BACKGROUND:Exosomes,as a type of extracellular vesicle,have become a key medium for cell-to-cell communication due to their nanoscale size and enrichment of various bioactive substances.The study of exosome secretion regulation not only has important scientific value,but also has broad application prospects in clinical practice,and is of great significance for promoting medical progress and improving human health.OBJECTIVE:To review the biological characteristics,biological functions,biogenesis process and biochemical regulation mechanism of exosomes,and to explore the application prospects of exosomes in disease diagnosis,treatment and vaccine development,so as to provide theoretical basis and reference for basic research and clinical transformation of exosomes.METHODS:The first author searched PubMed and CNKI databases in October 2024 for relevant literature published from January 2010 to October 2024.Key words were"exosomes,biological functions,biogenesis,secretion or release,regulatory mechanisms,application prospects"in Chinese and English.Finally,92 articles were included for analysis.RESULTS AND CONCLUSION:The secretion level of exosomes can be regulated through physical or biochemical means.Exosomes show broad application prospects in the fields of disease diagnosis,treatment,and vaccine development,and may play a key role in the treatment of cardiovascular and cerebrovascular diseases as well as cancer.This review provides valuable information for the clinical translation and application research of exosomes,helping to promote future progress in exosome research and application.

OBJECTIVE:Patients with osteoporotic vertebral compression fractures still have residual back pain after vertebral augmentation.The current research is characterized by limited sample size,complex confounding factors,and inconsistent research results.To gain a deeper understanding of this phenomenon,the aim of this study was to identify and evaluate the risk factors for residual back pain after surgery through a systematic review and meta-analysis.METHODS:A comprehensive search was conducted in CNKI,VIP,WanFang,CBMdisc,PubMed,The Cochrane Library,Embase,and Web of Science for case-control studies on residual back pain after vertebral body augmentation for osteoporotic vertebral compression fractures from database inception to July 2024.The search terms were a combination of subject terms and free terms.The basic information,patient characteristics,surgical-related indicators,and risk factors for surgical back pain of the included studies were extracted.After evaluating the bias risk of all included studies,a meta-analysis was conducted using Stata 14.0 software on the relevant indicators.RESULTS:(1)21 case-control studies with a total of 8 043 patients were included.Among them,965 patients developed back pain.The quality score of all 21 studies was ≥7.(2)The meta-analysis results showed that age(WMD=0.98,95％CI:0.40-1.56,P=0.010),bone mineral density(WMD=-0.28,95％CI:-0.34 to-0.21,P=0.000),the number of vertebral fractures(OR=3.50,95％CI:2.65-4.62,P=0.000),thoracolumbar fracture index(OR=3.65,95％CI:2.61-5.11,P=0.000),cement volume(OR=6.89,95％CI:2.62-18.17,P=0.000),and cement distribution(OR=2.38,95％CI:1.93-2.93,P=0.000)were risk factors for the development of back pain after vertebral body augmentation in patients with osteoporotic vertebral compression fractures.CONCLUSION:Current evidence indicates that age,bone mineral density,the number of vertebral fractures,thoracolumbar fracture index,bone cement injection volume,and the distribution of bone cement are risk factors for low back pain.Specifically,bone mineral density,the number of vertebral fractures,thoracolumbar fracture index,and non-uniform distribution of bone cement are identified as independent risk factors for low back pain.Patients exhibiting these high-risk factors require vigilant monitoring and prompt intervention to mitigate the occurrence of clinical low back pain,thereby enhancing patient outcomes and quality of life.

BACKGROUND:Exosomes,as a type of extracellular vesicle,have become a key medium for cell-to-cell communication due to their nanoscale size and enrichment of various bioactive substances.The study of exosome secretion regulation not only has important scientific value,but also has broad application prospects in clinical practice,and is of great significance for promoting medical progress and improving human health.OBJECTIVE:To review the biological characteristics,biological functions,biogenesis process and biochemical regulation mechanism of exosomes,and to explore the application prospects of exosomes in disease diagnosis,treatment and vaccine development,so as to provide theoretical basis and reference for basic research and clinical transformation of exosomes.METHODS:The first author searched PubMed and CNKI databases in October 2024 for relevant literature published from January 2010 to October 2024.Key words were"exosomes,biological functions,biogenesis,secretion or release,regulatory mechanisms,application prospects"in Chinese and English.Finally,92 articles were included for analysis.RESULTS AND CONCLUSION:The secretion level of exosomes can be regulated through physical or biochemical means.Exosomes show broad application prospects in the fields of disease diagnosis,treatment,and vaccine development,and may play a key role in the treatment of cardiovascular and cerebrovascular diseases as well as cancer.This review provides valuable information for the clinical translation and application research of exosomes,helping to promote future progress in exosome research and application.

BackgroundAnxiety symptoms have become a public health issue affecting the physical and mental health of the elderly population. Mental health literacy is a predictor of anxiety symptoms in the elderly. Currently， there are limited studies on the pathogenic mechanism between the two. Exploring the relationship and mechanism between mental health literacy and anxiety symptoms among the elderly is of great significance for improving the mental health level of the elderly. ObjectiveTo investigate the impact of mental health literacy on anxiety symptoms in the elderly， and to analyze the role of insomnia in this process， in order to provide references for the formulation of prevention and intervention strategies for anxiety symptoms in the elderly. MethodsFrom August 2021 to December 2022， a total of 10 650 older adults aged 60 years old and above were selected from a city in Sichuan Province using a multistage stratified sampling method. Participants completed the self-compiled demographic questionnaire， the Insomnia Severity Index （ISI）， the Generalized Anxiety Disorder Scale-7 item （GAD-7）， and the National Mental Health Literacy Questionnaire （NMHLQ）. Spearman correlation analysis was adopted to examine the correlation between the scores of the scales. Model 4 in SPSS 27.0 plugin Process 4.1 was employed to test the pathway of insomnia between mental health literacy （and its various dimensions） and anxiety symptoms. ResultsAmong the participants， 9 609 cases （90.23%） completed the valid questionnaire survey， and 1 680 cases （17.48%） were found to have anxiety symptoms. The total score of the NMHLQ for the elderly， as well as the scores of the knowledge， awareness， and skills dimensions， were negatively correlated with the GAD-7 score and the ISI score （r_s=-0.506–-0.054， P<0.01）， and the ISI score was positively correlated with the GAD-7 score （r_s=0.666， P<0.01）. Insomnia served as the mediating pathway between the mental health literacy and anxiety symptoms， with an indirect effect value of -0.210 （95% CI： -0.227–-0.193）， accounting for 54.97% of the total effect. Insomnia was the mediating pathway between the mental health literacy knowledge and anxiety symptoms of the elderly， with an indirect effect value of -0.161 （95% CI： -0.178–-0.144）， accounting for 52.61% of the total effect. Insomnia played a mediating role in the relationship between the awareness of mental health literacy and anxiety symptoms， with an indirect effect value of -0.323 （95% CI： -0.342–-0.302）， accounting for 76.36% of the total effect. Insomnia was the mediating pathway between the mental health literacy skills and anxiety symptoms of the elderly， with an indirect effect value of -0.172 （95% CI： -0.187–-0.159）， accounting for 53.75% of the total effect. ConclusionThe dimensions of mental health literacy， knowledge， awareness and skills of the elderly not only directly affect anxiety symptoms， but also indirectly influence anxiety symptoms through the pathway of insomnia.［Funded by Medical Research Project Plan of Sichuan Province （number， S23049）］

Objective Magnetoreception, the remarkable ability of diverse animals to sense and utilize the geomagnetic field for orientation and navigation, remains a molecularly unresolved mystery in sensory biology. The putative magnetoreceptor (MagR, previously known as IscA1) is a highly conserved iron-sulfur protein implicated in both magnetoreception and iron metabolism; however, the functional diversity among its cross-species homologs remains poorly understood. Cellular morphology is a key genetically determined trait that can be altered through genetic or environmental modifications—a process known as cell morphology engineering. Constructing engineered cells with specific morphological features and magnetic sensitivity to achieve remote, non-invasive magnetic modulation represents a crucial goal in this field with significant application potential. Therefore, this study aims to systematically investigate the effects of MagR heterologous expression on bacterial morphology and magnetic sensing capabilities, screen for MagR-based magnetically sensitive morphology engineering pathways, and reveal the underlying molecular mechanisms. Methods We systematically screened 28 MagR homologous genes from diverse prokaryotic and animal taxa to evaluate their expression and corresponding phenotypic effects in Escherichia coli (E. coli). To compare the differential magnetic responses among bacteria expressing various recombinant MagR proteins, we utilized high-throughput automated bright-field microscopic imaging and scanning electron microscopy (SEM). Furthermore, comprehensive biochemical and biophysical characterizations of iron and iron-sulfur cluster binding were performed using Ferrozine colorimetric assays, electron paramagnetic resonance (EPR) spectroscopy, ultraviolet-visible (UV-Vis) absorption, and circular dichroism (CD) spectroscopy. Additionally, 100 mT static magnetic field (SMF) exposure experiments were conducted to assess magnetically tunable phenotypes, while the intrinsic magnetic properties of purified MagR proteins were directly measured using a superconducting quantum interference device (SQUID) magnetometer. Results Our results demonstrated that the heterologous expression of MagR homologs induced varying degrees of bacterial filamentation. From this comprehensive screen, two distinct morphological patterns were identified: hydra (Hydra vulgaris) MagR (hyMagR) promoted uniform cell elongation and filamentation, exhibiting robust magnetic sensitivity manifested as significantly enhanced filamentation under the 100 mT SMF. In contrast, pigeon (Columba livia) MagR (clMagR) induced only low-frequency, extreme filamentation (sporadically exceeding 80 μm) with a relatively weaker magnetic morphological response. Mechanistically, our data unambiguously proved that these phenotypic differences are primarily driven by distinct iron redox preferences rather than total cellular iron accumulation. Specifically, hyMagR preferentially binds ferrous iron (Fe²⁺), whereas clMagR favors ferric iron (Fe³⁺) and forms more stable iron-sulfur clusters. Intriguingly, although SQUID magnetometry showed that purified clMagR exhibited approximately five-fold higher mass magnetic susceptibility than hyMagR, its cellular magnetic response was weaker. We hypothesize that the Fe²⁺-preferred intracellular environment associated with hyMagR overexpression primes the cell for enhanced generation of reactive oxygen species (ROS) via the Fenton reaction. Exposure to an SMF synergizes with this primed redox state, triggering the bacterial SOS response and upregulating cell division inhibitors to efficiently induce uniform filamentation. Conclusion Our findings identify the Fe²⁺/Fe³⁺ redox state as a critical determinant of MagR-mediated morphological remodeling and magnetic responsiveness. This discovery suggests a potential strategy for engineering magnetically responsive cellular systems for synthetic biology applications, and provides a plausible framework, which potentially combines intrinsic protein magnetism with redox-state modulation, for further investigating the evolutionary mechanisms of MagR-mediated magnetoreception.

Objective Magnetoreception, the remarkable ability of diverse animals to sense and utilize the geomagnetic field for orientation and navigation, remains a molecularly unresolved mystery in sensory biology. The putative magnetoreceptor (MagR, previously known as IscA1) is a highly conserved iron-sulfur protein implicated in both magnetoreception and iron metabolism; however, the functional diversity among its cross-species homologs remains poorly understood. Cellular morphology is a key genetically determined trait that can be altered through genetic or environmental modifications—a process known as cell morphology engineering. Constructing engineered cells with specific morphological features and magnetic sensitivity to achieve remote, non-invasive magnetic modulation represents a crucial goal in this field with significant application potential. Therefore, this study aims to systematically investigate the effects of MagR heterologous expression on bacterial morphology and magnetic sensing capabilities, screen for MagR-based magnetically sensitive morphology engineering pathways, and reveal the underlying molecular mechanisms. Methods We systematically screened 28 MagR homologous genes from diverse prokaryotic and animal taxa to evaluate their expression and corresponding phenotypic effects in Escherichia coli (E. coli). To compare the differential magnetic responses among bacteria expressing various recombinant MagR proteins, we utilized high-throughput automated bright-field microscopic imaging and scanning electron microscopy (SEM). Furthermore, comprehensive biochemical and biophysical characterizations of iron and iron-sulfur cluster binding were performed using Ferrozine colorimetric assays, electron paramagnetic resonance (EPR) spectroscopy, ultraviolet-visible (UV-Vis) absorption, and circular dichroism (CD) spectroscopy. Additionally, 100 mT static magnetic field (SMF) exposure experiments were conducted to assess magnetically tunable phenotypes, while the intrinsic magnetic properties of purified MagR proteins were directly measured using a superconducting quantum interference device (SQUID) magnetometer. Results Our results demonstrated that the heterologous expression of MagR homologs induced varying degrees of bacterial filamentation. From this comprehensive screen, two distinct morphological patterns were identified: hydra (Hydra vulgaris) MagR (hyMagR) promoted uniform cell elongation and filamentation, exhibiting robust magnetic sensitivity manifested as significantly enhanced filamentation under the 100 mT SMF. In contrast, pigeon (Columba livia) MagR (clMagR) induced only low-frequency, extreme filamentation (sporadically exceeding 80 μm) with a relatively weaker magnetic morphological response. Mechanistically, our data unambiguously proved that these phenotypic differences are primarily driven by distinct iron redox preferences rather than total cellular iron accumulation. Specifically, hyMagR preferentially binds ferrous iron (Fe²⁺), whereas clMagR favors ferric iron (Fe³⁺) and forms more stable iron-sulfur clusters. Intriguingly, although SQUID magnetometry showed that purified clMagR exhibited approximately five-fold higher mass magnetic susceptibility than hyMagR, its cellular magnetic response was weaker. We hypothesize that the Fe²⁺-preferred intracellular environment associated with hyMagR overexpression primes the cell for enhanced generation of reactive oxygen species (ROS) via the Fenton reaction. Exposure to an SMF synergizes with this primed redox state, triggering the bacterial SOS response and upregulating cell division inhibitors to efficiently induce uniform filamentation. Conclusion Our findings identify the Fe²⁺/Fe³⁺ redox state as a critical determinant of MagR-mediated morphological remodeling and magnetic responsiveness. This discovery suggests a potential strategy for engineering magnetically responsive cellular systems for synthetic biology applications, and provides a plausible framework, which potentially combines intrinsic protein magnetism with redox-state modulation, for further investigating the evolutionary mechanisms of MagR-mediated magnetoreception.

OBJECTIVE To establish the UPLC fingerprint and the method for multi-component content determination in Jingangteng capsules， and to evaluate its quality by combining chemical pattern recognition analysis. METHODS An UPLC method was established. Separation was performed on a Zorbax SB-C 18 Rapid Resolution HD column， with acetonitrile-0.1% formic acid as the mobile phase for gradient elution.Using the Similarity Evaluation System for Chromatographic Fingerprints of Traditional Chinese Medicines （2012 edition）， UPLC fi ngerprints were established for 10 batches of Jingangteng capsules， and similarity was evaluated. SPSS 22.0 and SIMCA 14.1 software were used to perform hierarchial-cluster analysis and orthogonal partial least squares discriminant analysis （OPLS-DA）， respectively. The same UPLC method was employed to determine the contents of chlorogenic acid， 3，5-dihydroxy-2-methylbenzoic acid-3- O -glucoside （M1）， caffeic acid， astilbin， oxyresveratrol， quercitrin and resveratrol in the 10 batches of samples. RESULTS A total of 17 common peaks were identified in UPLC fingerprints of the 10 batches of samples， of which 7 were identified as chlorogenic acid， M1， caffeic acid， astilbin， oxyresveratrol， quercitrin， and resveratrol. The similarities of 10 batches of samples ranged from 0.820 to 0.985. The results of hierarchial-cluster analysis showed that 10 batches of samples were grouped into four categories： S1-S4 formed one group， S5 and S6 formed another， S7， S8 and S10 formed a third， and S9 formed a fourth， consistent with the OPLS-DA results； the variable importance projection values for peaks 7， 10， 2， 16 （resveratrol）， 13 （oxyresveratrol）， 11， 6 （caffeic acid）， 5 （M1） and 15 （quercitrin） were ＞1. Quantitative analysis results showed that the contents of chlorogenic acid， M1， caffeic acid， astilbin， oxyresveratrol， quercitrin， and resveratrol were 1.650 8-4.213 7， 0.636 2-2.161 7， 0.031 0-0.086 5， 0.239 1-1.069 3， 0.211 9-1.104 0， 0.488 8-2.399 2， and 0.164 0-0.699 8 mg/g， respectively. CONCLUSIONS UPLC fingerprint and content determination methods established in this study are simple to operate， accurate， reliable and reproducible； when combined with chemical pattern recognition analysis， they can be used to evaluate the quality of Jingangteng capsules. Nine components， such as resveratrol， oxyresveratrol， caffeic acid， M1 and quercitrin， may serve as markers of quality variation.

Organ transplantation is an effective alternative treatment for patients with end-stage organ failure. However, the shortage of donor organs has limited the widespread application of clinical transplantation. In recent years, breakthroughs in CRISPR-Cas9 gene editing technology have overcome the barrier of hyperacute rejection in xenotransplantation, offering a potential solution to the organ shortage crisis. Rejection remains a critical factor affecting graft survival. Antigen-presenting cells play a vital role in the initiation and progression of rejection and immune regulation in xenotransplantation. Therefore, in-depth investigation into the role of antigen-presenting cells in xenotransplantation is of great significance. This article summarizes the roles and therapeutic strategies of professional antigen-presenting cells, including macrophages, dendritic cells and B cells in xenotransplantation, aiming to provide insights for future research on immune regulation mechanisms in this field.

ObjectiveTo investigate the effects of hypoxia-treated mesenchymal stem cell （MSCs） exosomes （Exo） and their loading with curcumin on microglial inflammatory responses， and to explore the enhancing effect of hypoxia treatment on the function of MSCs Exo. MethodsThe supernatants of human umbilical cord （hUC）-MSCs cultured under normal and hypoxic conditions were collected， and Exo were isolated using ultracentrifugation. After identification by transmission electron microscopy and Western blot， curcumin was loaded using the co-incubation method. The lipopolysaccharide （LPS）-induced microglial inflammation model was treated with dimethyl sulfoxide （DMSO）， curcumin， normoxia Exo， hypoxia Exo， normoxic Exo loaded with curcumin， and hypoxic Exo loaded with curcumin， respectively. The expression of the M1-type marker inducible nitric oxide synthase （iNOS） in BV2 cells was detected by immunofluorescence （IF）. Western blot and enzyme-linked immunosorbent assay （ELISA） were used to measure the expression and secretion levels of tumor necrosis factor-α （TNF-α）， interleukin-1β （IL-1β）， and IL-6 in the cells and their culture supernatants. ResultsNormoxia Exo， hypoxia Exo， normoxic Exo loaded with curcumin， and hypoxic Exo loaded with curcumin exhibited a "saucer-like" shape with a diameter ranging from 30~150 nm， and the expression of exosomal markers CD9， CD81， and TSG101 were positive. After treating the BV2 cell inflammation model， IF results showed that， compared with the normoxia Exo group， treatment with hypoxic Exo significantly reduced the expression of iNOS. Moreover， when compared with the curcumin group and the normoxic Exo loaded with curcumin group， the expression level of iNOS significantly decreased after treatment with hypoxic Exo loaded with curcumin. The results of Western blot and ELISA indicated that， in comparison with the normoxia Exo group， treatment with hypoxic Exo significantly reduced the expression and secretion of the inflammatory cytokines TNF-α， IL-1β， and IL-6. Additionally， when compared with the curcumin group and the normoxic Exo loaded with curcumin group， both the expression and secretion of TNF-α， IL-1β， and IL-6 significantly decreased after treatment with hypoxic Exo loaded with curcumin. ConclusionHypoxia preconditioning can enhance the ability of hUC-MSCs-Exo in the inhibition of microglial polarization and inflammatory factors’ secretion. Additionally， using Hypoxia-MSCs-Exo as a drug-delivery carrier of curcumin can improve its solubility and stability， facilitating its absorption by cells and exerting the therapeutic effect of combination therapy.

[摘 要] 目的：探讨DNA甲基转移酶1（DNMT1）通过稳定zeste基因增强子同源物2（EZH2）促进结直肠癌（CRC）HCT8细胞增殖与迁移的机制。方法：利用生物信息学方法分析DNMT1在CRC组织中的表达水平。WB法检测DNMT1在CRC细胞HCT8、SW620和正常结肠上皮细胞NCM460中的表达。通过siRNA或慢病毒载体转染HCT8细胞，分为siNC组、siDNMT1组、Vector组、DNMT1-OE组、siTRAF6组、siEZH2组、siEZH2 + DNMT1-OE组。采用克隆形成实验、CCK-8法、Transwell实验和划痕愈合实验检测敲低或过表达DNMT1对HCT8细胞增殖与迁移的影响，WB和qPCR法检测EZH2蛋白和mRNA水平，免疫沉淀（IP）法检测EZH2泛素化水平，免疫荧光双染检测肿瘤坏死因子受体相关因子6（TRAF6）与EZH2的细胞内共定位情况，克隆形成和划痕愈合实验验证EZH2对DNMT1功能的逆转作用。收集2022—2025年间郑州大学附属洛阳中心医院手术切除的12例CRC患者的癌及癌旁组织标本，采用免疫组化法检测CRC组织中DNMT1、TRAF6和EZH2的表达水平。结果：DNMT1在CRC组织中表达显著高于癌旁组织（P < 0.01），且在CRC细胞中表达上调（P < 0.05）；DNMT1敲低显著抑制HCT8细胞增殖及迁移（均P < 0.01），过表达则相反（均P < 0.01）。DNMT1正向调控EZH2的蛋白水平（P < 0.01），而mRNA水平不变（P > 0.05）。MG132可恢复siDNMT1组的EZH2蛋白表达（P < 0.01），且siDNMT1组EZH2泛素化水平升高。DNMT1负向调控TRAF6的表达（P < 0.01），且TRAF6与EZH2在细胞质中共定位，IP证实两者直接结合。敲低TRAF6可减弱EZH2的泛素化水平，敲低EZH2可逆转DNMT1对HCT8细胞增殖、迁移的促进作用（均P < 0.01）。DNMT1和EZH2在CRC组织中呈高表达（P < 0.01），TRAF6在CRC组织中表达显著低于癌旁组织（P < 0.05）。结论：DNMT1通过抑制TRAF6稳定EZH2促进CRC细胞的增殖和迁移，DNMT1、TRAF6和EZH2可能是CRC治疗的潜在靶点。