Giardia secretome highlights secreted tenascins as a key component of pathogenesis

Background

Giardia is a protozoan parasite of public health relevance that causes gastroenteritis in a wide range of hosts. Two genetically distinct lineages (assemblages A and B) are responsible for the human disease. Although it is clear that differences in virulence occur, the pathogenesis and virulence of Giardia remain poorly understood.

Results

The genome of Giardia is believed to contain open reading frames that could encode as many as 6000 proteins. By successfully applying quantitative proteomic analyses to the whole parasite and to the supernatants derived from parasite culture of assemblages A and B, we confirm expression of ∼1600 proteins from each assemblage, the vast majority of which are common to both lineages. To look for signature enrichment of secreted proteins, we considered the ratio of proteins in the supernatant compared with the pellet, which defined a small group of enriched proteins, putatively secreted at a steady state by cultured growing trophozoites of both assemblages. This secretome is enriched with proteins annotated to have N-terminal signal peptide. The most abundant secreted proteins include known virulence factors such as cathepsin B cysteine proteases and members of a Giardia superfamily of cysteine-rich proteins that comprise variant surface proteins, high-cysteine membrane proteins, and a new class of virulence factors, the Giardia tenascins. We demonstrate that physiological function of human enteric epithelial cells is disrupted by such soluble factors even in the absence of the trophozoites.

Conclusions

We are able to propose a straightforward model of Giardia pathogenesis incorporating key roles for the major Giardia-derived soluble mediators.

Glycolysis is important for optimal asexual growth and formation of mature tissue cysts by Toxoplasma gondii

Toxoplasma gondii can grow and replicate using either glucose or glutamine as the major carbon source. Here, we have studied the essentiality of glycolysis in the tachyzoite and bradyzoite stages of T. gondii, using transgenic parasites that lack a functional hexokinase gene (Δhk) in RH (Type-1) and Prugniaud (Type-II) strain parasites. Tachyzoite stage Δhk parasites exhibit a fitness defect similar to that reported previously for the major glucose transporter mutant, and remain virulent in mice. However, although Prugniaud strain Δhk tachyzoites were capable of transforming into bradyzoites in vitro, they were severely compromised in their ability to make mature bradyzoite cysts in the brain tissue of mice. Isotopic labelling studies reveal that glucose-deprived tacyzoites utilise glutamine to replenish glycolytic and pentose phosphate pathway intermediates via gluconeogenesis. Interestingly, while glutamine-deprived intracellular Δhk tachyzoites continued to replicate, extracellular parasites were unable to efficiently invade host cells. Further, studies on mutant tachyzoites lacking a functional phosphoenolpyruvate carboxykinase (Δpepck1) revealed that glutaminolysis is the sole source of gluconeogenic flux in glucose-deprived parasites. In addition, glutaminolysis is essential for sustaining oxidative phosphorylation in Δhk parasites, while wild type (wt) and Δpepck1 parasites can obtain ATP from either glycolysis or oxidative phosphorylation. This study provides insights into the role of nutrient metabolism during asexual propagation and development of T. gondii, and validates the versatile nature of central carbon and energy metabolism in this parasite.

Sorafenib and praziquantel synergistically attenuate Schistosoma japonicum-induced liver fibrosis in mice

Liver fibrosis is an important process that occurs in most types of chronic liver diseases and often results in the end stage of liver diseases, such as cirrhosis, portal hypertension, and hepatocellular carcinoma. Sorafenib, a multiple tyrosine kinase inhibitor, has been shown to inhibit liver fibrosis in multiple experimental fibrosis mouse and rat models. The aim of this study was to test the therapeutic effect of sorafenib on liver fibrosis induced by infection with a parasite, Schistosoma japonicum, in mice. Mice were percutaneously infected through the abdomen with Schistosoma cercariae to develop a schistosomula liver fibrosis model. Eight weeks after infection, infected mice were treated with the anti-parasitic agent praziquantel for 2 days and sorafenib for 2 weeks. Hepatic histopathological changes were assessed using hematoxylin and eosin (HE) and Masson's trichome staining. The hepatic expression levels of collagen I, collagen III, alpha-smooth muscle actin (α-SMA), platelet-derived growth factor (PDGF), and PDGF receptor-beta (PDGFR-β) were analyzed by immunohistochemistry and western blot. Praziquantel administration alone but not sorafenib reduced liver fibrosis, and the combination of praziquantel and sorafenib significantly attenuated liver fibrosis in S. japonicum-infected mice. Moreover, sorafenib plus praziquantel markedly decreased the hepatic deposition of collagen and expression of fibrogenic genes in these mice. In conclusion, the use of sorafenib following praziquantel treatment may represent a potential therapeutic strategy for liver fibrosis induced by S. japonicum in patients.

[The establishment of the immortalized mouse brain microvascular pericytes model and its preliminary application in screening of cerebrovascular toxicants]

Objective: To establish the immortalized mouse brain microvascular pericytes model and to apply to the cerebrovascular toxicants screening study. Methods: Brain pericytes were isolated from 3 weeks of mice by tissue digestion. Immortalized pericyte cell line was constructed by infecting with LT retrovirus. Monoclone was selected to purify the immortalized pericyte cell line. The pericyte characteristics and purity were explored by immunocytochemistry. Cell proliferation was measured by using the Pomega MTS cell Proliferation Colorimetric Assay Kit. Pericytes were treated with 0, 160, 320, 640, 1 280, 2 560 μmol/L lead acetate, 0, 5, 10, 20, 40, 80 μmol/L cadmium chloride and 0, 5, 10, 20, 40, 80 μmol/L sodium arsenite in 24 hours. Cell toxicity of each group was determined by MTS assay, median lethal dose (LD(50)) was calculated in linear regression. Results: Mouse brain pericytes were successfully isolated by tissue separation and enzyme digestion method. After immortalized by LT retroviruses, monoclone was selected and expanded to establish pericyte cell line. The brain pericytes exhibited typical long spindle morphology and positive staining for α-SMA and Vimentin. The proliferation of brain pericytes cell lines was very slowly, and the doubling time was about 48 hours. The proliferation of immortalized brain pericytes cell lines was very quickly, and the doubling time was about 24 hours. After lead acetate, cadmium chloride and sodium arsenite treatment for 24 hours respectively, gradual declines in cell viability were observed. The LD(50) of lead acetate was 2 025.0 μmol/L, the LD(50) of cadmium chloride was 36.6 μmol/L, and the LD(50) of sodium arsenite was 33.2 μmol/L. Conclusion: The immortalized mouse brain microvascular pericyte model is established successfully by infecting with LT retrovirus, and can be applied to screen cerebrovascular toxicants. The toxicity of these toxicants to immortalized mouse brain microvascular pericyte is in sequence: sodium arsenite,cadmium chloride, lead acetate.

Novel Fiber-Optic Ring Acoustic Emission Sensor

Acoustic emission technology has been applied to many fields for many years. However, the conventional piezoelectric acoustic emission sensors cannot be used in extreme environments, such as those with heavy electromagnetic interference, high pressure, or strong corrosion. In this paper, a novel fiber-optic ring acoustic emission sensor is proposed. The sensor exhibits high sensitivity, anti-electromagnetic interference, and corrosion resistance. First, the principle of a novel fiber-optic ring sensor is introduced. Different from piezoelectric and other fiber acoustic emission sensors, this novel sensor includes both a sensing skeleton and a sensing fiber. Second, a heterodyne interferometric demodulating method is presented. In addition, a fiber-optic ring sensor acoustic emission system is built based on this method. Finally, fiber-optic ring acoustic emission experiments are performed. The novel fiber-optic ring sensor is glued onto the surface of an aluminum plate. The 150 kHz standard continuous sinusoidal signals and broken lead signals are successfully detected by the novel fiber-optic ring acoustic emission sensor. In addition, comparison to the piezoelectric acoustic emission sensor is performed, which shows the availability and reliability of the novel fiber-optic ring acoustic emission sensor. In the future, this novel fiber-optic ring acoustic emission sensor will provide a new route to acoustic emission detection in harsh environments.

Identification of the internal ribosome entry sites (IRES) of prion protein gene

Many studies demonstrated that there are several type bands of prion protein in cells. However, the formation of different prion protein bands is elusive. After several low molecular weight bands of prion protein appeared in SMB-S15 cells infected with scrapie agent Chandler, we think that IRES-dependent translation mechanism induced by prion is involved in the formation of prion protein bands. Then we designed a series of pPrP-GFP fusing plasmids and bicistronic plasmids to identify the IRES sites of prion protein gene and found 3 IRES sites inside of PrP mRNA. We also demonstrated that cap-independent translation of PrP was associated with the ER stress through Tunicamycin treatment. We still found that only IRE1 and PERK pathway regulated the IRES-dependent translation of PrP in this study. Our results indicated, we found that PrP gene had an IRES-dependent translation initiation mechanism and we successfully identified the IRESs inside of the prion protein gene.

Butyric acid regulates progesterone and estradiol secretion via cAMP signaling pathway in porcine granulosa cells

Butyric acid (BA), one of the short chain fatty acids (SCFAs), has positive actions on the metabolism, inflammation, etc. However, whether it influences the reproductive physiology and if so the detail mechanism involved has not yet been determined. In this study, the porcine granulosa cells (PGCs) were treated with gradient concentrations of BA. After 24h culture, 0.05mM BA significantly stimulated the progesterone (P₄) secretion (P<0.05), 5mM and 10mM BA significantly inhibited the P₄ secretion (P<0.05). Simultaneously, BA up-regulated the estradiol (E₂) secretion in a dose dependent manner, 5mM and 10mM BA significantly promoted the E₂ level (P<0.05). In addition, 10mM BA significantly promoted the G-protein-coupled receptor 41/43 mRNA (P<0.05). Interestingly, 5mM BA treatment significantly down-regulated cyclic adenosine monophosphate (cAMP) content (P<0.05), steroidogenic acute regulatory (StAR), steroidogenic factor 1 (SF1), P450scc in the mRNA and/or protein level (P<0.05), and these actions were reversed by cAMP activator forskolin (FK). Moreover, the co-treatment of 5mM BA and bupivacaine (BPC, the cAMP inhibitor) significantly accumulated the inhibition action of BPC on cAMP, the secretion of P₄, and the abundance of StAR mRNA (P<0.05), inhibited the up-regulation of 5mM BA on the E₂ secretion (P<0.05). Further, the Global Proteome and KEGG pathway analysis found that 5mM BA significantly up-regulated the I3LM80 proteins (P<0.05), which is involved in the steroid biosynthesis signaling pathway. 5mM BA significantly decreased the F2Z5G3 protein level (P<0.05), and the cAMP signaling pathway. In conclusion, present findings for the first time demonstrated that BA could regulate the P₄ and E₂ hormone synthesis in PGCs via the cAMP signaling pathway.

Draft genome of the honey bee ectoparasitic mite, Tropilaelaps mercedesae, is shaped by the parasitic life history

The number of managed honey bee colonies has considerably decreased in many developed countries in recent years and ectoparasitic mites are considered as major threats to honey bee colonies and health. However, their general biology remains poorly understood. We sequenced the genome of Tropilaelaps mercedesae, the prevalent ectoparasitic mite infesting honey bees in Asia, and predicted 15 190 protein-coding genes that were well supported by the mite transcriptomes and proteomic data. Although amino acid substitutions have been accelerated within the conserved core genes of two mites, T. mercedesae and Metaseiulus occidentalis, T. mercedesae has undergone the least gene family expansion and contraction between the seven arthropods we tested. The number of sensory system genes has been dramatically reduced, but T. mercedesae contains all gene sets required to detoxify xenobiotics. T. mercedesae is closely associated with a symbiotic bacterium (Rickettsiella grylli-like) and Deformed Wing Virus, the most prevalent honey bee virus. T. mercedesae has a very specialized life history and habitat as the ectoparasitic mite strictly depends on the honey bee inside a stable colony. Thus, comparison of the genome and transcriptome sequences with those of a tick and free-living mites has revealed the specific features of the genome shaped by interaction with the honey bee and colony environment. Genome and transcriptome sequences of T. mercedesae, as well as Varroa destructor (another globally prevalent ectoparasitic mite of honey bee), not only provide insights into the mite biology, but may also help to develop measures to control the most serious pests of the honey bee.

Fractal features of soil particle size distribution under different land-use patterns in the alluvial fans of collapsing gullies in the hilly granitic region of southern China

Collapsing gullies are among the most severe soil erosion problems in the tropical and subtropical areas of southern China. However, few studies have examined the relationship of soil particle size distribution (PSD) changes with land-use patterns in the alluvial fans of collapsing gullies. Recently, the fractal method has been applied to estimate soil structure and has proven to be an effective tool in analyzing soil properties and their relationships with other eco-environmental factors. In this study, the soil fractal dimension (D), physico-chemical properties and their relationship with different land-use patterns in alluvial fans were investigated in an experiment that involved seven collapsing gully areas in seven counties of southern China. Our results demonstrated that different land-use patterns of alluvial fans had a significant effect on soil physico-chemical properties. Compared to grasslands and woodlands, farmlands and orchards generally contained more fine soil particles (silt and clay) and fewer coarse particles, whereas significant differences were found in the fractal dimension of soil PSD in different land-use patterns. Specifically, the soil fractal dimension was lower in grasslands and higher in orchards relative to that of other land-use patterns. The average soil fractal dimension of grasslands had a value that was 0.08 lower than that of orchards. Bulk density was lower but porosity was higher in farmlands and orchards. Saturated moisture content was lower in woodlands and grasslands, but saturated hydraulic conductivity was higher in all four land-use patterns. Additionally, the fractal dimension had significant linear relationships with the silt, clay and sand contents and soil properties and exhibited a positive correlation with the clay (R2 = 0.976, P<0.001), silt (R2 = 0.578, P<0.01), organic carbon (R2 = 0.777, P<0.001) and saturated water (R2 = 0.639, P<0.01) contents but a negative correlation with gravel content (R2 = 0.494, P<0.01), coarse sand content (R2 = 0.623, P<0.01) and saturated hydraulic conductivity (R2 = 0.788, P<0.001). However, the fractal dimension exhibited no significant correlation with pH, bulk density or total porosity. Furthermore, the second-degree polynomial equation was found to be more adequate for describing the correlations between soil fractal dimension and particle size distribution. The results of this study demonstrate that a fractal dimension analysis of soil particle size distribution is a useful method for the quantitative description of different land-use patterns in the alluvial fans of collapsing gullies in southern China.

A novel solid digestate-derived biochar-Cu NP composite activating H2O2 system for simultaneous adsorption and degradation of tetracycline

Solid digestate, a by-product of anaerobic digestion systems, has led to a range of environmental issues. In the present study, a novel composite based on a solid digestate-biochar-Cu NP composite was synthesized for tetracycline removal from an aqueous medium. The removal efficiency values for tetracycline (200 mg L^-1) were 31.5% and 97.8%, respectively, by the biochar-Cu NP composite (0.5 g L^-1) in the absence and presence of hydrogen peroxide (H₂O₂, 20 mM) within 6 h of reaction time. The possible degradation pathway of tetracycline was investigated using liquid chromatography-mass spectrometry. The desorption experiment results suggested that no significant concentration of tetracycline was detected on the composite after the reaction, but a small amount of intermediates in terms of total organic carbon (TOC) accounting for 3.1%, and 23.3% of the end-product NH₄⁺ was adsorbed onto the biochar sheets. The dispersive Cu NPs on the biochar resulted in an increase in the surface area and pore volume of the biochar-Cu NP composite, which enhanced tetracycline adsorption as well as the degradation efficiency. Relative tetracycline removal mechanisms were dominantly ascribed to ·OH generation from the Cu(II)/Cu(I) redox reaction with H₂O₂ and the electron-transfer process of free radicals (FRs) in biochar. The proposed approach serves dual purposes of waste digestate reuse and treatment of antibiotic pollutants. This study highlights the activation of H₂O₂ by the dispersive Cu NPs coupling with biochar derived from a waste solid digestate for tetracycline treatment.

Transcriptomic signatures differentiate survival from fatal outcomes in humans infected with Ebola virus

Background

In 2014, Western Africa experienced an unanticipated explosion of Ebola virus infections. What distinguishes fatal from non-fatal outcomes remains largely unknown, yet is key to optimising personalised treatment strategies. We used transcriptome data for peripheral blood taken from infected and convalescent recovering patients to identify early stage host factors that are associated with acute illness and those that differentiate patient survival from fatality.

Results

The data demonstrate that individuals who succumbed to the disease show stronger upregulation of interferon signalling and acute phase responses compared to survivors during the acute phase of infection. Particularly notable is the strong upregulation of albumin and fibrinogen genes, which suggest significant liver pathology. Cell subtype prediction using messenger RNA expression patterns indicated that NK-cell populations increase in patients who survive infection. By selecting genes whose expression properties discriminated between fatal cases and survivors, we identify a small panel of responding genes that act as strong predictors of patient outcome, independent of viral load.

Conclusions

Transcriptomic analysis of the host response to pathogen infection using blood samples taken during an outbreak situation can provide multiple levels of information on both disease state and mechanisms of pathogenesis. Host biomarkers were identified that provide high predictive value under conditions where other predictors, such as viral load, are poor prognostic indicators. The data suggested that rapid analysis of the host response to infection in an outbreak situation can provide valuable information to guide an understanding of disease outcome and mechanisms of disease.

Electronic supplementary material

The online version of this article (doi:10.1186/s13059-016-1137-3) contains supplementary material, which is available to authorized users.

Dual roles of AQDS as electron shuttles for microbes and dissolved organic matter involved in arsenic and iron mobilization in the arsenic-rich sediment

Microbially-mediated arsenic (As) metabolism and iron (Fe) bioreduction from sediments play crucial roles in global As/Fe cycle, and their mobilization is associated with the various effects within the alliance of "mediator-bacteria-DOM (Dissolved Organic Matter)". The gradient levels (0.05, 0.10 and 1.00mM) of sodium anthraquinone-2,6-disulphonate (AQDS) as a mediator were investigated for their impact on reductive dissolution of As(V) and Fe(III) from arsenic-rich sediment. For the overall performance of AQDS-mediated reductive dissolution on As(V) and Fe(III), a more positive effect resulting from 0.05mM AQDS was observed compared to 0.10mM, whereas an inhibitory effect was observed with 1.00mM. Compared to the biotic supplementation with acetate as electron donors, approximately 13- and 6-fold increased levels of As(III) were released with 0.05 and 0.10mM, respectively, compared to 1.00mM AQDS (107.51μg/L), and approximately 4- and 3-fold increased Fe(II) levels (40.72mg/L) were observed during the same conditions. Multiple-dynamic effects of "bacteria-AQDS-DOM", which result from AQDS, shifted the microbial community and synchronously derived terrestrial DOM, which potentially changes the DOM substrate and complex formation of As(III)-Fe(II)-humic DOM. High-throughput sequencing results indicated an increase in the abundance of metal-reducing bacteria (e.g., Bacillus (>16%), Lactococcus (>13%), Pseudomonas (>4%) and Geobacter (>3%)) when supplemented with 0.05 and 0.10mM of AQDS. However, a boost increasing the abundance of metal oxidizing bacteria was observed with Alicyclobacillus (>16%), Burkholderia (>7%), and Bradyrhizobium (>5%) upon supplementation with 1.00mM AQDS. These novel insights have profound environmental implications and significance in terms of engineering, not only for understanding the cycle of As/Fe in sediment biochemical processes but for considering future alternative bioremediation treatments.

The CD4+ T-lymphocyte count is an important predictor for the prognosis of cryptococcosis

There is great heterogeneity of immunity among patients with cryptococcosis, and severe immunodeficiency can lead to negative clinical outcomes. Underlying disease is a poor surrogate for immune status and inferior in predicting an individual’s prognosis. This study was intended to determine whether T-lymphocyte subgroups would be more suitable indicators regarding the severity of infection and clinical outcomes of such patients. We retrieved clinical data on 101 patients with cryptococcosis and compared the validity of multiple parameters (underlying disease and T-lymphocyte subgroups) in predicting the severity of infection and clinical outcome in these patients. For patients with CD4⁺ T-lymphocyte counts lower than 400/μL, the odds ratio of disseminated cryptococcosis was 23.3 (P = 0.005). There was a moderate negative correlation between CD4⁺ T-cell count and Apache II score (−0.609, P < 0.001). Mortality among patients with low levels of CD4⁺ T lymphocytes was significantly higher than among those with normal levels (23.8% vs 5.3%, P = 0.016). However, the difference was not significant if the patients were grouped by underlying disease (P = 0.067). The CD4⁺ T-lymphocyte count in peripheral blood is a simple and more accurate biomarker for predicting severity of infection and clinical outcome in patients with cryptococcosis.

Ex vivo comparative study on three sinus lift tools for transcrestal detaching maxillary sinus mucosa

The objective of this study was to comparatively evaluate 3 different sinus lift tools, namely umbrella-shaped sinus lift curette YSL-04, our recently designed probe-improved sinus lift curettes, and our newly invented elevator 014, using our previous developed goat ex vivo models for direct visualizing the effectiveness of detaching sinus mucosa in real time. Goat ex vivo models for direct visualizing the effectiveness of detaching sinus mucosa in real time were generated according to our previously developed protocol. The effectiveness for each tool was evaluated through the length of sinus mucosa detached in mesial and distal directions or buccal and palatal directions, and the space volume created by detaching maxillary sinus mucosa in mesial, distal, buccal and palatal directions. The results showed that all 3 sinus lift tools could transcrestally detach the maxillary sinus mucosa and create extra space under the elevated sinus floor on the goat ex vivo sinus models. Moreover, our newly invented elevator 014 had advantages over the other 2 in term of the capability to detach the sinus mucosa. Our newly invented elevator 014 might be a promising tool for detaching maxillary sinus mucosa in transcrestal maxillary sinus floor elevation.

Partial response to imatinib treatment in a patient with unresectable gastrointestinal stromal tumor: A case report and mini literature review

The aim of the present study was to evaluate the efficacy and safety of imatinib mesylate in unresectable gastrointestinal stromal tumor (GIST) and to discuss its therapeutic regimen. A patient with unresectable GIST is described, and several key clinical studies are reviewed, including the clinical trials B2222 and S0033, which contain recently reported results of the long-term clinical outcome of imatinib in patients with unresectable or metastatic GIST. The recent results of the two studies demonstrate the long-term efficacy and safety of imatinib for unresectable or metastatic GIST. A positive response to imatinib treatment was observed in the present patient, which is consistent with the data of the B2222 and S0033 trials. However, further long-term, large-scale, multicenter and controlled trials are required to determine the relative efficacy of combining imatinib agents with surgical procedures or administering imatinib alone.

Secondary sentinel lymph node tracing technique: a new method for tracing lymph nodes in radical gastrectomy for advanced gastric cancer

OBJECTIVE

To explore the feasibility and clinical value of secondary sentinel lymph node (SSLN) tracing technique in radical gastrectomy for advanced gastric cancer (AGC).

METHODS

From January 2009 to June 2011, 247 patients who suffered from gastric angle cancer with metastasis in No. 3 group lymph nodes were divided randomly into groups A and B. Methylthioninium chloride was injected into the peripheral tissue of the metastatic No. 3 group lymph nodes of 138 patients in group A before tumor resections. SSLNs were traced and individual lymphadenectomies were carried out based on the biopsy results of the SSLNs. Standard D2 radical gastrectomies were carried out directly on 109 patients in group B. Postoperative follow-up and survival analysis were carried out for patients in both groups.

RESULTS

SSLNs were found in 114 (82.6%) patients in group A. Ninety of those patients (78.9%) demonstrated existing metastasis in SSLNs. According to Kaplan-Meier's method, the postoperative 3-year cumulative survival rates were 63.5% and 47.5%, and the median survival time were 40 and 36 months for the patients of groups A and B, respectively (P<0.05).

CONCLUSIONS

The SSLN tracing technique is feasible in radical gastrectomy for AGC. It gives surgeons important information about the terminal status of lymph node metastasis and provides some scientific basis for individual lymphadenectomy.

Different Effects of Hypertension and Age on the Function of Large Conductance Calcium- and Voltage-Activated Potassium Channels in Human Mesentery Artery Smooth Muscle Cells

BACKGROUND

Large-conductance calcium- and voltage-activated potassium channels (BKC a channels) play important roles in the maintenance of vascular tone, and their dysregulation is associated with abnormal vascular relaxation and contraction. We tested the changes in BKC a channel properties in patients at different ages to assess the effects of hypertension and aging on the functional changes of BKC a channels.

METHODS AND RESULTS

Patch clamp was performed to detect the activities of BKC a channels in freshly isolated human mesenteric artery smooth muscle cells from younger patients (aged ≤45 years) without hypertension, older patients (aged ≥65 years) without hypertension, and older patients with hypertension. The expression of mRNA and protein from BKC a channels was evaluated by reverse transcription polymerase chain reaction and Western blot analysis, respectively. Results showed that the whole-cell current density, spontaneous transient outward current, and Ca(2+) sensitivity of the artery smooth muscle cells were significantly decreased in the older patients with hypertension; the decreases were insignificant in the older patients without hypertension, although a clear tendency to have spontaneous transient outward current was detected in these patients. The expression of both mRNA and protein of BKC a subunits α and β1 was significantly decreased in the older patients with hypertension but not in the older patients without hypertension compared with the younger patients without hypertension.

CONCLUSIONS

Our findings demonstrate for the first time that hypertension is an important factor for the pathological alteration of the properties of BKC a channels in human mesenteric artery smooth muscle cells, and aging itself may also be a factor in these changes in the cells.

Stage-specific Proteomes from Onchocerca ochengi, Sister Species of the Human River Blindness Parasite, Uncover Adaptations to a Nodular Lifestyle

Despite 40 years of control efforts, onchocerciasis (river blindness) remains one of the most important neglected tropical diseases, with 17 million people affected. The etiological agent, Onchocerca volvulus, is a filarial nematode with a complex lifecycle involving several distinct stages in the definitive host and blackfly vector. The challenges of obtaining sufficient material have prevented high-throughput studies and the development of novel strategies for disease control and diagnosis. Here, we utilize the closest relative of O. volvulus, the bovine parasite Onchocerca ochengi, to compare stage-specific proteomes and host-parasite interactions within the secretome. We identified a total of 4260 unique O. ochengi proteins from adult males and females, infective larvae, intrauterine microfilariae, and fluid from intradermal nodules. In addition, 135 proteins were detected from the obligate Wolbachia symbiont. Observed protein families that were enriched in all whole body extracts relative to the complete search database included immunoglobulin-domain proteins, whereas redox and detoxification enzymes and proteins involved in intracellular transport displayed stage-specific overrepresentation. Unexpectedly, the larval stages exhibited enrichment for several mitochondrial-related protein families, including members of peptidase family M16 and proteins which mediate mitochondrial fission and fusion. Quantification of proteins across the lifecycle using the Hi-3 approach supported these qualitative analyses. In nodule fluid, we identified 94 O. ochengi secreted proteins, including homologs of transforming growth factor-β and a second member of a novel 6-ShK toxin domain family, which was originally described from a model filarial nematode (Litomosoides sigmodontis). Strikingly, the 498 bovine proteins identified in nodule fluid were strongly dominated by antimicrobial proteins, especially cathelicidins. This first high-throughput analysis of an Onchocerca spp. proteome across the lifecycle highlights its profound complexity and emphasizes the extremely close relationship between O. ochengi and O. volvulus The insights presented here provide new candidates for vaccine development, drug targeting and diagnostic biomarkers.

Enhanced bioreduction of iron and arsenic in sediment by biochar amendment influencing microbial community composition and dissolved organic matter content and composition

Biochar derived from the pyrolysis at 500 °C with fresh biogas slurry and residue, was conducted to investigate its potential role in mediating the speciation and mobilization of As(V) and Fe(III) from arsenic-contaminated tailing mine sediment, with consideration of the changes in microbial populations and dissolved organic matter (DOM). The reduction of As(V) (10-13%) and Fe(III) (12-17%) were partly in response to biochar abiotically causing desorption and reduction effect, but were predominantly (87-90% and 83-88% for As(V) and Fe(III)) attributed to biochar stimulating biological reduction. The level of As(III) released from sediment upon biochar amendment (656.35±89.25 μg L(-1)) was significantly higher than the level released without biochar amendment (98.06±19.38 μg L(-1)) after 49 days incubation. Although a low level of Fe(II) (0.81±0.07 mg L(-1)) was determined in the solution when amending with biochar, most of released Fe(II) (166.25±40.25 mg L(-1)) was formed as biochar-Fe(II)minerals composite. More importantly, biochar stimulated the DOM bioavailability in association with bacterial activities mediating As(V) and Fe(III) reduction. High-throughput sequencing results indicated biochar application shifted the soil microbial community and increased the relative abundance of As(V)-/Fe(III)-reducing bacteria, mostly Geobacter, Anaeromyxobacter, Desulfosporosinus and Pedobacter. The discovery of biochar-bacteria-DOM consortium may broaden new understanding into speciation and mobilization of metals, which arouses attention to exploit feasible bioremediation for metal-contaminated sediment.

The proteome of the infectious bronchitis virus Beau-R virion

Infectious bronchitis is a highly contagious respiratory disease of poultry caused by the coronavirus infectious bronchitis virus (IBV). It was thought that coronavirus virions were composed of three major viral structural proteins until investigations of other coronaviruses showed that the virions also include viral non-structural and genus-specific accessory proteins as well as host-cell proteins. To study the proteome of IBV virions, virus was grown in embryonated chicken eggs, purified by sucrose-gradient ultracentrifugation and analysed by mass spectrometry. Analysis of three preparations of purified IBV yielded the three expected structural proteins plus 35 additional virion-associated host proteins. The virion-associated host proteins had a diverse range of functional attributions, being involved in cytoskeleton formation, RNA binding and protein folding pathways. Some of these proteins were unique to this study, while others were found to be orthologous to proteins identified in severe acute respiratory syndrome coronavirus virions and also virions from a number of other RNA and DNA viruses.