Understanding pathogen–host interplay by expression profiles of lncRNA and mRNA in the liver of Echinococcus multilocularis-infected mice

Almost all Echinococcus multilocularis (Em) infections occur in the liver of the intermediate host, causing a lethal zoonotic helminthic disease, alveolar echinococcosis (AE). However, the long non-coding RNAs (lncRNAs) expression profiles of the host and the potential regulatory function of lncRNA during Em infection are poorly understood. In this study, the profiles of lncRNAs and mRNAs in the liver of mice at different time points after Em infection were explored by microarray. Thirty-one differentially expressed mRNAs (DEMs) and 68 differentially expressed lncRNAs (DELs) were found continuously dysregulated. These DEMs were notably enriched in “antigen processing and presentation”, “Th1 and Th2 cell differentiation” and “Th17 cell differentiation” pathways. The potential predicted function of DELs revealed that most DELs might influence Th17 cell differentiation and TGF-β/Smad pathway of host by trans-regulating SMAD3, STAT1, and early growth response (EGR) genes. At 30 days post-infection (dpi), up-regulated DEMs were enriched in Toll-like and RIG-I-like receptor signaling pathways, which were validated by qRT-PCR, Western blotting and downstream cytokines detection. Furthermore, flow cytometric analysis and serum levels of the corresponding cytokines confirmed the changes in cell-mediated immunity in host during Em infection that showed Th1 and Th17-type CD4⁺ T-cells were predominant at the early infection stage whereas Th2-type CD4⁺ T-cells were significantly higher at the middle/late stage. Collectively, our study revealed the potential regulatory functions of lncRNAs in modulating host Th cell subsets and provide novel clues in understanding the influence of Em infection on host innate and adaptive immune response.     

Simultaneous tissue profiling of eicosanoid and endocannabinoid lipid families in a rat model of osteoarthritis

We describe a novel LC method for the simultaneous and quantitative profiling of 43 oxylipins including eicosanoids, endocannabinoids, and structurally related bioactive lipids with modified acyl groups. The LC-MS/MS method uses switching at a defined time between negative and positive electrospray ionization modes to achieve optimal detection sensitivity for all the lipids. The validated method is linear over a range of 0.01–5 nmol/g (0.1–50 nmol/g for 2-arachidonoyl glycerol) with intra- and interday precision and accuracy between 1.38 and 26.76% and 85.22 and 114.3%, respectively. The method successfully quantified bioactive lipids in different tissue types in the rat, including spinal cord, dorsal root ganglia (DRGs), knee joint, brain, and plasma. Distinct regional differences in the pattern of lipid measured between tissue types were observed using principle component analysis. The method was applied to analyze tissue samples from an established preclinical rat model of osteoarthritis (OA) pain and showed that levels of 12-hydroxyeicosatetraenoic acid were significantly increased in the OA rat knee joint compared with controls, and that 15-hydroxyeicosatetraenoic acid was significantly increased in the DRGs in the model of OA compared with controls. The developed LC-MS/MS method has the potential to provide detailed pathway profiling in tissues and biofluids where the disruption of bioactive oxylipins may be involved in disease states.     

Diazoxide Pretreatment Prevents Aβ1–42 Induced Oxidative Stress in Cholinergic Neurons Via Alleviating NOX2 Expression

The aggregation and accumulation of amyloid-β (Aβ) plays a significant role in the pathogenesis of Alzheimer’s disease. Aβ is known to increase free radical production in neuronal cells, leading to oxidative stress and cell death. Diazoxide (DZ), a highly selective drug capable of opening mitochondrial ATP-sensitive potassium channels, has neuroprotective effects against neuronal cell death. However, the mechanism through which DZ protects cholinergic neurons against Aβ-induced oxidative injury is still unclear. The present study was designed to investigate the effects of DZ pretreatment against Aβ_1–42 induced oxidative damage and cytotoxicity. Through measures of DZ effects on Aβ_1–42 induced cellular damage, reactive oxygen species (ROS) and MDA generation and expressions of gp91phox and p47phox in cholinergic neurons, new insights into the neuroprotective mechanisms can be derived. Aβ_1–42 significantly decreased 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide levels and increased ROS and MDA production; all effects were attenuated by pretreatment with DZ or diphenyleneiodonium chloride (a NOX2 inhibitor). Pretreatment with DZ also attenuated the upregulation of NOX2 subunits (gp91phox and p47phox) induced by Aβ_1–42. Since NOX2 is one of the main sources of free radicals, these results suggest that DZ can counteract Aβ_1–42 induced oxidative stress and associated cell death by reducing the level of ROS and MDA, in part, by alleviating NOX2 expression.     

Quality,bioactivity study,and preclinical acute toxicity,safety pharmacology evaluation of PEGylated recombinant human endostatin (M2ES)

Endostar, a potent endogenous antiangiogenic factor, is wildly used in clinics. However, it was easily degraded by enzymes and rapidly cleared by the kidneys. To overcome these shortcomings, PEGylated recombinant human endostatin was developed. In this study, the purity of M₂ES was evaluated by silver stain and reversed‐phase high‐performance liquid chromatography. Ultraviolet spectrum was used to examine the structural of M₂ES and endostar. The bioactivity and antitumor efficacy of M₂ES were evaluated using an in vitro endothelial cell migration model and athymic nude mouse xenograft model of a heterogeneous lung adenocarcinoma, respectively. A preclinical study was performed to evaluate the acute toxicity and safety pharmacology in rhesus monkeys. The purity of M₂ES was more than 98%; PEG modification has no effect on endostatin structure. Compared with the control group, M₂ES dramatically retards endothelial cell migration and tumor growth. After intravenous (IV) infusions of M₂ES at a dose level of three and 75 mg/kg in rhesus monkeys, there was no observable serious adverse event in both acute toxicity and safety pharmacology study. On the basis of the quality and bioactivity study data of M₂ES and the absence of serious side effect in rhesus monkeys, M₂ES was authorized to initiate a phase I clinical trial.     

Analysis of gamma c-family cytokine target genes. Identification of dual-specificity phosphatase 5 (DUSP5) as a regulator of mitogen-activated protein kinase activity in interleukin-2 signaling

Interleukin (IL)-2, IL-4, IL-7, IL-9, IL-15, and IL-21 form a family of cytokines based on their sharing the common cytokine receptor gamma chain, gamma(c), which is mutated in X-linked severe combined immunodeficiency (SCID). As a step toward further elucidating the mechanism of action of these cytokines in T-cell biology, we compared the gene expression profiles of IL-2, IL-4, IL-7, and IL-15 in T cells using cDNA microarrays. IL-2, IL-7, and IL-15 each induced a highly similar set of genes, whereas IL-4 induced distinct genes correlating with differential STAT protein activation by this cytokine. One gene induced by IL-2, IL-7, and IL-15 but not IL-4 was dual-specificity phosphatase 5 (DUSP5). In IL-2-dependent CTLL-2 cells, we show that IL-2-induced ERK-1/2 activity was inhibited by wild type DUSP5 but markedly increased by an inactive form of DUSP5, suggesting a negative feedback role for DUSP5 in IL-2 signaling. Our findings provide insights into the shared versus distinctive actions by different members of the gamma(c) family of cytokines. Moreover, we have identified a DUSP5-dependent negative regulatory pathway for MAPK activity in T cells.     

Recovery from nutrient starvation by a marine Vibrio sp.

A marine psychrophilic Vibrio sp., Ant-300, recovered from starvation after the addition of 1 volume of complete nutrient medium to 9 volumes of starvation menstruum. Turbidity (measured by optical density), viable cell counts, cell size (measured from electron micrographs), and cellular concentrations of protein, DNA, and RNA were monitored with recovery time. The usual growth curve of bacterial cultures was observed. On a per viable cell basis, protein, DNA, and RNA increased to maximum values just before cell division and then returned to close to the initial starved-cell value during the stationary phase. Cells under complete starvation conditions or missing only one nutrient in the stationary phase responded with cell division resulting in many smaller cells. The length of the lag phase during recovery was directly proportional to the length of the prior starvation period, even when identical numbers of cells were used for recovery. Cells appeared to pass more deeply into dormancy with starvation time.     

Impacts of Saltwater Incursion on Plant Communities,Anaerobic Microbial Metabolism,and Resulting Relationships in a Restored Freshwater Wetland

Saltwater incursion carries high concentrations of sea salts, including sulfate, which can alter anaerobic microbial processes and plant community composition of coastal freshwater marshes. We studied these phenomena in a recently restored wetland on the coastal plain of North Carolina. We measured water inundation patterns, porewater chemistry, microbial process rates, plant tissue chemistry and iron plaque on plant roots, and quantified plant community composition across a hydrologic and salinity gradient to understand the potential interactions between saltwater incursion and changes in microbial processes and plant communities. Plant communities showed no obvious response to incursion, but were structured by inundation patterns and plant growth form (for example, graminoid versus forb). Saltwater incursion increased chloride and sulfate concentrations in surface and porewater, and drove resulting spatial patterns in anaerobic microbial metabolism rates. Plots experiencing saltwater incursion had higher sulfate reduction rates and were dominated by graminoid plant species (for example, sedges, rushes, and grasses). Graminoid plant species’ roots had greater iron plaque formation than forb and submerged species, indicative that graminoid plant species are supplying more oxygen to the rhizosphere, potentially influencing microbial metabolism. Future studies should focus on how plant and microbial communities may respond to saltwater incursion at different time scales, and on parsing out the influence that plants and microbes have on each other as freshwater wetlands experience sea level rise.