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N-acetylaspartate (NAA) is synthesized by aspartate N-acetyltransferase (gene: Nat8l) from acetyl–coenzyme A and aspartate. In the brain, NAA is considered an important energy metabolite for lipid synthesis. However, the role of NAA in peripheral tissues remained elusive. Therefore, we characterized the metabolic phenotype of knockout (ko) and adipose tissue–specific (ako) Nat8l-ko mice as well as NAA-supplemented mice on various diets. We identified an important role of NAA availability in the brain during adolescence, as 75% of Nat8l-ko mice died on fat-free diet (FFD) after weaning but could be rescued by NAA supplementation. In adult life, NAA deficiency promotes a beneficial metabolic phenotype, as Nat8l-ko and Nat8l-ako mice showed reduced body weight, increased energy expenditure, and improved glucose tolerance on chow, high-fat, and FFDs. Furthermore, Nat8l-deficient adipocytes exhibited increased mitochondrial respiration, ATP synthesis, and an induction of browning. Conversely, NAA-treated wild-type mice showed reduced adipocyte respiration and lipolysis and increased de novo lipogenesis, culminating in reduced energy expenditure, glucose tolerance, and insulin sensitivity. Mechanistically, our data point to a possible role of NAA as modulator of pancreatic insulin secretion and suggest NAA as a critical energy metabolite for adipocyte and whole-body energy homeostasis.—Hofer, D. C., Zirkovits, G., Pelzmann, H. J., Huber, K., Pessentheiner, A. R., Xia, W., Uno, K., Miyazaki, T., Kon, K., Tsuneki, H., Pendl, T., Al Zoughbi, W., Madreiter-Sokolowski, C. T., Trausinger, G., Abdellatif, M., Schoiswohl, G., Schreiber, R., Eisenberg, T., Magnes, C., Sedej, S., Eckhardt, M., Sasahara, M., Sasaoka, T., Nitta, A., Hoefler, G., Graier, W. F., Kratky, D., Auwerx, J., Bogner-Strauss, J. G. N-acetylaspartate availability is essential for juvenile survival on fat-free diet and determines metabolic health.

To determine obstetric outcomes after external cephalic version (ECV) performed at term.In a retrospective study of ECV among pregnant women at term at Klinikum Kreuzschwestern Wels between January 1999 and June 2010, univariate and multivariate logistic regression was used to analyze factors influencing success rate.Among 379 ECV attempts, 49.1% (95% confidence interval, 44.1-54.1) were successful. Success rate was dependent on parity, gestational age, and performing physician. Increasing parity was associated with increasing success rate (P=0.05). Gestational age had no influence until week 39, after which the success rate increased (success after completion of week 35, 48.1%; week 37, 43.7%; week 38, 43.5%; week 39, 64.9%; week 40 or more, 90.9%; P=0.19). The performing physician had a significant influence (P0.0005). Regarding obstetric outcome, spontaneous re-version occurred in 8.1% of women, 81.1% of women delivered vaginally, 7.9% had unplanned cesarean delivery, and 4.9% had vacuum extraction. No harm to fetal or maternal health resulted from ECV.ECV was found to be a safe procedure at term. The skill of the physician significantly affected the success rate. The rate of surgical delivery after successful ECV was low. A trial of ECV at term and beyond is feasible.