Suppression of FoxO1 mRNA by ß2 -adrenoceptor-cAMP signaling through miR-374b-5p and miR-7a-1-3p in C2C12 myotubes.

ß2 -Adrenoceptor (ß2 -AR) signaling decreases the transcriptional activity of forkhead box O (FoxO), but the underlying mechanisms remain incompletely understood. Here, we investigated how ß2 -AR signaling regulates the protein abundance of FoxO and its transcriptional activity in skeletal muscle. We observed that stimulation of ß2 -AR with its selective agonist, clenbuterol, rapidly decreased FoxO1 mRNA expression, and this was accompanied by a decrease in either FoxO1 protein level or FoxO transcriptional activity. We subsequently observed that miR-374b-5p and miR-7a-1-3p were rapidly upregulated in response to ß2 -AR stimulation. Transfection with mimics of either miRNA successfully decreased FoxO1 mRNA. Moreover, because ß2 -AR stimulation increased cAMP concentration, pretreatment with an adenylyl cyclase inhibitor canceled out these effects of ß2 -AR stimulation. These results suggest that ß2 -AR stimulation results in rapid upregulation of miR-374b-5p and miR-7a-1-3p in myotubes, which in turn results in a decrease in FoxO1 mRNA expression via the ß2 -AR-cAMP signaling pathway.

Analyses of free amino acid and taste sensor traits in egg albumen and yolk revealed potential of value-added eggs in chickens.

To create high-quality eggs by using different breed and feed materials, we investigated free amino acid contents and taste sensor traits using two chicken breeds (Rhode Island Red; RIR and Australorp; AUS) fed two feeds (mixed and fermented feeds). Two-way ANOVA revealed significant breed and feed main and interaction effects on albumen bitterness and a significant interaction effect on yolk bitterness. Albumen from RIR fed mixed feed and AUS fed fermented feed was higher bitterness, whereas yolk from those groups was lower bitterness. Significant breed effects were detected in four albumen amino acid traits (His, Met, Ile, and Lys) and a yolk His, whereas significant feed effects were found in 15 albumen amino acid traits (Asp, Glu, Ser, His, Gly, Thr, Ala, Tyr, Val, Met, Trp, Ile, Leu, Lys, and Pro) and a yolk cystine trait. Compared to albumen amino acids, yolk amino acids had limited effects by breed and feed. The present results suggest that genetic and nutritional factors can alter not only amino acid contents but also sensor values of bitterness, indicating that selecting the combination of breed and feed enable us to make amino acids enriched and taste added designer eggs in future.

Effects of delaying post-hatch feeding on lipid peroxidation and antioxidant enzyme mRNA expression in the pectoralis major muscle of newly hatched chicks.

Excessive lipid peroxidation negatively affects the physiological response and meat quality of chickens. Delaying post-hatch feeding was previously found to increase lipid peroxidation in the skeletal muscle of finishing broiler chickens. The aims of this study were to investigate the effects of delayed post-hatch feeding on lipid peroxidation and the mRNA expressions of antioxidant enzymes in the pectoralis major muscle of broiler chicks during the post-hatching period. Newly hatched chicks either had immediate free access to feed (freely-fed chicks) or had no access to feed from 0 to 2 days old (delayed-fed chicks), after which both groups were fed ad libitum until 4 or 13 days old. The lipid peroxidation level was higher in the delayed-fed than freely-fed chicks at 2, 4, and 13 days old. At 2 days old, the mRNA expressions of Cu/Zn-SOD, Mn-SOD, and GPX7 were lower in the delayed-fed than freely-fed chicks, while catalase mRNA levels did not differ. Furthermore, at 4 and 13 days old, lower mRNA expressions of Cu/Zn-SOD and Mn-SOD were observed in the delayed-fed than freely-fed chicks. These results suggest that delaying post-hatch feeding reduces the mRNA levels of Cu/Zn-SOD and Mn-SOD, consequently affecting muscle lipid peroxidation in chicks during subsequent growth.

Insulin acutely increases glucose transporter 1 on plasma membranes and glucose uptake in an AKT-dependent manner in chicken adipocytes.

Avian glucose transporters (GLUT) responsible for insulin-responsive glucose uptake into adipocytes remain poorly characterized. We aimed to identify the insulin-responsive GLUT using primary culture of chicken adipocytes. Acute stimulation with 1 µM insulin for 20 min increased 2-deoxyglucose uptake, AKT protein phosphorylation, and GLUT1 protein levels on the plasma membrane of the chicken adipocytes, whereas pretreatment with 10 µM triciribine, an AKT inhibitor, canceled these effects. Furthermore, the insulin stimulation did not affect GLUT12 protein levels on the plasma membrane of the chicken adipocytes. Our results suggest that GLUT1 is an insulin-responsive GLUT in chicken adipocytes.

Effects of first exogenous nutrients on the mRNA levels of atrogin-1/MAFbx and GLUT1 in the skeletal muscles of newly hatched chicks.

The aim of this study was to examine the effects of first exogenous nutrients on the mRNA levels of muscle atrophy F-box (atrogin-1/MAFbx) and glucose transporters (GLUTs) in the skeletal muscles of newly hatched chicks with no feed experience. In experiment 1, newly hatched chicks had free access to feed or were fasted for the first 24h. The chicks having free access to feed for the first 24h increased their body weight and had decreased atrogin-1/MAFbx mRNA levels in their sartorius and pectoralis major muscles compared with the fasted chicks. In experiment 2, newly hatched chicks received a single feed via intubation into the crop. Three hours after intubation, levels of atrogin-1/MAFbx mRNA in the sartorius muscle were decreased whereas the plasma insulin concentration and phosphorylated AKT levels in the sartorius muscle were increased. In addition, the mRNA levels of GLUT1 and GLUT8 were increased in the sartorius muscle after the intubation. However, in the pectoralis major muscle, AKT phosphorylation and levels of atrogin-1/MAFbx, GLUT1 and GLUT8 mRNA were not affected 3h after intubation. The first exogenous nutrients increased the level of phosphorylated AKT in the sartorius muscle of newly hatched chicks, possibly because of the decrease in atrogin-1/MAFbx mRNA levels. Furthermore, the sartorius muscle in newly hatched chicks appeared to be more susceptible to the first feed compared with the pectoralis major muscle.

[Serious Coagulation Dysfunction in a Patient with Gallstone-related Cholecystitis Successfully Treated with Vitamin K].

An 85-year-old woman with a diagnosis of choledocholithiasis due to common duct stones gradually developed severe coagulation dysfunction over the course of 27 days after hospitalization. Initial clinical findings were fever, general malaise, and obstructive jaundice. She was treated with fasting, and received cephem antibiotics containing N-methyl-thio-tetrazole. Because the common duct stones were not removed endoscopically, cholecystectomy was scheduled. Coagulation on admission was normal, but gradually became impaired. On the scheduled day of the operation, 27 days after hospitalization, coagulation [both prothrombin time (PT) and activated partial thromboplastin time (APTT)] were severely impaired PT, < 10%; PT-international normalized ratio, 6.29; and APTT, 71.6 s. No other abnormalities were identified. Surgery was postponed and antibiotics were discontinued. Simultaneously, administration of vitamin K was initiated. Six days after starting vitamin K, coagulation dysfunction had resolved and the surgery was safely performed under general anesthesia combined with thoracic epidural anesthesia. Care is warranted regarding coagulation dysfunction due to vitamin K deficiency in patients with hepatobiliary disease treated by fasting and antibiotics.

Clenbuterol changes phosphorylated FOXO1 localization and decreases protein degradation in the sartorius muscle of neonatal chicks.

To investigate the intracellular signaling mechanisms by which clenbuterol reduces muscle protein degradation, we examined the phosphorylation level and intracellular localization of FOXO1 in the sartorius muscle of neonatal chicks. One-day-old chicks were given a single intraperitoneal injection of clenbuterol (0.1 mg/kg body weight). Three hours after injection, AKT protein was phosphorylated in the sartorius muscle by clenbuterol injection. Coincidentally, clenbuterol increased cytosolic level of phosphorylated FOXO1 protein, while it decreased nuclear level of FOXO1 protein in the sartorius muscle. Furthermore, clenbuterol decreased the expression of mRNAs for muscle-specific ubiquitin ligases (atrogin-1/MAFbx and MuRF1) in the sartorius muscle accompanied by decreased plasma 3-methylhistidine concentration, an index of muscle protein degradation, at 3 h after injection. These results suggested that, in the sartorius muscle of the chicks, clenbuterol changed the intracellular localization of phosphorylated FOXO1, and consequently decreased protein degradation via suppressing the expression of genes encoding muscle-specific ubiquitin ligases.

Gene expression pattern of glucose transporters in the skeletal muscles of newly hatched chicks.

The gene expression pattern of the glucose transporters (GLUT1, GLUT3, GLUT8, and GLUT12) among pectoralis major and minor, biceps femoris, and sartorius muscles from newly hatched chicks was examined. GLUT1 mRNA level was higher in pectoralis major muscle than in the other muscles. Phosphorylated AKT level was also high in the same muscle, suggesting a relationship between AKT and GLUT1 expression.