Objective:To investigate the effect of DEAD-box helicase (DDX) 21 on myocardial ischemia-reperfusion (I/R) injury and its potential mechanisms.Methods:In vivo, adult male Bama pigs and C57BL/6J mice were used to establish a myocardial I/R injury model by ligating the left anterior descending coronary artery, with sham-operated groups set as controls. The expression of DDX21 in myocardium after I/R injury was assessed by quantitative real-time PCR (qRT-PCR), Western blot, and immunofluorescence staining. Following the establishment of the myocardial I/R injury model in mice, AAV9 vectors with cardiac-specific expression were injected in situ into the peri-infarct region (The I/R+DDX21 group, I/R+negative control (NC) group, I/R+sh-NC group and I/R+sh-DDX21 group were injected with AAV9:cTnT-DDX21, AAV9:cTnT-NC, AAV9:cTnT-sh-NC and AAV9:cTnT-sh-DDX21, respectively). Additionally, the I/R+A-485 group received intraperitoneal injections of the cAMP response element-binding protein (CREB) binding protein inhibitor A-485, while the I/R+PBS group was injected with an equivalent volume of phosphate-buffered saline (PBS) as the control. Echocardiography was performed on postoperative days 1 and 28 to evaluate cardiac function (left ventricular ejection fraction and fractional shortening). At 28 days post-surgery, mice were euthanized and heart tissues were harvested for histological sectioning. Myocardial fibrosis was evaluated using Masson′s trichrome staining. In vitro, primary cardiomyocytes were isolated from neonatal day 1 C57BL/6J mice using enzymatic digestion method. Cardiomyocytes were transfected with plasmids or small interfering RNA (siRNA). The cardiomyocytes transfected with DDX21-siRNA were assigned to the siDDX21 group, those transfected with the DDX21 plasmid were assigned to the DDX21 group, and those transfected with the corresponding empty plasmid or siRNA were assigned to the NC group. Additionally, cardiomyocytes were treated with A-485 (A-485 group) or PBS (PBS group). An oxygen-glucose deprivation/reoxygenation (OGD/R) model was used to simulate cellular injury. Transcriptome sequencing was performed to identify downstream mechanisms of DDX21. Differential gene expression analysis was conducted using software such as DESeq2, and alternative splicing events in the mRNA transcriptome were analyzed using rMATS software. Mitochondrial superoxide, mitochondrial membrane potential, ATP content, and mitochondrial respiratory chain complex enzyme activity in cardiomyocytes were detected using immunofluorescence staining and commercial assay kits. The oxidative phosphorylation level of the cells was assessed by the Seahorse extracellular flux analyzer. Acetylated DDX21 levels were measured using co-immunoprecipitation and Western blot assays.Results:The expression levels of DDX21 in myocardium from the Bama pigs and mice in the I/R injury model were significantly higher than those in the sham group (all P<0.001). Echocardiographic results showed that at 28 days post-surgery, compared to the I/R+NC group, the I/R+DDX21 group exhibited higher left ventricular ejection fraction and fractional shortening, while the I/R+sh-DDX21 group showed lower values; Masson staining results demonstrated that, compared to the I/R+NC group, the myocardial fibrosis area in the I/R+DDX21 group was significantly reduced, whereas it was significantly increased in the I/R+sh-DDX21 group (all P<0.001). Transcriptomic sequencing results suggested that DDX21 may influence myocardial injury by regulating mitochondrial metabolic activity. In vitro, compared to the OGD/R+NC group, the OGD/R+DDX21 group exhibited lower mitochondrial superoxide levels, higher polymer/monomer ratio, maximal oxygen consumption, reserve capacity, and ATP content. In contrast, the OGD/R+siDDX21 group showed the opposite results, with reduced activity of mitochondrial respiratory chain complex V (all P<0.05). Mechanistically, rMATS software and other analyses indicated that knockdown of DDX21 affected the alternative 3′ splicing sites of ATP5J precursor mRNA, inhibiting the splicing of certain exonic sequences. Overexpression of DDX21 upregulated both mRNA and protein levels of ATP5J. Co-immunoprecipitation experiments showed that, compared to the PBS group, acetylated DDX21 levels were reduced in the A-485 group. Further in vivo experiments showed that, compared to the I/R+PBS group, the I/R+A-485 group exhibited higher left ventricular ejection fraction and fractional shortening, and a lower proportion of left ventricular fibrosis (all P<0.001). Conclusions:DDX21 improves cardiomyocyte energy metabolism and alleviates I/R injury by regulating the alternative splicing of ATP5J. A-485 holds potential as a novel small molecule candidate for the treatment of myocardial injury.

Objective:To compare the clinical efficacy of laparoscopic Miles surgery through extraperitoneal stoma and intraperitoneal stoma.Methods:The medical records of 140 patients with low rectal cancer after laparoscopic Miles surgery admitted to Gastrointestinal Surgery of Northern Jiangsu People′s Hospital of Jiangsu Province from January 2018 to December 2022 were retrospectively analyzed. Among them, 80 were males and 60 were females, aged 50 to 75 years old, with an average age of 63.95 years old. They were divided into observation group (extraperitoneal stoma, n=70) and control group (intraperitoneal stoma, n=70) based on the stoma method. Through telephone, WeChat, outpatient follow-up and other contact methods, the intraoperative and postoperative recovery, the incidence of perioperative complications (stoma edema, stoma ischemia, peristoma inflammation, perineal/pelvic infection, lung infection) and the incidence of complications at 6 months and 1 year after surgery (stoma stricture, parastoma hernia/internal hernia, stoma prolapse/retraction), and the difference in the ability of artificial anus to control defecation at 1 year after surgery were compared between the two groups. SPSS27.0 statistical software was used for data analysis and processing. Results:(1) Incidence of individual complications such as lung infection between the two groups of patients during the perioperative period (4.3% vs 4.3%, χ2=0.17, P=0.676), stoma edema (25.7% vs 21.4%, χ2=0.36, P=0.550), stoma ischemia (7.1% vs 7.1%, χ2=0.00, P=1.000), peristomal inflammation (20.0% vs. 18.6%, χ2=0.05, P=0.830), perineal/pelvic infection (15.7% vs 27.1%, χ2=2.72, P=0.099), there was no difference between the two groups. There was still no difference in the overall complication rate between the two groups (72.9% vs 78.6%, χ2=0.62, P=0.430). (2) After follow-up to 6 months after surgery, the overall complication rate was 5.7% in the observation group compared with 22.9% in the control group ( χ2=7.06, P=0.008). In particular, the incidence of post-operative parastomal hernia/internal hernia did not occur in the observation group, while 8.6% of patients in the control group occurred (18.6% vs 42.9%, χ2=4.35, P=0.037). (3) After follow-up to 1 year after surgery, the overall complication rate in the observation group was lower than that in the control group ( χ2=8.59, P=0.003). The incidence of parastomal hernia/internal hernia after operation in the observation group was lower than that in the control group (2.9% vs 14.3%, χ2=4.47, P=0.034). (4) At the one-year follow-up, the overall excellent and good rate in the evaluation of bowel function in the observation group was higher than that in the control group (71.4% vs 48.6%, χ2=7.62, P=0.006). Conclusions:In laparoscopic Miles surgery for patients with rectal cancer, choosing extraperitoneal stoma has achieved good results, which can reduce the risk of complications 6 months or even 1 year after surgery, especially in preventing and controlling parastomal hernia/internal hernia. It has significant advantages, and at the same time, it can also promote the recovery of patients′ bowel function and reduce other related complications, thereby ensuring patient safety.

Objective To investigate the regulatory role and mechanism of mitochondrial riboso-mal protein S35(MRPS35)in the proliferation,invasion,and migration of colon cancer cells.Meth-ods A total of 120 colon cancer tissues and adjacent normal tissues from patients undergoing radical resection for colon cancer were collected.Human colon cancer cell lines(HCT116,SW480,SW620)and a human normal colon epithelial cell line(NCM460)were cultured.Bioinformatics analysis,real-time quantitative polymerase chain reaction,Western blot,immunohistochemical(IHC)analysis,and cellular functional experiments(plate clone formation assay,scratch test,Transwell migration assay,CCK-8 cell viability assay)were conducted to evaluate the expression and regulatory mechanism of MRPS35 in colon cancer.Results Bioinformatics analysis showed that the expression level of the MRPS35 gene was higher in colorectal cancer tissues than in adjacent normal tissues(P＜0.05).The relative expression levels of MRPS35 mRNA and MRPS35 protein were higher in human colon cancer cell lines(HCT116,SW480,SW620)than in NCM460 cells(P＜0.05).The relative ex-pression level of MRPS35 protein was higher in colon cancer tissues than that in adjacent normal tis-sues(P＜0.05).The expression level of MRPS35 was significantly correlated with tumor diameter,tumor differentiation,and T stage(P=0.002,0.021,0.036).Patients with high MRPS35 expres-sion had a higher overall survival rate than those with low MRPS35 expression(Log-rank P=0.015).After knockdown of MRPS35,the abilities of colon cancer cell cloning,proliferation,invasion,and migration were significantly enhanced.Furthermore,the expression of Wnt1,β-Catenin,and their downstream target proteins increased significantly after MRPS35 knockdown.Conclusion MRPS35 is significantly overexpressed in both colon cancer tissues and colon cancer cells,and it may inhibit the occurrence and development of colon cancer by regulating the Wnt/β-Catenin signaling pathway.Therefore,MRPS35 has the potential to become a novel biomarker and therapeutic target for colon cancer.

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.

Objective To understand the changing profiles of antimicrobial susceptibility of the bacterial strains isolated from patients at Liuzhou Workers'Hospital in Guangxi from 2020 to 2022.Methods The bacteria were isolated,identified,and underwent antimicrobial susceptibility testing using VITEK 2 Compact,disk diffusion method,or E-test.The results were interpreted according to the breakpoints recommended by CLSI M100 32nd Edition in 2022.The data were analyzed using WHONET 5.6 software.Results A total of 26 254 nonduplicate strains were collected from 2020 to 2022,including Gram-positive bacteria(27.9％)and gram-negative bacteria(72.1％).The prevalence of methicillin-resistant strains was 20.0％in SS.aureus(MRSA),and 72.2％in coagulase-negative Staphylococcus(MRCNS).Methicillin-resistant staphylococcal strains were more resistant to most antimicrobial agents than methicillin-susceptible strains(MSSA and MSCNS).None of the staphylococcal strains was resistant to vancomycin,linezolid or tigecycline.Enterococcus faecium strains showed higher resistance rates to most antimicrobial agents than Enterococcus faecalis.None of enterococcal strains was resistant to vancomycin.A few enterococcal strains were resistant to linezolid.Overall,691 strains of the non-meningitis Streptococcus pneumoniae were isolated from children and 123 strains were isolated from adults.The prevalence of penicillin-resistant SS.pneumoniae(PRSP)was 0.4％in the strains from children and 1.6％in the strains from adults.None of S.pneumoniae strains was intermediate to penicillin.The prevalence of carbapenem-resistant Klebsiella pneumoniae(CRKpn)was 1.2％,1.2％,and 13.8％in 2020,2021,and 2022,respectively.The prevalence of carbapenem-resistant P.aeruginosa(CRPae)and carbapenem-resistant Acinetobacter baumannii(CRAba)was 10.7％and 68.4％in 2020,17.5％and 75.2％in 2021,14.3％and 77.3％in 2022,respectively.About 84.6％of the 1 269 strains of Haemophilus influenzae were isolated from children and 15.4％isolated from adults.The prevalence of beta-lactamase-producing strains was 39.4％in the isolates from children and 46.8％in the isolates from adults.The β-lactamase-producing H.influenzae was resistant to ampicillin.Furthermore,some β-lactamase-nonproducing ampicillin-resistant(BLNAR)H.influenzae strains(27.0％)were also identified.Conclusions Antimicrobial resistance is still serious in this hospital,especially high prevalence of carbapenem-resistant organisms(CRO).Hospital infection prevention and control measures,antibiotic stewardship,and proactive CRO screening should be strengthened.More clinical specimens should be collected for suspected infections.Antimicrobial treatment should be prescribed empirically in time and adjusted when the results of antimicrobial susceptibility testing are available.

Objective:To analyze the clinical features and prognosis of acute B lymphoblastic leukemia (B-ALL) children carrying a TCF3: : PBX1 fusion gene and to evaluate the prognostic value of this gene.Methods:Retrospective cohort study.A total of 2 164 B-ALL children aged 0-18 years diagnosed and treated at 19 pediatric centers from October 2016 to June 2022 were enrolled.They were divided into the positive group and the negative group according to whether they carried a TCF3: : PBX1 fusion gene.The clinical characteristics, treatment response, adverse reactions, and prognosis of the 2 groups of patients were analyzed.The rank sum and Kruskal-Wallis tests were used to compare two and more than two groups of numerical variables, respectively.Fisher′s exact test was used to compare categorical variables.Results:Among the 2 164 patients, 116 (5.4%) were TCF3: : PBX1 positive, of which 70 patients were female, accounting for 60.3%.There were 840 female patients in the TCF3: : PBX1-negative group, accounting for 41.0%.There was a significant difference in the ratio of females between the TCF3: : PBX1-positive and TCF3: : PBX1-negative groups ( P<0.001).No significant difference was observed in age of onset between the two groups( P>0.05).The proportion of bone marrow naive cells [54.00 (14.00, 76.50)% vs.29.00 (3.00, 68.00)%], white blood cell counts [25.30 (10.46, 60.94)×10 9/L vs.9.03 (4.38, 30.73)×10 9/L] and hemoglobin counts [82.00(63.00, 101.00) g/L vs.74.00(60.00, 90.00) g/L] in the TCF3: : PBX1-positive group were significantly higher than those in the negative group at the onset (all P<0.05).In terms of treatment response, the proportion of peripheral blood naive cells on Day 8 in the TCF3: : PBX1-positive group was significantly higher than that in the negative group [2.00 (0, 9.00)% vs.0 (0, 2.00)%, P<0.001].The proportion of minimal residual disease <0.1% on Day 15 in the TCF3: : PBX1-positive group was significantly higher than that in the negative group ( P=0.038).There were no significant differences in cumulative recurrence rate, treatment-related mortality (TRM), and overall survival (OS) between the TCF3: : PBX1-positive group and TCF3: : PBX1-negative group (all P>0.05).The cumulative recurrence risk of TCF3: : PBX1-positive patients was 9.646 times higher than that of ETV6: : RUNX1-positive patients with better prognosis( HR=9.646, 95% CI: 1.026-90.700, P=0.047).There were no significant differences in TRM and OS between TCF3: : PBX1-positive and ETV6: : RUNX1-positive patients (all P>0.05).A significant enrichment of PAX5 mutations was detected in TCF3: : PBX1-positive patients.Among the 7 high-risk TCF3: : PBX1-positive patients in a single center, 4 patients had PAX5 mutations, and this proportion was significantly higher than that in other patients ( P<0.001). Conclusions:B-ALL children carrying a TCF3: : PBX1 fusion gene have a high remission rate and good long-term prognosis after intensive chemotherapy.It is suggesting that TCF3: : PBX1-positive B-ALL patients should be rated at intermediate risk to receive intensive chemotherapy.

Objective To understand the changing profiles of antimicrobial susceptibility of the bacterial strains isolated from patients at Liuzhou Workers'Hospital in Guangxi from 2020 to 2022.Methods The bacteria were isolated,identified,and underwent antimicrobial susceptibility testing using VITEK 2 Compact,disk diffusion method,or E-test.The results were interpreted according to the breakpoints recommended by CLSI M100 32nd Edition in 2022.The data were analyzed using WHONET 5.6 software.Results A total of 26 254 nonduplicate strains were collected from 2020 to 2022,including Gram-positive bacteria(27.9％)and gram-negative bacteria(72.1％).The prevalence of methicillin-resistant strains was 20.0％in SS.aureus(MRSA),and 72.2％in coagulase-negative Staphylococcus(MRCNS).Methicillin-resistant staphylococcal strains were more resistant to most antimicrobial agents than methicillin-susceptible strains(MSSA and MSCNS).None of the staphylococcal strains was resistant to vancomycin,linezolid or tigecycline.Enterococcus faecium strains showed higher resistance rates to most antimicrobial agents than Enterococcus faecalis.None of enterococcal strains was resistant to vancomycin.A few enterococcal strains were resistant to linezolid.Overall,691 strains of the non-meningitis Streptococcus pneumoniae were isolated from children and 123 strains were isolated from adults.The prevalence of penicillin-resistant SS.pneumoniae(PRSP)was 0.4％in the strains from children and 1.6％in the strains from adults.None of S.pneumoniae strains was intermediate to penicillin.The prevalence of carbapenem-resistant Klebsiella pneumoniae(CRKpn)was 1.2％,1.2％,and 13.8％in 2020,2021,and 2022,respectively.The prevalence of carbapenem-resistant P.aeruginosa(CRPae)and carbapenem-resistant Acinetobacter baumannii(CRAba)was 10.7％and 68.4％in 2020,17.5％and 75.2％in 2021,14.3％and 77.3％in 2022,respectively.About 84.6％of the 1 269 strains of Haemophilus influenzae were isolated from children and 15.4％isolated from adults.The prevalence of beta-lactamase-producing strains was 39.4％in the isolates from children and 46.8％in the isolates from adults.The β-lactamase-producing H.influenzae was resistant to ampicillin.Furthermore,some β-lactamase-nonproducing ampicillin-resistant(BLNAR)H.influenzae strains(27.0％)were also identified.Conclusions Antimicrobial resistance is still serious in this hospital,especially high prevalence of carbapenem-resistant organisms(CRO).Hospital infection prevention and control measures,antibiotic stewardship,and proactive CRO screening should be strengthened.More clinical specimens should be collected for suspected infections.Antimicrobial treatment should be prescribed empirically in time and adjusted when the results of antimicrobial susceptibility testing are available.

Objective:To analyze the clinical features and prognosis of acute B lymphoblastic leukemia (B-ALL) children carrying a TCF3: : PBX1 fusion gene and to evaluate the prognostic value of this gene.Methods:Retrospective cohort study.A total of 2 164 B-ALL children aged 0-18 years diagnosed and treated at 19 pediatric centers from October 2016 to June 2022 were enrolled.They were divided into the positive group and the negative group according to whether they carried a TCF3: : PBX1 fusion gene.The clinical characteristics, treatment response, adverse reactions, and prognosis of the 2 groups of patients were analyzed.The rank sum and Kruskal-Wallis tests were used to compare two and more than two groups of numerical variables, respectively.Fisher′s exact test was used to compare categorical variables.Results:Among the 2 164 patients, 116 (5.4%) were TCF3: : PBX1 positive, of which 70 patients were female, accounting for 60.3%.There were 840 female patients in the TCF3: : PBX1-negative group, accounting for 41.0%.There was a significant difference in the ratio of females between the TCF3: : PBX1-positive and TCF3: : PBX1-negative groups ( P<0.001).No significant difference was observed in age of onset between the two groups( P>0.05).The proportion of bone marrow naive cells [54.00 (14.00, 76.50)% vs.29.00 (3.00, 68.00)%], white blood cell counts [25.30 (10.46, 60.94)×10 9/L vs.9.03 (4.38, 30.73)×10 9/L] and hemoglobin counts [82.00(63.00, 101.00) g/L vs.74.00(60.00, 90.00) g/L] in the TCF3: : PBX1-positive group were significantly higher than those in the negative group at the onset (all P<0.05).In terms of treatment response, the proportion of peripheral blood naive cells on Day 8 in the TCF3: : PBX1-positive group was significantly higher than that in the negative group [2.00 (0, 9.00)% vs.0 (0, 2.00)%, P<0.001].The proportion of minimal residual disease <0.1% on Day 15 in the TCF3: : PBX1-positive group was significantly higher than that in the negative group ( P=0.038).There were no significant differences in cumulative recurrence rate, treatment-related mortality (TRM), and overall survival (OS) between the TCF3: : PBX1-positive group and TCF3: : PBX1-negative group (all P>0.05).The cumulative recurrence risk of TCF3: : PBX1-positive patients was 9.646 times higher than that of ETV6: : RUNX1-positive patients with better prognosis( HR=9.646, 95% CI: 1.026-90.700, P=0.047).There were no significant differences in TRM and OS between TCF3: : PBX1-positive and ETV6: : RUNX1-positive patients (all P>0.05).A significant enrichment of PAX5 mutations was detected in TCF3: : PBX1-positive patients.Among the 7 high-risk TCF3: : PBX1-positive patients in a single center, 4 patients had PAX5 mutations, and this proportion was significantly higher than that in other patients ( P<0.001). Conclusions:B-ALL children carrying a TCF3: : PBX1 fusion gene have a high remission rate and good long-term prognosis after intensive chemotherapy.It is suggesting that TCF3: : PBX1-positive B-ALL patients should be rated at intermediate risk to receive intensive chemotherapy.

Objective:To investigate the effect of DEAD-box helicase (DDX) 21 on myocardial ischemia-reperfusion (I/R) injury and its potential mechanisms.Methods:In vivo, adult male Bama pigs and C57BL/6J mice were used to establish a myocardial I/R injury model by ligating the left anterior descending coronary artery, with sham-operated groups set as controls. The expression of DDX21 in myocardium after I/R injury was assessed by quantitative real-time PCR (qRT-PCR), Western blot, and immunofluorescence staining. Following the establishment of the myocardial I/R injury model in mice, AAV9 vectors with cardiac-specific expression were injected in situ into the peri-infarct region (The I/R+DDX21 group, I/R+negative control (NC) group, I/R+sh-NC group and I/R+sh-DDX21 group were injected with AAV9:cTnT-DDX21, AAV9:cTnT-NC, AAV9:cTnT-sh-NC and AAV9:cTnT-sh-DDX21, respectively). Additionally, the I/R+A-485 group received intraperitoneal injections of the cAMP response element-binding protein (CREB) binding protein inhibitor A-485, while the I/R+PBS group was injected with an equivalent volume of phosphate-buffered saline (PBS) as the control. Echocardiography was performed on postoperative days 1 and 28 to evaluate cardiac function (left ventricular ejection fraction and fractional shortening). At 28 days post-surgery, mice were euthanized and heart tissues were harvested for histological sectioning. Myocardial fibrosis was evaluated using Masson′s trichrome staining. In vitro, primary cardiomyocytes were isolated from neonatal day 1 C57BL/6J mice using enzymatic digestion method. Cardiomyocytes were transfected with plasmids or small interfering RNA (siRNA). The cardiomyocytes transfected with DDX21-siRNA were assigned to the siDDX21 group, those transfected with the DDX21 plasmid were assigned to the DDX21 group, and those transfected with the corresponding empty plasmid or siRNA were assigned to the NC group. Additionally, cardiomyocytes were treated with A-485 (A-485 group) or PBS (PBS group). An oxygen-glucose deprivation/reoxygenation (OGD/R) model was used to simulate cellular injury. Transcriptome sequencing was performed to identify downstream mechanisms of DDX21. Differential gene expression analysis was conducted using software such as DESeq2, and alternative splicing events in the mRNA transcriptome were analyzed using rMATS software. Mitochondrial superoxide, mitochondrial membrane potential, ATP content, and mitochondrial respiratory chain complex enzyme activity in cardiomyocytes were detected using immunofluorescence staining and commercial assay kits. The oxidative phosphorylation level of the cells was assessed by the Seahorse extracellular flux analyzer. Acetylated DDX21 levels were measured using co-immunoprecipitation and Western blot assays.Results:The expression levels of DDX21 in myocardium from the Bama pigs and mice in the I/R injury model were significantly higher than those in the sham group (all P<0.001). Echocardiographic results showed that at 28 days post-surgery, compared to the I/R+NC group, the I/R+DDX21 group exhibited higher left ventricular ejection fraction and fractional shortening, while the I/R+sh-DDX21 group showed lower values; Masson staining results demonstrated that, compared to the I/R+NC group, the myocardial fibrosis area in the I/R+DDX21 group was significantly reduced, whereas it was significantly increased in the I/R+sh-DDX21 group (all P<0.001). Transcriptomic sequencing results suggested that DDX21 may influence myocardial injury by regulating mitochondrial metabolic activity. In vitro, compared to the OGD/R+NC group, the OGD/R+DDX21 group exhibited lower mitochondrial superoxide levels, higher polymer/monomer ratio, maximal oxygen consumption, reserve capacity, and ATP content. In contrast, the OGD/R+siDDX21 group showed the opposite results, with reduced activity of mitochondrial respiratory chain complex V (all P<0.05). Mechanistically, rMATS software and other analyses indicated that knockdown of DDX21 affected the alternative 3′ splicing sites of ATP5J precursor mRNA, inhibiting the splicing of certain exonic sequences. Overexpression of DDX21 upregulated both mRNA and protein levels of ATP5J. Co-immunoprecipitation experiments showed that, compared to the PBS group, acetylated DDX21 levels were reduced in the A-485 group. Further in vivo experiments showed that, compared to the I/R+PBS group, the I/R+A-485 group exhibited higher left ventricular ejection fraction and fractional shortening, and a lower proportion of left ventricular fibrosis (all P<0.001). Conclusions:DDX21 improves cardiomyocyte energy metabolism and alleviates I/R injury by regulating the alternative splicing of ATP5J. A-485 holds potential as a novel small molecule candidate for the treatment of myocardial injury.

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.