Changes in Gene Expression Profile in Human Subcutaneous Adipose Tissue during Significant Weight Loss

Abstract

<b><i>Objective: </i></b>To analyze the expression of peroxisome proliferator-activated receptor-γ1 and 2 (PPARγ1 and 2), 11β-hydroxysteroid dehydrogenase type 1 (11βHSD1), and leptin in adipose tissue (AT) of obese women during weight loss following Roux-en-Y gastric bypass (RYGB) and to compare these levels with those obtained in AT of nonobese subjects. <b><i>Methods: </i></b>Gene expression was determined by real-time RT-PCR prior to surgery and at 3, 6, and 12 months after RYGB. <b><i>Results: </i></b>All obese patients lost weight, reaching a mean BMI of 29.3 ± 1.0 kg/m<sup>2</sup> at 1 year after surgery (–33.9 ± 1.5% of their initial body weight). In obese subjects leptin and 11βHSD1 were over-expressed, whereas <i>PPAR</i>γ<i>1</i> was expressed at lower levels compared to controls. After surgery, leptin and <i>11</i>β<i>HSD1</i> gene expression decreased, whereas <i>PPAR</i>γ<i>1</i> expression increased. At 12 months after RYGB, these 3 genes had reached levels similar to the controls. In contrast, <i>PPAR</i>γ<i>2</i> gene expression was not different between groups and types of tissue and remained unchanged during weight loss. We found a positive correlation between BMI and levels of gene expression of <i>leptin</i> and <i>11</i>β<i>HSD1</i>. <b><i>Conclusion: </i></b>Gene expression of <i>leptin</i>, <i>PPAR</i>γ<i>1</i>, and <i>11</i>β<i>HSD1</i> in AT is modified in human obesity. This default is completely corrected by RYGB.