Human adipose stromal-vascular fraction self-organizes to form vascularized adipose tissue in 3D cultures

Sandra Muller,Isabelle Ader,Audrey Carrière,Pauline Achard,Louis Casteilla,Luc Sensebé,Frédéric Deschaseaux,Justine Creff,Hélène Leménager

doi:10.1038/s41598-019-43624-6

Abstract

Native human subcutaneous adipose tissue (AT) is well organized into unilocular adipocytes interspersed within dense vascularization. This structure is completely lost under standard culture conditions and may impair the comparison with native tissue. Here, we developed a 3-D model of human white AT reminiscent of the cellular architecture found in vivo. Starting with adipose progenitors derived from the stromal-vascular fraction of human subcutaneous white AT, we generated spheroids in which endogenous endothelial cells self-assembled to form highly organized endothelial networks among stromal cells. Using an optimized adipogenic differentiation medium to preserve endothelial cells, we obtained densely vascularized spheroids containing mature adipocytes with unilocular lipid vacuoles. In vivo study showed that when differentiated spheroids were transplanted in immune-deficient mice, endothelial cells within the spheroids connected to the recipient circulatory system, forming chimeric vessels. In addition, adipocytes of human origin were still observed in transplanted mice. We therefore have developed an in vitro model of vascularized human AT-like organoids that constitute an excellent tool and model for any study of human AT.

Highlights

3-D type cultures have sparked great interest in basic research labs and for translational science
We developed a protocol to generate human 3-D structures in vitro that closely resemble the cellular architecture of human Adipose tissue (AT)
These adipose spheroids could be engrafted in immune-deficient mice by connecting their own vascularization to the host one, which allowed for maintaining human adipocyte integrity

Summary

Introduction

3-D type cultures have sparked great interest in basic research labs and for translational science. All cells reside within a 3-D complex environment composed of a large number of extracellular matrix molecules and are dispersed geometrically in 3-D space in the correct place This situation offers biophysical interactions that induce specific biological responses[2]. The strategy usually consisted of generating adipocytes from APs, adding ECs onto adipocytes[6,9,24,25,26,27] This method does not recapitulate AT development because ECs and adipocytes are usually obtained from diverse biological sources and sometimes different organisms, which precludes the use of these engineered tissues for autologous grafts

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