Subject(s)
Brain Neoplasms , Glioblastoma , Glioma , Immunotoxins , Humans , Animals , Mice , Glioblastoma/pathology , Immunotoxins/genetics , CD8-Positive T-Lymphocytes , Adaptive Immunity , ErbB Receptors/metabolism , Cell Line, Tumor , Brain Neoplasms/therapyABSTRACT
Apolipoprotein E (ApoE) is a major lipid carrier protein. In humans, ApoE is expressed in three polymorphic isoforms, which are encoded by three different alleles APOE2, APOE3, and APOE4. In the brains of Alzheimer's disease (AD) patients, each one of these three allelic isoforms is found in several "isoelectric" protein isoforms (qPI), i.e. protein isoforms resulting from PTMs altering the net charge (q) of the polypeptide. AD is a complex disease in which multiple causes and several risk factors affect the onset and disease outcome. A major risk factor for AD is ApoE4; therefore, it is important to characterize the different ApoE qPIs. We have implemented a detergent-based method for isolation and quantitation of protein isoforms, and we found differences in the solubility of protein isoforms depending on the type of solvent used. In this manuscript, we describe these methods and applied them to young human-ApoE targeted replacement mice. Our results indicate that there are no significant differences in the hippocampus proteome of these mice as a function of the APOE genotype.
Subject(s)
Apolipoprotein E3/biosynthesis , Apolipoprotein E4/biosynthesis , Proteome/analysis , Analysis of Variance , Animals , Apolipoprotein E3/analysis , Apolipoprotein E3/genetics , Apolipoprotein E3/metabolism , Apolipoprotein E4/analysis , Apolipoprotein E4/genetics , Apolipoprotein E4/metabolism , Creatine Kinase/analysis , Creatine Kinase/chemistry , Creatine Kinase/metabolism , Electrophoresis, Gel, Two-Dimensional , Genotype , Hippocampus/chemistry , Hippocampus/metabolism , Humans , Mice , Mice, Transgenic , Phosphopyruvate Hydratase/analysis , Phosphopyruvate Hydratase/chemistry , Phosphopyruvate Hydratase/metabolism , Protein Isoforms , Proteome/chemistry , Proteome/genetics , Proteome/metabolism , Proteomics/methods , SolubilityABSTRACT
To better elucidate temporal changes in protein oxidation resulting from aging and the Alzheimer's disease-associated Apolipoprotein E (ApoE), we developed a 2D-DIGE-based method for simultaneously detecting differential expression and carbonyl oxidation of proteins. Specifically, we examined changes in the levels of oxidation and total protein expression in hippocampi from young-adult (25-30 weeks) and old (76-97 weeks) mice transgenic for the human Apolipoprotein E gene (APOE, APOE3, APOE4) isoforms, APOE3 or APOE4. Protein samples were labeled with either a fluorescent aminooxyacetamide (Alexa Fluor 488) to detect carbonyl modifications or with NHS-Cy3 to detect total protein expression. A protein sample used as an internal control was labeled with NHS-Cy5 and run on each gel. DIGE analysis revealed 38 differentially oxidized and 100 differentially expressed protein spots with significantly different levels (P < 0.05). For oxidized proteins, principal component analysis revealed two distinct clusters: one in which oxidation increased with age independent of APOE genotype, and the second in which oxidation was dependent on APOE genotype. For total protein expression, principal component analysis revealed a large overlap between changes with overall aging and between APOE genotypes. The use of a fluorescent tag to label oxidized proteins, in combination with a NHS-Cy3 to label total protein, makes it possible to determine changes in both protein oxidation and protein expression levels in a single experiment. These studies reveal that the expression levels of peroxiredoxin protein family members Prdx2, 3, and 6 are modified by age, APOE genotype, or both.
Subject(s)
Aging/physiology , Apolipoprotein E3 , Apolipoprotein E4 , Genotype , Oxidation-Reduction , Animals , Apolipoprotein E3/chemistry , Apolipoprotein E3/genetics , Apolipoprotein E3/metabolism , Apolipoprotein E4/chemistry , Apolipoprotein E4/genetics , Apolipoprotein E4/metabolism , Humans , Mass Spectrometry/methods , Mice , Mice, Transgenic , Principal Component Analysis , Two-Dimensional Difference Gel Electrophoresis/methodsABSTRACT
The vast literature on the mode of action of polychlorinated biphenyls (PCBs) indicates that PCBs are a unique model for understanding the mechanisms of toxicity of environmental mixtures of persistent chemicals. PCBs have been shown to adversely affect psychomotor function and learning and memory in humans. Although the molecular mechanisms for PCB effects are unclear, several studies indicate that the disruption of Ca(2+)-mediated signal transduction plays significant roles in PCB-induced developmental neurotoxicity. Culminating events in signal transduction pathways include the regulation of gene and protein expression, which affects the growth and function of the nervous system. Our previous studies showed changes in gene expression related to signal transduction and neuronal growth. In this study, protein expression following developmental exposure to PCB is examined. Pregnant rats (Long Evans) were dosed with 0.0 or 6.0mg/kg/day of Aroclor-1254 from gestation day 6 through postnatal day (PND) 21, and the cerebellum and hippocampus from PND14 animals were analyzed to determine Aroclor 1254-induced differential protein expression. Two proteins were found to be differentially expressed in the cerebellum following PCB exposure while 18 proteins were differentially expressed in the hippocampus. These proteins are related to energy metabolism in mitochondria (ATP synthase, sub unit ß (ATP5B), creatine kinase, and malate dehydrogenase), calcium signaling (voltage-dependent anion-selective channel protein 1 (VDAC1) and ryanodine receptor type II (RyR2)), and growth of the nervous system (dihydropyrimidinase-related protein 4 (DPYSL4), valosin-containing protein (VCP)). Results suggest that Aroclor 1254-like persistent chemicals may alter energy metabolism and intracellular signaling, which might result in developmental neurotoxicity.
Subject(s)
Cerebellum/drug effects , Energy Metabolism/drug effects , Hippocampus/drug effects , Signal Transduction/drug effects , Animals , Blotting, Western , Cerebellum/cytology , Dose-Response Relationship, Drug , Electrophoresis, Gel, Two-Dimensional , Female , Hippocampus/cytology , Mitochondria/drug effects , Nerve Tissue Proteins/biosynthesis , Nerve Tissue Proteins/drug effects , Neurotoxicity Syndromes/etiology , Neurotoxicity Syndromes/metabolism , Pregnancy , Prenatal Exposure Delayed Effects/chemically induced , Proteomics , Rats , Rats, Long-EvansABSTRACT
The Cry1Ab δ-endotoxin V171C mutant protein exhibits a 25-fold increase in toxicity against Lymantria dispar, which correlates with a faster rate of partitioning into the midgut membrane and slightly decreased protein stability. This is an insect-specific mechanism; similar results were not observed in Manduca sexta, another Cry1Ab δ-endotoxin-susceptible insect.
Subject(s)
Bacillus thuringiensis/pathogenicity , Bacterial Proteins/genetics , Bacterial Proteins/metabolism , Endotoxins/genetics , Endotoxins/metabolism , Hemolysin Proteins/genetics , Hemolysin Proteins/metabolism , Lepidoptera/microbiology , Valine/genetics , Valine/metabolism , Animals , Bacillus thuringiensis Toxins , Lethal Dose 50 , Manduca/microbiology , Models, Molecular , Mutation, Missense , Protein Transport , Survival AnalysisABSTRACT
BACKGROUND: Three spin-labeled mutant proteins, mutated at the beginning, middle, and end of alpha-helix 5 of the Bacillus thuringiensis Cry1Ab delta-endotoxin, were used to study the involvement of these specific amino acid residues in ion transport and to determine conformational changes in the vicinity of these residues when the protein was translocated into a biological membrane. RESULTS: Amino acid residue leucine 157, located in the N-terminal portion of alpha-helix 5, showed no involvement in ion transport, and the environment that surrounds the residue did not show any change when transferred into the biological membrane. Serine 170, located in the middle of the alpha-helix, showed no involvement in ion transport, but our findings indicate that in the membrane-bound state this residue faces an environment that makes the spin less mobile, as opposed to the mobility observed in an aqueous environment. Serine 176, located in the C-terminal end of the alpha-helix 5 is shown to be involved in ion transport activity. CONCLUSION: Ion transport data for L157, S170, and S176, along with the mobility of the spin-labels, structural characterization of the resulting proteins, and toxicity assays against a target insect, suggest that the toxin undergoes conformational changes upon protein translocation into the midgut membrane. These conformational changes result in the midregion of the alpha-helix 5 being exposed to a hydrophobic-like environment. The location of these three residues in the toxin suggests that the entire alpha-helix becomes inserted in the insect midgut membrane.
Subject(s)
Bacterial Proteins/chemistry , Bacterial Proteins/metabolism , Cell Membrane/metabolism , Endotoxins/chemistry , Endotoxins/metabolism , Hemolysin Proteins/chemistry , Hemolysin Proteins/metabolism , Manduca/metabolism , Animals , Bacillus thuringiensis Toxins , Bacterial Proteins/genetics , Bacterial Proteins/pharmacology , Cell Membrane/drug effects , Endotoxins/genetics , Endotoxins/pharmacology , Hemolysin Proteins/genetics , Hemolysin Proteins/pharmacology , Hydrophobic and Hydrophilic Interactions , Ions/metabolism , Manduca/drug effects , Protein Structure, Secondary , Protein Transport , Serine/chemistry , Serine/genetics , Serine/metabolismABSTRACT
Auditory and perceptual processing of songs are required for a number of behaviors in songbirds such as vocal learning, territorial defense, mate selection and individual recognition. These neural processes are accompanied by increased expression of a few transcription factors, particularly in the caudomedial nidopallium (NCM), an auditory forebrain area believed to play a key role in auditory learning and song discrimination. However, these molecular changes are presumably part of a larger, yet uncharacterized, protein regulatory network. In order to gain further insight into this network, we performed two-dimensional differential in-gel expression (2D-DIGE) experiments, extensive protein quantification analyses, and tandem mass spectrometry in the NCM of adult songbirds hearing novel songs. A subset of proteins was selected for immunocytochemistry in NCM sections to confirm the 2D-DIGE findings and to provide additional quantitative and anatomical information. Using these methodologies, we found that stimulation of freely behaving birds with conspecific songs did not significantly impact the NCM proteome 5 min after stimulus onset. However, following 1 and 3 h of stimulation, a significant number of proteins were consistently regulated in NCM. These proteins spanned a range of functional categories that included metabolic enzymes, cytoskeletal molecules, and proteins involved in neurotransmitter secretion and calcium binding. Our findings suggest that auditory processing of vocal communication signals in freely behaving songbirds triggers a cascade of protein regulatory events that are dynamically regulated through activity-dependent changes in calcium levels.
Subject(s)
Gene Expression Profiling/methods , Learning/physiology , Nerve Tissue Proteins/biosynthesis , Prosencephalon/physiology , Proteomics/methods , Songbirds/metabolism , Acoustic Stimulation/methods , Animals , Auditory Pathways/chemistry , Auditory Pathways/physiology , Female , Finches , Nerve Tissue Proteins/analysis , Nerve Tissue Proteins/genetics , Prosencephalon/chemistry , Songbirds/genetics , Vocalization, Animal/physiologyABSTRACT
BACKGROUND: Polybrominated diphenyl ethers (PBDEs) are structurally similar to polychlorinated biphenyls (PCBs) and have both central (learning and memory deficits) and peripheral (motor dysfunction) neurotoxic effects at concentrations/doses similar to those of PCBs. The cellular and molecular mechanisms for these neurotoxic effects are not fully understood; however, several studies have shown that PBDEs affect thyroid hormones, cause oxidative stress, and disrupt Ca2+-mediated signal transduction. Changes in these signal transduction pathways can lead to differential gene regulation with subsequent changes in protein expression, which can affect the development and function of the nervous system. OBJECTIVE: In this study, we examined the protein expression profiles in the rat cerebellum and hippocampus following developmental exposure to a commercial PBDE mixture, DE-71. METHODS: Pregnant Long-Evans rats were dosed perinatally with 0 or 30.6 mg/kg/day of DE-71 from gestation day 6 through sampling on postnatal day 14. Proteins from the cerebellum and hippocampus were extracted, expression differences were detected by two-dimensional difference gel electrophoresis, and proteins were identified by tandem mass spectrometry. Protein network interaction analysis was performed using Ingenuity® Pathway Analysis, and the proteins of interest were validated by Western blotting. RESULTS: Four proteins were significantly differentially expressed in the cerebellum following DE-71 exposure, whereas 70 proteins were significantly differentially expressed in the hippocampus. Of these proteins, 4 from the cerebellum and 47 from the hippocampus, identifiable by mass spectrometry, were found to have roles in mitochondrial energy metabolism, oxidative stress, apoptosis, calcium signaling, and growth of the nervous system. CONCLUSIONS: Results suggest that changes in energy metabolism and processes related to neuroplasticity and growth may be involved in the developmental neurotoxicity of PBDEs.
Subject(s)
Cerebellum/metabolism , Halogenated Diphenyl Ethers/blood , Hippocampus/metabolism , Animals , Animals, Newborn , Female , Halogenated Diphenyl Ethers/toxicity , Pregnancy , Prenatal Exposure Delayed Effects , Rats , Rats, Long-Evans , Tandem Mass SpectrometryABSTRACT
INTRODUCTION: Alzheimer's disease (AD) is the major cause of dementia among the elderly. Finding blood-based biomarkers for disease diagnosis and prognosis is urgently needed. METHODS: We studied protein distributions in brain tissues, cerebrospinal fluid (CSF), and blood of AD patients by using proteomics and a new proteomic method that we call "2D multiplexed Western blot" (2D mxWd). This method allows us to determine in multiple samples the electrophoretic patterns of protein isoforms with different isoelectric points. RESULTS: Apolipoprotein E (ApoE) displays a unique distribution of electrophoretic isoforms in the presence of AD and also a unique pattern specific to the APOE genotype. CONCLUSIONS: The isoelectric distribution of differentially charged ApoE isoforms was used to determine the presence of AD in a small group of samples. Further studies are needed to validate their use as predictors of disease onset and progression, and as biomarkers for determining the efficacy of therapeutic treatments.
ABSTRACT
Mortalin is a highly conserved heat-shock chaperone usually found in multiple subcellular locations. It has several binding partners and has been implicated in various functions ranging from stress response, control of cell proliferation, and inhibition/prevention of apoptosis. The activity of this protein involves different structural and functional mechanisms, and minor alterations in its expression level may lead to serious biological consequences, including neurodegeneration. In this article we review the most current data associated with mortalin's binding partners and how these protein-protein interactions may be implicated in apoptosis and neurodegeneration. A complete understanding of the molecular pathways in which mortalin is involved is important for the development of therapeutic strategies for cancer and neurodegenerative diseases.
ABSTRACT
Difference gel electrophoresis (DIGE) is most often used to assess relative changes in the expression levels of individual proteins in multiple complex samples, and this information is valuable in making inferences about relative protein activity. However, a protein's activity is not solely dependent upon its expression level. A change in activity may also be influenced by myriad posttranslational modifications (PTMs), including palmitoylation, ubiquitination, oxidation, and phosphorylation. In this chapter, we describe the use of DIGE to determine specific PTMs by introducing specific labels or changes in pI and/or molecular weight.
Subject(s)
Protein Processing, Post-Translational , Proteins/metabolism , Proteomics/methods , Two-Dimensional Difference Gel Electrophoresis/methods , Analytic Sample Preparation Methods , Isoelectric Focusing , Lipoylation , Molecular Weight , Oxidation-Reduction , Phosphorylation , Proteins/chemistry , Proteins/isolation & purification , Staining and Labeling , Substrate Specificity , UbiquitinationABSTRACT
Difference gel electrophoresis (DIGE) is a common technique for characterizing differential protein expression in quantitative proteomics. Usually a combination of enzymatic digestion and peptide analysis by mass spectrometry is used to identify differentially expressed proteins following separation and statistical analysis by DIGE. In this chapter, methods for gel spot picking, enzymatic digestion, and matrix-assisted laser desorption/ionization (MALDI) mass spectrometry (MS) for protein identification of DIGE-analyzed proteins are discussed. Two examples are given: first, a specific protein is used to test the sensitivity of the 2D DIGE/MALDI MS combination for protein quantification and identification, and second, several proteins with and without the labels typically used in DIGE are identified to demonstrate that these labels do not alter MS-based protein identification. Technical variations of protein gel spot preparation, in-gel digestion, and mass spectral protein identification are discussed.
Subject(s)
Proteins/analysis , Proteins/chemistry , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization/methods , Two-Dimensional Difference Gel Electrophoresis/methods , Humans , Peptide Fragments/analysis , Peptide Fragments/chemistry , Peptide Fragments/isolation & purification , Peptide Fragments/metabolism , Proteins/isolation & purification , Proteins/metabolism , Proteomics , Trypsin/metabolismABSTRACT
INTRODUCTION: Alzheimer's disease is a multifactorial disease affecting approximately twenty million people worldwide. Numerous variables are associated with increased risk of developing this severe neurological disorder. Among the risk factors, diabetes mellitus, and the ε4 isoform of the APOE gene have been amply demonstrated as increasing the risk of developing this disease. OBJECTIVE: To determine if a correlation exists between APOE genotype, diabetes mellitus and Alzheimer's disease. MATERIALS AND METHODS: Clinical studies were carried out by surveying the clinical histories in a group of patients in the province of Antioquia, Colombia. Forty-three Alzheimer's patients were compared with 43 control subjects, paired by age and gender. Commercially available methods were used to determine whether the patients had diabetes, and restriction enzyme-based genotyping was used to determine the APOE genotypes. RESULTS: The most common non-neurological comorbidities were: arterial hypertension, acute myocardial infarction, chronic obstructive pulmonary disease and hypothyroidism. From the many variables investigated, two were conclusive: (1) the presence of Alzheimer's disease was higher in patients with diabetes mellitus, and (2) no correlation between late-onset sporadic Alzheimer's disease and APOE was found in the target population. CONCLUSIONS: To detect any association with the APOE genotype, a study involving much a larger population samples must be undertaken.
Subject(s)
Alzheimer Disease/epidemiology , Apolipoproteins E/genetics , Diabetes Mellitus/epidemiology , Aged , Aged, 80 and over , Apolipoprotein E4/genetics , Case-Control Studies , Colombia/epidemiology , Comorbidity , Craniocerebral Trauma/epidemiology , Diabetes Mellitus, Type 2/epidemiology , Epilepsy/epidemiology , Female , Gene Frequency , Genetic Predisposition to Disease , Genotype , Humans , Hypertension/epidemiology , Hypothyroidism/epidemiology , Male , Myocardial Infarction/epidemiology , Neuropsychological Tests , Pulmonary Disease, Chronic Obstructive/epidemiology , RiskABSTRACT
Mortalin is a chaperone protein associated with cell survival, stress response, intracellular trafficking, control of cell proliferation, mitochondrial biogenesis, and cell fate determination. Human APOE targeted replacement (TR) mice have been used to elucidate the role of APOE4 in Alzheimer's disease (AD), since these animals express the APOE4 gene without the classical pathological signatures of AD. Using proteomics we found that mortalin isoforms are differentially expressed in the hippocampus of APOE4 TR mice compared with the APOE3 (control) TR mice. We also observed that these mortalin isoforms are differentially phosphorylated. Then we studied mortalin expression in patients with AD (genotypes APOE 3/3 and APOE 4/4) compared with patients without AD (genotype APOE 3/3). We observed that mortalin isoforms are also differentially expressed in the hippocampi of patients with AD, and that the expression of these mortalin isoforms is regulated by the APOE genotype. We propose that the differential regulation of mortalin in AD and by the APOE genotype is a cellular defense mechanism responding to increases in oxidative stress.
Subject(s)
Alzheimer Disease/metabolism , Apolipoproteins E/metabolism , HSP70 Heat-Shock Proteins/metabolism , Hippocampus/metabolism , Aged , Aged, 80 and over , Animals , Apolipoproteins E/genetics , Female , Gene Expression Regulation , Humans , Male , Mice , Mice, TransgenicABSTRACT
Introduction. Alzheimer´s disease is a multifactorial disease affecting approximately twenty million people worldwide. Numerous variables are associated with increased risk of developing this severe neurological disorder. Among the risk factors, diabetes mellitus, and the ε4 isoform of the APOE gene have been amply demonstrated as increasing the risk of developing this disease. Objective. To determine if a correlation exists between APOE genotype, diabetes mellitus and Alzheimer´s disease. Materials and methods. Clinical studies were carried out by surveying the clinical histories in a group of patients in the province of Antioquia, Colombia. Forty-three Alzheimer´s patients were compared with 43 control subjects, paired by age and gender. Commercially available methods were used to determine whether the patients had diabetes, and restriction enzyme-based genotyping was used to determine the APOE genotypes. Results. The most common non-neurological comorbidities were: arterial hypertension, acute myocardial infarction, chronic obstructive pulmonary disease and hypothyroidism. From the many variables investigated, two were conclusive: (1) the presence of Alzheimer´s disease was higher in patients with diabetes mellitus, and (2) no correlation between late-onset sporadic Alzheimer´s disease and APOE was found in the target population. Conclusions. To detect any association with the APOE genotype, a study involving much a larger population samples must be undertaken.
Introducción. La enfermedad de Alzheimer es compleja y afecta, aproximadamente, a 20 millones de personas en todo el mundo. Muchas variables parecen aumentar el riesgo de desarrollar esta alteración neurológica. Entre los factores de riesgo, se ha demostrado ampliamente que la diabetes mellitus y la isoforma ε4 del gen APOE tienen incidencia positiva en el desarrollo de la enfermedad. Se reporta un estudio en el cual se investigó la posible correlación entre APOE, diabetes mellitus y la enfermedad de Alzheimer, en un grupo específico de pacientes del departamento de Antioquia, Colombia. Objetivo. Determinar si existe una correlación entre APOE, diabetes mellitus y la enfermedad de Alzheimer, en un grupo de pacientes de Antioquia, Colombia. Materiales y métodos. Se buscaron y analizaron las historias clínicas de los pacientes con diagnóstico de enfermedad de Alzheimer. Se seleccionaron aquellos que cumplían los criterios de inclusión. Se utilizaron métodos comercialmente disponibles para confirmar la presencia de diabetes mellitus. La genotipificación de APOE se hizo con un método basado en la PCR y la digestión con enzimas de restricción, en muestras de todos los participantes en el estudio. Resultados. En este estudio se analizan 43 casos de enfermedad de Alzheimer y 43 individuos sanos controles, pareados por edad y sexo. Las enfermedades concomitantes no neurológicas más comunes fueron: hipertensión arterial, infarto agudo del miocardio, enfermedad pulmonar obstructiva crónica e hipotiroidismo. Conclusiones. De las diferentes variables investigadas, dos arrojaron resultados concluyentes: i) la presencia de la enfermedad de Alzheimer es más frecuente en pacientes con diabetes mellitus, y 2) no se encontró correlación entre la enfermedad de Alzheimer de inicio tardío esporádico y el genotipo de APOE. Es importante indicar que debe llevarse a cabo un estudio con un tamaño de población mayor, para determinar cualquier posible correlación o inferencia con el genotipo de APOE.
Subject(s)
Aged , Aged, 80 and over , Female , Humans , Male , Alzheimer Disease/epidemiology , Apolipoproteins E/genetics , Diabetes Mellitus/epidemiology , /genetics , Case-Control Studies , Comorbidity , Colombia/epidemiology , Craniocerebral Trauma/epidemiology , /epidemiology , Epilepsy/epidemiology , Gene Frequency , Genetic Predisposition to Disease , Genotype , Hypertension/epidemiology , Hypothyroidism/epidemiology , Myocardial Infarction/epidemiology , Neuropsychological Tests , Pulmonary Disease, Chronic Obstructive/epidemiology , RiskABSTRACT
The centrally located a-helix 5 of Bacillus thuringiensis d-endotoxins is critical for insect toxicity through ion-channel formation. We analyzed the role of the highly conserved residue Histidine 168 (H168) using molecular biology, electrophysiology and biophysical techniques. Toxin H168R was ~3-fold more toxic than the wild type (wt) protein whereas H168Q was 3 times less toxic against Manduca sexta. Spectroscopic analysis revealed that the H168Q and H168R mutations did not produce gross structural alterations, and that H168R (Tm= 59 °C) was more stable than H168Q (Tm= 57.5 °C) or than the wt (Tm= 56 °C) toxins. These three toxins had similar binding affinities for larval midgut vesicles (Kcom) suggesting that the differences in toxicity did not result from changes in initial receptor binding. Dissociation binding assays and voltage clamping analysis suggest that the reduced toxicity of the H168Q toxin may result from reduced insertion and/or ion channel formation. In contrast, the H168R toxin had a greater inhibition of the short circuit current than the wt toxin and an increased rate of irreversible binding (kobs), consistent with its lower LC50 value. Molecular modeling analysis suggested that both the H168Q and H168R toxins could form additional hydrogen bonds that could account for their greater thermal stability. In addition to this, it is likely that H168R has an extra positive charge exposed to the surface which could increase its rate of insertion into susceptible membranes.
La a-Hélice 5 del domino I de las d-endotoxinas de Bacillus thuringiensis, es crítica para la toxicidad de las toxinas contra insectos al participar en la formación de canales iónicos. La participación en la función tóxica del residuo Histidina 168 (H168) el cual es altamente conservado fue estudiada mediante técnicas de biología molecular, electrofisiología y biofísica. La toxina mutante H168R fue ~ 3 veces más tóxica que la toxina silvestre (ts) en Manduca sexta, mientras que H168Q fue 3 veces menos tóxica. Los análisis espectroscópicos indicaron que las mutaciones no producen alteraciones estructurales significativas y que la toxina H168R (Tm= 59 °C) es más estable que las toxinas H168Q (Tm= 57.5 °C) y wt (Tm= 56 °C). Las tres toxinas exhibieron uniones de afinidad similares (Kcom) en vesículas de intestino de larvas de insecto, indicando que las diferencias en la toxicidad no se deben a cambios en la unión inicial al receptor. Los ensayos de unión/disociación y fijación de voltaje mostraron que la reducción de la toxicidad de la toxina H168Q se puede atribuir a una disminución en la inserción y/o en la formación de canales iónicos. De otro lado, H168R mostró una inhibición a la corriente de corto circuito mayor que la ts y un aumento en unión irreversible (kobs), lo cual es consistente con un menor valor de CL50. La modelación molecular sugiere que H168Q y H168R forman puentes de hidrógeno adicionales, lo que les confiere mayor estabilidad térmica. Adicionalmente, es probable que H168R tenga una carga positiva extra expuesta en la superficie, lo cual aumentaría su tasa de inserción en membranas susceptibles.
Subject(s)
Bacillus thuringiensis/radiation effects , Bacillus thuringiensis/ultrastructure , Bacillus thuringiensis/virology , Toxicity/analysis , Toxicity/classification , Toxicity/methodsABSTRACT
En el presente artículo se presentan los conceptos básicos que definen la patología de la enfermedad de Alzheimer (EA) y los métodos fundamentales utilizados en Neuroproteómica para su estudio. De igual manera, se discuten algunos resultados en el análisis de esta enfermedad y su relación con el genotipo APOE4 de APOE, el gen que codifica la Apolipoproteína E (ApoE). Finalmente se hacen algunas consideraciones generales sobre la EA, cómo evitar su progresión y se discute brevemente el futuro de la investigación en esta área.
Subject(s)
Humans , Middle Aged , Aged , Aged, 80 and over , Alzheimer Disease , Apolipoproteins E , Mass Spectrometry , Oxidative Stress , Proteomics , Proteomics/methodsABSTRACT
Introdução: A Hérnia Diafragmática Congênita (HDC) é a falha no fechamento do músculo diafragmático, ocasionando a migração de estruturasabdominais para o tórax, podendo causar hipoplasia pulmonar. O diagnóstico pré-natal se faz necessário para avaliação de malformações, aconselhamento familiar e caso seja preciso o encaminhamento para centrosespecializados. Em relação à ultra-sonografia quando utilizada como método de rastreamento apresenta o índice de falha diagnóstica de 41%. Já a ressonância magnética devido a melhor precisão da imagem, permite uma melhorvisualização anatômica, com achados mais precisos de herniações e uma boa acurácia em relação ao grau dehipoplasia pulmonar; no entanto com indicações restritas e selecionadas para realização do exame. A imagem porressonância magnética possibilitou que a cirurgia fetal aumentasse para até 75% a sobrevida dos fetos de altorisco com indicação para o procedimento.Objetivo: Através de uma revisão bibliográfica, avaliar o papel da imagem por ressonância magnética (IRM) no diagnóstico fetal de hérnia diafragmática. Métodos: Foi realizada uma extensa revisão utilizando os sites de pesquisa: Medline, Scielo e Cochrane. A pesquisa incluiu somente artigoscompreendidos no período de janeiro de 1996 a agosto de 2006. Conclusão: Na suspeita de Hérnia DiafragmáticaCongênita, está indicada a solicitação de ressonância magnética para confirmar o posicionamento dos órgãos abdominais, detectar o grau de hipodesenvolvimentopulmonar e avaliar anomalias associadas. Não é utilizado como método de rastreamento devido à sua restrita disponibilidade, alto custo e a segurança do método que ainda está em discussão.
Introduction: Congenital Diaphragmatic Hernia is the imperfection of closing of this muscle and it takes the migration of abdominal structures for the thorax, causing pulmonar hipoplasia. Prenatal diagnostic is useful for family counseling, to evaluation of malformations associated and, if necessary, guiding for specializedcenter. In relation to the ultrasonografy when used as screening method it presents a fail diagnostic in 41%Already the magnetic resonance which had the best precision of the image, allows one better anatomical visualization with more findings of herniations and a good accuracy in relation to the pulmonary hipoplasia degree however with restricted and selected indications for accomplishment of the exam Magnetic ResonanceImaging made possible that the fetal surgery increase to 75% fetus surl of high risc with indication to the procedure. Objective: Through a bibliographic revision to evaluate the role of Magnetic Resonance Imaging in fetal diagnostic of Congenital Diaphragmatic Hernia. Methodos: We realize a revision utilizing sites like:Medline, Scielo and Cochrane. We include in this research articles between January 1996 to August 2006 period.Conclusion: In the suspicion of congenital Diafragmatic Hernia, the request of magnetic resonance is indicated to confirm the positioning of the abdominal structures, to detect the degree of pulmonary hipodevelopment and to evaluate anomalies associates.It is not used as method of screening because it has a restricted availability, high cost and the security of the method that still is in quarrel.
Subject(s)
Humans , Female , Pregnancy , Hernia, Diaphragmatic , Magnetic Resonance Imaging , Ultrasonography, PrenatalABSTRACT
Introdução: Mioma uterino é o tumor benigno mais comum do trato genital feminino. As principais queixas de pacientes com miomatose são: sensação de massa pélvica e sangramento uterino irregular. A miomatose apresenta várias alternativas terapêuticas, entre elas, a embolização das artérias uterinas, a qual vem sendo muito discutida nos últimos anos por ser um método menos invasivo que a técnica cirúrgica.Objetivo: O objetivo deste estudo é revisar e demonstrar as possíveis complicações da embolização das artérias uterinas para o tratamento dos leiomiomas. Métodos: Foi realizada revisão da literatura através de portais de pesquisa como Portal Capes, PubMed, Cochrane e Bireme. Foram incluídos os artigos publicados nos últimos quinze anos, incluindo artigos originais, revisões e metanálises. Foi também realizada uma revisão da literatura através de livros cuja publicação ocorreu a partir do ano de 1998.Conclusão: A embolização das artérias uterinas pode resultar em complicações como: insuficiência ovariana, dor abdominal, infecção, prolapso transcervical do mioma, entre outros, porém, estas não apresentam taxas de incidência significativas. No entanto, maiores estudos são necessários para determinar o risco benefício da realização da embolização das artérias uterinas em relação as suas complicações.
Introduction: Uterine myoma is the most common benign tumor of the feminine genital tract. The main complaints of patients with myomatosis are: sensation of pelvic mass and irregular uterine bleeding. There are several therapeutical alternatives for myomatosis, among them, there is the embolization of the uterine arteries, which has been much discussed in recent years for being a method less invasive than the surgical technique.Objective: The objective of this study is to review and to demonstrate the possible complications of the embolization of the uterine arteries as a treatment of leiomyomas. Methods: A review of the literature was carried through research vestibules such as Vestibule Capes, PubMed, Cochrane and Bireme. It was included articles published in the last fifteen years, including original articles, revisions and methanalysis. Also a review of the literature was carried through books which have been published since the year of 1998. Conclusion: The embolization of the uterine arteries can result in complications such as: ovarian insufficiency, abdominal pain, infection, transcervical prolapse of myoma, among others, however, these do not present significant incidence rates. Thus, greater studies are necessary to determine the risk benefit of the accomplishment of the embolization of the uterine arteries over its complications.