Methyl-CpG binding proteins: specialized transcriptional repressors or structural components of chromatin?

DNA methylation is an epigenetic modification that is implicated in transcriptional silencing. It is becoming increasingly clear that both correct levels and proper interpretation of DNA methylation are important for normal development and function of many organisms, including humans. In this review we focus on recent advances in understanding of how proteins that bind to methylated DNA recognize their binding sites and translate the DNA methylation signal into functional states of chromatin. Although the function of methyl-CpG binding proteins in transcriptional repression has been attributed to their cooperation with corepressor complexes, additional roles for these proteins in chromatin compaction and spatial organization of nuclear domains have also been proposed. Finally, we provide a brief overview of how methyl-CpG proteins contribute to human disease processes such as Rett Syndrome and cancer

Pearl powder - an innovation in medicine and dermatocosmetics

Въведение: Познанието за перления прах, използван от традиционната китайска медицина като лечебно средство, датира от преди 2000 години. Добиван от природни източници - черупки и перли на миди, стриди и морски охлюви, днес перленият прах провокира сериозен научен интерес поради уникалните си характеристики и качества. Цел: Да се анализира достъпната литература, реферирана в базите данни MEDLINE (PubMed), Scopus и Web of Science през последните 10 г. Материал и методи: Проучени са съдържанията на резюметата и пълнотекстовите публикации по проблема. Резултати: Перленият прах се разглежда като активно вещество с овлажняващ, избелващ, стимулиращ регенерацията и заздравяването на рани, антиконвулсивен, антиоксидантен, седативен, остеогенен, антиостеопоротичен ефект. Доказано е и противостареещото му действие. Изводи: Приложението на перлен прах е иновация както в медицината, така и в дерматозметиката. Модифицирането на перлен прах посредством нанотехнологии демонстрира големи промени в абсорбцията и бионаличността на веществото, което го прави още по-ефективно средство.Introduction: Pearl powder has been known for more than 2000 years, including as a remedy in traditional Chinese medicine. Nowadays, pearl powder raises serious scientific interest due to its unique characteristics and properties. The main natural sources include shells and pearls of mussels, oysters and molluscs. Aim: The aim of this paper is to evaluate the literature referred in the last 10 years in MEDLINE (PubMed), Scopus and Web of Science-referred literature data bases. Materials and Methods: Abstracts and full text publications on the topic were reviewed. Results: Pearl powder is considered an active substance with numerous actions, including moisturizing, whitening, anticonvulsive, antioxidant, sedative, antiosteoporotic and osteogenic effects. It stimulates regeneration and wound healing and is shown to have anti-aging properties. In addition, pearl powder modifications via nanotechnology demonstrate considerable changes in absorption and bioavailability. Conclusion: Pearl powder application is an innovation in both medicine and dermatocosmetics. Combined with nanotechnology it can become even more effective

A role for SUMO modification in transcriptional repression and activation

Since the discovery of the SUMO (small ubiquitin-like modifier) family of proteins just over a decade ago, a plethora of substrates have been uncovered including many regulators of transcription. Conjugation of SUMO to target proteins has generally been considered as a repressive modification. However, there are now a growing number of examples where sumoylation has been shown to activate transcription. Here we discuss whether there is something intrinsically repressive about sumoylation, or if the outcome of this modification in the context of transcription will prove to be largely substrate-dependent. We highlight some of the technical challenges that will be faced by attempting to answer this question

DNA methylation in insects

Cytosine DNA methylation has been demonstrated in numerous eukaryotic organisms and has been shown to play an important role in human disease. The function of DNA methylation has been studied extensively in vertebrates, but establishing its primary role has proved difficult and controversial. Analysing methylation in insects has indicated an apparent functional diversity that seems to argue against a strict functional conservation. To investigate this hypothesis, we here assess the data reported in four different insect species in which DNA methylation has been analysed more thoroughly: the fruit fly Drosophila melanogaster, the cabbage moth Mamestra brassicae, the peach-potato aphid Myzus persicae and the mealybug Planococcus citri

The genome of the crustacean Parhyale hawaiensis, a model for animal development, regeneration, immunity and lignocellulose digestion

The amphipod crustacean Parhyale hawaiensis is a blossoming model system for studies of developmental mechanisms and more recently regeneration. We have sequenced the genome allowing annotation of all key signaling pathways, transcription factors, and non-coding RNAs that will enhance ongoing functional studies. Parhyale is a member of the Malacostraca clade, which includes crustacean food crop species. We analysed the immunity related genes of Parhyale as an important comparative system for these species, where immunity related aquaculture problems have increased as farming has intensified. We also find that Parhyale and other species within Multicrustacea contain the enzyme sets necessary to perform lignocellulose digestion ('wood eating'), suggesting this ability may predate the diversification of this lineage. Our data provide an essential resource for further development of Parhyale as an experimental model. The first malacostracan genome will underpin ongoing comparative work in food crop species and research investigating lignocellulose as an energy source

Разработка алгоритма кластеризации кардиокомплексов с посткоррекцией для задач длительного мониторирования электрокардиосигнала

Introduction. The most common method for diagnosing cardiovascular diseases is the method of ECG monitoring. In order to facilitate the analysis of the obtained monitorograms, special software solutions for automated ECG processing are required. One possible approach is the use of algorithms for automated ECG processing. Such algorithms perform  clustering of cardiac signals by dividing the ECG into complexes of similar cardiac signals. The most representative complexes obtained by statistical averaging are subject to further analysis.Aim. Development of an algorithm for automated ECG processing,  which performs clustering of cardiac signals by dividing the ECG into complexes of similar cardiac signals.Materials and methods. Experimental testing of the developed software was carried out using patient records provided by the Pavlov First State Medical University of St  Petersburg. The software module was implemented in the MatLab environment.Results. An algorithm for clustering cardiac signals with post-correction for the tasks of long-term ECG monitoring and a software module on its basis were proposed.Conclusion.  The presence of a small number of reference cardiac signal complexes, obtained through ECG processing using the proposed algorithm, allows physicians to optimize the process of ECG analysis. The as- obtained information serves as a basis for assessing dynamic changes in the shape and other parameters of cardiac signals for both a particular patient and groups of patients. The paper considers the effect of synchronization errors of clustered cardiac signals on the shape of the averaged cardiac complex. The classical solution to the deconvolution problem leads to significant errors in finding an estimate of the true form of a cardiac signal complex. On the basis of analytical calculations, expressions were obtained for the correction of clustered cardiac signals. Such correction was shown to reduce clusterization errors associated with desynchronization, which creates a basis for investigating the fine structure of ECG signals.Введение.  Наиболее распространенным методом диагностики сердечно- сосудистых заболеваний является длительное  мониторирование  электрокардиосигнала  (ЭКС) .  Для  облегчения  анализа  полученных  мониторограмм врачам- кардиологам необходимы специальные алгоритмы и программные средства автоматизированной обработки  ЭКС. Одним из  таких средств  является алгоритм автоматизированной обработки  ЭКС, выполня ющий  кластеризацию кардиокомплексов  (КК) , разделяя  ЭКС  на группы максимально близких по форме  КК. Дальнейшему анализу подвергаются только эталонные КК, полученные статистическим  усреднением  КК  в каждой группе.Цель  работы.  Разработка  алгоритма  автоматизированной  кластеризации  КК  ЭКС,  разделяющего  электрокардиосигнал на группы максимально близких по форме КК.Материалы и методы.  Экспериментальная апробация  алгоритма и  программного  модуля  проводилась на  базе обезличенных суточных записей ЭКС пациентов Первого Санкт- Петербургского государственного медицинского университета им.   акад.   И. П. Павлова Минздрава России.  Программный модуль был реализован в среде MatLab.Результаты.  Разработан  алгоритм  сортировки  КК  с  посткоррекцией  для  длительного  мониторирования  ЭКС; представлен программный модуль, реализованный на базе  разработанного алгоритма. Рассмотрено  влияние ошибок синхронизации  КК  при их накоплении  на форму усредняемого КК. Классическое решение задачи деконволюции приводит к значительным ошибкам при нахождении оценки "истинной" формы КК. На основании аналитических расчетов получены выражения для коррекции накапливаемого КК.  Показано, что в результате коррекции можно  нивелировать ошибки накопления, связанные с рассинхронизацией.Заключение.  Наличие  небольшого  количества  эталонных  КК,  полученных  в  результате  обработки  ЭКС с помощью  предложенного  алгоритма,  позволяет  врачу-исследователю  значительно  сократить  время, затрачиваемое  на  анализ  ЭКС,  и  является  основой  исследования  динамических  изменений  формы  и иных параметров КК  как для конкретного пациента, так и для их группы. Полученные результаты  позволяют создать основу для решения задач, направленных на исследование "тонкой" структуры ЭКС

Escherichia coli Frameshift Mutation Rate Depends on the Chromosomal Context but Not on the GATC Content Near the Mutation Site

Different studies have suggested that mutation rate varies at different positions in the genome. In this work we analyzed if the chromosomal context and/or the presence of GATC sites can affect the frameshift mutation rate in the Escherichia coli genome. We show that in a mismatch repair deficient background, a condition where the mutation rate reflects the fidelity of the DNA polymerization process, the frameshift mutation rate could vary up to four times among different chromosomal contexts. Furthermore, the mismatch repair efficiency could vary up to eight times when compared at different chromosomal locations, indicating that detection and/or repair of frameshift events also depends on the chromosomal context. Also, GATC sequences have been proved to be essential for the correct functioning of the E. coli mismatch repair system. Using bacteriophage heteroduplexes molecules it has been shown that GATC influence the mismatch repair efficiency in a distance- and number-dependent manner, being almost nonfunctional when GATC sequences are located at 1 kb or more from the mutation site. Interestingly, we found that in E. coli genomic DNA the mismatch repair system can efficiently function even if the nearest GATC sequence is located more than 2 kb away from the mutation site. The results presented in this work show that even though frameshift mutations can be efficiently generated and/or repaired anywhere in the genome, these processes can be modulated by the chromosomal context that surrounds the mutation site