Exogenous GDNF increases the migration of the neural stem cells with no protection against kainic acid-induced excitotoxic cell death in rats

Icariin Promotes Survival, Proliferation, and Differentiation of Neural Stem Cells In Vitro and in a Rat Model of Alzheimer's Disease

Alzheimer's disease (AD) involves the degeneration of cholinergic neurons in the basal forebrain. Neural stem cell (NSC) transplantation has emerged as a promising therapeutic approach for treating AD. Icariin (ICA) is the main active component in Epimedium, a traditional Chinese herb. The purpose of the present study was to investigate the effects and mechanisms of ICA on the proliferation and differentiation of NSCs in the basal forebrain of a fimbria-fornix transection (FFT) rat model. In the present study, ICA promoted the survival, proliferation, and migration of NSCs in vitro. In FFT rats, ICA promoted the proliferation and differentiation of NSCs into neurons and increased the number of cholinergic neurons in the MS and VDB of the basal forebrain. These results suggest that combination therapy of ICA oral administration and NSC transplantation may provide a new potential and effective approach for AD therapy.

Astrocytic nutritional dysfunction associated with hypoxia-induced neuronal vulnerability in stroke-prone spontaneously hypertensive rats

Stroke-prone spontaneously hypertensive rats (SHRSP) is a valuable animal model to investigate human strokes. SHRSP Izumo strain (Izm) neurons are highly sensitive to blood supply changes. Furthermore, SHRSP/Izm astrocytes show various abnormalities upon hypoxic stimulation compared to control Wistar Kyoto (WKY/Izm) rats. This study aimed to describe stroke-related characteristics of SHRSP/Izm-derived neurons and astrocytes. In addition, we discuss the role of astrocytes in the development of stroke in SHRSP/Izm model. In SHRSP/Izm, neuronal death is induced upon reoxygenation after hypoxia. Furthermore, it was shown that SHRSP/Izm astrocytes show significantly reduced lactate production and supply ability to nerve cells when subjected to hypoxic stimulation. In particular, decreased lactate production and monocarboxylic acid transporter (MCT) expression in SHRSP/Izm astrocytes are factors that induce neuronal cell death. Remarkable differences in glial cell line-derived neurotrophic factor (GDNF) expression and L-serine production were also observed in SHRSP/Izm-derived astrocytes compared to WKY/Izm. Reduced production of both GDNF and L-serine contributes to diminished neuronal survival. The differences between SHRSP/Izm and WKY/Izm astrocyte cellular properties may contribute to compromised neuronal nutrition and induction of neuronal death. These properties are likely to be the factors that enhance stroke in SHRSP/Izm.

Surveillance, phagocytosis, and inflammation: how never-resting microglia influence adult hippocampal neurogenesis

Microglia cells are the major orchestrator of the brain inflammatory response. As such, they are traditionally studied in various contexts of trauma, injury, and disease, where they are well-known for regulating a wide range of physiological processes by their release of proinflammatory cytokines, reactive oxygen species, and trophic factors, among other crucial mediators. In the last few years, however, this classical view of microglia was challenged by a series of discoveries showing their active and positive contribution to normal brain functions. In light of these discoveries, surveillant microglia are now emerging as an important effector of cellular plasticity in the healthy brain, alongside astrocytes and other types of inflammatory cells. Here, we will review the roles of microglia in adult hippocampal neurogenesis and their regulation by inflammation during chronic stress, aging, and neurodegenerative diseases, with a particular emphasis on their underlying molecular mechanisms and their functional consequences for learning and memory.

Coexpression of recombinant adenovirus carrying GDNF and EDNRB genes in neural stem cells in vitro

Gene therapy and nerve stem cells isolated from the developing human enteric nervous system (ENS) are significant. They may open the route for the cell therapy of Hirschsprung's disease (HD). We have constructed the recombinant adenovirus-carrying glial cell line-derived neurotrophic factor (GDNF) and endothelin receptor B (EDNRB) gene, and investigated the exosomatic coexpression in neural stem cells. The recombinant adenovirus Ad-GE coexpressing GDNF and EDNRB gene was constructed by the AdEasy system and confirmed by the reverse transcription polymerase chain reaction (RT-PCR) method. Expression of exogenous genes in neural stem cells after transfection was confirmed by the flow cytometry and real-time fluorescence quantitative PCR. Fragments of pAd Track-CMV-GE were consistent with GDNF and EDNRB. The green fluorescence of the positive cells was followed by fluorescence microscopy at 24 h after NSCs had been transfected, reaching a peak at 72 h after transfection. Flow cytometry showed that the efficiency of transfection was 15.0, 23.6, and 25.4% at 24, 48 and 72 h respectively. Real-time fluorescence quantitative PCR showed the expression levels of mRNA of GDNF and EDNRB in 48 and 72 h groups were obviously higher than that in 24 and 96 h groups. Recombinant adenovirus carrying GDNF and EDNRB genes are coexpressed in neural stem cells, which may offer the possibility of a novel approach to local combination gene therapy for Hirschsprung's disease.