• Pinhel Marcela Augusta de Souza MAS Department of Internal Medicine, Ribeirao Preto Medical School of University of Sao Paulo, Sao Paulo, Brazil; Department of Biochemist, Carolina Ferreira Nicoletti, Natalia Yumi Noronha, Bruno Affonso Parenti de Oliveira, Cristiana Cortes-Oliveira, Wilson Salgado, Wilson Araujo da Silva, Doroteia Rossi Silva Souza, Julio Sergio Marchini, and Carla Barbosa Nonino.
• Department of Internal Medicine, Ribeirao Preto Medical School of University of Sao Paulo, Sao Paulo, Brazil; Department of Biochemistry and Molecular Biology, Sao Jose do Rio Preto Medical School, Sao Paulo, Brazil.
• Nutrition. 2018 Oct 1; 54: 94-99.

ObjectivesAfter bariatric surgery, modifications to signaling pathway networks including those of the metabolic regulator called mammalian or mechanistic target of rapamycin (mTOR) may lead to molecular alterations related to energy source availability, systemic nutrients, and catabolic and anabolic cellular processes. This study aimed to identify gene expression changes with regard to the mTOR complex 2 subunit signaling pathway in obese patients before and after bariatric surgery.MethodsThe experimental group included 13 obese women who were examined before (preoperative) and 6 mo after (postoperative) Roux-en-Y gastric bypass (RYGB) surgery. The control group included nine apparently eutrophic women matched by age and without any other metabolic diseases (i.e., no diabetes and no liver or kidney diseases). Peripheral blood mononuclear cell samples were collected for RNA extraction and subsequent microarray analysis.ResultsAfter this methodological procedure, we identified 47 000 differentially expressed genes. A subsequent bioinformatic analysis showed that three diferentially expressed genes (rapamycin-insensitive companion of mTOR [RICTOR], phosphoinositide-3-kinase regulatory subunit 1 [PIK3 R1], and hypoxia inducible factor 1 alpha subunit 1A [HIF1 A]) participated in the mTOR signaling pathway. Real-time quantitative polymerase chain reaction revealed that RICTOR, PIK3 R1, and HIF1 A were upregulated 6 mo after RYGB surgery (P <0.05). In addition, patients in the experimental group lost weight significantly and presented significant improvement in biochemical/metabolic variables.ConclusionsThe weight loss that was induced by RYGB surgery alters the mTOR signaling pathway and specifically the mTOR complex 2 subunit. The increased expression of genes that act in this pathway such as RICTOR, PIK3 R1, and HIF1 A reflects the induced weight loss and improved metabolic indicators (e.g., insulin resistance and lipolysis) that are evidenced in this study.Copyright © 2018 Elsevier Inc. All rights reserved.

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