OBJECTIVE: To investigate the distribution characteristics of polymorphonuclear neutrophil (PMN) in the lungs during the early stage of severe burns and the mechanism of neutrophil elastase (NE) promoting lung injury. METHODS: 6-8-week-old male C57BL/6J mice were selected for the experiments. A 30% total body surface area (TBSA) III degree burn mouse model was established (severe burn group); the Sham-injury group was treated with 37 centigrade water. In the sodium sivelestat intervention group (SV intervention group), NE competitive inhibitor, sivelestat, 100 mg/kg, was injected via tail vein immediately after injury, while other groups received an equal volume of saline. Ten mice were harvested from each group to observe survival for 72 hours. Respiratory function tests were tested at 0 (immediate), 3, 6, 12, and 24 hours after molding. hematoxylin-eosin (HE) and immunohistochemical staining were used to observe lung tissue structure, inflammatory changes and PMN infiltration. The PMN absolute count in mice lung tissue was detected buy flow cytometry. At 6, 12, and 24 hours after molding, PMN counts and the concentration of NE [enzyme linked immunosorbent assay (ELISA)] in peripheral blood plasma, lung tissue, and bronchoalveolar lavage fluid (BALF) were detected. RESULTS: (1) HE staining results showed that compared with the Sham-injury group, the lungs of mice in the severe burn group showed inflammatory changes and PMN infiltration, with more significant changes at 6 hours. Immunohistochemistry results also confirmed that the expression of NE protein released from PMN significantly increased after 6 hours of severe burn injury [(3.79±0.62)% vs. (0.18±0.05)%, t = 11.56, P < 0.01]. (2) Compared with the Sham-injury group, the number of PMN and the concentration of NE in the peripheral blood and lung tissues in the severe burn group were significantly increased (F values were 13.709, 55.350 and 29.890, 13.286, respectively, all P < 0.01), peaking at 6 hours [plasma PMN count (×10⁹/L): 2.92±1.01 vs. 0.92±0.29, lung tissue PMN absolute count (cells): 48 788.03±11 833.91 vs. 1 516.72±415.35, plasma NE (ng/L): 24 522.71±3 842.92 vs. 7 009.34±4 067.86, lung tissue NE (ng/L): 262 189.04±9 695.13 vs. 65 026.03± 16 016.31, all P < 0.01]. The number of PMN in the lung of severely burned mice was highly correlated with NE concentration (r = 0.892, P < 0.001). There was no significantly difference in the PMN absolute count in the BALF of mice between the Sham-injury group and severe burn group (F = 1.403, P > 0.05). The Sham-injury group and severe burn group contained a small amount of NE in the BALF, and the concentration of NE in the BALF of the severely burned 6 hours and 12 hours groups were significantly higher than those of the Sham-injury group (ng/L: 328.58±158.10, 415.30±240.89 vs. 61.95±15.80, both P < 0.05). (3) Kaplan-Meier survival curve showed that the 72-hour survival rate of mice in the SV intervention group was significantly higher than that in the severe burn group (100% vs. 10%, Log-Rank test: χ² = 19.12, P < 0.001). (4) Compared with the Sham-injury group, all lung function indices of the severe burn group decreased significantly. All lung function indices of SV intervention group improved gradually over time, which were significantly better than those of the severe burn group. (5) Compared with the Sham-injury group, the PMN absolute count in lung tissue and the concentration of NE in plasma and lung tissue were significantly higher in the SV intervention group (F values were 46.709, 3.535, 32.701, respectively, all P < 0.05), with a peak at 6 hours. Compared with the severe burn group, the SV intervention group had a higher PMN absolute count in lung tissue (cells: 8 870.80±7 013.89 vs. 25 974.92±22 240.8, P < 0.05), and higher plasma and lung tissue NE concentrations (ng/L: 14 955.94±3 944.41 vs. 21 972.75±4 573.05, 81 956.87±38 658.35 vs. 168 182.30±83 513.91, both P < 0.01) were significantly decreased. CONCLUSIONS In the early stage of severe burns, there is a significant infiltration of PMN into the lungs. The NE promotes lung injury in the early stage of severe burn, and improve lung injury by inhibiting the action of NE.
Animals ; Burns/metabolism* ; Leukocyte Elastase/metabolism* ; Male ; Mice, Inbred C57BL ; Mice ; Neutrophils/metabolism* ; Lung/metabolism* ; Disease Models, Animal ; Neutrophil Infiltration ; Lung Injury/metabolism* ; Glycine/analogs & derivatives* ; Sulfonamides

The plant F-box protein more axillary growth 2 (MAX2) is a key factor in the signal transduction of strigolactones (SLs) and karrinkins (KARs). As the main component of the SKP1-CUL1-FBX (SCF) complex ubiquitin ligase E3, MAX2 is responsible for specifically recognizing the target proteins, suppressor of MAX2 1/SMAX1-like proteins (SMAX1/SMXLs), which would be degraded after ubiquitination. It can thereby regulate plant morphogenesis and stress responses. There exist homologous genes of MAX2 in the important grain and oil crop soybean (Glycine max). However, its role in plant defense responses has not been investigated yet. Here, GmMAX2b, a homologous gene of MAX2, was successfully cloned from stressed soybean. Bioinformatics analysis revealed that there were two MAX2 homologous genes, GmMAX2a and GmMAX2b, with a similarity of 96.2% in soybean. Their F-box regions were highly conserved. The sequence alignment and cluster analysis of plant MAX2 homologous proteins basically reflected the evolutionary relationship of plants and also suggested that soybean MAX2 might be a multifunctional protein. Expression analysis showed that plant pathogen infection and salicylic acid treatment induced the expression of GmMAX2b in soybean, which is consistent with that of MAX2 in Arabidopsis. Ectopic expression of GmMAX2b compensated for the susceptibility of Arabidopsis max2-2 mutant to pathogen, indicating that GmMAX2b positively regulated plant disease resistance. In addition, yeast two hybrid technology was used to explore the potential target proteins of GmMAX2b. The results showed that GmMAX2b interacted with SMXL6 and weakly interacted with SMXL2. In summary, GmMAX2b is a positive regulator in plant defense responses, and its expression is induced by pathogen infection and salicylic acid treatment. GmMAX2b might exert its effect through interaction with SMXL6 and SMXL2. This study expands the theoretical exploration of soybean disease resistant F-box and provides a scientific basis for future soybean disease resistant breeding.
Glycine max/metabolism* ; Disease Resistance/genetics* ; Plant Diseases/immunology* ; Plant Proteins/genetics* ; Cloning, Molecular ; Gene Expression Regulation, Plant ; F-Box Proteins/genetics* ; Arabidopsis/genetics* ; Phylogeny

BACKGROUND:Traditional methods of urinary tract reconstruction are limited by donor scarcity,high complication rates,and suboptimal functional recovery.Tissue engineering strategies offer new directions in this field.Since the urinary tract is mainly composed of muscle tissue,the key is to find suitable seed cells and efficiently induce them to differentiate into smooth muscle cells.Comparative studies on the efficacy of different smooth muscle cell induction regimens are still lacking. OBJECTIVE:To isolate,culture,and identify human urine-derived stem cells,and to compare the effects of two different induction protocols. METHODS:Human urine-derived stem cells were isolated from urine samples of 11 healthy adult volunteers by multiple centrifugations.Surface markers were identified by flow cytometry.The multi-directional differentiation potential of human urine-derived stem cells was verified through osteogenic and adipogenic differentiation.Differentiation was induced by transforming growth factor-β1 or transforming growth factor-β1 combined with platelet derived growth factor for 14 days.Immunofluorescence staining and western blot assay were employed to compare the expression differences of smooth muscle-specific proteins(α-SMA and SM22). RESULTS AND CONCLUSION:(1)Urine-derived stem cells were successfully isolated from the eight urine samples of healthy people.These cells exhibit a"rice grain"-like morphology and possess a robust proliferative capacity.(2)Urine-derived stem cells exhibited high expression of mesenchymal stem cell surface markers(CD73,CD90,and CD44)and extremely low expression of hematopoietic stem cell surface markers(CD34 and CD45).These cells did not express CD19,CD105,and HLA-DR.(3)After osteogenic and adipogenic differentiation,the formation of calcium nodules and lipid droplets was observed,with positive staining results from Alizarin Red S and Oil Red O staining.(4)After 14 days of smooth muscle induction culture,immunofluorescence staining revealed that the smooth muscle differentiation rate of urine-derived stem cells treated with a combination of transforming growth factor-β1 and platelet derived growth factor was significantly higher compared to those treated with transforming growth factor-β1 alone(P<0.005).(5)After 14 days of smooth muscle induction culture,western blot assay further demonstrated that the expression levels of α-SMA and SM22 in the transforming growth factor-β1/platelet derived growth factor group were significantly elevated compared to those in the transforming growth factor-β1 only group(P<0.005).These findings confirm that urine-derived stem cells can be non-invasively isolated using multiple rounds of centrifugation.Compared with transforming growth factor-β1 alone,the combination of transforming growth factor-β1 and platelet derived growth factor can improve the efficiency of inducing urine-derived stem cells to differentiate into smooth muscle cells.

Objective To investigate the changes in eosinophil counts and the activation of microglial cells in the brain tissues of mice at different stages of Angiostrongylus cantonensis infection, and to examine the role of microglia in regulating the progression of angiostrongyliasis and unravel the possible molecular mechanisms. Methods Fifty BALB/c mice were randomly divided into the control group and the 7-d, 14-d, 21-day and 25-d infection groups, of 10 mice in each group. All mice in infection groups were infected with 30 stage III A. cantonensis larvae by gavage, and animals in the control group was given an equal amount of physiological saline. Five mice were collected from each of infection groups on days 7, 14, 21 d and 25 d post-infection, and 5 mice were collected from the control group on the day of oral gavage. The general and focal functional impairment was scored using the Clark scoring method to assess the degree of mouse neurological impairment. Five mice from each of infection groups were sacrificed on days 7, 14, 21 d and 25 d post-infection, and 5 mice from the control group were sacrificed on the day of oral gavage. Mouse brain tissues were sampled, and the pathological changes of brain tissues were dynamically observed using hematoxylin and eosin (HE) staining. Immunofluorescence staining with eosinophilic cationic protein (ECP) and ionized calcium binding adaptor molecule 1 (Iba1) was used to assess the degree of eosinophil infiltration and the counts of microglial cells in mouse brain tissues in each group, and the morphological parameters of microglial cells (skeleton analysis and fractal analysis) were quantified by using Image J software to determine the morphological changes of microglial cells. In addition, the expression of M1 microglia markers Fcγ receptor III (Fcgr3), Fcγ receptor IIb (Fcgr2b) and CD86 antigen (Cd86), M2 microglia markers Arginase 1 (Arg1), macrophage mannose receptor C-type 1 (Mrc1), chitinase-like 3 (Chil3), and phagocytosis genes myeloid cell triggering receptor expressed on myeloid cells 2 (Trem2), CD68 antigen (Cd68), and apolipoprotein E (Apoe) was quantified using real-time quantitative reverse transcription PCR (RT-qPCR) assay in the mouse cerebral cortex of mice post-infection. Results A large number of A. cantonensis larvae were seen on the mouse meninges surface post-infection, and many neuronal nuclei were crumpled and deeply stained, with a large number of bleeding points in the meninges. The median Clark scores of mouse general functional impairment were 0 (interquartile range, 0), 0 (interquartile range, 0.5), 6 (interquartile range, 1.0), 14 (interquartile range, 8.5) points and 20 (interquartile range, 9.0) points in the control group and the 7-d, 14-d, 21-d and 25-d groups, respectively (H = 22.45, P < 0.01), and the median Clark scores of mouse focal functional impairment were 0 (interquartile range, 0), 2 (interquartile range, 2.5), 7 (interquartile range, 3.0), 18 (interquartile range, 5.0) points and 25 (interquartile range, 6.5) points in the control group and the 7-d, 14-d, 21-d and 25-d groups, respectively (H = 22.72, P < 0.01). The mean scores of mice general and focal functional impairment were all higher in the infection groups than in the control group (all P values < 0.05). Immunofluorescence staining showed a significant difference in the eosinophil counts in mouse brain tissues among the five groups (F = 40.05, P < 0.000 1), and the eosinophil counts were significantly higher in mouse brain tissues in the 14-d (3.08 ± 0.78) and 21-d infection groups (5.97 ± 1.37) than in the control group (1.00 ± 0.28) (both P values < 0.05). Semi-quantitative analysis of microglia immunofluorescence showed a significant difference in the counts of microglial cells among the five groups (F = 17.66, P < 0.000 1), and higher Iba1 levels were detected in mouse brain tissues in 14-d (5.75 ± 1.28), 21-d (6.23 ± 1.89) and 25-d infection groups (3.70 ± 1.30) than in the control group (1.00 ± 0.30) (all P values < 0.05). Skeleton and fractal analyses showed that the branch length [(162.04 ± 34.10) μm vs. (395.37 ± 64.11) μm; t = 5.566, P < 0.05] and fractal dimension of microglial cells (1.30 ± 0.01 vs. 1.41 ± 0.03; t = 5.266, P < 0.05) were reduced in mouse brain tissues in the 21-d infection group relative to the control group. In addition, there were significant differences among the 5 groups in terms of M1 and M2 microglia markers Fcgr3 (F = 48.34, P < 0.05), Fcgr2b (F = 55.46, P < 0.05), Cd86 (F = 24.44, P < 0.05), Arg1 (F = 31.18, P < 0.05), Mrc1 (F = 15.42, P < 0.05) and Chil3 (F = 24.41, P < 0.05), as well as phagocytosis markers Trem2 (F = 21.19, P < 0.05), Cd68 (F = 43.95, P < 0.05) and Apoe (F = 7.12, P < 0.05) in mice brain tissues. Conclusions A. cantonensis infections may induce severe pathological injuries in mouse brain tissues that are characterized by massive eosinophil infiltration and persistent activation of microglia cells, thereby resulting in progressive deterioration of neurological functions.

Objective To explore the effect of different pontic designs in resisting stress interruption effect and roller coaster phenomenon through three-dimensional finite element analysis,providing clinical guidance for the application of clear aligners in extraction cases.Methods Four three-dimensional finite element models of different pontic designs in the extraction area of clear aligners were established,including the pontic-free connection design,the conventional hollow pontic design,the partially solid-filled pontic design and the fully solid-filled pontic design.All four aligner models were individually assembled with the dental arch model.A 0.2 mm distal movement of the canine was simulated to observe the initial displacement and periodontal ligament stress distribution of canine and second premolar in each group of models.Results The initial displacement tendency diagram revealed that in all experimental conditions,both the canine and second premolar exhibited tipping movement patterns.However,significant variations in initial displacement magnitudes were observed across different pontic designs.The fully solid-filled pontic-connected clear aligner model exhibited the greatest initial displacement values(both crown and root)and the maximum initial displacement magnitude.Notably,this kind of design displayed movement characteristics closer to bodily movement,indicating superior control efficacy in tooth positioning.Periodontal ligament stress analysis revealed that the fully solid-filled pontic-connected clear aligner model generated the highest maximum principal stress in the periodontal ligament.Conclusion This three-dimensional finite element study reveals that the application of solid-filled pontic in clear aligner therapy could improve biomechanical control at extraction sites by minimizing aligner distortion,reducing stress interruption effect and preventing the roller coaster phenomenon.

Objective To explore the role of sevoflurane(SEV)in sepsis-induced acute lung injury(ALI)and observe its impact on the Wnt/β-catenin signaling pathway.Methods Forty C57 mice were randomly divided into 4 groups(n=10 each):Sham,CLP,SEV,and SEV+XAV(β-catenin inhibitor).A sepsis model was established via cecal ligation and puncture.Lung injury was evaluated using HE staining,lung wet/dry weight ratio,and TUNEL staining.Levels of inflammatory factors(TNF-α,IL-1β,IL-6)were detected by ELISA.Oxidative stress indices(SOD,MDA,ROS)were measured by colorimetry and flow cytometry.Hindlimb blood perfusion and oxygenation were assessed with laser speckle flowmetry.Expressions of key Wnt pathway molecules and down-stream target genes(c-Myc,Cyclin D1)were detected by RT-qPCR and Western blot.Co-localization of β-catenin and SP-C(a marker of type Ⅱ alveolar epithelial cells)in lung tissues was determined by immunofluorescence staining.Results Compared with the Sham group,the CLP group exhibited significant increases in sepsis severity,lung pathological damage including alveolar structure destruction,inflammatory infiltration,and apoptosis,elevation in pro-inflammatory cytokine levels,and significant decrease in SOD and increase in MDA and ROS.Additionally,lower limb blood flow and oxygenation levels were significantly reduced,while the expression of β-catenin and its downstream target genes,as well as the co-localization signal and fluorescence intensity of β-catenin with SP-C,were significantly downregulated(all P<0.05).Compared with the CLP group,the SEV group showed significant improvements in all these indicators.However,compared with the SEV group,the SEV+XAV group demon-strated a reversed protective effect,with all indicators approaching the levels observed in the CLP group(all P<0.05).Conclusion Sevoflurane alleviates sepsis-induced ALI by activating Wnt/β-catenin signaling pathway,exerting anti-inflammatory and antioxidant effects,and enhancing the expression and localization of β-catenin in type Ⅱ alveolar epithelial cells.

Objective To investigate the expression of ACTN1 in cutaneous squamous cell carcinoma (CSCC) and its association with clinicopathological features and prognosis. Methods A total of 150 patients with cutaneous squamous cell carcinoma (CSCC) and 100 healthy controls were enrolled in this study. The serum expres-sion levels of ACTN1 were measured using ELISA. All CSCC patients underwent post-surgical follow-up and were categorized into a poor prognosis group (n=69) and a good prognosis group (n=81). Additionally,the 69 patients in the poor prognosis group were further classified into an ACTN1 lower expression subgroup (n=35) and an ACTN1 higher expression subgroup (n=34) based on the median expression level of ACTN1. Logistic regression analysis was employed to identify risk factors associated with poor prognosis in CSCC patients. ROC curve analysis was conducted to evaluate the clinical utility of serum ACTN1 expression levels in predicting poor prognosis in CSCC patients. Kaplan-Meier (K-M) survival analysis was utilized to assess the relationship between serum ACTN1 expres-sion levels and the median time to poor prognosis in the 69 patients with poor prognosis. Furthermore,40 additional CSCC patients were recruited to compare the expression levels of ACTN1 in CSCC tissues and adjacent tissues using immunohistochemistry. Results The serum expression levels of ACTN1 in the Control group and the CSCC group were (12.12±2.26) ng/mL and (4.56±1.02) ng/mL,respectively. Compared to the Control group,the serum expres-sion level of ACTN1 in the CSCC group was significantly decreased,and the difference was statistically significant (t=31.37,P<0.001). In the poor prognosis group,the proportion of tumors with a diameter ≥ 5 cm,low degree of tumor cell differentiation,subadipocyte invasion depth,lymph node metastasis incidence,and serum ACTN1 expression levels were all significantly higher compared to the good prognosis group,with statistical significance (P<0.05). Logistic regression analysis revealed that lymph node metastasis (OR=3.253) and elevated ACTN1 expression (OR=2.894) were independent risk factors for poor prognosis following CSCC surgery. The area under the curve (AUC) for serum ACTN1 expression in predicting poor prognosis post-surgery in CSCC patients was 0.911. At a cut-off value of 13.19 ng/mL for ACTN1,the diagnostic sensitivity and specificity were 89.78％ and 92.12％,respectively. The median time to poor prognosis was 25 months in the ACTN1 low-expression group and 18.5 months in the ACTN1 high-expression group,respectively. The median time to poor prognosis was significantly shorter in the ACTN1 high-expression group compared to the low-expression group (HR=6.627,P<0.001). Among 40 CSCC tissue samples,32 cases exhibited higher ACTN1 expression,while 8 cases showed lower expression. In contrast,among 40 paracancerous tissue samples,11 cases had higher ACTN1 expression and 29 cases had lower expression. The higher expression rate of ACTN1 in CSCC tissues was significantly elevated compared to paracancerous tissues (x2=22.175,P<0.001). Conclusion The serum expression level of ACTN1 in CSCC patients was significantly elevated,suggesting its potential as a biomarker for assessing post-surgical prognosis in CSCC patients.

Objective:To measure the radial artery (RA) diameter and explore its related factors by using optical coherence tomography (OCT).Methods:This was a cross-sectional study conducted in Cardiac Care Unit of Beijing Luhe Hospital, Capital Medical University. Patients who underwent first-ever right forearm access and OCT guided coronary intervention via right distal RA, and measurement of the whole portion of RA diameter with OCT in our center between January 2021 to December 2021 were enrolled. Following the coronary intervention, OCT was used to assess the entire RA. The RA diameter was measured from the RA ostium to 2 cm above the radial styloid process, with a 1 mm interval. Multiple linear regression analysis was performed to determine the factors related the RA diameter.Results:The study enrolled 124 patients with an age of (61.6±12.6) years, of whom 98 (79%) were male. The total length of the RA was (19.5±1.8) cm, for males (20.2±1.3) cm and females (17.2±1.2) cm. The average RA diameter was (3.13±0.50) mm, and the RA diameter at 2 to 5 cm above the radial styloid process was (2.98±0.53) mm. The average RA diameter was significantly larger for male patients than for female patients ((3.21±0.50) mm vs. (2.84±0.37) mm, P<0.001). Multiple linear regression analysis indicated that gender was significantly associated with RA diameter ( P=0.019). Conclusions:The average RA diameter measured by OCT is (3.13±0.50) mm, (2.98±0.53) mm at 2 to 5 cm above the radial styloid process. Gender is identified as a factor related to the RA diameter.

In order to explore the effect of PGD2/DP1 receptor pathway on the expression of cyto-kines and injury-related factors in Escherichia coli(E.coli)induced bovine bone marrow derived macrophages,an in vitro model of E.coli induced bovine bone marrow derived macrophages was established.The effects of DP1 receptor agonist on phagocytosis and killing ability,mRNA expres-sion,secretion of pro-inflammatory cytokines(TNF-α,IL-1β)and activation of signaling pathway(MAPK,NF-κB)in cow bone marrow derived macrophages induced by E.coli were examined.The results showed that compared with the E.coli infection group,the phagocytosis and killing ability of BW-245C+E.coli group and 15 d-PGJ2+E.coli group were enhanced(P＜0.01).Compared with the blank control group,mRNA expression was at a higher level(P＜0.001),and the secre-tion of pro-inflammatory cytokines(TNF-α,IL-1β)was significantly increased after adding E.coli solution.The mRNA expression of BW-245C+E.coli group and 15 d-PGJ2+E.coli group were significantly decreased(P＜0.001),and the secretion of pro-inflammatory cytokines(TNF-α,IL-1β)was significantly decreased(P＜0.001).and signaling pathway(MAPK,NF-κB)were sig-nificantly down-regulated(P＜0.001).This study showed that DP1receptor agonist plays an inhib-itory role in the inflammatory response of cow bone marrow-derived macrophages induced by E.coli.This finding provides a potential target for future treatment of cow endometritis,laying the foundation for the development of novel anti-inflammatory treatment strategies.

Escherichia coli(E.coli)is a key pathogenic bacterium responsible for postpartum endo-metritis,with its colonization in the reproductive tract closely associated with endometrial damage and disruption of the ovarian cycle.This ultimately leads to infertility,causing significant economic losses to the dairy industry.Macrophages play a pivotal role in the inflammatory response.This study aims to investigate the mRNA expression profile of bovine bone marrow-derived macropha-ges following E.coli infection using RNA sequencing(RNA-seq)technology.Additionally,it seeks to identify the biological functions and signaling pathways of differentially expressed genes(DEGs)through Gene Ontology(GO)and Kyoto Encyclopedia of Genes and Genomes(KEGG)enrichment analyses.The results demonstrated that E.coli infection induced differential expression of 4 522 genes,with 2 141 upregulated and 2 381 downregulated.These genes were primarily asso-ciated with inflammatory responses,where TLR2,TLR4,NLRP3,and PTGS2 played pivotal roles.PGD2 synthesis was mediated by TLR2,TLR4,and NLRP3.Transcriptome sequencing of bovine bone marrow-derived macrophages infected with E.coli and treated with a PGD2 inhibitor revealed a marked downregulation of TLR2 and TLR4 gene expression.qPCR validation results were highly consistent with the RNA-seq findings.This study elucidates the interactive regulatory roles of TLR2,TLR4,and NLRP3 in conjunction with PGD2,which collectively modulate bovine endome-tritis.These findings offer significant molecular insights that enhance our understanding of the pathological mechanisms underlying bovine endometritis,thereby informing its prevention and treatment strategies.