Bioengineered最新文献

Oleuropein (OP) is an appreciated compound present not only in fruits but also in leaves of olive trees, which can be transformed into hydroxytyrosol (HT), a substance with high antioxidant activity. In this work, the transformation of an agricultural residue containing OP (olive leaves or wastewater from mills) to the high added value compound HT is accomplished through different enzymatic strategies. Different enzymes were used, immobilized on various supports by diverse binding forces: beta-glucosidase encapsulated in siliceous material, esterases and lipases immobilized on hydrophobic supports (octyl-functionalized amorphous silica and periodic mesoporous organosilica), and esterase immobilized on amine-functionalized ordered mesoporous silica. All these biocatalysts were tested for oleuropein hydrolysis through two different reaction approaches: a) split of glucosidic bond catalyzed by beta-glucosidase (β-glu), followed by hydrolysis of the aglycon and further ester hydrolysis. 5 mg·mL^-1 of β-glu fully hydrolyzed 5 mM OP at pH 7 and 50°C in 7 days, and further enzymatic hydrolysis of the aglycon yielded near to 0.5 mM HT in the best conditions tested. b) via direct hydrolysis of the ester bond to produce hydroxytyrosol in a one-step reaction using esterases or lipases. The latter reaction pathway catalyzed by lipase from Penicillium camemberti immobilized on octyl-silica (4 mg·mL^-1) at 35°C and pH 6 directly produced 6.8 mM HT (1 mg·mL^-1), transforming in 12 days near to 30% of the initial 25 mM OP from a commercial olive leaves extract.

Gastric cancer (GC) is the fourth most common cancer in the world. This work was designed to explore the biological effects of miR-148-3p on GC. Quantitative reverse transcription-polymerase chain reaction (RT-qPCR) was utilized to analyze the mRNA expression of miR-148-3p in GC cell lines. The mimics and inhibitors of miR-148-3p were carefully transfected into GC cells to up-regulate or down-regulate miR-148-3p expression. Observe the effect on miR-148-3p expression change to GC cell proliferation, colony formation, tumorigenesis, chemotherapy sensitivity, transwell migration, and invasion. Use online database tool to predict the miR-148-3p promising targets, and can be verified via RT-qPCR, Western blot, and luciferase report. We found that miR-148-3p expression level in GC cells was markedly down-regulated (P < 0.05), as compared with human normal gastric mucosal cells GES-1. Otherwise, miR-148-3p overexpression could effectively inhibit the cell proliferation, cell cycle progress, colony formation, anti-apoptosis, anti-migration and anti-invasion in gastric cancer cells, whereas miR-148-3p inhibition exhibited the opposite phenomenon (P < 0.05). Further research revealed that Bcl2 set as a direct downstream target of miR-148-3p. Our study firstly confirmed that, miR-148-3p might play a crucial role in tumorigenesis, as well as development of gastric cancer by targeting Bcl2, and could become a promising target for gastric cancer treatment.

With the aim to find new polysaccharides of rheological interest with innovated properties, rhamnofucans produced as exopolysaccharides (EPS) in a photobioreactor (PBR) and an airlift bioreactor (ABR) by the marine microalgae Glossomastix sp. RCC3707 and RCC3688 were fully studied. Chemical characterizations have been conducted (UHPLC - MS HR). Analyses by size-exclusion chromatography (SEC) coupled online with a multiangle light scattering detector (MALS) and a differential refractive index detector showed the presence of large structures with molar masses higher than 10⁶ g.mol^-1. The rheological studies of these EPS solutions, conducted at different concentrations and salinities, have evidenced interesting and rare behavior characteristic of weak and fragile hydrogels i.e. gel behavior with very low elastic moduli (between 10^-2 and 10 Pa) and yield stresses (between 10^-2 and 2 Pa) according to the EPS source, concentration, and salinity. These results were confirmed by diffusing wave spectroscopy. Finally, as one of potential application, solutions of EPS from Glossomastix sp. have evidenced very good properties as anti-settling stabilizers, using microcrystalline cellulose particles as model, studied by multiple light scattering (MLS) with utilization in cosmetic or food industry. Compared to alginate solution with same viscosity for which sedimentation is observed over few hours, microalgae EPS leads to a stable suspension over few days.