Cytogenetic analysis of 13 mesenchymal stem cell cultures isolated from normal human adipose tissue was carried out at different stages of culturing. The incidence of chromosomes 6, 8, 11, and X aneuploidy and polyploidy was studied by fluorescent in situ hybridization. During the early passages, monosomal cells were more often detected than trisomal ones. A clone with chromosome 6 monosomy was detected in three cultures during late passages.

The incidence of autosomes 6 and 8 aneuploidy in stem cell cultures derived from adipose tissue was evaluated at different stages of culturing. Monosomy was more incident than trisomy during the early passages. Distribution of cultures by the incidence of aneuploidy in different chromosomes was virtually the same. Clones with chromosome 6 monosomy were detected in two cultures during late passages.

Aim: To clarify mechanisms affecting the level and distribution of 5-hydroxymethylcytosine (5hmC) during aging. Materials & methods: We examined levels and genomic distribution of 5hmC along with the expression of ten–eleven translocation methylcytosine dioxygenases (TETs) in adipose stem cells in young and age-advanced individuals. Results: 5hmC levels were higher in adipose stem cells of age-advanced than young individuals (p = 0.0003), but were not associated with age-related changes in expression of TETs. 5hmC levels correlated with population doubling time (r = 0.62; p = 0.01). We identified 58 differentially hydroxymethylated regions. Hypo-hydroxymethylated differentially hydroxymethylated regions were approximately twofold enriched in CCCTC-binding factor binding sites. Conclusion: Accumulation of 5hmC in aged cells can result from inefficient active demethylation due to altered TETs activity and reduced passive demethylation due to slower proliferation.

We describe a method of isolation of human mesenchymal stromal cells from the umbilical cord (Wharton's jelly) and human placenta: amnion, placental villi, and trophoblast. Morphology, immunophenotypic characteristics, and differentiation potencies of isolated cells were studied. The capacity of mesenchymal stromal cells from extraembryonic tissues to osteogenic, adipogenic, and chondrogenic differentiation was demonstrated and the dynamics of this process was described. The isolated cells met the criteria for multipotent mesenchymal stem cells.