Objective:To utilize single-nucleus RNA sequencing(snRNA-seq) technology to investigate the primary cell subpopulations in human limb venous malformations (VMs) tissue and the role of the key gene RhoJ.Methods:Surgical resection specimens of VMs tissues and surrounding normal vein tissues were collected from 100 clinically diagnosed and screened patients with limb VMs at the Department of Hemangioma Surgery of the Third Affiliated Hospital of Zhengzhou University from January 2021 to December 2023. (1) Transcriptome analysis: Three patient samples were randomly selected for snRNA-seq studies, with the surgically removed VMs tissue serving as the experimental group and the surrounding normal vein tissue as the control group. A gene expression matrix for cell nuclei was established, followed by data quality control, dimensionality reduction, clustering, and cell type annotation. Cell-to-cell communication analysis was performed using the R language CellChat package to identify dominant cell subpopulations. The FindMarkers function was utilized to screen for differentially expressed genes (DEGs) between the dominant cell subpopulations of the experimental and control groups, and functional enrichment analysis was conducted. (2) Tissue experiments: An additional 35 patient samples from both the experimental and control groups were randomly selected. The mRNA and protein expression levels of the RhoJ gene were measured using real-time quantitative PCR (RT-qPCR) and Western blotting, respectively. (3) Validation experiments with human umbilical vein endothelial cells (HUVECs): HUVECs were transfected with pcDNA3.1-NC (blank control) and pcDNA3.1-RhoJ (plasmid expression vector carrying the RhoJ gene), respectively. The biological behavior differences between the two groups of cells were examined using the CCK-8 cell proliferation assay, Transwell invasion assay, and Matrigel angiogenesis assay. Measurement data conforming to a normal distribution were expressed as Mean±SD, and comparisons between the two groups were performed using an independent samples t-test. Results:Through CellChat intercellular communication analysis, it was discovered that endothelial cells were the predominant cell subpopulation in both the experimental and control groups, exhibiting strong communication links with other cell subpopulations. In the analysis of DEGs, it was found that the RhoJ gene in endothelial cells was significantly involved in the biological processes of angiogenesis and regulation. In tissue experiments, RT-qPCR and Western bloting results indicated that the relative expression levels of RhoJ mRNA (4.48±1.29 vs. 1.01±0.17) and protein (1.22±0.03 vs. 0.51±0.20) in the experimental group were significantly higher than those in the control group, with statistically significant differences ( P<0.01 for both). The results of the HUVECs validation experiment showed that the cell proliferation, invasion, and angiogenesis abilities of the pcDNA3.1-RhoJ group were significantly enhanced compared to the pcDNA3.1-NC group. Conclusion:Endothelial cells represent the dominant cell subpopulation during the occurrence and locally invasive progression of VMs, playing a crucial role in this process. The RhoJ gene is significant in regulating the biological behavior of VMs endothelial cells.

Objective:To utilize single-nucleus RNA sequencing(snRNA-seq) technology to investigate the primary cell subpopulations in human limb venous malformations (VMs) tissue and the role of the key gene RhoJ.Methods:Surgical resection specimens of VMs tissues and surrounding normal vein tissues were collected from 100 clinically diagnosed and screened patients with limb VMs at the Department of Hemangioma Surgery of the Third Affiliated Hospital of Zhengzhou University from January 2021 to December 2023. (1) Transcriptome analysis: Three patient samples were randomly selected for snRNA-seq studies, with the surgically removed VMs tissue serving as the experimental group and the surrounding normal vein tissue as the control group. A gene expression matrix for cell nuclei was established, followed by data quality control, dimensionality reduction, clustering, and cell type annotation. Cell-to-cell communication analysis was performed using the R language CellChat package to identify dominant cell subpopulations. The FindMarkers function was utilized to screen for differentially expressed genes (DEGs) between the dominant cell subpopulations of the experimental and control groups, and functional enrichment analysis was conducted. (2) Tissue experiments: An additional 35 patient samples from both the experimental and control groups were randomly selected. The mRNA and protein expression levels of the RhoJ gene were measured using real-time quantitative PCR (RT-qPCR) and Western blotting, respectively. (3) Validation experiments with human umbilical vein endothelial cells (HUVECs): HUVECs were transfected with pcDNA3.1-NC (blank control) and pcDNA3.1-RhoJ (plasmid expression vector carrying the RhoJ gene), respectively. The biological behavior differences between the two groups of cells were examined using the CCK-8 cell proliferation assay, Transwell invasion assay, and Matrigel angiogenesis assay. Measurement data conforming to a normal distribution were expressed as Mean±SD, and comparisons between the two groups were performed using an independent samples t-test. Results:Through CellChat intercellular communication analysis, it was discovered that endothelial cells were the predominant cell subpopulation in both the experimental and control groups, exhibiting strong communication links with other cell subpopulations. In the analysis of DEGs, it was found that the RhoJ gene in endothelial cells was significantly involved in the biological processes of angiogenesis and regulation. In tissue experiments, RT-qPCR and Western bloting results indicated that the relative expression levels of RhoJ mRNA (4.48±1.29 vs. 1.01±0.17) and protein (1.22±0.03 vs. 0.51±0.20) in the experimental group were significantly higher than those in the control group, with statistically significant differences ( P<0.01 for both). The results of the HUVECs validation experiment showed that the cell proliferation, invasion, and angiogenesis abilities of the pcDNA3.1-RhoJ group were significantly enhanced compared to the pcDNA3.1-NC group. Conclusion:Endothelial cells represent the dominant cell subpopulation during the occurrence and locally invasive progression of VMs, playing a crucial role in this process. The RhoJ gene is significant in regulating the biological behavior of VMs endothelial cells.