Objective To investigate the protective effect and underlying mechanism of human umbilical cord mesenchymal stem cell-derived exosomes (hucMSC-Exo) on renal ischemia-reperfusion injury (IRI). Methods hucMSC-Exos were isolated and characterized. A mouse renal IRI model was established and the animals were divided into Sham, IRI, IRI+hucMSC-Exo, IRI+hucMSC-Exo+JY-2 and Sham+JY-2 groups. Serum creatinine (Scr) and blood urea nitrogen (BUN) were measured. Hematoxylin-eosin (HE) staining was used to evaluate renal histopathology. Enzyme-linked immune absorbent assay was performed to determine serum interleukin (IL)-1β and IL-18 levels. Western blotting was used to detect the expression of activating transcription factor 3 (ATF3), Toll-like receptor 4 (TLR4), nuclear factor (NF)-κB, NOD-like receptor protein 3 (NLRP3), cysteineyl aspartate specific proteinase (Caspase)-1 p20 and Gasdermin D(GSDMD). Real-time fluorescent quantitative polymerase chain reaction was employed to measure ATF3, TLR4 and NF-κB messenger RNA (mRNA). Immunohistochemistry was conducted to examine NLRP3, Caspase-1 p20 and GSDMD. An in vitro hypoxia/reoxygenation (H/R) model was established in HK-2 cells and divided into Control, H/R, H/R+hucMSC-Exo, H/R+hucMSC-Exo+JY-2 and Control+JY-2 groups. Western blotting was used to detect the expression of ATF3, TLR4 and NF-κB. Real-time fluorescent quantitative polymerase chain reaction was used to measure NLRP3, GSDMD and Caspase-1 mRNA. Results HucMSC-Exos were successfully isolated and identified. Compared with the Sham group, the IRI group exhibited elevated Scr and BUN, higher tubular injury scores, increased protein expression levels of ATF3, TLR4, NF-κB p65, NLRP3, Caspase-1 p20 and GSDMD, and raised mRNA expression levels of ATF3, TLR4, NF-κB. Compared with the IRI group, the IRI+hucMSC-Exo group showed decreased Scr and BUN, lower tubular injury scores, up-regulated ATF3 protein and mRNA, down-regulated TLR4, NF-κB p65, NLRP3, Caspase-1 p20 and GSDMD protein, and declined TLR4 and NF-κB mRNA. Compared with the IRI+hucMSC-Exo group, the IRI+hucMSC-Exo+JY-2 group exhibited increased Scr and BUN levels, elevated renal tubular injury scores, decreased ATF3 protein expression levels, elevated protein expression levels of TLR4, NF-κB p65, NLRP3, Caspase-1 p20, and GSDMD, decreased ATF3 mRNA expression levels, and elevated mRNA expression levels of TLR4 and NF-κB. (all P < 0.05). Compared with the Control group, the expression levels of ATF3, TLR4 and NF-κB p65 proteins were increased in the H/R group, and the expression levels of NLRP3, Caspase-1 and GSDMD mRNA were increased. Compared with the H/R group, the expression level of ATF3 protein was increased, the expression levels of TLR4 and NF-κB p65 proteins were decreased, and the expression levels of NLRP3, Caspase-1 and GSDMD mRNA were decreased in the H/R+hucMSC-Exo group. Compared with the H/R+hucMSC-Exo group, the expression level of ATF3 protein was decreased, the expression levels of TLR4 and NF-κB p65 proteins were increased, and the expression levels of NLRP3, Caspase-1 and GSDMD mRNA were increased in the H/R+hucMSC-Exo+JY-2 group (all P < 0.05). Conclusions HucMSC-Exos alleviate renal IRI by up-regulating ATF3, thereby negatively regulating the TLR4/NF-κB signaling pathway and subsequently inhibiting pyroptosis.

The liver, skeletal muscle, and adipose tissue are central energy-metabolizing organs and insulin-sensitive tissues, playing a crucial role in maintaining glucose homeostasis. As the powerhouse of the cell, mitochondria not only regulate insulin secretion but also oversee the oxidative phosphorylation and β-oxidation of fatty acids, processes vital for the metabolism of carbohydrates and fats, as well as the synthesis of ATP. The mitochondrial quality control system is of paramount importance for sustaining mitochondrial homeostasis, achieved through mechanisms such as protein homeostasis, mitochondrial dynamics, mitophagy, and biogenesis. Evidence suggests that dysfunctional mitochondria may significantly contribute to insulin resistance and ectopic fat storage in the liver, offering new insights into the strong correlation between mitochondrial dysfunction and the development of obesity, diabetes mellitus type 2 (T2DM), and non-alcoholic fatty liver disease (NAFLD). This manuscript aims to delve into the precise mechanisms by which imbalances in mitochondrial quality control lead to metabolic disorders in the liver, skeletal muscle, and adipose tissue, the 3 major insulin-sensitive organs. In the liver, mitochondrial dysfunction can lead to disturbances in glucose and lipid metabolism, resulting in insulin resistance and fat accumulation—a key factor in the development of NAFLD. In skeletal muscle, reduced mitochondrial function can decrease ATP production, weakening the muscle’s ability to uptake glucose, thereby exacerbating insulin resistance. In adipose tissue, mitochondrial dysfunction can impair adipocyte function, leading to lipotoxicity and inflammatory responses,which further contribute to insulin resistance and the onset of metabolic syndrome. Moreover, the interorgan crosstalk among these 3 tissues is essential for overall metabolic homeostasis. For instance, hepatic gluconeogenesis and glucose utilization in skeletal muscle are both influenced by the health status of their respective mitochondrial populations. The conversion between different types of adipose tissue and the ability to store lipids depend on normal mitochondrial function to avert ectopic fat accumulation in other organs. In summary, this manuscript emphasizes the critical role of mitochondrial quality control in maintaining the metabolic stability of the liver, skeletal muscle, and adipose tissue. It elucidates the specific mechanisms by which mitochondrial dysfunction in these organs contributes to the development of metabolic diseases, providing a foundation for future research and the development of therapeutic strategies targeting mitochondrial dysfunction.

AIM:To investigate the effect of silent information regulator 1(SIRT1)on the degree of aging and apoptosis in a mouse cardiomyocyte aging model through the regulation of Wnt/β-catenin pathway.METHODS:An in vi-tro aging model was established by inducing HL-1 cells with 40 μmol/L D-galactose(D-Gal).The HL-1 cells were trans-fected with a lentivirus overexpressing SIRT1,and the transfection efficiency was verified by Western blot.Western blot was used to detect the protein expression levels of SIRT1,P53,P21,cleaved caspase-3,B-cell lymphoma-2(Bcl-2),Bcl-2-associated X protein(Bax),β-catenin,Wnt3a and c-Myc.Senescence-associated β-galactosidase(SA-β-Gal)staining was used to detect cellular senescence level.MTT colorimetric assay was used to detect the cell viability,and flow cytometry was used to detect the apoptosis.RESULTS:Treatment of HL-1 mouse cardiomyocytes with D-Gal led to in-creases in the expression levels of aging-related proteins P53 and P21,as well as an increase in SIRT1 protein level.Addi-tionally,the SA-β-Gal staining showed a significant increase in the positive area(P＜0.05).The expression levels of apop-tosis-related proteins cleaved caspase-3 and Bax were elevated,while the level of the anti-apoptotic protein Bcl-2 was re-duced(P＜0.05).There was a marked decrease in cell viability(P＜0.05),and flow cytometry analysis demonstrated a significant increase in cell apoptosis rate(P＜0.05),which was positively correlated with the duration of D-Gal treatment.Overexpression of SIRT1 notably reduced both aging and apoptosis levels after 48 h of D-Gal treatment(P＜0.05).After D-Gal treatment,the expression levels of β-catenin,c-Myc and Wnt3a proteins were up-regulated.However,these levels were reduced when SIRT1 was overexpressed.Moreover,the addition of LiCl,a Wnt/β-catenin pathway agonist,resulted in increased expression levels of β-catenin,c-Myc and Wnt3a proteins compared with the group with SIRT1 overexpres-sion and D-Gal treatment(P＜0.05).CONCLUSION:SIRT1 inhibits cardiomyocyte apoptosis and alleviates cardiomyo-cyte aging through the Wnt/β-catenin pathway.

Objective To investigate the distribution and antimicrobial resistance profiles of common pathogens isolated from cerebrospinal fluid(CSF)in CHINET program from 2015 to 2021.Methods The bacterial strains isolated from CSF were identified in accordance with clinical microbiology practice standards.Antimicrobial susceptibility test was conducted using Kirby-Bauer method and automated systems per the unified CHINET protocol.Results A total of 14 014 bacterial strains were isolated from CSF samples from 2015 to 2021,including the strains isolated from inpatients(95.3％)and from outpatient and emergency care patients(4.7％).Overall,19.6％of the isolates were from children and 80.4％were from adults.Gram-positive and Gram-negative bacteria accounted for 68.0％and 32.0％,respectively.Coagulase negative Staphylococcus accounted for 73.0％of the total Gram-positive bacterial isolates.The prevalence of MRSA was 38.2％in children and 45.6％in adults.The prevalence of MRCNS was 67.6％in adults and 69.5％in children.A small number of vancomycin-resistant Enterococcus faecium(2.2％)and linezolid-resistant Enterococcus faecalis(3.1％)were isolated from adult patients.The resistance rates of Escherichia coli and Klebsiella pneumoniae to ceftriaxone were 52.2％and 76.4％in children,70.5％and 63.5％in adults.The prevalence of carbapenem-resistant E.coli and K.pneumoniae(CRKP)was 1.3％and 47.7％in children,6.4％and 47.9％in adults.The prevalence of carbapenem-resistant Acinetobacter baumannii(CRAB)and Pseudomonas aeruginosa(CRPA)was 74.0％and 37.1％in children,81.7％and 39.9％in adults.Conclusions The data derived from antimicrobial resistance surveillance are crucial for clinicians to make evidence-based decisions regarding antibiotic therapy.Attention should be paid to the Gram-negative bacteria,especially CRKP and CRAB in central nervous system(CNS)infections.Ongoing antimicrobial resistance surveillance is helpful for optimizing antibiotic use in CNS infections.

Objective To investigate the antimicrobial resistance of clinical isolates from elderly patients(≥65 years)in major medical institutions across China.Methods Bacterial strains were isolated from elderly patients in 52 hospitals participating in the CHINET Antimicrobial Resistance Surveillance Program during the period from 2015 to 2021.Antimicrobial susceptibility test was carried out by disk diffusion method and automated systems according to the same CHINET protocol.The data were interpreted in accordance with the breakpoints recommended by the Clinical and Laboratory Standards Institute(CLSI)in 2021.Results A total of 514 715 nonduplicate clinical isolates were collected from elderly patients in 52 hospitals from January 1,2015 to December 31,2021.The number of isolates accounted for 34.3％of the total number of clinical isolates from all patients.Overall,21.8％of the 514 715 strains were gram-positive bacteria,and 78.2％were gram-negative bacteria.Majority(90.9％)of the strains were isolated from inpatients.About 42.9％of the strains were isolated from respiratory specimens,and 22.9％were isolated from urine.More than half(60.7％)of the strains were isolated from male patients,and 39.3％isolated from females.About 51.1％of the strains were isolated from patients aged 65-＜75 years.The prevalence of methicillin-resistant strains(MRSA)was 38.8％in 32 190 strains of Staphylococcus aureus.No vancomycin-or linezolid-resistant strains were found.The resistance rate of E.faecalis to most antibiotics was significantly lower than that of Enterococcus faecium,but a few vancomycin-resistant strains(0.2％,1.5％)and linezolid-resistant strains(3.4％,0.3％)were found in E.faecalis and E.faecium.The prevalence of penicillin-susceptible S.pneumoniae(PSSP),penicillin-intermediate S.pneumoniae(PISP),and penicillin-resistant S.pneumoniae(PRSP)was 94.3％,4.0％,and 1.7％in nonmeningitis S.pneumoniae isolates.The resistance rates of Klebsiella spp.(Klebsiella pneumoniae 93.2％)to imipenem and meropenem were 20.9％and 22.3％,respectively.Other Enterobacterales species were highly sensitive to carbapenem antibiotics.Only 1.7％-7.8％of other Enterobacterales strains were resistant to carbapenems.The resistance rates of Acinetobacter spp.(Acinetobacter baumannii 90.6％)to imipenem and meropenem were 68.4％and 70.6％respectively,while 28.5％and 24.3％of P.aeruginosa strains were resistant to imipenem and meropenem,respectively.Conclusions The number of clinical isolates from elderly patients is increasing year by year,especially in the 65-＜75 age group.Respiratory tract isolates were more prevalent in male elderly patients,and urinary tract isolates were more prevalent in female elderly patients.Klebsiella isolates were increasingly resistant to multiple antimicrobial agents,especially carbapenems.Antimicrobial resistance surveillance is helpful for accurate empirical antimicrobial therapy in elderly patients.

Objective To investigate the clinical efficacy and safety of facilitated percutaneous coronary intervention(PCI)with half-dose recombinant staphylokinase(r-SAK)in patients with ST-segment elevation myocardial infarction(STEMI)who are expected to undergo PCI within 120 minutes.Methods From October 2021 to August 2022,a total of 200 STEMI patients in eight centers were included and randomly assigned in a 1﹕1 ratio to either r-SAK group or control group.Patients received loading doses of aspirin and ticagrelor and intravenous heparin and were randomized to receive an intravenous bolus of either 5 mg r-SAK or normal saline prior to PCI.The outcomes were set as ST-segment resolution(STR)at 60-90 minutes after PCI,the proportion and transition of pathological Q waves on the 5th day after PCI,and the proportion of high-sensitivity cardiac troponin T(hs-cTnT)peaking within 12 hours of onset.The safety outcome was major bleeding events defined as Bleeding Academic Research Consortium(BARC)≥type 3 bleeding during hospitalization.Results Compared with the control group,the r-SAK group had a higher proportion of STR≥70%within 60-90 minutes after PCI(58.3%vs.40.3%,P=0.009);a lower proportion of pathological Q waves(59.1%vs.74.1%,P=0.040);a lower rate of Q wave progression(14.8%vs.43.2%,P＜0.001);a higher rate of Q wave disappearance(12.5%vs.3.7%,P=0.027);and a higher proportion of hs-cTnT peaking within 12 hours of symptom onset[31/40(77.5%)vs.17/33(51.5%),P=0.027].Regarding the safety outcome,no significant difference in BARC≥type 3 bleeding was found between the two groups during hospitalization(P＞0.05).Conclusions For STEMI patients who were expected to undergo primary PCI within 120 minutes of symptom onset,the facilitated PCI with half-dose r-SAK significantly increased the proportion of STR≥70%at 60-90 minutes after PCI,reduced the formation of pathological Q waves,and shortened the time to peak hs-cTnT,without increasing the risk of bleeding,which should be an alternative reperfusion strategy worthy of further study.

AIM:Flow cytometry was used to evaluate the effects of short-term storage conditions(fresh,frozen at-80℃for 7 d,and stored at 4℃for 7 d)on the median fluorescence intensity(MFI)of antibodies and the percentage of immune cell subsets in mouse peripheral blood mononuclear cells(PBMCs)and splenocytes.METHODS:The PBMC and splenocyte suspensions from six male Kunming mice were collected and analyzed under three different processing con-ditions to compare differences in the antibody MFI and percentages of monocyte subsets(Ly-6clow/Ly-6cmedium/Ly-6chigh),macrophages(M1/M2),and dendritic cells.RESULTS:Both tissue and antibody specificity were demonstrated by changes in the antibody MFI values.Following storage at-80℃,the MFIs of certain antibodies(such as CD45 and F4/80 in PBMCs,and CD115,Ly-6c,F4/80,CD80 and MHC-II in the spleen)were similar to those of the fresh groups,where-as after storage at 4℃,the MFIs of other antibodies(such as 7-AAD,CD115,Ly-6c and MHC-II in PBMCs,and CD11b,CD206 and CD11c in the spleen)were closer to those of the fresh groups.The MFI of most of the examined anti-bodies varied significantly following storage.Both storage conditions significantly reduced the viability of PBMCs and sple-nocytes.In PBMCs stored at 4℃,the percentages of total monocytes,Ly-6cmedium/Ly-6chigh monocytes,total macrophages,and dendritic cells were similar to those in the fresh group.Compared with the fresh group,both storage groups presented significantly lower percentages of M1 macrophages and dendritic cells(P<0.05).There were no statistically significant differences in the percentages of total monocytes,Ly-6cmedium monocytes,Ly-6chigh monocytes,total macrophages,M1 and M2 macrophages,or dendritic cells in the spleen among the three groups(P>0.05).The percentage of Ly-6clow monocytes did not differ substantially(P>0.05)between the fresh and-80℃frozen groups but was significantly lower in the 4℃storage group than in the fresh group(P<0.05).CONCLUSION:The storage conditions of the samples had a substantial effect on the flow cytometry results(antibody MFI and cell subset percentages)of the PBMCs and splenic cells,with tissue specificity.If the percentage of immune cell subgroups(particularly monocytes/macrophages/dendritic cells)in PBMCs is highly important,storage at 4℃for 7 d is preferable.If the MFI values of specific antibodies(such as CD45 and F4/80)are important,freezing at-80℃may be more appropriate.If the MFI values of most antibodies or the percentages of criti-cal subgroups(such as total monocytes/Ly-6chigh/total macrophages/dendritic cells)in splenic cells need to be close to those of fresh samples,4 ℃ storage for 7 d is more effective.Freezing at-80℃is preferable if the MFI values of particular anti-bodies(such as CD115 and Ly-6c)need to be determined.

Objective To examine the changing prevalence and antimicrobial resistance profiles of Burkholderia cepacia in 52 hospitals across China from 2015 to 2021.Methods A total of 9 261 strains of B.cepacia were collected from 52 hospitals between January 1,2015 and December 31,2021.Antimicrobial susceptibility of the strains was tested using Kirby-Bauer method or automated antimicrobial susceptibility testing systems according to a unified protocol.The results were interpreted according to the breakpoints released in the Clinical & Laboratory Standards Institute(CLSI)guidelines(2023 edition).Results A total of 9 261 strains of B.cepacia were isolated from all age groups,especially elderly patients.The proportion was 11.1％(1 032 strains)in children,significantly lower than the proportion in adults.About half(46.5％,4 310/9 261)of the strains were isolated from patients at least 60 years old and 42.3％(3 919/9 261)of the strains were isolated from young adults.Most isolates(71.1％)were isolated from sputum and respiratory secretions,followed by urine(10.7％)and blood samples(8.1％).B.cepacia isolates were highly susceptible to the five antimicrobial agents recommended in the CLSI M100 document(33rd edition,2023).B.cepacia isolates showed relatively higher resistance rates to meropenem and levofloxacin.However,the resistance rates to ceftazidime,trimethoprim-sulfamethoxazole,and minocycline remained below 8.1％.The percentage of B.cepacia strains resistant to levofloxacin was the highest compared to other antibiotics in any of the three age groups(from 12.4％in the patients＜18 years old to 20.6％in the patients aged 60 years or older).Conclusions B.cepacia is one of the clinically important non-fermenting gram-negative bacteria.Accurate and timely reporting of antimicrobial susceptibility test results and ongoing antimicrobial resistance surveillance are helpful for rational prescription of antimicrobial agents and proper prevention and control of nosocomial infections.

Objective:To explore the effect of Lactobacillus reuteri on testicular injury in mice exposed to neonicotinoid insec-ticides(NNI).Methods:Fifteen C57BL/6 male mice were randomly divided into control group(CTRI.group),exposure group(NNI group)and Lactobacillus intervention group(NNI-L group).The mice in CTRL group were given 0.02ml/g of 0.5％carboxym-ethyl cellulose sodium solution by gavage for 14 days.The mice in NNI group were given 0.02 ml/g of NNI mixture by gavage for 14 days.The mice in NNI-L group were given 0.02 ml/g of NNI mixture by gavage and 5 × 108cfu/ml of Lactobacillus reuteri powder so-lution for 14 days.Then,the histomorphology and function of testicle were evaluated by hematoxylin-eosin staining,immunofluores-cence staining and RNA sequencing.Results:Compared with CTRL group,the thickness of testicular seminiferous epithelium in the NNI group was significantly thinner.And the decline in the number of spermatogenic cells and sperm was observed.And the expression of spermatogonial stem cell marker UCHL1 was down-regulated which was significantly improved in NNI-L group compared with the NNI group.The abnormal expressions of hormone and sperm methylation related genes in testis of NNI group were detected by RNA sequen-cing,with significant down-regulation being found in NPFF and IGF2.While the expression of HSD3B8 was significantly up-regulated.The abnormal expression of these genes could be significantly improved after oral administration of Lactobacillus reuteri.Conclusion:Testicular spermatogenesis and endocrine function can be damaged by NNI exposure.And oral administration of Lactoba-cillus reuteri protects testis from the adverse effects of NNI toxicity.

AIM:Flow cytometry was used to evaluate the effects of short-term storage conditions(fresh,frozen at-80℃for 7 d,and stored at 4℃for 7 d)on the median fluorescence intensity(MFI)of antibodies and the percentage of immune cell subsets in mouse peripheral blood mononuclear cells(PBMCs)and splenocytes.METHODS:The PBMC and splenocyte suspensions from six male Kunming mice were collected and analyzed under three different processing con-ditions to compare differences in the antibody MFI and percentages of monocyte subsets(Ly-6clow/Ly-6cmedium/Ly-6chigh),macrophages(M1/M2),and dendritic cells.RESULTS:Both tissue and antibody specificity were demonstrated by changes in the antibody MFI values.Following storage at-80℃,the MFIs of certain antibodies(such as CD45 and F4/80 in PBMCs,and CD115,Ly-6c,F4/80,CD80 and MHC-II in the spleen)were similar to those of the fresh groups,where-as after storage at 4℃,the MFIs of other antibodies(such as 7-AAD,CD115,Ly-6c and MHC-II in PBMCs,and CD11b,CD206 and CD11c in the spleen)were closer to those of the fresh groups.The MFI of most of the examined anti-bodies varied significantly following storage.Both storage conditions significantly reduced the viability of PBMCs and sple-nocytes.In PBMCs stored at 4℃,the percentages of total monocytes,Ly-6cmedium/Ly-6chigh monocytes,total macrophages,and dendritic cells were similar to those in the fresh group.Compared with the fresh group,both storage groups presented significantly lower percentages of M1 macrophages and dendritic cells(P<0.05).There were no statistically significant differences in the percentages of total monocytes,Ly-6cmedium monocytes,Ly-6chigh monocytes,total macrophages,M1 and M2 macrophages,or dendritic cells in the spleen among the three groups(P>0.05).The percentage of Ly-6clow monocytes did not differ substantially(P>0.05)between the fresh and-80℃frozen groups but was significantly lower in the 4℃storage group than in the fresh group(P<0.05).CONCLUSION:The storage conditions of the samples had a substantial effect on the flow cytometry results(antibody MFI and cell subset percentages)of the PBMCs and splenic cells,with tissue specificity.If the percentage of immune cell subgroups(particularly monocytes/macrophages/dendritic cells)in PBMCs is highly important,storage at 4℃for 7 d is preferable.If the MFI values of specific antibodies(such as CD45 and F4/80)are important,freezing at-80℃may be more appropriate.If the MFI values of most antibodies or the percentages of criti-cal subgroups(such as total monocytes/Ly-6chigh/total macrophages/dendritic cells)in splenic cells need to be close to those of fresh samples,4 ℃ storage for 7 d is more effective.Freezing at-80℃is preferable if the MFI values of particular anti-bodies(such as CD115 and Ly-6c)need to be determined.