Foxp3+ Treg control allergic skin inflammation by restricting IFN-γ-driven neutrophilic infiltration and NETosis.

BACKGROUND: Atopic dermatitis (AD), a chronic inflammatory skin disease with T cell activation as a key feature, in which Th2 cell-mediated responses play a pivotal role. Regulatory T cells (Treg) are central immune cells that restrict autoimmunity and inflammation in the body. Patients with immune dysregulation, polyendocrinopathy, or enteropathy X-linked syndrome, an immune disease characterized by a deficiency in Treg, develop skin inflammation and allergic disorders, indicating that Treg play a crucial role in the development of allergic skin inflammation. OBJECTIVE: we investigated the underlying mechanisms by which Treg control cutaneous allergic inflammation. METHODS: An allergic skin inflammation mouse model was constructed using MC903, and Treg-depleted mouse model was constructed using diphtheria toxin. Neutralization of IFN-γ was constructed using anti-mouse-IFN-γ mouse antibody. Neutrophil infiltration was analyzed by flow cytometry and immunohistochemistry. Neutrophil extracellular traps (NETs), a process called NETosis, were detected using immunofluorescence. In vitro neutrophil stimulation and immunocytochemistry was conducted to demonstrate the effect of IFN-γ on NETosis. RESULTS: The depletion of Foxp3+ Treg led to significantly exacerbated AD-like skin inflammation, including increased recruitment of neutrophils and expression of Th1 cytokine IFN-γ. Neutrophil infiltrating in skin of Treg-depleted mice released more NETs than wild type. Neutralization of IFN-γ abolished neutrophil infiltration and NETosis in Treg-depleted mice. Neutrophils stimulated with IFN-γ were more prone to release NETs in vitro. Finally, Foxp3+ Treg control cutaneous allergic inflammation by regulating IFN-γ-driven neutrophilic infiltration and NETosis. CONCLUSION: Our results highlight the previously underestimated Treg-IFN-γ-neutrophil inflammatory axis.

Trinickia violacea sp. nov. and Trinickia terrae sp. nov., isolated from forest soil.

Two Gram-stain negative, aerobic and rod-shaped bacterial strains, DHOD12T and 7GSK02T, were isolated from forest soil of Dinghushan Biosphere Reserve, Guangdong Province, PR China. Strain DHOD12T grew at 4-42 °C (optimum, 28-33 °C), pH 4.0-8.5 (optimum, pH 5.5-6.5) and in the presence of 0-1.5 % (w/v; optimum, 0-0.5 %)NaCl; while strain 7GSK02T grew at 12-42 °C (optimum, 28-33 °C), pH 4.0-8.5 (optimum, pH 5.0-6.0) and in the presence of 0-0.5 % (w/v; optimum, 0 %) NaCl. Strains DHOD12T and 7GSK02T had the highest 16S rRNA sequence similarities of 98.0 and 98.3 % with the same species Trinickia mobilis DHG64T, respectively, and 98.4 % between themselves. In the 16S rRNA phylogeny, they formed a clade that was sister to a major cluster consisting of all described Trinickia species. Phylogenomic analyses with the UBCG and PhyloPhlAn methods consistently showed that strains DHOD12T and 7GSK02T formed a clade with T. mobilis DHG64T that was a sister of a cluster containing the remainder of the Trinickia species. The DNA G+C contents of strains DHOD12T and 7GSK02T were 63.1 and 64.6 mol%, respectively. Digital DNA-DNA hybridization and average nucleotide identity values of strains DHOD12T, 7GSK02T and their closely related strains were in the ranges of 21.6-31.4 % and 77.1-86.9 %, respectively. These two strains had the same major respiratory quinone, ubiquinone-8, and both had C16 : 0, C17 : 0 cyclo and summed feature 8 (C18 : 1 ω7c/C18 : 1 ω6c) as their major fatty acids. Their major polar lipids were phosphatidylethanolamine, phosphatidylglycerol and diphosphatidylglycerol. Genomic analysis indicated that the two strains could have the potential to degrade aromatic compounds like other Trinickia species. On the basis of phenotypic and phylogenetic results, strains DHOD12T and 7GSK02T represent two novel species of the genus Trinickia, for which the names Trinickia violacea sp. nov. (type strain DHOD12T=LMG 30258T=CGMCC 1.15436T) and Trinickia terrae sp. nov. (type strain 7GSK02T=CGMCC 1.15432T=KCTC 62468T) are proposed.

Unraveling the Role of Charge Patterning in the Micellar Structure of Sequence-Defined Amphiphilic Peptoid Oligomers by Molecular Dynamics Simulations.

Electrostatic interactions play a significant role in regulating biological systems and have received increasing attention due to their usefulness in designing advanced stimulus-responsive materials. Polypeptoids are highly tunable N-substituted peptidomimetic polymers that lack backbone hydrogen bonding and chirality. Therefore, polypeptoids are suitable systems to study the effect of noncovalent interactions of substituents without complications of backbone intramolecular and intermolecular hydrogen bonding. In this study, all-atom molecular dynamics (MD) simulations were performed on micelles formed by a series of sequence-defined ionic polypeptoid block copolymers consisting of a hydrophobic segment and a hydrophilic segment in an aqueous solution. By combining the results from MD simulations and experimental small-angle neutron scattering data, further insights were gained into the internal structure of the formed polypeptoid micelles, which is not always directly accessible from experiments. In addition, information was gained into the physics of the noncovalent interactions responsible for the self-assembly of weakly charged polypeptoids in an aqueous solution. While the aggregation number is governed by electrostatic repulsion of the negatively charged carboxylate (COO-) substituents on the polypeptoid chain within the micelle, MD simulations indicate that the position of the charge on singly charged chains mediates the shape of the micelle through the charge-dipole interactions between the COO- substituent and the surrounding water. Therefore, the polypeptoid micelles formed from the single-charged series offer the possibility for tailorable micelle shapes. In contrast, the polypeptoid micelles formed from the triple-charged series are characterized by more pronounced electrostatic repulsion that competes with more significant charge-sodium interactions, making it difficult to predict the shape of the micelles. This work has helped further develop design principles for the shape and structure of self-assembled micelles by controlling the position of charged moieties on the backbone of polypeptoid block copolymers.

Complexation of Lignin Dimers with ß-Cyclodextrin and Binding Stability Analysis by ESI-MS, Isothermal Titration Calorimetry, and Molecular Dynamics Simulations.

Lignin derived from lignocellulosic biomass is the largest source of renewable bioaromatics present on earth and requires environmentally sustainable separation strategies to selectively obtain high-value degradation products. Applications of supramolecular interactions have the potential to isolate lignin compounds from biomass degradation fractions by the formation of variable inclusion complexes with cyclodextrins (CDs). CDs are commonly used as selective adsorbents for many applications and can capture guest molecules in their internal hydrophobic cavity. The strength of supramolecular interactions between CDs and lignin model compounds that represent potential lignocellulosic biomass degradation products can be characterized by assessing the thermodynamics of binding stability. Consequently, the inclusion interactions of ß-CD and lignin model compounds G-(ß-O-4')-G, G-(ß-O-4')-truncG (guaiacylglycerol-ß-guaiacyl ether), and G-(ß-ß')-G (pinoresinol) were investigated empirically by electrospray ionization mass spectrometry and isothermal titration calorimetry, complemented by molecular dynamics (MD) simulations. Empirical results indicate that there are substantial differences in binding stability dependent on the linkage type. The lignin model ß-ß' dimer showed more potential bound states including 1:1, 2:1, and 1:2 (guest:host) complexation and, based on binding stability determinations, was consistently the most energetically favorable guest. Empirical results are supported by MD simulations that reveal that the capture of G-(ß-ß')-G by ß-CD is promising with a 66% probability of being bound for G-(ß-O-4')-truncG compared to 88% for G-(ß-ß')-G (unbiased distance trajectory and explicit counting of bound states). These outcomes indicate CDs as a promising material to assist in separations of lignin oligomers from heterogeneous mixtures for the development of environmentally sustainable isolations of lignin compounds from biomass fractions.

Interaction of lignin dimers with model cell membranes: A quartz crystal microbalance and molecular dynamics simulation study.

A study of the interaction between cell membranes and small molecules derived from lignin, a protective phenolic biopolymer found in vascular plants, is crucial for identifying their potential as pharmacological and toxicological agents. In this work, the interactions of model cell membranes [supported 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) lipid bilayers] are compared for three ßO4 dimers of coniferyl alcohol (G lignin monomer): guaiacylglycerol guaiacol ester with a hydroxypropenyl (HOC3H4-) tail (G-ßO4'-G), a truncated GG dimer without HOC3H4- (G-ßO4'-truncG), and a benzylated GG dimer (benzG-ßO4'-G). The uptake of the lignin dimers (per mass of lipid) and the energy dissipation (a measure of bilayer disorder) are higher for benzG-ßO4'-G and G-ßO4'-truncG than those for G-ßO4'-G in the gel-phase DPPC bilayer, as measured using quartz crystal microbalance with dissipation (QCM-D). A similar uptake of G-ßO4'-truncG is observed for a fluid-phase bilayer of 1,2-dioleoyl-sn-glycero-3-phosphocholine, suggesting that the effect of the bilayer phase on dimer uptake is minimal. The effects of increasing lignin dimer concentration are examined through an analysis of density profiles, potential of mean force curves, lipid order parameters, and bilayer area compressibilities (disorder) in the lipid bilayers obtained from molecular dynamics simulations. Dimer distributions and potentials of mean force indicate that the penetration into bilayers is higher for benzG-ßO4'-G and G-ßO4'-truncG than that for G-ßO4'-G, consistent with the QCM-D results. Increased lipid tail disorder due to dimer penetration leads to a thinning and softening of the bilayers. Minor differences in the structure of lignin derivatives (such as truncating the hydroxypropenyl tail) have significant impacts on their ability to penetrate lipid bilayers.

Molecular dynamics simulation study of the positioning and dynamics of α-tocopherol in phospholipid bilayers.

Using molecular dynamics simulations, we investigate the interaction of α-tocopherol (α-toc) with dipalmitoylphosphatidylcholine (DPPC), dimyristoylphosphatidylcholine (DMPC), palmitoyloleoylphosphatidylcholine (POPC), and palmitoyloleoylphosphatidylethanolamine (POPE) lipid bilayers. The goal is to develop a better understanding of the positioning and orientation of α-toc inside the bilayers; properties of significant relevance to α-toc anti-oxidant activity. We investigated bilayer systems with 128 lipids in the presence of either single or 14 α-toc molecules. The single α-toc bilayer systems were investigated via biased MD simulations in which the potential of mean force (PMF) and diffusivity were obtained as functions of the distance between α-toc head group and bilayer center. The higher α-toc concentration systems were investigated with unbiased MD simulations. For all four bilayers at both concentrations, the simulations show that the most probable location of the α-toc hydroxyl group is just below the lipid carbonyl group. Overall, the simulation results are in good agreement with existing experimental data except for the DMPC bilayer system for which some experiments predict α-toc to be located closer to bilayer center. The flip-flop frequency calculated shows that the α-toc flip-flop rate is sensitive to bilayer lipid type. In particular, α-toc has a much lower flip-flop rate in a POPE bilayer compared to the three PC lipid bilayers due to the smaller area per lipid in the POPE bilayer. For DMPC and POPC, the α-toc flip-flop rates are significantly higher at higher α-toc concentration and this appears to be related to the local structural disruption caused by α-toc clusters spanning the bilayer.

Single Nucleotides Moving through Nanoslits Composed of Self-Assembled Monolayers via Equilibrium and Nonequilibrium Molecular Dynamics.

Nonequilibrium molecular dynamics (MD) simulations were used to study the effect of three chemical surface groups on the separation of DNA mononucleotide velocity (or time-of-flight) distributions as they pass through nanoslits. We used nanoslits functionalize with self-assembled monolayers (SAMs) since they have relatively smooth surfaces. The SAM molecules were terminated with either a methyl, methylformyl, or phenoxy group, and the nucleotides were driven electrophoretically with an electric field intensity of 0.1 V/nm in slits about 3 nm wide. Although these large driving forces are physically difficult to achieve experimentally, the simulations are still of great value as they provide molecular level insight into nucleotide translocation events and allow comparison of different surfaces. Nucleotides adsorbed and desorbed from the slit surface multiple times during the simulations. The required slit length for 99% accuracy in identifying the deoxynucleotide monophosphates (dNMPs), based on the separation of the distributions of time of flight, was used to compare the surfaces with shorter lengths indicating more efficient separation. The lengths were 6.5 µm for phenoxy-terminated SAMs, 270 µm for methylformyl-terminated SAMs, and 2400 µm for methyl-terminated SAMs. Our study showed that a slit with a section with methyl termination and the second section with methylformyl termination lead to a required length of 120 µm, which was significantly lower than for only a methylformyl- or methyl-terminated surface.

Clinical Validation of the Chinese Version of Patient Completed Caprini Risk Assessment Form.

To create and validate patient-completed Caprini risk score (CRS) tools for Chinese people. We revised Chinese patient-completed CRS form according to previously published studies. We prospectively recruited 70 internal medical patients and 70 surgical patients. The average age of these patients was 54.26 ± 15.29 years, 54.29% of them were male and 80% of them had education beyond high school. The study compared: (1) patient-completed CRS and physician-completed CRS; (2) the final value of physician-completed CRS (physician-completed CRS + body mass index) and CRS in the electronic medical record (EMR) system. Patient-completed CRS was 3.71 ± 3.63, patients spent 3.60 ± 1.24 minutes, 57.14% patients were at high-highest risk; physician-completed CRS was 3.84 ± 3.63, physicians spent 2.11 ± 1.13 minutes, 59.28% patients were at high-highest risk; the final value of physician-completed CRS was 4.12 ± 3.62, 63.58% patients were at high-highest risk; CRS value in the EMR system was 4.07 ± 3.58, 65% patients were at high-highest risk. There were strong positive correlations (P < .0001) between patient-completed CRS and physician-completed CRS (r = 0.978, κ = 0.76) and between the final value of physician-completed CRS and CRS in EMR (r = 0.994, κ = 0.97). This study successfully developed and validated a Chinese patient-completed CRS that we found can replace physician-completed CRS. This results in considerable time saving for physicians and this process should increase the percentage of patients having complete risk assessment when they are admitted to the hospital.

Experimental and Molecular Dynamics Simulation Study of the Effects of Lignin Dimers on the Gel-to-Fluid Phase Transition in DPPC Bilayers.

High resolution differential scanning calorimetry (DSC) and molecular dynamics (MD) simulations were used to investigate the effect of three lignin dimers on the gel to fluid phase transition in DPPC lipid bilayers. The goal of this research is to begin to understand the partitioning of model lignin dimers into lipid bilayers and its effects on the gel to fluid transition temperature (Tm). The long-term objective is to establish structure-function relationships for well-defined lignin derivatives at biologically relevant surfaces. This work uses a newly synthesized guiacylglycerol guaiacol ester with a hydroxypropenyl (HOC3H4-) group resembling natural lignin (GG dimer), compared with a truncated GG dimer without the HOC3H4- and benzyl-modified GG dimers. The DSC results show that the dimer most like natural lignin (with a hydroxypropenyl tail) has log K = 2.72 ± 0.05, and MD simulations show that it associates with the headgroups of the lipid but does not penetrate strongly into the interior of the bilayer. Therefore, this dimer has little effect on the Tm value. In contrast, the truncated dimer, which has been used as a representative GG dimer in prior studies, partitions into the bilayer, as seen in MD simulations, and shifts Tm because of its increased lipophilicity (DSC log K = 3.45 ± 0.20). Similarly, modification of the natural GG dimer by benzylation of the phenol makes it lipophilic (DSC log K = 3.38 ± 0.28), causing it to partition into the bilayer, as seen in MD simulations and shift Tm. In MD, we capture the transition from gel to fluid phase by defining and analyzing a normalized deuterium order parameter averaged over all carbon atoms located in the middle of the lipid tails. In this way, the phase transition can be clearly observed and, importantly, MD results show the same trend of transition temperature shifts as the DSC results. Furthermore, we compare partition coefficients estimated from free energy profiles calculated in MD to those obtained from experiment and they are in qualitative agreement. The success at predicting the structural effects of lignin dimers on lipid bilayers suggests that MD simulations can be used in the future to screen the interactions of lignin oligomers and their derivatives with lipid bilayers.

The mechanism of formation of thin-walled cystic lung cancer.

Thin-wall cystic lung cancer is becoming of increasing interest in the study of pulmonary medicine. Consequently, more and more different images and pathologic manifestations have been found. The purpose of this article is to find pathologic characteristics and try to explain the formation mechanism of thin-walled cystic lung cancer.Sixty-five patients with this special lung cancer were analyzed retrospectively based on the review of medical records, radiologic findings, and pathologic changes.We found 3 pathologic types: adenocarcinoma, squamous cell carcinoma, and lymphoma. There were 60 cases of adenocarcinoma, 4 cases were squamous cell carcinoma, and only 1 lymphoma. Tumor cells, pulmonary vessels, fibrous tissues, and residual bronchi are the pathologic basis of different image findings.Thin-walled cystic lung cancers are mostly adenocarcinoma, but other pathologic types can also appear, such as squamous cell carcinoma and lymphoma. We can see that a large amount of fibrous tissues were generated by tumors around the bronchus, resulting in airway stenosis and degeneration. Tumor cells also can invade the bronchial wall and cause structural damage. All these lesions are similar to 1-way valves which can cause gas accumulation in the tumor area and result in thin-walled cystic lung cancer.

Risk Assessment in Chinese Hospitalized Patients Comparing the Padua and Caprini Scoring Algorithms.

The current venous thromboembolism (VTE) guidelines recommend all patients to be assessed for the risk of VTE using risk assessment models (RAMs). The study was to evaluate the performance of the Caprini and Padua RAMs among Chinese hospitalized patients. We reviewed data from 189 patients with deep venous thrombosis (DVT) and 201 non-DVT patients. Deep venous thrombosis risk factors were obtained from all patients. The sensitivity and specificity of the Caprini and Padua scores for all patients were calculated. The receiver operating curve (ROC) and the area under the ROC curve (AUC) were used to evaluate the performance of each score. We documented that age, acute infection, prothrombin time (PT), D-dimer, erythrocyte sedimentation rate, blood platelets, and anticoagulation were significantly associated with the occurrence of DVT (P < .05). These results were true for all medical and surgical patients group (G1), as well as the analysis of medical versus surgical patients (G2). Finally, analysis of the scores in patients with and without cancer was also done (G3). The Caprini has a higher sensitivity but a lower specificity than the Padua (P < .05). Caprini has a better predictive ability for the first 2 groups (P < .05). We found Caprini and Padua scores have a similar predictive value for patients with cancer (P > .05), while Caprini has a higher predictive ability for no cancer patients in G3 than Padua (P < .05). For Chinese hospitalized patients, Caprini has a higher sensitivity but a lower specificity than Padua. Overall, Caprini RAM has a better predictive ability than Padua RAM.