Differentiation最新文献

Emerging during embryogenesis, the neural crest are a migratory, transient population of multipotent stem cell that differentiates into various cell types in vertebrates. Neural crest cells arise along the anterior-posterior extent of the neural tube, delaminate and migrate along routes to their final destinations. The factors that orchestrate how neural crest cells undergo delamination and their subsequent sustained migration is not fully understood. This review provides a primer about neural crest epithelial-to-mesenchymal transition (EMT), with a special emphasis on the role of the Extracellular matrix (ECM), cellular effector proteins of EMT, and subsequent migration. We also summarize published findings that link the expression of Hox transcription factors to EMT and ECM modification, thereby implicating Hox factors in regulation of EMT and ECM remodeling during neural crest cell ontogenesis.

Non-human primates are important models for investigations of neural development and evolution, and the use of Japanese macaque monkeys has especially contributed to the advancement of neuroscience studies. However, these studies are restricted by the number of animals able to be evaluated and the invasiveness of the methodologies. Induced pluripotent stem cells (iPSCs) can provide an alternative strategy for investigating neural development in vitro. We have established direct neurosphere (dNS) formation cultures of primate iPSCs as an in vitro model of early neurodevelopment in primate species. Here, we used dNS formation and neuronal differentiation cultures established from Japanese macaque iPSCs (jm-iPSCs) to investigate the usefulness of these cells as an in vitro model of early neural development. Time-course analyses of developmental potency and gene expression kinetics were performed during dNS formation culture of jm-iPSCs. During a 1-week culture, jm-iPSC-derived dNSs became neurogenic by day 3 and underwent stepwise expression changes of key developmental regulators along early neural development in a similar manner to chimpanzee dNS formation previously reported. Meanwhile, a subset of genes, including CYP26A1 and NPTX1, showed differential expression propensity in Japanese macaque, chimpanzee, and human iPSC-derived dNSs. Spontaneous upregulation of NOTCH signaling-associated genes HES5 and DLL1 was also observed in neuronal differentiation cultures of Japanese macaque but not chimpanzee dNSs, possibly reflecting the earlier neurogenic competence in Japanese macaques. The use of jm-iPSCs provides an alternative approach to neurological studies of primate development. Furthermore, jm-iPSCs can be used to investigate species differences in early neural development that are key to primate evolution.

Myhre syndrome is a connective tissue disorder characterized by congenital cardiovascular, craniofacial, respiratory, skeletal, and cutaneous anomalies as well as intellectual disability and progressive fibrosis. It is caused by germline variants in the transcriptional co-regulator SMAD4 that localize at two positions within the SMAD4 protein, I500 and R496, with I500 V/T/M variants more commonly identified in individuals with Myhre syndrome. Here we assess the functional impact of SMAD4-I500V variant, identified in two previously unpublished individuals with Myhre syndrome, and provide novel insights into the molecular mechanism of SMAD4-I500V dysfunction. We show that SMAD4-I500V can dimerize, but its transcriptional activity is severely compromised. Our data show that SMAD4-I500V acts dominant-negatively on SMAD4 and on receptor-regulated SMADs, affecting transcription of target genes. Furthermore, SMAD4-I500V impacts the transcription and function of crucial developmental transcription regulator, NKX2-5. Overall, our data reveal a dominant-negative model of disease for SMAD4-I500V where the function of SMAD4 encoded on the remaining allele, and of co-factors, are perturbed by the continued heterodimerization of the variant, leading to dysregulation of TGF and BMP signaling. Our findings not only provide novel insights into the mechanism of Myhre syndrome pathogenesis but also extend the current knowledge of how pathogenic variants in SMAD proteins cause disease.

Macrophages derived from human monocytic leukemia THP-1 cell line are often used as the alternative of human primary macrophage. However, the polarization method of THP-1 to macrophages varies between different laboratories, which may unknowingly affect the relevance of research output across research groups. In this regard, a systematic search was developed in Pubmed, BioOne, Scopus, and Science Direct to identify articles focusing on THP-1 polarization into M1 and M2 macrophages. All selected articles were read and discussed by two independent reviewers. The selection process was based on selected keywords on the title, abstract and full-text level. A total of 85 articles were selected and categorized based on the field of studies, method of THP-1 differentiation, and markers or genes expressed upon differentiation. THP-1 derived macrophages were mainly used together with primary monocyte-derived macrophages in cellular inflammation studies, while it was commonly employed alone in cancer research. THP-1 derived macrophages are also of paramount importance in biomaterials studies to prevent unfavorable immune responses in-vivo. We explored various methods of THP-1 differentiation and suggested several common genes encountered to characterize M1 and M2 macrophages differentiated from THP-1. The systematic review highlights the relevance of using THP-1 derived macrophage as a useful alternative to primary macrophage. Although it is not possible to derive a standard method of THP-1 polarization into M1 and M2 macrophages from this review, it may lead researchers to obtain reproducible polarization protocol based on commonly used stimulants and markers of differentiation.

Bone is a rigid, mineralized connective tissue that constitutes part of the skeleton in most vertebrate animals. Bone remodeling is a complex process that involves the coordination of ossification and bone resorption activities by osteoblasts and osteoclasts, respectively, resulting in maintaining bone mass. This process involves several growth factors/cytokines and hormones regulating the various signaling pathways. Wnt is one of the major molecular signaling pathways that positively regulate the osteogenic differentiation of mesenchymal stem cells. Dysregulation in the Wnt signaling leads to serious bone-related disorders like osteoporosis and osteosclerosis. Recently, several studies reported the critical role of non-coding RNAs (ncRNAs), including microRNAs, long ncRNAs, and circular RNAs, in the regulation of bone homeostasis via modulating the Wnt signaling cascade. This review summarizes the importance of such ncRNAs in mediating the Wnt cascade and its effect on osteoblast differentiation. Understanding the regulatory role of these ncRNAs would serve as a novel therapeutic strategy for treating bone-related disorders.

Nuclear receptor subfamily 5 group A member 1 (NR5A1) encodes steroidogenic factor 1 (SF1), a key regulatory factor that determines gonadal development and coordinates endocrine functions. Here, we have established a stem cell-based model of human gonadal development and applied it to evaluate the effects of NR5A1 during the transition from bipotential gonad to testicular cells. We combined directed differentiation of human induced pluripotent stem cells (46,XY) with activation of endogenous NR5A1 expression by conditionally-inducible CRISPR activation. The resulting male gonadal-like cells expressed several Sertoli cell transcripts, secreted anti-Müllerian hormone and responded to follicle-stimulating hormone by producing sex steroid intermediates. These characteristics were not induced without NR5A1 activation. A total of 2691 differentially expressed genetic elements, including both coding and non-coding RNAs, were detected immediately following activation of NR5A1 expression. Of those, we identified novel gonad-related putative NR5A1 targets, such as SCARA5, which we validated also by immunocytochemistry. In addition, NR5A1 activation was associated with dynamic expression of multiple gonad- and infertility-related differentially expressed genes. In conclusion, by combining targeted differentiation and endogenous activation of NR5A1 we have for the first time, been able to examine in detail the effects of NR5A1 in early human gonadal cells. The model and results obtained provide a useful resource for future investigations exploring the causative reasons for gonadal dysgenesis and infertility in humans.

SOX10 gene and SOX10 protein are responsible for the gliogenesis of neuroglia from the neural crest cells. Expression of SOX10 gene encodes SOX10 protein which binds with DNA at its minor groove via its HMG domain upon activation. SOX10 protein undergoes bending and changes its conformation after binding with DNA. Via its transactivation domain and HMG domain, it further activates several other transcription factors, these cause gliogenesis of the neural crest cells into neuroglia. In literature, it is stated that the SOX10 gene helps in the formation of schwann cells, oligodendrocytes, and enteric ganglia from neural crest cells. Altered expression of the SOX10 gene results in agliogenesis, dysmyelination, and demyelination in the nervous system as well as intestinal aganglionosis. This review highlighted that there is a role of the SOX10 gene and SOX10 protein in enteric gliogenesis from the neural crest cells.

Major histocompatibility complex class I (MHC-I) has been implicated in several types of neuroplasticity phenomena. Interferon beta-1b (IFN-β) increases MHC-I expression by motoneurons after sciatic nerve crush in mice, improving axonal growth and functional recovery. Additionally, IFN-β induces glial hypertrophy associated with upregulation of glial fibrillary acidic protein (GFAP) and MHC-I in murine astrocytes in vitro. As knowledge about MHC-I and its role in synaptic plasticity in human astrocytes (HAs) is scarce, we investigated these aspects in mature HAs obtained from the neocortex of patients undergoing surgery due to hippocampal sclerosis. Cells were exposed to media in the absence (0 IU/ml) or presence of IFN-β for 5 days (500 IU/ml). Beta-2 microglobulin (β2m), a component of the MHC-I, GFAP and vimentin proteins, was quantified by flow cytometry (FC) and increased by 100%, 60% and 46%, respectively, after IFN-β exposure. We also performed qRT–PCR gene expression analyses for β2m, GFAP, vimentin, and pro- and anti-inflammatory cytokines. Our data showed that IFN-β-treated astrocytes displayed β2m and GFAP gene upregulation. Additionally, they presented a proinflammatory profile with increase in the IL-6 and IL-1β genes and a tendency to upregulate TNF-α. Moreover, we evaluated the effect of HAs conditioned medium (CM) on the formation/maintenance of neurites/synapses by the PC12 lineage. Synaptophysin protein expression was quantified by FC. The CM of IFN-β-activated astrocytes was not harmful to PC12 neurites, and there was no change in synaptophysin protein expression. Therefore, IFN-β activated HAs by increasing GFAP, vimentin and MHC-I protein expression. Like MHC-I modulation and astrocyte activation may be protective after peripheral nerve damage and in some neurodegenerative conditions, this study opens perspectives on the pathophysiological roles of astroglial MHC-I in the human CNS.

The cervical and anterior thoracic regions of mammals generally exhibit similar vertebral numbers and identities along the anterior-posterior axis. The position of the forelimbs along the axial skeleton is also generally conserved. In contrast, the number of lumbar and sacral vertebrae and pelvic position exhibit more variation, correlating with posture and locomotion. The molecular mechanisms that lead to these conserved and variable axial skeletal patterns between species are not fully understood. Here we use a human HOXB1-9 transgene to complement a HoxB1-9 deficiency in the mouse. In TgHOXB1-9 mice, human HOXB1, B2, B3, and B4 (HOXB1-4) genes were expressed in mouse embryos in patterns similar to mouse Hoxb1-4 genes. Human transgene expression rescued the cervical and anterior thoracic vertebral patterning defects of HoxB1-9^Δ/Δ mice. In addition, the posterior shift in forelimb position of HoxB1-9^Δ/Δ mice was rescued by the transgene. Interestingly, the position of the lumbar-sacral transition in both TgHOXB1-9; HoxB1-9^Δ/Δ and TgHOXB1-9; HoxB1-9^+/+ mice was altered from six lumbar and four sacral vertebrae found in wild-type controls to five lumbar and five sacral vertebrae. The change in the position of the lumbar-sacral transition consequently altered the position of the pelvis. In contrast to the conserved expression of human HOXB1-4 genes in TgHOXB1-9 mouse embryos, the anterior border of human HOXB9 expression in the neural tube and paraxial mesoderm was shifted posteriorly by 2–3 somites compared to the anterior boundary of endogenous Hoxb9 expression. These findings suggest that conservation and variation in Hoxb/HOXB expression contributes to conserved and species-specific vertebral pattern and limb position.

Neural differentiation as a major process during neural cell therapy is one of the main issues that is not fully characterized. This study focuses on the major deconstruction of the transcriptional networks that regulate cell fate determination during neural differentiation under the influence of RA signalling. In our studies, we used four different microarray datasets containing a total of 15,660 genes to determine which genes were differentially expressed during neural differentiation from pluripotent stem cells (P19), among the 17 samples from four different datasets that were integrated via meta-analysis approaches. Of the 15,660 gene expression in our data integration, 443 DEGs are induced during neural differentiation. Upstream dissection of these 443 DEGs revealed a network of protein-protein interactions (PPIs) from TFs and kinases, as well as intermediate proteins between them, which are indicated by three (POU51, NANOG, and FOXO1) down-expression genes and one PAX6 up-expression gene playing roles in up-stream of these 443 induced DEGs during neural differentiation. The constructed network from the PPIs database revealed that four novel sub-networks play major roles in neuron differentiation in cluster 3, retinol metabolism in cluster 4, Rap1 signalling pathways in cluster 2, and axonogenesis in cluster 6. These four clusters have revealed very useful information about how neural characterization will be created from pluripotent stem cells.

This research reveals a plethora of information on the neural differentiation process, including cell commitment and neural differentiation, and lays the groundwork for future research into particular pathways involving protein-protein interactions in neurogenesis.