At present, it is generally believed that the paracrine effect of stem cells in the repair of myocardial injury is one of the important ways for stem cell therapy. Exosomes are phospholipid bilayer-enclosed nanovesicles that secreted by cells under physiological and pathological conditions. Cargo loaded into exosomes including protein, lipids and nucleic acids can be delivered to recipient cells. Therefore, exosomes are recognized as important mediators for intercellular communication. It has been suggested that exosomes from stem cells (eg. embryonic stem cells, induced pluripotent stem cells, cardiac progenitor cells, mesenchymal stem cells and cardiosphere-derived cells) have protective effects against heart injury. In this review, we summarized recent research progresses on stem cell-derived exosomes in myocardial injury, including the therapeutic effects and mechanism.
Cell Communication ; Exosomes ; physiology ; Heart Injuries ; Humans ; Induced Pluripotent Stem Cells ; cytology ; Mesenchymal Stem Cells ; cytology

Male germ stem cells (mGSCs), which is in testis after sex differentiation, derive from primordial germ cells. In this study, bovine mGSCs were isolated from testis of 20 weeks fetuses. Number of CD9 positive cells of the cells through two-steps adhering plates velocity different was 95.8% by flow cytometer. The carina-type cells clones and the plane-type cells clones appeared in co-cultured system. One cells lines had been successively maintained for 4 passages, and the cells clusters showed AKP positive staining. The cells clusters showed nest-shape in third passage showed SSEA1 and Oct-4 positive staining. These cells can also spontaneously differentiate into c-kit positive staining germ cells, and the cells were directional induced to formaactin positive staining cardiac-like cells cluster and NF positive staining neuron-like cells. The conclusion showed that male germ stem cells from 20 weeks bovine fetuses could be in vitro formed like embryonic stem cells.
Animals ; Cattle ; Cell Differentiation ; physiology ; Cells, Cultured ; Embryonic Stem Cells ; cytology ; Fetus ; cytology ; Male ; Pluripotent Stem Cells ; cytology ; Spermatozoa ; cytology

Recent studies have confirmed that diverse adult tissue cells can be reprogrammed and induced to pluripotency, that is so-called induced pluripotent stem cells (iPS cells). But most of these dedifferentiated processes are induced by gene delivery with retroviral vectors. Some of the delivered genes are cancer causing. So, in current situation, these adult-derived embryonic stem-like cells cannot be used in clinical therapy to cure human diseases. Recently some articles that were published in the authoritative journals are receiving attentions. They show that, in mice and human, spermatogonial stem cells (SSCs) can be used for generating pluripotent stem cells without the exogenous genes and retroviruses, and they can also be used for autologous transplantation without ethical problems. These findings suggest that human SSCs may have considerable potential for cell-based, autologous organ regeneration therapy for various diseases. In this review, we describe and compare the methods that have been used to isolate, purificate and culture SSCs. We also describe the recent results in which SSCs can be transformed into pluripotent stem cells, and the pluripotent stem cells have potential applications in regenerative medicine and genetic medicine.
Cell Culture Techniques ; methods ; Cell Dedifferentiation ; physiology ; Cells, Cultured ; Humans ; Male ; Pluripotent Stem Cells ; cytology ; Spermatogonia ; cytology ; Stem Cells ; cytology

The parthenogenetic embryonic stem cells (pESCs) derived from parthenogenetic embryos have the totipotency and proliferation capacity similar to those of the fertilized embryonic stem cells (fESCs). Therefore, the establishment of pESCs line avoids destroy of embryo and kence may make pESCs less concerns with political and ethical issues. These cells are characterized by their histocompatibility with the oocyte donor and therefore is more suitable for cell and tissue replacement therapy. In addition, because of the typical imprinting status, pESCs also provide a valuable in vitro model system for studying the molecular mechanisms in genomic imprinting.
Animals ; Embryonic Stem Cells ; cytology ; Female ; Gene Expression Profiling ; methods ; Gene Expression Regulation, Developmental ; genetics ; physiology ; Genomic Imprinting ; Histocompatibility ; Parthenogenesis ; genetics ; physiology ; Pluripotent Stem Cells ; cytology

The phosphatidylinositol 3-kinase (PI3K) and its downstream target protein kinase B (Akt/PKB) can be activated by a variety of extracellular and intracellular signals. They are important signaling molecules and key survival factors involved in cell proliferation, differentiation, apoptosis and other cellular processes. Recently, many reports demonstrate that type I PI3K/Akt signaling pathway plays an important role in maintenance of self-renewal and pluripotency of embryonic stem (ES) cells. Further studies with regard to the self-renewal and pluripotency of ES cells and underlying molecular mechanisms are crucial to its application in cell replacement therapy, regenerative medicine and tissue engineering. The present review focuses on the recent progress on the mediation of PI3K/Akt signaling pathway on the maintenance of self-renewal and pluripotency of ES cells.
Cell Differentiation ; Cell Proliferation ; Embryonic Stem Cells ; cytology ; Humans ; Phosphatidylinositol 3-Kinases ; physiology ; Pluripotent Stem Cells ; cytology ; Proto-Oncogene Proteins c-akt ; physiology ; Signal Transduction

The present study was conducted to develop an effective method for establishment of porcine parthenogenetic embryonic stem cells (ppESCs) from parthenogenetically activated oocyte-derived blastocysts. The addition of 10% fetal bovine serum (FBS) to the medium on the 3rd day of oocyte culturing improved the development of blastocysts, attachment of inner cell masses (ICMs) onto feeder cells, and formation of primitive ppESC colonies. ICM attachment was further enhanced by basic fibroblast growth factor, stem cell factor, and leukemia inhibitory factor. From these attached ICMs, seven ppESC lines were established. ppESC pluripotency was verified by strong enzymatic alkaline phosphatase activity and the expression of pluripotent markers OCT3/4, Nanog, and SSEA4. Moreover, the ppESCs were induced to form an embryoid body and teratoma. Differentiation into three germ layers (ectoderm, mesoderm, and endoderm) was confirmed by the expression of specific markers for the layers and histological analysis. In conclusion, data from the present study suggested that our modified culture conditions using FBS and cytokines are highly useful for improving the generation of pluripotent ppESCs.
Animals ; Blastocyst/*cytology ; Cell Culture Techniques/*veterinary ; *Cell Differentiation ; Cytokines/metabolism ; Embryonic Stem Cells/*cytology ; Parthenogenesis ; Pluripotent Stem Cells/*cytology ; Swine/*physiology

Embryonic stem (ES) cells have the unique capacity to proliferate extensively and maintain the potential to differentiate into advanced derivatives of all three primary germ layers. ES cell lines can also be generated from human blastocyst embryos and are considered promising donor sources for cell transplantation therapies for diseases such as juvenile diabetes, Parkinson's disease, and heart failure. However, as for organ transplants, tissue rejection remains a significant concern for ES cell transplantation. Another concern is the use of human embryos. One possible means to avoid these issues is by reprogramming the nuclei of differentiated cells to ES cell-like, pluripotent cells. This review discusses the potential of these strategies to generate tailor-made pluripotent stem cells and the role of transcription factors in the reprogramming process.
Cell Culture Techniques ; Cell Differentiation ; physiology ; Cells, Cultured ; Cellular Reprogramming ; Humans ; Nuclear Transfer Techniques ; Pluripotent Stem Cells ; cytology

Human embryonic stem (hES) cells are considered to be a valuable resource for research in regenerative medicine, drug screening, and developmental studies. However, hES cells are usually established and maintained on mouse embryonic fibroblast feeder layers, and the risk of animal origin contamination from feeder layer generally excludes the clinical use of these hES cells. The main emphasis over the last several years has been in finding defined serum-and feeder layer-free system for derivation and culture of hES cells to enable the clinical use of hES cell for cell transplantation.
Cell Culture Techniques ; Cell Differentiation ; physiology ; Cell Division ; physiology ; Cell Line ; Coculture Techniques ; Culture Media, Serum-Free ; Embryo Culture Techniques ; Embryo, Mammalian ; cytology ; Embryonic Stem Cells ; physiology ; Humans ; Pluripotent Stem Cells ; cytology ; Stem Cells ; physiology ; Transcription Factors ; physiology ; Transplants

The mammalian brain is heterogeneous, containing billions of neurons and trillions of synapses forming various neural circuitries, through which sense, movement, thought, and emotion arise. The cellular heterogeneity of the brain has made it difficult to study the molecular logic of neural circuitry wiring, pruning, activation, and plasticity, until recently, transcriptome analyses with single cell resolution makes decoding of gene regulatory networks underlying aforementioned circuitry properties possible. Here we report success in performing both electrophysiological and whole-genome transcriptome analyses on single human neurons in culture. Using Weighted Gene Coexpression Network Analyses (WGCNA), we identified gene clusters highly correlated with neuronal maturation judged by electrophysiological characteristics. A tight link between neuronal maturation and genes involved in ubiquitination and mitochondrial function was revealed. Moreover, we identified a list of candidate genes, which could potentially serve as biomarkers for neuronal maturation. Coupled electrophysiological recording and single cell transcriptome analysis will serve as powerful tools in the future to unveil molecular logics for neural circuitry functions.
Antigens, Differentiation ; biosynthesis ; Electrophysiological Phenomena ; physiology ; Gene Expression Regulation ; physiology ; Genome-Wide Association Study ; Human Embryonic Stem Cells ; cytology ; metabolism ; Humans ; Induced Pluripotent Stem Cells ; cytology ; metabolism ; Multigene Family ; physiology ; Neurons ; cytology ; metabolism ; Transcriptome ; physiology

We previously reported the successful establishment of embryonic stem cell (ESC)-like multipotent spermatogonial stem cells (mSSCs) from neonatal mouse testis. Here, we examined the ability of mSSCs to differentiate into vascular endothelial cells and smooth muscle cells, and compared to that of mouse ESCs. We used real-time reverse transcriptase polymerase chain reaction and immunohistochemistry to examine gene expression profiles of mSSCs and ESCs during in vitro vascular differentiation. Both mSSCs and ESCs exhibited substantial increase in the expression of mesodermal markers, such as Brachyury, Flk1, Mesp1, Nkx2.5, and Islet1, and a decrease in the expression of pluripotency markers, such as Oct3/4 and Nanog during the early stage of differentiation. The mRNA levels of vascular endothelial (VE)-cadherin and CD31 gradually increased in both differentiated mSSCs and ESCs. VE-cadherin- or CD31-positive cells formed sprouting branch-like structures, as observed during embryonic vascular development. At the same time, vascular smooth muscle cell-specific markers, such as myocardin and alpha-smooth muscle actin (SMA), were also highly expressed in differentiated mSSCs and ESCs. Immunocytochemical analysis revealed that the differentiated cells expressed both alpha-SMA and SM22-alpha proteins, and exhibited the intracellular fibril structure typical of smooth muscle cells. Overall, our findings showed that mSSCs have similar vascular differentiation abilities to those of ESCs, suggesting that mSSCs may be an alternative source of autologous pluripotent stem cells for vascular regeneration.
Animals ; Animals, Newborn ; Biological Markers/metabolism ; Cell Differentiation/physiology ; Embryonic Stem Cells/cytology/physiology ; Endothelial Cells/*cytology/physiology ; Gene Expression ; Gene Expression Profiling ; Humans ; Immunohistochemistry ; Male ; Mice ; Muscle, Smooth, Vascular/*cytology/physiology ; Myocytes, Smooth Muscle/*cytology/physiology ; Pluripotent Stem Cells/*cytology/physiology ; Real-Time Polymerase Chain Reaction ; Spermatogonia/*cytology/physiology ; Testis/*cytology/physiology