OBJECTIVES: To explore the key role of myeloid-derived suppressive cells (MDSCs) in pre-metastatic niche (PMN) and analyze their interrelationships with the main components in the microenvironment using a mathematical model. METHODS: Mathematical descriptions were used to systematically analyze the functions of MDSCs in tumor metastasis and elucidate their association with the major components (vascular endothelial cells, mesenchymal stromal cells, and cancer-associated macrophages) contributing to the formation of the pre-metastatic microenvironment. Based on the formation principle of the pre-metastatic microenvironment of tumors, the key biological processes were assumed to construct a coupled partial differential diffusion equation model. The existence and uniqueness of the model solutions were investigated using approximation methods, the qualitative theory of partial differential equations and Banach's immovable point theorem, and numerical simulations were carried out by differential numerical methods to verify the reliability and accuracy of the model. RESULTS: The existence and uniqueness of the local and overall solutions of the model were proved using the approximation method, the qualitative theory of partial differential equations and Banach's immovable point theorem in combination with the regularity estimation of the local solutions and the embedding inequality. Numerical simulation results further validated the reliability of the model and demonstrated the important role of MDSCs in the pre-metastatic microenvironment of tumors, especially in angiogenesis and immunosuppression. CONCLUSIONS This study reveals the important functions of MDSCs in the pre-metastatic microenvironment of tumors through mathematical modeling and numerical simulation, which provides an important theoretical basis for understanding the mechanism of tumor metastasis and devising cancer treatment strategies.
Tumor Microenvironment ; Myeloid-Derived Suppressor Cells ; Neoplasm Metastasis ; Humans ; Models, Biological ; Models, Theoretical ; Neoplasms/pathology*

Objective:To investigate the expression characteristics of Zeste enhancer of Zeste homolog 2 (EZH2) in breast cancer tissue and its influence on tumor progression and prognosis.Methods:Transcriptome data of breast cancer tissue and normal breast tissue adjacent to cancer as well as clinical data of patients were obtained from the cancer genome atlas (TCGA) database, gene expression comprehensive database and European genome phenotype archives database, and the difference of EZH2 expression was analyzed using TIMER 2.0 platform. The survival information of breast cancer patients was obtained from the Kaplan Meier Plotter database, and the overall survival time, relapse free survival time and distant metastasis free survival time of breast cancer patients with low EZH2 expression and high EZH2 expression were compared. Select 14 nude mice were selected and randomly divided into si-EZH2 group and control group, with 7 mice in each group.MCF7 culture suspensions transfected with EZH2 knockdown plasmid and control plasmid were inoculated for corresponding group. The body mass and tumor volume of two groups of nude mice inoculated with MCF7 cells were compared at different times. On the 28th day, the nude mice were euthanized and the tumors were dissected to compare the tumor mass of the two groups of nude mice. The normally distributed quantitative data was represented by xˉ ± s. Two independent sample t-tests were used for comparison between two groups, repeated measures ANOVA was used for comparison of body mass and tumor volume between two groups of nude mice at different times, and Bonferroni test was used for pairwise comparison. The comparison of survival rates was conducted using log rank test. Results:A total of 1085 breast cancer tissues and 291 normal adjacent breast tissues were included in the TCGA database. EZH2 expression in breast cancer tissues was higher than that in normal adjacent breast tissues ( P<0.05). In the Kaplan Meier Plotter database, the total survival time, relapse free survival time, and distant metastasis free survival time of breast cancer patients in the EZH2 overexpression group were shorter than those in the EZH2 low expression group ( P=0.013, <0.001, <0.001). After 7 days of inoculation with MCF7 culture suspension, significant subcutaneous tumors were observed on the left back of both groups of nude mice. On the first day, there were no statistically significant difference in body mass between the two groups of nude mice ( P>0.05); On day 7, 13, 19, 25, and 28, the body mass and tumor volume of both groups of nude mice gradually increased (nude mouse body mass: within group F=29.31, P<0.001, between groups F=234.32, P<0.001, Finteraction=16.83, P<0.001; Tumor volume: within group F=34.00, P<0.001, between groups F=193.17, P<0.001, Finteraction=35.61, P<0.001). And the body mass of the siEZH2 group nude mice was higher than that of control group (all P<0.05). On days 19, 25, and 28, tumor the volume of the siEZH2 group nude mice was smaller than that of control group (all P<0.05). On the 28th day, the mass of tumors dissected in the siEZH2 group of nude mice was lower than that in the control group [(0.30±0.07) g vs. (0.61±0.14) g, t=5.16, P<0.001]。 Conclusions:EZH2 is highly expressed in breast cancer tissues and is significantly associated with poor prognosis. Knockdown of EZH2 can significantly inhibit the proliferation and tumor formation of breast cancer cells.

Objective:To analyze the clinical value of mannan binding lectin associated serine protease 2 (MASP-2), galectin-3, and midkine in the differential diagnosis of thyroid nodules.Methods:From March 2021 to March 2022, 75 patients (study group) with thyroid nodules admitted to the Nanchong Hospital of Traditional Chinese Medicine and 50 volunteers(control group) who underwent health examinations during the same period were retrospectively selected. The levels of MASP-2, galectin-3 and midkine were compared between the two groups, and the levels of MASP-2, galectin-3 and midkine in benign and malignant thyroid nodules in the study group were compared. The predictive value of MASP-2, galectin-3, midkine and combined tests for malignant thyroid nodules diagnosis was analyzed by receiver operating characteristic (ROC) curve.Results:The levels of MASP-2, galectin-3, midkine in the study group were higher than those in the control group: (433.92 ± 35.01) mg/L vs. (215.12 ± 22.60) mg/L, (26.73 ± 3.12) μg/L vs. (20.51 ± 2.10) μg/L, (258.96 ± 27.03) ng/L vs. (122.47 ± 15.72) ng/L, there were statistical differences ( P<0.05). The levels of MASP-2, galectin-3, midkine in the patients with malignant nodules were higher than those in the patients with benign thyroid nodules: (541.27 ± 57.35) mg/L vs. (400.02 ± 30.17) mg/L, (41.68 ± 5.23) μg/L vs. (22.01 ± 2.89) μg/L, (318.97 ± 40.23) ng/L vs. (240.01 ± 25.01) ng/L, there were statistical differences ( P<0.05). ROC curve analysis showed that the area under the curve (AUC) of MASP-2, galectin-3 and midkine in the diagnosis of malignant thyroid nodules was the highest (0.819), which was higher than that of any single index. Conclusions:The serum levels of MASP-2, galectin-3 and midkine in patients with malignant nodules were higher than those in patients with benign nodules, and the combined value of MASP-2, galectin-3 and midkine is higher in predicting malignant thyroid nodules.

AIM:The aim of this study was to explore the effects of Yiqi-Yangyin-Quyu prescription(YP)on skeletal muscle injury and related metabolic disorders in mice with Sj?gren syndrome(SS),and to clarify the role of hy-droxyacyl-CoA dehydrogenase trifunctional multienzyme complex subunit beta(Hadhb)in mediating the effect of YP on skeletal muscle in SS.METHODS:The SS mice underwent YP treatment for 8 weeks.The morphological changes of the submandibular gland and muscle tissue were examined using hematoxylin-eosin staining.The mitochondrial status in mus-cle tissue was assessed through transmission electron microscopy.Additionally,combined transcriptome and proteome se-quencing was conducted on skeletal muscle samples.The omics sequencing results were validated by RT-qPCR.Immuno-fluorescence was used to confirm the levels of key proteins involved in the P53/peroxisome proliferator-activated receptor gamma(PPARG)signaling pathway.Immunohistochemistry and Western blot were employed to determine the levels of Hadhb key targets.RESULTS:Combined transcriptome and proteome analysis identified 1 523 differentially expressed genes(DEGs)and 182 differentially expressed proteins(DEPs)between the muscle tissue of SS mice(model group)and that of control animals(ICR group),12 of which showed co-differential expression at both transcriptomic and proteomic levels.Compared with model group,1 232 genes and 432 proteins were found to be differentially expressed in the muscle tissue of the mice in YP group.Among these,23 exhibited co-differential expression at both mRNA and protein levels.Gene Ontology(GO)analysis showed that the DEGs and DEPs between ICR and model groups were mainly involved in ener-gy metabolism and fatty acid oxidation,while the DEGs and DEPs between YP and model groups were primarily associated with sarcomere tissue and actin structure.Kyoto Encyclopedia of Genes and Genomes(KEGG)enrichment analysis indi-cated that the DEGs and DEPs between ICR and model groups and between model and YP groups were enriched in the com-plement and coagulation cascade and lipid and pyruvate metabolism.The RT-qPCR validation results were consistent with those of the transcriptome analysis.Furthermore,the protein expression of the tumor suppressor P53 was significantly de-creased in YP group compared with model group,whereas that of PPARG was significantly increased.Western blot analy-sis showed that compared with ICR group,Hadhb protein expression was significantly decreased in model group,whereas the opposite trend was detected in YP group.CONCLUSION:The SS-related skeletal muscle damage is closely related to amino acid metabolism disorder and fatty acid degradation.Treatment with YP modulates innate immune defenses,lipid metabolism and energy metabolism in SS,and Hadhb is the key target of YP in SS-related skeletal muscle.

Objective The aim of this study was to clarify the role and mechanism of Pseudomonas aeruginosa vaccine subunit OprI in the fusion protein vaccine rePO(PcrV-OprI).Methods The in vitro stability of rePO,PcrV and OprI at 4 ℃,25 ℃,and 37 ℃ was examined.After immunizing mice with rePO,OprI and PcrV,respectively,the specific antibody potency in serum and the proportion of cells secreting IFN-γ and IL-4 in the spleen were examined;Additionally,detection of the levels of protein uptake by DC2.4 cells in vitro using laser confocal microscopy and flow cytometry,and their ability to promote the maturation of mouse bone marrow-derived dendritic cells(BMDC).Results The heat stability of fusion protein rePO was significantly better than that of PcrV.The induced anti-PcrV IgG and anti-OprI IgG potency of rePO was significantly higher than that of monomeric PcrV and OprI.Additionally,the number of cells secreting IFN-γ and IL-4 induced by immunization with rePO was significantly higher than that of PcrV and OprI.The uptake rate of fusion protein rePO by DC2.4 cells was significantly higher than that of PcrV and OprI.Furthermore,rePO promoted the maturation of mouse BMDC more effectively than PcrV and OprI.Conclusion OprI in the fusion protein rePO can significantly improve its thermal stability and immunogenicity,which lays the foundation for the successful development of Pseudomonas aeruginosa vaccine.

Objective The aim of this study was to clarify the role and mechanism of Pseudomonas aeruginosa vaccine subunit OprI in the fusion protein vaccine rePO(PcrV-OprI).Methods The in vitro stability of rePO,PcrV and OprI at 4 ℃,25 ℃,and 37 ℃ was examined.After immunizing mice with rePO,OprI and PcrV,respectively,the specific antibody potency in serum and the proportion of cells secreting IFN-γ and IL-4 in the spleen were examined;Additionally,detection of the levels of protein uptake by DC2.4 cells in vitro using laser confocal microscopy and flow cytometry,and their ability to promote the maturation of mouse bone marrow-derived dendritic cells(BMDC).Results The heat stability of fusion protein rePO was significantly better than that of PcrV.The induced anti-PcrV IgG and anti-OprI IgG potency of rePO was significantly higher than that of monomeric PcrV and OprI.Additionally,the number of cells secreting IFN-γ and IL-4 induced by immunization with rePO was significantly higher than that of PcrV and OprI.The uptake rate of fusion protein rePO by DC2.4 cells was significantly higher than that of PcrV and OprI.Furthermore,rePO promoted the maturation of mouse BMDC more effectively than PcrV and OprI.Conclusion OprI in the fusion protein rePO can significantly improve its thermal stability and immunogenicity,which lays the foundation for the successful development of Pseudomonas aeruginosa vaccine.

Objective:To investigate the effect of zine finger BED domain-containing protein 2(ZBED2)on immune escape of hepatocellular carcinoma(HCC)through glycolysis pathway and its potential mechanism.Methods:Expression of ZBED2 in HCC tis-sues and binding sites of them were analyzed in bioinformatics database,the pathway regulated by ZBED2 was analyzed,as well as the correlation between ZBED2 and glycolysis genes.qPCR and Western blot were used to detected expressions of ZBED2 and pro-grammed death-ligand 1(PD-L1)in HCC cells,cell viability was detected by MTT,toxicity of CD8+T cells was detected by cytotoxicity assay,and cytokine expression was detected by ELISA.Extracellular acidification rate(ECAR)and oxygen consumption rate(OCR)were detected by extracellular flow analyzer,glycolytic gene expression was detected by qPCR,and glycolytic index was detected by kit.Expression of CD8+T cell in tumor tissues was detected by immunohistochemical staining.Results:ZBED2 was up-regulated in HCC,overexpression of ZBED2 could promote expression of PD-L1,while inhibit cytotoxicity of CD8+T cells to HCC.Overexpression of ZBED2 inhibited CD8+T cell activity in HCC by activating glycolysis pathway,and further addition of glycolysis inhibitor 2-DG at-tenuated the above results.In vivo experiments showed that ZBED2 knockdown inhibited tumor growth,inhibited PD-L1 expression,while promoted CD8+T cell infiltration in vivo.Conclusion:ZBED2 induces expression of PD-L1 in HCC through glycolytic metabo-lism,and promotes immune escape.

Objective To investigate the correlation between serum vitamin D level and heart failure based on cross-sectional analysis.Methods A total of 10,411 subjects included in the Na-tional Health and Nutrition Examination Survey(NHANES)database from 2013 to 2016 were select-ed as the study population.The serum 25-hydroxyvitamin D[25(OH)D]levels of all subjects were measured.According to the quartiles of serum vitamin D levels,the subjects were divided into four groups.Multivariate logistic regression analysis and restricted cubic spline regression analysis were employed to explore the correlation between serum vitamin D level and heart failure.Results There were statistically significant differences among the four groups in terms of age,gender,educational at-tainment,race,diabetes,hypertension,alcohol consumption,physical activity,and body mass index(P＜0.05).The incidence rates of heart failure in the four vitamin D quartile groups(from low to high)were 3.9％,2.7％,2.9％and 4.1％respectively,with a statistically significant difference(P＜0.05).The results of multivariate logistic regression analysis revealed that,compared with the subjects in the first quartile group of vitamin D,the odds ratios(OR)and 95％confidence intervals(CI)of heart failure in the second,third,and fourth quartile groups of vitamin D were 0.64(0.46 to 0.89),0.53(0.38 to 0.73)and 0.48(0.35 to 0.66)respectively,and the trend test showed P was less than 0.001.The results of restricted cubic spline regression analysis indicated that serum vitamin D level was non-linearly negatively correlated with heart failure(non-linear test P=0.005).At the initial stage,the risk of heart failure decreased with the increase in vitamin D level;when the vitamin D level reached a certain level,the risk of heart failure tended to stabilize or even increase slightly.Con-clusion Serum vitamin D level is non-linearly negatively correlated with the risk of heart failure.

Objective:To investigate the relationship between individual and combined exposure to ambient air pollutants and vitamin D, as well as the potential role of ultraviolet radiation (UVR) in mediating the relationships.Methods:This study included 6 967 participants from the China Kadoorie Biobank, whose baseline (2004-2008) blood 25-hydroxyvitamin D had been tested. The average monthly concentrations of pollutants (PM 2.5, PM 10, NO 2, O 3) and the UVR estimates in the month of blood sample collection were derived from the ChinaHighAirPollutants and ultraviolet datasets covering China, respectively. Linear models and multinomial logistic regression models were used to analyze the associations of each air pollutant with vitamin D concentrations and groups. Principal component analysis integrated with quantile-based g-computation was applied to evaluate the co-effects and relative contribution weights of air pollutants. Mediation analyses were performed to investigate the potential role of UVR. Results:PM 2.5, PM 10, NO 2, and O 3 were individually associated with vitamin D concentrations, as well as vitamin D groups: insufficiency (20-30 ng/ml) and deficiency (<20 ng/ml). For each 10 μg/m3 increase in monthly PM 2.5, PM 10, NO 2, and O 3, the percentage changes (95% CIs) in vitamin D concentrations were -1.71% (-2.16% - -1.26%), -1.30% (-1.60% - -1.00%), -3.77% (-4.60% - -2.93%), and 1.27% (0.91%-1.63%), respectively, with corresponding ORs (95% CIs) for vitamin D deficiency of 1.17 (1.06-1.29), 1.12 (1.05-1.19), 1.66 (1.38-2.00), and 0.81 (0.74-0.89). The mixture of the first principal component of PM 2.5 and PM 10 (PM), along with NO 2 and O 3, was negatively correlated with vitamin D. The percentage change (95% CI) in vitamin D concentrations for a one-quintile increase in the mixture was -2.20% (-3.56%- -0.82%), with NO 2 contributing the most (83%), followed by PM (17%). UVR-mediated association was 12.2% (95% CI：2.5%-23.0%) for PM 2.5 and 4.9% (95% CI：2.2%-8.0%) for PM 10 with vitamin D concentrations, respectively. Conclusion:Higher concentrations of particulate matter, NO 2, and a mixture of air pollutants were associated with lower vitamin D concentrations in Chinese adults, with reduced UVR acting as a partial mediator in the particulate matter-vitamin D relationship.