ObjectiveTo investigate the effect and mechanism of simvastatin pretreatment on kidney ischemia reperfusion injury （IRI） in mice. MethodsFifteen male C57BL/6 mice aged 6-8 weeks were divided into three groups： Sham operation group （Sham group）， kidney IRI group （IR group）， and simvastatin pretreatment+kidney IRI group （SIM group）. Hematoxylin-eosin （HE） staining of kidney tissue and detection of serum creatinine （SCr） and lactate dehydrogenase （LDH） were used to evaluate kidney injury. The levels of superoxide dismutase （SOD）， reduced glutathione （GSH）， malondialdehyde （MDA） and reactive oxygen species （ROS） were detected to evaluate oxidative stress. The contents of ferrous iron （Fe²⁺） and ferric iron （Fe³⁺） in kidney tissue were detected， and the morphological changes of mitochondria were observed by transmission electron microscope. The relative expression levels of Kruppel-like factor 2 （KLF2）， glutathione peroxidase 4 （GPX4）， solute carrier family 7 member 11 （SLC7A11）， and acyl-coa synthetase long chain family member 4 （ACSL4） protein in kidney tissue were detected. ResultsCompared with the IR group， the SIM group had significantly reduced renal tubular injury and decreased contents of Scr and LDH in serum （P < 0.001）. It also showed increased expression of SOD and GSH and decreased expression of MDA and ROS （P < 0.01）. Simvastatin pretreatment reduced the contents of Fe²⁺ and Fe³⁺ in the tissues （P < 0.01） and alleviated mitochondrial damage. It also promoted the expression of KLF2 （P < 0.01）， up-regulated the expression of ferroptosis-related protective proteins GPX4 and SLC7A11， and down-regulated the expression of ferroptosis-related damage protein ACSL4 （P < 0.05）. ConclusionSimvastatin pretreatment may inhibit kidney ferroptosis by promoting the expression of KLF2 to alleviate kidney IRI.

[Objective] To investigate the factors influencing the detection of HLA-C expression by flow cytometry. [Methods] A total of 12 hematopoietic stem cell suspension samples from peripheral hematopoietic stem cell volunteer donors were randomly collected after CD34⁺ cell counting detection. The influence of detecting different number of nucleated cell (500 000, 50 000 and 5 000), sequential order of red blood cell lysis and antibody incubation, and the HLA-C antibody with varied remaining time from the expiration date on the detection results of HLA-C expression by flow cytometry were investigated, respectively. The significance of differences between different groups was analyzed through Student t test. [Results] There was no significant difference in the proportion of HLA-C positive cells and mean fluorescence intensity (MFI) among the three groups with different nucleated cell numbers detected (500 000, 50 000 and 5 000) (P>0.05). The sequential order of red blood cell lysis and antibody incubation had no influence on the proportion of HLA-C positive cells (P>0.05), but HLA-C MFI value was significantly lower when antibody incubation was performed after red blood cell lysis than that when antibody incubation was performed before red blood cell lysis (P<0.05). The proportion of HLA-C positive cells and MFI value detected by HLA-C antibody remaining 24 months from the expiration date were significantly higher than those detected by HLA-C antibody remaining only 5 months from the expiration date (P<0.05). [Conclusion] The present study has investigated the factors of influencing HLA-C expression level by flow cytometry, the results have important reference and application value for standardizing the experimental operation of HLA-C expression and improving the accuracy and comparability of detection results.

Objective To investigate the effect and mechanisms of celecoxib on right heart function in mice with acute high-altitude hypoxia exposure.Methods Male C57BL/6J mice(7 weeks old)were housed in a hypobaric chamber simulating an altitude of 5 800 m for 2 d to establish an animal model of acute hypobaric hypoxia.①Eighteen mice were randomly assigned to plain+saline(P+S),high-altitude hypoxia exposure+saline(H+S),and high-altitude hypoxia exposure+celecoxib(H+Cel).Body weight and routine blood indicators were measured,and cardiac ultrasound examination were performed for heart rate(HR),pulmonary artery acceleration time to ejection time ratio(AT/ET),tricuspid annular plane systolic excursion(TAPSE),tricuspid annular systolic velocity(S'),and left ventricular ejection fraction(LVEF)and fractional shortening(FS).Targeted metabolomic profiling was applied to detect the cardiac arachidonic acid(AA)metabolite levels.The contents of 12,13-dihydroxy-9Z-octadecenoic acid(12,13-diHOME)in the heart,liver,brown adipose tissue,and plasma were quantified by ELISA.② Eighteen mice were randomly assigned into plain+saline(P+S),high-altitude hypoxia exposure+saline(H+S)and high-altitude hypoxia exposure+12,13-diHOME(H+di)groups.Body weight,routine blood tests,and echocardiography were performed as above.③ Thirty-two mice were randomly divided into high-altitude hypoxia exposure+saline(H+S),high-altitude hypoxia exposure+celecoxib(H+Cel),high-altitude hypoxia exposure+soluble epoxide hydrolase inhibitor(sEHI)(H+sEHI),and high-altitude hypoxia exposure+sEHI+celecoxib(H+sEHI+Cel)groups.Body weight,routine blood tests,and echocardiography were performed as above.Cardiac and plasma contents of 12,13-diHOME and epoxyeicosatrienoic acids(EETs)were measured by ELISA.Results ① Compared to the P+S group,the H+S group exhibited significantly reduction of cardiac 12,13-diHOME level(P<0.001),increased counts of white blood cells(WBC)and neutrophils(P<0.01)and decreased TAPSE,S'and AT/ET both at resting state and under stress(P<0.01,P<0.001).Compared to the H+S group,the H+Cel group exhibited significantly increase of cardiac 12,13-diHOME level(P<0.05),reduced WBC and lymphocyte counts(P<0.01,P<0.05)and improved TAPSE and S'levels at resting state and under stress(P<0.01,P<0.001).② Compared to the H+S group,the H+di group demonstrated significantly improvement of TAPSE at basal and under stress(P<0.001)and a trend towards improved TAPSE at resting state(P=0.0532),but no obvious differences was observed in WBC and neutrophil counts between the H+di group and the H+S group.③ Compared to the H+Cel group,both the H+sEHI and H+sEHI+Cel groups exhibited significantly reduction of cardiac 12,13-diHOME level(P<0.01,P<0.05)though no statistical changes in cardiac function indicators.Compared to the H+S group,WBC counts and lymphocyte were decreased,and serum EETs level was incrased in the H+Cel group,H+sEHI group and H+sEHI+Cel group(P<0.01,P<0.001).Conclusion Celecoxib can elevate cardiac level of 12,13-diHOME and improves right heart function in mice after acute high-altitude hypoxia exposure through the CYP450-sEH metabolic pathway.

Objective To explore the impact of Shexiang Baoxin Pill(SXBXP,a traditional Chinese patent medicine,broadly applied for the treatment of cardiovascular diseases)on coronary microvascular disease(CMD)and investigate the role and underlying mechanisms of muscone,a key bioactive component of the pills,in the treatment.Methods A total of 16 ob/ob mice(8 weeks old)were randomly and equally divided into an ob/ob-SXBXP group and a ob/ob-Control group,receiving 10 mg/kg·d SXBXP or PBS via oral gavage,and another 8 wild-type mice with the same genetic background(WT group)were subjected as a negative control group.Cell model of CMD was established based on mouse coronary microvascular endothelial cells(MCMEC)under ischemia and hypoxic(HI)condition,and the cells were further treated with 20 μg/mL SXBXP(HI+SX)and 30 μmol/L muscone(HI+Muscone),respectively.Echocardiography was carried out for coronary flow reserve(CFR)and left ventricular function,and laser speckle imaging was applied to evaluate myocardial blood flow(MBF).Microvascular density in the heart was evaluated with CD31 immunofluorescence staining.The expression levels of vascular endothelial growth factor(VEGF)in cardiac microvascular endothelial cells of both mouse and cell models were detected by immunofluorescence staining and Western blot analysis.The proliferation and angiogenesis of MCMEC were observed by 5-ethynyl-2'-deoxyuridine staining and angiogenesis experiments.Results In the ob/ob-Control group of mice,the levels of CFR,MBF,and cardiac microvascular density were significantly lower than those in the WT group(P<0.05),and these indicators were significantly improved in the ob/ob-SXBXP group when compared with the ob/ob-Control group(P<0.05),which indicates that SXBXP improves the CMD phenotype.The expression level of VEGF in cardiac microvascular endothelial cells was significantly lower in the ob/ob-Control mice than the WT mice(P<0.05),while the level in the ob/ob-SXBXP group was significantly higher than that in the ob/ob-Control group(P<0.05),illustrating that SXBXP may ameliorate CMD through VEGF-mediated microvascular angiogenesis.In vitro experiments further revealed that the VEGF expression level and the proliferation and angiogenesis abilities in MCMEC were significantly lower in the HI group than the cells under the normoxia control condition(P<0.05).Both SXBXP and muscone treatment resulted in enhanced expression of VEGF and improved proliferative and angiogenesis abilities of MCMEC(P<0.05).These results suggest that muscone could improve CMD by VEGF-mediated microvascular angiogenesis.Conclusion SXBXP can improve CMD.Muscone,as a key component of SXBXP,promotes microvascular angiogenesis by inducing the expression of VEGF,then enhances myocardial perfusion,and consequently alleviates CMD.

Objective To investigate the effect of the petroleum ether extract of Sageretia thea on the proliferation and apoptosis of breast cancer cells.Methods After breast cancer cells were incubated with the petroleum ether extract for different times,cell viability was analyzed by CCK8 assay,cell proliferation was detected by plate cloning test,nuclear morphology was observed by DAPI staining,mitochondrial membrane potential(MMP)and reactive oxygen species(ROS)were determined by immunofluorescence,and the cell cycle and apoptosis were detected by flow cytometry.After incubating with the extract for 24 h,the CCK8 assay was used to observe the toxicity to normal human vascular endothelial cells.Results The IC50 of BT549 and MDA-MB-231 breast cancer cell lines treated with the petroleum ether extract for 24 h were 45.40 μg/ml and 12.23 μg/ml,respectively.The extract time and dose dependently inhibited breast cancer cell viability and clonal formation,induced cell apoptosis and cycle arrest in G1/S phase,decreased MMP and increased ROS levels.There was no toxic effect on normal endothelial cells.Conclusion The petroleum ether extract of Sageretia thea may induce apoptosis by increasing ROS to cause MMP collapse,followed by activating mitochondrial pathway,thereby hindering the growth of breast cancer cells.These results could support the application of Sageretia thea to anti-breast tumor in the folk.

Objective To establish a method for qualitative detection of the presence or absence of all KIR genes by quantitative polymerase chain reaction(Q-PCR).Methods Based on the polymorphism of high-resolution level KIR alleles in Chinese population and the IPD-KIR database,KIR gene-specific primers were designed to amplify all the 16 KIR genes and 2DS4-Normal and 2DS4-Deleted subtypes by Q-PCR.Meanwhile,one negative control and one positive control specific amplifying human growth hormone(HGH)gene fragment were set to monitor the false positive and false negative results in PCR amplification,respectively.A total of 302 samples with known KIR genotype previously identified by KIR PCR-SSP commercial kit were randomly selected for blind inspection to verify the reliability of KIR Q-PCR method established by au-thors.Results The results of 300 samples detected by our KIR Q-PCR method were consistent with the known results,but two samples showed inconsistent results.One sample was negative for 2DS5 by Q-PCR but positive by PCR-SSP,another sample was positive for 2DS1 by Q-PCR but negative by PCR-SSP.The two doubtful samples were genotyped by sequencing-based typing(PCR-SBT)for 2DS5and2DS1,respectively.PCR-SBT results confirmed that the results of Q-PCR test was correct.Conclusion The KIR Q-PCR method established in this paper can provide accurate and reliable results for testing the presence or absence of KIR genes.

Objective:To compare the clinical efficacy of rotator cuff repair combined with transposition of the long head of the biceps tendon in the treatment of massive rotator cuff tears with or without subscapularis injury.Methods:A total of 73 patients with massive rotator cuff tears who underwent arthroscopic rotator cuff repair combined with transposition of the long head of the biceps tendon in the Department of Upper Arm, Sichuan Orthopaedic Hospital from January 2019 to September 2022 were retrospectively analyzed, including 35 males and 38 females, aged 58.8±7.6 years (range, 46-73 years). There were 11 cases on the left side and 62 cases on the right side. Causes of injuries: 6 cases of car accidents, 13 cases of fall injuries, 54 cases of no obvious cause of injury. The patients were divided into subscapularis injury group (37 cases) and no subscapularis injury group (36 cases) according to the subscapularis injury or not. The visual analogue scale (VAS), Constant - Murley score, University of California Los Angeles (UCLA) shoulder score and range of motion were used to evaluate shoulder pain and functional improvement. MRI of the shoulder was taken at the final follow-up and the rotator cuff was assessed for retear using Sugaya grading.Results:All patients successfully completed the operation. The VAS score at 1 year postoperatively in the group without subscapularis injury was 0.58±0.87, which was less than 1.16±1.14 in the group with subscapularis injury ( t=-2.426, P=0.018). The Constant-Murley score and UCLA score at 1 year postoperatively in the group without subscapularis injury were 94.03±6.19 and 32.94±2.59, respectively, which were greater than those of the group with subscapularis injury, which were 86.51±11.96 and 30.38±3.33, and the difference was statistically significant ( P<0.05). Anterior flexion and body external rotation at 1 year postoperatively in the group without subscapularis injury were 137.22°±26.79° and 54.72°±13.20°, which were greater than those in the group with subscapularis injury of 121.08°±22.83° and 38.65°±17.19°, and the difference was statistically significant ( P<0.05), and the difference between the two groups in body internal rotation was not statistically significant ( P>0.05). The subacromial spacing at 1 year postoperatively was 9.4±1.3 mm in the group without subscapularis injury and 9.0±1.5 mm in the group with subscapularis injury, and the difference was not statistically significant ( t=1.318, P=0.192). There were 2 cases of rotator cuff retear 1 year after surgery without subscapular muscle injury and 5 cases of subscapular muscle injury. Conclusion:The clinical efficacy of arthroscopic rotator cuff repair combined with transposition of the tendon of the long head of the biceps tendon in the treatment of massive rotator cuff tears with or without subscapularis muscle injury is satisfactory, and the improvement of pain and function is more obvious in patients without subscapularis muscle injury.

Objective To generate minichromosome maintenance protein 2(MCM2)gene knockout cervi-cal cancer HeLa cell lines using inducible CRISPR/Cas9 technology,and to explore the effect of MCM2 on DNA replication and replication stress.Methods The inducible CRISPR/Cas9 system,TLCV2,was used to construct MCM2 knockout HeLa cell lines.And the cell lines were divided into control group(Control),knockout group 1(KO1),and knockout group 2(KO2).Western blot,Edu incorporation experiment,real-time quantitative PCR(qPCR),immunofluorescence and MTT assay were used to analyze the effects of MCM2 knockout on DNA replica-tion and replication stress induced by hydroxyurea.Results The CRISPR/Cas9 system successfully knocked out the MCM2 gene after induction,and MCM2 knockout affected the stability of MCM2-7 complex.Compared with the control cells,MCM2 knockout cells had a dramatic decrease in the capacity of DNA replication,and the mRNA levels of Cyclin A1,Cyclin E1 and CDK4.Under DNA replication stress,MCM2 knockout cells decreased cell viability,DNA damage repair capacity,and increased genomic instability compared with control cells.Conclusion Knockout of MCM2 gene reduces the DNA replication capacity of HeLa cells under normal conditions and cell viability under replication stress.This study successfully generates MCM2 gene inducible knockout HeLa cell lines,laying the foundation for further research on the role and biological function of MCM2 gene in the occurrence and progression of cervical cancer.

Objective:To study the genetic polymorphisms of short-tandem repeats (STR) for the D13S317 locus among an ethnic Han Chinese population and verify a novel tri-allelic pattern identified for the locus. Methods:A total of 378 paternity test cases from Guangdong Forensic Authentication Institute from October 17, 2017 to December 28, 2017 were selected as the study subjects. A GlobalFiler? Express kit was used for the STR genotyping. Samples suspected for having a novel tri-allelic pattern were verified with a PowerPlex ? 21 kit. Potential variant of the primer-binding region and flanking sequences underlying the tri-allelic pattern was excluded by molecular cloning and sequencing. Results:Six alleles were detected for the D13S317 locus, with the characteristic distribution frequencies being 8 (29.1%), 9 (13.1%), 10 (15.21%), 11 (24.21%), 12 (13.89%) and 13 (3.44%), respectively. In one of the families, the D13S317 locus of the proband was suspected to harbor a triband allele (8, 9, 10). A re-test has confirmed the result of initial test. Molecular cloning and sequencing analysis of the D13S317 locus in the proband and his daughter has failed to find allelic variants in the primer-binding region and flanking sequence, which has confirmed the novel tri-allelic pattern for the locus. Conclusion:A novel type 2 tri-allelic pattern (8, 9, 10) at the D13S317 locus has been identified among the ethnic Han Chinese population. The pattern has not been transmitted to the female offspring, and has been included in the international STRBase database for the first time.

[Objective]To investigate the genetic polymorphism of 42 short tandem repeats(STRs),including 41 non-CODIS loci from the Shenzhen Han population and evaluate their potential values in forensic application.[Methods]In our research,the AGCU 21+1 STR kit and Microreader? 23sp Direct ID System were applied to analyze the polymorphism of STR loci from 435 unrelated individuals of Shenzhen Han population.Modified-Powerstates and Arlequin v3.5 software were used to analyze the allele frequencies and forensic parameters,and perform the Hardy-Weinberg equilibrium test.[Results]A total of 418 alleles were detected from 435 unrelated individuals in Shenzhen,all consistent with Hardy-Weinberg equilibrium(P>0.05/42),with the allele frequency ranging from 0.001 1 to 0.552 9.Besides,the discrimination power(DP)ranged from 0.798 8(D1S1627)to 0.968 6(D7S3048),the polymorphic information content(PIC)ranged from 0.568 0(D1S1627)to 0.859 8(D7S3048),and the heterozygosity(H)ranged from 0.627 6(D1S1627)to 0.878 2(D20S470).Among all the STRs tested in the study,both D1S1656 and D21S1270 have 16 alleles and show the highest polymorphism.In comparison,only five alleles were observed in the D4S2408 locus,which displays the least polymorphism.[Conclusions]The 42 autosomal STR loci with high genetic polymorphism in Shenzhen Han population showed potential as an effective means for individual identification and paternity testing,especially in the cases with single parent or mutation detected.The obtained information can provide basic data for STR population genetics.