Background and Aims:Chronic skin ulcers are a significant disease affecting patients'daily lives and psychological well-being.Abnormalities in the cells and extracellular matrix within the tissue may disrupt the balance of the microenvironment,hindering the normal skin repair process and leading to delayed healing of the ulcer.There is currently a lack of research on the mechanisms underlying the development of chronic ulcers and their diagnostic biomarkers.Single-cell sequencing,a newly developed high-throughput sequencing method in recent years,uses gene sequencing at the single-cell resolution to precisely reveal disease mechanisms and has been applied in various diseases.This study used single-cell transcriptome sequencing(scRNA-Seq)to investigate the cellular heterogeneity in chronic skin ulcer tissue to elucidate the potential molecular mechanisms behind delayed healing and provide new insights for clinical treatment.Methods:The scRNA-Seq technology was used to compare the differences in cell subpopulations and gene expression between chronic ulcer tissue and normal skin tissue.Single cells were sorted using a microfluidic platform,and cDNA libraries were constructed for subsequent differential gene analysis and functional enrichment analysis.Results:scRNA-Seq analysis revealed significant immune-metabolic remodeling features in chronic ulcer tissue:the number of B cells,monocytes,and macrophages in ulcer tissue increased by 2.1 to 3.5 times compared to the normal tissue control.This was accompanied by widespread activation of collagen synthesis genes(COL1A1/COL3A1)and synergistic suppression of immune regulators(e.g.,granzyme family GZMA/GZMB/H).Cross-cell subpopulation functional network analysis showed that hypoxia response mediated by the HIF-1 signaling pathway and PI3K/Akt pathway abnormalities formed a positive feedback loop,exacerbating the imbalance in the secretion of inflammatory factors(CXCL3/8,TGFBI)and compensatory upregulation of mitochondrial oxidative phosphorylation.Conclusion:Chronic skin ulcers exhibit significant differences in cellular heterogeneity and gene expression,suggesting that chronic ulcers are not simply tissue defects but a complex pathological process dominated by chronic inflammation and immune dysregulation.The coordinated dysregulation of multiple cell subpopulations in the ulcer microenvironment,along with persistent inflammatory responses and metabolic abnormalities,is interconnected through the HIF-1/TNF/MAPK pathway network.Downregulation of granzyme gene family members and abnormal histone modifications may contribute to immune clearance defects,providing a theoretical basis for developing novel therapies targeting epigenetic regulation or mitochondrial function.

Objective:To establish a prognostic prediction model for hepatocellular carcinoma (HCC) using bioinformatics approaches to guide personalized therapy.Methods:Based on bioinformatics, the differential analysis was carried out on the GSE19665 data set of The Cancer Genome Atlas-Liver Hepatocellular Carcinoma (TCGA-LIHC) and Gene Expression Omnibus (GEO), and the same differentially expressed genes were obtained by means of Wayne diagram. Functional enrichment analyses using Gene Ontology, Kyoto Encyclopedia of Genes and Genome, and Gene Set Enrichment Analysis were conducted on co-expressed genes. Based on clinicopathological and transcriptomic profiles, TCGA-LIHC patients were stratified into training ( n=246) and internal validation ( n=116) cohorts, with external validation using Japanese liver cancer data ( n=231) from the International Cancer Genome Consortium. A LASSO-Cox regression-derived risk scoring model was established and visualized as a nomogram. The clinical utility of the risk score was evaluated through multiple analytical approaches.A nomogram incorporating the risk score was developed, and its predictive performance was validated using the concordance index (C-index) and calibration curves. The measurement data of normal distribution were expressed as mean±standard deviation( ± s), and the t-test was used for comparison between groups. The measurement data with non-normal distribution were expressed as M( Q1, Q3), and the Wilcoxon test was used for comparison between groups. The Kruskal-Wallis test was applied to evaluate the significance of the differences among multiple groups. The prognostic value of the risk score was estimated using Kaplan-Meier analysis and ROC curve. Multivariate Cox regression clarified the independent prognostic value of the risk score. Results:Differential analysis identified 457 commonly expressed differentially expressed genes (DEGs). Enrichment analysis revealed that these common DEGs were significantly enriched in pathways related to the cell cycle of tumor cells.The LASSO-Cox regression model selected eight candidate genes ( CENPA, NDC80, ANXA10, NEIL3, G6 PD, MCM10, SOCS2, MMP1). The predictive risk score generated using these eight genes demonstrated a strong association with the overall survival of HCC patients.The nomogram combining the predictive risk score with clinicopathological features exhibited high predictive performance in both the training and validation cohorts. Furthermore, the prognostic value of this risk score was successfully validated in the external validation cohort. Conclusion:This study successfully developed a new predictive model that accurately predicts the 1-year, 3-year and 5-year survival rates of patients with liver cancer. This can serve as a potential tool to help guide patients in personalized treatment.

OBJECTIVES: To investigate the mechanism by which chitosan (CS) hydrogel loaded with human umbilical cord mesenchymal stem cell (HUVECs)-derived exosomes (hUCMSC-exos) (Exos@CS-Gel) improves diabetic wound healing. METHODS: hUCMSC-exos were extracted and Exos@CS-Gel was prepared. The effect of Exos@CS-Gel on proliferation and migration of HUVECs were evaluated using scratch wound assay and CCK-8 assay. Diabetic rat models with full-thickness skin wounds established by streptozotocin induction were randomized divided into 4 groups for treatment with Exos@CS-Gel (100 µg hUCMSC-exos dissolved in 100 µL 24% CS hydrogel), hUCMSC-exos (100 µg hUCMSC-exos dissolved in 100 µL PBS), CS hydrogel (100 µL 24% CS hydrogel), or PBS (control group). Wound healing and the therapeutic mechanisms were assessed using immunohistochemistry, HE staining, immunofluorescence, and qRT-PCR. RESULTS: In cultured HUVECs, Exos@CS-Gel treatment significantly promoted cell proliferation and migration. In the rat models of chronic diabetic wounds, the wound healing rate in Exos@CS-Gel group reached 92.7% on day 14, significantly higher than those in hUCMSC-exos group (9.12%), CS hydrogel group (16.28%), and control group (25.98%). Microvessel density and the expression levels of vascular endothelial growth factor and transforming growth factor β-1 were significantly increased in the Exos@CS-Gel group. CONCLUSIONS Exos@CS-Gel promotes survival capacity of hUCMSC-exos in vitro and accelerates diabetic wound healing in rats by promoting angiogenesis and cell proliferation.
Animals ; Wound Healing ; Humans ; Chitosan ; Exosomes ; Mesenchymal Stem Cells/cytology* ; Diabetes Mellitus, Experimental ; Rats ; Umbilical Cord/cytology* ; Hydrogels ; Human Umbilical Vein Endothelial Cells ; Cell Proliferation ; Rats, Sprague-Dawley ; Male

The spatio-temporal heterogeneity of breast cell subsets forms the fundamental biological basis for physiological development and pathological progression, including tumorigenesis; however, its complex regulatory mechanisms are not yet fully elucidated. With its high-resolution capabilities, single-cell RNA sequencing (scRNA-seq) technology offers a powerful tool for dissecting this cellular heterogeneity. This technology enables the construction of high-precision breast cell atlases, the accurate identification of distinct cell subsets, and the reconstruction of differentiation trajectories from stem/progenitor cells to functional epithelial cells. By resolving the transcriptional regulatory networks that govern cell fate determination, intercellular communication patterns, and dynamic microenvironmental interactions, scRNA-seq has unveiled the molecular foundations of breast development and provided new perspectives on the pathogenesis of related diseases such as breast cancer and macromastia. Furthermore, scRNA-seq demonstrates significant potential for discovering early molecular markers of disease, deciphering tumor heterogeneity, and elucidating mechanisms of therapeutic resistance. The continued application of scRNA-seq for dissecting breast cell heterogeneity, combined with its integration with multi-modal data such as spatial omics, promises to provide critical evidence and new insights for revealing the molecular mechanisms of breast development-related diseases and for formulating precision therapeutic strategies.
Humans ; Single-Cell Analysis/methods* ; Female ; Breast Neoplasms/pathology* ; Sequence Analysis, RNA/methods* ; Breast/cytology*

OBJECTIVES: Keloids are fibrotic skin disorders characterized by excessive collagen deposition and a high recurrence rate, closely associated with inflammatory mediators. However, existing epidemiological studies are limited by confounding factors and reverse causality, making it difficult to establish causation. This study aims to investigate the causal relationship between circulating cytokines and keloids using Mendelian randomization analysis. METHODS: Significant single nucleotide polymorphisms (SNPs) associated with circulating cytokines (exposures) and keloids (outcomes) were extracted from genome-wide association study (GWAS) summary datasets. Eligible SNPs were selected as instrumental variables (IVs). Exposure data were derived from a cytokine GWAS including 8 293 Finnish participants, and outcome data from a keloid GWAS based on the UK Biobank. The inverse-variance weighted (IVW) method served as the primary analytical approach to estimate causal effects, supplemented by weighted median (WME), MR-Egger regression, and other sensitivity analyses. Horizontal pleiotropy was assessed using MR-Egger regression and the MR pleiotropy residual sum and outlier (MR-PRESSO) test, while Cochran's Q test evaluated heterogeneity. Leave-one-out analysis was used to verify robustness and consistency. A reverse MR analysis was also conducted, with keloid as the exposure and cytokines as outcomes, to rule out reverse causation. RESULTS: IVW analysis identified significant positive causal associations between two cytokines and keloids-macrophage migration inhibitory factor (MIF) [odds ratio (OR)=2.081, 95% confidence interval (CI) 1.219 to 3.552, P=0.007] and monocyte chemoattractant protein-1 (MCP-1) (OR=1.673, 95% CI 1.036 to 2.701, P=0.035). Conversely, stem cell factor (SCF) showed a negative causal relationship with keloids (OR=0.518, 95% CI 0.269 to 0.998, P=0.049). Results from the MR-Egger and weighted median analyses were consistent with IVW findings. No evidence of horizontal pleiotropy was observed (P>0.05). Except for interleukin-6 (P=0.014), no heterogeneity was detected in other cytokines. Leave-one-out analysis further confirmed the robustness of the causal associations. In reverse MR analysis, keloids were causally related only to β-nerve growth factor (beta-NGF) (OR=1.048, 95% CI 1.002 to 1.095, P=0.039), with no heterogeneity or pleiotropy detected in most cytokines (P>0.05). CONCLUSIONS MIF and MCP-1 exhibit positive causal associations with keloid formation, while SCF shows a negative causal relationship. These findings provide new evidence for the causal involvement of inflammatory cytokines in keloid pathogenesis and offer potential molecular targets for developing novel keloid therapies.
Humans ; Keloid/blood* ; Mendelian Randomization Analysis ; Cytokines/genetics* ; Polymorphism, Single Nucleotide ; Genome-Wide Association Study ; Chemokine CCL2/genetics* ; Interleukin-6/genetics* ; Macrophage Migration-Inhibitory Factors/genetics* ; Male ; Stem Cell Factor/blood* ; Female ; Intramolecular Oxidoreductases

Background and Aims:Chronic skin ulcers are a significant disease affecting patients'daily lives and psychological well-being.Abnormalities in the cells and extracellular matrix within the tissue may disrupt the balance of the microenvironment,hindering the normal skin repair process and leading to delayed healing of the ulcer.There is currently a lack of research on the mechanisms underlying the development of chronic ulcers and their diagnostic biomarkers.Single-cell sequencing,a newly developed high-throughput sequencing method in recent years,uses gene sequencing at the single-cell resolution to precisely reveal disease mechanisms and has been applied in various diseases.This study used single-cell transcriptome sequencing(scRNA-Seq)to investigate the cellular heterogeneity in chronic skin ulcer tissue to elucidate the potential molecular mechanisms behind delayed healing and provide new insights for clinical treatment.Methods:The scRNA-Seq technology was used to compare the differences in cell subpopulations and gene expression between chronic ulcer tissue and normal skin tissue.Single cells were sorted using a microfluidic platform,and cDNA libraries were constructed for subsequent differential gene analysis and functional enrichment analysis.Results:scRNA-Seq analysis revealed significant immune-metabolic remodeling features in chronic ulcer tissue:the number of B cells,monocytes,and macrophages in ulcer tissue increased by 2.1 to 3.5 times compared to the normal tissue control.This was accompanied by widespread activation of collagen synthesis genes(COL1A1/COL3A1)and synergistic suppression of immune regulators(e.g.,granzyme family GZMA/GZMB/H).Cross-cell subpopulation functional network analysis showed that hypoxia response mediated by the HIF-1 signaling pathway and PI3K/Akt pathway abnormalities formed a positive feedback loop,exacerbating the imbalance in the secretion of inflammatory factors(CXCL3/8,TGFBI)and compensatory upregulation of mitochondrial oxidative phosphorylation.Conclusion:Chronic skin ulcers exhibit significant differences in cellular heterogeneity and gene expression,suggesting that chronic ulcers are not simply tissue defects but a complex pathological process dominated by chronic inflammation and immune dysregulation.The coordinated dysregulation of multiple cell subpopulations in the ulcer microenvironment,along with persistent inflammatory responses and metabolic abnormalities,is interconnected through the HIF-1/TNF/MAPK pathway network.Downregulation of granzyme gene family members and abnormal histone modifications may contribute to immune clearance defects,providing a theoretical basis for developing novel therapies targeting epigenetic regulation or mitochondrial function.

Objective:This study aimed to investigate the clinical value of glucocorticoids in patients with neutropenic severe pneumonia at moderate to high risk according to the Pneumonia Severity Index (PSI) in patients with hematologic diseases.Methods:Clinical data were collected from 534 patients at the Fujian Medical University Union Hospital from October 2016 to December 2018. We evaluated the changes in inflammatory cytokines, treatment failure, in-hospital mortality, and other outcomes, adjusting for potential confounders through propensity score matching.Results:Patients were categorized into glucocorticoids ( n=176) and control ( n=358) groups. The glucocorticoid group demonstrated higher levels of C-reactive protein, procalcitonin, and interleukin-6, alongside higher PSI scores. The differences in comorbidities diminished, except for inflammatory cytokine levels, with a notable reduction in inflammatory cytokines observed in the glucocorticoid group, after matching 125 pairs based on propensity scores. Late treatment failure was more prevalent in the glucocorticoid group (39.2% vs 24.8%, P=0.015), but this was primarily caused by radiographic progression. The incidences of respiratory failure, mechanical ventilation, and septic shock were similar between the groups. Logistic regression analyses revealed that glucocorticoids reduced the risk of treatment failure ( OR=0.367, 95% CI 0.165-0.818, P=0.014). The 30-day in-hospital mortality rates were comparable (8.0% in glucocorticoids vs 7.2% in controls, P=0.811), with indications that glucocorticoids may exert a protective effect on mortality. The PSI score was determined as the sole independent risk factor for 30-day in-hospital mortality ( OR=1.077, 95% CI 1.032-1.123, P=0.001). No evidence indicated that glucocorticoids increased the incidence of hyperglycemia, gastrointestinal bleeding, or 30-day infection recurrence. Conclusion:Glucocorticoids reduce inflammatory cytokine levels and are potentially related to decreased treatment failure and mortality in patients with neutropenic pneumonia classified as PSI Ⅳ and Ⅴ among hematological patients.

BACKGROUND:Satellite cells are a specific population of adult stem cells contained in skeletal muscle that promote the regenerative reconstruction of injured skeletal muscle,but their specific mechanisms are not well established. OBJECTIVE:To review the regulatory role of satellite cells during skeletal muscle regeneration and the mechanism of interaction between satellite cells and their ecological niche signals,aiming to provide new research ideas and perspectives based on the summary of existing knowledge. METHODS:Web of Science,PubMed,CNKI,WanFang,and VIP databases were searched for literature published between January 2002 and June 2022.English search terms were"muscle,skeletal muscle,muscle injury,stem cells,satellite cells,muscle repair".Chinese search terms were"skeletal muscle,skeletal muscle regeneration,skeletal muscle reconstruction,satellite cells,ecological niche".The 66 included papers were organized and analyzed. RESULTS AND CONCLUSION:(1)Satellite cells exist in skeletal muscle and contribute to both the formation of new muscle fibers after injury and the effective growth of existing adult muscle fibers.(2)After the activation of quiescent satellite cells in satellite cells,the steps of satellite cell proliferation,differentiation and fusion to form muscle fibers during skeletal muscle regeneration are influenced by their intrinsic regulatory effects of different mechanisms.(3)Satellite cells can interact with myofibers,extracellular matrix,skeletal muscle junctions,fibroblast progenitor cells,immune cells and endothelial cells in the ecological niche signal to promote satellite cell activation,proliferation and differentiation to achieve effective skeletal muscle regeneration.(4)Possible breakthroughs in future research include:the division pattern of satellite cells in the body;the mechanisms regulating satellite cell transfer;the specific timing of satellite cell differentiation or self-renewal in vivo;and the interaction mechanisms between satellite cells and skeletal muscle junctions.(5)This review may provide some theoretical reference values for the field of injury reconstruction of skeletal muscle and its innovation.

BACKGROUND:Sarcopenia is a chronic condition that leads to strength loss and functional decline,increasing the risk of frailty,disability,falls,and death in older adults.Blood flow restriction training can be effective in the treatment of sarcopenia,but a comprehensive review of its advantages,disadvantages,biological mechanisms,and application options is lacking. OBJECTIVE:To review the advantages,limitations,and biological mechanisms of blood flow restriction training interventions for sarcopenia and to give recommendations for application protocols based on current published evidence. METHODS:A search of major databases was conducted for literature published in the time frame up to February 2023.The search terms were"blood flow restriction training,KAATSU,elderly,sarcopenia,muscle"in English and Chinese.Finally,82 included papers were compiled and analyzed. RESULTS AND CONCLUSION:Blood flow restriction training as an intervention for sarcopenia has been effective in peripheral muscle groups,but there are limitations in its application.Blood flow restriction training is highly operational and safe.This training can improve muscle strength and physical performance,but there are potential risks,including adverse events on skeletal muscle,cardiovascular and endothelial cells.Therefore,blood flow restriction training needs to be performed under scientific guidance and further studies are needed to verify its efficacy in patients with sarcopenia.The biological mechanisms of blood flow restriction training intervention in sarcopenia may include:increasing muscle hypertrophy due to reactive muscle congestion,improving muscle protein synthesis capacity,inducing metabolic stress adaptation,promoting skeletal muscle growth and repair,activating vascular endothelial growth factor signaling pathway to promote angiogenesis,and promoting satellite cell proliferation.However,these specific roles and combined effects of these mechanisms need to be determined by more in-depth studies.Blood flow restriction training interventions for sarcopenia are mainly influenced by training and cuffs.To avoid adverse events,it is recommended that 20%to 50%1RM,20 to 75 repetitions,2 to 3 times per week,30-60 seconds interval between sessions,smaller size cuffs with a pressurization value≤140 mmHg for upper limb training,and larger size cuffs with a pressurization value≤180 mmHg for lower limb training,usually 50%to 80%of the pressure value in the completely occluded artery.However,more research is needed on the training frequency and interval between sessions in older adults,and further research is needed on the optimal choice of cuff pressurization values.

BACKGROUND:Satellite cells are myogenic stem cells located between the muscle fiber membrane and the basement membrane.However,a comprehensive review of the aging mechanisms of satellite cells and their potential mitigation strategies is still lacking.This gap in knowledge hinders the effective guidance for current strategies aimed at attenuating skeletal muscle aging. OBJECTIVE:To review the mechanisms of satellite cell aging in skeletal muscle and the relevant strategies for mitigating this aging process. METHODS:Major databases were searched up to May 2023,including Web of Science,PubMed,China National Knowledge Infrastructure(CNKI),WanFang Data,and VIP.Chinese and English search terms included"skeletal muscle,satellite cells,aging,mechanism,and solution strategy".After strict inclusion and exclusion criteria were applied,78 articles were finally included. RESULTS AND CONCLUSION:(1)Satellite cells,situated between the muscle fiber membrane and basement membrane,possess proliferative and differentiative potential.They usually remain in a quiescent state but become activated in response to muscle tissue stimuli,participating in processes of repair and restoration of normal tissue structure.Aging leads to a reduction in satellite cell numbers,resulting in symptoms such as muscle weakness and decreased endurance.(2)Mechanisms of satellite cell aging primarily involve diminished regenerative capacity,perturbed niche interactions with changing ecology,age-dependent loss,and heterogeneity changes.Reduced satellite cell numbers and activity due to aging lead to slower muscle regeneration and increased injury recovery time.Errors during differentiation may occur,resulting in decreased muscle quality and function deterioration.(3)Strategies for mitigating satellite cell aging encompass modulation of the receptor environment of intra-body satellite cells,peripheral interventions to promote satellite cell regeneration,construction of human muscle models,and exercise and nutritional interventions to induce satellite cell proliferation.These strategies hold promise in offering novel insights and methods for satellite cell regeneration and treatment of skeletal muscle diseases.(4)Future research should delve into the mechanisms of satellite cell aging,explore the interaction between satellite cells and their niches,investigate the relationship of satellite cells with the immune system and mitochondrial function,and develop human muscle models to enhance research depth and accuracy.