Cellular reprogramming最新文献

Dental pulp stem cells (DPSCs) and stem cells from human exfoliated deciduous teeth (SHED) are a source of mesenchymal stem cells with the potential to differentiate into several cell types. We initially isolated SHED cells and compared their osteogenic capacity with commercially available DPSCs. Both cells exhibited similar capacities of growth and osteogenic differentiation. A fourfold to sixfold increase in endogenous microRNA26a (miR26a) expression during osteogenic differentiation of preosteoblasts and a similar but attenuated increase (twofold to fourfold) in differentiating SHED was observed, suggesting a role in the process. We, therefore, overexpressed miR26a in SHED to determine if the osteogenic differentiation capacity can be potentiated in vitro. SHED with a threefold increase in miR26a expression showed increased growth rate when compared with parent cells. When exposed to an osteogenic differentiating promoting medium, the miR26a overexpressing cells showed 100-fold increases in the expression of bone marker genes such as type 1 collagen, alkaline phosphatase, and Runx2. The mineralization capacity of these cells was also increased 15-fold. As miR26a targets regulate several bone-specific genes, we evaluated the effect of miR26a overexpression on established targets. We found a moderate decrease in SMAD1 and a profound decrease in PTEN expression. miR26a could potentiate its effect on osteoblast differentiation by its ability to inhibit PTEN and increase the viability of cells and their numbers, a process essential in osteoblast differentiation. Our studies suggest that the upregulation of miR26a can increase bone formation and may serve as an important target to further investigate its potential in tissue engineering applications.

This study investigated the antioxidant effects of β-cryptoxanthin (BCX), hesperetin (HES), and icariin (ICA), and their effects on in vitro maturation of porcine oocytes and subsequent embryonic development of somatic cell nuclear transfer (SCNT). Treatment with 1 μM BCX (BCX-1) increased the developmental rate of porcine oocytes more than treatment with 100 μM HES (HES-100) or 5 μM ICA (ICA-5). The glutathione level and mRNA expression of antioxidant genes (NFE2L2, SOD1, and SOD2) were more increased in the BCX-1 group than in the HES-100 and ICA-5 groups, while the reactive oxygen species level was more decreased. Moreover, BCX improved the developmental capacity and quality of SCNT embryos. The total cell number, apoptotic cell rate, and development-related gene expression were modulated in the BCX-1 group to enhance embryonic development of SCNT. These results show that the antioxidant effects of BCX enhance in vitro maturation of porcine oocytes and subsequent embryonic development of SCNT.

Exosomes are one kind of small-cell extracellular membranous vesicles that can regulate intercellular communication and give rise to mediating the biological behaviors of cells, involving in tissue formation, repair, the modulation of inflammation, and nerve regeneration. The abundant kinds of cells can secret exosomes, among them, mesenchymal stem cells (MSCs) are very perfect cells for mass production of exosomes. Dental tissue-derived mesenchymal stem cells (DT-MSCs), including dental pulp stem cells, stem cells from exfoliated deciduous teeth, stem cells from apical papilla, stem cells from human periodontal ligament (PDLSCs), gingiva-derived mesenchymal stem cells, dental follicle stem cells, tooth germ stem cells, and alveolar bone-derived mesenchymal stem cells, are now known as a potent tool in the area of cell regeneration and therapy, more importantly, DT-MSCs can also release numerous types of exosomes, participating in the biological functions of cells. Hence, we briefly depict the characteristics of exosomes, give a detailed description of the biological functions and clinical application in some respects of exosomes from DT-MSCs through systematically reviewing the latest evidence, and provide a rationale for their use as tools for potential application in tissue engineering.

Spermatogonial stem cells (SSCs) are a small group of testicular cells located in the basement membrane of seminiferous tubules and can balance self-renewal and differentiation during spermatogenesis. Our in vitro culture experiments of mouse SSCs indicated heterogeneity of cultured cells. Highly compact colonies were observed next to SSC colonies, which we call clump cells. We used immunocytochemical staining to identify SSCs and somatic cells with VASA and Vimentin antibodies. Subsequently, we compared mRNA expression levels of VASA, DAZL, PLZF, GFRA1, Lin28, Kit, Myc and Vimentin genes using Fluidigm real-time RT-polymerase chain reaction in clump cells, SSCs, and testicular stromal cells. To better understand the functions of selected genes, we created a protein-protein interaction network and performed an enrichment analysis using different databases. Based on the data collected, we state that clump cells do not express the molecular markers of SSCs, so we cannot consider them as SSCs; however, we claim that these cells are altered SSCs. The molecular mechanism of this conversion is still obscure. Therefore, this study can support the analysis of germ cell development both in vitro and in vivo. In addition, it can be effective in finding new and more efficient treatments for male infertility.

Short-term expression of Yamanaka factors early in life promotes epigenetic reprogramming and an increased healthy lifespan in a mouse model of accelerated aging.

Mesenchymal stem/stromal cells (MSCs) are found in almost all postnatal organs. Under appropriate environmental cues, multipotency enables MSCs to serve as progenitors for several lineage-specific, differentiated cell types. In vitro expansion and differentiation of MSCs give the opportunity to obtain hardly available somatic cells, such as neurons. The neurogenic potential of MSCs makes them a promising, autologous source to restore damaged tissue and as such, they have received much attention in the field of regenerative medicine. Several stem cell pool candidates have been studied thus far, but only a few of them showed neurogenic differentiation potential. Due to their embryonic ontology, stem cells residing in the stroma of the dental pulp chamber are an exciting source for in vitro neural cell differentiation. In this study, we review the key properties of dental pulp stem cells (DPSCs), with a particular focus on their neurogenic potential. Moreover, we summarize the various presently available methods used for neural differentiation of human DPSCs also emphasizing the difficulties in reproducibly high production of such cells. We postulate that because DPSCs are stem cells with very close ontology to neurogenic lineages, they may serve as excellent targets for neuronal differentiation in vitro and even for direct reprogramming.