BACKGROUND:Studies have shown that metformin has anti-inflammatory,anti-tumor,anti-aging and vasoprotective effects,and can inhibit the progression of osteoarthritis,but its specific mechanism of action remains unclear. OBJECTIVE:To investigate the mechanism of metformin on cartilage protection in a rat model of osteoarthritis. METHODS:Forty male Sprague-Dawley rats were randomly divided into four groups(n=10 per group):blank,control,sham-operated,and metformin groups.The blank group did not undergo any surgery.In the sham-operated group,the joint cavity was exposed.In the model group and the metformin group,the modified Hulth method was used to establish the osteoarthritis model.At 1 day after modeling,the rats in the metformin group were given 200 mg/kg/d metformin by gavage,and the model,blank,and sham-operated groups were given normal saline by gavage.Administration in each group was given for 4 weeks consecutively.Hematoxylin-eosin staining,toluidine blue staining,and safranin O-fast green staining were used to observe the morphological structure of rat knee joints.Immunohistochemical staining and western blot were used to detect the protein expression of SOX9,type Ⅱ collagen,a disintegrin and metalloproteinase with thrombospondin motifs 5(ADAMTS5),Beclin1,P62,phosphatidylinositol 3-kinase(PI3K),p-PI3K,protein kinase B(AKT),p-AKT,mammalian target of rapamycin(Mtor),and p-Mtor in rat cartilage tissue. RESULTS AND CONCLUSION:The results of hematoxylin-eosin,toluidine blue and safranin O-fast green staining showed smooth cartilage surface of the knee joints and normal histomorphology in the blank group and the sham-operated group,while in the model group,there was irregular cartilage surface of the knee joint and cartilage damage,with a decrease in the number of chondrocytes and the content of proteoglycans in the cartilage matrix.In the metformin group,there was a significant improvement in the damage to the structure of the cartilage in the knee joints of the rats,and the cartilage surface tended to be smooth,with an increase in the number of chondrocytes and the content of proteoglycans in the cartilage matrix.Immunohistochemistry staining and western blot results showed that compared with the control and sham-operated groups,the expression of SOX9,type Ⅱ collagen,and Beclin1 proteins in the cartilage tissue of rats in the model group was significantly decreased(P<0.05).Conversely,the expression of ADAMTS5,P62,as well as p-PI3K,p-AKT,and p-Mtor proteins was significantly increased(P<0.05).Furthermore,compared with the model group,the expression of SOX9,type Ⅱ collagen,and Beclin1 proteins in the cartilage tissue of rats in the metformin group was significantly increased(P<0.05),while the expression of ADAMTS5,P62,as well as p-PI3K,p-AKT,and p-Mtor proteins was significantly decreased(P<0.05).To conclude,Metformin can improve the autophagy activity of chondrocytes and reduce the degradation of cartilage matrix in osteoarthritis rats by inhibiting the activation of PI3K/AKT/Mtor signaling pathway,thus exerting a protective effect on articular cartilage.

Coronary restenosis is an important cause of poor long-term prognosis in patients with coronary heart disease. Here, we show that lysine methyltransferase SMYD2 expression in the nucleus is significantly elevated in serum- and PDGF-BB-induced vascular smooth muscle cells (VSMCs), and in tissues of carotid artery injury-induced neointimal hyperplasia. Smyd2 overexpression in VSMCs (Smyd2-vTg) facilitates, but treatment with its specific inhibitor LLY-507 or SMYD2 knockdown significantly inhibits VSMC phenotypic switching and carotid artery injury-induced neointima formation in mice. Transcriptome sequencing revealed that SMYD2 knockdown represses the expression of serum response factor (SRF) target genes and that SRF overexpression largely reverses the inhibitory effect of SMYD2 knockdown on VSMC proliferation. HDAC3 directly interacts with and deacetylates SRF, which enhances SRF transcriptional activity in VSMCs. Moreover, SMYD2 promotes HDAC3 expression via tri-methylation of H3K36 at its promoter. RGFP966, a specific inhibitor of HDAC3, not only counteracts the pro-proliferation effect of SMYD2 overexpression on VSMCs, but also inhibits carotid artery injury-induced neointima formation in mice. HDAC3 partially abolishes the inhibitory effect of SMYD2 knockdown on VSMC proliferation in a deacetylase activity-dependent manner. Our results reveal that the SMYD2-HDAC3-SRF axis constitutes a novel and critical epigenetic mechanism that regulates VSMC phenotypic switching and neointimal hyperplasia.

Objective:To investigate the current situation of the use of transjugular intrahepatic portosystemic shunt (TIPS) for portal hypertension, which should aid the development of TIPS in China.Methods:The China Portal Hypertension Alliance (CHESS) initiated this study that comprehensively investigated the basic situation of TIPS for portal hypertension in China through network research. The survey included the following: the number of surgical cases, main indications, the development of Early-TIPS, TIPS for portal vein cavernous transformation, collateral circulation embolization, intraoperative portal pressure gradient measurement, commonly used stent types, conventional anticoagulation and time, postoperative follow-up, obstacles, and the application of domestic instruments.Results:According to the survey, a total of 13 527 TIPS operations were carried out in 545 hospitals participating in the survey in 2021, and 94.1% of the hospital had the habit of routine follow-up after TIPS. Most hospitals believed that the main indications of TIPS were the control of acute bleeding (42.6%) and the prevention of rebleeding (40.7%). 48.1% of the teams carried out early or priority TIPS, 53.0% of the teams carried out TIPS for the cavernous transformation of the portal vein, and 81.0% chose routine embolization of collateral circulation during operation. Most of them used coils and biological glue as embolic materials, and 78.5% of the team routinely performed intraoperative portal pressure gradient measurements. In selecting TIPS stents, 57.1% of the hospitals woulel choose Viator-specific stents, 57.2% woulel choose conventional anticoagulation after TIPS, and the duration of anticoagulation was between 3-6 months (55.4%). The limitation of TIPS surgery was mainly due to cost (72.3%) and insufficient understanding of doctors in related departments (77.4%). Most teams accepted the domestic instruments used in TIPS (92.7%).Conclusions:This survey shows that TIPS treatment is an essential part of treating portal hypertension in China. The total number of TIPS cases is far from that of patients with portal hypertension. In the future, it is still necessary to popularize TIPS technology and further standardize surgical indications, routine operations, and instrument application.

Objective To observe the incidence of pericardial tamponade(PT)after left atrial appendage closure(LAAC)in patients with non-valvular atrial fibrillation(NVAF),and to explore its related factors and outcomes.Methods NVAF patients who were hospitalized and treated with LAAC in Department of Cardiology of our hospital from August 2014 to March 2023 were selected for the study.The general clinical data,preoperative transthoracic echocardiography and transesophageal echocardiography data,results of routine preoperative laboratory tests,intraoperative data and follow-up data of the patients were collected through the hospital medical record management system.The enrolled patients were classified into the non-PT group(n=8)and the PT group(n =1184)according to whether PT occurred after LAAC or not.The incidence of PT,related risk factors and outcomes were statistically analyzed.Results This study included 639 males(53.6%)and 553 females(46.4%),with an average age of 68.1±9.65 years.The CHA2 DS2-VASc score was 4.51±1.72,and the HAS-BLED score was 3.36±1.09.PT occurred in 8 cases(0.67%),among them,6 cases occurred 1 to 33 h after LAAC,and 2 cases occurred on day 19 and day 27 after LAAC.As for the results of transesophageal echocardiography(TEE)and LAA angiography,compared with the non-PT group,the PT group had the significantly larger maximum caliber of the LAA(P=0.025,P=0.015),smaller maximum depth of the LAA(P=0.028,P=0.031),and lower success rate of one-time placement of the occluder(P=0.031);The occluder compression rate of the PT group was significantly greater than that of the non-PT group(P=0.046).Multivariate analysis showed that larger maximum diameter of LAA,smaller average effective depth of LAA and larger compression rate of occluder were the main risk factors for PT.All the 8 PT patients were cured by stopping antithrombotic drugs,pericardiocentesis or surgical drainage.During a mean follow-up of 39±27 months,there were no device-related thrombosis(DRT),ischemic stroke,systemic embolism and other complications in the PT group.Conclusion The incidence of PT after LAAC is low,which is related to the large diameter of LAA,the relatively insufficient depth of the LAA and the large compression rate of the occlude.PT can be cured by stopping antithrombotic drugs and pericardiocentesis/surgical drainage.

Objective To analyze and verify the role of senescent genes in the treatment,prognosis,and tumor microenvironment(TME)characteristics of osteoblastic osteosarcoma,bioinformatic methods were employed.Methods Senescent genes were obtained from the China National Genome Science database(https://ngdc.cncb.ac.cn/aging/index).The gene expression profile and clinical information of osteosarcoma patients were sourced from the TARGET database(https://ocg.cancer.gov/programs/target),while single-cell RNA-sequencing(scRNA-seq)data was collected from GSE162454 on the Gene Expression Omnibus(GEO)for downstream analysis.Osteosarcoma cells were classified based on scRNA-seq,and differential expression analysis between osteoblasts/chondroblasts and other cell types was conducted to identify differently expressed genes(DEGs).After matching with the senescent genes,prognostic senescent DEGs were identified through univariable and multivariable Cox regression analysis.Subsequently,the osteosarcoma senescent-related model(OSRM)was constructed,and the risk score was calculated.The role of OSRM in treatment,prognosis,and TME of osteosarcoma was further investigated.Results The analysis revealed that GSE162454 contained 6 osteosarcoma samples,with 19933 cells identified after filtering,quality control,and normalization.Seventeen cellular subtypes were identified using uniform manifold approximation and projection(UMAP)methods.A total of 4821 DEGs were found between osteoblasts/chondroblasts and other subtypes,with 132 senescent DEGs obtained after matching with the senescent gene set.In the TARGET database,4 prognostic senescent DEGs[ADH5(alcohol dehydrogenase 5),ARHGAP1(Rho GTPase activating protein 1),APOE(apolipoprotein E),and ATF4(activating transcription factor 4)]were identified through univariable and multivariable Cox analyses to construct OSRM.Based on risk score,patients were stratified into high-and low-risk groups,with the latter showing better prognosis(HR=0.13,95%CI 0.06-0.28,P<0.001)and higher sensitivity to immune checkpoint inhibitors.qRT-PCR and Western blotting confirmed the high expression of senescent genes ADH5(P<0.01),APOE(P<0.01),and ATF4(P<0.05)in the K7M2 osteosarcoma cell line,suggesting the potential for predicting the response to anti-PD-1 immunotherapy for osteosarcoma.Conclusions scRNA-seq facilitated the division of osteosarcoma into 17 cell subtypes.ADH5,ARHGAP1,APOE,and ATF4 emerged as potential cancer-promoting or suppressing senescent genes in osteosarcoma.OSRM was found to be associated with treatment response,prognosis,and TME characteristics,thereby promoting the molecular pathological diagnosis of osteoblastic osteosarcoma and prediction for anti-PD-1 immunotherapy.

Objective To investigate the role and underlying mechanisms of miR-34a/SIRT1 in intensive care unit acquired weakness(ICU-AW).Methods(1)C2C12 mouse skeletal muscle cells were induced to differentiate into myotubes,and were divided into two groups:model group[ICU-AW group,treated with lipopolysaccharides(LPS)for 12 hours]and normal control group(treated with the same amount of sterile water for 12 hours).Western blotting was used to detect the protein expression level of Muscle ring finger 1(MuRF-1),atrophy gene 1(Atrogin-1)and Sirtuin-1(SIRT1).RT-qPCR was used to assess the mRNA expression level of microRNA-34a(miR-34a),MuRF-1,Atrogin-1 and SIRT1,and light microscope was used to observe the growth and differentiation of C2C12 skeletal muscle cells in each group.(2)ICU-AW cells were further subdivided into control group(treated with siRNA transfection agent intervention),Scra siRNA group(treated with transfection agent and non-specific siRNA),miR-34a siRNA group(treated with transfection agent and specific siRNA intervention),vehicle group(treated with agonist solvent dimethyl sulfoxide)and SRT1720 group(treated with SIRT1 agonist SRT1720).Western blotting was used to detect the protein expression level of SIRT1,Atrogin-1 and MuRF-1 in each group.RT-qPCR was used to detect the miR-34a and the mRNA expression level of SIRT1,Atrogin-1 and MuRF-1 in each group.(3)In addition,another group of ICU-AW cells were divided into control group(treated with siRNA transfection),miR-34a siRNA group(treated with transfection agent and specific siRNA intervention),miR-34a siRNA+vehicle group(treated with transfection agent,specific siRNA and Dimethyl sulfoxide intervention)and miR-34a siRNA+EX-527 group(treated with transfection agent,specific siRNA and SIRT1 inhibitor EX-527).Western blotting was used to detect the protein expression level of Atrogin-1 and MuRF-1.RT-qPCR was used to assess the mRNA expression level of Atrogin-1 and MuRF-1.Results Myotube differentiation was observed on the 4th day.Compared with control group,myotube atrophy was obvious in ICU-AW group.RT-qPCR and Western blotting results revealed that,compared with normal control group,in ICU-AW group,the mRNA and protein expression levels of Atrogin-1 and MuRF-1 significantly increased(P＜0.05),and the expression level of miR-34a significantly increased(P＜0.05),while the mRNA and protein expression levels of SIRT1 significantly decreased(P＜0.05).RT-qPCR results showed that,compared with control group(treated with siRNA transfection agent intervention)and Scra siRNA group,the expression of miR-34a and mRNA expression of Atrogin-1 and MuRF-1 in miR-34a siRNA group significantly decreased(P＜0.05),while the mRNA expression of SIRT1 significantly increased(P＜0.05),meanwhile the protein expression of Atrogin-1 and MuRF-1 decreased significantly(P＜0.01),and the protein expression of SIRT1 significantly increased(P＜0.05).RT-qPCR results also showed that,compared with vehicle group,the mRNA expression of Atrogin-1 and MuRF-1 in SRT1720 group decreased significantly(P＜0.05),while SIRT1 increased significantly(P＜0.05).Western blotting results demonstrated that,compared with control group and Scra siRNA group,the protein expression of Atrogin-1 and MuRF-1 in miR-34a siRNA group decreased significantly(P＜0.05),while SIRT1 increased significantly(P＜0.05).RT-qPCR and Western blotting results indicated that,compared with miR-34a siRNA+vehicle group,the mRNA and protein expression of Atrogin-1 and MuRF-1 in miR-34a siRNA+EX-527 group increased significantly(P＜0.05).Conclusion Overactivation of miR-34a in ICU-AW contributes to skeletal muscle atrophy by inhibiting the expression of SIRT1,which may play an important role in the pathogenesis of ICU-AW.

Aim To design the pyrimidoindole deriva-tive N-butyl-9H-pyrimido[4,5-b]indole-2-carboxamide(BFPI)and synthesize it to investigate whether it in-hibits macrophage pyroptosis and foaming effects through the NLRP3/Caspase-1 pathway.Methods BFPI was synthesized using 2,4,6-triethoxycarbonyl-l,3,5-triazine and 2-aminoindole as starting materials and structurally characterized by 1H NMR,13C NMR,and ESI-MS.The in vitro cultured mouse monocyte macro-phage cell line RAW264.7 was divided into blank,model(PA)and therapeutic(BFPI)groups,and the cells in each group were treated with the corresponding culture medium for 24 h.The proliferative viability was detected by MTT assay,and the formation of intracel-lular lipid droplets was detected by oil red O staining,and NLRP3 was detected by Western-blot and RT-qPCR,caspase-1 and MCP-1 mRNA and protein ex-pression levels by Western blot and RT-qPCR.Results Compared with the blank group,the proliferation vi-ability of cells in the model group significantly de-creased and the formation of lipid droplets significantly increased;compared with the model group,the prolif-eration viability of cells in the treatment group signifi-cantly increased and the formation of lipid droplets sig-nificantly decreased,and the differences were statisti-cally significant(P＜0.01);compared with the blank group,the cellular NLRP3,caspase-1 and MCP-1 mR-NA and protein expression levels of cells in the model group significantly increased;compared with the model group,the expression levels of the above indexes of the cells in the treatment group significantly decreased,and the difference was statistically significant(P＜0.01).Conclusions BFPI contributes to delaying macrophage-derived foam cell formation during athero-genesis by inhibiting macrophage NLRP3,caspase-1,and MCP-1 expression and thereby promoting their pro-liferation and inhibiting lipid phagocytosis.

Cells are the fundamental structural and functional units of biological organisms,with inherent differences in composition and interactions with exogenous substances,known as cellular heterogeneity.Single cell inductively coupled plasma-mass spectrometry(SC-ICP-MS)allows for the high-throughput introduction of individual cells,enabling the highly sensitive detection and quantification of elements within a single cell,thus effectively providing information on cellular heterogeneity.This review outlined the SC-ICP-MS sample preparation process for different types of cells(single-cell systems,aggregation-prone and adherent cell systems,animal tissues,and plant tissues),including steps such as separation,washing,and fixation,as well as the advantages and existing issues of the current sample introduction systems and quantification methods.The recent applications of SC-ICP-MS in detecting endogenous substances(endogenous elements and proteins),exogenous substances(heavy metals,metal-based drugs and nanoparticles),and the simultaneous detection of both endogenous and exogenous substances were summarized.Finally,the perspectives on the future development of SC-ICP-MS in analytical methods and application fields were presented,including the optimization of single-cell sample preparation,transport efficiency,evaluation standards of ionization efficiency,and the establishment of multiparametric cell analysis platforms.

Objective:To investigate the clinical effect of intraarticular vancomycin on early periprosthetic joint infection (PJI) in knee arthroplasty and the incidence of postoperative complications.Methods:This is a retrospective cohort study. The clinical data of 1 867 patients who underwent primary knee arthroplasty at Department of Joint Surgery, the Affiliated Hospital of Qingdao University from April 2022 to June 2023 were retrospectively analysed, including total knee arthroplasty (TKA), robotic-assisted total knee arthroplasty (RA-TKA) and unicondylar knee arthroplasty (UKA). There were 687 males and 1 180 females, aged (68.0±11.2)years(range:45 to 87 years). Patients were divided into the vancomycin group and the control group according to whether or not intra-articular injection of 1 g of vancomycin powder dissolved in 30 ml of saline was performed after intraoperative joint capsule closure. In the vancomycin group, 925 patients were included, including 782 TKA, 27 RA-TKA and 116 UKA.In the control group, 942 patients were included, including 767 TKA, 99 RA-TKA and 76 UKA. Early PJI, wound complications, and vancomycin-related toxicity including acute renal collapse, ototoxicity, and allergic reactions were assessed within 3 months postoperatively. The data were compared using the independent sample t test, χ2 test, and Fisher's exact probability method, as appropriate. Major Extremity Trauma Research Consortium (METRC). Results:No PJI was found in all patients in the vancomycin group.Five cases (0.7%,5/767) of early PJI were found in TKA patients in the control group, with a statistically significant difference ( P=0.030); 1 case of early PJI was found in each RA-TKA and UKA patients, with non-significant difference compared with vancomycin group (all P>0.05). Two cases (0.3%,2/782) of incisional complications were found in TKA patients in the vancomycin group, and 4 cases (0.5%, 4/767) of incisional complications were found in TKA patients in the control group, with non-significant difference( P=0.449); no incisional complication was found in RA-TKA patients in the vancomycin group, and 1 case (1.0%,1/99) of incisional complications were found in RA-TKA patients in the control group, the difference was not statistically significant ( P>0.05); no incisional complication was found in both groups of UKA patients.No vancomycin-related acute kidney injury, ototoxicity, or allergic reactions was observed in all patients. Conclusion:Intra-articular injection of 1 g of vancomycin suspension after arthrotomy closure during TKA maybe lower the risk of early PJI without increasing the risk of wound complication and vancomycin-associated systemic toxicity.

A boy,aged 14 years,was admitted due to recurrent cough and expectoration for more than 1 month,with aggravation and fever for 2 days. After admission,he presented with tachypnea and a significant reduction in transcutaneous oxygen saturation,and emergency chest CT examination showed large patchy exudation and consolidation of both lungs. The boy was given tracheal intubation and invasive mechanical ventilation immediately,and his condition was improved after active symptomatic treatment. On the 10th day of hospitalization,the boy experienced fever again,and the laboratory tests showed positive results for Epstein-Barr virus and Mycoplasma antibody IgM,along with pancytopenia,elevated triglycerides,decreased fibrinogen,and increased levels of ferritin and soluble CD25. The boy was diagnosed with hemophagocytic lymphohistiocytosis. Bone marrow biopsy showed the presence of atypical lymphocytes,and aggressive natural killer cell leukemia was considered according to clinical manifestations and flow cytometry immunophenotype. Therefore,the possibility of hemophagocytic lymphohistiocytosis should be suspected in case of severe infection with pancytopenia and rapid disease progression,and hematological malignancies should also be ruled out. Bone marrow biopsy should be performed as early as possible to make a confirmed diagnosis and perform timely treatment.