Obesity and inflammation: reduced cytokine expression due to resveratrol in a human in vitro model of inflamed adipose tissue

During winter hibernation, grizzly bears (Ursus arctos horribilis) do not eat but instead rely on internal fat stores as a primary source of metabolic energy. The resulting seasonal fluctuations in appetite and body mass make the grizzly bear a naturally occurring animal model for human conditions such as obesity and anorexia. An in vitro model of hibernating bear stem cells might enhance our understanding of processes such as stem cell proliferation and differentiation. Mesenchymal stem cells, derived from bone marrow and adipose tissue among others, differentiate into adipocytes and might play important roles in energy metabolism. In the current study, we examined the in vitro viability and morphology of mesenchymal stem cells isolated from grizzly bear adipose tissue (ADSC) and bone marrow (BMSC); these ADSC and BMSCs underwent adipogenic differentiation for 0, 7, 14, 21, and 28 days. Bone marrow stem cells and ADSC were isolated using mechanical disaggregation, collagenase digestion, centrifugation, and plating onto tissue culture polystyrene. Cell viability and proliferation was quantified using the colony forming unit assay and a hemocytometer. Both stem cell types were differentiated into adipocytes using 10 μM insulin, 1 μM dexamethasone, and 0.5 mM isobutylmethylxanthine (all Sigma- Aldrich, St. Louis, MO, USA) with the addition of 10% fetal bovine (FBS) or bear serum from the active feeding period. Adipogenic differentiation was confirmed using Oil Red O and quantified using ImageJ. Statistical analysis was performed using an unpaired t-test between treatments of the same time point. All cells were isolated within 28 h of tissue harvest. Adipose-derived stem cells formed an average of 11 colonies (0.011%), whereas BMSC formed 1.5 colonies (0.0015%) per 100 000 cells. Doubling time forADSC was approximately 54 h in 10% FBS. BothADSC and BMSC had an initial spindle-shaped morphology, which gradually became more rounded during adipogenic differentiation. For bear serum at Day 28, ADSC had a significantly (P < 0.01) greater stained area per cell than did BMSC. In summary, both types of mesenchymal stem cells successfully differentiated into adipocytes and maintained viability. In conclusion, grizzly bear mesenchymal stem cells canbesuccessfully isolated, expanded, and differentiated in culture. These results allow for future studies using the bear as an in vitro model for fat metabolism during hibernation and active periods. This work was partially supported by the Carle Foundation Hospital, the Intel Scholar’s Research Program, USDA Multi-State Research Project W1171, and the Illinois Regenerative Medicine Institute (IDPH # 63080017). In addition, the authors would like to thank Agatha Luszpak for support with the analysis.

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Autologous Microfragmented Adipose Tissue Reduces the Catabolic and Fibrosis Response in an In Vitro Model of Tendon Cell Inflammation

Stem Cells International ◽

10.1155/2019/5620286 ◽

2019 ◽

Vol 2019 ◽

pp. 1-10

Author(s):

Marco Viganò ◽

Gaia Lugano ◽

Carlotta Perucca Orfei ◽

Alessandra Menon ◽

Enrico Ragni ◽

...

Keyword(s):

Adipose Tissue ◽

In Vitro Model ◽

Collagen Type ◽

Cyclooxygenase 2 ◽

Type I ◽

Collagen Type Iii ◽

Tendon Cell ◽

Type Iii ◽

Vitro Model

Background. Mesenchymal stem cells (MSCs) emerged as a promising therapy for tendon pathologies. Microfragmented adipose tissue (μFAT) represents a convenient autologous product for the application of MSC-based therapies in the clinical setting. In the present study, the ability of μFAT to counteract inflammatory processes induced by IL-1β on human tendon cells (TCs) was evaluated. Methods. Cell viability and proliferation were evaluated after 48 hours of transwell coculture of TCs and autologous μFAT in the presence or absence of IL-1β. Gene expression of scleraxis, collagen type I and type III, metalloproteinases-1 and -3, and cyclooxygenase-2 was evaluated by real-time RT-PCR. The content of VEGF, IL-1Ra, TNFα, and IL-6 was evaluated by ELISA. Results. IL-1β-treated TCs showed augmented collagen type III, metalloproteases, and cyclooxygenase-2 expression. μFAT was able to reduce the expression of collagen type III and metalloproteases-1 in a significant manner, and at the same time, it enhanced the production of VEGF, IL-1Ra, and IL-6. Conclusions. In this in vitro model of tendon cell inflammation, the paracrine action of μFAT, exerted by anti-inflammatory molecules and growth factors, was able to inhibit the expression of fibrosis and catabolic markers. Then, these results suggest that the application of μFAT may represent an effective conservative or adjuvant therapy for the treatment of tendon disorders.

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Autologous human immunocompetent white adipose tissue-on-chip

10.1101/2021.08.08.455559 ◽

2021 ◽

Author(s):

Julia Rogal ◽

Raylin Xu ◽

Julia Roosz ◽

Claudia Teufel ◽

Madalena Cipriano ◽

...

Keyword(s):

Adipose Tissue ◽

White Adipose Tissue ◽

In Vitro Model ◽

Molecular Mechanisms ◽

Cell Types ◽

Associated Diseases ◽

Chip Technology ◽

Vitro Model ◽

On Chip

Obesity and associated diseases, such as diabetes, have reached epidemic proportions globally. In the era of 'diabesity' and due to its central role for metabolic and endocrine processes, adipose tissue (specifically white adipose tissue; WAT) has become a target of high interest for therapeutic strategies. To gain insights in cellular and molecular mechanisms of adipose (patho-)physiology, researchers traditionally relied on animal models since in vitro studies on human WAT are challenging due to the large size, buoyancy, and fragility of mature white adipocytes. Leveraging the Organ-on-Chip technology, we introduce a next-generation microphysiological in vitro model of human WAT based on a tailored microfluidic platform featuring vasculature-like perfusion. The platform integrates a 3D tissue comprising all major WAT-associated cellular components in an autologous manner, including not only mature adipocytes but also organotypic endothelial barriers and stromovascular cells featuring tissue-resident innate immune cells, specifically adipose tissue macrophages. This microphysiological tissue model recapitulates pivotal WAT functions, such as energy storage and mobilization as well as endocrine and immunomodulatory activities. The combination of all individual cell types with extra cellular matrix-like hydrogels in a precisely controllable bottom-up approach enables the generation of a multitude of replicates from the same donors circumventing issues of inter-donor variability and paving the way for personalized medicine. Moreover, it allows to adjust the model's degree of complexity to fit a specific purpose via a flexible mix-and-match approach with different cell component modules. This novel WAT-on-chip system constitutes a human- based, autologous and immunocompetent in vitro model of adipose tissue that recapitulates almost full tissue heterogeneity. In the future, the new WAT-on-chip model can become a powerful tool for human-relevant research in the field of metabolism and its associated diseases as well as for compound testing and personalized- and precision medicine applications.

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