Article

Adipose tissue engineering in three-dimensional levitation tissue culture system based on magnetic nanoparticles.

University of Texas Health Science Center at Houston, Institute of Molecular Medicine , 1825 Pressler st., Rm. 630-G, Houston, Texas, United States, 77030, 713-500-3146
Tissue Engineering Part C Methods (Impact Factor: 4.64). 09/2012; DOI: 10.1089/ten.TEC.2012.0198
Source: PubMed

ABSTRACT White adipose tissue (WAT) is becoming widely used in regenerative medicine / cell therapy applications, and its physiological and pathological importance is increasingly appreciated. WAT is a complex organ composed of differentiated adipocytes, stromal mesenchymal progenitors known as adipose stem cells (ASC), as well as endothelial vascular cells and infiltrating leukocytes. Two-dimensional (2D) culture that has been typically used for studying adipose cells does not adequately recapitulate WAT complexity. Improved methods for reconstruction of functional WAT ex vivo are instrumental for understanding of physiological interactions between the composing cell populations. Here, we used a three-dimensional (3D) tissue culture system based on magnetic nanoparticle levitation to model WAT development and growth in organoids termed "adipospheres". We show that 3T3-L1 preadipocytes remain viable in spheroids for a long period of time, while in 2D culture they lose adherence and die upon reaching confluence. Upon adipogenesis induction in 3T3-L1 adipospheres, cells efficiently formed large lipid droplets typical of white adipocytes in vivo, while only smaller lipid droplet formation is achievable in 2D. Adiposphere-based co-culture of 3T3-L1 preadipocytes with murine endothelial bEND.3 cells led to vascular network assembly concomitantly with lipogenesis in perivascular cells. Adipocyte-depleted stromal-vascular fraction (SVF) of mouse WAT cultured in 3D resulted in formation of organoids with vasculature containing luminal endothelial and perivascular stromal cells layers. Adipospheres made from primary WAT cells displayed robust proliferation and complex hierarchical organization reflected by a matricellular gradient incorporating ASC, endothelial cells and leukocytes, while ASC quickly outgrew other cell types in adherent culture. Upon adipogenesis induction, adipospheres derived from the SVF displayed more efficient lipid droplet accumulation than 2D cultures indicating that 3D intercellular signaling better recapitulates WAT organogenesis. Combined, our studies show that adipospheres are appropriate for WAT modeling ex vivo and provide a new platform for functional screens to identify molecules bioactive toward individual adipose cell populations. This 3D methodology could be adopted for WAT transplantation applications and aid approaches to WAT-based cell therapy.

0 Bookmarks
 · 
141 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Overgrowth of white adipose tissue (WAT) in obesity occurs as a result of adipocyte hypertrophy and hyperplasia. Expansion and renewal of adipocytes relies on proliferation and differentiation of white adipocyte progenitors (WAP); however, the requirement of WAP for obesity development has not been proven. Here, we investigate whether depletion of WAP can be used to prevent WAT expansion. We test this approach by using a hunter-killer peptide designed to induce apoptosis selectively in WAP. We show that targeted WAP cytoablation results in a long-term WAT growth suppression despite increased caloric intake in a mouse diet-induced obesity model. Our data indicate that WAP depletion results in a compensatory population of adipose tissue with beige adipocytes. Consistent with reported thermogenic capacity of beige adipose tissue, WAP-depleted mice display increased energy expenditure. We conclude that targeting of white adipocyte progenitors could be developed as a strategy to sustained modulation of WAT metabolic activity.Cell Death and Differentiation advance online publication, 24 October 2014; doi:10.1038/cdd.2014.148.
    Cell Death and Differentiation 10/2014; 22(2). · 8.39 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Wheat glutenin, the highly crosslinked protein from wheat, was electrospun into scaffolds with ultrafine fibers oriented randomly and evenly in three dimensions to simulate native extracellular matrices of soft tissues. The scaffolds were intrinsically water-stable without using any external crosslinkers and could support proliferation and differentiation of adipose-derived mesenchymal stem cells for soft tissue engineering. Regeneration of soft tissue favored water-stable fibrous protein scaffolds with three-dimensional arrangement and large volumes, which could be difficult to obtain via electrospinning. Wheat glutenin is an intrinsically water-stable protein due to the 2% cysteine in its amino acid composition. In this research, the disulfide crosslinks in wheat glutenin were cleaved while the backbones were preserved. The treated wheat glutenin was dissolved in aqueous solvent with an anionic surfactant and then electrospun into bulky scaffolds composed of ultrafine fibers oriented randomly in three dimensions. The scaffolds could maintain their fibrous structures after incubated in PBS for up to 35 days. In vitro study indicated that the three-dimensional wheat glutenin scaffolds well supported uniform distribution and adipogenic differentiation of adipose derived mesenchymal stem cells.
    Journal of Biotechnology 05/2014; · 2.88 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The ultimate goal of most biomedical research is to gain greater insight into mechanisms of human disease or to develop new and improved therapies or diagnostics. Although great advances have been made in terms of developing disease models in animals, such as transgenic mice, many of these models fail to faithfully recapitulate the human condition. In addition, it is difficult to identify critical cellular and molecular contributors to disease or to vary them independently in whole-animal models. This challenge has attracted the interest of engineers, who have begun to collaborate with biologists to leverage recent advances in tissue engineering and microfabrication to develop novel in vitro models of disease. As these models are synthetic systems, specific molecular factors and individual cell types, including parenchymal cells, vascular cells, and immune cells, can be varied independently while simultaneously measuring system-level responses in real time. In this article, we provide some examples of these efforts, including engineered models of diseases of the heart, lung, intestine, liver, kidney, cartilage, skin and vascular, endocrine, musculoskeletal, and nervous systems, as well as models of infectious diseases and cancer. We also describe how engineered in vitro models can be combined with human inducible pluripotent stem cells to enable new insights into a broad variety of disease mechanisms, as well as provide a test bed for screening new therapies.
    Annual review of pathology. 01/2015; 10:195-262.

Full-text

Download
61 Downloads
Available from
Jun 10, 2014