�����ƽ��

Human development relies on the correct replication, maintenance and segregation of our genetic blueprints. How these processes are monitored across embryonic lineages, and why genomic mosaicism varies during development remain unknown. Using pluripotent stem cells, we identify that several patterning signals—including WNT, BMP, and FGF—converge into the modulation of DNA replication stress and damage during S-phase, which in turn controls chromosome segregation fidelity in mitosis. We show that the WNT and BMP signals protect from excessive origin firing, DNA damage and chromosome missegregation derived from stalled forks in pluripotency. Cell signalling control of chromosome segregation declines during lineage specification into the three germ layers, but re-emerges in neural progenitors. In particular, we find that the neurogenic factor FGF2 induces DNA replication stress-mediated chromosome missegregation during the onset of neurogenesis, which could provide a rationale for the elevated chromosomal mosaicism of the developing brain. Our results highlight roles for morphogens and cellular identity in genome maintenance that contribute to somatic mosaicism during mammalian development. Here the authors show that the patterning signals WNT, BMP, and FGF control chromosome segregation fidelity during early lineage specification and neurogenesis, which could provide a rationale for the spatio-temporal distribution of genomic mosaicism during human development.

SummaryCardiovascular disease (CVD) is associated with both genetic variants and environmental factors. One unifying consequence of the molecular risk factors in CVD is DNA damage, which must be repaired by DNA damage response proteins. However, the impact of DNA damage on global cardiomyocyte protein abundance, and its relationship to CVD risk remains unclear. We therefore treated induced pluripotent stem cell-derived cardiomyocytes with the DNA-damaging agent Doxorubicin (DOX) and a vehicle control, and identified 4,178 proteins that contribute to a network comprising 12 co-expressed modules and 403 hub proteins with high intramodular connectivity. Five modules correlate with DOX and represent distinct biological processes including RNA processing, chromatin regulation and metabolism. DOX-correlated hub proteins are depleted for proteins that vary in expression across individuals due to genetic variation but are enriched for proteins encoded by loss-of-function intolerant genes. While proteins associated with genetic risk for CVD, such as arrhythmia are enriched in specific DOX-correlated modules, DOX-correlated hub proteins are not enriched for known CVD risk proteins. Instead, they are enriched among proteins that physically interact with CVD risk proteins. Our data demonstrate that DNA damage in cardiomyocytes induces diverse effects on biological processes through protein co-expression modules that are relevant for CVD, and that the level of protein connectivity in DNA damage-associated modules influences the tolerance to genetic variation.

Neurological damage caused by peripheral nerve injury can be devastating and is a common neurological disorder that, along with muscle disorders, reduces the quality of life. Neural crest cells (NCCs) are a transient cell population that occurs during embryogenesis, can differentiate into various cells upon transplantation, and has potential therapeutic effects on neurological diseases. However, there are limitations to cell therapy, such as uncontrolled differentiation and tumor formation. Extracellular vesicles (EVs), which are non-cellular potential therapeutic candidates, are nanosized membrane-bound vesicles. Studies have been reported using starch cells derived from neural cells, such as neural stem cells, because they are involved in cell-to-cell communication and carry a variety of bioactive molecules. We investigated the effects of EVs isolated from NCCs on neuronal cell death and inflammation. Additionally, we overexpressed the nerve growth factor (NGF), which is involved in neural cell growth and proliferation, in NCCs to further investigate the effects of EVs containing NGF. NCCoe-NGF-EVs showed neuroprotective and regenerative properties by modulating inflammatory pathway, promoting Schwann cell activation, and enhancing remyelination. In vitro studies on NCCoe-NGF-EVs suppressed pro-inflammatory cytokines and reduced oxidative stress-induced neuronal apoptosis through NF-?B pathway inhibition and ERK, AKT signal activation. We also evaluated the effect of EVs on neuropathy by performing in vivo study. Our results suggest that NCCoe-NGF-EV had neuroprotective effects by reducing neuronal apoptosis and promoting neuronal proliferation based on neurite outgrowth and anti-inflammation effects treated with NCCoe-NGF-EVs. In addition, NCCoe-NGF-EVs were protected muscle loss caused by peripheral nerve injury. NCCoe-NGF-EV induced regeneration of damaged nerves and inhibited cell death through anti-inflammatory effects. This study suggests the potential of NGF-enriched EVs as non-cellular therapeutic platform for peripheral neuropathies and other neuroinflammatory disorders.Graphical abstract Supplementary InformationThe online version contains supplementary material available at 10.1186/s40478-025-02033-9.

The induction of the germ cell lineage from pluripotent stem cells (in vitro gametogenesis) will help understand the mechanisms underlying germ cell differentiation and provide an alternative source of gametes for reproduction. This technology is especially important for cattle, which are among the most important livestock species for milk and meat production. Here, we developed a new method for robust induction of primordial germ cell-like cells (PGCLCs) from newly established bovine embryonic stem (bES) cells. First, we refined the pluripotent culture conditions for pre-implantation embryos and ES cells. Inhibition of RHO increased the number of epiblast cells in the pre-implantation embryos and dramatically improved the efficiency of ES cell establishment. We then determined suitable culture conditions for PGCLC differentiation using bES cells harboring BLIMP1-tdTomato and TFAP2C-mNeonGreen (BTTN) reporter constructs. After a 24-h culture with bone morphogenetic protein 4 (BMP4), followed by three-dimensional culture with BMP4 and a chemical agonist and WNT signaling chemical antagonist, bES cells became positive for the reporters. A set of primordial germ cells (PGC) marker genes, including PRDM1/BLIMP1, TFAP2C, SOX17, and NANOS3, were expressed in BTTN-positive cells. These bovine PGCLCs (bPGCLCs) were isolated as KIT/CD117-positive and CD44-negative cell populations. We anticipate that this method for the efficient establishment of bES cells and induction of PGCLCs will be useful for stem cell-based reproductive technologies in cattle.

Venoms comprise highly sophisticated bioactive molecules modulating ion channels, receptors, coagulation factors, and the cellular membranes. This array of targets and bioactivities requires advanced high-content bioassays to facilitate the development of novel envenomation treatments and biotechnological and pharmacological agents. In response to the existing gap in venom research, we developed a cutting-edge fluorescence-based high-throughput and high-content cellular assay. This assay enables the simultaneous identification of prevalent cellular activities induced by venoms such as membrane lysis, pore formation, and ion channel modulation. By integrating intracellular calcium with extracellular nucleic acid measurements, we have successfully distinguished these venom mechanisms within a single cellular assay. Our high-content bioassay was applied across three cell types exposed to venom components representing lytic, ion pore-forming or ion channel modulator toxins. Beyond unveiling distinct profiles for these action mechanisms, we found that the pore-forming latrotoxin ?-Lt1a prefers human neuroblastoma to kidney cells and cardiomyocytes, while the lytic bee peptide melittin is not selective. Furthermore, evaluation of snake venoms showed that Elapid species induced rapid membrane lysis, while Viper species showed variable to no activity on neuroblastoma cells. These findings underscore the ability of our high-content bioassay to discriminate between clades and interspecific traits, aligning with clinical observations at venom level, beyond discriminating among ion pore-forming, membrane lysis and ion channel modulation. We hope our research will expedite the comprehension of venom biology and the diversity of toxins that elicit cytotoxic, cardiotoxic and neurotoxic effects, and assist in identifying venom components that hold the potential to benefit humankind. Graphical abstractImage 1 Highlights•Optimization of bioassays to study venoms strengthens the discovery of novel drugs and envenomation treatments•We developed a high-content bioassay measuring DNA and [Ca2+]i that investigates multiple mechanisms in venom biology•This bioassay monitored membrane integrity, ion channels and ion pore formation to unravel venom's mechanism of action•We found the latrotoxin ?-Lt1a strikingly prefers neuron-like cells while the ?-helical melittin is non-selective•Evaluation of Elapid and Viper snake venoms demonstrates that this bioassay predicts the phylogeny and clinical findings

Liver disease secondary to an inborn or genetic error of metabolism is a rare group of conditions often associated with chronic ill health and reduced survival. Curative treatment is mainly limited to liver transplantation with major long-term risks. Cell therapy is a promising alternative, but current approaches are ineffective. To develop histotripsy, a non-invasive high-intensity ultrasound procedure for liver tissue mechanical ablation, combined with hepatocyte stem cell implantation as a novel method of reversing liver failure from genetic disease. This study assessed the safety and feasibility of this approach in healthy rodents. Under general anaesthesia, adult rats (n = 12) underwent laparotomy and ultrasound histotripsy to the exposed liver. Around 1 million cells were injected into a single histotripsy cavity in each animal under direct vision (n = 10) with two receiving only histotripsy without cell injection. On completion of cell implant, haemostasis was secured, laparotomy incision closed and the animals recovered. Groups of animals were terminated immediately and after 4 h, 8 h, 24 h, 4 days and 7 days. Liver and vital organs were assessed for procedure-related injuries and evidence of viable implanted cells by histology and immunohistochemistry. All animals successfully recovered, and no complication was observed throughout the study. Created cavities were successfully identified in histological analysis of rat. The presence of human cells was verified using anti-human nuclei antibody confirming successful implantation of liver organoids into decellularised cavities. In this feasibility study, we demonstrated suitability of histotripsy to create decellularised cavities in liver parenchyma. In addition, feasibility of direct transplantation of undissociated liver organoids into the created cavities was demonstrated as a potential approach to treat inborn liver disease by creating nodules of healthy cells capable of performing loss metabolic function. Therapeutic efficacy of this approach will be evaluated in an upcoming study. Graphical Abstract