Investigate the stemness of adult adipose-derived stromal cells based on single-cell RNA-sequencing

Integrative single-cell RNA-seq and ATAC-seq analysis of the evolutionary trajectory features of adipose-derived stem cells induced into astrocytes

This study employs single-cell RNA sequencing (scRNA-seq) and assay for transposase-accessible chromatin with high-throughput sequencing technologies (scATAC-seq) to perform joint sequencing on cells at various time points during the induction of adipose-derived stem cells (ADSCs) into astrocytes. We applied bioinformatics approaches to investigate the differentiation trajectories of ADSCs during their induced differentiation into astrocytes. Pseudotemporal analysis was used to infer differentiation trajectories. Additionally, we assessed chromatin accessibility patterns during the differentiation process. Key transcription factors driving the differentiation of ADSCs into astrocytes were identified using motif and footprint methods. Our analysis revealed significant shifts in gene expression during the induction process, with astrocyte-related genes upregulated and stem cell-related genes downregulated. ADSCs first differentiated into neural stem cell-like cells with high plasticity, which further matured into astrocytes via two distinct pathways. Marked changes in chromatin accessibility were observed during ADSC-induced differentiation, affecting transcription regulation and cell function. Transcription factors analysis identified NFIA/B/C/X and CEBPA/B/D as key regulators in ADSCs differentiation into astrocytes. We observed a correlation between chromatin accessibility and gene expression, with ADSCs exhibiting broad chromatin accessibility prior to lineage commitment, where chromatin opening precedes transcription initiation. In summary, we found that ADSCs first enter a neural stem cell-like state before differentiating into astrocytes. ADSCs also display extensive chromatin accessibility prior to astrocyte differentiation, although transcription has not yet been initiated. These findings offer a theoretical framework for understanding the molecular mechanisms underlying this process.

Single-Cell RNA-Seq Reveals the Pseudo-temporal Dynamic Evolution Characteristics of ADSCs to Neuronal Differentiation

Adipose-derived stromal cells (ADSCs) are commonly used in regenerative medicine, but the genetic features of their development into neuronal cells are unknown. This study used single-cell RNA sequencing (scRNA-seq) to reveal gene expression changes during ADSCs to neuronal differentiation. Sequencing of the ADSCs group, the prei-1d group, and the induction 1 h, 3 h, 5 h, 6 h, and 8 h groups was performed using the BD Rhapsody platform. Sequence data were analyzed using t-SNE, Monocle2, GO, and KEGG algorithms. Results showed that a total of 38,453 cells were collected, which were divided into 0-13 clusters. Monocle2 structured analysis revealed that ADSCs were located at the beginning of the trajectory, and the cells after 5 h of induction were mainly distributed at the end of the trajectory in branches 1 and 2. Up-regulated differentially expressed genes (DEGs) at 5 h after induction enriched GO items including cellular protein metabolism, cell adhesion, endocytosis, and cell migration. KEGG analysis showed that induced 6 h and 8 h groups mainly enriched pathways were oxidative phosphorylation, glutathione metabolism, and expression of Parkinson's disease-related genes. In conclusion, two distinct cell state mechanisms stimulate ADSCs to develop into mature neurons. ADSCs induced for 5 h had developed into mature neurons. Later, the differentiated cells undergo degenerative changes associated with senescence.

Dissecting human adipose tissue heterogeneity using single-cell omics technologies

Single-cell omics technologies that profile genes (genomic and epigenomic) and determine the abundance of mRNA (transcriptomic), protein (proteomic and secretomic), lipids (lipidomic), and extracellular matrix (matrisomic) support the dissection of adipose tissue heterogeneity at unprecedented resolution in a temporally and spatially defined manner. In particular, cell omics technologies may provide innovative biomarkers for the identification of rare specific progenitor cell subpopulations, assess transcriptional and proteomic changes affecting cell proliferation and immunomodulatory potential, and accurately define the lineage hierarchy and differentiation status of progenitor cells. Unraveling adipose tissue complexity may also provide for the precise assessment of a dysfunctional state, which has been associated with cancer, as cancer-associated adipocytes play an important role in shaping the tumor microenvironment supporting tumor progression and metastasis, obesity, metabolic syndrome, and type 2 diabetes mellitus. The information collected by single-cell omics has relevant implications for regenerative medicine because adipose tissue is an accessible source of multipotent cells; alternative cell-free approaches, including the use of adipose tissue stromal cell-conditioned medium, extracellular vesicles, or decellularized extracellular matrix, are clinically valid options. Subcutaneous white adipose tissue, which is generally harvested via liposuction, is highly heterogeneous because of intrinsic biological variability and extrinsic inconsistencies in the harvesting and processing procedures. The current limited understanding of adipose tissue heterogeneity impinges on the definition of quality standards appropriate for clinical translation, which requires consistency and uniformity of the administered product. We review the methods used for dissecting adipose tissue heterogeneity and provide an overview of advances in omics technology that may contribute to the exploration of heterogeneity and dynamics of adipose tissue at the single-cell level.

Characteristics of the Dynamic Evolutionary Pathway of ADSCs Induced Differentiation into Astrocytes Based on scRNA-Seq Analysis

We employed single-cell transcriptome sequencing to reveal the dynamic gene expression changes during the differentiation of adipose-derived stromal cells (ADSCs) into astrocytes. Single-cell RNA sequencing was conducted on cells from the ADSCs group and the induced groups at 2, 7, 14, and 21 days using the 10 × Chromium platform. Data underwent quality control and dimensionality reduction. Cell differentiation trajectories were constructed using Monocle2, and differentially expressed genes (DEGs) in each cell cluster were identified using differential selection algorithms. DEGs at each time point were annotated using Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG), and regulatory intensities of transcription factors were analyzed using SCENIC. Integrating all groups, a total of five samples were divided into 13 cell clusters (0-12 clusters). DEGs between clusters and those compared with ADSCs at various induced time points showed distinct specificities. Monocle2 constructed cell differentiation trajectories; ADSCs can differentiate into mature astrocytes not only through the direct pathway from the 1 branch to the 3 branch but also through an indirect pathway, involving the 1 branch to the 2 branch before progressing to the 3 branch. SCENIC analysis highlighted the critical regulatory roles of STAT1, MYEF2, and SOX6 transcription factors during the differentiation of ADSCs into astrocytes. ADSCs can differentiate into mature astrocytes through two distinct pathways: direct and indirect. By the 14th day of induction, mature astrocytes have formed, characterized by a cell cycle arrest in mitosis. Further induction leads to degenerative senescence changes in differentiated cells.

Genomic characteristics of adipose-derived stromal cells induced into neurons based on single-cell RNA sequencing

Adipose-derived stromal cells (ADSCs) can be induced to differentiate into neurons, representing the most promising avenue for cell therapy. However, the molecular mechanism and genomic characteristics of the differentiation of ADSCs into neurons remain poorly understood. In this study, cells from the adult ADSCs group, induction 1h, 3h, 5h, 6h, and 8h groups were selected for single-cell RNA sequencing (scRNA-Seq). Samples from these seven-time points were sequenced and analyzed. The expression of neuron marker genes, including NES, MAP2, TMEM59L, PTK2B, CHN1, DNM1, NRSN2, FBLN2, SCAMP1, SLC1A1, DLG4, CDK5, and ENO2, was found to be low in the ADSCs group, but highly expressed in differentiated cell clusters. The expression of stem cell marker genes, including CCND1, IL1B, MMP1, MMP3, MYO10, and BMP2, was the highest in the ADSCs cluster. This expression decreased significantly with the extension of induction time. Gene ontology (GO) enrichment analysis of upregulated genes in the induced samples showed that the biological processes related to neuronal differentiation and development, such as neuronal differentiation, projection, and apoptosis, were significantly upregulated with a longer induction time during cell cluster differentiation. The results of the cell communication analysis demonstrated the gradual formation of complex neural network connections between ADSC-derived neurons through receptor and ligand pairs at 5h after the induction of differentiation.

Synaptic endocytosis in adult adipose stromal cell-derived neurons

Synapses are essential for facilitating the transmission of information between neurons and for executing neurophysiological processes. Following the exocytosis of neurotransmitters, the synaptic vesicle may quickly undergo endocytosis to preserve the structural integrity of the synapse. When converting adipose-derived stromal cells (ADSCs) into neurons, the ADSCs have already demonstrated comparable morphology, structure, and electrophysiological characteristics to neurons. Nevertheless, there is currently no published study on the endocytotic function of neurons that are produced from ADSCs. This study aimed to examine synaptic endocytosis in neurons derived from ADSCs by qualitatively and quantitatively analyzing the presence of Ap-2, Clathrin, Endophilin, Dynamin, and Hsc70, which are the key proteins involved in clathrin-mediated endocytosis (CME), as well as by using FM1-43 and cadmium selenide quantum dots (CdSe QDs). Additionally, single-cell RNA sequencing (scRNA-seq) was used to look at the levels of both neuronal markers and markers related to CME at the same time. The results of this study provide evidence that synapses in neurons produced from ADSCs have a role in endocytosis, mainly through the CME route.