ObjectiveTo investigate the mechanisms by which Renshentang treats atherosclerosis （AS） in mice， focusing on the regulation of endothelial inflammatory responses mediated by transient receptor potential vanilloid subtype 1 （TRPV1）. MethodsAn AS model was established in apolipoprotein E knockout （ApoE^-/-） mice fed a high-fat diet. The mice were randomly divided into a simvastatin group （0.02 g·kg^-1·d^-1） and low-， medium-， and high-dose Renshentang groups （1.77， 3.54， 7.08 g·kg^-1·d^-1）， with 12 mice in each group. ApoE^-/- mice were fed a high-fat diet and treated simultaneously. C57BL/6J mice fed a normal diet served as the normal group （n=9）. After continuous administration for 12 weeks， mice were anesthetized and the aortas were collected. Oil Red O staining was used to observe lipid plaque formation in the aorta. Hematoxylin-eosin （HE） staining was performed to examine pathological changes in the aortic root. Immunohistochemistry was used to analyze the levels of pro-inflammatory factors tumor necrosis factor-α （TNF-α） and interleukin-1β （IL-1β）， as well as the expression of TRPV1， phosphorylated phosphoinositide 3-kinase （p-PI3K）， and phosphorylated protein kinase B （p-Akt） in the aortic root. Real-time quantitative polymerase chain reaction （Real-time PCR） was used to detect endothelial nitric oxide synthase （eNOS） mRNA expression in the aorta， and Western blot was used to detect TRPV1 protein expression. ResultsCompared with the normal group， the model group showed a significant increase in aortic plaque formation （P<0.01） and significantly elevated levels of TNF-α and IL-1β in the aortic root （P<0.01）. The expression levels of TRPV1， p-PI3K， and p-Akt were decreased （P<0.05， P<0.01）， and eNOS mRNA expression was reduced （P<0.05， P<0.01）. Compared with the model group， all Renshentang groups significantly reduced aortic plaque formation （P<0.01）， significantly decreased TNF-α and IL-1β levels （P<0.01）， and markedly increased the expression levels of TRPV1， p-PI3K， p-Akt， and eNOS mRNA （P<0.05， P<0.01）. ConclusionRenshentang may inhibit endothelial inflammation and suppress the formation of AS by increasing TRPV1 protein expression and up-regulating the PI3K/Akt/eNOS signaling pathway， which may be one of the molecular mechanisms underlying its therapeutic effect against AS.

Background The quality of occupational health technical services is directly linked to the protection of workers' health rights and the efficacy of occupational disease prevention and control. However, the industry still faces critical challenges: sporadic instances of institutional non-compliance and persistent irregularities in professional practice continue to undermine overall service performance. Objective To assess the current quality status of occupational health technical services in Zhejiang Province and propose countermeasures for quality improvement, providing a scientific basis for policy optimization and service delivery quality enhancement. Methods A total of 69 occupational health technical service institutions in Zhejiang Province that obtained formal accreditation as of April 30, 2024, were sampled, including 3 public institutions and 66 private institutions (comprising 3 formerly Class-A, 28 formerly Class-B, 11 formerly Class-C, and 24 newly certified institutions). Following the Technical Protocol for Quality Monitoring of Occupational Health Technical Service in Zhejiang Province and the Technical Protocol for Proficiency Testing of Occupational Health Detection in Zhejiang Province, a quality assessment task force comprising national and provincial experts was established. Evaluation was conducted across four dimensions: qualification maintenance and compliance, standardization of technical services, authenticity of technical services, and proficiency testing, utilizing a combination of document review, on-site inspections, and technical skill assessments. Results The occupational health technical service institutions in Zhejiang Province were predominantly private entities (82.5%), with significant disparities in overall service quality. The pass rates for qualification maintenance and compliance, technical service standardization, technical service authenticity, and the excellence rate for laboratory proficiency testing were 81.5%, 80.7%, 97.3%, and 90.4%, respectively. Regarding qualification maintenance, the pass rates for "environmental conditions" (49.8%, 56.7%) and "instrumentation and equipment" (58.2%、65.6%) were significantly lower for formerly Class-C and newly certified institutions compared to other categories. In terms of technical standardization, "standardized on-site inspections" recorded the lowest pass rate (67.4%), with newly certified institutions at only 48.0%. Regarding technical service authenticity, formerly Class-C institutions exhibited issues such as missing raw chromatograms for blank samples (85.7% pass rate). In laboratory proficiency testing, public and formerly Class-A institutions achieved 100% excellence rates, but the performance of formerly Class-C and newly certified institutions was comparatively weak; specifically, the failure rate for organic analysis in formerly Class-C institutions reached 20%; the failure rate for dust testing items in newly certified institutions was 10.3%. Conclusion The overall quality of occupational health technical services in Zhejiang Province still requires significant improvement, particularly in basic institutional conditions, the standardization of on-site inspections, and laboratory proficiency in organic and dust analysis. Formerly Class-C and newly certified institutions should be the primary focus of quality management efforts. Differentiated regulatory strategies are recommended, alongside strengthening interim and ex-post supervision to gradually enhance the quality of occupational health technical services across all institutions.

ObjectiveThe present study aimed to investigate alterations in white matter microstructure and spontaneous neural activity in male college smokers, and to further explore their associations with nicotine dependence. Given that adolescence and early adulthood represent critical periods for brain maturation, particularly for white matter development, understanding the neural correlates of smoking behavior during this stage is of substantial importance for both neuroscience and public health. MethodsA total of 115 male undergraduate students were initially recruited for this study. After quality control and exclusion procedures, 52 male college smokers and 42 demographically matched healthy non-smokers were included in the final analysis. All participants underwent multimodal magnetic resonance imaging (MRI), including diffusion tensor imaging (DTI) and resting-state functional MRI (rs-fMRI). White matter fiber tracts were reconstructed using the automated fiber quantification (AFQ) method, which enables precise identification and quantification of major fiber bundles. Eighteen major white matter tracts were segmented for each participant. Along the core trajectory of each tract, 100 equidistant nodes were sampled. Fractional anisotropy (FA) was calculated at each node to assess white matter microstructural integrity, while amplitude of low-frequency fluctuation (ALFF) was computed to evaluate spontaneous neural activity within white matter tracts. Between-group differences in FA and ALFF were assessed using two-sample t-tests, with appropriate corrections applied for multiple comparisons. Furthermore, Pearson correlation analyses were conducted to examine the relationships between imaging-derived metrics (FA and ALFF values in regions showing significant group differences) and nicotine dependence severity, as measured by the Fagerström test for nicotine dependence (FTND). ResultsCompared with healthy non-smokers, male college smokers exhibited significantly increased FA values in several white matter tracts, including the left thalamic radiation, right corticospinal tract, forceps major of the corpus callosum, left uncinate fasciculus, and right arcuate fasciculus. These findings suggest altered microstructural organization or increased directional coherence within these pathways. In addition, smokers demonstrated significantly elevated ALFF values in the forceps major, right uncinate fasciculus, and left arcuate fasciculus, indicating enhanced spontaneous neural activity in these white matter regions. Correlation analyses revealed that FA values in the left thalamic radiation and right corticospinal tract were negatively correlated with FTND scores, suggesting that higher levels of nicotine dependence were associated with reduced microstructural integrity or altered fiber organization in these regions. In contrast, ALFF values in the forceps major and right uncinate fasciculus were positively correlated with FTND scores, indicating that greater nicotine dependence was associated with increased spontaneous neural activity in specific white matter pathways. ConclusionThe present study provides evidence that male college smokers exhibit distinct alterations in both white matter microstructure and functional activity. These abnormalities are not uniformly distributed but rather localized to specific fiber tracts implicated in sensorimotor processing, interhemispheric communication, and higher-order cognitive and emotional regulation. Importantly, the observed associations between imaging metrics and nicotine dependence severity suggest that these structural and functional alterations may reflect neurobiological mechanisms underlying addiction. The combination of AFQ-based tract profiling and multimodal MRI offers a sensitive approach for detecting subtle changes along white matter pathways, highlighting its potential utility in identifying neuroimaging biomarkers of nicotine dependence. Overall, these findings indicate that smoking during early adulthood may disrupt ongoing white matter maturation, potentially leading to long-term consequences for brain function. This study provides novel insights into the neural basis of nicotine dependence and underscores the importance of early intervention and prevention strategies targeting young smokers.

Tumor drug resistance is an important problem in the failure of chemotherapy and targeted drug therapy, which is a complex process involving chromatin remodeling. SWI/SNF is one of the most studied ATP-dependent chromatin remodeling complexes in tumorigenesis, which plays an important role in the coordination of chromatin structural stability, gene expression, and post-translation modification. However, its mechanism in tumor drug resistance has not been systematically combed. SWI/SNF can be divided into 3 types according to its subunit composition: BAF, PBAF, and ncBAF. These 3 subtypes all contain two mutually exclusive ATPase catalytic subunits (SMARCA2 or SMARCA4), core subunits (SMARCC1 and SMARCD1), and regulatory subunits (ARID1A, PBRM1, and ACTB, etc.), which can control gene expression by regulating chromatin structure. The change of SWI/SNF complex subunits is one of the important factors of tumor drug resistance and progress. SMARCA4 and ARID1A are the most widely studied subunits in tumor drug resistance. Low expression of SMARCA4 can lead to the deletion of the transcription inhibitor of the BCL2L1 gene in mantle cell lymphoma, which will result in transcription up-regulation and significant resistance to the combination therapy of ibrutinib and venetoclax. Low expression of SMARCA4 and high expression of SMARCA2 can activate the FGFR1-pERK1/2 signaling pathway in ovarian high-grade serous carcinoma cells, which induces the overexpression of anti-apoptosis gene BCL2 and results in carboplatin resistance. SMARCA4 deletion can up-regulate epithelial-mesenchymal transition (EMT) by activating YAP1 gene expression in triple-negative breast cancer. It can also reduce the expression of Ca²⁺ channel IP3R3 in ovarian and lung cancer, resulting in the transfer of Ca²⁺ needed to induce apoptosis from endoplasmic reticulum to mitochondria damage. Thus, these two tumors are resistant to cisplatin. It has been found that verteporfin can overcome the drug resistance induced by SMARCA4 deletion. However, this inhibitor has not been applied in clinical practice. Therefore, it is a promising research direction to develop SWI/SNF ATPase targeted drugs with high oral bioavailability to treat patients with tumor resistance induced by low expression or deletion of SMARCA4. ARID1A deletion can activate the expression of ANXA1 protein in HER2+ breast cancer cells or down-regulate the expression of progesterone receptor B protein in endometrial cancer cells. The drug resistance of these two tumor cells to trastuzumab or progesterone is induced by activating AKT pathway. ARID1A deletion in ovarian cancer can increase the expression of MRP2 protein and make it resistant to carboplatin and paclitaxel. ARID1A deletion also can up-regulate the phosphorylation levels of EGFR, ErbB2, and RAF1 oncogene proteins.The ErbB and VEGF pathway are activated and EMT is increased. As a result, lung adenocarcinoma is resistant to epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs). Although great progress has been made in the research on the mechanism of SWI/SNF complex inducing tumor drug resistance, most of the research is still at the protein level. It is necessary to comprehensively and deeply explore the detailed mechanism of drug resistance from gene, transcription, protein, and metabolite levels by using multi-omics techniques, which can provide sufficient theoretical basis for the diagnosis and treatment of poor tumor prognosis caused by mutation or abnormal expression of SWI/SNF subunits in clinical practice.

Aim To investigate the protective effect of liraglutide(LIRA)on acetaminophen(APAP)-in-duced hepatotoxicity at the in vivo level and to reveal the underlying mechanism.Methods Forty SPF grade male C57BL/6J mice were randomly divided into the Control,LIRA(200 μg·kg-1),APAP(500 mg·kg-1),LIRA+APAP,LIRA+APAP+3-methylade-nine(3-MA,30 mg·kg-1)groups,with eight mice in each group.The mice were administered for three con-secutive days,and the materials were taken after 24 h.The general condition and body weight of mice in each group were recorded,and liver morphology was ob-served.Serum ALT and AST levels,as well as SOD ac-tivity,MDA,and GSH content in liver homogenates,were measured using biochemical assay kits.The levels of inflammatory cytokines IL-6,TNF-α,and IL-1β in serum were detected by ELISA.Liver pathological changes were assessed by HE staining,while mitochon-drial and autophagosome structures in liver tissues were observed using transmission electron microscopy.The number of PCNA-positive cells in liver tissues was e-valuated using immunohistochemical staining.The pro-tein expression levels of LC3Ⅱ,p62,Bax,Bcl-2,PC-NA,and CyclinD1 in liver tissues were determined by Western blot.Results LIRA pretreatment can im-prove the general condition of mice with acetamino-phen-induced liver injury(AILI),reduce serum ALT and AST levels,and effectively ameliorate the appear-ance and morphology of the liver as well as the patho-logical damage to liver tissue.Simultaneously,the lev-els of inflammatory cytokines IL-6,TNF-α,and IL-1βare significantly decreased;SOD activity and GSH con-tent are significantly increased,while MDA content is significantly reduced.Transmission electron microsco-py observations reveal the presence of numerous auto-phagosomes in the cytoplasm of liver tissue.Immuno-histochemical staining results indicate a significant in-crease in the number of PCNA-positive cells.Further-more,the expression of LC3Ⅱ,Bcl-2,PCNA,and Cy-clinD1 proteins in liver tissue is significantly upregulat-ed,while the expression of p62 and Bax proteins is significantly downregulated.However,after interven-tion with the autophagy inhibitor 3-MA,the aforemen-tioned protective effects of LIRA are significantly.Conclusions LIRA pretreatment can significantly im-prove liver injury in AILI mice.Its protective mecha-nism may be related to enhancing autophagy in hepato-cytes,thereby reducing oxidative stress,inflammatory response and apoptosis in liver of AILI mice.

Objective:To investigate the influencing factors and perinatal outcomes associated with monozygotic twins (MZT) following elective single embryo transfer (eSET) via in vitro fertilization or intracytoplasmic sperm injection and embryo transfer (IVF/ICSI-ET). Methods:A retrospective cohort study was conducted on 12 079 patients who achieved pregnancy after undergoing IVF/ICSI-eSET at Reproductive Health Hospital of the Third Affiliated Hospital of Zhengzhou University between January 2015 and September 2023. Patients were stratified into two groups based on ultrasound findings 30 d post-transfer: singleton pregnancy group and MZT pregnancy group. Finally, 300 MZT and 1 500 single pregnancies, which were randomly matched according to 1∶5 were included by study period. General patients' characteristics, embryo-related factors, and perinatal outcomes were compared between the two groups. A multivariate logistic regression model was employed to identify risk factors for MZT after single embryo transfer, adjusting for potential confounding variables.Results:The incidence of twin pregnancy following single embryo transfer was 2.48% (300/12 079), which was higher than that of naturally conceived monozygotic twin pregnancy. No significant difference was found in baseline characteristics between the two groups (all P>0.05). The blastocyst transfer rate was higher in the MZT pregnancy group [93.3% (280/300)] than in the singleton pregnancy group [88.8% (1 332/1 500), P=0.022]. Multivariate logistic regression analysis also showed that blastocyst transfer was associated with an increased risk of MZT ( OR=0.552, P=0.016, 95% CI: 0.341-0.894). Analysis of blastocyst cycles showed that the risk of MZT was higher when transferring high-quality blastocysts [79.6% (223/280) vs. 67.8% (903/1 332), P<0.001], where as a trophectoderm (TE) grading of C [20.4% (57/280) vs. 32.2% (429/1 332), P<0.001] had a lower risk of MZT. After adjusting for confounding factors, the risk of MZT was found to increase with the transfer of blastocysts with a B-grade inner cell mass (ICM) ( OR=0.601, P=0.001, 95% CI: 0.442-0.819) and A/B grade TE (grade A: OR=2.951, P<0.001, 95% CI: 1.980-4.399; grade B: OR=1.840, P<0.001, 95% CI: 1.315-2.576). The risk of complications during pregnancy [47.7% (143/300) vs. 19.3% (289/1 500), P<0.001], preterm labor [55.1% (140/254) vs. 7.4% (101/1 368), P<0.001], and the risk of stillbirth [3.7% (11/300) vs. 1.5% (22/1 500), P=0.016] were significantly higher in the MZT pregnancy group than in the singleton pregnancy group. Conclusion:Assisted reproductive technology may contribute to the risk of MZT. Transfer of blastocysts, particularly those with loose ICM arrangement and dense TE arrangement, appears to increase the risk of MZT in patients undergoing eSET.

Aim To investigate the effects of Congrong San(CRS)on learning and memory ability,hippocam-pal neuronal injury,and ferroptosis in rats with Alzhei-mer's disease(AD)and to explore the related mecha-nisms.Methods AD rat models were established and divided into Sham,Model,CRS low-dose,CRS medium-dose,CRS high-dose,and memantine groups.After treatment,Morris water maze,HE and Nissl staining,transmission electron microscopy,immunofluorescence staining,Western blot,and kit assays were performed to assess learning and memory ability,hippocampal neuro-nal injury,ferroptosis-related indicatorsand glucose reg-ulated protein 78 ku(GRP78)-(proteinkinaseR-li-keERkinase)PERK-(activating transcription factor 4)ATF4 pathway protein expression.Results Com-pared with the model group,rats in the CRS medium-and high-dose groups and the memantine group showed significant improvement in learning and memory abili-ty,reduced hippocampal neuronal injury,increased number of Nissl bodies,and ameliorated endoplasmic reticulum swelling and mitochondrial damage.In addi-tion,the expressions of GRP78,p-PERK/PERK,and ATF4 were downregulated,while GPX4 expression was upregulated in the CRS medium-and high-dose groups and the memantine group.Moreover,MDA content de-creased,and SOD and GSH-PX levels increased in these groups.Conclusions CRS can improve the learning and memory ability in AD rats,reduce hipp-ocampal neuronal injury and ferroptosis,and its mecha-nism may be related to the inhibition of the GRP78-PERK-ATF4 pathway,enhancement of GPX4 expres-sion,and reduction of oxidative stress levels,providing a new approach for the clinical treatment of AD.

Objective:To explore the changes in nutritional status and body composition of cervical cancer patients during concurrent chemoradiotherapy (CCRT) and their correlation with CCRT toxicities.Methods:In this prospective and observational clinical study, eligible treatment -na?ve patients with stage IB-IV primary cervical cancer were consecutively enrolled in the Department of Radiotherapy of Peking Union Medical College Hospital from September 2022 to August 2023. The patients were screened for nutritional risks, received dietary assessment, and were measured for body composition using multi-frequency bioelectrical impedance at baseline (prior to treatment), 4 weeks, and 8 weeks since treatment initiation. Insufficient muscle mass was diagnosed ccording to the Asian Working Group for Sarcopenia 2019 criteria. The severity of nausea, vomiting, abdominal pain, diarrhea, and hematological toxicity was assessed by the U.S. National Cancer Institute Common Terminology Criteria for Adverse Events (version 5.0).Results:A total of 109 patients were included. At baseline, there were 11 (10.1%) patients who were lean, 17 (15.6%) patients with insufficient muscle mass, and 28 patients (25.7%) at nutritional risk; at Week 8 of CCRT, patients at nutritional risk increased to 61 (56.0%). Compared to baseline, weight [(59.34±9.67) kg vs. (61.30±9.64) kg, P<0.001], skeletal muscle index [SMI, (6.15±0.74) kg/m 2vs. (6.39±0.74) kg/m 2, P<0.001], body fat percentage [(31.13±7.67) % vs. (32.07±7.70) %, P=0.004] were significantly decreased at Week 8 of CCRT. Besides, ≥10% SMI loss was only related to baseline body fat percentage ( HR=0.216, 95% CI: 0.001-0.724, P=0.038), but not related to age, nutritional status, or muscle mass (all P>0.05). At baseline and 8 weeks since CCRT, 8 (28.6%) and 40 (65.6%) patients at nutritional risk received nutritional support, respectively. During CCRT, the rates of grade ≥2 nausea and vomiting, diarrhea, and grade 3/4 hematological toxicity were 37.6%, 28.4% and 44.0%, respectively. Baseline nutritional risk was a risk factor for diarrhea ( HR=2.447, 95% CI: 1.017-6.068, P=0.047), and an advanced International Federation of Gynecology and Obstetrics (FIGO) stage was a risk factor for severe nausea and vomiting ( HR=1.735, 95% CI: 1.005-2.995, P=0.048). Patients presenting with severe nausea and vomiting had more significant reductions in body mass index [(-1.44±1.29) kg/m 2vs. (-0.59±0.84) kg/m 2, P<0.001] and SMI [(-0.37±0.41) kg/m 2vs. (-0.12±0.27) kg/m 2, P=0.013] compared to those without nausea and vomiting, while there was no significant difference in visceral fat area between these two groups [(-9.95±19.48) cm 2vs. (-5.12±15.79) cm 2, P=0.161]. Conclusions:Patients with cervical cancer have increased nutritional risk and more loss of body weight and muscle mass during CCRT. The presence of nutritional risk at baseline is a risk factor for diarrhea, while nausea and vomiting exacerbate the losses of body weight, muscle, and fat. Close monitoring, intensive symptomatic therapy, and appropriate nutritional interventions should be performed in the clinical setting to improve patients' tolerance of treatment and maintenance of body weight.

Objective:To explore the correlation among SMAD4 gene polymorphisms, early life traumatic experience and their interactions with clinical feature of obsessive-compulsive disorder (OCD). Methods:Totally 484 OCD patients who met the DSM-Ⅳ diagnostic criteria and 368 health controls who met the enrollment criteria were recruited from September 2013 to September 2018. The Yale-Brown obsessive-compulsive scale (Y-BOCS) was used to assess the severity of obsessive-compulsive symptoms, the Beck depression inventory Ⅱ (BDI-Ⅱ) was used to assess the severity of depressive symptoms, the Beck anxiety inventory (BAI) was used to assess the severity of anxiety symptoms, and early trauma inventory-short form (ETI-SF) was used to assess early traumatic experience. SMAD4: rs12452684, rs2276163, rs17663887 and rs3819122 were genotyped using the Taqman genotyping technique. Data were analyzed using SPSS 20.0 software, and comparisons among groups were performed using chi-square test, t-test, Mann-Whitney U non-parametric test and analysis of covariance. Correlation was analyzed using Spearman correlation analysis, and interactions were analyzed using general linear model. Results:All sites except rs17663887 met the Hardy-Weinberg equilibrium (rs12452684: χ2=0.29, P=0.59; rs2276163: χ2=2.58, P=0.11; rs3819122: χ2=0.22, P=0.64).Allele, genotype frequencies of SMAD4: rs12452684, rs2276163 and rs3819122 were not statistically significant between the OCD and the health control groups ( χ2=0.02, 1.20, 0.04, all P>0.05; χ2=1.85, 3.98, 1.45, all P>0.05). The results of covariance analysis (corrected for age and gender) showed that there were significantly differences in compulsion (CC: 12.47±4.23, CT: 12.53±4.15, TT: 13.97±3.11; AA: 12.63±4.08, AC: 12.49±4.19, CC: 13.87±2.93) and total Y-BOCS scores(CC: 25.31±6.42, CT: 25.68±5.90, TT: 27.75±6.01; AA: 25.54±6.52, AC: 25.56±5.98, CC: 27.63±5.75) among the three genotypes of the SMAD4: rs2276163 and rs3819122 between the two groups ( F=3.58, 3.87, 3.48, 3.73, all P<0.05). Emotional abuse in the ETI-SF was positively correlated with obsession and total Y-BOCS scores( r=0.14, 0.14, both P<0.05). The interactions of rs2276163, rs3819122 and emotional abuse were associated with obsession scores ( F=4.65, 3.63, 2.93, all P<0.01). Conclusions:The more emotional abuse experienced in early life, the more severe obsessive-compulsive symptoms, and the interaction between the SMAD4 gene and early traumatic experience is involved in the development of OCD.

Enhancer of zeste homolog 2(EZH2)is a histone methyltransferase It mediates trimethylation of lysine 27 on histone H3,thereby facilitating the epigenetic silencing of downstream genes.In conjunc-tion with SUZ12,EED,and other components,it constitutes the polycomb repressive complex 2(PRC2)complex.While EZH2 is intricately involved in cellular proliferation and cardiac development,the chan-ges in its expression during cardiac terminal differentiation remain elusive.In this study,we employed differential gene expression analysis of embryonic and adult myocardial cells using the GEO database,and found that EZH2 is highly expressed in embryonic myocardium,but is present at very low levels in adult myocardium(P＜0.0001).Conversely,the expression changes of PRC2 members SUZ12 and EED are not as pronounced.Online analysis through the Tabula Muris database indicates that under physiological conditions,various cell subpopulations in the adult mouse heart exhibit negligible expression of EZH2.Immunohistochemical staining of mouse cardiac tissues shows that EZH2 is highly expressed in embryonic and neonatal myocardium but declines progressively from the first day after birth(P＜0.0001),becoming almost undetectable by the third day.Western blotting further confirms the rapid disappearance of EZH2 expression post-birth(P＜0.05),with EZH1 compensating for the downregulation of EZH2 to maintain H3K27me3 modification levels.Additionally,using the P19 teratocarcinoma stem cell model for cardio-myocyte differentiation,it is observed that EZH2 is significantly upregulated during the transition from cardiac progenitor cells to spontaneously beating cardiomyocytes,correlating with the expression of the cardiomyocyte transcription factor Gata4(P＜0.01).Targeted degradation of EZH2 using the small mole-cule drug MS1943 significantly inhibits the proliferation of induced cardiomyocytes,as evidenced by 5-e-thynyl-2'-deoxyuridine(EdU)incorporation assays(P＜0.01),and RT-qPCR reveals a marked in-crease in the expression of the proliferation inhibitor CDKN1A(P＜0.01).In summary,the high expres-sion of EZH2 in embryonic myocardial cells is associated with enhanced cell proliferation.The rapid loss of EZH2 expression postnatally correlates with the loss of proliferative capacity in cardiomyocytes,mark-ing it as a key indicator of cardiac terminal differentiation.