Astrocytes have distinctive morphological and functional characteristics, and are found throughout the central nervous system. Astrocytes are now known to be far more than just housekeeping cells in the brain. Their functions include contributing to the formation of the blood–brain barrier, physically and metabolically supporting and communicating with neurons, regulating the formation and functions of synapses, and maintaining water homeostasis and the microenvironment in the brain. Aquaporins (AQPs) are transmembrane proteins responsible for fast water movement across cell membranes. Various subtypes of AQPs (AQP1, AQP3, AQP4, AQP5, AQP8 and AQP9) have been reported to be expressed in astrocytes, and the expressions and subcellular localizations of AQPs in astrocytes are highly correlated with both their physiological and pathophysiological functions. This review describes and summarizes the recent advances in our understanding of astrocytes and AQPs in regard to controlling water homeostasis in the brain. Findings regarding the features of different AQP subtypes, such as their expression, subcellular localization, physiological functions, and the pathophysiological roles of astrocytes are presented, with brain edema and glioma serving as two representative AQP-associated pathological conditions. The aim is to provide a better insight into the elaborate “water distribution” system in cells, exemplified by astrocytes, under normal and pathological conditions.

While our knowledge of gene expression in different human cell types is rapidly expanding with advances in transcriptomic profiling technologies, the next challenge is to understand gene function in each cell type. CRISPR-Cas9-based functional genomics screening offers a powerful approach to determine gene function in a high-throughput manner. With the maturation of stem cell technology, a variety of human cell types can be derived from human pluripotent stem cells (hPSCs). Recently, the integration of CRISPR screening with hPSC differentiation technologies opens up unprecedented opportunities to systematically examine gene function in different human cell types and identify mechanisms and therapeutic targets for human diseases. This review highlights recent progress in the development and applications of CRISPR-Cas9-based functional genomics screening in hPSC-derived cell types, discusses current challenges and limitations, and outlines future directions for this emerging field.

This study comprehensively addresses the involvement of the protein CKLF-like Marvel transmembrane domain-containing family member 5 (CMTM5) in the context of demyelination and cytodegenerative autoimmune diseases, particularly multiple Sclerosis (MS). An observed reduction in CMTM5 expression in post-mortem MS lesions prompted further investigations in both in vitro and in vivo animal models. In the cuprizone animal model, we detected a decrease in CMTM5 expression in oligodendrocytes that is absent in other members of the CMTM protein family. Our findings also confirm these results in the experimental autoimmune encephalomyelitis (EAE) model with decreased CMTM5 expression in both cerebellum and spinal cord white matter. We also examined the effects of a Cmtm5 knockdown in vitro in the oligodendroglial Oli-neu mouse cell line using the CRISPR interference technique. Interestingly, we found no effects on cell response to thapsigargin-induced endoplasmic reticulum (ER) stress as determined by Atf4 activity, an indicator of cellular stress responses. Overall, these results substantiate previous findings suggesting that CMTM5, rather than contributing to myelin biogenesis, is involved in maintaining axonal integrity. Our study further demonstrates that the knockdown of Cmtm5 in vitro does not modulate oligodendroglial responses to ER stress. These results warrant further investigation into the functional role of CMTM5 during axonal degeneration in the context of demyelinating conditions.

Inflammation is a central hallmark of cardiomyopathy, where misdirected immune responses contribute to chronic myocardial dysfunction. Among the emerging molecular mechanisms implicated in this process, the cyclic GMP–AMP synthase (cGAS)/stimulator of interferon genes (STING) signaling pathway has garnered increasing attention. Acting as a key cytosolic DNA sensor, the cGAS/STING pathway orchestrates inflammatory responses triggered by microbial infections or endogenous cellular stressors such as autophagy and apoptosis. Despite its pivotal role, the precise molecular mechanisms regulating this pathway and its role in cardiomyopathy-associated inflammation remain poorly understood and subject to ongoing debate. To address this scientific gap, we first reviewed key findings on cGAS/STING signaling in various forms of cardiomyopathy, drawing from in vivo and in vitro studies, as well as clinical samples. In the next step, we explored how the cGAS/STING pathway could be modulated by specific agonists and antagonists in the context of cardiac disease. Finally, by integrating publicly available human single-cell RNA sequencing (scRNA-seq) data and a systematic literature review, we identified existing molecular interventions and highlighted promising therapeutic targets aimed at mitigating cGAS/STING-driven inflammation. This comprehensive approach emphasizes the therapeutic potential of targeting the cGAS/STING pathway and provides a foundation for developing novel interventions aimed at alleviating inflammatory cardiomyopathy and improving patient outcomes. Future studies will be essential to validate these findings and facilitate their translation into clinical practice.

Inflammation is a key hallmark in cardiomyopathy where misdirected immune activation causes chronic myocardial dysfunction. Among the emerging mechanisms implicated in the dysfunction, the cyclic GMP-AMP synthase (cGAS) and stimulator of interferon genes (STING) signaling pathway has attracted significant attention. Acting as a critical DNA sensor, the cGAS/STING pathway coordinates inflammatory responses triggered by microbial invasions or endogenous stressors such as autophagic or apoptotic cell death. Despite its pivotal role, the precise molecular mechanisms regulating this pathway and its contribution to aberrant inflammation in cardiomyopathy remain poorly understood and controversial. To address this scientific gap, we first summarized the key findings on the cGAS/STING pathway in different cardiomyopathies using in vivo/in vitro models as well as clinical samples. In the next step, we explored how the cGAS/STING pathway could be modulated by it agonists and antagonists in cardiomyopathy. Finally, leveraging publicly available human single-cell ribonucleic acid sequencing (RNA-seq) dataset and systematic literature review, we identified existing molecular interventions and highlighted potential therapeutic targets to mitigate cGAS/STING-driven inflammation. This integrative approach underscores the therapeutic potential of targeting the cGAS/STING pathway and provides a foundation for developing novel interventions aimed at alleviating inflammatory cardiomyopathy and improving patient outcomes. Future studies will be crucial in validating these findings and translating them into clinics.

ZFTA–RELA is the most recurrent genetic alteration seen in paediatric supratentorial ependymoma (EPN) and is sufficient to initiate tumours in mice¹. Despite its oncogenic potential, ZFTA–RELA (ZR) is observed nearly exclusively in childhood EPN, with tumours located distinctly in the supratentorial brain of the central nervous system¹. We proposed that specific chromatin modules accessible during brain development would render distinct cell lineage programs at direct risk of transformation by ZR. To test this hypothesis, we performed combined single-nucleus assay for transposase-accessible chromatin and RNA (snMultiome) sequencing of the developing mouse forebrain compared with ZR-driven mouse and human EPN. We demonstrated that specific developmental lineage programs present in transient progenitor cells and regulated by PLAG/L family transcription factors were at risk of neoplastic transformation. Binding of this chromatin network by ZR or other PLAG/L family motifs targeting fusion oncoproteins led to persistent chromatin accessibility at oncogenic loci and oncogene expression. Cross-species analysis of mouse and human ZR EPN revealed significant cell type heterogeneity indicating incomplete neurogenic and gliogenic differentiation, with a small percentage of cycling progenitor-like or radial glial-like cells that established a putative tumour cell hierarchy. In vivo lineage tracing studies identified neoplastic clones that aggressively dominated tumour growth and established the entire EPN cellular hierarchy. These findings identify developmental epigenomic states that are critical for fusion-oncoprotein-driven transformation and show how these states continue to shape tumour progression.