Effects of Antibacterial Peptide Extracted from Bacillus subtilis fmbJ on the Growth, Physiological Response and Disease Resistance of Megalobrama amblycephala

The effects of an antibacterial peptide obtained from Bacillus subtilis fmbJ on growth, serum lysozyme complements 3 and 4, total protein content, aspartate aminotransferase (AST), alanine aminotransferase (ALT), total antioxidative capacity, superoxide dismutase (SOD) activity, malondialdehyde (MDA) content, and disease resistance of Wuchang bream (Megalobrama amblycephala) were examined. Fish were randomly divided into five groups: a control group which was fed a basic diet, and four groups fed the basic diet supplemented with 0.1%, 0.2%, 0.4%, or 0.8% antibacterial peptide. At eight weeks, M. amblycephala fed the diet containing 0.2% antibacterial peptide had higher serum lysozyme activity, complement 3 and 4 contents, and SOD activity than the control fish, but lower serum MDA content and AST activity. Fish fed the 0.4% diet had higher weight gain rate, serum lysozyme activity, complement 4 content, total antioxidative capacity, and total protein than the control, and lower serum ALT activity. Feed conversion ratios of fish fed the 0.2% or 0.4% diets were lower than those of control fish. Artificial infection with Aeromonas hydrophila resulted in 93% cumulative mortality in the control group, and 61-84% in the groups fed the 0.2% or 0.4% diets. The present study suggests that feed supplementation with 0.2-0.4% antibacterial peptides can stimulate immunity, increase resistance to pathogenic infection, and promote growth in M. amblycephala

Levels and clinical significance of the m6A methyltransferase METTL14 in patients with coronary heart disease

ObjectiveTo investigate the association of methyltransferase-like protein 14 (METTL14) expression with coronary heart disease (CHD).MethodsThree hundred and sixteen patients who attended Henan Provincial People's Hospital between June 2019 and February 2021 with principal symptoms of pain or tightness in the chest and who underwent coronary angiography for definitive diagnosis were enrolled. The uric acid, TG, TC, LDL-C, HDL-C, apolipoprotein A1, free fatty acid, lipoprotein a, homocysteine, CRP, and SAA levels were examined. The levels of METTL14, TNF-α, MCP-1, VCAM-1, ICAM-1, and IL-6 were evaluated by ELISA.ResultsPatients with CHD had significantly higher m6A methyltransferase activity. In addition, the incidence of diabetes and hypertension, as well as the concentrations of TC, CRP, and SAA were higher in CHD patients. Patients with coronary lesion branches also had significantly increased TG, LDL-C, CRP, and SAA levels. TNF-α, MCP-1, VCAM-1, ICAM-1, and IL-6 expression was also markedly increased in the CHD group (P < 0.001) as was the expression of METTL14 (P < 0.001). The METTL14 expression levels also differed significantly in relation to the number of branches with lesions (P < 0.01) and were correlated with SAA, VCAM-1, ICAM-1, IL-6, and the Gensini score. ROC curve analyses of METTL14 in CHD indicated an AUC of 0.881 (0.679, 0.894) with a cut-off value of 342.37, a sensitivity of 77%, and a specificity of 84%. MCP-1, VCAM-1, IL-6, SAA, and METTL14 were found to independently predict CHD risk.ConclusionsMETTL14 levels were found to be positively associated with inflammatory markers and to be an independent predictor of CHD risk

Numerical Simulation of the Fracture Propagation Mechanism during Supercritical Carbon Dioxide Fracturing in Shale Reservoirs

AbstractTo investigate the fracture propagation mechanism during supercritical CO2 fracturing in shale reservoirs, a numerical model was proposed based on the displacement discontinuity method. The Peng–Robinson equation was introduced to determine the variations in CO2 properties during the fracturing process. Considering natural fracture distribution in shale reservoirs, the fracture propagation mechanisms during supercritical CO2 fracturing in shale reservoirs under different horizontal stress differences and matrix permeabilities were analyzed. The influence of the proportion of CO2 preenergizing on fracture morphology was discussed. The results obtained via numerical simulation show that supercritical CO2 is beneficial to create a more complex fracture network by activating natural fractures under the same horizontal stress difference. CO2 easily penetrates into the matrix near the fracture surfaces, increasing reservoir energy. However, when the permeability of shale reservoirs exceeds 0.04×10−3 μm2, substantial filtration of CO2 into the reservoir matrix occurs near the well bore, limiting the activation of natural fractures around the fracture tip. A higher proportion of CO2 preenergizing during fracturing is conducive to improve the fracture complexity while reducing the fracture aperture

Sublytic C5b-9 Induces Glomerular Mesangial Cell Apoptosis Through miR-3546/SOX4/Survivin Axis in Rat Thy-1 Nephritis

Background/Aims: The activation of complement system and the formation of C5b-9 complex have been confirmed in the glomeruli of patients with mesangioproliferative glomerulonephritis (MsPGN). However, the role and mechanism of C5b-9-induced injury in glomerular mesangial cell (GMC) are poorly understood. Rat Thy-1N is an animal model for studying MsPGN. It has been revealed that the attack of C5b-9 to the GMC in rat Thy-1N is sublytic, and sublytic C5b-9 can cause GMC apoptosis, but the underlying mechanism is not fully elucidated. To explore the role and regulatory mechanism of C5b-9 in MsPGN lesion, we used rat Thy-1N model and first detected the change of microRNA (miRNA) profiles both in Thy-1N rat renal tissues (in vivo) and in the cultured GMCs with sublytic C5b-9 stimulation (in vitro). Then we determined the effect of miR-3546, which increased both in vivo and in vitro, on GMC apoptosis upon sublytic C5b-9 as well as the involved mechanism. Methods: Rat Thy-1N model was established and GMCs were treated with sublytic C5b-9. The rat renal cortex and the stimulated GMCs were obtained for miRNA microarray detection. Subsequently, the increased miRNAs were verified by real-time PCR. Meanwhile, to ascertain the ability of some miRNAs to upregulate cleaved caspase 3 and induce GMC apoptosis, the corresponding miRNA mimics were transfected into GMCs, followed by western blotting (WB) and flow cytometry mesurement. Thereafter, the miR-3546-targeted gene (SOX4) was predicted using bioinformatics approaches, and SOX4 expression in Thy-1N tissues and in the GMCs upon sublytic C5b-9 stimulation or miR-3546 mimic/inhibitor transfection were detected using real-time PCR and WB. To prove that miR-3546 can affect SOX4 gene transcription and SOX4 can regulate survivin expression, dual luciferase reporter assay, real-time PCR, WB and chromatin immunoprecipitation (ChIP) assays were performed. Furthermore, the role of miR-3546/SOX4/survivin axis in the GMC apoptosis induced by sublytic C5b-9 was examined using WB and flow cytometry. Results: Compared with normal renal tissues and untreated GMCs, there were 43 and 62 upregulated miRNAs (> 2-fold) in Thy-1N tissues and sublytic C5b-9-stimulated GMCs respectively. A total of 17 miRNAs were increased both in vivo and in vitro, 11 of which were validated by real-time PCR. Among them, miR-3546 could markedly promote GMC apoptosis and inhibit SOX4 or survivin expression in response to sublytic C5b-9, and either SOX4 or survivin overexpression markedly rescued the GMC apoptosis mediated by miR-3546 mimic. Additionally, SOX4 overexpression could reverse the survivin suppression by miR-3546 mimic, and SOX4 could bind to survivin promoter (-1,278 to -853 nt) and activate survivin gene transcription. Conclusion: MiR-3546/ SOX4/survivin axis has a promoting role in the GMC apoptosis triggered by sublytic C5b-9, and our findings may provide a new insight into the pathogenesis of rat Thy-1N and human MsPGN

Specific Binding and Mineralization of Calcified Surfaces by Small Peptides

Several small (<25aa) peptides have been designed based on the sequence of the dentin phosphoprotein, one of the major noncollagenous proteins thought to be involved in the mineralization of the dentin extracellular matrix during tooth development. These peptides, consisting of multiple repeats of the tripeptide aspartate-serine-serine (DSS), bind with high affinity to calcium phosphate compounds and, when immobilized, can recruit calcium phosphate to peptide-derivatized polystyrene beads or to demineralized human dentin surfaces. The affinity of binding to hydroxyapatite surfaces increases with the number of (DSS)n repeats, and though similar repeated sequences—(NTT)n, (DTT)n, (ETT)n, (NSS)n, (ESS)n, (DAA)n, (ASS)n, and (NAA)n—also showed HA binding activity, it was generally not at the same level as the natural sequence. Binding of the (DSS)n peptides to sectioned human teeth was shown to be tissue-specific, with high levels of binding to the mantle dentin, lower levels of binding to the circumpulpal dentin, and little or no binding to healthy enamel. Phosphorylation of the serines of these peptides was found to affect the avidity, but not the affinity, of binding. The potential utility of these peptides in the detection of carious lesions, the delivery of therapeutic compounds to mineralized tissues, and the modulation of remineralization is discussed

Preliminary clinical study of left ventricular myocardial strain in patients with non-ischemic dilated cardiomyopathy by three-dimensional speckle tracking imaging

<p>Abstract</p> <p>Background</p> <p>Non-ischemic dilated cardiomyopathy (DCM) is the most common cardiomyopathy worldwide, with significant mortality. Correct evaluation of the patient's myocardial function has important clinical significance in the diagnosis, therapeutic effect assessment and prognosis in non-ischemic DCM patients. This study evaluated the feasibility of three-dimensional speckle tracking imaging (3D-STE) for assessment of the left ventricular myocardial strain in patients with non-ischemic dilated cardiomyopathy (DCM).</p> <p>Methods</p> <p>Apical full-volume images were acquired from 65 patients with non-ischemic DCM (DCM group) and 59 age-matched normal controls (NC group), respectively. The following parameters were measured by 3D-STE: the peak systolic radial strain (RS), circumferential strain (CS), longitudinal strain (LS) of each segment. Then all the parameters were compared between the two groups.</p> <p>Results</p> <p>The peak systolic strain in different planes had certain regularities in normal groups, radial strain (RS) was the largest in the mid region, the smallest in the apical region, while circumferential strain (CS) and longitudinal strain (LS) increased from the basal to the apical region. In contrast, the regularity could not be applied to the DCM group. RS, CS, LS were significantly decreased in DCM group as compared with NC group (<it>P </it>< 0.001 for all). The interobserver, intraobserver and test-retest reliability were acceptable.</p> <p>Conclusions</p> <p>3D-STE is a reliable tool for evaluation of left ventricular myocardial strain in patients with non-ischemic DCM, with huge advantage in clinical application.</p

Rapid Probing of Biological Surfaces with a Sparse-Matrix Peptide Library

Finding unique peptides to target specific biological surfaces is crucial to basic research and technology development, though methods based on biological arrays or large libraries limit the speed and ease with which these necessary compounds can be found. We reasoned that because biological surfaces, such as cell surfaces, mineralized tissues, and various extracellular matrices have unique molecular compositions, they present unique physicochemical signatures to the surrounding medium which could be probed by peptides with appropriately corresponding physicochemical properties. To test this hypothesis, a naïve pilot library of 36 peptides, varying in their hydrophobicity and charge, was arranged in a two-dimensional matrix and screened against various biological surfaces. While the number of peptides in the matrix library was very small, we obtained “hits” against all biological surfaces probed. Sequence refinement of the “hits” led to peptides with markedly higher specificity and binding activity against screened biological surfaces. Genetic studies revealed that peptide binding to bacteria was mediated, at least in some cases, by specific cell-surface molecules, while examination of human tooth sections showed that this method can be used to derive peptides with highly specific binding to human tissue

PMRD: plant microRNA database

MicroRNAs (miRNA) are ∼21 nucleotide-long non-coding small RNAs, which function as post-transcriptional regulators in eukaryotes. miRNAs play essential roles in regulating plant growth and development. In recent years, research into the mechanism and consequences of miRNA action has made great progress. With whole genome sequence available in such plants as Arabidopsis thaliana, Oryza sativa, Populus trichocarpa, Glycine max, etc., it is desirable to develop a plant miRNA database through the integration of large amounts of information about publicly deposited miRNA data. The plant miRNA database (PMRD) integrates available plant miRNA data deposited in public databases, gleaned from the recent literature, and data generated in-house. This database contains sequence information, secondary structure, target genes, expression profiles and a genome browser. In total, there are 8433 miRNAs collected from 121 plant species in PMRD, including model plants and major crops such as Arabidopsis, rice, wheat, soybean, maize, sorghum, barley, etc. For Arabidopsis, rice, poplar, soybean, cotton, medicago and maize, we included the possible target genes for each miRNA with a predicted interaction site in the database. Furthermore, we provided miRNA expression profiles in the PMRD, including our local rice oxidative stress related microarray data (LC Sciences miRPlants_10.1) and the recently published microarray data for poplar, Arabidopsis, tomato, maize and rice. The PMRD database was constructed by open source technology utilizing a user-friendly web interface, and multiple search tools. The PMRD is freely available at http://bioinformatics.cau.edu.cn/PMRD. We expect PMRD to be a useful tool for scientists in the miRNA field in order to study the function of miRNAs and their target genes, especially in model plants and major crops

Single nucleotide polymorphisms at the TRAF1/C5 locus are associated with rheumatoid arthritis in a Han Chinese population

<p>Abstract</p> <p>Background</p> <p>Genetic variants in <it>TRAF1C5 </it>and <it>PTPN22 </it>genes have been shown to be significantly associated with arthritis rheumatoid in Caucasian populations. This study investigated the association between single nucleotide polymorphisms (SNPs) in <it>TRAF1/C5 </it>and <it>PTPN22 </it>genes and rheumatoid arthritis (RA) in a Han Chinese population. We genotyped SNPs rs3761847 and rs7021206 at the <it>TRAF1/C5 </it>locus and rs2476601 SNP in the <it>PTPN22 </it>gene in a Han Chinese cohort composed of 576 patients with RA and 689 controls. The concentrations of anti-cyclic citrullinated peptide antibodies (CCP) and rheumatoid factor (RF) were determined for all affected patients. The difference between the cases and the controls was compared using <it>χ</it>²analysis.</p> <p>Results</p> <p>Significant differences in SNPs rs3761847 and rs7021206 at <it>TRAF1/C5 </it>were observed between the case and control groups in this cohort; the allelic p-value was 0.0018 with an odds ratio of 1.28 for rs3761847 and 0.005 with an odds ratio of 1.27 for rs7021206. This significant association between rs3761847 and RA was independent of the concentrations of anti-CCP and RF. No polymorphism of rs2476601 was observed in this cohort.</p> <p>Conclusions</p> <p>We first demonstrated that genetic variants at the <it>TRAF1/C5 </it>locus are significantly associated with RA in Han Chinese, suggesting that <it>TRAF1/C5 </it>may play a role in the development of RA in this population, which expands the pathogenesis role of <it>TRAF1/C5 </it>in a different ethnicity.</p