Changes in gene expression profile in human subcutaneous adipose tissue during significant weight loss.

Objective: To analyze the expression of peroxisome proliferator-activated receptor- 1 and 2 (PPAR 1 and 2), 11 -hydroxysteroid dehydrogenase type 1 (11 HSD1), 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. Methods: Gene expression was determined by real-time RT-PCR prior to surgery and at 3, 6, and 12 months after RYGB. Results: All obese patients lost weight, reaching a mean BMI of 29.3 8 1.0 kg/m 2 at 1 year after surgery (–33.9 8 1.5% of their initial body weight). In obese subjects leptin and 11 HSD1 were over-expressed, whereas PPAR 1 was expressed at lower levels compared to controls. After surgery, leptin and 11 HSD1 gene expression decreased, whereas PPAR 1 expression increased. At 12 months after RYGB, these 3 genes had reached levels similar to the controls. In contrast, PPAR 2 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 leptin and 11 HSD1 . Conclusion: Gene expression of leptin , PPAR 1 , and 11 HSD1 in AT is modified in human obesity. This default is completely corrected by RYGB.