L235	The cells from the stroma-vascular fraction of human adipose tissue: involvement in neo vascularisation and inflammation.
A.Bouloumié
JWG-University/Cardiovascular Physiology, Frankfurt/Main, DE.

The white adipose tissue (WAT) is necessary for optimal energy homeostasis and the excessive development of the fat mass is clearly associated with metabolic syndrome. The mechanisms involved in the excessive development of the fat mass as well as the processes underlying the link between obesity and associated pathologies such as diabetes and cardiovascular pathologies are still to be clearly determined. We have recently developed an original approach to characterize the cells composing the stroma-vascular fraction (SVF) of the human WAT that combines analysis of various cell markers by multiparameter fluorescence activated cell sorting (FACS) and cell isolation by magnetic microbeads coupled to antibodies. The use of both cell surface markers CD34 and CD31 allowed to discriminate two distinct cell subsets: the capillary endothelial cells that co-expressed both CD34 and CD31 and cells positive only for CD34. Once isolated, the CD34+/CD31- cells could differentiate into adipocyte or endothelial-like cells depending on the culture condition (Sengenes et al, J.Cell Physiol., 2005). Their injection “in vivo” into nude mice promoted revascularisation of ischemic hindlimb (Miranville et al, Circulation, 2004). The present results demonstrated that the WAT-SVF contains a pool of progenitor cells that may be involved in the adipocyte hyperplasia and neovascularization during the growth of the fat mass. Besides the CD34+ cells, infiltrated leukocytes (CD45+), mainly composed by macrophages (CD14+/CD31+) as well as T-lymphocytes (CD45+/CD3+) were identified within the SVF. Real-time PCR analyses performed on isolated WAT-macrophages showed the expression of a wide range of inflammatory cytokines, chemokines and adipokines. Moreover, increase in body mass index (BMI) was associated with increased accumulation of macrophages and T-lymphocytes. Such an enhanced blood cell infiltration in the fat mass might be the result of the activation of WAT endothelial cells by adipocyte-derived products such as leptin (Curat et al, Diabetes, 2004). Taken together, these results suggest that human WAT-SVF contains local pool of progenitor cells that may be involved in the development of the fat mass, as well as inflammatory cells. Increased WAT inflammation during obesity may play a role in the genesis of the obesity-associated pathologies.

Copyright © 2005 S. Karger AG, Basel. Any further use of this abstract requires written permission from the publisher.