The critical importance of epigenetics in autoimmune-related skin diseases / 医学前沿

Autoimmune-related skin diseases are a group of disorders with diverse etiology and pathophysiology involved in autoimmunity. Genetics and environmental factors may contribute to the development of these autoimmune disorders. Although the etiology and pathogenesis of these disorders are poorly understood, environmental variables that induce aberrant epigenetic regulations may provide some insights. Epigenetics is the study of heritable mechanisms that regulate gene expression without changing DNA sequences. The most important epigenetic mechanisms are DNA methylation, histone modification, and noncoding RNAs. In this review, we discuss the most recent findings regarding the function of epigenetic mechanisms in autoimmune-related skin disorders, including systemic lupus erythematosus, bullous skin diseases, psoriasis, and systemic sclerosis. These findings will expand our understanding and highlight the possible clinical applications of precision epigenetics approaches.

MicroRNA en enfermedades autoinmunes / MicroRNA in autoimmune diseases

Resumen Los microRNA (miRNA) son pequeños RNA no codificantes de aproximadamente 17 a 24 nucleótidos de longitud, los cuales se unen complementaria y principalmente en las regiones 3' UTR (región no traducida) de diversos RNA mensajeros (mRNA, messenger RNA). Su función general es regular negativamente la expresión génica a nivel postranscripcional, inhibiendo la traducción. Perfiles de expresión de miRNA alterados han sido identificados en diferentes líquidos, células y tejidos humanos afectados con diversas enfermedades autoinmunes y algunos se han propuestos potencialmente como biomarcadores de diagnóstico, pronóstico, actividad, etcétera, en estas patologías. Adicionalmente, variantes comunes del genoma humano, denominados polimorfismos de un solo nucleótido (SNP, single nucleotide polymorphisms) localizados en genes de miRNA han sido asociados con susceptibilidad, gravedad, y actividad en estas enfermedades. El objetivo de esta revisión es describir la biogénesis de los miRNA, su función, así como los perfiles de expresión y SNP en genes de miRNA asociados con diversas enfermedades autoinmunes, incluyendo tiroiditis autoinmune (tiroiditis de Hashimoto y enfermedad de Graves), lupus eritematoso sistémico, artritis reumatoide y síndrome de Sjögren primario.

Abstract MicroRNAs (miRNAs) are small non-coding RNAs of approximately 17-24 nucleotides in length, which complementarily and mainly bind in 3' UTR (untranslated region) regions of different messenger RNAs (mRNAs). Their general function is to negatively regulate gene expression at the posttranscriptional level, thus inhibiting translation. miRNA abnormal expression profiles of have been found in different human fluids, cells and tissues affected by different autoimmune diseases, and some of them have been proposed as potential biomarkers of diagnosis, prognosis, activity etc. in these pathologies. In addition, common variants of the human genome, called single-nucleotide polymorphisms (SNPs), located within miRNA genes, have been associated with susceptibility, severity and activity in these diseases. The purpose of this review is to describe miRNA biogenesis and function, as well as the expression profiles and SNPs in miRNA genes that are associated with different autoimmune diseases, including autoimmune thyroiditis (HashimotoMs thyroiditis and Gravess disease), systemic lupus erythematosus, rheumatoid arthritis and primary Sjögren's syndrome.

Enfermedades autoinmunitarias asociadas a diabetes mellitus tipo 1A / Autoimmune diseases in type 1A diabetes mellitus

Type 1A diabetes (DM1A) is an autoimmune disease that comprises 10% of patients with diabetes mellitus. Its frequency is gradually increasing in countries like Mexico. Patients with DM1A commonly have hypothyroidism, Addison disease, celiac disease and less common diseases such as polyglandular syndrome. These diseases are related to susceptibility genes such as HLA, CTLA-4 and PTPN22, which induce central and peripheral immunologic tolerance. This review article emphasizes the importance of searching other autoimmune diseases in patients with DM1A, to improve their prognosis and quality of life.

Lúpus Eritematoso Sistêmico: Revisão das Manifestações Cardiovasculares / Systemic Lupus Erythematosus: Review of Cardiovascular Aspects

Lúpus eritematoso sistêmico (LES) é uma condição autoimune com processo fisiopatológico complexo, no qual sua atividade inflamatória é potencializadora da doença coronariana através de inflamação sistêmica, disfunção endotelial e predisposição à trombose. O acometimento cardiovascular no LES não é critério diagnóstico, sendo considerado somente como dano já estabelecido em longo prazo de doença. O objetivodeste artigo é destacar a importância da visão clínica para a identificação precoce do acometimento cardiovascular no LES. É feita uma análise crítica da abordagem cardiológica no LES, com ênfase nos aspectos clínicos, biomarcadores cardiovasculares e genética e solicitação racional dos exames complementares. Aparticularidade dos pacientes com nefrite lúpica e síndrome do anticorpo antifosfolipídeo também é destacada.A percepção do dano cardíaco subclínico é fundamental para interromper o ciclo de agressão miocárdica e evitar progressão de doença cardíaca.

Systemic lupus erythematosus (SLE) is an autoimmune condition with a complex pathophysiological process in which its inflammatory activity is an enhancer of coronary disease by systemic inflammation, endothelial dysfunction and predisposition to thrombosis. Thecardiovascular involvement in SLE is not a diagnostic criterion and is considered only as damage established in the long-term of the disease. The objective of this study is to highlight the importance of clinical vision for the early identification of cardiovascular involvement in SLE. A critical analysis of the cardiac approach in SLE, with emphasis on clinical aspects, cardiovascular biomarkers and genetics and rational request of additional tests. The particularity of patients with lupus nephritis and antiphospholipid antibodysyndrome is also highlighted. The perception of subclinical cardiac damage is critical for interrupting the cycle of myocardial injury and to avoid progression of heart disease.

Use of positive pressure in preoperative and intraoperative of bariatric surgery and its effect on the time of extubation / Utilização da pressão positiva no pré e no intraoperatório de cirurgia bariátrica e seus efeitos sobre o tempo de extubação / Utilización de la presión positiva en el pre- y en el intraoperatorio de cirugía bariátrica y sus efectos sobre el tiempo de extubación

BACKGROUND AND OBJECTIVE: To investigate the influence of intraoperative and preoperative positive pressure in the time of extubation in patients undergoing bariatric surgery. METHOD: Randomized clinical trial, in which 40 individuals with a body mass index between 40 and 55 kg/m2, age between 25 and 55 years, nonsmokers, underwent bariatric surgery type Roux-en-Y gastric bypass by laparotomy and with normal preoperative pulmonary function were randomized into the following groups: G-pre (n = 10): individuals who received treatment with noninvasive positive pressure before surgery for 1 h; G-intra (n = 10): individuals who received positive end-expiratory pressure of 10 cm H2O throughout the surgical procedure; and G-control (n = 20): not received any preoperative or intraoperative intervention. Following were recorded: time between induction of anesthesia and extubation, between the end of anesthesia and extubation, duration of mechanical ventilation, and time between extubation and discharge from the post-anesthetic recovery. RESULTS: There was no statistical difference between groups. However, when applied to the Cohen coefficient, the use of positive end-expiratory pressure of 10 cm H2O during surgery showed a large effect on the time between the end of anesthesia and extubation. About this same time, the treatment performed preoperatively showed moderate effect. CONCLUSION: The use of positive end-expiratory pressure of 10 cm H2O in the intraoperative and positive pressure preoperatively, influenced the time of extubation of patients undergoing bariatric surgery. .

JUSTIFICATIVA E OBJETIVO: investigar a influência do uso da pressão positiva nas vias aéreas intraoperatória e pré-operatória no tempo de extubação de pacientes submetidos à cirurgia bariátrica. MÉTODO: Trata-se de ensaio clínico randomizado, no qual 40 indivíduos com índice de massa corporal entre 40 e 55 kg/m2, idade entre 25 e 55 anos, não tabagistas, submetidos à cirurgia bariátrica do tipo derivação gástrica em Y de Roux por laparotomia e com prova de função pulmonar pré-operatória dentro da normalidade foram randomizados nos seguintes grupos: G-pré (n = 10): indivíduos que receberam tratamento com pressão positiva não invasiva antes da cirurgia, durante uma hora, G-intra (n = 10): indivíduos que receberam Positive End-expiratory Pressure de 10 cm H2O durante todo o procedimento cirúrgico e G-controle (n = 20): não receberam qualquer tipo de intervenção pré ou intraoperatória. foram anotados os seguintes tempos: tempo decorrido entre a indução anestésica e a extubação, entre o término da anestesia e extubação, tempo de ventilação mecânica, e tempo entre a extubação e a alta da Recuperação Pós-Anestésica. RESULTADOS: Não houve diferença estatística entre os grupos, porém quando aplicado ao Coeficiente de Cohen, o uso da Positive End-expiratory Pressure de 10 cm H2O no intraoperatório mostrou um efeito grande sobre o tempo entre o término da anestesia e a extubação. Sobre este mesmo tempo, o tratamento realizado no pré-operatório apresentou efeito moderado. CONCLUSÃO: O uso da Positive End-expiratory Pressure de 10 cm H2O no intraoperatório e da pressão positiva no pré-operatório, pode influenciar o tempo de extubação de pacientes submetidos à cirurgia bariátrica. .

JUSTIFICACIÓN Y OBJETIVO: Investigar la influencia del uso de la presión positiva en las vías aéreas intraoperatoria y preoperatoria en el tiempo de extubación de pacientes sometidos a la cirugía bariátrica. MÉTODO: Se trata de un ensayo clínico aleatorizado, en el cual 40 individuos con IMC entre 40 y 55 kg/m2, edad entre 25 y 55 años, no fumadores, sometidos a cirugía bariátrica del tipo derivación gástrica en Y de Roux por laparotomía y con prueba de función pulmonar preoperatoria dentro de la normalidad fueron aleatorizados en los siguientes grupos: G-pre (n = 10): individuos que recibieron tratamiento con presión positiva no invasiva antes de la cirugía durante una hora; G-intra (n = 10): individuos que recibieron PEEP de 10 cm H2O durante todo el procedimiento quirúrgico y G-control (n = 20): no recibieron ningún tipo de intervención pre- o intraoperatoria. Fueron anotados los siguientes tiempos: tiempo trascurrido entre la inducción anestésica y la extubación, entre el fin de la anestesia y la extubación, tiempo de ventilación mecánica, y tiempo entre la extubación y el alta de la sala de recuperación postanestésica. RESULTADOS: No hubo diferencia estadística entre los grupos, sin embargo cuando se aplicó el coeficiente de Cohen, el uso de la PEEP de 10 cm H2O en el intraoperatorio mostró un efecto importante sobre el tiempo entre el término de la anestesia y la extubación. Sobre ese mismo tiempo, el tratamiento realizado en el preoperatorio presentó un efecto moderado. CONCLUSIÓN: El uso de la PEEP de 10 cm H2O en el intraoperatorio y de la presión positiva en el preoperatorio puede influir en el tiempo de extubación de pacientes sometidos a cirugía bariátrica. .

Influência dos polimorfismos genéticos (IL10/CXCL8/CXCR2/ NF?B) na susceptibilidade das doenças reumatológicas autoimunes / Influence of genetic polymorphisms (IL-10/CXCL8/CXCR2/ NF?B) on the susceptibility of autoimmune rheumatic diseases

As doenças reumatológicas autoimunes, na maioria das vezes, possuem uma via genética comum para a autoimunidade. Vários genes foram associados com as doenças reumatológicas, para tanto iremos analisar somente alguns genes nos quais há várias evidências da existência de associação com risco ou proteção de doença autoimune. O fator de transcrição nuclear kappa B (NF-kappa B), o qual regula as respostas imunes e inflamatórias, está associado com esclerose sistêmica (ES), artrite reumatoide (AR) e lúpus eritematoso sistêmico (LES), assim como os genes CXCR2 e CXCL8. Já a interleucina 10 (IL-10), que é uma citocina anti-inflamatória, está associada com quase todas as doenças reumatológicas. Neste artigo, revisamos os potenciais papéis desses genes no sistema imunológico e em diversas doenças reumatológicas. Com relação à IL-10, diversos estudos foram realizados, porém em sua maioria contraditórios - alguns encontraram ausência de associação e outros encontraram associação em diferentes polimorfismos do genes. Já em relação ao NF-kappa B, somente foi estudado em AR e LES, e não foram observadas análises significativas relevantes. Os polimorfismos genéticos do gene CXCR2 foram associados com ES, mas não estão associados com AR e LES. Já os polimorfismos genéticos do gene CXCL8 não estão associados com ES, mas estão associados com AR.

The autoimmune rheumatologic disorders mostly have a common genetic path to the autoimmunity. Several genes have been associated with rheumatologic disorders; therefore, we are analyzing just the ones in those containing several evidences of the existence of association with the risk or protection from autoimmune disorder. The nuclear factor kappa beta (NF-kappa B), which regulates the autoimmune and anti-inflammatory responses, is associated with systemic sclerosis (SS), rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE), just as the CXCR2 e CXCL8 genes. On the other hand, the interleukin-10 (IL-10), which is an anti-inflammatory cytokine, is associated with almost all rheumatologic disorders. In this article, we are reviewing the potential roles of these genes in the immune system and in several rheumatologic disorders. In relation to IL-10, several studies have been carried out, but most of them are controversial - some detected the absence of association, and others found association in different genetic polymorphisms. Conversely, in relation to NF-kappa B, it was studied just in RA and SLE, and no relevant significant analyses were observed. The genetic polymorphisms of the CXCR2 gene were associated with SS, but not with RA e SLE. On the other side, the genetic polymorphisms of the CXCL8 gene are not associated with SS, but with RA.

Vitiligo - Part 1

Vitiligo is a chronic stigmatizing disease, already known for millennia, which mainly affects melanocytes from epidermis basal layer, leading to the development of hypochromic and achromic patches. Its estimated prevalence is 0.5% worldwide. The involvement of genetic factors controlling susceptibility to vitiligo has been studied over the last decades, and results of previous studies present vitiligo as a complex, multifactorial and polygenic disease. In this context, a few genes, including DDR1, XBP1 and NLRP1 have been consistently and functionally associated with the disease. Notwithstanding, environmental factors that precipitate or maintain the disease are yet to be described. The pathogenesis of vitiligo has not been totally clarified until now and many theories have been proposed. Of these, the autoimmune hypothesis is now the most cited and studied among experts. Dysfunction in metabolic pathways, which could lead to production of toxic metabolites causing damage to melanocytes, has also been investigated. Melanocytes adhesion deficit in patients with vitiligo is mainly speculated by the appearance of Köebner phenomenon, recently, new genes and proteins involved in this deficit have been found.

Association between pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections disease and tumor necrosis factor-α gene−308 g/a, −850 c/t polymorphisms in 4-12-year-old children in Adana/Turkey.

OBJECTIVES: Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal Infections (PANDAS) is a newly defined disease in neuropsychiatry and occurs with an autoimmune mechanism after Group A Beta Hemolytic Streptococcus (GABHS) infection. Tumor necrosis factor (TNF), encoded by TNF-α gene has an important role in the apoptotic mechanisms of autoimmune diseases. Recently, TNF-α polymorphisms and autoimmune/psychiatric disorders have been reported to be related. In this regard, we focused on to investigate a possible relation between the TNF-α gene promoter region−308 G/A and − 850 C/T polymorphisms and PANDAS. MATERIALS AND METHODS: In this study, ages of PANDAS patient and control groups were ranging from 4 years to 12-year-old. Patient group includes childhood onset PANDAS patients (n = 42) and control group includes healthy children (n = 58). Diagnoses have been carried out according to Diagnostic and Statistical Manual of Mental Disorder (DSM-IV) criteria with Affective Disorders and Schizophrenia-Present and Lifetime (KSAD-S-PL) and Children Yale-Brown Obsessive Compulsive Scale Moreover, PANDAS criteria established by the American National Psychiatry Institute have been employed for diagnoses. For identifying polymorphisms; Polymerase Chain Reaction, Restriction Fragment Length Polymorphism and Polyacrylamid Gel Electrophoresis were used. RESULTS AND DISCUSSION: For −308 polymorphism, 37 of 42 PANDAS patients’ results and for −850 C/T polymorphism, 38 of 42 PANDAS patients’ results were obtained. According to our statistical analysis there is a positive relationship between PANDAS patients for −308 G/A polymorphism but not for −850 C/T polymorphism. There is no positive relationship between −308 G/A polymorphism and antistrep-tolysin O (ASO) titers and no relationship between −850 C/T polymorphism and ASO titers. We found, however, positive relationship between genders of patients (boys) and the disease. According to our results, we propose that the AA polymorphism of −308 G/A polymorphism can be used as a molecular indicator for PANDAS.

Expression of activation-induced cytidine deaminase gene in B lymphocytes of patients with common variable immunodeficiency

Common variable immunodeficiency [CVID] is a heterogeneous disorder characterized by reduced serum level of IgG, IgA or IgM and recurrent bacterial infections. Class switch recombination [CSR] as a critical process in immunoglobulin production is defective in a group of CVID patients. Activation-induced cytidine deaminase [AID] protein is an important molecule involving CSR process. The aim of this study was to investigate the AID gene mRNA production in a group of CVID patients indicating possible role of this molecule in this disorder. Peripheral blood mononuclear cells [PBMC] of 29 CVID patients and 21 healthy controls were isolated and stimulated by CD40L and IL-4 to induce AID gene expression. After 5 days AID gene mRNA production was investigated by real time polymerase chain reaction. AID gene was expressed in all of the studied patients. However the mean density of extracted AID mRNA showed higher level in CVID patients [230.95 +/- 103.04 ng/ml] rather than controls [210.00 +/- 44.72 ng/ml; P=0.5]. CVID cases with lower level of AID had decreased total level of IgE [P=0.04] and stimulated IgE production [P=0.02]; while cases with increased level of AID presented higher level of IgA [P=0.04] and numbers of B cells [P=0.02] and autoimmune disease [P=0.02]. Different levels of AID gene expression may have important roles in dysregulation of immune system and final clinical presentation in CVID patients. Therefore investigating the expression of AID gene can help in classifying CVID patients

Doenças reumatológicas autoimunes e sua associação com os genes killer immunoglobulin-like receptors / Autoimmune rheumatic diseases and their association with killer immunoglobulin-like receptor genes

Os genes Killer Immunoglobulin-like Receptors (KIR) expressam-se como receptores que estimulam ou inibem as células Natural Killer (NK). As células NK fazem parte da imunidade inata e através de seus receptores KIR identificam células-alvo que apresentam moléculas HLA (Human Leukocyte Antigen) modificadas ou diferentes, induzindo à sua lise. Os receptores KIR são resultados da expressão dos genes KIR (19q13.14) na membrana celular das células NK, os quais são polimórficos e formam haplótipos. A diversidade de frequência dos haplótipos KIR em certas populações sugere que alguns indivíduos apresentam diferentes níveis de proteção contra algumas doenças e o balanço entre inibição e ativação celular mediada pelos receptores KIR e seus ligantes faz com que a célula NK possa auxiliar o organismo na vigilância imunológica. Além disso, há várias evidências da existência de associação de genótipos KIR ativadores com risco aumentado de doença autoimune.

Killer Immunoglobulin-like Receptor (KIR) genes express as receptors that activate or inhibit Natural Killer (NK) cells. The NK cells are part of the innate immune response and, through their KIR receptors, they identify target cells that have modified or different HLA (Human Leukocyte Antigen) molecules, inducing their lysis. The KIR receptors result from the expression of KIR genes (19q13.14) on the cell membrane of NK cells, which are polymorphic, and form haplotypes. The diversity of the frequency of KIR haplotypes in certain populations suggests that some individuals have different levels of protection against some diseases. The balance between cell inhibition and activation enables the NK cell to help the organism in immunological surveillance. In addition, there is evidence of the association of activating KIR genotypes with an increased risk for autoimmune disease.

Interferência por RNA: uma nova alternativa para terapia nas doenças reumáticas / RNA interference: a new alternative for rheumatic diseases therapy

A interferência por RNA (RNAi) é um mecanismo de silenciamento gênico pós-transcricional conservado durante a evolução. Esse mecanismo, recentemente descrito, é mediado por pequenos RNAs de fita dupla (dsRNAs) capazes de reconhecer especificamente uma sequência de mRNA-alvo e mediar sua clivagem ou repressão traducional. O emprego da RNAi como uma ferramenta de terapia gênica tem sido muito estudado, especialmente em infecções virais, câncer, desordens genéticas herdadas, doenças cardiovasculares e mesmo em doenças reumáticas. Aliados aos dados do genoma humano, os conhecimentos do silenciamento gênico mediado por RNAi podem permitir a determinação funcional de praticamente qualquer gene expresso em uma célula e sua implicação para o funcionamento e homeostase celular. Vários estudos terapêuticos in vitro e in vivo em modelos de doenças autoimunes vêm sendo realizados com resultados encorajadores. As vias de quebra de tolerância e inflamação são alvos potenciais para terapia com RNAi em doenças inflamatórias e autoimunes. Nesta revisão vamos recordar os princípios básicos da RNAi e discutir os aspectos que levaram ao desenvolvimento de propostas terapêuticas baseadas em RNAi, começando pelos estudos in vitro de desenvolvimento de ferramentas e identificação de alvos, chegando até os estudos pré-clínicos de disponibilização da droga in vivo, e testes em células humanas e modelos animais de doenças autoimunes. Por fim, vamos revisar os últimos avanços da experiência clínica da terapia com RNAi.

RNA interference (RNAi) is a post-transcriptional gene silencing mechanism preserved during evolution. This mechanism, recently described, is mediated by small double-stranded RNAs (dsRNAs) that can specifically recognize a target mRNA sequence and mediate its cleavage or translational repression. The use of RNAi as a tool for gene therapy has been extensively studied, especially in viral infections, cancer, inherited genetic disorders, cardiovascular and rheumatic diseases. Together with data from human genome, the knowledge of gene silencing mediated by RNAi could allow a functional determination of virtually any cell expressed gene and its involvement in cellular functioning and homeostasis. Several in vitro and in vivo therapeutic studies with autoimmune disease animal models have been carried out with promising results. The pathways of tolerance breakage and inflammation are potential targets for RNAi therapy in inflammatory autoimmune diseases. This review will present the basic principles of RNAi and discuss several aspects of RNAi-based therapeutic approaches, from in vitro tool design and target identification to in vivo pre-clinical drug delivery, and tests of autoimmune diseases in human cells and animal models. Finally, this review will present some recent clinical experience with RNAi-based therapy.

Doença de Graves e deficiência de IgA como manifestações da síndrome de deleção 22q11.2 / Graves disease and IgA deficiency as manifestations of 22q11.2 deletion syndrome:

A síndrome de deleção 22q11.2 (SD22q11.2) está associada à alta variabilidade fenotípica, abrangendo o espectro velocardiofacial/síndrome de DiGeorge. Manifestações autoimunes, endocrinológicas e de imunodeficiência vêm sendo relatadas associadas à síndrome. O objetivo deste estudo foi relatar um caso de SD22q11.2 associado à deficiência de IgA e à doença de Graves e rever a literatura visando verificar a frequência dessas alterações na SD22q11.2. Os distúrbios autoimunes, cada vez mais relacionadas a SD22q11.2 e novos fenótipos, vêm sendo incorporadas ao seu espectro clínico. No presente estudo, verificou-se que a doença de Graves associada à SD22q11.2 foi relatada em apenas dezesseis pacientes e quinze descritos na literatura nos últimos 13 anos. Com base na incidência e na amplitude de seu espectro de manifestações já reconhecidas, reforçaram-se os achados da literatura de que a doença de Graves deve ser incluída nas manifestações da SD22q11.2, o que nos levaria a pesquisá-la nos portadores da deleção 22q11.2.

The 22q11.2 deletion syndrome (22q11.2DS) is related to a high phenotypic variability including the velocardiofacial/DiGeorge spectrum. Autoimmune, endocrine and immunodeficiency manifestations have been reportedly associated with the syndrome. The objective of this study was to report a case of 22q11.2DS associated with IgA deficiency and Graves disease and review literature in order to verify the frequency of syndrome alterations. Autoimmune disorders have been increasingly related to 22q11.2DS, and new phenotypes are being incorporated in the clinical spectrum of this syndrome. In our study we found that Graves disease in association with 22q11.2DS was reported in only sixteen patients, and fifteen cases were described in the last 13 years. Based on the incidence and on the amplitude of this recognized spectrum, we reinforce the findings of literature that Graves disease should be included on the 22q11.2DS manifestations, which would lead us to seek it with 22q11.2 deletion patients.

Polimorfismos del gen del receptor de muerte celular programada 1 (PDCD1) y diabetes tipo 1 en población Chilena / Programmed cell death 1 (PDCD1) gene polymorphisms and type 1 diabetes in Chilean children

Background: Programmed cell death 1 (PDCD-1) immune-receptor is a key element in the negative regulation of peripheral tolerance in T cells. Several polymorphisms of this gene have been described and it is linked with susceptibility to autoimmune diseases like Lupus and Multiple Sclerosis. Aim: To analyze four gene polymorphisms of PDCD-1 gene and explore its possible contribution as a susceptibility gene for type 1 diabetes (T1D). Patients and Methods: We analyzed 160 cases with T1D of recent diagnosis aged 9.5 ± 3.3 years and 160 control children aged 10.7 ± 3.1 years. Four genetic variants of PDCD-1 gene were studied (PD1.2; PD1.5; PD1.6 and PD1.9) by polymerase chain reaction and restriction enzymes. Autoantibodies GAD65 and anti-IA-2 were also measured in all studied children. The comparison of allelic and genotypic frequency and consistency with respect to Hardy-Weinberg equilibrium test were analyzed using Chi-square and Fisher exact test. Results: No differences between cases and controls were observed for PDCD1.2; PDCD1.5 and PDCD1.9 polymorphisms. PDCD1.6 polymorphism (carriers of allele A) had a higher frequency in the control group (0.794 versus 0.644, p < 0.017). There was no particular association of these polymorphisms with anti- GAD65 and anti-IA-2 antibodies among patients with T1D. Conclusions: Only PDCD1.6 polymorphism showed differences between T1D cases and controls. Possibly, none of these genetic variants of PDCD1 has a relevant role as a marker for T1D in the Chilean population.

APO-1/Fas gene: Structural and functional characteristics in systemic lupus erythematosus and other autoimmune diseases.

Systemic lupus erythematosus (SLE) is an autoimmune disorder affecting multiple organ systems. It is characterized by the presence of autoantibodies reactive against various self-antigens. Susceptibility to SLE is found to be associated with many major histocompatibility complex (MHC) and non-MHC genes, one of which is APO-1/Fas gene, which is present on chromosome 10 in humans. The APO-1/Fas promoter contains consensus sequences for binding of several transcription factors that affect the intensity of Fas expression in cells. The mutations in the APO-1/Fas promoter are associated with risk and severity in various autoimmune diseases and other malignancies. The APO-1/Fas receptor is expressed by many cell types. Two forms of APO-1/Fas protein that are involved in regulation of apoptosis have been identified. Fas receptor-mediated apoptosis plays a physiological and pathological role in killing of infected cell targets. In this review, we have focused on APO-1/Fas gene structure, promoter variants and its association with SLE and other autoimmune diseases. Functional aspects of Fas receptor in apoptosis are also discussed.

Future perspective for diagnosis in autoimmune diseases

Human beings have taken successive approaches for the understanding and management of diseases. Initially brewed in supernatural concepts and mystical procedures, a vigorous scientific approach has emerged on the grounds of fundamental disciplines such as anatomy, microbiology, biochemistry, physiology, immunology, pathology, and pharmacology. The resulting integrated knowledge contributed to the current classification of diseases and the way Medicine is carried out today. Despite considerable progress, this approach is rather insufficient when it comes to systemic inflammatory conditions, such as systemic lupus erythematosus, that covers clinical conditions ranging from mild pauci-symptomatic diseases to rapidly fatal conditions. The treatment for such conditions is often insufficient and novel approaches are needed for further progress in these areas of Medicine. A recent breakthrough has been achieved with respect to chronic auto-inflammatory syndromes, in which molecular dissection of underlying gene defects has provided directions for target-oriented therapy. Such approach may be amenable to application in systemic auto-immune diseases with the comprehension that such conditions may be the consequence of interaction of specific environmental stimuli and an array of several and interconnected gene polymorphisms. On the bulk of this transformation, the application of principles of pharmacogenetics may lead the way towards a progressively stronger personalized Medicine.

O homem tem buscado sucessivas abordagens para o entendimento e manejo das doenças. Partindo de conceitos sobrenaturais e procedimentos místicos, uma abordagem científica vigorosa vicejou com base em disciplinas fundamentais como a anatomia, microbiologia, bioquímica, fisiologia, imunologia, patologia e farmacologia. O conhecimento integrado resultante contribuiu para a atual classificação das doenças e a formacom que a Medicina atual é praticada. Apesar deste considerável progresso, esta abordagem é insuficiente quando se trata de condições inflamatórias sistêmicas, como o lúpus eritematoso sistêmico, que abrange condições variando de formas brandas e pauci-sintomáticas até condições rapidamente fatais. O tratamento dessas condições é frequentemente insuficiente e novas abordagens são necessárias para progresso adicional nessas áreas da Medicina. Um avanço recente foi obtido no que tange às síndromes auto-inflamatórias hereditárias, nas quais a dissecção molecular dos defeitos gênicos subjacentes forneceu direcionamento para terapia orientada a alvos moleculares específicos. Esta abordagem é passível de aplicação às doenças auto-imunes sistêmicas com a compreensão de essas condições podem ser conseqüência da interação de estímulos ambientais específicos e uma gama de vários polimorfis mosgênicos interconectados. No escopo dessa transformação, a aplicação dos princípios de farmacogenéticas poderá contribuir para o progressivo desenvolvimento de uma Medicina personalizada vigorosa.

Polymorphisms of COTL1 gene identified by proteomic approach and their association with autoimmune disorders

To select candidate genes, we attempted to comparative analysis of protein levels between rheumatoid arthritis (RA) patients and healthy controls by two-dimensional electrophoresis (2-DE) and matrix-assisted laser desorption ionization mass spectrometry (MALDI-TOF-MS). We identified 17 proteins that showed up- or down-regulated spots in RA patients. We found that coactosin-like1 (COTL1) were highly expressed in RA patients compared with healthy controls. We performed a case-control study to determine whether the COTL1 gene polymorphisms were associated with RA and systemic lupus erythematosus (SLE). The genotype frequency of c.-1124G>T and the allelic frequency of c.484G>A in RA patients, and the genotype frequency of c.484G>A in SLE patients were significantly different from healthy controls (P = 0.009, 0.027, and 0.025, respectively). We also investigated the correlation with the levels of rheumatoid factor (RF) and anti-cyclic citrullinated peptide (CCP) antibody in RA patients, and anti-nuclear antibodies (ANA) in SLE patients. The c.484G>A polymorphism in RA patients has significant association with the levels of anti-CCP antibody (P = 0.03). Our findings demonstrated that c.-1124G>T and c.484G>A polymorphisms of the COTL1 gene might be associated with the genetic susceptibility of autoimmune disorders.

Polymorphisms of COTL1 gene identified by proteomic approach and their association with autoimmune disorders

To select candidate genes, we attempted to comparative analysis of protein levels between rheumatoid arthritis (RA) patients and healthy controls by two-dimensional electrophoresis (2-DE) and matrix-assisted laser desorption ionization mass spectrometry (MALDI-TOF-MS). We identified 17 proteins that showed up- or down-regulated spots in RA patients. We found that coactosin-like1 (COTL1) were highly expressed in RA patients compared with healthy controls. We performed a case-control study to determine whether the COTL1 gene polymorphisms were associated with RA and systemic lupus erythematosus (SLE). The genotype frequency of c.-1124G>T and the allelic frequency of c.484G>A in RA patients, and the genotype frequency of c.484G>A in SLE patients were significantly different from healthy controls (P = 0.009, 0.027, and 0.025, respectively). We also investigated the correlation with the levels of rheumatoid factor (RF) and anti-cyclic citrullinated peptide (CCP) antibody in RA patients, and anti-nuclear antibodies (ANA) in SLE patients. The c.484G>A polymorphism in RA patients has significant association with the levels of anti-CCP antibody (P = 0.03). Our findings demonstrated that c.-1124G>T and c.484G>A polymorphisms of the COTL1 gene might be associated with the genetic susceptibility of autoimmune disorders.

Epigenetics and epigenetic mechanisms in disease with emphasis on autoimmune diseases.

Epigenetics deals with molecular heritable patterns relating to chromatin, which exists in two alterable and inter-convertible states. The two conformations of chromatin i.e., compact and relaxed are due to epigenetic regulation. The alterations in chromatin normalize gene expression patterns. Thus, the epigenetic marks on chromatin are the deciding factors for either gene silencing or activation. The epigenetics introduced a new term viz., epiallele which deviates from the classical Mendelian allele. The remodeling of chromatin during embryonic phase, post-translational aberrations of chromatin proteins causing cellular dysfunction and possible epigenetic therapies are discussed in the present article. The role of epigenetic mechanisms in triggering / progression of several autoimmune diseases is being emphasized off late. The study of such complex epigenetic processes becomes very important in understanding the etiopathology of the disease as well as in designing target therapies.

E449X mutation in the thyroid hormone receptor β associated with autoimmune thyroid disease and severe neuropsychomotor involvement / Mutação E449X no receptor β do hormônio tireoidiano associada com doença tireoidiana auto-imune e retardo neuropscicomotor grave

OBJECTIVE: To report the clinical and molecular aspects of a patient with a diagnosis of Resistance to Thyroid Hormone (RTH) harboring the E449X mutation associated with autoimmune thyroid disease and severe neuropsychomotor retardation. METHODS: We present a case report including clinical and laboratory findings, and molecular analysis of a Brazilian patient with RTH. RESULTS: A 23-year old male presented hyperactivity disorder, attention deficit, delayed neuropsychomotor development, and goiter. Since the age of 1 year and 8 months, his mother had sought medical care for her son for the investigation of delayed neuropsychomotor development associated with irritability, aggressiveness, recurrent headache, profuse sudoresis, intermittent diarrhea, polyphagia, goiter, and low weight. Laboratory tests revealed normal TSH, increased T3, T4, antithyroglobulin and antimicrosomal antibody titers. Increasing doses of levothyroxine were prescribed, reaching 200 µg/day, without significant changes in his clinical-laboratory picture. Increasing doses of tiratricol were introduced, with a clear clinical improvement of aggressiveness, hyperactivity, tremor of the extremities, and greater weight gain. Molecular study revealed a nonsense mutation in exon 10, in which a substitution of a guanine to tyrosine in nucleotide 1345 (codon 449) generates the stop codon TAA, confirming the diagnosis of RTH. CONCLUSION: This patient has severe neuropsychomotor retardation not observed in a single previous report with the same mutation. This may reflect the lack of a genotype-phenotype correlation in affected cases with this syndrome, suggesting that genetic variability of factors other than β receptor of thyroid hormone (TRβ) might modulate the phenotype of RTH.

OBJETIVOS: Descrever aspectos clínicos e moleculares de um paciente com resistência ao hormônio tireoidiano (RHT) portador da mutação E449X associada a doença tireoideana auto-imune e retardo neuropscicomotor grave. MÉTODOS: Relatamos um caso incluindo achados clínicos, laboratoriais e análise molecular de um paciente brasileiro com RHT. RESULTADOS: Paciente masculino, 23 anos de idade, apresentou-se com distúrbio de hiperatividade, déficit de atenção, retardo no desenvolvimento neuropsicomotor e bócio. Desde 1 ano e 8 meses de idade, sua mãe procurou assistência médica para investigação do retardo do desenvolvimento neuropsicomotor associado com irritabilidade, agressividade, cefaléia recorrente, sudorese profusa, diarréia intermitente, polifagia, bócio e perda de peso. Avaliação laboratorial evidenciou TSH normal e aumento do T3, T4 e anticorpos antimicrossomal e antitireoglobulina. Doses crescentes de levotiroxina foram prescritas, máximo de 200 µg/dia, sem significativas alterações em seu quadro clínico-laboratorial. Doses crescentes de tiratricol foram introduzidas com melhora clínica evidente da agressividade, da hiperatividade, do tremor de extremidades e maior ganho de peso. O estudo molecular revelou uma mutação nonsense no éxon 10, no qual a substituição da guanina pela tirosina no nucleotídeo 1345 (códon 449) gerou um stop códon TAA, confirmando o diagnóstico da RHT. CONCLUSÃO: Este paciente tem um grave retardo neuropiscomotor não observado em um relato único anterior com a mesma mutação. Isto pode refletir a falta de relação genotipo-fenótipo nos casos afetados com esta síndrome sugerindo que a variabilidade genética de outros fatores, além do receptor do hormônio tireoidiano (HT), possa modular o fenótipo da RHT.