Search

BACKGROUND: Neurodegenerative diseases are a large class of major neurological diseases that can lead to the loss of patients’ ability to work and live. At present, there is no effective treatment for this disease. Adipose-derived stromal cells can induce differentiation into nerve cells in vitro, which is expected to provide a new method for the treatment of this kind of diseases. OBJECTIVE: To explore the expression changes of Bax/Bcl-2 protein during the differentiation of adipose-derived stromal cells into astrocytes, and to further investigate whether there is mitochondrial pathway-mediated apoptosis during the induction. METHODS: Immunocytochemistry and western blot assay were used to analyze the expression of glial fibrillary acidic protein, Bax, Bcl-2, cytochrome C, and casepase-3 in the process of adipose-derived stromal cell differentiation into astrocytes when induction for 48 hours and 7, 14, and 21 days. Transmission electron microscopy was used to observe the ultrastructure of cells and mitochondria. RESULTS AND CONCLUSION: (1) After being induced for 48 hours and 7, 14, and 21 days, the expression of glial fibrillary acidic protein reached the peak on day 7 (P < 0.05). There was no significant difference in glial fibrillary acidic protein expression between 14 days and 7 days after induction (P > 0.05). (2) The expression of Bax, cytochrome C, and casepase-3 increased gradually with the induction time extending and reached the peak on day 14 (P < 0.05). The expression of Bcl-2 was decreased gradually and reached the lowest level on day 14 after induction (P < 0.05). (3) Typical apoptotic bodies and mitochondrial damage were observed using transmission electron microscopy. (4) Adipose-derived stromal cells were in the best survival and differentiation state at the 7th to 14th day of differentiation. During adipose-derived stromal cell differentiation into astrocytes, the inhibitory effect of Bcl-2 on apoptosis was significantly weakened, and the pro apoptotic effect of Bax was gradually enhanced. Cytochrome C was released into the cytoplasm by damaged mitochondria, which led to apoptosis in mitochondrial pathway. [ABSTRACT FROM AUTHOR]

BACKGROUND: Astrocytes are the most abundant cells in the central nervous system, and various subsets of astrocytes are heterogeneous, performing a variety of special functions. Single-cell RNA sequencing (scRNA-seq) technology developed in recent years has extended our understanding of astrocyte heterogeneity from the perspective of transcriptome profiling. OBJECTIVE: To summarize the heterogeneity of scRNA-seq technology in different time and space, and pathological states and expand our knowledge of astrocyte heterogeneity on both molecular and functional levels. METHODS: The relevant articles on astrocyte heterogeneity and scRNA-seq were searched on PubMed, Elsevier, and CNKI databases. The search terms were “astrocytes, scRNA-seq, heterogeneity, Alzheimer disease, spinal cord injury, multiple sclerosis” in Chinese and English. Finally, 74 articles were selected for viewing after screening according to inclusion criteria. RESULTS AND CONCLUSION: scRNA-seq studies related to the heterogeneity of astrocytes have shown that astrocyte is significantly heterogeneous across four aspects: species, developmental stage, central nervous system region, and pathological state. (1) Unique expression of certain genes occurs in astrocytes of different species, and the discovery of species-specific genes is beneficial for the translation of clinical studies. (2) During astrocyte development, differential gene expression emerged in the cellular subtypes identified at each stage, which further refined the cellular lineage of astrocytes and laid the foundation for the study of astrocyte developmental trajectories and mechanisms. (3) The discovery of differential gene expression allows regional localization of different astrocyte subpopulations and assists in the diagnosis and treatment of neurological diseases. (4) Astrocyte heterogeneity revealed by scRNA-seq can provide specific markers at the time of disease diagnosis and identify potential therapeutic targets. (5) The heterogeneity of astrocytes exists in many aspects, interacts with each other and is complex. The mechanisms of its generation, maintenance and transformation remain unclear. At present, molecular research on the single-cell level is still lacking. Linking transcriptionally defined astrocyte subpopulations to cellular activity, behavior and disease markers in real time remains one of the great challenges in the field. [ABSTRACT FROM AUTHOR]