Global Single-Cell Sequencing Landscape of Adipose Tissue of Different Anatomical Site Origin in Humans.

Chronic refractory wounds (CRW) are one of the most serious clinical challenges for surgeons to address. Stromal vascular fraction gels (SVFG), including human adipose stem cells (hASCs), have excellent vascular regenerative and tissue repair properties. Here, we combined single-cell RNA sequencing (scRNA-seq) of leg subcutaneous adipose tissue samples with scRNA-seq data from abdominal subcutaneous adipose tissue, leg subcutaneous adipose tissue, and visceral adipose tissue samples from public databases. The results showed specific differences in cellular levels in adipose tissue from different anatomical site sources. We identified cells including CD4+ T cells, hASCs, adipocyte (APC), epithelial (Ep) cells, and preadipocyte. In particular, the dynamics between groups of hASCs, epithelial cells, APCs, and precursor cells in adipose tissue of different anatomical site origins were more significant. Furthermore, our analysis reveals alterations at the cellular level and molecular level, as well as the biological signaling pathways involved in these subpopulations of cells with specific alterations. In particular, certain subpopulations of hASCs have higher cell stemness, which may be related to lipogenic differentiation capacity and may be beneficial in promoting CRW treatment and healing. In general, our study captures a human single-cell transcriptome profile across adipose depots, the cell type identification and analysis of which may help dissect the function and role of cells with specific alterations present in adipose tissue and may provide new ideas and approaches for the treatment of CRW in the clinical setting.

Advanced Platelet-Rich Fibrin Extract Treatment Promotes the Proliferation and Differentiation of Human Adipose-Derived Mesenchymal Stem Cells through Activation of Tryptophan Metabolism.

BACKGROUND: Advanced platelet-rich fibrin extract (APRFE) contains a high concentration of various cytokines that are helpful for improving stem cells repair function. OBJECTIVE: However, the underlying mechanism of APRFE improving stem cell repairing is not clear. METHODS: We produced APRFE by centrifuging fresh peripheral blood samples and isolated and identified human adipose-derived mesenchymal stem cells (ADMSCs). The abundance of cytokines contained in APRFE was detected by the Enzyme-linked immunosorbent assay (ELISA). The ADMSCs treated with or without APRFE were collected for transcriptome sequencing. RESULTS: Based on the sequencing data, the expression profiles were contracted. The differentially expressed genes and lncRNA (DEGs and DElncRNAs) were obtained using for the differential expression analysis. The lncRNA-miRNA-mRNA network was constructed based on the miRNet database. The further enrichment analysis results showed that the biological functions were mainly related to proliferation, differentiation, and cell-cell function. To explore the role of APRFE, the protein-protein interaction network was constructed among the cytokines included in APRFE and DEGs. Furthermore, we constructed the global regulatory network based on the RNAInter and TRRUST database. The pathways in the global regulatory network were considered as the core pathways. We found that the DEGs in the core pathways were associated with stemness scores. CONCLUSION: In summary, we predicted that APRFE activated three pathways (tryptophan metabolism, mTOR signaling pathway, and adipocytokine signaling) to promote the proliferation and differentiation of ADMSCs. The finding may be helpful for guiding the application of ADMSCs in the clinic.

Molecular imbalance mechanism of skin and blood leucocytes in severe burn patients at different burn times.

Background: Severe burns are a leading cause of injuries worldwide and are usually accompanied by considerable morbidity and mortality. The purpose of this study was to investigate the changes of gene expression in blood and skin at different times after severe burn. Methods: Firstly, the gene expression profiles of different burn time samples in GSE19743 and GSE8056 were analyzed. Secondly, the maladjusted gene network was identified by protein-protein interaction (PPI) network, and the genes in the network were enriched and analyzed. In addition, the key dysfunctional genes were identified by betweenness algorithm, and evaluated by survival analysis, Cox analysis, receiver operating characteristic (ROC) analysis. Finally, crosstalk analysis and enrichment analysis were carried out between the blood- and skin-specific differentially expressed genes (DEGs) at different burn times. Results: The results showed that there were common DEGs in the blood and skin at different burn times. Importantly, we screened out the key dysfunctional genes BIRC5, NCAM1, PCNA, TOP2A, and VEGFA, which were related to the course of burns. Enrichment analysis showed that these maladjusted genes were mainly involved in the immune inflammation-related signal pathway. Additionally, significant crosstalk was identified between blood- and skin-specific genes at different burn times, especially in the blood. The signal pathways involved in specific genes represent their own pathological characteristics. Conclusions: Both blood and skin tissues express common pathological changes and unique molecular mechanisms at different times after burn injury. The results of this study provide guidance for clinical personalized treatment.

Rg1 Promotes the Proliferation and Adipogenic Differentiation of Human Adipose-Derived Stem Cells via FXR1/Lnc-GAS5-AS1 Pathway.

BACKGROUND: Human adipose-derived stem cells (hASCs) play an important role in regenerative medicine. OBJECTIVE: Exploring the mechanism of Rg1 in the promotion of the proliferation and adipogenic differentiation of hASCs is important in regenerative medicine research. METHODS: To observe ginsenoside Rg1 in promoting the proliferation and adipogenic differentiation of hASCs, Rg1 medium at different concentrations was established and tested using the cell counting kit-8 (CCK-8) assay, oil red O staining, alizarin red, and alcian blue. Compared to the control, differentially expressed genes (DEGs) were screened via DEG analysis, which was carried out in the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses. To explore the relationship among mRNA, long non-coding RNA (lncRNA) and microRNA (miRNA), we constructed a competing endogenous RNA (ceRNA) network. RESULTS: In this study, Rg1 was observed to promote the proliferation and adipogenic differentiation of hASCs. Additionally, enriched BPs and KEGG pathways may be involved in the promotion process, where FXR1 and Lnc-GAS5-AS1 were found to be regulatory factors. The regulatory network suggested that Rg1 could regulate the adipocytokine signaling pathway and IL-17 signaling pathway via FXR1 and Lnc-GAS5-AS1, which served as the mechanism encompassing the promotion of Rg1 on the proliferation and adipogenic differentiation of hASCs. CONCLUSION: A comprehensive transcriptional regulatory network related to the promotion ability of Rg1 was constructed, revealing mechanisms regarding Rg1's promotion of the proliferation and adipogenic differentiation of hASCs. The present study provides a theoretical basis for optimizing the function of hASCs.

Corrigendum to "Altered Genes and Biological Functions in Response to Severe Burns".

[This corrects the article DOI: 10.1155/2021/8836243.].

Altered Genes and Biological Functions in Response to Severe Burns.

Severe burns are acute wounds caused by local heat exposure, resulting in life-threatening systemic effects and poor survival. However, the specific molecular mechanisms remain unclear. First, we downloaded gene expression data related to severe burns from the GEO database (GSE19743, GSE37069, and GSE77791). Then, a gene expression analysis was performed to identify differentially expressed genes (DEGs) and construct protein-protein interaction (PPI) network. The molecular mechanism was identified by enrichment analysis and Gene Set Enrichment Analysis. In addition, STEM software was used to screen for genes persistently expressed during response to severe burns, and receiver operating characteristic (ROC) curve was used to identify key DEGs. A total of 2631 upregulated and 3451 downregulated DEGs were identified. PPI network analysis clustered these DEGs into 13 modules. Importantly, module genes mostly related with immune responses and metabolism. In addition, we identified genes persistently altered during the response to severe burns corresponding to survival and death status. Among the genes with high area under the ROC curve in the PPI network gene, CCL5 and LCK were identified as key DEGs, which may affect the prognosis of burn patients. Gene set variation analysis showed that the immune response was inhibited and several types of immune cells were decreased, while the metabolic response was enhanced. The results showed that persistent gene expression changes occur in response to severe burns, which may underlie chronic alterations in physiological pathways. Identifying the key altered genes may reveal potential therapeutic targets for mitigating the effects of severe burns.

Landscape of transcription and expression regulated by DNA methylation related to age of donor and cell passage in adipose-derived mesenchymal stem cells.

Adipose-derived mesenchymal stem cells (ADSCs) are pluripotent stromal cells that can differentiate into a variety of cell types, including skin cells. High-throughput sequencing was performed on cells of different ages and cell passage, obtaining their methylation, mRNA expression, and protein profile data. The stemness of each sample was then calculated using the TCGAbiolinks package in R. Co-expression modules were identified using WGCNA, and a crosstalk analysis was performed on the corresponding modules. The ClusterProfile package was used for the functional annotation of module genes. Finally, the regulatory network diagram was visualized using the Cytoscape software. First, a total of 16 modules were identified, where 3 modules were screened that were most relevant to the phenotype. 29 genes were screened in combination of the RNA seq, DNA methylation seq and protein iTRAQ. Finally, a comprehensive landscape comprised of RNA expression, DNA methylation and protein profiles of age relevant ADSCs was constructed. Overall, the different omics of ADSCs were comprehensively analyzed in order to reveal mechanisms pertaining to their growth and development. The effects of age, cell passage, and stemness on the therapeutic effect of ADSCs were explored. Additionally, a theoretical basis for selecting appropriate ADSC donors for regenerative medicine was provided.

Multiomics global landscape of stemness-related gene clusters in adipose-derived mesenchymal stem cells.

BACKGROUND: Adipose-derived mesenchymal stem cells (AD-MSCs) are a type of stem cell that is abundant and widely used. The molecular characteristics of AD-MSCs from different passages from donors of different ages have not been well elucidated. METHODS: Six kinds of AD-MSCs ((E1, E2, E3, Y1, Y2, and Y3) with E denoting cells derived from an elderly patient, Y denoting cells derived from a young patient, and 1, 2, and 3 representing passages 3, 6, and 10) were obtained from human abdominal adipose tissue. We obtained the protein expression profile, the mRNA expression profile, the lncRNA expression profile, and the methylation profile of each kind of AD-MSC by sequencing. After calculating the stemness indices, genes related to stemness were extracted. The multiomics correlation analysis was performed in the stemness-related genes. In addition, short time-series expression miner (STEM) analysis was performed for all cell passages and donor ages. To further explore the biological functions of the stemness-related genes, we performed Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses. Finally, the lncRNA-KEGG network and transcription factor (TF)-KEGG network were constructed based on the RNAInter database and TRRUST v2 database. RESULTS: The stemness of the Y1, E1, and Y2 cells was higher than that of the E2, Y3, and E3 cells. The stemness was the highest for Y1 cells and the lowest for E3 cells. STEM analysis showed that five stemness-related gene clusters were associated with the cell passages, and only one gene cluster was associated with age. The enrichment analysis results showed that the biological processes (BPs) and KEGG pathways were mainly involved in the proliferation, differentiation, and migration of cells. The global regulatory landscape of AD-MSCs was constructed: 25 TFs and 16 lncRNAs regulated 21 KEGG pathways through 27 mRNAs. Furthermore, we obtained a core stemness-related gene set consisting of ITGAV, MAD2L1, and PCNA. These genes were expressed at higher levels in Y1 cells than in E3 cells. CONCLUSION: The multiomics global landscape of stemness-related gene clusters was determined for AD-MSCs, which may be helpful for selecting AD-MSCs with increased stemness.

FGF2-induced PI3K/Akt signaling evokes greater proliferation and adipogenic differentiation of human adipose stem cells from breast than from abdomen or thigh.

In this study, human adipose stem cells were isolated from subcutaneous fat in the thigh (htASCs), abdomen (haASCs) and breast (hbASCs). Flow cytometry was used to detect cell surface markers, and an enzyme-linked immunosorbent assay was used to detect paracrine activity. Paracrine gene expression in the three cell types was examined using real-time qPCR, and adipogenic ability was assessed using Oil Red O staining. RNA from third-passage haASCs and hbASCs was sequenced. The results showed that the differentiation potential marker markers CD49d and CD54 were similar across hbASCs from 10 subjects. The hbASCs showed higher colony forming ability and expression of fibroblast growth factor-2, tissue inhibitor of metalloproteinase-1 and stromal cell derived factor-1 than htASCs and haASCs. Stimulating hbASCs with FGF2 promoted adipogenic differentiation, while treating the cells with the PI3K inhibitor LY294002 inhibited differentiation. These results suggest that the PI3K/Akt signaling pathway can promote proliferation and adipogenic differentiation of adipose stem cells, and that activation of this pathway by FGF2 may explain why hbASCs show greater proliferation and adipogenic differentiation than haASCs and htASCs.