Discovery of a class of endogenous mammalian lipids with anti-diabetic and anti-inflammatory effects
Authors: Edwin A Homan
Shili Chen
Jennifer Lee
Odile D Peroni
Timothy E McGraw
Barbara B Kahn
Mark A Herman
Mark M Yore
Tejia Zhang
Ulf Smith
Alan Saghatelian
Pedro M Moraes-Vieira
Ismail Syed
Ann Hammarstedt
Abha S Dhaneshwar
Rajesh T Patel
Journal: Cell (2014)
Discipline: MOLECULAR BIOLOGY & GENETICS
Keywords: adipose tissue; lipogenesis; Glut4 glucose transporter; FAHFAs; PAHSAs
Affiliations: Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA 02215, USA., Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA., Department of Biochemistry, Weill Cornell Medical College, New York, NY 10065, USA., Department of Molecular and Clinical Medicine, the Sahlgrenska Academy, University of Gothenburg, Gothenburg 41345, Sweden., Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA. Electronic address: ., Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA 02215, USA. Electronic address: .

Abstract:  Increased adipose tissue lipogenesis is associated with enhanced insulin sensitivity. Mice overexpressing the Glut4 glucose transporter in adipocytes have elevated lipogenesis and increased glucose tolerance despite being obese with elevated circulating fatty acids. Lipidomic analysis of adipose tissue revealed the existence of branched fatty acid esters of hydroxy fatty acids (FAHFAs) that were elevated 16- to 18-fold in these mice. FAHFA isomers differ by the branched ester position on the hydroxy fatty acid (e.g., palmitic-acid-9-hydroxy-stearic-acid, 9-PAHSA). PAHSAs are synthesized in vivo and regulated by fasting and high-fat feeding. PAHSA levels correlate highly with insulin sensitivity and are reduced in adipose tissue and serum of insulin-resistant humans. PAHSA administration in mice lowers ambient glycemia and improves glucose tolerance while stimulating GLP-1 and insulin secretion. PAHSAs also reduce adipose tissue inflammation. In adipocytes, PAHSAs signal through GPR120 to enhance insulin-stimulated glucose uptake. Thus, FAHFAs are endogenous lipids with the potential to treat type 2 diabetes. 

Retracted: No

PubPeer comments:
 Figure 4 and 5 appear to be the same image, albeit rotated and with dimensions substantially adjusted. Also note two areas where features appear to have been added deleted from original (yellow and red  ? ). Rotation did not include image metadata in footer. *** Illustration ![file] *** Original Figure 4 with legend ![file] *** Original Figure 5 with legend ![file] , 
 The Editor in Chief and Publisher of International Journal of Nanomedicine wish to retract the published article. The journal was notified of the potential duplication of images in Figure 4 and Figure 5 of the published article. It was observed that Figure 5 was an inverted version of Figure 4. The authors were asked for an explanation but were unable to provide a satisfactory response or provide the original raw data for the images. It was determined the first author, Ghullam Reza Barbari, was solely responsible for preparing the images, however all the authors had approved of the final article for publication. The Editor in Chief determined the results and findings of the article were no longer valid and advised a retraction was the only course of action. The authors wish to apologise for this error. Our decision-making was informed by our policy on publishing ethics and integrity and the COPE guidelines on retraction. The retracted article will remain online to maintain the scholarly record, but it will be digitally watermarked on each page as u201cRetractedu201d. ,