Characterized the Adipogenic Capacity of Adipose-Derived Stem Cell, Extracellular Matrix, and Microenvironment With Fat Components Grafting

Abstract

Background: Autologous fat grafting has been a widely used technique; however, the role of adipose-derived stem cells (ASCs), extracellular matrix (ECM), and microenvironment in fat regeneration are not fully understood.Methods: Lipoaspirates were obtained and processed by inter-syringe shifting to remove adipocytes, yielding an adipocyte-free fat (Aff). Aff was then exposed to lethal dose of radiation to obtain decellularized fat (Df). To further remove microenvironment, Df was rinsed with phosphate-buffered saline (PBS) yielding rinsed decellularized fat (Rdf). Green fluorescent protein (GFP) lentivirus (LV-GFP)-transfected ASCs were added to Df to generate cell-recombinant decellularized fat (Crdf). Grafts were transplanted subcutaneously into nude mice and harvested over 3 months.Results: Removal of adipocytes (Aff) didn’t compromise the retention of fat grafts, while additional removal of stromal vascular fraction (SVF) cells (Df) and microenvironment (Rdf) resulted in poor retention by day 90 (Aff, 82 ± 7.1% vs. Df, 28 ± 6.3%; p < 0.05; vs. Rdf, 5 ± 1.2%; p < 0.05). Addition of ASCs to Df (Crdf) partially restored its regenerative potential. Aff and Crdf exhibited rapid angiogenesis and M2-polarized macrophages infiltration, in contrast to impaired angiogenesis and M1-polarized inflammatory pattern in Df. GFP + ASCs participated in angiogenesis and displayed a phenotype of endothelial cells in Crdf.Conclusion: Adipose ECM and microenvironment have the capacity to stimulate early adipogenesis while ECM alone cannot induce adipogenesis in vivo. By directly differentiating into endothelial cells and regulating macrophage polarization, ASCs coordinate early adipogenesis with angiogenesis and tissue remodeling, leading to better long-term retention and greater tissue integrity.

Decellularized extracellular matrix (d-ECM): the key role of the inflammatory process in pre-regeneration after implantation

“…Besides, many researchers tend to use cross-linking to block the binding sites of the d-ECM, 112 delaying the exposure of active structural domains. It also reduces the involvement of d-ECM components in regulating inflammatory responses by loading cells 113,114 to prolong the degradation of the d-ECM to achieve the best tissue remodeling effect. However, specific residual components are necessary for structural support and functional involvement in mediating immune cell responses.…”

Study on promoting the regeneration of grafted fat by cell-assisted lipotransfer

“…In the process of exploring the mechanism of this part of the experiment, we detected the expression of classical angiogenesis and adipogenesis factors (PPARγ, bFGF, VEGF, C/EBPα, C/EBPβ, FABP4, Leptin, Adiponectin, IGF1, GAPDH [ [16] , [47] , [49] ]). We found that only VEGF, C/EBPα and IGF1 were significantly increased in the co-culture group of ADSCs and fibroblasts compared to ADSCs cultured alone ( Supplementary Fig.…”

“…The disadvantage of SVF is that its cell population is complex and the proportion of its cell population cannot be standardized during the SVF isolation process, making the final fat retention rate still very uncertain [ 8 , 15 ]. In addition, it is worth mentioning that one study showed that fat grafting utilizing SVF rather than ADSCs as its CAL component had higher long-term retention rates, suggesting that other cells in SVF may contribute to fat retention rates improvement [ 16 ]. Based on this, we focused our research on fibroblasts that produce ECMs.…”

CCNB1 may as a biomarker for the adipogenic differentiation of adipose-derived stem cells in the postoperative fat transplantation of breast cancer

“…However, previous study just showed that adipose ECM and microenvironment possess the capability to promote early adipogenesis, while the ECM alone cannot induce adipogenesis in vivo . ADSCs can adjust early adipogenesis with angiogenesis and tissue remodeling by directly differentiating into endothelial cells and regulating macrophage polarization, contributing to better long-term retention and greater tissue integrity ( 55 ). Few studies have explored the relationship between CCNB1 and adipogenic differentiation in human ADSCs, and this association is still poorly understood.…”