Adipogenic impairment of adipose tissue-derived mesenchymal stem cells in subjects with metabolic syndrome: possible protective role of FGF2

Abstract

Context: The decreased expansion capacity of adipose tissue plays a crucial role in the onset of disorders associated with metabolic syndrome. Objective: The aim of this study was to examine the state of adipose tissue-derived mesenchymal stem cells (ASCs) from obese subjects with different metabolic profiles. Design: This was a 2-year study to enroll subjects who underwent bariatric surgery or cholecystectomy. Setting: University Hospital. Patients and Intervention: Patients who underwent either bariatric surgery (20 morbidly obese) or cholecystectomy (40 subjects) participated in the study. Main Outcome Measures: ASCs were obtained from both visceral and subcutaneous adipose tissue. Adipogenic, fibrotic gene expression was quantified by quantitative polymerase chain reaction; Smad7 and fibroblast growth factor 2 were quantified by western blotting and enzyme-linked immunosorbent assay, respectively. The susceptibility of ASCs to apoptosis, their population doubling time, and their clonogenic potential were evaluated. Results: The worsening metabolic profile of the patients was accompanied by a decrease in the intrinsic levels of adipogenic gene expression, reduced proliferation rate, clonogenic potential, and exportation of fibroblast growth factor 2 to the cell surface of the ASCs derived from both tissues. In addition, the ASCs from patients without metabolic syndrome showed differences in susceptibility to apoptosis and expression of TGFβ-signaling inhibitory protein Smad7 with respect to the ASCs from patients with metabolic syndrome. Conclusion: Our results suggest that the decrease in adipogenic-gene mRNA and clonogenic potential, as well as the accumulation of fibrotic proteins with metabolic alterations, could be a relevant mechanism controlling the number and size of neogenerated adipocytes and involved in alteration of adipose-tissue expansion.