Characterisation of nuclear architectural alterations during in vitro differentiation of human stem cells of myogenic origin

• Published in: PloS one 2013-09, Vol.8 (9), p.e73231-e73231
• Main Authors: Rozwadowska, Natalia, Kolanowski, Tomasz, Wiland, Ewa, Siatkowski, Marcin, Pawlak, Piotr, Malcher, Agnieszka, Mietkiewski, Tomasz, Olszewska, Marta, Kurpisz, Maciej
• Format: Article
• Language: English
• Subjects: Cell culture; Cell Differentiation; Cell Nucleus; Centromere; Centromeres; Chromatin; Chromatin remodeling; Chromosomes; Chromosomes, Human, Pair 11; Chromosomes, Human, Pair 7; Deoxyribonucleic acid; Differentiation (biology); DNA; DNA binding proteins; DNA microarrays; Epigenetic inheritance; Epigenetics; Gene expression; Genes; Genetic aspects; Histones; Humans; In Situ Hybridization, Fluorescence; In Vitro Techniques; Muscle, Skeletal - cytology; Myoblasts; Myocytes; Myogenesis; Nuclei; Nuclei (cytology); Oligonucleotide Array Sequence Analysis; Rodents; Silence; Stem cells; Stem Cells - cytology; Transcription (Genetics); Transcription factors
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0073231

Cell differentiation is based on a synchronised orchestra of complex pathways of intrinsic and extrinsic signals that manifest in the induced expression of specific transcription factors and pivotal genes within the nucleus. One cannot ignore the epigenetic status of differentiating cells, comprising not only histones and DNA modifications but also the spatial and temporal intranuclear chromatin organisation, which is an important regulator of nuclear processes. In the present study, we investigated the nuclear architecture of human primary myoblasts and myocytes in an in vitro culture, with reference to global changes in genomic expression. Repositioning of the chromosomal centromeres, along with alterations in the nuclear shape and volume, was observed as a consequence of myotube formation. Moreover, the microarray data showed that during in vitro myogenesis cells tend to silence rather than induce gene expression. The creation of a chromosome map marked with gene expression changes that were at least 2-fold confirmed the observation. Additionally, almost all of the chromosomal centromeres in the differentiated cells preferentially localised near the nuclear periphery when compared to the undifferentiated cells. The exceptions were chromosomes 7 and 11, in which we were unable to confirm the centromere repositioning. In our opinion, this is the first reported observation of the movement of chromosomal centromeres along differentiating myogenic cells. Based on these data we can conclude that the myogenic differentiation with global gene expression changes is accompanied by the spatial repositioning of chromosomes and chromatin remodelling, which are important processes that regulate cell differentiation.