Non-cell-autonomous regulation of interneuron specification mediated by extracellular vesicles

Extracellular vesicle-mediated trafficking of molecular cues during human brain development

Cellular crosstalk is an essential process influenced by numerous factors, including secreted vesicles that transfer nucleic acids, lipids, and proteins between cells. Extracellular vesicles (EVs) have been the center of many studies focusing on neurodegenerative disorders, but whether EVs display cell-type-specific features for cellular crosstalk during neurodevelopment is unknown. Here, using human-induced pluripotent stem cell-derived cerebral organoids, neural progenitors, neurons, and astrocytes, we identify heterogeneity in EV protein content and dynamics in a cell-type-specific and time-dependent manner. Our results support the trafficking of key molecules via EVs in neurodevelopment, such as the transcription factor YAP1, and their localization to differing cell compartments depending on the EV recipient cell type. This study sheds new light on the biology of EVs during human brain development.

Huntington's disease cellular phenotypes are rescued non-cell autonomously by healthy cells in mosaic telencephalic organoids

Huntington's disease (HD) causes selective degeneration of striatal and cortical neurons, resulting in cell mosaicism of coexisting still functional and dysfunctional cells. The impact of non-cell autonomous mechanisms between these cellular states is poorly understood. Here we generated telencephalic organoids with healthy or HD cells, grown separately or as mosaics of the two genotypes. Single-cell RNA sequencing revealed neurodevelopmental abnormalities in the ventral fate acquisition of HD organoids, confirmed by cytoarchitectural and transcriptional defects leading to fewer GABAergic neurons, while dorsal populations showed milder phenotypes mainly in maturation trajectory. Healthy cells in mosaic organoids restored HD cell identity, trajectories, synaptic density, and communication pathways upon cell-cell contact, while showing no significant alterations when grown with HD cells. These findings highlight cell-type-specific alterations in HD and beneficial non-cell autonomous effects of healthy cells, emphasizing the therapeutic potential of modulating cell-cell communication in disease progression and treatment.

Asteroid impact: the potential of astrocytes to modulate human neural networks within organoids

Astrocytes are a vital cellular component of the central nervous system that impact neuronal function in both healthy and pathological states. This includes intercellular signals to neurons and non-neuronal cells during development, maturation, and aging that can modulate neural network formation, plasticity, and maintenance. Recently, human pluripotent stem cell-derived neural aggregate cultures, known as neurospheres or organoids, have emerged as improved experimental platforms for basic and pre-clinical neuroscience compared to traditional approaches. Here, we summarize the potential capability of using organoids to further understand the mechanistic role of astrocytes upon neural networks, including the production of extracellular matrix components and reactive signaling cues. Additionally, we discuss the application of organoid models to investigate the astrocyte-dependent aspects of neuropathological diseases and to test astrocyte-inspired technologies. We examine the shortcomings of organoid-based experimental platforms and plausible improvements made possible by cutting-edge neuroengineering technologies. These advancements are expected to enable the development of improved diagnostic strategies and high-throughput translational applications regarding neuroregeneration.

Bone-targeting exosome nanoparticles activate Keap1 / Nrf2 / GPX4 signaling pathway to induce ferroptosis in osteosarcoma cells

BACKGROUND

In recent years, the development of BMSCs-derived exosomes (EXO) for the treatment of osteosarcoma (OS) is a safe and promising modality for OS treatment, which can effectively deliver drugs to tumor cells in vivo. However, the differences in the drugs carried, and the binding of EXOs to other organs limit their therapeutic efficacy. Therefore, improving the OS-targeting ability of BMSCs EXOs and developing new drugs is crucial for the clinical application of targeted therapy for OS.

RESULTS

In this study, we constructed a potential therapeutic nano platform by modifying BMSCs EXOs using the bone-targeting peptide SDSSD and encapsulated capreomycin (CAP) within a shell. These constructed nanoparticles (NPs) showed the ability of homologous targeting and bone-targeting exosomes (BT-EXO) significantly promotes cellular endocytosis in vitro and tumor accumulation in vivo. Furthermore, our results revealed that the constructed NPs induced ferroptosis in OS cells by prompting excessive accumulation of reactive oxygen species (ROS), Fe2+ aggregation, and lipid peroxidation and further identified the potential anticancer molecular mechanism of ferroptosis as transduced by the Keap1/Nrf2/GPX4 signaling pathway. Also, these constructed NP-directed ferroptosis showed significant inhibition of tumor growth in vivo with no significant side effects.

CONCLUSION

These results suggest that these constructed NPs have superior anticancer activity in mouse models of OS in vitro and in vivo, providing a new and promising strategy for combining ferroptosis-based chemotherapy with targeted therapy for OS.

HNRNPU's multi-tasking is essential for proper cortical development

Heterogeneous nuclear ribonucleoprotein U (HNRNPU) is a nuclear protein that plays a crucial role in various biological functions, such as RNA splicing and chromatin organization. HNRNPU/scaffold attachment factor A (SAF-A) activities are essential for regulating gene expression, DNA replication, genome integrity, and mitotic fidelity. These functions are critical to ensure the robustness of developmental processes, particularly those involved in shaping the human brain. As a result, HNRNPU is associated with various neurodevelopmental disorders (HNRNPU-related neurodevelopmental disorder, HNRNPU-NDD) characterized by developmental delay and intellectual disability. Our research demonstrates that the loss of HNRNPU function results in the death of both neural progenitor cells and post-mitotic neurons, with a higher sensitivity observed in the former. We reported that HNRNPU truncation leads to the dysregulation of gene expression and alternative splicing of genes that converge on several signaling pathways, some of which are likely to be involved in the pathology of HNRNPU-related NDD.