Host Rather than Graft Origin of Matrigel-Induced Adipose Tissue in the Murine Tissue-Engineering Chamber

Abstract

We have recently shown that Matrigel-filled chambers containing fibroblast growth factor-2 (FGF2) and placed around an epigastric pedicle in the mouse were highly adipogenic. Contact of this construct with pre-existing tissue or a free adipose graft was required. To further investigate the mechanisms underpinning formation of new adipose tissue, we seeded these chambers with human adipose biopsies and human adipose-derived cell populations in severe combined immunodeficient mice and assessed the origin of the resultant adipose tissue after 6 weeks using species-specific probes. The tissues were negative for human-specific vimentin labeling, suggesting that the fat originates from the murine host rather than the human graft. This was supported by the strong presence of mouse-specific Cot-1 deoxyribonucleic acid labeling, and the absence of human Cot-1 labeling in the new fat. Even chambers seeded with FGF2/ Matrigel containing cultured human stromal-vascular fraction (SVF) labeled strongly only for human vimentin in cells that did not have a mature adipocyte phenotype; the newly formed fat tissue was negative for human vimentin. These findings indicate that grafts placed in the chamber have an inductive function for neo-adipogenesis, rather than supplying adipocyte-precursor cells to generate the new fat tissue, and preliminary observations implicate the SVF in producing inductive factors. This surprising finding opens the door for refinement of current adipose tissue-engineering approaches.

Angiogenic Growth Factor Synergism in a Murine Tissue Engineering Model of Angiogenesis and Adipogenesis

“…Recent studies in our model confirm that new adipose tissue is derived from host cells, systemically derived, 40 in line with other recent studies. 31 The addition of growth factor combinations of VEGF 120 , FGF-2, and PDGF-BB increased not only early angiogenesis but also the migration into the chamber construct of blood-borne adipogenic cell populations that exponentially increased adipose tissue formation.…”

Augmenting peripheral nerve regeneration using stem cells: A review of current opinion

“…N-methacrylate glycol chitosan, alginate, hyaluronic acid, polyethylene glycol, fibrin and Matrigel have all been shown to successfully fulfill these requirements [151][152][153][154][155][156][157] . In addition to their supportive role, scaffolds also help prevent unwanted cell dissipation from the site of injury and, when used in combination with nerve conduits, have emerged as useful adjuncts for improving the delivery of cells.…”

Effects of Tamoxifen and oestrogen on histology and radiographic density in high and low mammographic density human breast tissues maintained in murine tissue engineering chambers

“…ER nuclear staining was assessed by separately point counting the nuclear staining of epithelial and stromal cells, expressed as a percentage of total epithelial or stromal cells, in high and low MD tissues of the three treatment groups. IHC staining for Vimentin (V9) (DakoCytomation, Clone V9, Code M0725) was performed to examine the distribution of stromal and adipose cells in high and low MD biochamber tissues in the three treatment groups [14]. Pairs of high and low MD biochamber tissues were stained with Masson's Trichrome Blue (MTB) for assessment of collagen in the three treatment groups, then quantitative assessment performed, including blinded assessorscoring of the intensity of blue collagen staining in high and low MD biochamber tissues of the three treatment groups, on a scale of 1-6 (with 1-2 for weak staining, 3-4 moderate staining, and 5-6 strong staining).…”