Obesity and weight loss could alter the properties of adipose stem cells?

Abstract

The discovery that adipose tissue represents an interesting source of multipotent stem cells has led to many studies exploring the clinical potential of these cells in cell-based therapies. Recent advances in understanding the secretory capacity of adipose tissue and the role of adipokines in the development of obesity and associated disorders have added a new dimension to the study of adipose tissue biology in normal and diseased states. Subcutaneous adipose tissue forms the interface between the clinical application of regenerative medicine and the establishment of the pathological condition of obesity. These two facets of adipose tissue should be understood as potentially related phenomena. Because of the functional characteristics of adipose stem cells, these cells represent a fundamental tool for understanding how these two facets are interconnected and could be important for therapeutic applications. In fact, adipose tissue stem cells have multiple functions in obesity related to adipogenic, angiogenic and secretory capacities. In addition, we have also previously described a predominance of larger blood vessels and an adipogenic memory in the subcutaneous adipose tissue after massive weight loss subsequent to bariatric surgery (ex-obese patients). Understanding the reversibility of the behavior of adipose stem cells in obeses and in weight loss is relevant to both physiological studies and the potential use of these cells in regenerative medicine.

Keywords: Adipose stem cells; Obesity; Regenerative medicine; Subcutaneousadipose tissue; Weight loss.

Figures

Figure 1

Annual number of publications referenced in the PubMed database between 2000 and 2014 with the sentence “adipose stem cell in obesity”.

Figure 2

Multipotent stem cells as key players in tissue homeostasis disruption in obesity. The enormous increase in subcutaneous fat mass leads to an increase in secreted molecules such as monocyte chemotactic protein 1 (MCP-1), which causes monocyte infiltration and subsequent macrophage differentiation (blue lines). Inflammatory cytokines may change multipotent stem cells to a non-healthy phenotype (blue lines) that in turn impairs (red lines) the normal adipogenesis of subcutaneous adipose tissue.

Figure 3

The enrichment of preadipocytes and the density of blood vessels in the adipose tissues of ex-obese patients may play roles in accelerated weight regain. Even after massive weight loss, ex-obese adipose tissue does not return to a normal cellular state. This adipose tissue is characterized by a higher percentage of CD34 cells and a greater number of small and large blood vessels[26].