Integrative Proteome Analysis Revels 3-Hydroxybutyrate Exerts Neuroprotective Effect by Influencing Chromatin Bivalency.

3-hydroxybutyrate (3OHB) has been proved to act as a neuroprotective molecule in multiple neurodegenerative diseases. Here, we employed a quantitative proteomics approach to assess the changes of the global protein expression pattern of neural cells upon 3OHB administration. In combination with a disease-related, protein-protein interaction network we pinpointed a hub marker, histone lysine 27 trimethylation, which is one of the key epigenetic markers in multiple neurodegenerative diseases. Integrative analysis of transcriptomic and epigenomic datasets highlighted the involvement of bivalent transcription factors in 3OHB-mediated disease protection and its alteration of neuronal development processes. Transcriptomic profiling revealed that 3OHB impaired the fate decision process of neural precursor cells by repressing differentiation and promoting proliferation. Our study provides a new mechanism of 3OHB's neuroprotective effect, in which chromatin bivalency is sensitive to 3OHB alteration and drives its neuroprotective function both in neurodegenerative diseases and in neural development processes.

Highly efficient biocatalytic synthesis of L-DOPA using in situ immobilized Verrucomicrobium spinosum tyrosinase on polyhydroxyalkanoate nano-granules.

L-DOPA (3,4-dihydroxyphenyl-L-alanine) is a preferred drug for Parkinson's disease, and is currently in great demand every year worldwide. Biocatalytic conversion of L-tyrosine by tyrosinases is the most promising method for the low-cost production of L-DOPA in both research and industry. Yet, it has been hampered by low productivity, low conversion rate, and low stability of the biocatalyst, tyrosinase. An alternative tyrosinase TyrVs from Verrucomicrobium spinosum with more efficient expression in heterologous host and better stability than the commercially available Agaricus bisporus tyrosinase was identified in this study. Additionally, it was prepared as a novel nano-biocatalyst based on the distinct one-step in situ immobilization on the surface of polyhydroxyalkanoate (PHA) nano-granules. The resulting PHA-TyrVs nano-granules demonstrated improved L-DOPA-forming monophenolase activity of 9155.88 U/g (Tyr protein), which was 3.19-fold higher than that of free TyrVs. The nano-granules also exhibited remarkable thermo-stability, with an optimal temperature of 50 °C, and maintained more than 70% of the initial activity after incubation at 55 °C for 24 h. And an enhanced affinity of copper ion was observed in the PHA-TyrVs nano-granules, making them even better biocatalysts for L-DOPA production. Therefore, a considerable productivity of L-DOPA, amounting to 148.70 mg/L h, with a conversion rate of L-tyrosine of 90.62% can be achieved by the PHA-TyrVs nano-granules after 3 h of biocatalysis under optimized conditions, without significant loss of enzyme activity or L-DOPA yield after 8 cycles of repeated use. Our study provides an excellent and robust nano-biocatalyst for the cost-effective production of L-DOPA.

Microbial synthesized biodegradable PHBHHxPEG hybrid copolymer as an efficient intracellular delivery nanocarrier for kinase inhibitor.

BACKGROUND: Protein Kinases are key regulators of cell function and play essential roles in the occurrence and development of many human diseases. Many kinase inhibitors have been used for molecular targeted treatment of those diseases such as cancer and inflammation. However, those highly hydrophobic kinase inhibitors shared the common features of poor bioavailability and limited in vivo half-life, which strongly impeded their practical applications. Our previous study demonstrated that microbial synthesized biodegradable polyester poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx), a member of polyhydroxyalkanoates (PHAs) family, could serve as a promising delivery nanocarrier for those hydrophobic kinase inhibitors. Recently, a novel natural synthesized hybrid copolymer, PEG200 end-capped PHBHHx (PHBHHxPEG) was produced by Aeromonas hydrophila fermentation. In this study, the novel PHBHHxPEG NPs were prepared and investigated to serve as intracellular delivery nanocarriers for sustained release of hydrophobic kinase inhibitors. RESULTS: PHBHHxPEG nanoparticles (NPs) prepared by an emulsification-solvent evaporation method were spherical with a diameter around 200 nm. The entrapment efficiency on rapamycin in PHBHHxPEG NPs was 91.9% and the sustained release of rapamycin from PHBHHxPEG NPs could be achieved for almost 10 days. The cellular uptake of PHBHHxPEG NPs was significant higher than that of PHBHHx NPs. The anti-proliferation effect and mTOR inhibition ability of rapamycin-loaded PHBHHxPEG NPs was stronger than that of drug-loaded PHBHHx NPs and free rapamycin. CONCLUSIONS: PHBHHxPEG NPs could achieve the efficient entrapment and sustained release of rapamycin. The novel biodegradable PHBHHxPEG appeared a promising nanocarrier for sustained delivery of hydrophobic kinase inhibitors with improved cellular uptake and kinase inhibition efficiency.

Characterisation of flavourous sesame oil obtained from microwaved sesame seed by subcritical propane extraction.

This study developed a novel and green method to produce fragrant sesame oil using microwaves and subcritical extraction (SBE). Sesame seeds were microwaved at 540 W for 0-9 min before subcritical propane extraction at 40 °C and 0.5 MPa. SBE caused less deformation to the cellular microstructure of sesame cotyledons while dramatically improving oil yield (96.7-97.1 %) compared to screw processing (SP) (53.1-58.6 %). SBE improved extraction rates for γ-tocopherol (381.1-454.9 µg/g) and sesame lignans (917.9-970.4 mg/100 g) in sesame oil compared to SP (360.1-443.8 µg/g and 872.8-916.8 mg/100 g, respectively). Microwaves generated aroma-active heterocyclics and phenolics faster than hot-air roasting in sesame oil with a better sensory profile. SBE had a higher extraction rate for aroma-active terpenes, alcohols, and esters while reducing the concentrations of carcinogenic PAHs and HCAs in sesame oil. The novel combination process of microwaves and subcritical extraction is promising in producing fragrant sesame oil with superior qualities.