Ultrastructural analysis of mouse embryonic stem cell-derived chondrocytes.
Pluripotent embryonic stem (ES) cells cultivated as cellular aggregates, so called embryoid bodies (EBs), differentiate spontaneously into different cell types of all three germ layers in vitro resembling processes of cellular differentiation during embryonic development. Regarding chondrogenic differentiation, murine ES cells differentiate into progenitor cells, which form pre-cartilaginous condensations in the EB-outgrowths and express marker molecules characteristic for mesenchymal cell types such as Sox5 and Sox6. Later, mature chondrocytes appear which express collagen type II, and the collagen fibers show a typical morphology as demonstrated by electron-microscopical analysis. These mature chondrogenic cells are organized in cartilage nodules and produce large amounts of extracellular proteoglycans as revealed by staining with cupromeronic blue. Finally, cells organized in nodules express collagen type X, indicating the hypertrophic stage. In conclusion, differentiation of murine ES cells into chondrocytes proceeds from the undifferentiated stem cell via progenitor cells up to mature chondrogenic cells, which then undergo hypertrophy. Furthermore, because the ES-cell-derived chondrocytes did not express elastin, a marker for elastic cartilage tissue, we suggest the cartilage nodules to resemble hyaline cartilage tissue.
Kramer
Jan
J
Department of Medical Molecular Biology, University of Lübeck, Lübeck, Germany. Jan_Kramer@gmx.de
Klinger
Matthias
M
Kruse
Charli
C
Faza
Marius
M
Hargus
Gunnar
G
Rohwedel
Jürgen
J
D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D002356:Cartilage / Q000166:cytology / Q000196:embryology*; D002454:Cell Differentiation; D002460:Cell Line; D019902:Chondrocytes / Q000166:cytology* / Q000378:metabolism; D024043:Collagen Type II / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism; D004622:Embryo, Mammalian / Q000166:cytology*; D005109:Extracellular Matrix / Q000648:ultrastructure; D006609:High Mobility Group Proteins / Q000378:metabolism; D017404:In Situ Hybridization, Fluorescence; D051379:Mice / Q000196:embryology*; D018613:Microscopy, Confocal; D046529:Microscopy, Electron, Transmission; D009687:Nuclear Proteins / Q000378:metabolism; D039904:Pluripotent Stem Cells / Q000166:cytology* / Q000378:metabolism; D055755:SOXD Transcription Factors; D014157:Transcription Factors / Q000378:metabolism
D015415:Biomarkers; D024043:Collagen Type II; D004268:DNA-Binding Proteins; D006609:High Mobility Group Proteins; D009687:Nuclear Proteins; D055755:SOXD Transcription Factors; C089186:Sox5 protein, mouse; C095939:Sox6 protein, mouse; D014157:Transcription Factors