Identification of Novel Human Adipocyte Secreted Proteins by Using SGBS Cells

Abstract

Adipose tissue is an endocrine organ secreting different types of proteins, known as adipokines. These adipokines play important roles in homeostasis and metabolism. Adipocyte differentiation leads to a change in adipokine secretion profile which is probably involved in disruption of homeostasis. Many adipokines have been identified but species differences and limitations of human adipose tissue material urged the need for better model systems. Here we used a human cell strain derived from a Simpson Golabi Behmel syndrome (SGBS) patient. SGBS cells have already been used in functional studies on adipocytes but not in a proteomic search for adipokines. In this study, 2D-MS/MS and nLC-MALDI-MS/MS were applied to investigate secretion profiles of SGBS adipokines. A total of 80 secreted proteins were identified; 6 proteins are novel adipocyte secreted proteins, 20 proteins have not been detected before in human adipose material and 23 additional proteins previously detected in visceral adipose tissue have been found here secreted by SGBS-cells of subcutaneous origin. It can be concluded that SGBS cells are both a valid human cell model for adipocyte secretion profiling and for searching for novel human (pre)adipocytes secreted proteins.

Reliable typing of systemic amyloidoses through proteomic analysis of subcutaneous adipose tissue

“…In addition, other proteins (supplemental Table 3) were found to be over-represented across the various amyloidoses, including clusterin, 17 apolipoprotein E, 18,19 apolipoprotein A-IV, 20 vitronectin, 18 basement membrane-specific heparan sulfate proteoglycan core protein, 21 sushi-repeat-containing protein, and serum amyloid P. 22 Most of these had previously been described as associated with amyloid fibrils and involved in the mechanisms of amyloid formation; this confirms that MudPIT can fully characterize the deposits in whole adipose tissue and constitutes an internal validation parameter. In addition, sushi-repeat-containing protein may play a role in amyloid disease; indeed, it is secreted by adipocytes 23 and may intervene in adipogenic differentiation, 24 regulation of body weight, and metabolism. 24,25 Moreover, evidence of its involvement in tumor suppression, possibly through apoptosis induction, 26 emphasizes its potential interest in amyloid cell toxicity.…”

Regulation of De Novo Adipocyte Differentiation Through Cross Talk Between Adipocytes and Preadipocytes

“…Among the 98 proteins identified by mass spectrometry, adiponectin, cystatin C, resistin, adipsin, metalloproteinase inhibitor 1, chemerin, Vim, Sparc, and Vitamin D-binding protein are known adipokines (13,(26)(27)(28)(29). Taking into account which proteins have been reported to be secreted by adipocytes and adipose tissue, we identified Cpq, Got2, and Ecm1 as potential novel adipokines.…”

Identification and Validation of Novel Adipokines Released from Primary Human Adipocytes

“…Because of the relevance of adipose tissue in the progression of these common diseases, multiple unbiased, proteomic approaches have characterized the secretome from both rodent and human adipocytes and adipose tissue (10)(11)(12)(13)(14)(15)(16)(17). These studies have emphasized the complex nature of the adipokinome and have identified hundreds of adipokines.…”