Development of antler-type fruiting bodies of Ganoderma lucidum and determination of its biochemical properties

Following the importance of antler-type fruiting bodies of Ganoderma lucidum, in this study, the impact of main growth parameters such as ventilation and light on the development of antler-type fruiting bodies has been investigated together with the determination of physico-chemical properties of antler fruiting bodies. For this, the primordia bags of G. lucidum were kept under controlled ventilation to adjust the CO₂ produced by the mushrooms owing to its respiration under light and dark conditions. The bioactive compounds such as phenolics, flavonoids, water-soluble polysaccharides and ganoderic acid showed a two-fold increase in the antler-type fruiting bodies as compared to normal kidney-shaped fruiting bodies. It is assumed from this study that the antler type fruiting bodies are developed due to restricted ventilation which causes an increase in the level of CO₂ gas in the air as a result of respiration of mushroom. The shape and colour of antler fruiting bodies again dependent on the light provided in the growth chamber. This study also proves that with the manipulation of light and ventilation antler-type fruiting bodies of G. lucidum could be developed with higher quantity of bioactive compounds and with higher antioxidant potential.     

Enhancement of the thermal and alkaline pH stability of <Emphasis Type="Italic">Escherichia coli</Emphasis> lysine decarboxylase for efficient cadaverine production

Objective

To enhance the thermal and alkaline pH stability of the lysine decarboxylase from Escherichia coli (CadA) by engineering the decameric interface and explore its potential for industrial applications.

Results

The mutant T88S was designed for improved structural stability by computational analysis. The optimal pH and temperature of T88S were 7.0 and 55 °C (5.5 and 50 °C for wild-type). T88S showed higher thermostability with a 2.9-fold increase in the half-life at 70 °C (from 11 to 32 min) and increased melting temperature (from 76 to 78 °C). Additionally, the specific activity and pH stability (residual activity after 10 h incubation) of T88S at pH 8.0 were increased to 164 U/mg and 78% (58 U/mg and 57% for wild-type). The productivity of cadaverine with T88S (284 g l-lysine L^?1 and 5 g DCW L^?1) was 40 g L^?1 h^?1, in contrast to 28 g L^?1 h^?1 with wild-type.

Conclusion

The mutant T88S showed high thermostability, pH stability, and activity at alkaline pH, indicating that this mutant is a promising biocatalyst for industrial production of cadaverine.

     

RNA binding protein Lin28A promotes osteocarcinoma cells progression by associating with the long noncoding RNA MALAT1

Objectives

To explore the effects of Lin28A on progression of osteocarcinoma (OS) cells.

Results

Lin28A mRNA and protein expressions were significantly increased in OS tissues compared with that in normal adjacent tissues. Expressions of Lin28A and long noncoding RNA MALAT1 were positively correlated. Patients with higher Lin28A expression had shorter overall survival. Moreover, Lin28A knockdown inhibited OS cells proliferation, migration, invasion and promoted cell apoptosis; Lin28A was found to harbor binding sites on MALAT1 sequences and associated with MALAT1, and increased MALAT1 stability and expression. Notably, the inhibition of Lin28A knockdown was attenuated or even reversed by MALAT1 overexpression.

Conclusions

RNA binding protein Lin28A could facilitate OS cells progression by associating with the long noncoding RNA MALAT1.

     

Differential expression of AP-2gamma and AP-2alpha during human trophoblast differentiation.

Previous studies from our laboratory demonstrated that AP-2alpha induces the expression of the hPL and hCG genes in cultured trophoblast cells. In the current study, we have shown by transient transfection studies that AP-2gamma, which is the product of a separate gene from AP-2alpha, also stimulates hPL and hCGbeta promoter activities. However, AP-2gamma mRNA levels during in vitro differentiation of human cytotrophoblast cells were strikingly different than those of AP-2alpha mRNA levels, with AP-2alpha increasing and AP-2gamma markedly decreasing during the differentiation process. The amount of AP-2gamma protein binding to AP-2 elements on the hPL promoter, as determined by supershift assays, also markedly decreased during the differentiation process. These findings strongly suggest that AP-2gamma action in cytotrophoblast cells is repressed by a co-factor(s) that inhibits AP-2gamma action or is prevented by the absence of a co-factor(s) that is essential for AP-2gamma action.     

Infusion of beta-endorphin improves insulin resistance in fructose-fed rats.

In an attempt to probe the effect of beta-endorphin on insulin resistance, we used Wistar rats that were fed fructose-rich chow to induce insulin resistance. Insulin action on glucose disposal rate (GDR) was measured using the hyperinsulinemic euglycemic clamp technique, in which glucose (variable), insulin (40 mU/kg/min), and beta-endorphin (6 ng/kg/min) or vehicle were initiated simultaneously and continued for 120 min. A marked reduction in insulin-stimulated GDR was observed in fructose-fed rats compared to normal control rats. Infusion of beta-endorphin reversed the value of GDR, which was inhibited by naloxone and naloxonazine each at doses sufficient to block opioid mu-receptors. Opioid mu-receptors may therefore be activated by beta-endorphin to improve insulin resistance. Next, soleus muscle was isolated to investigate the effect of beta-endorphin on insulin signals. Insulin resistance in rats induced by excess fructose was associated with the impaired insulin receptor (IR), tyrosine autophosphorylation, and insulin receptor substrate (IRS)-1 protein content in addition to the significant decrease in IRS-1 tyrosine phosphorylation in soleus muscle. This impaired glucose transportation was also due to signaling defects that included an attenuated p85 regulatory subunit of phosphatidylinositol 3-kinase (PI3-kinase) and Akt serine phosphorylation. However, IR protein levels were not markedly changed in rats with insulin resistance. beta-endorphin infusion reversed the fructose-induced decrement in the insulin-signaling cascade with increased GDR. Apart from IR protein levels, infusion of beta-endorphin reversed the decrease in protein expression for the IRS-1, p85 regulatory subunit of PI3-kinase, and Akt serine phosphorylation in soleus muscle in fructose-fed rats. The decrease in insulin-stimulated protein expression of glucose transporter subtype 4 (GLUT 4) in fructose-fed rats returned to near-normal levels after beta-endorphin infusion. Infusion of beta-endorphin may improve insulin resistance by modulating the insulin-signaling pathway to reverse insulin responsiveness.