Adipose tissue and circulating endothelial cell specific molecule-1 in human obesity

Area of Science:

• Endocrinology
• Vascular Biology
• Cell Biology

Background:

• Endothelial-cell specific molecule-1 (ESM-1) is produced by adipocytes and inhibits leukocyte adhesion.
• Understanding ESM-1 regulation in human adipose tissue is crucial for its role in vascular health.

Purpose of the Study:

• To investigate ESM-1 expression and regulation in human adipose tissue.
• To explore the relationship between ESM-1, obesity, and weight reduction.

Main Methods:

• Gene expression analysis using TaqMan RT-PCR.
• ESM-1 protein quantification in serum and cell culture via ELISA.
• In vitro studies on isolated human adipocytes and preadipocytes.

Main Results:

• Mature adipocytes actively produce ESM-1, with higher gene expression than preadipocytes.
• Cortisol inhibited ESM-1 in preadipocytes; insulin and cortisol inhibited it in adipocytes.
• Insulin's inhibitory effect was reduced in insulin resistance; obese, hyperinsulinemic women showed increased adipose tissue ESM-1 gene expression.
• Obese women had reduced serum ESM-1 levels, inversely correlated with C-reactive protein.
• Modest weight loss did not significantly alter gene expression but increased circulating ESM-1.

Conclusions:

• Adipocytes are a source of ESM-1, but other sources likely contribute to circulating levels.
• Reduced circulating ESM-1 in obesity suggests a potential role in associated vascular complications.
• ESM-1 regulation is complex, influenced by hormones and metabolic status.