BACKGROUND:Exosomes derived from mesenchymal stem cells play pivotal roles in cell communication and epigenetic regulation due to their low immunogenicity and targeted delivery effects,and have been clinically applied in the treatment of various diseases.OBJECTIVE:To review the isolation,purification,identification methods,and application progress of mesenchymal stem cell-derived exosomes,and to facilitate the development of large-scale preparation techniques and clinical translation of mesenchymal stem cell-derived exosomes.METHODS:The Chinese search terms"exosome,mesenchymal stem cells,isolation,purification,characterization,clinical application"and the English search terms"exosome,extracellular vesicles,mesenchymal stem cells,isolation,characterization,application"were used to search the literature published before September 2024 in CNKI,PubMed,and Web of Science databases.Articles with poor relevance to the topic,outdated,or duplicated content were excluded,and finally,109 articles were included for review.RESULTS AND CONCLUSION:(1)This paper reviews recent methods for isolating and purifying exosomes,comparing the characteristics of ultracentrifugation,ultrafiltration,size-exclusion chromatography,polymer precipitation,immunoaffinity,microfluidic methods,and other novel approaches based on their underlying principles.(2)Methods for identifying exosomes can be categorized into physical and biochemical analyses,characterizing exosomes based on their shape,size,and characteristic proteins.(3)Mesenchymal stem cell-derived exosomes have broad applications in multiple fields such as medical aesthetics,wound repair,and cancer treatment,due to their immune-regulatory properties and ability to cross biological barriers.(4)The clinical translation of exosomes faces challenges due to their complex structure,lack of universal isolation techniques,and poor stability,making it difficult to achieve in a short period of time.

BACKGROUND:Exosomes derived from mesenchymal stem cells play pivotal roles in cell communication and epigenetic regulation due to their low immunogenicity and targeted delivery effects,and have been clinically applied in the treatment of various diseases.OBJECTIVE:To review the isolation,purification,identification methods,and application progress of mesenchymal stem cell-derived exosomes,and to facilitate the development of large-scale preparation techniques and clinical translation of mesenchymal stem cell-derived exosomes.METHODS:The Chinese search terms"exosome,mesenchymal stem cells,isolation,purification,characterization,clinical application"and the English search terms"exosome,extracellular vesicles,mesenchymal stem cells,isolation,characterization,application"were used to search the literature published before September 2024 in CNKI,PubMed,and Web of Science databases.Articles with poor relevance to the topic,outdated,or duplicated content were excluded,and finally,109 articles were included for review.RESULTS AND CONCLUSION:(1)This paper reviews recent methods for isolating and purifying exosomes,comparing the characteristics of ultracentrifugation,ultrafiltration,size-exclusion chromatography,polymer precipitation,immunoaffinity,microfluidic methods,and other novel approaches based on their underlying principles.(2)Methods for identifying exosomes can be categorized into physical and biochemical analyses,characterizing exosomes based on their shape,size,and characteristic proteins.(3)Mesenchymal stem cell-derived exosomes have broad applications in multiple fields such as medical aesthetics,wound repair,and cancer treatment,due to their immune-regulatory properties and ability to cross biological barriers.(4)The clinical translation of exosomes faces challenges due to their complex structure,lack of universal isolation techniques,and poor stability,making it difficult to achieve in a short period of time.

Objective To generate and characterize natural killer cell (NK cell)-conditional Cd226 gene knockout mice using Cre-loxP technology, and to explore the role of CD226 on NK cells in alleviating intestinal inflammation in a murine model of ulcerative colitis (UC). Methods NK cell-conditional Cd226 gene knockout mice were generated by crossing loxP-flanked Cd226 mice with Ncr1-Cre mice via the Cre-loxP system. Polymerase chain reaction (PCR) and agarose gel electrophoresis were used for genotyping. A UC model was established by dextran sulfate sodium (DSS) induction. Flow cytometry was performed to analyze CD226 expression levels on NK cells and the infiltration of related immune cells in colon tissues. Hematoxylin-eosin (HE) staining was performed to assess the degree of colonic inflammation. Results DNA gel electrophoresis and flow cytometry confirmed the successful generation of NK cell-specific Cd226 knockout mice. After conditional knockout of Cd226 in NK cells, inflammation in the UC mouse model was alleviated. Flow cytometry results showed a reduced proportion of NK cells in peripheral blood and the colon lamina propria, while HE staining demonstrated attenuated inflammatory responses. Conclusion Specific knockout of Cd226 in NK cells mitigates intestinal inflammation in UC mice by reducing NK cell numbers and inhibiting their pro-inflammatory functions.
Animals ; Colitis, Ulcerative/pathology* ; Killer Cells, Natural/metabolism* ; Mice, Knockout ; T Lineage-Specific Activation Antigen 1 ; Antigens, Differentiation, T-Lymphocyte/genetics* ; Mice ; Disease Models, Animal ; Mice, Inbred C57BL ; Male

Cardiac fibrosis is characterized by an elevated amount of extracellular matrix (ECM) within the heart. However, the persistence of cardiac fibrosis ultimately diminishes contractility and precipitates cardiac dysfunction. Circular RNAs (circRNAs) are emerging as important regulators of cardiac fibrosis. Here, we elucidate the functional role of a specific circular RNA CELF1 in cardiac fibrosis and delineate a novel feedback loop mechanism. Functionally, circ-CELF1 was involved in enhancing fibrosis-related markers' expression and promoting the proliferation of cardiac fibroblasts (CFs), thereby exacerbating cardiac fibrosis. Mechanistically, circ-CELF1 reduced the ubiquitination-degradation rate of BRPF3, leading to an elevation of BRPF3 protein levels. Additionally, BRPF3 acted as a modular scaffold for the recruitment of histone acetyltransferase KAT7 to facilitate the induction of H3K14 acetylation within the promoters of the Celf1 gene. Thus, the transcription of Celf1 was dramatically activated, thereby inhibiting the subsequent response of their downstream target gene Smad7 expression to promote cardiac fibrosis. Moreover, Celf1 further promoted Celf1 pre-mRNA transcription and back-splicing, thereby establishing a feedback loop for circ-CELF1 production. Consequently, a novel feedback loop involving CELF1/circ-CELF1/BRPF3/KAT7 was established, suggesting that circ-CELF1 may serve as a potential novel therapeutic target for cardiac fibrosis.

Objective To analyze the biomechanical responses after small incision lenticule extraction(SMILE)based on personalized biomechanical parameters of the human eye.Methods Through the results from the correlation analysis between corneal stromal elastic modulus and biomechanical parameters,the cornea elastic modulus was predicted and the material parameters were obtained.Based on clinical measurement data,52 personalized myopic human eye models were reconstructed to analyze the corneal biomechanical response after SMILE.Results The biomechanical response of the cornea varied from patients,and the vertex displacement and stress of the corneal surface increased or decreased after SMILE.On average,when residual stromal thickness(RST)ranged from 278 μm to 332 μm and IOP was 16-20 mmHg(1 mmHg=0.133 kPa),the change of vertex displacement and stress on the corneal surface after SMILE were less than those under IOP=11-16 mmHg.Under RST＞332 μm and IOP=11-16 mmHg,the corneal biomechanics was relatively stable.In addition,the corrected diopters of patients increased,and the deformation of corneal surface after SMILE was more drastic.Conclusions RST and IOP are important factors influencing corneal biomechanics.The material parameters of corneal tissues were predicted based on corneal biomechanical parameters.The cutting profiles and surgical parameters of SMILE may be optimized through analyzing the surgical effect after refractive surgery by reconstructing personalized finite element model of human eyes.

Objective:To analyze the prediction of pathological classification of ground glass nodules based on artificial intelligence computed tomography (CT) quantitative parameters combined with histogram parameters.Methods:The clinical data of 268 suspected patients with ground glass nodules admitted to Foshan Fosun Chancheng Hospital from June 2021 to June 2023 were retrospectively selected as the research subjects. They were divided into pre invasive lesions group (100 cases) and invasive lesions group(168 cases) according to pathological classification. Basic data of patients with different pathological classifications and the CT characteristics were compared, the prediction of pathological classification of ground glass nodules based on CT quantitative parameters combined and histogram parameters were analyzed by receiver operating characteristic (ROC) curve.Results:The edge and boundary of the tumor, shape of the lesion, the peripheral signs of the lesion and the boundary between the two groups had statistical differences ( P<0.05). The CT quantitative parameters of maximum diameter, lesion volume, average CT value in the invasive lesions group and pre invasive lesions group had statistical differences: (15.29 ± 3.20) cm vs. (9.75 ± 2.14) cm, (1.54 ± 0.31) cm 3 vs. (0.51 ± 0.10) cm 3, (- 328.16 ± 46.35) HU vs. (-541.25 ± 100.30) HU, P<0.05. The CT histogram parameters of inproportion of solid components, entropy and maximum CT value in the invasive lesions group and pre invasive lesions group had statistical differences: (66.39 ± 13.25)% vs. (42.65 ± 11.20)%, 4.31 ± 0.52 vs. 3.32 ± 0.39, (-75.34 ± 21.27) HU vs. (-141.72 ± 32.43)HU, P<0.05. Compared with the single prediction of CT quantitative parameters and CT histogram parameters, the combined prediction of the two parameters had higher value in predicting different pathological subtypes of ground glass nodules (the area under the curve was 0.877, P = 0.001). Conclusions:The combined detection of CT quantitative parameters and histogram parameters based on artificial intelligence can effectively evaluate the invasion status of ground glass nodules, which is beneficial for improving the detection of different pathological types of ground glass nodules.

Objective The purpose of the study is to breed homozygous interferon-γ knockout(IFN-γ-/-)mice and optimize the breeding strategies to achieve continuous and stable reproduction of IFN-γ-/-mice,which could be used as an ideal animal model for fundamental research.Methods Initially,heterozygous IFN-γ knockout(IFN-γ+/-)C57BL/6J mice were used as the parental generation for breeding.Subsequently,3 breeding strategies were employed using the offspring:(1)female heterozygotes mated with male heterozygotes;(2)male homozygotes mated with female heterozygotes;(3)female homozygotes mated with male homozygotes.The number and survival rate of IFN-γ-/-mice were compared across the three breeding strategies to determine the optimal breeding strategy.Under the optimal strategy,the effects of female mating age and diet type on the reproductive performance of IFN-γ-/-mice were further evaluated.Data from the first three litters of 60 IFN-γ-/-female mice,including litter size,number of weaning survivors,and weaning survival rate,were recorded and analyzed.In addition,the effects of dietary supplementation of pregnant mice and environmental optimization measures,such as the provision of shelters,were evaluated.Results Under conditions where the nutritional needs of pregnant mice were adequately met by supplementation with egg yolk and sunflower seeds,mating of female and male IFN-γ-/-mice result ed in a litter size of five to eight IFN-γ-/-mice,demonstrating higher efficiency compared to other breeding strategies.In addition,diet type and mating age significantly influenced female reproductive performance.When 7～9 weeks old female IFN-γ-/-mice were mated to male IFN-γ-/-mice and fed a high-protein breeding diet,litter size(6.9±1.7),weaning survival number(6.5％±2.0％)and weaning survival rate(93.2％±17.8％)were higher than those under other conditions.In addition,providing shelters to prevent fighting between breeding pairs further improved reproductive outcomes.Conclusions By adopting an optimized breeding strategy,combined with a high-protein diet,nutritional supplementation,and standardized mating age management,the breeding efficiency and stability of IFN-γ-/-mice can be significantly improved.This provides a reliable animal model for related research.

Objective To systematically summarize the real experiences of the patients with totally implanted venous access ports(TIVAP)over the survival period of port-carrying,and provide references for formulation of the targeted health management programs.Methods A systematic search was conducted on databases of PubMed,Web of Science,Cochrane Library,CINAHL,Embase,PsycNET,China National Knowledge Infrastructure(CNKI),SinoMed,Wanfang Data base,and Vip for a qualitative study on the life experiences,needs,and feelings of patients with implanted infusion ports.The search period spanned from the inception of the databases to 3rd August,2024.Results A total of 14 studies were included,in 12 categories extracted from 38 research findings.Four synthesised results were further summarised,they were:impact on individual physical and mental health,impact on home life,challenges and needs in self-management and self-coping strategies of patients.Conclusion The implantation of TIVAP can produce both positive and negative experiences to the treatment as well as the life of patients.Healthcare professionals should be aware of the differences in emotion,cognition,need and personal coping strategy among the patients,hence to take effective measures to optimise the port-carrying experience of the patients,enhance the self-management enthusiasm and improve the quality of life of patients.

Objective To evaluate the clinical utility of the f-wave to QRS complex amplitude ratio(f/R ratio)in intracardiac electrogram(IC-ECG)-guided positioning of peripherally inserted central catheter(PICC)tips in patients with atrial fibrillation(AF),providing evidence to enhance clinical practice.Methods This study employed a conve-nience sampling method to enroll eligible AF patients admitted to a tertiary hospital in Suzhou from July 2023 to July 2024.During PICC placement,IC-ECG was utilized to monitor f-wave and QRS complex amplitude variations.Following successful catheterization,the f/R ratio was measured,and chest X-ray was performed to confirm the catheter tip position.The accuracy of PICC tip positioning across different f/R ratio ranges was analyzed,and the incidence of arrhythmias was recorded.A receiver operating characteristic curve was constructed to assess the diag-nostic performance of the f/R ratio in PICC tip localization.Results A total of 68 AF patients were included,with f/R ratios ranging from 20.63％to 91.24％.PICC tip positioning accuracy varied significantly across different f/R ratio ranges(P=0.006).The area under the ROC curve(AUC)for f/R ratio in PICC tip positioning was 0.784(P=0.009),with a maximum Youden index of 0.567,an optimal diagnostic threshold of 40.00％,a sensitivity of 81.7％,a speci-ficity of 75.0％,a positive predictive value of 96.1％,and a negative predictive value of 35.3％.No arrhythmias other than AF occurred during the procedure.Conclusion The f/R ratio provides reliable and safe guidance for PICC tip positioning in AF patients.An f/R ratio ≥40％is associated with higher accuracy in identifying the optimal catheter tip position.

Breast cancer is a kind of malignant tumor with a complex mechanism， and its morbidity and mortality are increasing year by year， which seriously threatens women's health. At present， the main clinical treatments are surgical resection， radiotherapy， chemotherapy， and drug therapy， but they are often accompanied by side effects and adverse reactions， which affect the therapeutic effect. Traditional Chinese medicine （TCM） has the advantages of multi-component and multi-target treatment in the fight against breast cancer. The wnt/β-catenin signaling pathway is one of the classic pathways in cancer research. Abnormally activated Wnt/β-catenin signaling pathway inhibits β-catenin degradation by blocking the formation of Axin/glycogen synthase kinase 3β/adenomatous polyposis coli complex， thus promoting β-catenin nuclear metastasis， and it binds to T cell transcription factor/lymphoenhancer factor-1 to initiate downstream target genes and further interfere with the proliferation， migration， and invasion of tumor cells to affect the tumor process. Previous studies have shown that TCM monomers and compounds can mediate the Wnt/β-catenin signaling pathway to inhibit the malignant phenotype of breast cancer cells， thus playing an anti-breast cancer role， and the biochemical process involved in the regulation of therapeutic drugs has not been systematically combed. By analyzing and collating Chinese and foreign literature at the present stage， this paper discussed the association mechanism between Wnt/β-catenin signaling pathway and breast cancer and analyzed the internal mechanism of TCM monomers and compounds in mediating Wnt/β-catenin signaling pathway to exert anti-breast cancer effect. The statistical results showed that the flavonoids， alkaloids， and terpenoids in TCM monomers could target the Wnt/β-catenin signaling pathway and block the further development of malignant phenotype of breast cancer cells. TCM compounds with functions of clearing heat and detoxifying， promoting blood circulation and removing blood stasis， and tonifying kidney and liver were commonly used to intervene in the Wnt/β-catenin signaling pathway to prevent breast cancer. Compared with the current inhibitors of Wnt/β-catenin signaling pathway， the application of TCM monomers and compounds is expected to bring low-toxicity and high-efficiency breast cancer treatment drugs to the clinical practice， and the existing results provide a reference for the subsequent screening， research， and development of TCM small-molecule compounds and TCM compounds against breast cancer.