Frontiers in Cell and Developmental Biology最新文献

Introduction: Hepatocellular carcinoma (HCC) is the most common primary liver cancer, with microvascular invasion (MVI) identified as a major predictor of early recurrence. However, the intratumor cellular heterogeneity of MVI, the identification of pertinent biomarkers, and the role of intercellular signalling interactions in MVI progression are unclear. This study aims to explore these aspects using single-cell transcriptomic analysis.

Methods: The present study utilized single-cell transcriptomic data from public databases to conduct an in-depth transcriptome analysis of tumour tissues and adjacent nontumor tissues from five patients with hepatocellular carcinoma, with a particular focus on samples from three patients exhibiting microvascular invasion. Bioinformatics tools were employed to analyze gene expression patterns and signalling pathways.

Results: The findings indicated that MVI-positive malignant cells activate multiple signalling pathways to facilitate invasion and metastasis. Specific malignant cell subtypes strongly associated with MVI were identified, exhibiting distinctive gene expression patterns related to proliferation, invasion, and metabolic reprogramming of tumour cells. Further analysis revealed that the laminin and VEGF signalling pathways are crucial for remodelling the tumour microenvironment and angiogenesis associated with MVI. The MARCKSL1 gene was predominantly expressed in MVI-positive malignant cells and may contribute to MVI progression by interacting with the PTN signalling network. Additionally, MARCKSL1 is linked to tumour resistance to multiple anticancer drugs.

Discussion: This study sheds light on the molecular characteristics and functional heterogeneity of MVI-associated malignant cell subpopulations. The single-cell transcriptome and bioinformatics analyses provided insights into the mechanisms driving MVI, potentially aiding the development of targeted diagnostic and therapeutic strategies. Future research should further validate the role of MARCKSL1 in MVI progression and explore its potential clinical applications.

Spinal cord injury (SCI) results in severe disruption of communication between the brain and body, causing motor, sensory, and autonomic dysfunctions. While SCI in mammals leads to permanent impairment due to limited regenerative capacity, certain non-mammalian species, such as Xenopus laevis larval stages, exhibit remarkable regenerative abilities. During Xenopus laevis spinal cord regeneration, neural stem precursor cells (NSPCs) surrounding the central canal rapidly proliferate in response to SCI, compensating for cellular loss, restoring canal continuity, and generating new neurons to reestablish lost connections. It has been described that mitochondria and cellular metabolism play essential roles in stem cell proliferation, self-renewal, and differentiation. However, the mitochondrial and cellular metabolic response during spinal cord regeneration remains unexplored. This study uses electron and confocal microscopy to investigate the NSPCs mitochondrial response in Xenopus laevis following SCI. We observed that mitochondria exhibit a rapid and transient response after SCI, characterized by a disruption of the mitochondrial localization, a decrease in mitochondrial number per cell section, and an increase in mitochondrial area and circularity. Furthermore, mitochondria adopted a swollen phenotype, which did not impair mitochondrial function or cellular energy balance. This morphological shift was accompanied by a transient decrease in the mitochondrial membrane potential and a metabolic switch favoring glycolysis. Therefore, these findings demonstrate that a transient metabolic shift toward glycolysis occurs during spinal cord regeneration.

Porphyromonas gingivalis is the primary pathogen responsible for the development of periodontal inflammatory disease. Although gingipains are the major virulence factor of the pathogen, their role in impairing apoptosis and immune cell function is not fully understood. To investigate the impact of gingipains on neutrophil viability and function, we conducted studies using murine HoxB8 neutrophils and primary human neutrophils infected with wild-type strains of Porphyromonas gingivalis (W83 and ATCC 33277), or a gingipains-null mutant with deleted gingipains encoding genes, or wild-type bacteria preincubated with specific gingipain inhibitors. Flow cytometry revealed that wild-type Porphyromonas gingivalis had a marked effect on neutrophil viability regulated by anti-apoptotic proteins belonging to the Bcl-2 family; however, these effects were independent of gingipain expression or activity. Importantly, experiments using primary human neutrophils and macrophages revealed that gingipains play a significant role in the disruption of immune cell functions via the induction of reactive oxygen species and inactivation of neutrophil elastase activity. Additionally, although gingipains played a role in modulating the IL-8-dependent inflammatory response of human neutrophils, they did not affect the expression levels of pro-inflammatory cytokines TNF-α and IL-6.

Introduction: Blood proteomics offers a powerful approach for identifying disease-specific biomarkers. However, no reliable blood markers are currently available for the diagnosis stroke. Nervonic acid (NA), a vital long-chain monounsaturated fatty acid found in mammalian nervous tissue, shows promising therapeutic potential in neurological disorders. This study aimed to develop a reliable methodology for whole blood proteomics to identify early warning biomarkers and evaluate drug treatment efficacy.

Methods: After modeling via the classic thread embolization method, whole blood samples were collected from the rats. Morphological assessments of brain tissue indicated that NA significantly mitigated brain and neuronal damage in rats. The differential protein expression profile was analyzed using Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS) whole blood proteomics.

Results: ZZZGene Ontology (GO) analysis revealed that, compared to ginkgo biloba extract (EGb), the proteins differentially expressed under NA intervention were predominantly involved in oxidative stress response and calcium-dependent adhesion processes. Key targets of NA in the treatment of middle cerebral artery occlusion (MCAO) models included ENO1, STAT3, NME2, VCL, and CCT3.

Discussion: This whole blood proteomic approach provides a comprehensive understanding of protein profiles associated with disease states, offering valuable insights into potential therapeutic targets and enabling the evaluation of NA and EGb intervention efficacy. Our findings underscore the protective effects of NA against cerebral ischemia-reperfusion injury and highlight its potential as a treatment for stroke.

Autophagy-related protein 8 (ATG8) family proteins, including LC3 and GABARAP subfamilies, are pivotal in canonical autophagy, driving autophagosome formation, cargo selection, and lysosomal fusion. However, recent studies have identified non-canonical roles for lipidated ATG8 in processes such as LC3-associated phagocytosis (LAP), LC3-associated endocytosis (LANDO), and lipidated ATG8-mediated secretory autophagy. These pathways expand ATG8's functional repertoire in immune regulation, membrane repair, and pathogen clearance, as ATG8 becomes conjugated to single-membrane structures (e.g., phagosomes and lysosomes). This review examines the molecular mechanisms of ATG8 lipidation, focusing on its selective conjugation to phosphatidylethanolamine (PE) in autophagy and phosphatidylserine (PS) in CASM. We highlight LIR-based probes and LC3/GABARAP-specific deconjugases as critical tools that allow precise tracking and manipulation of ATG8 in autophagic and non-autophagic contexts. These advancements hold therapeutic promise for treating autophagy-related diseases, including cancer and neurodegenerative disorders, by targeting ATG8-driven pathways that maintain cellular homeostasis.

Fetal neural stem cells (NSCs) physiologically reside under low-oxygen conditions (1%-5% of tissue pO₂), but are often transferred and maintained under atmospheric oxygen levels of 21% pO₂ (hyperoxia) for in vitro investigations. These altered oxygen conditions lead to adaptive changes in NSCs which complicate the interpretation of in vitro data. However, the underlying adaption dynamics remain largely enigmatic. Here we investigated short-term hyperoxia effects (5 days in 3% pO₂ followed by 2 days in 21% pO₂) in comparison to continuous hyperoxia effects (7 days in 21% pO₂) and physioxic control (7 days in 3% pO₂). We utilized cortical NSCs to analyze the cell cycle phases by flow cytometry and cumulative BrdU incorporation assay. NSCs showed a severe reduction of cell proliferation when cultivated under continuous hyperoxia, but no changes after short-term hyperoxia. Subsequent cell cycle analysis as assessed by flow cytometry revealed a clear shift of NSCs from G0/G1-phase towards S- or G2/M-phase after both continuous and short-term hyperoxia. However, while cell cycle length was dramatically reduced by short-term hyperoxia, it was increased during continuous hyperoxia. Taken together, our results demonstrate the beneficial effect of physioxia for expanding NSCs in vitro and reveal differential effects of short-term hyperoxia compared to continuous hyperoxia.

Accurate segmentation of large choroidal vessels using optical coherence tomography (OCT) images enables unprecedented quantitative analysis to understand choroidal diseases. In this paper, we propose a novel multi-scale and fine-grained network called MFGNet. Since choroidal vessels are small targets, long-range dependencies need to be considered, therefore, we developed a two-branch fine-grained feature extraction module that can mix the long-range information extracted by TransFormer with the local information extracted by convolution in parallel, introducing information exchange between the two branches. To address the problem of low contrast and blurred boundaries of choroidal vessels in OCT images, we developed a large kernel and multi-scale attention module, which can improve the features of the target area through multi-scale convolution kernels, channel mixing and feature refinement. We quantitatively evaluated the MFGNet on 800 OCT images with large choroidal vessels manually annotated. The experimental results show that the proposed method has the best performance compared to the most advanced segmentation networks currently available. It is noteworthy that the large choroidal vessels were reconstructed in three dimensions (3D) based on the segmentation results and several 3D morphological parameters were calculated. The statistical analysis of these parameters revealed significant differences between the healthy control group and the high myopia group, thereby confirming the value of the proposed work in facilitating subsequent understanding of the disease and clinical decision-making.

YAP/TAZ (Yes-associated protein/paralog transcriptional co-activator with PDZ-binding domain) are transcriptional cofactors that are the key and major downstream effectors of the Hippo signaling pathway. Both are known to play a crucial role in defining cellular outcomes, including cell differentiation, cell proliferation, and apoptosis. Aside from the canonical Hippo signaling cascade with the key components MST1/2 (mammalian STE20-like kinase 1/2), SAV1 (Salvador homologue 1), MOB1A/B (Mps one binder kinase activator 1A/B) and LATS1/2 (large tumor suppressor kinase 1/2) upstream of YAP/TAZ, YAP/TAZ activation is also influenced by numerous other signaling pathways. Such non-canonical regulation of YAP/TAZ includes well-known growth factor signaling pathways such as the epidermal growth factor receptor (EGFR)/ErbB family, Notch, and Wnt signaling as well as cell-cell adhesion, cell-matrix interactions and mechanical cues from a cell's microenvironment. This puts YAP/TAZ at the center of a complex signaling network capable of regulating developmental processes and tissue regeneration. On the other hand, dysregulation of YAP/TAZ signaling has been implicated in numerous diseases including various cancers and neurodevelopmental disorders. Indeed, in recent years, parallels between cancer development and neurodevelopmental disorders have become apparent with YAP/TAZ signaling being one of these pathways. This review discusses the role of YAP/TAZ in brain development, cancer and neurodevelopmental disorders with a special focus on the interconnection in the role of YAP/TAZ in these different conditions.