ObjectiveTo observe the effects of Yiqi Huoxue Jiedu formula（YHJF） on immune cell exhaustion in the spleen of septic mice and to explore and validate its potential intervention targets. MethodsMice were randomly divided into the sham-operated， model， low-dose YHJF（4.1 g·kg^-1）， and high-dose YHJF（8.2 g·kg^-1） groups. Except for the sham-operated group， a cecal ligation and puncture（CLP） procedure was performed to establish a mouse sepsis model. The treatment groups received oral administration of the corresponding doses， while the sham-operated and model groups received an equal volume of physiological saline. After the intervention， the 7-day survival rate of each group was recorded， and spleen samples were collected 72 h post-intervention， and the spleen index was calculated. Terminal deoxynucleotidyl transferase deoxyuridine triphosphate（dUTP） nick end labeling（TUNEL） staining was used to detect apoptosis in spleen cells. Enzyme-linked immunosorbent assay（ELISA） was performed to measure the levels of interleukin（IL）-4 and IL-10 in the serum. Transcriptomics and metabolomics were used to screen for differentially expressed genes（DEGs） and differential metabolites in the spleen， followed by bioinformatics analysis to identify key targets. Real-time quantitative polymerase chain reaction（Real-time PCR）， flow cytometry， and multiplex immunofluorescence were used to verify the expressions of key genes and proteins. ResultsThe high-dose YHJF group significantly improved the 7-day survival rate of septic mice（P0.05）. Compared with the sham-operated group， the model group showed a significant increase in apoptosis of spleen cells and a decrease in the spleen index at 72 h post-modeling， with markedly elevated peripheral serum IL-4 and IL-10 levels（P0.01）. Compared with the model group， the high-dose YHJF group showed a reduction in apoptosis of spleen cells， an increase in the spleen index， and a significant decrease in peripheral serum IL-4 and IL-10 levels（P0.05）. Spleen transcriptomics identified 255 DEGs between groups， potentially serving as intervention targets for YHJF. Gene Ontology（GO） enrichment analysis revealed that DEGs were mainly involved in biological processes such as natural killer（NK） cell-mediated positive immune regulation， cell killing， cytokine production， positive regulation of innate immune cells， and interferon production. Kyoto Encyclopedia of Genes and Genomes（KEGG） pathway enrichment analysis showed that DEGs were mainly involved in cytokine-cytokine receptor interactions， viral protein interactions with cytokines and cytokine receptors， chemokine signaling pathway， and nuclear transcription factor-κB（NF-κB） signaling pathway. Protein-protein interaction（PPI） network analysis identified CD160， granzyme B（GZMB）， and chemokine ligand 4（CCL4） as key targets for YHJF in treating sepsis. Metabolomics identified 46 differential metabolites that were significantly reversed by YHJF intervention， and combined transcriptomics and metabolomics analysis identified 17 differential metabolites closely related to CD160. Pathway enrichment revealed that these metabolites were mainly involved in glycerophospholipid metabolism， arachidonic acid metabolism， glycosylphosphatidylinositol（GPI） anchor biosynthesis， linoleic acid metabolism， and α-linolenic acid metabolism pathways. Verification results showed that， compared with the sham-operated group， the model group exhibited significantly elevated CD160 mRNA expression level in the spleen， along with markedly decreased CCL4 and GZMB mRNA expression， and had a significant increase in CD160 expression on the surface of natural killer T（NKT） cells in the spleen（P0.01）. Compared with the model group， the high-dose YHJF group had a significant decrease in CD160 mRNA expression in the spleen， a significant increase in CCL4 and GZMB mRNA expressions. Further flow cytometry and immunofluorescence revealed that compared with the sham-operated group， CD160 expression on the surface of splenic NKT cells in the model group was significantly increased（P0.01）， while high-dose YHJF intervention significantly reduced CD160 expression（P0.01）. ConclusionYHJF may alleviate NKT cell exhaustion in sepsis by downregulating the expression of the negative co-stimulatory molecule CD160， and this regulatory effect is closely related to fatty acid metabolism pathways. This study provides new insights and targets for further exploration of strengthening vital Qi and detoxifying strategy to improve immune cell exhaustion in acute deficiency syndrome of sepsis.

ObjectiveTo observe the effects of Yiqi Huoxue Jiedu formula（YHJF） on immune cell exhaustion in the spleen of septic mice and to explore and validate its potential intervention targets. MethodsMice were randomly divided into the sham-operated， model， low-dose YHJF（4.1 g·kg^-1）， and high-dose YHJF（8.2 g·kg^-1） groups. Except for the sham-operated group， a cecal ligation and puncture（CLP） procedure was performed to establish a mouse sepsis model. The treatment groups received oral administration of the corresponding doses， while the sham-operated and model groups received an equal volume of physiological saline. After the intervention， the 7-day survival rate of each group was recorded， and spleen samples were collected 72 h post-intervention， and the spleen index was calculated. Terminal deoxynucleotidyl transferase deoxyuridine triphosphate（dUTP） nick end labeling（TUNEL） staining was used to detect apoptosis in spleen cells. Enzyme-linked immunosorbent assay（ELISA） was performed to measure the levels of interleukin（IL）-4 and IL-10 in the serum. Transcriptomics and metabolomics were used to screen for differentially expressed genes（DEGs） and differential metabolites in the spleen， followed by bioinformatics analysis to identify key targets. Real-time quantitative polymerase chain reaction（Real-time PCR）， flow cytometry， and multiplex immunofluorescence were used to verify the expressions of key genes and proteins. ResultsThe high-dose YHJF group significantly improved the 7-day survival rate of septic mice（P0.05）. Compared with the sham-operated group， the model group showed a significant increase in apoptosis of spleen cells and a decrease in the spleen index at 72 h post-modeling， with markedly elevated peripheral serum IL-4 and IL-10 levels（P0.01）. Compared with the model group， the high-dose YHJF group showed a reduction in apoptosis of spleen cells， an increase in the spleen index， and a significant decrease in peripheral serum IL-4 and IL-10 levels（P0.05）. Spleen transcriptomics identified 255 DEGs between groups， potentially serving as intervention targets for YHJF. Gene Ontology（GO） enrichment analysis revealed that DEGs were mainly involved in biological processes such as natural killer（NK） cell-mediated positive immune regulation， cell killing， cytokine production， positive regulation of innate immune cells， and interferon production. Kyoto Encyclopedia of Genes and Genomes（KEGG） pathway enrichment analysis showed that DEGs were mainly involved in cytokine-cytokine receptor interactions， viral protein interactions with cytokines and cytokine receptors， chemokine signaling pathway， and nuclear transcription factor-κB（NF-κB） signaling pathway. Protein-protein interaction（PPI） network analysis identified CD160， granzyme B（GZMB）， and chemokine ligand 4（CCL4） as key targets for YHJF in treating sepsis. Metabolomics identified 46 differential metabolites that were significantly reversed by YHJF intervention， and combined transcriptomics and metabolomics analysis identified 17 differential metabolites closely related to CD160. Pathway enrichment revealed that these metabolites were mainly involved in glycerophospholipid metabolism， arachidonic acid metabolism， glycosylphosphatidylinositol（GPI） anchor biosynthesis， linoleic acid metabolism， and α-linolenic acid metabolism pathways. Verification results showed that， compared with the sham-operated group， the model group exhibited significantly elevated CD160 mRNA expression level in the spleen， along with markedly decreased CCL4 and GZMB mRNA expression， and had a significant increase in CD160 expression on the surface of natural killer T（NKT） cells in the spleen（P0.01）. Compared with the model group， the high-dose YHJF group had a significant decrease in CD160 mRNA expression in the spleen， a significant increase in CCL4 and GZMB mRNA expressions. Further flow cytometry and immunofluorescence revealed that compared with the sham-operated group， CD160 expression on the surface of splenic NKT cells in the model group was significantly increased（P0.01）， while high-dose YHJF intervention significantly reduced CD160 expression（P0.01）. ConclusionYHJF may alleviate NKT cell exhaustion in sepsis by downregulating the expression of the negative co-stimulatory molecule CD160， and this regulatory effect is closely related to fatty acid metabolism pathways. This study provides new insights and targets for further exploration of strengthening vital Qi and detoxifying strategy to improve immune cell exhaustion in acute deficiency syndrome of sepsis.

Objective: To explore whether the long-term and frequent use of citrate anticoagulants negatively affects the bone metabolism balance of female frequent plateletpheresis donors, so as to better protect their health. Methods: A total of 65 female plateletpheresis donors and 55 female whole-blood donors from Guangzhou Blood Center (May to December 2024) were enrolled as experimental and control groups respectively, stratified into age subgroups (18-39 years and 40-60 years). Serum levels of 25-hydroxyvitamin D [25(OH)D], procollagen type I N-terminal propeptide (PINP), osteocalcin (OC), and type I collagen carboxy-terminal telopeptide (CTX) were measured. Differences in bone metabolism markers between experimental and control groups across age subgroups were compared. ANOVA was used to analyze dose-response relationships between donation age, annual apheresis donation frequency, and biochemical indicators. Results: In the 40-60 age subgroup, 25(OH)D levels were significantly lower in the experimental group (P<0.05), exhibiting a linear increase with age and a linear decrease with annual donation frequency. No significant differences in CTX or PINP levels were observed between experimental and control groups in either age subgroup. Conclusion: High-frequency plateletpheresis donation does not disrupt bone metabolic balance in female donors. However, it is associated with reduced vitamin D levels in female donors aged >40 years, potentially increasing the risk of osteoporosis. Vitamin D supplementation is recommended for high-frequency female plateletpheresis donors in this age group.

Objective:We aimed to explore the effect of exercise on cardiac function and APJ system in old mice.Meth-ods:Male C57/BL6 mice were divided into young group(n=30),old control group(n=30),old continuous moderate-intensity training(CMIT)group(n=30),and old high-intensity interval training(HIIT)group(n=30).Mice in the CMIT group and HIIT group underwent 8-week exercise intervention,respectively.Mice in the young group and old con-trol group were placed on stationary treadmill simultaneously.The heart function parameters were measured,and the ex-pression of APJ/Apelin in myocardium and circulating Apelin/Elabela were compared among above-mentioned groups.Results:Compared yo mice in old control group,those in the CMIT group and HIIT group had significant higher left ven-tricular ejection fraction[(67.74±6.18)％,(70.69±7.43)％vs.(61.17±4.78)％]and left ventricular fractional short-ening[(33.07±4.29)％,(33.37±5.57)％vs.(28.05±3.61)％](P＜0.05 or＜0.01);and significant lower Tei index[(0.78±0.09),(0.78±0.12)vs.(0.88±0.08)]and left ventricular posterior wall thickness at diastole[(1.01±0.09)mm,(1.02±0.10)mm vs.(1.19±0.14)mm](P＜0.05all).Compared to mice in old control group,those in the HIIT group had significant higher mitral valve E/A ratio[(1.63±0.11)vs.(1.42±0.18),P=0.043].Compared to mice in old control group,those in the HIIT group had significant higher expressions of APJ and Apelin in myocardium,as well as the levels of Apelin[(1186.23±393.74)pg/ml vs.(413.17±80.81)pg/ml]and Elabela[(5.38±2.76)ng/ml vs.(1.57±0.60)ng/ml]in the serum(P＜0.05 or＜0.01).Conclusion:Long-term exercise initiated late in life could im-prove heart function of mice.The APJ-Apelin/Elabela system may be involved in the exercise-mediated improvement of cardiac aging.

Objective:To analyze the therapeutic effect of a virtual reality (VR)-based accommodation training device on accommodative excess visual fatigue.Methods:A case-control study was conducted.A total of 20 normal subjects (20 eyes) and 20 patients with accommodative excess visual fatigue (20 eyes) were recruited at Zhongshan Ophthalmic Center, Sun Yat-sen University between January and December 2022.The study consisted of two phases.In the first phase, the effect of watching videos with VR glass on the subjects' subjective and objective visual function was evaluated.Normal subjects wore VR device to watch a 2D video for 30 minutes, and assessments were performed before and after viewing.These assessments included binocular accommodation/convergence function (accommodation response, accommodative convergence to accommodation ratio [AC/A]), tear film function (first tear film break-up time), subjective symptoms (visual fatigue score), and basic visual health parameters including best corrected visual acuity (BCVA) and intraocular pressure (IOP).In the second phase, the improvement in subjective and objective visual fatigue metrics with the VR-based accommodation training device was investigated.Patients with visual fatigue were divided into a traditional training group using traditional flipper lenses and a VR training group using the VR accommodation training device, with 10 eyes in each group.The effects of the VR accommodation training device on indicators such as accommodative sensitivity, accommodation response, convergence function, visual fatigue score, acceptability score, system usability score, BCVA, and IOP were evaluated and compared between the two groups.This study adhered to the Declaration of Helsinki.The study protocol was approved by the Ethics Committee of Zhongshan Ophthalmic Center, Sun Yat-sen University (No.IIT2021007).Written informed consent was obtained from each subject.Results:In normal subjects, there was no statistically significant difference in first tear film break-up time, distance phoria, near phoria, AC/A, accommodative response, BCVA, or IOP before and after 30 minutes of continuous viewing of 2D video using VR glass ( t=1.155, 1.360, 4.479, 1.979, -1.249, -3.017, 2.211; all P>0.05).The visual fatigue score remained unchanged at (1.00±0.00) points before and after viewing.Among the subjects with visual fatigue, there were statistically significant differences in binocular accommodative sensitivity, dominant eye accommodative sensitivity, and BCVA before and after using the VR accommodation training device ( F=8.693, 4.078, 4.942; all P<0.05).Ocular accommodation sensitivity at 8 weeks after training was improved compared with 1 week after training, and BCVA at 4 weeks after training was improved compared with before training, and the differences were statistically significant (both P<0.05).In the VR training group, the average tear film break-up time, first tear film break-up time, and BCVA increased and the visual fatigue score decreased compared with before training, the differences were statistically significant (all P<0.05).In the traditional training group, the accommodation sensitivity of the dominant eye increased after training compared with before training, with a statistically significant difference ( P<0.05). Conclusions:Watching 2D videos with VR glass for 30 minutes does not induce subjective or objective symptoms of visual fatigue.The VR-based accommodation training paradigm effectively improves accommodative sensitivity and alleviates subjective symptoms of visual fatigue in individuals with accommodative excess visual fatigue.

Objective:To analyze the therapeutic effect of a virtual reality (VR)-based accommodation training device on accommodative excess visual fatigue.Methods:A case-control study was conducted.A total of 20 normal subjects (20 eyes) and 20 patients with accommodative excess visual fatigue (20 eyes) were recruited at Zhongshan Ophthalmic Center, Sun Yat-sen University between January and December 2022.The study consisted of two phases.In the first phase, the effect of watching videos with VR glass on the subjects' subjective and objective visual function was evaluated.Normal subjects wore VR device to watch a 2D video for 30 minutes, and assessments were performed before and after viewing.These assessments included binocular accommodation/convergence function (accommodation response, accommodative convergence to accommodation ratio [AC/A]), tear film function (first tear film break-up time), subjective symptoms (visual fatigue score), and basic visual health parameters including best corrected visual acuity (BCVA) and intraocular pressure (IOP).In the second phase, the improvement in subjective and objective visual fatigue metrics with the VR-based accommodation training device was investigated.Patients with visual fatigue were divided into a traditional training group using traditional flipper lenses and a VR training group using the VR accommodation training device, with 10 eyes in each group.The effects of the VR accommodation training device on indicators such as accommodative sensitivity, accommodation response, convergence function, visual fatigue score, acceptability score, system usability score, BCVA, and IOP were evaluated and compared between the two groups.This study adhered to the Declaration of Helsinki.The study protocol was approved by the Ethics Committee of Zhongshan Ophthalmic Center, Sun Yat-sen University (No.IIT2021007).Written informed consent was obtained from each subject.Results:In normal subjects, there was no statistically significant difference in first tear film break-up time, distance phoria, near phoria, AC/A, accommodative response, BCVA, or IOP before and after 30 minutes of continuous viewing of 2D video using VR glass ( t=1.155, 1.360, 4.479, 1.979, -1.249, -3.017, 2.211; all P>0.05).The visual fatigue score remained unchanged at (1.00±0.00) points before and after viewing.Among the subjects with visual fatigue, there were statistically significant differences in binocular accommodative sensitivity, dominant eye accommodative sensitivity, and BCVA before and after using the VR accommodation training device ( F=8.693, 4.078, 4.942; all P<0.05).Ocular accommodation sensitivity at 8 weeks after training was improved compared with 1 week after training, and BCVA at 4 weeks after training was improved compared with before training, and the differences were statistically significant (both P<0.05).In the VR training group, the average tear film break-up time, first tear film break-up time, and BCVA increased and the visual fatigue score decreased compared with before training, the differences were statistically significant (all P<0.05).In the traditional training group, the accommodation sensitivity of the dominant eye increased after training compared with before training, with a statistically significant difference ( P<0.05). Conclusions:Watching 2D videos with VR glass for 30 minutes does not induce subjective or objective symptoms of visual fatigue.The VR-based accommodation training paradigm effectively improves accommodative sensitivity and alleviates subjective symptoms of visual fatigue in individuals with accommodative excess visual fatigue.

Objective Titanium ions were implanted into Bio-HPP materials using plasma immersion ion implantation(PIII)technology,and the biocompatibility against human gingival fibroblasts(HGFs)and antimicrobial activity against porphyromonas gingivalis(P.g)to the materials were preliminarily evaluated.Methods The cell experiments and antibacterial experiments in vitro were conducted,and the specimens were randomly divided into the modified group and the control group,and the modified specimens were placed in an ion implantation device and implanted with titanium ions by PIII technology.The morphology of the nanostructures on the surface of the materials was observed by scanning electron microscopy.The cytocompatibility of Bio-HPP materials was evaluated by proliferation detection,immunofluorescence staining and cell cycle distribution detection of HGFs.The antibacterial activity of the materials was evaluated by the detection of antibacterial rate of P.g and the expression analysis of pathogenic gene,and the antibacterial mechanism was preliminarily analyzed.Results The surface of Bio-HPP in the control group was relatively flat,and the modified group formed nanopores with diameters of 100 to 300 nm,with smaller nanoparticles distributed in the nanostructures.The cell proliferation rates of HGFs after cultured for 3,5 and 7 days in the modified group were higher than those in the control group(P<0.05).After 4 hours of incubation,the cells spread well on the surface of the both groups,and the cytoskeleton extended further outward,while the spreading area on the surface of the control group was slightly smaller than that of the modified group.After 24 hours of incubation,the cells on the surface of materials in the both groups showed elongated spindle or shuttle shape,with good growth.There was no significant difference in the proportions of cells at stages G1 and G2 between the control group and the modified group(P>0.05).The proportion of cells at stage S in the modified group was higher than that in the control group(P<0.05).After 24 hours of incubation,the number of colonies in the modified group was significantly reduced compared with the control group;the antibacterial rate of the modified group was significantly higher than that of the control group(P<0.05).The relative expression of pathogenic genes fimA on the surface in the modified group was significantly lower than that in the control group(P<0.05).Conclusion Bio-HPP materials modified by titanium plasma implantation promotes the adhesion and proliferation of HGFs,which was conducive to the adhesion of soft tissues around the gingiva,with good antibacterial activity.

Objective:To evaluate the efficacy and safety of nebulized inhalation of recombinant human interferon (IFN) α1b injection in the treatment of respiratory syncytial virus (RSV) associated lower respiratory tract infections (pneumonia and bronchiolitis) in children.Methods:A randomized, double-blind, parallel, placebo-controlled add-on design was used.Children with pneumonia or bronchiolitis aged 2 months to 5 years who tested positive for RSV antigen within 72 hours of onset from 30 clinical trial sites including Beijing Children′s Hospital, Capital Medical University between February 2021 and December 2022 were included in this study and randomly divided into 2 groups at a ratio of 1∶1 based on a stratified-block method.Both groups received basic treatments such as cough control, asthma relieving, expectorant treatment, fever reduction, oxygen therapy, etc.The experimental group received additional nebulized inhalation of IFN α1b injection at a dose of 2.0 μg/(kg·time), twice a day.The control group received nebulized inhalation of placebo twice a day.Clinical efficacy was evaluated based on indicators such as the duration of clinical symptoms and signs, and the Kaplan-Meier method was used to calculate the median and 95% CI of the duration of clinical symptoms and signs.The Log-rank test was used to compared data between groups.Safety was assessed through the incidence of adverse reactions and laboratory tests, and the Chi-square test was used to analyze the difference between groups. Results:There were 123 children in the experimental group and 122 children in the control group.The median durations of all the 5 clinical symptoms and signs [including shortness of breath, wheezing, dyspnea (visible retractions), decreased transcutaneous oxygen saturation, and abnormal mental state] in the experimental group after treatment were slightly shortened than those in the control group [2.7 d(95% CI: 1.9-3.0 d)] vs.[2.9 d(95% CI: 2.6-3.6 d), P=0.027].The improvement in dyspnea (retractions) was especially pronounced in the experimental group, with a relief rate of 50.0% (0, 100%) on the first day of administration[compared with 0 (0, 50.0%) in the control group ( Z=2.002, P=0.025)].The median duration of dyspnea in the experimental group was nearly 1 day shorter than that in the control group [1.0 d(95% CI: 0.7-1.7 d) vs.1.8 d(95% CI: 1.0-2.5 d), P=0.046].There were no significant difference in hospital stay [6.0(5.0, 8.0) d vs.6.5(5.0, 8.0) d, Z=0.675, P=0.500], oxygen therapy duration [32.0(14.0, 96.3) h vs.39.0 (24.0, 83.2) h, Z=0.094, P=0.925], the recovery rate from clinical symptoms during treatment [(105/106, 99.1%) vs.(96/101, 95.0%)], and recurrence rate [(0/106, 0) vs.(2/101, 2.0%)] between the 2 groups (all P>0.05).However, the above-mentioned four indicators in the experimental group showed a trend of clinical benefits.The quantitative virus detection results showed that the RSV viral load in both groups decreased after treatment compared to before treatment.After 2 days of treatment, the decline rate of RSV viral load from the baseline was 0.90 lg copies/(mL·d) in the experimental group and 0.25 lg copies/(mL·d)in the control group, with a statistically significant difference ( P<0.05).Furthermore, there was no statistically significant difference in the incidence of adverse reactions between the 2 groups ( P>0.05).Importantly, no drug-related serious adverse reactions occurred in both groups. Conclusions:The nebulized inhalation therapy of IFN α1b demonstrates efficacy and safety in treating pediatric RSV associated lower respiratory tract infections.It particularly offers outstanding clinical therapeutic value for severe children.

Objective To explore the pathogenesis and prognostic factors of liposarcoma in the head and neck region, and simultaneously analyze the efficacy of different treatment regimens. Methods A retrospective analysis was performed on all patients with primary untreated head and neck liposarcoma who were diagnosed and underwent surgical treatment at our hospital from January 2008 to January 2024. All patients were monitored during follow-up, and their prognoses were analyzed using SPSS software. Results A total of 30 patients were included in the study. Liposarcoma accounted for up to 60% of the cases in the orbit, while the remaining liposarcomas were primarily located in various interspaces of the neck. Dedifferentiated liposarcoma was the most common type, comprising 33%, while myxoid pleomorphic liposarcoma was the rarest at 4%. The tumor pathological type (P<0.001) and Ki67 (P=0.014) significantly affected the tumor control rate. However, an analysis of disease-specific survival rates revealed no significant differences across various factors (all P>0.05). Conclusion The prognosis of head and neck liposarcoma is better compared to that of liposarcomas in other parts of the body. However, myxoid pleomorphic liposarcoma, pleomorphic fat sarcoma, and high Ki67 levels are indicators of poor prognosis. Additionally, postoperative adjuvant radiotherapy does not significantly enhance disease-specific survival rates.

BACKGROUND:Macrophage migration inhibitory factor(MIF)is a pleiotropic cytokine,which is secreted in different types of stem cells and can regulate the proliferation,differentiation and migration of various types of stem cells.Our previous research has confirmed that human embryonic stem cells secrete MIF and that its concentration in the culture medium is relatively stable.However,whether MIF is involved in the survival,proliferation and differentiation of human embryonic stem cells remains unclear. OBJECTIVE:To investigate the effects of MIF on survival,proliferation,and differentiation of human embryonic stem cells. METHODS:(1)Human embryonic stem cells H9 were cultured.The growth curve of cells was detected and plotted by CCK-8 assay.Enzyme-linked immunosorbent assay was used to determine the level of MIF in the medium.(2)To determine the effects of exogenous MIF on the survival and proliferation of human embryonic stem cells,different groups were established:the control group,which was cultured in stem cell medium without any modifications;the exogenous MIF group,which was treated with different concentrations(30,100,300 ng/mL)of MIF in the stem cell medium;the MIF inhibitor ISO-1 group,which was treated with different concentrations(2,7,21 μmol/L)of ISO-1 in the stem cell medium;and the MIF+ISO-1 group,which was treated with different concentrations of ISO-1 along with 100 ng/mL of MIF.Cell viability was assessed using the CCK-8 assay.(3)To further elucidate the effect of MIF gene on survival and proliferation of human embryonic stem cell,the MIF knockout H9 cell line was constructed by CRISPR-Cas 9 technology to observe the lineage establishment.(4)To determine the effect of high concentrations of MIF on human embryonic stem cell differentiation,100 ng/mL MIF and 100 ng/mL of CXCR4 neutralizing antibody were separately added to the normal stem cell culture medium.The expression levels of self-renewal factors(KLF4,c-MYC,NANOG,OCT4,and SOX2)and differentiation transcription factors(FOXA2,OTX2)were measured using real-time quantitative polymerase chain reaction,immunofluorescence staining,and western blot analysis. RESULTS AND CONCLUSION:(1)The logarithmic growth phase of H9 cells was between 3-6 days.Under normal growth conditions,human embryonic stem cells secreted MIF at a concentration of approximately 20 ng/mL,independent of cell quantity.(2)Compared to the control group,the addition of different concentrations of MIF had no effect on the proliferation of human embryonic stem cells(P>0.05).ISO-1 significantly inhibited the proliferation of human embryonic stem cells,with a stronger inhibition observed at higher concentrations of ISO-1(P<0.05).The addition of MIF in the presence of ISO-1 reduced the inhibitory effect of ISO-1(P<0.05).(3)Real-time quantitative polymerase chain reaction showed that knocking out 50%of the MIF gene resulted in a significant decrease in the growth vitality of human embryonic stem cells and failure to establish cell lines.(4)Adding 100 ng/mL exogenous MIF to the culture medium resulted in a decrease in the mRNA,protein,and fluorescence expression levels of the self-renewal transcription factor KLF4,while the mRNA,protein,and fluorescence expression levels of the differentiation factor FOXA2 increased.(5)When 100 ng/mL CXCR4 neutralizing antibody was added to the culture medium,the mRNA and protein expression levels of KLF4 increased,while the mRNA and protein expression levels of FOXA2 decreased,contrary to the expression trend observed in the MIF group.In conclusion,the endogenous secretion of MIF by human embryonic stem cells is essential for their survival.The addition of MIF to the culture medium does not promote the proliferation of human embryonic stem cells.However,it can lead to a decrease in the expression of the self-renewal factor KLF4 and an increase in the expression of the transcription factor FOXA2.This provides a clue for further investigation into the effects and mechanisms of MIF on the differentiation of human embryonic stem cells.The MIF-CXCR4 axis plays a regulatory role in this process.