Cardiac telocytes. From basic science to cardiac diseases. I. Atrial fibrillation.

INTRODUCTION: Atrial fibrillation (AF) is nowadays considered to be one of the most important causes of heart failure, stroke, cognitive decline, vascular dementia, sudden death and overall cardiovascular morbidity. Recently were published a few articles suggesting a possible involvement of telocytes in the development of atrial fibrillation. The purpose of this article is to analyze the results obtained in the field systematically, and to see if there is enough data to support a possible involvement of telocytes in arrhythmogenesis. MATERIALS AND METHODS: To this end, we performed a systematic review of the relevant scientific literature, indexed in PubMed, Web of Science, and Scopus. RESULTS AND DISCUSSIONS: Our systematic review of the published data identified five articles containing original data, based on which the association between telocytes and atrial fibrillation was inferred in later studies. We analyzed the usefulness of the information contained in the original articles to support this association, showing a lack of definite proofs correlating telocytes with atrial fibrillation. CONCLUSIONS: Even if a few articles implied a potential association between AF and telocytes, the current data is not enough to support it. Moreover, even an association between the morphology, characteristics, or density of the telocytes in the atrium/pulmonary veins and AF is potentially speculative, and more studies should be performed before implying it with a reasonable degree of certainty.

Results of a collaborative study on DNA identification of aged bone samples.

AIM: A collaborative exercise with several institutes was organized by the Forensic DNA Service (FDNAS) and the Institute of the Legal Medicine, 2nd Faculty of Medicine, Charles University in Prague, Czech Republic, with the aim to test performance of different laboratories carrying out DNA analysis of relatively old bone samples. METHODS: Eighteen laboratories participating in the collaborative exercise were asked to perform DNA typing of two samples of bone powder. Two bone samples provided by the National Museum and the Institute of Archaelogy in Prague, Czech Republic, came from archeological excavations and were estimated to be approximately 150 and 400 years old. The methods of genetic characterization including autosomal, gonosomal, and mitochondrial markers was selected solely at the discretion of the participating laboratory. RESULTS: Although the participating laboratories used different extraction and amplification strategies, concordant results were obtained from the relatively intact 150 years old bone sample. Typing was more problematic with the analysis of the 400 years old bone sample due to poorer quality. CONCLUSION: The laboratories performing identification DNA analysis of bone and teeth samples should regularly test their ability to correctly perform DNA-based identification on bone samples containing degraded DNA and potential inhibitors and demonstrate that risk of contamination is minimized.

Molecular signatures of cardiac stem cells.

The discovery of cardiac stem cells (CSCs) able to renew the pool of cardiomyocyte raised the question of how these cells can be recognized and directed towards cardiac reconstruction after severe ischemic injury. The functional studies demonstrated that the differentiation of adult cardiac stem cells reproduce the stages observed in the embryonic development. Each stage is characterized by a complex molecular signature, which can be used for identification and molecular targeting. Three major markers have been used to isolate CSCs: c-kit, Sca-1, and Isl1 and different progenitor populations have been described: side-population (SP), cardiosphere-derived, epicardial-derived. Combinations between the main three markers and other transcription factors, cell surface proteins and regulatory RNAs may delimit even further the cardiac precursors. Accumulation of data leads to the idea that a single, yet unidentified unique cardiac stem cell is at the origin of those observed variants. In this review, we intended to summarize the actual knowledge about the main molecular markers of cardiac stem cells.