1.Status and correlations of psychological distress, job satisfaction, and sleep quality among prehospital emergency medical personnel in Guangzhou
Jiarui LIANG ; Huilin JIANG ; Baoling WU ; Hanxiang GONG ; Jiangli WU ; Tongtong DENG ; Zhengyu CHEN ; Xiaohui CHEN
Journal of Environmental and Occupational Medicine 2026;43(5):614-620
Background Prehospital emergency medical personnel (PEMP) are exposed to long-term high-pressure work, which can exacerbate psychological distress and impair job satisfaction and sleep quality. However, in-depth research on the interactions among these factors is lacking. Objective To assess the status of psychological distress, job satisfaction, and sleep quality of PEMP in Guangzhou and to explore the mediating role of sleep quality in the relationship between psychological distress and job satisfaction. Methods From February to May 2025, 1085 PEMP from "120" emergency network hospitals in Guangzhou were selected using convenience sampling. Data were collected via the General Information Questionnaire, Kessler Psychological Distress Scale, Minnesota Satisfaction Questionnaire, and Pittsburgh Sleep Quality Index. Statistical analyses were performed using SPSS 25.0, and The mediation model of sleep quality in linking psychological distress and job satisfaction was constructed using AMOS 28.0. The bias-corrected Bootstrap method was employed to assessed the significance of the mediating effect. Results A total of 1063 valid responses were received (97.97% valid response rate). The mean scores were: psychological distress (27.99±10.75), job satisfaction (69.45±15.84), and sleep quality (9.82±4.47). Significant differences in the three scores were found across gender, age, monthly night shift frequency, and hospital grade (P<0.05). Higher job satisfaction was linked to lower psychological distress and better sleep quality and its dimensions, while psychological distress directly correlated with poorer sleep quality (P<0.01). Sleep quality partially mediated the relationship between psychological distress and job satisfaction, with a mediating effect of −0.195, accounting for 43.62% of the total effect. Conclusion The participants report moderate psychological distress, moderate-to-high job satisfaction, and poor sleep quality. Psychological distress directly affects job satisfaction and indirectly through its impact on sleep quality. Interventions aimed at improving sleep health and mental health are essential to improve personnel well-being and work efficiency.
2.Status and correlations of psychological distress, job satisfaction, and sleep quality among prehospital emergency medical personnel in Guangzhou
Jiarui LIANG ; Huilin JIANG ; Baoling WU ; Hanxiang GONG ; Jiangli WU ; Tongtong DENG ; Zhengyu CHEN ; Xiaohui CHEN
Journal of Environmental and Occupational Medicine 2026;43(5):614-620
Background Prehospital emergency medical personnel (PEMP) are exposed to long-term high-pressure work, which can exacerbate psychological distress and impair job satisfaction and sleep quality. However, in-depth research on the interactions among these factors is lacking. Objective To assess the status of psychological distress, job satisfaction, and sleep quality of PEMP in Guangzhou and to explore the mediating role of sleep quality in the relationship between psychological distress and job satisfaction. Methods From February to May 2025, 1085 PEMP from "120" emergency network hospitals in Guangzhou were selected using convenience sampling. Data were collected via the General Information Questionnaire, Kessler Psychological Distress Scale, Minnesota Satisfaction Questionnaire, and Pittsburgh Sleep Quality Index. Statistical analyses were performed using SPSS 25.0, and The mediation model of sleep quality in linking psychological distress and job satisfaction was constructed using AMOS 28.0. The bias-corrected Bootstrap method was employed to assessed the significance of the mediating effect. Results A total of 1063 valid responses were received (97.97% valid response rate). The mean scores were: psychological distress (27.99±10.75), job satisfaction (69.45±15.84), and sleep quality (9.82±4.47). Significant differences in the three scores were found across gender, age, monthly night shift frequency, and hospital grade (P<0.05). Higher job satisfaction was linked to lower psychological distress and better sleep quality and its dimensions, while psychological distress directly correlated with poorer sleep quality (P<0.01). Sleep quality partially mediated the relationship between psychological distress and job satisfaction, with a mediating effect of −0.195, accounting for 43.62% of the total effect. Conclusion The participants report moderate psychological distress, moderate-to-high job satisfaction, and poor sleep quality. Psychological distress directly affects job satisfaction and indirectly through its impact on sleep quality. Interventions aimed at improving sleep health and mental health are essential to improve personnel well-being and work efficiency.
3.Effects of meropenem exposure and degradation levels on clinical efficacy in patients with purulent meningitis
Tongtong LI ; Jiantong SUN ; Xianglong CHEN ; Peng DENG ; Yanping XUE ; Yao XIAO ; Lijuan YANG ; Jinhui XU ; Yanxia YU ; Lian TANG
China Pharmacy 2025;36(24):3084-3090
OBJECTIVE To explore the effects of meropenem exposure and degradation levels on clinical efficacy in patients with purulent meningitis (PM). METHODS A total of 131 PM patients treated with meropenem at the Affiliated Suzhou Hospital of Nanjing Medical University from January 2022 to June 2025 were prospectively included. Relevant data were collected and divided into a cured group (91 cases) and a non-cured group (40 cases) based on the efficacy. High-performance liquid chromatography-tandem mass spectrometry was used to determine the concentration of meropenem and its open-loop metabolites. Risk factors that affect efficacy were screened, and their predictive power and correlation were evaluated by univariate analysis, and multivariate Logistic regression analysis, receiver operating characteristic (ROC) curves, and correlation analysis. RESULTS Univariate analysis showed that serum creatinine, creatinine clearance rate, minimum inhibitory concentration of meropenem ≥16 μg/mL, cerebrospinal fluid red blood cell count, cerebrospinal fluid white blood cell count, cerebrospinal fluid glucose content, blood trough concentration, blood open-loop metabolite concentration/trough concentration ratio, and intrathecal injection were all correlated with efficacy (P<0.05). The results of multiple Logistic regression analysis showed that serum creatinine blood open-loop metabolite concentration/trough concentration ratio, intrathecal injection, and cerebrospinal fluid glucose content were influencing factors for suboptimal anti-infective ltt efficacy (P<0.05). ROC curve analysis showed that when the blood open-loop metabolite concentration/trough concentration ratio was greater than 2.854 (AUC=0.647), serum creatinine was less than 59.5 μmol/L (AUC=0.647), and cerebrospinal fluid glucose content was less than 3.37 mmol/L (AUC=0.709), the risk of treatment failure significantly increased (P<0.05). Correlation analysis showed that the blood trough concentration of meropenem was positively correlated with the concentration of its open-loop metabolites (R 2=0.134 5, P<0.000 1). CONCLUSIONS Insufficient exposure level and rapid degradation of meropenem are key mechanisms affecting the anti-infective efficacy of PM. Elevated blood open-loop metabolite concentration/ trough concentration ratio, low serum creatinine level, lack of intrathecal injection, and low cerebrospinal fluid glucose content are independent risk factors for poor efficacy.
4.Association between screen time and anxiety-depression symptoms and their comorbidity among middle school students in Taiyuan City
Chinese Journal of School Health 2025;46(7):980-984
Objective:
To investigate the association between screen time (ST) during leisure time and anxiety-depression symptoms among middle school students, so as to provide a basis for formulating relevant intervention measures.
Methods:
From November to December 2023, a stratified cluster random sampling method was used to select 2 542 students from junior and senior high school in Taiyuan City. A self designed questionnaire, the Generalized Anxiety Disorder Scale (GAD-7), and the Patient Health Questionnaire (PHQ-9) were used to investigate ST and anxiety/depression symptoms among middle school students. The Logistic regression model was used to explore the association of ST with symptoms of anxiety and depression, as well as with anxiety and depression comorbiditles (CAD).
Results:
The detection rates of anxiety symptoms, depression symptoms, and CAD were 13.69%, 15.77%, and 10.11%, respectively. The median ST was 2.00 h/d [interquartile range ( IQR =2.38) for weekly averages], with 0.33 h/d ( IQR =1.67) on work days and 5.00 h/d ( IQR=5.50) on rest days. Logistic regression analysis indicated that the total ST of mobile phones during rest days ( OR =1.07, 1.10, 1.11) and the averages ST of mobile phones over a week ( OR = 1.20 , 1.22, 1.29), as well as the total ST of all screen types during rest days ( OR =1.04, 1.04, 1.05) and the averages ST of all screen types over a week ( OR =1.08, 1.09, 1.21) were positively correlated with anxiety symptoms, depression symptoms, and CAD (all P <0.01).
Conclusions
Among middle school students in Taiyuan City, screen time is positively correlated with symptoms of anxiety or depression and the comorbidity of anxiety and depression, especially smartphone screen time and weekend screen use. Therefore, measures should be implemented to reduce unnecessary screen time among middle school students, especially the use of mobile phones, in order to mitigate the occurrence of anxiety and depression.
5.Analysis of risk factors for multidrug resistance in patients with ventilator-associated pneumonia complicated by prolonged invasive mechanical ventilation in the ICU
Tongtong HU ; Yongwu CHEN ; Zhicheng HU
China Pharmacy 2025;36(16):2051-2056
OBJECTIVE To analyze the risk factors for multidrug-resistant organism (MDRO) infection in patients with prolonged invasive mechanical ventilation (IMV) complicated by ventilator-associated pneumonia (VAP) in the intensive care unit (ICU), thus providing a reference for improving the clinical effect of VAP treatment in this region. METHODS A retrospective analysis was performed on the clinical data of patients who were admitted to the ICU in Shexian Branch of the Second Affiliated Hospital of Zhejiang University School of Medicine (hereinafter referred to as “our hospital”) from October 2022 to February 2025, received prolonged IMV, and developed VAP. The distribution and drug resistance of pathogens were statistically analyzed. Patients were divided into the MDRO group and the non-MDRO group according to whether an MDRO infection occurred. Univariate analysis and multivariate Logistic regression analysis were used to screen independent risk factors for MDRO infection. RESULTS A total of 281 pathogenic strains were cultured from 97 patients, including 262 Gram-negative bacteria (93.24%), 9 Gram-positive bacteria (3.20%), and 10 fungi (3.56%). The main Gram-negative bacteria were Pseudomonas aeruginosa, Klebsiella pneumoniae subspecies pneumoniae, and Acinetobacter baumannii. The former two showed high resistance rates (all≥25%) to common antibiotics such as imipenem, while A. mail:64375689@qq.com baumannii demonstrated high resistance to most antimicrobial agents. The main Gram-positive bacteria were Staphylococcus aureus subspecies aureus and S. haemolyticus, which were resistant to multiple antibiotics such as clindamycin (resistance rates all>30%). Among 281 pathogenic strains, 121 were MDRO, 62 were resistant to carbapenems, and 33 produced extended-spectrum β-lactamases. The serum albumin<28 g/L, ICU stay≥14 days, and use of benzodiazepines were independent risk factors for MDRO infection in patients with prolonged IMV and VAP in our hospital’s ICU (odds ratios were 3.289, 2.991 and 2.680, 95% confidence intervals were 1.183-9.144, 1.021-8.765, and 1.012- 7.094, respectively, P<0.05). CONCLUSIONS Pathogens infecting patients with prolonged IMV and VAP in the ICU are mainly Gram-negative bacteria, with P. aeruginosa, K. pneumoniae subspecies pneumoniae and A. baumannii, accounting for a high proportion, and the drug resistance situation is severe. Serum albumin<28 g/L, ICU stay≥14 days, and use of benzodiazepines are independent risk factors for MDRO infection in such patients.
6.Distribution characteristics of serum HBsAg levels in Chinese patients with chronic hepatitis B based on CR-HepB
Shuyan CHEN ; Shan SHAN ; Yuanyuan KONG ; Xiaoqian XU ; Hao WANG ; Xiaoning WU ; Jialing ZHOU ; Bingqiong WANG ; Tongtong MENG ; Mengyang ZHANG ; Jidong JIA ; Yameng SUN ; Hong YOU
Chinese Journal of Hepatology 2025;33(1):34-40
Objective:To explore the distribution characteristics of HBsAg levels in treatment-na?ve and treatment-experienced patients with chronic hepatitis B (CHB) in China.Methods:Data were obtained from the China Registry of Hepatitis B (CR-HepB) platform from the establishment of the platform to April 11, 2024. Patients with CHB who were treatment-na?ve and treatment-experienced with nucleos(t)ide analogs (NAs) were included. Relevant clinical data were collected. The distribution of hepatitis B surface antigen (HBsAg) status, as well as the levels in populations of different age groups after different antiviral treatment durations, were retrospectively analyzed. Normally and non-normally distributed measured data were represented by Mean± SD, and M( Q1, Q3). Results:A total of 13 505 treatment-na?ve patients and 6 390 treatment-experienced patients were included in the analysis. The proportions of treatment-na?ve patients with HBsAg<100, <500, and <1 500 IU/mL were 10.51%, 28.47%, and 46.85%, and the corresponding proportions of treatment-experienced patients were 12.88%, 29.84%, and 52.07%. The proportions of treatment-na?ve patients with HBsAg levels≥1 500, ≥3 000, and≥8 000 IU/mL were 53.15%, 38.17%, and 15.62%, and the corresponding proportions of treatment-experienced patients were 47.93%, 31.77%, and 10.39%. HBsAg level showed a trend of gradual decrease with the increase of antiviral treatment time. The proportion of treatment-experienced patients with HBsAg<100 IU/mL increased from 12.73% when the treatment duration was less than three years to 26.92% when the treatment duration was≥10 years, while the proportion of patients with HBsAg levels≥3 000 IU/mL or≥8 000 IU/mL decreased from 34.66% to 23.08% and from 12.19% to 5.77%, respectively. The proportion of patients with HBsAg<100, <500, and<1 500 IU/mL increased with age, while the proportion of patients with HBsAg≥1 500, ≥3 000, and ≥8 000 IU/mL decreased sequentially.Conclusions:The CR-HepB platform provides a basis for clarifying the serum HBsAg levels in treatment-na?ve and treatment-experienced CHB patients in China. The HBsAg status indicates that with a prolonged antiviral treatment duration, there is a gradual decline trend in HBsAg level.
7.Predictive role of dynamic changes in liver stiffness measurement for liver-related endpoint events in chronic hepatitis B
Chenglin SUN ; Shuyan CHEN ; Xiaoning WU ; Jialing ZHOU ; Tongtong MENG ; Bingqiong WANG ; Xinyan ZHAO ; Xiaojuan OU ; Jidong JIA ; Yameng SUN ; Hong YOU
Chinese Journal of Hepatology 2025;33(10):993-1000
Objective:To investigate the role of dynamic changes in liver stiffness measurement (LSM) in predicting liver-related end-point events (LREs) occurrence in patients with chronic hepatitis B (CHB) with liver fibrosis during long-term antiviral therapy.Methods:Data were collected from CHB patients whose liver biopsy results showed Metavir fibrosis stage F2~F4 or clinically diagnosed cirrhosis. Entecavir antiviral therapy was mainly administered. Follow-up was conducted once every six months. Clinical data such as demographic information, blood routine tests, liver biochemical parameters, HBV virological and serological test results, and LSM were collected. Dynamic changes in LSM were categorized into four types based on LSM levels before treatment (0y) and following two years of antiviral therapy (2y) : (1) LSM 0y < 10 kPa and LSM 2y < 10 kPa, i.e., LSM persisted < 10 kPa; (2) LSM 0y < 10 kPa and LSM 2y ≥ 10 kPa, i.e., LSM increased to ≥ 10 kPa; (3) LSM 0y ≥ 10 kPa and LSM 2y < 10 kPa, i.e., LSM decreased to < 10 kPa; (4) LSM 0y ≥ 10 kPa and LSM 2y ≥ 10 kPa, i.e., LSM persisted ≥ 10 kPa. The predictive role of the dynamic changes of LSM in the occurrence of LREs was analyzed. The Wilcoxon rank-sum test was used for quantitative data. Fisher's exact test was used for categorical data. Multivariate analysis was performed using the Cox proportional hazards regression model. Survival curves were plotted and compared using the Kaplan-Meier. Results:A total of 713 CHB cases with liver fibrosis were included, among whom 512 had cirrhosis. The cumulative incidence of LREs following two years of antiviral therapy was low in patients with LSM 0y < 10 kPa during follow-up (all patients: LSM persisted < 10 kPa 1.6% vs. LSM increased to ≥ 10 kPa 0%; cirrhosis subgroup: LSM persisted < 10 kPa 0% vs. LSM increased to ≥ 10 kPa 0%). The 5-year cumulative incidence of LREs following two years of antiviral treatment was significantly higher in patients with LSM0y ≥ 10 kPa than in those with LSM persisting ≥ 10 kPa and those with LSM decreasing to < 10 kPa during follow-up (all patients: LSM persisted ≥ 10 kPa 12.4% vs. LSM decreased to < 10 kPa 3.6%; cirrhosis subgroup: LSM persisted ≥ 10 kPa 12.6% vs. LSM decreased to < 10 kPa 4.3%). Patients with LSM persisting at ≥ 10 kPa had a significantly increased risk of LREs following two years of antiviral treatment compared with those whose LSM decreased to <10 kPa during follow-up after adjusting for age, gender, baseline body mass index, platelet count, and alanine aminotransferase (all patients, aHR=2.96, 95% CI: 1.41~6.24, P=0.005; cirrhosis subgroup, aHR=2.74, 95% CI:1.26~5.95, P=0.011). Conclusions:LSM<10 kPa before antiviral treatment had a lower risk of liver-related endpoint events following two years of treatment among CHB patients with liver fibrosis. LSM ≥10 kPa before antiviral treatment and LSM persisted ≥10 kPa two years following treatment had a significantly higher occurrence risk of liver-related endpoints than LSM<10 kPa following treatment among CHB patients with liver fibrosis.
8.Effects of miR-483-3p on hypoxia/reoxygenation-induced apoptosis and pyroptosis in cardiomyocytes
Yufen LU ; Xiaoming ZHENG ; Shaojuan WEI ; Liqin CHEN ; Tongtong XU ; Xiangwei LÜ
The Journal of Practical Medicine 2025;41(3):339-346
Objective To investigate the effects of miR-483-3p on hypoxia/reoxygenation(H/R)-induced apoptosis and pyroptosis of H9c2 cardiomyocytes and its possible mechanism.Methods Rat H9c2 cardiomyocytes were cultured in vitro,adeno-associated virus-infected H9c2 and the H/R model were constructed by triple-air incuba-tor,and the cells were randomly divided into blank control(Sham)group,model(H/R)group,AAV-miR-483-3p mimic+H/R(AAV-miR-483-3p)group,AAV-miR-483-3p negative control+H/R(AAV-NC)group.The growth status of cells in each group was observed using an inverted microscope;cell proliferation activity was detected by cell counting kit-8(CCK-8);LDH release by lactate dehydrogenase(LDH)kit;apoptosis rate by flow cytometry;apoptosis by notched end labeling(TUNEL).Western blot(WB)was used to detect the expression levels of IL-1β and GSDMD proteins in each group.Results Compared with the Sham group,the H/R group showed abnormal cell status and increased cell death,decreased cell activity,increased LDH release,increased apoptosis rate and apopto-sis level,and increased expression levels of IL-1β and GSDMD proteins(P<0.05);compared with the H/R group,the AAV-miR-483-3p group showed improved cell status and less cell death,increased cell proliferation activity,increased LDH release,and increased IL-1β and GSDMD protein expression levels(P<0.05).Compared with the H/R group,the AAV-miR-483-3p group showed improved cell status and less cell death,increased cell proliferation activity,decreased LDH release,decreased apoptosis rate and apoptosis level,and decreased expression of IL-1β and GSDMD proteins(P<0.05).Conclusion Over-expression of miR-483-3p can improve H/R-inducedH9c2 cardiomyocyte injury by enhancing cell activity and cell metabolism,and inhibiting apoptosis and cell charring.
9.Characteristics and prognosis of patients with primary sclerosing cholangitis
Sha CHEN ; Tongtong MENG ; Weijia DUAN ; Shuxiang LI ; Tingting LYU ; Yu WANG ; Jidong JIA ; Yuanyuan KONG ; Hong YOU
Chinese Journal of Internal Medicine 2025;64(3):206-211
Objective:Primary sclerosing cholangitis (PSC) is a rare autoimmune disease. This study aims to describe the baseline characteristics and clinical outcomes of Chinese PSC patients and explore risk factors associated with prognosis, addressing the lack of long-term prognostic analysis in China.Methods:Clinical data of PSC patients were retrospectively collected from May 2009 to June 2023 in Beijing Friendship Hospital Affiliated to Capital Medical University, and patient follow-up was conducted through outpatient visits, telephone calls, and medical record reviews. The Cox proportional hazards model and the Kaplan-Meier method were employed to identify risk factors and estimate transplant-free survival.Results:A total of 65 PSC patients were enrolled, with male patients accounting for 50.8% and an average age of onset of 44 years. The disease types primarily included large duct PSC (57.9%) and whole duct PSC (22.8%). Most patients (78.5%) sought medical attention due to symptoms, with common clinical manifestations including jaundice (32.3%), fatigue (23.1%), abdominal discomfort (21.5%), pruritus (16.9%), and fever (10.8%). A total of 19 patients (29.2%) had concomitant ulcerative colitis. Compared to large duct PSC or whole duct PSC, small duct PSC showed a lower proportion of concomitant ulcerative colitis ( P<0.001) and milder baseline disease severity. After a median follow-up of 29 months (interquartile range: 11,53), 19 patients experienced liver transplantations and/or liver disease-related deaths. The overall 2-year and 5-year transplant-free survival rates for PSC patients were 76.0% and 59.5%, respectively. Elevated bile acid levels were identified as an independent risk factor for poor outcomes in PSC patients. Conclusion:The study population of Chinese PSC patients predominantly consisted of middle-aged males, characterized by a low ratio of asymptomatic cases, a low incidence of associated inflammatory bowel disease, and a low rate of transplant-free survival. Elevated bile acid level was identified as an independent risk factor for poor outcomes in PSC patients.
10.CHK1 attenuates cardiac senescence of mice through activating Rap1/Nox4 mediated oxidative stress homeostasis
Peng JING ; Liuhua ZHOU ; Yixi CHEN ; Lingfeng GU ; Chong DU ; Tongtong YANG ; Shuxuan CHEN ; Hao WANG ; Liansheng WANG
Chinese Journal of Cardiology 2025;53(12):1411-1421
Objective:To investigate the biological role and molecular mechanism of checkpoint kinase 1 (CHK1) in delaying cardiac aging in mice.Methods:In vitro, a senescence model of H9C2 cells (a cardiomyocyte line) was induced using H 2O 2. A control group (without H 2O 2 treatment) and three H 2O 2-treated groups (at concentrations of 10, 30, and 50 μmol/L) were set up. The CCK-8 assay was used to evaluate the proliferative activity of cells in each group; Western blot analysis was employed to detect the expression level of CHK1; and quantitative real-time polymerase chain reaction (qRT-PCR) was utilized to determine the messenger RNA (mRNA) expression levels of P16 and interleukin-1β (IL-1β). In vivo, C57BL/6 wild-type mice aged 2 months ( n=15) and 24 months ( n=40), as well as myocardial-specific CHK1-overexpressing (CHK1-TG) mice aged 2 months ( n=15) and 24 months ( n=40), were selected. The mice were divided into four groups based on age and genotype: 2-month-old wild-type (WT-2M), 24-month-old wild-type (WT-24M), 2-month-old CHK1-TG (CHK1-TG-2M), and 24-month-old CHK1-TG (CHK1-TG-24M). Echocardiography was used to evaluate cardiac function of mice in the WT-24M and CHK1-TG-24M groups. Western blot analysis was conducted to measure the protein expression levels of CHK1, total Ras-related protein 1 (Rap1), NADPH oxidase 4 (Nox4), and Rap1-guanosine triphosphate (Rap1-GTP, the active form of Rap1) in the cardiac tissue of mice in each group. qRT-PCR was used to detect the messenger RNA (mRNA) expression levels of CHK1, collagen type Ⅰ (Coll1), matrix metalloproteinase-2 (Mmp2), alpha-smooth muscle actin (α-SMA), P53, P21, P16, thioredoxin 1 (Trx1), thioredoxin reductase (TrxR), glutathione recluctase (GR), Rap1, and Nox4. Immunofluorescence staining was employed to determine the protein expression levels of P53, P21, and P16, as well as the proportion of histone H2AX phosphorylation-positive cells. Dihydroethidium (DHE) staining was used to detect the relative intensity of DHE. Wheat germ agglutinin staining, HE staining, Masson staining and Sirius red staining were applied to measure the cross-sectional area of cardiomyocytes, cardiac morphology, and myocardial fibrosis area. Mice in the WT-24M and CHK1-TG-24M groups were intraperitoneally injected with the Rap1 activity inhibitor GGTI298 (25 μmol/kg). After injection, the oxidative stress damage in the cardiac tissue of the mice was detected, along with the mRNA expression levels of fibrosis-related indicators (Coll1, Mmp2, and α-SMA) and cell cycle inhibitory proteins (P16, P21, and P53). Results:A concentration of 30 μmol/L was determined as the optimal concentration for establishing an H 2O 2-induced senescence model of myocardial cells in vitro. The expression level of CHK1 in H9C2 cells of the 30 μmol/L H 2O 2 group was lower than that in the control group ( P<0.05). Echocardiographic examination showed that the left ventricular ejection fraction ((61.08±1.13)% vs. (52.55±2.02)%) and fractional shortening ((31.80±1.27)% vs. (25.18±1.59)%) of mice in the CHK1-TG-24M group were higher than those in the WT-24M group (both P<0.05). qRT-PCR and Western blot analysis revealed that, compared with the WT-24M group, mice in CHK1-TG-24M group had higher expression levels of CHK1 and its mRNA, lower expression levels of Nox4 and its mRNA, and higher expression level of Rap1-guanosine triphosphate (Rap1-GTP) (all P<0.05). However, there were no statistically significant differences in the total expression level of Rap1 and its mRNA between the two groups (both P>0.05). In addition, the mRNA expression levels of Coll1, Mmp2, and α-SMA in myocardial tissue of mice in the CHK1-TG-24M group were lower than those in the WT-24M group (all P<0.05). Immunofluorescence staining results showed that the expression levels of P53, P21, and P16 proteins, as well as the proportion of phosphorylated histone H2AX-positive cells in myocardial tissue of mice in the WT-24M group were higher than those in the CHK1-TG-24M group (all P<0.05). qRT-PCR further confirmed that the mRNA expression levels of the above-mentioned proteins in cardiac tissue of mice in the WT-24M group were higher than those in the CHK1-TG-24M group (all P<0.05). DHE staining results indicated that the relative intensity of DHE in cardiac tissue of mice in the CHK1-TG-24M group was lower than that in the WT-24M group ( P<0.05). Meanwhile, the left ventricular internal diameter, cross-sectional area of cardiomyocytes, and myocardial fibrosis area of mice in the CHK1-TG-24M group were all smaller than those in the WT-24M group (all P<0.05). Furthermore, the degree of DNA damage in cardiac tissue as well as the mRNA levels of fibrosis-related indicators (Coll1, Mmp2, and α-SMA) and cell cycle inhibitory proteins (P53, P21, P16) in mice of the WT-24M+GGTI298 group were higher than those in the WT-24M group and the CHK1-TG-24M+GGTI298 group (all P<0.05). Conclusion:CHK1 alleviates oxidative stress-induced damage in mouse cardiomyocytes by activating the Rap1/Nox4 signaling pathway, thereby delaying cardiac aging in mice.


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