Activation of Pyruvate Dehydrogenase by Sodium Dichloroacetate Shifts Metabolic Consumption from Amino Acids to Glucose in IPEC-J2 Cells and Intestinal Bacteria in Pigs.

The extensive metabolism of amino acids (AA) as fuel is an important reason for the low use efficiency of protein in pigs. In this study, we investigated whether regulation of the pyruvate dehydrogenase kinase (PDK)/pyruvate dehydrogenase alpha 1 (PDHA1) pathway affected AA consumption by porcine intestinal epithelial (IPEC-J2) cells and intestinal bacteria in pigs. The effects of knockdown of PDHA1 and PDK1 with small interfering RNA (siRNA) on nutrient consumption by IPEC-J2 cells were evaluated. IPEC-J2 cells were then cultured with sodium dichloroacetate (DCA) to quantify AA and glucose consumption and nutrient oxidative metabolism. The results showed that knockdown of PDHA1 using siRNA decreased glucose consumption but increased total AA (TAA) and glutamate (Glu) consumption by IPEC-J2 cells ( P < 0.05). Opposite effects were observed using siRNA targeting PDK1 ( P < 0.05). Additionally, culturing IPEC-J2 cells in the presence of 5 mM DCA markedly increased the phosphorylation of PDHA1 and PDH phosphatase 1, but inhibited PDK1 phosphorylation ( P < 0.05). DCA treatment also reduced TAA and Glu consumption and increased glucose depletion ( P < 0.05). These results indicated that PDH was the regulatory target for shifting from AA metabolism to glucose metabolism and that culturing cells with DCA decreased the consumption of AAs by increasing the depletion of glucose through PDH activation.

Correlation between CD8 + T cells' balance and prognosis for patients with diffuse axonal injury / 中国医师杂志

Objective To study the correlation between CD8 + T cells' balance and prognosis for patients with diffuse axonal injury(DAI).Methods To collect the 41 patients with DAI as observation group,with 33 cases light craniocerebral injury (LCI) patients and 35 healthy volunteers as control group.We detect the peripheral blood CD8 + CD28 + T cells and CD8 + CD28-T cell percentage,and calculate the ratio of both.The subjects working curve method (ROC) of.the above CD8 + T cells and its ratio were used to predict the prognosis of patients with DAI efficiency evaluation.Results (1) Compared with control group,CD8 + CD28 + T cells in patients with DAI and LCI increased significantly,and DAI was significantly higher than that of LCI group (P ＜ 0.05).Compared with control group,CD8 + CD28-T cells in patients with DAI were decreased,but no statistical difference was found between LCI and the control group,but DAI group was significantly lower than the LCI group (P ＜ 0.05).(2) CD8 + CD28-T cells and CD8 + CD28 +/CD8 + CD28-ratio were correlated with DAI diagnosis (P =0.003,0.000).When the percentage of CD8 + CD28-T cells =2.95％,the sensitivity of the diagnosis of DAI was 87.49％,86.21％;When the ratio of CD8 + CD28 +/CD8 + CD28-=7.39,the sensitivity was 92.63％,90.71％.(3) a total of 7 cases of patients died within 1 week after injury,CD8 + CD28 + T cells and CD8 + CD28 +/CD8 + CD28-ratio were significantly negative correlated with survival time (r =-0.739,-0.834,P =0.021,0.002),and CD8 + CD28-T cells were significantly positive correlated with survival time (r =0.782,P =0.006).Conclu sions Decreasing CD8 + CD28-T cells and higher CD8 + CD28 +/CD8 + CD28-ratio in patients with DAI immunological characteristics,especially the ratio (balance) is closely corrected with the diagnosis and prognosis of DAI.

The combination of a synthetic promoter and a CMV promoter improves foreign gene expression efficiency in myocytes.

Skeletal muscle is becoming an attractive target tissue for gene therapy. Nevertheless, the low level of gene therapeutic expression in this tissue is the major limitation to it becoming an ideal target for gene transfer. The promoter is important element for gene transcription; however, the gene expression efficiencies and specificities of viral promoters and skeletal muscle-specific promotors are in themselves limiting factors. In this study, we established a dual-promoters system in skeletal muscle using a cytomegalovirus (CMV) promoter and a skeletal muscle-specific synthetic promoter. Mouse myoblast cell line C2C12 cells were transfected with the system. We demonstrated that the dual-promoters system could significantly improve exogenous gene expression rate in vitro when compared with a single CMV promoter system and a skeletal muscle-specific synthetic promoter system in C2C12 cell line, by 69.48% and 41.93%, respectively. Next, we evaluated the system efficiency in vivo, the results showed that the dual-promoters system increased gene expression in mice 1.23-fold and 1.60-fold, respectively compared with expression controlled by the two single promoter vectors. Finally, we tested the dual-promoters system in growth hormone-releasing hormone (GHRH) gene therapy, and revealed that when these two promoters co-drove the GHRH gene expression in vivo animal growth was enhanced significantly. All these results indicate that use of the dual-promoter vector was more efficient for gene expression in skeletal muscle tissue than use of the single promoter vectors. These finding could, hopefully, lead to the development of a high efficiency expression system in myocytes and form an ideal approach for gene therapy.

Tail-suspended model simulating mouse oocytes maturation inhibited with microgravity / 生物医学工程学杂志

We studied the effects of simulated microgravity on mouse oocytes maturation, and analyzed whether the tail-suspended model can be applied to investigate simulated microgravity effects on reproductive processes in female mice. Mouse oocytes were cultured in vitro with microgravity simulated by a rotating wall vessel bioreactor and by tail-suspended model, and the maturation rate of the mouse oocytes in the two models were examined in vivo. The maturation rate of mouse oocytes cultured in simulated microgravity was 8.93%, and that was 72.33% in 1g gravity. In ratio, oocyte maturation rate had no significant difference between the rotational group and control group. Microgravity simulated by the tail-suspended model inhibited mouse oocytes maturation and increased the rate of oocytes abnormity. The maturation rate of tail-suspended mouse oocytes was 14.54%, which was significantly lower than that of control group. Tail-suspended model should be an ideal model to investigate simulated microgravity effects on reproductive processes of female mice.