Changes in the MicroRNA Profile Observed in the Subcutaneous Adipose Tissue of Obese Patients after Laparoscopic Adjustable Gastric Banding

Abstract

Background. Laparoscopic adjustable gastric banding (LAGB) results in significant lasting weight loss and improved metabolism in obese patients. To evaluate whether epigenetic factors could concur to these benefits, we investigated the subcutaneous adipose tissue (SAT) microRNA (miRNA) profile before (T0) and three years (T1) after LAGB in three morbidly obese women. Case Reports. SAT miRNA profiling, evaluated by TaqMan Array, showed four downexpressed (miR-519d, miR-299-5p, miR-212, and miR-671-3p) and two upexpressed (miR-370 and miR-487a) miRNAs at T1 versus T0. Bioinformatics predicted that these miRNAs regulate genes belonging to pathways associated with the cytoskeleton, inflammation, and metabolism. Western blot analysis showed that PPAR-alpha, which is the target gene of miR-519d, increased after LAGB, thereby suggesting an improvement in SAT lipid metabolism. Accordingly, the number and diameter of adipocytes were significantly higher and lower, respectively, at T1 versus T0. Bioinformatics predicted that the decreased levels of miR-212, miR-299-5p, and miR-671-3p at T1 concur in reducing SAT inflammation. Conclusion. We show that the miRNA profile changes after LAGB. This finding, although obtained in only three cases, suggests that this epigenetic mechanism, by regulating the expression of genes involved in inflammation and lipid metabolism, could concur to improve SAT functionality in postoperative obese patients.

The Heterogeneity of White Adipose Tissue

“…miR-143 and -103 are both increased during adipocyte differentiation and have clear roles in lipid accumulation, especially within subcutaneous WAT, as confirmed by both over-expression and inhibition studies [212,213]. miR-519d inhibition of PPARα reduces fatty acid oxidation and increase lipid storage [214], and reduced adipocyte size in human subjects is correlated with reduced expression of miR-519d [215]. On the other hand, miRNAs that target PPARγ including miR-27 and miR-130 act as anti-adipogenic regulators [216,217] (Figure 2A).…”

Modulation of Human Subcutaneous Adipose Tissue MicroRNA Profile Associated with Changes in Adiposity‐Related Parameters

“…Several miRNAs with potential physiological functions are deregulated in obesity. Accordingly, weight‐reduction strategies induced with a low‐fat diet in mice and surgical procedures or an energy‐restricted diet plus exercise in humans modulate both circulating and adipose tissue miRNA expression. In our study, we failed to found major changes in miRNAs expression in response to the three different dietary interventions in the context of a weight‐loss program, supporting that not all physiological effects necessarily have epigenetic mechanisms (through miRNA changes).…”

Exercise and weight loss interventions and miRNA expression in women with breast cancer

“…The criterion for candidate miRNA inclusion was as follows, 1) to be associative with known breast tumorigenic processes 25, 48–50 ; and/or 2) known to regulate pathways associated with metabolism 51–53 , adipogenesis, and/or obesity 54–56 ; and/or 3) previously identified to be detectable in circulating biofluids such as plasma or serum 57–59 . We identified 68 miRNAs eligible for analysis; these miRNA were assessed in crude serum isolates from the HOPE trial utilizing the probe-hybridization multiplex profiling assay mentioned above 44 .…”