The effects of ionic liquid 1-ethyl-3-methylimidazolium trifluoromethanesulfonate on the production of 1,3-propanediol from crude glycerol by microbial consortium

Bioprocess and Biosystems Engineering - Ionic liquids (ILs) as “green” solvents have been widely used owing to their excellent properties, e.g., for biodiesel production. Crude glycerol...     

The treatment of purified maize oil bodies with organic solvents and exogenous diacylglycerol allows the detection and solubilization of diacylglycerol acyltransferase

In spite of its importance in the biosynthesis of reserve oils in plants, diacylglycerol acyltransferase (DAGAT, EC 2.3.1.20) has not been purified to homogeneity, and its study has remained incomplete. We found that the microsomal preparations from developing maize embryos contained substantial amounts of endogenous diacylglycerol (DAG). A solubilization procedure for extracting DAGAT from the microsomes (D. Little, R. Weselake, K. Pomeroy, S.T. Furukawa, J. Bagu, Biochem. J. 304 (1994)) was ineffective in eliminating the endogenous DAG, even after gel filtration. DAG removal through the preparation of acetone powders from the embryos led to the loss of DAGAT activity. Labelled triacylglycerol (TAG) was produced in the standard DAGAT assay when labelled DAG was supplied in benzene solution to the freeze-dried microsomes and the sample was dried and resuspended in an aqueous buffer. In contrast, no labelled TAG was produced when a similar sample supplied with non-labelled DAG was assayed with emulsified labelled DAG and acyl-CoA. Repeated washing of the microsomal freeze-dried fraction with benzene resulted in a complete loss of DAGAT activity in the standard assay, but the activity was restored by the addition of DAG plus phosphatidylcholine or Tween 20 in benzene. Although DAGAT has been reported to be confined mainly to the endoplasmic reticulum, we found that DAGAT activity was high in the purified oil bodies from both developing and mature maize embryos and was not removed by repeated washing with 6 M urea. The DAGAT activity was restored from delipidated oil bodies and from microsomes after the preparations had been resuspended in methanol/acetic acid/water (1:1:1, v/v). Although most of the proteins in the suspension were eluted as a single peak at the void volume after gel filtration chromatography, DAGAT activity was found in later fractions. SDS–PAGE of the peak activity fraction revealed no protein bands after silver staining, and the finding suggest that DAGAT protein is of low abundance and has a high k_cat.     

Upregulation of miR-183 represses neuropathic pain through inhibiton of MAP3K4 in CCI rat models

Many studies have verified that microRNAs contribute a lot to neuropathic pain progression. Furthermore, nerve-related inflammatory cytokines play vital roles in neuropathic pain progression. miR-183 has been identified to have a common relationship with multiple pathological diseases. However, the potential effects of miR-183 in the process of neuropathic pain remain undetermined. Therefore, we performed the current study with the purpose of finding the functions of miR-183 in neuropathic pain progression using a chronic sciatic nerve injury (CCI) rat model. We demonstrated that miR-183 expression levels were evidently reduced in CCI rats in contrast with the control group. Overexpression of miR-183 produced significant relief of mechanical hyperalgesia, as well as thermal hyperalgesia in CCI rats. Furthermore, neuropathic pain-correlated inflammatory cytokine expression levels containing interleukin-6 (IL-6) and interleukin-1β (IL-1β), cyclooxygenase-2 (COX-2) were obviously inhibited by upregulation of miR-183. Meanwhile, dual-luciferase reporter assays showed MAP3K4 was a direct downstream gene of miR-183. The expression levels of MAP3K4 were modulated by the increased miR-183 negatively, which lead to the downregulation of IL-6, IL-1β, and COX-2, and then reduced neuropathic pain progression, respectively. Overall, our study pointed out that miR-183 was a part of the negative regulator which could relieve neuropathic pain by targeting MAP3K4. Thus it may provide a new clinical treatment for neuropathic pain patients clinical therapy.     

Inhibition of Mitochondrial Complex II by the Anticancer Agent Lonidamine

The antitumor agent lonidamine (LND; 1-(2,4-dichlorobenzyl)-1H-indazole-3-carboxylic acid) is known to interfere with energy-yielding processes in cancer cells. However, the effect of LND on central energy metabolism has never been fully characterized. In this study, we report that a significant amount of succinate is accumulated in LND-treated cells. LND inhibits the formation of fumarate and malate and suppresses succinate-induced respiration of isolated mitochondria. Utilizing biochemical assays, we determined that LND inhibits the succinate-ubiquinone reductase activity of respiratory complex II without fully blocking succinate dehydrogenase activity. LND also induces cellular reactive oxygen species through complex II, which reduced the viability of the DB-1 melanoma cell line. The ability of LND to promote cell death was potentiated by its suppression of the pentose phosphate pathway, which resulted in inhibition of NADPH and glutathione generation. Using stable isotope tracers in combination with isotopologue analysis, we showed that LND increased glutaminolysis but decreased reductive carboxylation of glutamine-derived α-ketoglutarate. Our findings on the previously uncharacterized effects of LND may provide potential combinational therapeutic approaches for targeting cancer metabolism.     

基于享乐价格-结构方程双模型的西宁城市湿地生态系统服务价值及影响因素研究

湿地为城市发展提供巨大的生态系统服务，但其被市场“认可”的经济价值难以准确评估。以青海省西宁市城市湿地为例，筛选房屋结构、可达性、环境、湿地等10个因子，采用享乐价格模型对110个湿地周边社区样点的因子数据(2020年)进行分析，定量分析城市湿地被市场“认可”的价值量。采用断裂点理论和加权Voronoi图模型方法等，分析了湿地生态系统服务价值的空间影响范围；构建了湿地生态系统服务价值影响因素的结构方程模型，探究了影响湿地生态系统服务价值的主要因素。结果表明：(1)2020年湟水城市湿地的总价值达到3.367亿元，约有54.3%的生态系统服务通过房产被市场转化；(2)湟水湿地单位面积的生态系统服务价值为151.916元/m~2,生态系统服务价值由大到小排列：火烧沟(1.632亿元)>海湖湿地(0.710亿元)>宁海湿地(0.629亿元)>北川湿地(0.330亿元);(3)湿地生态系统服务价值占房产总价值的比例达到2.04%,位列10个因素中的第7位；线性函数模型结果显示，购买者对湿地的边际支付意愿是0.12元/m~2,即购买者愿意为房产与湿地之间的距离每缩小1m而多支付...     

Novel orally active morpholine N-arylsulfonamides γ-secretase inhibitors with low CYP 3A4 liability

A new class of 2,6-disubstituted morpholine N-arylsulfonamide γ-secretase inhibitors was designed based on the introduction of a morpholine core in lieu or piperidine in our lead series. This resulted in compounds with improved CYP 3A4 profiles. Several analogs that were active at lowering Aβ levels in Tg CRND8 mice upon oral administration were identified.