1.Lipid Interactions and Organization in Complex Bilayer Membranes.
Engberg O1, Yasuda T2, Hautala V1, Matsumori N3, Nyholm TK1, Murata M4, Slotte JP5. Biophys J. 2016 Apr 12;110(7):1563-73. doi: 10.1016/j.bpj.2015.12.043.
Bilayer lipids influence the lateral structure of the membranes, but the relationship between lipid properties and the lateral structure formed is not always understood. Model membrane studies on bilayers containing cholesterol and various phospholipids (PLs) suggest that high and low temperature melting PLs may segregate, especially in the presence of cholesterol. The effect of different PL headgroups on lateral structure of bilayers is also not clear. Here, we have examined the formation of lateral heterogeneity in increasingly complex (up to five-component) multilamellar bilayers. We have used time-resolved fluorescence spectroscopy with domain-selective fluorescent probes (PL-conjugated trans-parinaric acid), and (2)H NMR spectroscopy with site or perdeuterated PLs. We have measured changes in bilayer order using such domain-selective probes both as a function of temperature and composition. Our results from time-resolved fluorescence and (2)H NMR showed that in ternary bilayers, acyl chain order and thermostability in sphingomyelin-rich domains were not affected to any greater extent by the headgroup structure of the monounsaturated PLs (phosphatidylcholine, phosphatidylethanolamine, or phosphatidylserine) in the bilayer.
2.Autophagy protects ovarian cancer-associated fibroblasts against oxidative stress.
Wang Q1,2, Xue L3, Zhang X3, Bu S1, Zhu X3, Lai D1. Cell Cycle. 2016 Apr 13:0. [Epub ahead of print]
RNA-Seq and gene set enrichment anylysis revealed that ovarian cancer associated fibroblasts (CAFs) are mitotically active compared with normal fibroblasts (NFs). Cellular senescence is observed in CAFs treated with H2O2 as shown by elevated SA-β-gal activity and p21 (WAF1/Cip1) protein levels. Reactive oxygen species (ROS) production and p21 (WAF1/Cip1) elevation may account for H2O2-induced CAFs cell cycle arrest in S phase. Blockage of autophagy can increase ROS production in CAFs, leading to cell cycle arrest in S phase, cell proliferation inhibition and enhanced sensitivity to H2O2-induced cell death. ROS scavenger NAC can reduce ROS production and thus restore cell viability. Lactate dehydrogenase A (LDHA), monocarboxylic acid transporter 4 (MCT4) and superoxide dismutase 2 (SOD2) were up-regulated in CAFs compared with NFs. There was relatively high lactate content in CAFs than in NFs. Blockage of autophagy decreased LDHA, MCT4 and SOD2 protein levels in CAFs that might enhance ROS production.
3.Characterization of Glycolytic Pathway Genes Using RNA-Seq in Developing Kernels of Eucommia ulmoides.
Feng Y, Zhang L, Fu J, Li F, Wang L, Tan X, Mo W, Cao H. J Agric Food Chem. 2016 Apr 13. [Epub ahead of print]
Eucommia ulmoides Oliver, the only member of the Eucommiaceae family, is a rare and valuable tree used to produce a highly valued traditional Chinese medicine and contains α-linolenic acid (ALA) up to 60% of the total fatty acids in the kernels (embryos). Glycolysis provides both cellular energy and the intermediates for other biosynthetic processes. However, nothing was known about the molecular basis of the glycolytic pathway in E. ulmoides kernels. The purposes of this study were to identify novel genes of E. ulmoides related to glycolytic metabolism and to analyze the expression patterns of selected genes in the kernels. Transcriptome sequencing based on the Illumina platform generated 96,469 unigenes in four cDNA libraries constructed using RNAs from 70 and 160 days after flowering kernels of both low and high ALA varieties. We identified and characterized the digital expression of 120 unigenes coding for 24 protein families involved in kernel glycolytic pathway.
4.Highly selective binding of methyl orange dye by cationic water-soluble pillararenes.
Yakimova LS1, Shurpik DN1, Gilmanova LH1, Makhmutova AR1, Rakhimbekova A1, Stoikov II1. Org Biomol Chem. 2016 Apr 13. [Epub ahead of print]
A new water-soluble pillararene with an amide fragment and triethylammonium groups was synthesized by our original method of aminolysis of the ester groups. Using UV-spectroscopy, it is shown that cationic pillararenes are able to selectively form 1 : 1 complexes with some hydrophobic anions: the guests with bulky uncharged or negatively charged substituents hindering entry into the macrocycle cavity. Highly selective binding of the most lipophilic guest, methyl orange dye, in the form of organic anion salts by positively charged water-soluble pillararenes was detected. In the case of the azo dye the appropriate Kass values were 10-100-fold higher than those calculated for the other sulfonic acid derivatives studied. The 2D NMR NOESY 1H-1H spectroscopy confirms the formation of the inclusion complex: negative charge sulfonate head is outside the cavity of pillararenes and the hydrophobic fragment of the guest is located in the cavity.