摘要: Chromosomal abnormalities acquired during cell culture can compromise the differentiation potential of human pluripotent stem cells (hPSCs). In this work, we identified a diminished differentiation capacity to retinal progenitor cells in human embryonic stem cells (hESCs) with complex karyotypes that had in common the loss of part of chromosome 18q. Time-course gene-expression analysis during spontaneous differentiation and single-cell RNA sequencing found that these variant cell lines poorly specified into anterior neuroectoderm, and, when progressing through differentiation, they yielded poorly pigmented cells, with proliferating and pluripotent cell populations. The variant cell lines showed dysregulation of TGF beta signalling during differentiation, and chemical modulation of the TGF beta pathways showed that the basis of the improper specification was due to imbalances in the anteroposterior neuroectodermal fate commitment.

摘要: Pigs are important agricultural animals whose growth rate and meat production performance are related to muscle development. Musculoskeletal embryonic nuclear protein 1 (MUSTN1) participates in various biological processes, including myogenesis and growth in animals, but the physiological functions and mechanisms of porcine MUSTN1 on muscle development are unclear; thus, we aimed to elucidate them. We found that MUSTN1 was highly expressed in the muscles of fast-growing pigs. Functionally, MUSTN1 promoted myoblast proliferation and differentiation. MUSTN1 knockout mice exhibited reduced muscle mass and fibre cross-sectional area, decreased exercise endurance, and delayed muscle regeneration. Small muscle protein X-linked (SMPX) was identified as an interacting protein of MUSTN1, and its promotion of myogenic differentiation depended on MUSTN1. Furthermore, MUSTN1 stabilised SMPX and maintained myofiber morphology. This study suggests that MUSTN1 is a critical regulator in the control of muscle development and regeneration and is a potential target for animal genetic improvement and the treatment of human muscle disease.

摘要: Exploring effective, prompt and universally applicable approaches for inducing the differentiation of glioblastoma (GBM) into terminally differentiated cells, such as astrocytes or neurons that cease cell division, is pivotal for the success of GBM differentiation therapy. In this study, a neuronal-specific promoter-reporter system was employed to screen small molecules that promote neural differentiation. The cocktail YFSS, consisting of Y27632, Forskolin, SB431542 and SP600125, which selectively targets the ROCK, cAMP, TGF-beta and JNK signalling pathways, respectively, was found to effectively trigger differentiation in human GBM cells. This process yielded neuron-like cells within 7 days, inhibited GBM cell proliferation and reduced malignancy traits, such as stemness, migratory and invasive capabilities. Transcriptome sequencing revealed the pathways altered by YFSS, shedding light on its dual role in halting cell proliferation and initiating neuronal differentiation. A notable increase in CEND1 expression, a key molecule in cell cycle and neuronal differentiation regulation, was observed during differentiation. However, CEND1 alone could not replicate YFSS's high conversion efficiency and its depletion reduced the differentiation and restored proliferation of the GBM cells. In vivo, prolonged and localised YFSS application significantly curtailed tumour growth and extended survival in patient-derived xenograft mice models. In summary, our findings reveal that the small-molecule cocktail YFSS is an effective means for inducing neuronal differentiation in GBM cells, representing a novel and promising pathway for the advancement of GBM treatment.

摘要: Abnormalities in alternative splicing are a hallmark of cancer formation. In this study, we investigated the role of the splicing factor PHD finger protein 5A (PHF5A) in melanoma. Malignant melanoma is the deadliest form of skin cancer, and patients with a high PHF5A expression show poor overall survival. Our data revealed that an siRNA-mediated downregulation of PHF5A in different melanoma cell lines leads to massive splicing defects of different tumour-relevant genes. The loss of PHF5A results in an increased rate of apoptosis by triggering Fas- and unfolded protein response (UPR)-mediated apoptosis pathways in melanoma cells. These findings are tumour-specific because we did not observe this regulation in fibroblasts. Our study identifies a crucial role of PHF5A as driver for melanoma malignancy and the described underlying splicing network provides an interesting basis for the development of new therapeutic targets for this aggressive form of skin cancer.

摘要: The extracellular microenvironment encompasses the extracellular matrix, neighbouring cells, cytokines, and fluid components. Anomalies in the microenvironment can trigger aging and a decreased differentiation capacity in mesenchymal stem cells (MSCs). MSCs can perceive variations in the firmness of the extracellular matrix and respond by regulating mitochondrial function. Diminished mitochondrial function is intricately linked to cellular aging, and studies have shown that mitochondria-lysosome contacts (M-L contacts) can regulate mitochondrial function to sustain cellular equilibrium. Nonetheless, the influence of M-L contacts on MSC aging under varying matrix stiffness remains unclear. In this study, utilizing single-cell RNA sequencing and atomic force microscopy, we further demonstrate that reduced matrix stiffness in older individuals leads to MSC aging and subsequent decline in osteogenic ability. Mechanistically, augmented M-L contacts under low matrix stiffness exacerbate MSC aging by escalating mitochondrial oxidative stress and peripheral division. Moreover, under soft matrix stiffness, cytoskeleton reorganization facilitates rapid movement of lysosomes. The M-L contacts inhibitor ML282 ameliorates MSC aging by reinstating mitochondrial network and function. Overall, our findings confirm that MSC aging is instigated by disruption of the mitochondrial network and function induced by matrix stiffness, while also elucidating the potential mechanism by which M-L Contact regulates mitochondrial homeostasis. Crucially, this presents promise for cellular anti-aging strategies centred on mitochondria, particularly in the realm of stem cell therapy.