Our understanding of how aging affects the cellular and molecular components of the vasculature and contributes to cardiovascular diseases is still limited. Here we report a single-cell ...transcriptomic survey of aortas and coronary arteries in young and old cynomolgus monkeys. Our data define the molecular signatures of specialized arteries and identify eight markers discriminating aortic and coronary vasculatures. Gene network analyses characterize transcriptional landmarks that regulate vascular senility and position FOXO3A, a longevity-associated transcription factor, as a master regulator gene that is downregulated in six subtypes of monkey vascular cells during aging. Targeted inactivation of FOXO3A in human vascular endothelial cells recapitulates the major phenotypic defects observed in aged monkey arteries, verifying FOXO3A loss as a key driver for arterial endothelial aging. Our study provides a critical resource for understanding the principles underlying primate arterial aging and contributes important clues to future treatment of age-associated vascular disorders.
In vitro generation of functional gametes is a promising approach for treating infertility, although faithful replication of meiosis has proven to be a substantial obstacle to deriving haploid gamete ...cells in culture. Here we report complete in vitro meiosis from embryonic stem cell (ESC)-derived primordial germ cells (PGCLCs). Co-culture of PGCLCs with neonatal testicular somatic cells and sequential exposure to morphogens and sex hormones reproduced key hallmarks of meiosis, including erasure of genetic imprinting, chromosomal synapsis and recombination, and correct nuclear DNA and chromosomal content in the resulting haploid cells. Intracytoplasmic injection of the resulting spermatid-like cells into oocytes produced viable and fertile offspring, showing that this robust stepwise approach can functionally recapitulate male gametogenesis in vitro. These findings provide a platform for investigating meiotic mechanisms and the potential generation of human haploid spermatids in vitro.
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•Haploid spermatid-like cells (SLCs) were derived by stepwise differentiation of ESCs•This process completely recapitulated meiosis in vitro, meeting meiotic hallmarks•Intracytoplasmic injection of SLCs produced euploid and fertile offspring
In vitro production of haploid gametes could provide a treatment for infertility, but recapitulating meiosis in culture is a significant roadblock. Zhou et al. report the generation of haploid male gametes from mouse ESCs that can produce viable and fertile offspring, demonstrating functional reproduction of meiosis in vitro.
Gastrulation is a key event in embryonic development when the germ layers are specified and the basic animal body plan is established. The complexities of primate gastrulation remain a mystery ...because of the difficulties in accessing primate embryos at this stage. Here, we report the establishment of an in vitro culture (IVC) system that supports the continuous development of cynomolgus monkey blastocysts beyond early gastrulation up to 20 days after fertilization. The IVC embryos highly recapitulated the key events of in vivo early postimplantation development, including segregation of the epiblast and hypoblast, formation of the amniotic and yolk sac cavities, appearance of the primordial germ cells, and establishment of the anterior-posterior axis. Single-cell RNA-sequencing analyses of the IVC embryos provide information about lineage specification during primate early postimplantation development. This system provides a platform with which to explore the characteristics and mechanisms of early postimplantation embryogenesis in primates with possible conservation of cell movements and lineages in human embryogenesis.
Dear Editor,
Non-human primates （NHPs） are genetically, physiologically and psychologically more similar to humans than other model organisms, providing an important model for human development and ...diseases 1, 2. Precise genome modification in non-human primates （NHPs） holds great promise for biomedical researches. However, owing to the long sexual maturation time and low reproduction rate of NHPs, it is very challenging to generate biallelic mutant NHPs for loss-of-function studies through breeding. Recently, the site-specific nucleases, namely TALENs （transcription activator-like effector nucleases） and CRISPR （clustered regularly interspaced short palindromic repeat）/Cas （CRISPR-associated） system, make it feasible to generate NHPs with precise genome modifications, yet the resulting transgenic animals exhibited mosaic mutations accompanied by the presence of wild type allele in different tissues 3, 4. Thus, the feasibility of obtaining biallelic mutations in monkeys remains an open question. Here we report that by systematically optimizing the mutagenesis effi- ciency of the CRISPR/Cas-based method in monkeys, we have successfully obtained the first live p53 biallelic mutant monkey, and achieved homology directed repair （HDR）-driven gene editing with nucleotide-level preci- sion in monkey embryos.
The acrosome is a specialized organelle that covers the anterior part of the sperm nucleus and plays an essential role in the process of fertilization. The molecular mechanism underlying the ...biogenesis of this lysosome-related organelle （LRO） is still largely unknown. Here, we show that germ cell-specific Atg7-knockout mice were infertile due to a defect in aerosome biogenesis and displayed a phenotype similar to human globozoospermia; this reproductive defect was successfully rescued by intracytoplasmic sperm injections. Furthermore, the depletion of Atg7 in germ cells did not affect the early stages of development of germ cells, but at later stages of spermatogenesis, the proacroso- mal vesicles failed to fuse into a single acrosomal vesicle during the Golgi phase, which finally resulted in irregular or nearly round-headed spermatozoa. Autophagic flux was disrupted in Atg7-depleted germ cells, finally leading to the failure of LC3 conjugation to Golgi apparatus-derived vesicles. In addition, Atg7 partially regulated another giobozo- ospermia-related protein, Golgi-associated PDZ- and coiled-coil motif-containing protein （GOPC）, during acrosome biogenesis. Finally, the injection of either autophagy or lysosome inhibitors into testis resulted in a similar phenotype to that of germ cell-specific AtgT-knockout mice. Altogether, our results uncover a new role for Atg7 in the biogenesis of the acrosome, and we provide evidence to support the autolysosome origination hypothesis for the acrosome.
Existing studies on the biological activity of theabrownins are not based on their free state but on the complexes of theabrownins, polysaccharides, proteins, and flavonoids. In this study, ...theabrownins (TBs-C) were prepared by weak alkali oxidation of tea polyphenols. The ultraviolet-visible scanning spectrum of TBs-C showed two characteristic absorption peaks at 203 and 270 nm. The zeta potential of the TBs-C aqueous solution was negative, and the values varied from − 6.26 to -19.55 mV with a solution pH of 3–9. Storage conditions of pH 5.0–7.0 and around 25 °C were beneficial for the physical and chemical stability of the TBS-C solution. Cells were treated with series concentrations and examined by MTT, HE staining, PI immunofluorescence staining, flow cytometry, and real-time PCR to investigate the antiproliferative effect of TBs-C on human colon cancer HT-29 cells. The results showed that TBs-C, particularly at 500
µ
g/mL, inhibited cell growth. TBs-C induced HT-29 cell apoptosis, as confirmed by morphological changes, nucleus propidium iodide staining, and distributions of the cell cycle. The apoptotic mechanism may be due to the intracellular redox imbalance induced by TBs-C.
It has been established that exogenous expression of four transcription factors (Oct4, Klf4, Sox2, and c-Myc) can reprogram mammalian somatic cells to pluripotent states. Further studies demonstrated ...that such induced pluripotent stem cells (iPSCs) could be generated with fewer exogenous transcription factors, facilitated by endogenous expression of reprogramming factors and/or synthetic small molecules. Here, we reported identification of a new small molecule, a protein arginine methyltransferase inhibitor AMI-5, which enabled Oct4-induced reprogramming of mouse embryonic fibroblasts in combination with transforming growth factor (TGF)-β inhibitor A-83-01. The Oct4-induced iPSCs were shown similar to mouse embryonic stem cells with respect to typical pluripotency criteria. More importantly, they were shown to give rise to liveborn pups through tetraploid complementation assays, demonstrating the high quality of full reprogramming induced by this condition. Furthermore, this study suggests that regulation of protein arginine methylation might be involved in the reprogramming process.
Achieving high detection accuracy of pavement cracks with complex textures under different lighting conditions is still challenging. In this context, an encoder-decoder network-based architecture ...named CrackResAttentionNet was proposed in this study, and the position attention module and channel attention module were connected after each encoder to summarize remote contextual information. The experiment results demonstrated that, compared with other popular models (ENet, ExFuse, FCN, LinkNet, SegNet, and UNet), for the public dataset, CrackResAttentionNet with BCE loss function and PRelu activation function achieved the best performance in terms of precision (89.40), mean IoU (71.51), recall (81.09), and F1 (85.04). Meanwhile, for a self-developed dataset (Yantai dataset), CrackResAttentionNet with BCE loss function and PRelu activation function also had better performance in terms of precision (96.17), mean IoU (83.69), recall (93.44), and F1 (94.79). In particular, for the public dataset, the precision of BCE loss and PRelu activation function was improved by 3.21. For the Yantai dataset, the results indicated that the precision was improved by 0.99, the mean IoU was increased by 0.74, the recall was increased by 1.1, and the F1 for BCE loss and PRelu activation function was increased by 1.24.
Hepatocellular carcinoma (HCC) is the fifth most common malignancy and the third most common cause of cancer-related death worldwide. Due to asymptomatic patients in the early stage, most patients ...are diagnosed at an advanced stage and lose the opportunity for radical resection. In addition, for patients who underwent procedures with curative intent for early-stage HCC, up to 70% of patients may have disease recurrence within 5 years. With the advent of an increasing number of systemic therapy medications, we now have more options for the treatment of HCC. However, data from clinical studies show that with different combinations of regimens, the objective response rate is approximately 40%, and most patients will not respond to treatment. In this setting, biomarkers for predicting treatment response are of great significance for precise treatment, reducing drug side effects and saving medical resources. In this review, we summarized the existing and emerging biomarkers in the literature, with special emphasis on the pathways and mechanism underlying the prediction value of those biomarkers for systemic treatment response.
Blastocyst complementation by pluripotent stem cell (PSC) injection is believed to be the most promising method to generate xenogeneic organs. However, ethical issues prevent the study of human ...chimeras in the late embryonic stage of development. Primate embryonic stem cells (ESCs), which have similar pluripotency to human ESCs, are a good model for studying interspecies chimerism and organ generation. However, whether primate ESCs can be used in xenogenous grafts remains unclear. In this study, we evaluated the chimeric ability of cynomolgus monkey ( Macaca fascicularis) ESCs (cmESCs) in pigs, which are excellent hosts because of their many similarities to humans. We report an optimized culture medium that enhanced the anti-apoptotic ability of cmESCs and improved the development of chimeric embryos, in which domesticated cmESCs (D-ESCs) injected into pig blastocysts differentiated into cells of all three germ layers. In addition, we obtained two neonatal interspecies chimeras, in which we observed tissue-specific D-ESC differentiation. Taken together, the results demonstrate the capability of D-ESCs to integrate and differentiate into functional cells in a porcine model, with a chimeric ratio of 0.001-0.0001 in different neonate tissues. We believe this work will facilitate future developments in xenogeneic organogenesis, bringing us one step closer to producing tissue-specific functional cells and organs in a large animal model through interspecies blastocyst complementation.
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