title: Ultra-structural morphology of long-term cultivated white adipose tissue-derived stem cells.
abstract: White adipose tissue was long perceived as a passive lipid storage depot but it is now considered as an active and important endocrine organ. It also harbours not only adipocytes and vascular cells but also a wide array of immunologically active cells, including macrophages and lymphocytes, which may induce obesity-related inflammation. Recently, adipose tissue has been reported as a source of adult mesenchymal stem cells with wide use in regenerative medicine and tissue engineering. Their relatively non-complicated procurement and collection (often performed as liposuction during aesthetic surgery) and grand plasticity support this idea even more. We focused our research on exploring the issues of isolation and long-term cultivation of mesenchymal stem cells obtained from adipose tissue. Ultra-structural morphology of the cells cultivated in vitro has been studied and analysed in several cultivation time periods and following serial passages--up to 30 passages. In the first passages they had ultra-structural characteristics of cells with high proteosynthetic activity. Within the cytoplasm, big number of small lipid droplets and between them, sparsely placed, small and inconspicuous, electron-dense, lamellar bodies, which resembled myelin figures were observed. The cells from the later passages contained high number of lamellar electron-dense structures, which filled out almost the entire cytoplasm. In between, mitochondria were often found. These bodies were sometimes small and resembled myelin figures, but several of them reached huge dimensions (more than 1 µm) and their lamellar structure was not distinguishable. We did not have an answer to the question about their function, but they probably represented the evidence of active metabolism of lipids present in the cytoplasm of these cells or represented residual bodies, which arise after the breakdown of cellular organelles, notably mitochondria during long-term cultivation.
authors.affiliation: Institute of Histology and Embryology, Faculty of Medicine, Comenius University in Bratislava, Bratislava, Slovakia. ivan.varga@fmed.uniba.sk.
authors.forename: Ivan
authors.initials: I
authors.lastname: Varga
authors.affiliation: Institute of Histology and Embryology, Faculty of Medicine, Comenius University in Bratislava, Bratislava, Slovakia.
authors.forename: Michal
authors.initials: M
authors.lastname: Miko
authors.affiliation: Institute of Histology and Embryology, Faculty of Medicine, Comenius University in Bratislava, Bratislava, Slovakia.
authors.forename: Lenka
authors.initials: L
authors.lastname: Oravcová
authors.affiliation: Department of Pharmacology and Toxicology, Faculty of Pharmacy, Comenius University in Bratislava, Bratislava, Slovakia.
authors.forename: Tatiana
authors.initials: T
authors.lastname: Bačkayová
authors.affiliation: Department of Burns and Reconstruction Surgery, Faculty of Medicine, Comenius University in Bratislava, Bratislava, Slovakia.
authors.forename: Ján
authors.initials: J
authors.lastname: Koller
authors.affiliation: Institute of Medical Biology, Genetics and Clinical Genetics, Faculty of Medicine, Comenius University in Bratislava, Bratislava, Slovakia.
authors.forename: Ľuboš
authors.initials: Ľ
authors.lastname: Danišovič
mesh_terms: D052436:Adipose Tissue, White / Q000166:cytology* / Q000648:ultrastructure*; D000328:Adult; D061249:Batch Cell Culture Techniques / Q000379:methods*; D048429:Cell Size; D002478:Cells, Cultured; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D059630:Mesenchymal Stem Cells / Q000166:cytology* / Q000648:ultrastructure*
keywords: Adipose tissue-derived stem cells; Flow cytometry analysis; Isolation; Long-time cultivation; Transmission electron microscopy