title: Generation of mature fat pads in vitro and in vivo utilizing 3-D long-term culture of 3T3-L1 preadipocytes.
abstract: Tissue-inherent factors such as cell-cell and cell-extracellular matrix interactions are regarded to exert a potentially large impact on adipogenesis as well as on secretory functions of adipose tissue. However, an appropriate 3-D adipogenesis model useful for addressing such interactions is still lacking. In this study, using tissue-engineering techniques, we demonstrate for the first time the development of coherent fat pads consisting of unilocular signet-ring cells in vitro. The constructs were generated by differentiating 3T3-L1 preadipocytes on 3-D polymeric scaffolds for either 9, 21, or 35 days in vitro. Only long-term culture yielded uniform tissues histologically comparable to native fat. Light and scanning electron microscopy provided direct evidence of 3-D tissue coherence and cell-cell contact in a tissue context, which was in strong contrast to conventional 2-D monolayer culture. Further differences between the two culture systems included enhanced secretion of leptin in 3-D tissue culture and differences in laminin expression (mRNA and protein level). Increase of triglyceride content over culture time and mRNA expression of other adipocyte genes, such as PPARgamma and Glut-4, were found to be similar. Implantation of long-term differentiated tissue constructs in nude mice resulted in further development and maintenance of fat pads. The presented model system is suggested to contribute to a better understanding of adipose tissue development and function facilitating studies on tissue-inherent interactions in vitro and in vivo.
authors.affiliation: Department of Pharmaceutical Technology, University of Regensburg, 93040 Regensburg, Germany.
authors.forename: Claudia
authors.initials: C
authors.lastname: Fischbach
authors.forename: Thilo
authors.initials: T
authors.lastname: Spruss
authors.forename: Barbara
authors.initials: B
authors.lastname: Weiser
authors.forename: Markus
authors.initials: M
authors.lastname: Neubauer
authors.forename: Christian
authors.initials: C
authors.lastname: Becker
authors.forename: Michael
authors.initials: M
authors.lastname: Hacker
authors.forename: Achim
authors.initials: A
authors.lastname: Göpferich
authors.forename: Torsten
authors.initials: T
authors.lastname: Blunk
mesh_terms: D041721:3T3-L1 Cells; D017667:Adipocytes / Q000378:metabolism* / Q000648:ultrastructure; D000273:Adipose Tissue / Q000378:metabolism* / Q000648:ultrastructure; D000818:Animals; D002448:Cell Adhesion / Q000502:physiology; D002450:Cell Communication / Q000502:physiology*; D018929:Cell Culture Techniques / Q000379:methods; D005109:Extracellular Matrix / Q000378:metabolism; D051275:Glucose Transporter Type 4; D007797:Laminin / Q000378:metabolism; D020738:Leptin / Q000378:metabolism; D051379:Mice; D008819:Mice, Nude; D008855:Microscopy, Electron, Scanning; D009004:Monosaccharide Transport Proteins / Q000235:genetics; D009124:Muscle Proteins / Q000235:genetics; D009924:Organ Culture Techniques / Q000379:methods; D047495:PPAR gamma / Q000235:genetics; D012333:RNA, Messenger / Q000378:metabolism; D013997:Time Factors; D023822:Tissue Engineering / Q000379:methods*; D014280:Triglycerides / Q000378:metabolism; D015854:Up-Regulation / Q000502:physiology
chemical_list: D051275:Glucose Transporter Type 4; D007797:Laminin; D020738:Leptin; D009004:Monosaccharide Transport Proteins; D009124:Muscle Proteins; D047495:PPAR gamma; D012333:RNA, Messenger; C495693:Slc2a4 protein, mouse; D014280:Triglycerides