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

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

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.

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.

The global aging intensification has made geriatric wound repair a medical challenge. Diabetic foot and venous ulcers are highly prevalent and difficult to heal in the elderly population, seriously affecting patients′ quality of life and increasing medical burdens. The repair of geriatric wounds is constrained by multiple factors, including weakened regenerative capacity and immune dysfunction. Current research has gradually focused on mechanism analysis and precise intervention. Fibroblast growth factor (FGF) has been confirmed as a key factor in wound repair, and exogenous FGF can activate signaling pathways to promote wound healing. Exosomes have shown an important role in wound regeneration by promoting cell migration and proliferation, thereby accelerating the wound healing process. Geriatric wounds also face the challenge of drug-resistant bacterial infections, so future treatment strategies should combine microecological reconstruction and immune function recovery. Overall, research on geriatric wounds has formed a multidimensional repair framework aimed at activating the regenerative capacity of aging organisms.

Objective:To reveal the global evolution, cooperation models and research hotspots of wounds with drug-resistant bacterial infections in the elderly, and provide information support for future research directions.Methods:All literatures on wounds with drug-resistant bacterial infections in the elderly were retrieved from the Web of Science Core Collection. Bibliometric analysis was performed using CiteSpace and VOSviewer to visualize contributions from countries/regions, institutions, authors and journals, and to analyze keyword co-occurrence and temporal evolution.Results:After strict screening, a total of 130 literatures were included. Global research achievements on wounds with drug-resistant bacterial infections in the elderly showed a continuous growth. The United States was the main contributor in terms of the number of literatures, followed by Spain, Germany and the United Kingdom. However, international cooperation was still limited, and the institutional network was sparse. The most significant burst keywords at present included " risk factors", " methicillin-resistant", " inpatients", " molecular epidemiology", " Staphylococcus aureus", " long-term care facilities", " nosocomial infections", " mortality", " pressure ulcers", " complex wounds" and " emerging drug-resistant bacteria" .Conclusions:In the future, priority must be given to in-depth research on the pathogenesis of wounds with drug-resistant bacterial infections in the elderly (epidemiological investigation of drug-resistant bacterial infections in elderly patients, interaction between single cells of aging wounds and drug-resistant microbiome); verification of the mode and effect of stratified precise treatment through multi-country trials; and establishment of a professional database through data collection and multi-modal information integration.

Objective:To construct a temperature-sensitive hydrogel (PF-CA@AS-IV hydrogel) composed of Pluronic F-127 (PF-127)/calcium alginate (CA) loaded with astragaloside IV (AS-IV), and to explore its repair effect and potential mechanism on diabetic skin ulcers (DSU).Methods:The PF-CA@AS-IV hydrogel loaded with AS-IV and gelling at 37 ℃ was prepared. Its temperature sensitivity, rheological properties, and morphology were characterized. A rat model of DSU was established, and the rats were randomly divided into blank control group, model group, AS-IV spray group, PF-CA hydrogel group, and PF-CA@AS-IV hydrogel group ( n=5 each). After 21 days of intervention, the wound healing rate of each group was evaluated. Hematoxylin-eosin (HE) staining was used to observe the pathological changes of granulation tissue, and immunohistochemistry was applied to detect the expression level of CD34, a marker of new blood vessels. Results:Rheological analysis showed that the storage modulus (G′) of PF-CA@AS-IV hydrogel began to exceed the loss modulus (G″) at 33 ℃, and a stable three-dimensional network structure was formed at 37 ℃. Scanning electron microscopy confirmed its loose and porous microstructure. Animal experiment results indicated that compared with the blank control group, the model group had a significantly lower wound healing rate, massive infiltration of inflammatory cells, and fewer new capillaries and CD34 expression (all P<0.05). Compared with the model group, each treatment group can promote wound healing, reduce inflammatory infiltration and increase the positive expression of CD34 to varying degrees (all P<0.05), and the curative effect of PF-CA@AS-IV hydrogel group is the most significant, which is better than that of AS-IV spray group and PF-CA hydrogel group (all P<0.05). Conclusions:PF-CA@AS-IV hydrogel can effectively regulate inflammatory response and promote angiogenesis through sustained release of AS-IV, thereby accelerating DSU healing, and has good translational potential in the field of chronic wound repair.

The global aging intensification has made geriatric wound repair a medical challenge. Diabetic foot and venous ulcers are highly prevalent and difficult to heal in the elderly population, seriously affecting patients′ quality of life and increasing medical burdens. The repair of geriatric wounds is constrained by multiple factors, including weakened regenerative capacity and immune dysfunction. Current research has gradually focused on mechanism analysis and precise intervention. Fibroblast growth factor (FGF) has been confirmed as a key factor in wound repair, and exogenous FGF can activate signaling pathways to promote wound healing. Exosomes have shown an important role in wound regeneration by promoting cell migration and proliferation, thereby accelerating the wound healing process. Geriatric wounds also face the challenge of drug-resistant bacterial infections, so future treatment strategies should combine microecological reconstruction and immune function recovery. Overall, research on geriatric wounds has formed a multidimensional repair framework aimed at activating the regenerative capacity of aging organisms.

Objective:To reveal the global evolution, cooperation models and research hotspots of wounds with drug-resistant bacterial infections in the elderly, and provide information support for future research directions.Methods:All literatures on wounds with drug-resistant bacterial infections in the elderly were retrieved from the Web of Science Core Collection. Bibliometric analysis was performed using CiteSpace and VOSviewer to visualize contributions from countries/regions, institutions, authors and journals, and to analyze keyword co-occurrence and temporal evolution.Results:After strict screening, a total of 130 literatures were included. Global research achievements on wounds with drug-resistant bacterial infections in the elderly showed a continuous growth. The United States was the main contributor in terms of the number of literatures, followed by Spain, Germany and the United Kingdom. However, international cooperation was still limited, and the institutional network was sparse. The most significant burst keywords at present included " risk factors", " methicillin-resistant", " inpatients", " molecular epidemiology", " Staphylococcus aureus", " long-term care facilities", " nosocomial infections", " mortality", " pressure ulcers", " complex wounds" and " emerging drug-resistant bacteria" .Conclusions:In the future, priority must be given to in-depth research on the pathogenesis of wounds with drug-resistant bacterial infections in the elderly (epidemiological investigation of drug-resistant bacterial infections in elderly patients, interaction between single cells of aging wounds and drug-resistant microbiome); verification of the mode and effect of stratified precise treatment through multi-country trials; and establishment of a professional database through data collection and multi-modal information integration.