Ferroptosis has been shown to mediate the development of fibrosis. Polyphyllin VII (PP7), a bioactive component of Paris polyphylla, exhibits potent anti-inflammatory activity and can significantly alleviate liver fibrosis. In this study, treatment with PP7 significantly inhibited the proliferation and activation of hepatic stellate cells (HSCs), which could be suppressed by a ferroptosis inhibitor. In addition, it promoted HSC ferroptosis by suppressing glutathione (GSH) peroxidase 4 (GPX4) and enhanced the expression of CX3C chemokine ligand 1 (CX3CL1). Depletion of CX3CL1 attenuated the effects of PP7 on the activation and ferroptosis of HSCs and the expression of GPX4. Notably, CX3CL1 directly interacted with GPX4, triggering HSC ferroptosis. The transcription factor hypermethylated in cancer 1 (Hic1), which binds to the Cx3cl1 promoter, increased the expression of CX3CL1. Its absence resulted in downregulation of CX3CL1, suppressing the GPX4-dependent ferroptosis of PP7-treated HSCs and promoting their activation. HIC1 was found to directly interact with PP7 at the GLY164 site. Co-culture experiments showed that PP7-induced HSC ferroptosis attenuated macrophage recruitment by regulating inflammation-related genes. HSC-specific inhibition of HIC1 counteracted PP7-induced collagen depletion and HSC ferroptosis in vivo. These findings suggest that PP7 induces HSC ferroptosis through the HIC1/CX3CL1/GPX4 axis.

Ferroptosis has been shown to mediate the development of fibrosis.Polyphyllin Ⅶ(PP7),a bioactive component of Paris polyphylla,exhibits potent anti-inflammatory activity and can significantly alleviate liver fibrosis.In this study,treatment with PP7 significantly inhibited the proliferation and activation of hepatic stellate cells(HSCs),which could be suppressed by a ferroptosis inhibitor.In addition,it promoted HSC ferroptosis by suppressing glutathione(GSH)peroxidase 4(GPX4)and enhanced the expression of CX3C chemokine ligand 1(CX3CL1).Depletion of CX3CL1 attenuated the effects of PP7 on the activation and ferroptosis of HSCs and the expression of GPX4.Notably,CX3CL1 directly interacted with GPX4,triggering HSC ferroptosis.The transcription factor hypermethylated in cancer 1(Hic1),which binds to the Cx3cl1 promoter,increased the expression of CX3CL1.Its absence resulted in downregulation of CX3CL1,sup-pressing the GPX4-dependent ferroptosis of PP7-treated HSCs and promoting their activation.HIC1 was found to directly interact with PP7 at the GLY164 site.Co-culture experiments showed that PP7-induced HSC ferroptosis attenuated macrophage recruitment by regulating inflammation-related genes.HSC-specific inhibition of HIC1 counteracted PP7-induced collagen depletion and HSC ferroptosis in vivo.These findings suggest that PP7 induces HSC ferroptosis through the HIC1/CX3CL1/GPX4 axis.

Respiratory syncytial virus(RSV)is a major cause of severe lower respiratory disease and can infect all populations,posing a significant health threat to infants and the elderly.After more than 60 years of research,there are only 2 RSV vaccines and 2 preventive monoclonal antibodies be licensed,but the use of the population is severely limited,expensive and difficult to large-scale popularization.RSV vaccine development faces a number of obstacles,such as the lack of animal models,avoidance of RSV immunity,and short duration of immunity.Since the failure of formalin inactivated RSV vaccine trials,RSV vaccine development has become more cautious and difficult.This article briefly reviews the research status of RSV vaccines,and introduces several representative vaccines currently under development,in order to facilitate researchers to review the latest progress and contribute to promoting vaccine research.

Objective:To discuss the effect of long-term use of chlorhexidine on the resistance of Enterococcus faecalis(E.faecalis),and to clarify its mechanism.Methods:The standard strain of E.faecalis was repeatedly exposed to chlorhexidine for 10 generations,and the minimum inhibitory concentration(MIC)was recorded at each passage.The bacteria collected from the 10th generation with increased MIC values were designated as the E.faecalis chlorhexidine-resistant strains(E.faecalis-Cs).The growth curves of two strains were drawn;the morphology of two strains were observed by transmission electron microscope;the number of biofilm formation of two strains was detected by crystal violet staining;the bacterial hydrophobicities of two strains were detected by microbial adhesion to hydrocarbons(MATH)method;the expression levels of S-ribosylhomocysteine lyase(LuxS)mRNA in the bacterial biofilms of two strains were detected by real-time fluorescence quantitative PCR(RT-qPCR)method.Results:From the 0th to the 10th generation,the MIC values of E.faecalis were gradually increased.The growth curves of E.faecalis and E.faecalis-Cs showed no significant differences.The transmission electron microscope observation results showed that both E.faecalis and E.faecalis-Cs appeared oval or diplococcal,with intact cell wall structures,smooth edges,and evenly distributed cytoplasm.There were no significant differences in the morphology,size,cell wall thickness,or integrity between two types of bacteria.The crystal violet staining results showed that compared with E.faecalis,the number of biofilm formation of E.faecalis-Cs was significantly increased(P<0.05).The MATH results showed tha the hydrophobicity of E.faecalis-Cs was significantly higher than that of E.faecalis(P<0.05).The RT-qPCR results showed that the expression level of LuxS mRNA in the biofilms of E.faecalis-Cs was significantly higher than that of E.faecalis(P<0.05).Conclusion:E.faecalis develops the resistance after repeated exposure to the chlorhexidine,and the pathogenicity of the resistant strain is enhanced.The high expressin of quorum sensing(QS)system LuxS gene and stronger biofilm forming ability of bacteria may be the potential mechanism for E.faecalis to tolerate the chlorhexidine.

Objective:To analyze the root canal diameter of the mandibular first premolar by using finite element analysis to simulate the stress distribution of dentin under three different preparation methods,and to provide the basis for clinical root canal preparation strategies of the mandibular first premolars.Methods:Twenty-one patients with complete cone beam computed tomography(CBCT)images were selected.The original DICOM format data from CBCT were imported into Mimics 21.0 software to measure the root canal diameter at 3,6,9,and 12 mm from the apex and the root canal taper was segmentally calculated.Based on this,three-dimensional finite element models of the dental and periodontal tissues were constructed.Control group,maximum diameter preparation group,uniform preparation group,and 0.06 taper instrument preparation group were designed.In ANSYS Workbench 17.0 finite element analysis software,a 200 N load was applied to the buccal,lingual,and occlusal surfaces in various groups,and the stresses on dentin in various groups were analyzed.Results:The analysis of root canal taper at 3-6 mm,6-9 mm,and 9-12 mm from the apex of mandibular first premolar teeth showed that the taper was similar in the mesial-distal direction at 3-6 mm from the apex.The average taper in the buccal-lingual direction at 6-9 mm from the apex was 0.29,which was greater than the taper in the apical 1/3 and coronal 1/3.Under the same load,the peak stress values in dentin of mandibular first premolar teech in various groups were increased sequentially:4.693 6,16.304 0,14.278 0,and 18.682 0 MPa.The stress in maximum diameter preparation group concentrated on the canal wall with the highest stress value.The stress in uniform preparation group concentrated on the root surface,and the stress values on each section were lower than those in maximum diameter preparation group.The stress in 0.06 taper instrument preparation group concentrated on the apical 1/3 of the root surface.Conclusion:The root canal of the mandibular first premolar has a unique elliptical taper shape,and there are significant differences in diameter and taper between the mesial-distal and buccal-lingual directions.Different preparation methods result in different stress distributions on the canal wall,and the uniform preparation is the best method for enlarging the canal.

Respiratory syncytial virus(RSV)is a major cause of severe lower respiratory disease and can infect all populations,posing a significant health threat to infants and the elderly.After more than 60 years of research,there are only 2 RSV vaccines and 2 preventive monoclonal antibodies be licensed,but the use of the population is severely limited,expensive and difficult to large-scale popularization.RSV vaccine development faces a number of obstacles,such as the lack of animal models,avoidance of RSV immunity,and short duration of immunity.Since the failure of formalin inactivated RSV vaccine trials,RSV vaccine development has become more cautious and difficult.This article briefly reviews the research status of RSV vaccines,and introduces several representative vaccines currently under development,in order to facilitate researchers to review the latest progress and contribute to promoting vaccine research.

Klebsiella pneumoniae(K.pneumoniae)is an important pathogen that can cause severe hospital-and community-acquired infections.To systematically investigate its methylation features,we determined the whole-genome sequences of 14 K.pneumoniae strains covering varying serotypes,multilocus sequence types,clonal groups,viscosity/virulence,and drug resistance.Their methy-lomes were further characterized using Pacific Biosciences single-molecule real-time and bisulfite technologies.We identified 15 methylation motifs[13 N6-methyladenine(6mA)and two 5-methylcytosine(5mC)motifs],among which eight were novel.Their corresponding DNA methyl-transferases were also validated.Additionally,we analyzed the genomic distribution of GATC and CCWGG methylation motifs shared by all strains,and identified differential distribution pat-terns of some hemi-/un-methylated GATC motifs,which tend to be located within intergenic regions(IGRs).Specifically,we characterized the in vivo methylation kinetics at single-base resolu-tion on a genome-wide scale by simulating the dynamic processes of replication-mediated passive demethylation and MTase-catalyzed re-methylation.The slow methylation of the GATC motifs in the replication origin(oriC)regions and IGRs implicates the epigenetic regulation of replication initiation and transcription.Our findings illustrate the first comprehensive dynamic methylome map of K.pneumoniae at single-base resolution,and provide a useful reference to better understand epigenetic regulation in this and other bacterial species.

Although DNA 5-hydroxymethylcytosine (5hmC) is recognized as an important epige-netic mark in cancer, its precise role in lymph node metastasis remains elusive. In this study, we investigated how 5hmC associates with lymph node metastasis in breast cancer. Accompanying with high expression of TET1 and TET2 proteins, large numbers of genes in the metastasis-positive pri-mary tumors exhibit higher 5hmC levels than those in the metastasis-negative primary tumors. In contrast, the TET protein expression and DNA 5hmC decrease significantly within the metastatic lesions in the lymph nodes compared to those in their matched primary tumors. Through genome-wide analysis of 8 sets of primary tumors, we identified 100 high-confidence metastasis-associated 5hmC signatures, and it is found that increased levels of DNA 5hmC and gene expression of MAP7D1 associate with high risk of lymph node metastasis. Furthermore, we demonstrate that MAP7D1, regulated by TET1, promotes tumor growth and metastasis. In conclusion, the dynamic 5hmC profiles during lymph node metastasis suggest a link between DNA 5hmC and lymph node metastasis. Meanwhile, the role of MAP7D1 in breast cancer progression suggests that the metastasis-associated 5hmC signatures are potential biomarkers to predict the risk for lymph node metastasis, which may serve as diagnostic and therapeutic targets for metastatic breast cancer.

Long terms of chronic pain may induce emotional disorder such as depression,anxiety and aversion.It is worthy of studying the mechanism and therapy on pain emotional disorder.The animal model is important in basic researches,and the quantitative evaluation methods on the psychiatric factors are gradually applied in the pain research.The methods of evaluating the psychiatric disorder of pain are discussed in this paper,which will provide theory basis in the relevant fields.

Objective To explore the utility of different body composition for the prediction of myocardial ischemia in exercise in type 2 diabetes mellitus (T2DM) patients. Methods T2DM outpatients were selected from Jul. 2013 to Nov. 2014 (male 83, female 57) to measure body composition and clinical biochemical parameters, and divided them into two groups according to treadmill exercise testing results. Group A cases were positive (27 patients) and Group B cases were negative (113 patients). SPSS19.0 was used to make statistical analysis. Results (1) The age, gender, diabetes mellitus (DM) duration, medical history of hypertension and dyslipidemia, body mass index (BMI), waist circumference, the waist-hip fat ratio of the two groups had no significant difference (P>0.05). (2) The fasting blood glucose (FBG), glycosylated hemoglobin (HbA1c), total cholesterol (TC), triglycerides (TG), high density lipoprotein cholesterol (HDL-C) between the two groups had no significant difference. Compared with group B, the low density lipoprotein cholesterol (LDL-C) of group A [(2.48 ± 0.75) mmol/L vs. (2.81 ± 0.77) mmol/L, t=2.009, P<0.05] decreased significantly. (3) Overall body fat percentage, skeletal muscle weight of the two groups had no significant difference. Compared with group B, the waist-hip fat ratio (0.93±0.06 vs. 0.88±0.08, t=-2.790, P<0.01) andvisceral fat area [(99.47 ± 32.84) cm2 vs. (81.10 ± 25.47) cm2, t=-2.822, P<0.01] of group A increased significantly, while this difference mainly existed in male patients visceral fat area [(100.99±39.33) cm2 vs. (79.91 ± 27.09) cm2, t=-2.231, P<0.05], and waist-hip fat ratio was different in female patients of the two groups (0.91±0.06 vs. 0.85±0.09, t=-2.043, P<0.05) . Conclusion Abdominal obesity, especially visceral fat accumulation had close correlation with myocardial ischemia in exercise in T2DM patients. Waist-hip fat ratio and visceral fat area may be more effective indicators of myocardial ischemia in exercise in T 2DM patients than BMI.