Persistent neurogenesis exists in the subventricular zone (SVZ) of the ventricles and the subgranular zone (SGZ) of the dentate gyrus of the hippocampus in the adult mammalian brain. Adult endogenous neurogenesis not only plays an important role in the normal brain function, but also has important significance in the repair and treatment of brain injury or brain diseases. This article reviews the process of adult endogenous neurogenesis and its application in the repair of traumatic brain injury (TBI) or ischemic stroke, and discusses the strategies of activating adult endogenous neurogenesis to repair brain injury and its practical significance in promoting functional recovery after brain injury.
Adult ; Animals ; Humans ; Brain/physiopathology* ; Hippocampus/physiopathology* ; Mammals/physiology* ; Neurogenesis/physiology* ; Brain Hemorrhage, Traumatic/therapy* ; Ischemic Stroke/therapy* ; Recovery of Function ; Spinal Cord/physiopathology*

Chronic stress impairs radial neural stem cell (rNSC) differentiation and adult hippocampal neurogenesis (AHN), whereas promoting AHN can increase stress resilience against depression. Therefore, investigating the mechanism of neural differentiation and AHN is of great importance for developing antidepressant drugs. The nonpsychoactive phytocannabinoid cannabidiol (CBD) has been shown to be effective against depression. However, whether CBD can modulate rNSC differentiation and hippocampal neurogenesis is unknown. Here, by using the chronic restraint stress (CRS) mouse model, we showed that hippocampal rNSCs mostly differentiated into astrocytes under stress conditions. Moreover, transcriptome analysis revealed that the FoxO signaling pathway was involved in the regulation of this process. The administration of CBD rescued depressive-like symptoms in CRS mice and prevented rNSCs overactivation and differentiation into astrocyte, which was partly mediated by the modulation of the FoxO signaling pathway. These results revealed a previously unknown neural mechanism for neural differentiation and AHN in depression and provided mechanistic insights into the antidepressive effects of CBD.
Animals ; Cannabidiol/pharmacology* ; Cell Differentiation ; Depression/prevention & control* ; Hippocampus/metabolism* ; Humans ; Mice ; Neural Stem Cells ; Neurogenesis/physiology*

Temporal lobe epilepsy (TLE) is a common and severe neurological disorder which is often intractable. It can not only damage the normal structure and function of hippocampus, but also affect the neurogenesis in dentate gyrus (DG). It is well documented from researches on the animal models of TLE that after a latent period of several days, prolonged seizure activity leads to a dramatic increase in mitotic activity in the hippocampal DG. However, cell proliferation returns to baseline levels within 3-4 weeks after status epilepticus (SE). Meanwhile, there are two major abnormalities of DG neurogenesis, including the formation of hilar basal dendrites and the ectopic migration of newborn granule cells into the polymorphic cell layer, which may affect epileptogenesis and seizure onset. However, the specific contribution of these abnormalities to seizures is still unknown. In other words, whether they are anti-epileptic or pro-epileptic is still under heated discussion. This article systematically reviews current knowledge on neurogenesis and epilepsy based on the results of studies in recent years and discusses the possible roles of neurogenesis in epileptogenesis and pathologic mechanisms, so as to provide information for the potential application of neurogenesis as a new clinical therapeutic target for temporal lobe epilepsy.
Animals ; Brain ; Cell Movement ; physiology ; Cell Proliferation ; physiology ; Dendrites ; pathology ; Dentate Gyrus ; growth & development ; pathology ; Epilepsy, Temporal Lobe ; etiology ; pathology ; physiopathology ; Hippocampus ; growth & development ; pathology ; Humans ; Mitosis ; physiology ; Neurogenesis ; physiology ; Neurons ; pathology ; Seizures ; etiology ; physiopathology ; Status Epilepticus ; physiopathology

Vascular endothelial growth factor (VEGF) was originally recognized as a substance predominantly with vascular permeability and angiogenesis. Recently, more and more evidence indicated that VEGF is expressed in the neurons of the developing and adult brains. Functional investigation demonstrated that VEGF shows several important effects on the neuronal development and physiological function. For example, VEGF accelerates the development of neurons and neural dendritic and axon growth. Besides, VEGF directly and acutely regulates the functions of multiple ion channels of the neuron membrane and changes neural excitability. In traumatic or ischemic injured brains, VEGF produces neuroprotection, enhances capacity of adult neurogenesis and transformation of astroglial cells into new neurons, which are fundamental basis for re-establishment of neural network. Based on the knowledge obtained from the literatures, we propose that VEGF may play very important roles in neural plasticity in the normal brain, and the reconstruction of neurovascular units and neural repair in the traumatic injured brain. This review mainly focuses on neural activity and repair roles of VEGF in adult mammalian brains. Further study on the mechanism of VEGF's neurobiological effects in the brain will be helpful for understanding the regulation of brain functions and developing new therapeutic strategy for prevention of neurodegeneration of the brain.
Animals ; Astrocytes ; cytology ; Brain Injuries ; physiopathology ; Humans ; Neurogenesis ; Neuronal Plasticity ; Neurons ; cytology ; Vascular Endothelial Growth Factor A ; physiology

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

BACKGROUNDThe functional improvement following bone marrow stromal cells (BMSCs) transplantation after stroke is directly related to the number of engrafted cells and neurogenesis in the injured brain. Here, we tried to evaluate whether 3-methyl-1-phenyl-2-pyrazolin-5-one (MCI-186), a free radical scavenger, might influence BMSCs migration to ischemic brain, which could promote neurogenesis and thereby enhance treatment effects after stroke.

METHODSRat transient middle cerebral artery occlusion (MCAO) model was established. Two separate MCAO groups were administered with either MCI-186 or phosphate-buffered saline (PBS) solution to evaluate the expression of stromal cell-derived factor-1 (SDF-1) in ischemic brain, and compared to that in sham group (n = 5/ group/time point[at 1, 3, and 7 days after operation]). The content of chemokine receptor-4 (CXCR4, a main receptor of SDF-1) at 7 days after operation was also observed on cultured BMSCs. Another four MCAO groups were intravenously administered with either PBS, MCI-186, BMSCs (2 × 106), or a combination of MCI-186 and BMSCs (n = 10/group). 5-bromo-2-deoxyuridine (BrdU) and Nestin double-immunofluorescence staining was performed to identify the engrafted BMSCs and neuronal differentiation. Adhesive-removal test and foot-fault evaluation were used to test the neurological outcome.

RESULTSMCI-186 upregulated the expression of SDF-1 in ischemic brain and CXCR4 content in BMSCs was enhanced after hypoxic stimulation. When MCAO rats were treated with either MCI-186, BMSCs, or a combination of MCI-186 and BMSCs, the neurologic function was obviously recovered as compared to PBS control group (P < 0.01 or 0.05, respectively). Combination therapy represented a further restoration, increased the number of BMSCs and Nestin+ cells in ischemic brain as compared with BMSCs monotherapy (P < 0.01). The number of engrafted-BMSCs was correlated with the density of neuronal cells in ischemic brain (r = 0.72 , P < 0.01) and the improvement of foot-fault (r = 0.70, P < 0.01).

CONCLUSIONMCI-186 might promote BMSCs migration to the ischemic brain, amplify the neurogenesis, and improve the effects of cell therapy.

Animals ; Antipyrine ; analogs & derivatives ; therapeutic use ; Bone Marrow Cells ; cytology ; physiology ; Brain Ischemia ; drug therapy ; metabolism ; therapy ; Chemokine CXCL12 ; metabolism ; Disease Models, Animal ; Infarction, Middle Cerebral Artery ; drug therapy ; metabolism ; therapy ; Male ; Mesenchymal Stromal Cells ; physiology ; Neurogenesis ; physiology ; Rats ; Rats, Sprague-Dawley ; Stroke ; drug therapy ; metabolism ; therapy

To explore whether hypoxic condition could promote the olfactory mucosa mesenchymal stem cells (OM-MSCs) to differentiate into neurons with the olfactory ensheathing cells (OECs) supernatant and the potential mechanisms.
 Methods: The OM-MSCs and OECs were isolated and cultured, and they were identified by flow cytometry and immunofluorescence. The OM-MSCs were divided into three groups: a 3%O2+ HIF-1α inhibitors (lificiguat: YC-1) + OECs supernatant group (Group A) , a 3%O2 + OECs supernatant group (Group B) and a 21%O2 + OECs supernatant group (Control group). The neurons, which were differentiated from OM-MSCs, were assessed by immunofluorescence test. The mRNA and protein expression of hypoxia-inducible factor-1α (HIF-1α), βIII-tubulin and glial fibrillary acidic portein (GFAP) were detected by quantitative polymerase chain reaction (Q-PCR) and Western blot. The potassium channels were analyzed by patch clamp.
 Results: The neurons differentiated from OM-MSCs expressed the most amount of βIII-tubulin, and the result of Q-PCR showed that HIF-1α expression in the Group B was significantly higher than that in the other groups (all P<0.05). Western blot result showed that the βIII-tubulin protein expression was significantly higher and GFAP protein expression was obviously decreased in the Group B (both P<0.05). The patch clamp test confirmed that the potassium channels in the neurons were activated.
 Conclusion: Hypoxic condition can significantly increase the neuronal differentiation of OM-MSCs by the OECs supernatant and decrease the production of neuroglia cells, which is associated with the activation of HIF-1 signal pathway.
Blotting, Western ; Cell Differentiation ; physiology ; Cells, Cultured ; Culture Media, Conditioned ; chemistry ; pharmacology ; Flow Cytometry ; Glial Fibrillary Acidic Protein ; metabolism ; Hypoxia ; physiopathology ; Hypoxia-Inducible Factor 1, alpha Subunit ; metabolism ; Indazoles ; pharmacology ; Mesenchymal Stem Cells ; physiology ; Neurogenesis ; physiology ; Neuroglia ; metabolism ; physiology ; Neurons ; physiology ; Olfactory Mucosa ; Potassium Channels ; Signal Transduction ; Tubulin ; metabolism

Inducible cyclooxygenase-2 (COX-2) has received much attention because of its role in neuro-inflammation and synaptic plasticity. Even though COX-2 levels are high in healthy animals, the function of this factor in adult neurogenesis has not been clearly demonstrated. Therefore, we performed the present study to compare the effects of pharmacological and genetic inhibition of COX-2 on adult hippocampal neurogenesis. Physiological saline or the same volume containing celecoxib was administered perorally every day for 5 weeks using a feeding needle. Compared to the control, pharmacological and genetic inhibition of COX-2 reduced the appearance of nestin-immunoreactive neural stem cells, Ki67-positive nuclei, and doublecortin-immunoreactive neuroblasts in the dentate gyrus. In addition, a decrease in phosphorylated cAMP response element binding protein (pCREB) at Ser133 was observed. Compared to pharmacological inhibition, genetic inhibition of COX-2 resulted in significant reduction of neural stem cells, cell proliferation, and neuroblast differentiation as well as pCREB levels. These results suggest that COX-2 is part of the molecular machinery that regulates neural stem cells, cell proliferation, and neuroblast differentiation during adult hippocampal neurogenesis via pCREB. Additionally, genetic inhibition of COX-2 strongly reduced neural stem cell populations, cell proliferation, and neuroblast differentiation in the dentate gyrus compared to pharmacological inhibition.
Animals ; Celecoxib/*pharmacology ; Cell Differentiation/drug effects/physiology ; Cell Proliferation/drug effects/physiology ; Cyclooxygenase 2/*genetics/metabolism ; Cyclooxygenase 2 Inhibitors/*pharmacology ; Dentate Gyrus/drug effects/*physiology ; Male ; Mice ; Mice, Knockout ; Neural Stem Cells/drug effects/physiology ; Neurogenesis/drug effects

Neurologic deficits resulting from stroke remain largely intractable, which has prompted thousands of studies aimed at developing methods for treating these neurologic sequelae. Endogenous neurogenesis is also known to occur after brain damage, including that due to cerebral infarction. Focusing on this process may provide a solution for treating neurologic deficits caused by cerebral infarction. The phosphatidylinositol-3-kinase (PI3K) pathway is known to play important roles in cell survival, and many studies have focused on use of the PI3K pathway to treat brain injury after stroke. Furthermore, since the PI3K pathway may also play key roles in the physiology of neural stem cells (NSCs), eliciting the appropriate activation of the PI3K pathway in NSCs may help to improve the sequelae of cerebral infarction. This review describes the PI3K pathway, its roles in the brain and NSCs after cerebral infarction, and the therapeutic possibility of activating the pathway to improve neurologic deficits after cerebral infarction.
Brain Injuries ; Brain* ; Cell Survival ; Cerebral Infarction* ; Neural Stem Cells* ; Neurogenesis ; Neurologic Manifestations ; Physiology ; Regeneration* ; Stroke

OBJECTIVETo identify novel lncRNAs involved in cerebellar neurogenesis using neuronal specific Nbs1-deficient (Nbs1(CNS-del)) mouse model.

METHODSMicroarray analysis was performed to identify differentially expressed lncRNAs between Nbs1(CNS-ctr) and Nbs1(CNS-del) mice. Expression profiles of lncRNA Gm15577 and coding gene Negr1 in mice, primary cerebellar culture and cell lines were measured using RT-qPCR. Subcellular fractionation was performed to determine the subcellular localization of Gm15577.

RESULTSGm15577 was specifically expressed in mice cerebellum in a developmentally regulated manner, which could be abolished upon Nbs1-deficiency. Gm15577 was located in the intronic region of Negr1 in a reversed orientation. Gm15577 modulated the RNA expression of Negr1, Shh and β-catenin. NEGR1 had a distinct expression pattern between normal and medulloblastoma patients.

CONCLUSIONGm15577 may modulate cerebellar granule cell proliferation and differentiation by targeting Negr1, and their dysfunctions or abnormal expression may be related to tumorigenesis of medulloblastoma.

Animals ; Cell Differentiation ; Cell Proliferation ; Cell Transformation, Neoplastic ; Cerebellar Neoplasms ; pathology ; Cerebellum ; cytology ; physiology ; Disease Models, Animal ; Humans ; Introns ; Medulloblastoma ; pathology ; Mice ; Mice, Knockout ; Neurogenesis ; Neurons ; physiology ; RNA, Long Noncoding ; metabolism