Moreover, IL-1b has been shown to affect the function of the lung epithelial barrier

the activity of TOR in our cell culture model. We then analyzed the effect of AA with or without rapamycin on LC3 lipidation in presence of Baf A1 for 4 h. Our results showed that the inhibitory effect of AA on the ratio of LC3-II/b-tubulin was impaired in the presence of rapamycin to reach a non-significant value. This indicated an involvement of the TOR protein in the effect of AA on autophagy. However, the surprising inhibitory effect of rapamycin alone on LC3-II, although not significant, could weaken the observed effect of AA, making possible the involvement of other mechanisms in the observed effect of AA on autophagy. Fig. 3A, the ratio LC3-II/b-tubulin reached significantly lower level in fish fed the HPLC diet compared with fasted trout. In contrast, no significant decrease was observed in fish fed the MPMC and LPHC diets. Likewise, the analysis of the phosphorylation of Akt, FoxO1 and S6K1 showed that HPLC was the only diet significantly affecting each protein. The phosphorylation of AMPK showed no significant differences among dietary groups. Overall, these data demonstrated for the first time that the macronutrient composition of the diet may affect the autophagic response to feeding and suggest an involvement of TOR and/or Akt-FoxO1 signaling axis in this effect. Discussion Under physiological conditions, a basal autophagy is operating constantly for controlling the quality of proteins and organelles inside the cells. This catabolic pathway can also be strongly induced under stress conditions, particularly in response to nutrient starvation. Most studies focused on the mechanisms involved in nutrient starvation induced autophagy, but less attention has been paid on autophagy regulation under normal nutritional conditions when nutrients are not limiting. Therefore, the aim of the present work was to characterize both in vivo and in vitro, the response of the autophagy/lysosomal pathway to the availability of dietary amino acids and carbohydrates in the muscle of the carnivorous rainbow trout. We first analyzed the postprandial response of the autophagosomal 12414725 marker LC3-II as well as that of its upstream factors AktFoxO, TOR and AMPK to a single meal in the muscle of rainbow trout. The obtained results show a decrease of the ratio LC3-II/btubulin as early as 9450616 4 h after the meal. To our knowledge, this is the first study showing the postprandial evolution of LC3B lipidation. The obtained results are somewhat surprising in comparison to the late response of the Ubiquitin-Proteasome-dependent proteolytic system to refeeding as reported in trout and in rats. However, the activity of this last degradative system has been shown to be closely related to the “long term”transcription dependent control of the expression of several E3-Ubiquitine ligase Antagonistic Role of Amino Acids and Glucose in the Regulation of Autophagy in Trout Muscle Cell Culture In order to clarify the specific and combined role of amino acids and glucose in the above presented feeding-induced repression of muscle autophagy, primary cultures of trout muscle cells were used. More specifically, we monitored by western blotting the LC3 lipidation in 4-day old cells stimulated or not with amino acids and/or glucose in presence or MedChemExpress LOXO-101 absence of Bafilomycin A1, a vacuolar ATPase inhibitor that inhibits autophagosome-lysosome fusion and prevents the degradation of LC3-II. As expected, addition of Baf A1 increased the ratio LC3-II/ b-actin, validating its use in our cell c