Focus on genetic modifiers of polyglutamine diseases / 中华神经科杂志

Polyglutamine (PolyQ) diseases are a group of clinically and genetically heterogeneous neurodegenerative diseases, due to an expanded CAG repeat in a coding region of the respective genes leading to neurodegenerative phenotypes by selective neuronal loss. Overall, only part of variance (50%-70%) in age at onset is explained by (CAG)n length, suggesting genetic modifying factors independent of (CAG)n size may contribute to clinical heterogeneity. Here, the research history of genetic modifiers in polyQ diseases is reviewed, and the major findings and current research status are discussed.

Genes implicados en la gravedad de la infección por SARS-cov- 2

Resumen El COVID-19 es una patología producida por el SARS-CoV-2, virus de carácter zoonótico capaz de producir patologías multiorgánicas. La sintomatología que produce es variada. Ante la infección algunos pacientes presentan condiciones de gravedad. Los estudios han demostrado que el rol genético tiene gran afluencia sobre la respuesta ante la infección. El objetivo de investigación es detallar los genes que están implicados en la gravedad de la infección por SARS-CoV- 2. Metodología . Se realizó una revisión sistemática, con base a la búsqueda y análisis de artículos originales en bases de datos de alto impacto como PudMed, Google Académico, Scopus, Taylor & Francis, ProQuest SciencieDirect; se utilizaron operadores booleanos, criterios de inclusión y exclusión con el objetivo de obtener información precisa. Los genes de inmunidad como el HLA, ACE2 y TMPRSS2 están directamente involucrados con la gravedad de la infección por SARS-CoV- 2. Los polimorfismos de los genes del polyQ del receptor de andrógenos, factor ABO coadyuvan a un deterioro del estado patológico como consecuencia de la COVID-19. Conclusión. Los estudios demostraron que existen genes involucrados en la gravedad ante la infección de SARS -CoV-2, pues mencionan que los polimorfismos de los genes; HLA, del polyQ del receptor de andrógenos y factor ABO producen susceptibilidad ante el COVID-19. Así mismo los genes ACE2 y TMPRSS2 intervienen en el ingreso y expansión del virus. En las diversas razas existen variantes de los genes CCL2 y MBL lo que indica que algunas poblaciones son más susceptibles que otras.

Abstract COVID-19 is a pathology caused by SARS-CoV-2, a zoonotic virus capable of producing multi-organ pathologies. The symptomatology it produces is varied. Some patients present severe conditions after infection. Studies have shown that the genetic role has a great influence on the response to infection. Methodology . A systematic review was carried out, based on the search and analysis of original articles in high impact databases such as PudMed, Google Scholar, Scopus, Taylor & Francis, ProQuest SciencieDirect; Boolean operators, inclusion and exclusion criteria were used in order to obtain accurate information. Immunity genes such as HLA, ACE2 and TMPRSS2 are directly involved with the severity of SARS-CoV- 2 infection. Polymorphisms of androgen receptor polyQ genes, ABO factor contribute to a deterioration of the pathological state as a consequence of COVID-19. Conclusion . The studies demonstrated that there are genes involved in the severity of SARS-CoV-2 infection, since they mention that polymorphisms of the HLA, androgen receptor polyQ and ABO factor genes produce susceptibility to COVID-19. Likewise, ACE2 and TMPRSS2 genes intervene in the entry and expansion of the virus. In the different breeds there are variants of the CCL2 and MBL genes, which indicates that some populations are more susceptible than others.

Resumo COVID-19 é uma patologia causada pelo SARS-CoV-2, um vírus zoonótico capaz de produzir patologias multiorganismos. Os sintomas que ela produz são variados. Alguns pacientes se apresentam com condições severas após a infecção. Estudos demonstraram que o papel da genética desempenha um papel importante na resposta à infecção. O objetivo desta pesquisa é detalhar os genes que estão envolvidos na gravidade da infecção pelo SARS-CoV- 2. Metodologia. Foi realizada uma revisão sistemática, baseada na busca e análise de artigos originais em bancos de dados de alto impacto como PudMed, Google Scholar, Scopus, Taylor & Francis, ProQuest SciencieDirect; operadores booleanos, critérios de inclusão e exclusão foram utilizados para obter informações precisas. Resultados. Os genes de imunidade como HLA, ACE2 e TMPRSS2 estão diretamente envolvidos na gravidade da infecção pelo SARS-CoV- 2. Os polimorfismos dos genes receptores de androgênio polyQ, fator ABO contribuem para uma deterioração do estado patológico como conseqüência da COVID-19. Conclusão. Os estudos demonstraram que existem genes envolvidos na gravidade da infecção pelo SRA-CoV-2, pois mencionam que os polimorfismos dos genes HLA, androgênio receptor policarbonato e fator ABO produzem suscetibilidade à COVID-19. Os genes ACE2 e TMPRSS2 também estão envolvidos na entrada e propagação do vírus. Existem variantes dos genes CCL2 e MBL nas diferentes raças, indicando que algumas populações são mais suscetíveis do que outras.

Aplicaciones de terapias de reemplazo celular al tratamiento de enfermedades poliglutamínicas / Applications of cell replacement therapies to the treatment of poly-glutamine diseases

Se realizó una revisión de la literatura especializada con el objetivo de evaluar el estado del arte en cuanto a la aplicación de terapias de reemplazo celular en enfermedades poliglutamínicas. Se consultaron las bases de datos HighWire y PubMed, con el uso de descriptores y operadores booleanos. Se recuperaron 84 artículos sobre la temática, publicados en revistas con un factor de impacto promedio de 5,42. Se discuten los estudios experimentales y pre-clínicos realizados con relación a terapias de reemplazo celular en enfermedades poliglutamínicas. Se demuestra la efectividad del uso de células madre de distintas fuentes en el mejoramiento de la función motora en modelos experimentales de enfermedades poliglutamínicas. Se revela la necesidad de realizar estudios multicéntricos a mediano y largo plazos, para la evaluación de los efectos terapéuticos de las terapias de reemplazo celular en enfermedades poliglutamínicas.

A review of the specialized literature was carried out with the aim of evaluating the state of the art regarding the application of cell replacement therapies in polyglutamine diseases. The HighWire and PubMed databases were consulted, with the use of Boolean descriptors and operators. 84 articles were retrieved on the subject, published in journals with an average impact factor of 5.42. The experimental and pre-clinical studies carried out in relation to cell replacement therapies in polyglutamine diseases are discussed. The effectiveness of the use of stem cells from different sources in the improvement of motor function in experimental models of polyglutamine diseases is demonstrated. The need to perform multicenter studies in the medium and long term is revealed, for the evaluation of the therapeutic effects of cell replacement therapies in polyglutamine diseases.

Occupational therapy in spinocerebellar ataxia type 3: an open-label trial

Occupational therapy (OT) is a profession concerned with promoting health and well-being through occupation, by enabling handicapped people to participate in the activities of everyday life. OT is part of the clinical rehabilitation of progressive genetic neurodegenerative diseases such as spinocerebellar ataxias; however, its effects have never been determined in these diseases. Our aim was to investigate the effect of OT on both physical disabilities and depressive symptoms of spinocerebellar ataxia type 3 (SCA3) patients. Genomically diagnosed SCA3 patients older than 18 years were invited to participate in the study. Disability, as evaluated by functional independence measurement and Barthel incapacitation score, Hamilton Rating Scale for Depression, and World Health Organization Quality of Life questionnaire (WHOQOL-BREF), was determined at baseline and after 3 and 6 months of treatment. Twenty-six patients agreed to participate in the study. All were treated because OT prevents blinding of a control group. Fifteen sessions of rehabilitative OT were applied over a period of 6 months. Difficult access to food, clothing, personal hygiene, and leisure were some of the main disabilities focused by these patients. After this treatment, disability scores and quality of life were stable, and the Hamilton scores for depression improved. Since no medication was started up to 6 months before or during OT, this improvement was related to our intervention. No association was found between these endpoints and a CAG tract of the MJD1 gene (CAGn), age, age of onset, or neurological scores at baseline (Spearman test). Although the possibly temporary stabilization of the downhill disabilities as an effect of OT remains to be established, its clear effect on depressive symptoms confirms the recommendation of OT to any patient with SCA3 or spinocerebellar ataxia.

Diagnóstico molecular de la enfermedad de Huntington / Molecular diagnosis in Huntington's disease

La enfermedad de Huntington es un padecimiento neurológico degenerativo, de herencia autosómica dominante, causado por una expansión CAG que codifica una secuencia de poliglutamina en la proteína huntingtina. Su frecuencia varía de cinco a 10 afectados por 100 mil individuos en población caucásica. Clínicamente muestra manifestaciones motoras, cognoscitivas, psicológicas y muerte en 10 a 15 años. Avances concretos se han logrado en el conocimiento del mecanismo mutacional, alteraciones del producto proteico y su efecto neuropatológico. Un conjunto de procedimientos como PCR con o sin modificación del ADN, Southern blot y métodos mixtos son analizados en sus características y eficiencia para el diagnóstico molecular de esta enfermedad.

Huntington's disease (HD) is a neurological degenerative disorder, inherited by an autosomal dominant mode, and caused by a CAG triplet expansion coding for a poly-glutamine sequence in the huntingtin protein. HD affects 5-10 in 100,000 individuals from Caucasian population. Clinically patients display motor, cognitive and psychological impairment, and death within 10-15 years. Concrete advances have been achieved in the knowledge of the mutational mechanism, alteration of the protein product and their neuropathological effects. A number of tests such as PCR with or without DNA modification, Southern blot and mixed methods are analyzed. We describe their characteristics and effectiveness for the molecular diagnosis of HD.

Establishment of a Huntington’s Disease in vitro Drug Screening Cell Model / 中国生物工程杂志

To develop a Huntington’s disease(HD) cell model in vitro to screen drugs targeting the aggregation of polyQ,different length of CAG repeat fragments were amplified by random primer PCR, identified by DNA sequencing and were fused to the N-terminus of CAT in the pCAR system respectively which had been constructed and identified before. Recombinant plasmids were transformed into and induced to express in the host E.coli. SDS-PAGE and chloramphenicol resistance test were done to determine the solubility of the polyQ and chloramphenicol resistance levels of the fusions. With different length of CAG repeat fragments cloned and expressed in the CAT-fusion protein reporting system, it is found that when the length of the fragments increased over 40, their encoding polyQ expressed as insoluble protein and chloramphenicol resistance levels are lower, while under 40, the polyQ expressed as soluble ones and chloramphenicol resistance levels are higher. A in vitro HD model that could minimize the pathological process of the HD thus has been developed. With which by measure the recombinant bacteria’s resistance to chloramphenicol, the polyQ’ solubility and folding state in vitro by quality and quantity could be determined. Thus this model can be used to screen drugs or bioactivity materials that can inhibit aggregation of the polyQ, which thereby shedding new light on the prevent, diagnosis and therapy of HD.

Expression of Expanded Polyglutamine Disease Proteins in Drosophila (Drosophila Polyglutamine Disease Models) / 소아과

PURPOSE: Polyglutamine diseases are a group of diseases caused by the expansion of a polyglutamine tract in the protein. The present study was performed to verify if polyglutamine disease transgenic Drosophila models show similar dysfunctions as are seen in human patients. METHODS: Polyglutamine disease transgenic Drosophila were tested for their climbing ability. And using genetic methods, the effects of anti-apoptotic gene bcl-2 and chemical chaperones on neurodegeneration were observed. Also, spinocerebellar ataxia 2 (SCA2) transgenic Drosophila lines were generated for future studies. RESULTS: Expanded forms of spinocerebellar ataxia 3 (SCA3) transgenic protein causes characteristic locomotor dysfunction when expressed in the nervous system of Drosophila but the anti-apoptotic gene bcl-2 shows no evidence of ameliorating the deleterious effect of the expanded protein. However, Glycerol, a chemical chaperone, seemed to reduce the toxicity, at least in the eyes of the transgenic flies. The level SCA2 expression is too weak in the transgenic SCA2 Drosophila for evaluation. CONCLUSION: SCA3 transgenic Drosophila show ataxic behavior as observed in human patients. Chemical chaperones such as glycerol may prove beneficial in this class of genetic disease, which has no current method of cure.