Versatile Protein-A Coated Photoelectric Immunosensors with a Purple-Membrane Monolayer Transducer Fabricated by Affinity-Immobilization on a Graphene-Oxide Complexed Linker and by Shear Flow.

Bacteriorhodopsin-embedded purple membranes (PM) have been demonstrated to be a sensitive photoelectric transducer for microbial detection. To efficiently prepare versatile BR-based immunosensors with protein A as antibody captures, a large, high-coverage, and uniformly oriented PM monolayer was fabricated on an electrode as an effective foundation for protein A conjugation through bis-NHS esters, by first affinity-coating biotinylated PM on an aminated surface using a complex of oxidized avidin and graphene oxide as the planar linker and then washing the coating with a shear flow. Three different polyclonal antibodies, each against Escherichia coli, Lactobacillus acidophilus, and Streptococcus mutans, respectively, were individually, effectively and readily adsorbed on the protein A coated electrodes, leading to selective and sensitive quantitative detection of their respective target cells in a single step without any labeling. A single-cell detection limit was achieved for the former two cells. AFM, photocurrent, and Raman analyses all displayed each fabricated layer as well as the captured bacteria, with AFM particularly revealing the formation of a massive continuous PM monolayer on aminated mica. The facile cell-membrane monolayer fabrication and membrane surface conjugation techniques disclosed in this study may be widely applied to the preparation of different biomembrane-based biosensors.

EGR3 Inhibits Tumor Progression by Inducing Schwann Cell-Like Differentiation.

The mechanism and function of the expression of Schwann characteristics by nevus cells in the mature zone of the dermis are unknown. Early growth response 3 (EGR3) induces Schwann cell-like differentiation of melanoma cells by simulating the process of nevus maturation, which leads to a strong phenotypic transformation of the cells, including the formation of long protrusions and a decrease in cell motility, proliferation, and melanin production. Meanwhile, EGR3 regulates the levels of myelin protein zero (MPZ) and collagen type I alpha 1 chain (COL1A1) through SRY-box transcription factor 10 (SOX10)-dependent and independent mechanisms, by binding to non-strictly conserved motifs, respectively. Schwann cell-like differentiation demonstrates significant benefits in both in vivo and clinical studies. Finally, a CD86-P2A-EGR3 recombinant mRNA vaccine is developed which leads to tumor control through forced cell differentiation and enhanced immune infiltration. Together, these data support further development of the recombinant mRNA as a treatment for cancer.

Natural isoflavone formononetin inhibits IgE-mediated mast cell activation and allergic inflammation by increasing IgE receptor degradation.

Immunoglobulin (Ig)E-associated mast cell (MC) activation triggers pro-inflammatory signals that underlie type I allergic diseases. Here, we examined the effects of the natural isoflavone formononetin (FNT) on IgE-mediated MC activation and associated mechanisms of high-affinity IgE receptor (FcεRI) signal inhibition. The effects of FNT on the mRNA expression of inflammatory factors, release of histamine and ß-hexosaminidase (ß-hex), and expression of signaling proteins and ubiquitin (Ub)-specific proteases (USPs) were analyzed in two sensitized/stimulated MC lines. FcεRIγ-USP interactions were detected by co-immunoprecipitation (IP). FNT dose-dependently inhibited ß-hex activity, histamine release, and inflammatory cytokine expression in FcεRI-activated MCs. FNT suppressed IgE-induced NF-κB and MAPK activity in MCs. The oral administration of FNT attenuated passive cutaneous anaphylaxis (PCA) reactions and ovalbumin (OVA)-induced active systemic anaphylaxis (ASA) reactions in mice. FNT reduced the FcεRIγ chain expression, via increased proteasome-mediated degradation, and induced FcεRIγ ubiquitination by inhibiting USP5 and/or USP13. FNT and USP inhibition may be useful for suppressing IgE-mediated allergic diseases.

HSF4/COIL complex-dependent R-loop mediates ultraviolet-induced inflammatory skin injury.

Intense ultraviolet (UV) exposure can cause phototoxic reactions, such as skin inflammation, resulting in injury. UV is a direct cause of DNA damage, but the mechanisms underlying transcriptional regulation within cells after DNA damage are unclear. The bioinformatics analysis of transcriptome sequencing data from UV-irradiated and non-UV-irradiated skin showed that transcription-related proteins, such as HSF4 and COIL, mediate cellular response to UV irradiation. HSF4 and COIL can form a complex under UV irradiation, and the preference for binding target genes changed because of the presence of a large number of R-loops in cells under UV irradiation and the ability of COIL to recognize R-loops. The regulation of target genes was altered by the HSF4-COIL complex, and the expression of inflammation and ageing-related genes, such as Atg7, Tfpi, and Lims1, was enhanced. A drug screen was performed for the recognition sites of COIL and R-loop. N6-(2-hydroxyethyl)-adenosine can competitively bind COIL and inhibit the binding of COIL to the R-loop. Thus, the activation of downstream inflammation-related genes and inflammatory skin injury was inhibited.

The Relationship between Patterns of Remodeling and Degree of Enhancement in Patients with Atherosclerotic Middle Cerebral Artery Stenosis: A High-Resolution MRI Study.

PURPOSE: The aim of this research was to investigate the relationship between remodeling patterns and degree of enhancement in patients with atherosclerotic middle cerebral artery (MCA) stenosis using high-resolution magnetic resonance imaging (HR-MRI). MATERIALS AND METHODS: From August 2015 to May 2016, 38 consecutive patients with unilateral MCA stenosis on time-of-flight (TOF) MR angiography were prospectively enrolled. The routine MR scan and cross-sectional images of the stenotic MCA vessel wall on HR-MRI were performed in all patients. Among them, 17 patients displayed positive remodeling (PR) and the other 21 patients displayed negative remodeling or non-remodeling (non-PR). The patients displaying hyperintense on diffusion-weighted imaging (DWI) in the territory of ipsilateral stenotic MCA were considered to have had acute stroke. Subsequently, the differences in the degree of enhancement and the number of acute stroke patients between the PR group and the non-PR group were compared. The Spearman rank correlation analysis of the enhancement degree (ED) and the remodeling index (RI) was calculated. Then, receiver operating curve (ROC) was used to evaluate diagnostic efficiency of RI and ED for acute infarction. RESULTS: The PR group had more obvious enhancement plaques than the non-PR group (10 versus 3, P = 0.006). The PR group also had a larger number of acute stroke patients than the non-PR group (15 versus 4, P = 0.000). The spear-man rank correlation analysis showed that the degree of enhancement had a weak positive correlation with the remodeling index (r = 0.379, P = 0.019). The area under the curve (AUC) of RI and ED was higher than that of RI (0.924: 0.842). CONCLUSION: The PR, obvious enhancement predicted vulnerable plaques that were more prone to causing acute stroke. RI and ED had valuable diagnostic efficiency for acute infarction.

[Magnetic resonance signal detection of superparamagnetic iron oxide nanoparticles and its biological effects on endothelial cells].

OBJECTIVE: To investigate the magnetic resonance (MR) signal changes of superparamagnetic iron oxide (SPIO) and its biological effects on endothelial cells. METHODS: The citric-acid coated SPIO was synthesized by co-precipitation method. The human umbilical vein endothelial cells (HUVECs) were incubated with SPIO for 24 h in culture medium at iron concentration of 0.01, 0.05, 0.10, 0.15 mg/ml (experimental groups), and the cells incubated without SPIO served as control groups. The uptake efficiency of intracellular iron was measured by Prussian blue staining, and the cell viability was monitored by Calcein-AM method. The cell cytoskeleton (F-actin and tubulin), adherence and migration capacity were measured by immunofluorescence staining. The iron oxide nanoparticles distribution and the cellular organelle change were monitored by transmission electron microscopy (TEM). Quantification of particle uptake was measured by atomic absorption spectrometry. The MR signal of endothelial cells after labeling was monitored by Philips 3.0 T MR scanner. RESULTS: SPIO was uptaken by HUVECs in a concentration-dependence manner. Compared with the control group, cell viability was decreased along with the increase of iron concentration. Compared with the control group, the cell cytoskeleton was markedly disorganized and the FAK spot was bigger and sparser.The nanoparticles were mainly existed in lysosomes, and the higher concentration of SPIO, the more lysosomes and vacuoles presented in the cells. The iron content per cell was (55.86 +/-9.935) pg when the SPIO concentration was 0.15 mg/ml. The MR image showed that the cells labeled with SPIO resulted in the decrease of MR signal. CONCLUSION: The cells labeled with SPIO can be detected by MR. The cell viability, cytoskeleton, adherence and migration capacity of HUVECs are affected by citric-acid coated SPIO in a concentration-dependent manner.

[Effects of curcumin on sarcoplasmic reticulum Ca2+-ATPase in rabbits with heart failure].

OBJECTIVE: To investigate the effects of curcumin on sarcoplasmic reticulum Ca2+-ATPase in heart failure rabbits. METHODS: Rabbit heart failure model was made with aortic regurgitation and abdominal aorta constriction and 40 rabbits were randomly divided into 4 groups including: (1) heart failure treated with curcumin; (2) heart failure treated with placebo; (3) healthy control treated with curcumin and (4) healthy control treated with placebo. All rabbits were administrated with curcumin capsules or placebo capsules 100 mg x kg(-1) x d(-1), respectively. All groups were sacrificed after eight weeks. Myocardial ultrastructural organization was detected by transmission electron microscope. RT-PCR and Western blot were used to measure the expression of sarcoplasmic reticulum Ca2+-ATPase in mRNA and protein levels, respectively. Malachite green colorimetric assay was used to evaluate the activity of sarcoplasmic reticulum Ca2+-ATPase. RESULTS: All detected parameters were similar between control curcumin group and control placebo group. Compared with the control groups (Groups 3 and 4), the heart/body weight ratio was significantly increased in the heart failure-curcumin group (Group 1) and the heart failure-placebo group (Group 2, all P < 0.05), but the ratio was significantly lower in heart failure-curcumin group than in heart failure-placebo group (P < 0.05). The degree of heart failure was decreased by curcumin. Activity and mRNA and protein expression for sarcoplasmic reticulum Ca2+-ATPase were significantly reduced in the heart failure-placebo group and which could be significantly attenuated by curcumin (all P < 0.05). CONCLUSION: Curcumin could improve cardiac function via upregulating the expression of sarcoplasmic reticulum Ca2+-ATPase in this model.

Antiplatelet drug ticagrelor delays gastric ulcer healing in rats.

Adenosine diphosphate P2Y12 receptor antagonist clopidogrel is not sufficiently safe for the gastric mucosa in patients with high risk of peptic ulcer, since it may impair healing of gastric erosions. However, the safety of the novel P2Y12 receptor antagonist ticagrelor in the gastric mucosa has not been elucidated to date. The present study aimed to examine whether ticagrelor delays gastric ulcer healing and to elucidate the involved mechanisms. Gastric kissing ulcers were produced in rats by luminal application of acetic acid solution, and ticagrelor was administered at dose of 10 or 20 mg/kg/day orally for 7 days. On day 8 after ulcer induction, the ulcer size, mucosal epithelial cell proliferation of the ulcer margin, expression levels of epidermal growth factor (EGF) and vascular endothelial growth factor (VEGF), and signal transduction pathways for cell proliferation and angiogenesis were measured and compared between the ticagrelor-treated and untreated model groups. The results revealed that the ulcer size was significantly greater in the ticagrelor-treated group compared with the model group, while the mucosal epithelial cell proliferation of the ulcer margin was significantly decreased in the ticagrelor-treated group. In addition, ticagrelor significantly decreased the ulcer-stimulated expression levels of EGF, VEGF, phosphorylated extracellular signal-regulated kinase (ERK), phosphorylated P38 mitogen-activated protein kinase and nuclear factor-κB P65 at the ulcer margin (P<0.05). These findings suggested that ticagrelor delayed gastric ulcer healing. Furthermore, the possible mechanisms underlying the effect of ticagrelor were associated with its functions of attenuating the expression levels of VEGF and EGF, as well as suppressing the phosphorylation activation of ERK1/2, P38 and nuclear factor-κB P65. Finally, the gastric epithelial cell proliferation and angiogenesis were also inhibited.

High-sensitivity cardiac troponin T: A biomarker for the early risk stratification of type-A acute aortic dissection?

BACKGROUND: High-sensitivity cardiac troponin is the most specific and sensitive biomarker of myocardial injury. However, no study has investigated whether the early concentration of high-sensitivity cardiac troponin is increased or is of value in predicting short-term prognosis in patients with type-A acute aortic dissection (AAD) in the emergency department. AIMS: To measure the high-sensitivity cardiac troponin T (hs-TnT) concentration in patients with type-A AAD upon hospital admission, and to assess its value in predicting short-term prognosis. METHODS: We enrolled consecutive patients with type-A AAD. Blood samples were collected on admission; hs-TnT concentrations were measured on the Elecsys 2010 system. High-sensitivity C-reactive protein (hs-CRP), D-dimer and other biochemical indicators were measured. Patients were divided into two groups according to hs-TnT concentration on admission (< or ≥0.014ng/mL). RESULTS: More than half (61.2%) of the 103 included patients had an hs-TnT concentration ≥0.014ng/mL. hs-TnT concentrations were significantly higher in those who died compared with survivors (0.292±0.516 vs. 0.069±0.154ng/mL; P=0.003). Multivariable Cox regression analysis suggested that hs-TnT is an independent factor for predicting in-hospital mortality risk (odds ratio: 2.202, 95% confidence interval: 1.111-4.367; P=0.024). Kaplan-Meier curves revealed a significant increase in hospital mortality in the hs-TnT(+) group compared with the hs-TnT(-) group (P=0.021). When hs-TnT was ≥0.042ng/mL, the sensitivity and specificity in predicting hospital short-term mortality were 70.8% and 76.4%, respectively. CONCLUSIONS: Our study suggests that hs-TnT concentration could be used as an early biomarker for the risk stratification of patients with type-A AAD in the emergency department; the relationship between hs-TnT concentration and long-term prognosis needs further investigation.