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

The development of a cerebral organoid culture in vitro offers an opportunity to generate human brain-like organs to investigate mechanisms of human disease that are specific to the neurogenesis of radial glial (RG) and outer radial glial (oRG) cells in the ventricular zone (VZ) and subventricular zone (SVZ) of the developing neocortex. Modeling neuronal progenitors and the organization that produces mature subcortical neuron subtypes during early stages of development is essential for studying human brain developmental diseases. Several previous efforts have shown to grow neural organoid in culture dishes successfully, however we demonstrate a new paradigm that recapitulates neocortical development process with VZ, OSVZ formation and the lamination organization of cortical layer structure. In addition, using patient-specific induced pluripotent stem cells (iPSCs) with dysfunction of the Aspm gene from a primary microcephaly patient, we demonstrate neurogenesis defects result in defective neuronal activity in patient organoids, suggesting a new strategy to study human developmental diseases in central nerve system.
Action Potentials ; physiology ; Biomarkers ; metabolism ; Cell Culture Techniques ; Embryoid Bodies ; cytology ; metabolism ; Gene Expression ; Humans ; Induced Pluripotent Stem Cells ; cytology ; metabolism ; Lateral Ventricles ; cytology ; growth & development ; metabolism ; Microcephaly ; genetics ; metabolism ; pathology ; Models, Biological ; Mutation ; Neocortex ; cytology ; growth & development ; metabolism ; Nerve Tissue Proteins ; deficiency ; genetics ; Neurogenesis ; genetics ; Neurons ; cytology ; metabolism ; Organoids ; cytology ; metabolism ; PAX6 Transcription Factor ; genetics ; metabolism ; Patch-Clamp Techniques ; SOXB1 Transcription Factors ; genetics ; metabolism ; Zonula Occludens-1 Protein ; genetics ; metabolism

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

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

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

BACKGROUNDSince an effective method for generating induced pluripotent stem cells (iPSCs) from human neural stem cells (hNSCs) can offer us a promising tool for studying brain diseases, here we reported direct reprogramming of adult hNSCs into iPSCs by retroviral transduction of four defined factors.

METHODSNSCs were successfully isolated and cultured from the hippocampus tissue of epilepsy patients. When combined with four factors (OCT3/4, SOX2, KLF4, and c-MYC), iPSCs colonies were successfully obtained.

RESULTSMorphological characterization and specific genetic expression confirmed that these hNSCs-derived iPSCs showed embryonic stem cells-like properties, which include the ability to differentiate into all three germ layers both in vitro and in vivo.

CONCLUSIONOur method would be useful for generating human iPSCs from NSCs and provide an important tool for studying neurological diseases.

Cell Differentiation ; genetics ; physiology ; Cells, Cultured ; Cellular Reprogramming ; genetics ; physiology ; Humans ; Immunohistochemistry ; Induced Pluripotent Stem Cells ; cytology ; metabolism ; Kruppel-Like Transcription Factors ; metabolism ; Neural Stem Cells ; cytology ; metabolism ; Octamer Transcription Factor-3 ; metabolism ; Proto-Oncogene Proteins c-myc ; metabolism ; Reverse Transcriptase Polymerase Chain Reaction ; SOXB1 Transcription Factors ; metabolism

Animals ; Bone Regeneration ; physiology ; Cell Differentiation ; Dental Enamel Proteins ; pharmacology ; Dental Pulp ; cytology ; Fibroblasts ; cytology ; Gingiva ; cytology ; Guided Tissue Regeneration, Periodontal ; methods ; Humans ; Induced Pluripotent Stem Cells ; cytology ; physiology ; Mouth Mucosa ; cytology ; Periodontal Ligament ; cytology ; Tissue Engineering ; methods

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

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

Pluripotent stem cells are able to self-renew indefinitely and differentiate into all types of cells in the body. They can thus be an inexhaustible source for future cell transplantation therapy to treat degenerative diseases which currently have no cure. However, non-autologous cells will cause immune rejection. Induced pluripotent stem cell (iPSC) technology can convert somatic cells to the pluripotent state, and therefore offers a solution to this problem. Since the first generation of iPSCs, there has been an explosion of relevant research, from which we have learned much about the genetic networks and epigenetic landscape of pluripotency, as well as how to manipulate genes, epigenetics, and microRNAs to obtain iPSCs. In this review, we focus on the mechanism of cellular reprogramming and current methods to induce pluripotency. We also highlight new problems emerging from iPSCs. Better understanding of the fundamental mechanisms underlying pluripotenty and refining the methodology of iPSC generation will have a significant impact on future development of regenerative medicine.
Animals ; Cell Culture Techniques ; Cell Differentiation ; Epistasis, Genetic ; Genetic Engineering ; Humans ; Induced Pluripotent Stem Cells ; cytology ; physiology ; RNA Interference ; Recombinant Proteins ; genetics ; metabolism ; Regenerative Medicine