[Show abstract][Hide abstract] ABSTRACT: Objective:
Efforts have been made by tissue engineers to create a permissive environment for neural regeneration, and to enhance the efficiency of neural stem cell (NSC) transplantation. However, to acquire sufficient number of seed cells on the material appears to be the main obstacle to constructing functional transplantable NSC-biomaterial complexes. A culture system has been optimized in the current study to maintain the specific characteristics of NSCs/neural progenitor cells (NPCs) on the material and achieve sustaining increased multipotent seed cells.
The PHBHHx film was selected as biomaterial and the surface was firstly modified with NaOH treatment. The NSCs/NPCs isolated from the cerebral cortex of rat embryos were cultured on the treated PHBHHx films in growth medium containing 1%, 5%, and 10% fetal bovine serum (FBS). Then the attachment, survival, proliferation, and differentiation of NSCs/NPCs were assessed.
NaOH treatment significantly increased the hydrophilicity of PHBHHx and enhanced NSCs/NPCs attachment. On the treated PHBHHx film, NSCs/NPCs survived well and actively proliferated in the medium containing 1% FBS. After 7-14 days in culture, approximately two-thirds of cells remained as nestin and Sox2 positive NSCs/NPCs. However, in the medium containing 5% and 10% FBS, NSCs/NPCs proliferation was reduced and differentiation, particularly glial differentiation was significantly promoted.
Growth medium containing low concentration of FBS is favorable for maintaining the characteristics, in terms of self-renewal and multiple differentiation, of NSCs/NPCs on NaOH-treated PHBHHx films. This could be a useful method to construct functional transplantable NSCs/NPCs-biomaterial complex.
Full-text · Article · Mar 2014 · Neurological Research
[Show abstract][Hide abstract] ABSTRACT: Intracerebral hemorrhage (ICH) is a devastating disorder associated with high morbidity and mortality. ICH results in the formation of hematoma that affects not only the primary site of injury but also the remote regions. In fact, hematoma can extend via perivascular spaces (also called Virchow-Robin spaces, VRS) and perineurium in an animal model of ICH. In the present study, we used magnetic resonance imaging (MRI) with susceptibility-weighted imaging (SWI) to investigate the characteristics of the perivascular and perineural extensions of hematomas in patients with ICH. A total of 20 ICH patients without secondary subarachnoid and secondary intraventricular hemorrhages were recruited. Brain MRI scans, including SWI, T1, and T2-weighted images, were performed between 17 h to 7 days after the onset of ICH. MRI with SWI revealed that paramagnetic substances spread along the VRS or the perineurium. Such distribution could cause the formation of cerebral microbleeds (CMBs). However, the distribution of remote hemorrhagic lesions varied, depending on the size and location of the original hematoma. The unenhanced CT scans of the 20 patients did not show any hyperdensity around the blood vessels and nerve tracts outside the hematoma. These results indicate the perivascular and perineural extensions of hematomas in patients with ICH, which is formed by the leakage of the original hematoma via the VRS or perineurium. We also provide a new explanation for the series of pathological processes involved in ICH, including the remote effects of hematoma and the formation of CMBs in patients with ICH.
No preview · Article · Jul 2013 · The Tohoku Journal of Experimental Medicine
[Show abstract][Hide abstract] ABSTRACT: Neurogenesis and angiogenesis are two parallel processes that occur in brain development and repair, and so share some molecular signals. In order to better understand the interaction between the genesis of neural cells and vessels during brain development, the density of microvessels and the number of nestin positive neural stem/neural progenitor cells (NSCs/NPCs) around microvasculature in various brain regions was quantified. Results showed that the density of microvessels remained at a relative low level during embryonic development and dramatically increased after postnatal day 3 (P3), especially in subventricular zone. The number of nestin positive NSCs/NPCs per microvessel in neurogenic brain regions continually increased with fetal brain development and then gradually dropped down during postnatal development. The highest density of NSCs/NPCs appeared at postnatal day 1 (P1) and dramatically decreased after P3. Similar pattern was observed in striatum. In the olfactory bulb, the cerebral cortex and cerebellum, the dramatic decrease of NSCs/NPCs density appeared after P7, especially in the cerebral cortex. Our results demonstrated that anatomically, the spatial relationship between NSCs/NPCs and microvessels changed during brain development. The alteration patterns in neurogenic brain regions differed from non-neurogenic brain regions.
Full-text · Article · Mar 2013 · International journal of developmental neuroscience: the official journal of the International Society for Developmental Neuroscience
[Show abstract][Hide abstract] ABSTRACT: The mental retardation associated protein, srGAP3 is highly expressed in neurogenic sites. It is thought to regulate key aspects of neuronal development and functions. Little is known about the interaction between srGAP3 and immature neural stem cells/neural progenitor cells (NSCs/NPCs). In the current study, the expression of srGAP3 in NSCs/NPCs was detected. Then survival, proliferation, differentiation and morphological alteration of NSCs/NPCs were assessed after lentivirus-mediated knockdown of srGAP3. The results showed that srGAP3 is highly expressed in NSCs/NPCs both in vitro and in vivo. After knockdown of srGAP3 (LV3-srGAP3 infection), viability and proliferation of NSCs/NPCs dramatically decreased, approximately 85% displayed a similar morphology with type I cells that have no or only few indistinguishable processes. After 7 days culture in differentiation medium, 62.5%±8.3 of cells in the srGAP3 knockdown group were nestin positive and 24.8%±5.8 of them were β-tubulin III positive, which are significantly higher (30.2%±9.9 and 14.6%±2.7) than in the control group (LV3-NC infection). In addition, cells in the knockdown group had significantly fewer, but longer processes. Our results demonstrate that srGAP3 knockdown negatively regulates NSCs/NPCs survival, proliferation, differentiation and morphological alteration, particularly process formation. Taken together, our results provide strong evidence that srGAP3 is involved in the regulation of biological behavior and the morphological features in rat NSCs/NPCs in vitro.
Full-text · Article · Jan 2013 · Stem cells and development
[Show abstract][Hide abstract] ABSTRACT: To explore the pharmacokinetics of amphotericin B (AMB) in the cerebrospinal fluid (CSF) during continuous intrathecal administration of AMB for treatment of cryptococcal neoformans meningitis (CNM).
The concentration of AMB in the CSF was measured using reversed phase high performance liquid chromatography (RP-HPLC) in 3 patients receiving continuous intrathecal infusion of AMB for CNM.
AMB concentrations in the CSF of the 3 patients exceeded the minimal inhibitory concentration (MIC) of AMB against Cryptococcus neoformans. The concentration-time curve showed that AMB concentration in the CSF underwent obvious variations on the first day of intrathecal infusion and after additional AMB doses, but maintained a stable level (0.61-1.21 µg/ml) on the next day. CONCLUTION: Continuous intrathecal administration of AMB can enhance the drug concentration in the CSF and maintain a stable and effective drug level for treatment of CNM.
No preview · Article · Nov 2011 · Nan fang yi ke da xue xue bao = Journal of Southern Medical University
[Show abstract][Hide abstract] ABSTRACT: The transplantation of neural stem cells (NSCs) has been accepted as a promising therapeutic strategy for central nervous system disorders. However, the beneficial effect of NSC transplantation upon functional recovery is limited due to the unfavorable microenvironment (niche) at the site of trauma or degenerative disease in the brain. Combination of transplantation of NSCs with neurotrophins may overcome the hurdles of impaired cell survival and neuronal differentiation.
In the current study, the neurotrophin-3 (NT-3) gene was transduced into cultured mouse embryonic cortical NSCs via an AAV vector (NSC-NT-3). The effect of NT-3 over-expression on cell proliferation and differentiation in NSCs was observed by immunohistochemistry, cell culture and organotypic hippocampal slice cultures.
Results: The characteristics of self-renewal and multiple differentiation of NSCs were well-preserved. Cells in the NSC-NT-3 group proliferated faster and differentiated into more β-tubulin III-positive neurons compared to the control group in vitro. Furthermore, cells in the NSC-NT-3 group survived in a significantly higher percentage and undertook neuronal differentiation preferably in organotypic hippocampal slice cultures.
Our results suggest that the transduction of NT-3 into NSCs could effectively promote NSCs survival, proliferation, and neuronal differentiation in vitro without change of the stemness of NSCs. This work also offers evidence to better understand the safety and efficiency of combined treatment with NT-3 and NSCs for the central nervous system disorders.
Full-text · Article · Nov 2011 · Medical science monitor: international medical journal of experimental and clinical research