BACKGROUND:In the initial stage of growth plate injury inflammation,platelet-derived growth factor BB promotes the repair of growth plate injury by promoting mesenchymal progenitor cell infiltration,chondrogenesis,osteogenic response,and regulating bone remodeling. OBJECTIVE:To elucidate the action mechanism of platelet-derived growth factor BB after growth plate injury. METHODS:PubMed,VIP,WanFang,and CNKI databases were used as the literature sources.The search terms were"growth plate injury,bone bridge,platelet-derived growth factor BB,repair"in English and Chinese.Finally,66 articles were screened for this review. RESULTS AND CONCLUSION:Growth plate injury experienced early inflammation,vascular reconstruction,fibroossification,structural remodeling and other pathological processes,accompanied by the crosstalk of chondrocytes,vascular endothelial cells,stem cells,osteoblasts,osteoclasts and other cells.Platelet-derived growth factor BB,as an important factor in the early inflammatory response of injury,regulates the injury repair process by mediating a variety of cellular inflammatory responses.Targeting the inflammatory stimulation mediated by platelet-derived growth factor BB may delay the bone bridge formation process by improving the functional activities of osteoclasts,osteoblasts,and chondrocytes,so as to achieve the injury repair of growth plate.Platelet-derived growth factor BB plays an important role in angiogenesis and bone repair tissue formation at the injured site of growth plate and intrachondral bone lengthening function of uninjured growth plate.Inhibition of the coupling effect between angiogenesis initiated by platelet-derived growth factor BB and intrachondral bone formation may achieve the repair of growth plate injury.

Objective : To explore the role of lysophosphatidylcholine acyltransferase 3(LPCAT3) in Erastin-induced ferroptosis of acute myeloid leukemia(AML) cells and its related molecular regulatory mechanisms. Methods : Tetrazolium salt(MTS) method was used to detect the sensitivity of different AML cells to the classic ferroptosis inducer Erastin, real time quantitative polymerase chain reaction(qPCR) was used to detect the basal expression level ofLPCAT3mRNA, and the correlation between them was analyzed. Lentivirus-mediatedLPCAT3overexpression AML cell lines(OE group) and negative control lines(NC group) were constructed. After Erastin intervention, MTS, flow cytometry, and micromethods were used to detect cell viability, lipid reactive oxygen species(ROS), and Malondialdehyde(MDA), respectively. qPCR and Western blot were used to detect unfolded protein response(UPR) classic pathway signaling molecules(PERK, ATF4, GRP78, etc.) expression levels. The above ferroptosis-related indicators were detected after combined intervention with the UPR inhibitor 4-phenylbutyric acid(4-PBA), and the regulatory relationship was analyzed. Results : Four different types of AML cells had different sensitivities to ferroptosis, among which K562 cells were relatively insensitive. The IC50of the four types of AML cells to Erastin was negatively correlated with the expression level ofLPCAT3(r=-0.919,P<0.001). After Erastin intervention, the cell viability of K562 cells in the OE group was significantly inhibited by Erastin compared with the NC group(P<0.001), and the levels of lipid ROS and MDA increased(P<0.001). The results of qPCR and Western blot showed that, compared with the NC group, the mRNA and protein expression of UPR classic pathway moleculesPERK,ATF4, andGRP78mRNA and protein increased in the OE group(P<0.01). After inhibiting the UPR pathway by 4-PBA, the viability of K562 cells decreased(P<0.01), and lipid ROS and MDA levels increased(P<0.01) compared with the uninhibited state. Conclusion Overexpression ofLPCAT3can promote ferroptosis in K562 cells, and this process is negatively regulated by the classical UPR pathway PERK/ATF.

Diabetes is a very complex endocrine disease whose common feature is the increase in blood glucose concentration. Persistent hyperglycemia can lead to blindness, kidney and heart disease, neurodegeneration, and many other serious complications that have a significant impact on human health and quality of life. The number of people with diabetes is increasing yearly. The global diabetes prevalence in 20-79 year olds in 2021 was estimated to be 10.5% (536.6 million), and it will rise to 12.2% (783.2 million) in 2045. The main modes of intervention for diabetes include medication, dietary management, and exercise conditioning. Medication is the mainstay of treatment. Marketed diabetes drugs such as metformin and insulin, as well as GLP-1 receptor agonists, are effective in controlling blood sugar levels to some extent, but the preventive and therapeutic effects are still unsatisfactory. Peptide drugs have many advantages such as low toxicity, high target specificity, and good biocompatibility, which opens up new avenues for the treatment of diabetes and other diseases. Currently, insulin and its analogs are by far the main life-saving drugs in clinical diabetes treatment, enabling effective control of blood glucose levels, but the risk of hypoglycemia is relatively high and treatment is limited by the route of delivery. New and oral anti-diabetic drugs have always been a market demand and research hotspot. Inhibitor cystine knot (ICK) peptides are a class of multifunctional cyclic peptides. In structure, they contain three conserved disulfide bonds (C3-C20, C7-C22, and C15-C32) form a compact “knot” structure, which can resist degradation of digestive protease. Recent studies have shown that ICK peptides derived from legume, such as PA1b, Aglycin, Vglycin, Iglycin, Dglycin, and aM₁, exhibit excellent regulatory activities on glucose and lipid metabolism at the cellular and animal levels. Mechanistically, ICK peptides promote glucose utilization by muscle and liver through activation of IR/AKT signaling pathway, which also improves insulin resistance. They can repair the damaged pancrease through activation of PI3K/AKT/Erk signaling pathway, thus lowering blood glucose. The biostability and hypoglycemic efficacy of the ICK peptides meet the requirements for commercialization of oral drugs, and in theory, they can be developed into natural oral anti-diabetes peptide drugs. In this review, the structural properties, activity and mechanism of ICK pattern peptides in regulating glucose and lipid metabolism were summaried, which provided a reference for the development of new oral peptides for diabetes.

ObjectiveTo clarify whether epigallocatechin gallate （EGCG） is involved in the clearance of amyloid β-protein （Aβ） and autophagy induction by microglia， so as to explore the potential mechanisms of EGCG in the prevention and treatment of Alzheimer's disease （AD）. MethodsSix-month-old APP/PS1 mice were randomly divided into model and EGCG groups， with some additional wild type （WT） mice as the control group， each group consisting of 15 mice. The EGCG group received continuous gavage administration［5 mg/（kg·d）］ for 8 weeks， followed by the open field test and Y-maze to assess the learning and memory abilities of the mice. Thioflavin-S staining was used to evaluate the content and distribution of amyloid β-protein （Aβ）in the brain parenchyma of the mice， and immunofluorescence was employed to detect the expression levels of Aβ_1-42， glial fibrillary acidic protein （GFAP）， and ionized calcium-binding adapter molecule 1 （Iba1） in the hippocampal tissue of the mice. Additionally， N9 mouse microglial cells were induced with 20 µmol/L Aβ_1-42， and the cell viability was measured after treatment with different concentrations of EGCG （5 µmol/L， 10 µmol/L， 20 µmol/L）. Western blotting was used to detect the levels of Aβ_1-42， low density lipoprotein receptor-related protein 1（LRP1）， receptor for advanced glycation endproducts （RAGE）， amyloid precursor protein （APP）， insulin degrading enzyme （IDE）， neprilysin （NEP）， microtubule associated protein 1 hydrogen chain 3（LC3）-Ⅱ/LC3-Ⅰ， phosphatidylinositol 3-hydroxy kinase（PI3K）， p-PI3K， protein kinase B （AKT）， p-AKT， mammalian target of rapamycin （mTOR）， p-mTOR， and histone deacetylase 6（HDAC6）. Finally， through the co-culture of microglial cells and neuronal SH-SY5Y cells， cell viability and Caspase-3 levels were measured to verify the protective effect of EGCG-mediated Aβ clearance on neurons. ResultsEGCG increased the activity time and frequency of APP/PS1 mice in the central area of the open field （P<0.05）， and enhanced the percentage of alternation in the Y-maze test （P<0.01）； EGCG reduced Aβ deposition in the hippocampal tissue of APP/PS1 mice and increased the number of microglia； in vitro experiments showed that EGCG improved the survival rate of Aβ-induced N9 cells （P<0.01）， upregulated RAGE activity （P<0.05）， and promoted the internalization and phagocytosis of Aβ （P<0.01）. ECGC activated microglial autophagy by downregulating the level of HDAC6 （P<0.05）， inhibiting the phosphorylation of PI3K， AKT， mTOR （P<0.001）， and increasing the LC3-Ⅱ/LC3-I ratio （P<0.001）； EGCG improved the survival rate of SH-SY5Y cells （P<0.05） and reduced the activity of Caspase-3 （P<0.01） by clearing Aβ_1-42 through microglia， and had a protective effect on neurons. ConclusionEGCG activates microglial autophagy to clear Aβ by targeting and inhibiting the HDAC6-PI3K/AKT/mTOR axis.

Background::Thoracic aortic aneurysm (TAA) is a fatal cardiovascular disease, the pathogenesis of which has not yet been clarified. This study aimed to identify and validate the diagnostic markers of TAA to provide a strong theoretical basis for developing new methods to prevent and treat this disease.Methods::Gene expression profiles of the GSE9106, GSE26155, and GSE155468 datasets were acquired from the Gene Expression Omnibus (GEO) database. Differentially expressed genes (DEGs) were identified using the "limma" package in R. Least absolute shrinkage and selection operator (LASSO), support vector machine-recursive feature elimination (SVM-RFE), random forest, and binary logistic regression analyses were used to screen the diagnostic marker genes. Single-sample gene set enrichment analysis (ssGSEA) was used to estimate immune cell infiltration in TAA.Results::A total of 16 DEGs were identified. The enrichment and functional correlation analyses showed that DEGs were mainly associated with inflammatory response pathways and collagen-related diseases. Collagen type I alpha 1 chain ( COL1A1) and synaptotagmin like 2 ( SYTL2) were identified as diagnostic marker genes with a high diagnostic value for TAA. The expression of COL1A1 and SYTL2 was considerably higher in TAA vascular wall tissues than in the corresponding normal tissues, and there were significant differences in the infiltration of immune cells between TAA and normal vascular wall tissues. Additionally, COL1A1 and SYTL2 expression were associated with the infiltration of immune cells in the vascular wall tissue. Single-cell analysis showed that COL1A1 in TAA was mainly derived from fibroblasts and SYTL2 mainly from cluster of differentiation (CD)8 + T cells. In addition, single-cell analysis indicated that fibroblasts and CD8 + T cells in TAA were significantly higher than those in normal arterial wall tissue. Conclusions::COL1A1 and SYTL2 may serve as diagnostic marker genes for TAA. The upregulation of SYTL2 and COL1A1 may be involved in the inflammatory infiltration of the vessel wall and poor extracellular matrix remodeling, promoting the progression of TAA.

Objective To monitor the susceptibility of clinical isolates to antimicrobial agents in tertiary hospitals in major regions of China in 2022.Methods Clinical isolates from 58 hospitals in China were tested for antimicrobial susceptibility using a unified protocol based on disc diffusion method or automated testing systems.Results were interpreted using the 2022 Clinical &Laboratory Standards Institute(CLSI)breakpoints.Results A total of 318 013 clinical isolates were collected from January 1,2022 to December 31,2022,of which 29.5％were gram-positive and 70.5％were gram-negative.The prevalence of methicillin-resistant strains in Staphylococcus aureus,Staphylococcus epidermidis and other coagulase-negative Staphylococcus species(excluding Staphylococcus pseudintermedius and Staphylococcus schleiferi)was 28.3％,76.7％and 77.9％,respectively.Overall,94.0％of MRSA strains were susceptible to trimethoprim-sulfamethoxazole and 90.8％of MRSE strains were susceptible to rifampicin.No vancomycin-resistant strains were found.Enterococcus faecalis showed significantly lower resistance rates to most antimicrobial agents tested than Enterococcus faecium.A few vancomycin-resistant strains were identified in both E.faecalis and E.faecium.The prevalence of penicillin-susceptible Streptococcus pneumoniae was 94.2％in the isolates from children and 95.7％in the isolates from adults.The resistance rate to carbapenems was lower than 13.1％in most Enterobacterales species except for Klebsiella,21.7％-23.1％of which were resistant to carbapenems.Most Enterobacterales isolates were highly susceptible to tigecycline,colistin and polymyxin B,with resistance rates ranging from 0.1％to 13.3％.The prevalence of meropenem-resistant strains decreased from 23.5％in 2019 to 18.0％in 2022 in Pseudomonas aeruginosa,and decreased from 79.0％in 2019 to 72.5％in 2022 in Acinetobacter baumannii.Conclusions The resistance of clinical isolates to the commonly used antimicrobial agents is still increasing in tertiary hospitals.However,the prevalence of important carbapenem-resistant organisms such as carbapenem-resistant K.pneumoniae,P.aeruginosa,and A.baumannii showed a downward trend in recent years.This finding suggests that the strategy of combining antimicrobial resistance surveillance with multidisciplinary concerted action works well in curbing the spread of resistant bacteria.

Objective To investigate the distribution and antimicrobial resistance profiles of the common pathogens isolated from urine from 2015 to 2021 in the CHINET Antimicrobial Resistance Surveillance Program.Methods The bacterial strains were isolated from urine and identified routinely in 51 hospitals across China in the CHINET Antimicrobial Resistance Surveillance Program from 2015 to 2021.Antimicrobial susceptibility was determined by Kirby-Bauer method,automatic microbiological analysis system and E-test according to the unified protocol.Results A total of 261 893 nonduplicate strains were isolated from urine specimen from 2015 to 2021,of which gram-positive bacteria accounted for 23.8％(62 219/261 893),and gram-negative bacteria 76.2％(199 674/261 893).The most common species were E.coli(46.7％),E.faecium(10.4％),K.pneumoniae(9.8％),E.faecalis(8.7％),P.mirabilis(3.5％),P.aeruginosa(3.4％),SS.agalactiae(2.6％),and E.cloacae(2.1％).The strains were more frequently isolated from inpatients versus outpatients and emergency patients,from females versus males,and from adults versus children.The prevalence of ESBLs-producing strains in E.coli,K.pneumoniae and P.mirabilis was 53.2％,52.8％and 37.0％,respectively.The prevalence of carbapenem-resistant strains in E.coli,K.pneumoniae,P.aeruginosa and A.baumannii was 1.7％,18.5％,16.4％,and 40.3％,respectively.Lower than 10％of the E.faecalis isolates were resistant to ampicillin,nitrofurantoin,linezolid,vancomycin,teicoplanin and fosfomycin.More than 90％of the E.faecium isolates were ressitant to ampicillin,levofloxacin and erythromycin.The percentage of strains resistant to vancomycin,linezolid or teicoplanin was＜2％.The E.coli,K.pneumoniae,P.aeruginosa and A.baumannii strains isolated from ICU inpatients showed significantly higher resistance rates than the corresponding strains isolated from outpatients and non-ICU inpatients.Conclusions E.coli,Enterococcus and K.pneumoniae are the most common pathogens in urinary tract infection.The bacterial species and antimicrobial resistance of urinary isolates vary with different populations.More attention should be paid to antimicrobial resistance surveillance and reduce the irrational use of antimicrobial agents.

Objective To understand the distribution and changing resistance profiles of clinical isolates of Enterococcus in hospitals across China from 2015 to 2021.Methods Antimicrobial susceptibility testing was conducted for the clinical isolates of Enterococcus according to the unified protocol of CHINET program by automated systems,Kirby-Bauer method,or E-test strip.The results were interpreted according to the Clinical & Laboratory Standards Institute(CLSI)breakpoints in 2021.WHONET 5.6 software was used for statistical analysis.Results A total of 124 565 strains of Enterococcus were isolated during the 7-year period,mainly including Enterococcus faecalis(50.7％)and Enterococcus faecalis(41.5％).The strains were mainly isolated from urinary tract specimens(46.9％±2.6％),and primarily from the patients in the department of internal medicine,surgery and ICU.E.faecium and E.faecalis strains showed low level resistance rate to vancomycin,teicoplanin and linezolid(≤3.6％).The prevalence of vancomycin-resistant E.faecalis and E.faecium was 0.1％and 1.3％,respectively.The prevalence of linezolid-resistant E.faecalis increased from 0.7％in 2015 to 3.4％in 2021,while the prevalence of linezolid-resistant E.faecium was 0.3％.Conclusions The clinical isolates of Enterococcus were still highly susceptible to vancomycin,teicoplanin,and linezolid,evidenced by a low resistance rate.However,the prevalence of linezolid-resistant E.faecalis was increasing during the 7-year period.It is necessary to strengthen antimicrobial resistance surveillance to effectively identify the emergence of antibiotic-resistant bacteria and curb the spread of resistant pathogens.

Objective To examine the changing antimicrobial resistance profile of Enterobacter spp.isolates in 53 hospitals across China from 2015 t0 2021.Methods The clinical isolates of Enterobacter spp.were collected from 53 hospitals across China during 2015-2021 and tested for antimicrobial susceptibility using Kirby-Bauer method or automated testing systems according to the CHINET unified protocol.The results were interpreted according to the breakpoints issued by the Clinical & Laboratory Standards Institute(CLSI)in 2021(M100 31st edition)and analyzed with WHONET 5.6 software.Results A total of 37 966 Enterobacter strains were isolated from 2015 to 2021.The proportion of Enterobacter isolates among all clinical isolates showed a fluctuating trend over the 7-year period,overall 2.5％in all clinical isolates amd 5.7％in Enterobacterale strains.The most frequently isolated Enterobacter species was Enterobacter cloacae,accounting for 93.7％(35 571/37 966).The strains were mainly isolated from respiratory specimens(44.4±4.6)％,followed by secretions/pus(16.4±2.3)％and urine(16.0±0.9)％.The strains from respiratory samples decreased slightly,while those from sterile body fluids increased over the 7-year period.The Enterobacter strains were mainly isolated from inpatients(92.9％),and only(7.1±0.8)％of the strains were isolated from outpatients and emergency patients.The patients in surgical wards contributed the highest number of isolates(24.4±2.9)％compared to the inpatients in any other departement.Overall,≤ 7.9％of the E.cloacae strains were resistant to amikacin,tigecycline,polymyxin B,imipenem or meropenem,while ≤5.6％of the Enterobacter asburiae strains were resistant to these antimicrobial agents.E.asburiae showed higher resistance rate to polymyxin B than E.cloacae(19.7％vs 3.9％).Overall,≤8.1％of the Enterobacter gergoviae strains were resistant to tigecycline,amikacin,meropenem,or imipenem,while 10.5％of these strains were resistant to polycolistin B.The overall prevalence of carbapenem-resistant Enterobacter was 10.0％over the 7-year period,but showing an upward trend.The resistance profiles of Enterobacter isolates varied with the department from which they were isolated and whether the patient is an adult or a child.The prevalence of carbapenem-resistant E.cloacae was the highest in the E.cloacae isolates from ICU patients.Conclusions The results of the CHINET Antimicrobial Resistance Surveillance Program indicate that the proportion of Enterobacter strains in all clinical isolates fluctuates slightly over the 7-year period from 2015 to 2021.The Enterobacter strains showed increasing resistance to multiple antimicrobial drugs,especially carbapenems over the 7-year period.

Objective To understand the changing distribution and antimicrobial resistance profiles of Proteus,Morganella and Providencia in hospitals across China from January 1,2015 to December 31,2021 in the CHINET Antimicrobial Resistance Surveillance Program.Methods Antimicrobial susceptibility testing was carried out following the unified CHINET protocol.The results were interpreted in accordance with the breakpoints in the 2021 Clinical & Laboratory Standards Institute(CLSI)M100(31 st Edition).Results A total of 32 433 Enterobacterales strains were isolated during the 7-year period,including 24 160 strains of Proteus,6 704 strains of Morganella,and 1 569 strains of Providencia.The overall number of these Enterobacterales isolates increased significantly over the 7-year period.The top 3 specimen source of these strains were urine,lower respiratory tract specimens,and wound secretions.Proteus,Morganella,and Providencia isolates showed lower resistance rates to amikacin,meropenem,cefoxitin,cefepime,cefoperazone-sulbactam,and piperacillin-tazobactam.For most of the antibiotics tested,less than 10％of the Proteus and Morganella strains were resistant,while less than 20％of the Providencia strains were resistant.The prevalence of carbapenem-resistant Enterobacterales(CRE)was 1.4％in Proteus isolates,1.9％in Morganella isolates,and 15.6％in Providencia isolates.Conclusions The overall number of clinical isolates of Proteus,Morganella and Providencia increased significantly in the 7-year period from 2015 to 2021.The prevalence of CRE strains also increased.More attention should be paid to antimicrobial resistance surveillance and rational antibiotic use so as to prevent the emergence and increase of antimicrobial resistance.