| |  | | | | | | | | | | | | | | | |  | | | | | | | | | | | | | | | | | | | | | | | | Morphologic and transcriptomic comparison of adipose- and bone-marrow-derived porcine stem cells cultured in alginate hydrogels. Cell Tissue Res. 2010 Aug 3; Authors: Kim D, Monaco E, Maki A, de Lima AS, Kong HJ, Hurley WL, Wheeler MB Advances in bioengineering, material chemistry, and developmental biology have led to the design of three-dimensional (3D) culture systems that better resemble the surrounding structure and chemistry of the in situ niches of cells in tissues. This study was designed to characterize and compare porcine adipose-derived stem cells (ADSC) and bone-marrow-derived stem cells (BMSC) induced to differentiate toward osteogenic and adipogenic lineages in vitro by using a 3D alginate hydrogel. The morphology and gene expression of the two cell populations during differentiation were analyzed. Both ADSC and BMSC showed morphological evidence of osteogenic and adipogenic differentiation. Expression patterns of genes characteristic of the onset of osteogenic differentiation (ALP, COL1A1, SPARC, SPP1) were low at the beginning of culture and generally increased during the period of differentiation up to 28 days in culture. Expression of genes associated with adipogenic differentiation (ACSL1, ADFP, ADIPOQ, CD36, DBI, DGAT2, PPARG, SCD) was consistently increased in ADSC cultured in alginate hydrogel relative to the start of differentiation. However, adipogenic gene expression of BMSC cultured in alginate hydrogel was more limited when compared with that of ADSC. Evaluation of cell numbers (via the MTT staining assay) suggested a greater viability of BMSC under osteogenic conditions in alginate hydrogels than under adipogenic conditions, whereas ADSC had greater viability under adipogenic conditions than under osteogenic conditions. This study thus provides an important initial evaluation of ADSC and BMSC seeded and differentiated toward the osteogenic and adipogenic cell lineages in a 3D alginate hydrogel in vitro. PMID: 20680346 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | De novo generation of white adipocytes from the myeloid lineage via mesenchymal intermediates is age, adipose depot, and gender specific. Proc Natl Acad Sci U S A. 2010 Aug 2; Authors: Majka SM, Fox KE, Psilas JC, Helm KM, Childs CR, Acosta AS, Janssen RC, Friedman JE, Woessner BT, Shade TR, Varella-Garcia M, Klemm DJ It is generally assumed that white adipocytes arise from resident adipose tissue mesenchymal progenitor cells. We challenge this paradigm by defining a hematopoietic origin for both the de novo development of a subset of white adipocytes in adults and a previously uncharacterized adipose tissue resident mesenchymal progenitor population. Lineage and cytogenetic analysis revealed that bone marrow progenitor (BMP)-derived adipocytes and adipocyte progenitors arise from hematopoietic cells via the myeloid lineage in the absence of cell fusion. Global gene expression analysis indicated that the BMP-derived fat cells are bona fide adipocytes but differ from conventional white or brown adipocytes in decreased expression of genes involved in mitochondrial biogenesis and lipid oxidation, and increased inflammatory gene expression. The BMP-derived adipocytes accumulate with age, occur in higher numbers in visceral than in subcutaneous fat, and in female versus male mice. BMP-derived adipocytes may, therefore, account in part for adipose depot heterogeneity and detrimental changes in adipose metabolism and inflammation with aging and adiposity. PMID: 20679227 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Comprehensive transcriptome analysis of mouse embryonic stem cell adipogenesis unravels new processes of adipocyte development. Genome Biol. 2010 Aug 3;11(8):R80 Authors: Billon N, Kolde R, Reimand J, Monteiro MC, Kull M, Peterson H, Tretyakov K, Adler P, Wdziekonski B, Vilo J, Dani C ABSTRACT: BACKGROUND: The current epidemic of obesity has caused a surge of interest in the study of adipose tissue formation. While major progress has been made in defining the molecular networks that control adipocyte terminal differentiation, the early steps of adipocyte development and the embryonic origin of this lineage remain largely unknown. RESULTS: Here we performed genome-wide analysis of gene expression during adipogenesis of mouse embryonic stem cells (ESCs). We then pursued comprehensive bioinformatic analyses, including de novo functional annotation and curation of the generated data within the context of biological pathways, to uncover novel biological functions associated with the early steps of adipocyte development. By combining in-depth gene regulation studies and in silico analysis of transcription factor binding site enrichment, we also provide insights into the transcriptional networks that might govern these early steps. CONCLUSIONS: This study supports several biological findings: firstly, adipocyte development in mouse ESCs is coupled to blood vessel morphogenesis and neural development, just as it is during mouse development. Secondly, the early steps of adipocyte formation involve major changes in signaling and transcriptional networks. A large proportion of the transcription factors that we uncovered in mouse ESCs are also expressed in the mouse embryonic mesenchyme and in adipose tissues, demonstrating the power of our approach to probe for genes associated with early developmental processes on a genome-wide scale. Finally, we reveal a plethora of novel candidate genes for adipocyte development and present a unique resource that can be further explored in functional assays. PMID: 20678241 [PubMed - as supplied by publisher] | | | | | | | | | | |  |
No comments:
Post a Comment