The self-renewal and multipotent potentials in neural stem cells (NSCs) maintain the normal physiological functions of central nervous system (CNS). The abnormal differentiation of NSCs would lead to CNS disorders. However, the mechanisms of how NSCs differentiate into astrocytes, oligodendrocytes (OLs) and neurons are still unclear, which is mainly due to the complexity of differentiation processes and the limitation of the cell separation method. In this study, we modeled the dynamics of neural cell interactions in a systemic approach by mining the high-throughput genomic and proteomic data, and identified 8615 genes that are involved in various biological processes and functions with significant changes during the differentiation processes. A total of 1559 genes are specifically expressed in neural cells, in which 242 genes are NSC specific, 215 are astrocyte specific, 551 are OL specific, and 563 are neuron specific. In addition, we proposed 57 transcriptional regulators specifically expressed in NSCs may play essential roles in the development courses. These findings provide more comprehensive analysis for better understanding the endogenous mechanisms of NSC fate determination.
Animals ; Astrocytes ; cytology ; metabolism ; Cell Differentiation ; genetics ; Gene Expression Profiling ; Gene Regulatory Networks ; Mice ; Neural Stem Cells ; cytology ; metabolism ; Oligodendroglia ; cytology ; metabolism ; Protein Interaction Mapping

The differentiation and maturation of oligodendrocyte precursor cells (OPCs) is essential for myelination and remyelination in the CNS. The failure of OPCs to achieve terminal differentiation in demyelinating lesions often results in unsuccessful remyelination in a variety of human demyelinating diseases. However, the molecular mechanisms controlling OPC differentiation under pathological conditions remain largely unknown. Myt1L (myelin transcription factor 1-like), mainly expressed in neurons, has been associated with intellectual disability, schizophrenia, and depression. In the present study, we found that Myt1L was expressed in oligodendrocyte lineage cells during myelination and remyelination. The expression level of Myt1L in neuron/glia antigen 2-positive (NG2) OPCs was significantly higher than that in mature CC1 oligodendrocytes. In primary cultured OPCs, overexpression of Myt1L promoted, while knockdown inhibited OPC differentiation. Moreover, Myt1L was potently involved in promoting remyelination after lysolecithin-induced demyelination in vivo. ChIP assays showed that Myt1L bound to the promoter of Olig1 and transcriptionally regulated Olig1 expression. Taken together, our findings demonstrate that Myt1L is an essential regulator of OPC differentiation, thereby supporting Myt1L as a potential therapeutic target for demyelinating diseases.
Animals ; Cell Differentiation ; physiology ; Demyelinating Diseases ; chemically induced ; Lysophosphatidylcholines ; toxicity ; Mice ; Mice, Inbred C57BL ; Nerve Tissue Proteins ; metabolism ; Oligodendrocyte Precursor Cells ; cytology ; metabolism ; Oligodendroglia ; cytology ; metabolism ; Remyelination ; physiology ; Transcription Factors ; metabolism

OBJECTIVETo study the effects of umbilical cord blood monocytes (UCBMC) transplantation on erythropoietin (EPO) protein and oligodendrocyte progenitor cells in hypoxia-ischemia (HI) neonatal rats.

METHODSForty seven-day-old Sprague-Dawley rats were randomly divided into normal control (N), HI, UCBMC and HI+UCBMC groups (n=10 each). Hypoxic-ischemic brain damage (HIBD) model was prepared according to the Rice method. Twenty-four hours after hypoxia, the N and HI groups were injected with 2 μL phosphate buffered saline (PBS), and the UCBMC and HI+UCBMC groups were injected with 3×10(6) UCBMC via the lateral ventricle. EPO protein and oligodendrocyte progenitor cells in the subventricular zone of the injured brain were observed by EPO/DAPI and NG2/DAPI immunofluorescence double staining, and their correlation was analyzed.

RESULTSSeven days after transplantation, there were more NG2(+)DAPI(+) and EPO(+)DAPI(+) cells in the HI+UCBMC group than in the UCBMC (P<0.05), N and HI groups (P<0.01). More NG2(+)DAPI(+) and EPO(+)DAPI(+) cells were observed in the UCBMC group compared with the N and HI groups (P<0.01). There were more NG2(+)DAPI(+) cells in the N group than in the HI group (P<0.01). The number of NG2(+)DAPI(+) cells was correlated with the number of EPO(+)DAPI(+) cells in the HI+UCBMC group (r=0.898, β=1.4604, P<0.01).

CONCLUSIONSUCBMC can promote expression of oligodendrocyte progenitor cells, which is correlated with an increase in EPO protein and thus repairs brain white matter damage in neonatal rats with HIBD.

Animals ; Animals, Newborn ; Erythropoietin ; analysis ; biosynthesis ; Fetal Blood ; cytology ; Hypoxia-Ischemia, Brain ; metabolism ; pathology ; therapy ; Monocytes ; transplantation ; Oligodendroglia ; pathology ; Rats ; Rats, Sprague-Dawley ; Stem Cells ; pathology

OBJECTIVETo explore the differentiation fates of rat neural stem cells (NSCs) in different environmental conditions.

METHODSNSCs derived from 16-day-old rat embryo were proliferated in vitro and implanted into the brain of rats with intra-cerebral hemorrhage. At the same time some NSCs were co-cultured in vitro with Schwann cells derived from newborn rats. MAP-2, GFAP and GalC (which are the specific markers of neural cells, astrocytes and oligodendrocytes respectively), BrdU and beta-tubulin were detected by immunohistochemical and immunofluorescent methods.

RESULTSBrdU positive cells that were implanted into the brain distributed around the hemorrhagic area. The majority of them were GFAP positive astrocytes while a few of them were beta-tubulin positive neural cells or GalC positive oligodendrocytes. After being co-cultured with Schwann cells in vitro, NSCs are predominately shown beta-tubulin and MAP-2 positive, and only a minority of them were GFAP or GalC positive.

CONCLUSIONSThe hemorrhagic environment in vivo induces NSCs to differentiate mainly into astrocytes while co-culture with Schwann cells in vitro induce the majority of NSCs to differentiate into neural cells.

Animals ; Astrocytes ; cytology ; metabolism ; Caudate Nucleus ; metabolism ; pathology ; Cell Differentiation ; physiology ; Cell Movement ; physiology ; Cells, Cultured ; Cerebral Hemorrhage ; pathology ; surgery ; Coculture Techniques ; Fluorescent Antibody Technique ; Galactosylceramides ; metabolism ; Glial Fibrillary Acidic Protein ; metabolism ; Microscopy, Phase-Contrast ; Microtubule-Associated Proteins ; metabolism ; Oligodendroglia ; cytology ; metabolism ; Rats ; Rats, Sprague-Dawley ; Schwann Cells ; cytology ; Sciatic Nerve ; cytology ; Stem Cell Transplantation ; Stem Cells ; cytology

Endothelin (ET)-1 and its receptors (ETA and ETB receptor) are present in the central nervous system. ET exerts biological effects on gliogenesis and glial cell functions. In order to define a possible mechanism of ETA receptor signaling, the distribution of the ETA receptor in developing oligodendrocytes and the effects of ET-1 on the myelination of oligodendrocytes were examined. ETA receptor immunoreactivity was confined to the perivascular elements of the blood vessels during early postnatal development. However later in development, ETA receptor immunoreactivity was no longer observed in the vessels but became localized to the myelinating oligodendrocytes of the primitive corpus callosum of the white matter, apart from the vessels. ET-1 induced myelin basic protein (MBP) in primary oligodendrocyte precursor cell culture though the ETA receptor and was blocked by an ETA receptor antagonist. In addition, ET-1 evoked the release of Ca2+ which is a central regulator of oligodendrocyte differentiation. Our results provide a link between ET-1 and its ETA receptor and myelination during oligodendrocyte differentiation.
Animals ; Brain/pathology ; Calcium/metabolism ; Calcium Signaling ; Cells, Cultured ; Endothelin-1/metabolism/physiology ; Mice ; Mice, Inbred ICR ; Myelin Basic Proteins/genetics/metabolism ; Myelin Sheath/*physiology ; Oligodendroglia/cytology/*metabolism ; Rats ; Rats, Sprague-Dawley ; Receptor, Endothelin A/metabolism/*physiology

OBJECTIVETo study growth characteristics of neural stem cells (NSCs) from subventricular zone (SVZ) of the different human fetal brain at different gestational age and to provide experimental and theoretical evidences for clinical application of NSCs for treatment of certain diseases.

METHODSNinety human embryos at gestational age 16 - 36 weeks were collected and were divided into six groups according to gestational age: 16 w, 20 w, 24 w, 28 w, 32 w and 36 w. Each group had 15 embryos and brain tissues were taken from each embryo's SVZ. All subjects had congenital heart disease or digestive tract abnormity diagnosed with B ultrasound at antepartum, but none had abnormal development of brain. Pregnant mother and her husband desire termination of pregnancy. The morphology, existing mode and the number of neural stem cells in subventricular zone were examined with immunohistochemical method. The NSCs in subventricular zone were cultured, passaged and differentiated with cell culture technique, then were identified with immunohistochemical method.

RESULTSNSCs in SVZ from the different human fetal brain existed in a scattered manner in the network formed by stellate cells, NSCs had round, ellipse and fusiform shape, especially in stellate shape. NSCs had larger and smaller size and distributed in dense or scattered forms, each having zero to two enations, most had one or two. NSCs had less cytoplasm. The nucli of the NSCs had a round shape with loose chromatin and 1 - 4 nucleoli. Most of NSCs existed in singular scattered form, some of them showed symmetrical or asymmetrical division, some of them showed synaptic connection with other NSCs. The number of NSCs in SVZ from groups with different fetal age decreased with increasing gestational age (chi(2) = 4644.602, P < 0.01). NSCs in SVZ from the different human fetal brain cultured with serum-free medium formed typical neurospheres in suspension. The cells could be passaged continuously, and could express nestin antigen. Serum-contained medium induced neural stem cells to differentiate and express specific antigens of neuron, astrocyte and oligodendrocyte.

CONCLUSIONSNSCs existed in SVZ of human embryos at different gestational age. There are differences in morphology, existing pattern and the number of NSCs in SVZ at different gestational age. NSCs in SVZ at different gestational age may be cultured in vitro.

Age Factors ; Astrocytes ; Cell Differentiation ; Cell Proliferation ; Cells, Cultured ; Cerebral Ventricles ; cytology ; Female ; Fetal Stem Cells ; Fetus ; cytology ; Gestational Age ; Humans ; Immunohistochemistry ; Intermediate Filament Proteins ; metabolism ; Male ; Nerve Tissue Proteins ; metabolism ; Nestin ; Neurons ; Oligodendroglia ; Pregnancy

AMP-Activated Protein Kinases ; Animals ; Antioxidants ; pharmacology ; Apoptosis ; drug effects ; Humans ; Infant, Newborn ; Infection ; pathology ; Ischemia ; pathology ; Leukomalacia, Periventricular ; etiology ; Multienzyme Complexes ; physiology ; Nitric Oxide Synthase Type II ; antagonists & inhibitors ; Oligodendroglia ; cytology ; Protein-Serine-Threonine Kinases ; physiology ; Reactive Oxygen Species ; metabolism ; Stem Cells ; cytology