Experimental cell research最新文献

The development of a well-organised genome represents a hallmark in the evolution of species. In mammals, the nucleus of each cell is characterised by the presence of different compartments, among others nuclear speckles, membrane-less organelles that are self-shaped by liquid droplet-like phase separation. Functioning in the organisation of the transcription and splicing machinery, nuclear speckles are highly dynamic, moving and rearranging within the nucleus according to the needs of the cell. In line with a role of actin dynamics in speckle function, we could previously demonstrate that the actin-binding protein Simiate is not only enriched in nuclear speckles, but also able to associate with nuclear isoforms of the Focal Adhesion Kinase FAK1. Furthermore, nuclear speckles have recently been suggested to consist of specific sub-domains involved in the spatial organisation of chromatin handling and mRNA processing. In this study, we therefore examined the sub-speckular organisation of FAK1 and Simiate in mouse brain slices using three-dimensional reconstructions and stimulated emission depletion (STED) microscopy. While FAK1 is predominantly localised in peripheral areas, Simiate is highly enriched in the core domain. Aside, Simiate is also seen in the surrounding shell, and minor amounts of FAK1 are detected in the core domain. As the number of speckles increases, FAK1 is found to diminish from the core domain, whereas peripheral numbers remain constant. Both proteins, Simiate and FAK1, are organised in spherical clusters, which may occasionally colocalise in peripheral as well as core domains. Although our data obtained from mouse brain slices are merely descriptive, they may suggest for dynamic rearrangement of FAK1.

Background: Aortic dissection (AD) is a life-threatening vascular disease whose pathogenesis involves dysfunction of vascular smooth muscle cells (VSMCs) and cell death. This study aimed to investigate the role of the MT1E/LncRNA NEAT1/SLC39A14 axis in AD and its molecular mechanism in regulating ferroptosis.

Methods: The correlation between ferroptosis and AD was evaluated using single-sample gene set enrichment analysis (ssGSEA). Weighted gene co-expression network analysis (WGCNA) based on the GSE153434 dataset was performed to identify key modules. Differentially expressed genes were screened through GO, KEGG enrichment analyses, and protein-protein interaction (PPI) network analysis. The functions and interactions of MT1E, LncRNA NEAT1, and SLC39A14 were validated using RT-PCR, Western Blot, immunohistochemistry, Co-IP assay, RIP assay, and luciferase reporter assays. A mouse model was constructed to evaluate the role of MT1E in AD pathological injury and ferroptosis.

Results: AD was significantly associated with ferroptosis. WGCNA identified a blue module highly correlated with ferroptosis, and 236 differentially expressed genes were screened. MT1E, LncRNA NEAT1, and SLC39A14 were significantly upregulated in aortic tissues of AD patients. Knockdown of MT1E inhibited AngII-induced VSMC proliferation, migration, and ferroptosis, and restored the expression of VSMC phenotypic transformation markers. MT1E activates NEAT1 expression by forming a complex with YBX1, while MT1E activates NEAT1 through zinc ion release-mediated regulation of SFPQ and NONO. Besides, luciferase reporter assays demonstrated the direct binding of LncRNA NEAT1 to SLC39A14. Overexpression of LncRNA NEAT1 reversed the inhibitory effects of MT1E knockdown on VSMC proliferation, migration, and ferroptosis. Overexpression of SLC39A14 counteracted the effects of MT1E or LncRNA NEAT1 knockdown on VSMCs. Mouse model experiments validated the critical role of MT1E in AD pathological injury and ferroptosis.

Conclusion: This study reveals that MT1E plays a pivotal role in AD by targeting LncRNA NEAT1 to regulate SLC39A14-mediated ferroptosis. These findings provide novel insights into the molecular mechanisms of AD and offer potential therapeutic targets for related diseases.